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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  * DMA_ATTR_SYS_CACHE_ONLY: used to indicate that the buffer should be mapped
66  * with the correct memory attributes so that it can be cached in the system
67  * or last level cache. This is useful for buffers that are being mapped for
68  * devices that are non-coherent, but can use the system cache.
69  */
70 #define DMA_ATTR_SYS_CACHE_ONLY (1UL << 10)
71 
72 /*
73  * DMA_ATTR_SYS_CACHE_ONLY_NWA: used to indicate that the buffer should be
74  * mapped with the correct memory attributes so that it can be cached in the
75  * system or last level cache, with a no write allocate cache policy. This is
76  * useful for buffers that are being mapped for devices that are non-coherent,
77  * but can use the system cache.
78  */
79 #define DMA_ATTR_SYS_CACHE_ONLY_NWA (1UL << 11)
80 
81 /*
82  * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
83  * be given to a device to use as a DMA source or target.  It is specific to a
84  * given device and there may be a translation between the CPU physical address
85  * space and the bus address space.
86  *
87  * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
88  * be used directly in drivers, but checked for using dma_mapping_error()
89  * instead.
90  */
91 #define DMA_MAPPING_ERROR (~(dma_addr_t)0)
92 
93 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL << (n)) - 1))
94 
95 #ifdef CONFIG_DMA_API_DEBUG
96 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
97 void debug_dma_map_single(struct device *dev, const void *addr, unsigned long len);
98 #else
debug_dma_mapping_error(struct device * dev,dma_addr_t dma_addr)99 static inline void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
100 {
101 }
debug_dma_map_single(struct device * dev,const void * addr,unsigned long len)102 static inline void debug_dma_map_single(struct device *dev, const void *addr, unsigned long len)
103 {
104 }
105 #endif /* CONFIG_DMA_API_DEBUG */
106 
107 #ifdef CONFIG_HAS_DMA
dma_mapping_error(struct device * dev,dma_addr_t dma_addr)108 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
109 {
110     debug_dma_mapping_error(dev, dma_addr);
111 
112     if (dma_addr == DMA_MAPPING_ERROR) {
113         return -ENOMEM;
114     }
115     return 0;
116 }
117 
118 dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, size_t offset, size_t size,
119                               enum dma_data_direction dir, unsigned long attrs);
120 void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir,
121                           unsigned long attrs);
122 int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir,
123                      unsigned long attrs);
124 void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir,
125                         unsigned long attrs);
126 dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir,
127                             unsigned long attrs);
128 void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir,
129                         unsigned long attrs);
130 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir);
131 void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir);
132 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir);
133 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, enum dma_data_direction dir);
134 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs);
135 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs);
136 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs);
137 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle);
138 int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size,
139                           unsigned long attrs);
140 int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size,
141                    unsigned long attrs);
142 bool dma_can_mmap(struct device *dev);
143 int dma_supported(struct device *dev, u64 mask);
144 int dma_set_mask(struct device *dev, u64 mask);
145 int dma_set_coherent_mask(struct device *dev, u64 mask);
146 u64 dma_get_required_mask(struct device *dev);
147 size_t dma_max_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 #else  /* CONFIG_HAS_DMA */
dma_map_page_attrs(struct device * dev,struct page * page,size_t offset,size_t size,enum dma_data_direction dir,unsigned long attrs)151 static inline dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, size_t offset, size_t size,
152                                             enum dma_data_direction dir, unsigned long attrs)
153 {
154     return DMA_MAPPING_ERROR;
155 }
dma_unmap_page_attrs(struct device * dev,dma_addr_t addr,size_t size,enum dma_data_direction dir,unsigned long attrs)156 static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir,
157                                         unsigned long attrs)
158 {
159 }
dma_map_sg_attrs(struct device * dev,struct scatterlist * sg,int nents,enum dma_data_direction dir,unsigned long attrs)160 static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir,
161                                    unsigned long attrs)
162 {
163     return 0;
164 }
