summaryrefslogtreecommitdiff
path: root/include/linux/dma-mapping.h
blob: 2aaed35b556df47dfd0dc737784abeb780a18216 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DMA_MAPPING_H
#define _LINUX_DMA_MAPPING_H

#include <linux/sizes.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/dma-direction.h>
#include <linux/scatterlist.h>
#include <linux/bug.h>
#include <linux/mem_encrypt.h>

/**
 * List of possible attributes associated with a DMA mapping. The semantics
 * of each attribute should be defined in Documentation/core-api/dma-attributes.rst.
 */

/*
 * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping
 * may be weakly ordered, that is that reads and writes may pass each other.
 */
#define DMA_ATTR_WEAK_ORDERING		(1UL << 1)
/*
 * DMA_ATTR_WRITE_COMBINE: Specifies that writes to the mapping may be
 * buffered to improve performance.
 */
#define DMA_ATTR_WRITE_COMBINE		(1UL << 2)
/*
 * DMA_ATTR_NO_KERNEL_MAPPING: Lets the platform to avoid creating a kernel
 * virtual mapping for the allocated buffer.
 */
#define DMA_ATTR_NO_KERNEL_MAPPING	(1UL << 4)
/*
 * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of
 * the CPU cache for the given buffer assuming that it has been already
 * transferred to 'device' domain.
 */
#define DMA_ATTR_SKIP_CPU_SYNC		(1UL << 5)
/*
 * DMA_ATTR_FORCE_CONTIGUOUS: Forces contiguous allocation of the buffer
 * in physical memory.
 */
#define DMA_ATTR_FORCE_CONTIGUOUS	(1UL << 6)
/*
 * DMA_ATTR_ALLOC_SINGLE_PAGES: This is a hint to the DMA-mapping subsystem
 * that it's probably not worth the time to try to allocate memory to in a way
 * that gives better TLB efficiency.
 */
#define DMA_ATTR_ALLOC_SINGLE_PAGES	(1UL << 7)
/*
 * DMA_ATTR_NO_WARN: This tells the DMA-mapping subsystem to suppress
 * allocation failure reports (similarly to __GFP_NOWARN).
 */
#define DMA_ATTR_NO_WARN	(1UL << 8)

/*
 * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
 * accessible at an elevated privilege level (and ideally inaccessible or
 * at least read-only at lesser-privileged levels).
 */
#define DMA_ATTR_PRIVILEGED		(1UL << 9)

/*
 * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
 * be given to a device to use as a DMA source or target.  It is specific to a
 * given device and there may be a translation between the CPU physical address
 * space and the bus address space.
 *
 * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
 * be used directly in drivers, but checked for using dma_mapping_error()
 * instead.
 */
#define DMA_MAPPING_ERROR		(~(dma_addr_t)0)

#define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))

#ifdef CONFIG_DMA_API_DEBUG
void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
void debug_dma_map_single(struct device *dev, const void *addr,
		unsigned long len);
#else
static inline void debug_dma_mapping_error(struct device *dev,
		dma_addr_t dma_addr)
{
}
static inline void debug_dma_map_single(struct device *dev, const void *addr,
		unsigned long len)
{
}
#endif /* CONFIG_DMA_API_DEBUG */

#ifdef CONFIG_HAS_DMA
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	debug_dma_mapping_error(dev, dma_addr);

