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