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Rev | Author | Line No. | Line |
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1616 | serge | 1 | /* |
2 | * DMA Pool allocator |
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3 | * |
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4 | * Copyright 2001 David Brownell |
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5 | * Copyright 2007 Intel Corporation |
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6 | * Author: Matthew Wilcox |
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7 | * |
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8 | * This software may be redistributed and/or modified under the terms of |
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9 | * the GNU General Public License ("GPL") version 2 as published by the |
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10 | * Free Software Foundation. |
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11 | * |
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12 | * This allocator returns small blocks of a given size which are DMA-able by |
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13 | * the given device. It uses the dma_alloc_coherent page allocator to get |
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14 | * new pages, then splits them up into blocks of the required size. |
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15 | * Many older drivers still have their own code to do this. |
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16 | * |
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17 | * The current design of this allocator is fairly simple. The pool is |
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18 | * represented by the 'struct dma_pool' which keeps a doubly-linked list of |
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19 | * allocated pages. Each page in the page_list is split into blocks of at |
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20 | * least 'size' bytes. Free blocks are tracked in an unsorted singly-linked |
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21 | * list of free blocks within the page. Used blocks aren't tracked, but we |
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22 | * keep a count of how many are currently allocated from each page. |
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23 | */ |
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24 | |||
6295 | serge | 25 | #include |
26 | #include |
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27 | #include |
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28 | #include |
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6934 | serge | 29 | #include |
6295 | serge | 30 | #include |
1616 | serge | 31 | |
5270 | serge | 32 | #include |
6295 | serge | 33 | #include |
6934 | serge | 34 | #include |
6295 | serge | 35 | #include |
6934 | serge | 36 | #include |
6295 | serge | 37 | |
1616 | serge | 38 | #include |
39 | #include |
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40 | |||
41 | |||
42 | struct dma_pool { /* the pool */ |
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43 | struct list_head page_list; |
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6295 | serge | 44 | spinlock_t lock; |
45 | size_t size; |
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46 | struct device *dev; |
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1616 | serge | 47 | size_t allocation; |
48 | size_t boundary; |
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6295 | serge | 49 | char name[32]; |
1616 | serge | 50 | struct list_head pools; |
51 | }; |
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52 | |||
53 | struct dma_page { /* cacheable header for 'allocation' bytes */ |
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54 | struct list_head page_list; |
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55 | void *vaddr; |
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56 | dma_addr_t dma; |
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57 | unsigned int in_use; |
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58 | unsigned int offset; |
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59 | }; |
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60 | |||
61 | static DEFINE_MUTEX(pools_lock); |
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6295 | serge | 62 | static DEFINE_MUTEX(pools_reg_lock); |
1616 | serge | 63 | |
64 | |||
6295 | serge | 65 | |
66 | |||
1616 | serge | 67 | /** |
68 | * dma_pool_create - Creates a pool of consistent memory blocks, for dma. |
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69 | * @name: name of pool, for diagnostics |
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70 | * @dev: device that will be doing the DMA |
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71 | * @size: size of the blocks in this pool. |
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72 | * @align: alignment requirement for blocks; must be a power of two |
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73 | * @boundary: returned blocks won't cross this power of two boundary |
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74 | * Context: !in_interrupt() |
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75 | * |
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76 | * Returns a dma allocation pool with the requested characteristics, or |
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77 | * null if one can't be created. Given one of these pools, dma_pool_alloc() |
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78 | * may be used to allocate memory. Such memory will all have "consistent" |
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79 | * DMA mappings, accessible by the device and its driver without using |
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80 | * cache flushing primitives. The actual size of blocks allocated may be |
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81 | * larger than requested because of alignment. |
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82 | * |
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83 | * If @boundary is nonzero, objects returned from dma_pool_alloc() won't |
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84 | * cross that size boundary. This is useful for devices which have |
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85 | * addressing restrictions on individual DMA transfers, such as not crossing |
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86 | * boundaries of 4KBytes. |
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87 | */ |
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88 | struct dma_pool *dma_pool_create(const char *name, struct device *dev, |
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6295 | serge | 89 | size_t size, size_t align, size_t boundary) |
1616 | serge | 90 | { |
6295 | serge | 91 | struct dma_pool *retval; |
92 | size_t allocation; |
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93 | bool empty = false; |
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1616 | serge | 94 | |
6295 | serge | 95 | if (align == 0) |
96 | align = 1; |
