1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * This header is for implementations of dma_map_ops and related code. 4 * It should not be included in drivers just using the DMA API. 5 */ 6 #ifndef _LINUX_DMA_MAP_OPS_H 7 #define _LINUX_DMA_MAP_OPS_H 8 9 #include <linux/dma-mapping.h> 10 #include <linux/pgtable.h> 11 #include <linux/slab.h> 12 13 struct cma; 14 15 /* 16 * Values for struct dma_map_ops.flags: 17 * 18 * DMA_F_PCI_P2PDMA_SUPPORTED: Indicates the dma_map_ops implementation can 19 * handle PCI P2PDMA pages in the map_sg/unmap_sg operation. 20 */ 21 #define DMA_F_PCI_P2PDMA_SUPPORTED (1 << 0) 22 23 struct dma_map_ops { 24 unsigned int flags; 25 26 void *(*alloc)(struct device *dev, size_t size, 27 dma_addr_t *dma_handle, gfp_t gfp, 28 unsigned long attrs); 29 void (*free)(struct device *dev, size_t size, void *vaddr, 30 dma_addr_t dma_handle, unsigned long attrs); 31 struct page *(*alloc_pages)(struct device *dev, size_t size, 32 dma_addr_t *dma_handle, enum dma_data_direction dir, 33 gfp_t gfp); 34 void (*free_pages)(struct device *dev, size_t size, struct page *vaddr, 35 dma_addr_t dma_handle, enum dma_data_direction dir); 36 struct sg_table *(*alloc_noncontiguous)(struct device *dev, size_t size, 37 enum dma_data_direction dir, gfp_t gfp, 38 unsigned long attrs); 39 void (*free_noncontiguous)(struct device *dev, size_t size, 40 struct sg_table *sgt, enum dma_data_direction dir); 41 int (*mmap)(struct device *, struct vm_area_struct *, 42 void *, dma_addr_t, size_t, unsigned long attrs); 43 44 int (*get_sgtable)(struct device *dev, struct sg_table *sgt, 45 void *cpu_addr, dma_addr_t dma_addr, size_t size, 46 unsigned long attrs); 47 48 dma_addr_t (*map_page)(struct device *dev, struct page *page, 49 unsigned long offset, size_t size, 50 enum dma_data_direction dir, unsigned long attrs); 51 void (*unmap_page)(struct device *dev, dma_addr_t dma_handle, 52 size_t size, enum dma_data_direction dir, 53 unsigned long attrs); 54 /* 55 * map_sg should return a negative error code on error. See 56 * dma_map_sgtable() for a list of appropriate error codes 57 * and their meanings. 58 */ 59 int (*map_sg)(struct device *dev, struct scatterlist *sg, int nents, 60 enum dma_data_direction dir, unsigned long attrs); 61 void (*unmap_sg)(struct device *dev, struct scatterlist *sg, int nents, 62 enum dma_data_direction dir, unsigned long attrs); 63 dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr, 64 size_t size, enum dma_data_direction dir, 65 unsigned long attrs); 66 void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle, 67 size_t size, enum dma_data_direction dir, 68 unsigned long attrs); 69 void (*sync_single_for_cpu)(struct device *dev, dma_addr_t dma_handle, 70 size_t size, enum dma_data_direction dir); 71 void (*sync_single_for_device)(struct device *dev, 72 dma_addr_t dma_handle, size_t size, 73 enum dma_data_direction dir); 74 void (*sync_sg_for_cpu)(struct device *dev, struct scatterlist *sg, 75 int nents, enum dma_data_direction dir); 76 void (*sync_sg_for_device)(struct device *dev, struct scatterlist *sg, 77 int nents, enum dma_data_direction dir); 78 void (*cache_sync)(struct device *dev, void *vaddr, size_t size, 79 enum dma_data_direction direction); 80 int (*dma_supported)(struct device *dev, u64 mask); 81 u64 (*get_required_mask)(struct device *dev); 82 size_t (*max_mapping_size)(struct device *dev); 83 size_t (*opt_mapping_size)(void); 84 unsigned long (*get_merge_boundary)(struct device *dev); 85 }; 86 87 #ifdef CONFIG_DMA_OPS 88 #include <asm/dma-mapping.h> 89 90 static inline const struct dma_map_ops *get_dma_ops(struct device *dev) 91 { 92 if (dev->dma_ops) 93 return dev->dma_ops; 94 