dma_unmap_sg_attrs(struct device * dev,struct scatterlist * sg,int nents,enum dma_data_direction dir,unsigned long attrs)165 static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
166                                       enum dma_data_direction dir, unsigned long attrs)
167 {
168 }
dma_map_resource(struct device * dev,phys_addr_t phys_addr,size_t size,enum dma_data_direction dir,unsigned long attrs)169 static inline dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size,
170                                           enum dma_data_direction dir, unsigned long attrs)
171 {
172     return DMA_MAPPING_ERROR;
173 }
dma_unmap_resource(struct device * dev,dma_addr_t addr,size_t size,enum dma_data_direction dir,unsigned long attrs)174 static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir,
175                                       unsigned long attrs)
176 {
177 }
dma_sync_single_for_cpu(struct device * dev,dma_addr_t addr,size_t size,enum dma_data_direction dir)178 static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
179                                            enum dma_data_direction dir)
180 {
181 }
dma_sync_single_for_device(struct device * dev,dma_addr_t addr,size_t size,enum dma_data_direction dir)182 static inline void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size,
183                                               enum dma_data_direction dir)
184 {
185 }
dma_sync_sg_for_cpu(struct device * dev,struct scatterlist * sg,int nelems,enum dma_data_direction dir)186 static inline void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
187                                        enum dma_data_direction dir)
188 {
189 }
dma_sync_sg_for_device(struct device * dev,struct scatterlist * sg,int nelems,enum dma_data_direction dir)190 static inline void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
191                                           enum dma_data_direction dir)
192 {
193 }
dma_mapping_error(struct device * dev,dma_addr_t dma_addr)194 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
195 {
196     return -ENOMEM;
197 }
dma_alloc_attrs(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t flag,unsigned long attrs)198 static inline void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag,
199                                     unsigned long attrs)
200 {
201     return NULL;
202 }
dma_free_attrs(struct device * dev,size_t size,void * cpu_addr,dma_addr_t dma_handle,unsigned long attrs)203 static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
204 {
205 }
dmam_alloc_attrs(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp,unsigned long attrs)206 static inline void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp,
207                                      unsigned long attrs)
208 {
209     return NULL;
210 }
dmam_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)211 static inline void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle)
212 {
213 }
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)214 static inline int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr,
215                                         size_t size, unsigned long attrs)
216 {
217     return -ENXIO;
218 }
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)219 static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr,
220                                  size_t size, unsigned long attrs)
221 {
222     return -ENXIO;
223 }
dma_can_mmap(struct device * dev)224 static inline bool dma_can_mmap(struct device *dev)
225 {
226     return false;
227 }
dma_supported(struct device * dev,u64 mask)228 static inline int dma_supported(struct device *dev, u64 mask)
229 {
230     return 0;
231 }
dma_set_mask(struct device * dev,u64 mask)232 static inline int dma_set_mask(struct device *dev, u64 mask)
233 {
234     return -EIO;
235 }
dma_set_coherent_mask(struct device * dev,u64 mask)236 static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
237 {
238     return -EIO;
239 }
dma_get_required_mask(struct device * dev)240 static inline u64 dma_get_required_mask(struct device *dev)
241 {
242     return 0;
243 }
dma_max_mapping_size(struct device * dev)244 static inline size_t dma_max_mapping_size(struct device *dev)
245 {
246     return 0;
247 }
dma_need_sync(struct device * dev,dma_addr_t dma_addr)248 static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
249 {
250     return false;
251 }
dma_get_merge_boundary(struct device * dev)252 static inline unsigned long dma_get_merge_boundary(struct device *dev)
253 {
254     return 0;
255 }
256 #endif /* CONFIG_HAS_DMA */
257 
258 struct page *dma_alloc_pages(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir,
259                              gfp_t gfp);
260 void dma_free_pages(struct device *dev, size_t size, struct page *page, dma_addr_t dma_handle,
261                     enum dma_data_direction dir);
262 void *dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir,
263                             gfp_t gfp);
264 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle,
265                           enum dma_data_direction dir);
266 
