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11#include <linux/mm.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/mempool.h>
15#include <linux/blkdev.h>
16#include <linux/writeback.h>
17
18static void add_element(mempool_t *pool, void *element)
19{
20 BUG_ON(pool->curr_nr >= pool->min_nr);
21 pool->elements[pool->curr_nr++] = element;
22}
23
24static void *remove_element(mempool_t *pool)
25{
26 BUG_ON(pool->curr_nr <= 0);
27 return pool->elements[--pool->curr_nr];
28}
29
30static void free_pool(mempool_t *pool)
31{
32 while (pool->curr_nr) {
33 void *element = remove_element(pool);
34 pool->free(element, pool->pool_data);
35 }
36 kfree(pool->elements);
37 kfree(pool);
38}
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54mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
55 mempool_free_t *free_fn, void *pool_data)
56{
57 return mempool_create_node(min_nr,alloc_fn,free_fn, pool_data,-1);
58}
59EXPORT_SYMBOL(mempool_create);
60
61mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
62 mempool_free_t *free_fn, void *pool_data, int node_id)
63{
64 mempool_t *pool;
65 pool = kmalloc_node(sizeof(*pool), GFP_KERNEL | __GFP_ZERO, node_id);
66 if (!pool)
67 return NULL;
68 pool->elements = kmalloc_node(min_nr * sizeof(void *),
69 GFP_KERNEL, node_id);
70 if (!pool->elements) {
71 kfree(pool);
72 return NULL;
73 }
74 spin_lock_init(&pool->lock);
75 pool->min_nr = min_nr;
76 pool->pool_data = pool_data;
77 init_waitqueue_head(&pool->wait);
78 pool->alloc = alloc_fn;
79 pool->free = free_fn;
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83
84 while (pool->curr_nr < pool->min_nr) {
85 void *element;
86
87 element = pool->alloc(GFP_KERNEL, pool->pool_data);
88 if (unlikely(!element)) {
89 free_pool(pool);
90 return NULL;
91 }
92 add_element(pool, element);
93 }
94 return pool;
95}
96EXPORT_SYMBOL(mempool_create_node);
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114int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask)
115{
116 void *element;
117 void **new_elements;
118 unsigned long flags;
119
120 BUG_ON(new_min_nr <= 0);
121
122 spin_lock_irqsave(&pool->lock, flags);
123 if (new_min_nr <= pool->min_nr) {
124 while (new_min_nr < pool->curr_nr) {
125 element = remove_element(pool);
126 spin_unlock_irqrestore(&pool->lock, flags);
127 pool->free(element, pool->pool_data);
128 spin_lock_irqsave(&pool->lock, flags);
129 }
130 pool->min_nr = new_min_nr;
131 goto out_unlock;
132 }
133 spin_unlock_irqrestore(&pool->lock, flags);
134
135
136 new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
137 if (!new_elements)
138 return -ENOMEM;
139
140 spin_lock_irqsave(&pool->lock, flags);
141 if (unlikely(new_min_nr <= pool->min_nr)) {
142
143 spin_unlock_irqrestore(&pool->lock, flags);
144 kfree(new_elements);
145 goto out;
146 }
147 memcpy(new_elements, pool->elements,
148 pool->curr_nr * sizeof(*new_elements));
149 kfree(pool->elements);
150 pool->elements = new_elements;
151 pool->min_nr = new_min_nr;
152
153 while (pool->curr_nr < pool->min_nr) {
154 spin_unlock_irqrestore(&pool->lock, flags);
155 element = pool->alloc(gfp_mask, pool->pool_data);
156 if (!element)
157 goto out;
158 spin_lock_irqsave(&pool->lock, flags);
159 if (pool->curr_nr < pool->min_nr) {
160 add_element(pool, element);
161 } else {
162 spin_unlock_irqrestore(&pool->lock, flags);
163 pool->free(element, pool->pool_data);
164 goto out;
165 }
166 }
167out_unlock:
168 spin_unlock_irqrestore(&pool->lock, flags);
169out:
170 return 0;
171}
172EXPORT_SYMBOL(mempool_resize);
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183void mempool_destroy(mempool_t *pool)
184{
185
186 BUG_ON(pool->curr_nr != pool->min_nr);
187 free_pool(pool);
188}
189EXPORT_SYMBOL(mempool_destroy);
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202void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
203{
204 void *element;
205 unsigned long flags;
206 wait_queue_t wait;
207 gfp_t gfp_temp;
208
209 might_sleep_if(gfp_mask & __GFP_WAIT);
210
211 gfp_mask |= __GFP_NOMEMALLOC;
212 gfp_mask |= __GFP_NORETRY;
213 gfp_mask |= __GFP_NOWARN;
214
215 gfp_temp = gfp_mask & ~(__GFP_WAIT|__GFP_IO);
216
217repeat_alloc:
218
219 element = pool->alloc(gfp_temp, pool->pool_data);
220 if (likely(element != NULL))
221 return element;
222
223 spin_lock_irqsave(&pool->lock, flags);
224 if (likely(pool->curr_nr)) {
225 element = remove_element(pool);
226 spin_unlock_irqrestore(&pool->lock, flags);
227 return element;
228 }
229 spin_unlock_irqrestore(&pool->lock, flags);
230
231
232 if (!(gfp_mask & __GFP_WAIT))
233 return NULL;
234
235
236 gfp_temp = gfp_mask;
237 init_wait(&wait);
238 prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
239 smp_mb();
240 if (!pool->curr_nr) {
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244
245 io_schedule_timeout(5*HZ);
246 }
247 finish_wait(&pool->wait, &wait);
248
249 goto repeat_alloc;
250}
251EXPORT_SYMBOL(mempool_alloc);
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261void mempool_free(void *element, mempool_t *pool)
262{
263 unsigned long flags;
264
265 if (unlikely(element == NULL))
266 return;
267
268 smp_mb();
269 if (pool->curr_nr < pool->min_nr) {
270 spin_lock_irqsave(&pool->lock, flags);
271 if (pool->curr_nr < pool->min_nr) {
272 add_element(pool, element);
273 spin_unlock_irqrestore(&pool->lock, flags);
274 wake_up(&pool->wait);
275 return;
276 }
277 spin_unlock_irqrestore(&pool->lock, flags);
278 }
279 pool->free(element, pool->pool_data);
280}
281EXPORT_SYMBOL(mempool_free);
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286void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data)
287{
288 struct kmem_cache *mem = pool_data;
289 return kmem_cache_alloc(mem, gfp_mask);
290}
291EXPORT_SYMBOL(mempool_alloc_slab);
292
293void mempool_free_slab(void *element, void *pool_data)
294{
295 struct kmem_cache *mem = pool_data;
296 kmem_cache_free(mem, element);
297}
298EXPORT_SYMBOL(mempool_free_slab);
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304void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
305{
306 size_t size = (size_t)pool_data;
307 return kmalloc(size, gfp_mask);
308}
309EXPORT_SYMBOL(mempool_kmalloc);
310
311void mempool_kfree(void *element, void *pool_data)
312{
313 kfree(element);
314}
315EXPORT_SYMBOL(mempool_kfree);
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321void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data)
322{
323 int order = (int)(long)pool_data;
324 return alloc_pages(gfp_mask, order);
325}
326EXPORT_SYMBOL(mempool_alloc_pages);
327
328void mempool_free_pages(void *element, void *pool_data)
329{
330 int order = (int)(long)pool_data;
331 __free_pages(element, order);
332}
333EXPORT_SYMBOL(mempool_free_pages);
334