xref: /illumos-gate/usr/src/uts/common/vm/seg_vn.c (revision 581cede61ac9c14d8d4ea452562a567189eead78)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 /*
40  * VM - shared or copy-on-write from a vnode/anonymous memory.
41  */
42 
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/t_lock.h>
46 #include <sys/errno.h>
47 #include <sys/systm.h>
48 #include <sys/mman.h>
49 #include <sys/debug.h>
50 #include <sys/cred.h>
51 #include <sys/vmsystm.h>
52 #include <sys/tuneable.h>
53 #include <sys/bitmap.h>
54 #include <sys/swap.h>
55 #include <sys/kmem.h>
56 #include <sys/sysmacros.h>
57 #include <sys/vtrace.h>
58 #include <sys/cmn_err.h>
59 #include <sys/callb.h>
60 #include <sys/vm.h>
61 #include <sys/dumphdr.h>
62 #include <sys/lgrp.h>
63 
64 #include <vm/hat.h>
65 #include <vm/as.h>
66 #include <vm/seg.h>
67 #include <vm/seg_vn.h>
68 #include <vm/pvn.h>
69 #include <vm/anon.h>
70 #include <vm/page.h>
71 #include <vm/vpage.h>
72 #include <sys/proc.h>
73 #include <sys/task.h>
74 #include <sys/project.h>
75 #include <sys/zone.h>
76 #include <sys/shm_impl.h>
77 /*
78  * Private seg op routines.
79  */
80 static int	segvn_dup(struct seg *seg, struct seg *newseg);
81 static int	segvn_unmap(struct seg *seg, caddr_t addr, size_t len);
82 static void	segvn_free(struct seg *seg);
83 static faultcode_t segvn_fault(struct hat *hat, struct seg *seg,
84 		    caddr_t addr, size_t len, enum fault_type type,
85 		    enum seg_rw rw);
86 static faultcode_t segvn_faulta(struct seg *seg, caddr_t addr);
87 static int	segvn_setprot(struct seg *seg, caddr_t addr,
88 		    size_t len, uint_t prot);
89 static int	segvn_checkprot(struct seg *seg, caddr_t addr,
90 		    size_t len, uint_t prot);
91 static int	segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta);
92 static size_t	segvn_swapout(struct seg *seg);
93 static int	segvn_sync(struct seg *seg, caddr_t addr, size_t len,
94 		    int attr, uint_t flags);
95 static size_t	segvn_incore(struct seg *seg, caddr_t addr, size_t len,
96 		    char *vec);
97 static int	segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
98 		    int attr, int op, ulong_t *lockmap, size_t pos);
99 static int	segvn_getprot(struct seg *seg, caddr_t addr, size_t len,
100 		    uint_t *protv);
101 static u_offset_t	segvn_getoffset(struct seg *seg, caddr_t addr);
102 static int	segvn_gettype(struct seg *seg, caddr_t addr);
103 static int	segvn_getvp(struct seg *seg, caddr_t addr,
104 		    struct vnode **vpp);
105 static int	segvn_advise(struct seg *seg, caddr_t addr, size_t len,
106 		    uint_t behav);
107 static void	segvn_dump(struct seg *seg);
108 static int	segvn_pagelock(struct seg *seg, caddr_t addr, size_t len,
109 		    struct page ***ppp, enum lock_type type, enum seg_rw rw);
110 static int	segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len,
111 		    uint_t szc);
112 static int	segvn_getmemid(struct seg *seg, caddr_t addr,
113 		    memid_t *memidp);
114 static lgrp_mem_policy_info_t	*segvn_getpolicy(struct seg *, caddr_t);
115 static int	segvn_capable(struct seg *seg, segcapability_t capable);
116 
117 struct	seg_ops segvn_ops = {
118 	segvn_dup,
119 	segvn_unmap,
120 	segvn_free,
121 	segvn_fault,
122 	segvn_faulta,
123 	segvn_setprot,
124 	segvn_checkprot,
125 	segvn_kluster,
126 	segvn_swapout,
127 	segvn_sync,
128 	segvn_incore,
129 	segvn_lockop,
130 	segvn_getprot,
131 	segvn_getoffset,
132 	segvn_gettype,
133 	segvn_getvp,
134 	segvn_advise,
135 	segvn_dump,
136 	segvn_pagelock,
137 	segvn_setpagesize,
138 	segvn_getmemid,
139 	segvn_getpolicy,
140 	segvn_capable,
141 };
142 
143 /*
144  * Common zfod structures, provided as a shorthand for others to use.
145  */
146 static segvn_crargs_t zfod_segvn_crargs =
147 	SEGVN_ZFOD_ARGS(PROT_ZFOD, PROT_ALL);
148 static segvn_crargs_t kzfod_segvn_crargs =
149 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_USER,
150 	PROT_ALL & ~PROT_USER);
151 static segvn_crargs_t stack_noexec_crargs =
152 	SEGVN_ZFOD_ARGS(PROT_ZFOD & ~PROT_EXEC, PROT_ALL);
153 
154 caddr_t	zfod_argsp = (caddr_t)&zfod_segvn_crargs;	/* user zfod argsp */
155 caddr_t	kzfod_argsp = (caddr_t)&kzfod_segvn_crargs;	/* kernel zfod argsp */
156 caddr_t	stack_exec_argsp = (caddr_t)&zfod_segvn_crargs;	/* executable stack */
157 caddr_t	stack_noexec_argsp = (caddr_t)&stack_noexec_crargs; /* noexec stack */
158 
159 #define	vpgtob(n)	((n) * sizeof (struct vpage))	/* For brevity */
160 
161 size_t	segvn_comb_thrshld = UINT_MAX;	/* patchable -- see 1196681 */
162 
163 size_t	segvn_pglock_comb_thrshld = (1UL << 16);	/* 64K */
164 size_t	segvn_pglock_comb_balign = (1UL << 16);		/* 64K */
165 uint_t	segvn_pglock_comb_bshift;
166 size_t	segvn_pglock_comb_palign;
167 
168 static int	segvn_concat(struct seg *, struct seg *, int);
169 static int	segvn_extend_prev(struct seg *, struct seg *,
170 		    struct segvn_crargs *, size_t);
171 static int	segvn_extend_next(struct seg *, struct seg *,
172 		    struct segvn_crargs *, size_t);
173 static void	segvn_softunlock(struct seg *, caddr_t, size_t, enum seg_rw);
174 static void	segvn_pagelist_rele(page_t **);
175 static void	segvn_setvnode_mpss(vnode_t *);
176 static void	segvn_relocate_pages(page_t **, page_t *);
177 static int	segvn_full_szcpages(page_t **, uint_t, int *, uint_t *);
178 static int	segvn_fill_vp_pages(struct segvn_data *, vnode_t *, u_offset_t,
179     uint_t, page_t **, page_t **, uint_t *, int *);
180 static faultcode_t segvn_fault_vnodepages(struct hat *, struct seg *, caddr_t,
181     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
182 static faultcode_t segvn_fault_anonpages(struct hat *, struct seg *, caddr_t,
183     caddr_t, enum fault_type, enum seg_rw, caddr_t, caddr_t, int);
184 static faultcode_t segvn_faultpage(struct hat *, struct seg *, caddr_t,
185     u_offset_t, struct vpage *, page_t **, uint_t,
186     enum fault_type, enum seg_rw, int);
187 static void	segvn_vpage(struct seg *);
188 static size_t	segvn_count_swap_by_vpages(struct seg *);
189 
190 static void segvn_purge(struct seg *seg);
191 static int segvn_reclaim(void *, caddr_t, size_t, struct page **,
192     enum seg_rw, int);
193 static int shamp_reclaim(void *, caddr_t, size_t, struct page **,
194     enum seg_rw, int);
195 
196 static int sameprot(struct seg *, caddr_t, size_t);
197 
198 static int segvn_demote_range(struct seg *, caddr_t, size_t, int, uint_t);
199 static int segvn_clrszc(struct seg *);
200 static struct seg *segvn_split_seg(struct seg *, caddr_t);
201 static int segvn_claim_pages(struct seg *, struct vpage *, u_offset_t,
202     ulong_t, uint_t);
203 
204 static void segvn_hat_rgn_unload_callback(caddr_t, caddr_t, caddr_t,
205     size_t, void *, u_offset_t);
206 
207 static struct kmem_cache *segvn_cache;
208 static struct kmem_cache **segvn_szc_cache;
209 
210 #ifdef VM_STATS
211 static struct segvnvmstats_str {
212 	ulong_t	fill_vp_pages[31];
213 	ulong_t fltvnpages[49];
214 	ulong_t	fullszcpages[10];
215 	ulong_t	relocatepages[3];
216 	ulong_t	fltanpages[17];
217 	ulong_t pagelock[2];
218 	ulong_t	demoterange[3];
219 } segvnvmstats;
220 #endif /* VM_STATS */
221 
222 #define	SDR_RANGE	1		/* demote entire range */
223 #define	SDR_END		2		/* demote non aligned ends only */
224 
225 #define	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr) {	    \
226 		if ((len) != 0) { 		      	      		      \
227 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)(addr), pgsz);  \
228 			ASSERT(lpgaddr >= (seg)->s_base);	      	      \
229 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)((addr) +    \
230 			    (len)), pgsz);				      \
231 			ASSERT(lpgeaddr > lpgaddr);		      	      \
232 			ASSERT(lpgeaddr <= (seg)->s_base + (seg)->s_size);    \
233 		} else {					      	      \
234 			lpgeaddr = lpgaddr = (addr);	      		      \
235 		}							      \
236 	}
237 
238 /*ARGSUSED*/
239 static int
240 segvn_cache_constructor(void *buf, void *cdrarg, int kmflags)
241 {
242 	struct segvn_data *svd = buf;
243 
244 	rw_init(&svd->lock, NULL, RW_DEFAULT, NULL);
245 	mutex_init(&svd->segfree_syncmtx, NULL, MUTEX_DEFAULT, NULL);
246 	svd->svn_trnext = svd->svn_trprev = NULL;
247 	return (0);
248 }
249 
250 /*ARGSUSED1*/
251 static void
252 segvn_cache_destructor(void *buf, void *cdrarg)
253 {
254 	struct segvn_data *svd = buf;
255 
256 	rw_destroy(&svd->lock);
257 	mutex_destroy(&svd->segfree_syncmtx);
258 }
259 
260 /*ARGSUSED*/
261 static int
262 svntr_cache_constructor(void *buf, void *cdrarg, int kmflags)
263 {
264 	bzero(buf, sizeof (svntr_t));
265 	return (0);
266 }
267 
268 /*
269  * Patching this variable to non-zero allows the system to run with
270  * stacks marked as "not executable".  It's a bit of a kludge, but is
271  * provided as a tweakable for platforms that export those ABIs
272  * (e.g. sparc V8) that have executable stacks enabled by default.
273  * There are also some restrictions for platforms that don't actually
274  * implement 'noexec' protections.
275  *
276  * Once enabled, the system is (therefore) unable to provide a fully
277  * ABI-compliant execution environment, though practically speaking,
278  * most everything works.  The exceptions are generally some interpreters
279  * and debuggers that create executable code on the stack and jump
280  * into it (without explicitly mprotecting the address range to include
281  * PROT_EXEC).
282  *
283  * One important class of applications that are disabled are those
284  * that have been transformed into malicious agents using one of the
285  * numerous "buffer overflow" attacks.  See 4007890.
286  */
287 int noexec_user_stack = 0;
288 int noexec_user_stack_log = 1;
289 
290 int segvn_lpg_disable = 0;
291 uint_t segvn_maxpgszc = 0;
292 
293 ulong_t segvn_vmpss_clrszc_cnt;
294 ulong_t segvn_vmpss_clrszc_err;
295 ulong_t segvn_fltvnpages_clrszc_cnt;
296 ulong_t segvn_fltvnpages_clrszc_err;
297 ulong_t segvn_setpgsz_align_err;
298 ulong_t segvn_setpgsz_anon_align_err;
299 ulong_t segvn_setpgsz_getattr_err;
300 ulong_t segvn_setpgsz_eof_err;
301 ulong_t segvn_faultvnmpss_align_err1;
302 ulong_t segvn_faultvnmpss_align_err2;
303 ulong_t segvn_faultvnmpss_align_err3;
304 ulong_t segvn_faultvnmpss_align_err4;
305 ulong_t segvn_faultvnmpss_align_err5;
306 ulong_t	segvn_vmpss_pageio_deadlk_err;
307 
308 int segvn_use_regions = 1;
309 
310 /*
311  * Segvn supports text replication optimization for NUMA platforms. Text
312  * replica's are represented by anon maps (amp). There's one amp per text file
313  * region per lgroup. A process chooses the amp for each of its text mappings
314  * based on the lgroup assignment of its main thread (t_tid = 1). All
315  * processes that want a replica on a particular lgroup for the same text file
316  * mapping share the same amp. amp's are looked up in svntr_hashtab hash table
317  * with vp,off,size,szc used as a key. Text replication segments are read only
318  * MAP_PRIVATE|MAP_TEXT segments that map vnode. Replication is achieved by
319  * forcing COW faults from vnode to amp and mapping amp pages instead of vnode
320  * pages. Replication amp is assigned to a segment when it gets its first
321  * pagefault. To handle main thread lgroup rehoming segvn_trasync_thread
322  * rechecks periodically if the process still maps an amp local to the main
323  * thread. If not async thread forces process to remap to an amp in the new
324  * home lgroup of the main thread. Current text replication implementation
325  * only provides the benefit to workloads that do most of their work in the
326  * main thread of a process or all the threads of a process run in the same
327  * lgroup. To extend text replication benefit to different types of
328  * multithreaded workloads further work would be needed in the hat layer to
329  * allow the same virtual address in the same hat to simultaneously map
330  * different physical addresses (i.e. page table replication would be needed
331  * for x86).
332  *
333  * amp pages are used instead of vnode pages as long as segment has a very
334  * simple life cycle.  It's created via segvn_create(), handles S_EXEC
335  * (S_READ) pagefaults and is fully unmapped.  If anything more complicated
336  * happens such as protection is changed, real COW fault happens, pagesize is
337  * changed, MC_LOCK is requested or segment is partially unmapped we turn off
338  * text replication by converting the segment back to vnode only segment
339  * (unmap segment's address range and set svd->amp to NULL).
340  *
341  * The original file can be changed after amp is inserted into
342  * svntr_hashtab. Processes that are launched after the file is already
343  * changed can't use the replica's created prior to the file change. To
344  * implement this functionality hash entries are timestamped. Replica's can
345  * only be used if current file modification time is the same as the timestamp
346  * saved when hash entry was created. However just timestamps alone are not
347  * sufficient to detect file modification via mmap(MAP_SHARED) mappings. We
348  * deal with file changes via MAP_SHARED mappings differently. When writable
349  * MAP_SHARED mappings are created to vnodes marked as executable we mark all
350  * existing replica's for this vnode as not usable for future text
351  * mappings. And we don't create new replica's for files that currently have
352  * potentially writable MAP_SHARED mappings (i.e. vn_is_mapped(V_WRITE) is
353  * true).
354  */
355 
356 #define	SEGVN_TEXTREPL_MAXBYTES_FACTOR	(20)
357 size_t	segvn_textrepl_max_bytes_factor = SEGVN_TEXTREPL_MAXBYTES_FACTOR;
358 
359 static ulong_t			svntr_hashtab_sz = 512;
360 static svntr_bucket_t		*svntr_hashtab = NULL;
361 static struct kmem_cache	*svntr_cache;
362 static svntr_stats_t		*segvn_textrepl_stats;
363 static ksema_t 			segvn_trasync_sem;
364 
365 int				segvn_disable_textrepl = 1;
366 size_t				textrepl_size_thresh = (size_t)-1;
367 size_t				segvn_textrepl_bytes = 0;
368 size_t				segvn_textrepl_max_bytes = 0;
369 clock_t				segvn_update_textrepl_interval = 0;
370 int				segvn_update_tr_time = 10;
371 int				segvn_disable_textrepl_update = 0;
372 
373 static void segvn_textrepl(struct seg *);
374 static void segvn_textunrepl(struct seg *, int);
375 static void segvn_inval_trcache(vnode_t *);
376 static void segvn_trasync_thread(void);
377 static void segvn_trupdate_wakeup(void *);
378 static void segvn_trupdate(void);
379 static void segvn_trupdate_seg(struct seg *, segvn_data_t *, svntr_t *,
380     ulong_t);
381 
382 /*
383  * Initialize segvn data structures
384  */
385 void
386 segvn_init(void)
387 {
388 	uint_t maxszc;
389 	uint_t szc;
390 	size_t pgsz;
391 
392 	segvn_cache = kmem_cache_create("segvn_cache",
393 	    sizeof (struct segvn_data), 0,
394 	    segvn_cache_constructor, segvn_cache_destructor, NULL,
395 	    NULL, NULL, 0);
396 
397 	if (segvn_lpg_disable == 0) {
398 		szc = maxszc = page_num_pagesizes() - 1;
399 		if (szc == 0) {
400 			segvn_lpg_disable = 1;
401 		}
402 		if (page_get_pagesize(0) != PAGESIZE) {
403 			panic("segvn_init: bad szc 0");
404 			/*NOTREACHED*/
405 		}
406 		while (szc != 0) {
407 			pgsz = page_get_pagesize(szc);
408 			if (pgsz <= PAGESIZE || !IS_P2ALIGNED(pgsz, pgsz)) {
409 				panic("segvn_init: bad szc %d", szc);
410 				/*NOTREACHED*/
411 			}
412 			szc--;
413 		}
414 		if (segvn_maxpgszc == 0 || segvn_maxpgszc > maxszc)
415 			segvn_maxpgszc = maxszc;
416 	}
417 
418 	if (segvn_maxpgszc) {
419 		segvn_szc_cache = (struct kmem_cache **)kmem_alloc(
420 		    (segvn_maxpgszc + 1) * sizeof (struct kmem_cache *),
421 		    KM_SLEEP);
422 	}
423 
424 	for (szc = 1; szc <= segvn_maxpgszc; szc++) {
425 		char	str[32];
426 
427 		(void) sprintf(str, "segvn_szc_cache%d", szc);
428 		segvn_szc_cache[szc] = kmem_cache_create(str,
429 		    page_get_pagecnt(szc) * sizeof (page_t *), 0,
430 		    NULL, NULL, NULL, NULL, NULL, KMC_NODEBUG);
431 	}
432 
433 
434 	if (segvn_use_regions && !hat_supported(HAT_SHARED_REGIONS, NULL))
435 		segvn_use_regions = 0;
436 
437 	/*
438 	 * For now shared regions and text replication segvn support
439 	 * are mutually exclusive. This is acceptable because
440 	 * currently significant benefit from text replication was
441 	 * only observed on AMD64 NUMA platforms (due to relatively
442 	 * small L2$ size) and currently we don't support shared
443 	 * regions on x86.
444 	 */
445 	if (segvn_use_regions && !segvn_disable_textrepl) {
446 		segvn_disable_textrepl = 1;
447 	}
448 
449 #if defined(_LP64)
450 	if (lgrp_optimizations() && textrepl_size_thresh != (size_t)-1 &&
451 	    !segvn_disable_textrepl) {
452 		ulong_t i;
453 		size_t hsz = svntr_hashtab_sz * sizeof (svntr_bucket_t);
454 
455 		svntr_cache = kmem_cache_create("svntr_cache",
456 		    sizeof (svntr_t), 0, svntr_cache_constructor, NULL,
457 		    NULL, NULL, NULL, 0);
458 		svntr_hashtab = kmem_zalloc(hsz, KM_SLEEP);
459 		for (i = 0; i < svntr_hashtab_sz; i++) {
460 			mutex_init(&svntr_hashtab[i].tr_lock,  NULL,
461 			    MUTEX_DEFAULT, NULL);
462 		}
463 		segvn_textrepl_max_bytes = ptob(physmem) /
464 		    segvn_textrepl_max_bytes_factor;
465 		segvn_textrepl_stats = kmem_zalloc(NCPU *
466 		    sizeof (svntr_stats_t), KM_SLEEP);
467 		sema_init(&segvn_trasync_sem, 0, NULL, SEMA_DEFAULT, NULL);
468 		(void) thread_create(NULL, 0, segvn_trasync_thread,
469 		    NULL, 0, &p0, TS_RUN, minclsyspri);
470 	}
471 #endif
472 
473 	if (!ISP2(segvn_pglock_comb_balign) ||
474 	    segvn_pglock_comb_balign < PAGESIZE) {
475 		segvn_pglock_comb_balign = 1UL << 16; /* 64K */
476 	}
477 	segvn_pglock_comb_bshift = highbit(segvn_pglock_comb_balign) - 1;
478 	segvn_pglock_comb_palign = btop(segvn_pglock_comb_balign);
479 }
480 
481 #define	SEGVN_PAGEIO	((void *)0x1)
482 #define	SEGVN_NOPAGEIO	((void *)0x2)
483 
484 static void
485 segvn_setvnode_mpss(vnode_t *vp)
486 {
487 	int err;
488 
489 	ASSERT(vp->v_mpssdata == NULL ||
490 	    vp->v_mpssdata == SEGVN_PAGEIO ||
491 	    vp->v_mpssdata == SEGVN_NOPAGEIO);
492 
493 	if (vp->v_mpssdata == NULL) {
494 		if (vn_vmpss_usepageio(vp)) {
495 			err = VOP_PAGEIO(vp, (page_t *)NULL,
496 			    (u_offset_t)0, 0, 0, CRED(), NULL);
497 		} else {
498 			err = ENOSYS;
499 		}
500 		/*
501 		 * set v_mpssdata just once per vnode life
502 		 * so that it never changes.
503 		 */
504 		mutex_enter(&vp->v_lock);
505 		if (vp->v_mpssdata == NULL) {
506 			if (err == EINVAL) {
507 				vp->v_mpssdata = SEGVN_PAGEIO;
508 			} else {
509 				vp->v_mpssdata = SEGVN_NOPAGEIO;
510 			}
511 		}
512 		mutex_exit(&vp->v_lock);
513 	}
514 }
515 
516 int
517 segvn_create(struct seg *seg, void *argsp)
518 {
519 	struct segvn_crargs *a = (struct segvn_crargs *)argsp;
520 	struct segvn_data *svd;
521 	size_t swresv = 0;
522 	struct cred *cred;
523 	struct anon_map *amp;
524 	int error = 0;
525 	size_t pgsz;
526 	lgrp_mem_policy_t mpolicy = LGRP_MEM_POLICY_DEFAULT;
527 	int use_rgn = 0;
528 	int trok = 0;
529 
530 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
531 
532 	if (a->type != MAP_PRIVATE && a->type != MAP_SHARED) {
533 		panic("segvn_create type");
534 		/*NOTREACHED*/
535 	}
536 
537 	/*
538 	 * Check arguments.  If a shared anon structure is given then
539 	 * it is illegal to also specify a vp.
540 	 */
541 	if (a->amp != NULL && a->vp != NULL) {
542 		panic("segvn_create anon_map");
543 		/*NOTREACHED*/
544 	}
545 
546 	if (a->type == MAP_PRIVATE && (a->flags & MAP_TEXT) &&
547 	    a->vp != NULL && a->prot == (PROT_USER | PROT_READ | PROT_EXEC) &&
548 	    segvn_use_regions) {
549 		use_rgn = 1;
550 	}
551 
552 	/* MAP_NORESERVE on a MAP_SHARED segment is meaningless. */
553 	if (a->type == MAP_SHARED)
554 		a->flags &= ~MAP_NORESERVE;
555 
556 	if (a->szc != 0) {
557 		if (segvn_lpg_disable != 0 || (a->szc == AS_MAP_NO_LPOOB) ||
558 		    (a->amp != NULL && a->type == MAP_PRIVATE) ||
559 		    (a->flags & MAP_NORESERVE) || seg->s_as == &kas) {
560 			a->szc = 0;
561 		} else {
562 			if (a->szc > segvn_maxpgszc)
563 				a->szc = segvn_maxpgszc;
564 			pgsz = page_get_pagesize(a->szc);
565 			if (!IS_P2ALIGNED(seg->s_base, pgsz) ||
566 			    !IS_P2ALIGNED(seg->s_size, pgsz)) {
567 				a->szc = 0;
568 			} else if (a->vp != NULL) {
569 				extern struct vnode kvp;
570 				if (IS_SWAPFSVP(a->vp) || VN_ISKAS(a->vp)) {
571 					/*
572 					 * paranoid check.
573 					 * hat_page_demote() is not supported
574 					 * on swapfs pages.
575 					 */
576 					a->szc = 0;
577 				} else if (map_addr_vacalign_check(seg->s_base,
578 				    a->offset & PAGEMASK)) {
579 					a->szc = 0;
580 				}
581 			} else if (a->amp != NULL) {
582 				pgcnt_t anum = btopr(a->offset);
583 				pgcnt_t pgcnt = page_get_pagecnt(a->szc);
584 				if (!IS_P2ALIGNED(anum, pgcnt)) {
585 					a->szc = 0;
586 				}
587 			}
588 		}
589 	}
590 
591 	/*
592 	 * If segment may need private pages, reserve them now.
593 	 */
594 	if (!(a->flags & MAP_NORESERVE) && ((a->vp == NULL && a->amp == NULL) ||
595 	    (a->type == MAP_PRIVATE && (a->prot & PROT_WRITE)))) {
596 		if (anon_resv_zone(seg->s_size,
597 		    seg->s_as->a_proc->p_zone) == 0)
598 			return (EAGAIN);
599 		swresv = seg->s_size;
600 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
601 		    seg, swresv, 1);
602 	}
603 
604 	/*
605 	 * Reserve any mapping structures that may be required.
606 	 *
607 	 * Don't do it for segments that may use regions. It's currently a
608 	 * noop in the hat implementations anyway.
609 	 */
610 	if (!use_rgn) {
611 		hat_map(seg->s_as->a_hat, seg->s_base, seg->s_size, HAT_MAP);
612 	}
613 
614 	if (a->cred) {
615 		cred = a->cred;
616 		crhold(cred);
617 	} else {
618 		crhold(cred = CRED());
619 	}
620 
621 	/* Inform the vnode of the new mapping */
622 	if (a->vp != NULL) {
623 		error = VOP_ADDMAP(a->vp, a->offset & PAGEMASK,
624 		    seg->s_as, seg->s_base, seg->s_size, a->prot,
625 		    a->maxprot, a->type, cred, NULL);
626 		if (error) {
627 			if (swresv != 0) {
628 				anon_unresv_zone(swresv,
629 				    seg->s_as->a_proc->p_zone);
630 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
631 				    "anon proc:%p %lu %u", seg, swresv, 0);
632 			}
633 			crfree(cred);
634 			if (!use_rgn) {
635 				hat_unload(seg->s_as->a_hat, seg->s_base,
636 				    seg->s_size, HAT_UNLOAD_UNMAP);
637 			}
638 			return (error);
639 		}
640 		/*
641 		 * svntr_hashtab will be NULL if we support shared regions.
642 		 */
643 		trok = ((a->flags & MAP_TEXT) &&
644 		    (seg->s_size > textrepl_size_thresh ||
645 		    (a->flags & _MAP_TEXTREPL)) &&
646 		    lgrp_optimizations() && svntr_hashtab != NULL &&
647 		    a->type == MAP_PRIVATE && swresv == 0 &&
648 		    !(a->flags & MAP_NORESERVE) &&
649 		    seg->s_as != &kas && a->vp->v_type == VREG);
650 
651 		ASSERT(!trok || !use_rgn);
652 	}
653 
654 	/*
655 	 * If more than one segment in the address space, and they're adjacent
656 	 * virtually, try to concatenate them.  Don't concatenate if an
657 	 * explicit anon_map structure was supplied (e.g., SystemV shared
658 	 * memory) or if we'll use text replication for this segment.
659 	 */
660 	if (a->amp == NULL && !use_rgn && !trok) {
661 		struct seg *pseg, *nseg;
662 		struct segvn_data *psvd, *nsvd;
663 		lgrp_mem_policy_t ppolicy, npolicy;
664 		uint_t	lgrp_mem_policy_flags = 0;
665 		extern lgrp_mem_policy_t lgrp_mem_default_policy;
666 
667 		/*
668 		 * Memory policy flags (lgrp_mem_policy_flags) is valid when
669 		 * extending stack/heap segments.
670 		 */
671 		if ((a->vp == NULL) && (a->type == MAP_PRIVATE) &&
672 		    !(a->flags & MAP_NORESERVE) && (seg->s_as != &kas)) {
673 			lgrp_mem_policy_flags = a->lgrp_mem_policy_flags;
674 		} else {
675 			/*
676 			 * Get policy when not extending it from another segment
677 			 */
678 			mpolicy = lgrp_mem_policy_default(seg->s_size, a->type);
679 		}
680 
681 		/*
682 		 * First, try to concatenate the previous and new segments
683 		 */
684 		pseg = AS_SEGPREV(seg->s_as, seg);
685 		if (pseg != NULL &&
686 		    pseg->s_base + pseg->s_size == seg->s_base &&
687 		    pseg->s_ops == &segvn_ops) {
688 			/*
689 			 * Get memory allocation policy from previous segment.
690 			 * When extension is specified (e.g. for heap) apply
691 			 * this policy to the new segment regardless of the
692 			 * outcome of segment concatenation.  Extension occurs
693 			 * for non-default policy otherwise default policy is
694 			 * used and is based on extended segment size.
695 			 */
696 			psvd = (struct segvn_data *)pseg->s_data;
697 			ppolicy = psvd->policy_info.mem_policy;
698 			if (lgrp_mem_policy_flags ==
699 			    LGRP_MP_FLAG_EXTEND_UP) {
700 				if (ppolicy != lgrp_mem_default_policy) {
701 					mpolicy = ppolicy;
702 				} else {
703 					mpolicy = lgrp_mem_policy_default(
704 					    pseg->s_size + seg->s_size,
705 					    a->type);
706 				}
707 			}
708 
709 			if (mpolicy == ppolicy &&
710 			    (pseg->s_size + seg->s_size <=
711 			    segvn_comb_thrshld || psvd->amp == NULL) &&
712 			    segvn_extend_prev(pseg, seg, a, swresv) == 0) {
713 				/*
714 				 * success! now try to concatenate
715 				 * with following seg
716 				 */
717 				crfree(cred);
718 				nseg = AS_SEGNEXT(pseg->s_as, pseg);
719 				if (nseg != NULL &&
720 				    nseg != pseg &&
721 				    nseg->s_ops == &segvn_ops &&
722 				    pseg->s_base + pseg->s_size ==
723 				    nseg->s_base)
724 					(void) segvn_concat(pseg, nseg, 0);
725 				ASSERT(pseg->s_szc == 0 ||
726 				    (a->szc == pseg->s_szc &&
727 				    IS_P2ALIGNED(pseg->s_base, pgsz) &&
728 				    IS_P2ALIGNED(pseg->s_size, pgsz)));
729 				return (0);
730 			}
731 		}
732 
733 		/*
734 		 * Failed, so try to concatenate with following seg
735 		 */
736 		nseg = AS_SEGNEXT(seg->s_as, seg);
737 		if (nseg != NULL &&
738 		    seg->s_base + seg->s_size == nseg->s_base &&
739 		    nseg->s_ops == &segvn_ops) {
740 			/*
741 			 * Get memory allocation policy from next segment.
742 			 * When extension is specified (e.g. for stack) apply
743 			 * this policy to the new segment regardless of the
744 			 * outcome of segment concatenation.  Extension occurs
745 			 * for non-default policy otherwise default policy is
746 			 * used and is based on extended segment size.
747 			 */
748 			nsvd = (struct segvn_data *)nseg->s_data;
749 			npolicy = nsvd->policy_info.mem_policy;
750 			if (lgrp_mem_policy_flags ==
751 			    LGRP_MP_FLAG_EXTEND_DOWN) {
752 				if (npolicy != lgrp_mem_default_policy) {
753 					mpolicy = npolicy;
754 				} else {
755 					mpolicy = lgrp_mem_policy_default(
756 					    nseg->s_size + seg->s_size,
757 					    a->type);
758 				}
759 			}
760 
761 			if (mpolicy == npolicy &&
762 			    segvn_extend_next(seg, nseg, a, swresv) == 0) {
763 				crfree(cred);
764 				ASSERT(nseg->s_szc == 0 ||
765 				    (a->szc == nseg->s_szc &&
766 				    IS_P2ALIGNED(nseg->s_base, pgsz) &&
767 				    IS_P2ALIGNED(nseg->s_size, pgsz)));
768 				return (0);
769 			}
770 		}
771 	}
772 
773 	if (a->vp != NULL) {
774 		VN_HOLD(a->vp);
775 		if (a->type == MAP_SHARED)
776 			lgrp_shm_policy_init(NULL, a->vp);
777 	}
778 	svd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
779 
780 	seg->s_ops = &segvn_ops;
781 	seg->s_data = (void *)svd;
782 	seg->s_szc = a->szc;
783 
784 	svd->seg = seg;
785 	svd->vp = a->vp;
786 	/*
787 	 * Anonymous mappings have no backing file so the offset is meaningless.
788 	 */
789 	svd->offset = a->vp ? (a->offset & PAGEMASK) : 0;
790 	svd->prot = a->prot;
791 	svd->maxprot = a->maxprot;
792 	svd->pageprot = 0;
793 	svd->type = a->type;
794 	svd->vpage = NULL;
795 	svd->cred = cred;
796 	svd->advice = MADV_NORMAL;
797 	svd->pageadvice = 0;
798 	svd->flags = (ushort_t)a->flags;
799 	svd->softlockcnt = 0;
800 	svd->softlockcnt_sbase = 0;
801 	svd->softlockcnt_send = 0;
802 	svd->rcookie = HAT_INVALID_REGION_COOKIE;
803 	svd->pageswap = 0;
804 
805 	if (a->szc != 0 && a->vp != NULL) {
806 		segvn_setvnode_mpss(a->vp);
807 	}
808 	if (svd->type == MAP_SHARED && svd->vp != NULL &&
809 	    (svd->vp->v_flag & VVMEXEC) && (svd->prot & PROT_WRITE)) {
810 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
811 		segvn_inval_trcache(svd->vp);
812 	}
813 
814 	amp = a->amp;
815 	if ((svd->amp = amp) == NULL) {
816 		svd->anon_index = 0;
817 		if (svd->type == MAP_SHARED) {
818 			svd->swresv = 0;
819 			/*
820 			 * Shared mappings to a vp need no other setup.
821 			 * If we have a shared mapping to an anon_map object
822 			 * which hasn't been allocated yet,  allocate the
823 			 * struct now so that it will be properly shared
824 			 * by remembering the swap reservation there.
825 			 */
826 			if (a->vp == NULL) {
827 				svd->amp = anonmap_alloc(seg->s_size, swresv,
828 				    ANON_SLEEP);
829 				svd->amp->a_szc = seg->s_szc;
830 			}
831 		} else {
832 			/*
833 			 * Private mapping (with or without a vp).
834 			 * Allocate anon_map when needed.
835 			 */
836 			svd->swresv = swresv;
837 		}
838 	} else {
839 		pgcnt_t anon_num;
840 
841 		/*
842 		 * Mapping to an existing anon_map structure without a vp.
843 		 * For now we will insure that the segment size isn't larger
844 		 * than the size - offset gives us.  Later on we may wish to
845 		 * have the anon array dynamically allocated itself so that
846 		 * we don't always have to allocate all the anon pointer slots.
847 		 * This of course involves adding extra code to check that we
848 		 * aren't trying to use an anon pointer slot beyond the end
849 		 * of the currently allocated anon array.
850 		 */
851 		if ((amp->size - a->offset) < seg->s_size) {
852 			panic("segvn_create anon_map size");
853 			/*NOTREACHED*/
854 		}
855 
856 		anon_num = btopr(a->offset);
857 
858 		if (a->type == MAP_SHARED) {
859 			/*
860 			 * SHARED mapping to a given anon_map.
861 			 */
862 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
863 			amp->refcnt++;
864 			if (a->szc > amp->a_szc) {
865 				amp->a_szc = a->szc;
866 			}
867 			ANON_LOCK_EXIT(&amp->a_rwlock);
868 			svd->anon_index = anon_num;
869 			svd->swresv = 0;
870 		} else {
871 			/*
872 			 * PRIVATE mapping to a given anon_map.
873 			 * Make sure that all the needed anon
874 			 * structures are created (so that we will
875 			 * share the underlying pages if nothing
876 			 * is written by this mapping) and then
877 			 * duplicate the anon array as is done
878 			 * when a privately mapped segment is dup'ed.
879 			 */
880 			struct anon *ap;
881 			caddr_t addr;
882 			caddr_t eaddr;
883 			ulong_t	anon_idx;
884 			int hat_flag = HAT_LOAD;
885 
886 			if (svd->flags & MAP_TEXT) {
887 				hat_flag |= HAT_LOAD_TEXT;
888 			}
889 
890 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
891 			svd->amp->a_szc = seg->s_szc;
892 			svd->anon_index = 0;
893 			svd->swresv = swresv;
894 
895 			/*
896 			 * Prevent 2 threads from allocating anon
897 			 * slots simultaneously.
898 			 */
899 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
900 			eaddr = seg->s_base + seg->s_size;
901 
902 			for (anon_idx = anon_num, addr = seg->s_base;
903 			    addr < eaddr; addr += PAGESIZE, anon_idx++) {
904 				page_t *pp;
905 
906 				if ((ap = anon_get_ptr(amp->ahp,
907 				    anon_idx)) != NULL)
908 					continue;
909 
910 				/*
911 				 * Allocate the anon struct now.
912 				 * Might as well load up translation
913 				 * to the page while we're at it...
914 				 */
915 				pp = anon_zero(seg, addr, &ap, cred);
916 				if (ap == NULL || pp == NULL) {
917 					panic("segvn_create anon_zero");
918 					/*NOTREACHED*/
919 				}
920 
921 				/*
922 				 * Re-acquire the anon_map lock and
923 				 * initialize the anon array entry.
924 				 */
925 				ASSERT(anon_get_ptr(amp->ahp,
926 				    anon_idx) == NULL);
927 				(void) anon_set_ptr(amp->ahp, anon_idx, ap,
928 				    ANON_SLEEP);
929 
930 				ASSERT(seg->s_szc == 0);
931 				ASSERT(!IS_VMODSORT(pp->p_vnode));
932 
933 				ASSERT(use_rgn == 0);
934 				hat_memload(seg->s_as->a_hat, addr, pp,
935 				    svd->prot & ~PROT_WRITE, hat_flag);
936 
937 				page_unlock(pp);
938 			}
939 			ASSERT(seg->s_szc == 0);
940 			anon_dup(amp->ahp, anon_num, svd->amp->ahp,
941 			    0, seg->s_size);
942 			ANON_LOCK_EXIT(&amp->a_rwlock);
943 		}
944 	}
945 
946 	/*
947 	 * Set default memory allocation policy for segment
948 	 *
949 	 * Always set policy for private memory at least for initialization
950 	 * even if this is a shared memory segment
951 	 */
952 	(void) lgrp_privm_policy_set(mpolicy, &svd->policy_info, seg->s_size);
953 
954 	if (svd->type == MAP_SHARED)
955 		(void) lgrp_shm_policy_set(mpolicy, svd->amp, svd->anon_index,
956 		    svd->vp, svd->offset, seg->s_size);
957 
958 	if (use_rgn) {
959 		ASSERT(!trok);
960 		ASSERT(svd->amp == NULL);
961 		svd->rcookie = hat_join_region(seg->s_as->a_hat, seg->s_base,
962 		    seg->s_size, (void *)svd->vp, svd->offset, svd->prot,
963 		    (uchar_t)seg->s_szc, segvn_hat_rgn_unload_callback,
964 		    HAT_REGION_TEXT);
965 	}
966 
967 	ASSERT(!trok || !(svd->prot & PROT_WRITE));
968 	svd->tr_state = trok ? SEGVN_TR_INIT : SEGVN_TR_OFF;
969 
970 	return (0);
971 }
972 
973 /*
974  * Concatenate two existing segments, if possible.
975  * Return 0 on success, -1 if two segments are not compatible
976  * or -2 on memory allocation failure.
977  * If amp_cat == 1 then try and concat segments with anon maps
978  */
979 static int
980 segvn_concat(struct seg *seg1, struct seg *seg2, int amp_cat)
981 {
982 	struct segvn_data *svd1 = seg1->s_data;
983 	struct segvn_data *svd2 = seg2->s_data;
984 	struct anon_map *amp1 = svd1->amp;
985 	struct anon_map *amp2 = svd2->amp;
986 	struct vpage *vpage1 = svd1->vpage;
987 	struct vpage *vpage2 = svd2->vpage, *nvpage = NULL;
988 	size_t size, nvpsize;
989 	pgcnt_t npages1, npages2;
990 
991 	ASSERT(seg1->s_as && seg2->s_as && seg1->s_as == seg2->s_as);
992 	ASSERT(AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
993 	ASSERT(seg1->s_ops == seg2->s_ops);
994 
995 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie) ||
996 	    HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
997 		return (-1);
998 	}
999 
1000 	/* both segments exist, try to merge them */
1001 #define	incompat(x)	(svd1->x != svd2->x)
1002 	if (incompat(vp) || incompat(maxprot) ||
1003 	    (!svd1->pageadvice && !svd2->pageadvice && incompat(advice)) ||
1004 	    (!svd1->pageprot && !svd2->pageprot && incompat(prot)) ||
1005 	    incompat(type) || incompat(cred) || incompat(flags) ||
1006 	    seg1->s_szc != seg2->s_szc || incompat(policy_info.mem_policy) ||
1007 	    (svd2->softlockcnt > 0) || svd1->softlockcnt_send > 0)
1008 		return (-1);
1009 #undef incompat
1010 
1011 	/*
1012 	 * vp == NULL implies zfod, offset doesn't matter
1013 	 */
1014 	if (svd1->vp != NULL &&
1015 	    svd1->offset + seg1->s_size != svd2->offset) {
1016 		return (-1);
1017 	}
1018 
1019 	/*
1020 	 * Don't concatenate if either segment uses text replication.
1021 	 */
1022 	if (svd1->tr_state != SEGVN_TR_OFF || svd2->tr_state != SEGVN_TR_OFF) {
1023 		return (-1);
1024 	}
1025 
1026 	/*
1027 	 * Fail early if we're not supposed to concatenate
1028 	 * segments with non NULL amp.
1029 	 */
1030 	if (amp_cat == 0 && (amp1 != NULL || amp2 != NULL)) {
1031 		return (-1);
1032 	}
1033 
1034 	if (svd1->vp == NULL && svd1->type == MAP_SHARED) {
1035 		if (amp1 != amp2) {
1036 			return (-1);
1037 		}
1038 		if (amp1 != NULL && svd1->anon_index + btop(seg1->s_size) !=
1039 		    svd2->anon_index) {
1040 			return (-1);
1041 		}
1042 		ASSERT(amp1 == NULL || amp1->refcnt >= 2);
1043 	}
1044 
1045 	/*
1046 	 * If either seg has vpages, create a new merged vpage array.
1047 	 */
1048 	if (vpage1 != NULL || vpage2 != NULL) {
1049 		struct vpage *vp, *evp;
1050 
1051 		npages1 = seg_pages(seg1);
1052 		npages2 = seg_pages(seg2);
1053 		nvpsize = vpgtob(npages1 + npages2);
1054 
1055 		if ((nvpage = kmem_zalloc(nvpsize, KM_NOSLEEP)) == NULL) {
1056 			return (-2);
1057 		}
1058 
1059 		if (vpage1 != NULL) {
1060 			bcopy(vpage1, nvpage, vpgtob(npages1));
1061 		} else {
1062 			evp = nvpage + npages1;
1063 			for (vp = nvpage; vp < evp; vp++) {
1064 				VPP_SETPROT(vp, svd1->prot);
1065 				VPP_SETADVICE(vp, svd1->advice);
1066 			}
1067 		}
1068 
1069 		if (vpage2 != NULL) {
1070 			bcopy(vpage2, nvpage + npages1, vpgtob(npages2));
1071 		} else {
1072 			evp = nvpage + npages1 + npages2;
1073 			for (vp = nvpage + npages1; vp < evp; vp++) {
1074 				VPP_SETPROT(vp, svd2->prot);
1075 				VPP_SETADVICE(vp, svd2->advice);
1076 			}
1077 		}
1078 
1079 		if (svd2->pageswap && (!svd1->pageswap && svd1->swresv)) {
1080 			ASSERT(svd1->swresv == seg1->s_size);
1081 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1082 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1083 			evp = nvpage + npages1;
1084 			for (vp = nvpage; vp < evp; vp++) {
1085 				VPP_SETSWAPRES(vp);
1086 			}
1087 		}
1088 
1089 		if (svd1->pageswap && (!svd2->pageswap && svd2->swresv)) {
1090 			ASSERT(svd2->swresv == seg2->s_size);
1091 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1092 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1093 			vp = nvpage + npages1;
1094 			evp = vp + npages2;
1095 			for (; vp < evp; vp++) {
1096 				VPP_SETSWAPRES(vp);
1097 			}
1098 		}
1099 	}
1100 	ASSERT((vpage1 != NULL || vpage2 != NULL) ||
1101 	    (svd1->pageswap == 0 && svd2->pageswap == 0));
1102 
1103 	/*
1104 	 * If either segment has private pages, create a new merged anon
1105 	 * array. If mergeing shared anon segments just decrement anon map's
1106 	 * refcnt.
1107 	 */
1108 	if (amp1 != NULL && svd1->type == MAP_SHARED) {
1109 		ASSERT(amp1 == amp2 && svd1->vp == NULL);
1110 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1111 		ASSERT(amp1->refcnt >= 2);
1112 		amp1->refcnt--;
1113 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1114 		svd2->amp = NULL;
1115 	} else if (amp1 != NULL || amp2 != NULL) {
1116 		struct anon_hdr *nahp;
1117 		struct anon_map *namp = NULL;
1118 		size_t asize;
1119 
1120 		ASSERT(svd1->type == MAP_PRIVATE);
1121 
1122 		asize = seg1->s_size + seg2->s_size;
1123 		if ((nahp = anon_create(btop(asize), ANON_NOSLEEP)) == NULL) {
1124 			if (nvpage != NULL) {
1125 				kmem_free(nvpage, nvpsize);
1126 			}
1127 			return (-2);
1128 		}
1129 		if (amp1 != NULL) {
1130 			/*
1131 			 * XXX anon rwlock is not really needed because
1132 			 * this is a private segment and we are writers.
1133 			 */
1134 			ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1135 			ASSERT(amp1->refcnt == 1);
1136 			if (anon_copy_ptr(amp1->ahp, svd1->anon_index,
1137 			    nahp, 0, btop(seg1->s_size), ANON_NOSLEEP)) {
1138 				anon_release(nahp, btop(asize));
1139 				ANON_LOCK_EXIT(&amp1->a_rwlock);
1140 				if (nvpage != NULL) {
1141 					kmem_free(nvpage, nvpsize);
1142 				}
1143 				return (-2);
1144 			}
1145 		}
1146 		if (amp2 != NULL) {
1147 			ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1148 			ASSERT(amp2->refcnt == 1);
1149 			if (anon_copy_ptr(amp2->ahp, svd2->anon_index,
1150 			    nahp, btop(seg1->s_size), btop(seg2->s_size),
1151 			    ANON_NOSLEEP)) {
1152 				anon_release(nahp, btop(asize));
1153 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1154 				if (amp1 != NULL) {
1155 					ANON_LOCK_EXIT(&amp1->a_rwlock);
1156 				}
1157 				if (nvpage != NULL) {
1158 					kmem_free(nvpage, nvpsize);
1159 				}
1160 				return (-2);
1161 			}
1162 		}
1163 		if (amp1 != NULL) {
1164 			namp = amp1;
1165 			anon_release(amp1->ahp, btop(amp1->size));
1166 		}
1167 		if (amp2 != NULL) {
1168 			if (namp == NULL) {
1169 				ASSERT(amp1 == NULL);
1170 				namp = amp2;
1171 				anon_release(amp2->ahp, btop(amp2->size));
1172 			} else {
1173 				amp2->refcnt--;
1174 				ANON_LOCK_EXIT(&amp2->a_rwlock);
1175 				anonmap_free(amp2);
1176 			}
1177 			svd2->amp = NULL; /* needed for seg_free */
1178 		}
1179 		namp->ahp = nahp;
1180 		namp->size = asize;
1181 		svd1->amp = namp;
1182 		svd1->anon_index = 0;
1183 		ANON_LOCK_EXIT(&namp->a_rwlock);
1184 	}
1185 	/*
1186 	 * Now free the old vpage structures.
1187 	 */
1188 	if (nvpage != NULL) {
1189 		if (vpage1 != NULL) {
1190 			kmem_free(vpage1, vpgtob(npages1));
1191 		}
1192 		if (vpage2 != NULL) {
1193 			svd2->vpage = NULL;
1194 			kmem_free(vpage2, vpgtob(npages2));
1195 		}
1196 		if (svd2->pageprot) {
1197 			svd1->pageprot = 1;
1198 		}
1199 		if (svd2->pageadvice) {
1200 			svd1->pageadvice = 1;
1201 		}
1202 		if (svd2->pageswap) {
1203 			svd1->pageswap = 1;
1204 		}
1205 		svd1->vpage = nvpage;
1206 	}
1207 
1208 	/* all looks ok, merge segments */
1209 	svd1->swresv += svd2->swresv;
1210 	svd2->swresv = 0;  /* so seg_free doesn't release swap space */
1211 	size = seg2->s_size;
1212 	seg_free(seg2);
1213 	seg1->s_size += size;
1214 	return (0);
1215 }
1216 
1217 /*
1218  * Extend the previous segment (seg1) to include the
1219  * new segment (seg2 + a), if possible.
1220  * Return 0 on success.
