From c73bc7026d7785fc627a8da7bbdd9d172001a59f Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sun, 25 Nov 2012 16:48:23 +0900 Subject: 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 Cc: Mike Frysinger Cc: uclinux-dist-devel@blackfin.uclinux.org Signed-off-by: Bob Liu --- arch/blackfin/kernel/dma-mapping.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) (limited to 'arch/blackfin') 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 #include #include +#include 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); } -- cgit v1.2.2