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 0;
  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, int 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, int 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         consistent_sync(cpu_addr, size, dir);
 149         return virt_to_dma(dev, (unsigned long)cpu_addr);
 150 }
 151 #else
 152 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
 153 #endif
 154
 155 /**
 156  * dma_map_page - map a portion of a page for streaming DMA
 157  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 158  * @page: page that buffer resides in
 159  * @offset: offset into page for start of buffer
 160  * @size: size of buffer to map
 161  * @dir: DMA transfer direction
 162  *
 163  * Ensure that any data held in the cache is appropriately discarded
 164  * or written back.
 165  *
 166  * The device owns this memory once this call has completed.  The CPU
 167  * can regain ownership by calling dma_unmap_page() or
 168  * dma_sync_single_for_cpu().
 169  */
 170 static inline dma_addr_t
 171 dma_map_page(struct device *dev, struct page *page,
 172              unsigned long offset, size_t size,
 173              enum dma_data_direction dir)
 174 {
 175         return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
 176 }
 177
 178 /**
 179  * dma_unmap_single - unmap a single buffer previously mapped
 180  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 181  * @handle: DMA address of buffer
 182  * @size: size of buffer to map
 183  * @dir: DMA transfer direction
 184  *
 185  * Unmap a single streaming mode DMA translation.  The handle and size
 186  * must match what was provided in the previous dma_map_single() call.
 187  * All other usages are undefined.
 188  *
 189  * After this call, reads by the CPU to the buffer are guaranteed to see
 190  * whatever the device wrote there.
 191  */
 192 #ifndef CONFIG_DMABOUNCE
 193 static inline void
 194 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
 195                  enum dma_data_direction dir)
 196 {
 197         /* nothing to do */
 198 }
 199 #else
 200 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
 201 #endif
 202
 203 /**
 204  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 205  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 206  * @handle: DMA address of buffer
 207  * @size: size of buffer to map
 208  * @dir: DMA transfer direction
 209  *
 210  * Unmap a single streaming mode DMA translation.  The handle and size
 211  * must match what was provided in the previous dma_map_single() call.
 212  * All other usages are undefined.
 213  *
 214  * After this call, reads by the CPU to the buffer are guaranteed to see
 215  * whatever the device wrote there.
 216  */
 217 static inline void
 218 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
 219                enum dma_data_direction dir)
 220 {
 221         dma_unmap_single(dev, handle, size, (int)dir);
 222 }
 223
 224 /**
 225  * dma_map_sg - map a set of SG buffers for streaming mode DMA
 226  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 227  * @sg: list of buffers
 228  * @nents: number of buffers to map
 229  * @dir: DMA transfer direction
 230  *
 231  * Map a set of buffers described by scatterlist in streaming
 232  * mode for DMA.  This is the scatter-gather version of the
 233  * above dma_map_single interface.  Here the scatter gather list
 234  * elements are each tagged with the appropriate dma address
 235  * and length.  They are obtained via sg_dma_{address,length}(SG).
 236  *
 237  * NOTE: An implementation may be able to use a smaller number of
 238  *       DMA address/length pairs than there are SG table elements.
 239  *       (for example via virtual mapping capabilities)
 240  *       The routine returns the number of addr/length pairs actually
 241  *       used, at most nents.
 242  *
 243  * Device ownership issues as mentioned above for dma_map_single are
 244  * the same here.
 245  */
 246 #ifndef CONFIG_DMABOUNCE
 247 static inline int
 248 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 249            enum dma_data_direction dir)
 250 {
 251         int i;
 252
 253         for (i = 0; i < nents; i++, sg++) {
 254                 char *virt;
 255
 256                 sg->dma_address = page_to_dma(dev, sg->page) + sg->offset;
 257                 virt = page_address(sg->page) + sg->offset;
 258                 consistent_sync(virt, sg->length, dir);
 259         }
 260
 261         return nents;
 262 }
 263 #else
 264 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 265 #endif
 266
 267 /**
 268  * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
 269  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 270  * @sg: list of buffers
 271  * @nents: number of buffers to map
 272  * @dir: DMA transfer direction
 273  *
 274  * Unmap a set of streaming mode DMA translations.
 275  * Again, CPU read rules concerning calls here are the same as for
 276  * dma_unmap_single() above.
