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 <linux/scatterlist.h>
   9
  10 #include <asm-generic/dma-coherent.h>
  11
  12 /*
  13  * DMA-consistent mapping functions.  These allocate/free a region of
  14  * uncached, unwrite-buffered mapped memory space for use with DMA
  15  * devices.  This is the "generic" version.  The PCI specific version
  16  * is in pci.h
  17  *
  18  * Note: Drivers should NOT use this function directly, as it will break
  19  * platforms with CONFIG_DMABOUNCE.
  20  * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
  21  */
  22 extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
  23
  24 /*
  25  * Return whether the given device DMA address mask can be supported
  26  * properly.  For example, if your device can only drive the low 24-bits
  27  * during bus mastering, then you would pass 0x00ffffff as the mask
  28  * to this function.
  29  *
  30  * FIXME: This should really be a platform specific issue - we should
  31  * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
  32  */
  33 static inline int dma_supported(struct device *dev, u64 mask)
  34 {
  35         return dev->dma_mask && *dev->dma_mask != 0;
  36 }
  37
  38 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  39 {
  40         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
  41                 return -EIO;
  42
  43         *dev->dma_mask = dma_mask;
  44
  45         return 0;
  46 }
  47
  48 static inline int dma_get_cache_alignment(void)
  49 {
  50         return 32;
  51 }
  52
  53 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
  54 {
  55         return !!arch_is_coherent();
  56 }
  57
  58 /*
  59  * DMA errors are defined by all-bits-set in the DMA address.
  60  */
  61 static inline int dma_mapping_error(dma_addr_t dma_addr)
  62 {
  63         return dma_addr == ~0;
  64 }
  65
  66 /*
  67  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
  68  * function so drivers using this API are highlighted with build warnings.
  69  */
  70 static inline void *
  71 dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
  72 {
  73         return NULL;
  74 }
  75
  76 static inline void
  77 dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
  78                      dma_addr_t handle)
  79 {
  80 }
  81
  82 /**
  83  * dma_alloc_coherent - allocate consistent memory for DMA
  84  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  85  * @size: required memory size
  86  * @handle: bus-specific DMA address
  87  *
  88  * Allocate some uncached, unbuffered memory for a device for
  89  * performing DMA.  This function allocates pages, and will
  90  * return the CPU-viewed address, and sets @handle to be the
  91  * device-viewed address.
  92  */
  93 extern void *
  94 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
  95
  96 /**
  97  * dma_free_coherent - free memory allocated by dma_alloc_coherent
  98  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  99  * @size: size of memory originally requested in dma_alloc_coherent
 100  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 101  * @handle: device-view address returned from dma_alloc_coherent
 102  *
 103  * Free (and unmap) a DMA buffer previously allocated by
 104  * dma_alloc_coherent().
 105  *
 106  * References to memory and mappings associated with cpu_addr/handle
 107  * during and after this call executing are illegal.
 108  */
 109 extern void
 110 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
 111                   dma_addr_t handle);
 112
 113 /**
 114  * dma_mmap_coherent - map a coherent DMA allocation into user space
 115  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 116  * @vma: vm_area_struct describing requested user mapping
 117  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 118  * @handle: device-view address returned from dma_alloc_coherent
 119  * @size: size of memory originally requested in dma_alloc_coherent
 120  *
 121  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 122  * into user space.  The coherent DMA buffer must not be freed by the
 123  * driver until the user space mapping has been released.
 124  */
 125 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 126                       void *cpu_addr, dma_addr_t handle, size_t size);
 127
 128
 129 /**
 130  * dma_alloc_writecombine - allocate writecombining memory for DMA
 131  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 132  * @size: required memory size
 133  * @handle: bus-specific DMA address
 134  *
 135  * Allocate some uncached, buffered memory for a device for
 136  * performing DMA.  This function allocates pages, and will
 137  * return the CPU-viewed address, and sets @handle to be the
 138  * device-viewed address.
 139  */
 140 extern void *
 141 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
 142
 143 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 144         dma_free_coherent(dev,size,cpu_addr,handle)
 145
 146 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
 147                           void *cpu_addr, dma_addr_t handle, size_t size);
 148
 149
 150 /**
 151  * dma_map_single - map a single buffer for streaming DMA
 152  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 153  * @cpu_addr: CPU direct mapped address of buffer
 154  * @size: size of buffer to map
 155  * @dir: DMA transfer direction
 156  *
 157  * Ensure that any data held in the cache is appropriately discarded
 158  * or written back.