dma_map_single_attrs(struct device * dev,void * ptr,size_t size,enum dma_data_direction dir,unsigned long attrs)267 static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr, size_t size, enum dma_data_direction dir,
268                                               unsigned long attrs)
269 {
270     /* DMA must never operate on areas that might be remapped. */
271     if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr), "rejecting DMA map of vmalloc memory\n")) {
272         return DMA_MAPPING_ERROR;
273     }
274     debug_dma_map_single(dev, ptr, size);
275     return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr), size, dir, attrs);
276 }
277 
dma_unmap_single_attrs(struct device * dev,dma_addr_t addr,size_t size,enum dma_data_direction dir,unsigned long attrs)278 static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir,
279                                           unsigned long attrs)
280 {
281     return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
282 }
283 
dma_sync_single_range_for_cpu(struct device * dev,dma_addr_t addr,unsigned long offset,size_t size,enum dma_data_direction dir)284 static inline void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t addr, unsigned long offset, size_t size,
285                                                  enum dma_data_direction dir)
286 {
287     return dma_sync_single_for_cpu(dev, addr + offset, size, dir);
288 }
289 
dma_sync_single_range_for_device(struct device * dev,dma_addr_t addr,unsigned long offset,size_t size,enum dma_data_direction dir)290 static inline void dma_sync_single_range_for_device(struct device *dev, dma_addr_t addr, unsigned long offset,
291                                                     size_t size, enum dma_data_direction dir)
292 {
293     return dma_sync_single_for_device(dev, addr + offset, size, dir);
294 }
295 
296 /**
297  * dma_map_sgtable - Map the given buffer for DMA
298  * @dev:    The device for which to perform the DMA operation
299  * @sgt:    The sg_table object describing the buffer
300  * @dir:    DMA direction
301  * @attrs:    Optional DMA attributes for the map operation
302  *
303  * Maps a buffer described by a scatterlist stored in the given sg_table
304  * object for the @dir DMA operation by the @dev device. After success the
305  * ownership for the buffer is transferred to the DMA domain.  One has to
306  * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the
307  * ownership of the buffer back to the CPU domain before touching the
308  * buffer by the CPU.
309  *
310  * Returns 0 on success or -EINVAL on error during mapping the buffer.
311  */
dma_map_sgtable(struct device * dev,struct sg_table * sgt,enum dma_data_direction dir,unsigned long attrs)312 static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, enum dma_data_direction dir,
313                                   unsigned long attrs)
314 {
315     int nents;
316 
317     nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
318     if (nents <= 0) {
319         return -EINVAL;
320     }
321     sgt->nents = nents;
322     return 0;
323 }
324 
325 /**
326  * dma_unmap_sgtable - Unmap the given buffer for DMA
327  * @dev:    The device for which to perform the DMA operation
328  * @sgt:    The sg_table object describing the buffer
329  * @dir:    DMA direction
330  * @attrs:    Optional DMA attributes for the unmap operation
331  *
332  * Unmaps a buffer described by a scatterlist stored in the given sg_table
333  * object for the @dir DMA operation by the @dev device. After this function
334  * the ownership of the buffer is transferred back to the CPU domain.
335  */
dma_unmap_sgtable(struct device * dev,struct sg_table * sgt,enum dma_data_direction dir,unsigned long attrs)336 static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt, enum dma_data_direction dir,
337                                      unsigned long attrs)
338 {
339     dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
340 }
341 
342 /**
343  * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
344  * @dev:    The device for which to perform the DMA operation
345  * @sgt:    The sg_table object describing the buffer
346  * @dir:    DMA direction
347  *
348  * Performs the needed cache synchronization and moves the ownership of the
349  * buffer back to the CPU domain, so it is safe to perform any access to it
350  * by the CPU. Before doing any further DMA operations, one has to transfer
351  * the ownership of the buffer back to the DMA domain by calling the
352  * dma_sync_sgtable_for_device().
353  */
dma_sync_sgtable_for_cpu(struct device * dev,struct sg_table * sgt,enum dma_data_direction dir)354 static inline void dma_sync_sgtable_for_cpu(struct device *dev, struct sg_table *sgt, enum dma_data_direction dir)
355 {
356     dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
357 }
358 
359 /**
360  * dma_sync_sgtable_for_device - Synchronize 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  *
365  * Performs the needed cache synchronization and moves the ownership of the
366  * buffer back to the DMA domain, so it is safe to perform the DMA operation.
