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b2139ce0 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6182a094 MW |
2 | /* |
3 | * DMA Pool allocator | |
4 | * | |
5 | * Copyright 2001 David Brownell | |
6 | * Copyright 2007 Intel Corporation | |
7 | * Author: Matthew Wilcox <willy@linux.intel.com> | |
8 | * | |
6182a094 MW |
9 | * This allocator returns small blocks of a given size which are DMA-able by |
10 | * the given device. It uses the dma_alloc_coherent page allocator to get | |
11 | * new pages, then splits them up into blocks of the required size. | |
12 | * Many older drivers still have their own code to do this. | |
13 | * | |
14 | * The current design of this allocator is fairly simple. The pool is | |
15 | * represented by the 'struct dma_pool' which keeps a doubly-linked list of | |
16 | * allocated pages. Each page in the page_list is split into blocks of at | |
a35a3455 MW |
17 | * least 'size' bytes. Free blocks are tracked in an unsorted singly-linked |
18 | * list of free blocks within the page. Used blocks aren't tracked, but we | |
19 | * keep a count of how many are currently allocated from each page. | |
6182a094 | 20 | */ |
1da177e4 LT |
21 | |
22 | #include <linux/device.h> | |
1da177e4 LT |
23 | #include <linux/dma-mapping.h> |
24 | #include <linux/dmapool.h> | |
6182a094 MW |
25 | #include <linux/kernel.h> |
26 | #include <linux/list.h> | |
b95f1b31 | 27 | #include <linux/export.h> |
6182a094 | 28 | #include <linux/mutex.h> |
c9cf5528 | 29 | #include <linux/poison.h> |
e8edc6e0 | 30 | #include <linux/sched.h> |
0f2f89b6 | 31 | #include <linux/sched/mm.h> |
6182a094 | 32 | #include <linux/slab.h> |
7c77509c | 33 | #include <linux/stat.h> |
6182a094 MW |
34 | #include <linux/spinlock.h> |
35 | #include <linux/string.h> | |
36 | #include <linux/types.h> | |
37 | #include <linux/wait.h> | |
1da177e4 | 38 | |
b5ee5bef AK |
39 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON) |
40 | #define DMAPOOL_DEBUG 1 | |
41 | #endif | |
42 | ||
e87aa773 MW |
43 | struct dma_pool { /* the pool */ |
44 | struct list_head page_list; | |
45 | spinlock_t lock; | |
e87aa773 MW |
46 | size_t size; |
47 | struct device *dev; | |
48 | size_t allocation; | |
e34f44b3 | 49 | size_t boundary; |
e87aa773 | 50 | char name[32]; |
e87aa773 | 51 | struct list_head pools; |
1da177e4 LT |
52 | }; |
53 | ||
e87aa773 MW |
54 | struct dma_page { /* cacheable header for 'allocation' bytes */ |
55 | struct list_head page_list; | |
56 | void *vaddr; | |
57 | dma_addr_t dma; | |
a35a3455 MW |
58 | unsigned int in_use; |
59 | unsigned int offset; | |
1da177e4 LT |
60 | }; |
61 | ||
e87aa773 | 62 | static DEFINE_MUTEX(pools_lock); |
01c2965f | 63 | static DEFINE_MUTEX(pools_reg_lock); |
1da177e4 LT |
64 | |
65 | static ssize_t | |
e87aa773 | 66 | show_pools(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
67 | { |
68 | unsigned temp; | |
69 | unsigned size; | |
70 | char *next; | |
71 | struct dma_page *page; | |
72 | struct dma_pool *pool; | |
73 | ||
74 | next = buf; | |
75 | size = PAGE_SIZE; | |
76 | ||
77 | temp = scnprintf(next, size, "poolinfo - 0.1\n"); | |
78 | size -= temp; | |
79 | next += temp; | |
80 | ||
b2366d68 | 81 | mutex_lock(&pools_lock); |
1da177e4 LT |
82 | list_for_each_entry(pool, &dev->dma_pools, pools) { |
83 | unsigned pages = 0; | |
84 | unsigned blocks = 0; | |
85 | ||
c4956823 | 86 | spin_lock_irq(&pool->lock); |
1da177e4 LT |
87 | list_for_each_entry(page, &pool->page_list, page_list) { |
88 | pages++; | |
