Commit | Line | Data |
---|---|---|
ee7e5516 DB |
1 | /* |
2 | * Coherent per-device memory handling. | |
3 | * Borrowed from i386 | |
4 | */ | |
5a0e3ad6 | 5 | #include <linux/slab.h> |
ee7e5516 | 6 | #include <linux/kernel.h> |
08a999ce | 7 | #include <linux/module.h> |
ee7e5516 DB |
8 | #include <linux/dma-mapping.h> |
9 | ||
10 | struct dma_coherent_mem { | |
11 | void *virt_base; | |
ed1d218c | 12 | dma_addr_t device_base; |
ee7e5516 DB |
13 | int size; |
14 | int flags; | |
15 | unsigned long *bitmap; | |
16 | }; | |
17 | ||
18 | int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, | |
19 | dma_addr_t device_addr, size_t size, int flags) | |
20 | { | |
21 | void __iomem *mem_base = NULL; | |
22 | int pages = size >> PAGE_SHIFT; | |
23 | int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); | |
24 | ||
25 | if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0) | |
26 | goto out; | |
27 | if (!size) | |
28 | goto out; | |
29 | if (dev->dma_mem) | |
30 | goto out; | |
31 | ||
32 | /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ | |
33 | ||
34 | mem_base = ioremap(bus_addr, size); | |
35 | if (!mem_base) | |
36 | goto out; | |
37 | ||
38 | dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); | |
39 | if (!dev->dma_mem) | |
40 | goto out; | |
41 | dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); | |
42 | if (!dev->dma_mem->bitmap) | |
43 | goto free1_out; | |
44 | ||
45 | dev->dma_mem->virt_base = mem_base; | |
46 | dev->dma_mem->device_base = device_addr; | |
47 | dev->dma_mem->size = pages; | |
48 | dev->dma_mem->flags = flags; | |
49 | ||
50 | if (flags & DMA_MEMORY_MAP) | |
51 | return DMA_MEMORY_MAP; | |
52 | ||
53 | return DMA_MEMORY_IO; | |
54 | ||
55 | free1_out: | |
56 | kfree(dev->dma_mem); | |
57 | out: | |
58 | if (mem_base) | |
59 | iounmap(mem_base); | |
60 | return 0; | |
61 | } | |
62 | EXPORT_SYMBOL(dma_declare_coherent_memory); | |
63 | ||
64 | void dma_release_declared_memory(struct device *dev) | |
65 | { | |
66 | struct dma_coherent_mem *mem = dev->dma_mem; | |
67 | ||
68 | if (!mem) | |
69 | return; | |
70 | dev->dma_mem = NULL; | |
71 | iounmap(mem->virt_base); | |
72 | kfree(mem->bitmap); | |
73 | kfree(mem); | |
74 | } | |
75 | EXPORT_SYMBOL(dma_release_declared_memory); | |
76 | ||
77 | void *dma_mark_declared_memory_occupied(struct device *dev, | |
78 | dma_addr_t device_addr, size_t size) | |
79 | { | |
80 | struct dma_coherent_mem *mem = dev->dma_mem; | |
81 | int pos, err; | |
ee7e5516 | 82 | |
d2dc1f4a | 83 | size += device_addr & ~PAGE_MASK; |
ee7e5516 DB |
84 | |
85 | if (!mem) | |
86 | return ERR_PTR(-EINVAL); | |
87 | ||
88 | pos = (device_addr - mem->device_base) >> PAGE_SHIFT; | |
d2dc1f4a | 89 | err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); |
ee7e5516 DB |
90 | if (err != 0) |
91 | return ERR_PTR(err); | |
92 | return mem->virt_base + (pos << PAGE_SHIFT); | |
93 | } | |
94 | EXPORT_SYMBOL(dma_mark_declared_memory_occupied); | |
95 | ||
b6d4f7e3 | 96 | /** |
cb3952bf | 97 | * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area |
b6d4f7e3 DB |
98 | * |
99 | * @dev: device from which we allocate memory | |
100 | * @size: size of requested memory area | |