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97 | else if (align & (align - 1)) |
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98 | return NULL; |
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1616 | serge | 99 | |
6295 | serge | 100 | if (size == 0) |
101 | return NULL; |
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102 | else if (size < 4) |
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103 | size = 4; |
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1616 | serge | 104 | |
6295 | serge | 105 | if ((size % align) != 0) |
106 | size = ALIGN(size, align); |
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1616 | serge | 107 | |
6295 | serge | 108 | allocation = max_t(size_t, size, PAGE_SIZE); |
1616 | serge | 109 | |
110 | allocation = (allocation+0x7FFF) & ~0x7FFF; |
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111 | |||
6295 | serge | 112 | if (!boundary) |
113 | boundary = allocation; |
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114 | else if ((boundary < size) || (boundary & (boundary - 1))) |
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115 | return NULL; |
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1616 | serge | 116 | |
117 | retval = kmalloc(sizeof(*retval), GFP_KERNEL); |
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118 | |||
119 | if (!retval) |
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120 | return retval; |
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121 | |||
6295 | serge | 122 | strlcpy(retval->name, name, sizeof(retval->name)); |
1616 | serge | 123 | |
6295 | serge | 124 | retval->dev = dev; |
1616 | serge | 125 | |
6295 | serge | 126 | INIT_LIST_HEAD(&retval->page_list); |
127 | spin_lock_init(&retval->lock); |
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1616 | serge | 128 | retval->size = size; |
129 | retval->boundary = boundary; |
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130 | retval->allocation = allocation; |
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131 | |||
132 | INIT_LIST_HEAD(&retval->pools); |
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133 | |||
134 | return retval; |
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135 | } |
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136 | |||
137 | static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page) |
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138 | { |
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139 | unsigned int offset = 0; |
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140 | unsigned int next_boundary = pool->boundary; |
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141 | |||
142 | do { |
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143 | unsigned int next = offset + pool->size; |
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144 | if (unlikely((next + pool->size) >= next_boundary)) { |
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145 | next = next_boundary; |
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146 | next_boundary += pool->boundary; |
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147 | } |
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148 | *(int *)(page->vaddr + offset) = next; |
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149 | offset = next; |
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150 | } while (offset < pool->allocation); |
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151 | } |
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152 | |||
6295 | serge | 153 | static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags) |
1616 | serge | 154 | { |
155 | struct dma_page *page; |
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156 | |||
6295 | serge | 157 | page = kmalloc(sizeof(*page), mem_flags); |
158 | if (!page) |
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159 | return NULL; |
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1616 | serge | 160 | page->vaddr = (void*)KernelAlloc(pool->allocation); |
161 | |||
162 | dbgprintf("%s 0x%0x ",__FUNCTION__, page->vaddr); |
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163 | |||
6295 | serge | 164 | if (page->vaddr) { |
165 | #ifdef DMAPOOL_DEBUG |
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166 | memset(page->vaddr, POOL_POISON_FREED, pool->allocation); |
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167 | #endif |
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168 | |||
1616 | serge | 169 | page->dma = GetPgAddr(page->vaddr); |
170 | |||
171 | dbgprintf("dma 0x%0x\n", page->dma); |
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172 | |||
173 | pool_initialise_page(pool, page); |
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174 | page->in_use = 0; |
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175 | page->offset = 0; |
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176 | } else { |
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6295 | serge | 177 | kfree(page); |
1616 | serge | 178 | page = NULL; |
179 | } |
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180 | return page; |
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181 | } |
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182 | |||
6295 | serge | 183 | static inline bool is_page_busy(struct dma_page *page) |
1616 | serge | 184 | { |
6295 | serge | 185 | return page->in_use != 0; |
1616 | serge | 186 | } |
187 | |||
188 | static void pool_free_page(struct dma_pool *pool, struct dma_page *page) |
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189 | { |
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6295 | serge | 190 | dma_addr_t dma = page->dma; |
1616 | serge | 191 | |
6295 | serge | 192 | #ifdef DMAPOOL_DEBUG |
193 | memset(page->vaddr, POOL_POISON_FREED, pool->allocation); |
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194 | #endif |
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195 | |||
1616 | serge | 196 | KernelFree(page->vaddr); |
6295 | serge | 197 | list_del(&page->page_list); |
198 | kfree(page); |
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1616 | serge | 199 | } |
200 | |||
201 | /** |
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202 | * dma_pool_destroy - destroys a pool of dma memory blocks. |
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203 | * @pool: dma pool that will be destroyed |
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204 | * Context: !in_interrupt() |
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205 | * |
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206 | * Caller guarantees that no more memory from the pool is in use, |
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207 | * and that nothing will try to use the pool after this call. |
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208 | */ |
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209 | void dma_pool_destroy(struct dma_pool *pool) |
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210 | { |
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6295 | serge | 211 | bool empty = false; |
212 | |||
213 | if (unlikely(!pool)) |
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214 | return; |
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215 | |||
216 | mutex_lock(&pools_reg_lock); |
