kernel/2.6.29.6-aldebaran-rt/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         if (mask < ISA_DMA_THRESHOLD)
  73                 return 0;
  74         return 1;
  75 }
  76
  77 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  78 {
  79         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
  80                 return -EIO;
  81
  82         *dev->dma_mask = dma_mask;
  83
  84         return 0;
  85 }
  86
  87 static inline int dma_get_cache_alignment(void)
  88 {
  89         return 32;
  90 }
  91
  92 static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
  93 {
  94         return !!arch_is_coherent();
  95 }
  96
  97 /*
  98  * DMA errors are defined by all-bits-set in the DMA address.
  99  */
 100 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 101 {
 102         return dma_addr == ~0;
 103 }
 104
 105 /*
 106  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 107  * function so drivers using this API are highlighted with build warnings.
 108  */
 109 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
 110                 dma_addr_t *handle, gfp_t gfp)
 111 {
 112         return NULL;
 113 }
 114
 115 static inline void dma_free_noncoherent(struct device *dev, size_t size,
 116                 void *cpu_addr, dma_addr_t handle)
 117 {
 118 }
 119
 120 /**
 121  * dma_alloc_coherent - allocate consistent memory for DMA
 122  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 123  * @size: required memory size
 124  * @handle: bus-specific DMA address
 125  *
 126  * Allocate some uncached, unbuffered memory for a device for
 127  * performing DMA.  This function allocates pages, and will
 128  * return the CPU-viewed address, and sets @handle to be the
 129  * device-viewed address.
 130  */
 131 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
 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 dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
 147
 148 /**
 149  * dma_mmap_coherent - map a coherent DMA allocation into user space
 150  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 151  * @vma: vm_area_struct describing requested user mapping
 152  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 153  * @handle: device-view address returned from dma_alloc_coherent
 154  * @size: size of memory originally requested in dma_alloc_coherent
 155  *
 156  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 157  * into user space.  The coherent DMA buffer must not be freed by the
 158  * driver until the user space mapping has been released.
 159  */
 160 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
 161                 void *, dma_addr_t, size_t);
 162
 163
 164 /**
 165  * dma_alloc_writecombine - allocate writecombining memory for DMA
 166  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 167  * @size: required memory size
 168  * @handle: bus-specific DMA address
 169  *
 170  * Allocate some uncached, buffered memory for a device for
 171  * performing DMA.  This function allocates pages, and will
 172  * return the CPU-viewed address, and sets @handle to be the
 173  * device-viewed address.
 174  */
 175 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
 176                 gfp_t);
 177
 178 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
 179         dma_free_coherent(dev,size,cpu_addr,handle)
 180
 181 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
 182                 void *, dma_addr_t, size_t);
 183
 184
 185 #ifdef CONFIG_DMABOUNCE
 186 /*
 187  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 188  * and utilize bounce buffers as needed to work around limited DMA windows.
 189  *
 190  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 191  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 192  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 193  *
 194  * The following are helper functions used by the dmabounce subystem
 195  *
 196  */
 197
 198 /**
 199  * dmabounce_register_dev
 200  *
 201  * @dev: valid struct device pointer
 202  * @small_buf_size: size of buffers to use with small buffer pool
 203  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 204  *
 205  * This function should be called by low-level platform code to register
 206  * a device as requireing DMA buffer bouncing. The function will allocate
 207  * appropriate DMA pools for the device.
 208  *
 209  */
 210 extern int dmabounce_register_dev(struct device *, unsigned long,
 211                 unsigned long);
 212
 213 /**
 214  * dmabounce_unregister_dev
 215  *
 216  * @dev: valid struct device pointer
 217  *
 218  * This function should be called by low-level platform code when device
 219  * that was previously registered with dmabounce_register_dev is removed
 220  * from the system.
 221  *
 222  */
 223 extern void dmabounce_unregister_dev(struct device *);
 224
 225 /**
 226  * dma_needs_bounce
 227  *
 228  * @dev: valid struct device pointer
 229  * @dma_handle: dma_handle of unbounced buffer
 230  * @size: size of region being mapped
 231  *
 232  * Platforms that utilize the dmabounce mechanism must implement
 233  * this function.
 234  *
 235  * The dmabounce routines call this function whenever a dma-mapping
 236  * is requested to determine whether a given buffer needs to be bounced
 237  * or not. The function must return 0 if the buffer is OK for
 238  * DMA access and 1 if the buffer needs to be bounced.
 239  *
 240  */
 241 extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
 242
 243 /*
 244  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
 245  */
 246 extern dma_addr_t dma_map_single(struct device *, void *, size_t,
 247                 enum dma_data_direction);
 248 extern dma_addr_t dma_map_page(struct device *, struct page *,
 249                 unsigned long, size_t, enum dma_data_direction);
 250 extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
 251                 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 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
 262         unsigned long offset, size_t size, enum dma_data_direction dir)
 263 {
 264         return 1;
 265 }
 266
 267 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
 268         unsigned long offset, size_t size, enum dma_data_direction dir)
 269 {
 270         return 1;
 271 }
 272
 273
 274 /**
 275  * dma_map_single - map a single buffer for streaming DMA
 276  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 277  * @cpu_addr: CPU direct mapped address of buffer
 278  * @size: size of buffer to map
 279  * @dir: DMA transfer direction
 280  *
 281  * Ensure that any data held in the cache is appropriately discarded
 282  * or written back.
