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Matthew Wilcox6182a092007-12-03 12:16:57 -05001/*
2 * DMA Pool allocator
3 *
4 * Copyright 2001 David Brownell
5 * Copyright 2007 Intel Corporation
6 * Author: Matthew Wilcox <willy@linux.intel.com>
7 *
8 * This software may be redistributed and/or modified under the terms of
9 * the GNU General Public License ("GPL") version 2 as published by the
10 * Free Software Foundation.
11 *
12 * This allocator returns small blocks of a given size which are DMA-able by
13 * the given device. It uses the dma_alloc_coherent page allocator to get
14 * new pages, then splits them up into blocks of the required size.
15 * Many older drivers still have their own code to do this.
16 *
17 * The current design of this allocator is fairly simple. The pool is
18 * represented by the 'struct dma_pool' which keeps a doubly-linked list of
19 * allocated pages. Each page in the page_list is split into blocks of at
Matthew Wilcoxa35a3452007-12-03 14:08:28 -050020 * least 'size' bytes. Free blocks are tracked in an unsorted singly-linked
21 * list of free blocks within the page. Used blocks aren't tracked, but we
22 * keep a count of how many are currently allocated from each page.
Matthew Wilcox6182a092007-12-03 12:16:57 -050023 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/dma-mapping.h>
27#include <linux/dmapool.h>
Matthew Wilcox6182a092007-12-03 12:16:57 -050028#include <linux/kernel.h>
29#include <linux/list.h>
Paul Gortmakerb95f1b312011-10-16 02:01:52 -040030#include <linux/export.h>
Matthew Wilcox6182a092007-12-03 12:16:57 -050031#include <linux/mutex.h>
Randy Dunlapc9cf5522006-06-27 02:53:52 -070032#include <linux/poison.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040033#include <linux/sched.h>
Matthew Wilcox6182a092007-12-03 12:16:57 -050034#include <linux/slab.h>
Paul Gortmaker7c775092011-10-16 02:03:46 -040035#include <linux/stat.h>
Matthew Wilcox6182a092007-12-03 12:16:57 -050036#include <linux/spinlock.h>
37#include <linux/string.h>
38#include <linux/types.h>
39#include <linux/wait.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Andi Kleenb5ee5be2008-04-28 02:12:37 -070041#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON)
42#define DMAPOOL_DEBUG 1
43#endif
44
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050045struct dma_pool { /* the pool */
46 struct list_head page_list;
47 spinlock_t lock;
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050048 size_t size;
49 struct device *dev;
50 size_t allocation;
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -050051 size_t boundary;
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050052 char name[32];
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050053 struct list_head pools;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054};
55
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050056struct dma_page { /* cacheable header for 'allocation' bytes */
57 struct list_head page_list;
58 void *vaddr;
59 dma_addr_t dma;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -050060 unsigned int in_use;
61 unsigned int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062};
63
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050064static DEFINE_MUTEX(pools_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66static ssize_t
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050067show_pools(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
69 unsigned temp;
70 unsigned size;
71 char *next;
72 struct dma_page *page;
73 struct dma_pool *pool;
74
75 next = buf;
76 size = PAGE_SIZE;
77
78 temp = scnprintf(next, size, "poolinfo - 0.1\n");
79 size -= temp;
80 next += temp;
81
Matthias Kaehlckeb2366d62007-04-24 22:45:25 +020082 mutex_lock(&pools_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 list_for_each_entry(pool, &dev->dma_pools, pools) {
84 unsigned pages = 0;
85 unsigned blocks = 0;
86
Thomas Gleixnerc4956822009-06-30 11:41:25 -070087 spin_lock_irq(&pool->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 list_for_each_entry(page, &pool->page_list, page_list) {
89 pages++;
90 blocks += page->in_use;
91 }
Thomas Gleixnerc4956822009-06-30 11:41:25 -070092 spin_unlock_irq(&pool->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94 /* per-pool info, no real statistics yet */
95 temp = scnprintf(next, size, "%-16s %4u %4Zu %4Zu %2u\n",
Matthew Wilcoxa35a3452007-12-03 14:08:28 -050096 pool->name, blocks,
97 pages * (pool->allocation / pool->size),
Matthew Wilcoxe87aa772007-12-03 12:04:31 -050098 pool->size, pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 size -= temp;
100 next += temp;
101 }
Matthias Kaehlckeb2366d62007-04-24 22:45:25 +0200102 mutex_unlock(&pools_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104 return PAGE_SIZE - size;
105}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500106
107static DEVICE_ATTR(pools, S_IRUGO, show_pools, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109/**
110 * dma_pool_create - Creates a pool of consistent memory blocks, for dma.
