[PATCH] ARM: use common utility function in dma

From: Minchan Kim
Date: Fri May 11 2012 - 03:04:10 EST


mm provides alloc_pages_exact so use it instead of open coded hack.

Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
arch/arm/mm/dma-mapping.c | 23 +++++------------------
1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index b982602..98c9bbd 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -184,20 +184,12 @@ static void __dma_clear_buffer(struct page *page, size_t size)
*/
static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
{
- unsigned long order = get_order(size);
- struct page *page, *p, *e;
-
- page = alloc_pages(gfp, order);
- if (!page)
+ struct page *page;
+ void *addr = alloc_pages_exact(size, gfp);
+ if (!addr)
return NULL;

- /*
- * Now split the huge page and free the excess pages
- */
- split_page(page, order);
- for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
- __free_page(p);
-
+ page = virt_to_page(addr);
__dma_clear_buffer(page, size);

return page;
@@ -208,12 +200,7 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gf
*/
static void __dma_free_buffer(struct page *page, size_t size)
{
- struct page *e = page + (size >> PAGE_SHIFT);
-
- while (page < e) {
- __free_page(page);
- page++;
- }
+ free_pages_exact(page_address(page), size);
}

#ifdef CONFIG_MMU
--
1.7.9.5

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