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 struct dma_map_ops *dma_ops;
  29
  30 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
  31 {
  32 #ifndef CONFIG_X86_DEV_DMA_OPS
  33         return dma_ops;
  34 #else
  35         if (unlikely(!dev) || !dev->archdata.dma_ops)
  36                 return dma_ops;
  37         else
  38                 return dev->archdata.dma_ops;
  39 #endif
  40 }
  41
  42 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
  43 #define arch_dma_alloc_attrs arch_dma_alloc_attrs
  44
  45 #define HAVE_ARCH_DMA_SUPPORTED 1
  46 extern int dma_supported(struct device *hwdev, u64 mask);
  47
  48 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  49                                         dma_addr_t *dma_addr, gfp_t flag,
  50                                         unsigned long attrs);
  51
  52 extern void dma_generic_free_coherent(struct device *dev, size_t size,
  53                                       void *vaddr, dma_addr_t dma_addr,
  54                                       unsigned long attrs);
  55
  56 #ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
  57 extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
  58 extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
  59 extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
  60 #else
  61
  62 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
  63 {
  64         if (!dev->dma_mask)
  65                 return 0;
  66
  67         return addr + size - 1 <= *dev->dma_mask;
  68 }
  69
  70 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  71 {
  72         return paddr;
  73 }
  74
  75 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  76 {
  77         return daddr;
  78 }
  79 #endif /* CONFIG_X86_DMA_REMAP */
  80
  81 static inline void
  82 dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  83         enum dma_data_direction dir)
  84 {
  85         flush_write_buffers();
  86 }
  87
  88 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
  89                                                     gfp_t gfp)
  90 {
  91         unsigned long dma_mask = 0;
  92
  93         dma_mask = dev->coherent_dma_mask;
  94         if (!dma_mask)
  95                 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
  96
  97         return dma_mask;
  98 }
  99
 100 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
 101 {
 102         unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
 103
 104         if (dma_mask <= DMA_BIT_MASK(24))
 105                 gfp |= GFP_DMA;
 106 #ifdef CONFIG_X86_64
 107         if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
 108                 gfp |= GFP_DMA32;
 109 #endif
 110        return gfp;
 111 }
 112
 113 #endif