1221  */
1222 static int
1223 segvn_extend_prev(seg1, seg2, a, swresv)
1224 	struct seg *seg1, *seg2;
1225 	struct segvn_crargs *a;
1226 	size_t swresv;
1227 {
1228 	struct segvn_data *svd1 = (struct segvn_data *)seg1->s_data;
1229 	size_t size;
1230 	struct anon_map *amp1;
1231 	struct vpage *new_vpage;
1232 
1233 	/*
1234 	 * We don't need any segment level locks for "segvn" data
1235 	 * since the address space is "write" locked.
1236 	 */
1237 	ASSERT(seg1->s_as && AS_WRITE_HELD(seg1->s_as, &seg1->s_as->a_lock));
1238 
1239 	if (HAT_IS_REGION_COOKIE_VALID(svd1->rcookie)) {
1240 		return (-1);
1241 	}
1242 
1243 	/* second segment is new, try to extend first */
1244 	/* XXX - should also check cred */
1245 	if (svd1->vp != a->vp || svd1->maxprot != a->maxprot ||
1246 	    (!svd1->pageprot && (svd1->prot != a->prot)) ||
1247 	    svd1->type != a->type || svd1->flags != a->flags ||
1248 	    seg1->s_szc != a->szc || svd1->softlockcnt_send > 0)
1249 		return (-1);
1250 
1251 	/* vp == NULL implies zfod, offset doesn't matter */
1252 	if (svd1->vp != NULL &&
1253 	    svd1->offset + seg1->s_size != (a->offset & PAGEMASK))
1254 		return (-1);
1255 
1256 	if (svd1->tr_state != SEGVN_TR_OFF) {
1257 		return (-1);
1258 	}
1259 
1260 	amp1 = svd1->amp;
1261 	if (amp1) {
1262 		pgcnt_t newpgs;
1263 
1264 		/*
1265 		 * Segment has private pages, can data structures
1266 		 * be expanded?
1267 		 *
1268 		 * Acquire the anon_map lock to prevent it from changing,
1269 		 * if it is shared.  This ensures that the anon_map
1270 		 * will not change while a thread which has a read/write
1271 		 * lock on an address space references it.
1272 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1273 		 * is 1.
1274 		 *
1275 		 * Can't grow a MAP_SHARED segment with an anonmap because
1276 		 * there may be existing anon slots where we want to extend
1277 		 * the segment and we wouldn't know what to do with them
1278 		 * (e.g., for tmpfs right thing is to just leave them there,
1279 		 * for /dev/zero they should be cleared out).
1280 		 */
1281 		if (svd1->type == MAP_SHARED)
1282 			return (-1);
1283 
1284 		ANON_LOCK_ENTER(&amp1->a_rwlock, RW_WRITER);
1285 		if (amp1->refcnt > 1) {
1286 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1287 			return (-1);
1288 		}
1289 		newpgs = anon_grow(amp1->ahp, &svd1->anon_index,
1290 		    btop(seg1->s_size), btop(seg2->s_size), ANON_NOSLEEP);
1291 
1292 		if (newpgs == 0) {
1293 			ANON_LOCK_EXIT(&amp1->a_rwlock);
1294 			return (-1);
1295 		}
1296 		amp1->size = ptob(newpgs);
1297 		ANON_LOCK_EXIT(&amp1->a_rwlock);
1298 	}
1299 	if (svd1->vpage != NULL) {
1300 		struct vpage *vp, *evp;
1301 		new_vpage =
1302 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1303 			KM_NOSLEEP);
1304 		if (new_vpage == NULL)
1305 			return (-1);
1306 		bcopy(svd1->vpage, new_vpage, vpgtob(seg_pages(seg1)));
1307 		kmem_free(svd1->vpage, vpgtob(seg_pages(seg1)));
1308 		svd1->vpage = new_vpage;
1309 
1310 		vp = new_vpage + seg_pages(seg1);
1311 		evp = vp + seg_pages(seg2);
1312 		for (; vp < evp; vp++)
1313 			VPP_SETPROT(vp, a->prot);
1314 		if (svd1->pageswap && swresv) {
1315 			ASSERT(!(svd1->flags & MAP_NORESERVE));
1316 			ASSERT(swresv == seg2->s_size);
1317 			vp = new_vpage + seg_pages(seg1);
1318 			for (; vp < evp; vp++) {
1319 				VPP_SETSWAPRES(vp);
1320 			}
1321 		}
1322 	}
1323 	ASSERT(svd1->vpage != NULL || svd1->pageswap == 0);
1324 	size = seg2->s_size;
1325 	seg_free(seg2);
1326 	seg1->s_size += size;
1327 	svd1->swresv += swresv;
1328 	if (svd1->pageprot && (a->prot & PROT_WRITE) &&
1329 	    svd1->type == MAP_SHARED && svd1->vp != NULL &&
1330 	    (svd1->vp->v_flag & VVMEXEC)) {
1331 		ASSERT(vn_is_mapped(svd1->vp, V_WRITE));
1332 		segvn_inval_trcache(svd1->vp);
1333 	}
1334 	return (0);
1335 }
1336 
1337 /*
1338  * Extend the next segment (seg2) to include the
1339  * new segment (seg1 + a), if possible.
1340  * Return 0 on success.
1341  */
1342 static int
1343 segvn_extend_next(
1344 	struct seg *seg1,
1345 	struct seg *seg2,
1346 	struct segvn_crargs *a,
1347 	size_t swresv)
1348 {
1349 	struct segvn_data *svd2 = (struct segvn_data *)seg2->s_data;
1350 	size_t size;
1351 	struct anon_map *amp2;
1352 	struct vpage *new_vpage;
1353 
1354 	/*
1355 	 * We don't need any segment level locks for "segvn" data
1356 	 * since the address space is "write" locked.
1357 	 */
1358 	ASSERT(seg2->s_as && AS_WRITE_HELD(seg2->s_as, &seg2->s_as->a_lock));
1359 
1360 	if (HAT_IS_REGION_COOKIE_VALID(svd2->rcookie)) {
1361 		return (-1);
1362 	}
1363 
1364 	/* first segment is new, try to extend second */
1365 	/* XXX - should also check cred */
1366 	if (svd2->vp != a->vp || svd2->maxprot != a->maxprot ||
1367 	    (!svd2->pageprot && (svd2->prot != a->prot)) ||
1368 	    svd2->type != a->type || svd2->flags != a->flags ||
1369 	    seg2->s_szc != a->szc || svd2->softlockcnt_sbase > 0)
1370 		return (-1);
1371 	/* vp == NULL implies zfod, offset doesn't matter */
1372 	if (svd2->vp != NULL &&
1373 	    (a->offset & PAGEMASK) + seg1->s_size != svd2->offset)
1374 		return (-1);
1375 
1376 	if (svd2->tr_state != SEGVN_TR_OFF) {
1377 		return (-1);
1378 	}
1379 
1380 	amp2 = svd2->amp;
1381 	if (amp2) {
1382 		pgcnt_t newpgs;
1383 
1384 		/*
1385 		 * Segment has private pages, can data structures
1386 		 * be expanded?
1387 		 *
1388 		 * Acquire the anon_map lock to prevent it from changing,
1389 		 * if it is shared.  This ensures that the anon_map
1390 		 * will not change while a thread which has a read/write
1391 		 * lock on an address space references it.
1392 		 *
1393 		 * XXX - Don't need the anon_map lock at all if "refcnt"
1394 		 * is 1.
1395 		 */
1396 		if (svd2->type == MAP_SHARED)
1397 			return (-1);
1398 
1399 		ANON_LOCK_ENTER(&amp2->a_rwlock, RW_WRITER);
1400 		if (amp2->refcnt > 1) {
1401 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1402 			return (-1);
1403 		}
1404 		newpgs = anon_grow(amp2->ahp, &svd2->anon_index,
1405 		    btop(seg2->s_size), btop(seg1->s_size),
1406 		    ANON_NOSLEEP | ANON_GROWDOWN);
1407 
1408 		if (newpgs == 0) {
1409 			ANON_LOCK_EXIT(&amp2->a_rwlock);
1410 			return (-1);
1411 		}
1412 		amp2->size = ptob(newpgs);
1413 		ANON_LOCK_EXIT(&amp2->a_rwlock);
1414 	}
1415 	if (svd2->vpage != NULL) {
1416 		struct vpage *vp, *evp;
1417 		new_vpage =
1418 		    kmem_zalloc(vpgtob(seg_pages(seg1) + seg_pages(seg2)),
1419 		    KM_NOSLEEP);
1420 		if (new_vpage == NULL) {
1421 			/* Not merging segments so adjust anon_index back */
1422 			if (amp2)
1423 				svd2->anon_index += seg_pages(seg1);
1424 			return (-1);
1425 		}
1426 		bcopy(svd2->vpage, new_vpage + seg_pages(seg1),
1427 		    vpgtob(seg_pages(seg2)));
1428 		kmem_free(svd2->vpage, vpgtob(seg_pages(seg2)));
1429 		svd2->vpage = new_vpage;
1430 
1431 		vp = new_vpage;
1432 		evp = vp + seg_pages(seg1);
1433 		for (; vp < evp; vp++)
1434 			VPP_SETPROT(vp, a->prot);
1435 		if (svd2->pageswap && swresv) {
1436 			ASSERT(!(svd2->flags & MAP_NORESERVE));
1437 			ASSERT(swresv == seg1->s_size);
1438 			vp = new_vpage;
1439 			for (; vp < evp; vp++) {
1440 				VPP_SETSWAPRES(vp);
1441 			}
1442 		}
1443 	}
1444 	ASSERT(svd2->vpage != NULL || svd2->pageswap == 0);
1445 	size = seg1->s_size;
1446 	seg_free(seg1);
1447 	seg2->s_size += size;
1448 	seg2->s_base -= size;
1449 	svd2->offset -= size;
1450 	svd2->swresv += swresv;
1451 	if (svd2->pageprot && (a->prot & PROT_WRITE) &&
1452 	    svd2->type == MAP_SHARED && svd2->vp != NULL &&
1453 	    (svd2->vp->v_flag & VVMEXEC)) {
1454 		ASSERT(vn_is_mapped(svd2->vp, V_WRITE));
1455 		segvn_inval_trcache(svd2->vp);
1456 	}
1457 	return (0);
1458 }
1459 
1460 static int
1461 segvn_dup(struct seg *seg, struct seg *newseg)
1462 {
1463 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1464 	struct segvn_data *newsvd;
1465 	pgcnt_t npages = seg_pages(seg);
1466 	int error = 0;
1467 	uint_t prot;
1468 	size_t len;
1469 	struct anon_map *amp;
1470 
1471 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1472 	ASSERT(newseg->s_as->a_proc->p_parent == curproc);
1473 
1474 	/*
1475 	 * If segment has anon reserved, reserve more for the new seg.
1476 	 * For a MAP_NORESERVE segment swresv will be a count of all the
1477 	 * allocated anon slots; thus we reserve for the child as many slots
1478 	 * as the parent has allocated. This semantic prevents the child or
1479 	 * parent from dieing during a copy-on-write fault caused by trying
1480 	 * to write a shared pre-existing anon page.
1481 	 */
1482 	if ((len = svd->swresv) != 0) {
1483 		if (anon_resv(svd->swresv) == 0)
1484 			return (ENOMEM);
1485 
1486 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
1487 		    seg, len, 0);
1488 	}
1489 
1490 	newsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
1491 
1492 	newseg->s_ops = &segvn_ops;
1493 	newseg->s_data = (void *)newsvd;
1494 	newseg->s_szc = seg->s_szc;
1495 
1496 	newsvd->seg = newseg;
1497 	if ((newsvd->vp = svd->vp) != NULL) {
1498 		VN_HOLD(svd->vp);
1499 		if (svd->type == MAP_SHARED)
1500 			lgrp_shm_policy_init(NULL, svd->vp);
1501 	}
1502 	newsvd->offset = svd->offset;
1503 	newsvd->prot = svd->prot;
1504 	newsvd->maxprot = svd->maxprot;
1505 	newsvd->pageprot = svd->pageprot;
1506 	newsvd->type = svd->type;
1507 	newsvd->cred = svd->cred;
1508 	crhold(newsvd->cred);
1509 	newsvd->advice = svd->advice;
1510 	newsvd->pageadvice = svd->pageadvice;
1511 	newsvd->swresv = svd->swresv;
1512 	newsvd->pageswap = svd->pageswap;
1513 	newsvd->flags = svd->flags;
1514 	newsvd->softlockcnt = 0;
1515 	newsvd->softlockcnt_sbase = 0;
1516 	newsvd->softlockcnt_send = 0;
1517 	newsvd->policy_info = svd->policy_info;
1518 	newsvd->rcookie = HAT_INVALID_REGION_COOKIE;
1519 
1520 	if ((amp = svd->amp) == NULL || svd->tr_state == SEGVN_TR_ON) {
1521 		/*
1522 		 * Not attaching to a shared anon object.
1523 		 */
1524 		ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie) ||
1525 		    svd->tr_state == SEGVN_TR_OFF);
1526 		if (svd->tr_state == SEGVN_TR_ON) {
1527 			ASSERT(newsvd->vp != NULL && amp != NULL);
1528 			newsvd->tr_state = SEGVN_TR_INIT;
1529 		} else {
1530 			newsvd->tr_state = svd->tr_state;
1531 		}
1532 		newsvd->amp = NULL;
1533 		newsvd->anon_index = 0;
1534 	} else {
1535 		/* regions for now are only used on pure vnode segments */
1536 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
1537 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1538 		newsvd->tr_state = SEGVN_TR_OFF;
1539 		if (svd->type == MAP_SHARED) {
1540 			newsvd->amp = amp;
1541 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1542 			amp->refcnt++;
1543 			ANON_LOCK_EXIT(&amp->a_rwlock);
1544 			newsvd->anon_index = svd->anon_index;
1545 		} else {
1546 			int reclaim = 1;
1547 
1548 			/*
1549 			 * Allocate and initialize new anon_map structure.
1550 			 */
1551 			newsvd->amp = anonmap_alloc(newseg->s_size, 0,
1552 			    ANON_SLEEP);
1553 			newsvd->amp->a_szc = newseg->s_szc;
1554 			newsvd->anon_index = 0;
1555 
1556 			/*
1557 			 * We don't have to acquire the anon_map lock
1558 			 * for the new segment (since it belongs to an
1559 			 * address space that is still not associated
1560 			 * with any process), or the segment in the old
1561 			 * address space (since all threads in it
1562 			 * are stopped while duplicating the address space).
1563 			 */
1564 
1565 			/*
1566 			 * The goal of the following code is to make sure that
1567 			 * softlocked pages do not end up as copy on write
1568 			 * pages.  This would cause problems where one
1569 			 * thread writes to a page that is COW and a different
1570 			 * thread in the same process has softlocked it.  The
1571 			 * softlock lock would move away from this process
1572 			 * because the write would cause this process to get
1573 			 * a copy (without the softlock).
1574 			 *
1575 			 * The strategy here is to just break the
1576 			 * sharing on pages that could possibly be
1577 			 * softlocked.
1578 			 */
1579 retry:
1580 			if (svd->softlockcnt) {
1581 				struct anon *ap, *newap;
1582 				size_t i;
1583 				uint_t vpprot;
1584 				page_t *anon_pl[1+1], *pp;
1585 				caddr_t addr;
1586 				ulong_t old_idx = svd->anon_index;
1587 				ulong_t new_idx = 0;
1588 
1589 				/*
1590 				 * The softlock count might be non zero
1591 				 * because some pages are still stuck in the
1592 				 * cache for lazy reclaim. Flush the cache
1593 				 * now. This should drop the count to zero.
1594 				 * [or there is really I/O going on to these
1595 				 * pages]. Note, we have the writers lock so
1596 				 * nothing gets inserted during the flush.
1597 				 */
1598 				if (reclaim == 1) {
1599 					segvn_purge(seg);
1600 					reclaim = 0;
1601 					goto retry;
1602 				}
1603 				i = btopr(seg->s_size);
1604 				addr = seg->s_base;
1605 				/*
1606 				 * XXX break cow sharing using PAGESIZE
1607 				 * pages. They will be relocated into larger
1608 				 * pages at fault time.
1609 				 */
1610 				while (i-- > 0) {
1611 					if (ap = anon_get_ptr(amp->ahp,
1612 					    old_idx)) {
1613 						error = anon_getpage(&ap,
1614 						    &vpprot, anon_pl, PAGESIZE,
1615 						    seg, addr, S_READ,
1616 						    svd->cred);
1617 						if (error) {
1618 							newsvd->vpage = NULL;
1619 							goto out;
1620 						}
1621 						/*
1622 						 * prot need not be computed
1623 						 * below 'cause anon_private is
1624 						 * going to ignore it anyway
1625 						 * as child doesn't inherit
1626 						 * pagelock from parent.
1627 						 */
1628 						prot = svd->pageprot ?
1629 						    VPP_PROT(
1630 						    &svd->vpage[
1631 						    seg_page(seg, addr)])
1632 						    : svd->prot;
1633 						pp = anon_private(&newap,
1634 						    newseg, addr, prot,
1635 						    anon_pl[0],	0,
1636 						    newsvd->cred);
1637 						if (pp == NULL) {
1638 							/* no mem abort */
1639 							newsvd->vpage = NULL;
1640 							error = ENOMEM;
1641 							goto out;
1642 						}
1643 						(void) anon_set_ptr(
1644 						    newsvd->amp->ahp, new_idx,
1645 						    newap, ANON_SLEEP);
1646 						page_unlock(pp);
1647 					}
1648 					addr += PAGESIZE;
1649 					old_idx++;
1650 					new_idx++;
1651 				}
1652 			} else {	/* common case */
1653 				if (seg->s_szc != 0) {
1654 					/*
1655 					 * If at least one of anon slots of a
1656 					 * large page exists then make sure
1657 					 * all anon slots of a large page
1658 					 * exist to avoid partial cow sharing
1659 					 * of a large page in the future.
1660 					 */
1661 					anon_dup_fill_holes(amp->ahp,
1662 					    svd->anon_index, newsvd->amp->ahp,
1663 					    0, seg->s_size, seg->s_szc,
1664 					    svd->vp != NULL);
1665 				} else {
1666 					anon_dup(amp->ahp, svd->anon_index,
1667 					    newsvd->amp->ahp, 0, seg->s_size);
1668 				}
1669 
1670 				hat_clrattr(seg->s_as->a_hat, seg->s_base,
1671 				    seg->s_size, PROT_WRITE);
1672 			}
1673 		}
1674 	}
1675 	/*
1676 	 * If necessary, create a vpage structure for the new segment.
1677 	 * Do not copy any page lock indications.
1678 	 */
1679 	if (svd->vpage != NULL) {
1680 		uint_t i;
1681 		struct vpage *ovp = svd->vpage;
1682 		struct vpage *nvp;
1683 
1684 		nvp = newsvd->vpage =
1685 		    kmem_alloc(vpgtob(npages), KM_SLEEP);
1686 		for (i = 0; i < npages; i++) {
1687 			*nvp = *ovp++;
1688 			VPP_CLRPPLOCK(nvp++);
1689 		}
1690 	} else
1691 		newsvd->vpage = NULL;
1692 
1693 	/* Inform the vnode of the new mapping */
1694 	if (newsvd->vp != NULL) {
1695 		error = VOP_ADDMAP(newsvd->vp, (offset_t)newsvd->offset,
1696 		    newseg->s_as, newseg->s_base, newseg->s_size, newsvd->prot,
1697 		    newsvd->maxprot, newsvd->type, newsvd->cred, NULL);
1698 	}
1699 out:
1700 	if (error == 0 && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1701 		ASSERT(newsvd->amp == NULL);
1702 		ASSERT(newsvd->tr_state == SEGVN_TR_OFF);
1703 		newsvd->rcookie = svd->rcookie;
1704 		hat_dup_region(newseg->s_as->a_hat, newsvd->rcookie);
1705 	}
1706 	return (error);
1707 }
1708 
1709 
1710 /*
1711  * callback function to invoke free_vp_pages() for only those pages actually
1712  * processed by the HAT when a shared region is destroyed.
1713  */
1714 extern int free_pages;
1715 
1716 static void
1717 segvn_hat_rgn_unload_callback(caddr_t saddr, caddr_t eaddr, caddr_t r_saddr,
1718     size_t r_size, void *r_obj, u_offset_t r_objoff)
1719 {
1720 	u_offset_t off;
1721 	size_t len;
1722 	vnode_t *vp = (vnode_t *)r_obj;
1723 
1724 	ASSERT(eaddr > saddr);
1725 	ASSERT(saddr >= r_saddr);
1726 	ASSERT(saddr < r_saddr + r_size);
1727 	ASSERT(eaddr > r_saddr);
1728 	ASSERT(eaddr <= r_saddr + r_size);
1729 	ASSERT(vp != NULL);
1730 
1731 	if (!free_pages) {
1732 		return;
1733 	}
1734 
1735 	len = eaddr - saddr;
1736 	off = (saddr - r_saddr) + r_objoff;
1737 	free_vp_pages(vp, off, len);
1738 }
1739 
1740 /*
1741  * callback function used by segvn_unmap to invoke free_vp_pages() for only
1742  * those pages actually processed by the HAT
1743  */
1744 static void
1745 segvn_hat_unload_callback(hat_callback_t *cb)
1746 {
1747 	struct seg		*seg = cb->hcb_data;
1748 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
1749 	size_t			len;
1750 	u_offset_t		off;
1751 
1752 	ASSERT(svd->vp != NULL);
1753 	ASSERT(cb->hcb_end_addr > cb->hcb_start_addr);
1754 	ASSERT(cb->hcb_start_addr >= seg->s_base);
1755 
1756 	len = cb->hcb_end_addr - cb->hcb_start_addr;
1757 	off = cb->hcb_start_addr - seg->s_base;
1758 	free_vp_pages(svd->vp, svd->offset + off, len);
1759 }
1760 
1761 /*
1762  * This function determines the number of bytes of swap reserved by
1763  * a segment for which per-page accounting is present. It is used to
1764  * calculate the correct value of a segvn_data's swresv.
1765  */
1766 static size_t
1767 segvn_count_swap_by_vpages(struct seg *seg)
1768 {
1769 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1770 	struct vpage *vp, *evp;
1771 	size_t nswappages = 0;
1772 
1773 	ASSERT(svd->pageswap);
1774 	ASSERT(svd->vpage != NULL);
1775 
1776 	evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
1777 
1778 	for (vp = svd->vpage; vp < evp; vp++) {
1779 		if (VPP_ISSWAPRES(vp))
1780 			nswappages++;
1781 	}
1782 
1783 	return (nswappages << PAGESHIFT);
1784 }
1785 
1786 static int
1787 segvn_unmap(struct seg *seg, caddr_t addr, size_t len)
1788 {
1789 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
1790 	struct segvn_data *nsvd;
1791 	struct seg *nseg;
1792 	struct anon_map *amp;
1793 	pgcnt_t	opages;		/* old segment size in pages */
1794 	pgcnt_t	npages;		/* new segment size in pages */
1795 	pgcnt_t	dpages;		/* pages being deleted (unmapped) */
1796 	hat_callback_t callback;	/* used for free_vp_pages() */
1797 	hat_callback_t *cbp = NULL;
1798 	caddr_t nbase;
1799 	size_t nsize;
1800 	size_t oswresv;
1801 	int reclaim = 1;
1802 
1803 	/*
1804 	 * We don't need any segment level locks for "segvn" data
1805 	 * since the address space is "write" locked.
1806 	 */
1807 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
1808 
1809 	/*
1810 	 * Fail the unmap if pages are SOFTLOCKed through this mapping.
1811 	 * softlockcnt is protected from change by the as write lock.
1812 	 */
1813 retry:
1814 	if (svd->softlockcnt > 0) {
1815 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1816 
1817 		/*
1818 		 * If this is shared segment non 0 softlockcnt
1819 		 * means locked pages are still in use.
1820 		 */
1821 		if (svd->type == MAP_SHARED) {
1822 			return (EAGAIN);
1823 		}
1824 
1825 		/*
1826 		 * since we do have the writers lock nobody can fill
1827 		 * the cache during the purge. The flush either succeeds
1828 		 * or we still have pending I/Os.
1829 		 */
1830 		if (reclaim == 1) {
1831 			segvn_purge(seg);
1832 			reclaim = 0;
1833 			goto retry;
1834 		}
1835 		return (EAGAIN);
1836 	}
1837 
1838 	/*
1839 	 * Check for bad sizes
1840 	 */
1841 	if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size ||
1842 	    (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) {
1843 		panic("segvn_unmap");
1844 		/*NOTREACHED*/
1845 	}
1846 
1847 	if (seg->s_szc != 0) {
1848 		size_t pgsz = page_get_pagesize(seg->s_szc);
1849 		int err;
1850 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
1851 			ASSERT(seg->s_base != addr || seg->s_size != len);
1852 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1853 				ASSERT(svd->amp == NULL);
1854 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1855 				hat_leave_region(seg->s_as->a_hat,
1856 				    svd->rcookie, HAT_REGION_TEXT);
1857 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
1858 				/*
1859 				 * could pass a flag to segvn_demote_range()
1860 				 * below to tell it not to do any unloads but
1861 				 * this case is rare enough to not bother for
1862 				 * now.
1863 				 */
1864 			} else if (svd->tr_state == SEGVN_TR_INIT) {
1865 				svd->tr_state = SEGVN_TR_OFF;
1866 			} else if (svd->tr_state == SEGVN_TR_ON) {
1867 				ASSERT(svd->amp != NULL);
1868 				segvn_textunrepl(seg, 1);
1869 				ASSERT(svd->amp == NULL);
1870 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
1871 			}
1872 			VM_STAT_ADD(segvnvmstats.demoterange[0]);
1873 			err = segvn_demote_range(seg, addr, len, SDR_END, 0);
1874 			if (err == 0) {
1875 				return (IE_RETRY);
1876 			}
1877 			return (err);
1878 		}
1879 	}
1880 
1881 	/* Inform the vnode of the unmapping. */
1882 	if (svd->vp) {
1883 		int error;
1884 
1885 		error = VOP_DELMAP(svd->vp,
1886 		    (offset_t)svd->offset + (uintptr_t)(addr - seg->s_base),
1887 		    seg->s_as, addr, len, svd->prot, svd->maxprot,
1888 		    svd->type, svd->cred, NULL);
1889 
1890 		if (error == EAGAIN)
1891 			return (error);
1892 	}
1893 
1894 	/*
1895 	 * Remove any page locks set through this mapping.
1896 	 * If text replication is not off no page locks could have been
1897 	 * established via this mapping.
1898 	 */
1899 	if (svd->tr_state == SEGVN_TR_OFF) {
1900 		(void) segvn_lockop(seg, addr, len, 0, MC_UNLOCK, NULL, 0);
1901 	}
1902 
1903 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
1904 		ASSERT(svd->amp == NULL);
1905 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
1906 		ASSERT(svd->type == MAP_PRIVATE);
1907 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
1908 		    HAT_REGION_TEXT);
1909 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
1910 	} else if (svd->tr_state == SEGVN_TR_ON) {
1911 		ASSERT(svd->amp != NULL);
1912 		ASSERT(svd->pageprot == 0 && !(svd->prot & PROT_WRITE));
1913 		segvn_textunrepl(seg, 1);
1914 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
1915 	} else {
1916 		if (svd->tr_state != SEGVN_TR_OFF) {
1917 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
1918 			svd->tr_state = SEGVN_TR_OFF;
1919 		}
1920 		/*
1921 		 * Unload any hardware translations in the range to be taken
1922 		 * out. Use a callback to invoke free_vp_pages() effectively.
1923 		 */
1924 		if (svd->vp != NULL && free_pages != 0) {
1925 			callback.hcb_data = seg;
1926 			callback.hcb_function = segvn_hat_unload_callback;
1927 			cbp = &callback;
1928 		}
1929 		hat_unload_callback(seg->s_as->a_hat, addr, len,
1930 		    HAT_UNLOAD_UNMAP, cbp);
1931 
1932 		if (svd->type == MAP_SHARED && svd->vp != NULL &&
1933 		    (svd->vp->v_flag & VVMEXEC) &&
1934 		    ((svd->prot & PROT_WRITE) || svd->pageprot)) {
1935 			segvn_inval_trcache(svd->vp);
1936 		}
1937 	}
1938 
1939 	/*
1940 	 * Check for entire segment
1941 	 */
1942 	if (addr == seg->s_base && len == seg->s_size) {
1943 		seg_free(seg);
1944 		return (0);
1945 	}
1946 
1947 	opages = seg_pages(seg);
1948 	dpages = btop(len);
1949 	npages = opages - dpages;
1950 	amp = svd->amp;
1951 	ASSERT(amp == NULL || amp->a_szc >= seg->s_szc);
1952 
1953 	/*
1954 	 * Check for beginning of segment
1955 	 */
1956 	if (addr == seg->s_base) {
1957 		if (svd->vpage != NULL) {
1958 			size_t nbytes;
1959 			struct vpage *ovpage;
1960 
1961 			ovpage = svd->vpage;	/* keep pointer to vpage */
1962 
1963 			nbytes = vpgtob(npages);
1964 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
1965 			bcopy(&ovpage[dpages], svd->vpage, nbytes);
1966 
1967 			/* free up old vpage */
1968 			kmem_free(ovpage, vpgtob(opages));
1969 		}
1970 		if (amp != NULL) {
1971 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
1972 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
1973 				/*
1974 				 * Shared anon map is no longer in use. Before
1975 				 * freeing its pages purge all entries from
1976 				 * pcache that belong to this amp.
1977 				 */
1978 				if (svd->type == MAP_SHARED) {
1979 					ASSERT(amp->refcnt == 1);
1980 					ASSERT(svd->softlockcnt == 0);
1981 					anonmap_purge(amp);
1982 				}
1983 				/*
1984 				 * Free up now unused parts of anon_map array.
1985 				 */
1986 				if (amp->a_szc == seg->s_szc) {
1987 					if (seg->s_szc != 0) {
1988 						anon_free_pages(amp->ahp,
1989 						    svd->anon_index, len,
1990 						    seg->s_szc);
1991 					} else {
1992 						anon_free(amp->ahp,
1993 						    svd->anon_index,
1994 						    len);
1995 					}
1996 				} else {
1997 					ASSERT(svd->type == MAP_SHARED);
1998 					ASSERT(amp->a_szc > seg->s_szc);
1999 					anon_shmap_free_pages(amp,
2000 					    svd->anon_index, len);
2001 				}
2002 
2003 				/*
2004 				 * Unreserve swap space for the
2005 				 * unmapped chunk of this segment in
2006 				 * case it's MAP_SHARED
2007 				 */
2008 				if (svd->type == MAP_SHARED) {
2009 					anon_unresv_zone(len,
2010 					    seg->s_as->a_proc->p_zone);
2011 					amp->swresv -= len;
2012 				}
2013 			}
2014 			ANON_LOCK_EXIT(&amp->a_rwlock);
2015 			svd->anon_index += dpages;
2016 		}
2017 		if (svd->vp != NULL)
2018 			svd->offset += len;
2019 
2020 		seg->s_base += len;
2021 		seg->s_size -= len;
2022 
2023 		if (svd->swresv) {
2024 			if (svd->flags & MAP_NORESERVE) {
2025 				ASSERT(amp);
2026 				oswresv = svd->swresv;
2027 
2028 				svd->swresv = ptob(anon_pages(amp->ahp,
2029 				    svd->anon_index, npages));
2030 				anon_unresv_zone(oswresv - svd->swresv,
2031 				    seg->s_as->a_proc->p_zone);
2032 				if (SEG_IS_PARTIAL_RESV(seg))
2033 					seg->s_as->a_resvsize -= oswresv -
2034 					    svd->swresv;
2035 			} else {
2036 				size_t unlen;
2037 
2038 				if (svd->pageswap) {
2039 					oswresv = svd->swresv;
2040 					svd->swresv =
2041 					    segvn_count_swap_by_vpages(seg);
2042 					ASSERT(oswresv >= svd->swresv);
2043 					unlen = oswresv - svd->swresv;
2044 				} else {
2045 					svd->swresv -= len;
2046 					ASSERT(svd->swresv == seg->s_size);
2047 					unlen = len;
2048 				}
2049 				anon_unresv_zone(unlen,
2050 				    seg->s_as->a_proc->p_zone);
2051 			}
2052 			TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2053 			    seg, len, 0);
2054 		}
2055 
2056 		return (0);
2057 	}
2058 
2059 	/*
2060 	 * Check for end of segment
2061 	 */
2062 	if (addr + len == seg->s_base + seg->s_size) {
2063 		if (svd->vpage != NULL) {
2064 			size_t nbytes;
2065 			struct vpage *ovpage;
2066 
2067 			ovpage = svd->vpage;	/* keep pointer to vpage */
2068 
2069 			nbytes = vpgtob(npages);
2070 			svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2071 			bcopy(ovpage, svd->vpage, nbytes);
2072 
2073 			/* free up old vpage */
2074 			kmem_free(ovpage, vpgtob(opages));
2075 
2076 		}
2077 		if (amp != NULL) {
2078 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2079 			if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2080 				/*
2081 				 * Free up now unused parts of anon_map array.
2082 				 */
2083 				ulong_t an_idx = svd->anon_index + npages;
2084 
2085 				/*
2086 				 * Shared anon map is no longer in use. Before
2087 				 * freeing its pages purge all entries from
2088 				 * pcache that belong to this amp.
2089 				 */
2090 				if (svd->type == MAP_SHARED) {
2091 					ASSERT(amp->refcnt == 1);
2092 					ASSERT(svd->softlockcnt == 0);
2093 					anonmap_purge(amp);
2094 				}
2095 
2096 				if (amp->a_szc == seg->s_szc) {
2097 					if (seg->s_szc != 0) {
2098 						anon_free_pages(amp->ahp,
2099 						    an_idx, len,
2100 						    seg->s_szc);
2101 					} else {
2102 						anon_free(amp->ahp, an_idx,
2103 						    len);
2104 					}
2105 				} else {
2106 					ASSERT(svd->type == MAP_SHARED);
2107 					ASSERT(amp->a_szc > seg->s_szc);
2108 					anon_shmap_free_pages(amp,
2109 					    an_idx, len);
2110 				}
2111 
2112 				/*
2113 				 * Unreserve swap space for the
2114 				 * unmapped chunk of this segment in
2115 				 * case it's MAP_SHARED
2116 				 */
2117 				if (svd->type == MAP_SHARED) {
2118 					anon_unresv_zone(len,
2119 					    seg->s_as->a_proc->p_zone);
2120 					amp->swresv -= len;
2121 				}
2122 			}
2123 			ANON_LOCK_EXIT(&amp->a_rwlock);
2124 		}
2125 
2126 		seg->s_size -= len;
2127 
2128 		if (svd->swresv) {
2129 			if (svd->flags & MAP_NORESERVE) {
2130 				ASSERT(amp);
2131 				oswresv = svd->swresv;
2132 				svd->swresv = ptob(anon_pages(amp->ahp,
2133 				    svd->anon_index, npages));
2134 				anon_unresv_zone(oswresv - svd->swresv,
2135 				    seg->s_as->a_proc->p_zone);
2136 				if (SEG_IS_PARTIAL_RESV(seg))
2137 					seg->s_as->a_resvsize -= oswresv -
2138 					    svd->swresv;
2139 			} else {
2140 				size_t unlen;
2141 
2142 				if (svd->pageswap) {
2143 					oswresv = svd->swresv;
2144 					svd->swresv =
2145 					    segvn_count_swap_by_vpages(seg);
2146 					ASSERT(oswresv >= svd->swresv);
2147 					unlen = oswresv - svd->swresv;
2148 				} else {
2149 					svd->swresv -= len;
2150 					ASSERT(svd->swresv == seg->s_size);
2151 					unlen = len;
2152 				}
2153 				anon_unresv_zone(unlen,
2154 				    seg->s_as->a_proc->p_zone);
2155 			}
2156 			TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2157 			    "anon proc:%p %lu %u", seg, len, 0);
2158 		}
2159 
2160 		return (0);
2161 	}
2162 
2163 	/*
2164 	 * The section to go is in the middle of the segment,
2165 	 * have to make it into two segments.  nseg is made for
2166 	 * the high end while seg is cut down at the low end.
2167 	 */
2168 	nbase = addr + len;				/* new seg base */
2169 	nsize = (seg->s_base + seg->s_size) - nbase;	/* new seg size */
2170 	seg->s_size = addr - seg->s_base;		/* shrink old seg */
2171 	nseg = seg_alloc(seg->s_as, nbase, nsize);
2172 	if (nseg == NULL) {
2173 		panic("segvn_unmap seg_alloc");
2174 		/*NOTREACHED*/
2175 	}
2176 	nseg->s_ops = seg->s_ops;
2177 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
2178 	nseg->s_data = (void *)nsvd;
2179 	nseg->s_szc = seg->s_szc;
2180 	*nsvd = *svd;
2181 	nsvd->seg = nseg;
2182 	nsvd->offset = svd->offset + (uintptr_t)(nseg->s_base - seg->s_base);
2183 	nsvd->swresv = 0;
2184 	nsvd->softlockcnt = 0;
2185 	nsvd->softlockcnt_sbase = 0;
2186 	nsvd->softlockcnt_send = 0;
2187 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
2188 
2189 	if (svd->vp != NULL) {
2190 		VN_HOLD(nsvd->vp);
2191 		if (nsvd->type == MAP_SHARED)
2192 			lgrp_shm_policy_init(NULL, nsvd->vp);
2193 	}
2194 	crhold(svd->cred);
2195 
2196 	if (svd->vpage == NULL) {
2197 		nsvd->vpage = NULL;
2198 	} else {
2199 		/* need to split vpage into two arrays */
2200 		size_t nbytes;
2201 		struct vpage *ovpage;
2202 
2203 		ovpage = svd->vpage;		/* keep pointer to vpage */
2204 
2205 		npages = seg_pages(seg);	/* seg has shrunk */
2206 		nbytes = vpgtob(npages);
2207 		svd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2208 
2209 		bcopy(ovpage, svd->vpage, nbytes);
2210 
2211 		npages = seg_pages(nseg);
2212 		nbytes = vpgtob(npages);
2213 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
2214 
2215 		bcopy(&ovpage[opages - npages], nsvd->vpage, nbytes);
2216 
2217 		/* free up old vpage */
2218 		kmem_free(ovpage, vpgtob(opages));
2219 	}
2220 
2221 	if (amp == NULL) {
2222 		nsvd->amp = NULL;
2223 		nsvd->anon_index = 0;
2224 	} else {
2225 		/*
2226 		 * Need to create a new anon map for the new segment.
2227 		 * We'll also allocate a new smaller array for the old
2228 		 * smaller segment to save space.
2229 		 */
2230 		opages = btop((uintptr_t)(addr - seg->s_base));
2231 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2232 		if (amp->refcnt == 1 || svd->type == MAP_PRIVATE) {
2233 			/*
2234 			 * Free up now unused parts of anon_map array.
2235 			 */
2236 			ulong_t an_idx = svd->anon_index + opages;
2237 
2238 			/*
2239 			 * Shared anon map is no longer in use. Before
2240 			 * freeing its pages purge all entries from
2241 			 * pcache that belong to this amp.
2242 			 */
2243 			if (svd->type == MAP_SHARED) {
2244 				ASSERT(amp->refcnt == 1);
2245 				ASSERT(svd->softlockcnt == 0);
2246 				anonmap_purge(amp);
2247 			}
2248 
2249 			if (amp->a_szc == seg->s_szc) {
2250 				if (seg->s_szc != 0) {
2251 					anon_free_pages(amp->ahp, an_idx, len,
2252 					    seg->s_szc);
2253 				} else {
2254 					anon_free(amp->ahp, an_idx,
2255 					    len);
2256 				}
2257 			} else {
2258 				ASSERT(svd->type == MAP_SHARED);
2259 				ASSERT(amp->a_szc > seg->s_szc);
2260 				anon_shmap_free_pages(amp, an_idx, len);
2261 			}
2262 
2263 			/*
2264 			 * Unreserve swap space for the
2265 			 * unmapped chunk of this segment in
2266 			 * case it's MAP_SHARED
2267 			 */
2268 			if (svd->type == MAP_SHARED) {
2269 				anon_unresv_zone(len,
2270 				    seg->s_as->a_proc->p_zone);
2271 				amp->swresv -= len;
2272 			}
2273 		}
2274 		nsvd->anon_index = svd->anon_index +
2275 		    btop((uintptr_t)(nseg->s_base - seg->s_base));
2276 		if (svd->type == MAP_SHARED) {
2277 			amp->refcnt++;
2278 			nsvd->amp = amp;
2279 		} else {
2280 			struct anon_map *namp;
2281 			struct anon_hdr *nahp;
2282 
2283 			ASSERT(svd->type == MAP_PRIVATE);
2284 			nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
2285 			namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
2286 			namp->a_szc = seg->s_szc;
2287 			(void) anon_copy_ptr(amp->ahp, svd->anon_index, nahp,
2288 			    0, btop(seg->s_size), ANON_SLEEP);
2289 			(void) anon_copy_ptr(amp->ahp, nsvd->anon_index,
2290 			    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
2291 			anon_release(amp->ahp, btop(amp->size));
2292 			svd->anon_index = 0;
2293 			nsvd->anon_index = 0;
2294 			amp->ahp = nahp;
2295 			amp->size = seg->s_size;
2296 			nsvd->amp = namp;
2297 		}
2298 		ANON_LOCK_EXIT(&amp->a_rwlock);
2299 	}
2300 	if (svd->swresv) {
2301 		if (svd->flags & MAP_NORESERVE) {
2302 			ASSERT(amp);
2303 			oswresv = svd->swresv;
2304 			svd->swresv = ptob(anon_pages(amp->ahp,
2305 			    svd->anon_index, btop(seg->s_size)));
2306 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
2307 			    nsvd->anon_index, btop(nseg->s_size)));
2308 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2309 			anon_unresv_zone(oswresv - (svd->swresv + nsvd->swresv),
2310 			    seg->s_as->a_proc->p_zone);
2311 			if (SEG_IS_PARTIAL_RESV(seg))
2312 				seg->s_as->a_resvsize -= oswresv -
2313 				    (svd->swresv + nsvd->swresv);
2314 		} else {
2315 			size_t unlen;
2316 
2317 			if (svd->pageswap) {
2318 				oswresv = svd->swresv;
2319 				svd->swresv = segvn_count_swap_by_vpages(seg);
2320 				nsvd->swresv = segvn_count_swap_by_vpages(nseg);
2321 				ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
2322 				unlen = oswresv - (svd->swresv + nsvd->swresv);
2323 			} else {
2324 				if (seg->s_size + nseg->s_size + len !=
2325 				    svd->swresv) {
2326 					panic("segvn_unmap: cannot split "
2327 					    "swap reservation");
2328 					/*NOTREACHED*/
2329 				}
2330 				svd->swresv = seg->s_size;
2331 				nsvd->swresv = nseg->s_size;
2332 				unlen = len;
2333 			}
2334 			anon_unresv_zone(unlen,
2335 			    seg->s_as->a_proc->p_zone);
2336 		}
2337 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2338 		    seg, len, 0);
2339 	}
2340 
2341 	return (0);			/* I'm glad that's all over with! */
2342 }
2343 
2344 static void
2345 segvn_free(struct seg *seg)
2346 {
2347 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2348 	pgcnt_t npages = seg_pages(seg);
2349 	struct anon_map *amp;
2350 	size_t len;
2351 
2352 	/*
2353 	 * We don't need any segment level locks for "segvn" data
2354 	 * since the address space is "write" locked.
2355 	 */
2356 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
2357 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
2358 
2359 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2360 
2361 	/*
2362 	 * Be sure to unlock pages. XXX Why do things get free'ed instead
2363 	 * of unmapped? XXX
2364 	 */
2365 	(void) segvn_lockop(seg, seg->s_base, seg->s_size,
2366 	    0, MC_UNLOCK, NULL, 0);
2367 
2368 	/*
2369 	 * Deallocate the vpage and anon pointers if necessary and possible.
2370 	 */
2371 	if (svd->vpage != NULL) {
2372 		kmem_free(svd->vpage, vpgtob(npages));
2373 		svd->vpage = NULL;
2374 	}
2375 	if ((amp = svd->amp) != NULL) {
2376 		/*
2377 		 * If there are no more references to this anon_map
2378 		 * structure, then deallocate the structure after freeing
2379 		 * up all the anon slot pointers that we can.
2380 		 */
2381 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
2382 		ASSERT(amp->a_szc >= seg->s_szc);
2383 		if (--amp->refcnt == 0) {
2384 			if (svd->type == MAP_PRIVATE) {
2385 				/*
2386 				 * Private - we only need to anon_free
2387 				 * the part that this segment refers to.
2388 				 */
2389 				if (seg->s_szc != 0) {
2390 					anon_free_pages(amp->ahp,
2391 					    svd->anon_index, seg->s_size,
2392 					    seg->s_szc);
2393 				} else {
2394 					anon_free(amp->ahp, svd->anon_index,
2395 					    seg->s_size);
2396 				}
2397 			} else {
2398 
2399 				/*
2400 				 * Shared anon map is no longer in use. Before
2401 				 * freeing its pages purge all entries from
2402 				 * pcache that belong to this amp.
2403 				 */
2404 				ASSERT(svd->softlockcnt == 0);
2405 				anonmap_purge(amp);
2406 
2407 				/*
2408 				 * Shared - anon_free the entire
2409 				 * anon_map's worth of stuff and
2410 				 * release any swap reservation.
2411 				 */
2412 				if (amp->a_szc != 0) {
2413 					anon_shmap_free_pages(amp, 0,
2414 					    amp->size);
2415 				} else {
2416 					anon_free(amp->ahp, 0, amp->size);
2417 				}
2418 				if ((len = amp->swresv) != 0) {
2419 					anon_unresv_zone(len,
2420 					    seg->s_as->a_proc->p_zone);
2421 					TRACE_3(TR_FAC_VM, TR_ANON_PROC,
2422 					    "anon proc:%p %lu %u", seg, len, 0);
2423 				}
2424 			}
2425 			svd->amp = NULL;
2426 			ANON_LOCK_EXIT(&amp->a_rwlock);
2427 			anonmap_free(amp);
2428 		} else if (svd->type == MAP_PRIVATE) {
2429 			/*
2430 			 * We had a private mapping which still has
2431 			 * a held anon_map so just free up all the
2432 			 * anon slot pointers that we were using.
2433 			 */
2434 			if (seg->s_szc != 0) {
2435 				anon_free_pages(amp->ahp, svd->anon_index,
2436 				    seg->s_size, seg->s_szc);
2437 			} else {
2438 				anon_free(amp->ahp, svd->anon_index,
2439 				    seg->s_size);
2440 			}
2441 			ANON_LOCK_EXIT(&amp->a_rwlock);
2442 		} else {
2443 			ANON_LOCK_EXIT(&amp->a_rwlock);
2444 		}
2445 	}
2446 
2447 	/*
2448 	 * Release swap reservation.
2449 	 */
2450 	if ((len = svd->swresv) != 0) {
2451 		anon_unresv_zone(svd->swresv,
2452 		    seg->s_as->a_proc->p_zone);
2453 		TRACE_3(TR_FAC_VM, TR_ANON_PROC, "anon proc:%p %lu %u",
2454 		    seg, len, 0);
2455 		if (SEG_IS_PARTIAL_RESV(seg))
2456 			seg->s_as->a_resvsize -= svd->swresv;
2457 		svd->swresv = 0;
2458 	}
2459 	/*
2460 	 * Release claim on vnode, credentials, and finally free the
2461 	 * private data.
2462 	 */
2463 	if (svd->vp != NULL) {
2464 		if (svd->type == MAP_SHARED)
2465 			lgrp_shm_policy_fini(NULL, svd->vp);
2466 		VN_RELE(svd->vp);
2467 		svd->vp = NULL;
2468 	}
2469 	crfree(svd->cred);
2470 	svd->pageprot = 0;
2471 	svd->pageadvice = 0;
2472 	svd->pageswap = 0;
2473 	svd->cred = NULL;
2474 
2475 	/*
2476 	 * Take segfree_syncmtx lock to let segvn_reclaim() finish if it's
2477 	 * still working with this segment without holding as lock (in case
2478 	 * it's called by pcache async thread).
2479 	 */
2480 	ASSERT(svd->softlockcnt == 0);
2481 	mutex_enter(&svd->segfree_syncmtx);
2482 	mutex_exit(&svd->segfree_syncmtx);
2483 
2484 	seg->s_data = NULL;
2485 	kmem_cache_free(segvn_cache, svd);
2486 }
2487 
2488 /*
2489  * Do a F_SOFTUNLOCK call over the range requested.  The range must have
2490  * already been F_SOFTLOCK'ed.
2491  * Caller must always match addr and len of a softunlock with a previous
2492  * softlock with exactly the same addr and len.
2493  */
2494 static void
2495 segvn_softunlock(struct seg *seg, caddr_t addr, size_t len, enum seg_rw rw)
2496 {
2497 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2498 	page_t *pp;
2499 	caddr_t adr;
2500 	struct vnode *vp;
2501 	u_offset_t offset;
2502 	ulong_t anon_index;
2503 	struct anon_map *amp;
2504 	struct anon *ap = NULL;
2505 
2506 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
2507 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
2508 
2509 	if ((amp = svd->amp) != NULL)
2510 		anon_index = svd->anon_index + seg_page(seg, addr);
2511 
2512 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
2513 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2514 		hat_unlock_region(seg->s_as->a_hat, addr, len, svd->rcookie);
2515 	} else {
2516 		hat_unlock(seg->s_as->a_hat, addr, len);
2517 	}
2518 	for (adr = addr; adr < addr + len; adr += PAGESIZE) {
2519 		if (amp != NULL) {
2520 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
2521 			if ((ap = anon_get_ptr(amp->ahp, anon_index++))
2522 			    != NULL) {
2523 				swap_xlate(ap, &vp, &offset);
2524 			} else {
2525 				vp = svd->vp;
2526 				offset = svd->offset +
2527 				    (uintptr_t)(adr - seg->s_base);
2528 			}
2529 			ANON_LOCK_EXIT(&amp->a_rwlock);
2530 		} else {
2531 			vp = svd->vp;
2532 			offset = svd->offset +
2533 			    (uintptr_t)(adr - seg->s_base);
2534 		}
2535 
2536 		/*
2537 		 * Use page_find() instead of page_lookup() to
2538 		 * find the page since we know that it is locked.
