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
translate_phys_to_dma(struct device * dev,phys_addr_t paddr)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
translate_dma_to_phys(struct device * dev,dma_addr_t dma_addr)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
phys_to_dma_unencrypted(struct device * dev,phys_addr_t paddr)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 */
phys_to_dma(struct device * dev,phys_addr_t paddr)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
dma_to_phys(struct device * dev,dma_addr_t dma_addr)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
force_dma_unencrypted(struct device * dev)98 static inline bool force_dma_unencrypted(struct device *dev)
99 {
100 return false;
101 }
102 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
103
dma_capable(struct device * dev,dma_addr_t addr,size_t size,bool is_ram)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