xref: /linux/arch/x86/include/asm/dma-mapping.h (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 #ifndef _ASM_X86_DMA_MAPPING_H
2 #define _ASM_X86_DMA_MAPPING_H
3 
4 /*
5  * IOMMU interface. See Documentation/DMA-API-HOWTO.txt and
6  * Documentation/DMA-API.txt for documentation.
7  */
8 
9 #include <linux/kmemcheck.h>
10 #include <linux/scatterlist.h>
11 #include <linux/dma-debug.h>
12 #include <linux/dma-attrs.h>
13 #include <asm/io.h>
14 #include <asm/swiotlb.h>
15 #include <linux/dma-contiguous.h>
16 
17 #ifdef CONFIG_ISA
18 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
19 #else
20 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
21 #endif
22 
23 #define DMA_ERROR_CODE	0
24 
25 extern int iommu_merge;
26 extern struct device x86_dma_fallback_dev;
27 extern int panic_on_overflow;
28 
29 extern struct dma_map_ops *dma_ops;
30 
31 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
32 {
33 #ifndef CONFIG_X86_DEV_DMA_OPS
34 	return dma_ops;
35 #else
36 	if (unlikely(!dev) || !dev->archdata.dma_ops)
37 		return dma_ops;
38 	else
39 		return dev->archdata.dma_ops;
40 #endif
41 }
42 
43 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
44 #define arch_dma_alloc_attrs arch_dma_alloc_attrs
45 
46 #define HAVE_ARCH_DMA_SUPPORTED 1
47 extern int dma_supported(struct device *hwdev, u64 mask);
48 
49 #include <asm-generic/dma-mapping-common.h>
50 
51 extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
52 					dma_addr_t *dma_addr, gfp_t flag,
53 					struct dma_attrs *attrs);
54 
55 extern void dma_generic_free_coherent(struct device *dev, size_t size,
56 				      void *vaddr, dma_addr_t dma_addr,
57 				      struct dma_attrs *attrs);
58 
59 #ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
60 extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
61 extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
62 extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
63 #else
64 
65 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
66 {
67 	if (!dev->dma_mask)
68 		return 0;
69 
70 	return addr + size - 1 <= *dev->dma_mask;
71 }
72 
73 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
74 {
75 	return paddr;
76 }
77 
78 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
79 {
80 	return daddr;
81 }
82 #endif /* CONFIG_X86_DMA_REMAP */
83 
84 static inline void
85 dma_cache_sync(struct device *dev, void *vaddr, size_t size,
86 	enum dma_data_direction dir)
87 {
88 	flush_write_buffers();
89 }
90 
91 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
92 						    gfp_t gfp)
93 {
94 	unsigned long dma_mask = 0;
95 
96 	dma_mask = dev->coherent_dma_mask;
97 	if (!dma_mask)
98 		dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
99 
100 	return dma_mask;
101 }
102 
103 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
104 {
105 	unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
106 
107 	if (dma_mask <= DMA_BIT_MASK(24))
108 		gfp |= GFP_DMA;
109 #ifdef CONFIG_X86_64
110 	if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
111 		gfp |= GFP_DMA32;
112 #endif
113        return gfp;
114 }
115 
116 #endif
117