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Commit | Line | Data |
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ee7e5516 DB |
1 | /* |
2 | * Coherent per-device memory handling. | |
3 | * Borrowed from i386 | |
4 | */ | |
5a0e3ad6 | 5 | #include <linux/slab.h> |
ee7e5516 DB |
6 | #include <linux/kernel.h> |
7 | #include <linux/dma-mapping.h> | |
8 | ||
9 | struct dma_coherent_mem { | |
10 | void *virt_base; | |
ed1d218c | 11 | dma_addr_t device_base; |
ee7e5516 DB |
12 | int size; |
13 | int flags; | |
14 | unsigned long *bitmap; | |
15 | }; | |
16 | ||
17 | int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, | |
18 | dma_addr_t device_addr, size_t size, int flags) | |
19 | { | |
20 | void __iomem *mem_base = NULL; | |
21 | int pages = size >> PAGE_SHIFT; | |
22 | int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); | |
23 | ||
24 | if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0) | |
25 | goto out; | |
26 | if (!size) | |
27 | goto out; | |
28 | if (dev->dma_mem) | |
29 | goto out; | |
30 | ||
31 | /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ | |
32 | ||
33 | mem_base = ioremap(bus_addr, size); | |
34 | if (!mem_base) | |
35 | goto out; | |
36 | ||
37 | dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); | |
38 | if (!dev->dma_mem) | |
39 | goto out; | |
40 | dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); | |
41 | if (!dev->dma_mem->bitmap) | |
42 | goto free1_out; | |
43 | ||
44 | dev->dma_mem->virt_base = mem_base; | |
45 | dev->dma_mem->device_base = device_addr; | |
46 | dev->dma_mem->size = pages; | |
47 | dev->dma_mem->flags = flags; | |
48 | ||
49 | if (flags & DMA_MEMORY_MAP) | |
50 | return DMA_MEMORY_MAP; | |
51 | ||
52 | return DMA_MEMORY_IO; | |
53 | ||
54 | free1_out: | |
55 | kfree(dev->dma_mem); | |
56 | out: | |
57 | if (mem_base) | |
58 | iounmap(mem_base); | |
59 | return 0; | |
60 | } | |
61 | EXPORT_SYMBOL(dma_declare_coherent_memory); | |
62 | ||
63 | void dma_release_declared_memory(struct device *dev) | |
64 | { | |
65 | struct dma_coherent_mem *mem = dev->dma_mem; | |
66 | ||
67 | if (!mem) | |
68 | return; | |
69 | dev->dma_mem = NULL; | |
70 | iounmap(mem->virt_base); | |
71 | kfree(mem->bitmap); | |
72 | kfree(mem); | |
73 | } | |
74 | EXPORT_SYMBOL(dma_release_declared_memory); | |
75 | ||
76 | void *dma_mark_declared_memory_occupied(struct device *dev, | |
77 | dma_addr_t device_addr, size_t size) | |
78 | { | |
79 | struct dma_coherent_mem *mem = dev->dma_mem; | |
80 | int pos, err; | |
ee7e5516 | 81 | |
d2dc1f4a | 82 | size += device_addr & ~PAGE_MASK; |
ee7e5516 DB |
83 | |
84 | if (!mem) | |
85 | return ERR_PTR(-EINVAL); | |
86 | ||
87 | pos = (device_addr - mem->device_base) >> PAGE_SHIFT; | |
d2dc1f4a | 88 | err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); |
ee7e5516 DB |
89 | if (err != 0) |
90 | return ERR_PTR(err); | |
91 | return mem->virt_base + (pos << PAGE_SHIFT); | |
92 | } | |
93 | EXPORT_SYMBOL(dma_mark_declared_memory_occupied); | |
94 | ||
b6d4f7e3 | 95 | /** |
cb3952bf | 96 | * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area |
b6d4f7e3 DB |
97 | * |
98 | * @dev: device from which we allocate memory | |
99 | * @size: size of requested memory area | |
100 | * @dma_handle: This will be filled with the correct dma handle | |
101 | * @ret: This pointer will be filled with the virtual address | |
0609697e | 102 | * to allocated area. |
b6d4f7e3 | 103 | * |
cb3952bf | 104 | * This function should be only called from per-arch dma_alloc_coherent() |
b6d4f7e3 DB |
105 | * to support allocation from per-device coherent memory pools. |
106 | * | |
107 | * Returns 0 if dma_alloc_coherent should continue with allocating from | |
cb3952bf | 108 | * generic memory areas, or !0 if dma_alloc_coherent should return @ret. |
b6d4f7e3 | 109 | */ |
ee7e5516 DB |
110 | int dma_alloc_from_coherent(struct device *dev, ssize_t size, |
111 | dma_addr_t *dma_handle, void **ret) | |
112 | { | |
eccd83e1 | 113 | struct dma_coherent_mem *mem; |
ee7e5516 | 114 | int order = get_order(size); |
eccd83e1 | 115 | int pageno; |
ee7e5516 | 116 | |
eccd83e1 AM |
117 | if (!dev) |
118 | return 0; | |
119 | mem = dev->dma_mem; | |
120 | if (!mem) | |
121 | return 0; | |
0609697e PM |
122 | |
123 | *ret = NULL; | |
124 | ||
cdf57cab | 125 | if (unlikely(size > (mem->size << PAGE_SHIFT))) |
0609697e | 126 | goto err; |
eccd83e1 AM |
127 | |
128 | pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); | |
0609697e PM |
129 | if (unlikely(pageno < 0)) |
130 | goto err; | |
131 | ||
132 | /* | |
133 | * Memory was found in the per-device area. | |
134 | */ | |
135 | *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); | |
136 | *ret = mem->virt_base + (pageno << PAGE_SHIFT); | |
137 | memset(*ret, 0, size); | |
138 | ||
eccd83e1 | 139 | return 1; |
0609697e PM |
140 | |
141 | err: | |
142 | /* | |
143 | * In the case where the allocation can not be satisfied from the | |
144 | * per-device area, try to fall back to generic memory if the | |
145 | * constraints allow it. | |
146 | */ | |
147 | return mem->flags & DMA_MEMORY_EXCLUSIVE; | |
ee7e5516 | 148 | } |
a38409fb | 149 | EXPORT_SYMBOL(dma_alloc_from_coherent); |
ee7e5516 | 150 | |
b6d4f7e3 | 151 | /** |
cb3952bf | 152 | * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool |
b6d4f7e3 DB |
153 | * @dev: device from which the memory was allocated |
154 | * @order: the order of pages allocated | |
155 | * @vaddr: virtual address of allocated pages | |
156 | * | |
157 | * This checks whether the memory was allocated from the per-device | |
158 | * coherent memory pool and if so, releases that memory. | |
159 | * | |
160 | * Returns 1 if we correctly released the memory, or 0 if | |
cb3952bf | 161 | * dma_release_coherent() should proceed with releasing memory from |
b6d4f7e3 DB |
162 | * generic pools. |
163 | */ | |
ee7e5516 DB |
164 | int dma_release_from_coherent(struct device *dev, int order, void *vaddr) |
165 | { | |
166 | struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; | |
167 | ||
168 | if (mem && vaddr >= mem->virt_base && vaddr < | |
169 | (mem->virt_base + (mem->size << PAGE_SHIFT))) { | |
170 | int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; | |
171 | ||
172 | bitmap_release_region(mem->bitmap, page, order); | |
173 | return 1; | |
174 | } | |
175 | return 0; | |
176 | } | |
a38409fb | 177 | EXPORT_SYMBOL(dma_release_from_coherent); |