xref: /linux-6.15/include/linux/dma-mapping.h (revision fbeac3df)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_DMA_MAPPING_H
3 #define _LINUX_DMA_MAPPING_H
4 
5 #include <linux/sizes.h>
6 #include <linux/string.h>
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/dma-direction.h>
10 #include <linux/scatterlist.h>
11 #include <linux/bug.h>
12 #include <linux/mem_encrypt.h>
13 
14 /**
15  * List of possible attributes associated with a DMA mapping. The semantics
16  * of each attribute should be defined in Documentation/core-api/dma-attributes.rst.
17  */
18 
19 /*
20  * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping
21  * may be weakly ordered, that is that reads and writes may pass each other.
22  */
23 #define DMA_ATTR_WEAK_ORDERING		(1UL << 1)
24 /*
25  * DMA_ATTR_WRITE_COMBINE: Specifies that writes to the mapping may be
26  * buffered to improve performance.
27  */
28 #define DMA_ATTR_WRITE_COMBINE		(1UL << 2)
29 /*
30  * DMA_ATTR_NO_KERNEL_MAPPING: Lets the platform to avoid creating a kernel
31  * virtual mapping for the allocated buffer.
32  */
33 #define DMA_ATTR_NO_KERNEL_MAPPING	(1UL << 4)
34 /*
35  * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of
36  * the CPU cache for the given buffer assuming that it has been already
37  * transferred to 'device' domain.
38  */
39 #define DMA_ATTR_SKIP_CPU_SYNC		(1UL << 5)
40 /*
41  * DMA_ATTR_FORCE_CONTIGUOUS: Forces contiguous allocation of the buffer
42  * in physical memory.
43  */
44 #define DMA_ATTR_FORCE_CONTIGUOUS	(1UL << 6)
45 /*
46  * DMA_ATTR_ALLOC_SINGLE_PAGES: This is a hint to the DMA-mapping subsystem
47  * that it's probably not worth the time to try to allocate memory to in a way
48  * that gives better TLB efficiency.
49  */
50 #define DMA_ATTR_ALLOC_SINGLE_PAGES	(1UL << 7)
51 /*
52  * DMA_ATTR_NO_WARN: This tells the DMA-mapping subsystem to suppress
53  * allocation failure reports (similarly to __GFP_NOWARN).
54  */
55 #define DMA_ATTR_NO_WARN	(1UL << 8)
56 
57 /*
58  * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
59  * accessible at an elevated privilege level (and ideally inaccessible or
60  * at least read-only at lesser-privileged levels).
61  */
62 #define DMA_ATTR_PRIVILEGED		(1UL << 9)
63 
64 /*
65  * This is a hint to the DMA-mapping subsystem that the device is expected
66  * to overwrite the entire mapped size, thus the caller does not require any
67  * of the previous buffer contents to be preserved. This allows
68  * bounce-buffering implementations to optimise DMA_FROM_DEVICE transfers.
69  */
70 #define DMA_ATTR_OVERWRITE		(1UL << 10)
71 
72 /*
73  * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
74  * be given to a device to use as a DMA source or target.  It is specific to a
75  * given device and there may be a translation between the CPU physical address
76  * space and the bus address space.
77  *
78  * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
79  * be used directly in drivers, but checked for using dma_mapping_error()
80  * instead.