111 * @name: name of pool, for diagnostics
112 * @dev: device that will be doing the DMA
113 * @size: size of the blocks in this pool.
114 * @align: alignment requirement for blocks; must be a power of two
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500115 * @boundary: returned blocks won't cross this power of two boundary
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 * Context: !in_interrupt()
117 *
118 * Returns a dma allocation pool with the requested characteristics, or
119 * null if one can't be created. Given one of these pools, dma_pool_alloc()
120 * may be used to allocate memory. Such memory will all have "consistent"
121 * DMA mappings, accessible by the device and its driver without using
122 * cache flushing primitives. The actual size of blocks allocated may be
123 * larger than requested because of alignment.
124 *
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500125 * If @boundary is nonzero, objects returned from dma_pool_alloc() won't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 * cross that size boundary. This is useful for devices which have
127 * addressing restrictions on individual DMA transfers, such as not crossing
128 * boundaries of 4KBytes.
129 */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500130struct dma_pool *dma_pool_create(const char *name, struct device *dev,
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500131 size_t size, size_t align, size_t boundary)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500133 struct dma_pool *retval;
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500134 size_t allocation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
Matthew Wilcox399154b2007-12-03 12:10:24 -0500136 if (align == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 align = 1;
Matthew Wilcox399154b2007-12-03 12:10:24 -0500138 } else if (align & (align - 1)) {
139 return NULL;
140 }
141
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500142 if (size == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 return NULL;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500144 } else if (size < 4) {
145 size = 4;
146 }
Matthew Wilcox399154b2007-12-03 12:10:24 -0500147
148 if ((size % align) != 0)
149 size = ALIGN(size, align);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500151 allocation = max_t(size_t, size, PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500153 if (!boundary) {
154 boundary = allocation;
155 } else if ((boundary < size) || (boundary & (boundary - 1))) {
156 return NULL;
157 }
158
159 retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
160 if (!retval)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 return retval;
162
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500163 strlcpy(retval->name, name, sizeof(retval->name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 retval->dev = dev;
166
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500167 INIT_LIST_HEAD(&retval->page_list);
168 spin_lock_init(&retval->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 retval->size = size;
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500170 retval->boundary = boundary;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 retval->allocation = allocation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Daeseok Youncc6b6642014-06-04 16:08:05 -0700173 INIT_LIST_HEAD(&retval->pools);
Cornelia Huck141ecc52006-09-22 11:37:27 +0200174
Daeseok Youncc6b6642014-06-04 16:08:05 -0700175 mutex_lock(&pools_lock);
176 if (list_empty(&dev->dma_pools) &&
177 device_create_file(dev, &dev_attr_pools)) {
178 kfree(retval);
179 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 } else
Daeseok Youncc6b6642014-06-04 16:08:05 -0700181 list_add(&retval->pools, &dev->dma_pools);
182 mutex_unlock(&pools_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 return retval;
185}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500186EXPORT_SYMBOL(dma_pool_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500188static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
189{
190 unsigned int offset = 0;
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500191 unsigned int next_boundary = pool->boundary;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500192
193 do {
194 unsigned int next = offset + pool->size;
Matthew Wilcoxe34f44b2007-12-03 14:16:24 -0500195 if (unlikely((next + pool->size) >= next_boundary)) {
196 next = next_boundary;
197 next_boundary += pool->boundary;
198 }
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500199 *(int *)(page->vaddr + offset) = next;
200 offset = next;
201 } while (offset < pool->allocation);
202}
203
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500204static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500206 struct dma_page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500208 page = kmalloc(sizeof(*page), mem_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 if (!page)
210 return NULL;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500211 page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500212 &page->dma, mem_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 if (page->vaddr) {
Andi Kleenb5ee5be2008-04-28 02:12:37 -0700214#ifdef DMAPOOL_DEBUG
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500215 memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216#endif
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500217 pool_initialise_page(pool, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 page->in_use = 0;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500219 page->offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 } else {
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500221 kfree(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 page = NULL;
223 }
224 return page;
225}
226
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500227static inline int is_page_busy(struct dma_page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500229 return page->in_use != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230}
231
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500232static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500234 dma_addr_t dma = page->dma;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
Andi Kleenb5ee5be2008-04-28 02:12:37 -0700236#ifdef DMAPOOL_DEBUG
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500237 memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238#endif
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500239 dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
240 list_del(&page->page_list);
241 kfree(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244/**
245 * dma_pool_destroy - destroys a pool of dma memory blocks.
246 * @pool: dma pool that will be destroyed
247 * Context: !in_interrupt()
248 *
249 * Caller guarantees that no more memory from the pool is in use,
250 * and that nothing will try to use the pool after this call.
