mm/dmapool.c: take lock only once in dma_pool_free()

[cascardo/linux.git] / mm / dmapool.c

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 4df2de7..a2f6295 100644 (file)
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -355,20 +355,15 @@ 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 +381,10 @@ 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 +398,7 @@ 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 +416,7 @@ 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,
@@ -432,7 +431,6 @@ 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;