LXR linux/arch/blackfin/include/asm/dma-mapping.h

   1/*
   2 * Copyright 2004-2009 Analog Devices Inc.
   3 *
   4 * Licensed under the GPL-2 or later.
   5 */
   6
   7#ifndef _BLACKFIN_DMA_MAPPING_H
   8#define _BLACKFIN_DMA_MAPPING_H
   9
  10#include <asm/scatterlist.h>
  11
  12void dma_alloc_init(unsigned long start, unsigned long end);
  13void *dma_alloc_coherent(struct device *dev, size_t size,
  14                         dma_addr_t *dma_handle, gfp_t gfp);
  15void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
  16                       dma_addr_t dma_handle);
  17
  18/*
  19 * Now for the API extensions over the pci_ one
  20 */
  21#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
  22#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
  23
  24static inline
  25int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  26{
  27        return 0;
  28}
  29
  30/*
  31 * Map a single buffer of the indicated size for DMA in streaming mode.
  32 * The 32-bit bus address to use is returned.
  33 *
  34 * Once the device is given the dma address, the device owns this memory
  35 * until either pci_unmap_single or pci_dma_sync_single is performed.
  36 */
  37extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  38                                 enum dma_data_direction direction);
  39
  40static inline dma_addr_t
  41dma_map_page(struct device *dev, struct page *page,
  42             unsigned long offset, size_t size,
  43             enum dma_data_direction dir)
  44{
  45        return dma_map_single(dev, page_address(page) + offset, size, dir);
  46}
  47
  48/*
  49 * Unmap a single streaming mode DMA translation.  The dma_addr and size
  50 * must match what was provided for in a previous pci_map_single call.  All
  51 * other usages are undefined.
  52 *
  53 * After this call, reads by the cpu to the buffer are guarenteed to see
  54 * whatever the device wrote there.
  55 */
  56extern void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
  57                          enum dma_data_direction direction);
  58
  59static inline void
  60dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
  61               enum dma_data_direction dir)
  62{
  63        dma_unmap_single(dev, dma_addr, size, dir);
  64}
  65
  66/*
  67 * Map a set of buffers described by scatterlist in streaming
  68 * mode for DMA.  This is the scather-gather version of the
  69 * above pci_map_single interface.  Here the scatter gather list
  70 * elements are each tagged with the appropriate dma address
  71 * and length.  They are obtained via sg_dma_{address,length}(SG).
  72 *
  73 * NOTE: An implementation may be able to use a smaller number of
  74 *       DMA address/length pairs than there are SG table elements.
  75 *       (for example via virtual mapping capabilities)
  76 *       The routine returns the number of addr/length pairs actually
  77 *       used, at most nents.
  78 *
  79 * Device ownership issues as mentioned above for pci_map_single are
  80 * the same here.
  81 */
  82extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  83                      enum dma_data_direction direction);
  84
  85/*
  86 * Unmap a set of streaming mode DMA translations.
  87 * Again, cpu read rules concerning calls here are the same as for
  88 * pci_unmap_single() above.
  89 */
  90extern void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
  91                      int nhwentries, enum dma_data_direction direction);
  92
  93static inline void dma_sync_single_for_cpu(struct device *dev,
  94                                        dma_addr_t handle, size_t size,
  95                                        enum dma_data_direction dir)
  96{
  97}
  98
  99static inline void dma_sync_single_for_device(struct device *dev,
 100                                        dma_addr_t handle, size_t size,
 101                                        enum dma_data_direction dir)
 102{
 103}
 104
 105static inline void dma_sync_sg_for_cpu(struct device *dev,
 106                                        struct scatterlist *sg,
 107                                        int nents, enum dma_data_direction dir)
 108{
 109}
 110
 111static inline void dma_sync_sg_for_device(struct device *dev,
 112                                        struct scatterlist *sg,
 113                                        int nents, enum dma_data_direction dir)
 114{
 115}
 116
 117#endif                          /* _BLACKFIN_DMA_MAPPING_H */
 118