xref: /illumos-gate/usr/src/uts/common/sys/ddidmareq.h (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 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_SYS_DDIDMAREQ_H
27 #define	_SYS_DDIDMAREQ_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #ifdef	__cplusplus
32 extern "C" {
33 #endif
34 
35 /*
36  * Memory Objects
37  *
38  * Definitions of structures that can describe
39  * an object that can be mapped for DMA.
40  */
41 
42 /*
43  * Structure describing a virtual address
44  */
45 struct v_address {
46 	caddr_t		v_addr;		/* base virtual address */
47 	struct	as	*v_as;		/* pointer to address space */
48 	void 		*v_priv;	/* priv data for shadow I/O */
49 };
50 
51 /*
52  * Structure describing a page-based address
53  */
54 struct pp_address {
55 	/*
56 	 * A pointer to a circularly linked list of page structures.
57 	 */
58 	struct page *pp_pp;
59 	uint_t pp_offset;	/* offset within first page */
60 };
61 
62 /*
63  * Structure to describe a physical memory address.
64  */
65 struct phy_address {
66 	ulong_t	p_addr;		/* base physical address */
67 	ulong_t	p_memtype;	/* memory type */
68 };
69 
70 /*
71  * A union of all of the above structures.
72  *
73  * This union describes the relationship between
74  * the kind of an address description and an object.
75  */
76 typedef union {
77 	struct v_address virt_obj;	/* Some virtual address		*/
78 	struct pp_address pp_obj;	/* Some page-based address	*/
79 	struct phy_address phys_obj;	/* Some physical address	*/
80 } ddi_dma_aobj_t;
81 
82 /*
83  * DMA object types - used to select how the object
84  * being mapped is being addressed by the IU.
85  */
86 typedef enum {
87 	DMA_OTYP_VADDR = 0,	/* enforce starting value of zero */
88 	DMA_OTYP_PAGES,
89 	DMA_OTYP_PADDR,
90 	DMA_OTYP_BUFVADDR
91 } ddi_dma_atyp_t;
92 
93 /*
94  * A compact package to describe an object that is to be mapped for DMA.
95  */
96 typedef struct {
97 	uint_t		dmao_size;	/* size, in bytes, of the object */
98 	ddi_dma_atyp_t	dmao_type;	/* type of object */
99 	ddi_dma_aobj_t	dmao_obj;	/* the object described */
100 } ddi_dma_obj_t;
101 
102 /*
103  * DMA addressing limits.
104  *
105  * This structure describes the constraints that a particular device's
106  * DMA engine has to its parent so that the parent may correctly set
107  * things up for a DMA mapping. Each parent may in turn modify the
108  * constraints listed in a DMA request structure in order to describe
109  * to its parent any changed or additional constraints. The rules
110  * are that each parent may modify a constraint in order to further
111  * constrain things (e.g., picking a more limited address range than
112  * that permitted by the child), but that the parent may not ignore
113  * a child's constraints.
114  *
115  * A particular constraint that we do *not* address is whether or not
116  * a requested mapping is too large for a DMA engine's counter to
117  * correctly track. It is still up to each driver to explicitly handle
118  * transfers that are too large for its own hardware to deal with directly.
119  *
120  * The mapping routines that are cognizant of this structure will
121  * copy any user defined limits structure if they need to modify
122  * the fields (as alluded to above).
123  *
124  * A note as to how to define constraints:
125  *
126  * How you define the constraints for your device depends on how you
127  * define your device. For example, you may have an SBus card with a
128  * device on it that address only the bottom 16mb of virtual DMA space.
129  * However, if the card also has ancillary circuitry that pulls the high 8
130  * bits of address lines high, the more correct expression for your device
131  * is that it address [0xff000000..0xffffffff] rather than [0..0x00ffffff].
132  */
133 #if defined(__sparc)
134 typedef struct ddi_dma_lim {
135 
136 	/*
137 	 * Low range of 32 bit addressing capability.
138 	 */
139 	uint_t	dlim_addr_lo;
140 
141 	/*
142 	 * Upper inclusive bound of addressing capability. It is an
143 	 * inclusive boundary limit to allow for the addressing range
144 	 * [0..0xffffffff] to be specified in preference to [0..0].
145 	 */
146 	uint_t	dlim_addr_hi;
147 
148 	/*
149 	 * Inclusive upper bound with which The DMA engine's counter acts as
150 	 * a register.
