dma-mapping.h 2.9 KB

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  1. #ifndef _BLACKFIN_DMA_MAPPING_H
  2. #define _BLACKFIN_DMA_MAPPING_H
  3. #include <asm/scatterlist.h>
  4. void dma_alloc_init(unsigned long start, unsigned long end);
  5. void *dma_alloc_coherent(struct device *dev, size_t size,
  6. dma_addr_t *dma_handle, gfp_t gfp);
  7. void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
  8. dma_addr_t dma_handle);
  9. /*
  10. * Now for the API extensions over the pci_ one
  11. */
  12. #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
  13. #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
  14. #define dma_mapping_error
  15. /*
  16. * Map a single buffer of the indicated size for DMA in streaming mode.
  17. * The 32-bit bus address to use is returned.
  18. *
  19. * Once the device is given the dma address, the device owns this memory
  20. * until either pci_unmap_single or pci_dma_sync_single is performed.
  21. */
  22. extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  23. enum dma_data_direction direction);
  24. static inline dma_addr_t
  25. dma_map_page(struct device *dev, struct page *page,
  26. unsigned long offset, size_t size,
  27. enum dma_data_direction dir)
  28. {
  29. return dma_map_single(dev, page_address(page) + offset, size, dir);
  30. }
  31. /*
  32. * Unmap a single streaming mode DMA translation. The dma_addr and size
  33. * must match what was provided for in a previous pci_map_single call. All
  34. * other usages are undefined.
  35. *
  36. * After this call, reads by the cpu to the buffer are guarenteed to see
  37. * whatever the device wrote there.
  38. */
  39. extern void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
  40. enum dma_data_direction direction);
  41. static inline void
  42. dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
  43. enum dma_data_direction dir)
  44. {
  45. dma_unmap_single(dev, dma_addr, size, dir);
  46. }
  47. /*
  48. * Map a set of buffers described by scatterlist in streaming
  49. * mode for DMA. This is the scather-gather version of the
  50. * above pci_map_single interface. Here the scatter gather list
  51. * elements are each tagged with the appropriate dma address
  52. * and length. They are obtained via sg_dma_{address,length}(SG).
  53. *
  54. * NOTE: An implementation may be able to use a smaller number of
  55. * DMA address/length pairs than there are SG table elements.
  56. * (for example via virtual mapping capabilities)
  57. * The routine returns the number of addr/length pairs actually
  58. * used, at most nents.
  59. *
  60. * Device ownership issues as mentioned above for pci_map_single are
  61. * the same here.
  62. */
  63. extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  64. enum dma_data_direction direction);
  65. /*
  66. * Unmap a set of streaming mode DMA translations.
  67. * Again, cpu read rules concerning calls here are the same as for
  68. * pci_unmap_single() above.
  69. */
  70. extern void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
  71. int nhwentries, enum dma_data_direction direction);
  72. #endif /* _BLACKFIN_DMA_MAPPING_H */