251 */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500252void dma_pool_destroy(struct dma_pool *pool)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
Matthias Kaehlckeb2366d62007-04-24 22:45:25 +0200254 mutex_lock(&pools_lock);
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500255 list_del(&pool->pools);
256 if (pool->dev && list_empty(&pool->dev->dma_pools))
257 device_remove_file(pool->dev, &dev_attr_pools);
Matthias Kaehlckeb2366d62007-04-24 22:45:25 +0200258 mutex_unlock(&pools_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500260 while (!list_empty(&pool->page_list)) {
261 struct dma_page *page;
262 page = list_entry(pool->page_list.next,
263 struct dma_page, page_list);
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500264 if (is_page_busy(page)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 if (pool->dev)
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500266 dev_err(pool->dev,
267 "dma_pool_destroy %s, %p busy\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 pool->name, page->vaddr);
269 else
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500270 printk(KERN_ERR
271 "dma_pool_destroy %s, %p busy\n",
272 pool->name, page->vaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 /* leak the still-in-use consistent memory */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500274 list_del(&page->page_list);
275 kfree(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 } else
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500277 pool_free_page(pool, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 }
279
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500280 kfree(pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500282EXPORT_SYMBOL(dma_pool_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284/**
285 * dma_pool_alloc - get a block of consistent memory
286 * @pool: dma pool that will produce the block
287 * @mem_flags: GFP_* bitmask
288 * @handle: pointer to dma address of block
289 *
290 * This returns the kernel virtual address of a currently unused block,
291 * and reports its dma address through the handle.
Matthew Wilcox6182a092007-12-03 12:16:57 -0500292 * If such a memory block can't be allocated, %NULL is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500294void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
295 dma_addr_t *handle)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500297 unsigned long flags;
298 struct dma_page *page;
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500299 size_t offset;
300 void *retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
Dima Zavinea05c842010-10-26 14:21:54 -0700302 might_sleep_if(mem_flags & __GFP_WAIT);
303
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500304 spin_lock_irqsave(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 list_for_each_entry(page, &pool->page_list, page_list) {
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500306 if (page->offset < pool->allocation)
307 goto ready;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309
Marek Szyprowski387870f2012-11-07 15:37:07 +0100310 /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
311 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Marek Szyprowski387870f2012-11-07 15:37:07 +0100313 page = pool_alloc_page(pool, mem_flags);
314 if (!page)
315 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
Marek Szyprowski387870f2012-11-07 15:37:07 +0100317 spin_lock_irqsave(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Marek Szyprowski387870f2012-11-07 15:37:07 +0100319 list_add(&page->page_list, &pool->page_list);
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500320 ready:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 page->in_use++;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500322 offset = page->offset;
323 page->offset = *(int *)(page->vaddr + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 retval = offset + page->vaddr;
325 *handle = offset + page->dma;
Andi Kleenb5ee5be2008-04-28 02:12:37 -0700326#ifdef DMAPOOL_DEBUG
Matthieu CASTET5de55b22012-12-11 16:01:31 -0800327 {
328 int i;
329 u8 *data = retval;
330 /* page->offset is stored in first 4 bytes */
331 for (i = sizeof(page->offset); i < pool->size; i++) {
332 if (data[i] == POOL_POISON_FREED)
333 continue;
334 if (pool->dev)
335 dev_err(pool->dev,
Hiroshige Sato5835f252014-04-16 21:28:34 +0900336 "dma_pool_alloc %s, %p (corrupted)\n",
Matthieu CASTET5de55b22012-12-11 16:01:31 -0800337 pool->name, retval);
338 else
Hiroshige Sato5835f252014-04-16 21:28:34 +0900339 pr_err("dma_pool_alloc %s, %p (corrupted)\n",
Matthieu CASTET5de55b22012-12-11 16:01:31 -0800340 pool->name, retval);
341
342 /*
343 * Dump the first 4 bytes even if they are not
344 * POOL_POISON_FREED
345 */
346 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
347 data, pool->size, 1);
348 break;
349 }
350 }
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500351 memset(retval, POOL_POISON_ALLOCATED, pool->size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352#endif
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500353 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 return retval;
355}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500356EXPORT_SYMBOL(dma_pool_alloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500358static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500360 struct dma_page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 list_for_each_entry(page, &pool->page_list, page_list) {
363 if (dma < page->dma)
364 continue;
365 if (dma < (page->dma + pool->allocation))
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800366 return page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 }
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800368 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369}
370
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371/**
372 * dma_pool_free - put block back into dma pool
373 * @pool: the dma pool holding the block
374 * @vaddr: virtual address of block
375 * @dma: dma address of block
376 *
377 * Caller promises neither device nor driver will again touch this block
378 * unless it is first re-allocated.