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1616 | serge | 217 | mutex_lock(&pools_lock); |
218 | list_del(&pool->pools); |
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219 | mutex_unlock(&pools_lock); |
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220 | |||
6295 | serge | 221 | mutex_unlock(&pools_reg_lock); |
222 | |||
1616 | serge | 223 | while (!list_empty(&pool->page_list)) { |
224 | struct dma_page *page; |
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225 | page = list_entry(pool->page_list.next, |
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226 | struct dma_page, page_list); |
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6295 | serge | 227 | if (is_page_busy(page)) { |
1616 | serge | 228 | printk(KERN_ERR "dma_pool_destroy %p busy\n", |
229 | page->vaddr); |
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230 | /* leak the still-in-use consistent memory */ |
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231 | list_del(&page->page_list); |
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232 | kfree(page); |
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233 | } else |
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234 | pool_free_page(pool, page); |
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235 | } |
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236 | |||
237 | kfree(pool); |
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238 | } |
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6295 | serge | 239 | EXPORT_SYMBOL(dma_pool_destroy); |
1616 | serge | 240 | |
241 | /** |
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242 | * dma_pool_alloc - get a block of consistent memory |
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243 | * @pool: dma pool that will produce the block |
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244 | * @mem_flags: GFP_* bitmask |
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245 | * @handle: pointer to dma address of block |
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246 | * |
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247 | * This returns the kernel virtual address of a currently unused block, |
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248 | * and reports its dma address through the handle. |
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249 | * If such a memory block can't be allocated, %NULL is returned. |
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250 | */ |
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251 | void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, |
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252 | dma_addr_t *handle) |
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253 | { |
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6295 | serge | 254 | unsigned long flags; |
1616 | serge | 255 | struct dma_page *page; |
256 | size_t offset; |
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257 | void *retval; |
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258 | |||
6295 | serge | 259 | |
260 | spin_lock_irqsave(&pool->lock, flags); |
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1616 | serge | 261 | list_for_each_entry(page, &pool->page_list, page_list) { |
262 | if (page->offset < pool->allocation) |
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263 | goto ready; |
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264 | } |
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6295 | serge | 265 | |
266 | /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */ |
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267 | spin_unlock_irqrestore(&pool->lock, flags); |
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268 | |||
269 | page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO)); |
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1616 | serge | 270 | if (!page) |
6295 | serge | 271 | return NULL; |
1616 | serge | 272 | |
6295 | serge | 273 | spin_lock_irqsave(&pool->lock, flags); |
274 | |||
275 | list_add(&page->page_list, &pool->page_list); |
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1616 | serge | 276 | ready: |
6295 | serge | 277 | page->in_use++; |
1616 | serge | 278 | offset = page->offset; |
279 | page->offset = *(int *)(page->vaddr + offset); |
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280 | retval = offset + page->vaddr; |
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6295 | serge | 281 | *handle = offset + page->dma; |
282 | #ifdef DMAPOOL_DEBUG |
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283 | { |
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284 | int i; |
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285 | u8 *data = retval; |
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286 | /* page->offset is stored in first 4 bytes */ |
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287 | for (i = sizeof(page->offset); i < pool->size; i++) { |
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288 | if (data[i] == POOL_POISON_FREED) |
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289 | continue; |
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290 | if (pool->dev) |
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291 | dev_err(pool->dev, |
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292 | "dma_pool_alloc %s, %p (corrupted)\n", |
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293 | pool->name, retval); |
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294 | else |
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295 | pr_err("dma_pool_alloc %s, %p (corrupted)\n", |
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296 | pool->name, retval); |
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297 | |||
298 | /* |
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299 | * Dump the first 4 bytes even if they are not |
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300 | * POOL_POISON_FREED |
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301 | */ |
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302 | print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, |
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303 | data, pool->size, 1); |
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304 | break; |
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305 | } |
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306 | } |
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307 | if (!(mem_flags & __GFP_ZERO)) |
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308 | memset(retval, POOL_POISON_ALLOCATED, pool->size); |
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309 | #endif |
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310 | spin_unlock_irqrestore(&pool->lock, flags); |
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311 | |||
312 | if (mem_flags & __GFP_ZERO) |
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313 | memset(retval, 0, pool->size); |
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314 | |||
1616 | serge | 315 | return retval; |
316 | } |
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6295 | serge | 317 | EXPORT_SYMBOL(dma_pool_alloc); |
1616 | serge | 318 | |
319 | static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma) |