	if (dma_addr == DMA_MAPPING_ERROR)
		return -ENOMEM;
	return 0;
}

dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
		size_t offset, size_t size, enum dma_data_direction dir,
		unsigned long attrs);
void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
		enum dma_data_direction dir, unsigned long attrs);
int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
		enum dma_data_direction dir, unsigned long attrs);
void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
				      int nents, enum dma_data_direction dir,
				      unsigned long attrs);
dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
		size_t size, enum dma_data_direction dir, unsigned long attrs);
void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
		enum dma_data_direction dir, unsigned long attrs);
void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
		enum dma_data_direction dir);
void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
		size_t size, enum dma_data_direction dir);
void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
		    int nelems, enum dma_data_direction dir);
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
		       int nelems, enum dma_data_direction dir);
void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
		gfp_t flag, unsigned long attrs);
void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
		dma_addr_t dma_handle, unsigned long attrs);
void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
		gfp_t gfp, unsigned long attrs);
void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
		dma_addr_t dma_handle);
int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
		void *cpu_addr, dma_addr_t dma_addr, size_t size,
		unsigned long attrs);
int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
		void *cpu_addr, dma_addr_t dma_addr, size_t size,
		unsigned long attrs);
bool dma_can_mmap(struct device *dev);
int dma_supported(struct device *dev, u64 mask);
int dma_set_mask(struct device *dev, u64 mask);
int dma_set_coherent_mask(struct device *dev, u64 mask);
u64 dma_get_required_mask(struct device *dev);
size_t dma_max_mapping_size(struct device *dev);
bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
unsigned long dma_get_merge_boundary(struct device *dev);
#else /* CONFIG_HAS_DMA */
static inline dma_addr_t dma_map_page_attrs(struct device *dev,
		struct page *page, size_t offset, size_t size,
		enum dma_data_direction dir, unsigned long attrs)
{
	return DMA_MAPPING_ERROR;
}
static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr,
		size_t size, enum dma_data_direction dir, unsigned long attrs)
{
}
static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
		int nents, enum dma_data_direction dir, unsigned long attrs)
{
	return 0;
}
static inline void dma_unmap_sg_attrs(struct device *dev,
		struct scatterlist *sg, int nents, enum dma_data_direction dir,
		unsigned long attrs)
{
}
static inline dma_addr_t dma_map_resource(struct device *dev,
		phys_addr_t phys_addr, size_t size, enum dma_data_direction dir,
		unsigned long attrs)
{
	return DMA_MAPPING_ERROR;
}
static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
		size_t size, enum dma_data_direction dir, unsigned long attrs)
{
}
static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
		size_t size, enum dma_data_direction dir)
{
}
static inline void dma_sync_single_for_device(struct device *dev,
		dma_addr_t addr, size_t size, enum dma_data_direction dir)
{
}
static inline void dma_sync_sg_for_cpu(struct device *dev,
		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
{
}
static inline void dma_sync_sg_for_device(struct device *dev,
		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
{
}
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	return -ENOMEM;
}
static inline void *dma_alloc_attrs(struct device *dev, size_t size,
		dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
{
	return NULL;
}
static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
		dma_addr_t dma_handle, unsigned long attrs)
{
}
static inline void *dmam_alloc_attrs(struct device *dev, size_t size,
		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
	return NULL;
}
static inline void dmam_free_coherent(struct device *dev, size_t size,
		void *vaddr, dma_addr_t dma_handle)
{
}
static inline int dma_get_sgtable_attrs(struct device *dev,
		struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr,
		size_t size, unsigned long attrs)
{
	return -ENXIO;
}
static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
		void *cpu_addr, dma_addr_t dma_addr, size_t size,
		unsigned long attrs)
{
	return -ENXIO;
}
static inline bool dma_can_mmap(struct device *dev)
{
	return false;
}
static inline int dma_supported(struct device *dev, u64 mask)
{
	return 0;
}
static inline int dma_set_mask(struct device *dev, u64 mask)
{
	return -EIO;
}
static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
{
	return -EIO;
}
static inline u64 dma_get_required_mask(struct device *dev)
{
	return 0;
}
static inline size_t dma_max_mapping_size(struct device *dev)
{
	return 0;
}
static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
{
	return false;
}
static inline unsigned long dma_get_merge_boundary(struct device *dev)
{
	return 0;
}
#endif /* CONFIG_HAS_DMA */

struct page *dma_alloc_pages(struct device *dev, size_t size,
		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
void dma_free_pages(struct device *dev, size_t size, struct page *page,
		dma_addr_t dma_handle, enum dma_data_direction dir);
void *dma_alloc_noncoherent(struct device *dev, size_t size,
		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
		dma_addr_t dma_handle, enum dma_data_direction dir);

