tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef _ASM_DMA_MAPPING_H
2#define _ASM_DMA_MAPPING_H
3
4#include <linux/device.h>
5#include <asm/cache.h>
6#include <asm/cacheflush.h>
7#include <asm/scatterlist.h>
8#include <asm/io.h>
9
10#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
11#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
12
13extern unsigned long __nongprelbss dma_coherent_mem_start;
14extern unsigned long __nongprelbss dma_coherent_mem_end;
15
16void *dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp);
17void dma_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle);
18
19/*
20 * Map a single buffer of the indicated size for DMA in streaming mode.
21 * The 32-bit bus address to use is returned.
22 *
23 * Once the device is given the dma address, the device owns this memory
24 * until either pci_unmap_single or pci_dma_sync_single is performed.
25 */
26extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
27 enum dma_data_direction direction);
28
29/*
30 * Unmap a single streaming mode DMA translation. The dma_addr and size
31 * must match what was provided for in a previous pci_map_single call. All
32 * other usages are undefined.
33 *
34 * After this call, reads by the cpu to the buffer are guarenteed to see
35 * whatever the device wrote there.
36 */
37static inline
38void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
39 enum dma_data_direction direction)
40{
41 BUG_ON(direction == DMA_NONE);
42}
43
44/*
45 * Map a set of buffers described by scatterlist in streaming
46 * mode for DMA. This is the scather-gather version of the
47 * above pci_map_single interface. Here the scatter gather list
48 * elements are each tagged with the appropriate dma address
49 * and length. They are obtained via sg_dma_{address,length}(SG).
50 *
51 * NOTE: An implementation may be able to use a smaller number of
52 * DMA address/length pairs than there are SG table elements.
53 * (for example via virtual mapping capabilities)
54 * The routine returns the number of addr/length pairs actually
55 * used, at most nents.
56 *
57 * Device ownership issues as mentioned above for pci_map_single are
58 * the same here.
59 */
60extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
61 enum dma_data_direction direction);
62
63/*
64 * Unmap a set of streaming mode DMA translations.
65 * Again, cpu read rules concerning calls here are the same as for
66 * pci_unmap_single() above.
67 */
68static inline
69void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
70 enum dma_data_direction direction)
71{
72 BUG_ON(direction == DMA_NONE);
73}
74
75extern
76dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
77 size_t size, enum dma_data_direction direction);
78
79static inline
80void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
81 enum dma_data_direction direction)
82{
83 BUG_ON(direction == DMA_NONE);
84}
85
86
87static inline
88void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
89 enum dma_data_direction direction)
90{
91}
92
93static inline
94void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
95 enum dma_data_direction direction)
96{
97 flush_write_buffers();
98}
99
100static inline
101void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
102 unsigned long offset, size_t size,
103 enum dma_data_direction direction)
104{
105}
106
107static inline
108void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
109 unsigned long offset, size_t size,
110 enum dma_data_direction direction)
111{
112 flush_write_buffers();
113}
114
115static inline
116void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
117 enum dma_data_direction direction)
118{
119}
120
121static inline
122void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
123 enum dma_data_direction direction)
124{
125 flush_write_buffers();
126}
127
128static inline
129int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
130{
131 return 0;
132}
133
134static inline
135int dma_supported(struct device *dev, u64 mask)
136{
137 /*
138 * we fall back to GFP_DMA when the mask isn't all 1s,
139 * so we can't guarantee allocations that must be
140 * within a tighter range than GFP_DMA..
141 */
142 if (mask < 0x00ffffff)
143 return 0;
144
145 return 1;
146}
147
148static inline
149int dma_set_mask(struct device *dev, u64 mask)
150{
151 if (!dev->dma_mask || !dma_supported(dev, mask))
152 return -EIO;
153
154 *dev->dma_mask = mask;
155
156 return 0;
157}
158
159static inline
160int dma_get_cache_alignment(void)
161{
162 return 1 << L1_CACHE_SHIFT;
163}
164
165#define dma_is_consistent(d, h) (1)
166
167static inline
168void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
169 enum dma_data_direction direction)
170{
171 flush_write_buffers();
172}
173
174#endif /* _ASM_DMA_MAPPING_H */