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 swiotlb_sync_single_for_device(dev, addr: paddr, size, dir);
62
63 if (!dev_is_dma_coherent(dev))
64 arch_sync_dma_for_device(paddr, size, dir);
65}
66
67static 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, dma_addr: 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, addr: paddr, size, dir);
78
79 if (dir == DMA_FROM_DEVICE)
80 arch_dma_mark_clean(paddr, size);
81}
82
83static inline dma_addr_t dma_direct_map_phys(struct device *dev,
84 phys_addr_t phys, size_t size, enum dma_data_direction dir,
85 unsigned long attrs)
86{
87 dma_addr_t dma_addr;
88
89 if (is_swiotlb_force_bounce(dev)) {
90 if (attrs & DMA_ATTR_MMIO)
91 goto err_overflow;
92
93 return swiotlb_map(dev, phys, size, dir, attrs);
94 }
95
96 if (attrs & DMA_ATTR_MMIO) {
97 dma_addr = phys;
98 if (unlikely(!dma_capable(dev, dma_addr, size, false)))
99 goto err_overflow;
100 } else {
101 dma_addr = phys_to_dma(dev, paddr: phys);
102 if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
103 dma_kmalloc_needs_bounce(dev, size, dir)) {
104 if (is_swiotlb_active(dev))
105 return swiotlb_map(dev, phys, size, dir, attrs);
106
107 goto err_overflow;
108 }
109 }
110
111 if (!dev_is_dma_coherent(dev) &&
112 !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
113 arch_sync_dma_for_device(paddr: phys, size, dir);
114 return dma_addr;
115
116err_overflow:
117 dev_WARN_ONCE(
118 dev, 1,
119 "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
120 &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
121 return DMA_MAPPING_ERROR;
122}
123
124static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
125 size_t size, enum dma_data_direction dir, unsigned long attrs)
126{
127 phys_addr_t phys;
128
129 if (attrs & DMA_ATTR_MMIO)
130 /* nothing to do: uncached and no swiotlb */
131 return;
132
133 phys = dma_to_phys(dev, dma_addr: addr);
134 if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
135 dma_direct_sync_single_for_cpu(dev, addr, size, dir);
136
137 swiotlb_tbl_unmap_single(dev, addr: phys, size, dir,
138 attrs: attrs | DMA_ATTR_SKIP_CPU_SYNC);
139}
140#endif /* _KERNEL_DMA_DIRECT_H */
141

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