xref: /linux/include/linux/dma-mapping.h (revision 2da68a77)
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  * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
66  * be given to a device to use as a DMA source or target.  It is specific to a
67  * given device and there may be a translation between the CPU physical address
68  * space and the bus address space.
69  *
70  * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
71  * be used directly in drivers, but checked for using dma_mapping_error()
72  * instead.
73  */
74 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
75 
76 #define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
77 
78 #ifdef CONFIG_DMA_API_DEBUG
79 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
80 void debug_dma_map_single(struct device *dev, const void *addr,
81 		unsigned long len);
82 #else
83 static inline void debug_dma_mapping_error(struct device *dev,
84 		dma_addr_t dma_addr)
85 {
86 }
87 static inline void debug_dma_map_single(struct device *dev, const void *addr,
88 		unsigned long len)
89 {
90 }
91 #endif /* CONFIG_DMA_API_DEBUG */
92 
93 #ifdef CONFIG_HAS_DMA
94 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
95 {
96 	debug_dma_mapping_error(dev, dma_addr);
97 
98 	if (unlikely(dma_addr == DMA_MAPPING_ERROR))
99 		return -ENOMEM;
100 	return 0;
101 }
102 
103 dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
104 		size_t offset, size_t size, enum dma_data_direction dir,
105 		unsigned long attrs);
106 void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
107 		enum dma_data_direction dir, unsigned long attrs);
108 unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
109 		int nents, enum dma_data_direction dir, unsigned long attrs);
110 void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
111 				      int nents, enum dma_data_direction dir,
112 				      unsigned long attrs);
113 int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
114 		enum dma_data_direction dir, unsigned long attrs);
115 dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
116 		size_t size, enum dma_data_direction dir, unsigned long attrs);
117 void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
118 		enum dma_data_direction dir, unsigned long attrs);
119 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
120 		enum dma_data_direction dir);
121 void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
122 		size_t size, enum dma_data_direction dir);
123 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
124 		    int nelems, enum dma_data_direction dir);
125 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
126 		       int nelems, enum dma_data_direction dir);
127 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
128 		gfp_t flag, unsigned long attrs);
129 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
130 		dma_addr_t dma_handle, unsigned long attrs);
131 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
132 		gfp_t gfp, unsigned long attrs);
133 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
134 		dma_addr_t dma_handle);
135 int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
136 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
137 		unsigned long attrs);
138 int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
139 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
140 		unsigned long attrs);
141 bool dma_can_mmap(struct device *dev);
142 bool dma_pci_p2pdma_supported(struct device *dev);
143 int dma_set_mask(struct device *dev, u64 mask);
144 int dma_set_coherent_mask(struct device *dev, u64 mask);
145 u64 dma_get_required_mask(struct device *dev);
146 size_t dma_max_mapping_size(struct device *dev);
147 size_t dma_opt_mapping_size(struct device *dev);
148 bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
149 unsigned long dma_get_merge_boundary(struct device *dev);
150 struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size,
151 		enum dma_data_direction dir, gfp_t gfp, unsigned long attrs);
152 void dma_free_noncontiguous(struct device *dev, size_t size,
153 		struct sg_table *sgt, enum dma_data_direction dir);
154 void *dma_vmap_noncontiguous(struct device *dev, size_t size,
155 		struct sg_table *sgt);
156 void dma_vunmap_noncontiguous(struct device *dev, void *vaddr);
157 int dma_mmap_noncontiguous(struct device *dev, struct vm_area_struct *vma,
158 		size_t size, struct sg_table *sgt);
159 #else /* CONFIG_HAS_DMA */
160 static inline dma_addr_t dma_map_page_attrs(struct device *dev,
161 		struct page *page, size_t offset, size_t size,
162 		enum dma_data_direction dir, unsigned long attrs)
163 {
164 	return DMA_MAPPING_ERROR;
165 }
166 static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr,
167 		size_t size, enum dma_data_direction dir, unsigned long attrs)
168 {
169 }
170 static inline unsigned int dma_map_sg_attrs(struct device *dev,
171 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
172 		unsigned long attrs)
