arch/arm/include/asm/dma-mapping.h

   1 #ifndef ASMARM_DMA_MAPPING_H
   2 #define ASMARM_DMA_MAPPING_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/mm_types.h>
   7 #include <linux/scatterlist.h>
   8 #include <linux/dma-debug.h>
   9
  10 #include <asm-generic/dma-coherent.h>
  11 #include <asm/memory.h>
  12
  13 #ifdef __arch_page_to_dma
  14 #error Please update to __arch_pfn_to_dma
  15 #endif
  16
  17 /*
  18  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
  19  * functions used internally by the DMA-mapping API to provide DMA
  20  * addresses. They must not be used by drivers.
  21  */
  22 #ifndef __arch_pfn_to_dma
  23 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  24 {
  25         return (dma_addr_t)__pfn_to_bus(pfn);
  26 }
  27
  28 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  29 {
  30         return __bus_to_pfn(addr);
  31 }
  32
  33 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  34 {
  35         return (void *)__bus_to_virt(addr);
  36 }
  37
  38 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  39 {
  40         return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
  41 }
  42 #else
  43 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
  44 {
  45         return __arch_pfn_to_dma(dev, pfn);
  46 }
  47
  48 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
  49 {
  50         return __arch_dma_to_pfn(dev, addr);
  51 }
  52
  53 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  54 {
  55         return __arch_dma_to_virt(dev, addr);
  56 }
  57
  58 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  59 {
  60         return __arch_virt_to_dma(dev, addr);
  61 }
  62 #endif
  63
  64 /*
  65  * The DMA API is built upon the notion of "buffer ownership".  A buffer
  66  * is either exclusively owned by the CPU (and therefore may be accessed
  67  * by it) or exclusively owned by the DMA device.  These helper functions
  68  * represent the transitions between these two ownership states.
  69  *
  70  * Note, however, that on later ARMs, this notion does not work due to
  71  * speculative prefetches.  We model our approach on the assumption that
  72  * the CPU does do speculative prefetches, which means we clean caches
  73  * before transfers and delay cache invalidation until transfer completion.
  74  *
  75  * Private support functions: these are not part of the API and are
  76  * liable to change.  Drivers must not use these.
  77  */
  78 static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
  79         enum dma_data_direction dir)
  80 {
  81         extern void ___dma_single_cpu_to_dev(const void *, size_t,
  82                 enum dma_data_direction);
  83
  84         if (!arch_is_coherent())
  85                 ___dma_single_cpu_to_dev(kaddr, size, dir);
  86 }
  87
  88 static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
  89         enum dma_data_direction dir)
  90 {
  91         extern void ___dma_single_dev_to_cpu(const void *, size_t,
  92                 enum dma_data_direction);
  93
  94         if (!arch_is_coherent())
  95                 ___dma_single_dev_to_cpu(kaddr, size, dir);
  96 }
  97
  98 static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
  99         size_t size, enum dma_data_direction dir)
 100 {
 101         extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
 102                 size_t, enum dma_data_direction);
 103
 104         if (!arch_is_coherent())
 105                 ___dma_page_cpu_to_dev(page, off, size, dir);
 106 }
 107
 108 static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 109         size_t size, enum dma_data_direction dir)
 110 {
 111         extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
 112                 size_t, enum dma_data_direction);
 113
 114         if (!arch_is_coherent())
 115                 ___dma_page_dev_to_cpu(page, off, size, dir);
 116 }
 117
 118 extern int dma_supported(struct device *, u64);
 119 extern int dma_set_mask(struct device *, u64);
 120
 121 /*
 122  * DMA errors are defined by all-bits-set in the DMA address.
 123  */
 124 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 125 {
 126         return dma_addr == ~0;
 127 }
 128
 129 /*
 130  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 131  * function so drivers using this API are highlighted with build warnings.
 132  */
 133 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 134                 dma_addr_t *handle, gfp_t gfp)
 135 {
 136         return NULL;
 137 }
 138
 139 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 140                 void *cpu_addr, dma_addr_t handle)
 141 {
 142 }
 143
 144 /**
 145  * dma_alloc_coherent - allocate consistent memory for DMA
 146  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 147  * @size: required memory size
 148  * @handle: bus-specific DMA address
 149  *
 150  * Allocate some uncached, unbuffered memory for a device for
 151  * performing DMA.  This function allocates pages, and will
 152  * return the CPU-viewed address, and sets @handle to be the
 153  * device-viewed address.
 154  */
 155 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 156
 157 /**
 158  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 159  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 160  * @size: size of memory originally requested in dma_alloc_coherent
 161  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 162  * @handle: device-view address returned from dma_alloc_coherent
 163  *
 164  * Free (and unmap) a DMA buffer previously allocated by
 165  * dma_alloc_coherent().
