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 /*
 119  * Return whether the given device DMA address mask can be supported
 120  * properly.  For example, if your device can only drive the low 24-bits
 121  * during bus mastering, then you would pass 0x00ffffff as the mask
 122  * to this function.
 123  *
 124  * FIXME: This should really be a platform specific issue - we should
 125  * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
 126  */
 127 static inline int dma_supported(struct device *dev, u64 mask)
 128 {
 129         if (mask < ISA_DMA_THRESHOLD)
 130                 return 0;
 131         return 1;
 132 }
 133
 134 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
 135 {
 136 #ifdef CONFIG_DMABOUNCE
 137         if (dev->archdata.dmabounce) {
 138                 if (dma_mask >= ISA_DMA_THRESHOLD)
 139                         return 0;
 140                 else
 141                         return -EIO;
 142         }
 143 #endif
 144         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
 145                 return -EIO;
 146
 147         *dev->dma_mask = dma_mask;
 148
 149         return 0;
 150 }
 151
 152 /*
 153  * DMA errors are defined by all-bits-set in the DMA address.
 154  */
 155 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 156 {
 157         return dma_addr == ~0;
 158 }
 159
 160 /*
 161  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 162  * function so drivers using this API are highlighted with build warnings.
 163  */
 164 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 165                 dma_addr_t *handle, gfp_t gfp)
 166 {
 167         return NULL;
 168 }
 169
 170 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 171                 void *cpu_addr, dma_addr_t handle)
 172 {
 173 }
 174
 175 /**
 176  * dma_alloc_coherent - allocate consistent memory for DMA
 177  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 178  * @size: required memory size
 179  * @handle: bus-specific DMA address
 180  *
 181  * Allocate some uncached, unbuffered memory for a device for
 182  * performing DMA.  This function allocates pages, and will
 183  * return the CPU-viewed address, and sets @handle to be the
 184  * device-viewed address.
 185  */
 186 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 187
 188 /**
 189  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 190  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 191  * @size: size of memory originally requested in dma_alloc_coherent
 192  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 193  * @handle: device-view address returned from dma_alloc_coherent
 194  *
 195  * Free (and unmap) a DMA buffer previously allocated by
 196  * dma_alloc_coherent().
 197  *
 198  * References to memory and mappings associated with cpu_addr/handle
 199  * during and after this call executing are illegal.
 200  */
 201 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 202
 203 /**
 204  * dma_mmap_coherent - map a coherent DMA allocation into user space
 205  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 206  * @vma: vm_area_struct describing requested user mapping
 207  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 208  * @handle: device-view address returned from dma_alloc_coherent
 209  * @size: size of memory originally requested in dma_alloc_coherent
 210  *
 211  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 212  * into user space.  The coherent DMA buffer must not be freed by the
 213  * driver until the user space mapping has been released.
 214  */
 215 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 216                 void *, dma_addr_t, size_t);
 217
 218
 219 /**
 220  * dma_alloc_writecombine - allocate writecombining memory for DMA
 221  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 222  * @size: required memory size
 223  * @handle: bus-specific DMA address
 224  *
 225  * Allocate some uncached, buffered memory for a device for
 226  * performing DMA.  This function allocates pages, and will
 227  * return the CPU-viewed address, and sets @handle to be the
 228  * device-viewed address.
 229  */
 230 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 231                 gfp_t);
 232
 233 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 234         dma_free_coherent(dev,size,cpu_addr,handle)
 235
 236 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 237                 void *, dma_addr_t, size_t);
 238
 239
 240 #ifdef CONFIG_DMABOUNCE
 241 /*
 242  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 243  * and utilize bounce buffers as needed to work around limited DMA windows.
