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 extern dma_addr_t bad_dma_address; 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 #ifdef CONFIG_X86_32 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 #include <asm-generic/dma-mapping-common.h> 43 44 /* Make sure we keep the same behaviour */ 45 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 46 { 47 struct dma_map_ops *ops = get_dma_ops(dev); 48 if (ops->mapping_error) 49 return ops->mapping_error(dev, dma_addr); 50 51 return (dma_addr == bad_dma_address); 52 } 53 54 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f) 55 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h) 56 #define dma_is_consistent(d, h) (1) 57 58 extern int dma_supported(struct device *hwdev, u64 mask); 59 extern int dma_set_mask(struct device *dev, u64 mask); 60 61 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size, 62 dma_addr_t *dma_addr, gfp_t flag); 63 64 static 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 <= *dev->dma_mask; 70 } 71 72 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) 73 { 74 return paddr; 75 } 76 77 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) 78 { 79 return daddr; 80 } 81 82 static inline void 83 dma_cache_sync(struct device *dev, void *vaddr, size_t size, 84 enum dma_data_direction dir) 85 { 86 flush_write_buffers(); 87 } 88 89 static inline int dma_get_cache_alignment(void) 90 { 91 /* no easy way to get cache size on all x86, so return the 92 * maximum possible, to be safe */ 93 return boot_cpu_data.x86_clflush_size; 94 } 95 96 static inline unsigned long dma_alloc_coherent_mask(struct device *dev, 97 gfp_t gfp) 98 { 99 unsigned long dma_mask = 0; 100 101 dma_mask = dev->coherent_dma_mask; 102 if (!dma_mask) 103 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32); 104 105 return dma_mask; 106 } 107 108 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp) 109 { 110 unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp); 111 112 if (dma_mask <= DMA_BIT_MASK(24)) 113 gfp |= GFP_DMA; 114 #ifdef CONFIG_X86_64 115 if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) 116 gfp |= GFP_DMA32; 117 #endif 118 return gfp; 119 } 120 121 static inline void * 122 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, 123 gfp_t gfp) 124 { 125 struct dma_map_ops *ops = get_dma_ops(dev); 126 void *memory; 127 128 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32); 129 130 if (dma_alloc_from_coherent(dev, size, dma_handle, &memory)) 131 return memory; 132 133 if (!dev) 134 dev = &x86_dma_fallback_dev; 135 136 if (!is_device_dma_capable(dev)) 137 return NULL; 138 139 if (!ops->alloc_coherent) 140 return NULL; 141 142 memory = ops->alloc_coherent(dev, size, dma_handle, 143 dma_alloc_coherent_gfp_flags(dev, gfp)); 144 debug_dma_alloc_coherent(dev, size, *dma_handle, memory); 145 146 return memory; 147 } 148 149 static inline void dma_free_coherent(struct device *dev, size_t size, 150 void *vaddr, dma_addr_t bus) 151 { 152 struct dma_map_ops *ops = get_dma_ops(dev); 153 154 WARN_ON(irqs_disabled()); /* for portability */ 155 156 if (dma_release_from_coherent(dev, get_order(size), vaddr)) 157 return; 158 159 debug_dma_free_coherent(dev, size, vaddr, bus); 160 if (ops->free_coherent) 161 ops->free_coherent(dev, size, vaddr, bus); 162 } 163 164 #endif 165