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 /*
 148  * DMA errors are defined by all-bits-set in the DMA address.
 149  */
 150 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 151 {
 152         return dma_addr == ~0;
 153 }
 154
 155 /*
 156  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 157  * function so drivers using this API are highlighted with build warnings.
 158  */
 159 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 160                 dma_addr_t *handle, gfp_t gfp)
 161 {
 162         return NULL;
 163 }
 164
 165 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 166                 void *cpu_addr, dma_addr_t handle)
 167 {
 168 }
 169
 170 /**
 171  * dma_alloc_coherent - allocate consistent memory for DMA
 172  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 173  * @size: required memory size
 174  * @handle: bus-specific DMA address
 175  *
 176  * Allocate some uncached, unbuffered memory for a device for
 177  * performing DMA.  This function allocates pages, and will
 178  * return the CPU-viewed address, and sets @handle to be the
 179  * device-viewed address.
 180  */
 181 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 182
 183 /**
 184  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 185  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 186  * @size: size of memory originally requested in dma_alloc_coherent
 187  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 188  * @handle: device-view address returned from dma_alloc_coherent
 189  *
 190  * Free (and unmap) a DMA buffer previously allocated by
 191  * dma_alloc_coherent().
 192  *
 193  * References to memory and mappings associated with cpu_addr/handle
 194  * during and after this call executing are illegal.
 195  */
 196 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 197
 198 /**
 199  * dma_mmap_coherent - map a coherent DMA allocation into user space
 200  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 201  * @vma: vm_area_struct describing requested user mapping
 202  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 203  * @handle: device-view address returned from dma_alloc_coherent
 204  * @size: size of memory originally requested in dma_alloc_coherent
 205  *
 206  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 207  * into user space.  The coherent DMA buffer must not be freed by the
 208  * driver until the user space mapping has been released.
 209  */
 210 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 211                 void *, dma_addr_t, size_t);
 212
 213
 214 /**
 215  * dma_alloc_writecombine - allocate writecombining memory for DMA
 216  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 217  * @size: required memory size
 218  * @handle: bus-specific DMA address
 219  *
 220  * Allocate some uncached, buffered memory for a device for
 221  * performing DMA.  This function allocates pages, and will
 222  * return the CPU-viewed address, and sets @handle to be the
 223  * device-viewed address.
 224  */
 225 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 226                 gfp_t);
 227
 228 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 229         dma_free_coherent(dev,size,cpu_addr,handle)
 230
 231 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 232                 void *, dma_addr_t, size_t);
 233
 234
 235 #ifdef CONFIG_DMABOUNCE
 236 /*
 237  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 238  * and utilize bounce buffers as needed to work around limited DMA windows.
 239  *
 240  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 241  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 242  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 243  *
 244  * The following are helper functions used by the dmabounce subystem
 245  *
 246  */
 247
 248 /**
 249  * dmabounce_register_dev
 250  *
 251  * @dev: valid struct device pointer
 252  * @small_buf_size: size of buffers to use with small buffer pool
 253  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 254  *
 255  * This function should be called by low-level platform code to register
 256  * a device as requireing DMA buffer bouncing. The function will allocate
 257  * appropriate DMA pools for the device.
 258  *
 259  */
 260 extern int dmabounce_register_dev(struct device *, unsigned long,
 261                 unsigned long);
 262
 263 /**
 264  * dmabounce_unregister_dev
 265  *
 266  * @dev: valid struct device pointer
 267  *
 268  * This function should be called by low-level platform code when device
 269  * that was previously registered with dmabounce_register_dev is removed
 270  * from the system.
 271  *
 272  */
 273 extern void dmabounce_unregister_dev(struct device *);
 274
 275 /**
 276  * dma_needs_bounce
 277  *
 278  * @dev: valid struct device pointer
 279  * @dma_handle: dma_handle of unbounced buffer
 280  * @size: size of region being mapped
 281  *
 282  * Platforms that utilize the dmabounce mechanism must implement
 283  * this function.
 284  *
 285  * The dmabounce routines call this function whenever a dma-mapping
 286  * is requested to determine whether a given buffer needs to be bounced
 287  * or not. The function must return 0 if the buffer is OK for
 288  * DMA access and 1 if the buffer needs to be bounced.
 289  *
 290  */
 291 #ifdef CONFIG_SA1111
 292 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 293 #else
 294 static inline int dma_needs_bounce(struct device *dev, dma_addr_t addr,
 295                                    size_t size)
 296 {
 297         return 0;
 298 }
 299 #endif
 300
 301 /*
 302  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 303  */
 304 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
 305                 enum dma_data_direction);
 306 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
 307                 enum dma_data_direction);
 308 extern dma_addr_t dma_map_page(struct device *, struct page *,
 309                 unsigned long, size_t, enum dma_data_direction);
 310 extern void dma_unmap_page(struct device *, dma_addr_t, size_t,
 311                 enum dma_data_direction);
 312
 313 /*
 314  * Private functions
 315  */
 316 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 317                 size_t, enum dma_data_direction);
 318 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 319                 size_t, enum dma_data_direction);
 320 #else
 321 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 322         unsigned long offset, size_t size, enum dma_data_direction dir)
 323 {
 324         return 1;
 325 }
 326
 327 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 328         unsigned long offset, size_t size, enum dma_data_direction dir)
 329 {
 330         return 1;
 331 }
 332
 333
 334 /**
 335  * dma_map_single - map a single buffer for streaming DMA
 336  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 337  * @cpu_addr: CPU direct mapped address of buffer
 338  * @size: size of buffer to map
 339  * @dir: DMA transfer direction
 340  *
 341  * Ensure that any data held in the cache is appropriately discarded
 342  * or written back.
