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
  12 void dma_alloc_init(unsigned long start, unsigned long end);
  13 void *dma_alloc_coherent(struct device *dev, size_t size,
  14                          dma_addr_t *dma_handle, gfp_t gfp);
  15 void 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
  24 static inline
  25 int 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  */
  37 extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  38                                  enum dma_data_direction direction);
  39
  40 static inline dma_addr_t
  41 dma_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  */
  56 extern void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
  57                           enum dma_data_direction direction);
  58
  59 static inline void
  60 dma_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  */
  82 extern 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  */
  90 extern void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
  91                       int nhwentries, enum dma_data_direction direction);
  92
  93 static 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
  99 static 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
 105 static 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
 111 static 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 */