include/asm-arm/dma-mapping.h

   1 #ifndef ASMARM_DMA_MAPPING_H
   2 #define ASMARM_DMA_MAPPING_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/mm.h> /* need struct page */
   7
   8 #include <asm/scatterlist.h>
   9
  10 #define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
  11 extern int
  12 dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
  13                             dma_addr_t device_addr, size_t size, int flags);
  14
  15 extern void
  16 dma_release_declared_memory(struct device *dev);
  17
  18 extern void *
  19 dma_mark_declared_memory_occupied(struct device *dev,
  20                                   dma_addr_t device_addr, size_t size);
  21
  22 /*
  23  * DMA-consistent mapping functions.  These allocate/free a region of
  24  * uncached, unwrite-buffered mapped memory space for use with DMA
  25  * devices.  This is the "generic" version.  The PCI specific version
  26  * is in pci.h
  27  *
  28  * Note: Drivers should NOT use this function directly, as it will break
  29  * platforms with CONFIG_DMABOUNCE.
  30  * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
  31  */
  32 extern void consistent_sync(void *kaddr, size_t size, int rw);
  33
  34 /*
  35  * Return whether the given device DMA address mask can be supported
  36  * properly.  For example, if your device can only drive the low 24-bits
  37  * during bus mastering, then you would pass 0x00ffffff as the mask
  38  * to this function.
  39  *
  40  * FIXME: This should really be a platform specific issue - we should
  41  * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
  42  */
  43 static inline int dma_supported(struct device *dev, u64 mask)
  44 {
  45         return dev->dma_mask && *dev->dma_mask != 0;
  46 }
  47
  48 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  49 {
  50         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
  51                 return -EIO;
  52
  53         *dev->dma_mask = dma_mask;
  54
  55         return 0;
  56 }
  57
  58 static inline int dma_get_cache_alignment(void)
  59 {
  60         return 32;
  61 }
  62
  63 static inline int dma_is_consistent(dma_addr_t handle)
  64 {
  65         return !!arch_is_coherent();
  66 }
  67
  68 /*
  69  * DMA errors are defined by all-bits-set in the DMA address.
  70  */
  71 static inline int dma_mapping_error(dma_addr_t dma_addr)
  72 {
  73         return dma_addr == ~0;
  74 }
  75
  76 /**
  77  * dma_alloc_coherent - allocate consistent memory for DMA
  78  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  79  * @size: required memory size
  80  * @handle: bus-specific DMA address
  81  *
  82  * Allocate some uncached, unbuffered memory for a device for
  83  * performing DMA.  This function allocates pages, and will
  84  * return the CPU-viewed address, and sets @handle to be the
  85  * device-viewed address.
  86  */
  87 extern void *
  88 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
  89
  90 /**
  91  * dma_free_coherent - free memory allocated by dma_alloc_coherent
  92  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  93  * @size: size of memory originally requested in dma_alloc_coherent
  94  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
  95  * @handle: device-view address returned from dma_alloc_coherent
  96  *
  97  * Free (and unmap) a DMA buffer previously allocated by
  98  * dma_alloc_coherent().
  99  *
 100  * References to memory and mappings associated with cpu_addr/handle
 101  * during and after this call executing are illegal.
 102  */
 103 extern void
 104 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
 105                   dma_addr_t handle);
 106
 107 /**
 108  * dma_mmap_coherent - map a coherent DMA allocation into user space
 109  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 110  * @vma: vm_area_struct describing requested user mapping
 111  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 112  * @handle: device-view address returned from dma_alloc_coherent
 113  * @size: size of memory originally requested in dma_alloc_coherent
 114  *
 115  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 116  * into user space.  The coherent DMA buffer must not be freed by the
 117  * driver until the user space mapping has been released.
 118  */
 119 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 120                       void *cpu_addr, dma_addr_t handle, size_t size);
 121
 122
 123 /**
 124  * dma_alloc_writecombine - allocate writecombining memory for DMA
 125  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 126  * @size: required memory size
 127  * @handle: bus-specific DMA address
 128  *
 129  * Allocate some uncached, buffered memory for a device for
 130  * performing DMA.  This function allocates pages, and will
 131  * return the CPU-viewed address, and sets @handle to be the
 132  * device-viewed address.
 133  */
 134 extern void *
 135 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
 136
 137 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 138         dma_free_coherent(dev,size,cpu_addr,handle)
 139
 140 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
 141                           void *cpu_addr, dma_addr_t handle, size_t size);
 142
 143
 144 /**
 145  * dma_map_single - map a single buffer for streaming DMA
 146  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 147  * @cpu_addr: CPU direct mapped address of buffer
 148  * @size: size of buffer to map
 149  * @dir: DMA transfer direction
 150  *
 151  * Ensure that any data held in the cache is appropriately discarded
 152  * or written back.
