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Diffstat (limited to 'mm/dmapool.c')
-rw-r--r--mm/dmapool.c99
1 files changed, 48 insertions, 51 deletions
diff --git a/mm/dmapool.c b/mm/dmapool.c
index 4df2de77e06..306baa594f9 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -27,11 +27,12 @@
#include <linux/dmapool.h>
#include <linux/kernel.h>
#include <linux/list.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/poison.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/stat.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -49,7 +50,6 @@ struct dma_pool { /* the pool */
size_t allocation;
size_t boundary;
char name[32];
- wait_queue_head_t waitq;
struct list_head pools;
};
@@ -61,8 +61,6 @@ struct dma_page { /* cacheable header for 'allocation' bytes */
unsigned int offset;
};
-#define POOL_TIMEOUT_JIFFIES ((100 /* msec */ * HZ) / 1000)
-
static DEFINE_MUTEX(pools_lock);
static ssize_t
@@ -171,26 +169,17 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
retval->size = size;
retval->boundary = boundary;
retval->allocation = allocation;
- init_waitqueue_head(&retval->waitq);
- if (dev) {
- int ret;
+ INIT_LIST_HEAD(&retval->pools);
- mutex_lock(&pools_lock);
- if (list_empty(&dev->dma_pools))
- ret = device_create_file(dev, &dev_attr_pools);
- else
- ret = 0;
- /* note: not currently insisting "name" be unique */
- if (!ret)
- list_add(&retval->pools, &dev->dma_pools);
- else {
- kfree(retval);
- retval = NULL;
- }
- mutex_unlock(&pools_lock);
+ mutex_lock(&pools_lock);
+ if (list_empty(&dev->dma_pools) &&
+ device_create_file(dev, &dev_attr_pools)) {
+ kfree(retval);
+ return NULL;
} else
- INIT_LIST_HEAD(&retval->pools);
+ list_add(&retval->pools, &dev->dma_pools);
+ mutex_unlock(&pools_lock);
return retval;
}
@@ -226,7 +215,6 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
#endif
pool_initialise_page(pool, page);
- list_add(&page->page_list, &pool->page_list);
page->in_use = 0;
page->offset = 0;
} else {
@@ -314,30 +302,21 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
might_sleep_if(mem_flags & __GFP_WAIT);
spin_lock_irqsave(&pool->lock, flags);
- restart:
list_for_each_entry(page, &pool->page_list, page_list) {
if (page->offset < pool->allocation)
goto ready;
}
- page = pool_alloc_page(pool, GFP_ATOMIC);
- if (!page) {
- if (mem_flags & __GFP_WAIT) {
- DECLARE_WAITQUEUE(wait, current);
- __set_current_state(TASK_INTERRUPTIBLE);
- __add_wait_queue(&pool->waitq, &wait);
- spin_unlock_irqrestore(&pool->lock, flags);
+ /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
+ spin_unlock_irqrestore(&pool->lock, flags);
- schedule_timeout(POOL_TIMEOUT_JIFFIES);
+ page = pool_alloc_page(pool, mem_flags);
+ if (!page)
+ return NULL;
- spin_lock_irqsave(&pool->lock, flags);
- __remove_wait_queue(&pool->waitq, &wait);
- goto restart;
- }
- retval = NULL;
- goto done;
- }
+ spin_lock_irqsave(&pool->lock, flags);
+ list_add(&page->page_list, &pool->page_list);
ready:
page->in_use++;
offset = page->offset;
@@ -345,9 +324,32 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
retval = offset + page->vaddr;
*handle = offset + page->dma;
#ifdef DMAPOOL_DEBUG
+ {
+ int i;
+ u8 *data = retval;
+ /* page->offset is stored in first 4 bytes */
+ for (i = sizeof(page->offset); i < pool->size; i++) {
+ if (data[i] == POOL_POISON_FREED)
+ continue;
+ if (pool->dev)
+ dev_err(pool->dev,
+ "dma_pool_alloc %s, %p (corrupted)\n",
+ pool->name, retval);
+ else
+ pr_err("dma_pool_alloc %s, %p (corrupted)\n",
+ pool->name, retval);
+
+ /*
+ * Dump the first 4 bytes even if they are not
+ * POOL_POISON_FREED
+ */
+ print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
+ data, pool->size, 1);
+ break;
+ }
+ }
memset(retval, POOL_POISON_ALLOCATED, pool->size);
#endif
- done:
spin_unlock_irqrestore(&pool->lock, flags);
return retval;
}
@@ -355,20 +357,15 @@ EXPORT_SYMBOL(dma_pool_alloc);
static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
{
- unsigned long flags;
struct dma_page *page;
- spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry(page, &pool->page_list, page_list) {
if (dma < page->dma)
continue;
if (dma < (page->dma + pool->allocation))
- goto done;
+ return page;
}
- page = NULL;
- done:
- spin_unlock_irqrestore(&pool->lock, flags);
- return page;
+ return NULL;
}
/**
@@ -386,8 +383,10 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
unsigned long flags;
unsigned int offset;
+ spin_lock_irqsave(&pool->lock, flags);
page = pool_find_page(pool, dma);
if (!page) {
+ spin_unlock_irqrestore(&pool->lock, flags);
if (pool->dev)
dev_err(pool->dev,
"dma_pool_free %s, %p/%lx (bad dma)\n",
@@ -401,6 +400,7 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
offset = vaddr - page->vaddr;
#ifdef DMAPOOL_DEBUG
if ((dma - page->dma) != offset) {
+ spin_unlock_irqrestore(&pool->lock, flags);
if (pool->dev)
dev_err(pool->dev,
"dma_pool_free %s, %p (bad vaddr)/%Lx\n",
@@ -418,6 +418,7 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
chain = *(int *)(page->vaddr + chain);
continue;
}
+ spin_unlock_irqrestore(&pool->lock, flags);
if (pool->dev)
dev_err(pool->dev, "dma_pool_free %s, dma %Lx "
"already free\n", pool->name,
@@ -432,12 +433,9 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
memset(vaddr, POOL_POISON_FREED, pool->size);
#endif
- spin_lock_irqsave(&pool->lock, flags);
page->in_use--;
*(int *)vaddr = page->offset;
page->offset = offset;
- if (waitqueue_active(&pool->waitq))
- wake_up_locked(&pool->waitq);
/*
* Resist a temptation to do
* if (!is_page_busy(page)) pool_free_page(pool, page);
@@ -502,7 +500,6 @@ void dmam_pool_destroy(struct dma_pool *pool)
{
struct device *dev = pool->dev;
- dma_pool_destroy(pool);
- WARN_ON(devres_destroy(dev, dmam_pool_release, dmam_pool_match, pool));
+ WARN_ON(devres_release(dev, dmam_pool_release, dmam_pool_match, pool));
}
EXPORT_SYMBOL(dmam_pool_destroy);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 01:22:32 +0000