2539 		 */
2540 		pp = page_find(vp, offset);
2541 		if (pp == NULL) {
2542 			panic(
2543 			    "segvn_softunlock: addr %p, ap %p, vp %p, off %llx",
2544 			    (void *)adr, (void *)ap, (void *)vp, offset);
2545 			/*NOTREACHED*/
2546 		}
2547 
2548 		if (rw == S_WRITE) {
2549 			hat_setrefmod(pp);
2550 			if (seg->s_as->a_vbits)
2551 				hat_setstat(seg->s_as, adr, PAGESIZE,
2552 				    P_REF | P_MOD);
2553 		} else if (rw != S_OTHER) {
2554 			hat_setref(pp);
2555 			if (seg->s_as->a_vbits)
2556 				hat_setstat(seg->s_as, adr, PAGESIZE, P_REF);
2557 		}
2558 		TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2559 		    "segvn_fault:pp %p vp %p offset %llx", pp, vp, offset);
2560 		page_unlock(pp);
2561 	}
2562 	ASSERT(svd->softlockcnt >= btop(len));
2563 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -btop(len))) {
2564 		/*
2565 		 * All SOFTLOCKS are gone. Wakeup any waiting
2566 		 * unmappers so they can try again to unmap.
2567 		 * Check for waiters first without the mutex
2568 		 * held so we don't always grab the mutex on
2569 		 * softunlocks.
2570 		 */
2571 		if (AS_ISUNMAPWAIT(seg->s_as)) {
2572 			mutex_enter(&seg->s_as->a_contents);
2573 			if (AS_ISUNMAPWAIT(seg->s_as)) {
2574 				AS_CLRUNMAPWAIT(seg->s_as);
2575 				cv_broadcast(&seg->s_as->a_cv);
2576 			}
2577 			mutex_exit(&seg->s_as->a_contents);
2578 		}
2579 	}
2580 }
2581 
2582 #define	PAGE_HANDLED	((page_t *)-1)
2583 
2584 /*
2585  * Release all the pages in the NULL terminated ppp list
2586  * which haven't already been converted to PAGE_HANDLED.
2587  */
2588 static void
2589 segvn_pagelist_rele(page_t **ppp)
2590 {
2591 	for (; *ppp != NULL; ppp++) {
2592 		if (*ppp != PAGE_HANDLED)
2593 			page_unlock(*ppp);
2594 	}
2595 }
2596 
2597 static int stealcow = 1;
2598 
2599 /*
2600  * Workaround for viking chip bug.  See bug id 1220902.
2601  * To fix this down in pagefault() would require importing so
2602  * much as and segvn code as to be unmaintainable.
2603  */
2604 int enable_mbit_wa = 0;
2605 
2606 /*
2607  * Handles all the dirty work of getting the right
2608  * anonymous pages and loading up the translations.
2609  * This routine is called only from segvn_fault()
2610  * when looping over the range of addresses requested.
2611  *
2612  * The basic algorithm here is:
2613  * 	If this is an anon_zero case
2614  *		Call anon_zero to allocate page
2615  *		Load up translation
2616  *		Return
2617  *	endif
2618  *	If this is an anon page
2619  *		Use anon_getpage to get the page
2620  *	else
2621  *		Find page in pl[] list passed in
2622  *	endif
2623  *	If not a cow
2624  *		Load up the translation to the page
2625  *		return
2626  *	endif
2627  *	Call anon_private to handle cow
2628  *	Load up (writable) translation to new page
2629  */
2630 static faultcode_t
2631 segvn_faultpage(
2632 	struct hat *hat,		/* the hat to use for mapping */
2633 	struct seg *seg,		/* seg_vn of interest */
2634 	caddr_t addr,			/* address in as */
2635 	u_offset_t off,			/* offset in vp */
2636 	struct vpage *vpage,		/* pointer to vpage for vp, off */
2637 	page_t *pl[],			/* object source page pointer */
2638 	uint_t vpprot,			/* access allowed to object pages */
2639 	enum fault_type type,		/* type of fault */
2640 	enum seg_rw rw,			/* type of access at fault */
2641 	int brkcow)			/* we may need to break cow */
2642 {
2643 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
2644 	page_t *pp, **ppp;
2645 	uint_t pageflags = 0;
2646 	page_t *anon_pl[1 + 1];
2647 	page_t *opp = NULL;		/* original page */
2648 	uint_t prot;
2649 	int err;
2650 	int cow;
2651 	int claim;
2652 	int steal = 0;
2653 	ulong_t anon_index;
2654 	struct anon *ap, *oldap;
2655 	struct anon_map *amp;
2656 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
2657 	int anon_lock = 0;
2658 	anon_sync_obj_t cookie;
2659 
2660 	if (svd->flags & MAP_TEXT) {
2661 		hat_flag |= HAT_LOAD_TEXT;
2662 	}
2663 
2664 	ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
2665 	ASSERT(seg->s_szc == 0);
2666 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
2667 
2668 	/*
2669 	 * Initialize protection value for this page.
2670 	 * If we have per page protection values check it now.
2671 	 */
2672 	if (svd->pageprot) {
2673 		uint_t protchk;
2674 
2675 		switch (rw) {
2676 		case S_READ:
2677 			protchk = PROT_READ;
2678 			break;
2679 		case S_WRITE:
2680 			protchk = PROT_WRITE;
2681 			break;
2682 		case S_EXEC:
2683 			protchk = PROT_EXEC;
2684 			break;
2685 		case S_OTHER:
2686 		default:
2687 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
2688 			break;
2689 		}
2690 
2691 		prot = VPP_PROT(vpage);
2692 		if ((prot & protchk) == 0)
2693 			return (FC_PROT);	/* illegal access type */
2694 	} else {
2695 		prot = svd->prot;
2696 	}
2697 
2698 	if (type == F_SOFTLOCK) {
2699 		atomic_add_long((ulong_t *)&svd->softlockcnt, 1);
2700 	}
2701 
2702 	/*
2703 	 * Always acquire the anon array lock to prevent 2 threads from
2704 	 * allocating separate anon slots for the same "addr".
2705 	 */
2706 
2707 	if ((amp = svd->amp) != NULL) {
2708 		ASSERT(RW_READ_HELD(&amp->a_rwlock));
2709 		anon_index = svd->anon_index + seg_page(seg, addr);
2710 		anon_array_enter(amp, anon_index, &cookie);
2711 		anon_lock = 1;
2712 	}
2713 
2714 	if (svd->vp == NULL && amp != NULL) {
2715 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL) {
2716 			/*
2717 			 * Allocate a (normally) writable anonymous page of
2718 			 * zeroes. If no advance reservations, reserve now.
2719 			 */
2720 			if (svd->flags & MAP_NORESERVE) {
2721 				if (anon_resv_zone(ptob(1),
2722 				    seg->s_as->a_proc->p_zone)) {
2723 					atomic_add_long(&svd->swresv, ptob(1));
2724 					atomic_add_long(&seg->s_as->a_resvsize,
2725 					    ptob(1));
2726 				} else {
2727 					err = ENOMEM;
2728 					goto out;
2729 				}
2730 			}
2731 			if ((pp = anon_zero(seg, addr, &ap,
2732 			    svd->cred)) == NULL) {
2733 				err = ENOMEM;
2734 				goto out;	/* out of swap space */
2735 			}
2736 			/*
2737 			 * Re-acquire the anon_map lock and
2738 			 * initialize the anon array entry.
2739 			 */
2740 			(void) anon_set_ptr(amp->ahp, anon_index, ap,
2741 			    ANON_SLEEP);
2742 
2743 			ASSERT(pp->p_szc == 0);
2744 
2745 			/*
2746 			 * Handle pages that have been marked for migration
2747 			 */
2748 			if (lgrp_optimizations())
2749 				page_migrate(seg, addr, &pp, 1);
2750 
2751 			if (enable_mbit_wa) {
2752 				if (rw == S_WRITE)
2753 					hat_setmod(pp);
2754 				else if (!hat_ismod(pp))
2755 					prot &= ~PROT_WRITE;
2756 			}
2757 			/*
2758 			 * If AS_PAGLCK is set in a_flags (via memcntl(2)
2759 			 * with MC_LOCKAS, MCL_FUTURE) and this is a
2760 			 * MAP_NORESERVE segment, we may need to
2761 			 * permanently lock the page as it is being faulted
2762 			 * for the first time. The following text applies
2763 			 * only to MAP_NORESERVE segments:
2764 			 *
2765 			 * As per memcntl(2), if this segment was created
2766 			 * after MCL_FUTURE was applied (a "future"
2767 			 * segment), its pages must be locked.  If this
2768 			 * segment existed at MCL_FUTURE application (a
2769 			 * "past" segment), the interface is unclear.
2770 			 *
2771 			 * We decide to lock only if vpage is present:
2772 			 *
2773 			 * - "future" segments will have a vpage array (see
2774 			 *    as_map), and so will be locked as required
2775 			 *
2776 			 * - "past" segments may not have a vpage array,
2777 			 *    depending on whether events (such as
2778 			 *    mprotect) have occurred. Locking if vpage
2779 			 *    exists will preserve legacy behavior.  Not
2780 			 *    locking if vpage is absent, will not break
2781 			 *    the interface or legacy behavior.  Note that
2782 			 *    allocating vpage here if it's absent requires
2783 			 *    upgrading the segvn reader lock, the cost of
2784 			 *    which does not seem worthwhile.
2785 			 *
2786 			 * Usually testing and setting VPP_ISPPLOCK and
2787 			 * VPP_SETPPLOCK requires holding the segvn lock as
2788 			 * writer, but in this case all readers are
2789 			 * serializing on the anon array lock.
2790 			 */
2791 			if (AS_ISPGLCK(seg->s_as) && vpage != NULL &&
2792 			    (svd->flags & MAP_NORESERVE) &&
2793 			    !VPP_ISPPLOCK(vpage)) {
2794 				proc_t *p = seg->s_as->a_proc;
2795 				ASSERT(svd->type == MAP_PRIVATE);
2796 				mutex_enter(&p->p_lock);
2797 				if (rctl_incr_locked_mem(p, NULL, PAGESIZE,
2798 				    1) == 0) {
2799 					claim = VPP_PROT(vpage) & PROT_WRITE;
2800 					if (page_pp_lock(pp, claim, 0)) {
2801 						VPP_SETPPLOCK(vpage);
2802 					} else {
2803 						rctl_decr_locked_mem(p, NULL,
2804 						    PAGESIZE, 1);
2805 					}
2806 				}
2807 				mutex_exit(&p->p_lock);
2808 			}
2809 
2810 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2811 			hat_memload(hat, addr, pp, prot, hat_flag);
2812 
2813 			if (!(hat_flag & HAT_LOAD_LOCK))
2814 				page_unlock(pp);
2815 
2816 			anon_array_exit(&cookie);
2817 			return (0);
2818 		}
2819 	}
2820 
2821 	/*
2822 	 * Obtain the page structure via anon_getpage() if it is
2823 	 * a private copy of an object (the result of a previous
2824 	 * copy-on-write).
2825 	 */
2826 	if (amp != NULL) {
2827 		if ((ap = anon_get_ptr(amp->ahp, anon_index)) != NULL) {
2828 			err = anon_getpage(&ap, &vpprot, anon_pl, PAGESIZE,
2829 			    seg, addr, rw, svd->cred);
2830 			if (err)
2831 				goto out;
2832 
2833 			if (svd->type == MAP_SHARED) {
2834 				/*
2835 				 * If this is a shared mapping to an
2836 				 * anon_map, then ignore the write
2837 				 * permissions returned by anon_getpage().
2838 				 * They apply to the private mappings
2839 				 * of this anon_map.
2840 				 */
2841 				vpprot |= PROT_WRITE;
2842 			}
2843 			opp = anon_pl[0];
2844 		}
2845 	}
2846 
2847 	/*
2848 	 * Search the pl[] list passed in if it is from the
2849 	 * original object (i.e., not a private copy).
2850 	 */
2851 	if (opp == NULL) {
2852 		/*
2853 		 * Find original page.  We must be bringing it in
2854 		 * from the list in pl[].
2855 		 */
2856 		for (ppp = pl; (opp = *ppp) != NULL; ppp++) {
2857 			if (opp == PAGE_HANDLED)
2858 				continue;
2859 			ASSERT(opp->p_vnode == svd->vp); /* XXX */
2860 			if (opp->p_offset == off)
2861 				break;
2862 		}
2863 		if (opp == NULL) {
2864 			panic("segvn_faultpage not found");
2865 			/*NOTREACHED*/
2866 		}
2867 		*ppp = PAGE_HANDLED;
2868 
2869 	}
2870 
2871 	ASSERT(PAGE_LOCKED(opp));
2872 
2873 	TRACE_3(TR_FAC_VM, TR_SEGVN_FAULT,
2874 	    "segvn_fault:pp %p vp %p offset %llx", opp, NULL, 0);
2875 
2876 	/*
2877 	 * The fault is treated as a copy-on-write fault if a
2878 	 * write occurs on a private segment and the object
2879 	 * page (i.e., mapping) is write protected.  We assume
2880 	 * that fatal protection checks have already been made.
2881 	 */
2882 
2883 	if (brkcow) {
2884 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
2885 		cow = !(vpprot & PROT_WRITE);
2886 	} else if (svd->tr_state == SEGVN_TR_ON) {
2887 		/*
2888 		 * If we are doing text replication COW on first touch.
2889 		 */
2890 		ASSERT(amp != NULL);
2891 		ASSERT(svd->vp != NULL);
2892 		ASSERT(rw != S_WRITE);
2893 		cow = (ap == NULL);
2894 	} else {
2895 		cow = 0;
2896 	}
2897 
2898 	/*
2899 	 * If not a copy-on-write case load the translation
2900 	 * and return.
2901 	 */
2902 	if (cow == 0) {
2903 
2904 		/*
2905 		 * Handle pages that have been marked for migration
2906 		 */
2907 		if (lgrp_optimizations())
2908 			page_migrate(seg, addr, &opp, 1);
2909 
2910 		if (IS_VMODSORT(opp->p_vnode) || enable_mbit_wa) {
2911 			if (rw == S_WRITE)
2912 				hat_setmod(opp);
2913 			else if (rw != S_OTHER && !hat_ismod(opp))
2914 				prot &= ~PROT_WRITE;
2915 		}
2916 
2917 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
2918 		    (!svd->pageprot && svd->prot == (prot & vpprot)));
2919 		ASSERT(amp == NULL ||
2920 		    svd->rcookie == HAT_INVALID_REGION_COOKIE);
2921 		hat_memload_region(hat, addr, opp, prot & vpprot, hat_flag,
2922 		    svd->rcookie);
2923 
2924 		if (!(hat_flag & HAT_LOAD_LOCK))
2925 			page_unlock(opp);
2926 
2927 		if (anon_lock) {
2928 			anon_array_exit(&cookie);
2929 		}
2930 		return (0);
2931 	}
2932 
2933 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2934 
2935 	hat_setref(opp);
2936 
2937 	ASSERT(amp != NULL && anon_lock);
2938 
2939 	/*
2940 	 * Steal the page only if it isn't a private page
2941 	 * since stealing a private page is not worth the effort.
2942 	 */
2943 	if ((ap = anon_get_ptr(amp->ahp, anon_index)) == NULL)
2944 		steal = 1;
2945 
2946 	/*
2947 	 * Steal the original page if the following conditions are true:
2948 	 *
2949 	 * We are low on memory, the page is not private, page is not large,
2950 	 * not shared, not modified, not `locked' or if we have it `locked'
2951 	 * (i.e., p_cowcnt == 1 and p_lckcnt == 0, which also implies
2952 	 * that the page is not shared) and if it doesn't have any
2953 	 * translations. page_struct_lock isn't needed to look at p_cowcnt
2954 	 * and p_lckcnt because we first get exclusive lock on page.
2955 	 */
2956 	(void) hat_pagesync(opp, HAT_SYNC_DONTZERO | HAT_SYNC_STOPON_MOD);
2957 
2958 	if (stealcow && freemem < minfree && steal && opp->p_szc == 0 &&
2959 	    page_tryupgrade(opp) && !hat_ismod(opp) &&
2960 	    ((opp->p_lckcnt == 0 && opp->p_cowcnt == 0) ||
2961 	    (opp->p_lckcnt == 0 && opp->p_cowcnt == 1 &&
2962 	    vpage != NULL && VPP_ISPPLOCK(vpage)))) {
2963 		/*
2964 		 * Check if this page has other translations
2965 		 * after unloading our translation.
2966 		 */
2967 		if (hat_page_is_mapped(opp)) {
2968 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
2969 			hat_unload(seg->s_as->a_hat, addr, PAGESIZE,
2970 			    HAT_UNLOAD);
2971 		}
2972 
2973 		/*
2974 		 * hat_unload() might sync back someone else's recent
2975 		 * modification, so check again.
2976 		 */
2977 		if (!hat_ismod(opp) && !hat_page_is_mapped(opp))
2978 			pageflags |= STEAL_PAGE;
2979 	}
2980 
2981 	/*
2982 	 * If we have a vpage pointer, see if it indicates that we have
2983 	 * ``locked'' the page we map -- if so, tell anon_private to
2984 	 * transfer the locking resource to the new page.
2985 	 *
2986 	 * See Statement at the beginning of segvn_lockop regarding
2987 	 * the way lockcnts/cowcnts are handled during COW.
2988 	 *
2989 	 */
2990 	if (vpage != NULL && VPP_ISPPLOCK(vpage))
2991 		pageflags |= LOCK_PAGE;
2992 
2993 	/*
2994 	 * Allocate a private page and perform the copy.
2995 	 * For MAP_NORESERVE reserve swap space now, unless this
2996 	 * is a cow fault on an existing anon page in which case
2997 	 * MAP_NORESERVE will have made advance reservations.
2998 	 */
2999 	if ((svd->flags & MAP_NORESERVE) && (ap == NULL)) {
3000 		if (anon_resv_zone(ptob(1), seg->s_as->a_proc->p_zone)) {
3001 			atomic_add_long(&svd->swresv, ptob(1));
3002 			atomic_add_long(&seg->s_as->a_resvsize, ptob(1));
3003 		} else {
3004 			page_unlock(opp);
3005 			err = ENOMEM;
3006 			goto out;
3007 		}
3008 	}
3009 	oldap = ap;
3010 	pp = anon_private(&ap, seg, addr, prot, opp, pageflags, svd->cred);
3011 	if (pp == NULL) {
3012 		err = ENOMEM;	/* out of swap space */
3013 		goto out;
3014 	}
3015 
3016 	/*
3017 	 * If we copied away from an anonymous page, then
3018 	 * we are one step closer to freeing up an anon slot.
3019 	 *
3020 	 * NOTE:  The original anon slot must be released while
3021 	 * holding the "anon_map" lock.  This is necessary to prevent
3022 	 * other threads from obtaining a pointer to the anon slot
3023 	 * which may be freed if its "refcnt" is 1.
3024 	 */
3025 	if (oldap != NULL)
3026 		anon_decref(oldap);
3027 
3028 	(void) anon_set_ptr(amp->ahp, anon_index, ap, ANON_SLEEP);
3029 
3030 	/*
3031 	 * Handle pages that have been marked for migration
3032 	 */
3033 	if (lgrp_optimizations())
3034 		page_migrate(seg, addr, &pp, 1);
3035 
3036 	ASSERT(pp->p_szc == 0);
3037 
3038 	ASSERT(!IS_VMODSORT(pp->p_vnode));
3039 	if (enable_mbit_wa) {
3040 		if (rw == S_WRITE)
3041 			hat_setmod(pp);
3042 		else if (!hat_ismod(pp))
3043 			prot &= ~PROT_WRITE;
3044 	}
3045 
3046 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
3047 	hat_memload(hat, addr, pp, prot, hat_flag);
3048 
3049 	if (!(hat_flag & HAT_LOAD_LOCK))
3050 		page_unlock(pp);
3051 
3052 	ASSERT(anon_lock);
3053 	anon_array_exit(&cookie);
3054 	return (0);
3055 out:
3056 	if (anon_lock)
3057 		anon_array_exit(&cookie);
3058 
3059 	if (type == F_SOFTLOCK) {
3060 		atomic_add_long((ulong_t *)&svd->softlockcnt, -1);
3061 	}
3062 	return (FC_MAKE_ERR(err));
3063 }
3064 
3065 /*
3066  * relocate a bunch of smaller targ pages into one large repl page. all targ
3067  * pages must be complete pages smaller than replacement pages.
3068  * it's assumed that no page's szc can change since they are all PAGESIZE or
3069  * complete large pages locked SHARED.
3070  */
3071 static void
3072 segvn_relocate_pages(page_t **targ, page_t *replacement)
3073 {
3074 	page_t *pp;
3075 	pgcnt_t repl_npgs, curnpgs;
3076 	pgcnt_t i;
3077 	uint_t repl_szc = replacement->p_szc;
3078 	page_t *first_repl = replacement;
3079 	page_t *repl;
3080 	spgcnt_t npgs;
3081 
3082 	VM_STAT_ADD(segvnvmstats.relocatepages[0]);
3083 
3084 	ASSERT(repl_szc != 0);
3085 	npgs = repl_npgs = page_get_pagecnt(repl_szc);
3086 
3087 	i = 0;
3088 	while (repl_npgs) {
3089 		spgcnt_t nreloc;
3090 		int err;
3091 		ASSERT(replacement != NULL);
3092 		pp = targ[i];
3093 		ASSERT(pp->p_szc < repl_szc);
3094 		ASSERT(PAGE_EXCL(pp));
3095 		ASSERT(!PP_ISFREE(pp));
3096 		curnpgs = page_get_pagecnt(pp->p_szc);
3097 		if (curnpgs == 1) {
3098 			VM_STAT_ADD(segvnvmstats.relocatepages[1]);
3099 			repl = replacement;
3100 			page_sub(&replacement, repl);
3101 			ASSERT(PAGE_EXCL(repl));
3102 			ASSERT(!PP_ISFREE(repl));
3103 			ASSERT(repl->p_szc == repl_szc);
3104 		} else {
3105 			page_t *repl_savepp;
3106 			int j;
3107 			VM_STAT_ADD(segvnvmstats.relocatepages[2]);
3108 			repl_savepp = replacement;
3109 			for (j = 0; j < curnpgs; j++) {
3110 				repl = replacement;
3111 				page_sub(&replacement, repl);
3112 				ASSERT(PAGE_EXCL(repl));
3113 				ASSERT(!PP_ISFREE(repl));
3114 				ASSERT(repl->p_szc == repl_szc);
3115 				ASSERT(page_pptonum(targ[i + j]) ==
3116 				    page_pptonum(targ[i]) + j);
3117 			}
3118 			repl = repl_savepp;
3119 			ASSERT(IS_P2ALIGNED(page_pptonum(repl), curnpgs));
3120 		}
3121 		err = page_relocate(&pp, &repl, 0, 1, &nreloc, NULL);
3122 		if (err || nreloc != curnpgs) {
3123 			panic("segvn_relocate_pages: "
3124 			    "page_relocate failed err=%d curnpgs=%ld "
3125 			    "nreloc=%ld", err, curnpgs, nreloc);
3126 		}
3127 		ASSERT(curnpgs <= repl_npgs);
3128 		repl_npgs -= curnpgs;
3129 		i += curnpgs;
3130 	}
3131 	ASSERT(replacement == NULL);
3132 
3133 	repl = first_repl;
3134 	repl_npgs = npgs;
3135 	for (i = 0; i < repl_npgs; i++) {
3136 		ASSERT(PAGE_EXCL(repl));
3137 		ASSERT(!PP_ISFREE(repl));
3138 		targ[i] = repl;
3139 		page_downgrade(targ[i]);
3140 		repl++;
3141 	}
3142 }
3143 
3144 /*
3145  * Check if all pages in ppa array are complete smaller than szc pages and
3146  * their roots will still be aligned relative to their current size if the
3147  * entire ppa array is relocated into one szc page. If these conditions are
3148  * not met return 0.
3149  *
3150  * If all pages are properly aligned attempt to upgrade their locks
3151  * to exclusive mode. If it fails set *upgrdfail to 1 and return 0.
3152  * upgrdfail was set to 0 by caller.
3153  *
3154  * Return 1 if all pages are aligned and locked exclusively.
3155  *
3156  * If all pages in ppa array happen to be physically contiguous to make one
3157  * szc page and all exclusive locks are successfully obtained promote the page
3158  * size to szc and set *pszc to szc. Return 1 with pages locked shared.
3159  */
3160 static int
3161 segvn_full_szcpages(page_t **ppa, uint_t szc, int *upgrdfail, uint_t *pszc)
3162 {
3163 	page_t *pp;
3164 	pfn_t pfn;
3165 	pgcnt_t totnpgs = page_get_pagecnt(szc);
3166 	pfn_t first_pfn;
3167 	int contig = 1;
3168 	pgcnt_t i;
3169 	pgcnt_t j;
3170 	uint_t curszc;
3171 	pgcnt_t curnpgs;
3172 	int root = 0;
3173 
3174 	ASSERT(szc > 0);
3175 
3176 	VM_STAT_ADD(segvnvmstats.fullszcpages[0]);
3177 
3178 	for (i = 0; i < totnpgs; i++) {
3179 		pp = ppa[i];
3180 		ASSERT(PAGE_SHARED(pp));
3181 		ASSERT(!PP_ISFREE(pp));
3182 		pfn = page_pptonum(pp);
3183 		if (i == 0) {
3184 			if (!IS_P2ALIGNED(pfn, totnpgs)) {
3185 				contig = 0;
3186 			} else {
3187 				first_pfn = pfn;
3188 			}
3189 		} else if (contig && pfn != first_pfn + i) {
3190 			contig = 0;
3191 		}
3192 		if (pp->p_szc == 0) {
3193 			if (root) {
3194 				VM_STAT_ADD(segvnvmstats.fullszcpages[1]);
3195 				return (0);
3196 			}
3197 		} else if (!root) {
3198 			if ((curszc = pp->p_szc) >= szc) {
3199 				VM_STAT_ADD(segvnvmstats.fullszcpages[2]);
3200 				return (0);
3201 			}
3202 			if (curszc == 0) {
3203 				/*
3204 				 * p_szc changed means we don't have all pages
3205 				 * locked. return failure.
3206 				 */
3207 				VM_STAT_ADD(segvnvmstats.fullszcpages[3]);
3208 				return (0);
3209 			}
3210 			curnpgs = page_get_pagecnt(curszc);
3211 			if (!IS_P2ALIGNED(pfn, curnpgs) ||
3212 			    !IS_P2ALIGNED(i, curnpgs)) {
3213 				VM_STAT_ADD(segvnvmstats.fullszcpages[4]);
3214 				return (0);
3215 			}
3216 			root = 1;
3217 		} else {
3218 			ASSERT(i > 0);
3219 			VM_STAT_ADD(segvnvmstats.fullszcpages[5]);
3220 			if (pp->p_szc != curszc) {
3221 				VM_STAT_ADD(segvnvmstats.fullszcpages[6]);
3222 				return (0);
3223 			}
3224 			if (pfn - 1 != page_pptonum(ppa[i - 1])) {
3225 				panic("segvn_full_szcpages: "
3226 				    "large page not physically contiguous");
3227 			}
3228 			if (P2PHASE(pfn, curnpgs) == curnpgs - 1) {
3229 				root = 0;
3230 			}
3231 		}
3232 	}
3233 
3234 	for (i = 0; i < totnpgs; i++) {
3235 		ASSERT(ppa[i]->p_szc < szc);
3236 		if (!page_tryupgrade(ppa[i])) {
3237 			for (j = 0; j < i; j++) {
3238 				page_downgrade(ppa[j]);
3239 			}
3240 			*pszc = ppa[i]->p_szc;
3241 			*upgrdfail = 1;
3242 			VM_STAT_ADD(segvnvmstats.fullszcpages[7]);
3243 			return (0);
3244 		}
3245 	}
3246 
3247 	/*
3248 	 * When a page is put a free cachelist its szc is set to 0.  if file
3249 	 * system reclaimed pages from cachelist targ pages will be physically
3250 	 * contiguous with 0 p_szc.  in this case just upgrade szc of targ
3251 	 * pages without any relocations.
3252 	 * To avoid any hat issues with previous small mappings
3253 	 * hat_pageunload() the target pages first.
3254 	 */
3255 	if (contig) {
3256 		VM_STAT_ADD(segvnvmstats.fullszcpages[8]);
3257 		for (i = 0; i < totnpgs; i++) {
3258 			(void) hat_pageunload(ppa[i], HAT_FORCE_PGUNLOAD);
3259 		}
3260 		for (i = 0; i < totnpgs; i++) {
3261 			ppa[i]->p_szc = szc;
3262 		}
3263 		for (i = 0; i < totnpgs; i++) {
3264 			ASSERT(PAGE_EXCL(ppa[i]));
3265 			page_downgrade(ppa[i]);
3266 		}
3267 		if (pszc != NULL) {
3268 			*pszc = szc;
3269 		}
3270 	}
3271 	VM_STAT_ADD(segvnvmstats.fullszcpages[9]);
3272 	return (1);
3273 }
3274 
3275 /*
3276  * Create physically contiguous pages for [vp, off] - [vp, off +
3277  * page_size(szc)) range and for private segment return them in ppa array.
3278  * Pages are created either via IO or relocations.
3279  *
3280  * Return 1 on success and 0 on failure.
3281  *
3282  * If physically contiguous pages already exist for this range return 1 without
3283  * filling ppa array. Caller initializes ppa[0] as NULL to detect that ppa
3284  * array wasn't filled. In this case caller fills ppa array via VOP_GETPAGE().
3285  */
3286 
3287 static int
3288 segvn_fill_vp_pages(struct segvn_data *svd, vnode_t *vp, u_offset_t off,
3289     uint_t szc, page_t **ppa, page_t **ppplist, uint_t *ret_pszc,
3290     int *downsize)
3291 
3292 {
3293 	page_t *pplist = *ppplist;
3294 	size_t pgsz = page_get_pagesize(szc);
3295 	pgcnt_t pages = btop(pgsz);
3296 	ulong_t start_off = off;
3297 	u_offset_t eoff = off + pgsz;
3298 	spgcnt_t nreloc;
3299 	u_offset_t io_off = off;
3300 	size_t io_len;
3301 	page_t *io_pplist = NULL;
3302 	page_t *done_pplist = NULL;
3303 	pgcnt_t pgidx = 0;
3304 	page_t *pp;
3305 	page_t *newpp;
3306 	page_t *targpp;
3307 	int io_err = 0;
3308 	int i;
3309 	pfn_t pfn;
3310 	ulong_t ppages;
3311 	page_t *targ_pplist = NULL;
3312 	page_t *repl_pplist = NULL;
3313 	page_t *tmp_pplist;
3314 	int nios = 0;
3315 	uint_t pszc;
3316 	struct vattr va;
3317 
3318 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[0]);
3319 
3320 	ASSERT(szc != 0);
3321 	ASSERT(pplist->p_szc == szc);
3322 
3323 	/*
3324 	 * downsize will be set to 1 only if we fail to lock pages. this will
3325 	 * allow subsequent faults to try to relocate the page again. If we
3326 	 * fail due to misalignment don't downsize and let the caller map the
3327 	 * whole region with small mappings to avoid more faults into the area
3328 	 * where we can't get large pages anyway.
3329 	 */
3330 	*downsize = 0;
3331 
3332 	while (off < eoff) {
3333 		newpp = pplist;
3334 		ASSERT(newpp != NULL);
3335 		ASSERT(PAGE_EXCL(newpp));
3336 		ASSERT(!PP_ISFREE(newpp));
3337 		/*
3338 		 * we pass NULL for nrelocp to page_lookup_create()
3339 		 * so that it doesn't relocate. We relocate here
3340 		 * later only after we make sure we can lock all
3341 		 * pages in the range we handle and they are all
3342 		 * aligned.
3343 		 */
3344 		pp = page_lookup_create(vp, off, SE_SHARED, newpp, NULL, 0);
3345 		ASSERT(pp != NULL);
3346 		ASSERT(!PP_ISFREE(pp));
3347 		ASSERT(pp->p_vnode == vp);
3348 		ASSERT(pp->p_offset == off);
3349 		if (pp == newpp) {
3350 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[1]);
3351 			page_sub(&pplist, pp);
3352 			ASSERT(PAGE_EXCL(pp));
3353 			ASSERT(page_iolock_assert(pp));
3354 			page_list_concat(&io_pplist, &pp);
3355 			off += PAGESIZE;
3356 			continue;
3357 		}
3358 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[2]);
3359 		pfn = page_pptonum(pp);
3360 		pszc = pp->p_szc;
3361 		if (pszc >= szc && targ_pplist == NULL && io_pplist == NULL &&
3362 		    IS_P2ALIGNED(pfn, pages)) {
3363 			ASSERT(repl_pplist == NULL);
3364 			ASSERT(done_pplist == NULL);
3365 			ASSERT(pplist == *ppplist);
3366 			page_unlock(pp);
3367 			page_free_replacement_page(pplist);
3368 			page_create_putback(pages);
3369 			*ppplist = NULL;
3370 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[3]);
3371 			return (1);
3372 		}
3373 		if (pszc >= szc) {
3374 			page_unlock(pp);
3375 			segvn_faultvnmpss_align_err1++;
3376 			goto out;
3377 		}
3378 		ppages = page_get_pagecnt(pszc);
3379 		if (!IS_P2ALIGNED(pfn, ppages)) {
3380 			ASSERT(pszc > 0);
3381 			/*
3382 			 * sizing down to pszc won't help.
3383 			 */
3384 			page_unlock(pp);
3385 			segvn_faultvnmpss_align_err2++;
3386 			goto out;
3387 		}
3388 		pfn = page_pptonum(newpp);
3389 		if (!IS_P2ALIGNED(pfn, ppages)) {
3390 			ASSERT(pszc > 0);
3391 			/*
3392 			 * sizing down to pszc won't help.
3393 			 */
3394 			page_unlock(pp);
3395 			segvn_faultvnmpss_align_err3++;
3396 			goto out;
3397 		}
3398 		if (!PAGE_EXCL(pp)) {
3399 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[4]);
3400 			page_unlock(pp);
3401 			*downsize = 1;
3402 			*ret_pszc = pp->p_szc;
3403 			goto out;
3404 		}
3405 		targpp = pp;
3406 		if (io_pplist != NULL) {
3407 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[5]);
3408 			io_len = off - io_off;
3409 			/*
3410 			 * Some file systems like NFS don't check EOF
3411 			 * conditions in VOP_PAGEIO(). Check it here
3412 			 * now that pages are locked SE_EXCL. Any file
3413 			 * truncation will wait until the pages are
3414 			 * unlocked so no need to worry that file will
3415 			 * be truncated after we check its size here.
3416 			 * XXX fix NFS to remove this check.
3417 			 */
3418 			va.va_mask = AT_SIZE;
3419 			if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL)) {
3420 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[6]);
3421 				page_unlock(targpp);
3422 				goto out;
3423 			}
3424 			if (btopr(va.va_size) < btopr(io_off + io_len)) {
3425 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[7]);
3426 				*downsize = 1;
3427 				*ret_pszc = 0;
3428 				page_unlock(targpp);
3429 				goto out;
3430 			}
3431 			io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3432 				B_READ, svd->cred, NULL);
3433 			if (io_err) {
3434 				VM_STAT_ADD(segvnvmstats.fill_vp_pages[8]);
3435 				page_unlock(targpp);
3436 				if (io_err == EDEADLK) {
3437 					segvn_vmpss_pageio_deadlk_err++;
3438 				}
3439 				goto out;
3440 			}
3441 			nios++;
3442 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[9]);
3443 			while (io_pplist != NULL) {
3444 				pp = io_pplist;
3445 				page_sub(&io_pplist, pp);
3446 				ASSERT(page_iolock_assert(pp));
3447 				page_io_unlock(pp);
3448 				pgidx = (pp->p_offset - start_off) >>
3449 				    PAGESHIFT;
3450 				ASSERT(pgidx < pages);
3451 				ppa[pgidx] = pp;
3452 				page_list_concat(&done_pplist, &pp);
3453 			}
3454 		}
3455 		pp = targpp;
3456 		ASSERT(PAGE_EXCL(pp));
3457 		ASSERT(pp->p_szc <= pszc);
3458 		if (pszc != 0 && !group_page_trylock(pp, SE_EXCL)) {
3459 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[10]);
3460 			page_unlock(pp);
3461 			*downsize = 1;
3462 			*ret_pszc = pp->p_szc;
3463 			goto out;
3464 		}
3465 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[11]);
3466 		/*
3467 		 * page szc chould have changed before the entire group was
3468 		 * locked. reread page szc.
3469 		 */
3470 		pszc = pp->p_szc;
3471 		ppages = page_get_pagecnt(pszc);
3472 
3473 		/* link just the roots */
3474 		page_list_concat(&targ_pplist, &pp);
3475 		page_sub(&pplist, newpp);
3476 		page_list_concat(&repl_pplist, &newpp);
3477 		off += PAGESIZE;
3478 		while (--ppages != 0) {
3479 			newpp = pplist;
3480 			page_sub(&pplist, newpp);
3481 			off += PAGESIZE;
3482 		}
3483 		io_off = off;
3484 	}
3485 	if (io_pplist != NULL) {
3486 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[12]);
3487 		io_len = eoff - io_off;
3488 		va.va_mask = AT_SIZE;
3489 		if (VOP_GETATTR(vp, &va, ATTR_HINT, svd->cred, NULL) != 0) {
3490 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[13]);
3491 			goto out;
3492 		}
3493 		if (btopr(va.va_size) < btopr(io_off + io_len)) {
3494 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[14]);
3495 			*downsize = 1;
3496 			*ret_pszc = 0;
3497 			goto out;
3498 		}
3499 		io_err = VOP_PAGEIO(vp, io_pplist, io_off, io_len,
3500 		    B_READ, svd->cred, NULL);
3501 		if (io_err) {
3502 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[15]);
3503 			if (io_err == EDEADLK) {
3504 				segvn_vmpss_pageio_deadlk_err++;
3505 			}
3506 			goto out;
3507 		}
3508 		nios++;
3509 		while (io_pplist != NULL) {
3510 			pp = io_pplist;
3511 			page_sub(&io_pplist, pp);
3512 			ASSERT(page_iolock_assert(pp));
3513 			page_io_unlock(pp);
3514 			pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3515 			ASSERT(pgidx < pages);
3516 			ppa[pgidx] = pp;
3517 		}
3518 	}
3519 	/*
3520 	 * we're now bound to succeed or panic.
3521 	 * remove pages from done_pplist. it's not needed anymore.
3522 	 */
3523 	while (done_pplist != NULL) {
3524 		pp = done_pplist;
3525 		page_sub(&done_pplist, pp);
3526 	}
3527 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[16]);
3528 	ASSERT(pplist == NULL);
3529 	*ppplist = NULL;
3530 	while (targ_pplist != NULL) {
3531 		int ret;
3532 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[17]);
3533 		ASSERT(repl_pplist);
3534 		pp = targ_pplist;
3535 		page_sub(&targ_pplist, pp);
3536 		pgidx = (pp->p_offset - start_off) >> PAGESHIFT;
3537 		newpp = repl_pplist;
3538 		page_sub(&repl_pplist, newpp);
3539 #ifdef DEBUG
3540 		pfn = page_pptonum(pp);
3541 		pszc = pp->p_szc;
3542 		ppages = page_get_pagecnt(pszc);
3543 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3544 		pfn = page_pptonum(newpp);
3545 		ASSERT(IS_P2ALIGNED(pfn, ppages));
3546 		ASSERT(P2PHASE(pfn, pages) == pgidx);
3547 #endif
3548 		nreloc = 0;
3549 		ret = page_relocate(&pp, &newpp, 0, 1, &nreloc, NULL);
3550 		if (ret != 0 || nreloc == 0) {
3551 			panic("segvn_fill_vp_pages: "
3552 			    "page_relocate failed");
3553 		}
3554 		pp = newpp;
3555 		while (nreloc-- != 0) {
3556 			ASSERT(PAGE_EXCL(pp));
3557 			ASSERT(pp->p_vnode == vp);
3558 			ASSERT(pgidx ==
3559 			    ((pp->p_offset - start_off) >> PAGESHIFT));
3560 			ppa[pgidx++] = pp;
3561 			pp++;
3562 		}
3563 	}
3564 
3565 	if (svd->type == MAP_PRIVATE) {
3566 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[18]);
3567 		for (i = 0; i < pages; i++) {
3568 			ASSERT(ppa[i] != NULL);
3569 			ASSERT(PAGE_EXCL(ppa[i]));
3570 			ASSERT(ppa[i]->p_vnode == vp);
3571 			ASSERT(ppa[i]->p_offset ==
3572 			    start_off + (i << PAGESHIFT));
3573 			page_downgrade(ppa[i]);
3574 		}
3575 		ppa[pages] = NULL;
3576 	} else {
3577 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[19]);
3578 		/*
3579 		 * the caller will still call VOP_GETPAGE() for shared segments
3580 		 * to check FS write permissions. For private segments we map
3581 		 * file read only anyway.  so no VOP_GETPAGE is needed.
3582 		 */
3583 		for (i = 0; i < pages; i++) {
3584 			ASSERT(ppa[i] != NULL);
3585 			ASSERT(PAGE_EXCL(ppa[i]));
3586 			ASSERT(ppa[i]->p_vnode == vp);
3587 			ASSERT(ppa[i]->p_offset ==
3588 			    start_off + (i << PAGESHIFT));
3589 			page_unlock(ppa[i]);
3590 		}
3591 		ppa[0] = NULL;
3592 	}
3593 
3594 	return (1);
3595 out:
3596 	/*
3597 	 * Do the cleanup. Unlock target pages we didn't relocate. They are
3598 	 * linked on targ_pplist by root pages. reassemble unused replacement
3599 	 * and io pages back to pplist.
3600 	 */
3601 	if (io_pplist != NULL) {
3602 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[20]);
3603 		pp = io_pplist;
3604 		do {
3605 			ASSERT(pp->p_vnode == vp);
3606 			ASSERT(pp->p_offset == io_off);
3607 			ASSERT(page_iolock_assert(pp));
3608 			page_io_unlock(pp);
3609 			page_hashout(pp, NULL);
3610 			io_off += PAGESIZE;
3611 		} while ((pp = pp->p_next) != io_pplist);
3612 		page_list_concat(&io_pplist, &pplist);
3613 		pplist = io_pplist;
3614 	}
3615 	tmp_pplist = NULL;
3616 	while (targ_pplist != NULL) {
3617 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[21]);
3618 		pp = targ_pplist;
3619 		ASSERT(PAGE_EXCL(pp));
3620 		page_sub(&targ_pplist, pp);
3621 
3622 		pszc = pp->p_szc;
3623 		ppages = page_get_pagecnt(pszc);
3624 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3625 
3626 		if (pszc != 0) {
3627 			group_page_unlock(pp);
3628 		}
3629 		page_unlock(pp);
3630 
3631 		pp = repl_pplist;
3632 		ASSERT(pp != NULL);
3633 		ASSERT(PAGE_EXCL(pp));
3634 		ASSERT(pp->p_szc == szc);
3635 		page_sub(&repl_pplist, pp);
3636 
3637 		ASSERT(IS_P2ALIGNED(page_pptonum(pp), ppages));
3638 
3639 		/* relink replacement page */
3640 		page_list_concat(&tmp_pplist, &pp);
3641 		while (--ppages != 0) {
3642 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[22]);
3643 			pp++;
3644 			ASSERT(PAGE_EXCL(pp));
3645 			ASSERT(pp->p_szc == szc);
3646 			page_list_concat(&tmp_pplist, &pp);
3647 		}
3648 	}
3649 	if (tmp_pplist != NULL) {
3650 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[23]);
3651 		page_list_concat(&tmp_pplist, &pplist);
3652 		pplist = tmp_pplist;
3653 	}
3654 	/*
3655 	 * at this point all pages are either on done_pplist or
3656 	 * pplist. They can't be all on done_pplist otherwise
3657 	 * we'd've been done.
3658 	 */
3659 	ASSERT(pplist != NULL);
3660 	if (nios != 0) {
3661 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[24]);
3662 		pp = pplist;
3663 		do {
3664 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[25]);
3665 			ASSERT(pp->p_szc == szc);
3666 			ASSERT(PAGE_EXCL(pp));
3667 			ASSERT(pp->p_vnode != vp);
3668 			pp->p_szc = 0;
3669 		} while ((pp = pp->p_next) != pplist);
3670 
3671 		pp = done_pplist;
3672 		do {
3673 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[26]);
3674 			ASSERT(pp->p_szc == szc);
3675 			ASSERT(PAGE_EXCL(pp));
3676 			ASSERT(pp->p_vnode == vp);
3677 			pp->p_szc = 0;
3678 		} while ((pp = pp->p_next) != done_pplist);
3679 
3680 		while (pplist != NULL) {
3681 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[27]);
3682 			pp = pplist;
3683 			page_sub(&pplist, pp);
3684 			page_free(pp, 0);
3685 		}
3686 
3687 		while (done_pplist != NULL) {
3688 			VM_STAT_ADD(segvnvmstats.fill_vp_pages[28]);
3689 			pp = done_pplist;
3690 			page_sub(&done_pplist, pp);
3691 			page_unlock(pp);
3692 		}
3693 		*ppplist = NULL;
3694 		return (0);
3695 	}
3696 	ASSERT(pplist == *ppplist);
3697 	if (io_err) {
3698 		VM_STAT_ADD(segvnvmstats.fill_vp_pages[29]);
3699 		/*
3700 		 * don't downsize on io error.
3701 		 * see if vop_getpage succeeds.
3702 		 * pplist may still be used in this case
3703 		 * for relocations.
3704 		 */
3705 		return (0);
3706 	}
3707 	VM_STAT_ADD(segvnvmstats.fill_vp_pages[30]);
3708 	page_free_replacement_page(pplist);
3709 	page_create_putback(pages);
3710 	*ppplist = NULL;
3711 	return (0);
3712 }
3713 
3714 int segvn_anypgsz = 0;
3715 
3716 #define	SEGVN_RESTORE_SOFTLOCK_VP(type, pages) 				\
3717 		if ((type) == F_SOFTLOCK) {				\
3718 			atomic_add_long((ulong_t *)&(svd)->softlockcnt, \
3719 			    -(pages));					\
3720 		}
3721 
3722 #define	SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot)		\
3723 		if (IS_VMODSORT((ppa)[0]->p_vnode)) {			\
3724 			if ((rw) == S_WRITE) {				\
3725 				for (i = 0; i < (pages); i++) {		\
3726 					ASSERT((ppa)[i]->p_vnode ==	\
3727 					    (ppa)[0]->p_vnode);		\
3728 					hat_setmod((ppa)[i]);		\
3729 				}					\
3730 			} else if ((rw) != S_OTHER &&			\
3731 			    ((prot) & (vpprot) & PROT_WRITE)) {		\
3732 				for (i = 0; i < (pages); i++) {		\
3733 					ASSERT((ppa)[i]->p_vnode ==	\
3734 					    (ppa)[0]->p_vnode);		\
3735 					if (!hat_ismod((ppa)[i])) {	\
3736 						prot &= ~PROT_WRITE;	\
3737 						break;			\
3738 					}				\
3739 				}					\
3740 			}						\
3741 		}
3742 
3743 #ifdef  VM_STATS
3744 
3745 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)					\
3746 		VM_STAT_ADD(segvnvmstats.fltvnpages[(idx)]);
3747 
3748 #else /* VM_STATS */
3749 
3750 #define	SEGVN_VMSTAT_FLTVNPAGES(idx)
3751 
3752 #endif
3753 
3754 static faultcode_t
3755 segvn_fault_vnodepages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
3756     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
3757     caddr_t eaddr, int brkcow)
3758 {
3759 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
3760 	struct anon_map *amp = svd->amp;
3761 	uchar_t segtype = svd->type;
3762 	uint_t szc = seg->s_szc;
3763 	size_t pgsz = page_get_pagesize(szc);
3764 	size_t maxpgsz = pgsz;
3765 	pgcnt_t pages = btop(pgsz);
3766 	pgcnt_t maxpages = pages;
3767 	size_t ppasize = (pages + 1) * sizeof (page_t *);
3768 	caddr_t a = lpgaddr;
3769 	caddr_t	maxlpgeaddr = lpgeaddr;
3770 	u_offset_t off = svd->offset + (uintptr_t)(a - seg->s_base);
3771 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
3772 	struct vpage *vpage = (svd->vpage != NULL) ?
