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
13int 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);
16bool dma_direct_can_mmap(struct device *dev);
17int 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);
20bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
21int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
22 enum dma_data_direction dir, unsigned long attrs);
23bool dma_direct_all_ram_mapped(struct device *dev);
24size_t dma_direct_max_mapping_size(struct device *dev);
25
26#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
27 defined(CONFIG_SWIOTLB)
28void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
29 int nents, enum dma_data_direction dir);
30#else
31static 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)
40void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
41 int nents, enum dma_data_direction dir, unsigned long attrs);
42void dma_direct_sync_sg_for_cpu(struct device *dev,
43 struct scatterlist *sgl, int nents, enum dma_data_direction dir);
44#else
45static 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}
50static 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
56static 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, dma_addr: addr);
60
61 if (unlikely(is_swiotlb_buffer(dev, paddr)))
62 swiotlb_sync_single_for_device(dev, tlb_addr: paddr, size, dir);
63
64 if (!dev_is_dma_coherent(dev))
65 arch_sync_dma_for_device(paddr, size, dir);
66}
67
68static 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, dma_addr: 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, tlb_addr: paddr, size, dir);
80
81 if (dir == DMA_FROM_DEVICE)
82 arch_dma_mark_clean(paddr, size);
83}
84
85static 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, paddr: 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(paddr: phys, size, dir);
113 return dma_addr;
114}
115
116static 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, dma_addr: 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(hwdev: dev, tlb_addr: phys, mapping_size: size, dir,
126 attrs: attrs | DMA_ATTR_SKIP_CPU_SYNC);
127}
128#endif /* _KERNEL_DMA_DIRECT_H */
129

source code of linux/kernel/dma/direct.h