return get_arch_dma_ops(); 95 } 96 97 static inline void set_dma_ops(struct device *dev, 98 const struct dma_map_ops *dma_ops) 99 { 100 dev->dma_ops = dma_ops; 101 } 102 #else /* CONFIG_DMA_OPS */ 103 static inline const struct dma_map_ops *get_dma_ops(struct device *dev) 104 { 105 return NULL; 106 } 107 static inline void set_dma_ops(struct device *dev, 108 const struct dma_map_ops *dma_ops) 109 { 110 } 111 #endif /* CONFIG_DMA_OPS */ 112 113 #ifdef CONFIG_DMA_CMA 114 extern struct cma *dma_contiguous_default_area; 115 116 static inline struct cma *dev_get_cma_area(struct device *dev) 117 { 118 if (dev && dev->cma_area) 119 return dev->cma_area; 120 return dma_contiguous_default_area; 121 } 122 123 void dma_contiguous_reserve(phys_addr_t addr_limit); 124 int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, 125 phys_addr_t limit, struct cma **res_cma, bool fixed); 126 127 struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, 128 unsigned int order, bool no_warn); 129 bool dma_release_from_contiguous(struct device *dev, struct page *pages, 130 int count); 131 struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp); 132 void dma_free_contiguous(struct device *dev, struct page *page, size_t size); 133 134 void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size); 135 #else /* CONFIG_DMA_CMA */ 136 static inline struct cma *dev_get_cma_area(struct device *dev) 137 { 138 return NULL; 139 } 140 static inline void dma_contiguous_reserve(phys_addr_t limit) 141 { 142 } 143 static inline int dma_contiguous_reserve_area(phys_addr_t size, 144 phys_addr_t base, phys_addr_t limit, struct cma **res_cma, 145 bool fixed) 146 { 147 return -ENOSYS; 148 } 149 static inline struct page *dma_alloc_from_contiguous(struct device *dev, 150 size_t count, unsigned int order, bool no_warn) 151 { 152 return NULL; 153 } 154 static inline bool dma_release_from_contiguous(struct device *dev, 155 struct page *pages, int count) 156 { 157 return false; 158 } 159 /* Use fallback alloc() and free() when CONFIG_DMA_CMA=n */ 160 static inline struct page *dma_alloc_contiguous(struct device *dev, size_t size, 161 gfp_t gfp) 162 { 163 return NULL; 164 } 165 static inline void dma_free_contiguous(struct device *dev, struct page *page, 166 size_t size) 167 { 168 __free_pages(page, get_order(size)); 169 } 170 #endif /* CONFIG_DMA_CMA*/ 171 172 #ifdef CONFIG_DMA_DECLARE_COHERENT 173 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, 174 dma_addr_t device_addr, size_t size); 175 void dma_release_coherent_memory(struct device *dev); 176 int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, 177 dma_addr_t *dma_handle, void **ret); 178 int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr); 179 int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, 180 void *cpu_addr, size_t size, int *ret); 181 #else 182 static inline int dma_declare_coherent_memory(struct device *dev, 183 phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) 184 { 185 return -ENOSYS; 186 } 187 188 #define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0) 189 #define dma_release_from_dev_coherent(dev, order, vaddr) (0) 190 #define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0) 191 static inline void dma_release_coherent_memory(struct device *dev) { } 192 #endif /* CONFIG_DMA_DECLARE_COHERENT */ 193 194 #ifdef CONFIG_DMA_GLOBAL_POOL 195 void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, 196 dma_addr_t *dma_handle); 197 int dma_release_from_global_coherent(int order, void *vaddr); 198 int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr, 199 size_t size, int *ret); 200 int dma_init_global_coherent(phys_addr_t phys_addr, size_t size); 201 #else 202 static inline void *dma_alloc_from_global_coherent(struct device *dev, 203 ssize_t size, dma_addr_t *dma_handle) 204 { 205 return NULL; 206 } 207 static inline int dma_release_from_global_coherent(int order, void *vaddr) 208 { 209 return 0; 210 } 211 static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma, 212 void *cpu_addr, size_t size, int *ret) 213 { 214 return 0; 215 } 216 #endif /* CONFIG_DMA_GLOBAL_POOL */ 217 218 /* 219 * This is the actual return value from the ->alloc_noncontiguous method. 