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Commit | Line | Data |
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1394f032 | 1 | /* |
96f1050d | 2 | * Dynamic DMA mapping support |
1394f032 | 3 | * |
96f1050d | 4 | * Copyright 2005-2009 Analog Devices Inc. |
1394f032 | 5 | * |
96f1050d | 6 | * Licensed under the GPL-2 or later |
1394f032 BW |
7 | */ |
8 | ||
9 | #include <linux/types.h> | |
dd3b0e3e | 10 | #include <linux/gfp.h> |
1394f032 | 11 | #include <linux/string.h> |
1394f032 | 12 | #include <linux/spinlock.h> |
1394f032 | 13 | #include <linux/dma-mapping.h> |
82861924 | 14 | #include <linux/scatterlist.h> |
8dc7a9c8 | 15 | #include <linux/export.h> |
c73bc702 | 16 | #include <linux/bitmap.h> |
1394f032 BW |
17 | |
18 | static spinlock_t dma_page_lock; | |
cb5ae60f | 19 | static unsigned long *dma_page; |
1394f032 BW |
20 | static unsigned int dma_pages; |
21 | static unsigned long dma_base; | |
22 | static unsigned long dma_size; | |
23 | static unsigned int dma_initialized; | |
24 | ||
dd3b0e3e | 25 | static void dma_alloc_init(unsigned long start, unsigned long end) |
1394f032 BW |
26 | { |
27 | spin_lock_init(&dma_page_lock); | |
28 | dma_initialized = 0; | |
29 | ||
cb5ae60f | 30 | dma_page = (unsigned long *)__get_free_page(GFP_KERNEL); |
1394f032 BW |
31 | memset(dma_page, 0, PAGE_SIZE); |
32 | dma_base = PAGE_ALIGN(start); | |
33 | dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start); | |
34 | dma_pages = dma_size >> PAGE_SHIFT; | |
35 | memset((void *)dma_base, 0, DMA_UNCACHED_REGION); | |
36 | dma_initialized = 1; | |
37 | ||
b85d858b | 38 | printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __func__, |
1394f032 BW |
39 | dma_page, dma_pages, dma_base); |
40 | } | |
41 | ||
42 | static inline unsigned int get_pages(size_t size) | |
43 | { | |
44 | return ((size - 1) >> PAGE_SHIFT) + 1; | |
45 | } | |
46 | ||
47 | static unsigned long __alloc_dma_pages(unsigned int pages) | |
48 | { | |
49 | unsigned long ret = 0, flags; | |
c73bc702 | 50 | unsigned long start; |
1394f032 BW |
51 | |
52 | if (dma_initialized == 0) | |
53 | dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend); | |
54 | ||
55 | spin_lock_irqsave(&dma_page_lock, flags); | |
56 | ||
c73bc702 AM |
57 | start = bitmap_find_next_zero_area(dma_page, dma_pages, 0, pages, 0); |
58 | if (start < dma_pages) { | |
59 | ret = dma_base + (start << PAGE_SHIFT); | |
60 | bitmap_set(dma_page, start, pages); | |
1394f032 BW |
61 | } |
62 | spin_unlock_irqrestore(&dma_page_lock, flags); | |
63 | return ret; | |
64 | } | |
65 | ||
66 | static void __free_dma_pages(unsigned long addr, unsigned int pages) | |
67 | { | |
68 | unsigned long page = (addr - dma_base) >> PAGE_SHIFT; | |
69 | unsigned long flags; | |
1394f032 BW |
70 | |
71 | if ((page + pages) > dma_pages) { | |
b85d858b | 72 | printk(KERN_ERR "%s: freeing outside range.\n", __func__); |
1394f032 BW |
73 | BUG(); |
74 | } | |
75 | ||
76 | spin_lock_irqsave(&dma_page_lock, flags); | |
c73bc702 | 77 | bitmap_clear(dma_page, page, pages); |
1394f032 BW |
78 | spin_unlock_irqrestore(&dma_page_lock, flags); |
79 | } | |
80 | ||
6f620975 CH |