3773 	    &svd->vpage[seg_page(seg, a)] : NULL;
3774 	vnode_t *vp = svd->vp;
3775 	page_t **ppa;
3776 	uint_t	pszc;
3777 	size_t	ppgsz;
3778 	pgcnt_t	ppages;
3779 	faultcode_t err = 0;
3780 	int ierr;
3781 	int vop_size_err = 0;
3782 	uint_t protchk, prot, vpprot;
3783 	ulong_t i;
3784 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
3785 	anon_sync_obj_t an_cookie;
3786 	enum seg_rw arw;
3787 	int alloc_failed = 0;
3788 	int adjszc_chk;
3789 	struct vattr va;
3790 	int xhat = 0;
3791 	page_t *pplist;
3792 	pfn_t pfn;
3793 	int physcontig;
3794 	int upgrdfail;
3795 	int segvn_anypgsz_vnode = 0; /* for now map vnode with 2 page sizes */
3796 	int tron = (svd->tr_state == SEGVN_TR_ON);
3797 
3798 	ASSERT(szc != 0);
3799 	ASSERT(vp != NULL);
3800 	ASSERT(brkcow == 0 || amp != NULL);
3801 	ASSERT(tron == 0 || amp != NULL);
3802 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
3803 	ASSERT(!(svd->flags & MAP_NORESERVE));
3804 	ASSERT(type != F_SOFTUNLOCK);
3805 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
3806 	ASSERT(amp == NULL || IS_P2ALIGNED(aindx, maxpages));
3807 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
3808 	ASSERT(seg->s_szc < NBBY * sizeof (int));
3809 	ASSERT(type != F_SOFTLOCK || lpgeaddr - a == maxpgsz);
3810 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
3811 
3812 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltvnpages[0]);
3813 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltvnpages[1]);
3814 
3815 	if (svd->flags & MAP_TEXT) {
3816 		hat_flag |= HAT_LOAD_TEXT;
3817 	}
3818 
3819 	if (svd->pageprot) {
3820 		switch (rw) {
3821 		case S_READ:
3822 			protchk = PROT_READ;
3823 			break;
3824 		case S_WRITE:
3825 			protchk = PROT_WRITE;
3826 			break;
3827 		case S_EXEC:
3828 			protchk = PROT_EXEC;
3829 			break;
3830 		case S_OTHER:
3831 		default:
3832 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
3833 			break;
3834 		}
3835 	} else {
3836 		prot = svd->prot;
3837 		/* caller has already done segment level protection check. */
3838 	}
3839 
3840 	if (seg->s_as->a_hat != hat) {
3841 		xhat = 1;
3842 	}
3843 
3844 	if (rw == S_WRITE && segtype == MAP_PRIVATE) {
3845 		SEGVN_VMSTAT_FLTVNPAGES(2);
3846 		arw = S_READ;
3847 	} else {
3848 		arw = rw;
3849 	}
3850 
3851 	ppa = kmem_alloc(ppasize, KM_SLEEP);
3852 
3853 	VM_STAT_COND_ADD(amp != NULL, segvnvmstats.fltvnpages[3]);
3854 
3855 	for (;;) {
3856 		adjszc_chk = 0;
3857 		for (; a < lpgeaddr; a += pgsz, off += pgsz, aindx += pages) {
3858 			if (adjszc_chk) {
3859 				while (szc < seg->s_szc) {
3860 					uintptr_t e;
3861 					uint_t tszc;
3862 					tszc = segvn_anypgsz_vnode ? szc + 1 :
3863 					    seg->s_szc;
3864 					ppgsz = page_get_pagesize(tszc);
3865 					if (!IS_P2ALIGNED(a, ppgsz) ||
3866 					    ((alloc_failed >> tszc) & 0x1)) {
3867 						break;
3868 					}
3869 					SEGVN_VMSTAT_FLTVNPAGES(4);
3870 					szc = tszc;
3871 					pgsz = ppgsz;
3872 					pages = btop(pgsz);
3873 					e = P2ROUNDUP((uintptr_t)eaddr, pgsz);
3874 					lpgeaddr = (caddr_t)e;
3875 				}
3876 			}
3877 
3878 		again:
3879 			if (IS_P2ALIGNED(a, maxpgsz) && amp != NULL) {
3880 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
3881 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
3882 				anon_array_enter(amp, aindx, &an_cookie);
3883 				if (anon_get_ptr(amp->ahp, aindx) != NULL) {
3884 					SEGVN_VMSTAT_FLTVNPAGES(5);
3885 					ASSERT(anon_pages(amp->ahp, aindx,
3886 					    maxpages) == maxpages);
3887 					anon_array_exit(&an_cookie);
3888 					ANON_LOCK_EXIT(&amp->a_rwlock);
3889 					err = segvn_fault_anonpages(hat, seg,
3890 					    a, a + maxpgsz, type, rw,
3891 					    MAX(a, addr),
3892 					    MIN(a + maxpgsz, eaddr), brkcow);
3893 					if (err != 0) {
3894 						SEGVN_VMSTAT_FLTVNPAGES(6);
3895 						goto out;
3896 					}
3897 					if (szc < seg->s_szc) {
3898 						szc = seg->s_szc;
3899 						pgsz = maxpgsz;
3900 						pages = maxpages;
3901 						lpgeaddr = maxlpgeaddr;
3902 					}
3903 					goto next;
3904 				} else {
3905 					ASSERT(anon_pages(amp->ahp, aindx,
3906 					    maxpages) == 0);
3907 					SEGVN_VMSTAT_FLTVNPAGES(7);
3908 					anon_array_exit(&an_cookie);
3909 					ANON_LOCK_EXIT(&amp->a_rwlock);
3910 				}
3911 			}
3912 			ASSERT(!brkcow || IS_P2ALIGNED(a, maxpgsz));
3913 			ASSERT(!tron || IS_P2ALIGNED(a, maxpgsz));
3914 
3915 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
3916 				ASSERT(vpage != NULL);
3917 				prot = VPP_PROT(vpage);
3918 				ASSERT(sameprot(seg, a, maxpgsz));
3919 				if ((prot & protchk) == 0) {
3920 					SEGVN_VMSTAT_FLTVNPAGES(8);
3921 					err = FC_PROT;
3922 					goto out;
3923 				}
3924 			}
3925 			if (type == F_SOFTLOCK) {
3926 				atomic_add_long((ulong_t *)&svd->softlockcnt,
3927 				    pages);
3928 			}
3929 
3930 			pplist = NULL;
3931 			physcontig = 0;
3932 			ppa[0] = NULL;
3933 			if (!brkcow && !tron && szc &&
3934 			    !page_exists_physcontig(vp, off, szc,
3935 			    segtype == MAP_PRIVATE ? ppa : NULL)) {
3936 				SEGVN_VMSTAT_FLTVNPAGES(9);
3937 				if (page_alloc_pages(vp, seg, a, &pplist, NULL,
3938 				    szc, 0, 0) && type != F_SOFTLOCK) {
3939 					SEGVN_VMSTAT_FLTVNPAGES(10);
3940 					pszc = 0;
3941 					ierr = -1;
3942 					alloc_failed |= (1 << szc);
3943 					break;
3944 				}
3945 				if (pplist != NULL &&
3946 				    vp->v_mpssdata == SEGVN_PAGEIO) {
3947 					int downsize;
3948 					SEGVN_VMSTAT_FLTVNPAGES(11);
3949 					physcontig = segvn_fill_vp_pages(svd,
3950 					    vp, off, szc, ppa, &pplist,
3951 					    &pszc, &downsize);
3952 					ASSERT(!physcontig || pplist == NULL);
3953 					if (!physcontig && downsize &&
3954 					    type != F_SOFTLOCK) {
3955 						ASSERT(pplist == NULL);
3956 						SEGVN_VMSTAT_FLTVNPAGES(12);
3957 						ierr = -1;
3958 						break;
3959 					}
3960 					ASSERT(!physcontig ||
3961 					    segtype == MAP_PRIVATE ||
3962 					    ppa[0] == NULL);
3963 					if (physcontig && ppa[0] == NULL) {
3964 						physcontig = 0;
3965 					}
3966 				}
3967 			} else if (!brkcow && !tron && szc && ppa[0] != NULL) {
3968 				SEGVN_VMSTAT_FLTVNPAGES(13);
3969 				ASSERT(segtype == MAP_PRIVATE);
3970 				physcontig = 1;
3971 			}
3972 
3973 			if (!physcontig) {
3974 				SEGVN_VMSTAT_FLTVNPAGES(14);
3975 				ppa[0] = NULL;
3976 				ierr = VOP_GETPAGE(vp, (offset_t)off, pgsz,
3977 				    &vpprot, ppa, pgsz, seg, a, arw,
3978 				    svd->cred, NULL);
3979 #ifdef DEBUG
3980 				if (ierr == 0) {
3981 					for (i = 0; i < pages; i++) {
3982 						ASSERT(PAGE_LOCKED(ppa[i]));
3983 						ASSERT(!PP_ISFREE(ppa[i]));
3984 						ASSERT(ppa[i]->p_vnode == vp);
3985 						ASSERT(ppa[i]->p_offset ==
3986 						    off + (i << PAGESHIFT));
3987 					}
3988 				}
3989 #endif /* DEBUG */
3990 				if (segtype == MAP_PRIVATE) {
3991 					SEGVN_VMSTAT_FLTVNPAGES(15);
3992 					vpprot &= ~PROT_WRITE;
3993 				}
3994 			} else {
3995 				ASSERT(segtype == MAP_PRIVATE);
3996 				SEGVN_VMSTAT_FLTVNPAGES(16);
3997 				vpprot = PROT_ALL & ~PROT_WRITE;
3998 				ierr = 0;
3999 			}
4000 
4001 			if (ierr != 0) {
4002 				SEGVN_VMSTAT_FLTVNPAGES(17);
4003 				if (pplist != NULL) {
4004 					SEGVN_VMSTAT_FLTVNPAGES(18);
4005 					page_free_replacement_page(pplist);
4006 					page_create_putback(pages);
4007 				}
4008 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4009 				if (a + pgsz <= eaddr) {
4010 					SEGVN_VMSTAT_FLTVNPAGES(19);
4011 					err = FC_MAKE_ERR(ierr);
4012 					goto out;
4013 				}
4014 				va.va_mask = AT_SIZE;
4015 				if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL)) {
4016 					SEGVN_VMSTAT_FLTVNPAGES(20);
4017 					err = FC_MAKE_ERR(EIO);
4018 					goto out;
4019 				}
4020 				if (btopr(va.va_size) >= btopr(off + pgsz)) {
4021 					SEGVN_VMSTAT_FLTVNPAGES(21);
4022 					err = FC_MAKE_ERR(ierr);
4023 					goto out;
4024 				}
4025 				if (btopr(va.va_size) <
4026 				    btopr(off + (eaddr - a))) {
4027 					SEGVN_VMSTAT_FLTVNPAGES(22);
4028 					err = FC_MAKE_ERR(ierr);
4029 					goto out;
4030 				}
4031 				if (brkcow || tron || type == F_SOFTLOCK) {
4032 					/* can't reduce map area */
4033 					SEGVN_VMSTAT_FLTVNPAGES(23);
4034 					vop_size_err = 1;
4035 					goto out;
4036 				}
4037 				SEGVN_VMSTAT_FLTVNPAGES(24);
4038 				ASSERT(szc != 0);
4039 				pszc = 0;
4040 				ierr = -1;
4041 				break;
4042 			}
4043 
4044 			if (amp != NULL) {
4045 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4046 				anon_array_enter(amp, aindx, &an_cookie);
4047 			}
4048 			if (amp != NULL &&
4049 			    anon_get_ptr(amp->ahp, aindx) != NULL) {
4050 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4051 
4052 				SEGVN_VMSTAT_FLTVNPAGES(25);
4053 				ASSERT(anon_pages(amp->ahp, taindx,
4054 				    maxpages) == maxpages);
4055 				for (i = 0; i < pages; i++) {
4056 					page_unlock(ppa[i]);
4057 				}
4058 				anon_array_exit(&an_cookie);
4059 				ANON_LOCK_EXIT(&amp->a_rwlock);
4060 				if (pplist != NULL) {
4061 					page_free_replacement_page(pplist);
4062 					page_create_putback(pages);
4063 				}
4064 				SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4065 				if (szc < seg->s_szc) {
4066 					SEGVN_VMSTAT_FLTVNPAGES(26);
4067 					/*
4068 					 * For private segments SOFTLOCK
4069 					 * either always breaks cow (any rw
4070 					 * type except S_READ_NOCOW) or
4071 					 * address space is locked as writer
4072 					 * (S_READ_NOCOW case) and anon slots
4073 					 * can't show up on second check.
4074 					 * Therefore if we are here for
4075 					 * SOFTLOCK case it must be a cow
4076 					 * break but cow break never reduces
4077 					 * szc. text replication (tron) in
4078 					 * this case works as cow break.
4079 					 * Thus the assert below.
4080 					 */
4081 					ASSERT(!brkcow && !tron &&
4082 					    type != F_SOFTLOCK);
4083 					pszc = seg->s_szc;
4084 					ierr = -2;
4085 					break;
4086 				}
4087 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4088 				goto again;
4089 			}
4090 #ifdef DEBUG
4091 			if (amp != NULL) {
4092 				ulong_t taindx = P2ALIGN(aindx, maxpages);
4093 				ASSERT(!anon_pages(amp->ahp, taindx, maxpages));
4094 			}
4095 #endif /* DEBUG */
4096 
4097 			if (brkcow || tron) {
4098 				ASSERT(amp != NULL);
4099 				ASSERT(pplist == NULL);
4100 				ASSERT(szc == seg->s_szc);
4101 				ASSERT(IS_P2ALIGNED(a, maxpgsz));
4102 				ASSERT(IS_P2ALIGNED(aindx, maxpages));
4103 				SEGVN_VMSTAT_FLTVNPAGES(27);
4104 				ierr = anon_map_privatepages(amp, aindx, szc,
4105 				    seg, a, prot, ppa, vpage, segvn_anypgsz,
4106 				    tron ? PG_LOCAL : 0, svd->cred);
4107 				if (ierr != 0) {
4108 					SEGVN_VMSTAT_FLTVNPAGES(28);
4109 					anon_array_exit(&an_cookie);
4110 					ANON_LOCK_EXIT(&amp->a_rwlock);
4111 					SEGVN_RESTORE_SOFTLOCK_VP(type, pages);
4112 					err = FC_MAKE_ERR(ierr);
4113 					goto out;
4114 				}
4115 
4116 				ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4117 				/*
4118 				 * p_szc can't be changed for locked
4119 				 * swapfs pages.
4120 				 */
4121 				ASSERT(svd->rcookie ==
4122 				    HAT_INVALID_REGION_COOKIE);
4123 				hat_memload_array(hat, a, pgsz, ppa, prot,
4124 				    hat_flag);
4125 
4126 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4127 					SEGVN_VMSTAT_FLTVNPAGES(29);
4128 					for (i = 0; i < pages; i++) {
4129 						page_unlock(ppa[i]);
4130 					}
4131 				}
4132 				anon_array_exit(&an_cookie);
4133 				ANON_LOCK_EXIT(&amp->a_rwlock);
4134 				goto next;
4135 			}
4136 
4137 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE ||
4138 			    (!svd->pageprot && svd->prot == (prot & vpprot)));
4139 
4140 			pfn = page_pptonum(ppa[0]);
4141 			/*
4142 			 * hat_page_demote() needs an SE_EXCL lock on one of
4143 			 * constituent page_t's and it decreases root's p_szc
4144 			 * last. This means if root's p_szc is equal szc and
4145 			 * all its constituent pages are locked
4146 			 * hat_page_demote() that could have changed p_szc to
4147 			 * szc is already done and no new have page_demote()
4148 			 * can start for this large page.
4149 			 */
4150 
4151 			/*
4152 			 * we need to make sure same mapping size is used for
4153 			 * the same address range if there's a possibility the
4154 			 * adddress is already mapped because hat layer panics
4155 			 * when translation is loaded for the range already
4156 			 * mapped with a different page size.  We achieve it
4157 			 * by always using largest page size possible subject
4158 			 * to the constraints of page size, segment page size
4159 			 * and page alignment.  Since mappings are invalidated
4160 			 * when those constraints change and make it
4161 			 * impossible to use previously used mapping size no
4162 			 * mapping size conflicts should happen.
4163 			 */
4164 
4165 		chkszc:
4166 			if ((pszc = ppa[0]->p_szc) == szc &&
4167 			    IS_P2ALIGNED(pfn, pages)) {
4168 
4169 				SEGVN_VMSTAT_FLTVNPAGES(30);
4170 #ifdef DEBUG
4171 				for (i = 0; i < pages; i++) {
4172 					ASSERT(PAGE_LOCKED(ppa[i]));
4173 					ASSERT(!PP_ISFREE(ppa[i]));
4174 					ASSERT(page_pptonum(ppa[i]) ==
4175 					    pfn + i);
4176 					ASSERT(ppa[i]->p_szc == szc);
4177 					ASSERT(ppa[i]->p_vnode == vp);
4178 					ASSERT(ppa[i]->p_offset ==
4179 					    off + (i << PAGESHIFT));
4180 				}
4181 #endif /* DEBUG */
4182 				/*
4183 				 * All pages are of szc we need and they are
4184 				 * all locked so they can't change szc. load
4185 				 * translations.
4186 				 *
4187 				 * if page got promoted since last check
4188 				 * we don't need pplist.
4189 				 */
4190 				if (pplist != NULL) {
4191 					page_free_replacement_page(pplist);
4192 					page_create_putback(pages);
4193 				}
4194 				if (PP_ISMIGRATE(ppa[0])) {
4195 					page_migrate(seg, a, ppa, pages);
4196 				}
4197 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4198 				    prot, vpprot);
4199 				if (!xhat) {
4200 					hat_memload_array_region(hat, a, pgsz,
4201 					    ppa, prot & vpprot, hat_flag,
4202 					    svd->rcookie);
4203 				} else {
4204 					/*
4205 					 * avoid large xhat mappings to FS
4206 					 * pages so that hat_page_demote()
4207 					 * doesn't need to check for xhat
4208 					 * large mappings.
4209 					 * Don't use regions with xhats.
4210 					 */
4211 					for (i = 0; i < pages; i++) {
4212 						hat_memload(hat,
4213 						    a + (i << PAGESHIFT),
4214 						    ppa[i], prot & vpprot,
4215 						    hat_flag);
4216 					}
4217 				}
4218 
4219 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4220 					for (i = 0; i < pages; i++) {
4221 						page_unlock(ppa[i]);
4222 					}
4223 				}
4224 				if (amp != NULL) {
4225 					anon_array_exit(&an_cookie);
4226 					ANON_LOCK_EXIT(&amp->a_rwlock);
4227 				}
4228 				goto next;
4229 			}
4230 
4231 			/*
4232 			 * See if upsize is possible.
4233 			 */
4234 			if (pszc > szc && szc < seg->s_szc &&
4235 			    (segvn_anypgsz_vnode || pszc >= seg->s_szc)) {
4236 				pgcnt_t aphase;
4237 				uint_t pszc1 = MIN(pszc, seg->s_szc);
4238 				ppgsz = page_get_pagesize(pszc1);
4239 				ppages = btop(ppgsz);
4240 				aphase = btop(P2PHASE((uintptr_t)a, ppgsz));
4241 
4242 				ASSERT(type != F_SOFTLOCK);
4243 
4244 				SEGVN_VMSTAT_FLTVNPAGES(31);
4245 				if (aphase != P2PHASE(pfn, ppages)) {
4246 					segvn_faultvnmpss_align_err4++;
4247 				} else {
4248 					SEGVN_VMSTAT_FLTVNPAGES(32);
4249 					if (pplist != NULL) {
4250 						page_t *pl = pplist;
4251 						page_free_replacement_page(pl);
4252 						page_create_putback(pages);
4253 					}
4254 					for (i = 0; i < pages; i++) {
4255 						page_unlock(ppa[i]);
4256 					}
4257 					if (amp != NULL) {
4258 						anon_array_exit(&an_cookie);
4259 						ANON_LOCK_EXIT(&amp->a_rwlock);
4260 					}
4261 					pszc = pszc1;
4262 					ierr = -2;
4263 					break;
4264 				}
4265 			}
4266 
4267 			/*
4268 			 * check if we should use smallest mapping size.
4269 			 */
4270 			upgrdfail = 0;
4271 			if (szc == 0 || xhat ||
4272 			    (pszc >= szc &&
4273 			    !IS_P2ALIGNED(pfn, pages)) ||
4274 			    (pszc < szc &&
4275 			    !segvn_full_szcpages(ppa, szc, &upgrdfail,
4276 			    &pszc))) {
4277 
4278 				if (upgrdfail && type != F_SOFTLOCK) {
4279 					/*
4280 					 * segvn_full_szcpages failed to lock
4281 					 * all pages EXCL. Size down.
4282 					 */
4283 					ASSERT(pszc < szc);
4284 
4285 					SEGVN_VMSTAT_FLTVNPAGES(33);
4286 
4287 					if (pplist != NULL) {
4288 						page_t *pl = pplist;
4289 						page_free_replacement_page(pl);
4290 						page_create_putback(pages);
4291 					}
4292 
4293 					for (i = 0; i < pages; i++) {
4294 						page_unlock(ppa[i]);
4295 					}
4296 					if (amp != NULL) {
4297 						anon_array_exit(&an_cookie);
4298 						ANON_LOCK_EXIT(&amp->a_rwlock);
4299 					}
4300 					ierr = -1;
4301 					break;
4302 				}
4303 				if (szc != 0 && !xhat && !upgrdfail) {
4304 					segvn_faultvnmpss_align_err5++;
4305 				}
4306 				SEGVN_VMSTAT_FLTVNPAGES(34);
4307 				if (pplist != NULL) {
4308 					page_free_replacement_page(pplist);
4309 					page_create_putback(pages);
4310 				}
4311 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4312 				    prot, vpprot);
4313 				if (upgrdfail && segvn_anypgsz_vnode) {
4314 					/* SOFTLOCK case */
4315 					hat_memload_array_region(hat, a, pgsz,
4316 					    ppa, prot & vpprot, hat_flag,
4317 					    svd->rcookie);
4318 				} else {
4319 					for (i = 0; i < pages; i++) {
4320 						hat_memload_region(hat,
4321 						    a + (i << PAGESHIFT),
4322 						    ppa[i], prot & vpprot,
4323 						    hat_flag, svd->rcookie);
4324 					}
4325 				}
4326 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4327 					for (i = 0; i < pages; i++) {
4328 						page_unlock(ppa[i]);
4329 					}
4330 				}
4331 				if (amp != NULL) {
4332 					anon_array_exit(&an_cookie);
4333 					ANON_LOCK_EXIT(&amp->a_rwlock);
4334 				}
4335 				goto next;
4336 			}
4337 
4338 			if (pszc == szc) {
4339 				/*
4340 				 * segvn_full_szcpages() upgraded pages szc.
4341 				 */
4342 				ASSERT(pszc == ppa[0]->p_szc);
4343 				ASSERT(IS_P2ALIGNED(pfn, pages));
4344 				goto chkszc;
4345 			}
4346 
4347 			if (pszc > szc) {
4348 				kmutex_t *szcmtx;
4349 				SEGVN_VMSTAT_FLTVNPAGES(35);
4350 				/*
4351 				 * p_szc of ppa[0] can change since we haven't
4352 				 * locked all constituent pages. Call
4353 				 * page_lock_szc() to prevent szc changes.
4354 				 * This should be a rare case that happens when
4355 				 * multiple segments use a different page size
4356 				 * to map the same file offsets.
4357 				 */
4358 				szcmtx = page_szc_lock(ppa[0]);
4359 				pszc = ppa[0]->p_szc;
4360 				ASSERT(szcmtx != NULL || pszc == 0);
4361 				ASSERT(ppa[0]->p_szc <= pszc);
4362 				if (pszc <= szc) {
4363 					SEGVN_VMSTAT_FLTVNPAGES(36);
4364 					if (szcmtx != NULL) {
4365 						mutex_exit(szcmtx);
4366 					}
4367 					goto chkszc;
4368 				}
4369 				if (pplist != NULL) {
4370 					/*
4371 					 * page got promoted since last check.
4372 					 * we don't need preaalocated large
4373 					 * page.
4374 					 */
4375 					SEGVN_VMSTAT_FLTVNPAGES(37);
4376 					page_free_replacement_page(pplist);
4377 					page_create_putback(pages);
4378 				}
4379 				SEGVN_UPDATE_MODBITS(ppa, pages, rw,
4380 				    prot, vpprot);
4381 				hat_memload_array_region(hat, a, pgsz, ppa,
4382 				    prot & vpprot, hat_flag, svd->rcookie);
4383 				mutex_exit(szcmtx);
4384 				if (!(hat_flag & HAT_LOAD_LOCK)) {
4385 					for (i = 0; i < pages; i++) {
4386 						page_unlock(ppa[i]);
4387 					}
4388 				}
4389 				if (amp != NULL) {
4390 					anon_array_exit(&an_cookie);
4391 					ANON_LOCK_EXIT(&amp->a_rwlock);
4392 				}
4393 				goto next;
4394 			}
4395 
4396 			/*
4397 			 * if page got demoted since last check
4398 			 * we could have not allocated larger page.
4399 			 * allocate now.
4400 			 */
4401 			if (pplist == NULL &&
4402 			    page_alloc_pages(vp, seg, a, &pplist, NULL,
4403 			    szc, 0, 0) && type != F_SOFTLOCK) {
4404 				SEGVN_VMSTAT_FLTVNPAGES(38);
4405 				for (i = 0; i < pages; i++) {
4406 					page_unlock(ppa[i]);
4407 				}
4408 				if (amp != NULL) {
4409 					anon_array_exit(&an_cookie);
4410 					ANON_LOCK_EXIT(&amp->a_rwlock);
4411 				}
4412 				ierr = -1;
4413 				alloc_failed |= (1 << szc);
4414 				break;
4415 			}
4416 
4417 			SEGVN_VMSTAT_FLTVNPAGES(39);
4418 
4419 			if (pplist != NULL) {
4420 				segvn_relocate_pages(ppa, pplist);
4421 #ifdef DEBUG
4422 			} else {
4423 				ASSERT(type == F_SOFTLOCK);
4424 				SEGVN_VMSTAT_FLTVNPAGES(40);
4425 #endif /* DEBUG */
4426 			}
4427 
4428 			SEGVN_UPDATE_MODBITS(ppa, pages, rw, prot, vpprot);
4429 
4430 			if (pplist == NULL && segvn_anypgsz_vnode == 0) {
4431 				ASSERT(type == F_SOFTLOCK);
4432 				for (i = 0; i < pages; i++) {
4433 					ASSERT(ppa[i]->p_szc < szc);
4434 					hat_memload_region(hat,
4435 					    a + (i << PAGESHIFT),
4436 					    ppa[i], prot & vpprot, hat_flag,
4437 					    svd->rcookie);
4438 				}
4439 			} else {
4440 				ASSERT(pplist != NULL || type == F_SOFTLOCK);
4441 				hat_memload_array_region(hat, a, pgsz, ppa,
4442 				    prot & vpprot, hat_flag, svd->rcookie);
4443 			}
4444 			if (!(hat_flag & HAT_LOAD_LOCK)) {
4445 				for (i = 0; i < pages; i++) {
4446 					ASSERT(PAGE_SHARED(ppa[i]));
4447 					page_unlock(ppa[i]);
4448 				}
4449 			}
4450 			if (amp != NULL) {
4451 				anon_array_exit(&an_cookie);
4452 				ANON_LOCK_EXIT(&amp->a_rwlock);
4453 			}
4454 
4455 		next:
4456 			if (vpage != NULL) {
4457 				vpage += pages;
4458 			}
4459 			adjszc_chk = 1;
4460 		}
4461 		if (a == lpgeaddr)
4462 			break;
4463 		ASSERT(a < lpgeaddr);
4464 
4465 		ASSERT(!brkcow && !tron && type != F_SOFTLOCK);
4466 
4467 		/*
4468 		 * ierr == -1 means we failed to map with a large page.
4469 		 * (either due to allocation/relocation failures or
4470 		 * misalignment with other mappings to this file.
4471 		 *
4472 		 * ierr == -2 means some other thread allocated a large page
4473 		 * after we gave up tp map with a large page.  retry with
4474 		 * larger mapping.
4475 		 */
4476 		ASSERT(ierr == -1 || ierr == -2);
4477 		ASSERT(ierr == -2 || szc != 0);
4478 		ASSERT(ierr == -1 || szc < seg->s_szc);
4479 		if (ierr == -2) {
4480 			SEGVN_VMSTAT_FLTVNPAGES(41);
4481 			ASSERT(pszc > szc && pszc <= seg->s_szc);
4482 			szc = pszc;
4483 		} else if (segvn_anypgsz_vnode) {
4484 			SEGVN_VMSTAT_FLTVNPAGES(42);
4485 			szc--;
4486 		} else {
4487 			SEGVN_VMSTAT_FLTVNPAGES(43);
4488 			ASSERT(pszc < szc);
4489 			/*
4490 			 * other process created pszc large page.
4491 			 * but we still have to drop to 0 szc.
4492 			 */
4493 			szc = 0;
4494 		}
4495 
4496 		pgsz = page_get_pagesize(szc);
4497 		pages = btop(pgsz);
4498 		if (ierr == -2) {
4499 			/*
4500 			 * Size up case. Note lpgaddr may only be needed for
4501 			 * softlock case so we don't adjust it here.
4502 			 */
4503 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4504 			ASSERT(a >= lpgaddr);
4505 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4506 			off = svd->offset + (uintptr_t)(a - seg->s_base);
4507 			aindx = svd->anon_index + seg_page(seg, a);
4508 			vpage = (svd->vpage != NULL) ?
4509 			    &svd->vpage[seg_page(seg, a)] : NULL;
4510 		} else {
4511 			/*
4512 			 * Size down case. Note lpgaddr may only be needed for
4513 			 * softlock case so we don't adjust it here.
4514 			 */
4515 			ASSERT(IS_P2ALIGNED(a, pgsz));
4516 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4517 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4518 			ASSERT(a < lpgeaddr);
4519 			if (a < addr) {
4520 				SEGVN_VMSTAT_FLTVNPAGES(44);
4521 				/*
4522 				 * The beginning of the large page region can
4523 				 * be pulled to the right to make a smaller
4524 				 * region. We haven't yet faulted a single
4525 				 * page.
4526 				 */
4527 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4528 				ASSERT(a >= lpgaddr);
4529 				off = svd->offset +
4530 				    (uintptr_t)(a - seg->s_base);
4531 				aindx = svd->anon_index + seg_page(seg, a);
4532 				vpage = (svd->vpage != NULL) ?
4533 				    &svd->vpage[seg_page(seg, a)] : NULL;
4534 			}
4535 		}
4536 	}
4537 out:
4538 	kmem_free(ppa, ppasize);
4539 	if (!err && !vop_size_err) {
4540 		SEGVN_VMSTAT_FLTVNPAGES(45);
4541 		return (0);
4542 	}
4543 	if (type == F_SOFTLOCK && a > lpgaddr) {
4544 		SEGVN_VMSTAT_FLTVNPAGES(46);
4545 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4546 	}
4547 	if (!vop_size_err) {
4548 		SEGVN_VMSTAT_FLTVNPAGES(47);
4549 		return (err);
4550 	}
4551 	ASSERT(brkcow || tron || type == F_SOFTLOCK);
4552 	/*
4553 	 * Large page end is mapped beyond the end of file and it's a cow
4554 	 * fault (can be a text replication induced cow) or softlock so we can't
4555 	 * reduce the map area.  For now just demote the segment. This should
4556 	 * really only happen if the end of the file changed after the mapping
4557 	 * was established since when large page segments are created we make
4558 	 * sure they don't extend beyond the end of the file.
4559 	 */
4560 	SEGVN_VMSTAT_FLTVNPAGES(48);
4561 
4562 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4563 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4564 	err = 0;
4565 	if (seg->s_szc != 0) {
4566 		segvn_fltvnpages_clrszc_cnt++;
4567 		ASSERT(svd->softlockcnt == 0);
4568 		err = segvn_clrszc(seg);
4569 		if (err != 0) {
4570 			segvn_fltvnpages_clrszc_err++;
4571 		}
4572 	}
4573 	ASSERT(err || seg->s_szc == 0);
4574 	SEGVN_LOCK_DOWNGRADE(seg->s_as, &svd->lock);
4575 	/* segvn_fault will do its job as if szc had been zero to begin with */
4576 	return (err == 0 ? IE_RETRY : FC_MAKE_ERR(err));
4577 }
4578 
4579 /*
4580  * This routine will attempt to fault in one large page.
4581  * it will use smaller pages if that fails.
4582  * It should only be called for pure anonymous segments.
4583  */
4584 static faultcode_t
4585 segvn_fault_anonpages(struct hat *hat, struct seg *seg, caddr_t lpgaddr,
4586     caddr_t lpgeaddr, enum fault_type type, enum seg_rw rw, caddr_t addr,
4587     caddr_t eaddr, int brkcow)
4588 {
4589 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4590 	struct anon_map *amp = svd->amp;
4591 	uchar_t segtype = svd->type;
4592 	uint_t szc = seg->s_szc;
4593 	size_t pgsz = page_get_pagesize(szc);
4594 	size_t maxpgsz = pgsz;
4595 	pgcnt_t pages = btop(pgsz);
4596 	uint_t ppaszc = szc;
4597 	caddr_t a = lpgaddr;
4598 	ulong_t aindx = svd->anon_index + seg_page(seg, a);
4599 	struct vpage *vpage = (svd->vpage != NULL) ?
4600 	    &svd->vpage[seg_page(seg, a)] : NULL;
4601 	page_t **ppa;
4602 	uint_t	ppa_szc;
4603 	faultcode_t err;
4604 	int ierr;
4605 	uint_t protchk, prot, vpprot;
4606 	ulong_t i;
4607 	int hat_flag = (type == F_SOFTLOCK) ? HAT_LOAD_LOCK : HAT_LOAD;
4608 	anon_sync_obj_t cookie;
4609 	int adjszc_chk;
4610 	int pgflags = (svd->tr_state == SEGVN_TR_ON) ? PG_LOCAL : 0;
4611 
4612 	ASSERT(szc != 0);
4613 	ASSERT(amp != NULL);
4614 	ASSERT(enable_mbit_wa == 0); /* no mbit simulations with large pages */
4615 	ASSERT(!(svd->flags & MAP_NORESERVE));
4616 	ASSERT(type != F_SOFTUNLOCK);
4617 	ASSERT(IS_P2ALIGNED(a, maxpgsz));
4618 	ASSERT(!brkcow || svd->tr_state == SEGVN_TR_OFF);
4619 	ASSERT(svd->tr_state != SEGVN_TR_INIT);
4620 
4621 	ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
4622 
4623 	VM_STAT_COND_ADD(type == F_SOFTLOCK, segvnvmstats.fltanpages[0]);
4624 	VM_STAT_COND_ADD(type != F_SOFTLOCK, segvnvmstats.fltanpages[1]);
4625 
4626 	if (svd->flags & MAP_TEXT) {
4627 		hat_flag |= HAT_LOAD_TEXT;
4628 	}
4629 
4630 	if (svd->pageprot) {
4631 		switch (rw) {
4632 		case S_READ:
4633 			protchk = PROT_READ;
4634 			break;
4635 		case S_WRITE:
4636 			protchk = PROT_WRITE;
4637 			break;
4638 		case S_EXEC:
4639 			protchk = PROT_EXEC;
4640 			break;
4641 		case S_OTHER:
4642 		default:
4643 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4644 			break;
4645 		}
4646 		VM_STAT_ADD(segvnvmstats.fltanpages[2]);
4647 	} else {
4648 		prot = svd->prot;
4649 		/* caller has already done segment level protection check. */
4650 	}
4651 
4652 	ppa = kmem_cache_alloc(segvn_szc_cache[ppaszc], KM_SLEEP);
4653 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
4654 	for (;;) {
4655 		adjszc_chk = 0;
4656 		for (; a < lpgeaddr; a += pgsz, aindx += pages) {
4657 			if (svd->pageprot != 0 && IS_P2ALIGNED(a, maxpgsz)) {
4658 				VM_STAT_ADD(segvnvmstats.fltanpages[3]);
4659 				ASSERT(vpage != NULL);
4660 				prot = VPP_PROT(vpage);
4661 				ASSERT(sameprot(seg, a, maxpgsz));
4662 				if ((prot & protchk) == 0) {
4663 					err = FC_PROT;
4664 					goto error;
4665 				}
4666 			}
4667 			if (adjszc_chk && IS_P2ALIGNED(a, maxpgsz) &&
4668 			    pgsz < maxpgsz) {
4669 				ASSERT(a > lpgaddr);
4670 				szc = seg->s_szc;
4671 				pgsz = maxpgsz;
4672 				pages = btop(pgsz);
4673 				ASSERT(IS_P2ALIGNED(aindx, pages));
4674 				lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr,
4675 				    pgsz);
4676 			}
4677 			if (type == F_SOFTLOCK) {
4678 				atomic_add_long((ulong_t *)&svd->softlockcnt,
4679 				    pages);
4680 			}
4681 			anon_array_enter(amp, aindx, &cookie);
4682 			ppa_szc = (uint_t)-1;
4683 			ierr = anon_map_getpages(amp, aindx, szc, seg, a,
4684 			    prot, &vpprot, ppa, &ppa_szc, vpage, rw, brkcow,
4685 			    segvn_anypgsz, pgflags, svd->cred);
4686 			if (ierr != 0) {
4687 				anon_array_exit(&cookie);
4688 				VM_STAT_ADD(segvnvmstats.fltanpages[4]);
4689 				if (type == F_SOFTLOCK) {
4690 					atomic_add_long(
4691 					    (ulong_t *)&svd->softlockcnt,
4692 					    -pages);
4693 				}
4694 				if (ierr > 0) {
4695 					VM_STAT_ADD(segvnvmstats.fltanpages[6]);
4696 					err = FC_MAKE_ERR(ierr);
4697 					goto error;
4698 				}
4699 				break;
4700 			}
4701 
4702 			ASSERT(!IS_VMODSORT(ppa[0]->p_vnode));
4703 
4704 			ASSERT(segtype == MAP_SHARED ||
4705 			    ppa[0]->p_szc <= szc);
4706 			ASSERT(segtype == MAP_PRIVATE ||
4707 			    ppa[0]->p_szc >= szc);
4708 
4709 			/*
4710 			 * Handle pages that have been marked for migration
4711 			 */
4712 			if (lgrp_optimizations())
4713 				page_migrate(seg, a, ppa, pages);
4714 
4715 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
4716 
4717 			if (segtype == MAP_SHARED) {
4718 				vpprot |= PROT_WRITE;
4719 			}
4720 
4721 			hat_memload_array(hat, a, pgsz, ppa,
4722 			    prot & vpprot, hat_flag);
4723 
4724 			if (hat_flag & HAT_LOAD_LOCK) {
4725 				VM_STAT_ADD(segvnvmstats.fltanpages[7]);
4726 			} else {
4727 				VM_STAT_ADD(segvnvmstats.fltanpages[8]);
4728 				for (i = 0; i < pages; i++)
4729 					page_unlock(ppa[i]);
4730 			}
4731 			if (vpage != NULL)
4732 				vpage += pages;
4733 
4734 			anon_array_exit(&cookie);
4735 			adjszc_chk = 1;
4736 		}
4737 		if (a == lpgeaddr)
4738 			break;
4739 		ASSERT(a < lpgeaddr);
4740 		/*
4741 		 * ierr == -1 means we failed to allocate a large page.
4742 		 * so do a size down operation.
4743 		 *
4744 		 * ierr == -2 means some other process that privately shares
4745 		 * pages with this process has allocated a larger page and we
4746 		 * need to retry with larger pages. So do a size up
4747 		 * operation. This relies on the fact that large pages are
4748 		 * never partially shared i.e. if we share any constituent
4749 		 * page of a large page with another process we must share the
4750 		 * entire large page. Note this cannot happen for SOFTLOCK
4751 		 * case, unless current address (a) is at the beginning of the
4752 		 * next page size boundary because the other process couldn't
4753 		 * have relocated locked pages.
4754 		 */
4755 		ASSERT(ierr == -1 || ierr == -2);
4756 
4757 		if (segvn_anypgsz) {
4758 			ASSERT(ierr == -2 || szc != 0);
4759 			ASSERT(ierr == -1 || szc < seg->s_szc);
4760 			szc = (ierr == -1) ? szc - 1 : szc + 1;
4761 		} else {
4762 			/*
4763 			 * For non COW faults and segvn_anypgsz == 0
4764 			 * we need to be careful not to loop forever
4765 			 * if existing page is found with szc other
4766 			 * than 0 or seg->s_szc. This could be due
4767 			 * to page relocations on behalf of DR or
4768 			 * more likely large page creation. For this
4769 			 * case simply re-size to existing page's szc
4770 			 * if returned by anon_map_getpages().
4771 			 */
4772 			if (ppa_szc == (uint_t)-1) {
4773 				szc = (ierr == -1) ? 0 : seg->s_szc;
4774 			} else {
4775 				ASSERT(ppa_szc <= seg->s_szc);
4776 				ASSERT(ierr == -2 || ppa_szc < szc);
4777 				ASSERT(ierr == -1 || ppa_szc > szc);
4778 				szc = ppa_szc;
4779 			}
4780 		}
4781 
4782 		pgsz = page_get_pagesize(szc);
4783 		pages = btop(pgsz);
4784 		ASSERT(type != F_SOFTLOCK || ierr == -1 ||
4785 		    (IS_P2ALIGNED(a, pgsz) && IS_P2ALIGNED(lpgeaddr, pgsz)));
4786 		if (type == F_SOFTLOCK) {
4787 			/*
4788 			 * For softlocks we cannot reduce the fault area
4789 			 * (calculated based on the largest page size for this
4790 			 * segment) for size down and a is already next
4791 			 * page size aligned as assertted above for size
4792 			 * ups. Therefore just continue in case of softlock.
4793 			 */
4794 			VM_STAT_ADD(segvnvmstats.fltanpages[9]);
4795 			continue; /* keep lint happy */
4796 		} else if (ierr == -2) {
4797 
4798 			/*
4799 			 * Size up case. Note lpgaddr may only be needed for
4800 			 * softlock case so we don't adjust it here.
4801 			 */
4802 			VM_STAT_ADD(segvnvmstats.fltanpages[10]);
4803 			a = (caddr_t)P2ALIGN((uintptr_t)a, pgsz);
4804 			ASSERT(a >= lpgaddr);
4805 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4806 			aindx = svd->anon_index + seg_page(seg, a);
4807 			vpage = (svd->vpage != NULL) ?
4808 			    &svd->vpage[seg_page(seg, a)] : NULL;
4809 		} else {
4810 			/*
4811 			 * Size down case. Note lpgaddr may only be needed for
4812 			 * softlock case so we don't adjust it here.
4813 			 */
4814 			VM_STAT_ADD(segvnvmstats.fltanpages[11]);
4815 			ASSERT(IS_P2ALIGNED(a, pgsz));
4816 			ASSERT(IS_P2ALIGNED(lpgeaddr, pgsz));
4817 			lpgeaddr = (caddr_t)P2ROUNDUP((uintptr_t)eaddr, pgsz);
4818 			ASSERT(a < lpgeaddr);
4819 			if (a < addr) {
4820 				/*
4821 				 * The beginning of the large page region can
4822 				 * be pulled to the right to make a smaller
4823 				 * region. We haven't yet faulted a single
4824 				 * page.
4825 				 */
4826 				VM_STAT_ADD(segvnvmstats.fltanpages[12]);
4827 				a = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
4828 				ASSERT(a >= lpgaddr);
4829 				aindx = svd->anon_index + seg_page(seg, a);
4830 				vpage = (svd->vpage != NULL) ?
4831 				    &svd->vpage[seg_page(seg, a)] : NULL;
4832 			}
4833 		}
4834 	}
4835 	VM_STAT_ADD(segvnvmstats.fltanpages[13]);
4836 	ANON_LOCK_EXIT(&amp->a_rwlock);
4837 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4838 	return (0);
4839 error:
4840 	VM_STAT_ADD(segvnvmstats.fltanpages[14]);
4841 	ANON_LOCK_EXIT(&amp->a_rwlock);
4842 	kmem_cache_free(segvn_szc_cache[ppaszc], ppa);
4843 	if (type == F_SOFTLOCK && a > lpgaddr) {
4844 		VM_STAT_ADD(segvnvmstats.fltanpages[15]);
4845 		segvn_softunlock(seg, lpgaddr, a - lpgaddr, S_OTHER);
4846 	}
4847 	return (err);
4848 }
4849 
4850 int fltadvice = 1;	/* set to free behind pages for sequential access */
4851 
4852 /*
4853  * This routine is called via a machine specific fault handling routine.
4854  * It is also called by software routines wishing to lock or unlock
4855  * a range of addresses.
4856  *
4857  * Here is the basic algorithm:
4858  *	If unlocking
4859  *		Call segvn_softunlock
4860  *		Return
4861  *	endif
4862  *	Checking and set up work
4863  *	If we will need some non-anonymous pages
4864  *		Call VOP_GETPAGE over the range of non-anonymous pages
4865  *	endif
4866  *	Loop over all addresses requested
4867  *		Call segvn_faultpage passing in page list
4868  *		    to load up translations and handle anonymous pages
4869  *	endloop
4870  *	Load up translation to any additional pages in page list not
4871  *	    already handled that fit into this segment
4872  */
4873 static faultcode_t
4874 segvn_fault(struct hat *hat, struct seg *seg, caddr_t addr, size_t len,
4875     enum fault_type type, enum seg_rw rw)
4876 {
4877 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
4878 	page_t **plp, **ppp, *pp;
4879 	u_offset_t off;
4880 	caddr_t a;
4881 	struct vpage *vpage;
4882 	uint_t vpprot, prot;
4883 	int err;
4884 	page_t *pl[PVN_GETPAGE_NUM + 1];
4885 	size_t plsz, pl_alloc_sz;
4886 	size_t page;
4887 	ulong_t anon_index;
4888 	struct anon_map *amp;
4889 	int dogetpage = 0;
4890 	caddr_t	lpgaddr, lpgeaddr;
4891 	size_t pgsz;
4892 	anon_sync_obj_t cookie;
4893 	int brkcow = BREAK_COW_SHARE(rw, type, svd->type);
4894 
4895 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
4896 	ASSERT(svd->amp == NULL || svd->rcookie == HAT_INVALID_REGION_COOKIE);
4897 
4898 	/*
4899 	 * First handle the easy stuff
4900 	 */
4901 	if (type == F_SOFTUNLOCK) {
4902 		if (rw == S_READ_NOCOW) {
4903 			rw = S_READ;
4904 			ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
4905 		}
4906 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4907 		pgsz = (seg->s_szc == 0) ? PAGESIZE :
4908 		    page_get_pagesize(seg->s_szc);
4909 		VM_STAT_COND_ADD(pgsz > PAGESIZE, segvnvmstats.fltanpages[16]);
4910 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
4911 		segvn_softunlock(seg, lpgaddr, lpgeaddr - lpgaddr, rw);
4912 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4913 		return (0);
4914 	}
4915 
4916 	ASSERT(svd->tr_state == SEGVN_TR_OFF ||
4917 	    !HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
4918 	if (brkcow == 0) {
4919 		if (svd->tr_state == SEGVN_TR_INIT) {
4920 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4921 			if (svd->tr_state == SEGVN_TR_INIT) {
4922 				ASSERT(svd->vp != NULL && svd->amp == NULL);
4923 				ASSERT(svd->flags & MAP_TEXT);
4924 				ASSERT(svd->type == MAP_PRIVATE);
4925 				segvn_textrepl(seg);
4926 				ASSERT(svd->tr_state != SEGVN_TR_INIT);
4927 				ASSERT(svd->tr_state != SEGVN_TR_ON ||
4928 				    svd->amp != NULL);
4929 			}
4930 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4931 		}
4932 	} else if (svd->tr_state != SEGVN_TR_OFF) {
4933 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4934 
4935 		if (rw == S_WRITE && svd->tr_state != SEGVN_TR_OFF) {
4936 			ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
4937 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4938 			return (FC_PROT);
4939 		}
4940 
4941 		if (svd->tr_state == SEGVN_TR_ON) {
4942 			ASSERT(svd->vp != NULL && svd->amp != NULL);
4943 			segvn_textunrepl(seg, 0);
4944 			ASSERT(svd->amp == NULL &&
4945 			    svd->tr_state == SEGVN_TR_OFF);
4946 		} else if (svd->tr_state != SEGVN_TR_OFF) {
4947 			svd->tr_state = SEGVN_TR_OFF;
4948 		}
4949 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
4950 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4951 	}
4952 
4953 top:
4954 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
4955 
4956 	/*
4957 	 * If we have the same protections for the entire segment,
4958 	 * insure that the access being attempted is legitimate.
4959 	 */
4960 
4961 	if (svd->pageprot == 0) {
4962 		uint_t protchk;
4963 
4964 		switch (rw) {
4965 		case S_READ:
4966 		case S_READ_NOCOW:
4967 			protchk = PROT_READ;
4968 			break;
4969 		case S_WRITE:
4970 			protchk = PROT_WRITE;
4971 			break;
4972 		case S_EXEC:
4973 			protchk = PROT_EXEC;
4974 			break;
4975 		case S_OTHER:
4976 		default:
4977 			protchk = PROT_READ | PROT_WRITE | PROT_EXEC;
4978 			break;
4979 		}
4980 
4981 		if ((svd->prot & protchk) == 0) {
4982 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4983 			return (FC_PROT);	/* illegal access type */
4984 		}
4985 	}
4986 
4987 	if (brkcow && HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4988 		/* this must be SOFTLOCK S_READ fault */
4989 		ASSERT(svd->amp == NULL);
4990 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
4991 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
4992 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
4993 		if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
4994 			/*
4995 			 * this must be the first ever non S_READ_NOCOW
4996 			 * softlock for this segment.
4997 			 */
4998 			ASSERT(svd->softlockcnt == 0);
4999 			hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5000 			    HAT_REGION_TEXT);
5001 			svd->rcookie = HAT_INVALID_REGION_COOKIE;
5002 		}
5003 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5004 		goto top;
5005 	}
5006 
5007 	/*
5008 	 * We can't allow the long term use of softlocks for vmpss segments,
5009 	 * because in some file truncation cases we should be able to demote
5010 	 * the segment, which requires that there are no softlocks.  The
5011 	 * only case where it's ok to allow a SOFTLOCK fault against a vmpss
5012 	 * segment is S_READ_NOCOW, where the caller holds the address space
5013 	 * locked as writer and calls softunlock before dropping the as lock.
5014 	 * S_READ_NOCOW is used by /proc to read memory from another user.
5015 	 *
5016 	 * Another deadlock between SOFTLOCK and file truncation can happen
5017 	 * because segvn_fault_vnodepages() calls the FS one pagesize at
5018 	 * a time. A second VOP_GETPAGE() call by segvn_fault_vnodepages()
5019 	 * can cause a deadlock because the first set of page_t's remain
5020 	 * locked SE_SHARED.  To avoid this, we demote segments on a first
5021 	 * SOFTLOCK if they have a length greater than the segment's
5022 	 * page size.
