arch/avr32/include/asm/dma-mapping.h

   1 #ifndef __ASM_AVR32_DMA_MAPPING_H
   2 #define __ASM_AVR32_DMA_MAPPING_H
   3
   4 #include <linux/mm.h>
   5 #include <linux/device.h>
   6 #include <linux/scatterlist.h>
   7 #include <asm/processor.h>
   8 #include <asm/cacheflush.h>
   9 #include <asm/io.h>
  10
  11 extern void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  12         int direction);
  13
  14 /*
  15  * Return whether the given device DMA address mask can be supported
  16  * properly.  For example, if your device can only drive the low 24-bits
  17  * during bus mastering, then you would pass 0x00ffffff as the mask
  18  * to this function.
  19  */
  20 static inline int dma_supported(struct device *dev, u64 mask)
  21 {
  22         /* Fix when needed. I really don't know of any limitations */
  23         return 1;
  24 }
  25
  26 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
  27 {
  28         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
  29                 return -EIO;
  30
  31         *dev->dma_mask = dma_mask;
  32         return 0;
  33 }
  34
  35 /*
  36  * dma_map_single can't fail as it is implemented now.
  37  */
  38 static inline int dma_mapping_error(struct device *dev, dma_addr_t addr)
  39 {
  40         return 0;
  41 }
  42
  43 /**
  44  * dma_alloc_coherent - allocate consistent memory for DMA
  45  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  46  * @size: required memory size
  47  * @handle: bus-specific DMA address
  48  *
  49  * Allocate some uncached, unbuffered memory for a device for
  50  * performing DMA.  This function allocates pages, and will
  51  * return the CPU-viewed address, and sets @handle to be the
  52  * device-viewed address.
  53  */
  54 extern void *dma_alloc_coherent(struct device *dev, size_t size,
  55                                 dma_addr_t *handle, gfp_t gfp);
  56
  57 /**
  58  * dma_free_coherent - free memory allocated by dma_alloc_coherent
  59  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  60  * @size: size of memory originally requested in dma_alloc_coherent
  61  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
  62  * @handle: device-view address returned from dma_alloc_coherent
  63  *
  64  * Free (and unmap) a DMA buffer previously allocated by
  65  * dma_alloc_coherent().
  66  *
  67  * References to memory and mappings associated with cpu_addr/handle
  68  * during and after this call executing are illegal.
  69  */
  70 extern void dma_free_coherent(struct device *dev, size_t size,
  71                               void *cpu_addr, dma_addr_t handle);
  72
  73 /**
  74  * dma_alloc_writecombine - allocate write-combining memory for DMA
  75  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  76  * @size: required memory size
  77  * @handle: bus-specific DMA address
  78  *
  79  * Allocate some uncached, buffered memory for a device for
  80  * performing DMA.  This function allocates pages, and will
  81  * return the CPU-viewed address, and sets @handle to be the
  82  * device-viewed address.
  83  */
  84 extern void *dma_alloc_writecombine(struct device *dev, size_t size,
  85                                     dma_addr_t *handle, gfp_t gfp);
  86
  87 /**
  88  * dma_free_coherent - free memory allocated by dma_alloc_writecombine
  89  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
  90  * @size: size of memory originally requested in dma_alloc_writecombine
  91  * @cpu_addr: CPU-view address returned from dma_alloc_writecombine
  92  * @handle: device-view address returned from dma_alloc_writecombine
  93  *
  94  * Free (and unmap) a DMA buffer previously allocated by
  95  * dma_alloc_writecombine().
  96  *
  97  * References to memory and mappings associated with cpu_addr/handle
  98  * during and after this call executing are illegal.
  99  */
 100 extern void dma_free_writecombine(struct device *dev, size_t size,
 101                                   void *cpu_addr, dma_addr_t handle);
 102
 103 /**
 104  * dma_map_single - map a single buffer for streaming DMA
 105  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 106  * @cpu_addr: CPU direct mapped address of buffer
 107  * @size: size of buffer to map
 108  * @dir: DMA transfer direction
 109  *
 110  * Ensure that any data held in the cache is appropriately discarded
 111  * or written back.
 112  *
 113  * The device owns this memory once this call has completed.  The CPU
 114  * can regain ownership by calling dma_unmap_single() or dma_sync_single().
 115  */
 116 static inline dma_addr_t
 117 dma_map_single(struct device *dev, void *cpu_addr, size_t size,
 118                enum dma_data_direction direction)
 119 {
 120         dma_cache_sync(dev, cpu_addr, size, direction);
 121         return virt_to_bus(cpu_addr);
 122 }
 123
 124 /**
 125  * dma_unmap_single - unmap a single buffer previously mapped
 126  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 127  * @handle: DMA address of buffer
 128  * @size: size of buffer to map
 129  * @dir: DMA transfer direction
 130  *
 131  * Unmap a single streaming mode DMA translation.  The handle and size
 132  * must match what was provided in the previous dma_map_single() call.
 133  * All other usages are undefined.
 134  *
 135  * After this call, reads by the CPU to the buffer are guaranteed to see
 136  * whatever the device wrote there.
 137  */
 138 static inline void
 139 dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 140                  enum dma_data_direction direction)
 141 {
 142
 143 }
 144
 145 /**
 146  * dma_map_page - map a portion of a page for streaming DMA
 147  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 148  * @page: page that buffer resides in
 149  * @offset: offset into page for start of buffer
 150  * @size: size of buffer to map
 151  * @dir: DMA transfer direction
 152  *
 153  * Ensure that any data held in the cache is appropriately discarded
 154  * or written back.
 155  *
 156  * The device owns this memory once this call has completed.  The CPU
 157  * can regain ownership by calling dma_unmap_page() or dma_sync_single().