89 | blocks += page->in_use; | |
90 | } | |
c4956823 | 91 | spin_unlock_irq(&pool->lock); |
1da177e4 LT |
92 | |
93 | /* per-pool info, no real statistics yet */ | |
5b5e0928 | 94 | temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n", |
a35a3455 MW |
95 | pool->name, blocks, |
96 | pages * (pool->allocation / pool->size), | |
e87aa773 | 97 | pool->size, pages); |
1da177e4 LT |
98 | size -= temp; |
99 | next += temp; | |
100 | } | |
b2366d68 | 101 | mutex_unlock(&pools_lock); |
1da177e4 LT |
102 | |
103 | return PAGE_SIZE - size; | |
104 | } | |
e87aa773 | 105 | |
0825a6f9 | 106 | static DEVICE_ATTR(pools, 0444, show_pools, NULL); |
1da177e4 LT |
107 | |
108 | /** | |
109 | * dma_pool_create - Creates a pool of consistent memory blocks, for dma. | |
110 | * @name: name of pool, for diagnostics | |
111 | * @dev: device that will be doing the DMA | |
112 | * @size: size of the blocks in this pool. | |
113 | * @align: alignment requirement for blocks; must be a power of two | |
e34f44b3 | 114 | * @boundary: returned blocks won't cross this power of two boundary |
a862f68a | 115 | * Context: not in_interrupt() |
1da177e4 | 116 | * |
a862f68a | 117 | * Given one of these pools, dma_pool_alloc() |
1da177e4 LT |
118 | * may be used to allocate memory. Such memory will all have "consistent" |
119 | * DMA mappings, accessible by the device and its driver without using | |
120 | * cache flushing primitives. The actual size of blocks allocated may be | |
121 | * larger than requested because of alignment. | |
122 | * | |
e34f44b3 | 123 | * If @boundary is nonzero, objects returned from dma_pool_alloc() won't |
1da177e4 LT |
124 | * cross that size boundary. This is useful for devices which have |
125 | * addressing restrictions on individual DMA transfers, such as not crossing | |
126 | * boundaries of 4KBytes. | |
a862f68a MR |
127 | * |
128 | * Return: a dma allocation pool with the requested characteristics, or | |
129 | * %NULL if one can't be created. | |
1da177e4 | 130 | */ |
e87aa773 | 131 | struct dma_pool *dma_pool_create(const char *name, struct device *dev, |
e34f44b3 | 132 | size_t size, size_t align, size_t boundary) |
1da177e4 | 133 | { |
e87aa773 | 134 | struct dma_pool *retval; |
e34f44b3 | 135 | size_t allocation; |
01c2965f | 136 | bool empty = false; |
1da177e4 | 137 | |
baa2ef83 | 138 | if (align == 0) |
1da177e4 | 139 | align = 1; |
baa2ef83 | 140 | else if (align & (align - 1)) |
1da177e4 | 141 | return NULL; |
1da177e4 | 142 | |
baa2ef83 | 143 | if (size == 0) |
399154be | 144 | return NULL; |
baa2ef83 | 145 | else if (size < 4) |
a35a3455 | 146 | size = 4; |
399154be | 147 | |
1386f7a3 | 148 | size = ALIGN(size, align); |
e34f44b3 MW |
149 | allocation = max_t(size_t, size, PAGE_SIZE); |
150 | ||
baa2ef83 | 151 | if (!boundary) |
e34f44b3 | 152 | boundary = allocation; |
baa2ef83 | 153 | else if ((boundary < size) || (boundary & (boundary - 1))) |
1da177e4 LT |
154 | return NULL; |
155 | ||
e34f44b3 MW |
156 | retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev)); |
157 | if (!retval) | |
1da177e4 LT |
158 | return retval; |
159 | ||
e34f44b3 | 160 | strlcpy(retval->name, name, sizeof(retval->name)); |
1da177e4 LT |
161 | |
162 | retval->dev = dev; | |
163 | ||
e87aa773 MW |
164 | INIT_LIST_HEAD(&retval->page_list); |
165 | spin_lock_init(&retval->lock); | |
1da177e4 | 166 | retval->size = size; |
e34f44b3 | 167 | retval->boundary = boundary; |
1da177e4 | 168 | retval->allocation = allocation; |
1da177e4 | 169 | |