 166  *
 167  * References to memory and mappings associated with cpu_addr/handle
 168  * during and after this call executing are illegal.
 169  */
 170 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 171
 172 /**
 173  * dma_mmap_coherent - map a coherent DMA allocation into user space
 174  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 175  * @vma: vm_area_struct describing requested user mapping
 176  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 177  * @handle: device-view address returned from dma_alloc_coherent
 178  * @size: size of memory originally requested in dma_alloc_coherent
 179  *
 180  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 181  * into user space.  The coherent DMA buffer must not be freed by the
 182  * driver until the user space mapping has been released.
 183  */
 184 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 185                 void *, dma_addr_t, size_t);
 186
 187
 188 /**
 189  * dma_alloc_writecombine - allocate writecombining memory for DMA
 190  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 191  * @size: required memory size
 192  * @handle: bus-specific DMA address
 193  *
 194  * Allocate some uncached, buffered memory for a device for
 195  * performing DMA.  This function allocates pages, and will
 196  * return the CPU-viewed address, and sets @handle to be the
 197  * device-viewed address.
 198  */
 199 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 200                 gfp_t);
 201
 202 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 203         dma_free_coherent(dev,size,cpu_addr,handle)
 204
 205 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 206                 void *, dma_addr_t, size_t);
 207
 208
 209 #ifdef CONFIG_DMABOUNCE
 210 /*
 211  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 212  * and utilize bounce buffers as needed to work around limited DMA windows.
 213  *
 214  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 215  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 216  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 217  *
 218  * The following are helper functions used by the dmabounce subystem
 219  *
 220  */
 221
 222 /**
 223  * dmabounce_register_dev
 224  *
 225  * @dev: valid struct device pointer
 226  * @small_buf_size: size of buffers to use with small buffer pool
 227  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 228  * @needs_bounce_fn: called to determine whether buffer needs bouncing
 229  *
 230  * This function should be called by low-level platform code to register
 231  * a device as requireing DMA buffer bouncing. The function will allocate
 232  * appropriate DMA pools for the device.
 233  */
 234 extern int dmabounce_register_dev(struct device *, unsigned long,
 235                 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
 236
 237 /**
 238  * dmabounce_unregister_dev
 239  *
 240  * @dev: valid struct device pointer
 241  *
 242  * This function should be called by low-level platform code when device
 243  * that was previously registered with dmabounce_register_dev is removed
 244  * from the system.
 245  *
 246  */
 247 extern void dmabounce_unregister_dev(struct device *);
 248
 249 /*
 250  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 251  */
 252 extern dma_addr_t __dma_map_page(struct device *, struct page *,
 253                 unsigned long, size_t, enum dma_data_direction);
 254 extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
 255                 enum dma_data_direction);
 256
 257 /*
 258  * Private functions
 259  */
 260 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 261                 size_t, enum dma_data_direction);
 262 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 263                 size_t, enum dma_data_direction);
 264 #else
 265 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 266         unsigned long offset, size_t size, enum dma_data_direction dir)
 267 {
 268         return 1;
 269 }
 270
 271 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 272         unsigned long offset, size_t size, enum dma_data_direction dir)
 273 {
 274         return 1;
 275 }
 276
 277
 278 static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
 279              unsigned long offset, size_t size, enum dma_data_direction dir)
 280 {
 281         __dma_page_cpu_to_dev(page, offset, size, dir);
 282         return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 283 }
 284
 285 static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
 286                 size_t size, enum dma_data_direction dir)
 287 {
 288         __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
 289                 handle & ~PAGE_MASK, size, dir);
 290 }
 291 #endif /* CONFIG_DMABOUNCE */
 292
 293 /**
 294  * dma_map_single - map a single buffer for streaming DMA
 295  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 296  * @cpu_addr: CPU direct mapped address of buffer
 297  * @size: size of buffer to map
 298  * @dir: DMA transfer direction
 299  *
 300  * Ensure that any data held in the cache is appropriately discarded
 301  * or written back.
 302  *
 303  * The device owns this memory once this call has completed.  The CPU
 304  * can regain ownership by calling dma_unmap_single() or
 305  * dma_sync_single_for_cpu().
 306  */
 307 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 308                 size_t size, enum dma_data_direction dir)
 309 {
 310         unsigned long offset;
 311         struct page *page;
 312         dma_addr_t addr;
 313
 314         BUG_ON(!virt_addr_valid(cpu_addr));
 315         BUG_ON(!virt_addr_valid(cpu_addr + size - 1));
 316         BUG_ON(!valid_dma_direction(dir));
 317
 318         page = virt_to_page(cpu_addr);
 319         offset = (unsigned long)cpu_addr & ~PAGE_MASK;
 320         addr = __dma_map_page(dev, page, offset, size, dir);
 321         debug_dma_map_page(dev, page, offset, size, dir, addr, true);
 322
 323         return addr;
 324 }
 325
 326 /**
 327  * dma_map_page - map a portion of a page for streaming DMA
 328  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 329  * @page: page that buffer resides in
 330  * @offset: offset into page for start of buffer
 331  * @size: size of buffer to map
 332  * @dir: DMA transfer direction
 333  *
 334  * Ensure that any data held in the cache is appropriately discarded
 335  * or written back.