151 	 *
152 	 * This handles the case where an upper portion of a DMA address
153 	 * register is a latch instead of being a full 32 bit register
154 	 * (e.g., the upper 8 bits may remain constant while the lower
155 	 * 24 bits are the real address register).
156 	 *
157 	 * This essentially gives a hint about segment limitations
158 	 * to the mapping routines.
159 	 */
160 	uint_t	dlim_cntr_max;
161 
162 	/*
163 	 * DMA burst sizes.
164 	 *
165 	 * At the time of a mapping request, this tag defines the possible
166 	 * DMA burst cycle sizes that the requestor's DMA engine can
167 	 * emit. The format of the data is binary encoding of burst sizes
168 	 * assumed to be powers of two. That is, if a DMA engine is capable
169 	 * of doing 1, 2, 4 and 16 byte transfers, the encoding would be 0x17.
170 	 *
171 	 * As the mapping request is handled by intervening nexi, the
172 	 * burstsizes value may be modified. Prior to enabling DMA for
173 	 * the specific device, the driver that owns the DMA engine should
174 	 * check (via ddi_dma_burstsizes(9F)) what the allowed burstsizes
175 	 * have become and program their DMA engine appropriately.
176 	 */
177 	uint_t	dlim_burstsizes;
178 
179 	/*
180 	 * Minimum effective DMA transfer size, in units of bytes.
181 	 *
182 	 * This value specifies the minimum effective granularity of the
183 	 * DMA engine. It is distinct from dlim_burtsizes in that it
184 	 * describes the minimum amount of access a DMA transfer will
185 	 * effect. dlim_burtsizes describes in what electrical fashion
186 	 * the DMA engine might perform its accesses, while dlim_minxfer
187 	 * describes the minimum amount of memory that can be touched by
188 	 * the DMA transfer.
189 	 *
190 	 * As the mapping request is handled by intervening nexi, the
191 	 * dlim_minxfer value may be modifed contingent upon the presence
192 	 * (and use) of I/O caches and DMA write buffers in between the
193 	 * DMA engine and the object that DMA is being performed on.
194 	 *
195 	 */
196 	uint_t	dlim_minxfer;
197 
198 	/*
199 	 * Expected average data rate for this DMA engine
200 	 * while transferring data.
201 	 *
202 	 * This is used as a hint for a number of operations that might
203 	 * want to know the possible optimal latency requirements of this
204 	 * device. A value of zero will be interpreted as a 'do not care'.
205 	 */
206 	uint_t	dlim_dmaspeed;
207 
208 } ddi_dma_lim_t;
209 
210 #elif defined(__x86)
211 
212 /*
213  * values for dlim_minxfer
214  */
215 #define	DMA_UNIT_8  1
216 #define	DMA_UNIT_16 2
217 #define	DMA_UNIT_32 4
218 
219 /*
220  * Version number
221  */
222 #define	DMALIM_VER0	((0x86000000) + 0)
223 
224 typedef struct ddi_dma_lim {
225 
226 	/*
227 	 * Low range of 32 bit addressing capability.
228 	 */
229 	uint_t	dlim_addr_lo;
230 
231 	/*
232 	 * Upper Inclusive bound of 32 bit addressing capability.
233 	 *
234 	 * The ISA nexus restricts this to 0x00ffffff, since this bus has
235 	 * only 24 address lines.  This enforces the 16 Mb address limitation.
236 	 * The EISA nexus restricts this to 0xffffffff.
237 	 */
238 	uint_t	dlim_addr_hi;
239 
240 	/*
241 	 * DMA engine counter not used; set to 0
242 	 */
243 	uint_t	dlim_cntr_max;
244 
245 	/*
246 	 *  DMA burst sizes not used; set to 1
247 	 */
248 	uint_t	dlim_burstsizes;
249 
250 	/*
251 	 * Minimum effective DMA transfer size.
252 	 *
253 	 * This value specifies the minimum effective granularity of the
254 	 * DMA engine. It is distinct from dlim_burstsizes in that it
255 	 * describes the minimum amount of access a DMA transfer will
256 	 * effect. dlim_burstsizes describes in what electrical fashion
257 	 * the DMA engine might perform its accesses, while dlim_minxfer
258 	 * describes the minimum amount of memory that can be touched by
259 	 * the DMA transfer.
260 	 *
261 	 * This value also implies the required address alignment.
