arch/arm/include/asm/dma-mapping.h

   1 #ifndef ASMARM_DMA_MAPPING_H
   2 #define ASMARM_DMA_MAPPING_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/mm_types.h>
   7 #include <linux/scatterlist.h>
   8
   9 #include <asm-generic/dma-coherent.h>
  10 #include <asm/memory.h>
  11
  12 /*
  13  * page_to_dma/dma_to_virt/virt_to_dma are architecture private functions
  14  * used internally by the DMA-mapping API to provide DMA addresses. They
  15  * must not be used by drivers.
  16  */
  17 #ifndef __arch_page_to_dma
  18 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
  19 {
  20         return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page));
  21 }
  22
  23 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  24 {
  25         return (void *)__bus_to_virt(addr);
  26 }
  27
  28 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  29 {
  30         return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
  31 }
  32 #else
  33 static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
  34 {
  35         return __arch_page_to_dma(dev, page);
  36 }
  37
  38 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
  39 {
  40         return __arch_dma_to_virt(dev, addr);
  41 }
  42
  43 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
  44 {
  45         return __arch_virt_to_dma(dev, addr);
  46 }
  47 #endif
  48
  49 /*
  50  * DMA-consistent mapping functions.  These allocate/free a region of
  51  * uncached, unwrite-buffered mapped memory space for use with DMA
  52  * devices.  This is the "generic" version.  The PCI specific version
  53  * is in pci.h
  54  *
  55  * Note: Drivers should NOT use this function directly, as it will break
  56  * platforms with CONFIG_DMABOUNCE.
  57  * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
  58  */
  59 extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
  60
  61 /*
  62  * Return whether the given device DMA address mask can be supported
  63  * properly.  For example, if your device can only drive the low 24-bits
  64  * during bus mastering, then you would pass 0x00ffffff as the mask
  65  * to this function.
  66  *
  67  * FIXME: This should really be a platform specific issue - we should
  68  * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
  69  */
  70 static inline int dma_supported(struct device *dev, u64 mask)
  71 {
  72         return dev->dma_mask && *dev->dma_mask != 0;
  73 }
  74
  75 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  76 {
  77         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
  78                 return -EIO;
  79
  80         *dev->dma_mask = dma_mask;
  81
  82         return 0;
  83 }
  84
  85 static inline int dma_get_cache_alignment(void)
  86 {
  87         return 32;
  88 }
  89
  90 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
  91 {
  92         return !!arch_is_coherent();
  93 }
  94
  95 /*
  96  * DMA errors are defined by all-bits-set in the DMA address.
  97  */
  98 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  99 {
 100         return dma_addr == ~0;
 101 }
 102
 103 /*
 104  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 105  * function so drivers using this API are highlighted with build warnings.
 106  */
 107 static inline void *
 108 dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
 109 {
 110         return NULL;
 111 }
 112
 113 static inline void
 114 dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
 115                      dma_addr_t handle)
 116 {
 117 }
 118
 119 /**
 120  * dma_alloc_coherent - allocate consistent memory for DMA
 121  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 122  * @size: required memory size
 123  * @handle: bus-specific DMA address
 124  *
 125  * Allocate some uncached, unbuffered memory for a device for
 126  * performing DMA.  This function allocates pages, and will
 127  * return the CPU-viewed address, and sets @handle to be the
 128  * device-viewed address.
 129  */
 130 extern void *
 131 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
 132
 133 /**
 134  * dma_free_coherent - free memory allocated by dma_alloc_coherent
 135  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 136  * @size: size of memory originally requested in dma_alloc_coherent
 137  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 138  * @handle: device-view address returned from dma_alloc_coherent
 139  *
 140  * Free (and unmap) a DMA buffer previously allocated by
 141  * dma_alloc_coherent().
 142  *
 143  * References to memory and mappings associated with cpu_addr/handle
 144  * during and after this call executing are illegal.