220 * The users of the DMA API should only care about the sg_table, but to make 221 * the DMA-API internal vmaping and freeing easier we stash away the page 222 * array as well (except for the fallback case). This can go away any time, 223 * e.g. when a vmap-variant that takes a scatterlist comes along. 224 */ 225 struct dma_sgt_handle { 226 struct sg_table sgt; 227 struct page **pages; 228 }; 229 #define sgt_handle(sgt) \ 230 container_of((sgt), struct dma_sgt_handle, sgt) 231 232 int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, 233 void *cpu_addr, dma_addr_t dma_addr, size_t size, 234 unsigned long attrs); 235 int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, 236 void *cpu_addr, dma_addr_t dma_addr, size_t size, 237 unsigned long attrs); 238 struct page *dma_common_alloc_pages(struct device *dev, size_t size, 239 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); 240 void dma_common_free_pages(struct device *dev, size_t size, struct page *vaddr, 241 dma_addr_t dma_handle, enum dma_data_direction dir); 242 243 struct page **dma_common_find_pages(void *cpu_addr); 244 void *dma_common_contiguous_remap(struct page *page, size_t size, pgprot_t prot, 245 const void *caller); 246 void *dma_common_pages_remap(struct page **pages, size_t size, pgprot_t prot, 247 const void *caller); 248 void dma_common_free_remap(void *cpu_addr, size_t size); 249 250 struct page *dma_alloc_from_pool(struct device *dev, size_t size, 251 void **cpu_addr, gfp_t flags, 252 bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)); 253 bool dma_free_from_pool(struct device *dev, void *start, size_t size); 254 255 int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start, 256 dma_addr_t dma_start, u64 size); 257 258 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ 259 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ 260 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) 261 extern bool dma_default_coherent; 262 static inline bool dev_is_dma_coherent(struct device *dev) 263 { 264 return dev->dma_coherent; 265 } 266 #else 267 #define dma_default_coherent true 268 269 static inline bool dev_is_dma_coherent(struct device *dev) 270 { 271 return true; 272 } 273 #endif /* CONFIG_ARCH_HAS_DMA_COHERENCE_H */ 274 275 /* 276 * Check whether potential kmalloc() buffers are safe for non-coherent DMA. 277 */ 278 static inline bool dma_kmalloc_safe(struct device *dev, 279 enum dma_data_direction dir) 280 { 281 /* 282 * If DMA bouncing of kmalloc() buffers is disabled, the kmalloc() 283 * caches have already been aligned to a DMA-safe size. 284 */ 285 if (!IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC)) 286 return true; 287 288 /* 289 * kmalloc() buffers are DMA-safe irrespective of size if the device 290 * is coherent or the direction is DMA_TO_DEVICE (non-desctructive 291 * cache maintenance and benign cache line evictions). 292 */ 293 if (dev_is_dma_coherent(dev) || dir == DMA_TO_DEVICE) 294 return true; 295 296 return false; 297 } 298 299 /* 300 * Check whether the given size, assuming it is for a kmalloc()'ed buffer, is 301 * sufficiently aligned for non-coherent DMA. 302 */ 303 static inline bool dma_kmalloc_size_aligned(size_t size) 304 { 305 /* 306 * Larger kmalloc() sizes are guaranteed to be aligned to 307 * ARCH_DMA_MINALIGN. 