262 	 * The number of bytes transferred is assumed to be
263 	 * 	dlim_minxfer * (DMA engine count)
264 	 *
265 	 * It should be set to DMA_UNIT_8, DMA_UNIT_16, or DMA_UNIT_32.
266 	 */
267 	uint_t	dlim_minxfer;
268 
269 	/*
270 	 * Expected average data rate for this DMA engine
271 	 * while transferring data.
272 	 *
273 	 * This is used as a hint for a number of operations that might
274 	 * want to know the possible optimal latency requirements of this
275 	 * device. A value of zero will be interpreted as a 'do not care'.
276 	 */
277 	uint_t	dlim_dmaspeed;
278 
279 
280 	/*
281 	 * Version number of this structure
282 	 */
283 	uint_t	dlim_version;	/* = 0x86 << 24 + 0 */
284 
285 	/*
286 	 * Inclusive upper bound with which the DMA engine's Address acts as
287 	 * a register.
288 	 * This handles the case where an upper portion of a DMA address
289 	 * register is a latch instead of being a full 32 bit register
290 	 * (e.g., the upper 16 bits remain constant while the lower 16 bits
291 	 * are incremented for each DMA transfer).
292 	 *
293 	 * The ISA nexus restricts only 3rd-party DMA requests to 0x0000ffff,
294 	 * since the ISA DMA engine has a 16-bit register for low address and
295 	 * an 8-bit latch for high address.  This enforces the first 64 Kb
296 	 * limitation (address boundary).
297 	 * The EISA nexus restricts only 3rd-party DMA requests to 0xffffffff.
298 	 */
299 	uint_t	dlim_adreg_max;
300 
301 	/*
302 	 * Maximum transfer count that the DMA engine can handle.
303 	 *
304 	 * The ISA nexus restricts only 3rd-party DMA requests to 0x0000ffff,
305 	 * since the ISA DMA engine has a 16-bit register for counting.
306 	 * This enforces the other 64 Kb limitation (count size).
307 	 * The EISA nexus restricts only 3rd-party DMA requests to 0x00ffffff,
308 	 * since the EISA DMA engine has a 24-bit register for counting.
309 	 *
310 	 * This transfer count limitation is a per segment limitation.
311 	 * It can also be used to restrict the size of segments.
312 	 *
313 	 * This is used as a bit mask, so it must be a power of 2, minus 1.
314 	 */
315 	uint_t	dlim_ctreg_max;
316 
317 	/*
318 	 * Granularity of DMA transfer, in units of bytes.
319 	 *
320 	 * Breakup sizes must be multiples of this value.
321 	 * If no scatter/gather capabilty is specified, then the size of
322 	 * each DMA transfer must be a multiple of this value.
323 	 *
324 	 * If there is scatter/gather capability, then a single cookie cannot
325 	 * be smaller in size than the minimum xfer value, and may be less
326 	 * than the granularity value.  The total transfer length of the
327 	 * scatter/gather list should be a multiple of the granularity value;
328 	 * use dlim_sgllen to specify the length of the scatter/gather list.
329 	 *
330 	 * This value should be equal to the sector size of the device.
331 	 */
332 	uint_t	dlim_granular;
333 
334 	/*
335 	 * Length of scatter/gather list
336 	 *
337 	 * This value specifies the number of segments or cookies that a DMA
338 	 * engine can consume in one i/o request to the device.  For 3rd-party
339 	 * DMA that uses the bus nexus this should be set to 1.  Devices with
340 	 * 1st-party DMA capability should specify the number of entries in
341 	 * its scatter/gather list.  The breakup routine will ensure that each
342 	 * group of dlim_sgllen cookies (within a DMA window) will have a
343 	 * total transfer length that is a multiple of dlim_granular.
344 	 *
345 	 *	< 0  :  tbd
346 	 *	= 0  :  breakup is for PIO.
347 	 *	= 1  :  breakup is for DMA engine with no scatter/gather
348 	 *		capability.
349 	 *	>= 2 :  breakup is for DMA engine with scatter/gather
350 	 *		capability; value is max number of entries in list.
351 	 *
352 	 * Note that this list length is not dependent on the DMA window
353 	 * size.  The size of the DMA window is based on resources consumed,
354 	 * such as intermediate buffers.  Several s/g lists may exist within
355 	 * a window.  But the end of a window does imply the end of the s/g
356 	 * list.