cc6b664a DY |
170 | INIT_LIST_HEAD(&retval->pools); |
171 | ||
01c2965f SAS |
172 | /* |
173 | * pools_lock ensures that the ->dma_pools list does not get corrupted. | |
174 | * pools_reg_lock ensures that there is not a race between | |
175 | * dma_pool_create() and dma_pool_destroy() or within dma_pool_create() | |
176 | * when the first invocation of dma_pool_create() failed on | |
177 | * device_create_file() and the second assumes that it has been done (I | |
178 | * know it is a short window). | |
179 | */ | |
180 | mutex_lock(&pools_reg_lock); | |
cc6b664a | 181 | mutex_lock(&pools_lock); |
01c2965f SAS |
182 | if (list_empty(&dev->dma_pools)) |
183 | empty = true; | |
184 | list_add(&retval->pools, &dev->dma_pools); | |
cc6b664a | 185 | mutex_unlock(&pools_lock); |
01c2965f SAS |
186 | if (empty) { |
187 | int err; | |
188 | ||
189 | err = device_create_file(dev, &dev_attr_pools); | |
190 | if (err) { | |
191 | mutex_lock(&pools_lock); | |
192 | list_del(&retval->pools); | |
193 | mutex_unlock(&pools_lock); | |
194 | mutex_unlock(&pools_reg_lock); | |
195 | kfree(retval); | |
196 | return NULL; | |
197 | } | |
198 | } | |
199 | mutex_unlock(&pools_reg_lock); | |
1da177e4 LT |
200 | return retval; |
201 | } | |
e87aa773 | 202 | EXPORT_SYMBOL(dma_pool_create); |
1da177e4 | 203 | |
a35a3455 MW |
204 | static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page) |
205 | { | |
206 | unsigned int offset = 0; | |
e34f44b3 | 207 | unsigned int next_boundary = pool->boundary; |
a35a3455 MW |
208 | |
209 | do { | |
210 | unsigned int next = offset + pool->size; | |
e34f44b3 MW |
211 | if (unlikely((next + pool->size) >= next_boundary)) { |
212 | next = next_boundary; | |
213 | next_boundary += pool->boundary; | |
214 | } | |
a35a3455 MW |
215 | *(int *)(page->vaddr + offset) = next; |
216 | offset = next; | |
217 | } while (offset < pool->allocation); | |
218 | } | |
219 | ||
e87aa773 | 220 | static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags) |
1da177e4 | 221 | { |
e87aa773 | 222 | struct dma_page *page; |
1da177e4 | 223 | |
a35a3455 | 224 | page = kmalloc(sizeof(*page), mem_flags); |
1da177e4 LT |
225 | if (!page) |
226 | return NULL; | |
a35a3455 | 227 | page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation, |
e87aa773 | 228 | &page->dma, mem_flags); |
1da177e4 | 229 | if (page->vaddr) { |
b5ee5bef | 230 | #ifdef DMAPOOL_DEBUG |
e87aa773 | 231 | memset(page->vaddr, POOL_POISON_FREED, pool->allocation); |
1da177e4 | 232 | #endif |
a35a3455 | 233 | pool_initialise_page(pool, page); |
1da177e4 | 234 | page->in_use = 0; |
a35a3455 | 235 | page->offset = 0; |
1da177e4 | 236 | } else { |
e87aa773 | 237 | kfree(page); |
1da177e4 LT |
238 | page = NULL; |
239 | } | |
240 | return page; | |
241 | } | |
242 | ||
d9e7e37b | 243 | static inline bool is_page_busy(struct dma_page *page) |
1da177e4 | 244 | { |
a35a3455 | 245 | return page->in_use != 0; |
1da177e4 LT |
246 | } |
247 | ||
e87aa773 | 248 | static void pool_free_page(struct dma_pool *pool, struct dma_page *page) |
1da177e4 | 249 | { |
e87aa773 | 250 | dma_addr_t dma = page->dma; |
1da177e4 | 251 | |
b5ee5bef | 252 | #ifdef DMAPOOL_DEBUG |
e87aa773 | 253 | memset(page->vaddr, POOL_POISON_FREED, pool->allocation); |
1da177e4 | 254 | #endif |
e87aa773 MW |
255 | dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma); |
256 | list_del(&page->page_list); | |
257 | kfree(page); | |
1da177e4 LT |
258 | } |
259 | ||
1da177e4 LT |
260 | /** |
