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 size_t dma_direct_max_mapping_size(struct device *dev); 24 25 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ 26 defined(CONFIG_SWIOTLB) 27 void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl, 28 int nents, enum dma_data_direction dir); 29 #else 30 static inline void dma_direct_sync_sg_for_device(struct device *dev, 31 struct scatterlist *sgl, int nents, enum dma_data_direction dir) 32 { 33 } 34 #endif 35 36 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ 37 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \ 38 defined(CONFIG_SWIOTLB) 39 void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, 40 int nents, enum dma_data_direction dir, unsigned long attrs); 41 void dma_direct_sync_sg_for_cpu(struct device *dev, 42 struct scatterlist *sgl, int nents, enum dma_data_direction dir); 43 #else 44 static inline void dma_direct_unmap_sg(struct device *dev, 45 struct scatterlist *sgl, int nents, enum dma_data_direction dir, 46 unsigned long attrs) 47 { 48 } 49 static inline void dma_direct_sync_sg_for_cpu(struct device *dev, 50 struct scatterlist *sgl, int nents, enum dma_data_direction dir) 51 { 52 } 53 #endif 54 55 static inline void dma_direct_sync_single_for_device(struct device *dev, 56 dma_addr_t addr, size_t size, enum dma_data_direction dir) 57 { 58 phys_addr_t paddr = dma_to_phys(dev, addr); 59 60 if (unlikely(is_swiotlb_buffer(dev, paddr))) 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 if (unlikely(is_swiotlb_buffer(dev, paddr))) 78 swiotlb_sync_single_for_cpu(dev, paddr, size, dir); 79 80 if (dir == DMA_FROM_DEVICE) 81 arch_dma_mark_clean(paddr, size); 82 } 83 84 static inline dma_addr_t dma_direct_map_page(struct device *dev, 85 struct page *page, unsigned long offset, size_t size, 86 enum dma_data_direction dir, unsigned long attrs) 87 { 88 phys_addr_t phys = page_to_phys(page) + offset; 89 dma_addr_t dma_addr = phys_to_dma(dev, phys); 90 91 if (is_swiotlb_force_bounce(dev)) { 92 if (is_pci_p2pdma_page(page)) 93 return DMA_MAPPING_ERROR; 94 return swiotlb_map(dev, phys, size, dir, attrs); 95 } 96 97 if (unlikely(!dma_capable(dev, dma_addr, size, true)) || 98 dma_kmalloc_needs_bounce(dev, size, dir)) { 99 if (is_pci_p2pdma_page(page)) 100 return DMA_MAPPING_ERROR; 101 if (is_swiotlb_active(dev)) 102 return swiotlb_map(dev, phys, size, dir, attrs); 103 104 dev_WARN_ONCE(dev, 1, 105 "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", 106 &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); 107 return DMA_MAPPING_ERROR; 108 } 109 110 if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) 111 arch_sync_dma_for_device(phys, size, dir); 112 return dma_addr; 113 } 114 115 static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, 116 size_t size, enum dma_data_direction dir, unsigned long attrs) 117 { 118 phys_addr_t phys = dma_to_phys(dev, addr); 119 120 if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) 121 dma_direct_sync_single_for_cpu(dev, addr, size, dir); 122 123 if (unlikely(is_swiotlb_buffer(dev, phys))) 124 swiotlb_tbl_unmap_single(dev, phys, size, dir, 125 attrs | DMA_ATTR_SKIP_CPU_SYNC); 126 } 127 #endif /* _KERNEL_DMA_DIRECT_H */ 128