 343  *
 344  * The device owns this memory once this call has completed.  The CPU
 345  * can regain ownership by calling dma_unmap_single() or
 346  * dma_sync_single_for_cpu().
 347  */
 348 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 349                 size_t size, enum dma_data_direction dir)
 350 {
 351         BUG_ON(!valid_dma_direction(dir));
 352
 353         __dma_single_cpu_to_dev(cpu_addr, size, dir);
 354
 355         return virt_to_dma(dev, cpu_addr);
 356 }
 357
 358 /**
 359  * dma_map_page - map a portion of a page for streaming DMA
 360  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 361  * @page: page that buffer resides in
 362  * @offset: offset into page for start of buffer
 363  * @size: size of buffer to map
 364  * @dir: DMA transfer direction
 365  *
 366  * Ensure that any data held in the cache is appropriately discarded
 367  * or written back.
 368  *
 369  * The device owns this memory once this call has completed.  The CPU
 370  * can regain ownership by calling dma_unmap_page().
 371  */
 372 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 373              unsigned long offset, size_t size, enum dma_data_direction dir)
 374 {
 375         BUG_ON(!valid_dma_direction(dir));
 376
 377         __dma_page_cpu_to_dev(page, offset, size, dir);
 378
 379         return page_to_dma(dev, page) + offset;
 380 }
 381
 382 /**
 383  * dma_unmap_single - unmap a single buffer previously mapped
 384  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 385  * @handle: DMA address of buffer
 386  * @size: size of buffer (same as passed to dma_map_single)
 387  * @dir: DMA transfer direction (same as passed to dma_map_single)
 388  *
 389  * Unmap a single streaming mode DMA translation.  The handle and size
 390  * must match what was provided in the previous dma_map_single() call.
 391  * All other usages are undefined.
 392  *
 393  * After this call, reads by the CPU to the buffer are guaranteed to see
 394  * whatever the device wrote there.
 395  */
 396 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 397                 size_t size, enum dma_data_direction dir)
 398 {
 399         __dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir);
 400 }
 401
 402 /**
 403  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 404  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 405  * @handle: DMA address of buffer
 406  * @size: size of buffer (same as passed to dma_map_page)
 407  * @dir: DMA transfer direction (same as passed to dma_map_page)
 408  *
 409  * Unmap a page streaming mode DMA translation.  The handle and size
 410  * must match what was provided in the previous dma_map_page() call.
 411  * All other usages are undefined.
 412  *
 413  * After this call, reads by the CPU to the buffer are guaranteed to see
 414  * whatever the device wrote there.
 415  */
 416 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 417                 size_t size, enum dma_data_direction dir)
 418 {
 419         __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK,
 420                 size, dir);
 421 }
 422 #endif /* CONFIG_DMABOUNCE */
 423
 424 /**
 425  * dma_sync_single_range_for_cpu
 426  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 427  * @handle: DMA address of buffer
 428  * @offset: offset of region to start sync
 429  * @size: size of region to sync
 430  * @dir: DMA transfer direction (same as passed to dma_map_single)
 431  *
 432  * Make physical memory consistent for a single streaming mode DMA
 433  * translation after a transfer.
 434  *
 435  * If you perform a dma_map_single() but wish to interrogate the
 436  * buffer using the cpu, yet do not wish to teardown the PCI dma
 437  * mapping, you must call this function before doing so.  At the
 438  * next point you give the PCI dma address back to the card, you
 439  * must first the perform a dma_sync_for_device, and then the
 440  * device again owns the buffer.
 441  */
 442 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 443                 dma_addr_t handle, unsigned long offset, size_t size,
 444                 enum dma_data_direction dir)
 445 {
 446         BUG_ON(!valid_dma_direction(dir));
 447
 448         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 449                 return;
 450
 451         __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
 452 }
 453
 454 static inline void dma_sync_single_range_for_device(struct device *dev,
 455                 dma_addr_t handle, unsigned long offset, size_t size,
 456                 enum dma_data_direction dir)
 457 {
 458         BUG_ON(!valid_dma_direction(dir));
 459
 460         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 461                 return;
 462
 463         __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
 464 }
 465
 466 static inline void dma_sync_single_for_cpu(struct device *dev,
 467                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 468 {
 469         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 470 }
 471
 472 static inline void dma_sync_single_for_device(struct device *dev,
 473                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 474 {
 475         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 476 }
 477
 478 /*
 479  * The scatter list versions of the above methods.
 480  */
 481 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 482                 enum dma_data_direction);
 483 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 484                 enum dma_data_direction);
 485 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 486                 enum dma_data_direction);
 487 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 488                 enum dma_data_direction);
 489
 490
 491 #endif /* __KERNEL__ */
 492 #endif