81  */
82 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
83 
84 #define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
85 
86 #ifdef CONFIG_DMA_API_DEBUG
87 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
88 void debug_dma_map_single(struct device *dev, const void *addr,
89 		unsigned long len);
90 #else
91 static inline void debug_dma_mapping_error(struct device *dev,
92 		dma_addr_t dma_addr)
93 {
94 }
95 static inline void debug_dma_map_single(struct device *dev, const void *addr,
96 		unsigned long len)
97 {
98 }
99 #endif /* CONFIG_DMA_API_DEBUG */
100 
101 #ifdef CONFIG_HAS_DMA
102 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
103 {
104 	debug_dma_mapping_error(dev, dma_addr);
105 
106 	if (unlikely(dma_addr == DMA_MAPPING_ERROR))
107 		return -ENOMEM;
108 	return 0;
109 }
110 
111 dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
112 		size_t offset, size_t size, enum dma_data_direction dir,
113 		unsigned long attrs);
114 void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
115 		enum dma_data_direction dir, unsigned long attrs);
116 unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
117 		int nents, enum dma_data_direction dir, unsigned long attrs);
118 void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
119 				      int nents, enum dma_data_direction dir,
120 				      unsigned long attrs);
121 int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
122 		enum dma_data_direction dir, unsigned long attrs);
123 dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
124 		size_t size, enum dma_data_direction dir, unsigned long attrs);
125 void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
126 		enum dma_data_direction dir, unsigned long attrs);
127 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
128 		enum dma_data_direction dir);
129 void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
130 		size_t size, enum dma_data_direction dir);
131 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
132 		    int nelems, enum dma_data_direction dir);
133 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
134 		       int nelems, enum dma_data_direction dir);
135 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
136 		gfp_t flag, unsigned long attrs);
137 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
138 		dma_addr_t dma_handle, unsigned long attrs);
139 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
140 		gfp_t gfp, unsigned long attrs);
141 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
142 		dma_addr_t dma_handle);
143 int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
144 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
145 		unsigned long attrs);
146 int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
147 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
148 		unsigned long attrs);
149 bool dma_can_mmap(struct device *dev);
150 int dma_supported(struct device *dev, u64 mask);
151 int dma_set_mask(struct device *dev, u64 mask);
152 int dma_set_coherent_mask(struct device *dev, u64 mask);
153 u64 dma_get_required_mask(struct device *dev);
154 size_t dma_max_mapping_size(struct device *dev);
155 bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
156 unsigned long dma_get_merge_boundary(struct device *dev);
157 struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size,
158 		enum dma_data_direction dir, gfp_t gfp, unsigned long attrs);
159 void dma_free_noncontiguous(struct device *dev, size_t size,
160 		struct sg_table *sgt, enum dma_data_direction dir);
161 void *dma_vmap_noncontiguous(struct device *dev, size_t size,
162 		struct sg_table *sgt);
163 void dma_vunmap_noncontiguous(struct device *dev, void *vaddr);
164 int dma_mmap_noncontiguous(struct device *dev, struct vm_area_struct *vma,
165 		size_t size, struct sg_table *sgt);
166 #else /* CONFIG_HAS_DMA */
167 static inline dma_addr_t dma_map_page_attrs(struct device *dev,
168 		struct page *page, size_t offset, size_t size,
169 		enum dma_data_direction dir, unsigned long attrs)
170 {
171 	return DMA_MAPPING_ERROR;
172 }
173 static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr,
174 		size_t size, enum dma_data_direction dir, unsigned long attrs)
175 {
176 }
177 static inline unsigned int dma_map_sg_attrs(struct device *dev,
178 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
179 		unsigned long attrs)
180 {
181 	return 0;
182 }
183 static inline void dma_unmap_sg_attrs(struct device *dev,
184 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
185 		unsigned long attrs)
186 {
187 }
188 static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
189 		enum dma_data_direction dir, unsigned long attrs)
190 {
191 	return -EOPNOTSUPP;
192 }
193 static inline dma_addr_t dma_map_resource(struct device *dev,
194 		phys_addr_t phys_addr, size_t size, enum dma_data_direction dir,
195 		unsigned long attrs)
196 {
197 	return DMA_MAPPING_ERROR;
198 }
199 static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
200 		size_t size, enum dma_data_direction dir, unsigned long attrs)
201 {
202 }
203 static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
204 		size_t size, enum dma_data_direction dir)
205 {
206 }
207 static inline void dma_sync_single_for_device(struct device *dev,
208 		dma_addr_t addr, size_t size, enum dma_data_direction dir)
209 {
210 }
211 static inline void dma_sync_sg_for_cpu(struct device *dev,
