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
zone_dma32_is_empty(int node)27 static inline bool zone_dma32_is_empty(int node)
28 {
29 #ifdef CONFIG_ZONE_DMA32
30 pg_data_t *pgdat = NODE_DATA(node);
31
32 return zone_is_empty(&pgdat->node_zones[ZONE_DMA32]);
33 #else
34 return true;
35 #endif
36 }
37
zone_dma32_are_empty(void)38 static inline bool zone_dma32_are_empty(void)
39 {
40 #ifdef CONFIG_NUMA
41 int node;
42
43 for_each_node(node)
44 if (!zone_dma32_is_empty(node))
45 return false;
46 #else
47 if (!zone_dma32_is_empty(numa_node_id()))
48 return false;
49 #endif
50
51 return true;
52 }
53
translate_phys_to_dma(struct device * dev,phys_addr_t paddr)54 static inline dma_addr_t translate_phys_to_dma(struct device *dev,
55 phys_addr_t paddr)
56 {
57 const struct bus_dma_region *m;
58
59 for (m = dev->dma_range_map; m->size; m++)
60 if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
61 return (dma_addr_t)paddr - m->offset;
62
63 /* make sure dma_capable fails when no translation is available */
64 return DMA_MAPPING_ERROR;
65 }
66
translate_dma_to_phys(struct device * dev,dma_addr_t dma_addr)67 static inline phys_addr_t translate_dma_to_phys(struct device *dev,
68 dma_addr_t dma_addr)
69 {
70 const struct bus_dma_region *m;
71
72 for (m = dev->dma_range_map; m->size; m++)
73 if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
74 return (phys_addr_t)dma_addr + m->offset;
75
76 return (phys_addr_t)-1;
77 }
78
79 #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
80 #include <asm/dma-direct.h>
81 #ifndef phys_to_dma_unencrypted
82 #define phys_to_dma_unencrypted phys_to_dma
83 #endif
84 #else
phys_to_dma_unencrypted(struct device * dev,phys_addr_t paddr)85 static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
86 phys_addr_t paddr)
87 {
88 if (dev->dma_range_map)
89 return translate_phys_to_dma(dev, paddr);
90 return paddr;
91 }
92
93 /*
94 * If memory encryption is supported, phys_to_dma will set the memory encryption
95 * bit in the DMA address, and dma_to_phys will clear it.
96 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
97 * buffers.
98 */
phys_to_dma(struct device * dev,phys_addr_t paddr)99 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
100 {
101 return __sme_set(phys_to_dma_unencrypted(dev, paddr));
102 }
103
dma_to_phys(struct device * dev,dma_addr_t dma_addr)104 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
105 {
106 phys_addr_t paddr;
107
108 if (dev->dma_range_map)
109 paddr = translate_dma_to_phys(dev, dma_addr);
110 else
111 paddr = dma_addr;
112
113 return __sme_clr(paddr);
114 }
115 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
116
117 #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
118 bool force_dma_unencrypted(struct device *dev);
119 #else
force_dma_unencrypted(struct device * dev)120 static inline bool force_dma_unencrypted(struct device *dev)
121 {
122 return false;
123 }
124 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
125
dma_capable(struct device * dev,dma_addr_t addr,size_t size,bool is_ram)126 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
127 bool is_ram)
128 {
129 dma_addr_t end = addr + size - 1;
130
131 if (addr == DMA_MAPPING_ERROR)
132 return false;
133 if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
134 min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
135 return false;
136
137 return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_limit);
138 }
139
140 u64 dma_direct_get_required_mask(struct device *dev);
141 void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
142 gfp_t gfp, unsigned long attrs);
143 void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
144 dma_addr_t dma_addr, unsigned long attrs);
145 struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
146 dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
147 void dma_direct_free_pages(struct device *dev, size_t size,
148 struct page *page, dma_addr_t dma_addr,
149 enum dma_data_direction dir);
150 int dma_direct_supported(struct device *dev, u64 mask);
151 dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
152 size_t size, enum dma_data_direction dir, unsigned long attrs);
153
154 #endif /* _LINUX_DMA_DIRECT_H */
155