261 | * dma_pool_destroy - destroys a pool of dma memory blocks. | |
262 | * @pool: dma pool that will be destroyed | |
263 | * Context: !in_interrupt() | |
264 | * | |
265 | * Caller guarantees that no more memory from the pool is in use, | |
266 | * and that nothing will try to use the pool after this call. | |
267 | */ | |
e87aa773 | 268 | void dma_pool_destroy(struct dma_pool *pool) |
1da177e4 | 269 | { |
42286f83 | 270 | struct dma_page *page, *tmp; |
01c2965f SAS |
271 | bool empty = false; |
272 | ||
44d7175d SS |
273 | if (unlikely(!pool)) |
274 | return; | |
275 | ||
01c2965f | 276 | mutex_lock(&pools_reg_lock); |
b2366d68 | 277 | mutex_lock(&pools_lock); |
e87aa773 MW |
278 | list_del(&pool->pools); |
279 | if (pool->dev && list_empty(&pool->dev->dma_pools)) | |
01c2965f | 280 | empty = true; |
b2366d68 | 281 | mutex_unlock(&pools_lock); |
01c2965f SAS |
282 | if (empty) |
283 | device_remove_file(pool->dev, &dev_attr_pools); | |
284 | mutex_unlock(&pools_reg_lock); | |
1da177e4 | 285 | |
42286f83 | 286 | list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) { |
a35a3455 | 287 | if (is_page_busy(page)) { |
1da177e4 | 288 | if (pool->dev) |
41a04814 | 289 | dev_err(pool->dev, "%s %s, %p busy\n", __func__, |
1da177e4 LT |
290 | pool->name, page->vaddr); |
291 | else | |
41a04814 | 292 | pr_err("%s %s, %p busy\n", __func__, |
e87aa773 | 293 | pool->name, page->vaddr); |
1da177e4 | 294 | /* leak the still-in-use consistent memory */ |
e87aa773 MW |
295 | list_del(&page->page_list); |
296 | kfree(page); | |
1da177e4 | 297 | } else |
e87aa773 | 298 | pool_free_page(pool, page); |
1da177e4 LT |
299 | } |
300 | ||
e87aa773 | 301 | kfree(pool); |
1da177e4 | 302 | } |
e87aa773 | 303 | EXPORT_SYMBOL(dma_pool_destroy); |
1da177e4 LT |
304 | |
305 | /** | |
306 | * dma_pool_alloc - get a block of consistent memory | |
307 | * @pool: dma pool that will produce the block | |
308 | * @mem_flags: GFP_* bitmask | |
309 | * @handle: pointer to dma address of block | |
310 | * | |
a862f68a | 311 | * Return: the kernel virtual address of a currently unused block, |
1da177e4 | 312 | * and reports its dma address through the handle. |
6182a094 | 313 | * If such a memory block can't be allocated, %NULL is returned. |
1da177e4 | 314 | */ |
e87aa773 MW |
315 | void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, |
316 | dma_addr_t *handle) | |
1da177e4 | 317 | { |
e87aa773 MW |
318 | unsigned long flags; |
319 | struct dma_page *page; | |
e87aa773 MW |
320 | size_t offset; |
321 | void *retval; | |
322 | ||
0f2f89b6 | 323 | might_alloc(mem_flags); |
ea05c844 | 324 | |
e87aa773 | 325 | spin_lock_irqsave(&pool->lock, flags); |
1da177e4 | 326 | list_for_each_entry(page, &pool->page_list, page_list) { |
a35a3455 MW |
327 | if (page->offset < pool->allocation) |
328 | goto ready; | |
1da177e4 | 329 | } |
1da177e4 | 330 | |
387870f2 MS |
331 | /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */ |
332 | spin_unlock_irqrestore(&pool->lock, flags); | |
1da177e4 | 333 | |
fa23f56d | 334 | page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO)); |
387870f2 MS |
335 | if (!page) |
336 | return NULL; | |
1da177e4 | 337 | |
387870f2 | 338 | spin_lock_irqsave(&pool->lock, flags); |
1da177e4 | 339 | |
387870f2 | 340 | list_add(&page->page_list, &pool->page_list); |
e87aa773 | 341 | ready: |
1da177e4 | 342 | page->in_use++; |
a35a3455 MW |
343 | offset = page->offset; |
344 | page->offset = *(int *)(page->vaddr + offset); | |
1da177e4 LT |
345 | retval = offset + page->vaddr; |