5023 	 *
5024 	 * So for now, we only avoid demoting a segment on a SOFTLOCK when
5025 	 * the access type is S_READ_NOCOW and the fault length is less than
5026 	 * or equal to the segment's page size. While this is quite restrictive,
5027 	 * it should be the most common case of SOFTLOCK against a vmpss
5028 	 * segment.
5029 	 *
5030 	 * For S_READ_NOCOW, it's safe not to do a copy on write because the
5031 	 * caller makes sure no COW will be caused by another thread for a
5032 	 * softlocked page.
5033 	 */
5034 	if (type == F_SOFTLOCK && svd->vp != NULL && seg->s_szc != 0) {
5035 		int demote = 0;
5036 
5037 		if (rw != S_READ_NOCOW) {
5038 			demote = 1;
5039 		}
5040 		if (!demote && len > PAGESIZE) {
5041 			pgsz = page_get_pagesize(seg->s_szc);
5042 			CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr,
5043 			    lpgeaddr);
5044 			if (lpgeaddr - lpgaddr > pgsz) {
5045 				demote = 1;
5046 			}
5047 		}
5048 
5049 		ASSERT(demote || AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5050 
5051 		if (demote) {
5052 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5053 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5054 			if (seg->s_szc != 0) {
5055 				segvn_vmpss_clrszc_cnt++;
5056 				ASSERT(svd->softlockcnt == 0);
5057 				err = segvn_clrszc(seg);
5058 				if (err) {
5059 					segvn_vmpss_clrszc_err++;
5060 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5061 					return (FC_MAKE_ERR(err));
5062 				}
5063 			}
5064 			ASSERT(seg->s_szc == 0);
5065 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5066 			goto top;
5067 		}
5068 	}
5069 
5070 	/*
5071 	 * Check to see if we need to allocate an anon_map structure.
5072 	 */
5073 	if (svd->amp == NULL && (svd->vp == NULL || brkcow)) {
5074 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5075 		/*
5076 		 * Drop the "read" lock on the segment and acquire
5077 		 * the "write" version since we have to allocate the
5078 		 * anon_map.
5079 		 */
5080 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5081 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5082 
5083 		if (svd->amp == NULL) {
5084 			svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
5085 			svd->amp->a_szc = seg->s_szc;
5086 		}
5087 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5088 
5089 		/*
5090 		 * Start all over again since segment protections
5091 		 * may have changed after we dropped the "read" lock.
5092 		 */
5093 		goto top;
5094 	}
5095 
5096 	/*
5097 	 * S_READ_NOCOW vs S_READ distinction was
5098 	 * only needed for the code above. After
5099 	 * that we treat it as S_READ.
5100 	 */
5101 	if (rw == S_READ_NOCOW) {
5102 		ASSERT(type == F_SOFTLOCK);
5103 		ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
5104 		rw = S_READ;
5105 	}
5106 
5107 	amp = svd->amp;
5108 
5109 	/*
5110 	 * MADV_SEQUENTIAL work is ignored for large page segments.
5111 	 */
5112 	if (seg->s_szc != 0) {
5113 		pgsz = page_get_pagesize(seg->s_szc);
5114 		ASSERT(SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
5115 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
5116 		if (svd->vp == NULL) {
5117 			err = segvn_fault_anonpages(hat, seg, lpgaddr,
5118 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5119 		} else {
5120 			err = segvn_fault_vnodepages(hat, seg, lpgaddr,
5121 			    lpgeaddr, type, rw, addr, addr + len, brkcow);
5122 			if (err == IE_RETRY) {
5123 				ASSERT(seg->s_szc == 0);
5124 				ASSERT(SEGVN_READ_HELD(seg->s_as, &svd->lock));
5125 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5126 				goto top;
5127 			}
5128 		}
5129 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5130 		return (err);
5131 	}
5132 
5133 	page = seg_page(seg, addr);
5134 	if (amp != NULL) {
5135 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
5136 		anon_index = svd->anon_index + page;
5137 
5138 		if (type == F_PROT && rw == S_READ &&
5139 		    svd->tr_state == SEGVN_TR_OFF &&
5140 		    svd->type == MAP_PRIVATE && svd->pageprot == 0) {
5141 			size_t index = anon_index;
5142 			struct anon *ap;
5143 
5144 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5145 			/*
5146 			 * The fast path could apply to S_WRITE also, except
5147 			 * that the protection fault could be caused by lazy
5148 			 * tlb flush when ro->rw. In this case, the pte is
5149 			 * RW already. But RO in the other cpu's tlb causes
5150 			 * the fault. Since hat_chgprot won't do anything if
5151 			 * pte doesn't change, we may end up faulting
5152 			 * indefinitely until the RO tlb entry gets replaced.
5153 			 */
5154 			for (a = addr; a < addr + len; a += PAGESIZE, index++) {
5155 				anon_array_enter(amp, index, &cookie);
5156 				ap = anon_get_ptr(amp->ahp, index);
5157 				anon_array_exit(&cookie);
5158 				if ((ap == NULL) || (ap->an_refcnt != 1)) {
5159 					ANON_LOCK_EXIT(&amp->a_rwlock);
5160 					goto slow;
5161 				}
5162 			}
5163 			hat_chgprot(seg->s_as->a_hat, addr, len, svd->prot);
5164 			ANON_LOCK_EXIT(&amp->a_rwlock);
5165 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5166 			return (0);
5167 		}
5168 	}
5169 slow:
5170 
5171 	if (svd->vpage == NULL)
5172 		vpage = NULL;
5173 	else
5174 		vpage = &svd->vpage[page];
5175 
5176 	off = svd->offset + (uintptr_t)(addr - seg->s_base);
5177 
5178 	/*
5179 	 * If MADV_SEQUENTIAL has been set for the particular page we
5180 	 * are faulting on, free behind all pages in the segment and put
5181 	 * them on the free list.
5182 	 */
5183 
5184 	if ((page != 0) && fltadvice && svd->tr_state != SEGVN_TR_ON) {
5185 		struct vpage *vpp;
5186 		ulong_t fanon_index;
5187 		size_t fpage;
5188 		u_offset_t pgoff, fpgoff;
5189 		struct vnode *fvp;
5190 		struct anon *fap = NULL;
5191 
5192 		if (svd->advice == MADV_SEQUENTIAL ||
5193 		    (svd->pageadvice &&
5194 		    VPP_ADVICE(vpage) == MADV_SEQUENTIAL)) {
5195 			pgoff = off - PAGESIZE;
5196 			fpage = page - 1;
5197 			if (vpage != NULL)
5198 				vpp = &svd->vpage[fpage];
5199 			if (amp != NULL)
5200 				fanon_index = svd->anon_index + fpage;
5201 
5202 			while (pgoff > svd->offset) {
5203 				if (svd->advice != MADV_SEQUENTIAL &&
5204 				    (!svd->pageadvice || (vpage &&
5205 				    VPP_ADVICE(vpp) != MADV_SEQUENTIAL)))
5206 					break;
5207 
5208 				/*
5209 				 * If this is an anon page, we must find the
5210 				 * correct <vp, offset> for it
5211 				 */
5212 				fap = NULL;
5213 				if (amp != NULL) {
5214 					ANON_LOCK_ENTER(&amp->a_rwlock,
5215 					    RW_READER);
5216 					anon_array_enter(amp, fanon_index,
5217 					    &cookie);
5218 					fap = anon_get_ptr(amp->ahp,
5219 					    fanon_index);
5220 					if (fap != NULL) {
5221 						swap_xlate(fap, &fvp, &fpgoff);
5222 					} else {
5223 						fpgoff = pgoff;
5224 						fvp = svd->vp;
5225 					}
5226 					anon_array_exit(&cookie);
5227 					ANON_LOCK_EXIT(&amp->a_rwlock);
5228 				} else {
5229 					fpgoff = pgoff;
5230 					fvp = svd->vp;
5231 				}
5232 				if (fvp == NULL)
5233 					break;	/* XXX */
5234 				/*
5235 				 * Skip pages that are free or have an
5236 				 * "exclusive" lock.
5237 				 */
5238 				pp = page_lookup_nowait(fvp, fpgoff, SE_SHARED);
5239 				if (pp == NULL)
5240 					break;
5241 				/*
5242 				 * We don't need the page_struct_lock to test
5243 				 * as this is only advisory; even if we
5244 				 * acquire it someone might race in and lock
5245 				 * the page after we unlock and before the
5246 				 * PUTPAGE, then VOP_PUTPAGE will do nothing.
5247 				 */
5248 				if (pp->p_lckcnt == 0 && pp->p_cowcnt == 0) {
5249 					/*
5250 					 * Hold the vnode before releasing
5251 					 * the page lock to prevent it from
5252 					 * being freed and re-used by some
5253 					 * other thread.
5254 					 */
5255 					VN_HOLD(fvp);
5256 					page_unlock(pp);
5257 					/*
5258 					 * We should build a page list
5259 					 * to kluster putpages XXX
5260 					 */
5261 					(void) VOP_PUTPAGE(fvp,
5262 					    (offset_t)fpgoff, PAGESIZE,
5263 					    (B_DONTNEED|B_FREE|B_ASYNC),
5264 					    svd->cred, NULL);
5265 					VN_RELE(fvp);
5266 				} else {
5267 					/*
5268 					 * XXX - Should the loop terminate if
5269 					 * the page is `locked'?
5270 					 */
5271 					page_unlock(pp);
5272 				}
5273 				--vpp;
5274 				--fanon_index;
5275 				pgoff -= PAGESIZE;
5276 			}
5277 		}
5278 	}
5279 
5280 	plp = pl;
5281 	*plp = NULL;
5282 	pl_alloc_sz = 0;
5283 
5284 	/*
5285 	 * See if we need to call VOP_GETPAGE for
5286 	 * *any* of the range being faulted on.
5287 	 * We can skip all of this work if there
5288 	 * was no original vnode.
5289 	 */
5290 	if (svd->vp != NULL) {
5291 		u_offset_t vp_off;
5292 		size_t vp_len;
5293 		struct anon *ap;
5294 		vnode_t *vp;
5295 
5296 		vp_off = off;
5297 		vp_len = len;
5298 
5299 		if (amp == NULL)
5300 			dogetpage = 1;
5301 		else {
5302 			/*
5303 			 * Only acquire reader lock to prevent amp->ahp
5304 			 * from being changed.  It's ok to miss pages,
5305 			 * hence we don't do anon_array_enter
5306 			 */
5307 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5308 			ap = anon_get_ptr(amp->ahp, anon_index);
5309 
5310 			if (len <= PAGESIZE)
5311 				/* inline non_anon() */
5312 				dogetpage = (ap == NULL);
5313 			else
5314 				dogetpage = non_anon(amp->ahp, anon_index,
5315 				    &vp_off, &vp_len);
5316 			ANON_LOCK_EXIT(&amp->a_rwlock);
5317 		}
5318 
5319 		if (dogetpage) {
5320 			enum seg_rw arw;
5321 			struct as *as = seg->s_as;
5322 
5323 			if (len > ptob((sizeof (pl) / sizeof (pl[0])) - 1)) {
5324 				/*
5325 				 * Page list won't fit in local array,
5326 				 * allocate one of the needed size.
5327 				 */
5328 				pl_alloc_sz =
5329 				    (btop(len) + 1) * sizeof (page_t *);
5330 				plp = kmem_alloc(pl_alloc_sz, KM_SLEEP);
5331 				plp[0] = NULL;
5332 				plsz = len;
5333 			} else if (rw == S_WRITE && svd->type == MAP_PRIVATE ||
5334 			    svd->tr_state == SEGVN_TR_ON || rw == S_OTHER ||
5335 			    (((size_t)(addr + PAGESIZE) <
5336 			    (size_t)(seg->s_base + seg->s_size)) &&
5337 			    hat_probe(as->a_hat, addr + PAGESIZE))) {
5338 				/*
5339 				 * Ask VOP_GETPAGE to return the exact number
5340 				 * of pages if
5341 				 * (a) this is a COW fault, or
5342 				 * (b) this is a software fault, or
5343 				 * (c) next page is already mapped.
5344 				 */
5345 				plsz = len;
5346 			} else {
5347 				/*
5348 				 * Ask VOP_GETPAGE to return adjacent pages
5349 				 * within the segment.
5350 				 */
5351 				plsz = MIN((size_t)PVN_GETPAGE_SZ, (size_t)
5352 				    ((seg->s_base + seg->s_size) - addr));
5353 				ASSERT((addr + plsz) <=
5354 				    (seg->s_base + seg->s_size));
5355 			}
5356 
5357 			/*
5358 			 * Need to get some non-anonymous pages.
5359 			 * We need to make only one call to GETPAGE to do
5360 			 * this to prevent certain deadlocking conditions
5361 			 * when we are doing locking.  In this case
5362 			 * non_anon() should have picked up the smallest
5363 			 * range which includes all the non-anonymous
5364 			 * pages in the requested range.  We have to
5365 			 * be careful regarding which rw flag to pass in
5366 			 * because on a private mapping, the underlying
5367 			 * object is never allowed to be written.
5368 			 */
5369 			if (rw == S_WRITE && svd->type == MAP_PRIVATE) {
5370 				arw = S_READ;
5371 			} else {
5372 				arw = rw;
5373 			}
5374 			vp = svd->vp;
5375 			TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5376 			    "segvn_getpage:seg %p addr %p vp %p",
5377 			    seg, addr, vp);
5378 			err = VOP_GETPAGE(vp, (offset_t)vp_off, vp_len,
5379 			    &vpprot, plp, plsz, seg, addr + (vp_off - off), arw,
5380 			    svd->cred, NULL);
5381 			if (err) {
5382 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5383 				segvn_pagelist_rele(plp);
5384 				if (pl_alloc_sz)
5385 					kmem_free(plp, pl_alloc_sz);
5386 				return (FC_MAKE_ERR(err));
5387 			}
5388 			if (svd->type == MAP_PRIVATE)
5389 				vpprot &= ~PROT_WRITE;
5390 		}
5391 	}
5392 
5393 	/*
5394 	 * N.B. at this time the plp array has all the needed non-anon
5395 	 * pages in addition to (possibly) having some adjacent pages.
5396 	 */
5397 
5398 	/*
5399 	 * Always acquire the anon_array_lock to prevent
5400 	 * 2 threads from allocating separate anon slots for
5401 	 * the same "addr".
5402 	 *
5403 	 * If this is a copy-on-write fault and we don't already
5404 	 * have the anon_array_lock, acquire it to prevent the
5405 	 * fault routine from handling multiple copy-on-write faults
5406 	 * on the same "addr" in the same address space.
5407 	 *
5408 	 * Only one thread should deal with the fault since after
5409 	 * it is handled, the other threads can acquire a translation
5410 	 * to the newly created private page.  This prevents two or
5411 	 * more threads from creating different private pages for the
5412 	 * same fault.
5413 	 *
5414 	 * We grab "serialization" lock here if this is a MAP_PRIVATE segment
5415 	 * to prevent deadlock between this thread and another thread
5416 	 * which has soft-locked this page and wants to acquire serial_lock.
5417 	 * ( bug 4026339 )
5418 	 *
5419 	 * The fix for bug 4026339 becomes unnecessary when using the
5420 	 * locking scheme with per amp rwlock and a global set of hash
5421 	 * lock, anon_array_lock.  If we steal a vnode page when low
5422 	 * on memory and upgrad the page lock through page_rename,
5423 	 * then the page is PAGE_HANDLED, nothing needs to be done
5424 	 * for this page after returning from segvn_faultpage.
5425 	 *
5426 	 * But really, the page lock should be downgraded after
5427 	 * the stolen page is page_rename'd.
5428 	 */
5429 
5430 	if (amp != NULL)
5431 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5432 
5433 	/*
5434 	 * Ok, now loop over the address range and handle faults
5435 	 */
5436 	for (a = addr; a < addr + len; a += PAGESIZE, off += PAGESIZE) {
5437 		err = segvn_faultpage(hat, seg, a, off, vpage, plp, vpprot,
5438 		    type, rw, brkcow);
5439 		if (err) {
5440 			if (amp != NULL)
5441 				ANON_LOCK_EXIT(&amp->a_rwlock);
5442 			if (type == F_SOFTLOCK && a > addr) {
5443 				segvn_softunlock(seg, addr, (a - addr),
5444 				    S_OTHER);
5445 			}
5446 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5447 			segvn_pagelist_rele(plp);
5448 			if (pl_alloc_sz)
5449 				kmem_free(plp, pl_alloc_sz);
5450 			return (err);
5451 		}
5452 		if (vpage) {
5453 			vpage++;
5454 		} else if (svd->vpage) {
5455 			page = seg_page(seg, addr);
5456 			vpage = &svd->vpage[++page];
5457 		}
5458 	}
5459 
5460 	/* Didn't get pages from the underlying fs so we're done */
5461 	if (!dogetpage)
5462 		goto done;
5463 
5464 	/*
5465 	 * Now handle any other pages in the list returned.
5466 	 * If the page can be used, load up the translations now.
5467 	 * Note that the for loop will only be entered if "plp"
5468 	 * is pointing to a non-NULL page pointer which means that
5469 	 * VOP_GETPAGE() was called and vpprot has been initialized.
5470 	 */
5471 	if (svd->pageprot == 0)
5472 		prot = svd->prot & vpprot;
5473 
5474 
5475 	/*
5476 	 * Large Files: diff should be unsigned value because we started
5477 	 * supporting > 2GB segment sizes from 2.5.1 and when a
5478 	 * large file of size > 2GB gets mapped to address space
5479 	 * the diff value can be > 2GB.
5480 	 */
5481 
5482 	for (ppp = plp; (pp = *ppp) != NULL; ppp++) {
5483 		size_t diff;
5484 		struct anon *ap;
5485 		int anon_index;
5486 		anon_sync_obj_t cookie;
5487 		int hat_flag = HAT_LOAD_ADV;
5488 
5489 		if (svd->flags & MAP_TEXT) {
5490 			hat_flag |= HAT_LOAD_TEXT;
5491 		}
5492 
5493 		if (pp == PAGE_HANDLED)
5494 			continue;
5495 
5496 		if (svd->tr_state != SEGVN_TR_ON &&
5497 		    pp->p_offset >=  svd->offset &&
5498 		    pp->p_offset < svd->offset + seg->s_size) {
5499 
5500 			diff = pp->p_offset - svd->offset;
5501 
5502 			/*
5503 			 * Large Files: Following is the assertion
5504 			 * validating the above cast.
5505 			 */
5506 			ASSERT(svd->vp == pp->p_vnode);
5507 
5508 			page = btop(diff);
5509 			if (svd->pageprot)
5510 				prot = VPP_PROT(&svd->vpage[page]) & vpprot;
5511 
5512 			/*
5513 			 * Prevent other threads in the address space from
5514 			 * creating private pages (i.e., allocating anon slots)
5515 			 * while we are in the process of loading translations
5516 			 * to additional pages returned by the underlying
5517 			 * object.
5518 			 */
5519 			if (amp != NULL) {
5520 				anon_index = svd->anon_index + page;
5521 				anon_array_enter(amp, anon_index, &cookie);
5522 				ap = anon_get_ptr(amp->ahp, anon_index);
5523 			}
5524 			if ((amp == NULL) || (ap == NULL)) {
5525 				if (IS_VMODSORT(pp->p_vnode) ||
5526 				    enable_mbit_wa) {
5527 					if (rw == S_WRITE)
5528 						hat_setmod(pp);
5529 					else if (rw != S_OTHER &&
5530 					    !hat_ismod(pp))
5531 						prot &= ~PROT_WRITE;
5532 				}
5533 				/*
5534 				 * Skip mapping read ahead pages marked
5535 				 * for migration, so they will get migrated
5536 				 * properly on fault
5537 				 */
5538 				ASSERT(amp == NULL ||
5539 				    svd->rcookie == HAT_INVALID_REGION_COOKIE);
5540 				if ((prot & PROT_READ) && !PP_ISMIGRATE(pp)) {
5541 					hat_memload_region(hat,
5542 					    seg->s_base + diff,
5543 					    pp, prot, hat_flag,
5544 					    svd->rcookie);
5545 				}
5546 			}
5547 			if (amp != NULL)
5548 				anon_array_exit(&cookie);
5549 		}
5550 		page_unlock(pp);
5551 	}
5552 done:
5553 	if (amp != NULL)
5554 		ANON_LOCK_EXIT(&amp->a_rwlock);
5555 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5556 	if (pl_alloc_sz)
5557 		kmem_free(plp, pl_alloc_sz);
5558 	return (0);
5559 }
5560 
5561 /*
5562  * This routine is used to start I/O on pages asynchronously.  XXX it will
5563  * only create PAGESIZE pages. At fault time they will be relocated into
5564  * larger pages.
5565  */
5566 static faultcode_t
5567 segvn_faulta(struct seg *seg, caddr_t addr)
5568 {
5569 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5570 	int err;
5571 	struct anon_map *amp;
5572 	vnode_t *vp;
5573 
5574 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5575 
5576 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
5577 	if ((amp = svd->amp) != NULL) {
5578 		struct anon *ap;
5579 
5580 		/*
5581 		 * Reader lock to prevent amp->ahp from being changed.
5582 		 * This is advisory, it's ok to miss a page, so
5583 		 * we don't do anon_array_enter lock.
5584 		 */
5585 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5586 		if ((ap = anon_get_ptr(amp->ahp,
5587 		    svd->anon_index + seg_page(seg, addr))) != NULL) {
5588 
5589 			err = anon_getpage(&ap, NULL, NULL,
5590 			    0, seg, addr, S_READ, svd->cred);
5591 
5592 			ANON_LOCK_EXIT(&amp->a_rwlock);
5593 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5594 			if (err)
5595 				return (FC_MAKE_ERR(err));
5596 			return (0);
5597 		}
5598 		ANON_LOCK_EXIT(&amp->a_rwlock);
5599 	}
5600 
5601 	if (svd->vp == NULL) {
5602 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5603 		return (0);			/* zfod page - do nothing now */
5604 	}
5605 
5606 	vp = svd->vp;
5607 	TRACE_3(TR_FAC_VM, TR_SEGVN_GETPAGE,
5608 	    "segvn_getpage:seg %p addr %p vp %p", seg, addr, vp);
5609 	err = VOP_GETPAGE(vp,
5610 	    (offset_t)(svd->offset + (uintptr_t)(addr - seg->s_base)),
5611 	    PAGESIZE, NULL, NULL, 0, seg, addr,
5612 	    S_OTHER, svd->cred, NULL);
5613 
5614 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5615 	if (err)
5616 		return (FC_MAKE_ERR(err));
5617 	return (0);
5618 }
5619 
5620 static int
5621 segvn_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
5622 {
5623 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
5624 	struct vpage *cvp, *svp, *evp;
5625 	struct vnode *vp;
5626 	size_t pgsz;
5627 	pgcnt_t pgcnt;
5628 	anon_sync_obj_t cookie;
5629 	int unload_done = 0;
5630 
5631 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
5632 
5633 	if ((svd->maxprot & prot) != prot)
5634 		return (EACCES);			/* violated maxprot */
5635 
5636 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
5637 
5638 	/* return if prot is the same */
5639 	if (!svd->pageprot && svd->prot == prot) {
5640 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5641 		return (0);
5642 	}
5643 
5644 	/*
5645 	 * Since we change protections we first have to flush the cache.
5646 	 * This makes sure all the pagelock calls have to recheck
5647 	 * protections.
5648 	 */
5649 	if (svd->softlockcnt > 0) {
5650 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5651 
5652 		/*
5653 		 * If this is shared segment non 0 softlockcnt
5654 		 * means locked pages are still in use.
5655 		 */
5656 		if (svd->type == MAP_SHARED) {
5657 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5658 			return (EAGAIN);
5659 		}
5660 
5661 		/*
5662 		 * Since we do have the segvn writers lock nobody can fill
5663 		 * the cache with entries belonging to this seg during
5664 		 * the purge. The flush either succeeds or we still have
5665 		 * pending I/Os.
5666 		 */
5667 		segvn_purge(seg);
5668 		if (svd->softlockcnt > 0) {
5669 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5670 			return (EAGAIN);
5671 		}
5672 	}
5673 
5674 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
5675 		ASSERT(svd->amp == NULL);
5676 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
5677 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
5678 		    HAT_REGION_TEXT);
5679 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
5680 		unload_done = 1;
5681 	} else if (svd->tr_state == SEGVN_TR_INIT) {
5682 		svd->tr_state = SEGVN_TR_OFF;
5683 	} else if (svd->tr_state == SEGVN_TR_ON) {
5684 		ASSERT(svd->amp != NULL);
5685 		segvn_textunrepl(seg, 0);
5686 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
5687 		unload_done = 1;
5688 	}
5689 
5690 	if ((prot & PROT_WRITE) && svd->type == MAP_SHARED &&
5691 	    svd->vp != NULL && (svd->vp->v_flag & VVMEXEC)) {
5692 		ASSERT(vn_is_mapped(svd->vp, V_WRITE));
5693 		segvn_inval_trcache(svd->vp);
5694 	}
5695 	if (seg->s_szc != 0) {
5696 		int err;
5697 		pgsz = page_get_pagesize(seg->s_szc);
5698 		pgcnt = pgsz >> PAGESHIFT;
5699 		ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
5700 		if (!IS_P2ALIGNED(addr, pgsz) || !IS_P2ALIGNED(len, pgsz)) {
5701 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5702 			ASSERT(seg->s_base != addr || seg->s_size != len);
5703 			/*
5704 			 * If we are holding the as lock as a reader then
5705 			 * we need to return IE_RETRY and let the as
5706 			 * layer drop and re-acquire the lock as a writer.
5707 			 */
5708 			if (AS_READ_HELD(seg->s_as, &seg->s_as->a_lock))
5709 				return (IE_RETRY);
5710 			VM_STAT_ADD(segvnvmstats.demoterange[1]);
5711 			if (svd->type == MAP_PRIVATE || svd->vp != NULL) {
5712 				err = segvn_demote_range(seg, addr, len,
5713 				    SDR_END, 0);
5714 			} else {
5715 				uint_t szcvec = map_pgszcvec(seg->s_base,
5716 				    pgsz, (uintptr_t)seg->s_base,
5717 				    (svd->flags & MAP_TEXT), MAPPGSZC_SHM, 0);
5718 				err = segvn_demote_range(seg, addr, len,
5719 				    SDR_END, szcvec);
5720 			}
5721 			if (err == 0)
5722 				return (IE_RETRY);
5723 			if (err == ENOMEM)
5724 				return (IE_NOMEM);
5725 			return (err);
5726 		}
5727 	}
5728 
5729 
5730 	/*
5731 	 * If it's a private mapping and we're making it writable then we
5732 	 * may have to reserve the additional swap space now. If we are
5733 	 * making writable only a part of the segment then we use its vpage
5734 	 * array to keep a record of the pages for which we have reserved
5735 	 * swap. In this case we set the pageswap field in the segment's
5736 	 * segvn structure to record this.
5737 	 *
5738 	 * If it's a private mapping to a file (i.e., vp != NULL) and we're
5739 	 * removing write permission on the entire segment and we haven't
5740 	 * modified any pages, we can release the swap space.
5741 	 */
5742 	if (svd->type == MAP_PRIVATE) {
5743 		if (prot & PROT_WRITE) {
5744 			if (!(svd->flags & MAP_NORESERVE) &&
5745 			    !(svd->swresv && svd->pageswap == 0)) {
5746 				size_t sz = 0;
5747 
5748 				/*
5749 				 * Start by determining how much swap
5750 				 * space is required.
5751 				 */
5752 				if (addr == seg->s_base &&
5753 				    len == seg->s_size &&
5754 				    svd->pageswap == 0) {
5755 					/* The whole segment */
5756 					sz = seg->s_size;
5757 				} else {
5758 					/*
5759 					 * Make sure that the vpage array
5760 					 * exists, and make a note of the
5761 					 * range of elements corresponding
5762 					 * to len.
5763 					 */
5764 					segvn_vpage(seg);
5765 					svp = &svd->vpage[seg_page(seg, addr)];
5766 					evp = &svd->vpage[seg_page(seg,
5767 					    addr + len)];
5768 
5769 					if (svd->pageswap == 0) {
5770 						/*
5771 						 * This is the first time we've
5772 						 * asked for a part of this
5773 						 * segment, so we need to
5774 						 * reserve everything we've
5775 						 * been asked for.
5776 						 */
5777 						sz = len;
5778 					} else {
5779 						/*
5780 						 * We have to count the number
5781 						 * of pages required.
5782 						 */
5783 						for (cvp = svp;  cvp < evp;
5784 						    cvp++) {
5785 							if (!VPP_ISSWAPRES(cvp))
5786 								sz++;
5787 						}
5788 						sz <<= PAGESHIFT;
5789 					}
5790 				}
5791 
5792 				/* Try to reserve the necessary swap. */
5793 				if (anon_resv_zone(sz,
5794 				    seg->s_as->a_proc->p_zone) == 0) {
5795 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5796 					return (IE_NOMEM);
5797 				}
5798 
5799 				/*
5800 				 * Make a note of how much swap space
5801 				 * we've reserved.
5802 				 */
5803 				if (svd->pageswap == 0 && sz == seg->s_size) {
5804 					svd->swresv = sz;
5805 				} else {
5806 					ASSERT(svd->vpage != NULL);
5807 					svd->swresv += sz;
5808 					svd->pageswap = 1;
5809 					for (cvp = svp; cvp < evp; cvp++) {
5810 						if (!VPP_ISSWAPRES(cvp))
5811 							VPP_SETSWAPRES(cvp);
5812 					}
5813 				}
5814 			}
5815 		} else {
5816 			/*
5817 			 * Swap space is released only if this segment
5818 			 * does not map anonymous memory, since read faults
5819 			 * on such segments still need an anon slot to read
5820 			 * in the data.
5821 			 */
5822 			if (svd->swresv != 0 && svd->vp != NULL &&
5823 			    svd->amp == NULL && addr == seg->s_base &&
5824 			    len == seg->s_size && svd->pageprot == 0) {
5825 				ASSERT(svd->pageswap == 0);
5826 				anon_unresv_zone(svd->swresv,
5827 				    seg->s_as->a_proc->p_zone);
5828 				svd->swresv = 0;
5829 				TRACE_3(TR_FAC_VM, TR_ANON_PROC,
5830 				    "anon proc:%p %lu %u", seg, 0, 0);
5831 			}
5832 		}
5833 	}
5834 
5835 	if (addr == seg->s_base && len == seg->s_size && svd->vpage == NULL) {
5836 		if (svd->prot == prot) {
5837 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5838 			return (0);			/* all done */
5839 		}
5840 		svd->prot = (uchar_t)prot;
5841 	} else if (svd->type == MAP_PRIVATE) {
5842 		struct anon *ap = NULL;
5843 		page_t *pp;
5844 		u_offset_t offset, off;
5845 		struct anon_map *amp;
5846 		ulong_t anon_idx = 0;
5847 
5848 		/*
5849 		 * A vpage structure exists or else the change does not
5850 		 * involve the entire segment.  Establish a vpage structure
5851 		 * if none is there.  Then, for each page in the range,
5852 		 * adjust its individual permissions.  Note that write-
5853 		 * enabling a MAP_PRIVATE page can affect the claims for
5854 		 * locked down memory.  Overcommitting memory terminates
5855 		 * the operation.
5856 		 */
5857 		segvn_vpage(seg);
5858 		svd->pageprot = 1;
5859 		if ((amp = svd->amp) != NULL) {
5860 			anon_idx = svd->anon_index + seg_page(seg, addr);
5861 			ASSERT(seg->s_szc == 0 ||
5862 			    IS_P2ALIGNED(anon_idx, pgcnt));
5863 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
5864 		}
5865 
5866 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
5867 		evp = &svd->vpage[seg_page(seg, addr + len)];
5868 
5869 		/*
5870 		 * See Statement at the beginning of segvn_lockop regarding
5871 		 * the way cowcnts and lckcnts are handled.
5872 		 */
5873 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5874 
5875 			if (seg->s_szc != 0) {
5876 				if (amp != NULL) {
5877 					anon_array_enter(amp, anon_idx,
5878 					    &cookie);
5879 				}
5880 				if (IS_P2ALIGNED(anon_idx, pgcnt) &&
5881 				    !segvn_claim_pages(seg, svp, offset,
5882 				    anon_idx, prot)) {
5883 					if (amp != NULL) {
5884 						anon_array_exit(&cookie);
5885 					}
5886 					break;
5887 				}
5888 				if (amp != NULL) {
5889 					anon_array_exit(&cookie);
5890 				}
5891 				anon_idx++;
5892 			} else {
5893 				if (amp != NULL) {
5894 					anon_array_enter(amp, anon_idx,
5895 					    &cookie);
5896 					ap = anon_get_ptr(amp->ahp, anon_idx++);
5897 				}
5898 
5899 				if (VPP_ISPPLOCK(svp) &&
5900 				    VPP_PROT(svp) != prot) {
5901 
5902 					if (amp == NULL || ap == NULL) {
5903 						vp = svd->vp;
5904 						off = offset;
5905 					} else
5906 						swap_xlate(ap, &vp, &off);
5907 					if (amp != NULL)
5908 						anon_array_exit(&cookie);
5909 
5910 					if ((pp = page_lookup(vp, off,
5911 					    SE_SHARED)) == NULL) {
5912 						panic("segvn_setprot: no page");
5913 						/*NOTREACHED*/
5914 					}
5915 					ASSERT(seg->s_szc == 0);
5916 					if ((VPP_PROT(svp) ^ prot) &
5917 					    PROT_WRITE) {
5918 						if (prot & PROT_WRITE) {
5919 							if (!page_addclaim(
5920 							    pp)) {
5921 								page_unlock(pp);
5922 								break;
5923 							}
5924 						} else {
5925 							if (!page_subclaim(
5926 							    pp)) {
5927 								page_unlock(pp);
5928 								break;
5929 							}
5930 						}
5931 					}
5932 					page_unlock(pp);
5933 				} else if (amp != NULL)
5934 					anon_array_exit(&cookie);
5935 			}
5936 			VPP_SETPROT(svp, prot);
5937 			offset += PAGESIZE;
5938 		}
5939 		if (amp != NULL)
5940 			ANON_LOCK_EXIT(&amp->a_rwlock);
5941 
5942 		/*
5943 		 * Did we terminate prematurely?  If so, simply unload
5944 		 * the translations to the things we've updated so far.
5945 		 */
5946 		if (svp != evp) {
5947 			if (unload_done) {
5948 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5949 				return (IE_NOMEM);
5950 			}
5951 			len = (svp - &svd->vpage[seg_page(seg, addr)]) *
5952 			    PAGESIZE;
5953 			ASSERT(seg->s_szc == 0 || IS_P2ALIGNED(len, pgsz));
5954 			if (len != 0)
5955 				hat_unload(seg->s_as->a_hat, addr,
5956 				    len, HAT_UNLOAD);
5957 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5958 			return (IE_NOMEM);
5959 		}
5960 	} else {
5961 		segvn_vpage(seg);
5962 		svd->pageprot = 1;
5963 		evp = &svd->vpage[seg_page(seg, addr + len)];
5964 		for (svp = &svd->vpage[seg_page(seg, addr)]; svp < evp; svp++) {
5965 			VPP_SETPROT(svp, prot);
5966 		}
5967 	}
5968 
5969 	if (unload_done) {
5970 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
5971 		return (0);
5972 	}
5973 
5974 	if (((prot & PROT_WRITE) != 0 &&
5975 	    (svd->vp != NULL || svd->type == MAP_PRIVATE)) ||
5976 	    (prot & ~PROT_USER) == PROT_NONE) {
5977 		/*
5978 		 * Either private or shared data with write access (in
5979 		 * which case we need to throw out all former translations
5980 		 * so that we get the right translations set up on fault
5981 		 * and we don't allow write access to any copy-on-write pages
5982 		 * that might be around or to prevent write access to pages
5983 		 * representing holes in a file), or we don't have permission
5984 		 * to access the memory at all (in which case we have to
5985 		 * unload any current translations that might exist).
5986 		 */
5987 		hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
5988 	} else {
5989 		/*
5990 		 * A shared mapping or a private mapping in which write
5991 		 * protection is going to be denied - just change all the
5992 		 * protections over the range of addresses in question.
5993 		 * segvn does not support any other attributes other
5994 		 * than prot so we can use hat_chgattr.
5995 		 */
5996 		hat_chgattr(seg->s_as->a_hat, addr, len, prot);
5997 	}
5998 
5999 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6000 
6001 	return (0);
6002 }
6003 
6004 /*
6005  * segvn_setpagesize is called via SEGOP_SETPAGESIZE from as_setpagesize,
6006  * to determine if the seg is capable of mapping the requested szc.
6007  */
6008 static int
6009 segvn_setpagesize(struct seg *seg, caddr_t addr, size_t len, uint_t szc)
6010 {
6011 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6012 	struct segvn_data *nsvd;
6013 	struct anon_map *amp = svd->amp;
6014 	struct seg *nseg;
6015 	caddr_t eaddr = addr + len, a;
6016 	size_t pgsz = page_get_pagesize(szc);
6017 	pgcnt_t pgcnt = page_get_pagecnt(szc);
6018 	int err;
6019 	u_offset_t off = svd->offset + (uintptr_t)(addr - seg->s_base);
6020 	extern struct vnode kvp;
6021 
6022 	ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6023 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6024 
6025 	if (seg->s_szc == szc || segvn_lpg_disable != 0) {
6026 		return (0);
6027 	}
6028 
6029 	/*
6030 	 * addr should always be pgsz aligned but eaddr may be misaligned if
6031 	 * it's at the end of the segment.
6032 	 *
6033 	 * XXX we should assert this condition since as_setpagesize() logic
6034 	 * guarantees it.
6035 	 */
6036 	if (!IS_P2ALIGNED(addr, pgsz) ||
6037 	    (!IS_P2ALIGNED(eaddr, pgsz) &&
6038 	    eaddr != seg->s_base + seg->s_size)) {
6039 
6040 		segvn_setpgsz_align_err++;
6041 		return (EINVAL);
6042 	}
6043 
6044 	if (amp != NULL && svd->type == MAP_SHARED) {
6045 		ulong_t an_idx = svd->anon_index + seg_page(seg, addr);
6046 		if (!IS_P2ALIGNED(an_idx, pgcnt)) {
6047 
6048 			segvn_setpgsz_anon_align_err++;
6049 			return (EINVAL);
6050 		}
6051 	}
6052 
6053 	if ((svd->flags & MAP_NORESERVE) || seg->s_as == &kas ||
6054 	    szc > segvn_maxpgszc) {
6055 		return (EINVAL);
6056 	}
6057 
6058 	/* paranoid check */
6059 	if (svd->vp != NULL &&
6060 	    (IS_SWAPFSVP(svd->vp) || VN_ISKAS(svd->vp))) {
6061 		return (EINVAL);
6062 	}
6063 
6064 	if (seg->s_szc == 0 && svd->vp != NULL &&
6065 	    map_addr_vacalign_check(addr, off)) {
6066 		return (EINVAL);
6067 	}
6068 
6069 	/*
6070 	 * Check that protections are the same within new page
6071 	 * size boundaries.
6072 	 */
6073 	if (svd->pageprot) {
6074 		for (a = addr; a < eaddr; a += pgsz) {
6075 			if ((a + pgsz) > eaddr) {
6076 				if (!sameprot(seg, a, eaddr - a)) {
6077 					return (EINVAL);
6078 				}
6079 			} else {
6080 				if (!sameprot(seg, a, pgsz)) {
6081 					return (EINVAL);
6082 				}
6083 			}
6084 		}
6085 	}
6086 
6087 	/*
6088 	 * Since we are changing page size we first have to flush
6089 	 * the cache. This makes sure all the pagelock calls have
6090 	 * to recheck protections.
6091 	 */
6092 	if (svd->softlockcnt > 0) {
6093 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6094 
6095 		/*
6096 		 * If this is shared segment non 0 softlockcnt
6097 		 * means locked pages are still in use.
6098 		 */
6099 		if (svd->type == MAP_SHARED) {
6100 			return (EAGAIN);
6101 		}
6102 
6103 		/*
6104 		 * Since we do have the segvn writers lock nobody can fill
6105 		 * the cache with entries belonging to this seg during
6106 		 * the purge. The flush either succeeds or we still have
6107 		 * pending I/Os.
6108 		 */
6109 		segvn_purge(seg);
6110 		if (svd->softlockcnt > 0) {
6111 			return (EAGAIN);
6112 		}
6113 	}
6114 
6115 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6116 		ASSERT(svd->amp == NULL);
6117 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6118 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6119 		    HAT_REGION_TEXT);
6120 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6121 	} else if (svd->tr_state == SEGVN_TR_INIT) {
6122 		svd->tr_state = SEGVN_TR_OFF;
6123 	} else if (svd->tr_state == SEGVN_TR_ON) {
6124 		ASSERT(svd->amp != NULL);
6125 		segvn_textunrepl(seg, 1);
6126 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6127 		amp = NULL;
6128 	}
6129 
6130 	/*
6131 	 * Operation for sub range of existing segment.
6132 	 */
6133 	if (addr != seg->s_base || eaddr != (seg->s_base + seg->s_size)) {
6134 		if (szc < seg->s_szc) {
6135 			VM_STAT_ADD(segvnvmstats.demoterange[2]);
6136 			err = segvn_demote_range(seg, addr, len, SDR_RANGE, 0);
6137 			if (err == 0) {
6138 				return (IE_RETRY);
6139 			}
6140 			if (err == ENOMEM) {
6141 				return (IE_NOMEM);
6142 			}
6143 			return (err);
6144 		}
6145 		if (addr != seg->s_base) {
6146 			nseg = segvn_split_seg(seg, addr);
6147 			if (eaddr != (nseg->s_base + nseg->s_size)) {
6148 				/* eaddr is szc aligned */
6149 				(void) segvn_split_seg(nseg, eaddr);
6150 			}
6151 			return (IE_RETRY);
6152 		}
6153 		if (eaddr != (seg->s_base + seg->s_size)) {
6154 			/* eaddr is szc aligned */
6155 			(void) segvn_split_seg(seg, eaddr);
6156 		}
6157 		return (IE_RETRY);
6158 	}
6159 
6160 	/*
6161 	 * Break any low level sharing and reset seg->s_szc to 0.
6162 	 */
6163 	if ((err = segvn_clrszc(seg)) != 0) {
6164 		if (err == ENOMEM) {
6165 			err = IE_NOMEM;
6166 		}
6167 		return (err);
6168 	}
6169 	ASSERT(seg->s_szc == 0);
6170 
6171 	/*
6172 	 * If the end of the current segment is not pgsz aligned
6173 	 * then attempt to concatenate with the next segment.
6174 	 */
6175 	if (!IS_P2ALIGNED(eaddr, pgsz)) {
6176 		nseg = AS_SEGNEXT(seg->s_as, seg);
6177 		if (nseg == NULL || nseg == seg || eaddr != nseg->s_base) {
6178 			return (ENOMEM);
6179 		}
6180 		if (nseg->s_ops != &segvn_ops) {
6181 			return (EINVAL);
6182 		}
6183 		nsvd = (struct segvn_data *)nseg->s_data;
6184 		if (nsvd->softlockcnt > 0) {
6185 			/*
6186 			 * If this is shared segment non 0 softlockcnt
6187 			 * means locked pages are still in use.
6188 			 */
6189 			if (nsvd->type == MAP_SHARED) {
6190 				return (EAGAIN);
6191 			}
6192 			segvn_purge(nseg);
6193 			if (nsvd->softlockcnt > 0) {
6194 				return (EAGAIN);
6195 			}
6196 		}
6197 		err = segvn_clrszc(nseg);
6198 		if (err == ENOMEM) {
6199 			err = IE_NOMEM;
6200 		}
6201 		if (err != 0) {
6202 			return (err);
6203 		}
6204 		ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6205 		err = segvn_concat(seg, nseg, 1);
6206 		if (err == -1) {
6207 			return (EINVAL);
6208 		}
6209 		if (err == -2) {
6210 			return (IE_NOMEM);
6211 		}
6212 		return (IE_RETRY);
6213 	}
6214 
6215 	/*
6216 	 * May need to re-align anon array to
6217 	 * new szc.
6218 	 */
6219 	if (amp != NULL) {
6220 		if (!IS_P2ALIGNED(svd->anon_index, pgcnt)) {
6221 			struct anon_hdr *nahp;
6222 
6223 			ASSERT(svd->type == MAP_PRIVATE);
6224 
6225 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6226 			ASSERT(amp->refcnt == 1);
6227 			nahp = anon_create(btop(amp->size), ANON_NOSLEEP);
6228 			if (nahp == NULL) {
6229 				ANON_LOCK_EXIT(&amp->a_rwlock);
6230 				return (IE_NOMEM);
6231 			}
6232 			if (anon_copy_ptr(amp->ahp, svd->anon_index,
6233 			    nahp, 0, btop(seg->s_size), ANON_NOSLEEP)) {
6234 				anon_release(nahp, btop(amp->size));
6235 				ANON_LOCK_EXIT(&amp->a_rwlock);
6236 				return (IE_NOMEM);
6237 			}
6238 			anon_release(amp->ahp, btop(amp->size));
6239 			amp->ahp = nahp;
6240 			svd->anon_index = 0;
6241 			ANON_LOCK_EXIT(&amp->a_rwlock);
6242 		}
6243 	}
6244 	if (svd->vp != NULL && szc != 0) {
6245 		struct vattr va;
6246 		u_offset_t eoffpage = svd->offset;
6247 		va.va_mask = AT_SIZE;
6248 		eoffpage += seg->s_size;
6249 		eoffpage = btopr(eoffpage);
6250 		if (VOP_GETATTR(svd->vp, &va, 0, svd->cred, NULL) != 0) {
6251 			segvn_setpgsz_getattr_err++;
6252 			return (EINVAL);
6253 		}
6254 		if (btopr(va.va_size) < eoffpage) {
6255 			segvn_setpgsz_eof_err++;
6256 			return (EINVAL);
6257 		}
6258 		if (amp != NULL) {
6259 			/*
6260 			 * anon_fill_cow_holes() may call VOP_GETPAGE().
6261 			 * don't take anon map lock here to avoid holding it
6262 			 * across VOP_GETPAGE() calls that may call back into
6263 			 * segvn for klsutering checks. We don't really need
6264 			 * anon map lock here since it's a private segment and
6265 			 * we hold as level lock as writers.
6266 			 */
6267 			if ((err = anon_fill_cow_holes(seg, seg->s_base,
6268 			    amp->ahp, svd->anon_index, svd->vp, svd->offset,
6269 			    seg->s_size, szc, svd->prot, svd->vpage,
6270 			    svd->cred)) != 0) {
6271 				return (EINVAL);
6272 			}
6273 		}
6274 		segvn_setvnode_mpss(svd->vp);
6275 	}
6276 
6277 	if (amp != NULL) {
6278 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6279 		if (svd->type == MAP_PRIVATE) {
6280 			amp->a_szc = szc;
6281 		} else if (szc > amp->a_szc) {
6282 			amp->a_szc = szc;
6283 		}
6284 		ANON_LOCK_EXIT(&amp->a_rwlock);
6285 	}
6286 
6287 	seg->s_szc = szc;
6288 
6289 	return (0);
6290 }
6291 
6292 static int
6293 segvn_clrszc(struct seg *seg)
6294 {
6295 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6296 	struct anon_map *amp = svd->amp;
6297 	size_t pgsz;
6298 	pgcnt_t pages;
6299 	int err = 0;
6300 	caddr_t a = seg->s_base;
6301 	caddr_t ea = a + seg->s_size;
6302 	ulong_t an_idx = svd->anon_index;
6303 	vnode_t *vp = svd->vp;
6304 	struct vpage *vpage = svd->vpage;
6305 	page_t *anon_pl[1 + 1], *pp;
6306 	struct anon *ap, *oldap;
6307 	uint_t prot = svd->prot, vpprot;
6308 	int pageflag = 0;
6309 
6310 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6311 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
6312 	ASSERT(svd->softlockcnt == 0);
6313 
6314 	if (vp == NULL && amp == NULL) {
6315 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6316 		seg->s_szc = 0;
6317 		return (0);
6318 	}
6319 
6320 	if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
6321 		ASSERT(svd->amp == NULL);
6322 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
6323 		hat_leave_region(seg->s_as->a_hat, svd->rcookie,
6324 		    HAT_REGION_TEXT);
6325 		svd->rcookie = HAT_INVALID_REGION_COOKIE;
6326 	} else if (svd->tr_state == SEGVN_TR_ON) {
6327 		ASSERT(svd->amp != NULL);
6328 		segvn_textunrepl(seg, 1);
6329 		ASSERT(svd->amp == NULL && svd->tr_state == SEGVN_TR_OFF);
6330 		amp = NULL;
6331 	} else {
6332 		if (svd->tr_state != SEGVN_TR_OFF) {
6333 			ASSERT(svd->tr_state == SEGVN_TR_INIT);
6334 			svd->tr_state = SEGVN_TR_OFF;
6335 		}
6336 
6337 		/*
6338 		 * do HAT_UNLOAD_UNMAP since we are changing the pagesize.
6339 		 * unload argument is 0 when we are freeing the segment
6340 		 * and unload was already done.
6341 		 */
6342 		hat_unload(seg->s_as->a_hat, seg->s_base, seg->s_size,
6343 		    HAT_UNLOAD_UNMAP);
6344 	}
6345 
6346 	if (amp == NULL || svd->type == MAP_SHARED) {
6347 		seg->s_szc = 0;
6348 		return (0);
6349 	}
6350 
6351 	pgsz = page_get_pagesize(seg->s_szc);
6352 	pages = btop(pgsz);
6353 
6354 	/*
6355 	 * XXX anon rwlock is not really needed because this is a
6356 	 * private segment and we are writers.
