include/linux/dma-mapping.h

   1 #ifndef _LINUX_DMA_MAPPING_H
   2 #define _LINUX_DMA_MAPPING_H
   3
   4 #include <linux/device.h>
   5 #include <linux/err.h>
   6
   7 /* These definitions mirror those in pci.h, so they can be used
   8  * interchangeably with their PCI_ counterparts */
   9 enum dma_data_direction {
  10         DMA_BIDIRECTIONAL = 0,
  11         DMA_TO_DEVICE = 1,
  12         DMA_FROM_DEVICE = 2,
  13         DMA_NONE = 3,
  14 };
  15
  16 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
  17
  18 /*
  19  * NOTE: do not use the below macros in new code and do not add new definitions
  20  * here.
  21  *
  22  * Instead, just open-code DMA_BIT_MASK(n) within your driver
  23  */
  24 #define DMA_64BIT_MASK  DMA_BIT_MASK(64)
  25 #define DMA_48BIT_MASK  DMA_BIT_MASK(48)
  26 #define DMA_47BIT_MASK  DMA_BIT_MASK(47)
  27 #define DMA_40BIT_MASK  DMA_BIT_MASK(40)
  28 #define DMA_39BIT_MASK  DMA_BIT_MASK(39)
  29 #define DMA_35BIT_MASK  DMA_BIT_MASK(35)
  30 #define DMA_32BIT_MASK  DMA_BIT_MASK(32)
  31 #define DMA_31BIT_MASK  DMA_BIT_MASK(31)
  32 #define DMA_30BIT_MASK  DMA_BIT_MASK(30)
  33 #define DMA_29BIT_MASK  DMA_BIT_MASK(29)
  34 #define DMA_28BIT_MASK  DMA_BIT_MASK(28)
  35 #define DMA_24BIT_MASK  DMA_BIT_MASK(24)
  36
  37 #define DMA_MASK_NONE   0x0ULL
  38
  39 static inline int valid_dma_direction(int dma_direction)
  40 {
  41         return ((dma_direction == DMA_BIDIRECTIONAL) ||
  42                 (dma_direction == DMA_TO_DEVICE) ||
  43                 (dma_direction == DMA_FROM_DEVICE));
  44 }
  45
  46 static inline int is_device_dma_capable(struct device *dev)
  47 {
  48         return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
  49 }
  50
  51 #ifdef CONFIG_HAS_DMA
  52 #include <asm/dma-mapping.h>
  53 #else
  54 #include <asm-generic/dma-mapping-broken.h>
  55 #endif
  56
  57 /* Backwards compat, remove in 2.7.x */
  58 #define dma_sync_single         dma_sync_single_for_cpu
  59 #define dma_sync_sg             dma_sync_sg_for_cpu
  60
  61 extern u64 dma_get_required_mask(struct device *dev);
  62
  63 static inline unsigned int dma_get_max_seg_size(struct device *dev)
  64 {
  65         return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536;
  66 }
  67
  68 static inline unsigned int dma_set_max_seg_size(struct device *dev,
  69                                                 unsigned int size)
  70 {
  71         if (dev->dma_parms) {
  72                 dev->dma_parms->max_segment_size = size;
  73                 return 0;
  74         } else
  75                 return -EIO;
  76 }
  77
  78 static inline unsigned long dma_get_seg_boundary(struct device *dev)
  79 {
  80         return dev->dma_parms ?
  81                 dev->dma_parms->segment_boundary_mask : 0xffffffff;
  82 }
  83
  84 static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
  85 {
  86         if (dev->dma_parms) {
  87                 dev->dma_parms->segment_boundary_mask = mask;
  88                 return 0;
  89         } else
  90                 return -EIO;
  91 }
  92
  93 /* flags for the coherent memory api */
  94 #define DMA_MEMORY_MAP                  0x01
  95 #define DMA_MEMORY_IO                   0x02
  96 #define DMA_MEMORY_INCLUDES_CHILDREN    0x04
  97 #define DMA_MEMORY_EXCLUSIVE            0x08
  98
  99 #ifndef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 100 static inline int
 101 dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 102                             dma_addr_t device_addr, size_t size, int flags)
 103 {
 104         return 0;
 105 }
 106
 107 static inline void
 108 dma_release_declared_memory(struct device *dev)
 109 {
 110 }
 111
 112 static inline void *
 113 dma_mark_declared_memory_occupied(struct device *dev,
 114                                   dma_addr_t device_addr, size_t size)
 115 {
 116         return ERR_PTR(-EBUSY);
 117 }
 118 #endif
 119
 120 /*
 121  * Managed DMA API
 122  */
 123 extern void *dmam_alloc_coherent(struct device *dev, size_t size,
 124                                  dma_addr_t *dma_handle, gfp_t gfp);
 125 extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
 126                                dma_addr_t dma_handle);
 127 extern void *dmam_alloc_noncoherent(struct device *dev, size_t size,
 128                                     dma_addr_t *dma_handle, gfp_t gfp);
 129 extern void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 130                                   dma_addr_t dma_handle);
 131 #ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 132 extern int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 133                                         dma_addr_t device_addr, size_t size,
 134                                         int flags);
 135 extern void dmam_release_declared_memory(struct device *dev);
 136 #else /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
 137 static inline int dmam_declare_coherent_memory(struct device *dev,
 138                                 dma_addr_t bus_addr, dma_addr_t device_addr,
 139                                 size_t size, gfp_t gfp)
 140 {
 141         return 0;
 142 }
 143
 144 static inline void dmam_release_declared_memory(struct device *dev)
 145 {
 146 }
 147 #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
 148
 149 #endif