 244  *
 245  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 246  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 247  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 248  *
 249  * The following are helper functions used by the dmabounce subystem
 250  *
 251  */
 252
 253 /**
 254  * dmabounce_register_dev
 255  *
 256  * @dev: valid struct device pointer
 257  * @small_buf_size: size of buffers to use with small buffer pool
 258  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 259  * @needs_bounce_fn: called to determine whether buffer needs bouncing
 260  *
 261  * This function should be called by low-level platform code to register
 262  * a device as requireing DMA buffer bouncing. The function will allocate
 263  * appropriate DMA pools for the device.
 264  */
 265 extern int dmabounce_register_dev(struct device *, unsigned long,
 266                 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
 267
 268 /**
 269  * dmabounce_unregister_dev
 270  *
 271  * @dev: valid struct device pointer
 272  *
 273  * This function should be called by low-level platform code when device
 274  * that was previously registered with dmabounce_register_dev is removed
 275  * from the system.
 276  *
 277  */
 278 extern void dmabounce_unregister_dev(struct device *);
 279
 280 /*
 281  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 282  */
 283 extern dma_addr_t __dma_map_page(struct device *, struct page *,
 284                 unsigned long, size_t, enum dma_data_direction);
 285 extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
 286                 enum dma_data_direction);
 287
 288 /*
 289  * Private functions
 290  */
 291 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 292                 size_t, enum dma_data_direction);
 293 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 294                 size_t, enum dma_data_direction);
 295 #else
 296 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 297         unsigned long offset, size_t size, enum dma_data_direction dir)
 298 {
 299         return 1;
 300 }
 301
 302 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 303         unsigned long offset, size_t size, enum dma_data_direction dir)
 304 {
 305         return 1;
 306 }
 307
 308
 309 static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
 310              unsigned long offset, size_t size, enum dma_data_direction dir)
 311 {
 312         __dma_page_cpu_to_dev(page, offset, size, dir);
 313         return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 314 }
 315
 316 static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
 317                 size_t size, enum dma_data_direction dir)
 318 {
 319         __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
 320                 handle & ~PAGE_MASK, size, dir);
 321 }
 322 #endif /* CONFIG_DMABOUNCE */
 323
 324 /**
 325  * dma_map_single - map a single buffer for streaming DMA
 326  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 327  * @cpu_addr: CPU direct mapped address of buffer
 328  * @size: size of buffer to map
 329  * @dir: DMA transfer direction
 330  *
 331  * Ensure that any data held in the cache is appropriately discarded
 332  * or written back.
 333  *
 334  * The device owns this memory once this call has completed.  The CPU
 335  * can regain ownership by calling dma_unmap_single() or
 336  * dma_sync_single_for_cpu().
 337  */
 338 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 339                 size_t size, enum dma_data_direction dir)
 340 {
 341         unsigned long offset;
 342         struct page *page;
 343         dma_addr_t addr;
 344
 345         BUG_ON(!virt_addr_valid(cpu_addr));
 346         BUG_ON(!virt_addr_valid(cpu_addr + size - 1));
 347         BUG_ON(!valid_dma_direction(dir));
 348
 349         page = virt_to_page(cpu_addr);
 350         offset = (unsigned long)cpu_addr & ~PAGE_MASK;
 351         addr = __dma_map_page(dev, page, offset, size, dir);
 352         debug_dma_map_page(dev, page, offset, size, dir, addr, true);
 353
 354         return addr;
 355 }
 356
 357 /**
 358  * dma_map_page - map a portion of a page for streaming DMA
 359  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 360  * @page: page that buffer resides in
 361  * @offset: offset into page for start of buffer
 362  * @size: size of buffer to map
 363  * @dir: DMA transfer direction
 364  *
 365  * Ensure that any data held in the cache is appropriately discarded
 366  * or written back.
 367  *
 368  * The device owns this memory once this call has completed.  The CPU
 369  * can regain ownership by calling dma_unmap_page().