308 */ 309 if (size >= 2 * ARCH_DMA_MINALIGN || 310 IS_ALIGNED(kmalloc_size_roundup(size), dma_get_cache_alignment())) 311 return true; 312 313 return false; 314 } 315 316 /* 317 * Check whether the given object size may have originated from a kmalloc() 318 * buffer with a slab alignment below the DMA-safe alignment and needs 319 * bouncing for non-coherent DMA. The pointer alignment is not considered and 320 * in-structure DMA-safe offsets are the responsibility of the caller. Such 321 * code should use the static ARCH_DMA_MINALIGN for compiler annotations. 322 * 323 * The heuristics can have false positives, bouncing unnecessarily, though the 324 * buffers would be small. False negatives are theoretically possible if, for 325 * example, multiple small kmalloc() buffers are coalesced into a larger 326 * buffer that passes the alignment check. There are no such known constructs 327 * in the kernel. 328 */ 329 static inline bool dma_kmalloc_needs_bounce(struct device *dev, size_t size, 330 enum dma_data_direction dir) 331 { 332 return !dma_kmalloc_safe(dev, dir) && !dma_kmalloc_size_aligned(size); 333 } 334 335 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 336 gfp_t gfp, unsigned long attrs); 337 void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, 338 dma_addr_t dma_addr, unsigned long attrs); 339 340 #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK 341 void arch_dma_set_mask(struct device *dev, u64 mask); 342 #else 343 #define arch_dma_set_mask(dev, mask) do { } while (0) 344 #endif 345 346 #ifdef CONFIG_MMU 347 /* 348 * Page protection so that devices that can't snoop CPU caches can use the 349 * memory coherently. We default to pgprot_noncached which is usually used 350 * for ioremap as a safe bet, but architectures can override this with less 351 * strict semantics if possible. 352 */ 353 #ifndef pgprot_dmacoherent 354 #define pgprot_dmacoherent(prot) pgprot_noncached(prot) 355 #endif 356 357 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs); 358 #else 359 static inline pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, 360 unsigned long attrs) 361 { 362 return prot; /* no protection bits supported without page tables */ 363 } 364 #endif /* CONFIG_MMU */ 365 366 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE 367 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 368 enum dma_data_direction dir); 369 #else 370 static inline void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 371 enum dma_data_direction dir) 372 { 373 } 374 #endif /* ARCH_HAS_SYNC_DMA_FOR_DEVICE */ 375 376 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU 377 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, 378 enum dma_data_direction dir); 379 #else 380 static inline void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, 381 enum dma_data_direction dir) 382 { 383 } 384 #endif /* ARCH_HAS_SYNC_DMA_FOR_CPU */ 385 386 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL 387 void arch_sync_dma_for_cpu_all(void); 388 #else 389 static inline void arch_sync_dma_for_cpu_all(void) 390 { 391 } 392 #endif /* CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL */ 393 394 #ifdef CONFIG_ARCH_HAS_DMA_PREP_COHERENT 395 void arch_dma_prep_coherent(struct page *page, size_t size); 396 #else 397 static inline void arch_dma_prep_coherent(struct page *page, size_t size) 398 { 399 } 400 #endif /* CONFIG_ARCH_HAS_DMA_PREP_COHERENT */ 401 402 #ifdef CONFIG_ARCH_HAS_DMA_MARK_CLEAN 403 void arch_dma_mark_clean(phys_addr_t paddr, size_t size); 404 #else 405 static inline