LXR linux/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/PCI/PCI-DMA-mapping.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
  25extern int iommu_merge;
  26extern struct device x86_dma_fallback_dev;
  27extern int panic_on_overflow;
  28
  29extern struct dma_map_ops *dma_ops;
  30
  31static 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 */
  46static 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
  58extern int dma_supported(struct device *hwdev, u64 mask);
  59extern int dma_set_mask(struct device *dev, u64 mask);
  60
  61extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  62                                        dma_addr_t *dma_addr, gfp_t flag);
  63
  64static 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
  72static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  73{
  74        return paddr;
  75}
  76
  77static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  78{
  79        return daddr;
  80}
  81
  82static inline void
  83dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  84        enum dma_data_direction dir)
  85{
  86        flush_write_buffers();
  87}
  88
  89static 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
 101static 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
 114static inline void *
 115dma_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
 142static 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
 158