1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_DMA_MAPPING_H
3#define _LINUX_DMA_MAPPING_H
4
5#include <linux/cache.h>
6#include <linux/sizes.h>
7#include <linux/string.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/dma-direction.h>
11#include <linux/scatterlist.h>
12#include <linux/bug.h>
13#include <linux/mem_encrypt.h>
14
15/**
16 * List of possible attributes associated with a DMA mapping. The semantics
17 * of each attribute should be defined in Documentation/core-api/dma-attributes.rst.
18 */
19
20/*
21 * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping
22 * may be weakly ordered, that is that reads and writes may pass each other.
23 */
24#define DMA_ATTR_WEAK_ORDERING (1UL << 1)
25/*
26 * DMA_ATTR_WRITE_COMBINE: Specifies that writes to the mapping may be
27 * buffered to improve performance.
28 */
29#define DMA_ATTR_WRITE_COMBINE (1UL << 2)
30/*
31 * DMA_ATTR_NO_KERNEL_MAPPING: Lets the platform to avoid creating a kernel
32 * virtual mapping for the allocated buffer.
33 */
34#define DMA_ATTR_NO_KERNEL_MAPPING (1UL << 4)
35/*
36 * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of
37 * the CPU cache for the given buffer assuming that it has been already
38 * transferred to 'device' domain.
39 */
40#define DMA_ATTR_SKIP_CPU_SYNC (1UL << 5)
41/*
42 * DMA_ATTR_FORCE_CONTIGUOUS: Forces contiguous allocation of the buffer
43 * in physical memory.
44 */
45#define DMA_ATTR_FORCE_CONTIGUOUS (1UL << 6)
46/*
47 * DMA_ATTR_ALLOC_SINGLE_PAGES: This is a hint to the DMA-mapping subsystem
48 * that it's probably not worth the time to try to allocate memory to in a way
49 * that gives better TLB efficiency.
50 */
51#define DMA_ATTR_ALLOC_SINGLE_PAGES (1UL << 7)
52/*
53 * DMA_ATTR_NO_WARN: This tells the DMA-mapping subsystem to suppress
54 * allocation failure reports (similarly to __GFP_NOWARN).
55 */
56#define DMA_ATTR_NO_WARN (1UL << 8)
57
58/*
59 * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
60 * accessible at an elevated privilege level (and ideally inaccessible or
61 * at least read-only at lesser-privileged levels).
62 */
63#define DMA_ATTR_PRIVILEGED (1UL << 9)
64
65/*
66 * A dma_addr_t can hold any valid DMA or bus address for the platform. It can
67 * be given to a device to use as a DMA source or target. It is specific to a
68 * given device and there may be a translation between the CPU physical address
69 * space and the bus address space.
70 *
71 * DMA_MAPPING_ERROR is the magic error code if a mapping failed. It should not
72 * be used directly in drivers, but checked for using dma_mapping_error()
73 * instead.
