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