81 | static void *bfin_dma_alloc(struct device *dev, size_t size, |
82 | dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs) | |
1394f032 BW |
83 | { |
84 | void *ret; | |
85 | ||
86 | ret = (void *)__alloc_dma_pages(get_pages(size)); | |
87 | ||
88 | if (ret) { | |
89 | memset(ret, 0, size); | |
90 | *dma_handle = virt_to_phys(ret); | |
91 | } | |
92 | ||
93 | return ret; | |
94 | } | |
1394f032 | 95 | |
6f620975 CH |
96 | static void bfin_dma_free(struct device *dev, size_t size, void *vaddr, |
97 | dma_addr_t dma_handle, struct dma_attrs *attrs) | |
1394f032 BW |
98 | { |
99 | __free_dma_pages((unsigned long)vaddr, get_pages(size)); | |
100 | } | |
1394f032 BW |
101 | |
102 | /* | |
dd3b0e3e | 103 | * Streaming DMA mappings |
1394f032 | 104 | */ |
dd3b0e3e BS |
105 | void __dma_sync(dma_addr_t addr, size_t size, |
106 | enum dma_data_direction dir) | |
1394f032 | 107 | { |
a3a6a590 | 108 | __dma_sync_inline(addr, size, dir); |
1394f032 | 109 | } |
dd3b0e3e | 110 | EXPORT_SYMBOL(__dma_sync); |
1394f032 | 111 | |
6f620975 CH |
112 | static int bfin_dma_map_sg(struct device *dev, struct scatterlist *sg_list, |
113 | int nents, enum dma_data_direction direction, | |
114 | struct dma_attrs *attrs) | |
1394f032 | 115 | { |
86d688a3 | 116 | struct scatterlist *sg; |
1394f032 BW |
117 | int i; |
118 | ||
86d688a3 | 119 | for_each_sg(sg_list, sg, nents, i) { |
58b053e4 | 120 | sg->dma_address = (dma_addr_t) sg_virt(sg); |
dd3b0e3e | 121 | __dma_sync(sg_dma_address(sg), sg_dma_len(sg), direction); |
b07af760 | 122 | } |
1394f032 BW |
123 | |
124 | return nents; | |
125 | } | |
1394f032 | 126 | |
6f620975 CH |
127 | static void bfin_dma_sync_sg_for_device(struct device *dev, |
128 | struct scatterlist *sg_list, int nelems, | |
129 | enum dma_data_direction direction) | |
1394f032 | 130 | { |
86d688a3 | 131 | struct scatterlist *sg; |
dd3b0e3e | 132 | int i; |
1394f032 | 133 | |
86d688a3 | 134 | for_each_sg(sg_list, sg, nelems, i) { |
dd3b0e3e BS |
135 | sg->dma_address = (dma_addr_t) sg_virt(sg); |
136 | __dma_sync(sg_dma_address(sg), sg_dma_len(sg), direction); | |
137 | } | |
1394f032 | 138 | } |
6f620975 CH |
139 | |
140 | static dma_addr_t bfin_dma_map_page(struct device *dev, struct page *page, | |
141 | unsigned long offset, size_t size, enum dma_data_direction dir, | |
142 | struct dma_attrs *attrs) | |
143 | { | |
144 | dma_addr_t handle = (dma_addr_t)(page_address(page) + offset); | |
145 | ||
146 | _dma_sync(handle, size, dir); | |
147 | return handle; | |
148 | } | |
149 | ||
150 | static inline void bfin_dma_sync_single_for_device(struct device *dev, | |
151 | dma_addr_t handle, size_t size, enum dma_data_direction dir) | |
152 | { | |
153 | _dma_sync(handle, size, dir); | |
154 | } | |
155 | ||
156 | struct dma_map_ops bfin_dma_ops = { | |
157 | .alloc = bfin_dma_alloc, | |
158 | .free = bfin_dma_free, | |
159 | ||
160 | .map_page = bfin_dma_map_page, | |
161 | .map_sg = bfin_dma_map_sg, | |
162 | ||
163 | .sync_single_for_device = bfin_dma_sync_single_for_device, | |
164 | .sync_sg_for_device = bfin_dma_sync_sg_for_device, | |
165 | }; | |
166 | EXPORT_SYMBOL(bfin_dma_ops); |