379 */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500380void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381{
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500382 struct dma_page *page;
383 unsigned long flags;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500384 unsigned int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800386 spin_lock_irqsave(&pool->lock, flags);
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500387 page = pool_find_page(pool, dma);
388 if (!page) {
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800389 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 if (pool->dev)
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500391 dev_err(pool->dev,
392 "dma_pool_free %s, %p/%lx (bad dma)\n",
393 pool->name, vaddr, (unsigned long)dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 else
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500395 printk(KERN_ERR "dma_pool_free %s, %p/%lx (bad dma)\n",
396 pool->name, vaddr, (unsigned long)dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 return;
398 }
399
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500400 offset = vaddr - page->vaddr;
Andi Kleenb5ee5be2008-04-28 02:12:37 -0700401#ifdef DMAPOOL_DEBUG
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500402 if ((dma - page->dma) != offset) {
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800403 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 if (pool->dev)
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500405 dev_err(pool->dev,
406 "dma_pool_free %s, %p (bad vaddr)/%Lx\n",
407 pool->name, vaddr, (unsigned long long)dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 else
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500409 printk(KERN_ERR
410 "dma_pool_free %s, %p (bad vaddr)/%Lx\n",
411 pool->name, vaddr, (unsigned long long)dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 return;
413 }
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500414 {
415 unsigned int chain = page->offset;
416 while (chain < pool->allocation) {
417 if (chain != offset) {
418 chain = *(int *)(page->vaddr + chain);
419 continue;
420 }
Rolf Eike Beer84bc2272011-01-13 15:47:24 -0800421 spin_unlock_irqrestore(&pool->lock, flags);
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500422 if (pool->dev)
423 dev_err(pool->dev, "dma_pool_free %s, dma %Lx "
424 "already free\n", pool->name,
425 (unsigned long long)dma);
426 else
427 printk(KERN_ERR "dma_pool_free %s, dma %Lx "
428 "already free\n", pool->name,
429 (unsigned long long)dma);
430 return;
431 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 }
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500433 memset(vaddr, POOL_POISON_FREED, pool->size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434#endif
435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 page->in_use--;
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500437 *(int *)vaddr = page->offset;
438 page->offset = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 /*
440 * Resist a temptation to do
Matthew Wilcoxa35a3452007-12-03 14:08:28 -0500441 * if (!is_page_busy(page)) pool_free_page(pool, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 * Better have a few empty pages hang around.
443 */
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500444 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500446EXPORT_SYMBOL(dma_pool_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
Tejun Heo9ac78492007-01-20 16:00:26 +0900448/*
449 * Managed DMA pool
450 */
451static void dmam_pool_release(struct device *dev, void *res)
452{
453 struct dma_pool *pool = *(struct dma_pool **)res;
454
455 dma_pool_destroy(pool);
456}
457
458static int dmam_pool_match(struct device *dev, void *res, void *match_data)
459{
460 return *(struct dma_pool **)res == match_data;
461}
462
463/**
464 * dmam_pool_create - Managed dma_pool_create()
465 * @name: name of pool, for diagnostics
466 * @dev: device that will be doing the DMA
467 * @size: size of the blocks in this pool.
468 * @align: alignment requirement for blocks; must be a power of two
469 * @allocation: returned blocks won't cross this boundary (or zero)
470 *
471 * Managed dma_pool_create(). DMA pool created with this function is
472 * automatically destroyed on driver detach.
473 */
474struct dma_pool *dmam_pool_create(const char *name, struct device *dev,
475 size_t size, size_t align, size_t allocation)
476{
477 struct dma_pool **ptr, *pool;
478
479 ptr = devres_alloc(dmam_pool_release, sizeof(*ptr), GFP_KERNEL);
480 if (!ptr)
481 return NULL;
482
483 pool = *ptr = dma_pool_create(name, dev, size, align, allocation);
484 if (pool)
485 devres_add(dev, ptr);
486 else
487 devres_free(ptr);
488
489 return pool;
490}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500491EXPORT_SYMBOL(dmam_pool_create);
Tejun Heo9ac78492007-01-20 16:00:26 +0900492
493/**
494 * dmam_pool_destroy - Managed dma_pool_destroy()
495 * @pool: dma pool that will be destroyed
496 *
497 * Managed dma_pool_destroy().
498 */
499void dmam_pool_destroy(struct dma_pool *pool)
500{
501 struct device *dev = pool->dev;
502
Andy Shevchenko172cb4b2014-06-04 16:10:02 -0700503 WARN_ON(devres_release(dev, dmam_pool_release, dmam_pool_match, pool));
Tejun Heo9ac78492007-01-20 16:00:26 +0900504}
Matthew Wilcoxe87aa772007-12-03 12:04:31 -0500505EXPORT_SYMBOL(dmam_pool_destroy);