74 */
75#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
76
77#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
78
79#ifdef CONFIG_DMA_API_DEBUG
80void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
81void debug_dma_map_single(struct device *dev, const void *addr,
82 unsigned long len);
83#else
84static inline void debug_dma_mapping_error(struct device *dev,
85 dma_addr_t dma_addr)
86{
87}
88static inline void debug_dma_map_single(struct device *dev, const void *addr,
89 unsigned long len)
90{
91}
92#endif /* CONFIG_DMA_API_DEBUG */
93
94#ifdef CONFIG_HAS_DMA
95static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
96{
97 debug_dma_mapping_error(dev, dma_addr);
98
99 if (unlikely(dma_addr == DMA_MAPPING_ERROR))
100 return -ENOMEM;
101 return 0;
102}
103
104dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
105 size_t offset, size_t size, enum dma_data_direction dir,
106 unsigned long attrs);
107void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
108 enum dma_data_direction dir, unsigned long attrs);
109unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
110 int nents, enum dma_data_direction dir, unsigned long attrs);
111void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
112 int nents, enum dma_data_direction dir,
113 unsigned long attrs);
114int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
115 enum dma_data_direction dir, unsigned long attrs);
116dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
117 size_t size, enum dma_data_direction dir, unsigned long attrs);
118void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
119 enum dma_data_direction dir, unsigned long attrs);
120void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
121 enum dma_data_direction dir);
122void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
123 size_t size, enum dma_data_direction dir);
124void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
125 int nelems, enum dma_data_direction dir);
126void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
127 int nelems, enum dma_data_direction dir);
128void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
129 gfp_t flag, unsigned long attrs);
130void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
131 dma_addr_t dma_handle, unsigned long attrs);
132void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
133 gfp_t gfp, unsigned long attrs);
134void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
135 dma_addr_t dma_handle);
136int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
137 void *cpu_addr, dma_addr_t dma_addr, size_t size,
138 unsigned long attrs);
139int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
140 void *cpu_addr, dma_addr_t dma_addr, size_t size,
141 unsigned long attrs);
142bool dma_can_mmap(struct device *dev);
143bool dma_pci_p2pdma_supported(struct device *dev);
144int dma_set_mask(struct device *dev, u64 mask);
145int dma_set_coherent_mask(struct device *dev, u64 mask);
146u64 dma_get_required_mask(struct device *dev);
147size_t dma_max_mapping_size(struct device *dev);
148size_t dma_opt_mapping_size(struct device *dev);
149bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
150unsigned long dma_get_merge_boundary(struct device *dev);
151struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size,
152 enum dma_data_direction dir, gfp_t gfp, unsigned long attrs);
153void dma_free_noncontiguous(struct device *dev, size_t size,
154 struct sg_table *sgt, enum dma_data_direction dir);
155void *dma_vmap_noncontiguous(struct device *dev, size_t size,
156 struct sg_table *sgt);
157void dma_vunmap_noncontiguous(struct device *dev, void *vaddr);
158int dma_mmap_noncontiguous(struct device *dev, struct vm_area_struct *vma,
159 size_t size, struct sg_table *sgt);
160#else /* CONFIG_HAS_DMA */
161static inline dma_addr_t dma_map_page_attrs(struct device *dev,
162 struct page *page, size_t offset, size_t size,
163 enum dma_data_direction dir, unsigned long attrs)
164{
165 return DMA_MAPPING_ERROR;
166}
167static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr,
168 size_t size, enum dma_data_direction dir, unsigned long attrs)
169{
170}
171static inline unsigned int dma_map_sg_attrs(struct device *dev,
172 struct scatterlist *sg, int nents, enum dma_data_direction dir,
173 unsigned long attrs)
174{
175 return 0;
176}
177static inline void dma_unmap_sg_attrs(struct device *dev,
178 struct scatterlist *sg, int nents, enum dma_data_direction dir,
179 unsigned long attrs)
180{
181}
182static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
183 enum dma_data_direction dir, unsigned long attrs)
184{
185 return -EOPNOTSUPP;
186}
187static inline dma_addr_t dma_map_resource(struct device *dev,
188 phys_addr_t phys_addr, size_t size, enum dma_data_direction dir,
189 unsigned long attrs)
190{
191 return DMA_MAPPING_ERROR;
192}
193static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
194 size_t size, enum dma_data_direction dir, unsigned long attrs)
195{
196}
197static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
198 size_t size, enum dma_data_direction dir)
199{
200}
201static inline void dma_sync_single_for_device(struct device *dev,
202 dma_addr_t addr, size_t size, enum dma_data_direction dir)
203{
204}
205static inline void dma_sync_sg_for_cpu(struct device *dev,
