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