release/src-rt-6.x.4708/linux/linux-2.6.36/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
   9 #include <asm-generic/dma-coherent.h>
  10 #include <asm/memory.h>
  11
  12 /*
  13  * page_to_dma/dma_to_virt/virt_to_dma are architecture private functions
  14  * used internally by the DMA-mapping API to provide DMA addresses. They
  15  * must not be used by drivers.
  16  */
  17 #ifndef __arch_page_to_dma
  18 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
  19 {
  20         return (dma_addr_t)__pfn_to_bus(page_to_pfn(page));
  21 }
  22
  23 static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr)
  24 {
  25         return pfn_to_page(__bus_to_pfn(addr));
  26 }
  27
  28 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  29 {
  30         return (void *)__bus_to_virt(addr);
  31 }
  32
  33 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  34 {
  35         return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
  36 }
  37 #else
  38 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
  39 {
  40         return __arch_page_to_dma(dev, page);
  41 }
  42
  43 static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr)
  44 {
  45         return __arch_dma_to_page(dev, addr);
  46 }
  47
  48 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  49 {
  50         return __arch_dma_to_virt(dev, addr);
  51 }
  52
  53 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  54 {
  55         return __arch_virt_to_dma(dev, addr);
  56 }
  57 #endif
  58
  59 /*
  60  * The DMA API is built upon the notion of "buffer ownership".  A buffer
  61  * is either exclusively owned by the CPU (and therefore may be accessed
  62  * by it) or exclusively owned by the DMA device.  These helper functions
  63  * represent the transitions between these two ownership states.
  64  *
  65  * Note, however, that on later ARMs, this notion does not work due to
  66  * speculative prefetches.  We model our approach on the assumption that
  67  * the CPU does do speculative prefetches, which means we clean caches
  68  * before transfers and delay cache invalidation until transfer completion.
  69  *
  70  * Private support functions: these are not part of the API and are
  71  * liable to change.  Drivers must not use these.
  72  */
  73 static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
  74         enum dma_data_direction dir)
  75 {
  76         extern void ___dma_single_cpu_to_dev(const void *, size_t,
  77                 enum dma_data_direction);
  78
  79         if (!arch_is_coherent())
  80                 ___dma_single_cpu_to_dev(kaddr, size, dir);
  81 }
  82
  83 static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
  84         enum dma_data_direction dir)
  85 {
  86         extern void ___dma_single_dev_to_cpu(const void *, size_t,
  87                 enum dma_data_direction);
  88
  89         if (!arch_is_coherent())
  90                 ___dma_single_dev_to_cpu(kaddr, size, dir);
  91 }
  92
  93 static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
  94         size_t size, enum dma_data_direction dir)
  95 {
  96         extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
  97                 size_t, enum dma_data_direction);
  98
  99         if (!arch_is_coherent())
 100                 ___dma_page_cpu_to_dev(page, off, size, dir);
 101 }
 102
 103 static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 104         size_t size, enum dma_data_direction dir)
 105 {
 106         extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
 107                 size_t, enum dma_data_direction);
 108
 109         if (!arch_is_coherent())
 110                 ___dma_page_dev_to_cpu(page, off, size, dir);
 111 }
 112
 113 static inline int dma_supported(struct device *dev, u64 mask)
 114 {
 115         if (mask < ISA_DMA_THRESHOLD)
 116                 return 0;
 117         return 1;
 118 }
 119
 120 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
 121 {
 122 #ifdef CONFIG_DMABOUNCE
 123         if (dev->archdata.dmabounce) {
 124                 if (dma_mask >= ISA_DMA_THRESHOLD)
 125                         return 0;
 126                 else
 127                         return -EIO;
 128         }
 129 #endif
 130         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
 131                 return -EIO;
 132
 133         *dev->dma_mask = dma_mask;
 134
 135         return 0;
 136 }
 137
 138 /*
 139  * DMA errors are defined by all-bits-set in the DMA address.
 140  */
 141 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 142 {
 143         return dma_addr == ~0;
 144 }
 145
 146 /*
 147  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 148  * function so drivers using this API are highlighted with build warnings.
