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 extern dma_addr_t bad_dma_address;
  18 extern int iommu_merge;
  19 extern struct device x86_dma_fallback_dev;
  20 extern int panic_on_overflow;
  21
  22 extern struct dma_map_ops *dma_ops;
  23
  24 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
  25 {
  26 #ifdef CONFIG_X86_32
  27         return dma_ops;
  28 #else
  29         if (unlikely(!dev) || !dev->archdata.dma_ops)
  30                 return dma_ops;
  31         else
  32                 return dev->archdata.dma_ops;
  33 #endif
  34 }
  35
  36 #include <asm-generic/dma-mapping-common.h>
  37
  38 /* Make sure we keep the same behaviour */
  39 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  40 {
  41         struct dma_map_ops *ops = get_dma_ops(dev);
  42         if (ops->mapping_error)
  43                 return ops->mapping_error(dev, dma_addr);
  44
  45         return (dma_addr == bad_dma_address);
  46 }
  47
  48 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
  49 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
  50 #define dma_is_consistent(d, h) (1)
  51
  52 extern int dma_supported(struct device *hwdev, u64 mask);
  53 extern int dma_set_mask(struct device *dev, u64 mask);
  54
  55 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  56                                         dma_addr_t *dma_addr, gfp_t flag);
  57
  58 static inline void
  59 dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  60         enum dma_data_direction dir)
  61 {
  62         flush_write_buffers();
  63 }
  64
  65 static inline int dma_get_cache_alignment(void)
  66 {
  67         /* no easy way to get cache size on all x86, so return the
  68          * maximum possible, to be safe */
  69         return boot_cpu_data.x86_clflush_size;
  70 }
  71
  72 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
  73                                                     gfp_t gfp)
  74 {
  75         unsigned long dma_mask = 0;
  76
  77         dma_mask = dev->coherent_dma_mask;
  78         if (!dma_mask)
  79                 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
  80
  81         return dma_mask;
  82 }
  83
  84 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
  85 {
  86         unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
  87
  88         if (dma_mask <= DMA_BIT_MASK(24))
  89                 gfp |= GFP_DMA;
  90 #ifdef CONFIG_X86_64
  91         if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
  92                 gfp |= GFP_DMA32;
  93 #endif
  94        return gfp;
  95 }
  96
  97 static inline void *
  98 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
  99                 gfp_t gfp)
 100 {
 101         struct dma_map_ops *ops = get_dma_ops(dev);
 102         void *memory;
 103
 104         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
 105
 106         if (dma_alloc_from_coherent(dev, size, dma_handle, &memory))
 107                 return memory;
 108
 109         if (!dev) {
 110                 dev = &x86_dma_fallback_dev;
 111                 gfp |= GFP_DMA;
 112         }
 113
 114         if (!is_device_dma_capable(dev))
 115                 return NULL;
 116
 117         if (!ops->alloc_coherent)
 118                 return NULL;
 119
 120         memory = ops->alloc_coherent(dev, size, dma_handle,
 121                                      dma_alloc_coherent_gfp_flags(dev, gfp));
 122         debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
 123
 124         return memory;
 125 }
 126
 127 static inline void dma_free_coherent(struct device *dev, size_t size,
 128                                      void *vaddr, dma_addr_t bus)
 129 {
 130         struct dma_map_ops *ops = get_dma_ops(dev);
 131
 132         WARN_ON(irqs_disabled());       /* for portability */
 133
 134         if (dma_release_from_coherent(dev, get_order(size), vaddr))
 135                 return;
 136
 137         debug_dma_free_coherent(dev, size, vaddr, bus);
 138         if (ops->free_coherent)
 139                 ops->free_coherent(dev, size, vaddr, bus);
 140 }
 141
 142 #endif