 158  */
 159 static inline dma_addr_t
 160 dma_map_page(struct device *dev, struct page *page,
 161              unsigned long offset, size_t size,
 162              enum dma_data_direction direction)
 163 {
 164         return dma_map_single(dev, page_address(page) + offset,
 165                               size, direction);
 166 }
 167
 168 /**
 169  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 170  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 171  * @handle: DMA address of buffer
 172  * @size: size of buffer to map
 173  * @dir: DMA transfer direction
 174  *
 175  * Unmap a single streaming mode DMA translation.  The handle and size
 176  * must match what was provided in the previous dma_map_single() call.
 177  * All other usages are undefined.
 178  *
 179  * After this call, reads by the CPU to the buffer are guaranteed to see
 180  * whatever the device wrote there.
 181  */
 182 static inline void
 183 dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
 184                enum dma_data_direction direction)
 185 {
 186         dma_unmap_single(dev, dma_address, size, direction);
 187 }
 188
 189 /**
 190  * dma_map_sg - map a set of SG buffers for streaming mode DMA
 191  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 192  * @sg: list of buffers
 193  * @nents: number of buffers to map
 194  * @dir: DMA transfer direction
 195  *
 196  * Map a set of buffers described by scatterlist in streaming
 197  * mode for DMA.  This is the scatter-gather version of the
 198  * above pci_map_single interface.  Here the scatter gather list
 199  * elements are each tagged with the appropriate dma address
 200  * and length.  They are obtained via sg_dma_{address,length}(SG).
 201  *
 202  * NOTE: An implementation may be able to use a smaller number of
 203  *       DMA address/length pairs than there are SG table elements.
 204  *       (for example via virtual mapping capabilities)
 205  *       The routine returns the number of addr/length pairs actually
 206  *       used, at most nents.
 207  *
 208  * Device ownership issues as mentioned above for pci_map_single are
 209  * the same here.
 210  */
 211 static inline int
 212 dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 213            enum dma_data_direction direction)
 214 {
 215         int i;
 216
 217         for (i = 0; i < nents; i++) {
 218                 char *virt;
 219
 220                 sg[i].dma_address = page_to_bus(sg_page(&sg[i])) + sg[i].offset;
 221                 virt = sg_virt(&sg[i]);
 222                 dma_cache_sync(dev, virt, sg[i].length, direction);
 223         }
 224
 225         return nents;
 226 }
 227
 228 /**
 229  * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
 230  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 231  * @sg: list of buffers
 232  * @nents: number of buffers to map
 233  * @dir: DMA transfer direction
 234  *
 235  * Unmap a set of streaming mode DMA translations.
 236  * Again, CPU read rules concerning calls here are the same as for
 237  * pci_unmap_single() above.
 238  */
 239 static inline void
 240 dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
 241              enum dma_data_direction direction)
 242 {
 243
 244 }
 245
 246 /**
 247  * dma_sync_single_for_cpu
 248  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 249  * @handle: DMA address of buffer
 250  * @size: size of buffer to map
 251  * @dir: DMA transfer direction
 252  *
 253  * Make physical memory consistent for a single streaming mode DMA
 254  * translation after a transfer.
 255  *
 256  * If you perform a dma_map_single() but wish to interrogate the
 257  * buffer using the cpu, yet do not wish to teardown the DMA mapping,
 258  * you must call this function before doing so.  At the next point you
 259  * give the DMA address back to the card, you must first perform a
 260  * dma_sync_single_for_device, and then the device again owns the
 261  * buffer.
 262  */
 263 static inline void
 264 dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 265                         size_t size, enum dma_data_direction direction)
 266 {
 267         /*
 268          * No need to do anything since the CPU isn't supposed to
 269          * touch this memory after we flushed it at mapping- or
 270          * sync-for-device time.
 271          */
 272 }
 273
 274 static inline void
 275 dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
 276                            size_t size, enum dma_data_direction direction)
 277 {
 278         dma_cache_sync(dev, bus_to_virt(dma_handle), size, direction);
 279 }
 280
 281 static inline void
 282 dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
 283                               unsigned long offset, size_t size,
 284                               enum dma_data_direction direction)
 285 {
 286         /* just sync everything, that's all the pci API can do */
 287         dma_sync_single_for_cpu(dev, dma_handle, offset+size, direction);
 288 }
 289
 290 static inline void
 291 dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
 292                                  unsigned long offset, size_t size,
 293                                  enum dma_data_direction direction)
 294 {
 295         /* just sync everything, that's all the pci API can do */
 296         dma_sync_single_for_device(dev, dma_handle, offset+size, direction);
 297 }
 298
 299 /**
 300  * dma_sync_sg_for_cpu
 301  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 302  * @sg: list of buffers
 303  * @nents: number of buffers to map
 304  * @dir: DMA transfer direction
 305  *
 306  * Make physical memory consistent for a set of streaming
 307  * mode DMA translations after a transfer.
 308  *
 309  * The same as dma_sync_single_for_* but for a scatter-gather list,
 310  * same rules and usage.
 311  */
 312 static inline void
 313 dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 314                     int nents, enum dma_data_direction direction)
 315 {
 316         /*
 317          * No need to do anything since the CPU isn't supposed to
 318          * touch this memory after we flushed it at mapping- or
 319          * sync-for-device time.
 320          */
 321 }
 322
 323 static inline void
 324 dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 325                        int nents, enum dma_data_direction direction)
 326 {
 327         int i;
 328
 329         for (i = 0; i < nents; i++) {
 330                 dma_cache_sync(dev, sg_virt(&sg[i]), sg[i].length, direction);
 331         }
 332 }
 333
 334 /* Now for the API extensions over the pci_ one */
 335
 336 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 337 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 338
 339 #endif /* __ASM_AVR32_DMA_MAPPING_H */