212 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
213 {
214 }
215 static inline void dma_sync_sg_for_device(struct device *dev,
216 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
217 {
218 }
219 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
220 {
221 	return -ENOMEM;
222 }
223 static inline void *dma_alloc_attrs(struct device *dev, size_t size,
224 		dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
225 {
226 	return NULL;
227 }
228 static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
229 		dma_addr_t dma_handle, unsigned long attrs)
230 {
231 }
232 static inline void *dmam_alloc_attrs(struct device *dev, size_t size,
233 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
234 {
235 	return NULL;
236 }
237 static inline void dmam_free_coherent(struct device *dev, size_t size,
238 		void *vaddr, dma_addr_t dma_handle)
239 {
240 }
241 static inline int dma_get_sgtable_attrs(struct device *dev,
242 		struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr,
243 		size_t size, unsigned long attrs)
244 {
245 	return -ENXIO;
246 }
247 static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
248 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
249 		unsigned long attrs)
250 {
251 	return -ENXIO;
252 }
253 static inline bool dma_can_mmap(struct device *dev)
254 {
255 	return false;
256 }
257 static inline int dma_supported(struct device *dev, u64 mask)
258 {
259 	return 0;
260 }
261 static inline int dma_set_mask(struct device *dev, u64 mask)
262 {
263 	return -EIO;
264 }
265 static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
266 {
267 	return -EIO;
268 }
269 static inline u64 dma_get_required_mask(struct device *dev)
270 {
271 	return 0;
272 }
273 static inline size_t dma_max_mapping_size(struct device *dev)
274 {
275 	return 0;
276 }
277 static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
278 {
279 	return false;
280 }
281 static inline unsigned long dma_get_merge_boundary(struct device *dev)
282 {
283 	return 0;
284 }
285 static inline struct sg_table *dma_alloc_noncontiguous(struct device *dev,
286 		size_t size, enum dma_data_direction dir, gfp_t gfp,
287 		unsigned long attrs)
288 {
289 	return NULL;
290 }
291 static inline void dma_free_noncontiguous(struct device *dev, size_t size,
292 		struct sg_table *sgt, enum dma_data_direction dir)
293 {
294 }
295 static inline void *dma_vmap_noncontiguous(struct device *dev, size_t size,
296 		struct sg_table *sgt)
297 {
298 	return NULL;
299 }
300 static inline void dma_vunmap_noncontiguous(struct device *dev, void *vaddr)
301 {
302 }
303 static inline int dma_mmap_noncontiguous(struct device *dev,
304 		struct vm_area_struct *vma, size_t size, struct sg_table *sgt)
305 {
306 	return -EINVAL;
307 }
308 #endif /* CONFIG_HAS_DMA */
309 
310 struct page *dma_alloc_pages(struct device *dev, size_t size,
311 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
312 void dma_free_pages(struct device *dev, size_t size, struct page *page,
313 		dma_addr_t dma_handle, enum dma_data_direction dir);
314 int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma,
315 		size_t size, struct page *page);
316 
317 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
318 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
319 {
320 	struct page *page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
321 	return page ? page_address(page) : NULL;
322 }
323 
324 static inline void dma_free_noncoherent(struct device *dev, size_t size,
325 		void *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir)
326 {
327 	dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
328 }
329 
330 static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
331 		size_t size, enum dma_data_direction dir, unsigned long attrs)
332 {
333 	/* DMA must never operate on areas that might be remapped. */
334 	if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
335 			  "rejecting DMA map of vmalloc memory\n"))
336 		return DMA_MAPPING_ERROR;
337 	debug_dma_map_single(dev, ptr, size);
338 	return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
339 			size, dir, attrs);
340 }
341 
342 static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
343 		size_t size, enum dma_data_direction dir, unsigned long attrs)
344 {
345 	return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
346 }
347 
348 static inline void dma_sync_single_range_for_cpu(struct device *dev,
349 		dma_addr_t addr, unsigned long offset, size_t size,
350 		enum dma_data_direction dir)
351 {
352 	return dma_sync_single_for_cpu(dev, addr + offset, size, dir);
353 }
354 
355 static inline void dma_sync_single_range_for_device(struct device *dev,
356 		dma_addr_t addr, unsigned long offset, size_t size,
357 		enum dma_data_direction dir)
358 {
359 	return dma_sync_single_for_device(dev, addr + offset, size, dir);
360 }
361 
362 /**
363  * dma_unmap_sgtable - Unmap the given buffer for DMA
364  * @dev:	The device for which to perform the DMA operation
365  * @sgt:	The sg_table object describing the buffer
366  * @dir:	DMA direction
367  * @attrs:	Optional DMA attributes for the unmap operation
368  *
369  * Unmaps a buffer described by a scatterlist stored in the given sg_table
370  * object for the @dir DMA operation by the @dev device. After this function
371  * the ownership of the buffer is transferred back to the CPU domain.