 153  *
 154  * The device owns this memory once this call has completed.  The CPU
 155  * can regain ownership by calling dma_unmap_single() or
 156  * dma_sync_single_for_cpu().
 157  */
 158 #ifndef CONFIG_DMABOUNCE
 159 static inline dma_addr_t
 160 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
 161                enum dma_data_direction dir)
 162 {
 163         if (!arch_is_coherent())
 164                 consistent_sync(cpu_addr, size, dir);
 165
 166         return virt_to_dma(dev, (unsigned long)cpu_addr);
 167 }
 168 #else
 169 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
 170 #endif
 171
 172 /**
 173  * dma_map_page - map a portion of a page for streaming DMA
 174  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 175  * @page: page that buffer resides in
 176  * @offset: offset into page for start of buffer
 177  * @size: size of buffer to map
 178  * @dir: DMA transfer direction
 179  *
 180  * Ensure that any data held in the cache is appropriately discarded
 181  * or written back.
 182  *
 183  * The device owns this memory once this call has completed.  The CPU
 184  * can regain ownership by calling dma_unmap_page() or
 185  * dma_sync_single_for_cpu().
 186  */
 187 static inline dma_addr_t
 188 dma_map_page(struct device *dev, struct page *page,
 189              unsigned long offset, size_t size,
 190              enum dma_data_direction dir)
 191 {
 192         return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
 193 }
 194
 195 /**
 196  * dma_unmap_single - unmap a single buffer previously mapped
 197  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 198  * @handle: DMA address of buffer
 199  * @size: size of buffer to map
 200  * @dir: DMA transfer direction
 201  *
 202  * Unmap a single streaming mode DMA translation.  The handle and size
 203  * must match what was provided in the previous dma_map_single() call.
 204  * All other usages are undefined.
 205  *
 206  * After this call, reads by the CPU to the buffer are guaranteed to see
 207  * whatever the device wrote there.
 208  */
 209 #ifndef CONFIG_DMABOUNCE
 210 static inline void
 211 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
 212                  enum dma_data_direction dir)
 213 {
 214         /* nothing to do */
 215 }
 216 #else
 217 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
 218 #endif
 219
 220 /**
 221  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 222  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 223  * @handle: DMA address of buffer
 224  * @size: size of buffer to map
 225  * @dir: DMA transfer direction
 226  *
 227  * Unmap a single streaming mode DMA translation.  The handle and size
 228  * must match what was provided in the previous dma_map_single() call.
 229  * All other usages are undefined.
 230  *
 231  * After this call, reads by the CPU to the buffer are guaranteed to see
 232  * whatever the device wrote there.
 233  */
 234 static inline void
 235 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
 236                enum dma_data_direction dir)
 237 {
 238         dma_unmap_single(dev, handle, size, (int)dir);
 239 }
 240
 241 /**
 242  * dma_map_sg - map a set of SG buffers for streaming mode DMA
 243  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 244  * @sg: list of buffers
 245  * @nents: number of buffers to map
 246  * @dir: DMA transfer direction
 247  *
 248  * Map a set of buffers described by scatterlist in streaming
 249  * mode for DMA.  This is the scatter-gather version of the
 250  * above dma_map_single interface.  Here the scatter gather list
 251  * elements are each tagged with the appropriate dma address
 252  * and length.  They are obtained via sg_dma_{address,length}(SG).
 253  *
 254  * NOTE: An implementation may be able to use a smaller number of
 255  *       DMA address/length pairs than there are SG table elements.
 256  *       (for example via virtual mapping capabilities)
 257  *       The routine returns the number of addr/length pairs actually
 258  *       used, at most nents.
 259  *
 260  * Device ownership issues as mentioned above for dma_map_single are
 261  * the same here.
 262  */
 263 #ifndef CONFIG_DMABOUNCE
 264 static inline int
 265 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 266            enum dma_data_direction dir)
 267 {
 268         int i;
 269
 270         for (i = 0; i < nents; i++, sg++) {
 271                 char *virt;
 272
 273                 sg->dma_address = page_to_dma(dev, sg->page) + sg->offset;
 274                 virt = page_address(sg->page) + sg->offset;
 275
 276                 if (!arch_is_coherent())
 277                         consistent_sync(virt, sg->length, dir);
 278         }
 279
 280         return nents;
 281 }
 282 #else
 283 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 284 #endif
 285
 286 /**
 287  * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
 288  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 289  * @sg: list of buffers
 290  * @nents: number of buffers to map
 291  * @dir: DMA transfer direction
 292  *
 293  * Unmap a set of streaming mode DMA translations.