357 	 */
358 	short	dlim_sgllen;
359 
360 	/*
361 	 * Size of device i/o request
362 	 *
363 	 * This value indicates the maximum number of bytes the device
364 	 * can transmit/receive for one i/o command.  This limitation is
365 	 * significant ony if it is less than (dlim_ctreg_max * dlim_sgllen).
366 	 */
367 	uint_t	dlim_reqsize;
368 
369 } ddi_dma_lim_t;
370 
371 #else
372 #error "struct ddi_dma_lim not defined for this architecture"
373 #endif	/* defined(__sparc) */
374 
375 /*
376  * Flags definition for dma_attr_flags
377  */
378 
379 /*
380  * return physical DMA address on platforms
381  * which support DVMA
382  */
383 #define	DDI_DMA_FORCE_PHYSICAL		0x0100
384 
385 /*
386  * An error will be flagged for DMA data path errors
387  */
388 #define	DDI_DMA_FLAGERR			0x200
389 
390 /*
391  * Enable relaxed ordering
392  */
393 #define	DDI_DMA_RELAXED_ORDERING	0x400
394 
395 #define	DMA_ATTR_V0		0
396 #define	DMA_ATTR_VERSION	DMA_ATTR_V0
397 
398 typedef struct ddi_dma_attr {
399 	uint_t		dma_attr_version;	/* version number */
400 	uint64_t	dma_attr_addr_lo;	/* low DMA address range */
401 	uint64_t	dma_attr_addr_hi;	/* high DMA address range */
402 	uint64_t	dma_attr_count_max;	/* DMA counter register */
403 	uint64_t	dma_attr_align;		/* DMA address alignment */
404 	uint_t		dma_attr_burstsizes;	/* DMA burstsizes */
405 	uint32_t	dma_attr_minxfer;	/* min effective DMA size */
406 	uint64_t 	dma_attr_maxxfer;	/* max DMA xfer size */
407 	uint64_t 	dma_attr_seg;		/* segment boundary */
408 	int		dma_attr_sgllen;	/* s/g length */
409 	uint32_t	dma_attr_granular;	/* granularity of device */
410 	uint_t		dma_attr_flags;		/* Bus specific DMA flags */
411 } ddi_dma_attr_t;
412 
413 /*
414  * Handy macro to set a maximum bit value (should be elsewhere)
415  *
416  * Clear off all bits lower then 'mybit' in val; if there are no
417  * bits higher than or equal to mybit in val then set mybit. Assumes
418  * mybit equals some power of 2 and is not zero.
419  */
420 #define	maxbit(val, mybit)	\
421 	((val) & ~((mybit)-1)) | ((((val) & ~((mybit)-1)) == 0) ? (mybit) : 0)
422 
423 /*
424  * Handy macro to set a minimum bit value (should be elsewhere)
425  *
426  * Clear off all bits higher then 'mybit' in val; if there are no
427  * bits lower than or equal to mybit in val then set mybit. Assumes
428  * mybit equals some pow2 and is not zero.
429  */
430 #define	minbit(val, mybit)	\
431 	(((val)&((mybit)|((mybit)-1))) | \
432 	((((val) & ((mybit)-1)) == 0) ? (mybit) : 0))
433 
434 /*
435  * Structure of a request to map an object for DMA.
436  */
437 typedef struct ddi_dma_req {
438 	/*
439 	 * Caller's DMA engine constraints.
440 	 *
441 	 * If there are no particular constraints to the caller's DMA
442 	 * engine, this field may be set to NULL. The implementation DMA
443 	 * setup functions will then select a set of standard beginning
444 	 * constraints.
445 	 *
446 	 * In either case, as the mapping proceeds, the initial DMA
447 	 * constraints may become more restrictive as each intervening
448 	 * nexus might add further restrictions.
449 	 */
450 	ddi_dma_lim_t	*dmar_limits;
451 
452 	/*
453 	 * Contains the information passed to the DMA mapping allocation
454 	 * routine(s).
455 	 */
456 	uint_t		dmar_flags;
457 
458 	/*
459 	 * Callback function. A caller of the DMA mapping functions must
460 	 * specify by filling in this field whether the allocation routines
461 	 * can sleep awaiting mapping resources, must *not* sleep awaiting
462 	 * resources, or may *not* sleep awaiting any resources and must
463 	 * call the function specified by dmar_fp with the the argument
464 	 * dmar_arg when resources might have become available at a future
465 	 * time.
