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