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 if (unlikely(is_swiotlb_buffer(dev, paddr))) 62 swiotlb_sync_single_for_device(dev, paddr, size, dir); 63 64 if (!dev_is_dma_coherent(dev)) 65 arch_sync_dma_for_device(paddr, size, dir); 66 } 67 68 static inline void dma_direct_sync_single_for_cpu(struct device *dev, 69 dma_addr_t addr, size_t size, enum dma_data_direction dir) 70 { 71 phys_addr_t paddr = dma_to_phys(dev, addr); 72 73 if (!dev_is_dma_coherent(dev)) { 74 arch_sync_dma_for_cpu(paddr, size, dir); 75 arch_sync_dma_for_cpu_all(); 76 } 77 78 if (unlikely(is_swiotlb_buffer(dev, paddr))) 79 swiotlb_sync_single_for_cpu(dev, paddr, size, dir); 80 81 if (dir == DMA_FROM_DEVICE) 82 arch_dma_mark_clean(paddr, size); 83 } 84 85 static inline dma_addr_t dma_direct_map_page(struct device *dev, 86 struct page *page, unsigned long offset, size_t size, 87 enum dma_data_direction dir, unsigned long attrs) 88 { 89 phys_addr_t phys = page_to_phys(page) + offset; 90 dma_addr_t dma_addr = phys_to_dma(dev, phys); 91 92 if (is_swiotlb_force_bounce(dev)) { 93 if (is_pci_p2pdma_page(page)) 94 return DMA_MAPPING_ERROR; 95 return swiotlb_map(dev, phys, size, dir, attrs); 96 } 97 98 if (unlikely(!dma_capable(dev, dma_addr, size, true)) || 99 dma_kmalloc_needs_bounce(dev, size, dir)) { 100 if (is_pci_p2pdma_page(page)) 101 return DMA_MAPPING_ERROR; 102 if (is_swiotlb_active(dev)) 103 return swiotlb_map(dev, phys, size, dir, attrs); 104 105 dev_WARN_ONCE(dev, 1, 106 "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", 107 &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); 108 return DMA_MAPPING_ERROR; 109 } 110 111 if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) 112 arch_sync_dma_for_device(phys, size, dir); 113 return dma_addr; 114 } 115 116 static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr, 117 size_t size, enum dma_data_direction dir, unsigned long attrs) 118 { 119 phys_addr_t phys = dma_to_phys(dev, addr); 120 121 if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) 122 dma_direct_sync_single_for_cpu(dev, addr, size, dir); 123 124 if (unlikely(is_swiotlb_buffer(dev, phys))) 125 swiotlb_tbl_unmap_single(dev, phys, size, dir, 126 attrs | DMA_ATTR_SKIP_CPU_SYNC); 127 } 128 #endif /* _KERNEL_DMA_DIRECT_H */ 129