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