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 * These macros should be used after a pci_map_sg call has been done
21 * to get bus addresses of each of the SG entries and their lengths.
22 * You should only work with the number of sg entries pci_map_sg
23 * returns, or alternatively stop on the first sg_dma_len(sg) which
24 * is 0.
25 */
26#define sg_dma_address(sg)	((sg)->dma_address)
27#define sg_dma_len(sg)		((sg)->length)
28
29/*
30 * Map a single buffer of the indicated size for DMA in streaming mode.
31 * The 32-bit bus address to use is returned.
32 *
33 * Once the device is given the dma address, the device owns this memory
34 * until either pci_unmap_single or pci_dma_sync_single is performed.
35 */
36extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
37				 enum dma_data_direction direction);
38
39/*
40 * Unmap a single streaming mode DMA translation.  The dma_addr and size
41 * must match what was provided for in a previous pci_map_single call.  All
42 * other usages are undefined.
43 *
44 * After this call, reads by the cpu to the buffer are guarenteed to see
45 * whatever the device wrote there.
46 */
47static inline
48void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
49		      enum dma_data_direction direction)
50{
51	BUG_ON(direction == DMA_NONE);
52}
53
54/*
55 * Map a set of buffers described by scatterlist in streaming
56 * mode for DMA.  This is the scather-gather version of the
57 * above pci_map_single interface.  Here the scatter gather list
58 * elements are each tagged with the appropriate dma address
59 * and length.  They are obtained via sg_dma_{address,length}(SG).
60 *
61 * NOTE: An implementation may be able to use a smaller number of
62 *       DMA address/length pairs than there are SG table elements.
63 *       (for example via virtual mapping capabilities)
64 *       The routine returns the number of addr/length pairs actually
65 *       used, at most nents.
66 *
67 * Device ownership issues as mentioned above for pci_map_single are
68 * the same here.
69 */
70extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
71		      enum dma_data_direction direction);
72
73/*
74 * Unmap a set of streaming mode DMA translations.
75 * Again, cpu read rules concerning calls here are the same as for
76 * pci_unmap_single() above.
77 */
78static inline
79void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
80	     enum dma_data_direction direction)
81{
82	BUG_ON(direction == DMA_NONE);
83}
84
85extern
86dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
87			size_t size, enum dma_data_direction direction);
88
89static inline
90void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
91		    enum dma_data_direction direction)
92{
93	BUG_ON(direction == DMA_NONE);
94}
95
96
97static inline
98void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
99			     enum dma_data_direction direction)
100{
101}
102
103static inline
104void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
105				enum dma_data_direction direction)
106{
107	flush_write_buffers();
108}
109
110static inline
111void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
112				   unsigned long offset, size_t size,
113				   enum dma_data_direction direction)
114{
115}
116
117static inline
118void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
119				      unsigned long offset, size_t size,
120				      enum dma_data_direction direction)
121{
122	flush_write_buffers();
123}
124
125static inline
126void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
127			 enum dma_data_direction direction)
128{
129}
130
131static inline
132void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
133			    enum dma_data_direction direction)
134{
135	flush_write_buffers();
136}
137
138static inline
139int dma_mapping_error(dma_addr_t dma_addr)
140{
141	return 0;
142}
143
144static inline
145int dma_supported(struct device *dev, u64 mask)
146{
147        /*
148         * we fall back to GFP_DMA when the mask isn't all 1s,
149         * so we can't guarantee allocations that must be
150         * within a tighter range than GFP_DMA..
151         */
152        if (mask < 0x00ffffff)
153                return 0;
154
155	return 1;
156}
157
158static inline
159int dma_set_mask(struct device *dev, u64 mask)
160{
161	if (!dev->dma_mask || !dma_supported(dev, mask))
162		return -EIO;
163
164	*dev->dma_mask = mask;
165
166	return 0;
167}
168
169static inline
170int dma_get_cache_alignment(void)
171{
172	return 1 << L1_CACHE_SHIFT;
173}
174
175#define dma_is_consistent(d, h)	(1)
176
177static inline
178void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
179		    enum dma_data_direction direction)
180{
181	flush_write_buffers();
182}
183
184#endif  /* _ASM_DMA_MAPPING_H */
185