xref: /illumos-gate/usr/src/uts/common/sys/ddidmareq.h (revision 5ee6ac27d4fd4c9412183aa8cc1143f36ae04a8c)
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 (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #ifndef	_SYS_DDIDMAREQ_H
26 #define	_SYS_DDIDMAREQ_H
27 
28 #ifdef	__cplusplus
29 extern "C" {
30 #endif
31 
32 /*
33  * Memory Objects
34  *
35  * Definitions of structures that can describe
36  * an object that can be mapped for DMA.
37  */
38 
39 /*
40  * Structure describing a virtual address
41  */
42 struct v_address {
43 	caddr_t		v_addr;		/* base virtual address */
44 	struct	as	*v_as;		/* pointer to address space */
45 	void 		*v_priv;	/* priv data for shadow I/O */
46 };
47 
48 /*
49  * Structure describing a page-based address
50  */
51 struct pp_address {
52 	/*
53 	 * A pointer to a circularly linked list of page structures.
54 	 */
55 	struct page *pp_pp;
56 	uint_t pp_offset;	/* offset within first page */
57 };
58 
59 /*
60  * Structure to describe a physical memory address.
61  */
62 struct phy_address {
63 	ulong_t	p_addr;		/* base physical address */
64 	ulong_t	p_memtype;	/* memory type */
65 };
66 
67 /*
68  * Structure to describe an array DVMA addresses.
69  * Under normal circumstances, dv_nseg will be 1.
70  * dvs_start is always page aligned.
71  */
72 struct dvma_address {
73 	size_t dv_off;
74 	size_t dv_nseg;
75 	struct dvmaseg {
76 		uint64_t dvs_start;
77 		size_t dvs_len;
78 	} *dv_seg;
79 };
80 
81 /*
82  * A union of all of the above structures.
83  *
84  * This union describes the relationship between
85  * the kind of an address description and an object.
86  */
87 typedef union {
88 	struct v_address virt_obj;	/* Some virtual address		*/
89 	struct pp_address pp_obj;	/* Some page-based address	*/
90 	struct phy_address phys_obj;	/* Some physical address	*/
91 	struct dvma_address dvma_obj;
92 } ddi_dma_aobj_t;
93 
94 /*
95  * DMA object types - used to select how the object
96  * being mapped is being addressed by the IU.
97  */
98 typedef enum {
99 	DMA_OTYP_VADDR = 0,	/* enforce starting value of zero */
100 	DMA_OTYP_PAGES,
101 	DMA_OTYP_PADDR,
102 	DMA_OTYP_BUFVADDR,
103 	DMA_OTYP_DVADDR
104 } ddi_dma_atyp_t;
105 
106 /*
107  * A compact package to describe an object that is to be mapped for DMA.
108  */
109 typedef struct {
110 	uint_t		dmao_size;	/* size, in bytes, of the object */
111 	ddi_dma_atyp_t	dmao_type;	/* type of object */
112 	ddi_dma_aobj_t	dmao_obj;	/* the object described */
113 } ddi_dma_obj_t;
114 
115 /*
116  * DMA addressing limits.
117  *
118  * This structure describes the constraints that a particular device's
119  * DMA engine has to its parent so that the parent may correctly set
120  * things up for a DMA mapping. Each parent may in turn modify the
121  * constraints listed in a DMA request structure in order to describe
122  * to its parent any changed or additional constraints. The rules
123  * are that each parent may modify a constraint in order to further
124  * constrain things (e.g., picking a more limited address range than
125  * that permitted by the child), but that the parent may not ignore
126  * a child's constraints.
127  *
128  * A particular constraint that we do *not* address is whether or not
129  * a requested mapping is too large for a DMA engine's counter to
130  * correctly track. It is still up to each driver to explicitly handle
131  * transfers that are too large for its own hardware to deal with directly.
132  *
133  * The mapping routines that are cognizant of this structure will
134  * copy any user defined limits structure if they need to modify
135  * the fields (as alluded to above).
