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 <asm/io.h>
  13 #include <asm/swiotlb.h>
  14 #include <linux/dma-contiguous.h>
  15
  16 #ifdef CONFIG_ISA
  17 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
  18 #else
  19 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
  20 #endif
  21
  22 #define DMA_ERROR_CODE  0
  23
  24 extern int iommu_merge;
  25 extern struct device x86_dma_fallback_dev;
  26 extern int panic_on_overflow;
  27
  28 extern const struct dma_map_ops *dma_ops;
  29
  30 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
  31 {
  32         return dma_ops;
  33 }
  34
  35 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
  36 #define arch_dma_alloc_attrs arch_dma_alloc_attrs
  37
  38 #define HAVE_ARCH_DMA_SUPPORTED 1
  39 extern int dma_supported(struct device *hwdev, u64 mask);
  40
  41 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  42                                         dma_addr_t *dma_addr, gfp_t flag,
  43                                         unsigned long attrs);
  44
  45 extern void dma_generic_free_coherent(struct device *dev, size_t size,
  46                                       void *vaddr, dma_addr_t dma_addr,
  47                                       unsigned long attrs);
  48
  49 #ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
  50 extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
  51 extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
  52 extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
  53 #else
  54
  55 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
  56 {
  57         if (!dev->dma_mask)
  58                 return 0;
  59
  60         return addr + size - 1 <= *dev->dma_mask;
  61 }
  62
  63 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  64 {
  65         return paddr;
  66 }
  67
  68 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  69 {
  70         return daddr;
  71 }
  72 #endif /* CONFIG_X86_DMA_REMAP */
  73
  74 static inline void
  75 dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  76         enum dma_data_direction dir)
  77 {
  78         flush_write_buffers();
  79 }
  80
  81 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
  82                                                     gfp_t gfp)
  83 {
  84         unsigned long dma_mask = 0;
  85
  86         dma_mask = dev->coherent_dma_mask;
  87         if (!dma_mask)
  88                 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
  89
  90         return dma_mask;
  91 }
  92
  93 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
  94 {
  95         unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
  96
  97         if (dma_mask <= DMA_BIT_MASK(24))
  98                 gfp |= GFP_DMA;
  99 #ifdef CONFIG_X86_64
 100         if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
 101                 gfp |= GFP_DMA32;
 102 #endif
 103        return gfp;
 104 }
 105
 106 #endif