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 /*
 114  * Return whether the given device DMA address mask can be supported
 115  * properly.  For example, if your device can only drive the low 24-bits
 116  * during bus mastering, then you would pass 0x00ffffff as the mask
 117  * to this function.
 118  *
 119  * FIXME: This should really be a platform specific issue - we should
 120  * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
 121  */
 122 static inline int dma_supported(struct device *dev, u64 mask)
 123 {
 124         if (mask < ISA_DMA_THRESHOLD)
 125                 return 0;
 126         return 1;
 127 }
 128
 129 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
 130 {
 131 #ifdef CONFIG_DMABOUNCE
 132         if (dev->archdata.dmabounce) {
 133                 if (dma_mask >= ISA_DMA_THRESHOLD)
 134                         return 0;
 135                 else
 136                         return -EIO;
 137         }
 138 #endif
 139         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
 140                 return -EIO;
 141
 142         *dev->dma_mask = dma_mask;
 143
 144         return 0;
 145 }
 146
 147 static inline int dma_get_cache_alignment(void)
 148 {
 149         return 32;
 150 }
 151
 152 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
 153 {
 154         return !!arch_is_coherent();
 155 }
 156
 157 /*
 158  * DMA errors are defined by all-bits-set in the DMA address.
 159  */
 160 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 161 {
 162         return dma_addr == ~0;
 163 }
 164
 165 /*
 166  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 167  * function so drivers using this API are highlighted with build warnings.
 168  */
 169 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 170                 dma_addr_t *handle, gfp_t gfp)
 171 {
 172         return NULL;
 173 }
 174
 175 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 176                 void *cpu_addr, dma_addr_t handle)
 177 {
 178 }
 179
 180 /**
 181  * dma_alloc_coherent - allocate consistent memory for DMA
 182  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 183  * @size: required memory size
 184  * @handle: bus-specific DMA address
 185  *
 186  * Allocate some uncached, unbuffered memory for a device for
 187  * performing DMA.  This function allocates pages, and will
 188  * return the CPU-viewed address, and sets @handle to be the
 189  * device-viewed address.
 190  */
 191 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 192
 193 /**
 194  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 195  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 196  * @size: size of memory originally requested in dma_alloc_coherent
 197  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 198  * @handle: device-view address returned from dma_alloc_coherent
 199  *
 200  * Free (and unmap) a DMA buffer previously allocated by
 201  * dma_alloc_coherent().
 202  *
 203  * References to memory and mappings associated with cpu_addr/handle
 204  * during and after this call executing are illegal.
 205  */
 206 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 207
 208 /**
 209  * dma_mmap_coherent - map a coherent DMA allocation into user space
 210  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 211  * @vma: vm_area_struct describing requested user mapping
 212  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 213  * @handle: device-view address returned from dma_alloc_coherent
 214  * @size: size of memory originally requested in dma_alloc_coherent
 215  *
 216  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 217  * into user space.  The coherent DMA buffer must not be freed by the
 218  * driver until the user space mapping has been released.
 219  */
 220 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 221                 void *, dma_addr_t, size_t);
 222
 223
 224 /**
 225  * dma_alloc_writecombine - allocate writecombining memory for DMA
 226  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 227  * @size: required memory size
 228  * @handle: bus-specific DMA address
 229  *
 230  * Allocate some uncached, buffered memory for a device for
 231  * performing DMA.  This function allocates pages, and will
 232  * return the CPU-viewed address, and sets @handle to be the
 233  * device-viewed address.
 234  */
 235 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 236                 gfp_t);
 237
 238 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 239         dma_free_coherent(dev,size,cpu_addr,handle)
 240
 241 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 242                 void *, dma_addr_t, size_t);
 243
 244
 245 #ifdef CONFIG_DMABOUNCE
 246 /*
 247  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 248  * and utilize bounce buffers as needed to work around limited DMA windows.
 249  *
 250  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 251  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 252  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 253  *
 254  * The following are helper functions used by the dmabounce subystem
 255  *
 256  */
 257
 258 /**
 259  * dmabounce_register_dev
 260  *
 261  * @dev: valid struct device pointer
 262  * @small_buf_size: size of buffers to use with small buffer pool
 263  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 264  *
 265  * This function should be called by low-level platform code to register
 266  * a device as requireing DMA buffer bouncing. The function will allocate
 267  * appropriate DMA pools for the device.
 268  *
 269  */
 270 extern int dmabounce_register_dev(struct device *, unsigned long,
 271                 unsigned long);
 272
 273 /**
 274  * dmabounce_unregister_dev
 275  *
 276  * @dev: valid struct device pointer
 277  *
 278  * This function should be called by low-level platform code when device
 279  * that was previously registered with dmabounce_register_dev is removed
 280  * from the system.
