1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Internals of the DMA direct mapping implementation. Only for use by the |
4 | * DMA mapping code and IOMMU drivers. |
5 | */ |
6 | #ifndef _LINUX_DMA_DIRECT_H |
7 | #define _LINUX_DMA_DIRECT_H 1 |
8 | |
9 | #include <linux/dma-mapping.h> |
10 | #include <linux/dma-map-ops.h> |
11 | #include <linux/memblock.h> /* for min_low_pfn */ |
12 | #include <linux/mem_encrypt.h> |
13 | #include <linux/swiotlb.h> |
14 | |
15 | extern unsigned int zone_dma_bits; |
16 | |
17 | /* |
18 | * Record the mapping of CPU physical to DMA addresses for a given region. |
19 | */ |
20 | struct bus_dma_region { |
21 | phys_addr_t cpu_start; |
22 | dma_addr_t dma_start; |
23 | u64 size; |
24 | }; |
25 | |
26 | static inline dma_addr_t translate_phys_to_dma(struct device *dev, |
27 | phys_addr_t paddr) |
28 | { |
29 | const struct bus_dma_region *m; |
30 | |
31 | for (m = dev->dma_range_map; m->size; m++) { |
32 | u64 offset = paddr - m->cpu_start; |
33 | |
34 | if (paddr >= m->cpu_start && offset < m->size) |
35 | return m->dma_start + offset; |
36 | } |
37 | |
38 | /* make sure dma_capable fails when no translation is available */ |
39 | return DMA_MAPPING_ERROR; |
40 | } |
41 | |
42 | static inline phys_addr_t translate_dma_to_phys(struct device *dev, |
43 | dma_addr_t dma_addr) |
44 | { |
45 | const struct bus_dma_region *m; |
46 | |
47 | for (m = dev->dma_range_map; m->size; m++) { |
48 | u64 offset = dma_addr - m->dma_start; |
49 | |
50 | if (dma_addr >= m->dma_start && offset < m->size) |
51 | return m->cpu_start + offset; |
52 | } |
53 | |
54 | return (phys_addr_t)-1; |
55 | } |
56 | |
57 | #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA |
58 | #include <asm/dma-direct.h> |
59 | #ifndef phys_to_dma_unencrypted |
60 | #define phys_to_dma_unencrypted phys_to_dma |
61 | #endif |
62 | #else |
63 | static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev, |
64 | phys_addr_t paddr) |
65 | { |
66 | if (dev->dma_range_map) |
67 | return translate_phys_to_dma(dev, paddr); |
68 | return paddr; |
69 | } |
70 | |
71 | /* |
72 | * If memory encryption is supported, phys_to_dma will set the memory encryption |
73 | * bit in the DMA address, and dma_to_phys will clear it. |
74 | * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb |
75 | * buffers. |
76 | */ |
77 | static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) |
78 | { |
79 | return __sme_set(phys_to_dma_unencrypted(dev, paddr)); |
80 | } |
81 | |
82 | static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) |
83 | { |
84 | phys_addr_t paddr; |
85 | |
86 | if (dev->dma_range_map) |
87 | paddr = translate_dma_to_phys(dev, dma_addr); |
88 | else |
89 | paddr = dma_addr; |
90 | |
91 | return __sme_clr(paddr); |
92 | } |
93 | #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */ |
94 | |
95 | #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED |
96 | bool force_dma_unencrypted(struct device *dev); |
97 | #else |
98 | static inline bool force_dma_unencrypted(struct device *dev) |
99 | { |
100 | return false; |
101 | } |
102 | #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */ |
103 | |
104 | static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, |
105 | bool is_ram) |
106 | { |
107 | dma_addr_t end = addr + size - 1; |
108 | |
109 | if (addr == DMA_MAPPING_ERROR) |
110 | return false; |
111 | if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && |
112 | min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) |
113 | return false; |
114 | |
115 | return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit); |
116 | } |
117 | |
118 | u64 dma_direct_get_required_mask(struct device *dev); |
119 | void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, |
120 | gfp_t gfp, unsigned long attrs); |
121 | void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, |
122 | dma_addr_t dma_addr, unsigned long attrs); |
123 | struct page *dma_direct_alloc_pages(struct device *dev, size_t size, |
124 | dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); |
125 | void dma_direct_free_pages(struct device *dev, size_t size, |
126 | struct page *page, dma_addr_t dma_addr, |
127 | enum dma_data_direction dir); |
128 | int dma_direct_supported(struct device *dev, u64 mask); |
129 | dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, |
130 | size_t size, enum dma_data_direction dir, unsigned long attrs); |
131 | |
132 | #endif /* _LINUX_DMA_DIRECT_H */ |
133 | |