 277  */
 278 #ifndef CONFIG_DMABOUNCE
 279 static inline void
 280 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 281              enum dma_data_direction dir)
 282 {
 283
 284         /* nothing to do */
 285 }
 286 #else
 287 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 288 #endif
 289
 290
 291 /**
 292  * dma_sync_single_for_cpu
 293  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 294  * @handle: DMA address of buffer
 295  * @size: size of buffer to map
 296  * @dir: DMA transfer direction
 297  *
 298  * Make physical memory consistent for a single streaming mode DMA
 299  * translation after a transfer.
 300  *
 301  * If you perform a dma_map_single() but wish to interrogate the
 302  * buffer using the cpu, yet do not wish to teardown the PCI dma
 303  * mapping, you must call this function before doing so.  At the
 304  * next point you give the PCI dma address back to the card, you
 305  * must first the perform a dma_sync_for_device, and then the
 306  * device again owns the buffer.
 307  */
 308 #ifndef CONFIG_DMABOUNCE
 309 static inline void
 310 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
 311                         enum dma_data_direction dir)
 312 {
 313         consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
 314 }
 315
 316 static inline void
 317 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
 318                            enum dma_data_direction dir)
 319 {
 320         consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
 321 }
 322 #else
 323 extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 324 extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 325 #endif
 326
 327
 328 /**
 329  * dma_sync_sg_for_cpu
 330  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 331  * @sg: list of buffers
 332  * @nents: number of buffers to map
 333  * @dir: DMA transfer direction
 334  *
 335  * Make physical memory consistent for a set of streaming
 336  * mode DMA translations after a transfer.
 337  *
 338  * The same as dma_sync_single_for_* but for a scatter-gather list,
 339  * same rules and usage.
 340  */
 341 #ifndef CONFIG_DMABOUNCE
 342 static inline void
 343 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
 344                     enum dma_data_direction dir)
 345 {
 346         int i;
 347
 348         for (i = 0; i < nents; i++, sg++) {
 349                 char *virt = page_address(sg->page) + sg->offset;
 350                 consistent_sync(virt, sg->length, dir);
 351         }
 352 }
 353
 354 static inline void
 355 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
 356                        enum dma_data_direction dir)
 357 {
 358         int i;
 359
 360         for (i = 0; i < nents; i++, sg++) {
 361                 char *virt = page_address(sg->page) + sg->offset;
 362                 consistent_sync(virt, sg->length, dir);
 363         }
 364 }
 365 #else
 366 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
 367 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
 368 #endif
 369
 370 #ifdef CONFIG_DMABOUNCE
 371 /*
 372  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 373  * and utilize bounce buffers as needed to work around limited DMA windows.
 374  *
 375  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 376  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 377  * On some ADI engineering sytems, PCI inbound window is 32MB (12MB total RAM)
 378  *
 379  * The following are helper functions used by the dmabounce subystem
 380  *
 381  */
 382
 383 /**
 384  * dmabounce_register_dev
 385  *
 386  * @dev: valid struct device pointer
 387  * @small_buf_size: size of buffers to use with small buffer pool
 388  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 389  *
 390  * This function should be called by low-level platform code to register
 391  * a device as requireing DMA buffer bouncing. The function will allocate
 392  * appropriate DMA pools for the device.
 393  *
 394  */
 395 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
 396
 397 /**
 398  * dmabounce_unregister_dev
 399  *
 400  * @dev: valid struct device pointer
 401  *
 402  * This function should be called by low-level platform code when device
 403  * that was previously registered with dmabounce_register_dev is removed
 404  * from the system.
 405  *
 406  */
 407 extern void dmabounce_unregister_dev(struct device *);
 408
 409 /**
 410  * dma_needs_bounce
 411  *
 412  * @dev: valid struct device pointer
 413  * @dma_handle: dma_handle of unbounced buffer
 414  * @size: size of region being mapped
 415  *
 416  * Platforms that utilize the dmabounce mechanism must implement
 417  * this function.
 418  *
 419  * The dmabounce routines call this function whenever a dma-mapping
 420  * is requested to determine whether a given buffer needs to be bounced
 421  * or not. The function must return 0 if the the buffer is OK for
 422  * DMA access and 1 if the buffer needs to be bounced.
 423  *
 424  */
 425 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 426 #endif /* CONFIG_DMABOUNCE */
 427
 428 #endif /* __KERNEL__ */
 429 #endif