466 	 */
467 	int		(*dmar_fp)();
468 
469 	caddr_t		dmar_arg;	/* Callback function argument */
470 
471 	/*
472 	 * Description of the object to be mapped for DMA.
473 	 * Must be last in this structure in case that the
474 	 * union ddi_dma_obj_t changes in the future.
475 	 */
476 	ddi_dma_obj_t	dmar_object;
477 
478 } ddi_dma_req_t;
479 
480 /*
481  * Defines for the DMA mapping allocation functions
482  *
483  * If a DMA callback funtion is set to anything other than the following
484  * defines then it is assumed that one wishes a callback and is providing
485  * a function address.
486  */
487 #ifdef __STDC__
488 #define	DDI_DMA_DONTWAIT	((int (*)(caddr_t))0)
489 #define	DDI_DMA_SLEEP		((int (*)(caddr_t))1)
490 #else
491 #define	DDI_DMA_DONTWAIT	((int (*)())0)
492 #define	DDI_DMA_SLEEP		((int (*)())1)
493 #endif
494 
495 /*
496  * Return values from callback functions.
497  */
498 #define	DDI_DMA_CALLBACK_RUNOUT	0
499 #define	DDI_DMA_CALLBACK_DONE	1
500 
501 /*
502  * Flag definitions for the allocation functions.
503  */
504 #define	DDI_DMA_WRITE		0x0001	/* Direction memory --> IO 	*/
505 #define	DDI_DMA_READ		0x0002	/* Direction IO --> memory	*/
506 #define	DDI_DMA_RDWR		(DDI_DMA_READ | DDI_DMA_WRITE)
507 
508 /*
509  * If possible, establish a MMU redzone after the mapping (to protect
510  * against cheap DMA hardware that might get out of control).
511  */
512 #define	DDI_DMA_REDZONE		0x0004
513 
514 /*
515  * A partial allocation is allowed. That is, if the size of the object
516  * exceeds the mapping resources available, only map a portion of the
517  * object and return status indicating that this took place. The caller
518  * can use the functions ddi_dma_numwin(9F) and ddi_dma_getwin(9F) to
519  * change, at a later point, the actual mapped portion of the object.
520  *
521  * The mapped portion begins at offset 0 of the object.
522  *
523  */
524 #define	DDI_DMA_PARTIAL		0x0008
525 
526 /*
527  * Map the object for byte consistent access. Note that explicit
528  * synchronization (via ddi_dma_sync(9F)) will still be required.
529  * Consider this flag to be a hint to the mapping routines as to
530  * the intended use of the mapping.
531  *
532  * Normal data transfers can be usually consider to use 'streaming'
533  * modes of operations. They start at a specific point, transfer a
534  * fairly large amount of data sequentially, and then stop (usually
535  * on a well aligned boundary).
536  *
537  * Control mode data transfers (for memory resident device control blocks,
538  * e.g., ethernet message descriptors) do not access memory in such
539  * a streaming sequential fashion. Instead, they tend to modify a few
540  * words or bytes, move around and maybe modify a few more.
541  *
542  * There are many machine implementations that make this difficult to
543  * control in a generic and seamless fashion. Therefore, explicit synch-
544  * ronization steps (via ddi_dma_sync(9F)) are still required (even if you
545  * ask for a byte-consistent mapping) in order to make the view of the
546  * memory object shared between a CPU and a DMA master in consistent.
547  * However, judicious use of this flag can give sufficient hints to
548  * the mapping routines to attempt to pick the most efficacious mapping
549  * such that the synchronization steps are as efficient as possible.
550  *
551  */
552 #define	DDI_DMA_CONSISTENT	0x0010
553 
554 /*
555  * Some DMA mappings have to be 'exclusive' access.
556  */
557 #define	DDI_DMA_EXCLUSIVE	0x0020
558 
559 /*
560  * Sequential, unidirectional, block-sized and block aligned transfers
561  */
562 #define	DDI_DMA_STREAMING	0x0040
563 
564 /*
565  * Support for 64-bit SBus devices
566  */
567 #define	DDI_DMA_SBUS_64BIT	0x2000
568 
569 /*
570  * Return values from the mapping allocation functions.
571  */
572 
573 /*
574  * succeeded in satisfying request
575  */
576 #define	DDI_DMA_MAPPED		0
577 
578 /*
579  * Mapping is legitimate (for advisory calls).