static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
		size_t size, enum dma_data_direction dir, unsigned long attrs)
{
	/* DMA must never operate on areas that might be remapped. */
	if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
			  "rejecting DMA map of vmalloc memory\n"))
		return DMA_MAPPING_ERROR;
	debug_dma_map_single(dev, ptr, size);
	return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
			size, dir, attrs);
}

static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
		size_t size, enum dma_data_direction dir, unsigned long attrs)
{
	return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
}

static inline void dma_sync_single_range_for_cpu(struct device *dev,
		dma_addr_t addr, unsigned long offset, size_t size,
		enum dma_data_direction dir)
{
	return dma_sync_single_for_cpu(dev, addr + offset, size, dir);
}

static inline void dma_sync_single_range_for_device(struct device *dev,
		dma_addr_t addr, unsigned long offset, size_t size,
		enum dma_data_direction dir)
{
	return dma_sync_single_for_device(dev, addr + offset, size, dir);
}

/**
 * dma_map_sgtable - Map the given buffer for DMA
 * @dev:	The device for which to perform the DMA operation
 * @sgt:	The sg_table object describing the buffer
 * @dir:	DMA direction
 * @attrs:	Optional DMA attributes for the map operation
 *
 * Maps a buffer described by a scatterlist stored in the given sg_table
 * object for the @dir DMA operation by the @dev device. After success the
 * ownership for the buffer is transferred to the DMA domain.  One has to
 * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the
 * ownership of the buffer back to the CPU domain before touching the
 * buffer by the CPU.
 *
 * Returns 0 on success or -EINVAL on error during mapping the buffer.
 */
static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
		enum dma_data_direction dir, unsigned long attrs)
{
	int nents;

	nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
	if (nents <= 0)
		return -EINVAL;
	sgt->nents = nents;
	return 0;
}

/**
 * dma_unmap_sgtable - Unmap the given buffer for DMA
 * @dev:	The device for which to perform the DMA operation
 * @sgt:	The sg_table object describing the buffer
 * @dir:	DMA direction
 * @attrs:	Optional DMA attributes for the unmap operation
 *
 * Unmaps a buffer described by a scatterlist stored in the given sg_table
 * object for the @dir DMA operation by the @dev device. After this function
 * the ownership of the buffer is transferred back to the CPU domain.
 */
static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
		enum dma_data_direction dir, unsigned long attrs)
{
	dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
}

/**
 * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
 * @dev:	The device for which to perform the DMA operation
 * @sgt:	The sg_table object describing the buffer
 * @dir:	DMA direction
 *
 * Performs the needed cache synchronization and moves the ownership of the
 * buffer back to the CPU domain, so it is safe to perform any access to it
 * by the CPU. Before doing any further DMA operations, one has to transfer
 * the ownership of the buffer back to the DMA domain by calling the
 * dma_sync_sgtable_for_device().
 */
static inline void dma_sync_sgtable_for_cpu(struct device *dev,
		struct sg_table *sgt, enum dma_data_direction dir)
{
	dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
}

/**
 * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
 * @dev:	The device for which to perform the DMA operation
 * @sgt:	The sg_table object describing the buffer
 * @dir:	DMA direction
 *
 * Performs the needed cache synchronization and moves the ownership of the
 * buffer back to the DMA domain, so it is safe to perform the DMA operation.
 * Once finished, one has to call dma_sync_sgtable_for_cpu() or
 * dma_unmap_sgtable().
 */
static inline void dma_sync_sgtable_for_device(struct device *dev,
		struct sg_table *sgt, enum dma_data_direction dir)
{
	dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir);
}

#define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)

static inline void *dma_alloc_coherent(struct device *dev, size_t size,
		dma_addr_t *dma_handle, gfp_t gfp)
{

	return dma_alloc_attrs(dev, size, dma_handle, gfp,
			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
}

static inline void dma_free_coherent(struct device *dev, size_t size,
		void *cpu_addr, dma_addr_t dma_handle)
{
	return dma_free_attrs(dev, size, cpu_addr, dma_handle, 0);
}


static inline u64 dma_get_mask(struct device *dev)
{
	if (dev->dma_mask && *dev->dma_mask)
		return *dev->dma_mask;
	return DMA_BIT_MASK(32);
}