367  * Once finished, one has to call dma_sync_sgtable_for_cpu() or
368  * dma_unmap_sgtable().
369  */
dma_sync_sgtable_for_device(struct device * dev,struct sg_table * sgt,enum dma_data_direction dir)370 static inline void dma_sync_sgtable_for_device(struct device *dev, struct sg_table *sgt, enum dma_data_direction dir)
371 {
372     dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir);
373 }
374 
375 #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
376 #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
377 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
378 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
379 #define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
380 #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
381 #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
382 #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
383 
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp)384 static inline void *dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
385 {
386     return dma_alloc_attrs(dev, size, dma_handle, gfp, (gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
387 }
388 
dma_free_coherent(struct device * dev,size_t size,void * cpu_addr,dma_addr_t dma_handle)389 static inline void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle)
390 {
391     return dma_free_attrs(dev, size, cpu_addr, dma_handle, 0);
392 }
393 
dma_get_mask(struct device * dev)394 static inline u64 dma_get_mask(struct device *dev)
395 {
396     if (dev->dma_mask && *dev->dma_mask) {
397         return *dev->dma_mask;
398     }
399     return DMA_BIT_MASK(32);
400 }
401 
402 /*
403  * Set both the DMA mask and the coherent DMA mask to the same thing.
404  * Note that we don't check the return value from dma_set_coherent_mask()
405  * as the DMA API guarantees that the coherent DMA mask can be set to
406  * the same or smaller than the streaming DMA mask.
407  */
dma_set_mask_and_coherent(struct device * dev,u64 mask)408 static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
409 {
410     int rc = dma_set_mask(dev, mask);
411     if (rc == 0) {
412         dma_set_coherent_mask(dev, mask);
413     }
414     return rc;
415 }
416 
417 /*
418  * Similar to the above, except it deals with the case where the device
419  * does not have dev->dma_mask appropriately setup.
420  */
dma_coerce_mask_and_coherent(struct device * dev,u64 mask)421 static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
422 {
423     dev->dma_mask = &dev->coherent_dma_mask;
424     return dma_set_mask_and_coherent(dev, mask);
425 }
426 
427 /**
428  * dma_addressing_limited - return if the device is addressing limited
429  * @dev:    device to check
430  *
431  * Return %true if the devices DMA mask is too small to address all memory in
432  * the system, else %false.  Lack of addressing bits is the prime reason for
433  * bounce buffering, but might not be the only one.
434  */
dma_addressing_limited(struct device * dev)435 static inline bool dma_addressing_limited(struct device *dev)
436 {
437     return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) < dma_get_required_mask(dev);
438 }
439 
dma_get_max_seg_size(struct device * dev)440 static inline unsigned int dma_get_max_seg_size(struct device *dev)
441 {
442     if (dev->dma_parms && dev->dma_parms->max_segment_size) {
443         return dev->dma_parms->max_segment_size;
444     }
445     return SZ_64K;
446 }
447 
dma_set_max_seg_size(struct device * dev,unsigned int size)448 static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
449 {
450     if (dev->dma_parms) {
451         dev->dma_parms->max_segment_size = size;
452         return 0;
453     }
454     return -EIO;
455 }
456 
dma_get_seg_boundary(struct device * dev)457 static inline unsigned long dma_get_seg_boundary(struct device *dev)
458 {
459     if (dev->dma_parms && dev->dma_parms->segment_boundary_mask) {
460         return dev->dma_parms->segment_boundary_mask;
461     }
462     return ULONG_MAX;
463 }
464 
465 /**
466  * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
467  * @dev: device to guery the boundary for
468  * @page_shift: ilog() of the IOMMU page size
469  *
470  * Return the segment boundary in IOMMU page units (which may be different from
471  * the CPU page size) for the passed in device.
472  *
473  * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
474  * non-DMA API callers.
