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5f97f7f9 HS |
1 | /* |
2 | * Copyright (C) 2004-2006 Atmel Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | #include <linux/dma-mapping.h> | |
10 | ||
11 | #include <asm/addrspace.h> | |
12 | #include <asm/cacheflush.h> | |
13 | ||
d3fa72e4 | 14 | void dma_cache_sync(struct device *dev, void *vaddr, size_t size, int direction) |
5f97f7f9 HS |
15 | { |
16 | /* | |
17 | * No need to sync an uncached area | |
18 | */ | |
19 | if (PXSEG(vaddr) == P2SEG) | |
20 | return; | |
21 | ||
22 | switch (direction) { | |
23 | case DMA_FROM_DEVICE: /* invalidate only */ | |
24 | dma_cache_inv(vaddr, size); | |
25 | break; | |
26 | case DMA_TO_DEVICE: /* writeback only */ | |
27 | dma_cache_wback(vaddr, size); | |
28 | break; | |
29 | case DMA_BIDIRECTIONAL: /* writeback and invalidate */ | |
30 | dma_cache_wback_inv(vaddr, size); | |
31 | break; | |
32 | default: | |
33 | BUG(); | |
34 | } | |
35 | } | |
36 | EXPORT_SYMBOL(dma_cache_sync); | |
37 | ||
38 | static struct page *__dma_alloc(struct device *dev, size_t size, | |
39 | dma_addr_t *handle, gfp_t gfp) | |
40 | { | |
41 | struct page *page, *free, *end; | |
42 | int order; | |
43 | ||
44 | size = PAGE_ALIGN(size); | |
45 | order = get_order(size); | |
46 | ||
47 | page = alloc_pages(gfp, order); | |
48 | if (!page) | |
49 | return NULL; | |
50 | split_page(page, order); | |
51 | ||
52 | /* | |
53 | * When accessing physical memory with valid cache data, we | |
54 | * get a cache hit even if the virtual memory region is marked | |
55 | * as uncached. | |
56 | * | |
57 | * Since the memory is newly allocated, there is no point in | |
58 | * doing a writeback. If the previous owner cares, he should | |
59 | * have flushed the cache before releasing the memory. | |
60 | */ | |
61 | invalidate_dcache_region(phys_to_virt(page_to_phys(page)), size); | |
62 | ||
63 | *handle = page_to_bus(page); | |
64 | free = page + (size >> PAGE_SHIFT); | |
65 | end = page + (1 << order); | |
66 | ||
67 | /* | |
68 | * Free any unused pages | |
69 | */ | |
70 | while (free < end) { | |
71 | __free_page(free); | |
72 | free++; | |
73 | } | |
74 | ||
75 | return page; | |
76 | } | |
77 | ||
78 | static void __dma_free(struct device *dev, size_t size, | |
79 | struct page *page, dma_addr_t handle) | |
80 | { | |
81 | struct page *end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT); | |
82 | ||
83 | while (page < end) | |
84 | __free_page(page++); | |
85 | } | |
86 | ||
87 | void *dma_alloc_coherent(struct device *dev, size_t size, | |
88 | dma_addr_t *handle, gfp_t gfp) | |
89 | { | |
90 | struct page *page; | |
91 | void *ret = NULL; | |
92 | ||
93 | page = __dma_alloc(dev, size, handle, gfp); | |
94 | if (page) | |
95 | ret = phys_to_uncached(page_to_phys(page)); | |
96 | ||
97 | return ret; | |
98 | } | |
99 | EXPORT_SYMBOL(dma_alloc_coherent); | |
100 | ||
101 | void dma_free_coherent(struct device *dev, size_t size, | |
102 | void *cpu_addr, dma_addr_t handle) | |
103 | { | |
104 | void *addr = phys_to_cached(uncached_to_phys(cpu_addr)); | |
105 | struct page *page; | |
106 | ||
107 | pr_debug("dma_free_coherent addr %p (phys %08lx) size %u\n", | |
108 | cpu_addr, (unsigned long)handle, (unsigned)size); | |
109 | BUG_ON(!virt_addr_valid(addr)); | |
110 | page = virt_to_page(addr); | |
111 | __dma_free(dev, size, page, handle); | |
112 | } | |
113 | EXPORT_SYMBOL(dma_free_coherent); | |
114 | ||
5f97f7f9 HS |
115 | void *dma_alloc_writecombine(struct device *dev, size_t size, |
116 | dma_addr_t *handle, gfp_t gfp) | |
117 | { | |
118 | struct page *page; | |
a492dbb9 | 119 | dma_addr_t phys; |
5f97f7f9 HS |
120 | |
121 | page = __dma_alloc(dev, size, handle, gfp); | |
a492dbb9 HS |
122 | if (!page) |
123 | return NULL; | |
124 | ||
125 | phys = page_to_phys(page); | |
126 | *handle = phys; | |
5f97f7f9 HS |
127 | |
128 | /* Now, map the page into P3 with write-combining turned on */ | |
a492dbb9 | 129 | return __ioremap(phys, size, _PAGE_BUFFER); |
5f97f7f9 HS |
130 | } |
131 | EXPORT_SYMBOL(dma_alloc_writecombine); | |
132 | ||
133 | void dma_free_writecombine(struct device *dev, size_t size, | |
134 | void *cpu_addr, dma_addr_t handle) | |
135 | { | |
136 | struct page *page; | |
137 | ||
138 | iounmap(cpu_addr); | |
139 | ||
a492dbb9 | 140 | page = phys_to_page(handle); |
5f97f7f9 HS |
141 | __dma_free(dev, size, page, handle); |
142 | } | |
143 | EXPORT_SYMBOL(dma_free_writecombine); |