346 | *handle = offset + page->dma; | |
b5ee5bef | 347 | #ifdef DMAPOOL_DEBUG |
5de55b26 MC |
348 | { |
349 | int i; | |
350 | u8 *data = retval; | |
351 | /* page->offset is stored in first 4 bytes */ | |
352 | for (i = sizeof(page->offset); i < pool->size; i++) { | |
353 | if (data[i] == POOL_POISON_FREED) | |
354 | continue; | |
355 | if (pool->dev) | |
41a04814 AS |
356 | dev_err(pool->dev, "%s %s, %p (corrupted)\n", |
357 | __func__, pool->name, retval); | |
5de55b26 | 358 | else |
41a04814 AS |
359 | pr_err("%s %s, %p (corrupted)\n", |
360 | __func__, pool->name, retval); | |
5de55b26 MC |
361 | |
362 | /* | |
363 | * Dump the first 4 bytes even if they are not | |
364 | * POOL_POISON_FREED | |
365 | */ | |
366 | print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, | |
367 | data, pool->size, 1); | |
368 | break; | |
369 | } | |
370 | } | |
fa23f56d SS |
371 | if (!(mem_flags & __GFP_ZERO)) |
372 | memset(retval, POOL_POISON_ALLOCATED, pool->size); | |
1da177e4 | 373 | #endif |
e87aa773 | 374 | spin_unlock_irqrestore(&pool->lock, flags); |
fa23f56d | 375 | |
6471384a | 376 | if (want_init_on_alloc(mem_flags)) |
fa23f56d SS |
377 | memset(retval, 0, pool->size); |
378 | ||
1da177e4 LT |
379 | return retval; |
380 | } | |
e87aa773 | 381 | EXPORT_SYMBOL(dma_pool_alloc); |
1da177e4 | 382 | |
e87aa773 | 383 | static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma) |
1da177e4 | 384 | { |
e87aa773 | 385 | struct dma_page *page; |
1da177e4 | 386 | |
1da177e4 LT |
387 | list_for_each_entry(page, &pool->page_list, page_list) { |
388 | if (dma < page->dma) | |
389 | continue; | |
676bd991 | 390 | if ((dma - page->dma) < pool->allocation) |
84bc227d | 391 | return page; |
1da177e4 | 392 | } |
84bc227d | 393 | return NULL; |
1da177e4 LT |
394 | } |
395 | ||
1da177e4 LT |
396 | /** |
397 | * dma_pool_free - put block back into dma pool | |
398 | * @pool: the dma pool holding the block | |
399 | * @vaddr: virtual address of block | |
400 | * @dma: dma address of block | |
401 | * | |
402 | * Caller promises neither device nor driver will again touch this block | |
403 | * unless it is first re-allocated. | |
404 | */ | |
e87aa773 | 405 | void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) |
1da177e4 | 406 | { |
e87aa773 MW |
407 | struct dma_page *page; |
408 | unsigned long flags; | |
a35a3455 | 409 | unsigned int offset; |
1da177e4 | 410 | |
84bc227d | 411 | spin_lock_irqsave(&pool->lock, flags); |
e87aa773 MW |
412 | page = pool_find_page(pool, dma); |
413 | if (!page) { | |
84bc227d | 414 | spin_unlock_irqrestore(&pool->lock, flags); |
1da177e4 | 415 | if (pool->dev) |
41a04814 AS |
416 | dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n", |
417 | __func__, pool->name, vaddr, &dma); | |
1da177e4 | 418 | else |
41a04814 AS |
419 | pr_err("%s %s, %p/%pad (bad dma)\n", |
420 | __func__, pool->name, vaddr, &dma); | |
1da177e4 LT |
421 | return; |
422 | } | |
423 | ||
a35a3455 | 424 | offset = vaddr - page->vaddr; |
6471384a AP |
425 | if (want_init_on_free()) |
426 | memset(vaddr, 0, pool->size); | |
b5ee5bef | 427 | #ifdef DMAPOOL_DEBUG |
a35a3455 | 428 | if ((dma - page->dma) != offset) { |
84bc227d | 429 | spin_unlock_irqrestore(&pool->lock, flags); |
1da177e4 | 430 | if (pool->dev) |
41a04814 AS |
431 | dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n", |
432 | __func__, pool->name, vaddr, &dma); | |
1da177e4 | 433 | else |
41a04814 AS |
434 | pr_err("%s %s, %p (bad vaddr)/%pad\n", |
435 | __func__, pool->name, vaddr, &dma); | |
