1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2018 Christoph Hellwig. 4 * 5 * DMA operations that map physical memory directly without using an IOMMU. 6 */ 7 #ifndef _KERNEL_DMA_DIRECT_H 8 #define _KERNEL_DMA_DIRECT_H 9 10 #include <linux/dma-direct.h> 11 #include <linux/memremap.h> 12 13 int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt, 14 void *cpu_addr, dma_addr_t dma_addr, size_t size, 15 unsigned long attrs); 16 bool dma_direct_can_mmap(struct device *dev); 17 int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, 18 void *cpu_addr, dma_addr_t dma_addr, size_t size, 19 unsigned long attrs); 20 bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr); 21 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, 22 enum dma_data_direction dir, unsigned long attrs); 23 bool dma_direct_all_ram_mapped(struct device *dev); 24 size_t dma_direct_max_mapping_size(struct device *dev); 25 26 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ 27 defined(CONFIG_SWIOTLB) 28 void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl, 29 int nents, enum dma_data_direction dir); 30 #else 31 static inline void dma_direct_sync_sg_for_device(struct device *dev, 32 struct scatterlist *sgl, int nents, enum dma_data_direction dir) 33 { 34 } 35 #endif 36 37 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ 38 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \ 39 defined(CONFIG_SWIOTLB) 40 void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, 41 int nents, enum dma_data_direction dir, unsigned long attrs); 42 void dma_direct_sync_sg_for_cpu(struct device *dev, 43 struct scatterlist *sgl, int nents, enum dma_data_direction dir); 44 #else 45 static inline void dma_direct_unmap_sg(struct device *dev, 46 struct scatterlist *sgl, int nents, enum dma_data_direction dir, 47 unsigned long attrs) 48 { 49 } 50 static inline void dma_direct_sync_sg_for_cpu(struct device *dev, 51 struct scatterlist *sgl, int nents, enum dma_data_direction dir) 52 { 53 } 54 #endif 55 56 static inline void dma_direct_sync_single_for_device(struct device *dev, 57 dma_addr_t addr, size_t size, enum dma_data_direction dir) 58 { 59 phys_addr_t paddr = dma_to_phys(dev, addr); 60 61 swiotlb_sync_single_for_device(dev, paddr, size, dir); 62 63 if (!dev_is_dma_coherent(dev)) 64 arch_sync_dma_for_device(paddr, size, dir); 65 } 66 67 static inline void dma_direct_sync_single_for_cpu(struct device *dev, 68 dma_addr_t addr, size_t size, enum dma_data_direction dir) 69 { 70 phys_addr_t paddr = dma_to_phys(dev, addr); 71 72 if (!dev_is_dma_coherent(dev)) { 73 arch_sync_dma_for_cpu(paddr, size, dir); 74 arch_sync_dma_for_cpu_all(); 75 } 76 77 swiotlb_sync_single_for_cpu(dev, paddr, size, dir); 78 } 79 80 static inline dma_addr_t dma_direct_map_phys(struct device *dev, 81 phys_addr_t phys, size_t size, enum dma_data_direction dir, 82 unsigned long attrs) 83 { 84 dma_addr_t dma_addr; 85 86 if (is_swiotlb_force_bounce(dev)) { 87 if (attrs & DMA_ATTR_MMIO) 88 goto err_overflow; 89 90 return swiotlb_map(dev, phys, size, dir, attrs); 91 } 92 93 if (attrs & DMA_ATTR_MMIO) { 94 dma_addr = phys; 95 if (unlikely(!dma_capable(dev, dma_addr, size, false))) 96 goto err_overflow; 97 } else { 98 dma_addr = phys_to_dma(dev, phys); 99 if (unlikely(!dma_capable(dev, dma_addr, size, true)) || 100 dma_kmalloc_needs_bounce(dev, size, dir)) { 101 if (is_swiotlb_active(dev)) 102 return swiotlb_map(dev, phys, size, dir, attrs); 103 104 goto err_overflow; 105 } 106 } 107 108 if (!dev_is_dma_coherent(dev) && 109 !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) 110 arch_sync_dma_for_device(phys, size, dir); 111 return dma_addr; 112 113 err_overflow: 114 dev_WARN_ONCE( 115 dev, 1, 116 "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", 117 &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); 118 return DMA_MAPPING_ERROR; 119 } 120 121 static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr, 122 size_t size, enum dma_data_direction dir, unsigned long attrs) 123 { 124 phys_addr_t phys; 125 126 if (attrs & DMA_ATTR_MMIO) 127 /* nothing to do: uncached and no swiotlb */ 128 return; 129 130 phys = dma_to_phys(dev, addr); 131 if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) 132 dma_direct_sync_single_for_cpu(dev, addr, size, dir); 133 134 swiotlb_tbl_unmap_single(dev, phys, size, dir, 135 attrs | DMA_ATTR_SKIP_CPU_SYNC); 136 } 137 #endif /* _KERNEL_DMA_DIRECT_H */ 138