looks good to me.
On Sun, Nov 25, 2012 at 3:48 PM, Akinobu Mita <akinobu.m...@gmail.com>wrote:
> 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.m...@gmail.com>
> Cc: Mike Frysinger <vap...@gentoo.org>
> Cc: uclinux-dist-devel@blackfin.uclinux.org
> ---
> arch/blackfin/kernel/dma-mapping.c | 23 +++++++----------------
> 1 file changed, 7 insertions(+), 16 deletions(-)
>
> diff --git a/arch/blackfin/kernel/dma-mapping.c
> b/arch/blackfin/kernel/dma-mapping.c
> index e7be653..df437e5 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);
> }
>
> --
> 1.7.11.7
>
> _______________________________________________
> Uclinux-dist-devel mailing list
> Uclinux-dist-devel@blackfin.uclinux.org
> https://blackfin.uclinux.org/mailman/listinfo/uclinux-dist-devel
>
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