173 {
174 	return 0;
175 }
176 static inline void dma_unmap_sg_attrs(struct device *dev,
177 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
178 		unsigned long attrs)
179 {
180 }
181 static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
182 		enum dma_data_direction dir, unsigned long attrs)
183 {
184 	return -EOPNOTSUPP;
185 }
186 static inline dma_addr_t dma_map_resource(struct device *dev,
187 		phys_addr_t phys_addr, size_t size, enum dma_data_direction dir,
188 		unsigned long attrs)
189 {
190 	return DMA_MAPPING_ERROR;
191 }
192 static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
193 		size_t size, enum dma_data_direction dir, unsigned long attrs)
194 {
195 }
196 static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
197 		size_t size, enum dma_data_direction dir)
198 {
199 }
200 static inline void dma_sync_single_for_device(struct device *dev,
201 		dma_addr_t addr, size_t size, enum dma_data_direction dir)
202 {
203 }
204 static inline void dma_sync_sg_for_cpu(struct device *dev,
205 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
206 {
207 }
208 static inline void dma_sync_sg_for_device(struct device *dev,
209 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
210 {
211 }
212 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
213 {
214 	return -ENOMEM;
215 }
216 static inline void *dma_alloc_attrs(struct device *dev, size_t size,
217 		dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
218 {
219 	return NULL;
220 }
221 static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
222 		dma_addr_t dma_handle, unsigned long attrs)
223 {
224 }
225 static inline void *dmam_alloc_attrs(struct device *dev, size_t size,
226 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
227 {
228 	return NULL;
229 }
230 static inline void dmam_free_coherent(struct device *dev, size_t size,
231 		void *vaddr, dma_addr_t dma_handle)
232 {
233 }
234 static inline int dma_get_sgtable_attrs(struct device *dev,
235 		struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr,
236 		size_t size, unsigned long attrs)
237 {
238 	return -ENXIO;
239 }
240 static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
241 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
242 		unsigned long attrs)
243 {
244 	return -ENXIO;
245 }
246 static inline bool dma_can_mmap(struct device *dev)
247 {
248 	return false;
249 }
250 static inline bool dma_pci_p2pdma_supported(struct device *dev)
251 {
252 	return false;
253 }
254 static inline int dma_set_mask(struct device *dev, u64 mask)
255 {
256 	return -EIO;
257 }
258 static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
259 {
260 	return -EIO;
261 }
262 static inline u64 dma_get_required_mask(struct device *dev)
263 {
264 	return 0;
265 }
266 static inline size_t dma_max_mapping_size(struct device *dev)
267 {
268 	return 0;
269 }
270 static inline size_t dma_opt_mapping_size(struct device *dev)
271 {
272 	return 0;
273 }
274 static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
275 {
276 	return false;
277 }
278 static inline unsigned long dma_get_merge_boundary(struct device *dev)
279 {
280 	return 0;
281 }
282 static inline struct sg_table *dma_alloc_noncontiguous(struct device *dev,
283 		size_t size, enum dma_data_direction dir, gfp_t gfp,
284 		unsigned long attrs)
285 {
286 	return NULL;
287 }
288 static inline void dma_free_noncontiguous(struct device *dev, size_t size,
289 		struct sg_table *sgt, enum dma_data_direction dir)
290 {
291 }
292 static inline void *dma_vmap_noncontiguous(struct device *dev, size_t size,
293 		struct sg_table *sgt)
294 {
295 	return NULL;
296 }
297 static inline void dma_vunmap_noncontiguous(struct device *dev, void *vaddr)
298 {
299 }
300 static inline int dma_mmap_noncontiguous(struct device *dev,
301 		struct vm_area_struct *vma, size_t size, struct sg_table *sgt)
302 {
303 	return -EINVAL;
304 }
305 #endif /* CONFIG_HAS_DMA */
306 
307 struct page *dma_alloc_pages(struct device *dev, size_t size,
308 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
309 void dma_free_pages(struct device *dev, size_t size, struct page *page,
310 		dma_addr_t dma_handle, enum dma_data_direction dir);
311 int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma,
312 		size_t size, struct page *page);
313 
314 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
315 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
316 {
317 	struct page *page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
318 	return page ? page_address(page) : NULL;
319 }
320 
321 static inline void dma_free_noncoherent(struct device *dev, size_t size,
322 		void *vaddr, dma_addr_t dma_handle, enum dma_data_direction dir)
323 {
324 	dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
325 }
326 
327 static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
328 		size_t size, enum dma_data_direction dir, unsigned long attrs)
329 {
330 	/* DMA must never operate on areas that might be remapped. */