6357 	 */
6358 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_WRITER);
6359 
6360 	for (; a < ea; a += pgsz, an_idx += pages) {
6361 		if ((oldap = anon_get_ptr(amp->ahp, an_idx)) != NULL) {
6362 			ASSERT(vpage != NULL || svd->pageprot == 0);
6363 			if (vpage != NULL) {
6364 				ASSERT(sameprot(seg, a, pgsz));
6365 				prot = VPP_PROT(vpage);
6366 				pageflag = VPP_ISPPLOCK(vpage) ? LOCK_PAGE : 0;
6367 			}
6368 			if (seg->s_szc != 0) {
6369 				ASSERT(vp == NULL || anon_pages(amp->ahp,
6370 				    an_idx, pages) == pages);
6371 				if ((err = anon_map_demotepages(amp, an_idx,
6372 				    seg, a, prot, vpage, svd->cred)) != 0) {
6373 					goto out;
6374 				}
6375 			} else {
6376 				if (oldap->an_refcnt == 1) {
6377 					continue;
6378 				}
6379 				if ((err = anon_getpage(&oldap, &vpprot,
6380 				    anon_pl, PAGESIZE, seg, a, S_READ,
6381 				    svd->cred))) {
6382 					goto out;
6383 				}
6384 				if ((pp = anon_private(&ap, seg, a, prot,
6385 				    anon_pl[0], pageflag, svd->cred)) == NULL) {
6386 					err = ENOMEM;
6387 					goto out;
6388 				}
6389 				anon_decref(oldap);
6390 				(void) anon_set_ptr(amp->ahp, an_idx, ap,
6391 				    ANON_SLEEP);
6392 				page_unlock(pp);
6393 			}
6394 		}
6395 		vpage = (vpage == NULL) ? NULL : vpage + pages;
6396 	}
6397 
6398 	amp->a_szc = 0;
6399 	seg->s_szc = 0;
6400 out:
6401 	ANON_LOCK_EXIT(&amp->a_rwlock);
6402 	return (err);
6403 }
6404 
6405 static int
6406 segvn_claim_pages(
6407 	struct seg *seg,
6408 	struct vpage *svp,
6409 	u_offset_t off,
6410 	ulong_t anon_idx,
6411 	uint_t prot)
6412 {
6413 	pgcnt_t	pgcnt = page_get_pagecnt(seg->s_szc);
6414 	size_t ppasize = (pgcnt + 1) * sizeof (page_t *);
6415 	page_t	**ppa;
6416 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6417 	struct anon_map *amp = svd->amp;
6418 	struct vpage *evp = svp + pgcnt;
6419 	caddr_t addr = ((uintptr_t)(svp - svd->vpage) << PAGESHIFT)
6420 	    + seg->s_base;
6421 	struct anon *ap;
6422 	struct vnode *vp = svd->vp;
6423 	page_t *pp;
6424 	pgcnt_t pg_idx, i;
6425 	int err = 0;
6426 	anoff_t aoff;
6427 	int anon = (amp != NULL) ? 1 : 0;
6428 
6429 	ASSERT(svd->type == MAP_PRIVATE);
6430 	ASSERT(svd->vpage != NULL);
6431 	ASSERT(seg->s_szc != 0);
6432 	ASSERT(IS_P2ALIGNED(pgcnt, pgcnt));
6433 	ASSERT(amp == NULL || IS_P2ALIGNED(anon_idx, pgcnt));
6434 	ASSERT(sameprot(seg, addr, pgcnt << PAGESHIFT));
6435 
6436 	if (VPP_PROT(svp) == prot)
6437 		return (1);
6438 	if (!((VPP_PROT(svp) ^ prot) & PROT_WRITE))
6439 		return (1);
6440 
6441 	ppa = kmem_alloc(ppasize, KM_SLEEP);
6442 	if (anon && vp != NULL) {
6443 		if (anon_get_ptr(amp->ahp, anon_idx) == NULL) {
6444 			anon = 0;
6445 			ASSERT(!anon_pages(amp->ahp, anon_idx, pgcnt));
6446 		}
6447 		ASSERT(!anon ||
6448 		    anon_pages(amp->ahp, anon_idx, pgcnt) == pgcnt);
6449 	}
6450 
6451 	for (*ppa = NULL, pg_idx = 0; svp < evp; svp++, anon_idx++) {
6452 		if (!VPP_ISPPLOCK(svp))
6453 			continue;
6454 		if (anon) {
6455 			ap = anon_get_ptr(amp->ahp, anon_idx);
6456 			if (ap == NULL) {
6457 				panic("segvn_claim_pages: no anon slot");
6458 			}
6459 			swap_xlate(ap, &vp, &aoff);
6460 			off = (u_offset_t)aoff;
6461 		}
6462 		ASSERT(vp != NULL);
6463 		if ((pp = page_lookup(vp,
6464 		    (u_offset_t)off, SE_SHARED)) == NULL) {
6465 			panic("segvn_claim_pages: no page");
6466 		}
6467 		ppa[pg_idx++] = pp;
6468 		off += PAGESIZE;
6469 	}
6470 
6471 	if (ppa[0] == NULL) {
6472 		kmem_free(ppa, ppasize);
6473 		return (1);
6474 	}
6475 
6476 	ASSERT(pg_idx <= pgcnt);
6477 	ppa[pg_idx] = NULL;
6478 
6479 	if (prot & PROT_WRITE)
6480 		err = page_addclaim_pages(ppa);
6481 	else
6482 		err = page_subclaim_pages(ppa);
6483 
6484 	for (i = 0; i < pg_idx; i++) {
6485 		ASSERT(ppa[i] != NULL);
6486 		page_unlock(ppa[i]);
6487 	}
6488 
6489 	kmem_free(ppa, ppasize);
6490 	return (err);
6491 }
6492 
6493 /*
6494  * Returns right (upper address) segment if split occurred.
6495  * If the address is equal to the beginning or end of its segment it returns
6496  * the current segment.
6497  */
6498 static struct seg *
6499 segvn_split_seg(struct seg *seg, caddr_t addr)
6500 {
6501 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6502 	struct seg *nseg;
6503 	size_t nsize;
6504 	struct segvn_data *nsvd;
6505 
6506 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6507 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6508 
6509 	ASSERT(addr >= seg->s_base);
6510 	ASSERT(addr <= seg->s_base + seg->s_size);
6511 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6512 
6513 	if (addr == seg->s_base || addr == seg->s_base + seg->s_size)
6514 		return (seg);
6515 
6516 	nsize = seg->s_base + seg->s_size - addr;
6517 	seg->s_size = addr - seg->s_base;
6518 	nseg = seg_alloc(seg->s_as, addr, nsize);
6519 	ASSERT(nseg != NULL);
6520 	nseg->s_ops = seg->s_ops;
6521 	nsvd = kmem_cache_alloc(segvn_cache, KM_SLEEP);
6522 	nseg->s_data = (void *)nsvd;
6523 	nseg->s_szc = seg->s_szc;
6524 	*nsvd = *svd;
6525 	ASSERT(nsvd->rcookie == HAT_INVALID_REGION_COOKIE);
6526 	nsvd->seg = nseg;
6527 	rw_init(&nsvd->lock, NULL, RW_DEFAULT, NULL);
6528 
6529 	if (nsvd->vp != NULL) {
6530 		VN_HOLD(nsvd->vp);
6531 		nsvd->offset = svd->offset +
6532 		    (uintptr_t)(nseg->s_base - seg->s_base);
6533 		if (nsvd->type == MAP_SHARED)
6534 			lgrp_shm_policy_init(NULL, nsvd->vp);
6535 	} else {
6536 		/*
6537 		 * The offset for an anonymous segment has no signifigance in
6538 		 * terms of an offset into a file. If we were to use the above
6539 		 * calculation instead, the structures read out of
6540 		 * /proc/<pid>/xmap would be more difficult to decipher since
6541 		 * it would be unclear whether two seemingly contiguous
6542 		 * prxmap_t structures represented different segments or a
6543 		 * single segment that had been split up into multiple prxmap_t
6544 		 * structures (e.g. if some part of the segment had not yet
6545 		 * been faulted in).
6546 		 */
6547 		nsvd->offset = 0;
6548 	}
6549 
6550 	ASSERT(svd->softlockcnt == 0);
6551 	ASSERT(svd->softlockcnt_sbase == 0);
6552 	ASSERT(svd->softlockcnt_send == 0);
6553 	crhold(svd->cred);
6554 
6555 	if (svd->vpage != NULL) {
6556 		size_t bytes = vpgtob(seg_pages(seg));
6557 		size_t nbytes = vpgtob(seg_pages(nseg));
6558 		struct vpage *ovpage = svd->vpage;
6559 
6560 		svd->vpage = kmem_alloc(bytes, KM_SLEEP);
6561 		bcopy(ovpage, svd->vpage, bytes);
6562 		nsvd->vpage = kmem_alloc(nbytes, KM_SLEEP);
6563 		bcopy(ovpage + seg_pages(seg), nsvd->vpage, nbytes);
6564 		kmem_free(ovpage, bytes + nbytes);
6565 	}
6566 	if (svd->amp != NULL && svd->type == MAP_PRIVATE) {
6567 		struct anon_map *oamp = svd->amp, *namp;
6568 		struct anon_hdr *nahp;
6569 
6570 		ANON_LOCK_ENTER(&oamp->a_rwlock, RW_WRITER);
6571 		ASSERT(oamp->refcnt == 1);
6572 		nahp = anon_create(btop(seg->s_size), ANON_SLEEP);
6573 		(void) anon_copy_ptr(oamp->ahp, svd->anon_index,
6574 		    nahp, 0, btop(seg->s_size), ANON_SLEEP);
6575 
6576 		namp = anonmap_alloc(nseg->s_size, 0, ANON_SLEEP);
6577 		namp->a_szc = nseg->s_szc;
6578 		(void) anon_copy_ptr(oamp->ahp,
6579 		    svd->anon_index + btop(seg->s_size),
6580 		    namp->ahp, 0, btop(nseg->s_size), ANON_SLEEP);
6581 		anon_release(oamp->ahp, btop(oamp->size));
6582 		oamp->ahp = nahp;
6583 		oamp->size = seg->s_size;
6584 		svd->anon_index = 0;
6585 		nsvd->amp = namp;
6586 		nsvd->anon_index = 0;
6587 		ANON_LOCK_EXIT(&oamp->a_rwlock);
6588 	} else if (svd->amp != NULL) {
6589 		pgcnt_t pgcnt = page_get_pagecnt(seg->s_szc);
6590 		ASSERT(svd->amp == nsvd->amp);
6591 		ASSERT(seg->s_szc <= svd->amp->a_szc);
6592 		nsvd->anon_index = svd->anon_index + seg_pages(seg);
6593 		ASSERT(IS_P2ALIGNED(nsvd->anon_index, pgcnt));
6594 		ANON_LOCK_ENTER(&svd->amp->a_rwlock, RW_WRITER);
6595 		svd->amp->refcnt++;
6596 		ANON_LOCK_EXIT(&svd->amp->a_rwlock);
6597 	}
6598 
6599 	/*
6600 	 * Split the amount of swap reserved.
6601 	 */
6602 	if (svd->swresv) {
6603 		/*
6604 		 * For MAP_NORESERVE, only allocate swap reserve for pages
6605 		 * being used.  Other segments get enough to cover whole
6606 		 * segment.
6607 		 */
6608 		if (svd->flags & MAP_NORESERVE) {
6609 			size_t	oswresv;
6610 
6611 			ASSERT(svd->amp);
6612 			oswresv = svd->swresv;
6613 			svd->swresv = ptob(anon_pages(svd->amp->ahp,
6614 			    svd->anon_index, btop(seg->s_size)));
6615 			nsvd->swresv = ptob(anon_pages(nsvd->amp->ahp,
6616 			    nsvd->anon_index, btop(nseg->s_size)));
6617 			ASSERT(oswresv >= (svd->swresv + nsvd->swresv));
6618 		} else {
6619 			if (svd->pageswap) {
6620 				svd->swresv = segvn_count_swap_by_vpages(seg);
6621 				ASSERT(nsvd->swresv >= svd->swresv);
6622 				nsvd->swresv -= svd->swresv;
6623 			} else {
6624 				ASSERT(svd->swresv == seg->s_size +
6625 				    nseg->s_size);
6626 				svd->swresv = seg->s_size;
6627 				nsvd->swresv = nseg->s_size;
6628 			}
6629 		}
6630 	}
6631 
6632 	return (nseg);
6633 }
6634 
6635 /*
6636  * called on memory operations (unmap, setprot, setpagesize) for a subset
6637  * of a large page segment to either demote the memory range (SDR_RANGE)
6638  * or the ends (SDR_END) by addr/len.
6639  *
6640  * returns 0 on success. returns errno, including ENOMEM, on failure.
6641  */
6642 static int
6643 segvn_demote_range(
6644 	struct seg *seg,
6645 	caddr_t addr,
6646 	size_t len,
6647 	int flag,
6648 	uint_t szcvec)
6649 {
6650 	caddr_t eaddr = addr + len;
6651 	caddr_t lpgaddr, lpgeaddr;
6652 	struct seg *nseg;
6653 	struct seg *badseg1 = NULL;
6654 	struct seg *badseg2 = NULL;
6655 	size_t pgsz;
6656 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6657 	int err;
6658 	uint_t szc = seg->s_szc;
6659 	uint_t tszcvec;
6660 
6661 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock));
6662 	ASSERT(svd->tr_state == SEGVN_TR_OFF);
6663 	ASSERT(szc != 0);
6664 	pgsz = page_get_pagesize(szc);
6665 	ASSERT(seg->s_base != addr || seg->s_size != len);
6666 	ASSERT(addr >= seg->s_base && eaddr <= seg->s_base + seg->s_size);
6667 	ASSERT(svd->softlockcnt == 0);
6668 	ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
6669 	ASSERT(szcvec == 0 || (flag == SDR_END && svd->type == MAP_SHARED));
6670 
6671 	CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
6672 	ASSERT(flag == SDR_RANGE || eaddr < lpgeaddr || addr > lpgaddr);
6673 	if (flag == SDR_RANGE) {
6674 		/* demote entire range */
6675 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6676 		(void) segvn_split_seg(nseg, lpgeaddr);
6677 		ASSERT(badseg1->s_base == lpgaddr);
6678 		ASSERT(badseg1->s_size == lpgeaddr - lpgaddr);
6679 	} else if (addr != lpgaddr) {
6680 		ASSERT(flag == SDR_END);
6681 		badseg1 = nseg = segvn_split_seg(seg, lpgaddr);
6682 		if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz &&
6683 		    eaddr < lpgaddr + 2 * pgsz) {
6684 			(void) segvn_split_seg(nseg, lpgeaddr);
6685 			ASSERT(badseg1->s_base == lpgaddr);
6686 			ASSERT(badseg1->s_size == 2 * pgsz);
6687 		} else {
6688 			nseg = segvn_split_seg(nseg, lpgaddr + pgsz);
6689 			ASSERT(badseg1->s_base == lpgaddr);
6690 			ASSERT(badseg1->s_size == pgsz);
6691 			if (eaddr != lpgeaddr && eaddr > lpgaddr + pgsz) {
6692 				ASSERT(lpgeaddr - lpgaddr > 2 * pgsz);
6693 				nseg = segvn_split_seg(nseg, lpgeaddr - pgsz);
6694 				badseg2 = nseg;
6695 				(void) segvn_split_seg(nseg, lpgeaddr);
6696 				ASSERT(badseg2->s_base == lpgeaddr - pgsz);
6697 				ASSERT(badseg2->s_size == pgsz);
6698 			}
6699 		}
6700 	} else {
6701 		ASSERT(flag == SDR_END);
6702 		ASSERT(eaddr < lpgeaddr);
6703 		badseg1 = nseg = segvn_split_seg(seg, lpgeaddr - pgsz);
6704 		(void) segvn_split_seg(nseg, lpgeaddr);
6705 		ASSERT(badseg1->s_base == lpgeaddr - pgsz);
6706 		ASSERT(badseg1->s_size == pgsz);
6707 	}
6708 
6709 	ASSERT(badseg1 != NULL);
6710 	ASSERT(badseg1->s_szc == szc);
6711 	ASSERT(flag == SDR_RANGE || badseg1->s_size == pgsz ||
6712 	    badseg1->s_size == 2 * pgsz);
6713 	ASSERT(sameprot(badseg1, badseg1->s_base, pgsz));
6714 	ASSERT(badseg1->s_size == pgsz ||
6715 	    sameprot(badseg1, badseg1->s_base + pgsz, pgsz));
6716 	if (err = segvn_clrszc(badseg1)) {
6717 		return (err);
6718 	}
6719 	ASSERT(badseg1->s_szc == 0);
6720 
6721 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6722 		uint_t tszc = highbit(tszcvec) - 1;
6723 		caddr_t ta = MAX(addr, badseg1->s_base);
6724 		caddr_t te;
6725 		size_t tpgsz = page_get_pagesize(tszc);
6726 
6727 		ASSERT(svd->type == MAP_SHARED);
6728 		ASSERT(flag == SDR_END);
6729 		ASSERT(tszc < szc && tszc > 0);
6730 
6731 		if (eaddr > badseg1->s_base + badseg1->s_size) {
6732 			te = badseg1->s_base + badseg1->s_size;
6733 		} else {
6734 			te = eaddr;
6735 		}
6736 
6737 		ASSERT(ta <= te);
6738 		badseg1->s_szc = tszc;
6739 		if (!IS_P2ALIGNED(ta, tpgsz) || !IS_P2ALIGNED(te, tpgsz)) {
6740 			if (badseg2 != NULL) {
6741 				err = segvn_demote_range(badseg1, ta, te - ta,
6742 				    SDR_END, tszcvec);
6743 				if (err != 0) {
6744 					return (err);
6745 				}
6746 			} else {
6747 				return (segvn_demote_range(badseg1, ta,
6748 				    te - ta, SDR_END, tszcvec));
6749 			}
6750 		}
6751 	}
6752 
6753 	if (badseg2 == NULL)
6754 		return (0);
6755 	ASSERT(badseg2->s_szc == szc);
6756 	ASSERT(badseg2->s_size == pgsz);
6757 	ASSERT(sameprot(badseg2, badseg2->s_base, badseg2->s_size));
6758 	if (err = segvn_clrszc(badseg2)) {
6759 		return (err);
6760 	}
6761 	ASSERT(badseg2->s_szc == 0);
6762 
6763 	if (szc > 1 && (tszcvec = P2PHASE(szcvec, 1 << szc)) > 1) {
6764 		uint_t tszc = highbit(tszcvec) - 1;
6765 		size_t tpgsz = page_get_pagesize(tszc);
6766 
6767 		ASSERT(svd->type == MAP_SHARED);
6768 		ASSERT(flag == SDR_END);
6769 		ASSERT(tszc < szc && tszc > 0);
6770 		ASSERT(badseg2->s_base > addr);
6771 		ASSERT(eaddr > badseg2->s_base);
6772 		ASSERT(eaddr < badseg2->s_base + badseg2->s_size);
6773 
6774 		badseg2->s_szc = tszc;
6775 		if (!IS_P2ALIGNED(eaddr, tpgsz)) {
6776 			return (segvn_demote_range(badseg2, badseg2->s_base,
6777 			    eaddr - badseg2->s_base, SDR_END, tszcvec));
6778 		}
6779 	}
6780 
6781 	return (0);
6782 }
6783 
6784 static int
6785 segvn_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot)
6786 {
6787 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6788 	struct vpage *vp, *evp;
6789 
6790 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6791 
6792 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6793 	/*
6794 	 * If segment protection can be used, simply check against them.
6795 	 */
6796 	if (svd->pageprot == 0) {
6797 		int err;
6798 
6799 		err = ((svd->prot & prot) != prot) ? EACCES : 0;
6800 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6801 		return (err);
6802 	}
6803 
6804 	/*
6805 	 * Have to check down to the vpage level.
6806 	 */
6807 	evp = &svd->vpage[seg_page(seg, addr + len)];
6808 	for (vp = &svd->vpage[seg_page(seg, addr)]; vp < evp; vp++) {
6809 		if ((VPP_PROT(vp) & prot) != prot) {
6810 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6811 			return (EACCES);
6812 		}
6813 	}
6814 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6815 	return (0);
6816 }
6817 
6818 static int
6819 segvn_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv)
6820 {
6821 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6822 	size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1;
6823 
6824 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6825 
6826 	if (pgno != 0) {
6827 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
6828 		if (svd->pageprot == 0) {
6829 			do {
6830 				protv[--pgno] = svd->prot;
6831 			} while (pgno != 0);
6832 		} else {
6833 			size_t pgoff = seg_page(seg, addr);
6834 
6835 			do {
6836 				pgno--;
6837 				protv[pgno] = VPP_PROT(&svd->vpage[pgno+pgoff]);
6838 			} while (pgno != 0);
6839 		}
6840 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
6841 	}
6842 	return (0);
6843 }
6844 
6845 static u_offset_t
6846 segvn_getoffset(struct seg *seg, caddr_t addr)
6847 {
6848 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6849 
6850 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6851 
6852 	return (svd->offset + (uintptr_t)(addr - seg->s_base));
6853 }
6854 
6855 /*ARGSUSED*/
6856 static int
6857 segvn_gettype(struct seg *seg, caddr_t addr)
6858 {
6859 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6860 
6861 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6862 
6863 	return (svd->type | (svd->flags & (MAP_NORESERVE | MAP_TEXT |
6864 	    MAP_INITDATA)));
6865 }
6866 
6867 /*ARGSUSED*/
6868 static int
6869 segvn_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp)
6870 {
6871 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6872 
6873 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6874 
6875 	*vpp = svd->vp;
6876 	return (0);
6877 }
6878 
6879 /*
6880  * Check to see if it makes sense to do kluster/read ahead to
6881  * addr + delta relative to the mapping at addr.  We assume here
6882  * that delta is a signed PAGESIZE'd multiple (which can be negative).
6883  *
6884  * For segvn, we currently "approve" of the action if we are
6885  * still in the segment and it maps from the same vp/off,
6886  * or if the advice stored in segvn_data or vpages allows it.
6887  * Currently, klustering is not allowed only if MADV_RANDOM is set.
6888  */
6889 static int
6890 segvn_kluster(struct seg *seg, caddr_t addr, ssize_t delta)
6891 {
6892 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
6893 	struct anon *oap, *ap;
6894 	ssize_t pd;
6895 	size_t page;
6896 	struct vnode *vp1, *vp2;
6897 	u_offset_t off1, off2;
6898 	struct anon_map *amp;
6899 
6900 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
6901 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
6902 	    SEGVN_LOCK_HELD(seg->s_as, &svd->lock));
6903 
6904 	if (addr + delta < seg->s_base ||
6905 	    addr + delta >= (seg->s_base + seg->s_size))
6906 		return (-1);		/* exceeded segment bounds */
6907 
6908 	pd = delta / (ssize_t)PAGESIZE;	/* divide to preserve sign bit */
6909 	page = seg_page(seg, addr);
6910 
6911 	/*
6912 	 * Check to see if either of the pages addr or addr + delta
6913 	 * have advice set that prevents klustering (if MADV_RANDOM advice
6914 	 * is set for entire segment, or MADV_SEQUENTIAL is set and delta
6915 	 * is negative).
6916 	 */
6917 	if (svd->advice == MADV_RANDOM ||
6918 	    svd->advice == MADV_SEQUENTIAL && delta < 0)
6919 		return (-1);
6920 	else if (svd->pageadvice && svd->vpage) {
6921 		struct vpage *bvpp, *evpp;
6922 
6923 		bvpp = &svd->vpage[page];
6924 		evpp = &svd->vpage[page + pd];
6925 		if (VPP_ADVICE(bvpp) == MADV_RANDOM ||
6926 		    VPP_ADVICE(evpp) == MADV_SEQUENTIAL && delta < 0)
6927 			return (-1);
6928 		if (VPP_ADVICE(bvpp) != VPP_ADVICE(evpp) &&
6929 		    VPP_ADVICE(evpp) == MADV_RANDOM)
6930 			return (-1);
6931 	}
6932 
6933 	if (svd->type == MAP_SHARED)
6934 		return (0);		/* shared mapping - all ok */
6935 
6936 	if ((amp = svd->amp) == NULL)
6937 		return (0);		/* off original vnode */
6938 
6939 	page += svd->anon_index;
6940 
6941 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
6942 
6943 	oap = anon_get_ptr(amp->ahp, page);
6944 	ap = anon_get_ptr(amp->ahp, page + pd);
6945 
6946 	ANON_LOCK_EXIT(&amp->a_rwlock);
6947 
6948 	if ((oap == NULL && ap != NULL) || (oap != NULL && ap == NULL)) {
6949 		return (-1);		/* one with and one without an anon */
6950 	}
6951 
6952 	if (oap == NULL) {		/* implies that ap == NULL */
6953 		return (0);		/* off original vnode */
6954 	}
6955 
6956 	/*
6957 	 * Now we know we have two anon pointers - check to
6958 	 * see if they happen to be properly allocated.
6959 	 */
6960 
6961 	/*
6962 	 * XXX We cheat here and don't lock the anon slots. We can't because
6963 	 * we may have been called from the anon layer which might already
6964 	 * have locked them. We are holding a refcnt on the slots so they
6965 	 * can't disappear. The worst that will happen is we'll get the wrong
6966 	 * names (vp, off) for the slots and make a poor klustering decision.
6967 	 */
6968 	swap_xlate(ap, &vp1, &off1);
6969 	swap_xlate(oap, &vp2, &off2);
6970 
6971 
6972 	if (!VOP_CMP(vp1, vp2, NULL) || off1 - off2 != delta)
6973 		return (-1);
6974 	return (0);
6975 }
6976 
6977 /*
6978  * Swap the pages of seg out to secondary storage, returning the
6979  * number of bytes of storage freed.
6980  *
6981  * The basic idea is first to unload all translations and then to call
6982  * VOP_PUTPAGE() for all newly-unmapped pages, to push them out to the
6983  * swap device.  Pages to which other segments have mappings will remain
6984  * mapped and won't be swapped.  Our caller (as_swapout) has already
6985  * performed the unloading step.
6986  *
6987  * The value returned is intended to correlate well with the process's
6988  * memory requirements.  However, there are some caveats:
6989  * 1)	When given a shared segment as argument, this routine will
6990  *	only succeed in swapping out pages for the last sharer of the
6991  *	segment.  (Previous callers will only have decremented mapping
6992  *	reference counts.)
6993  * 2)	We assume that the hat layer maintains a large enough translation
6994  *	cache to capture process reference patterns.
6995  */
6996 static size_t
6997 segvn_swapout(struct seg *seg)
6998 {
6999 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7000 	struct anon_map *amp;
7001 	pgcnt_t pgcnt = 0;
7002 	pgcnt_t npages;
7003 	pgcnt_t page;
7004 	ulong_t anon_index;
7005 
7006 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7007 
7008 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7009 	/*
7010 	 * Find pages unmapped by our caller and force them
7011 	 * out to the virtual swap device.
7012 	 */
7013 	if ((amp = svd->amp) != NULL)
7014 		anon_index = svd->anon_index;
7015 	npages = seg->s_size >> PAGESHIFT;
7016 	for (page = 0; page < npages; page++) {
7017 		page_t *pp;
7018 		struct anon *ap;
7019 		struct vnode *vp;
7020 		u_offset_t off;
7021 		anon_sync_obj_t cookie;
7022 
7023 		/*
7024 		 * Obtain <vp, off> pair for the page, then look it up.
7025 		 *
7026 		 * Note that this code is willing to consider regular
7027 		 * pages as well as anon pages.  Is this appropriate here?
7028 		 */
7029 		ap = NULL;
7030 		if (amp != NULL) {
7031 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7032 			if (anon_array_try_enter(amp, anon_index + page,
7033 			    &cookie)) {
7034 				ANON_LOCK_EXIT(&amp->a_rwlock);
7035 				continue;
7036 			}
7037 			ap = anon_get_ptr(amp->ahp, anon_index + page);
7038 			if (ap != NULL) {
7039 				swap_xlate(ap, &vp, &off);
7040 			} else {
7041 				vp = svd->vp;
7042 				off = svd->offset + ptob(page);
7043 			}
7044 			anon_array_exit(&cookie);
7045 			ANON_LOCK_EXIT(&amp->a_rwlock);
7046 		} else {
7047 			vp = svd->vp;
7048 			off = svd->offset + ptob(page);
7049 		}
7050 		if (vp == NULL) {		/* untouched zfod page */
7051 			ASSERT(ap == NULL);
7052 			continue;
7053 		}
7054 
7055 		pp = page_lookup_nowait(vp, off, SE_SHARED);
7056 		if (pp == NULL)
7057 			continue;
7058 
7059 
7060 		/*
7061 		 * Examine the page to see whether it can be tossed out,
7062 		 * keeping track of how many we've found.
7063 		 */
7064 		if (!page_tryupgrade(pp)) {
7065 			/*
7066 			 * If the page has an i/o lock and no mappings,
7067 			 * it's very likely that the page is being
7068 			 * written out as a result of klustering.
7069 			 * Assume this is so and take credit for it here.
7070 			 */
7071 			if (!page_io_trylock(pp)) {
7072 				if (!hat_page_is_mapped(pp))
7073 					pgcnt++;
7074 			} else {
7075 				page_io_unlock(pp);
7076 			}
7077 			page_unlock(pp);
7078 			continue;
7079 		}
7080 		ASSERT(!page_iolock_assert(pp));
7081 
7082 
7083 		/*
7084 		 * Skip if page is locked or has mappings.
7085 		 * We don't need the page_struct_lock to look at lckcnt
7086 		 * and cowcnt because the page is exclusive locked.
7087 		 */
7088 		if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0 ||
7089 		    hat_page_is_mapped(pp)) {
7090 			page_unlock(pp);
7091 			continue;
7092 		}
7093 
7094 		/*
7095 		 * dispose skips large pages so try to demote first.
7096 		 */
7097 		if (pp->p_szc != 0 && !page_try_demote_pages(pp)) {
7098 			page_unlock(pp);
7099 			/*
7100 			 * XXX should skip the remaining page_t's of this
7101 			 * large page.
7102 			 */
7103 			continue;
7104 		}
7105 
7106 		ASSERT(pp->p_szc == 0);
7107 
7108 		/*
7109 		 * No longer mapped -- we can toss it out.  How
7110 		 * we do so depends on whether or not it's dirty.
7111 		 */
7112 		if (hat_ismod(pp) && pp->p_vnode) {
7113 			/*
7114 			 * We must clean the page before it can be
7115 			 * freed.  Setting B_FREE will cause pvn_done
7116 			 * to free the page when the i/o completes.
7117 			 * XXX:	This also causes it to be accounted
7118 			 *	as a pageout instead of a swap: need
7119 			 *	B_SWAPOUT bit to use instead of B_FREE.
7120 			 *
7121 			 * Hold the vnode before releasing the page lock
7122 			 * to prevent it from being freed and re-used by
7123 			 * some other thread.
7124 			 */
7125 			VN_HOLD(vp);
7126 			page_unlock(pp);
7127 
7128 			/*
7129 			 * Queue all i/o requests for the pageout thread
7130 			 * to avoid saturating the pageout devices.
7131 			 */
7132 			if (!queue_io_request(vp, off))
7133 				VN_RELE(vp);
7134 		} else {
7135 			/*
7136 			 * The page was clean, free it.
7137 			 *
7138 			 * XXX:	Can we ever encounter modified pages
7139 			 *	with no associated vnode here?
7140 			 */
7141 			ASSERT(pp->p_vnode != NULL);
7142 			/*LINTED: constant in conditional context*/
7143 			VN_DISPOSE(pp, B_FREE, 0, kcred);
7144 		}
7145 
7146 		/*
7147 		 * Credit now even if i/o is in progress.
7148 		 */
7149 		pgcnt++;
7150 	}
7151 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7152 
7153 	/*
7154 	 * Wakeup pageout to initiate i/o on all queued requests.
7155 	 */
7156 	cv_signal_pageout();
7157 	return (ptob(pgcnt));
7158 }
7159 
7160 /*
7161  * Synchronize primary storage cache with real object in virtual memory.
7162  *
7163  * XXX - Anonymous pages should not be sync'ed out at all.
7164  */
7165 static int
7166 segvn_sync(struct seg *seg, caddr_t addr, size_t len, int attr, uint_t flags)
7167 {
7168 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7169 	struct vpage *vpp;
7170 	page_t *pp;
7171 	u_offset_t offset;
7172 	struct vnode *vp;
7173 	u_offset_t off;
7174 	caddr_t eaddr;
7175 	int bflags;
7176 	int err = 0;
7177 	int segtype;
7178 	int pageprot;
7179 	int prot;
7180 	ulong_t anon_index;
7181 	struct anon_map *amp;
7182 	struct anon *ap;
7183 	anon_sync_obj_t cookie;
7184 
7185 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7186 
7187 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7188 
7189 	if (svd->softlockcnt > 0) {
7190 		/*
7191 		 * If this is shared segment non 0 softlockcnt
7192 		 * means locked pages are still in use.
7193 		 */
7194 		if (svd->type == MAP_SHARED) {
7195 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7196 			return (EAGAIN);
7197 		}
7198 
7199 		/*
7200 		 * flush all pages from seg cache
7201 		 * otherwise we may deadlock in swap_putpage
7202 		 * for B_INVAL page (4175402).
7203 		 *
7204 		 * Even if we grab segvn WRITER's lock
7205 		 * here, there might be another thread which could've
7206 		 * successfully performed lookup/insert just before
7207 		 * we acquired the lock here.  So, grabbing either
7208 		 * lock here is of not much use.  Until we devise
7209 		 * a strategy at upper layers to solve the
7210 		 * synchronization issues completely, we expect
7211 		 * applications to handle this appropriately.
7212 		 */
7213 		segvn_purge(seg);
7214 		if (svd->softlockcnt > 0) {
7215 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7216 			return (EAGAIN);
7217 		}
7218 	} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
7219 	    svd->amp->a_softlockcnt > 0) {
7220 		/*
7221 		 * Try to purge this amp's entries from pcache. It will
7222 		 * succeed only if other segments that share the amp have no
7223 		 * outstanding softlock's.
7224 		 */
7225 		segvn_purge(seg);
7226 		if (svd->amp->a_softlockcnt > 0 || svd->softlockcnt > 0) {
7227 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7228 			return (EAGAIN);
7229 		}
7230 	}
7231 
7232 	vpp = svd->vpage;
7233 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7234 	bflags = ((flags & MS_ASYNC) ? B_ASYNC : 0) |
7235 	    ((flags & MS_INVALIDATE) ? B_INVAL : 0);
7236 
7237 	if (attr) {
7238 		pageprot = attr & ~(SHARED|PRIVATE);
7239 		segtype = (attr & SHARED) ? MAP_SHARED : MAP_PRIVATE;
7240 
7241 		/*
7242 		 * We are done if the segment types don't match
7243 		 * or if we have segment level protections and
7244 		 * they don't match.
7245 		 */
7246 		if (svd->type != segtype) {
7247 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7248 			return (0);
7249 		}
7250 		if (vpp == NULL) {
7251 			if (svd->prot != pageprot) {
7252 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7253 				return (0);
7254 			}
7255 			prot = svd->prot;
7256 		} else
7257 			vpp = &svd->vpage[seg_page(seg, addr)];
7258 
7259 	} else if (svd->vp && svd->amp == NULL &&
7260 	    (flags & MS_INVALIDATE) == 0) {
7261 
7262 		/*
7263 		 * No attributes, no anonymous pages and MS_INVALIDATE flag
7264 		 * is not on, just use one big request.
7265 		 */
7266 		err = VOP_PUTPAGE(svd->vp, (offset_t)offset, len,
7267 		    bflags, svd->cred, NULL);
7268 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7269 		return (err);
7270 	}
7271 
7272 	if ((amp = svd->amp) != NULL)
7273 		anon_index = svd->anon_index + seg_page(seg, addr);
7274 
7275 	for (eaddr = addr + len; addr < eaddr; addr += PAGESIZE) {
7276 		ap = NULL;
7277 		if (amp != NULL) {
7278 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7279 			anon_array_enter(amp, anon_index, &cookie);
7280 			ap = anon_get_ptr(amp->ahp, anon_index++);
7281 			if (ap != NULL) {
7282 				swap_xlate(ap, &vp, &off);
7283 			} else {
7284 				vp = svd->vp;
7285 				off = offset;
7286 			}
7287 			anon_array_exit(&cookie);
7288 			ANON_LOCK_EXIT(&amp->a_rwlock);
7289 		} else {
7290 			vp = svd->vp;
7291 			off = offset;
7292 		}
7293 		offset += PAGESIZE;
7294 
7295 		if (vp == NULL)		/* untouched zfod page */
7296 			continue;
7297 
7298 		if (attr) {
7299 			if (vpp) {
7300 				prot = VPP_PROT(vpp);
7301 				vpp++;
7302 			}
7303 			if (prot != pageprot) {
7304 				continue;
7305 			}
7306 		}
7307 
7308 		/*
7309 		 * See if any of these pages are locked --  if so, then we
7310 		 * will have to truncate an invalidate request at the first
7311 		 * locked one. We don't need the page_struct_lock to test
7312 		 * as this is only advisory; even if we acquire it someone
7313 		 * might race in and lock the page after we unlock and before
7314 		 * we do the PUTPAGE, then PUTPAGE simply does nothing.
7315 		 */
7316 		if (flags & MS_INVALIDATE) {
7317 			if ((pp = page_lookup(vp, off, SE_SHARED)) != NULL) {
7318 				if (pp->p_lckcnt != 0 || pp->p_cowcnt != 0) {
7319 					page_unlock(pp);
7320 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7321 					return (EBUSY);
7322 				}
7323 				if (ap != NULL && pp->p_szc != 0 &&
7324 				    page_tryupgrade(pp)) {
7325 					if (pp->p_lckcnt == 0 &&
7326 					    pp->p_cowcnt == 0) {
7327 						/*
7328 						 * swapfs VN_DISPOSE() won't
7329 						 * invalidate large pages.
7330 						 * Attempt to demote.
7331 						 * XXX can't help it if it
7332 						 * fails. But for swapfs
7333 						 * pages it is no big deal.
7334 						 */
7335 						(void) page_try_demote_pages(
7336 						    pp);
7337 					}
7338 				}
7339 				page_unlock(pp);
7340 			}
7341 		} else if (svd->type == MAP_SHARED && amp != NULL) {
7342 			/*
7343 			 * Avoid writing out to disk ISM's large pages
7344 			 * because segspt_free_pages() relies on NULL an_pvp
7345 			 * of anon slots of such pages.
7346 			 */
7347 
7348 			ASSERT(svd->vp == NULL);
7349 			/*
7350 			 * swapfs uses page_lookup_nowait if not freeing or
7351 			 * invalidating and skips a page if
7352 			 * page_lookup_nowait returns NULL.
7353 			 */
7354 			pp = page_lookup_nowait(vp, off, SE_SHARED);
7355 			if (pp == NULL) {
7356 				continue;
7357 			}
7358 			if (pp->p_szc != 0) {
7359 				page_unlock(pp);
7360 				continue;
7361 			}
7362 
7363 			/*
7364 			 * Note ISM pages are created large so (vp, off)'s
7365 			 * page cannot suddenly become large after we unlock
7366 			 * pp.
7367 			 */
7368 			page_unlock(pp);
7369 		}
7370 		/*
7371 		 * XXX - Should ultimately try to kluster
7372 		 * calls to VOP_PUTPAGE() for performance.
7373 		 */
7374 		VN_HOLD(vp);
7375 		err = VOP_PUTPAGE(vp, (offset_t)off, PAGESIZE,
7376 		    (bflags | (IS_SWAPFSVP(vp) ? B_PAGE_NOWAIT : 0)),
7377 		    svd->cred, NULL);
7378 
7379 		VN_RELE(vp);
7380 		if (err)
7381 			break;
7382 	}
7383 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7384 	return (err);
7385 }
7386 
7387 /*
7388  * Determine if we have data corresponding to pages in the
7389  * primary storage virtual memory cache (i.e., "in core").
7390  */
7391 static size_t
7392 segvn_incore(struct seg *seg, caddr_t addr, size_t len, char *vec)
7393 {
7394 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7395 	struct vnode *vp, *avp;
7396 	u_offset_t offset, aoffset;
7397 	size_t p, ep;
7398 	int ret;
7399 	struct vpage *vpp;
7400 	page_t *pp;
7401 	uint_t start;
7402 	struct anon_map *amp;		/* XXX - for locknest */
7403 	struct anon *ap;
7404 	uint_t attr;
7405 	anon_sync_obj_t cookie;
7406 
7407 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7408 
7409 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
7410 	if (svd->amp == NULL && svd->vp == NULL) {
7411 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7412 		bzero(vec, btopr(len));
7413 		return (len);	/* no anonymous pages created yet */
7414 	}
7415 
7416 	p = seg_page(seg, addr);
7417 	ep = seg_page(seg, addr + len);
7418 	start = svd->vp ? SEG_PAGE_VNODEBACKED : 0;
7419 
7420 	amp = svd->amp;
7421 	for (; p < ep; p++, addr += PAGESIZE) {
7422 		vpp = (svd->vpage) ? &svd->vpage[p]: NULL;
7423 		ret = start;
7424 		ap = NULL;
7425 		avp = NULL;
7426 		/* Grab the vnode/offset for the anon slot */
7427 		if (amp != NULL) {
7428 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7429 			anon_array_enter(amp, svd->anon_index + p, &cookie);
7430 			ap = anon_get_ptr(amp->ahp, svd->anon_index + p);
7431 			if (ap != NULL) {
7432 				swap_xlate(ap, &avp, &aoffset);
7433 			}
7434 			anon_array_exit(&cookie);
7435 			ANON_LOCK_EXIT(&amp->a_rwlock);
7436 		}
7437 		if ((avp != NULL) && page_exists(avp, aoffset)) {
7438 			/* A page exists for the anon slot */
7439 			ret |= SEG_PAGE_INCORE;
7440 
7441 			/*
7442 			 * If page is mapped and writable
7443 			 */
7444 			attr = (uint_t)0;
7445 			if ((hat_getattr(seg->s_as->a_hat, addr,
7446 			    &attr) != -1) && (attr & PROT_WRITE)) {
7447 				ret |= SEG_PAGE_ANON;
7448 			}
7449 			/*
7450 			 * Don't get page_struct lock for lckcnt and cowcnt,
7451 			 * since this is purely advisory.
7452 			 */
7453 			if ((pp = page_lookup_nowait(avp, aoffset,
7454 			    SE_SHARED)) != NULL) {
7455 				if (pp->p_lckcnt)
7456 					ret |= SEG_PAGE_SOFTLOCK;
7457 				if (pp->p_cowcnt)
7458 					ret |= SEG_PAGE_HASCOW;
7459 				page_unlock(pp);
7460 			}
7461 		}
7462 
7463 		/* Gather vnode statistics */
7464 		vp = svd->vp;
7465 		offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7466 
7467 		if (vp != NULL) {
7468 			/*
7469 			 * Try to obtain a "shared" lock on the page
7470 			 * without blocking.  If this fails, determine
7471 			 * if the page is in memory.
7472 			 */
7473 			pp = page_lookup_nowait(vp, offset, SE_SHARED);
7474 			if ((pp == NULL) && (page_exists(vp, offset))) {
7475 				/* Page is incore, and is named */
7476 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7477 			}
7478 			/*
7479 			 * Don't get page_struct lock for lckcnt and cowcnt,
7480 			 * since this is purely advisory.
7481 			 */
7482 			if (pp != NULL) {
7483 				ret |= (SEG_PAGE_INCORE | SEG_PAGE_VNODE);
7484 				if (pp->p_lckcnt)
7485 					ret |= SEG_PAGE_SOFTLOCK;
7486 				if (pp->p_cowcnt)
7487 					ret |= SEG_PAGE_HASCOW;
7488 				page_unlock(pp);
7489 			}
7490 		}
7491 
7492 		/* Gather virtual page information */
7493 		if (vpp) {
7494 			if (VPP_ISPPLOCK(vpp))
7495 				ret |= SEG_PAGE_LOCKED;
7496 			vpp++;
7497 		}
7498 
7499 		*vec++ = (char)ret;
7500 	}
7501 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7502 	return (len);
7503 }
7504 
7505 /*
7506  * Statement for p_cowcnts/p_lckcnts.
7507  *
7508  * p_cowcnt is updated while mlock/munlocking MAP_PRIVATE and PROT_WRITE region
7509  * irrespective of the following factors or anything else:
7510  *
7511  *	(1) anon slots are populated or not
7512  *	(2) cow is broken or not
7513  *	(3) refcnt on ap is 1 or greater than 1
7514  *
7515  * If it's not MAP_PRIVATE and PROT_WRITE, p_lckcnt is updated during mlock
7516  * and munlock.
7517  *
7518  *
7519  * Handling p_cowcnts/p_lckcnts during copy-on-write fault:
7520  *
7521  *	if vpage has PROT_WRITE
7522  *		transfer cowcnt on the oldpage -> cowcnt on the newpage
7523  *	else
7524  *		transfer lckcnt on the oldpage -> lckcnt on the newpage
7525  *
7526  *	During copy-on-write, decrement p_cowcnt on the oldpage and increment
7527  *	p_cowcnt on the newpage *if* the corresponding vpage has PROT_WRITE.
7528  *
7529  *	We may also break COW if softlocking on read access in the physio case.
7530  *	In this case, vpage may not have PROT_WRITE. So, we need to decrement
7531  *	p_lckcnt on the oldpage and increment p_lckcnt on the newpage *if* the
7532  *	vpage doesn't have PROT_WRITE.
7533  *
7534  *
7535  * Handling p_cowcnts/p_lckcnts during mprotect on mlocked region:
7536  *
7537  * 	If a MAP_PRIVATE region loses PROT_WRITE, we decrement p_cowcnt and
7538  *	increment p_lckcnt by calling page_subclaim() which takes care of
7539  * 	availrmem accounting and p_lckcnt overflow.
7540  *
7541  *	If a MAP_PRIVATE region gains PROT_WRITE, we decrement p_lckcnt and
7542  *	increment p_cowcnt by calling page_addclaim() which takes care of
7543  *	availrmem availability and p_cowcnt overflow.
7544  */
7545 
7546 /*
7547  * Lock down (or unlock) pages mapped by this segment.
7548  *
7549  * XXX only creates PAGESIZE pages if anon slots are not initialized.
7550  * At fault time they will be relocated into larger pages.
7551  */
7552 static int
7553 segvn_lockop(struct seg *seg, caddr_t addr, size_t len,
7554     int attr, int op, ulong_t *lockmap, size_t pos)
7555 {
7556 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7557 	struct vpage *vpp;
7558 	struct vpage *evp;
7559 	page_t *pp;
7560 	u_offset_t offset;
7561 	u_offset_t off;
7562 	int segtype;
7563 	int pageprot;
7564 	int claim;
7565 	struct vnode *vp;
7566 	ulong_t anon_index;
7567 	struct anon_map *amp;
7568 	struct anon *ap;
7569 	struct vattr va;
7570 	anon_sync_obj_t cookie;
7571 	struct kshmid *sp = NULL;
7572 	struct proc	*p = curproc;
7573 	kproject_t	*proj = NULL;
7574 	int chargeproc = 1;
7575 	size_t locked_bytes = 0;
7576 	size_t unlocked_bytes = 0;
7577 	int err = 0;
7578 
7579 	/*
7580 	 * Hold write lock on address space because may split or concatenate
7581 	 * segments
7582 	 */
7583 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7584 
7585 	/*
7586 	 * If this is a shm, use shm's project and zone, else use
7587 	 * project and zone of calling process
7588 	 */
7589 
7590 	/* Determine if this segment backs a sysV shm */
7591 	if (svd->amp != NULL && svd->amp->a_sp != NULL) {
7592 		ASSERT(svd->type == MAP_SHARED);
7593 		ASSERT(svd->tr_state == SEGVN_TR_OFF);
7594 		sp = svd->amp->a_sp;
7595 		proj = sp->shm_perm.ipc_proj;
7596 		chargeproc = 0;
7597 	}
7598 
7599 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
7600 	if (attr) {
7601 		pageprot = attr & ~(SHARED|PRIVATE);
7602 		segtype = attr & SHARED ? MAP_SHARED : MAP_PRIVATE;
7603 
7604 		/*
7605 		 * We are done if the segment types don't match
7606 		 * or if we have segment level protections and
7607 		 * they don't match.
7608 		 */
7609 		if (svd->type != segtype) {
7610 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7611 			return (0);
7612 		}
7613 		if (svd->pageprot == 0 && svd->prot != pageprot) {
7614 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7615 			return (0);
7616 		}
7617 	}
7618 
7619 	if (op == MC_LOCK) {
7620 		if (svd->tr_state == SEGVN_TR_INIT) {
7621 			svd->tr_state = SEGVN_TR_OFF;
7622 		} else if (svd->tr_state == SEGVN_TR_ON) {
7623 			ASSERT(svd->amp != NULL);
7624 			segvn_textunrepl(seg, 0);
7625 			ASSERT(svd->amp == NULL &&
7626 			    svd->tr_state == SEGVN_TR_OFF);
7627 		}
7628 	}
7629 
7630 	/*
7631 	 * If we're locking, then we must create a vpage structure if
7632 	 * none exists.  If we're unlocking, then check to see if there
7633 	 * is a vpage --  if not, then we could not have locked anything.
7634 	 */
7635 
7636 	if ((vpp = svd->vpage) == NULL) {
7637 		if (op == MC_LOCK)
7638 			segvn_vpage(seg);
7639 		else {
7640 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7641 			return (0);
7642 		}
7643 	}
7644 
7645 	/*
7646 	 * The anonymous data vector (i.e., previously
7647 	 * unreferenced mapping to swap space) can be allocated
7648 	 * by lazily testing for its existence.