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320 | { |
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321 | struct dma_page *page; |
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322 | |||
323 | list_for_each_entry(page, &pool->page_list, page_list) { |
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324 | if (dma < page->dma) |
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325 | continue; |
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6295 | serge | 326 | if ((dma - page->dma) < pool->allocation) |
327 | return page; |
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1616 | serge | 328 | } |
6295 | serge | 329 | return NULL; |
1616 | serge | 330 | } |
331 | |||
332 | /** |
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333 | * dma_pool_free - put block back into dma pool |
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334 | * @pool: the dma pool holding the block |
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335 | * @vaddr: virtual address of block |
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336 | * @dma: dma address of block |
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337 | * |
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338 | * Caller promises neither device nor driver will again touch this block |
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339 | * unless it is first re-allocated. |
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340 | */ |
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341 | void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) |
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342 | { |
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343 | struct dma_page *page; |
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344 | unsigned long flags; |
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345 | unsigned int offset; |
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346 | |||
6295 | serge | 347 | spin_lock_irqsave(&pool->lock, flags); |
1616 | serge | 348 | page = pool_find_page(pool, dma); |
349 | if (!page) { |
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6295 | serge | 350 | spin_unlock_irqrestore(&pool->lock, flags); |
351 | printk(KERN_ERR "dma_pool_free %s, %p/%lx (bad dma)\n", |
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352 | pool->name, vaddr, (unsigned long)dma); |
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1616 | serge | 353 | return; |
354 | } |
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355 | |||
356 | offset = vaddr - page->vaddr; |
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6295 | serge | 357 | #ifdef DMAPOOL_DEBUG |
358 | if ((dma - page->dma) != offset) { |
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359 | spin_unlock_irqrestore(&pool->lock, flags); |
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360 | if (pool->dev) |
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361 | dev_err(pool->dev, |
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362 | "dma_pool_free %s, %p (bad vaddr)/%Lx\n", |
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363 | pool->name, vaddr, (unsigned long long)dma); |
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364 | else |
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365 | printk(KERN_ERR |
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366 | "dma_pool_free %s, %p (bad vaddr)/%Lx\n", |
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367 | pool->name, vaddr, (unsigned long long)dma); |
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368 | return; |
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369 | } |
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370 | { |
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371 | unsigned int chain = page->offset; |
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372 | while (chain < pool->allocation) { |
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373 | if (chain != offset) { |
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374 | chain = *(int *)(page->vaddr + chain); |
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375 | continue; |
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376 | } |
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377 | spin_unlock_irqrestore(&pool->lock, flags); |
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378 | if (pool->dev) |
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379 | dev_err(pool->dev, "dma_pool_free %s, dma %Lx " |
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380 | "already free\n", pool->name, |
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381 | (unsigned long long)dma); |
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382 | else |
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383 | printk(KERN_ERR "dma_pool_free %s, dma %Lx " |
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384 | "already free\n", pool->name, |
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385 | (unsigned long long)dma); |
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386 | return; |
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387 | } |
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388 | } |
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389 | memset(vaddr, POOL_POISON_FREED, pool->size); |
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390 | #endif |
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1616 | serge | 391 | |
6295 | serge | 392 | page->in_use--; |
393 | *(int *)vaddr = page->offset; |
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394 | page->offset = offset; |
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1616 | serge | 395 | /* |
396 | * Resist a temptation to do |
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397 | * if (!is_page_busy(page)) pool_free_page(pool, page); |
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398 | * Better have a few empty pages hang around. |
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399 | */ |
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6295 | serge | 400 | spin_unlock_irqrestore(&pool->lock, flags); |
1616 | serge | 401 | } |
6295 | serge | 402 | EXPORT_SYMBOL(dma_pool_free); |
1616 | serge | 403 | |
6295 | serge | 404 | /* |
405 | * Managed DMA pool |
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406 | */ |
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407 | static void dmam_pool_release(struct device *dev, void *res) |
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408 | { |
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409 | struct dma_pool *pool = *(struct dma_pool **)res; |
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410 | |||
411 | dma_pool_destroy(pool); |
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412 | } |
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413 | |||
414 | static int dmam_pool_match(struct device *dev, void *res, void *match_data) |
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415 | { |
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416 | return *(struct dma_pool **)res == match_data; |
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417 | }>>>>>>>> |
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418 |