331 	if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
332 			  "rejecting DMA map of vmalloc memory\n"))
333 		return DMA_MAPPING_ERROR;
334 	debug_dma_map_single(dev, ptr, size);
335 	return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
336 			size, dir, attrs);
337 }
338 
339 static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
340 		size_t size, enum dma_data_direction dir, unsigned long attrs)
341 {
342 	return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
343 }
344 
345 static inline void dma_sync_single_range_for_cpu(struct device *dev,
346 		dma_addr_t addr, unsigned long offset, size_t size,
347 		enum dma_data_direction dir)
348 {
349 	return dma_sync_single_for_cpu(dev, addr + offset, size, dir);
350 }
351 
352 static inline void dma_sync_single_range_for_device(struct device *dev,
353 		dma_addr_t addr, unsigned long offset, size_t size,
354 		enum dma_data_direction dir)
355 {
356 	return dma_sync_single_for_device(dev, addr + offset, size, dir);
357 }
358 
359 /**
360  * dma_unmap_sgtable - Unmap the given buffer for DMA
361  * @dev:	The device for which to perform the DMA operation
362  * @sgt:	The sg_table object describing the buffer
363  * @dir:	DMA direction
364  * @attrs:	Optional DMA attributes for the unmap operation
365  *
366  * Unmaps a buffer described by a scatterlist stored in the given sg_table
367  * object for the @dir DMA operation by the @dev device. After this function
368  * the ownership of the buffer is transferred back to the CPU domain.
369  */
370 static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
371 		enum dma_data_direction dir, unsigned long attrs)
372 {
373 	dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
374 }
375 
376 /**
377  * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
378  * @dev:	The device for which to perform the DMA operation
379  * @sgt:	The sg_table object describing the buffer
380  * @dir:	DMA direction
381  *
382  * Performs the needed cache synchronization and moves the ownership of the
383  * buffer back to the CPU domain, so it is safe to perform any access to it
384  * by the CPU. Before doing any further DMA operations, one has to transfer
385  * the ownership of the buffer back to the DMA domain by calling the
386  * dma_sync_sgtable_for_device().
387  */
388 static inline void dma_sync_sgtable_for_cpu(struct device *dev,
389 		struct sg_table *sgt, enum dma_data_direction dir)
390 {
391 	dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
392 }
393 
394 /**
395  * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
396  * @dev:	The device for which to perform the DMA operation
397  * @sgt:	The sg_table object describing the buffer
398  * @dir:	DMA direction
399  *
400  * Performs the needed cache synchronization and moves the ownership of the
401  * buffer back to the DMA domain, so it is safe to perform the DMA operation.
402  * Once finished, one has to call dma_sync_sgtable_for_cpu() or
403  * dma_unmap_sgtable().
404  */
405 static inline void dma_sync_sgtable_for_device(struct device *dev,
406 		struct sg_table *sgt, enum dma_data_direction dir)
407 {
408 	dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir);
409 }
410 
411 #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
412 #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
413 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
414 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
415 #define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
416 #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
417 #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
418 #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
419 
420 static inline void *dma_alloc_coherent(struct device *dev, size_t size,
421 		dma_addr_t *dma_handle, gfp_t gfp)
422 {
423 	return dma_alloc_attrs(dev, size, dma_handle, gfp,
424 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
425 }
426 
427 static inline void dma_free_coherent(struct device *dev, size_t size,
428 		void *cpu_addr, dma_addr_t dma_handle)
429 {
430 	return dma_free_attrs(dev, size, cpu_addr, dma_handle, 0);
431 }
432 
433 
434 static inline u64 dma_get_mask(struct device *dev)
435 {
436 	if (dev->dma_mask && *dev->dma_mask)
437 		return *dev->dma_mask;
438 	return DMA_BIT_MASK(32);
439 }
440 
441 /*
442  * Set both the DMA mask and the coherent DMA mask to the same thing.
443  * Note that we don't check the return value from dma_set_coherent_mask()
444  * as the DMA API guarantees that the coherent DMA mask can be set to
445  * the same or smaller than the streaming DMA mask.
446  */
447 static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
448 {
449 	int rc = dma_set_mask(dev, mask);
450 	if (rc == 0)
451 		dma_set_coherent_mask(dev, mask);
452 	return rc;
453 }
454 
455 /*
456  * Similar to the above, except it deals with the case where the device
457  * does not have dev->dma_mask appropriately setup.