136  *
137  * A note as to how to define constraints:
138  *
139  * How you define the constraints for your device depends on how you
140  * define your device. For example, you may have an SBus card with a
141  * device on it that address only the bottom 16mb of virtual DMA space.
142  * However, if the card also has ancillary circuitry that pulls the high 8
143  * bits of address lines high, the more correct expression for your device
144  * is that it address [0xff000000..0xffffffff] rather than [0..0x00ffffff].
145  */
146 #if defined(__sparc)
147 typedef struct ddi_dma_lim {
148 
149 	/*
150 	 * Low range of 32 bit addressing capability.
151 	 */
152 	uint_t	dlim_addr_lo;
153 
154 	/*
155 	 * Upper inclusive bound of addressing capability. It is an
156 	 * inclusive boundary limit to allow for the addressing range
157 	 * [0..0xffffffff] to be specified in preference to [0..0].
158 	 */
159 	uint_t	dlim_addr_hi;
160 
161 	/*
162 	 * Inclusive upper bound with which The DMA engine's counter acts as
163 	 * a register.
164 	 *
165 	 * This handles the case where an upper portion of a DMA address
166 	 * register is a latch instead of being a full 32 bit register
167 	 * (e.g., the upper 8 bits may remain constant while the lower
168 	 * 24 bits are the real address register).
169 	 *
170 	 * This essentially gives a hint about segment limitations
171 	 * to the mapping routines.
172 	 */
173 	uint_t	dlim_cntr_max;
174 
175 	/*
176 	 * DMA burst sizes.
177 	 *
178 	 * At the time of a mapping request, this tag defines the possible
179 	 * DMA burst cycle sizes that the requestor's DMA engine can
180 	 * emit. The format of the data is binary encoding of burst sizes
181 	 * assumed to be powers of two. That is, if a DMA engine is capable
182 	 * of doing 1, 2, 4 and 16 byte transfers, the encoding would be 0x17.
183 	 *
184 	 * As the mapping request is handled by intervening nexi, the
185 	 * burstsizes value may be modified. Prior to enabling DMA for
186 	 * the specific device, the driver that owns the DMA engine should
187 	 * check (via ddi_dma_burstsizes(9F)) what the allowed burstsizes
188 	 * have become and program their DMA engine appropriately.
189 	 */
190 	uint_t	dlim_burstsizes;
191 
192 	/*
193 	 * Minimum effective DMA transfer size, in units of bytes.
194 	 *
195 	 * This value specifies the minimum effective granularity of the
196 	 * DMA engine. It is distinct from dlim_burtsizes in that it
197 	 * describes the minimum amount of access a DMA transfer will
198 	 * effect. dlim_burtsizes describes in what electrical fashion
199 	 * the DMA engine might perform its accesses, while dlim_minxfer
200 	 * describes the minimum amount of memory that can be touched by
201 	 * the DMA transfer.
202 	 *
203 	 * As the mapping request is handled by intervening nexi, the
204 	 * dlim_minxfer value may be modifed contingent upon the presence
205 	 * (and use) of I/O caches and DMA write buffers in between the
206 	 * DMA engine and the object that DMA is being performed on.
207 	 *
208 	 */
209 	uint_t	dlim_minxfer;
210 
211 	/*
212 	 * Expected average data rate for this DMA engine
213 	 * while transferring data.
214 	 *
215 	 * This is used as a hint for a number of operations that might
216 	 * want to know the possible optimal latency requirements of this
217 	 * device. A value of zero will be interpreted as a 'do not care'.
218 	 */
219 	uint_t	dlim_dmaspeed;
220 
221 } ddi_dma_lim_t;
222 
223 #elif defined(__x86)
224 
225 /*
226  * values for dlim_minxfer
227  */
228 #define	DMA_UNIT_8  1
229 #define	DMA_UNIT_16 2
230 #define	DMA_UNIT_32 4
231 
232 /*
233  * Version number
234  */
235 #define	DMALIM_VER0	((0x86000000) + 0)
236 
237 typedef struct ddi_dma_lim {
238 
239 	/*
240 	 * Low range of 32 bit addressing capability.