 336  *
 337  * The device owns this memory once this call has completed.  The CPU
 338  * can regain ownership by calling dma_unmap_page().
 339  */
 340 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 341              unsigned long offset, size_t size, enum dma_data_direction dir)
 342 {
 343         dma_addr_t addr;
 344
 345         BUG_ON(!valid_dma_direction(dir));
 346
 347         addr = __dma_map_page(dev, page, offset, size, dir);
 348         debug_dma_map_page(dev, page, offset, size, dir, addr, false);
 349
 350         return addr;
 351 }
 352
 353 /**
 354  * dma_unmap_single - unmap a single buffer previously mapped
 355  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 356  * @handle: DMA address of buffer
 357  * @size: size of buffer (same as passed to dma_map_single)
 358  * @dir: DMA transfer direction (same as passed to dma_map_single)
 359  *
 360  * Unmap a single streaming mode DMA translation.  The handle and size
 361  * must match what was provided in the previous dma_map_single() call.
 362  * All other usages are undefined.
 363  *
 364  * After this call, reads by the CPU to the buffer are guaranteed to see
 365  * whatever the device wrote there.
 366  */
 367 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 368                 size_t size, enum dma_data_direction dir)
 369 {
 370         debug_dma_unmap_page(dev, handle, size, dir, true);
 371         __dma_unmap_page(dev, handle, size, dir);
 372 }
 373
 374 /**
 375  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 376  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 377  * @handle: DMA address of buffer
 378  * @size: size of buffer (same as passed to dma_map_page)
 379  * @dir: DMA transfer direction (same as passed to dma_map_page)
 380  *
 381  * Unmap a page streaming mode DMA translation.  The handle and size
 382  * must match what was provided in the previous dma_map_page() call.
 383  * All other usages are undefined.
 384  *
 385  * After this call, reads by the CPU to the buffer are guaranteed to see
 386  * whatever the device wrote there.
 387  */
 388 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 389                 size_t size, enum dma_data_direction dir)
 390 {
 391         debug_dma_unmap_page(dev, handle, size, dir, false);
 392         __dma_unmap_page(dev, handle, size, dir);
 393 }
 394
 395 /**
 396  * dma_sync_single_range_for_cpu
 397  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 398  * @handle: DMA address of buffer
 399  * @offset: offset of region to start sync
 400  * @size: size of region to sync
 401  * @dir: DMA transfer direction (same as passed to dma_map_single)
 402  *
 403  * Make physical memory consistent for a single streaming mode DMA
 404  * translation after a transfer.
 405  *
 406  * If you perform a dma_map_single() but wish to interrogate the
 407  * buffer using the cpu, yet do not wish to teardown the PCI dma
 408  * mapping, you must call this function before doing so.  At the
 409  * next point you give the PCI dma address back to the card, you
 410  * must first the perform a dma_sync_for_device, and then the
 411  * device again owns the buffer.
 412  */
 413 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 414                 dma_addr_t handle, unsigned long offset, size_t size,
 415                 enum dma_data_direction dir)
 416 {
 417         BUG_ON(!valid_dma_direction(dir));
 418
 419         debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);
 420
 421         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 422                 return;
 423
 424         __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 425 }
 426
 427 static inline void dma_sync_single_range_for_device(struct device *dev,
 428                 dma_addr_t handle, unsigned long offset, size_t size,
 429                 enum dma_data_direction dir)
 430 {
 431         BUG_ON(!valid_dma_direction(dir));
 432
 433         debug_dma_sync_single_for_device(dev, handle + offset, size, dir);
 434
 435         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 436                 return;
 437
 438         __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 439 }
 440
 441 static inline void dma_sync_single_for_cpu(struct device *dev,
 442                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 443 {
 444         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 445 }
 446
 447 static inline void dma_sync_single_for_device(struct device *dev,
 448                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 449 {
 450         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 451 }
 452
 453 /*
 454  * The scatter list versions of the above methods.
 455  */
 456 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 457                 enum dma_data_direction);
 458 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 459                 enum dma_data_direction);
 460 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 461                 enum dma_data_direction);
 462 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 463                 enum dma_data_direction);
 464
 465
 466 #endif /* __KERNEL__ */
 467 #endif