/*
 * Set both the DMA mask and the coherent DMA mask to the same thing.
 * Note that we don't check the return value from dma_set_coherent_mask()
 * as the DMA API guarantees that the coherent DMA mask can be set to
 * the same or smaller than the streaming DMA mask.
 */
static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
{
	int rc = dma_set_mask(dev, mask);
	if (rc == 0)
		dma_set_coherent_mask(dev, mask);
	return rc;
}

/*
 * Similar to the above, except it deals with the case where the device
 * does not have dev->dma_mask appropriately setup.
 */
static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
{
	dev->dma_mask = &dev->coherent_dma_mask;
	return dma_set_mask_and_coherent(dev, mask);
}

/**
 * dma_addressing_limited - return if the device is addressing limited
 * @dev:	device to check
 *
 * Return %true if the devices DMA mask is too small to address all memory in
 * the system, else %false.  Lack of addressing bits is the prime reason for
 * bounce buffering, but might not be the only one.
 */
static inline bool dma_addressing_limited(struct device *dev)
{
	return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
			    dma_get_required_mask(dev);
}

static inline unsigned int dma_get_max_seg_size(struct device *dev)
{
	if (dev->dma_parms && dev->dma_parms->max_segment_size)
		return dev->dma_parms->max_segment_size;
	return SZ_64K;
}

static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
{
	if (dev->dma_parms) {
		dev->dma_parms->max_segment_size = size;
		return 0;
	}
	return -EIO;
}

static inline unsigned long dma_get_seg_boundary(struct device *dev)
{
	if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
		return dev->dma_parms->segment_boundary_mask;
	return ULONG_MAX;
}

/**
 * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
 * @dev: device to guery the boundary for
 * @page_shift: ilog() of the IOMMU page size
 *
 * Return the segment boundary in IOMMU page units (which may be different from
 * the CPU page size) for the passed in device.
 *
 * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
 * non-DMA API callers.
 */
static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
		unsigned int page_shift)
{
	if (!dev)
		return (U32_MAX >> page_shift) + 1;
	return (dma_get_seg_boundary(dev) >> page_shift) + 1;
}

static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
{
	if (dev->dma_parms) {
		dev->dma_parms->segment_boundary_mask = mask;
		return 0;
	}
	return -EIO;
}

static inline int dma_get_cache_alignment(void)
{
#ifdef ARCH_DMA_MINALIGN
	return ARCH_DMA_MINALIGN;
#endif
	return 1;
}

static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
		dma_addr_t *dma_handle, gfp_t gfp)
{
	return dmam_alloc_attrs(dev, size, dma_handle, gfp,
			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
}

static inline void *dma_alloc_wc(struct device *dev, size_t size,
				 dma_addr_t *dma_addr, gfp_t gfp)
{
	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;

	if (gfp & __GFP_NOWARN)
		attrs |= DMA_ATTR_NO_WARN;

	return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
}

static inline void dma_free_wc(struct device *dev, size_t size,
			       void *cpu_addr, dma_addr_t dma_addr)
{
	return dma_free_attrs(dev, size, cpu_addr, dma_addr,
			      DMA_ATTR_WRITE_COMBINE);
}

static inline int dma_mmap_wc(struct device *dev,
			      struct vm_area_struct *vma,
			      void *cpu_addr, dma_addr_t dma_addr,
			      size_t size)
{
	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size,
			      DMA_ATTR_WRITE_COMBINE);
}

#ifdef CONFIG_NEED_DMA_MAP_STATE
#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
#define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
#define dma_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
#else
#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
#define dma_unmap_addr(PTR, ADDR_NAME)           (0)
#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
#define dma_unmap_len(PTR, LEN_NAME)             (0)
#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
#endif

/*
 * Legacy interface to set up the dma offset map.  Drivers really should not
 * actually use it, but we have a few legacy cases left.
 */
int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
		dma_addr_t dma_start, u64 size);

#endif /* _LINUX_DMA_MAPPING_H */