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David Howellsb920de12008-02-08 04:19:31 -08001/* DMA mapping routines for the MN10300 arch
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#ifndef _ASM_DMA_MAPPING_H
12#define _ASM_DMA_MAPPING_H
13
14#include <linux/mm.h>
15#include <linux/scatterlist.h>
16
17#include <asm/cache.h>
18#include <asm/io.h>
19
20extern void *dma_alloc_coherent(struct device *dev, size_t size,
21 dma_addr_t *dma_handle, int flag);
22
23extern void dma_free_coherent(struct device *dev, size_t size,
24 void *vaddr, dma_addr_t dma_handle);
25
26#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent((d), (s), (h), (f))
27#define dma_free_noncoherent(d, s, v, h) dma_free_coherent((d), (s), (v), (h))
28
29/*
30 * Map a single buffer of the indicated size for DMA in streaming mode. The
31 * 32-bit bus address to use is returned.
32 *
33 * Once the device is given the dma address, the device owns this memory until
34 * either pci_unmap_single or pci_dma_sync_single is performed.
35 */
36static inline
37dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
38 enum dma_data_direction direction)
39{
40 BUG_ON(direction == DMA_NONE);
41 mn10300_dcache_flush_inv();
42 return virt_to_bus(ptr);
43}
44
45/*
46 * Unmap a single streaming mode DMA translation. The dma_addr and size must
47 * match what was provided for in a previous pci_map_single call. All other
48 * usages are undefined.
49 *
50 * After this call, reads by the cpu to the buffer are guarenteed to see
51 * whatever the device wrote there.
52 */
53static inline
54void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
55 enum dma_data_direction direction)
56{
57 BUG_ON(direction == DMA_NONE);
58}
59
60/*
61 * Map a set of buffers described by scatterlist in streaming mode for DMA.
62 * This is the scather-gather version of the above pci_map_single interface.
63 * Here the scatter gather list elements are each tagged with the appropriate
64 * dma address and length. They are obtained via sg_dma_{address,length}(SG).
65 *
66 * NOTE: An implementation may be able to use a smaller number of DMA
67 * address/length pairs than there are SG table elements. (for example
68 * via virtual mapping capabilities) The routine returns the number of
69 * addr/length pairs actually used, at most nents.
70 *
71 * Device ownership issues as mentioned above for pci_map_single are the same
72 * here.
73 */
74static inline
75int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
76 enum dma_data_direction direction)
77{
78 struct scatterlist *sg;
79 int i;
80
81 BUG_ON(!valid_dma_direction(direction));
82 WARN_ON(nents == 0 || sglist[0].length == 0);
83
84 for_each_sg(sglist, sg, nents, i) {
85 BUG_ON(!sg_page(sg));
86
87 sg->dma_address = sg_phys(sg);
88 }
89
90 mn10300_dcache_flush_inv();
91 return nents;
92}
93
94/*
95 * Unmap a set of streaming mode DMA translations.
96 * Again, cpu read rules concerning calls here are the same as for
97 * pci_unmap_single() above.
98 */
99static inline
100void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
101 enum dma_data_direction direction)
102{
103 BUG_ON(!valid_dma_direction(direction));
104}
105
106/*
107 * pci_{map,unmap}_single_page maps a kernel page to a dma_addr_t. identical
108 * to pci_map_single, but takes a struct page instead of a virtual address
109 */
110static inline
111dma_addr_t dma_map_page(struct device *dev, struct page *page,
112 unsigned long offset, size_t size,
113 enum dma_data_direction direction)
114{
115 BUG_ON(direction == DMA_NONE);
116 return page_to_bus(page) + offset;
117}
118
119static inline
120void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
121 enum dma_data_direction direction)
122{
123 BUG_ON(direction == DMA_NONE);
124}
125
126/*
127 * Make physical memory consistent for a single streaming mode DMA translation
128 * after a transfer.
129 *
130 * If you perform a pci_map_single() but wish to interrogate the buffer using
131 * the cpu, yet do not wish to teardown the PCI dma mapping, you must call this
132 * function before doing so. At the next point you give the PCI dma address
133 * back to the card, the device again owns the buffer.
134 */
135static inline
136void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
137 size_t size, enum dma_data_direction direction)
138{
139}
140
141static inline
142void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
143 size_t size, enum dma_data_direction direction)
144{
145 mn10300_dcache_flush_inv();
146}
147
148static inline
149void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
150 unsigned long offset, size_t size,
151 enum dma_data_direction direction)
152{
153}
154
155static inline void
156dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
157 unsigned long offset, size_t size,
158 enum dma_data_direction direction)
159{
160 mn10300_dcache_flush_inv();
161}
162
163
164/*
165 * Make physical memory consistent for a set of streaming mode DMA translations
166 * after a transfer.
167 *
168 * The same as pci_dma_sync_single but for a scatter-gather list, same rules
169 * and usage.
170 */
171static inline
172void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
173 int nelems, enum dma_data_direction direction)
174{
175}
176
177static inline
178void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
179 int nelems, enum dma_data_direction direction)
180{
181 mn10300_dcache_flush_inv();
182}
183
184static inline
185int dma_mapping_error(dma_addr_t dma_addr)
186{
187 return 0;
188}
189
190/*
191 * Return whether the given PCI device DMA address mask can be supported
192 * properly. For example, if your device can only drive the low 24-bits during
193 * PCI bus mastering, then you would pass 0x00ffffff as the mask to this
194 * function.
195 */
196static inline
197int dma_supported(struct device *dev, u64 mask)
198{
199 /*
200 * we fall back to GFP_DMA when the mask isn't all 1s, so we can't
201 * guarantee allocations that must be within a tighter range than
202 * GFP_DMA
203 */
204 if (mask < 0x00ffffff)
205 return 0;
206 return 1;
207}
208
209static inline
210int dma_set_mask(struct device *dev, u64 mask)
211{
212 if (!dev->dma_mask || !dma_supported(dev, mask))
213 return -EIO;
214
215 *dev->dma_mask = mask;
216 return 0;
217}
218
219static inline
220int dma_get_cache_alignment(void)
221{
222 return 1 << L1_CACHE_SHIFT;
223}
224
225#define dma_is_consistent(d) (1)
226
227static inline
228void dma_cache_sync(void *vaddr, size_t size,
229 enum dma_data_direction direction)
230{
231 mn10300_dcache_flush_inv();
232}
233
234#endif