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authorAkinobu Mita <akinobu.mita@gmail.com>2012-11-25 16:48:23 +0900
committerBob Liu <lliubbo@gmail.com>2013-02-20 15:21:22 +0800
commitc73bc7026d7785fc627a8da7bbdd9d172001a59f (patch)
treede8990ff59aef779890982a23c91d06be241d419 /arch/blackfin
parentc428f8eb2f473963585b0c0a31cb33dccad62b9a (diff)
downloadlinux-c73bc7026d7785fc627a8da7bbdd9d172001a59f.tar.gz
blackfin: use bitmap library functions
The bitmap library provides more efficient functions than accessing individual bits with bitops. This uses bitmap_find_next_zero_area() to find a continuing zero area, and uses bitmap_set()/bitmap_clear() to set/clear specified bit area. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: uclinux-dist-devel@blackfin.uclinux.org Signed-off-by: Bob Liu <lliubbo@gmail.com>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/kernel/dma-mapping.c23
1 files changed, 7 insertions, 16 deletions
diff --git a/arch/blackfin/kernel/dma-mapping.c b/arch/blackfin/kernel/dma-mapping.c
index e7be6532d6a..df437e52d9d 100644
--- a/arch/blackfin/kernel/dma-mapping.c
+++ b/arch/blackfin/kernel/dma-mapping.c
@@ -13,6 +13,7 @@
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/export.h>
+#include <linux/bitmap.h>
static spinlock_t dma_page_lock;
static unsigned long *dma_page;
@@ -46,24 +47,17 @@ static inline unsigned int get_pages(size_t size)
static unsigned long __alloc_dma_pages(unsigned int pages)
{
unsigned long ret = 0, flags;
- int i, count = 0;
+ unsigned long start;
if (dma_initialized == 0)
dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend);
spin_lock_irqsave(&dma_page_lock, flags);
- for (i = 0; i < dma_pages;) {
- if (test_bit(i++, dma_page) == 0) {
- if (++count == pages) {
- while (count--)
- __set_bit(--i, dma_page);
-
- ret = dma_base + (i << PAGE_SHIFT);
- break;
- }
- } else
- count = 0;
+ start = bitmap_find_next_zero_area(dma_page, dma_pages, 0, pages, 0);
+ if (start < dma_pages) {
+ ret = dma_base + (start << PAGE_SHIFT);
+ bitmap_set(dma_page, start, pages);
}
spin_unlock_irqrestore(&dma_page_lock, flags);
return ret;
@@ -73,7 +67,6 @@ static void __free_dma_pages(unsigned long addr, unsigned int pages)
{
unsigned long page = (addr - dma_base) >> PAGE_SHIFT;
unsigned long flags;
- int i;
if ((page + pages) > dma_pages) {
printk(KERN_ERR "%s: freeing outside range.\n", __func__);
@@ -81,9 +74,7 @@ static void __free_dma_pages(unsigned long addr, unsigned int pages)
}
spin_lock_irqsave(&dma_page_lock, flags);
- for (i = page; i < page + pages; i++)
- __clear_bit(i, dma_page);
-
+ bitmap_clear(dma_page, page, pages);
spin_unlock_irqrestore(&dma_page_lock, flags);
}