void arch_dma_mark_clean(phys_addr_t paddr, size_t size) 406 { 407 } 408 #endif /* ARCH_HAS_DMA_MARK_CLEAN */ 409 410 void *arch_dma_set_uncached(void *addr, size_t size); 411 void arch_dma_clear_uncached(void *addr, size_t size); 412 413 #ifdef CONFIG_ARCH_HAS_DMA_MAP_DIRECT 414 bool arch_dma_map_page_direct(struct device *dev, phys_addr_t addr); 415 bool arch_dma_unmap_page_direct(struct device *dev, dma_addr_t dma_handle); 416 bool arch_dma_map_sg_direct(struct device *dev, struct scatterlist *sg, 417 int nents); 418 bool arch_dma_unmap_sg_direct(struct device *dev, struct scatterlist *sg, 419 int nents); 420 #else 421 #define arch_dma_map_page_direct(d, a) (false) 422 #define arch_dma_unmap_page_direct(d, a) (false) 423 #define arch_dma_map_sg_direct(d, s, n) (false) 424 #define arch_dma_unmap_sg_direct(d, s, n) (false) 425 #endif 426 427 #ifdef CONFIG_ARCH_HAS_SETUP_DMA_OPS 428 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, 429 const struct iommu_ops *iommu, bool coherent); 430 #else 431 static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, 432 u64 size, const struct iommu_ops *iommu, bool coherent) 433 { 434 } 435 #endif /* CONFIG_ARCH_HAS_SETUP_DMA_OPS */ 436 437 #ifdef CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS 438 void arch_teardown_dma_ops(struct device *dev); 439 #else 440 static inline void arch_teardown_dma_ops(struct device *dev) 441 { 442 } 443 #endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */ 444 445 #ifdef CONFIG_DMA_API_DEBUG 446 void dma_debug_add_bus(struct bus_type *bus); 447 void debug_dma_dump_mappings(struct device *dev); 448 #else 449 static inline void dma_debug_add_bus(struct bus_type *bus) 450 { 451 } 452 static inline void debug_dma_dump_mappings(struct device *dev) 453 { 454 } 455 #endif /* CONFIG_DMA_API_DEBUG */ 456 457 extern const struct dma_map_ops dma_dummy_ops; 458 459 enum pci_p2pdma_map_type { 460 /* 461 * PCI_P2PDMA_MAP_UNKNOWN: Used internally for indicating the mapping 462 * type hasn't been calculated yet. Functions that return this enum 463 * never return this value. 464 */ 465 PCI_P2PDMA_MAP_UNKNOWN = 0, 466 467 /* 468 * PCI_P2PDMA_MAP_NOT_SUPPORTED: Indicates the transaction will 469 * traverse the host bridge and the host bridge is not in the 470 * allowlist. DMA Mapping routines should return an error when 471 * this is returned. 472 */ 473 PCI_P2PDMA_MAP_NOT_SUPPORTED, 474 475 /* 476 * PCI_P2PDMA_BUS_ADDR: Indicates that two devices can talk to 477 * each other directly through a PCI switch and the transaction will 478 * not traverse the host bridge. Such a mapping should program 479 * the DMA engine with PCI bus addresses. 480 */ 481 PCI_P2PDMA_MAP_BUS_ADDR, 482 483 /* 484 * PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: Indicates two devices can talk 485 * to each other, but the transaction traverses a host bridge on the 486 * allowlist. In this case, a normal mapping either with CPU physical 487 * addresses (in the case of dma-direct) or IOVA addresses (in the 488 * case of IOMMUs) should be used to program the DMA engine. 489 */ 490 PCI_P2PDMA_MAP_THRU_HOST_BRIDGE, 491 }; 492 493 struct pci_p2pdma_map_state { 494 struct dev_pagemap *pgmap; 495 int map; 496 u64 bus_off; 497 }; 498 499 #ifdef CONFIG_PCI_P2PDMA 500 enum pci_p2pdma_map_type 501 pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, 502 struct scatterlist *sg); 503 #else /* CONFIG_PCI_P2PDMA */ 504 static inline enum pci_p2pdma_map_type 505 pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, 506 struct scatterlist *sg) 507 { 508 return PCI_P2PDMA_MAP_NOT_SUPPORTED; 509 } 510 #endif /* CONFIG_PCI_P2PDMA */ 511 512 #endif /* _LINUX_DMA_MAP_OPS_H */ 513