372  */
373 static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
374 		enum dma_data_direction dir, unsigned long attrs)
375 {
376 	dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
377 }
378 
379 /**
380  * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
381  * @dev:	The device for which to perform the DMA operation
382  * @sgt:	The sg_table object describing the buffer
383  * @dir:	DMA direction
384  *
385  * Performs the needed cache synchronization and moves the ownership of the
386  * buffer back to the CPU domain, so it is safe to perform any access to it
387  * by the CPU. Before doing any further DMA operations, one has to transfer
388  * the ownership of the buffer back to the DMA domain by calling the
389  * dma_sync_sgtable_for_device().
390  */
391 static inline void dma_sync_sgtable_for_cpu(struct device *dev,
392 		struct sg_table *sgt, enum dma_data_direction dir)
393 {
394 	dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
395 }
396 
397 /**
398  * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
399  * @dev:	The device for which to perform the DMA operation
400  * @sgt:	The sg_table object describing the buffer
401  * @dir:	DMA direction
402  *
403  * Performs the needed cache synchronization and moves the ownership of the
404  * buffer back to the DMA domain, so it is safe to perform the DMA operation.
405  * Once finished, one has to call dma_sync_sgtable_for_cpu() or
406  * dma_unmap_sgtable().
407  */
408 static inline void dma_sync_sgtable_for_device(struct device *dev,
409 		struct sg_table *sgt, enum dma_data_direction dir)
410 {
411 	dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir);
412 }
413 
414 #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
415 #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
416 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
417 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
418 #define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
419 #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
420 #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
421 #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
422 
423 static 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, gfp,
427 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
428 }
429 
430 static 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, 0);
434 }
435 
436 
437 static 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  */
450 static 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  */
462 static 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  */
476 static 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 
482 static 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 
489 static 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 
498 static 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  */
516 static 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 
524 static 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 
533 static 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 
540 static 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 static inline int dma_get_cache_alignment(void)
550 {
551 #ifdef ARCH_DMA_MINALIGN
552 	return ARCH_DMA_MINALIGN;
553 #endif
554 	return 1;
555 }
556 
557 static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
558 		dma_addr_t *dma_handle, gfp_t gfp)
559 {
560 	return dmam_alloc_attrs(dev, size, dma_handle, gfp,
561 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
562 }
563 
564 static inline void *dma_alloc_wc(struct device *dev, size_t size,
565 				 dma_addr_t *dma_addr, gfp_t gfp)
566 {
567 	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;
568 
569 	if (gfp & __GFP_NOWARN)
570 		attrs |= DMA_ATTR_NO_WARN;
571 
572 	return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
573 }
574 
575 static inline void dma_free_wc(struct device *dev, size_t size,
576 			       void *cpu_addr, dma_addr_t dma_addr)
577 {
578 	return dma_free_attrs(dev, size, cpu_addr, dma_addr,
579 			      DMA_ATTR_WRITE_COMBINE);
580 }
581 
582 static inline int dma_mmap_wc(struct device *dev,
583 			      struct vm_area_struct *vma,
584 			      void *cpu_addr, dma_addr_t dma_addr,
585 			      size_t size)
586 {
587 	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size,
588 			      DMA_ATTR_WRITE_COMBINE);
589 }
590 
591 #ifdef CONFIG_NEED_DMA_MAP_STATE
592 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
593 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
594 #define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
595 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
596 #define dma_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
597 #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
598 #else
599 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
600 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
601 #define dma_unmap_addr(PTR, ADDR_NAME)           (0)
602 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
603 #define dma_unmap_len(PTR, LEN_NAME)             (0)
604 #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
605 #endif
606 
607 #endif /* _LINUX_DMA_MAPPING_H */
608