1da177e4 LT |
436 | return; |
437 | } | |
a35a3455 MW |
438 | { |
439 | unsigned int chain = page->offset; | |
440 | while (chain < pool->allocation) { | |
441 | if (chain != offset) { | |
442 | chain = *(int *)(page->vaddr + chain); | |
443 | continue; | |
444 | } | |
84bc227d | 445 | spin_unlock_irqrestore(&pool->lock, flags); |
a35a3455 | 446 | if (pool->dev) |
41a04814 AS |
447 | dev_err(pool->dev, "%s %s, dma %pad already free\n", |
448 | __func__, pool->name, &dma); | |
a35a3455 | 449 | else |
41a04814 AS |
450 | pr_err("%s %s, dma %pad already free\n", |
451 | __func__, pool->name, &dma); | |
a35a3455 MW |
452 | return; |
453 | } | |
1da177e4 | 454 | } |
e87aa773 | 455 | memset(vaddr, POOL_POISON_FREED, pool->size); |
1da177e4 LT |
456 | #endif |
457 | ||
1da177e4 | 458 | page->in_use--; |
a35a3455 MW |
459 | *(int *)vaddr = page->offset; |
460 | page->offset = offset; | |
1da177e4 LT |
461 | /* |
462 | * Resist a temptation to do | |
a35a3455 | 463 | * if (!is_page_busy(page)) pool_free_page(pool, page); |
1da177e4 LT |
464 | * Better have a few empty pages hang around. |
465 | */ | |
e87aa773 | 466 | spin_unlock_irqrestore(&pool->lock, flags); |
1da177e4 | 467 | } |
e87aa773 | 468 | EXPORT_SYMBOL(dma_pool_free); |
1da177e4 | 469 | |
9ac7849e TH |
470 | /* |
471 | * Managed DMA pool | |
472 | */ | |
473 | static void dmam_pool_release(struct device *dev, void *res) | |
474 | { | |
475 | struct dma_pool *pool = *(struct dma_pool **)res; | |
476 | ||
477 | dma_pool_destroy(pool); | |
478 | } | |
479 | ||
480 | static int dmam_pool_match(struct device *dev, void *res, void *match_data) | |
481 | { | |
482 | return *(struct dma_pool **)res == match_data; | |
483 | } | |
484 | ||
485 | /** | |
486 | * dmam_pool_create - Managed dma_pool_create() | |
487 | * @name: name of pool, for diagnostics | |
488 | * @dev: device that will be doing the DMA | |
489 | * @size: size of the blocks in this pool. | |
490 | * @align: alignment requirement for blocks; must be a power of two | |
491 | * @allocation: returned blocks won't cross this boundary (or zero) | |
492 | * | |
493 | * Managed dma_pool_create(). DMA pool created with this function is | |
494 | * automatically destroyed on driver detach. | |
a862f68a MR |
495 | * |
496 | * Return: a managed dma allocation pool with the requested | |
497 | * characteristics, or %NULL if one can't be created. | |
9ac7849e TH |
498 | */ |
499 | struct dma_pool *dmam_pool_create(const char *name, struct device *dev, | |
500 | size_t size, size_t align, size_t allocation) | |
501 | { | |
502 | struct dma_pool **ptr, *pool; | |
503 | ||
504 | ptr = devres_alloc(dmam_pool_release, sizeof(*ptr), GFP_KERNEL); | |
505 | if (!ptr) | |
506 | return NULL; | |
507 | ||
508 | pool = *ptr = dma_pool_create(name, dev, size, align, allocation); | |
509 | if (pool) | |
510 | devres_add(dev, ptr); | |
511 | else | |
512 | devres_free(ptr); | |
513 | ||
514 | return pool; | |
515 | } | |
e87aa773 | 516 | EXPORT_SYMBOL(dmam_pool_create); |
9ac7849e TH |
517 | |
518 | /** | |
519 | * dmam_pool_destroy - Managed dma_pool_destroy() | |
520 | * @pool: dma pool that will be destroyed | |
521 | * | |
522 | * Managed dma_pool_destroy(). | |
523 | */ | |
524 | void dmam_pool_destroy(struct dma_pool *pool) | |
525 | { | |
526 | struct device *dev = pool->dev; | |
527 | ||
172cb4b3 | 528 | WARN_ON(devres_release(dev, dmam_pool_release, dmam_pool_match, pool)); |
9ac7849e | 529 | } |
e87aa773 | 530 | EXPORT_SYMBOL(dmam_pool_destroy); |