241 	 */
242 	uint_t	dlim_addr_lo;
243 
244 	/*
245 	 * Upper Inclusive bound of 32 bit addressing capability.
246 	 *
247 	 * The ISA nexus restricts this to 0x00ffffff, since this bus has
248 	 * only 24 address lines.  This enforces the 16 Mb address limitation.
249 	 * The EISA nexus restricts this to 0xffffffff.
250 	 */
251 	uint_t	dlim_addr_hi;
252 
253 	/*
254 	 * DMA engine counter not used; set to 0
255 	 */
256 	uint_t	dlim_cntr_max;
257 
258 	/*
259 	 *  DMA burst sizes not used; set to 1
260 	 */
261 	uint_t	dlim_burstsizes;
262 
263 	/*
264 	 * Minimum effective DMA transfer size.
265 	 *
266 	 * This value specifies the minimum effective granularity of the
267 	 * DMA engine. It is distinct from dlim_burstsizes in that it
268 	 * describes the minimum amount of access a DMA transfer will
269 	 * effect. dlim_burstsizes describes in what electrical fashion
270 	 * the DMA engine might perform its accesses, while dlim_minxfer
271 	 * describes the minimum amount of memory that can be touched by
272 	 * the DMA transfer.
273 	 *
274 	 * This value also implies the required address alignment.
275 	 * The number of bytes transferred is assumed to be
276 	 * 	dlim_minxfer * (DMA engine count)
277 	 *
278 	 * It should be set to DMA_UNIT_8, DMA_UNIT_16, or DMA_UNIT_32.
279 	 */
280 	uint_t	dlim_minxfer;
281 
282 	/*
283 	 * Expected average data rate for this DMA engine
284 	 * while transferring data.
285 	 *
286 	 * This is used as a hint for a number of operations that might
287 	 * want to know the possible optimal latency requirements of this
288 	 * device. A value of zero will be interpreted as a 'do not care'.
289 	 */
290 	uint_t	dlim_dmaspeed;
291 
292 
293 	/*
294 	 * Version number of this structure
295 	 */
296 	uint_t	dlim_version;	/* = 0x86 << 24 + 0 */
297 
298 	/*
299 	 * Inclusive upper bound with which the DMA engine's Address acts as
300 	 * a register.
301 	 * This handles the case where an upper portion of a DMA address
302 	 * register is a latch instead of being a full 32 bit register
303 	 * (e.g., the upper 16 bits remain constant while the lower 16 bits
304 	 * are incremented for each DMA transfer).
305 	 *
306 	 * The ISA nexus restricts only 3rd-party DMA requests to 0x0000ffff,
307 	 * since the ISA DMA engine has a 16-bit register for low address and
308 	 * an 8-bit latch for high address.  This enforces the first 64 Kb
309 	 * limitation (address boundary).
310 	 * The EISA nexus restricts only 3rd-party DMA requests to 0xffffffff.
311 	 */
312 	uint_t	dlim_adreg_max;
313 
314 	/*
315 	 * Maximum transfer count that the DMA engine can handle.
316 	 *
317 	 * The ISA nexus restricts only 3rd-party DMA requests to 0x0000ffff,
318 	 * since the ISA DMA engine has a 16-bit register for counting.
319 	 * This enforces the other 64 Kb limitation (count size).
320 	 * The EISA nexus restricts only 3rd-party DMA requests to 0x00ffffff,
321 	 * since the EISA DMA engine has a 24-bit register for counting.
322 	 *
323 	 * This transfer count limitation is a per segment limitation.
324 	 * It can also be used to restrict the size of segments.
325 	 *
326 	 * This is used as a bit mask, so it must be a power of 2, minus 1.
327 	 */
328 	uint_t	dlim_ctreg_max;
329 
330 	/*
331 	 * Granularity of DMA transfer, in units of bytes.
332 	 *
333 	 * Breakup sizes must be multiples of this value.
