1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Internals of the DMA direct mapping implementation. Only for use by the 4 * DMA mapping code and IOMMU drivers. 5 */ 6 #ifndef _LINUX_DMA_DIRECT_H 7 #define _LINUX_DMA_DIRECT_H 1 8 9 #include <linux/dma-mapping.h> 10 #include <linux/dma-map-ops.h> 11 #include <linux/memblock.h> /* for min_low_pfn */ 12 #include <linux/mem_encrypt.h> 13 #include <linux/swiotlb.h> 14 15 extern u64 zone_dma_limit; 16 17 /* 18 * Record the mapping of CPU physical to DMA addresses for a given region. 19 */ 20 struct bus_dma_region { 21 phys_addr_t cpu_start; 22 dma_addr_t dma_start; 23 u64 size; 24 }; 25 26 static inline dma_addr_t translate_phys_to_dma(struct device *dev, 27 phys_addr_t paddr) 28 { 29 const struct bus_dma_region *m; 30 31 for (m = dev->dma_range_map; m->size; m++) { 32 u64 offset = paddr - m->cpu_start; 33 34 if (paddr >= m->cpu_start && offset < m->size) 35 return m->dma_start + offset; 36 } 37 38 /* make sure dma_capable fails when no translation is available */ 39 return DMA_MAPPING_ERROR; 40 } 41 42 static inline phys_addr_t translate_dma_to_phys(struct device *dev, 43 dma_addr_t dma_addr) 44 { 45 const struct bus_dma_region *m; 46 47 for (m = dev->dma_range_map; m->size; m++) { 48 u64 offset = dma_addr - m->dma_start; 49 50 if (dma_addr >= m->dma_start && offset < m->size) 51 return m->cpu_start + offset; 52 } 53 54 return (phys_addr_t)-1; 55 } 56 57 static inline dma_addr_t dma_range_map_min(const struct bus_dma_region *map) 58 { 59 dma_addr_t ret = (dma_addr_t)U64_MAX; 60 61 for (; map->size; map++) 62 ret = min(ret, map->dma_start); 63 return ret; 64 } 65 66 static inline dma_addr_t dma_range_map_max(const struct bus_dma_region *map) 67 { 68 dma_addr_t ret = 0; 69 70 for (; map->size; map++) 71 ret = max(ret, map->dma_start + map->size - 1); 72 return ret; 73 } 74 75 #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA 76 #include <asm/dma-direct.h> 77 #ifndef phys_to_dma_unencrypted 78 #define phys_to_dma_unencrypted phys_to_dma 79 #endif 80 #else 81 static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) 82 { 83 if (dev->dma_range_map) 84 return translate_phys_to_dma(dev, paddr); 85 return paddr; 86 } 87 88 static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev, 89 phys_addr_t paddr) 90 { 91 return dma_addr_unencrypted(__phys_to_dma(dev, paddr)); 92 } 93 /* 94 * If memory encryption is supported, phys_to_dma will set the memory encryption 95 * bit in the DMA address, and dma_to_phys will clear it. 96 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb 97 * buffers. 98 */ 99 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) 100 { 101 return dma_addr_encrypted(__phys_to_dma(dev, paddr)); 102 } 103 104 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) 105 { 106 phys_addr_t paddr; 107 108 dma_addr = dma_addr_canonical(dma_addr); 109 if (dev->dma_range_map) 110 paddr = translate_dma_to_phys(dev, dma_addr); 111 else 112 paddr = dma_addr; 113 114 return paddr; 115 } 116 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */ 117 118 #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED 119 bool force_dma_unencrypted(struct device *dev); 120 #else 121 static inline bool force_dma_unencrypted(struct device *dev) 122 { 123 return false; 124 } 125 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */ 126 127 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, 128 bool is_ram) 129 { 130 dma_addr_t end = addr + size - 1; 131 132 if (addr == DMA_MAPPING_ERROR) 133 return false; 134 if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && 135 min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) 136 return false; 137 138 return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit); 139 } 140 141 u64 dma_direct_get_required_mask(struct device *dev); 142 void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 143 gfp_t gfp, unsigned long attrs); 144 void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, 145 dma_addr_t dma_addr, unsigned long attrs); 146 struct page *dma_direct_alloc_pages(struct device *dev, size_t size, 147 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); 148 void dma_direct_free_pages(struct device *dev, size_t size, 149 struct page *page, dma_addr_t dma_addr, 150 enum dma_data_direction dir); 151 int dma_direct_supported(struct device *dev, u64 mask); 152 dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, 153 size_t size, enum dma_data_direction dir, unsigned long attrs); 154 155 #endif /* _LINUX_DMA_DIRECT_H */ 156