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