 149  */
 150 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 151                 dma_addr_t *handle, gfp_t gfp)
 152 {
 153         return NULL;
 154 }
 155
 156 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 157                 void *cpu_addr, dma_addr_t handle)
 158 {
 159 }
 160
 161 /**
 162  * dma_alloc_coherent - allocate consistent memory for DMA
 163  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 164  * @size: required memory size
 165  * @handle: bus-specific DMA address
 166  *
 167  * Allocate some uncached, unbuffered memory for a device for
 168  * performing DMA.  This function allocates pages, and will
 169  * return the CPU-viewed address, and sets @handle to be the
 170  * device-viewed address.
 171  */
 172 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 173
 174 /**
 175  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 176  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 177  * @size: size of memory originally requested in dma_alloc_coherent
 178  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 179  * @handle: device-view address returned from dma_alloc_coherent
 180  *
 181  * Free (and unmap) a DMA buffer previously allocated by
 182  * dma_alloc_coherent().
 183  *
 184  * References to memory and mappings associated with cpu_addr/handle
 185  * during and after this call executing are illegal.
 186  */
 187 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 188
 189 /**
 190  * dma_mmap_coherent - map a coherent DMA allocation into user space
 191  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 192  * @vma: vm_area_struct describing requested user mapping
 193  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 194  * @handle: device-view address returned from dma_alloc_coherent
 195  * @size: size of memory originally requested in dma_alloc_coherent
 196  *
 197  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 198  * into user space.  The coherent DMA buffer must not be freed by the
 199  * driver until the user space mapping has been released.
 200  */
 201 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 202                 void *, dma_addr_t, size_t);
 203
 204
 205 /**
 206  * dma_alloc_writecombine - allocate writecombining memory for DMA
 207  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 208  * @size: required memory size
 209  * @handle: bus-specific DMA address
 210  *
 211  * Allocate some uncached, buffered memory for a device for
 212  * performing DMA.  This function allocates pages, and will
 213  * return the CPU-viewed address, and sets @handle to be the
 214  * device-viewed address.
 215  */
 216 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 217                 gfp_t);
 218
 219 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 220         dma_free_coherent(dev,size,cpu_addr,handle)
 221
 222 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 223                 void *, dma_addr_t, size_t);
 224
 225
 226 #ifdef CONFIG_DMABOUNCE
 227
 228 /**
 229  * dmabounce_register_dev
 230  *
 231  * @dev: valid struct device pointer
 232  * @small_buf_size: size of buffers to use with small buffer pool
 233  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 234  *
 235  * This function should be called by low-level platform code to register
 236  * a device as requireing DMA buffer bouncing. The function will allocate
 237  * appropriate DMA pools for the device.
 238  *
 239  */
 240 extern int dmabounce_register_dev(struct device *, unsigned long,
 241                 unsigned long);
 242
 243 /**
 244  * dmabounce_unregister_dev
 245  *
 246  * @dev: valid struct device pointer
 247  *
 248  * This function should be called by low-level platform code when device
 249  * that was previously registered with dmabounce_register_dev is removed
 250  * from the system.
 251  *
 252  */
 253 extern void dmabounce_unregister_dev(struct device *);
 254
 255 /**
 256  * dma_needs_bounce
 257  *
 258  * @dev: valid struct device pointer
 259  * @dma_handle: dma_handle of unbounced buffer
 260  * @size: size of region being mapped
 261  *
 262  * Platforms that utilize the dmabounce mechanism must implement
 263  * this function.
 264  *
 265  * The dmabounce routines call this function whenever a dma-mapping
 266  * is requested to determine whether a given buffer needs to be bounced
 267  * or not. The function must return 0 if the buffer is OK for
 268  * DMA access and 1 if the buffer needs to be bounced.
 269  *
 270  */
 271 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 272
 273 /*
 274  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 275  */
 276 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
 277                 enum dma_data_direction);
 278 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
 279                 enum dma_data_direction);
 280 extern dma_addr_t dma_map_page(struct device *, struct page *,
 281                 unsigned long, size_t, enum dma_data_direction);
 282 extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
 283                 enum dma_data_direction);
 284
 285 /*
 286  * Private functions
 287  */
 288 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 289                 size_t, enum dma_data_direction);
 290 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 291                 size_t, enum dma_data_direction);
 292 #else
 293 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 294         unsigned long offset, size_t size, enum dma_data_direction dir)
 295 {
 296         return 1;
 297 }
 298
 299 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 300         unsigned long offset, size_t size, enum dma_data_direction dir)
 301 {
 302         return 1;
 303 }
 304
 305
 306 /**
 307  * dma_map_single - map a single buffer for streaming DMA
 308  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 309  * @cpu_addr: CPU direct mapped address of buffer
 310  * @size: size of buffer to map
 311  * @dir: DMA transfer direction
 312  *
 313  * Ensure that any data held in the cache is appropriately discarded
 314  * or written back.