 294  * Again, CPU read rules concerning calls here are the same as for
 295  * dma_unmap_single() above.
 296  */
 297 #ifndef CONFIG_DMABOUNCE
 298 static inline void
 299 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 300              enum dma_data_direction dir)
 301 {
 302
 303         /* nothing to do */
 304 }
 305 #else
 306 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 307 #endif
 308
 309
 310 /**
 311  * dma_sync_single_for_cpu
 312  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 313  * @handle: DMA address of buffer
 314  * @size: size of buffer to map
 315  * @dir: DMA transfer direction
 316  *
 317  * Make physical memory consistent for a single streaming mode DMA
 318  * translation after a transfer.
 319  *
 320  * If you perform a dma_map_single() but wish to interrogate the
 321  * buffer using the cpu, yet do not wish to teardown the PCI dma
 322  * mapping, you must call this function before doing so.  At the
 323  * next point you give the PCI dma address back to the card, you
 324  * must first the perform a dma_sync_for_device, and then the
 325  * device again owns the buffer.
 326  */
 327 #ifndef CONFIG_DMABOUNCE
 328 static inline void
 329 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
 330                         enum dma_data_direction dir)
 331 {
 332         if (!arch_is_coherent())
 333                 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
 334 }
 335
 336 static inline void
 337 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
 338                            enum dma_data_direction dir)
 339 {
 340         if (!arch_is_coherent())
 341                 consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
 342 }
 343 #else
 344 extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 345 extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 346 #endif
 347
 348
 349 /**
 350  * dma_sync_sg_for_cpu
 351  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 352  * @sg: list of buffers
 353  * @nents: number of buffers to map
 354  * @dir: DMA transfer direction
 355  *
 356  * Make physical memory consistent for a set of streaming
 357  * mode DMA translations after a transfer.
 358  *
 359  * The same as dma_sync_single_for_* but for a scatter-gather list,
 360  * same rules and usage.
 361  */
 362 #ifndef CONFIG_DMABOUNCE
 363 static inline void
 364 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
 365                     enum dma_data_direction dir)
 366 {
 367         int i;
 368
 369         for (i = 0; i < nents; i++, sg++) {
 370                 char *virt = page_address(sg->page) + sg->offset;
 371                 if (!arch_is_coherent())
 372                         consistent_sync(virt, sg->length, dir);
 373         }
 374 }
 375
 376 static inline void
 377 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
 378                        enum dma_data_direction dir)
 379 {
 380         int i;
 381
 382         for (i = 0; i < nents; i++, sg++) {
 383                 char *virt = page_address(sg->page) + sg->offset;
 384                 if (!arch_is_coherent())
 385                         consistent_sync(virt, sg->length, dir);
 386         }
 387 }
 388 #else
 389 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
 390 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
 391 #endif
 392
 393 #ifdef CONFIG_DMABOUNCE
 394 /*
 395  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 396  * and utilize bounce buffers as needed to work around limited DMA windows.
 397  *
 398  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 399  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 400  * On some ADI engineering sytems, PCI inbound window is 32MB (12MB total RAM)
 401  *
 402  * The following are helper functions used by the dmabounce subystem
 403  *
 404  */
 405
 406 /**
 407  * dmabounce_register_dev
 408  *
 409  * @dev: valid struct device pointer
 410  * @small_buf_size: size of buffers to use with small buffer pool
 411  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 412  *
 413  * This function should be called by low-level platform code to register
 414  * a device as requireing DMA buffer bouncing. The function will allocate
 415  * appropriate DMA pools for the device.
 416  *
 417  */
 418 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
 419
 420 /**
 421  * dmabounce_unregister_dev
 422  *
 423  * @dev: valid struct device pointer
 424  *
 425  * This function should be called by low-level platform code when device
 426  * that was previously registered with dmabounce_register_dev is removed
 427  * from the system.
 428  *
 429  */
 430 extern void dmabounce_unregister_dev(struct device *);
 431
 432 /**
 433  * dma_needs_bounce
 434  *
 435  * @dev: valid struct device pointer
 436  * @dma_handle: dma_handle of unbounced buffer
 437  * @size: size of region being mapped
 438  *
 439  * Platforms that utilize the dmabounce mechanism must implement
 440  * this function.
 441  *
 442  * The dmabounce routines call this function whenever a dma-mapping
 443  * is requested to determine whether a given buffer needs to be bounced
 444  * or not. The function must return 0 if the the buffer is OK for
 445  * DMA access and 1 if the buffer needs to be bounced.
 446  *
 447  */
 448 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 449 #endif /* CONFIG_DMABOUNCE */
 450
 451 #endif /* __KERNEL__ */
 452 #endif