334 	 * If no scatter/gather capabilty is specified, then the size of
335 	 * each DMA transfer must be a multiple of this value.
336 	 *
337 	 * If there is scatter/gather capability, then a single cookie cannot
338 	 * be smaller in size than the minimum xfer value, and may be less
339 	 * than the granularity value.  The total transfer length of the
340 	 * scatter/gather list should be a multiple of the granularity value;
341 	 * use dlim_sgllen to specify the length of the scatter/gather list.
342 	 *
343 	 * This value should be equal to the sector size of the device.
344 	 */
345 	uint_t	dlim_granular;
346 
347 	/*
348 	 * Length of scatter/gather list
349 	 *
350 	 * This value specifies the number of segments or cookies that a DMA
351 	 * engine can consume in one i/o request to the device.  For 3rd-party
352 	 * DMA that uses the bus nexus this should be set to 1.  Devices with
353 	 * 1st-party DMA capability should specify the number of entries in
354 	 * its scatter/gather list.  The breakup routine will ensure that each
355 	 * group of dlim_sgllen cookies (within a DMA window) will have a
356 	 * total transfer length that is a multiple of dlim_granular.
357 	 *
358 	 *	< 0  :  tbd
359 	 *	= 0  :  breakup is for PIO.
360 	 *	= 1  :  breakup is for DMA engine with no scatter/gather
361 	 *		capability.
362 	 *	>= 2 :  breakup is for DMA engine with scatter/gather
363 	 *		capability; value is max number of entries in list.
364 	 *
365 	 * Note that this list length is not dependent on the DMA window
366 	 * size.  The size of the DMA window is based on resources consumed,
367 	 * such as intermediate buffers.  Several s/g lists may exist within
368 	 * a window.  But the end of a window does imply the end of the s/g
369 	 * list.
370 	 */
371 	short	dlim_sgllen;
372 
373 	/*
374 	 * Size of device i/o request
375 	 *
376 	 * This value indicates the maximum number of bytes the device
377 	 * can transmit/receive for one i/o command.  This limitation is
378 	 * significant ony if it is less than (dlim_ctreg_max * dlim_sgllen).
379 	 */
380 	uint_t	dlim_reqsize;
381 
382 } ddi_dma_lim_t;
383 
384 #else
385 #error "struct ddi_dma_lim not defined for this architecture"
386 #endif	/* defined(__sparc) */
387 
388 /*
389  * Flags definition for dma_attr_flags
390  */
391 
392 /*
393  * return physical DMA address on platforms
394  * which support DVMA
395  */
396 #define	DDI_DMA_FORCE_PHYSICAL		0x0100
397 
398 /*
399  * An error will be flagged for DMA data path errors
400  */
401 #define	DDI_DMA_FLAGERR			0x200
402 
403 /*
404  * Enable relaxed ordering
405  */
406 #define	DDI_DMA_RELAXED_ORDERING	0x400
407 
408 
409 /*
410  * Consolidation private x86 only flag which will cause a bounce buffer
411  * (paddr < dma_attr_seg) to be used if the buffer passed to the bind
412  * operation contains pages both above and below dma_attr_seg. If this flag
413  * is set, dma_attr_seg must be <= dma_attr_addr_hi.
414  */
415 #define	_DDI_DMA_BOUNCE_ON_SEG		0x8000
416 
417 #define	DMA_ATTR_V0		0
418 #define	DMA_ATTR_VERSION	DMA_ATTR_V0
419 
420 typedef struct ddi_dma_attr {
421 	uint_t		dma_attr_version;	/* version number */
422 	uint64_t	dma_attr_addr_lo;	/* low DMA address range */
423 	uint64_t	dma_attr_addr_hi;	/* high DMA address range */
424 	uint64_t	dma_attr_count_max;	/* DMA counter register */
425 	uint64_t	dma_attr_align;		/* DMA address alignment */
426 	uint_t		dma_attr_burstsizes;	/* DMA burstsizes */
427 	uint32_t	dma_attr_minxfer;	/* min effective DMA size */
428 	uint64_t 	dma_attr_maxxfer;	/* max DMA xfer size */
429 	uint64_t 	dma_attr_seg;		/* segment boundary */
430 	int		dma_attr_sgllen;	/* s/g length */
431 	uint32_t	dma_attr_granular;	/* granularity of device */
432 	uint_t		dma_attr_flags;		/* Bus specific DMA flags */
433 } ddi_dma_attr_t;
434 
435 /*
436  * Handy macro to set a maximum bit value (should be elsewhere)
437  *
438  * Clear off all bits lower then 'mybit' in val; if there are no
439  * bits higher than or equal to mybit in val then set mybit. Assumes
440  * mybit equals some power of 2 and is not zero.
