tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef _ASM_X86_DMA_MAPPING_H
2#define _ASM_X86_DMA_MAPPING_H
3
4/*
5 * IOMMU interface. See Documentation/PCI/PCI-DMA-mapping.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 <asm-generic/dma-coherent.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
25extern int iommu_merge;
26extern struct device x86_dma_fallback_dev;
27extern int panic_on_overflow;
28
29extern struct dma_map_ops *dma_ops;
30
31static inline struct dma_map_ops *get_dma_ops(struct device *dev)
32{
33#ifdef CONFIG_X86_32
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#include <asm-generic/dma-mapping-common.h>
44
45/* Make sure we keep the same behaviour */
46static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
47{
48 struct dma_map_ops *ops = get_dma_ops(dev);
49 if (ops->mapping_error)
50 return ops->mapping_error(dev, dma_addr);
51
52 return (dma_addr == DMA_ERROR_CODE);
53}
54
55#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
56#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
57#define dma_is_consistent(d, h) (1)
58
59extern int dma_supported(struct device *hwdev, u64 mask);
60extern int dma_set_mask(struct device *dev, u64 mask);
61
62extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
63 dma_addr_t *dma_addr, gfp_t flag);
64
65static 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
73static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
74{
75 return paddr;
76}
77
78static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
79{
80 return daddr;
81}
82
83static inline void
84dma_cache_sync(struct device *dev, void *vaddr, size_t size,
85 enum dma_data_direction dir)
86{
87 flush_write_buffers();
88}
89
90static inline int dma_get_cache_alignment(void)
91{
92 /* no easy way to get cache size on all x86, so return the
93 * maximum possible, to be safe */
94 return boot_cpu_data.x86_clflush_size;
95}
96
97static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
98 gfp_t gfp)
99{
100 unsigned long dma_mask = 0;
101
102 dma_mask = dev->coherent_dma_mask;
103 if (!dma_mask)
104 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
105
106 return dma_mask;
107}
108
109static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
110{
111 unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
112
113 if (dma_mask <= DMA_BIT_MASK(24))
114 gfp |= GFP_DMA;
115#ifdef CONFIG_X86_64
116 if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
117 gfp |= GFP_DMA32;
118#endif
119 return gfp;
120}
121
122static inline void *
123dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
124 gfp_t gfp)
125{
126 struct dma_map_ops *ops = get_dma_ops(dev);
127 void *memory;
128
129 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
130
131 if (dma_alloc_from_coherent(dev, size, dma_handle, &memory))
132 return memory;
133
134 if (!dev)
135 dev = &x86_dma_fallback_dev;
136
137 if (!is_device_dma_capable(dev))
138 return NULL;
139
140 if (!ops->alloc_coherent)
141 return NULL;
142
143 memory = ops->alloc_coherent(dev, size, dma_handle,
144 dma_alloc_coherent_gfp_flags(dev, gfp));
145 debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
146
147 return memory;
148}
149
150static inline void dma_free_coherent(struct device *dev, size_t size,
151 void *vaddr, dma_addr_t bus)
152{
153 struct dma_map_ops *ops = get_dma_ops(dev);
154
155 WARN_ON(irqs_disabled()); /* for portability */
156
157 if (dma_release_from_coherent(dev, get_order(size), vaddr))
158 return;
159
160 debug_dma_free_coherent(dev, size, vaddr, bus);
161 if (ops->free_coherent)
162 ops->free_coherent(dev, size, vaddr, bus);
163}
164
165#endif