206 struct scatterlist *sg, int nelems, enum dma_data_direction dir)
207{
208}
209static inline void dma_sync_sg_for_device(struct device *dev,
210 struct scatterlist *sg, int nelems, enum dma_data_direction dir)
211{
212}
213static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
214{
215 return -ENOMEM;
216}
217static inline void *dma_alloc_attrs(struct device *dev, size_t size,
218 dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
219{
220 return NULL;
221}
222static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
223 dma_addr_t dma_handle, unsigned long attrs)
224{
225}
226static inline void *dmam_alloc_attrs(struct device *dev, size_t size,
227 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
228{
229 return NULL;
230}
231static inline void dmam_free_coherent(struct device *dev, size_t size,
232 void *vaddr, dma_addr_t dma_handle)
233{
234}
235static inline int dma_get_sgtable_attrs(struct device *dev,
236 struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr,
237 size_t size, unsigned long attrs)
238{
239 return -ENXIO;
240}
241static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
242 void *cpu_addr, dma_addr_t dma_addr, size_t size,
243 unsigned long attrs)
244{
245 return -ENXIO;
246}
247static inline bool dma_can_mmap(struct device *dev)
248{
249 return false;
250}
251static inline bool dma_pci_p2pdma_supported(struct device *dev)
252{
253 return false;
254}
255static inline int dma_set_mask(struct device *dev, u64 mask)
256{
257 return -EIO;
258}
259static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
260{
261 return -EIO;
262}
263static inline u64 dma_get_required_mask(struct device *dev)
264{
265 return 0;
266}
267static inline size_t dma_max_mapping_size(struct device *dev)
268{
269 return 0;
270}
271static inline size_t dma_opt_mapping_size(struct device *dev)
272{
273 return 0;
274}
275static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
276{
277 return false;
278}
279static inline unsigned long dma_get_merge_boundary(struct device *dev)
280{
281 return 0;
282}
283static inline struct sg_table *dma_alloc_noncontiguous(struct device *dev,
284 size_t size, enum dma_data_direction dir, gfp_t gfp,
285 unsigned long attrs)
286{
287 return NULL;
288}
289static inline void dma_free_noncontiguous(struct device *dev, size_t size,
290 struct sg_table *sgt, enum dma_data_direction dir)
291{
292}
293static inline void *dma_vmap_noncontiguous(struct device *dev, size_t size,
294 struct sg_table *sgt)
295{
296 return NULL;
297}
298static inline void dma_vunmap_noncontiguous(struct device *dev, void *vaddr)
299{
300}
301static inline int dma_mmap_noncontiguous(struct device *dev,
302 struct vm_area_struct *vma, size_t size, struct sg_table *sgt)
303{
304 return -EINVAL;
305}
306#endif /* CONFIG_HAS_DMA */
307
308struct page *dma_alloc_pages(struct device *dev, size_t size,
309 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
310void dma_free_pages(struct device *dev, size_t size, struct page *page,
311 dma_addr_t dma_handle, enum dma_data_direction dir);
312int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma,
313 size_t size, struct page *page);
314
315static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
316 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
317{
318 struct page *page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
319 return page ? page_address(page) : NULL;
320}
321
322static inline void dma_free_noncoherent(struct device *dev, size_t size,
323 void *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir)
324{
325 dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
326}
327
328static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
329 size_t size, enum dma_data_direction dir, unsigned long attrs)
330{
331 /* DMA must never operate on areas that might be remapped. */
332 if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
333 "rejecting DMA map of vmalloc memory\n"))
334 return DMA_MAPPING_ERROR;
335 debug_dma_map_single(dev, addr: ptr, len: size);
336 return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
337 size, dir, attrs);
338}
339
340static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
341 size_t size, enum dma_data_direction dir, unsigned long attrs)
342{
343 return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
344}
345
346static inline void dma_sync_single_range_for_cpu(struct device *dev,
347 dma_addr_t addr, unsigned long offset, size_t size,
348 enum dma_data_direction dir)
349{
350 return dma_sync_single_for_cpu(dev, addr: addr + offset, size, dir);
351}
352
353static inline void dma_sync_single_range_for_device(struct device *dev,
354 dma_addr_t addr, unsigned long offset, size_t size,
355 enum dma_data_direction dir)
356{
357 return dma_sync_single_for_device(dev, addr: addr + offset, size, dir);
358}
359
360/**
361 * dma_unmap_sgtable - Unmap the given buffer for DMA
362 * @dev: The device for which to perform the DMA operation
363 * @sgt: The sg_table object describing the buffer
364 * @dir: DMA direction
365 * @attrs: Optional DMA attributes for the unmap operation
366 *
367 * Unmaps a buffer described by a scatterlist stored in the given sg_table
368 * object for the @dir DMA operation by the @dev device. After this function
369 * the ownership of the buffer is transferred back to the CPU domain.