 315  *
 316  * The device owns this memory once this call has completed.  The CPU
 317  * can regain ownership by calling dma_unmap_single() or
 318  * dma_sync_single_for_cpu().
 319  */
 320 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 321                 size_t size, enum dma_data_direction dir)
 322 {
 323         BUG_ON(!valid_dma_direction(dir));
 324
 325         __dma_single_cpu_to_dev(cpu_addr, size, dir);
 326
 327         return virt_to_dma(dev, cpu_addr);
 328 }
 329
 330 /**
 331  * dma_map_page - map a portion of a page for streaming DMA
 332  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 333  * @page: page that buffer resides in
 334  * @offset: offset into page for start of buffer
 335  * @size: size of buffer to map
 336  * @dir: DMA transfer direction
 337  *
 338  * Ensure that any data held in the cache is appropriately discarded
 339  * or written back.
 340  *
 341  * The device owns this memory once this call has completed.  The CPU
 342  * can regain ownership by calling dma_unmap_page().
 343  */
 344 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 345              unsigned long offset, size_t size, enum dma_data_direction dir)
 346 {
 347         BUG_ON(!valid_dma_direction(dir));
 348
 349         __dma_page_cpu_to_dev(page, offset, size, dir);
 350
 351         return page_to_dma(dev, page) + offset;
 352 }
 353
 354 /**
 355  * dma_unmap_single - unmap a single buffer previously mapped
 356  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 357  * @handle: DMA address of buffer
 358  * @size: size of buffer (same as passed to dma_map_single)
 359  * @dir: DMA transfer direction (same as passed to dma_map_single)
 360  *
 361  * Unmap a single streaming mode DMA translation.  The handle and size
 362  * must match what was provided in the previous dma_map_single() call.
 363  * All other usages are undefined.
 364  *
 365  * After this call, reads by the CPU to the buffer are guaranteed to see
 366  * whatever the device wrote there.
 367  */
 368 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 369                 size_t size, enum dma_data_direction dir)
 370 {
 371         __dma_single_dev_to_cpu(dma_to_virt(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         __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK,
 392                 size, dir);
 393 }
 394 #endif /* CONFIG_DMABOUNCE */
 395
 396 /**
 397  * dma_sync_single_range_for_cpu
 398  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 399  * @handle: DMA address of buffer
 400  * @offset: offset of region to start sync
 401  * @size: size of region to sync
 402  * @dir: DMA transfer direction (same as passed to dma_map_single)
 403  *
 404  * Make physical memory consistent for a single streaming mode DMA
 405  * translation after a transfer.
 406  *
 407  * If you perform a dma_map_single() but wish to interrogate the
 408  * buffer using the cpu, yet do not wish to teardown the PCI dma
 409  * mapping, you must call this function before doing so.  At the
 410  * next point you give the PCI dma address back to the card, you
 411  * must first the perform a dma_sync_for_device, and then the
 412  * device again owns the buffer.
 413  */
 414 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 415                 dma_addr_t handle, unsigned long offset, size_t size,
 416                 enum dma_data_direction dir)
 417 {
 418         BUG_ON(!valid_dma_direction(dir));
 419
 420         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 421                 return;
 422
 423         __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 424 }
 425
 426 static inline void dma_sync_single_range_for_device(struct device *dev,
 427                 dma_addr_t handle, unsigned long offset, size_t size,
 428                 enum dma_data_direction dir)
 429 {
 430         BUG_ON(!valid_dma_direction(dir));
 431
 432         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 433                 return;
 434
 435         __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 436 }
 437
 438 static inline void dma_sync_single_for_cpu(struct device *dev,
 439                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 440 {
 441         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 442 }
 443
 444 static inline void dma_sync_single_for_device(struct device *dev,
 445                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 446 {
 447         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 448 }
 449
 450 /*
 451  * The scatter list versions of the above methods.
 452  */
 453 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 454                 enum dma_data_direction);
 455 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 456                 enum dma_data_direction);
 457 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 458                 enum dma_data_direction);
 459 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 460                 enum dma_data_direction);
 461
 462
 463 #endif /* __KERNEL__ */
 464 #endif