441  */
442 #define	maxbit(val, mybit)	\
443 	((val) & ~((mybit)-1)) | ((((val) & ~((mybit)-1)) == 0) ? (mybit) : 0)
444 
445 /*
446  * Handy macro to set a minimum bit value (should be elsewhere)
447  *
448  * Clear off all bits higher then 'mybit' in val; if there are no
449  * bits lower than or equal to mybit in val then set mybit. Assumes
450  * mybit equals some pow2 and is not zero.
451  */
452 #define	minbit(val, mybit)	\
453 	(((val)&((mybit)|((mybit)-1))) | \
454 	((((val) & ((mybit)-1)) == 0) ? (mybit) : 0))
455 
456 /*
457  * Structure of a request to map an object for DMA.
458  */
459 typedef struct ddi_dma_req {
460 	/*
461 	 * Caller's DMA engine constraints.
462 	 *
463 	 * If there are no particular constraints to the caller's DMA
464 	 * engine, this field may be set to NULL. The implementation DMA
465 	 * setup functions will then select a set of standard beginning
466 	 * constraints.
467 	 *
468 	 * In either case, as the mapping proceeds, the initial DMA
469 	 * constraints may become more restrictive as each intervening
470 	 * nexus might add further restrictions.
471 	 */
472 	ddi_dma_lim_t	*dmar_limits;
473 
474 	/*
475 	 * Contains the information passed to the DMA mapping allocation
476 	 * routine(s).
477 	 */
478 	uint_t		dmar_flags;
479 
480 	/*
481 	 * Callback function. A caller of the DMA mapping functions must
482 	 * specify by filling in this field whether the allocation routines
483 	 * can sleep awaiting mapping resources, must *not* sleep awaiting
484 	 * resources, or may *not* sleep awaiting any resources and must
485 	 * call the function specified by dmar_fp with the the argument
486 	 * dmar_arg when resources might have become available at a future
487 	 * time.
488 	 */
489 	int		(*dmar_fp)();
490 
491 	caddr_t		dmar_arg;	/* Callback function argument */
492 
493 	/*
494 	 * Description of the object to be mapped for DMA.
495 	 * Must be last in this structure in case that the
496 	 * union ddi_dma_obj_t changes in the future.
497 	 */
498 	ddi_dma_obj_t	dmar_object;
499 
500 } ddi_dma_req_t;
501 
502 /*
503  * Defines for the DMA mapping allocation functions
504  *
505  * If a DMA callback funtion is set to anything other than the following
506  * defines then it is assumed that one wishes a callback and is providing
507  * a function address.
508  */
509 #ifdef __STDC__
510 #define	DDI_DMA_DONTWAIT	((int (*)(caddr_t))0)
511 #define	DDI_DMA_SLEEP		((int (*)(caddr_t))1)
512 #else
513 #define	DDI_DMA_DONTWAIT	((int (*)())0)
514 #define	DDI_DMA_SLEEP		((int (*)())1)
515 #endif
516 
517 /*
518  * Return values from callback functions.
519  */
520 #define	DDI_DMA_CALLBACK_RUNOUT	0
521 #define	DDI_DMA_CALLBACK_DONE	1
522 
523 /*
524  * Flag definitions for the allocation functions.
