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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Dynamic DMA mapping support. | |
3 | * | |
4 | * On i386 there is no hardware dynamic DMA address translation, | |
5 | * so consistent alloc/free are merely page allocation/freeing. | |
6 | * The rest of the dynamic DMA mapping interface is implemented | |
7 | * in asm/pci.h. | |
8 | */ | |
9 | ||
10 | #include <linux/types.h> | |
11 | #include <linux/mm.h> | |
12 | #include <linux/string.h> | |
13 | #include <linux/pci.h> | |
129f6946 | 14 | #include <linux/module.h> |
1da177e4 LT |
15 | #include <asm/io.h> |
16 | ||
17 | struct dma_coherent_mem { | |
18 | void *virt_base; | |
19 | u32 device_base; | |
20 | int size; | |
21 | int flags; | |
22 | unsigned long *bitmap; | |
23 | }; | |
24 | ||
25 | void *dma_alloc_coherent(struct device *dev, size_t size, | |
dd0fc66f | 26 | dma_addr_t *dma_handle, gfp_t gfp) |
1da177e4 LT |
27 | { |
28 | void *ret; | |
29 | struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; | |
30 | int order = get_order(size); | |
31 | /* ignore region specifiers */ | |
32 | gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); | |
33 | ||
34 | if (mem) { | |
35 | int page = bitmap_find_free_region(mem->bitmap, mem->size, | |
36 | order); | |
37 | if (page >= 0) { | |
38 | *dma_handle = mem->device_base + (page << PAGE_SHIFT); | |
39 | ret = mem->virt_base + (page << PAGE_SHIFT); | |
40 | memset(ret, 0, size); | |
41 | return ret; | |
42 | } | |
43 | if (mem->flags & DMA_MEMORY_EXCLUSIVE) | |
44 | return NULL; | |
45 | } | |
46 | ||
47 | if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) | |
48 | gfp |= GFP_DMA; | |
49 | ||
50 | ret = (void *)__get_free_pages(gfp, order); | |
51 | ||
52 | if (ret != NULL) { | |
53 | memset(ret, 0, size); | |
54 | *dma_handle = virt_to_phys(ret); | |
55 | } | |
56 | return ret; | |
57 | } | |
129f6946 | 58 | EXPORT_SYMBOL(dma_alloc_coherent); |
1da177e4 LT |
59 | |
60 | void dma_free_coherent(struct device *dev, size_t size, | |
61 | void *vaddr, dma_addr_t dma_handle) | |
62 | { | |
63 | struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; | |
64 | int order = get_order(size); | |
65 | ||
66 | if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) { | |
67 | int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; | |
68 | ||
69 | bitmap_release_region(mem->bitmap, page, order); | |
70 | } else | |
71 | free_pages((unsigned long)vaddr, order); | |
72 | } | |
129f6946 | 73 | EXPORT_SYMBOL(dma_free_coherent); |
1da177e4 LT |
74 | |
75 | int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, | |
76 | dma_addr_t device_addr, size_t size, int flags) | |
77 | { | |
039d09a8 | 78 | void __iomem *mem_base = NULL; |
1da177e4 LT |
79 | int pages = size >> PAGE_SHIFT; |
80 | int bitmap_size = (pages + 31)/32; | |
81 | ||
82 | if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0) | |
83 | goto out; | |
84 | if (!size) | |
85 | goto out; | |
86 | if (dev->dma_mem) | |
87 | goto out; | |
88 | ||
89 | /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ | |
90 | ||
91 | mem_base = ioremap(bus_addr, size); | |
92 | if (!mem_base) | |
93 | goto out; | |
94 | ||
116780fc | 95 | dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); |
1da177e4 LT |
96 | if (!dev->dma_mem) |
97 | goto out; | |
116780fc | 98 | dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); |
1da177e4 LT |
99 | if (!dev->dma_mem->bitmap) |
100 | goto free1_out; | |
1da177e4 LT |
101 | |
102 | dev->dma_mem->virt_base = mem_base; | |
103 | dev->dma_mem->device_base = device_addr; | |
104 | dev->dma_mem->size = pages; | |
105 | dev->dma_mem->flags = flags; | |
106 | ||
107 | if (flags & DMA_MEMORY_MAP) | |
108 | return DMA_MEMORY_MAP; | |
109 | ||
110 | return DMA_MEMORY_IO; | |
111 | ||
112 | free1_out: | |
3a0ee2ce | 113 | kfree(dev->dma_mem); |
1da177e4 | 114 | out: |
039d09a8 AL |
115 | if (mem_base) |
116 | iounmap(mem_base); | |
1da177e4 LT |
117 | return 0; |
118 | } | |
119 | EXPORT_SYMBOL(dma_declare_coherent_memory); | |
120 | ||
121 | void dma_release_declared_memory(struct device *dev) | |
122 | { | |
123 | struct dma_coherent_mem *mem = dev->dma_mem; | |
124 | ||
125 | if(!mem) | |
126 | return; | |
127 | dev->dma_mem = NULL; | |
128 | iounmap(mem->virt_base); | |
129 | kfree(mem->bitmap); | |
130 | kfree(mem); | |
131 | } | |
132 | EXPORT_SYMBOL(dma_release_declared_memory); | |
133 | ||
134 | void *dma_mark_declared_memory_occupied(struct device *dev, | |
135 | dma_addr_t device_addr, size_t size) | |
136 | { | |
137 | struct dma_coherent_mem *mem = dev->dma_mem; | |
138 | int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
139 | int pos, err; | |
140 | ||
141 | if (!mem) | |
142 | return ERR_PTR(-EINVAL); | |
143 | ||
144 | pos = (device_addr - mem->device_base) >> PAGE_SHIFT; | |
145 | err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages)); | |
146 | if (err != 0) | |
147 | return ERR_PTR(err); | |
148 | return mem->virt_base + (pos << PAGE_SHIFT); | |
149 | } | |
150 | EXPORT_SYMBOL(dma_mark_declared_memory_occupied); |