 281  *
 282  */
 283 extern void dmabounce_unregister_dev(struct device *);
 284
 285 /**
 286  * dma_needs_bounce
 287  *
 288  * @dev: valid struct device pointer
 289  * @dma_handle: dma_handle of unbounced buffer
 290  * @size: size of region being mapped
 291  *
 292  * Platforms that utilize the dmabounce mechanism must implement
 293  * this function.
 294  *
 295  * The dmabounce routines call this function whenever a dma-mapping
 296  * is requested to determine whether a given buffer needs to be bounced
 297  * or not. The function must return 0 if the buffer is OK for
 298  * DMA access and 1 if the buffer needs to be bounced.
 299  *
 300  */
 301 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 302
 303 /*
 304  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 305  */
 306 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
 307                 enum dma_data_direction);
 308 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
 309                 enum dma_data_direction);
 310 extern dma_addr_t dma_map_page(struct device *, struct page *,
 311                 unsigned long, size_t, enum dma_data_direction);
 312 extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
 313                 enum dma_data_direction);
 314
 315 /*
 316  * Private functions
 317  */
 318 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 319                 size_t, enum dma_data_direction);
 320 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 321                 size_t, enum dma_data_direction);
 322 #else
 323 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 324         unsigned long offset, size_t size, enum dma_data_direction dir)
 325 {
 326         return 1;
 327 }
 328
 329 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 330         unsigned long offset, size_t size, enum dma_data_direction dir)
 331 {
 332         return 1;
 333 }
 334
 335
 336 /**
 337  * dma_map_single - map a single buffer for streaming DMA
 338  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 339  * @cpu_addr: CPU direct mapped address of buffer
 340  * @size: size of buffer to map
 341  * @dir: DMA transfer direction
 342  *
 343  * Ensure that any data held in the cache is appropriately discarded
 344  * or written back.
 345  *
 346  * The device owns this memory once this call has completed.  The CPU
 347  * can regain ownership by calling dma_unmap_single() or
 348  * dma_sync_single_for_cpu().
 349  */
 350 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 351                 size_t size, enum dma_data_direction dir)
 352 {
 353         BUG_ON(!valid_dma_direction(dir));
 354
 355         __dma_single_cpu_to_dev(cpu_addr, size, dir);
 356
 357         return virt_to_dma(dev, cpu_addr);
 358 }
 359
 360 /**
 361  * dma_map_page - map a portion of a page for streaming DMA
 362  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 363  * @page: page that buffer resides in
 364  * @offset: offset into page for start of buffer
 365  * @size: size of buffer to map
 366  * @dir: DMA transfer direction
 367  *
 368  * Ensure that any data held in the cache is appropriately discarded
 369  * or written back.
 370  *
 371  * The device owns this memory once this call has completed.  The CPU
 372  * can regain ownership by calling dma_unmap_page().
 373  */
 374 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 375              unsigned long offset, size_t size, enum dma_data_direction dir)
 376 {
 377         BUG_ON(!valid_dma_direction(dir));
 378
 379         __dma_page_cpu_to_dev(page, offset, size, dir);
 380
 381         return page_to_dma(dev, page) + offset;
 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         __dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
 402 }
 403
 404 /**
 405  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 406  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 407  * @handle: DMA address of buffer
 408  * @size: size of buffer (same as passed to dma_map_page)
 409  * @dir: DMA transfer direction (same as passed to dma_map_page)
 410  *
 411  * Unmap a page streaming mode DMA translation.  The handle and size
 412  * must match what was provided in the previous dma_map_page() call.
 413  * All other usages are undefined.
 414  *
 415  * After this call, reads by the CPU to the buffer are guaranteed to see
 416  * whatever the device wrote there.
 417  */
 418 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 419                 size_t size, enum dma_data_direction dir)
 420 {
 421         __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK,
 422                 size, dir);
 423 }
 424 #endif /* CONFIG_DMABOUNCE */
 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         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 451                 return;
 452
 453         __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 454 }
 455
 456 static inline void dma_sync_single_range_for_device(struct device *dev,
 457                 dma_addr_t handle, unsigned long offset, size_t size,
 458                 enum dma_data_direction dir)
 459 {
 460         BUG_ON(!valid_dma_direction(dir));
 461
 462         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 463                 return;
 464
 465         __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 466 }
 467
 468 static inline void dma_sync_single_for_cpu(struct device *dev,
 469                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 470 {
 471         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 472 }
 473
 474 static inline void dma_sync_single_for_device(struct device *dev,
 475                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 476 {
 477         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 478 }
 479
 480 /*
 481  * The scatter list versions of the above methods.
 482  */
 483 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 484                 enum dma_data_direction);
 485 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 486                 enum dma_data_direction);
 487 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 488                 enum dma_data_direction);
 489 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 490                 enum dma_data_direction);
 491
 492
 493 #endif /* __KERNEL__ */
 494 #endif