370 */
371static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
372 enum dma_data_direction dir, unsigned long attrs)
373{
374 dma_unmap_sg_attrs(dev, sg: sgt->sgl, nents: sgt->orig_nents, dir, attrs);
375}
376
377/**
378 * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
379 * @dev: The device for which to perform the DMA operation
380 * @sgt: The sg_table object describing the buffer
381 * @dir: DMA direction
382 *
383 * Performs the needed cache synchronization and moves the ownership of the
384 * buffer back to the CPU domain, so it is safe to perform any access to it
385 * by the CPU. Before doing any further DMA operations, one has to transfer
386 * the ownership of the buffer back to the DMA domain by calling the
387 * dma_sync_sgtable_for_device().
388 */
389static inline void dma_sync_sgtable_for_cpu(struct device *dev,
390 struct sg_table *sgt, enum dma_data_direction dir)
391{
392 dma_sync_sg_for_cpu(dev, sg: sgt->sgl, nelems: sgt->orig_nents, dir);
393}
394
395/**
396 * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
397 * @dev: The device for which to perform the DMA operation
398 * @sgt: The sg_table object describing the buffer
399 * @dir: DMA direction
400 *
401 * Performs the needed cache synchronization and moves the ownership of the
402 * buffer back to the DMA domain, so it is safe to perform the DMA operation.
403 * Once finished, one has to call dma_sync_sgtable_for_cpu() or
404 * dma_unmap_sgtable().
405 */
406static inline void dma_sync_sgtable_for_device(struct device *dev,
407 struct sg_table *sgt, enum dma_data_direction dir)
408{
409 dma_sync_sg_for_device(dev, sg: sgt->sgl, nelems: sgt->orig_nents, dir);
410}
411
412#define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
413#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
414#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
415#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
416#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
417#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
418#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
419#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
420
421bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size);
422
423static inline void *dma_alloc_coherent(struct device *dev, size_t size,
424 dma_addr_t *dma_handle, gfp_t gfp)
425{
426 return dma_alloc_attrs(dev, size, dma_handle, flag: gfp,
427 attrs: (gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
428}
429
430static inline void dma_free_coherent(struct device *dev, size_t size,
431 void *cpu_addr, dma_addr_t dma_handle)
432{
433 return dma_free_attrs(dev, size, cpu_addr, dma_handle, attrs: 0);
434}
435
436
437static inline u64 dma_get_mask(struct device *dev)
438{
439 if (dev->dma_mask && *dev->dma_mask)
440 return *dev->dma_mask;
441 return DMA_BIT_MASK(32);
442}
443
444/*
445 * Set both the DMA mask and the coherent DMA mask to the same thing.
446 * Note that we don't check the return value from dma_set_coherent_mask()
447 * as the DMA API guarantees that the coherent DMA mask can be set to
448 * the same or smaller than the streaming DMA mask.
449 */
450static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
451{
452 int rc = dma_set_mask(dev, mask);
453 if (rc == 0)
454 dma_set_coherent_mask(dev, mask);
455 return rc;
456}
457
458/*
459 * Similar to the above, except it deals with the case where the device
460 * does not have dev->dma_mask appropriately setup.
461 */
462static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
463{
464 dev->dma_mask = &dev->coherent_dma_mask;
465 return dma_set_mask_and_coherent(dev, mask);
466}
467
468/**
469 * dma_addressing_limited - return if the device is addressing limited
470 * @dev: device to check
471 *
472 * Return %true if the devices DMA mask is too small to address all memory in
473 * the system, else %false. Lack of addressing bits is the prime reason for
474 * bounce buffering, but might not be the only one.
