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