arch/x86/include/asm/dma-mapping.h

   1 #ifndef _ASM_X86_DMA_MAPPING_H
   2 #define _ASM_X86_DMA_MAPPING_H
   3
   4 /*
   5  * IOMMU interface. See Documentation/DMA-API-HOWTO.txt and
   6  * Documentation/DMA-API.txt for documentation.
   7  */
   8
   9 #include <linux/kmemcheck.h>
  10 #include <linux/scatterlist.h>
  11 #include <linux/dma-debug.h>
  12 #include <linux/dma-attrs.h>
  13 #include <asm/io.h>
  14 #include <asm/swiotlb.h>
  15 #include <asm-generic/dma-coherent.h>
  16 #include <linux/dma-contiguous.h>
  17
  18 #ifdef CONFIG_ISA
  19 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
  20 #else
  21 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
  22 #endif
  23
  24 #define DMA_ERROR_CODE  0
  25
  26 extern int iommu_merge;
  27 extern struct device x86_dma_fallback_dev;
  28 extern int panic_on_overflow;
  29
  30 extern struct dma_map_ops *dma_ops;
  31
  32 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
  33 {
  34 #ifdef CONFIG_X86_32
  35         return dma_ops;
  36 #else
  37         if (unlikely(!dev) || !dev->archdata.dma_ops)
  38                 return dma_ops;
  39         else
  40                 return dev->archdata.dma_ops;
  41 #endif
  42 }
  43
  44 #include <asm-generic/dma-mapping-common.h>
  45
  46 /* Make sure we keep the same behaviour */
  47 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  48 {
  49         struct dma_map_ops *ops = get_dma_ops(dev);
  50         if (ops->mapping_error)
  51                 return ops->mapping_error(dev, dma_addr);
  52
  53         return (dma_addr == DMA_ERROR_CODE);
  54 }
  55
  56 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
  57 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
  58
  59 extern int dma_supported(struct device *hwdev, u64 mask);
  60 extern int dma_set_mask(struct device *dev, u64 mask);
  61
  62 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  63                                         dma_addr_t *dma_addr, gfp_t flag,
  64                                         struct dma_attrs *attrs);
  65
  66 extern void dma_generic_free_coherent(struct device *dev, size_t size,
  67                                       void *vaddr, dma_addr_t dma_addr,
  68                                       struct dma_attrs *attrs);
  69
  70 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
  71 {
  72         if (!dev->dma_mask)
  73                 return 0;
  74
  75         return addr + size - 1 <= *dev->dma_mask;
  76 }
  77
  78 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  79 {
  80         return paddr;
  81 }
  82
  83 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  84 {
  85         return daddr;
  86 }
  87
  88 static inline void
  89 dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  90         enum dma_data_direction dir)
  91 {
  92         flush_write_buffers();
  93 }
  94
  95 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
  96                                                     gfp_t gfp)
  97 {
  98         unsigned long dma_mask = 0;
  99
 100         dma_mask = dev->coherent_dma_mask;
 101         if (!dma_mask)
 102                 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
 103
 104         return dma_mask;
 105 }
 106
 107 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
 108 {
 109         unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
 110
 111         if (dma_mask <= DMA_BIT_MASK(24))
 112                 gfp |= GFP_DMA;
 113 #ifdef CONFIG_X86_64
 114         if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
 115                 gfp |= GFP_DMA32;
 116 #endif
 117        return gfp;
 118 }
 119
 120 #define dma_alloc_coherent(d,s,h,f)     dma_alloc_attrs(d,s,h,f,NULL)
 121
 122 static inline void *
 123 dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
 124                 gfp_t gfp, struct dma_attrs *attrs)
 125 {
 126         struct dma_map_ops *ops = get_dma_ops(dev);
 127         void *memory;
 128
 129         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
 130
 131         if (dma_alloc_from_coherent(dev, size, dma_handle, &memory))
 132                 return memory;
 133
 134         if (!dev)
 135                 dev = &x86_dma_fallback_dev;
 136
 137         if (!is_device_dma_capable(dev))
 138                 return NULL;
 139
 140         if (!ops->alloc)
 141                 return NULL;
 142
 143         memory = ops->alloc(dev, size, dma_handle,
 144                             dma_alloc_coherent_gfp_flags(dev, gfp), attrs);
 145         debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
 146
 147         return memory;
 148 }
 149
 150 #define dma_free_coherent(d,s,c,h) dma_free_attrs(d,s,c,h,NULL)
 151
 152 static inline void dma_free_attrs(struct device *dev, size_t size,
 153                                   void *vaddr, dma_addr_t bus,
 154                                   struct dma_attrs *attrs)
 155 {
 156         struct dma_map_ops *ops = get_dma_ops(dev);
 157
 158         WARN_ON(irqs_disabled());       /* for portability */
 159
 160         if (dma_release_from_coherent(dev, get_order(size), vaddr))
 161                 return;
 162
 163         debug_dma_free_coherent(dev, size, vaddr, bus);
 164         if (ops->free)
 165                 ops->free(dev, size, vaddr, bus, attrs);
 166 }
 167
 168 #endif