525  */
526 #define	DDI_DMA_WRITE		0x0001	/* Direction memory --> IO 	*/
527 #define	DDI_DMA_READ		0x0002	/* Direction IO --> memory	*/
528 #define	DDI_DMA_RDWR		(DDI_DMA_READ | DDI_DMA_WRITE)
529 
530 /*
531  * If possible, establish a MMU redzone after the mapping (to protect
532  * against cheap DMA hardware that might get out of control).
533  */
534 #define	DDI_DMA_REDZONE		0x0004
535 
536 /*
537  * A partial allocation is allowed. That is, if the size of the object
538  * exceeds the mapping resources available, only map a portion of the
539  * object and return status indicating that this took place. The caller
540  * can use the functions ddi_dma_numwin(9F) and ddi_dma_getwin(9F) to
541  * change, at a later point, the actual mapped portion of the object.
542  *
543  * The mapped portion begins at offset 0 of the object.
544  *
545  */
546 #define	DDI_DMA_PARTIAL		0x0008
547 
548 /*
549  * Map the object for byte consistent access. Note that explicit
550  * synchronization (via ddi_dma_sync(9F)) will still be required.
551  * Consider this flag to be a hint to the mapping routines as to
552  * the intended use of the mapping.
553  *
554  * Normal data transfers can be usually consider to use 'streaming'
555  * modes of operations. They start at a specific point, transfer a
556  * fairly large amount of data sequentially, and then stop (usually
557  * on a well aligned boundary).
558  *
559  * Control mode data transfers (for memory resident device control blocks,
560  * e.g., ethernet message descriptors) do not access memory in such
561  * a streaming sequential fashion. Instead, they tend to modify a few
562  * words or bytes, move around and maybe modify a few more.
563  *
564  * There are many machine implementations that make this difficult to
565  * control in a generic and seamless fashion. Therefore, explicit synch-
566  * ronization steps (via ddi_dma_sync(9F)) are still required (even if you
567  * ask for a byte-consistent mapping) in order to make the view of the
568  * memory object shared between a CPU and a DMA master in consistent.
569  * However, judicious use of this flag can give sufficient hints to
570  * the mapping routines to attempt to pick the most efficacious mapping
571  * such that the synchronization steps are as efficient as possible.
572  *
573  */
574 #define	DDI_DMA_CONSISTENT	0x0010
575 
576 /*
577  * Some DMA mappings have to be 'exclusive' access.
578  */
579 #define	DDI_DMA_EXCLUSIVE	0x0020
580 
581 /*
582  * Sequential, unidirectional, block-sized and block aligned transfers
583  */
584 #define	DDI_DMA_STREAMING	0x0040
585 
586 /*
587  * Support for 64-bit SBus devices
588  */
589 #define	DDI_DMA_SBUS_64BIT	0x2000
590 
591 /*
592  * Return values from the mapping allocation functions.
593  */
594 
595 /*
596  * succeeded in satisfying request
597  */
598 #define	DDI_DMA_MAPPED		0
599 
600 /*
601  * Mapping is legitimate (for advisory calls).
602  */
603 #define	DDI_DMA_MAPOK		0
604 
605 /*
606  * Succeeded in mapping a portion of the request.
607  */
608 #define	DDI_DMA_PARTIAL_MAP	1
609 
610 /*
611  * indicates end of window/segment list
612  */
613 #define	DDI_DMA_DONE		2
614 
615 /*
616  * No resources to map request.
617  */
618 #define	DDI_DMA_NORESOURCES	-1
619 
620 /*
621  * Can't establish a mapping to the specified object
622  * (no specific reason).
623  */
624 #define	DDI_DMA_NOMAPPING	-2
625 
626 /*
627  * The request is too big to be mapped.
628  */
629 #define	DDI_DMA_TOOBIG		-3
630 
631 /*
632  * The request is too small to be mapped.
633  */
634 #define	DDI_DMA_TOOSMALL	-4
635 
636 /*
637  * The request cannot be mapped because the object
638  * is locked against mapping by another DMA master.