580  */
581 #define	DDI_DMA_MAPOK		0
582 
583 /*
584  * Succeeded in mapping a portion of the request.
585  */
586 #define	DDI_DMA_PARTIAL_MAP	1
587 
588 /*
589  * indicates end of window/segment list
590  */
591 #define	DDI_DMA_DONE		2
592 
593 /*
594  * No resources to map request.
595  */
596 #define	DDI_DMA_NORESOURCES	-1
597 
598 /*
599  * Can't establish a mapping to the specified object
600  * (no specific reason).
601  */
602 #define	DDI_DMA_NOMAPPING	-2
603 
604 /*
605  * The request is too big to be mapped.
606  */
607 #define	DDI_DMA_TOOBIG		-3
608 
609 /*
610  * The request is too small to be mapped.
611  */
612 #define	DDI_DMA_TOOSMALL	-4
613 
614 /*
615  * The request cannot be mapped because the object
616  * is locked against mapping by another DMA master.
617  */
618 #define	DDI_DMA_LOCKED		-5
619 
620 /*
621  * The request cannot be mapped because the limits
622  * structure has bogus values.
623  */
624 #define	DDI_DMA_BADLIMITS	-6
625 
626 /*
627  * the segment/window pointer is stale
628  */
629 #define	DDI_DMA_STALE		-7
630 
631 /*
632  * The system can't allocate DMA resources using
633  * the given DMA attributes
634  */
635 #define	DDI_DMA_BADATTR		-8
636 
637 /*
638  * A DMA handle is already used for a DMA
639  */
640 #define	DDI_DMA_INUSE		-9
641 
642 /*
643  * In order for the access to a memory object to be consistent
644  * between a device and a CPU, the function ddi_dma_sync(9F)
645  * must be called upon the DMA handle. The following flags
646  * define whose view of the object should be made consistent.
647  * There are different flags here because on different machines
648  * there are definite performance implications of how long
649  * such synchronization takes.
650  *
651  * DDI_DMA_SYNC_FORDEV makes all device references to the object
652  * mapped by the DMA handle up to date. It should be used by a
653  * driver after a cpu modifies the memory object (over the range
654  * specified by the other arguments to the ddi_dma_sync(9F) call).
655  *
656  * DDI_DMA_SYNC_FORCPU makes all cpu references to the object
657  * mapped by the DMA handle up to date. It should be used
658  * by a driver after the receipt of data from the device to
659  * the memory object is done (over the range specified by
660  * the other arguments to the ddi_dma_sync(9F) call).
661  *
662  * If the only mapping that concerns the driver is one for the
663  * kernel (such as memory allocated by ddi_iopb_alloc(9F)), the
664  * flag DDI_DMA_SYNC_FORKERNEL can be used. This is a hint to the
665  * system that if it can synchronize the kernel's view faster
666  * that the CPU's view, it can do so, otherwise it acts the
667  * same as DDI_DMA_SYNC_FORCPU. DDI_DMA_SYNC_FORKERNEL might
668  * speed up the synchronization of kernel mappings in case of
669  * non IO-coherent CPU caches.
670  */
671 #define	DDI_DMA_SYNC_FORDEV	0x0
672 #define	DDI_DMA_SYNC_FORCPU	0x1
673 #define	DDI_DMA_SYNC_FORKERNEL	0x2
674 
675 /*
676  * Bus nexus control functions for DMA
677  */
678 
679 /*
680  * Control operations, defined here so that devops.h can be included
681  * by drivers without having to include a specific SYSDDI implementation
682  * header file.