458  */
459 static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
460 {
461 	dev->dma_mask = &dev->coherent_dma_mask;
462 	return dma_set_mask_and_coherent(dev, mask);
463 }
464 
465 /**
466  * dma_addressing_limited - return if the device is addressing limited
467  * @dev:	device to check
468  *
469  * Return %true if the devices DMA mask is too small to address all memory in
470  * the system, else %false.  Lack of addressing bits is the prime reason for
471  * bounce buffering, but might not be the only one.
472  */
473 static inline bool dma_addressing_limited(struct device *dev)
474 {
475 	return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
476 			    dma_get_required_mask(dev);
477 }
478 
479 static inline unsigned int dma_get_max_seg_size(struct device *dev)
480 {
481 	if (dev->dma_parms && dev->dma_parms->max_segment_size)
482 		return dev->dma_parms->max_segment_size;
483 	return SZ_64K;
484 }
485 
486 static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
487 {
488 	if (dev->dma_parms) {
489 		dev->dma_parms->max_segment_size = size;
490 		return 0;
491 	}
492 	return -EIO;
493 }
494 
495 static inline unsigned long dma_get_seg_boundary(struct device *dev)
496 {
497 	if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
498 		return dev->dma_parms->segment_boundary_mask;
499 	return ULONG_MAX;
500 }
501 
502 /**
503  * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
504  * @dev: device to guery the boundary for
505  * @page_shift: ilog() of the IOMMU page size
506  *
507  * Return the segment boundary in IOMMU page units (which may be different from
508  * the CPU page size) for the passed in device.
509  *
510  * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
511  * non-DMA API callers.
512  */
513 static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
514 		unsigned int page_shift)
515 {
516 	if (!dev)
517 		return (U32_MAX >> page_shift) + 1;
518 	return (dma_get_seg_boundary(dev) >> page_shift) + 1;
519 }
520 
521 static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
522 {
523 	if (dev->dma_parms) {
524 		dev->dma_parms->segment_boundary_mask = mask;
525 		return 0;
526 	}
527 	return -EIO;
528 }
529 
530 static inline unsigned int dma_get_min_align_mask(struct device *dev)
531 {
532 	if (dev->dma_parms)
533 		return dev->dma_parms->min_align_mask;
534 	return 0;
535 }
536 
537 static inline int dma_set_min_align_mask(struct device *dev,
538 		unsigned int min_align_mask)
539 {
540 	if (WARN_ON_ONCE(!dev->dma_parms))
541 		return -EIO;
542 	dev->dma_parms->min_align_mask = min_align_mask;
543 	return 0;
544 }
545 
546 static inline int dma_get_cache_alignment(void)
547 {
548 #ifdef ARCH_DMA_MINALIGN
549 	return ARCH_DMA_MINALIGN;
550 #endif
551 	return 1;
552 }
553 
554 static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
555 		dma_addr_t *dma_handle, gfp_t gfp)
556 {
557 	return dmam_alloc_attrs(dev, size, dma_handle, gfp,
558 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
559 }
560 
561 static inline void *dma_alloc_wc(struct device *dev, size_t size,
562 				 dma_addr_t *dma_addr, gfp_t gfp)
563 {
564 	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;
565 
566 	if (gfp & __GFP_NOWARN)
567 		attrs |= DMA_ATTR_NO_WARN;
568 
569 	return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
570 }
571 
572 static inline void dma_free_wc(struct device *dev, size_t size,
573 			       void *cpu_addr, dma_addr_t dma_addr)
574 {
575 	return dma_free_attrs(dev, size, cpu_addr, dma_addr,
576 			      DMA_ATTR_WRITE_COMBINE);
577 }
578 
579 static inline int dma_mmap_wc(struct device *dev,
580 			      struct vm_area_struct *vma,
581 			      void *cpu_addr, dma_addr_t dma_addr,
582 			      size_t size)
583 {
584 	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size,
585 			      DMA_ATTR_WRITE_COMBINE);
586 }
587 
588 #ifdef CONFIG_NEED_DMA_MAP_STATE
589 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
590 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
591 #define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
592 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
593 #define dma_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
594 #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
595 #else
596 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
597 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
598 #define dma_unmap_addr(PTR, ADDR_NAME)           (0)
599 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
600 #define dma_unmap_len(PTR, LEN_NAME)             (0)
601 #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
602 #endif
603 
604 #endif /* _LINUX_DMA_MAPPING_H */
605