 145  */
 146 extern void
 147 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
 148                   dma_addr_t handle);
 149
 150 /**
 151  * dma_mmap_coherent - map a coherent DMA allocation into user space
 152  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 153  * @vma: vm_area_struct describing requested user mapping
 154  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 155  * @handle: device-view address returned from dma_alloc_coherent
 156  * @size: size of memory originally requested in dma_alloc_coherent
 157  *
 158  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 159  * into user space.  The coherent DMA buffer must not be freed by the
 160  * driver until the user space mapping has been released.
 161  */
 162 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 163                       void *cpu_addr, dma_addr_t handle, size_t size);
 164
 165
 166 /**
 167  * dma_alloc_writecombine - allocate writecombining memory for DMA
 168  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 169  * @size: required memory size
 170  * @handle: bus-specific DMA address
 171  *
 172  * Allocate some uncached, buffered memory for a device for
 173  * performing DMA.  This function allocates pages, and will
 174  * return the CPU-viewed address, and sets @handle to be the
 175  * device-viewed address.
 176  */
 177 extern void *
 178 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
 179
 180 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 181         dma_free_coherent(dev,size,cpu_addr,handle)
 182
 183 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
 184                           void *cpu_addr, dma_addr_t handle, size_t size);
 185
 186
 187 #ifdef CONFIG_DMABOUNCE
 188 /*
 189  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 190  * and utilize bounce buffers as needed to work around limited DMA windows.
 191  *
 192  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 193  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 194  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 195  *
 196  * The following are helper functions used by the dmabounce subystem
 197  *
 198  */
 199
 200 /**
 201  * dmabounce_register_dev
 202  *
 203  * @dev: valid struct device pointer
 204  * @small_buf_size: size of buffers to use with small buffer pool
 205  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 206  *
 207  * This function should be called by low-level platform code to register
 208  * a device as requireing DMA buffer bouncing. The function will allocate
 209  * appropriate DMA pools for the device.
 210  *
 211  */
 212 extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);
 213
 214 /**
 215  * dmabounce_unregister_dev
 216  *
 217  * @dev: valid struct device pointer
 218  *
 219  * This function should be called by low-level platform code when device
 220  * that was previously registered with dmabounce_register_dev is removed
 221  * from the system.
 222  *
 223  */
 224 extern void dmabounce_unregister_dev(struct device *);
 225
 226 /**
 227  * dma_needs_bounce
 228  *
 229  * @dev: valid struct device pointer
 230  * @dma_handle: dma_handle of unbounced buffer
 231  * @size: size of region being mapped
 232  *
 233  * Platforms that utilize the dmabounce mechanism must implement
 234  * this function.
 235  *
 236  * The dmabounce routines call this function whenever a dma-mapping
 237  * is requested to determine whether a given buffer needs to be bounced
 238  * or not. The function must return 0 if the buffer is OK for
 239  * DMA access and 1 if the buffer needs to be bounced.
 240  *
 241  */
 242 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 243
 244 /*
 245  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 246  */
 247 extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
 248 extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
 249                         unsigned long offset, size_t size,
 250                         enum dma_data_direction dir);
 251 extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
 252
 253 /*
 254  * Private functions
 255  */
 256 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
 257                         size_t, enum dma_data_direction);
 258 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
 259                         size_t, enum dma_data_direction);
 260 #else
 261 #define dmabounce_sync_for_cpu(dev,dma,off,sz,dir)      (1)
 262 #define dmabounce_sync_for_device(dev,dma,off,sz,dir)   (1)
 263
 264
 265 /**
 266  * dma_map_single - map a single buffer for streaming DMA
 267  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 268  * @cpu_addr: CPU direct mapped address of buffer
 269  * @size: size of buffer to map
 270  * @dir: DMA transfer direction
 271  *
 272  * Ensure that any data held in the cache is appropriately discarded
 273  * or written back.
 274  *
 275  * The device owns this memory once this call has completed.  The CPU
 276  * can regain ownership by calling dma_unmap_single() or
 277  * dma_sync_single_for_cpu().
