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