 159  *
 160  * The device owns this memory once this call has completed.  The CPU
 161  * can regain ownership by calling dma_unmap_single() or
 162  * dma_sync_single_for_cpu().
 163  */
 164 #ifndef CONFIG_DMABOUNCE
 165 static inline dma_addr_t
 166 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
 167                enum dma_data_direction dir)
 168 {
 169         if (!arch_is_coherent())
 170                 dma_cache_maint(cpu_addr, size, dir);
 171
 172         return virt_to_dma(dev, (unsigned long)cpu_addr);
 173 }
 174 #else
 175 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
 176 #endif
 177
 178 /**
 179  * dma_map_page - map a portion of a page for streaming DMA
 180  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 181  * @page: page that buffer resides in
 182  * @offset: offset into page for start of buffer
 183  * @size: size of buffer to map
 184  * @dir: DMA transfer direction
 185  *
 186  * Ensure that any data held in the cache is appropriately discarded
 187  * or written back.
 188  *
 189  * The device owns this memory once this call has completed.  The CPU
 190  * can regain ownership by calling dma_unmap_page() or
 191  * dma_sync_single_for_cpu().
 192  */
 193 static inline dma_addr_t
 194 dma_map_page(struct device *dev, struct page *page,
 195              unsigned long offset, size_t size,
 196              enum dma_data_direction dir)
 197 {
 198         return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
 199 }
 200
 201 /**
 202  * dma_unmap_single - unmap a single buffer previously mapped
 203  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 204  * @handle: DMA address of buffer
 205  * @size: size of buffer to map
 206  * @dir: DMA transfer direction
 207  *
 208  * Unmap a single streaming mode DMA translation.  The handle and size
 209  * must match what was provided in the previous dma_map_single() call.
 210  * All other usages are undefined.
 211  *
 212  * After this call, reads by the CPU to the buffer are guaranteed to see
 213  * whatever the device wrote there.
 214  */
 215 #ifndef CONFIG_DMABOUNCE
 216 static inline void
 217 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
 218                  enum dma_data_direction dir)
 219 {
 220         /* nothing to do */
 221 }
 222 #else
 223 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
 224 #endif
 225
 226 /**
 227  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 228  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 229  * @handle: DMA address of buffer
 230  * @size: size of buffer to map
 231  * @dir: DMA transfer direction
 232  *
 233  * Unmap a single streaming mode DMA translation.  The handle and size
 234  * must match what was provided in the previous dma_map_single() call.
 235  * All other usages are undefined.
 236  *
 237  * After this call, reads by the CPU to the buffer are guaranteed to see
 238  * whatever the device wrote there.
 239  */
 240 static inline void
 241 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
 242                enum dma_data_direction dir)
 243 {
 244         dma_unmap_single(dev, handle, size, (int)dir);
 245 }
 246
 247 /**
 248  * dma_map_sg - map a set of SG buffers for streaming mode DMA
 249  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 250  * @sg: list of buffers
 251  * @nents: number of buffers to map
 252  * @dir: DMA transfer direction
 253  *
 254  * Map a set of buffers described by scatterlist in streaming
 255  * mode for DMA.  This is the scatter-gather version of the
 256  * above dma_map_single interface.  Here the scatter gather list
 257  * elements are each tagged with the appropriate dma address
 258  * and length.  They are obtained via sg_dma_{address,length}(SG).
 259  *
 260  * NOTE: An implementation may be able to use a smaller number of
 261  *       DMA address/length pairs than there are SG table elements.
 262  *       (for example via virtual mapping capabilities)
 263  *       The routine returns the number of addr/length pairs actually
 264  *       used, at most nents.
 265  *
 266  * Device ownership issues as mentioned above for dma_map_single are
 267  * the same here.
 268  */
 269 #ifndef CONFIG_DMABOUNCE
 270 static inline int
 271 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 272            enum dma_data_direction dir)
 273 {
 274         int i;
 275
 276         for (i = 0; i < nents; i++, sg++) {
 277                 char *virt;
 278
 279                 sg->dma_address = page_to_dma(dev, sg_page(sg)) + sg->offset;
 280                 virt = sg_virt(sg);
 281
 282                 if (!arch_is_coherent())
 283                         dma_cache_maint(virt, sg->length, dir);
 284         }
 285
 286         return nents;
 287 }
 288 #else
 289 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 290 #endif
 291
 292 /**
 293  * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
 294  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 295  * @sg: list of buffers
 296  * @nents: number of buffers to map
 297  * @dir: DMA transfer direction
 298  *
 299  * Unmap a set of streaming mode DMA translations.