7649 	 */
7650 	if (op == MC_LOCK && svd->amp == NULL && svd->vp == NULL) {
7651 		ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
7652 		svd->amp = anonmap_alloc(seg->s_size, 0, ANON_SLEEP);
7653 		svd->amp->a_szc = seg->s_szc;
7654 	}
7655 
7656 	if ((amp = svd->amp) != NULL) {
7657 		anon_index = svd->anon_index + seg_page(seg, addr);
7658 	}
7659 
7660 	offset = svd->offset + (uintptr_t)(addr - seg->s_base);
7661 	evp = &svd->vpage[seg_page(seg, addr + len)];
7662 
7663 	if (sp != NULL)
7664 		mutex_enter(&sp->shm_mlock);
7665 
7666 	/* determine number of unlocked bytes in range for lock operation */
7667 	if (op == MC_LOCK) {
7668 
7669 		if (sp == NULL) {
7670 			for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7671 			    vpp++) {
7672 				if (!VPP_ISPPLOCK(vpp))
7673 					unlocked_bytes += PAGESIZE;
7674 			}
7675 		} else {
7676 			ulong_t		i_idx, i_edx;
7677 			anon_sync_obj_t	i_cookie;
7678 			struct anon	*i_ap;
7679 			struct vnode	*i_vp;
7680 			u_offset_t	i_off;
7681 
7682 			/* Only count sysV pages once for locked memory */
7683 			i_edx = svd->anon_index + seg_page(seg, addr + len);
7684 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7685 			for (i_idx = anon_index; i_idx < i_edx; i_idx++) {
7686 				anon_array_enter(amp, i_idx, &i_cookie);
7687 				i_ap = anon_get_ptr(amp->ahp, i_idx);
7688 				if (i_ap == NULL) {
7689 					unlocked_bytes += PAGESIZE;
7690 					anon_array_exit(&i_cookie);
7691 					continue;
7692 				}
7693 				swap_xlate(i_ap, &i_vp, &i_off);
7694 				anon_array_exit(&i_cookie);
7695 				pp = page_lookup(i_vp, i_off, SE_SHARED);
7696 				if (pp == NULL) {
7697 					unlocked_bytes += PAGESIZE;
7698 					continue;
7699 				} else if (pp->p_lckcnt == 0)
7700 					unlocked_bytes += PAGESIZE;
7701 				page_unlock(pp);
7702 			}
7703 			ANON_LOCK_EXIT(&amp->a_rwlock);
7704 		}
7705 
7706 		mutex_enter(&p->p_lock);
7707 		err = rctl_incr_locked_mem(p, proj, unlocked_bytes,
7708 		    chargeproc);
7709 		mutex_exit(&p->p_lock);
7710 
7711 		if (err) {
7712 			if (sp != NULL)
7713 				mutex_exit(&sp->shm_mlock);
7714 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7715 			return (err);
7716 		}
7717 	}
7718 	/*
7719 	 * Loop over all pages in the range.  Process if we're locking and
7720 	 * page has not already been locked in this mapping; or if we're
7721 	 * unlocking and the page has been locked.
7722 	 */
7723 	for (vpp = &svd->vpage[seg_page(seg, addr)]; vpp < evp;
7724 	    vpp++, pos++, addr += PAGESIZE, offset += PAGESIZE, anon_index++) {
7725 		if ((attr == 0 || VPP_PROT(vpp) == pageprot) &&
7726 		    ((op == MC_LOCK && !VPP_ISPPLOCK(vpp)) ||
7727 		    (op == MC_UNLOCK && VPP_ISPPLOCK(vpp)))) {
7728 
7729 			if (amp != NULL)
7730 				ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
7731 			/*
7732 			 * If this isn't a MAP_NORESERVE segment and
7733 			 * we're locking, allocate anon slots if they
7734 			 * don't exist.  The page is brought in later on.
7735 			 */
7736 			if (op == MC_LOCK && svd->vp == NULL &&
7737 			    ((svd->flags & MAP_NORESERVE) == 0) &&
7738 			    amp != NULL &&
7739 			    ((ap = anon_get_ptr(amp->ahp, anon_index))
7740 			    == NULL)) {
7741 				anon_array_enter(amp, anon_index, &cookie);
7742 
7743 				if ((ap = anon_get_ptr(amp->ahp,
7744 				    anon_index)) == NULL) {
7745 					pp = anon_zero(seg, addr, &ap,
7746 					    svd->cred);
7747 					if (pp == NULL) {
7748 						anon_array_exit(&cookie);
7749 						ANON_LOCK_EXIT(&amp->a_rwlock);
7750 						err = ENOMEM;
7751 						goto out;
7752 					}
7753 					ASSERT(anon_get_ptr(amp->ahp,
7754 					    anon_index) == NULL);
7755 					(void) anon_set_ptr(amp->ahp,
7756 					    anon_index, ap, ANON_SLEEP);
7757 					page_unlock(pp);
7758 				}
7759 				anon_array_exit(&cookie);
7760 			}
7761 
7762 			/*
7763 			 * Get name for page, accounting for
7764 			 * existence of private copy.
7765 			 */
7766 			ap = NULL;
7767 			if (amp != NULL) {
7768 				anon_array_enter(amp, anon_index, &cookie);
7769 				ap = anon_get_ptr(amp->ahp, anon_index);
7770 				if (ap != NULL) {
7771 					swap_xlate(ap, &vp, &off);
7772 				} else {
7773 					if (svd->vp == NULL &&
7774 					    (svd->flags & MAP_NORESERVE)) {
7775 						anon_array_exit(&cookie);
7776 						ANON_LOCK_EXIT(&amp->a_rwlock);
7777 						continue;
7778 					}
7779 					vp = svd->vp;
7780 					off = offset;
7781 				}
7782 				if (op != MC_LOCK || ap == NULL) {
7783 					anon_array_exit(&cookie);
7784 					ANON_LOCK_EXIT(&amp->a_rwlock);
7785 				}
7786 			} else {
7787 				vp = svd->vp;
7788 				off = offset;
7789 			}
7790 
7791 			/*
7792 			 * Get page frame.  It's ok if the page is
7793 			 * not available when we're unlocking, as this
7794 			 * may simply mean that a page we locked got
7795 			 * truncated out of existence after we locked it.
7796 			 *
7797 			 * Invoke VOP_GETPAGE() to obtain the page struct
7798 			 * since we may need to read it from disk if its
7799 			 * been paged out.
7800 			 */
7801 			if (op != MC_LOCK)
7802 				pp = page_lookup(vp, off, SE_SHARED);
7803 			else {
7804 				page_t *pl[1 + 1];
7805 				int error;
7806 
7807 				ASSERT(vp != NULL);
7808 
7809 				error = VOP_GETPAGE(vp, (offset_t)off, PAGESIZE,
7810 				    (uint_t *)NULL, pl, PAGESIZE, seg, addr,
7811 				    S_OTHER, svd->cred, NULL);
7812 
7813 				if (error && ap != NULL) {
7814 					anon_array_exit(&cookie);
7815 					ANON_LOCK_EXIT(&amp->a_rwlock);
7816 				}
7817 
7818 				/*
7819 				 * If the error is EDEADLK then we must bounce
7820 				 * up and drop all vm subsystem locks and then
7821 				 * retry the operation later
7822 				 * This behavior is a temporary measure because
7823 				 * ufs/sds logging is badly designed and will
7824 				 * deadlock if we don't allow this bounce to
7825 				 * happen.  The real solution is to re-design
7826 				 * the logging code to work properly.  See bug
7827 				 * 4125102 for details of the problem.
7828 				 */
7829 				if (error == EDEADLK) {
7830 					err = error;
7831 					goto out;
7832 				}
7833 				/*
7834 				 * Quit if we fail to fault in the page.  Treat
7835 				 * the failure as an error, unless the addr
7836 				 * is mapped beyond the end of a file.
7837 				 */
7838 				if (error && svd->vp) {
7839 					va.va_mask = AT_SIZE;
7840 					if (VOP_GETATTR(svd->vp, &va, 0,
7841 					    svd->cred, NULL) != 0) {
7842 						err = EIO;
7843 						goto out;
7844 					}
7845 					if (btopr(va.va_size) >=
7846 					    btopr(off + 1)) {
7847 						err = EIO;
7848 						goto out;
7849 					}
7850 					goto out;
7851 
7852 				} else if (error) {
7853 					err = EIO;
7854 					goto out;
7855 				}
7856 				pp = pl[0];
7857 				ASSERT(pp != NULL);
7858 			}
7859 
7860 			/*
7861 			 * See Statement at the beginning of this routine.
7862 			 *
7863 			 * claim is always set if MAP_PRIVATE and PROT_WRITE
7864 			 * irrespective of following factors:
7865 			 *
7866 			 * (1) anon slots are populated or not
7867 			 * (2) cow is broken or not
7868 			 * (3) refcnt on ap is 1 or greater than 1
7869 			 *
7870 			 * See 4140683 for details
7871 			 */
7872 			claim = ((VPP_PROT(vpp) & PROT_WRITE) &&
7873 			    (svd->type == MAP_PRIVATE));
7874 
7875 			/*
7876 			 * Perform page-level operation appropriate to
7877 			 * operation.  If locking, undo the SOFTLOCK
7878 			 * performed to bring the page into memory
7879 			 * after setting the lock.  If unlocking,
7880 			 * and no page was found, account for the claim
7881 			 * separately.
7882 			 */
7883 			if (op == MC_LOCK) {
7884 				int ret = 1;	/* Assume success */
7885 
7886 				ASSERT(!VPP_ISPPLOCK(vpp));
7887 
7888 				ret = page_pp_lock(pp, claim, 0);
7889 				if (ap != NULL) {
7890 					if (ap->an_pvp != NULL) {
7891 						anon_swap_free(ap, pp);
7892 					}
7893 					anon_array_exit(&cookie);
7894 					ANON_LOCK_EXIT(&amp->a_rwlock);
7895 				}
7896 				if (ret == 0) {
7897 					/* locking page failed */
7898 					page_unlock(pp);
7899 					err = EAGAIN;
7900 					goto out;
7901 				}
7902 				VPP_SETPPLOCK(vpp);
7903 				if (sp != NULL) {
7904 					if (pp->p_lckcnt == 1)
7905 						locked_bytes += PAGESIZE;
7906 				} else
7907 					locked_bytes += PAGESIZE;
7908 
7909 				if (lockmap != (ulong_t *)NULL)
7910 					BT_SET(lockmap, pos);
7911 
7912 				page_unlock(pp);
7913 			} else {
7914 				ASSERT(VPP_ISPPLOCK(vpp));
7915 				if (pp != NULL) {
7916 					/* sysV pages should be locked */
7917 					ASSERT(sp == NULL || pp->p_lckcnt > 0);
7918 					page_pp_unlock(pp, claim, 0);
7919 					if (sp != NULL) {
7920 						if (pp->p_lckcnt == 0)
7921 							unlocked_bytes
7922 							    += PAGESIZE;
7923 					} else
7924 						unlocked_bytes += PAGESIZE;
7925 					page_unlock(pp);
7926 				} else {
7927 					ASSERT(sp == NULL);
7928 					unlocked_bytes += PAGESIZE;
7929 				}
7930 				VPP_CLRPPLOCK(vpp);
7931 			}
7932 		}
7933 	}
7934 out:
7935 	if (op == MC_LOCK) {
7936 		/* Credit back bytes that did not get locked */
7937 		if ((unlocked_bytes - locked_bytes) > 0) {
7938 			if (proj == NULL)
7939 				mutex_enter(&p->p_lock);
7940 			rctl_decr_locked_mem(p, proj,
7941 			    (unlocked_bytes - locked_bytes), chargeproc);
7942 			if (proj == NULL)
7943 				mutex_exit(&p->p_lock);
7944 		}
7945 
7946 	} else {
7947 		/* Account bytes that were unlocked */
7948 		if (unlocked_bytes > 0) {
7949 			if (proj == NULL)
7950 				mutex_enter(&p->p_lock);
7951 			rctl_decr_locked_mem(p, proj, unlocked_bytes,
7952 			    chargeproc);
7953 			if (proj == NULL)
7954 				mutex_exit(&p->p_lock);
7955 		}
7956 	}
7957 	if (sp != NULL)
7958 		mutex_exit(&sp->shm_mlock);
7959 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
7960 
7961 	return (err);
7962 }
7963 
7964 /*
7965  * Set advice from user for specified pages
7966  * There are 5 types of advice:
7967  *	MADV_NORMAL	- Normal (default) behavior (whatever that is)
7968  *	MADV_RANDOM	- Random page references
7969  *				do not allow readahead or 'klustering'
7970  *	MADV_SEQUENTIAL	- Sequential page references
7971  *				Pages previous to the one currently being
7972  *				accessed (determined by fault) are 'not needed'
7973  *				and are freed immediately
7974  *	MADV_WILLNEED	- Pages are likely to be used (fault ahead in mctl)
7975  *	MADV_DONTNEED	- Pages are not needed (synced out in mctl)
7976  *	MADV_FREE	- Contents can be discarded
7977  *	MADV_ACCESS_DEFAULT- Default access
7978  *	MADV_ACCESS_LWP	- Next LWP will access heavily
7979  *	MADV_ACCESS_MANY- Many LWPs or processes will access heavily
7980  */
7981 static int
7982 segvn_advise(struct seg *seg, caddr_t addr, size_t len, uint_t behav)
7983 {
7984 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
7985 	size_t page;
7986 	int err = 0;
7987 	int already_set;
7988 	struct anon_map *amp;
7989 	ulong_t anon_index;
7990 	struct seg *next;
7991 	lgrp_mem_policy_t policy;
7992 	struct seg *prev;
7993 	struct vnode *vp;
7994 
7995 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
7996 
7997 	/*
7998 	 * In case of MADV_FREE, we won't be modifying any segment private
7999 	 * data structures; so, we only need to grab READER's lock
8000 	 */
8001 	if (behav != MADV_FREE) {
8002 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_WRITER);
8003 		if (svd->tr_state != SEGVN_TR_OFF) {
8004 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8005 			return (0);
8006 		}
8007 	} else {
8008 		SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8009 	}
8010 
8011 	/*
8012 	 * Large pages are assumed to be only turned on when accesses to the
8013 	 * segment's address range have spatial and temporal locality. That
8014 	 * justifies ignoring MADV_SEQUENTIAL for large page segments.
8015 	 * Also, ignore advice affecting lgroup memory allocation
8016 	 * if don't need to do lgroup optimizations on this system
8017 	 */
8018 
8019 	if ((behav == MADV_SEQUENTIAL &&
8020 	    (seg->s_szc != 0 || HAT_IS_REGION_COOKIE_VALID(svd->rcookie))) ||
8021 	    (!lgrp_optimizations() && (behav == MADV_ACCESS_DEFAULT ||
8022 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY))) {
8023 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8024 		return (0);
8025 	}
8026 
8027 	if (behav == MADV_SEQUENTIAL || behav == MADV_ACCESS_DEFAULT ||
8028 	    behav == MADV_ACCESS_LWP || behav == MADV_ACCESS_MANY) {
8029 		/*
8030 		 * Since we are going to unload hat mappings
8031 		 * we first have to flush the cache. Otherwise
8032 		 * this might lead to system panic if another
8033 		 * thread is doing physio on the range whose
8034 		 * mappings are unloaded by madvise(3C).
8035 		 */
8036 		if (svd->softlockcnt > 0) {
8037 			/*
8038 			 * If this is shared segment non 0 softlockcnt
8039 			 * means locked pages are still in use.
8040 			 */
8041 			if (svd->type == MAP_SHARED) {
8042 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8043 				return (EAGAIN);
8044 			}
8045 			/*
8046 			 * Since we do have the segvn writers lock
8047 			 * nobody can fill the cache with entries
8048 			 * belonging to this seg during the purge.
8049 			 * The flush either succeeds or we still
8050 			 * have pending I/Os. In the later case,
8051 			 * madvise(3C) fails.
8052 			 */
8053 			segvn_purge(seg);
8054 			if (svd->softlockcnt > 0) {
8055 				/*
8056 				 * Since madvise(3C) is advisory and
8057 				 * it's not part of UNIX98, madvise(3C)
8058 				 * failure here doesn't cause any hardship.
8059 				 * Note that we don't block in "as" layer.
8060 				 */
8061 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8062 				return (EAGAIN);
8063 			}
8064 		} else if (svd->type == MAP_SHARED && svd->amp != NULL &&
8065 		    svd->amp->a_softlockcnt > 0) {
8066 			/*
8067 			 * Try to purge this amp's entries from pcache. It
8068 			 * will succeed only if other segments that share the
8069 			 * amp have no outstanding softlock's.
8070 			 */
8071 			segvn_purge(seg);
8072 		}
8073 	}
8074 
8075 	amp = svd->amp;
8076 	vp = svd->vp;
8077 	if (behav == MADV_FREE) {
8078 		/*
8079 		 * MADV_FREE is not supported for segments with
8080 		 * underlying object; if anonmap is NULL, anon slots
8081 		 * are not yet populated and there is nothing for
8082 		 * us to do. As MADV_FREE is advisory, we don't
8083 		 * return error in either case.
8084 		 */
8085 		if (vp != NULL || amp == NULL) {
8086 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8087 			return (0);
8088 		}
8089 
8090 		segvn_purge(seg);
8091 
8092 		page = seg_page(seg, addr);
8093 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8094 		anon_disclaim(amp, svd->anon_index + page, len);
8095 		ANON_LOCK_EXIT(&amp->a_rwlock);
8096 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8097 		return (0);
8098 	}
8099 
8100 	/*
8101 	 * If advice is to be applied to entire segment,
8102 	 * use advice field in seg_data structure
8103 	 * otherwise use appropriate vpage entry.
8104 	 */
8105 	if ((addr == seg->s_base) && (len == seg->s_size)) {
8106 		switch (behav) {
8107 		case MADV_ACCESS_LWP:
8108 		case MADV_ACCESS_MANY:
8109 		case MADV_ACCESS_DEFAULT:
8110 			/*
8111 			 * Set memory allocation policy for this segment
8112 			 */
8113 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8114 			if (svd->type == MAP_SHARED)
8115 				already_set = lgrp_shm_policy_set(policy, amp,
8116 				    svd->anon_index, vp, svd->offset, len);
8117 			else {
8118 				/*
8119 				 * For private memory, need writers lock on
8120 				 * address space because the segment may be
8121 				 * split or concatenated when changing policy
8122 				 */
8123 				if (AS_READ_HELD(seg->s_as,
8124 				    &seg->s_as->a_lock)) {
8125 					SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8126 					return (IE_RETRY);
8127 				}
8128 
8129 				already_set = lgrp_privm_policy_set(policy,
8130 				    &svd->policy_info, len);
8131 			}
8132 
8133 			/*
8134 			 * If policy set already and it shouldn't be reapplied,
8135 			 * don't do anything.
8136 			 */
8137 			if (already_set &&
8138 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8139 				break;
8140 
8141 			/*
8142 			 * Mark any existing pages in given range for
8143 			 * migration
8144 			 */
8145 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8146 			    vp, svd->offset, 1);
8147 
8148 			/*
8149 			 * If same policy set already or this is a shared
8150 			 * memory segment, don't need to try to concatenate
8151 			 * segment with adjacent ones.
8152 			 */
8153 			if (already_set || svd->type == MAP_SHARED)
8154 				break;
8155 
8156 			/*
8157 			 * Try to concatenate this segment with previous
8158 			 * one and next one, since we changed policy for
8159 			 * this one and it may be compatible with adjacent
8160 			 * ones now.
8161 			 */
8162 			prev = AS_SEGPREV(seg->s_as, seg);
8163 			next = AS_SEGNEXT(seg->s_as, seg);
8164 
8165 			if (next && next->s_ops == &segvn_ops &&
8166 			    addr + len == next->s_base)
8167 				(void) segvn_concat(seg, next, 1);
8168 
8169 			if (prev && prev->s_ops == &segvn_ops &&
8170 			    addr == prev->s_base + prev->s_size) {
8171 				/*
8172 				 * Drop lock for private data of current
8173 				 * segment before concatenating (deleting) it
8174 				 * and return IE_REATTACH to tell as_ctl() that
8175 				 * current segment has changed
8176 				 */
8177 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8178 				if (!segvn_concat(prev, seg, 1))
8179 					err = IE_REATTACH;
8180 
8181 				return (err);
8182 			}
8183 			break;
8184 
8185 		case MADV_SEQUENTIAL:
8186 			/*
8187 			 * unloading mapping guarantees
8188 			 * detection in segvn_fault
8189 			 */
8190 			ASSERT(seg->s_szc == 0);
8191 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8192 			hat_unload(seg->s_as->a_hat, addr, len,
8193 			    HAT_UNLOAD);
8194 			/* FALLTHROUGH */
8195 		case MADV_NORMAL:
8196 		case MADV_RANDOM:
8197 			svd->advice = (uchar_t)behav;
8198 			svd->pageadvice = 0;
8199 			break;
8200 		case MADV_WILLNEED:	/* handled in memcntl */
8201 		case MADV_DONTNEED:	/* handled in memcntl */
8202 		case MADV_FREE:		/* handled above */
8203 			break;
8204 		default:
8205 			err = EINVAL;
8206 		}
8207 	} else {
8208 		caddr_t			eaddr;
8209 		struct seg		*new_seg;
8210 		struct segvn_data	*new_svd;
8211 		u_offset_t		off;
8212 		caddr_t			oldeaddr;
8213 
8214 		page = seg_page(seg, addr);
8215 
8216 		segvn_vpage(seg);
8217 
8218 		switch (behav) {
8219 			struct vpage *bvpp, *evpp;
8220 
8221 		case MADV_ACCESS_LWP:
8222 		case MADV_ACCESS_MANY:
8223 		case MADV_ACCESS_DEFAULT:
8224 			/*
8225 			 * Set memory allocation policy for portion of this
8226 			 * segment
8227 			 */
8228 
8229 			/*
8230 			 * Align address and length of advice to page
8231 			 * boundaries for large pages
8232 			 */
8233 			if (seg->s_szc != 0) {
8234 				size_t	pgsz;
8235 
8236 				pgsz = page_get_pagesize(seg->s_szc);
8237 				addr = (caddr_t)P2ALIGN((uintptr_t)addr, pgsz);
8238 				len = P2ROUNDUP(len, pgsz);
8239 			}
8240 
8241 			/*
8242 			 * Check to see whether policy is set already
8243 			 */
8244 			policy = lgrp_madv_to_policy(behav, len, svd->type);
8245 
8246 			anon_index = svd->anon_index + page;
8247 			off = svd->offset + (uintptr_t)(addr - seg->s_base);
8248 
8249 			if (svd->type == MAP_SHARED)
8250 				already_set = lgrp_shm_policy_set(policy, amp,
8251 				    anon_index, vp, off, len);
8252 			else
8253 				already_set =
8254 				    (policy == svd->policy_info.mem_policy);
8255 
8256 			/*
8257 			 * If policy set already and it shouldn't be reapplied,
8258 			 * don't do anything.
8259 			 */
8260 			if (already_set &&
8261 			    !LGRP_MEM_POLICY_REAPPLICABLE(policy))
8262 				break;
8263 
8264 			/*
8265 			 * For private memory, need writers lock on
8266 			 * address space because the segment may be
8267 			 * split or concatenated when changing policy
8268 			 */
8269 			if (svd->type == MAP_PRIVATE &&
8270 			    AS_READ_HELD(seg->s_as, &seg->s_as->a_lock)) {
8271 				SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8272 				return (IE_RETRY);
8273 			}
8274 
8275 			/*
8276 			 * Mark any existing pages in given range for
8277 			 * migration
8278 			 */
8279 			page_mark_migrate(seg, addr, len, amp, svd->anon_index,
8280 			    vp, svd->offset, 1);
8281 
8282 			/*
8283 			 * Don't need to try to split or concatenate
8284 			 * segments, since policy is same or this is a shared
8285 			 * memory segment
8286 			 */
8287 			if (already_set || svd->type == MAP_SHARED)
8288 				break;
8289 
8290 			if (HAT_IS_REGION_COOKIE_VALID(svd->rcookie)) {
8291 				ASSERT(svd->amp == NULL);
8292 				ASSERT(svd->tr_state == SEGVN_TR_OFF);
8293 				ASSERT(svd->softlockcnt == 0);
8294 				hat_leave_region(seg->s_as->a_hat, svd->rcookie,
8295 				    HAT_REGION_TEXT);
8296 				svd->rcookie = HAT_INVALID_REGION_COOKIE;
8297 			}
8298 
8299 			/*
8300 			 * Split off new segment if advice only applies to a
8301 			 * portion of existing segment starting in middle
8302 			 */
8303 			new_seg = NULL;
8304 			eaddr = addr + len;
8305 			oldeaddr = seg->s_base + seg->s_size;
8306 			if (addr > seg->s_base) {
8307 				/*
8308 				 * Must flush I/O page cache
8309 				 * before splitting segment
8310 				 */
8311 				if (svd->softlockcnt > 0)
8312 					segvn_purge(seg);
8313 
8314 				/*
8315 				 * Split segment and return IE_REATTACH to tell
8316 				 * as_ctl() that current segment changed
8317 				 */
8318 				new_seg = segvn_split_seg(seg, addr);
8319 				new_svd = (struct segvn_data *)new_seg->s_data;
8320 				err = IE_REATTACH;
8321 
8322 				/*
8323 				 * If new segment ends where old one
8324 				 * did, try to concatenate the new
8325 				 * segment with next one.
8326 				 */
8327 				if (eaddr == oldeaddr) {
8328 					/*
8329 					 * Set policy for new segment
8330 					 */
8331 					(void) lgrp_privm_policy_set(policy,
8332 					    &new_svd->policy_info,
8333 					    new_seg->s_size);
8334 
8335 					next = AS_SEGNEXT(new_seg->s_as,
8336 					    new_seg);
8337 
8338 					if (next &&
8339 					    next->s_ops == &segvn_ops &&
8340 					    eaddr == next->s_base)
8341 						(void) segvn_concat(new_seg,
8342 						    next, 1);
8343 				}
8344 			}
8345 
8346 			/*
8347 			 * Split off end of existing segment if advice only
8348 			 * applies to a portion of segment ending before
8349 			 * end of the existing segment
8350 			 */
8351 			if (eaddr < oldeaddr) {
8352 				/*
8353 				 * Must flush I/O page cache
8354 				 * before splitting segment
8355 				 */
8356 				if (svd->softlockcnt > 0)
8357 					segvn_purge(seg);
8358 
8359 				/*
8360 				 * If beginning of old segment was already
8361 				 * split off, use new segment to split end off
8362 				 * from.
8363 				 */
8364 				if (new_seg != NULL && new_seg != seg) {
8365 					/*
8366 					 * Split segment
8367 					 */
8368 					(void) segvn_split_seg(new_seg, eaddr);
8369 
8370 					/*
8371 					 * Set policy for new segment
8372 					 */
8373 					(void) lgrp_privm_policy_set(policy,
8374 					    &new_svd->policy_info,
8375 					    new_seg->s_size);
8376 				} else {
8377 					/*
8378 					 * Split segment and return IE_REATTACH
8379 					 * to tell as_ctl() that current
8380 					 * segment changed
8381 					 */
8382 					(void) segvn_split_seg(seg, eaddr);
8383 					err = IE_REATTACH;
8384 
8385 					(void) lgrp_privm_policy_set(policy,
8386 					    &svd->policy_info, seg->s_size);
8387 
8388 					/*
8389 					 * If new segment starts where old one
8390 					 * did, try to concatenate it with
8391 					 * previous segment.
8392 					 */
8393 					if (addr == seg->s_base) {
8394 						prev = AS_SEGPREV(seg->s_as,
8395 						    seg);
8396 
8397 						/*
8398 						 * Drop lock for private data
8399 						 * of current segment before
8400 						 * concatenating (deleting) it
8401 						 */
8402 						if (prev &&
8403 						    prev->s_ops ==
8404 						    &segvn_ops &&
8405 						    addr == prev->s_base +
8406 						    prev->s_size) {
8407 							SEGVN_LOCK_EXIT(
8408 							    seg->s_as,
8409 							    &svd->lock);
8410 							(void) segvn_concat(
8411 							    prev, seg, 1);
8412 							return (err);
8413 						}
8414 					}
8415 				}
8416 			}
8417 			break;
8418 		case MADV_SEQUENTIAL:
8419 			ASSERT(seg->s_szc == 0);
8420 			ASSERT(svd->rcookie == HAT_INVALID_REGION_COOKIE);
8421 			hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD);
8422 			/* FALLTHROUGH */
8423 		case MADV_NORMAL:
8424 		case MADV_RANDOM:
8425 			bvpp = &svd->vpage[page];
8426 			evpp = &svd->vpage[page + (len >> PAGESHIFT)];
8427 			for (; bvpp < evpp; bvpp++)
8428 				VPP_SETADVICE(bvpp, behav);
8429 			svd->advice = MADV_NORMAL;
8430 			break;
8431 		case MADV_WILLNEED:	/* handled in memcntl */
8432 		case MADV_DONTNEED:	/* handled in memcntl */
8433 		case MADV_FREE:		/* handled above */
8434 			break;
8435 		default:
8436 			err = EINVAL;
8437 		}
8438 	}
8439 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8440 	return (err);
8441 }
8442 
8443 /*
8444  * Create a vpage structure for this seg.
8445  */
8446 static void
8447 segvn_vpage(struct seg *seg)
8448 {
8449 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8450 	struct vpage *vp, *evp;
8451 
8452 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
8453 
8454 	/*
8455 	 * If no vpage structure exists, allocate one.  Copy the protections
8456 	 * and the advice from the segment itself to the individual pages.
8457 	 */
8458 	if (svd->vpage == NULL) {
8459 		svd->pageadvice = 1;
8460 		svd->vpage = kmem_zalloc(seg_pages(seg) * sizeof (struct vpage),
8461 		    KM_SLEEP);
8462 		evp = &svd->vpage[seg_page(seg, seg->s_base + seg->s_size)];
8463 		for (vp = svd->vpage; vp < evp; vp++) {
8464 			VPP_SETPROT(vp, svd->prot);
8465 			VPP_SETADVICE(vp, svd->advice);
8466 		}
8467 	}
8468 }
8469 
8470 /*
8471  * Dump the pages belonging to this segvn segment.
8472  */
8473 static void
8474 segvn_dump(struct seg *seg)
8475 {
8476 	struct segvn_data *svd;
8477 	page_t *pp;
8478 	struct anon_map *amp;
8479 	ulong_t	anon_index;
8480 	struct vnode *vp;
8481 	u_offset_t off, offset;
8482 	pfn_t pfn;
8483 	pgcnt_t page, npages;
8484 	caddr_t addr;
8485 
8486 	npages = seg_pages(seg);
8487 	svd = (struct segvn_data *)seg->s_data;
8488 	vp = svd->vp;
8489 	off = offset = svd->offset;
8490 	addr = seg->s_base;
8491 
8492 	if ((amp = svd->amp) != NULL) {
8493 		anon_index = svd->anon_index;
8494 		ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
8495 	}
8496 
8497 	for (page = 0; page < npages; page++, offset += PAGESIZE) {
8498 		struct anon *ap;
8499 		int we_own_it = 0;
8500 
8501 		if (amp && (ap = anon_get_ptr(svd->amp->ahp, anon_index++))) {
8502 			swap_xlate_nopanic(ap, &vp, &off);
8503 		} else {
8504 			vp = svd->vp;
8505 			off = offset;
8506 		}
8507 
8508 		/*
8509 		 * If pp == NULL, the page either does not exist
8510 		 * or is exclusively locked.  So determine if it
8511 		 * exists before searching for it.
8512 		 */
8513 
8514 		if ((pp = page_lookup_nowait(vp, off, SE_SHARED)))
8515 			we_own_it = 1;
8516 		else
8517 			pp = page_exists(vp, off);
8518 
8519 		if (pp) {
8520 			pfn = page_pptonum(pp);
8521 			dump_addpage(seg->s_as, addr, pfn);
8522 			if (we_own_it)
8523 				page_unlock(pp);
8524 		}
8525 		addr += PAGESIZE;
8526 		dump_timeleft = dump_timeout;
8527 	}
8528 
8529 	if (amp != NULL)
8530 		ANON_LOCK_EXIT(&amp->a_rwlock);
8531 }
8532 
8533 #ifdef DEBUG
8534 static uint32_t segvn_pglock_mtbf = 0;
8535 #endif
8536 
8537 #define	PCACHE_SHWLIST		((page_t *)-2)
8538 #define	NOPCACHE_SHWLIST	((page_t *)-1)
8539 
8540 /*
8541  * Lock/Unlock anon pages over a given range. Return shadow list. This routine
8542  * uses global segment pcache to cache shadow lists (i.e. pp arrays) of pages
8543  * to avoid the overhead of per page locking, unlocking for subsequent IOs to
8544  * the same parts of the segment. Currently shadow list creation is only
8545  * supported for pure anon segments. MAP_PRIVATE segment pcache entries are
8546  * tagged with segment pointer, starting virtual address and length. This
8547  * approach for MAP_SHARED segments may add many pcache entries for the same
8548  * set of pages and lead to long hash chains that decrease pcache lookup
8549  * performance. To avoid this issue for shared segments shared anon map and
8550  * starting anon index are used for pcache entry tagging. This allows all
8551  * segments to share pcache entries for the same anon range and reduces pcache
8552  * chain's length as well as memory overhead from duplicate shadow lists and
8553  * pcache entries.
8554  *
8555  * softlockcnt field in segvn_data structure counts the number of F_SOFTLOCK'd
8556  * pages via segvn_fault() and pagelock'd pages via this routine. But pagelock
8557  * part of softlockcnt accounting is done differently for private and shared
8558  * segments. In private segment case softlock is only incremented when a new
8559  * shadow list is created but not when an existing one is found via
8560  * seg_plookup(). pcache entries have reference count incremented/decremented
8561  * by each seg_plookup()/seg_pinactive() operation. Only entries that have 0
8562  * reference count can be purged (and purging is needed before segment can be
8563  * freed). When a private segment pcache entry is purged segvn_reclaim() will
8564  * decrement softlockcnt. Since in private segment case each of its pcache
8565  * entries only belongs to this segment we can expect that when
8566  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8567  * segment purge will succeed and softlockcnt will drop to 0. In shared
8568  * segment case reference count in pcache entry counts active locks from many
8569  * different segments so we can't expect segment purging to succeed even when
8570  * segvn_pagelock(L_PAGEUNLOCK) was called for all outstanding IOs in this
8571  * segment. To be able to determine when there're no pending pagelocks in
8572  * shared segment case we don't rely on purging to make softlockcnt drop to 0
8573  * but instead softlockcnt is incremented and decremented for every
8574  * segvn_pagelock(L_PAGELOCK/L_PAGEUNLOCK) call regardless if a new shadow
8575  * list was created or an existing one was found. When softlockcnt drops to 0
8576  * this segment no longer has any claims for pcached shadow lists and the
8577  * segment can be freed even if there're still active pcache entries
8578  * shared by this segment anon map. Shared segment pcache entries belong to
8579  * anon map and are typically removed when anon map is freed after all
8580  * processes destroy the segments that use this anon map.
8581  */
8582 static int
8583 segvn_pagelock(struct seg *seg, caddr_t addr, size_t len, struct page ***ppp,
8584     enum lock_type type, enum seg_rw rw)
8585 {
8586 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
8587 	size_t np;
8588 	pgcnt_t adjustpages;
8589 	pgcnt_t npages;
8590 	ulong_t anon_index;
8591 	uint_t protchk = (rw == S_READ) ? PROT_READ : PROT_WRITE;
8592 	uint_t error;
8593 	struct anon_map *amp;
8594 	pgcnt_t anpgcnt;
8595 	struct page **pplist, **pl, *pp;
8596 	caddr_t a;
8597 	size_t page;
8598 	caddr_t lpgaddr, lpgeaddr;
8599 	anon_sync_obj_t cookie;
8600 	int anlock;
8601 	struct anon_map *pamp;
8602 	caddr_t paddr;
8603 	seg_preclaim_cbfunc_t preclaim_callback;
8604 	size_t pgsz;
8605 	int use_pcache;
8606 	size_t wlen;
8607 	uint_t pflags = 0;
8608 	int sftlck_sbase = 0;
8609 	int sftlck_send = 0;
8610 
8611 #ifdef DEBUG
8612 	if (type == L_PAGELOCK && segvn_pglock_mtbf) {
8613 		hrtime_t ts = gethrtime();
8614 		if ((ts % segvn_pglock_mtbf) == 0) {
8615 			return (ENOTSUP);
8616 		}
8617 		if ((ts % segvn_pglock_mtbf) == 1) {
8618 			return (EFAULT);
8619 		}
8620 	}
8621 #endif
8622 
8623 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_START,
8624 	    "segvn_pagelock: start seg %p addr %p", seg, addr);
8625 
8626 	ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
8627 	ASSERT(type == L_PAGELOCK || type == L_PAGEUNLOCK);
8628 
8629 	SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
8630 
8631 	/*
8632 	 * for now we only support pagelock to anon memory. We would have to
8633 	 * check protections for vnode objects and call into the vnode driver.
8634 	 * That's too much for a fast path. Let the fault entry point handle
8635 	 * it.
8636 	 */
8637 	if (svd->vp != NULL) {
8638 		if (type == L_PAGELOCK) {
8639 			error = ENOTSUP;
8640 			goto out;
8641 		}
8642 		panic("segvn_pagelock(L_PAGEUNLOCK): vp != NULL");
8643 	}
8644 	if ((amp = svd->amp) == NULL) {
8645 		if (type == L_PAGELOCK) {
8646 			error = EFAULT;
8647 			goto out;
8648 		}
8649 		panic("segvn_pagelock(L_PAGEUNLOCK): amp == NULL");
8650 	}
8651 	if (rw != S_READ && rw != S_WRITE) {
8652 		if (type == L_PAGELOCK) {
8653 			error = ENOTSUP;
8654 			goto out;
8655 		}
8656 		panic("segvn_pagelock(L_PAGEUNLOCK): bad rw");
8657 	}
8658 
8659 	if (seg->s_szc != 0) {
8660 		/*
8661 		 * We are adjusting the pagelock region to the large page size
8662 		 * boundary because the unlocked part of a large page cannot
8663 		 * be freed anyway unless all constituent pages of a large
8664 		 * page are locked. Bigger regions reduce pcache chain length
8665 		 * and improve lookup performance. The tradeoff is that the
8666 		 * very first segvn_pagelock() call for a given page is more
8667 		 * expensive if only 1 page_t is needed for IO. This is only
8668 		 * an issue if pcache entry doesn't get reused by several
8669 		 * subsequent calls. We optimize here for the case when pcache
8670 		 * is heavily used by repeated IOs to the same address range.
8671 		 *
8672 		 * Note segment's page size cannot change while we are holding
8673 		 * as lock.  And then it cannot change while softlockcnt is
8674 		 * not 0. This will allow us to correctly recalculate large
8675 		 * page size region for the matching pageunlock/reclaim call
8676 		 * since as_pageunlock() caller must always match
8677 		 * as_pagelock() call's addr and len.
8678 		 *
8679 		 * For pageunlock *ppp points to the pointer of page_t that
8680 		 * corresponds to the real unadjusted start address. Similar
8681 		 * for pagelock *ppp must point to the pointer of page_t that
8682 		 * corresponds to the real unadjusted start address.
8683 		 */
8684 		pgsz = page_get_pagesize(seg->s_szc);
8685 		CALC_LPG_REGION(pgsz, seg, addr, len, lpgaddr, lpgeaddr);
8686 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8687 	} else if (len < segvn_pglock_comb_thrshld) {
8688 		lpgaddr = addr;
8689 		lpgeaddr = addr + len;
8690 		adjustpages = 0;
8691 		pgsz = PAGESIZE;
8692 	} else {
8693 		/*
8694 		 * Align the address range of large enough requests to allow
8695 		 * combining of different shadow lists into 1 to reduce memory
8696 		 * overhead from potentially overlapping large shadow lists
8697 		 * (worst case is we have a 1MB IO into buffers with start
8698 		 * addresses separated by 4K).  Alignment is only possible if
8699 		 * padded chunks have sufficient access permissions. Note
8700 		 * permissions won't change between L_PAGELOCK and
8701 		 * L_PAGEUNLOCK calls since non 0 softlockcnt will force
8702 		 * segvn_setprot() to wait until softlockcnt drops to 0. This
8703 		 * allows us to determine in L_PAGEUNLOCK the same range we
8704 		 * computed in L_PAGELOCK.
8705 		 *
8706 		 * If alignment is limited by segment ends set
8707 		 * sftlck_sbase/sftlck_send flags. In L_PAGELOCK case when
8708 		 * these flags are set bump softlockcnt_sbase/softlockcnt_send
8709 		 * per segment counters. In L_PAGEUNLOCK case decrease
8710 		 * softlockcnt_sbase/softlockcnt_send counters if
8711 		 * sftlck_sbase/sftlck_send flags are set.  When
8712 		 * softlockcnt_sbase/softlockcnt_send are non 0
8713 		 * segvn_concat()/segvn_extend_prev()/segvn_extend_next()
8714 		 * won't merge the segments. This restriction combined with
8715 		 * restriction on segment unmapping and splitting for segments
8716 		 * that have non 0 softlockcnt allows L_PAGEUNLOCK to
8717 		 * correctly determine the same range that was previously
8718 		 * locked by matching L_PAGELOCK.
8719 		 */
8720 		pflags = SEGP_PSHIFT | (segvn_pglock_comb_bshift << 16);
8721 		pgsz = PAGESIZE;
8722 		if (svd->type == MAP_PRIVATE) {
8723 			lpgaddr = (caddr_t)P2ALIGN((uintptr_t)addr,
8724 			    segvn_pglock_comb_balign);
8725 			if (lpgaddr < seg->s_base) {
8726 				lpgaddr = seg->s_base;
8727 				sftlck_sbase = 1;
8728 			}
8729 		} else {
8730 			ulong_t aix = svd->anon_index + seg_page(seg, addr);
8731 			ulong_t aaix = P2ALIGN(aix, segvn_pglock_comb_palign);
8732 			if (aaix < svd->anon_index) {
8733 				lpgaddr = seg->s_base;
8734 				sftlck_sbase = 1;
8735 			} else {
8736 				lpgaddr = addr - ptob(aix - aaix);
8737 				ASSERT(lpgaddr >= seg->s_base);
8738 			}
8739 		}
8740 		if (svd->pageprot && lpgaddr != addr) {
8741 			struct vpage *vp = &svd->vpage[seg_page(seg, lpgaddr)];
8742 			struct vpage *evp = &svd->vpage[seg_page(seg, addr)];
8743 			while (vp < evp) {
8744 				if ((VPP_PROT(vp) & protchk) == 0) {
8745 					break;
8746 				}
8747 				vp++;
8748 			}
8749 			if (vp < evp) {
8750 				lpgaddr = addr;
8751 				pflags = 0;
8752 			}
8753 		}
8754 		lpgeaddr = addr + len;
8755 		if (pflags) {
8756 			if (svd->type == MAP_PRIVATE) {
8757 				lpgeaddr = (caddr_t)P2ROUNDUP(
8758 				    (uintptr_t)lpgeaddr,
8759 				    segvn_pglock_comb_balign);
8760 			} else {
8761 				ulong_t aix = svd->anon_index +
8762 				    seg_page(seg, lpgeaddr);
8763 				ulong_t aaix = P2ROUNDUP(aix,
8764 				    segvn_pglock_comb_palign);
8765 				if (aaix < aix) {
8766 					lpgeaddr = 0;
8767 				} else {
8768 					lpgeaddr += ptob(aaix - aix);
8769 				}
8770 			}
8771 			if (lpgeaddr == 0 ||
8772 			    lpgeaddr > seg->s_base + seg->s_size) {
8773 				lpgeaddr = seg->s_base + seg->s_size;
8774 				sftlck_send = 1;
8775 			}
8776 		}
8777 		if (svd->pageprot && lpgeaddr != addr + len) {
8778 			struct vpage *vp;
8779 			struct vpage *evp;
8780 
8781 			vp = &svd->vpage[seg_page(seg, addr + len)];
8782 			evp = &svd->vpage[seg_page(seg, lpgeaddr)];
8783 
8784 			while (vp < evp) {
8785 				if ((VPP_PROT(vp) & protchk) == 0) {
8786 					break;
8787 				}
8788 				vp++;
8789 			}
8790 			if (vp < evp) {
8791 				lpgeaddr = addr + len;
8792 			}
8793 		}
8794 		adjustpages = btop((uintptr_t)(addr - lpgaddr));
8795 	}
8796 
8797 	/*
8798 	 * For MAP_SHARED segments we create pcache entries tagged by amp and
8799 	 * anon index so that we can share pcache entries with other segments
8800 	 * that map this amp.  For private segments pcache entries are tagged
8801 	 * with segment and virtual address.
8802 	 */
8803 	if (svd->type == MAP_SHARED) {
8804 		pamp = amp;
8805 		paddr = (caddr_t)((lpgaddr - seg->s_base) +
8806 		    ptob(svd->anon_index));
8807 		preclaim_callback = shamp_reclaim;
8808 	} else {
8809 		pamp = NULL;
8810 		paddr = lpgaddr;
8811 		preclaim_callback = segvn_reclaim;
8812 	}
8813 
8814 	if (type == L_PAGEUNLOCK) {
8815 		VM_STAT_ADD(segvnvmstats.pagelock[0]);
8816 
8817 		/*
8818 		 * update hat ref bits for /proc. We need to make sure
8819 		 * that threads tracing the ref and mod bits of the
8820 		 * address space get the right data.
8821 		 * Note: page ref and mod bits are updated at reclaim time
8822 		 */
8823 		if (seg->s_as->a_vbits) {
8824 			for (a = addr; a < addr + len; a += PAGESIZE) {
8825 				if (rw == S_WRITE) {
8826 					hat_setstat(seg->s_as, a,
8827 					    PAGESIZE, P_REF | P_MOD);
8828 				} else {
8829 					hat_setstat(seg->s_as, a,
8830 					    PAGESIZE, P_REF);
8831 				}
8832 			}
8833 		}
8834 
8835 		/*
8836 		 * Check the shadow list entry after the last page used in
8837 		 * this IO request. If it's NOPCACHE_SHWLIST the shadow list
8838 		 * was not inserted into pcache and is not large page
8839 		 * adjusted.  In this case call reclaim callback directly and
8840 		 * don't adjust the shadow list start and size for large
8841 		 * pages.
8842 		 */
8843 		npages = btop(len);
8844 		if ((*ppp)[npages] == NOPCACHE_SHWLIST) {
8845 			void *ptag;
8846 			if (pamp != NULL) {
8847 				ASSERT(svd->type == MAP_SHARED);
8848 				ptag = (void *)pamp;
8849 				paddr = (caddr_t)((addr - seg->s_base) +
8850 				    ptob(svd->anon_index));
8851 			} else {
8852 				ptag = (void *)seg;
8853 				paddr = addr;
8854 			}
8855 			(*preclaim_callback)(ptag, paddr, len, *ppp, rw, 0);
8856 		} else {
8857 			ASSERT((*ppp)[npages] == PCACHE_SHWLIST ||
8858 			    IS_SWAPFSVP((*ppp)[npages]->p_vnode));
8859 			len = lpgeaddr - lpgaddr;
8860 			npages = btop(len);
8861 			seg_pinactive(seg, pamp, paddr, len,
8862 			    *ppp - adjustpages, rw, pflags, preclaim_callback);
8863 		}
8864 
8865 		if (pamp != NULL) {
8866 			ASSERT(svd->type == MAP_SHARED);
8867 			ASSERT(svd->softlockcnt >= npages);
8868 			atomic_add_long((ulong_t *)&svd->softlockcnt, -npages);
8869 		}
8870 
8871 		if (sftlck_sbase) {
8872 			ASSERT(svd->softlockcnt_sbase > 0);
8873 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, -1);
8874 		}
8875 		if (sftlck_send) {
8876 			ASSERT(svd->softlockcnt_send > 0);
8877 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, -1);
8878 		}
8879 
8880 		/*
8881 		 * If someone is blocked while unmapping, we purge
8882 		 * segment page cache and thus reclaim pplist synchronously
8883 		 * without waiting for seg_pasync_thread. This speeds up
8884 		 * unmapping in cases where munmap(2) is called, while
8885 		 * raw async i/o is still in progress or where a thread
8886 		 * exits on data fault in a multithreaded application.
8887 		 */
8888 		if (AS_ISUNMAPWAIT(seg->s_as)) {
8889 			if (svd->softlockcnt == 0) {
8890 				mutex_enter(&seg->s_as->a_contents);
8891 				if (AS_ISUNMAPWAIT(seg->s_as)) {
8892 					AS_CLRUNMAPWAIT(seg->s_as);
8893 					cv_broadcast(&seg->s_as->a_cv);
8894 				}
8895 				mutex_exit(&seg->s_as->a_contents);
8896 			} else if (pamp == NULL) {
8897 				/*
8898 				 * softlockcnt is not 0 and this is a
8899 				 * MAP_PRIVATE segment. Try to purge its
8900 				 * pcache entries to reduce softlockcnt.
8901 				 * If it drops to 0 segvn_reclaim()
8902 				 * will wake up a thread waiting on
8903 				 * unmapwait flag.
8904 				 *
8905 				 * We don't purge MAP_SHARED segments with non
8906 				 * 0 softlockcnt since IO is still in progress
8907 				 * for such segments.
8908 				 */
8909 				ASSERT(svd->type == MAP_PRIVATE);
8910 				segvn_purge(seg);
8911 			}
8912 		}
8913 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8914 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_UNLOCK_END,
8915 		    "segvn_pagelock: unlock seg %p addr %p", seg, addr);
8916 		return (0);
8917 	}
8918 
8919 	/* The L_PAGELOCK case ... */
8920 
8921 	VM_STAT_ADD(segvnvmstats.pagelock[1]);
8922 
8923 	/*
8924 	 * For MAP_SHARED segments we have to check protections before
8925 	 * seg_plookup() since pcache entries may be shared by many segments
8926 	 * with potentially different page protections.
