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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2012-11-25 16:48:23 +0900 |
|---|---|---|
| committer | Bob Liu <lliubbo@gmail.com> | 2013-02-20 15:21:22 +0800 |
| commit | c73bc7026d7785fc627a8da7bbdd9d172001a59f (patch) | |
| tree | de8990ff59aef779890982a23c91d06be241d419 /arch/blackfin/kernel/dma-mapping.c | |
| parent | c428f8eb2f473963585b0c0a31cb33dccad62b9a (diff) | |
| download | linux-c73bc7026d7785fc627a8da7bbdd9d172001a59f.tar.bz2 | |
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/kernel/dma-mapping.c')
| -rw-r--r-- | arch/blackfin/kernel/dma-mapping.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/arch/blackfin/kernel/dma-mapping.c b/arch/blackfin/kernel/dma-mapping.c index e7be6532d6a0..df437e52d9df 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); } |