 300  * Again, CPU read rules concerning calls here are the same as for
 301  * dma_unmap_single() above.
 302  */
 303 #ifndef CONFIG_DMABOUNCE
 304 static inline void
 305 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 306              enum dma_data_direction dir)
 307 {
 308
 309         /* nothing to do */
 310 }
 311 #else
 312 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 313 #endif
 314
 315
 316 /**
 317  * dma_sync_single_for_cpu
 318  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 319  * @handle: DMA address of buffer
 320  * @size: size of buffer to map
 321  * @dir: DMA transfer direction
 322  *
 323  * Make physical memory consistent for a single streaming mode DMA
 324  * translation after a transfer.
 325  *
 326  * If you perform a dma_map_single() but wish to interrogate the
 327  * buffer using the cpu, yet do not wish to teardown the PCI dma
 328  * mapping, you must call this function before doing so.  At the
 329  * next point you give the PCI dma address back to the card, you
 330  * must first the perform a dma_sync_for_device, and then the
 331  * device again owns the buffer.
 332  */
 333 #ifndef CONFIG_DMABOUNCE
 334 static inline void
 335 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
 336                         enum dma_data_direction dir)
 337 {
 338         if (!arch_is_coherent())
 339                 dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
 340 }
 341
 342 static inline void
 343 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
 344                            enum dma_data_direction dir)
 345 {
 346         if (!arch_is_coherent())
 347                 dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
 348 }
 349 #else
 350 extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 351 extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
 352 #endif
 353
 354
 355 /**
 356  * dma_sync_sg_for_cpu
 357  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 358  * @sg: list of buffers
 359  * @nents: number of buffers to map
 360  * @dir: DMA transfer direction
 361  *
 362  * Make physical memory consistent for a set of streaming
 363  * mode DMA translations after a transfer.
 364  *
 365  * The same as dma_sync_single_for_* but for a scatter-gather list,
 366  * same rules and usage.
 367  */
 368 #ifndef CONFIG_DMABOUNCE
 369 static inline void
 370 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
 371                     enum dma_data_direction dir)
 372 {
 373         int i;
 374
 375         for (i = 0; i < nents; i++, sg++) {
 376                 char *virt = sg_virt(sg);
 377                 if (!arch_is_coherent())
 378                         dma_cache_maint(virt, sg->length, dir);
 379         }
 380 }
 381
 382 static inline void
 383 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
 384                        enum dma_data_direction dir)
 385 {
 386         int i;
 387
 388         for (i = 0; i < nents; i++, sg++) {
 389                 char *virt = sg_virt(sg);
 390                 if (!arch_is_coherent())
 391                         dma_cache_maint(virt, sg->length, dir);
 392         }
 393 }
 394 #else
 395 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
 396 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
 397 #endif
 398
 399 #ifdef CONFIG_DMABOUNCE
 400 /*
 401  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 402  * and utilize bounce buffers as needed to work around limited DMA windows.
 403  *
 404  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 405  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 406  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 407  *
 408  * The following are helper functions used by the dmabounce subystem
 409  *
 410  */
 411
 412 /**
 413  * dmabounce_register_dev
 414  *
 415  * @dev: valid struct device pointer
 416  * @small_buf_size: size of buffers to use with small buffer pool
 417  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 418  *
 419  * This function should be called by low-level platform code to register
 420  * a device as requireing DMA buffer bouncing. The function will allocate
 421  * appropriate DMA pools for the device.
 422  *
 423  */
 424 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
 425
 426 /**
 427  * dmabounce_unregister_dev
 428  *
 429  * @dev: valid struct device pointer
 430  *
 431  * This function should be called by low-level platform code when device
 432  * that was previously registered with dmabounce_register_dev is removed
 433  * from the system.
 434  *
 435  */
 436 extern void dmabounce_unregister_dev(struct device *);
 437
 438 /**
 439  * dma_needs_bounce
 440  *
 441  * @dev: valid struct device pointer
 442  * @dma_handle: dma_handle of unbounced buffer
 443  * @size: size of region being mapped
 444  *
 445  * Platforms that utilize the dmabounce mechanism must implement
 446  * this function.
 447  *
 448  * The dmabounce routines call this function whenever a dma-mapping
 449  * is requested to determine whether a given buffer needs to be bounced
 450  * or not. The function must return 0 if the buffer is OK for
 451  * DMA access and 1 if the buffer needs to be bounced.
 452  *
 453  */
 454 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 455 #endif /* CONFIG_DMABOUNCE */
 456
 457 #endif /* __KERNEL__ */
 458 #endif