475 */
476static inline bool dma_addressing_limited(struct device *dev)
477{
478 return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
479 dma_get_required_mask(dev);
480}
481
482static inline unsigned int dma_get_max_seg_size(struct device *dev)
483{
484 if (dev->dma_parms && dev->dma_parms->max_segment_size)
485 return dev->dma_parms->max_segment_size;
486 return SZ_64K;
487}
488
489static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
490{
491 if (dev->dma_parms) {
492 dev->dma_parms->max_segment_size = size;
493 return 0;
494 }
495 return -EIO;
496}
497
498static inline unsigned long dma_get_seg_boundary(struct device *dev)
499{
500 if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
501 return dev->dma_parms->segment_boundary_mask;
502 return ULONG_MAX;
503}
504
505/**
506 * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
507 * @dev: device to guery the boundary for
508 * @page_shift: ilog() of the IOMMU page size
509 *
510 * Return the segment boundary in IOMMU page units (which may be different from
511 * the CPU page size) for the passed in device.
512 *
513 * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
514 * non-DMA API callers.
515 */
516static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
517 unsigned int page_shift)
518{
519 if (!dev)
520 return (U32_MAX >> page_shift) + 1;
521 return (dma_get_seg_boundary(dev) >> page_shift) + 1;
522}
523
524static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
525{
526 if (dev->dma_parms) {
527 dev->dma_parms->segment_boundary_mask = mask;
528 return 0;
529 }
530 return -EIO;
531}
532
533static inline unsigned int dma_get_min_align_mask(struct device *dev)
534{
535 if (dev->dma_parms)
536 return dev->dma_parms->min_align_mask;
537 return 0;
538}
539
540static inline int dma_set_min_align_mask(struct device *dev,
541 unsigned int min_align_mask)
542{
543 if (WARN_ON_ONCE(!dev->dma_parms))
544 return -EIO;
545 dev->dma_parms->min_align_mask = min_align_mask;
546 return 0;
547}
548
549#ifndef dma_get_cache_alignment
550static inline int dma_get_cache_alignment(void)
551{
552#ifdef ARCH_HAS_DMA_MINALIGN
553 return ARCH_DMA_MINALIGN;
554#endif
555 return 1;
556}
557#endif
558
559static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
560 dma_addr_t *dma_handle, gfp_t gfp)
561{
562 return dmam_alloc_attrs(dev, size, dma_handle, gfp,
563 attrs: (gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
564}
565
566static inline void *dma_alloc_wc(struct device *dev, size_t size,
567 dma_addr_t *dma_addr, gfp_t gfp)
568{
569 unsigned long attrs = DMA_ATTR_WRITE_COMBINE;
570
571 if (gfp & __GFP_NOWARN)
572 attrs |= DMA_ATTR_NO_WARN;
573
574 return dma_alloc_attrs(dev, size, dma_handle: dma_addr, flag: gfp, attrs);
575}
576
577static inline void dma_free_wc(struct device *dev, size_t size,
578 void *cpu_addr, dma_addr_t dma_addr)
579{
580 return dma_free_attrs(dev, size, cpu_addr, dma_handle: dma_addr,
581 DMA_ATTR_WRITE_COMBINE);
582}
583
584static inline int dma_mmap_wc(struct device *dev,
585 struct vm_area_struct *vma,
586 void *cpu_addr, dma_addr_t dma_addr,
587 size_t size)
588{
589 return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size,
590 DMA_ATTR_WRITE_COMBINE);
591}
592
593#ifdef CONFIG_NEED_DMA_MAP_STATE
594#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME) dma_addr_t ADDR_NAME
595#define DEFINE_DMA_UNMAP_LEN(LEN_NAME) __u32 LEN_NAME
596#define dma_unmap_addr(PTR, ADDR_NAME) ((PTR)->ADDR_NAME)
597#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) (((PTR)->ADDR_NAME) = (VAL))
598#define dma_unmap_len(PTR, LEN_NAME) ((PTR)->LEN_NAME)
599#define dma_unmap_len_set(PTR, LEN_NAME, VAL) (((PTR)->LEN_NAME) = (VAL))
600#else
601#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
602#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
603#define dma_unmap_addr(PTR, ADDR_NAME) (0)
604#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) do { } while (0)
605#define dma_unmap_len(PTR, LEN_NAME) (0)
606#define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
607#endif
608
609#endif /* _LINUX_DMA_MAPPING_H */
610

source code of linux/include/linux/dma-mapping.h