 370  */
 371 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 372              unsigned long offset, size_t size, enum dma_data_direction dir)
 373 {
 374         dma_addr_t addr;
 375
 376         BUG_ON(!valid_dma_direction(dir));
 377
 378         addr = __dma_map_page(dev, page, offset, size, dir);
 379         debug_dma_map_page(dev, page, offset, size, dir, addr, false);
 380
 381         return addr;
 382 }
 383
 384 /**
 385  * dma_unmap_single - unmap a single buffer previously mapped
 386  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 387  * @handle: DMA address of buffer
 388  * @size: size of buffer (same as passed to dma_map_single)
 389  * @dir: DMA transfer direction (same as passed to dma_map_single)
 390  *
 391  * Unmap a single streaming mode DMA translation.  The handle and size
 392  * must match what was provided in the previous dma_map_single() call.
 393  * All other usages are undefined.
 394  *
 395  * After this call, reads by the CPU to the buffer are guaranteed to see
 396  * whatever the device wrote there.
 397  */
 398 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 399                 size_t size, enum dma_data_direction dir)
 400 {
 401         debug_dma_unmap_page(dev, handle, size, dir, true);
 402         __dma_unmap_page(dev, handle, size, dir);
 403 }
 404
 405 /**
 406  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 407  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 408  * @handle: DMA address of buffer
 409  * @size: size of buffer (same as passed to dma_map_page)
 410  * @dir: DMA transfer direction (same as passed to dma_map_page)
 411  *
 412  * Unmap a page streaming mode DMA translation.  The handle and size
 413  * must match what was provided in the previous dma_map_page() call.
 414  * All other usages are undefined.
 415  *
 416  * After this call, reads by the CPU to the buffer are guaranteed to see
 417  * whatever the device wrote there.
 418  */
 419 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 420                 size_t size, enum dma_data_direction dir)
 421 {
 422         debug_dma_unmap_page(dev, handle, size, dir, false);
 423         __dma_unmap_page(dev, handle, size, dir);
 424 }
 425
 426 /**
 427  * dma_sync_single_range_for_cpu
 428  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 429  * @handle: DMA address of buffer
 430  * @offset: offset of region to start sync
 431  * @size: size of region to sync
 432  * @dir: DMA transfer direction (same as passed to dma_map_single)
 433  *
 434  * Make physical memory consistent for a single streaming mode DMA
 435  * translation after a transfer.
 436  *
 437  * If you perform a dma_map_single() but wish to interrogate the
 438  * buffer using the cpu, yet do not wish to teardown the PCI dma
 439  * mapping, you must call this function before doing so.  At the
 440  * next point you give the PCI dma address back to the card, you
 441  * must first the perform a dma_sync_for_device, and then the
 442  * device again owns the buffer.
 443  */
 444 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 445                 dma_addr_t handle, unsigned long offset, size_t size,
 446                 enum dma_data_direction dir)
 447 {
 448         BUG_ON(!valid_dma_direction(dir));
 449
 450         debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);
 451
 452         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 453                 return;
 454
 455         __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 456 }
 457
 458 static inline void dma_sync_single_range_for_device(struct device *dev,
 459                 dma_addr_t handle, unsigned long offset, size_t size,
 460                 enum dma_data_direction dir)
 461 {
 462         BUG_ON(!valid_dma_direction(dir));
 463
 464         debug_dma_sync_single_for_device(dev, handle + offset, size, dir);
 465
 466         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 467                 return;
 468
 469         __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 470 }
 471
 472 static inline void dma_sync_single_for_cpu(struct device *dev,
 473                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 474 {
 475         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 476 }
 477
 478 static inline void dma_sync_single_for_device(struct device *dev,
 479                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 480 {
 481         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 482 }
 483
 484 /*
 485  * The scatter list versions of the above methods.
 486  */
 487 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 488                 enum dma_data_direction);
 489 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 490                 enum dma_data_direction);
 491 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 492                 enum dma_data_direction);
 493 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 494                 enum dma_data_direction);
 495
 496
 497 #endif /* __KERNEL__ */
 498 #endif