475  */
dma_get_seg_boundary_nr_pages(struct device * dev,unsigned int page_shift)476 static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev, unsigned int page_shift)
477 {
478     if (!dev) {
479         return (U32_MAX >> page_shift) + 1;
480     }
481     return (dma_get_seg_boundary(dev) >> page_shift) + 1;
482 }
483 
dma_set_seg_boundary(struct device * dev,unsigned long mask)484 static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
485 {
486     if (dev->dma_parms) {
487         dev->dma_parms->segment_boundary_mask = mask;
488         return 0;
489     }
490     return -EIO;
491 }
492 
dma_get_min_align_mask(struct device * dev)493 static inline unsigned int dma_get_min_align_mask(struct device *dev)
494 {
495     if (dev->dma_parms) {
496         return dev->dma_parms->min_align_mask;
497     }
498     return 0;
499 }
500 
dma_set_min_align_mask(struct device * dev,unsigned int min_align_mask)501 static inline int dma_set_min_align_mask(struct device *dev, unsigned int min_align_mask)
502 {
503     if (WARN_ON_ONCE(!dev->dma_parms)) {
504         return -EIO;
505     }
506     dev->dma_parms->min_align_mask = min_align_mask;
507     return 0;
508 }
509 
dma_get_cache_alignment(void)510 static inline int dma_get_cache_alignment(void)
511 {
512 #ifdef ARCH_DMA_MINALIGN
513     return ARCH_DMA_MINALIGN;
514 #endif
515     return 1;
516 }
517 
dmam_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp)518 static inline void *dmam_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
519 {
520     return dmam_alloc_attrs(dev, size, dma_handle, gfp, (gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
521 }
522 
dma_alloc_wc(struct device * dev,size_t size,dma_addr_t * dma_addr,gfp_t gfp)523 static inline void *dma_alloc_wc(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t gfp)
524 {
525     unsigned long attrs = DMA_ATTR_WRITE_COMBINE;
526 
527     if (gfp & __GFP_NOWARN) {
528         attrs |= DMA_ATTR_NO_WARN;
529     }
530 
531     return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
532 }
533 
dma_free_wc(struct device * dev,size_t size,void * cpu_addr,dma_addr_t dma_addr)534 static inline void dma_free_wc(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr)
535 {
536     return dma_free_attrs(dev, size, cpu_addr, dma_addr, DMA_ATTR_WRITE_COMBINE);
537 }
538 
dma_mmap_wc(struct device * dev,struct vm_area_struct * vma,void * cpu_addr,dma_addr_t dma_addr,size_t size)539 static inline int dma_mmap_wc(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr,
540                               size_t size)
541 {
542     return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, DMA_ATTR_WRITE_COMBINE);
543 }
544 
545 #ifdef CONFIG_NEED_DMA_MAP_STATE
546 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME) dma_addr_t ADDR_NAME
547 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME) __u32 LEN_NAME
548 #define dma_unmap_addr(PTR, ADDR_NAME) ((PTR)->ADDR_NAME)
549 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) (((PTR)->ADDR_NAME) = (VAL))
550 #define dma_unmap_len(PTR, LEN_NAME) ((PTR)->LEN_NAME)
551 #define dma_unmap_len_set(PTR, LEN_NAME, VAL) (((PTR)->LEN_NAME) = (VAL))
552 #else
553 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
554 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
555 #define dma_unmap_addr(PTR, ADDR_NAME) (0)
556 #define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)                                                                        \
557     do {                                                                                                               \
558     } while (0)
559 #define dma_unmap_len(PTR, LEN_NAME) (0)
560 #define dma_unmap_len_set(PTR, LEN_NAME, VAL)                                                                          \
561     do {                                                                                                               \
562     } while (0)
563 #endif
564 
565 /*
566  * Legacy interface to set up the dma offset map.  Drivers really should not
567  * actually use it, but we have a few legacy cases left.
568  */
569 int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start, dma_addr_t dma_start, u64 size);
570 
571 extern const struct dma_map_ops dma_virt_ops;
572 
573 #endif /* _LINUX_DMA_MAPPING_H */
574