8927 	 */
8928 	if (pamp != NULL) {
8929 		ASSERT(svd->type == MAP_SHARED);
8930 		if (svd->pageprot == 0) {
8931 			if ((svd->prot & protchk) == 0) {
8932 				error = EACCES;
8933 				goto out;
8934 			}
8935 		} else {
8936 			/*
8937 			 * check page protections
8938 			 */
8939 			caddr_t ea;
8940 
8941 			if (seg->s_szc) {
8942 				a = lpgaddr;
8943 				ea = lpgeaddr;
8944 			} else {
8945 				a = addr;
8946 				ea = addr + len;
8947 			}
8948 			for (; a < ea; a += pgsz) {
8949 				struct vpage *vp;
8950 
8951 				ASSERT(seg->s_szc == 0 ||
8952 				    sameprot(seg, a, pgsz));
8953 				vp = &svd->vpage[seg_page(seg, a)];
8954 				if ((VPP_PROT(vp) & protchk) == 0) {
8955 					error = EACCES;
8956 					goto out;
8957 				}
8958 			}
8959 		}
8960 	}
8961 
8962 	/*
8963 	 * try to find pages in segment page cache
8964 	 */
8965 	pplist = seg_plookup(seg, pamp, paddr, lpgeaddr - lpgaddr, rw, pflags);
8966 	if (pplist != NULL) {
8967 		if (pamp != NULL) {
8968 			npages = btop((uintptr_t)(lpgeaddr - lpgaddr));
8969 			ASSERT(svd->type == MAP_SHARED);
8970 			atomic_add_long((ulong_t *)&svd->softlockcnt,
8971 			    npages);
8972 		}
8973 		if (sftlck_sbase) {
8974 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
8975 		}
8976 		if (sftlck_send) {
8977 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
8978 		}
8979 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
8980 		*ppp = pplist + adjustpages;
8981 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_HIT_END,
8982 		    "segvn_pagelock: cache hit seg %p addr %p", seg, addr);
8983 		return (0);
8984 	}
8985 
8986 	/*
8987 	 * For MAP_SHARED segments we already verified above that segment
8988 	 * protections allow this pagelock operation.
8989 	 */
8990 	if (pamp == NULL) {
8991 		ASSERT(svd->type == MAP_PRIVATE);
8992 		if (svd->pageprot == 0) {
8993 			if ((svd->prot & protchk) == 0) {
8994 				error = EACCES;
8995 				goto out;
8996 			}
8997 			if (svd->prot & PROT_WRITE) {
8998 				wlen = lpgeaddr - lpgaddr;
8999 			} else {
9000 				wlen = 0;
9001 				ASSERT(rw == S_READ);
9002 			}
9003 		} else {
9004 			int wcont = 1;
9005 			/*
9006 			 * check page protections
9007 			 */
9008 			for (a = lpgaddr, wlen = 0; a < lpgeaddr; a += pgsz) {
9009 				struct vpage *vp;
9010 
9011 				ASSERT(seg->s_szc == 0 ||
9012 				    sameprot(seg, a, pgsz));
9013 				vp = &svd->vpage[seg_page(seg, a)];
9014 				if ((VPP_PROT(vp) & protchk) == 0) {
9015 					error = EACCES;
9016 					goto out;
9017 				}
9018 				if (wcont && (VPP_PROT(vp) & PROT_WRITE)) {
9019 					wlen += pgsz;
9020 				} else {
9021 					wcont = 0;
9022 					ASSERT(rw == S_READ);
9023 				}
9024 			}
9025 		}
9026 		ASSERT(rw == S_READ || wlen == lpgeaddr - lpgaddr);
9027 		ASSERT(rw == S_WRITE || wlen <= lpgeaddr - lpgaddr);
9028 	}
9029 
9030 	/*
9031 	 * Only build large page adjusted shadow list if we expect to insert
9032 	 * it into pcache. For large enough pages it's a big overhead to
9033 	 * create a shadow list of the entire large page. But this overhead
9034 	 * should be amortized over repeated pcache hits on subsequent reuse
9035 	 * of this shadow list (IO into any range within this shadow list will
9036 	 * find it in pcache since we large page align the request for pcache
9037 	 * lookups). pcache performance is improved with bigger shadow lists
9038 	 * as it reduces the time to pcache the entire big segment and reduces
9039 	 * pcache chain length.
9040 	 */
9041 	if (seg_pinsert_check(seg, pamp, paddr,
9042 	    lpgeaddr - lpgaddr, pflags) == SEGP_SUCCESS) {
9043 		addr = lpgaddr;
9044 		len = lpgeaddr - lpgaddr;
9045 		use_pcache = 1;
9046 	} else {
9047 		use_pcache = 0;
9048 		/*
9049 		 * Since this entry will not be inserted into the pcache, we
9050 		 * will not do any adjustments to the starting address or
9051 		 * size of the memory to be locked.
9052 		 */
9053 		adjustpages = 0;
9054 	}
9055 	npages = btop(len);
9056 
9057 	pplist = kmem_alloc(sizeof (page_t *) * (npages + 1), KM_SLEEP);
9058 	pl = pplist;
9059 	*ppp = pplist + adjustpages;
9060 	/*
9061 	 * If use_pcache is 0 this shadow list is not large page adjusted.
9062 	 * Record this info in the last entry of shadow array so that
9063 	 * L_PAGEUNLOCK can determine if it should large page adjust the
9064 	 * address range to find the real range that was locked.
9065 	 */
9066 	pl[npages] = use_pcache ? PCACHE_SHWLIST : NOPCACHE_SHWLIST;
9067 
9068 	page = seg_page(seg, addr);
9069 	anon_index = svd->anon_index + page;
9070 
9071 	anlock = 0;
9072 	ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9073 	ASSERT(amp->a_szc >= seg->s_szc);
9074 	anpgcnt = page_get_pagecnt(amp->a_szc);
9075 	for (a = addr; a < addr + len; a += PAGESIZE, anon_index++) {
9076 		struct anon *ap;
9077 		struct vnode *vp;
9078 		u_offset_t off;
9079 
9080 		/*
9081 		 * Lock and unlock anon array only once per large page.
9082 		 * anon_array_enter() locks the root anon slot according to
9083 		 * a_szc which can't change while anon map is locked.  We lock
9084 		 * anon the first time through this loop and each time we
9085 		 * reach anon index that corresponds to a root of a large
9086 		 * page.
9087 		 */
9088 		if (a == addr || P2PHASE(anon_index, anpgcnt) == 0) {
9089 			ASSERT(anlock == 0);
9090 			anon_array_enter(amp, anon_index, &cookie);
9091 			anlock = 1;
9092 		}
9093 		ap = anon_get_ptr(amp->ahp, anon_index);
9094 
9095 		/*
9096 		 * We must never use seg_pcache for COW pages
9097 		 * because we might end up with original page still
9098 		 * lying in seg_pcache even after private page is
9099 		 * created. This leads to data corruption as
9100 		 * aio_write refers to the page still in cache
9101 		 * while all other accesses refer to the private
9102 		 * page.
9103 		 */
9104 		if (ap == NULL || ap->an_refcnt != 1) {
9105 			struct vpage *vpage;
9106 
9107 			if (seg->s_szc) {
9108 				error = EFAULT;
9109 				break;
9110 			}
9111 			if (svd->vpage != NULL) {
9112 				vpage = &svd->vpage[seg_page(seg, a)];
9113 			} else {
9114 				vpage = NULL;
9115 			}
9116 			ASSERT(anlock);
9117 			anon_array_exit(&cookie);
9118 			anlock = 0;
9119 			pp = NULL;
9120 			error = segvn_faultpage(seg->s_as->a_hat, seg, a, 0,
9121 			    vpage, &pp, 0, F_INVAL, rw, 1);
9122 			if (error) {
9123 				error = fc_decode(error);
9124 				break;
9125 			}
9126 			anon_array_enter(amp, anon_index, &cookie);
9127 			anlock = 1;
9128 			ap = anon_get_ptr(amp->ahp, anon_index);
9129 			if (ap == NULL || ap->an_refcnt != 1) {
9130 				error = EFAULT;
9131 				break;
9132 			}
9133 		}
9134 		swap_xlate(ap, &vp, &off);
9135 		pp = page_lookup_nowait(vp, off, SE_SHARED);
9136 		if (pp == NULL) {
9137 			error = EFAULT;
9138 			break;
9139 		}
9140 		if (ap->an_pvp != NULL) {
9141 			anon_swap_free(ap, pp);
9142 		}
9143 		/*
9144 		 * Unlock anon if this is the last slot in a large page.
9145 		 */
9146 		if (P2PHASE(anon_index, anpgcnt) == anpgcnt - 1) {
9147 			ASSERT(anlock);
9148 			anon_array_exit(&cookie);
9149 			anlock = 0;
9150 		}
9151 		*pplist++ = pp;
9152 	}
9153 	if (anlock) {		/* Ensure the lock is dropped */
9154 		anon_array_exit(&cookie);
9155 	}
9156 	ANON_LOCK_EXIT(&amp->a_rwlock);
9157 
9158 	if (a >= addr + len) {
9159 		atomic_add_long((ulong_t *)&svd->softlockcnt, npages);
9160 		if (pamp != NULL) {
9161 			ASSERT(svd->type == MAP_SHARED);
9162 			atomic_add_long((ulong_t *)&pamp->a_softlockcnt,
9163 			    npages);
9164 			wlen = len;
9165 		}
9166 		if (sftlck_sbase) {
9167 			atomic_add_long((ulong_t *)&svd->softlockcnt_sbase, 1);
9168 		}
9169 		if (sftlck_send) {
9170 			atomic_add_long((ulong_t *)&svd->softlockcnt_send, 1);
9171 		}
9172 		if (use_pcache) {
9173 			(void) seg_pinsert(seg, pamp, paddr, len, wlen, pl,
9174 			    rw, pflags, preclaim_callback);
9175 		}
9176 		SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9177 		TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_FILL_END,
9178 		    "segvn_pagelock: cache fill seg %p addr %p", seg, addr);
9179 		return (0);
9180 	}
9181 
9182 	pplist = pl;
9183 	np = ((uintptr_t)(a - addr)) >> PAGESHIFT;
9184 	while (np > (uint_t)0) {
9185 		ASSERT(PAGE_LOCKED(*pplist));
9186 		page_unlock(*pplist);
9187 		np--;
9188 		pplist++;
9189 	}
9190 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9191 out:
9192 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9193 	*ppp = NULL;
9194 	TRACE_2(TR_FAC_PHYSIO, TR_PHYSIO_SEGVN_MISS_END,
9195 	    "segvn_pagelock: cache miss seg %p addr %p", seg, addr);
9196 	return (error);
9197 }
9198 
9199 /*
9200  * purge any cached pages in the I/O page cache
9201  */
9202 static void
9203 segvn_purge(struct seg *seg)
9204 {
9205 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9206 
9207 	/*
9208 	 * pcache is only used by pure anon segments.
9209 	 */
9210 	if (svd->amp == NULL || svd->vp != NULL) {
9211 		return;
9212 	}
9213 
9214 	/*
9215 	 * For MAP_SHARED segments non 0 segment's softlockcnt means
9216 	 * active IO is still in progress via this segment. So we only
9217 	 * purge MAP_SHARED segments when their softlockcnt is 0.
9218 	 */
9219 	if (svd->type == MAP_PRIVATE) {
9220 		if (svd->softlockcnt) {
9221 			seg_ppurge(seg, NULL, 0);
9222 		}
9223 	} else if (svd->softlockcnt == 0 && svd->amp->a_softlockcnt != 0) {
9224 		seg_ppurge(seg, svd->amp, 0);
9225 	}
9226 }
9227 
9228 /*
9229  * If async argument is not 0 we are called from pcache async thread and don't
9230  * hold AS lock.
9231  */
9232 
9233 /*ARGSUSED*/
9234 static int
9235 segvn_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9236 	enum seg_rw rw, int async)
9237 {
9238 	struct seg *seg = (struct seg *)ptag;
9239 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9240 	pgcnt_t np, npages;
9241 	struct page **pl;
9242 
9243 	npages = np = btop(len);
9244 	ASSERT(npages);
9245 
9246 	ASSERT(svd->vp == NULL && svd->amp != NULL);
9247 	ASSERT(svd->softlockcnt >= npages);
9248 	ASSERT(async || AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9249 
9250 	pl = pplist;
9251 
9252 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9253 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9254 
9255 	while (np > (uint_t)0) {
9256 		if (rw == S_WRITE) {
9257 			hat_setrefmod(*pplist);
9258 		} else {
9259 			hat_setref(*pplist);
9260 		}
9261 		page_unlock(*pplist);
9262 		np--;
9263 		pplist++;
9264 	}
9265 
9266 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9267 
9268 	/*
9269 	 * If we are pcache async thread we don't hold AS lock. This means if
9270 	 * softlockcnt drops to 0 after the decrement below address space may
9271 	 * get freed. We can't allow it since after softlock derement to 0 we
9272 	 * still need to access as structure for possible wakeup of unmap
9273 	 * waiters. To prevent the disappearance of as we take this segment
9274 	 * segfree_syncmtx. segvn_free() also takes this mutex as a barrier to
9275 	 * make sure this routine completes before segment is freed.
9276 	 *
9277 	 * The second complication we have to deal with in async case is a
9278 	 * possibility of missed wake up of unmap wait thread. When we don't
9279 	 * hold as lock here we may take a_contents lock before unmap wait
9280 	 * thread that was first to see softlockcnt was still not 0. As a
9281 	 * result we'll fail to wake up an unmap wait thread. To avoid this
9282 	 * race we set nounmapwait flag in as structure if we drop softlockcnt
9283 	 * to 0 when we were called by pcache async thread.  unmapwait thread
9284 	 * will not block if this flag is set.
9285 	 */
9286 	if (async) {
9287 		mutex_enter(&svd->segfree_syncmtx);
9288 	}
9289 
9290 	if (!atomic_add_long_nv((ulong_t *)&svd->softlockcnt, -npages)) {
9291 		if (async || AS_ISUNMAPWAIT(seg->s_as)) {
9292 			mutex_enter(&seg->s_as->a_contents);
9293 			if (async) {
9294 				AS_SETNOUNMAPWAIT(seg->s_as);
9295 			}
9296 			if (AS_ISUNMAPWAIT(seg->s_as)) {
9297 				AS_CLRUNMAPWAIT(seg->s_as);
9298 				cv_broadcast(&seg->s_as->a_cv);
9299 			}
9300 			mutex_exit(&seg->s_as->a_contents);
9301 		}
9302 	}
9303 
9304 	if (async) {
9305 		mutex_exit(&svd->segfree_syncmtx);
9306 	}
9307 	return (0);
9308 }
9309 
9310 /*ARGSUSED*/
9311 static int
9312 shamp_reclaim(void *ptag, caddr_t addr, size_t len, struct page **pplist,
9313 	enum seg_rw rw, int async)
9314 {
9315 	amp_t *amp = (amp_t *)ptag;
9316 	pgcnt_t np, npages;
9317 	struct page **pl;
9318 
9319 	npages = np = btop(len);
9320 	ASSERT(npages);
9321 	ASSERT(amp->a_softlockcnt >= npages);
9322 
9323 	pl = pplist;
9324 
9325 	ASSERT(pl[np] == NOPCACHE_SHWLIST || pl[np] == PCACHE_SHWLIST);
9326 	ASSERT(!async || pl[np] == PCACHE_SHWLIST);
9327 
9328 	while (np > (uint_t)0) {
9329 		if (rw == S_WRITE) {
9330 			hat_setrefmod(*pplist);
9331 		} else {
9332 			hat_setref(*pplist);
9333 		}
9334 		page_unlock(*pplist);
9335 		np--;
9336 		pplist++;
9337 	}
9338 
9339 	kmem_free(pl, sizeof (page_t *) * (npages + 1));
9340 
9341 	/*
9342 	 * If somebody sleeps in anonmap_purge() wake them up if a_softlockcnt
9343 	 * drops to 0. anon map can't be freed until a_softlockcnt drops to 0
9344 	 * and anonmap_purge() acquires a_purgemtx.
9345 	 */
9346 	mutex_enter(&amp->a_purgemtx);
9347 	if (!atomic_add_long_nv((ulong_t *)&amp->a_softlockcnt, -npages) &&
9348 	    amp->a_purgewait) {
9349 		amp->a_purgewait = 0;
9350 		cv_broadcast(&amp->a_purgecv);
9351 	}
9352 	mutex_exit(&amp->a_purgemtx);
9353 	return (0);
9354 }
9355 
9356 /*
9357  * get a memory ID for an addr in a given segment
9358  *
9359  * XXX only creates PAGESIZE pages if anon slots are not initialized.
9360  * At fault time they will be relocated into larger pages.
9361  */
9362 static int
9363 segvn_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp)
9364 {
9365 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9366 	struct anon 	*ap = NULL;
9367 	ulong_t		anon_index;
9368 	struct anon_map	*amp;
9369 	anon_sync_obj_t cookie;
9370 
9371 	if (svd->type == MAP_PRIVATE) {
9372 		memidp->val[0] = (uintptr_t)seg->s_as;
9373 		memidp->val[1] = (uintptr_t)addr;
9374 		return (0);
9375 	}
9376 
9377 	if (svd->type == MAP_SHARED) {
9378 		if (svd->vp) {
9379 			memidp->val[0] = (uintptr_t)svd->vp;
9380 			memidp->val[1] = (u_longlong_t)svd->offset +
9381 			    (uintptr_t)(addr - seg->s_base);
9382 			return (0);
9383 		} else {
9384 
9385 			SEGVN_LOCK_ENTER(seg->s_as, &svd->lock, RW_READER);
9386 			if ((amp = svd->amp) != NULL) {
9387 				anon_index = svd->anon_index +
9388 				    seg_page(seg, addr);
9389 			}
9390 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
9391 
9392 			ASSERT(amp != NULL);
9393 
9394 			ANON_LOCK_ENTER(&amp->a_rwlock, RW_READER);
9395 			anon_array_enter(amp, anon_index, &cookie);
9396 			ap = anon_get_ptr(amp->ahp, anon_index);
9397 			if (ap == NULL) {
9398 				page_t		*pp;
9399 
9400 				pp = anon_zero(seg, addr, &ap, svd->cred);
9401 				if (pp == NULL) {
9402 					anon_array_exit(&cookie);
9403 					ANON_LOCK_EXIT(&amp->a_rwlock);
9404 					return (ENOMEM);
9405 				}
9406 				ASSERT(anon_get_ptr(amp->ahp, anon_index)
9407 				    == NULL);
9408 				(void) anon_set_ptr(amp->ahp, anon_index,
9409 				    ap, ANON_SLEEP);
9410 				page_unlock(pp);
9411 			}
9412 
9413 			anon_array_exit(&cookie);
9414 			ANON_LOCK_EXIT(&amp->a_rwlock);
9415 
9416 			memidp->val[0] = (uintptr_t)ap;
9417 			memidp->val[1] = (uintptr_t)addr & PAGEOFFSET;
9418 			return (0);
9419 		}
9420 	}
9421 	return (EINVAL);
9422 }
9423 
9424 static int
9425 sameprot(struct seg *seg, caddr_t a, size_t len)
9426 {
9427 	struct segvn_data *svd = (struct segvn_data *)seg->s_data;
9428 	struct vpage *vpage;
9429 	spgcnt_t pages = btop(len);
9430 	uint_t prot;
9431 
9432 	if (svd->pageprot == 0)
9433 		return (1);
9434 
9435 	ASSERT(svd->vpage != NULL);
9436 
9437 	vpage = &svd->vpage[seg_page(seg, a)];
9438 	prot = VPP_PROT(vpage);
9439 	vpage++;
9440 	pages--;
9441 	while (pages-- > 0) {
9442 		if (prot != VPP_PROT(vpage))
9443 			return (0);
9444 		vpage++;
9445 	}
9446 	return (1);
9447 }
9448 
9449 /*
9450  * Get memory allocation policy info for specified address in given segment
9451  */
9452 static lgrp_mem_policy_info_t *
9453 segvn_getpolicy(struct seg *seg, caddr_t addr)
9454 {
9455 	struct anon_map		*amp;
9456 	ulong_t			anon_index;
9457 	lgrp_mem_policy_info_t	*policy_info;
9458 	struct segvn_data	*svn_data;
9459 	u_offset_t		vn_off;
9460 	vnode_t			*vp;
9461 
9462 	ASSERT(seg != NULL);
9463 
9464 	svn_data = (struct segvn_data *)seg->s_data;
9465 	if (svn_data == NULL)
9466 		return (NULL);
9467 
9468 	/*
9469 	 * Get policy info for private or shared memory
9470 	 */
9471 	if (svn_data->type != MAP_SHARED) {
9472 		if (svn_data->tr_state != SEGVN_TR_ON) {
9473 			policy_info = &svn_data->policy_info;
9474 		} else {
9475 			policy_info = &svn_data->tr_policy_info;
9476 			ASSERT(policy_info->mem_policy ==
9477 			    LGRP_MEM_POLICY_NEXT_SEG);
9478 		}
9479 	} else {
9480 		amp = svn_data->amp;
9481 		anon_index = svn_data->anon_index + seg_page(seg, addr);
9482 		vp = svn_data->vp;
9483 		vn_off = svn_data->offset + (uintptr_t)(addr - seg->s_base);
9484 		policy_info = lgrp_shm_policy_get(amp, anon_index, vp, vn_off);
9485 	}
9486 
9487 	return (policy_info);
9488 }
9489 
9490 /*ARGSUSED*/
9491 static int
9492 segvn_capable(struct seg *seg, segcapability_t capability)
9493 {
9494 	return (0);
9495 }
9496 
9497 /*
9498  * Bind text vnode segment to an amp. If we bind successfully mappings will be
9499  * established to per vnode mapping per lgroup amp pages instead of to vnode
9500  * pages. There's one amp per vnode text mapping per lgroup. Many processes
9501  * may share the same text replication amp. If a suitable amp doesn't already
9502  * exist in svntr hash table create a new one.  We may fail to bind to amp if
9503  * segment is not eligible for text replication.  Code below first checks for
9504  * these conditions. If binding is successful segment tr_state is set to on
9505  * and svd->amp points to the amp to use. Otherwise tr_state is set to off and
9506  * svd->amp remains as NULL.
9507  */
9508 static void
9509 segvn_textrepl(struct seg *seg)
9510 {
9511 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9512 	vnode_t			*vp = svd->vp;
9513 	u_offset_t		off = svd->offset;
9514 	size_t			size = seg->s_size;
9515 	u_offset_t		eoff = off + size;
9516 	uint_t			szc = seg->s_szc;
9517 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9518 	svntr_t			*svntrp;
9519 	struct vattr		va;
9520 	proc_t			*p = seg->s_as->a_proc;
9521 	lgrp_id_t		lgrp_id;
9522 	lgrp_id_t		olid;
9523 	int			first;
9524 	struct anon_map		*amp;
9525 
9526 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9527 	ASSERT(SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9528 	ASSERT(p != NULL);
9529 	ASSERT(svd->tr_state == SEGVN_TR_INIT);
9530 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9531 	ASSERT(svd->flags & MAP_TEXT);
9532 	ASSERT(svd->type == MAP_PRIVATE);
9533 	ASSERT(vp != NULL && svd->amp == NULL);
9534 	ASSERT(!svd->pageprot && !(svd->prot & PROT_WRITE));
9535 	ASSERT(!(svd->flags & MAP_NORESERVE) && svd->swresv == 0);
9536 	ASSERT(seg->s_as != &kas);
9537 	ASSERT(off < eoff);
9538 	ASSERT(svntr_hashtab != NULL);
9539 
9540 	/*
9541 	 * If numa optimizations are no longer desired bail out.
9542 	 */
9543 	if (!lgrp_optimizations()) {
9544 		svd->tr_state = SEGVN_TR_OFF;
9545 		return;
9546 	}
9547 
9548 	/*
9549 	 * Avoid creating anon maps with size bigger than the file size.
9550 	 * If VOP_GETATTR() call fails bail out.
9551 	 */
9552 	va.va_mask = AT_SIZE | AT_MTIME | AT_CTIME;
9553 	if (VOP_GETATTR(vp, &va, 0, svd->cred, NULL) != 0) {
9554 		svd->tr_state = SEGVN_TR_OFF;
9555 		SEGVN_TR_ADDSTAT(gaerr);
9556 		return;
9557 	}
9558 	if (btopr(va.va_size) < btopr(eoff)) {
9559 		svd->tr_state = SEGVN_TR_OFF;
9560 		SEGVN_TR_ADDSTAT(overmap);
9561 		return;
9562 	}
9563 
9564 	/*
9565 	 * VVMEXEC may not be set yet if exec() prefaults text segment. Set
9566 	 * this flag now before vn_is_mapped(V_WRITE) so that MAP_SHARED
9567 	 * mapping that checks if trcache for this vnode needs to be
9568 	 * invalidated can't miss us.
9569 	 */
9570 	if (!(vp->v_flag & VVMEXEC)) {
9571 		mutex_enter(&vp->v_lock);
9572 		vp->v_flag |= VVMEXEC;
9573 		mutex_exit(&vp->v_lock);
9574 	}
9575 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9576 	/*
9577 	 * Bail out if potentially MAP_SHARED writable mappings exist to this
9578 	 * vnode.  We don't want to use old file contents from existing
9579 	 * replicas if this mapping was established after the original file
9580 	 * was changed.
9581 	 */
9582 	if (vn_is_mapped(vp, V_WRITE)) {
9583 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9584 		svd->tr_state = SEGVN_TR_OFF;
9585 		SEGVN_TR_ADDSTAT(wrcnt);
9586 		return;
9587 	}
9588 	svntrp = svntr_hashtab[hash].tr_head;
9589 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9590 		ASSERT(svntrp->tr_refcnt != 0);
9591 		if (svntrp->tr_vp != vp) {
9592 			continue;
9593 		}
9594 
9595 		/*
9596 		 * Bail out if the file or its attributes were changed after
9597 		 * this replication entry was created since we need to use the
9598 		 * latest file contents. Note that mtime test alone is not
9599 		 * sufficient because a user can explicitly change mtime via
9600 		 * utimes(2) interfaces back to the old value after modifiying
9601 		 * the file contents. To detect this case we also have to test
9602 		 * ctime which among other things records the time of the last
9603 		 * mtime change by utimes(2). ctime is not changed when the file
9604 		 * is only read or executed so we expect that typically existing
9605 		 * replication amp's can be used most of the time.
9606 		 */
9607 		if (!svntrp->tr_valid ||
9608 		    svntrp->tr_mtime.tv_sec != va.va_mtime.tv_sec ||
9609 		    svntrp->tr_mtime.tv_nsec != va.va_mtime.tv_nsec ||
9610 		    svntrp->tr_ctime.tv_sec != va.va_ctime.tv_sec ||
9611 		    svntrp->tr_ctime.tv_nsec != va.va_ctime.tv_nsec) {
9612 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9613 			svd->tr_state = SEGVN_TR_OFF;
9614 			SEGVN_TR_ADDSTAT(stale);
9615 			return;
9616 		}
9617 		/*
9618 		 * if off, eoff and szc match current segment we found the
9619 		 * existing entry we can use.
9620 		 */
9621 		if (svntrp->tr_off == off && svntrp->tr_eoff == eoff &&
9622 		    svntrp->tr_szc == szc) {
9623 			break;
9624 		}
9625 		/*
9626 		 * Don't create different but overlapping in file offsets
9627 		 * entries to avoid replication of the same file pages more
9628 		 * than once per lgroup.
9629 		 */
9630 		if ((off >= svntrp->tr_off && off < svntrp->tr_eoff) ||
9631 		    (eoff > svntrp->tr_off && eoff <= svntrp->tr_eoff)) {
9632 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9633 			svd->tr_state = SEGVN_TR_OFF;
9634 			SEGVN_TR_ADDSTAT(overlap);
9635 			return;
9636 		}
9637 	}
9638 	/*
9639 	 * If we didn't find existing entry create a new one.
9640 	 */
9641 	if (svntrp == NULL) {
9642 		svntrp = kmem_cache_alloc(svntr_cache, KM_NOSLEEP);
9643 		if (svntrp == NULL) {
9644 			mutex_exit(&svntr_hashtab[hash].tr_lock);
9645 			svd->tr_state = SEGVN_TR_OFF;
9646 			SEGVN_TR_ADDSTAT(nokmem);
9647 			return;
9648 		}
9649 #ifdef DEBUG
9650 		{
9651 			lgrp_id_t i;
9652 			for (i = 0; i < NLGRPS_MAX; i++) {
9653 				ASSERT(svntrp->tr_amp[i] == NULL);
9654 			}
9655 		}
9656 #endif /* DEBUG */
9657 		svntrp->tr_vp = vp;
9658 		svntrp->tr_off = off;
9659 		svntrp->tr_eoff = eoff;
9660 		svntrp->tr_szc = szc;
9661 		svntrp->tr_valid = 1;
9662 		svntrp->tr_mtime = va.va_mtime;
9663 		svntrp->tr_ctime = va.va_ctime;
9664 		svntrp->tr_refcnt = 0;
9665 		svntrp->tr_next = svntr_hashtab[hash].tr_head;
9666 		svntr_hashtab[hash].tr_head = svntrp;
9667 	}
9668 	first = 1;
9669 again:
9670 	/*
9671 	 * We want to pick a replica with pages on main thread's (t_tid = 1,
9672 	 * aka T1) lgrp. Currently text replication is only optimized for
9673 	 * workloads that either have all threads of a process on the same
9674 	 * lgrp or execute their large text primarily on main thread.
9675 	 */
9676 	lgrp_id = p->p_t1_lgrpid;
9677 	if (lgrp_id == LGRP_NONE) {
9678 		/*
9679 		 * In case exec() prefaults text on non main thread use
9680 		 * current thread lgrpid.  It will become main thread anyway
9681 		 * soon.
9682 		 */
9683 		lgrp_id = lgrp_home_id(curthread);
9684 	}
9685 	/*
9686 	 * Set p_tr_lgrpid to lgrpid if it hasn't been set yet.  Otherwise
9687 	 * just set it to NLGRPS_MAX if it's different from current process T1
9688 	 * home lgrp.  p_tr_lgrpid is used to detect if process uses text
9689 	 * replication and T1 new home is different from lgrp used for text
9690 	 * replication. When this happens asyncronous segvn thread rechecks if
9691 	 * segments should change lgrps used for text replication.  If we fail
9692 	 * to set p_tr_lgrpid with cas32 then set it to NLGRPS_MAX without cas
9693 	 * if it's not already NLGRPS_MAX and not equal lgrp_id we want to
9694 	 * use.  We don't need to use cas in this case because another thread
9695 	 * that races in between our non atomic check and set may only change
9696 	 * p_tr_lgrpid to NLGRPS_MAX at this point.
9697 	 */
9698 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9699 	olid = p->p_tr_lgrpid;
9700 	if (lgrp_id != olid && olid != NLGRPS_MAX) {
9701 		lgrp_id_t nlid = (olid == LGRP_NONE) ? lgrp_id : NLGRPS_MAX;
9702 		if (cas32((uint32_t *)&p->p_tr_lgrpid, olid, nlid) != olid) {
9703 			olid = p->p_tr_lgrpid;
9704 			ASSERT(olid != LGRP_NONE);
9705 			if (olid != lgrp_id && olid != NLGRPS_MAX) {
9706 				p->p_tr_lgrpid = NLGRPS_MAX;
9707 			}
9708 		}
9709 		ASSERT(p->p_tr_lgrpid != LGRP_NONE);
9710 		membar_producer();
9711 		/*
9712 		 * lgrp_move_thread() won't schedule async recheck after
9713 		 * p->p_t1_lgrpid update unless p->p_tr_lgrpid is not
9714 		 * LGRP_NONE. Recheck p_t1_lgrpid once now that p->p_tr_lgrpid
9715 		 * is not LGRP_NONE.
9716 		 */
9717 		if (first && p->p_t1_lgrpid != LGRP_NONE &&
9718 		    p->p_t1_lgrpid != lgrp_id) {
9719 			first = 0;
9720 			goto again;
9721 		}
9722 	}
9723 	/*
9724 	 * If no amp was created yet for lgrp_id create a new one as long as
9725 	 * we have enough memory to afford it.
9726 	 */
9727 	if ((amp = svntrp->tr_amp[lgrp_id]) == NULL) {
9728 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
9729 		if (trmem > segvn_textrepl_max_bytes) {
9730 			SEGVN_TR_ADDSTAT(normem);
9731 			goto fail;
9732 		}
9733 		if (anon_try_resv_zone(size, NULL) == 0) {
9734 			SEGVN_TR_ADDSTAT(noanon);
9735 			goto fail;
9736 		}
9737 		amp = anonmap_alloc(size, size, ANON_NOSLEEP);
9738 		if (amp == NULL) {
9739 			anon_unresv_zone(size, NULL);
9740 			SEGVN_TR_ADDSTAT(nokmem);
9741 			goto fail;
9742 		}
9743 		ASSERT(amp->refcnt == 1);
9744 		amp->a_szc = szc;
9745 		svntrp->tr_amp[lgrp_id] = amp;
9746 		SEGVN_TR_ADDSTAT(newamp);
9747 	}
9748 	svntrp->tr_refcnt++;
9749 	ASSERT(svd->svn_trnext == NULL);
9750 	ASSERT(svd->svn_trprev == NULL);
9751 	svd->svn_trnext = svntrp->tr_svnhead;
9752 	svd->svn_trprev = NULL;
9753 	if (svntrp->tr_svnhead != NULL) {
9754 		svntrp->tr_svnhead->svn_trprev = svd;
9755 	}
9756 	svntrp->tr_svnhead = svd;
9757 	ASSERT(amp->a_szc == szc && amp->size == size && amp->swresv == size);
9758 	ASSERT(amp->refcnt >= 1);
9759 	svd->amp = amp;
9760 	svd->anon_index = 0;
9761 	svd->tr_policy_info.mem_policy = LGRP_MEM_POLICY_NEXT_SEG;
9762 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
9763 	svd->tr_state = SEGVN_TR_ON;
9764 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9765 	SEGVN_TR_ADDSTAT(repl);
9766 	return;
9767 fail:
9768 	ASSERT(segvn_textrepl_bytes >= size);
9769 	atomic_add_long(&segvn_textrepl_bytes, -size);
9770 	ASSERT(svntrp != NULL);
9771 	ASSERT(svntrp->tr_amp[lgrp_id] == NULL);
9772 	if (svntrp->tr_refcnt == 0) {
9773 		ASSERT(svntrp == svntr_hashtab[hash].tr_head);
9774 		svntr_hashtab[hash].tr_head = svntrp->tr_next;
9775 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9776 		kmem_cache_free(svntr_cache, svntrp);
9777 	} else {
9778 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9779 	}
9780 	svd->tr_state = SEGVN_TR_OFF;
9781 }
9782 
9783 /*
9784  * Convert seg back to regular vnode mapping seg by unbinding it from its text
9785  * replication amp.  This routine is most typically called when segment is
9786  * unmapped but can also be called when segment no longer qualifies for text
9787  * replication (e.g. due to protection changes). If unload_unmap is set use
9788  * HAT_UNLOAD_UNMAP flag in hat_unload_callback().  If we are the last user of
9789  * svntr free all its anon maps and remove it from the hash table.
9790  */
9791 static void
9792 segvn_textunrepl(struct seg *seg, int unload_unmap)
9793 {
9794 	struct segvn_data	*svd = (struct segvn_data *)seg->s_data;
9795 	vnode_t			*vp = svd->vp;
9796 	u_offset_t		off = svd->offset;
9797 	size_t			size = seg->s_size;
9798 	u_offset_t		eoff = off + size;
9799 	uint_t			szc = seg->s_szc;
9800 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9801 	svntr_t			*svntrp;
9802 	svntr_t			**prv_svntrp;
9803 	lgrp_id_t		lgrp_id = svd->tr_policy_info.mem_lgrpid;
9804 	lgrp_id_t		i;
9805 
9806 	ASSERT(AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock));
9807 	ASSERT(AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock) ||
9808 	    SEGVN_WRITE_HELD(seg->s_as, &svd->lock));
9809 	ASSERT(svd->tr_state == SEGVN_TR_ON);
9810 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
9811 	ASSERT(svd->amp != NULL);
9812 	ASSERT(svd->amp->refcnt >= 1);
9813 	ASSERT(svd->anon_index == 0);
9814 	ASSERT(lgrp_id != LGRP_NONE && lgrp_id < NLGRPS_MAX);
9815 	ASSERT(svntr_hashtab != NULL);
9816 
9817 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9818 	prv_svntrp = &svntr_hashtab[hash].tr_head;
9819 	for (; (svntrp = *prv_svntrp) != NULL; prv_svntrp = &svntrp->tr_next) {
9820 		ASSERT(svntrp->tr_refcnt != 0);
9821 		if (svntrp->tr_vp == vp && svntrp->tr_off == off &&
9822 		    svntrp->tr_eoff == eoff && svntrp->tr_szc == szc) {
9823 			break;
9824 		}
9825 	}
9826 	if (svntrp == NULL) {
9827 		panic("segvn_textunrepl: svntr record not found");
9828 	}
9829 	if (svntrp->tr_amp[lgrp_id] != svd->amp) {
9830 		panic("segvn_textunrepl: amp mismatch");
9831 	}
9832 	svd->tr_state = SEGVN_TR_OFF;
9833 	svd->amp = NULL;
9834 	if (svd->svn_trprev == NULL) {
9835 		ASSERT(svntrp->tr_svnhead == svd);
9836 		svntrp->tr_svnhead = svd->svn_trnext;
9837 		if (svntrp->tr_svnhead != NULL) {
9838 			svntrp->tr_svnhead->svn_trprev = NULL;
9839 		}
9840 		svd->svn_trnext = NULL;
9841 	} else {
9842 		svd->svn_trprev->svn_trnext = svd->svn_trnext;
9843 		if (svd->svn_trnext != NULL) {
9844 			svd->svn_trnext->svn_trprev = svd->svn_trprev;
9845 			svd->svn_trnext = NULL;
9846 		}
9847 		svd->svn_trprev = NULL;
9848 	}
9849 	if (--svntrp->tr_refcnt) {
9850 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9851 		goto done;
9852 	}
9853 	*prv_svntrp = svntrp->tr_next;
9854 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9855 	for (i = 0; i < NLGRPS_MAX; i++) {
9856 		struct anon_map *amp = svntrp->tr_amp[i];
9857 		if (amp == NULL) {
9858 			continue;
9859 		}
9860 		ASSERT(amp->refcnt == 1);
9861 		ASSERT(amp->swresv == size);
9862 		ASSERT(amp->size == size);
9863 		ASSERT(amp->a_szc == szc);
9864 		if (amp->a_szc != 0) {
9865 			anon_free_pages(amp->ahp, 0, size, szc);
9866 		} else {
9867 			anon_free(amp->ahp, 0, size);
9868 		}
9869 		svntrp->tr_amp[i] = NULL;
9870 		ASSERT(segvn_textrepl_bytes >= size);
9871 		atomic_add_long(&segvn_textrepl_bytes, -size);
9872 		anon_unresv_zone(amp->swresv, NULL);
9873 		amp->refcnt = 0;
9874 		anonmap_free(amp);
9875 	}
9876 	kmem_cache_free(svntr_cache, svntrp);
9877 done:
9878 	hat_unload_callback(seg->s_as->a_hat, seg->s_base, size,
9879 	    unload_unmap ? HAT_UNLOAD_UNMAP : 0, NULL);
9880 }
9881 
9882 /*
9883  * This is called when a MAP_SHARED writable mapping is created to a vnode
9884  * that is currently used for execution (VVMEXEC flag is set). In this case we
9885  * need to prevent further use of existing replicas.
9886  */
9887 static void
9888 segvn_inval_trcache(vnode_t *vp)
9889 {
9890 	ulong_t			hash = SVNTR_HASH_FUNC(vp);
9891 	svntr_t			*svntrp;
9892 
9893 	ASSERT(vp->v_flag & VVMEXEC);
9894 
9895 	if (svntr_hashtab == NULL) {
9896 		return;
9897 	}
9898 
9899 	mutex_enter(&svntr_hashtab[hash].tr_lock);
9900 	svntrp = svntr_hashtab[hash].tr_head;
9901 	for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9902 		ASSERT(svntrp->tr_refcnt != 0);
9903 		if (svntrp->tr_vp == vp && svntrp->tr_valid) {
9904 			svntrp->tr_valid = 0;
9905 		}
9906 	}
9907 	mutex_exit(&svntr_hashtab[hash].tr_lock);
9908 }
9909 
9910 static void
9911 segvn_trasync_thread(void)
9912 {
9913 	callb_cpr_t cpr_info;
9914 	kmutex_t cpr_lock;	/* just for CPR stuff */
9915 
9916 	mutex_init(&cpr_lock, NULL, MUTEX_DEFAULT, NULL);
9917 
9918 	CALLB_CPR_INIT(&cpr_info, &cpr_lock,
9919 	    callb_generic_cpr, "segvn_async");
9920 
9921 	if (segvn_update_textrepl_interval == 0) {
9922 		segvn_update_textrepl_interval = segvn_update_tr_time * hz;
9923 	} else {
9924 		segvn_update_textrepl_interval *= hz;
9925 	}
9926 	(void) timeout(segvn_trupdate_wakeup, NULL,
9927 	    segvn_update_textrepl_interval);
9928 
9929 	for (;;) {
9930 		mutex_enter(&cpr_lock);
9931 		CALLB_CPR_SAFE_BEGIN(&cpr_info);
9932 		mutex_exit(&cpr_lock);
9933 		sema_p(&segvn_trasync_sem);
9934 		mutex_enter(&cpr_lock);
9935 		CALLB_CPR_SAFE_END(&cpr_info, &cpr_lock);
9936 		mutex_exit(&cpr_lock);
9937 		segvn_trupdate();
9938 	}
9939 }
9940 
9941 static uint64_t segvn_lgrp_trthr_migrs_snpsht = 0;
9942 
9943 static void
9944 segvn_trupdate_wakeup(void *dummy)
9945 {
9946 	uint64_t cur_lgrp_trthr_migrs = lgrp_get_trthr_migrations();
9947 
9948 	if (cur_lgrp_trthr_migrs != segvn_lgrp_trthr_migrs_snpsht) {
9949 		segvn_lgrp_trthr_migrs_snpsht = cur_lgrp_trthr_migrs;
9950 		sema_v(&segvn_trasync_sem);
9951 	}
9952 
9953 	if (!segvn_disable_textrepl_update &&
9954 	    segvn_update_textrepl_interval != 0) {
9955 		(void) timeout(segvn_trupdate_wakeup, dummy,
9956 		    segvn_update_textrepl_interval);
9957 	}
9958 }
9959 
9960 static void
9961 segvn_trupdate(void)
9962 {
9963 	ulong_t		hash;
9964 	svntr_t		*svntrp;
9965 	segvn_data_t	*svd;
9966 
9967 	ASSERT(svntr_hashtab != NULL);
9968 
9969 	for (hash = 0; hash < svntr_hashtab_sz; hash++) {
9970 		mutex_enter(&svntr_hashtab[hash].tr_lock);
9971 		svntrp = svntr_hashtab[hash].tr_head;
9972 		for (; svntrp != NULL; svntrp = svntrp->tr_next) {
9973 			ASSERT(svntrp->tr_refcnt != 0);
9974 			svd = svntrp->tr_svnhead;
9975 			for (; svd != NULL; svd = svd->svn_trnext) {
9976 				segvn_trupdate_seg(svd->seg, svd, svntrp,
9977 				    hash);
9978 			}
9979 		}
9980 		mutex_exit(&svntr_hashtab[hash].tr_lock);
9981 	}
9982 }
9983 
9984 static void
9985 segvn_trupdate_seg(struct seg *seg,
9986 	segvn_data_t *svd,
9987 	svntr_t *svntrp,
9988 	ulong_t hash)
9989 {
9990 	proc_t			*p;
9991 	lgrp_id_t		lgrp_id;
9992 	struct as		*as;
9993 	size_t			size;
9994 	struct anon_map		*amp;
9995 
9996 	ASSERT(svd->vp != NULL);
9997 	ASSERT(svd->vp == svntrp->tr_vp);
9998 	ASSERT(svd->offset == svntrp->tr_off);
9999 	ASSERT(svd->offset + seg->s_size == svntrp->tr_eoff);
10000 	ASSERT(seg != NULL);
10001 	ASSERT(svd->seg == seg);
10002 	ASSERT(seg->s_data == (void *)svd);
10003 	ASSERT(seg->s_szc == svntrp->tr_szc);
10004 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10005 	ASSERT(!HAT_IS_REGION_COOKIE_VALID(svd->rcookie));
10006 	ASSERT(svd->amp != NULL);
10007 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10008 	ASSERT(svd->tr_policy_info.mem_lgrpid != LGRP_NONE);
10009 	ASSERT(svd->tr_policy_info.mem_lgrpid < NLGRPS_MAX);
10010 	ASSERT(svntrp->tr_amp[svd->tr_policy_info.mem_lgrpid] == svd->amp);
10011 	ASSERT(svntrp->tr_refcnt != 0);
10012 	ASSERT(mutex_owned(&svntr_hashtab[hash].tr_lock));
10013 
10014 	as = seg->s_as;
10015 	ASSERT(as != NULL && as != &kas);
10016 	p = as->a_proc;
10017 	ASSERT(p != NULL);
10018 	ASSERT(p->p_tr_lgrpid != LGRP_NONE);
10019 	lgrp_id = p->p_t1_lgrpid;
10020 	if (lgrp_id == LGRP_NONE) {
10021 		return;
10022 	}
10023 	ASSERT(lgrp_id < NLGRPS_MAX);
10024 	if (svd->tr_policy_info.mem_lgrpid == lgrp_id) {
10025 		return;
10026 	}
10027 
10028 	/*
10029 	 * Use tryenter locking since we are locking as/seg and svntr hash
10030 	 * lock in reverse from syncrounous thread order.
10031 	 */
10032 	if (!AS_LOCK_TRYENTER(as, &as->a_lock, RW_READER)) {
10033 		SEGVN_TR_ADDSTAT(nolock);
10034 		if (segvn_lgrp_trthr_migrs_snpsht) {
10035 			segvn_lgrp_trthr_migrs_snpsht = 0;
10036 		}
10037 		return;
10038 	}
10039 	if (!SEGVN_LOCK_TRYENTER(seg->s_as, &svd->lock, RW_WRITER)) {
10040 		AS_LOCK_EXIT(as, &as->a_lock);
10041 		SEGVN_TR_ADDSTAT(nolock);
10042 		if (segvn_lgrp_trthr_migrs_snpsht) {
10043 			segvn_lgrp_trthr_migrs_snpsht = 0;
10044 		}
10045 		return;
10046 	}
10047 	size = seg->s_size;
10048 	if (svntrp->tr_amp[lgrp_id] == NULL) {
10049 		size_t trmem = atomic_add_long_nv(&segvn_textrepl_bytes, size);
10050 		if (trmem > segvn_textrepl_max_bytes) {
10051 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10052 			AS_LOCK_EXIT(as, &as->a_lock);
10053 			atomic_add_long(&segvn_textrepl_bytes, -size);
10054 			SEGVN_TR_ADDSTAT(normem);
10055 			return;
10056 		}
10057 		if (anon_try_resv_zone(size, NULL) == 0) {
10058 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10059 			AS_LOCK_EXIT(as, &as->a_lock);
10060 			atomic_add_long(&segvn_textrepl_bytes, -size);
10061 			SEGVN_TR_ADDSTAT(noanon);
10062 			return;
10063 		}
10064 		amp = anonmap_alloc(size, size, KM_NOSLEEP);
10065 		if (amp == NULL) {
10066 			SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10067 			AS_LOCK_EXIT(as, &as->a_lock);
10068 			atomic_add_long(&segvn_textrepl_bytes, -size);
10069 			anon_unresv_zone(size, NULL);
10070 			SEGVN_TR_ADDSTAT(nokmem);
10071 			return;
10072 		}
10073 		ASSERT(amp->refcnt == 1);
10074 		amp->a_szc = seg->s_szc;
10075 		svntrp->tr_amp[lgrp_id] = amp;
10076 	}
10077 	/*
10078 	 * We don't need to drop the bucket lock but here we give other
10079 	 * threads a chance.  svntr and svd can't be unlinked as long as
10080 	 * segment lock is held as a writer and AS held as well.  After we
10081 	 * retake bucket lock we'll continue from where we left. We'll be able
10082 	 * to reach the end of either list since new entries are always added
10083 	 * to the beginning of the lists.
10084 	 */
10085 	mutex_exit(&svntr_hashtab[hash].tr_lock);
10086 	hat_unload_callback(as->a_hat, seg->s_base, size, 0, NULL);
10087 	mutex_enter(&svntr_hashtab[hash].tr_lock);
10088 
10089 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10090 	ASSERT(svd->amp != NULL);
10091 	ASSERT(svd->tr_policy_info.mem_policy == LGRP_MEM_POLICY_NEXT_SEG);
10092 	ASSERT(svd->tr_policy_info.mem_lgrpid != lgrp_id);
10093 	ASSERT(svd->amp != svntrp->tr_amp[lgrp_id]);
10094 
10095 	svd->tr_policy_info.mem_lgrpid = lgrp_id;
10096 	svd->amp = svntrp->tr_amp[lgrp_id];
10097 	p->p_tr_lgrpid = NLGRPS_MAX;
10098 	SEGVN_LOCK_EXIT(seg->s_as, &svd->lock);
10099 	AS_LOCK_EXIT(as, &as->a_lock);
10100 
10101 	ASSERT(svntrp->tr_refcnt != 0);
10102 	ASSERT(svd->vp == svntrp->tr_vp);
10103 	ASSERT(svd->tr_policy_info.mem_lgrpid == lgrp_id);
10104 	ASSERT(svd->amp != NULL && svd->amp == svntrp->tr_amp[lgrp_id]);
10105 	ASSERT(svd->seg == seg);
10106 	ASSERT(svd->tr_state == SEGVN_TR_ON);
10107 
10108 	SEGVN_TR_ADDSTAT(asyncrepl);
10109 }
10110