};
static DEFINE_MUTEX(pools_lock);
+static DEFINE_MUTEX(pools_reg_lock);
static ssize_t
show_pools(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dma_pool *retval;
size_t allocation;
+ bool empty = false;
- if (align == 0) {
+ if (align == 0)
align = 1;
- } else if (align & (align - 1)) {
+ else if (align & (align - 1))
return NULL;
- }
- if (size == 0) {
+ if (size == 0)
return NULL;
- } else if (size < 4) {
+ else if (size < 4)
size = 4;
- }
if ((size % align) != 0)
size = ALIGN(size, align);
allocation = max_t(size_t, size, PAGE_SIZE);
- if (!boundary) {
+ if (!boundary)
boundary = allocation;
- } else if ((boundary < size) || (boundary & (boundary - 1))) {
+ else if ((boundary < size) || (boundary & (boundary - 1)))
return NULL;
- }
retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
if (!retval)
INIT_LIST_HEAD(&retval->pools);
+ /*
+ * pools_lock ensures that the ->dma_pools list does not get corrupted.
+ * pools_reg_lock ensures that there is not a race between
+ * dma_pool_create() and dma_pool_destroy() or within dma_pool_create()
+ * when the first invocation of dma_pool_create() failed on
+ * device_create_file() and the second assumes that it has been done (I
+ * know it is a short window).
+ */
+ mutex_lock(&pools_reg_lock);
mutex_lock(&pools_lock);
- if (list_empty(&dev->dma_pools) &&
- device_create_file(dev, &dev_attr_pools)) {
- kfree(retval);
- retval = NULL;
- } else
- list_add(&retval->pools, &dev->dma_pools);
+ if (list_empty(&dev->dma_pools))
+ empty = true;
+ list_add(&retval->pools, &dev->dma_pools);
mutex_unlock(&pools_lock);
-
+ if (empty) {
+ int err;
+
+ err = device_create_file(dev, &dev_attr_pools);
+ if (err) {
+ mutex_lock(&pools_lock);
+ list_del(&retval->pools);
+ mutex_unlock(&pools_lock);
+ mutex_unlock(&pools_reg_lock);
+ kfree(retval);
+ return NULL;
+ }
+ }
+ mutex_unlock(&pools_reg_lock);
return retval;
}
EXPORT_SYMBOL(dma_pool_create);
return page;
}
-static inline int is_page_busy(struct dma_page *page)
+static inline bool is_page_busy(struct dma_page *page)
{
return page->in_use != 0;
}
*/
void dma_pool_destroy(struct dma_pool *pool)
{
+ bool empty = false;
+
+ mutex_lock(&pools_reg_lock);
mutex_lock(&pools_lock);
list_del(&pool->pools);
if (pool->dev && list_empty(&pool->dev->dma_pools))
- device_remove_file(pool->dev, &dev_attr_pools);
+ empty = true;
mutex_unlock(&pools_lock);
+ if (empty)
+ device_remove_file(pool->dev, &dev_attr_pools);
+ mutex_unlock(&pools_reg_lock);
while (!list_empty(&pool->page_list)) {
struct dma_page *page;