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