101 | * @dma_handle: This will be filled with the correct dma handle | |
102 | * @ret: This pointer will be filled with the virtual address | |
0609697e | 103 | * to allocated area. |
b6d4f7e3 | 104 | * |
cb3952bf | 105 | * This function should be only called from per-arch dma_alloc_coherent() |
b6d4f7e3 DB |
106 | * to support allocation from per-device coherent memory pools. |
107 | * | |
108 | * Returns 0 if dma_alloc_coherent should continue with allocating from | |
cb3952bf | 109 | * generic memory areas, or !0 if dma_alloc_coherent should return @ret. |
b6d4f7e3 | 110 | */ |
ee7e5516 DB |
111 | int dma_alloc_from_coherent(struct device *dev, ssize_t size, |
112 | dma_addr_t *dma_handle, void **ret) | |
113 | { | |
eccd83e1 | 114 | struct dma_coherent_mem *mem; |
ee7e5516 | 115 | int order = get_order(size); |
eccd83e1 | 116 | int pageno; |
ee7e5516 | 117 | |
eccd83e1 AM |
118 | if (!dev) |
119 | return 0; | |
120 | mem = dev->dma_mem; | |
121 | if (!mem) | |
122 | return 0; | |
0609697e PM |
123 | |
124 | *ret = NULL; | |
125 | ||
cdf57cab | 126 | if (unlikely(size > (mem->size << PAGE_SHIFT))) |
0609697e | 127 | goto err; |
eccd83e1 AM |
128 | |
129 | pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); | |
0609697e PM |
130 | if (unlikely(pageno < 0)) |
131 | goto err; | |
132 | ||
133 | /* | |
134 | * Memory was found in the per-device area. | |
135 | */ | |
136 | *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); | |
137 | *ret = mem->virt_base + (pageno << PAGE_SHIFT); | |
138 | memset(*ret, 0, size); | |
139 | ||
eccd83e1 | 140 | return 1; |
0609697e PM |
141 | |
142 | err: | |
143 | /* | |
144 | * In the case where the allocation can not be satisfied from the | |
145 | * per-device area, try to fall back to generic memory if the | |
146 | * constraints allow it. | |
147 | */ | |
148 | return mem->flags & DMA_MEMORY_EXCLUSIVE; | |
ee7e5516 | 149 | } |
a38409fb | 150 | EXPORT_SYMBOL(dma_alloc_from_coherent); |
ee7e5516 | 151 | |
b6d4f7e3 | 152 | /** |
cb3952bf | 153 | * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool |
b6d4f7e3 DB |
154 | * @dev: device from which the memory was allocated |
155 | * @order: the order of pages allocated | |
156 | * @vaddr: virtual address of allocated pages | |
157 | * | |
158 | * This checks whether the memory was allocated from the per-device | |
159 | * coherent memory pool and if so, releases that memory. | |
160 | * | |
161 | * Returns 1 if we correctly released the memory, or 0 if | |
cb3952bf | 162 | * dma_release_coherent() should proceed with releasing memory from |
b6d4f7e3 DB |
163 | * generic pools. |
164 | */ | |
ee7e5516 DB |
165 | int dma_release_from_coherent(struct device *dev, int order, void *vaddr) |
166 | { | |
167 | struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; | |
168 | ||
169 | if (mem && vaddr >= mem->virt_base && vaddr < | |
170 | (mem->virt_base + (mem->size << PAGE_SHIFT))) { | |
171 | int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; | |
172 | ||
173 | bitmap_release_region(mem->bitmap, page, order); | |
174 | return 1; | |
175 | } | |
176 | return 0; | |
177 | } | |
a38409fb | 178 | EXPORT_SYMBOL(dma_release_from_coherent); |