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 u64 offset;
25 };
26
translate_phys_to_dma(struct device * dev,phys_addr_t paddr)27 static inline dma_addr_t translate_phys_to_dma(struct device *dev,
28 phys_addr_t paddr)
29 {
30 const struct bus_dma_region *m;
31
32 for (m = dev->dma_range_map; m->size; m++)
33 if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
34 return (dma_addr_t)paddr - m->offset;
35
36 /* make sure dma_capable fails when no translation is available */
37 return DMA_MAPPING_ERROR;
38 }
39
translate_dma_to_phys(struct device * dev,dma_addr_t dma_addr)40 static inline phys_addr_t translate_dma_to_phys(struct device *dev,
41 dma_addr_t dma_addr)
42 {
43 const struct bus_dma_region *m;
44
45 for (m = dev->dma_range_map; m->size; m++)
46 if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
47 return (phys_addr_t)dma_addr + m->offset;
48
49 return (phys_addr_t)-1;
50 }
51
52 #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
53 #include <asm/dma-direct.h>
54 #ifndef phys_to_dma_unencrypted
55 #define phys_to_dma_unencrypted phys_to_dma
56 #endif
57 #else
phys_to_dma_unencrypted(struct device * dev,phys_addr_t paddr)58 static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
59 phys_addr_t paddr)
60 {
61 if (dev->dma_range_map)
62 return translate_phys_to_dma(dev, paddr);
63 return paddr;
64 }
65
66 /*
67 * If memory encryption is supported, phys_to_dma will set the memory encryption
68 * bit in the DMA address, and dma_to_phys will clear it.
69 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
70 * buffers.
71 */
phys_to_dma(struct device * dev,phys_addr_t paddr)72 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
73 {
74 return __sme_set(phys_to_dma_unencrypted(dev, paddr));
75 }
76
dma_to_phys(struct device * dev,dma_addr_t dma_addr)77 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
78 {
79 phys_addr_t paddr;
80
81 if (dev->dma_range_map)
82 paddr = translate_dma_to_phys(dev, dma_addr);
83 else
84 paddr = dma_addr;
85
86 return __sme_clr(paddr);
87 }
88 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
89
90 #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
91 bool force_dma_unencrypted(struct device *dev);
92 #else
force_dma_unencrypted(struct device * dev)93 static inline bool force_dma_unencrypted(struct device *dev)
94 {
95 return false;
96 }
97 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
98
dma_capable(struct device * dev,dma_addr_t addr,size_t size,bool is_ram)99 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
100 bool is_ram)
101 {
102 dma_addr_t end = addr + size - 1;
103
104 if (addr == DMA_MAPPING_ERROR)
105 return false;
106 if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
107 min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
108 return false;
109
110 return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
111 }
112
113 u64 dma_direct_get_required_mask(struct device *dev);
114 void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
115 gfp_t gfp, unsigned long attrs);
116 void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
117 dma_addr_t dma_addr, unsigned long attrs);
118 struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
119 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
120 void dma_direct_free_pages(struct device *dev, size_t size,
121 struct page *page, dma_addr_t dma_addr,
122 enum dma_data_direction dir);
123 int dma_direct_supported(struct device *dev, u64 mask);
124 dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
125 size_t size, enum dma_data_direction dir, unsigned long attrs);
126
127 #endif /* _LINUX_DMA_DIRECT_H */
128