 278  */
 279 static inline dma_addr_t
 280 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
 281                enum dma_data_direction dir)
 282 {
 283         if (!arch_is_coherent())
 284                 dma_cache_maint(cpu_addr, size, dir);
 285
 286         return virt_to_dma(dev, cpu_addr);
 287 }
 288
 289
 290 /**
 291  * dma_map_page - map a portion of a page for streaming DMA
 292  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 293  * @page: page that buffer resides in
 294  * @offset: offset into page for start of buffer
 295  * @size: size of buffer to map
 296  * @dir: DMA transfer direction
 297  *
 298  * Ensure that any data held in the cache is appropriately discarded
 299  * or written back.
 300  *
 301  * The device owns this memory once this call has completed.  The CPU
 302  * can regain ownership by calling dma_unmap_page() or
 303  * dma_sync_single_for_cpu().
 304  */
 305 static inline dma_addr_t
 306 dma_map_page(struct device *dev, struct page *page,
 307              unsigned long offset, size_t size,
 308              enum dma_data_direction dir)
 309 {
 310         if (!arch_is_coherent())
 311                 dma_cache_maint(page_address(page) + offset, size, dir);
 312
 313         return page_to_dma(dev, page) + offset;
 314 }
 315
 316 /**
 317  * dma_unmap_single - unmap a single buffer previously mapped
 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  * Unmap a single streaming mode DMA translation.  The handle and size
 324  * must match what was provided in the previous dma_map_single() call.
 325  * All other usages are undefined.
 326  *
 327  * After this call, reads by the CPU to the buffer are guaranteed to see
 328  * whatever the device wrote there.
 329  */
 330 static inline void
 331 dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
 332                  enum dma_data_direction dir)
 333 {
 334         /* nothing to do */
 335 }
 336 #endif /* CONFIG_DMABOUNCE */
 337
 338 /**
 339  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 340  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 341  * @handle: DMA address of buffer
 342  * @size: size of buffer to map
 343  * @dir: DMA transfer direction
 344  *
 345  * Unmap a single streaming mode DMA translation.  The handle and size
 346  * must match what was provided in the previous dma_map_single() call.
 347  * All other usages are undefined.
 348  *
 349  * After this call, reads by the CPU to the buffer are guaranteed to see
 350  * whatever the device wrote there.
 351  */
 352 static inline void
 353 dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
 354                enum dma_data_direction dir)
 355 {
 356         dma_unmap_single(dev, handle, size, dir);
 357 }
 358
 359 /**
 360  * dma_sync_single_range_for_cpu
 361  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 362  * @handle: DMA address of buffer
 363  * @offset: offset of region to start sync
 364  * @size: size of region to sync
 365  * @dir: DMA transfer direction (same as passed to dma_map_single)
 366  *
 367  * Make physical memory consistent for a single streaming mode DMA
 368  * translation after a transfer.
 369  *
 370  * If you perform a dma_map_single() but wish to interrogate the
 371  * buffer using the cpu, yet do not wish to teardown the PCI dma
 372  * mapping, you must call this function before doing so.  At the
 373  * next point you give the PCI dma address back to the card, you
 374  * must first the perform a dma_sync_for_device, and then the
 375  * device again owns the buffer.
 376  */
 377 static inline void
 378 dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t handle,
 379                               unsigned long offset, size_t size,
 380                               enum dma_data_direction dir)
 381 {
 382         if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
 383                 return;
 384
 385         if (!arch_is_coherent())
 386                 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
 387 }
 388
 389 static inline void
 390 dma_sync_single_range_for_device(struct device *dev, dma_addr_t handle,
 391                                  unsigned long offset, size_t size,
 392                                  enum dma_data_direction dir)
 393 {
 394         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 395                 return;
 396
 397         if (!arch_is_coherent())
 398                 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
 399 }
 400
 401 static inline void
 402 dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
 403                         enum dma_data_direction dir)
 404 {
 405         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 406 }
 407
 408 static inline void
 409 dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
 410                            enum dma_data_direction dir)
 411 {
 412         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 413 }
 414
 415 /*
 416  * The scatter list versions of the above methods.
 417  */
 418 extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 419 extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
 420 extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
 421 extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
 422
 423
 424 #endif /* __KERNEL__ */
 425 #endif