 283  *
 284  * The device owns this memory once this call has completed.  The CPU
 285  * can regain ownership by calling dma_unmap_single() or
 286  * dma_sync_single_for_cpu().
 287  */
 288 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
 289                 size_t size, enum dma_data_direction dir)
 290 {
 291         BUG_ON(!valid_dma_direction(dir));
 292
 293         if (!arch_is_coherent())
 294                 dma_cache_maint(cpu_addr, size, dir);
 295
 296         return virt_to_dma(dev, cpu_addr);
 297 }
 298
 299 /**
 300  * dma_map_page - map a portion of a page for streaming DMA
 301  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 302  * @page: page that buffer resides in
 303  * @offset: offset into page for start of buffer
 304  * @size: size of buffer to map
 305  * @dir: DMA transfer direction
 306  *
 307  * Ensure that any data held in the cache is appropriately discarded
 308  * or written back.
 309  *
 310  * The device owns this memory once this call has completed.  The CPU
 311  * can regain ownership by calling dma_unmap_page().
 312  */
 313 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
 314              unsigned long offset, size_t size, enum dma_data_direction dir)
 315 {
 316         BUG_ON(!valid_dma_direction(dir));
 317
 318         if (!arch_is_coherent())
 319                 dma_cache_maint(page_address(page) + offset, size, dir);
 320
 321         return page_to_dma(dev, page) + offset;
 322 }
 323
 324 /**
 325  * dma_unmap_single - unmap a single buffer previously mapped
 326  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 327  * @handle: DMA address of buffer
 328  * @size: size of buffer (same as passed to dma_map_single)
 329  * @dir: DMA transfer direction (same as passed to dma_map_single)
 330  *
 331  * Unmap a single streaming mode DMA translation.  The handle and size
 332  * must match what was provided in the previous dma_map_single() call.
 333  * All other usages are undefined.
 334  *
 335  * After this call, reads by the CPU to the buffer are guaranteed to see
 336  * whatever the device wrote there.
 337  */
 338 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
 339                 size_t size, enum dma_data_direction dir)
 340 {
 341         /* nothing to do */
 342 }
 343 #endif /* CONFIG_DMABOUNCE */
 344
 345 /**
 346  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 347  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 348  * @handle: DMA address of buffer
 349  * @size: size of buffer (same as passed to dma_map_page)
 350  * @dir: DMA transfer direction (same as passed to dma_map_page)
 351  *
 352  * Unmap a page streaming mode DMA translation.  The handle and size
 353  * must match what was provided in the previous dma_map_page() call.
 354  * All other usages are undefined.
 355  *
 356  * After this call, reads by the CPU to the buffer are guaranteed to see
 357  * whatever the device wrote there.
 358  */
 359 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
 360                 size_t size, enum dma_data_direction dir)
 361 {
 362         dma_unmap_single(dev, handle, size, dir);
 363 }
 364
 365 /**
 366  * dma_sync_single_range_for_cpu
 367  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 368  * @handle: DMA address of buffer
 369  * @offset: offset of region to start sync
 370  * @size: size of region to sync
 371  * @dir: DMA transfer direction (same as passed to dma_map_single)
 372  *
 373  * Make physical memory consistent for a single streaming mode DMA
 374  * translation after a transfer.
 375  *
 376  * If you perform a dma_map_single() but wish to interrogate the
 377  * buffer using the cpu, yet do not wish to teardown the PCI dma
 378  * mapping, you must call this function before doing so.  At the
 379  * next point you give the PCI dma address back to the card, you
 380  * must first the perform a dma_sync_for_device, and then the
 381  * device again owns the buffer.
 382  */
 383 static inline void dma_sync_single_range_for_cpu(struct device *dev,
 384                 dma_addr_t handle, unsigned long offset, size_t size,
 385                 enum dma_data_direction dir)
 386 {
 387         BUG_ON(!valid_dma_direction(dir));
 388
 389         dmabounce_sync_for_cpu(dev, handle, offset, size, dir);
 390 }
 391
 392 static inline void dma_sync_single_range_for_device(struct device *dev,
 393                 dma_addr_t handle, unsigned long offset, size_t size,
 394                 enum dma_data_direction dir)
 395 {
 396         BUG_ON(!valid_dma_direction(dir));
 397
 398         if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
 399                 return;
 400
 401         if (!arch_is_coherent())
 402                 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
 403 }
 404
 405 static inline void dma_sync_single_for_cpu(struct device *dev,
 406                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 407 {
 408         dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
 409 }
 410
 411 static inline void dma_sync_single_for_device(struct device *dev,
 412                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
 413 {
 414         dma_sync_single_range_for_device(dev, handle, 0, size, dir);
 415 }
 416
 417 /*
 418  * The scatter list versions of the above methods.
 419  */
 420 extern int dma_map_sg(struct device *, struct scatterlist *, int,
 421                 enum dma_data_direction);
 422 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
 423                 enum dma_data_direction);
 424 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
 425                 enum dma_data_direction);
 426 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
 427                 enum dma_data_direction);
 428
 429
 430 #endif /* __KERNEL__ */
 431 #endif