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