639  */
640 #define	DDI_DMA_LOCKED		-5
641 
642 /*
643  * The request cannot be mapped because the limits
644  * structure has bogus values.
645  */
646 #define	DDI_DMA_BADLIMITS	-6
647 
648 /*
649  * the segment/window pointer is stale
650  */
651 #define	DDI_DMA_STALE		-7
652 
653 /*
654  * The system can't allocate DMA resources using
655  * the given DMA attributes
656  */
657 #define	DDI_DMA_BADATTR		-8
658 
659 /*
660  * A DMA handle is already used for a DMA
661  */
662 #define	DDI_DMA_INUSE		-9
663 
664 
665 /*
666  * DVMA disabled or not supported. use physical DMA
667  */
668 #define	DDI_DMA_USE_PHYSICAL		-10
669 
670 
671 /*
672  * In order for the access to a memory object to be consistent
673  * between a device and a CPU, the function ddi_dma_sync(9F)
674  * must be called upon the DMA handle. The following flags
675  * define whose view of the object should be made consistent.
676  * There are different flags here because on different machines
677  * there are definite performance implications of how long
678  * such synchronization takes.
679  *
680  * DDI_DMA_SYNC_FORDEV makes all device references to the object
681  * mapped by the DMA handle up to date. It should be used by a
682  * driver after a cpu modifies the memory object (over the range
683  * specified by the other arguments to the ddi_dma_sync(9F) call).
684  *
685  * DDI_DMA_SYNC_FORCPU makes all cpu references to the object
686  * mapped by the DMA handle up to date. It should be used
687  * by a driver after the receipt of data from the device to
688  * the memory object is done (over the range specified by
689  * the other arguments to the ddi_dma_sync(9F) call).
690  *
691  * If the only mapping that concerns the driver is one for the
692  * kernel (such as memory allocated by ddi_iopb_alloc(9F)), the
693  * flag DDI_DMA_SYNC_FORKERNEL can be used. This is a hint to the
694  * system that if it can synchronize the kernel's view faster
695  * that the CPU's view, it can do so, otherwise it acts the
696  * same as DDI_DMA_SYNC_FORCPU. DDI_DMA_SYNC_FORKERNEL might
697  * speed up the synchronization of kernel mappings in case of
698  * non IO-coherent CPU caches.
699  */
700 #define	DDI_DMA_SYNC_FORDEV	0x0
701 #define	DDI_DMA_SYNC_FORCPU	0x1
702 #define	DDI_DMA_SYNC_FORKERNEL	0x2
703 
704 /*
705  * Bus nexus control functions for DMA
706  */
707 
708 /*
709  * Control operations, defined here so that devops.h can be included
710  * by drivers without having to include a specific SYSDDI implementation
711  * header file.
712  */
713 
714 enum ddi_dma_ctlops {
715 	DDI_DMA_FREE,		/* free reference to object		*/
716 	DDI_DMA_SYNC,		/* synchronize cache references		*/
717 	DDI_DMA_HTOC,		/* return DMA cookie for handle		*/
718 	DDI_DMA_KVADDR,		/* return kernel virtual address	*/
719 	DDI_DMA_MOVWIN,		/* change mapped DMA window on object	*/
720 	DDI_DMA_REPWIN,		/* report current window on DMA object	*/
721 	DDI_DMA_GETERR,		/* report any post-transfer DMA errors	*/
722 	DDI_DMA_COFF,		/* convert a DMA cookie to an offset	*/
723 	DDI_DMA_NEXTWIN,	/* get next window within object	*/
724 	DDI_DMA_NEXTSEG,	/* get next segment within window	*/
725 	DDI_DMA_SEGTOC,		/* return segment DMA cookie		*/