683  */
684 
685 enum ddi_dma_ctlops {
686 	DDI_DMA_FREE,		/* free reference to object		*/
687 	DDI_DMA_SYNC,		/* synchronize cache references		*/
688 	DDI_DMA_HTOC,		/* return DMA cookie for handle		*/
689 	DDI_DMA_KVADDR,		/* return kernel virtual address	*/
690 	DDI_DMA_MOVWIN,		/* change mapped DMA window on object	*/
691 	DDI_DMA_REPWIN,		/* report current window on DMA object	*/
692 	DDI_DMA_GETERR,		/* report any post-transfer DMA errors	*/
693 	DDI_DMA_COFF,		/* convert a DMA cookie to an offset	*/
694 	DDI_DMA_NEXTWIN,	/* get next window within object	*/
695 	DDI_DMA_NEXTSEG,	/* get next segment within window	*/
696 	DDI_DMA_SEGTOC,		/* return segment DMA cookie		*/
697 	DDI_DMA_RESERVE,	/* reserve some DVMA range		*/
698 	DDI_DMA_RELEASE,	/* free preallocated DVMA range		*/
699 	DDI_DMA_RESETH,		/* reset next cookie ptr in handle	*/
700 	DDI_DMA_CKSYNC,		/* sync intermediate buffer to cookies	*/
701 	DDI_DMA_IOPB_ALLOC,	/* get contiguous DMA-able memory	*/
702 	DDI_DMA_IOPB_FREE,	/* return contiguous DMA-able memory	*/
703 	DDI_DMA_SMEM_ALLOC,	/* get contiguous DMA-able memory	*/
704 	DDI_DMA_SMEM_FREE,	/* return contiguous DMA-able memory	*/
705 	DDI_DMA_SET_SBUS64,	/* 64 bit SBus support			*/
706 	DDI_DMA_REMAP,		/* remap DMA buffers after relocation	*/
707 
708 		/*
709 		 * control ops for DMA engine on motherboard
710 		 */
711 	DDI_DMA_E_ACQUIRE,	/* get channel for exclusive use	*/
712 	DDI_DMA_E_FREE,		/* release channel			*/
713 	DDI_DMA_E_1STPTY,	/* setup channel for 1st party DMA	*/
714 	DDI_DMA_E_GETCB,	/* get control block for DMA engine	*/
715 	DDI_DMA_E_FREECB,	/* free control blk for DMA engine	*/
716 	DDI_DMA_E_PROG,		/* program channel of DMA engine	*/
717 	DDI_DMA_E_SWSETUP,	/* setup channel for software control	*/
718 	DDI_DMA_E_SWSTART,	/* software operation of DMA channel	*/
719 	DDI_DMA_E_ENABLE,	/* enable channel of DMA engine		*/
720 	DDI_DMA_E_STOP,		/* stop a channel of DMA engine		*/
721 	DDI_DMA_E_DISABLE,	/* disable channel of DMA engine	*/
722 	DDI_DMA_E_GETCNT,	/* get remaining xfer count		*/
723 	DDI_DMA_E_GETLIM,	/* get DMA engine limits		*/
724 	DDI_DMA_E_GETATTR	/* get DMA engine attributes		*/
725 };
726 
727 /*
728  * Cache attribute flags:
729  *
730  * IOMEM_DATA_CACHED
731  *   The CPU can cache the data it fetches and push it to memory at a later
732  *   time. This is the default attribute and used if no cache attributes is
733  *   specified.
734  *
735  * IOMEM_DATA_UC_WR_COMBINE
736  *   The CPU never caches the data but writes may occur out of order or be
737  *   combined. It implies re-ordering.
738  *
739  * IOMEM_DATA_UNCACHED
740  *   The CPU never caches the data and has uncacheable access to memory.
741  *   It also implies strict ordering.
742  *
743  * The cache attributes are mutually exclusive, and any combination of the
744  * values leads to a failure. On the sparc architecture, only IOMEM_DATA_CACHED
745  * is meaningful, but others lead to a failure.
746  */
747 #define	IOMEM_DATA_CACHED		0x10000 /* data is cached */
748 #define	IOMEM_DATA_UC_WR_COMBINE	0x20000 /* data is not cached, but */
749 						/* writes might be combined */
750 #define	IOMEM_DATA_UNCACHED		0x40000 /* data is not cached. */
751 #define	IOMEM_DATA_MASK			0xF0000	/* cache attrs mask */
752 
753 /*
754  * Check if either uncacheable or write-combining specified. (those flags are
755  * mutually exclusive) This macro is used to override hat attributes if either
756  * one is set.
757  */
758 #define	OVERRIDE_CACHE_ATTR(attr)	\
759 	(attr & (IOMEM_DATA_UNCACHED | IOMEM_DATA_UC_WR_COMBINE))
760 
761 /*
762  * Get the cache attribute from flags. If there is no attributes,
763  * return IOMEM_DATA_CACHED (default attribute).
764  */
765 #define	IOMEM_CACHE_ATTR(flags)	\
766 	((flags & IOMEM_DATA_MASK) ? (flags & IOMEM_DATA_MASK) : \
767 	    IOMEM_DATA_CACHED)
768 
769 #ifdef	__cplusplus
770 }
771 #endif
772 
773 #endif	/* _SYS_DDIDMAREQ_H */
774