[PATCH 08/10] dmapool: cleanup dma_pool_destroy

[Tony Battersby]

Remove a small amount of code duplication between dma_pool_destroy() and
pool_free_page() in preparation for adding more code without having to
duplicate it.  No functional changes.

Signed-off-by: Tony Battersby <to...@cybernetics.com>
---
 mm/dmapool.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 8749a9d7927e..58c11dcaa4e4 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -250,14 +250,25 @@ static inline bool is_page_busy(struct dma_page *page)
        return page->in_use != 0;
 }
 
-static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
+static void pool_free_page(struct dma_pool *pool,
+                          struct dma_page *page,
+                          bool destroying_pool)
 {
+       void *vaddr = page->vaddr;
        dma_addr_t dma = page->dma;
 
+       if (destroying_pool && is_page_busy(page)) {
+               dev_err(pool->dev,
+                       "dma_pool_destroy %s, %p busy\n",
+                       pool->name, vaddr);
+               /* leak the still-in-use consistent memory */
+       } else {
 #ifdef DMAPOOL_DEBUG
-       memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
+               memset(vaddr, POOL_POISON_FREED, pool->allocation);
 #endif
-       dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
+               dma_free_coherent(pool->dev, pool->allocation, vaddr, dma);
+       }
+
        list_del(&page->page_list);
        kfree(page);
 }
@@ -272,7 +283,7 @@ static void pool_free_page(struct dma_pool *pool, struct 
dma_page *page)
  */
 void dma_pool_destroy(struct dma_pool *pool)
 {
-       struct dma_page *page, *tmp;
+       struct dma_page *page;
        bool empty = false;
 
        if (unlikely(!pool))
@@ -288,15 +299,10 @@ void dma_pool_destroy(struct dma_pool *pool)
                device_remove_file(pool->dev, &dev_attr_pools);
        mutex_unlock(&pools_reg_lock);
 
-       list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
-               if (is_page_busy(page)) {
-                       dev_err(pool->dev, "%s %s, %p busy\n", __func__,
-                               pool->name, page->vaddr);
-                       /* leak the still-in-use consistent memory */
-                       list_del(&page->page_list);
-                       kfree(page);
-               } else
-                       pool_free_page(pool, page);
+       while ((page = list_first_entry_or_null(&pool->page_list,
+                                               struct dma_page,
+                                               page_list))) {
+               pool_free_page(pool, page, true);
        }
 
        kfree(pool);
@@ -469,7 +475,7 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, 
dma_addr_t dma)
        page->offset = offset;
        /*
         * Resist a temptation to do
-        *    if (!is_page_busy(page)) pool_free_page(pool, page);
+        *    if (!is_page_busy(page)) pool_free_page(pool, page, false);
         * Better have a few empty pages hang around.
         */
        spin_unlock_irqrestore(&pool->lock, flags);
-- 
2.25.1

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