726 	DDI_DMA_RESERVE,	/* reserve some DVMA range		*/
727 	DDI_DMA_RELEASE,	/* free preallocated DVMA range		*/
728 	DDI_DMA_RESETH,		/* reset next cookie ptr in handle	*/
729 	DDI_DMA_CKSYNC,		/* sync intermediate buffer to cookies	*/
730 	DDI_DMA_IOPB_ALLOC,	/* get contiguous DMA-able memory	*/
731 	DDI_DMA_IOPB_FREE,	/* return contiguous DMA-able memory	*/
732 	DDI_DMA_SMEM_ALLOC,	/* get contiguous DMA-able memory	*/
733 	DDI_DMA_SMEM_FREE,	/* return contiguous DMA-able memory	*/
734 	DDI_DMA_SET_SBUS64,	/* 64 bit SBus support			*/
735 	DDI_DMA_REMAP,		/* remap DMA buffers after relocation	*/
736 
737 		/*
738 		 * control ops for DMA engine on motherboard
739 		 */
740 	DDI_DMA_E_ACQUIRE,	/* get channel for exclusive use	*/
741 	DDI_DMA_E_FREE,		/* release channel			*/
742 	DDI_DMA_E_1STPTY,	/* setup channel for 1st party DMA	*/
743 	DDI_DMA_E_GETCB,	/* get control block for DMA engine	*/
744 	DDI_DMA_E_FREECB,	/* free control blk for DMA engine	*/
745 	DDI_DMA_E_PROG,		/* program channel of DMA engine	*/
746 	DDI_DMA_E_SWSETUP,	/* setup channel for software control	*/
747 	DDI_DMA_E_SWSTART,	/* software operation of DMA channel	*/
748 	DDI_DMA_E_ENABLE,	/* enable channel of DMA engine		*/
749 	DDI_DMA_E_STOP,		/* stop a channel of DMA engine		*/
750 	DDI_DMA_E_DISABLE,	/* disable channel of DMA engine	*/
751 	DDI_DMA_E_GETCNT,	/* get remaining xfer count		*/
752 	DDI_DMA_E_GETLIM,	/* get DMA engine limits		*/
753 	DDI_DMA_E_GETATTR	/* get DMA engine attributes		*/
754 };
755 
756 /*
757  * Cache attribute flags:
758  *
759  * IOMEM_DATA_CACHED
760  *   The CPU can cache the data it fetches and push it to memory at a later
761  *   time. This is the default attribute and used if no cache attributes is
762  *   specified.
763  *
764  * IOMEM_DATA_UC_WR_COMBINE
765  *   The CPU never caches the data but writes may occur out of order or be
766  *   combined. It implies re-ordering.
767  *
768  * IOMEM_DATA_UNCACHED
769  *   The CPU never caches the data and has uncacheable access to memory.
770  *   It also implies strict ordering.
771  *
772  * The cache attributes are mutually exclusive, and any combination of the
773  * values leads to a failure. On the sparc architecture, only IOMEM_DATA_CACHED
774  * is meaningful, but others lead to a failure.
775  */
776 #define	IOMEM_DATA_CACHED		0x10000 /* data is cached */
777 #define	IOMEM_DATA_UC_WR_COMBINE	0x20000 /* data is not cached, but */
778 						/* writes might be combined */
779 #define	IOMEM_DATA_UNCACHED		0x40000 /* data is not cached. */
780 #define	IOMEM_DATA_MASK			0xF0000	/* cache attrs mask */
781 
782 /*
783  * Check if either uncacheable or write-combining specified. (those flags are
784  * mutually exclusive) This macro is used to override hat attributes if either
785  * one is set.
786  */
787 #define	OVERRIDE_CACHE_ATTR(attr)	\
788 	(attr & (IOMEM_DATA_UNCACHED | IOMEM_DATA_UC_WR_COMBINE))
789 
790 /*
791  * Get the cache attribute from flags. If there is no attributes,
792  * return IOMEM_DATA_CACHED (default attribute).
793  */
794 #define	IOMEM_CACHE_ATTR(flags)	\
795 	((flags & IOMEM_DATA_MASK) ? (flags & IOMEM_DATA_MASK) : \
796 	    IOMEM_DATA_CACHED)
797 
798 #ifdef	__cplusplus
799 }
800 #endif
801 
802 #endif	/* _SYS_DDIDMAREQ_H */
803