diff options
author | Andrew Morton <akpm@linux-foundation.org> | 2009-01-06 22:43:09 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 23:59:31 (GMT) |
commit | eccd83e116e7f414a1da3aae3745384b7b171883 (patch) | |
tree | 3cc2e2778ecafa34be3380bc85ec9d72b94b5292 | |
parent | 0bef3c2dc7d0c8238330785c8f4504761b0e370b (diff) | |
download | linux-fsl-qoriq-eccd83e116e7f414a1da3aae3745384b7b171883.tar.xz |
dma_alloc_coherent: clean it up
This thing was rather stupidly coded. Rework it all prior to making
changes.
Also, rename local variable `page': kernel readers expect something called
`page' to have type `struct page *'.
Cc: Guennadi Liakhovetski <lg@denx.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | kernel/dma-coherent.c | 54 |
1 files changed, 29 insertions, 25 deletions
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c index 4bdcea8..8056d08 100644 --- a/kernel/dma-coherent.c +++ b/kernel/dma-coherent.c @@ -109,34 +109,38 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied); int dma_alloc_from_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret) { - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + struct dma_coherent_mem *mem; int order = get_order(size); + int pageno; - if (mem) { - int page = bitmap_find_free_region(mem->bitmap, mem->size, - order); - if (page >= 0) { - /* - * Memory was found in the per-device arena. - */ - *dma_handle = mem->device_base + (page << PAGE_SHIFT); - *ret = mem->virt_base + (page << PAGE_SHIFT); - memset(*ret, 0, size); - } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) { - /* - * The per-device arena is exhausted and we are not - * permitted to fall back to generic memory. - */ - *ret = NULL; - } else { - /* - * The per-device arena is exhausted and we are - * permitted to fall back to generic memory. - */ - return 0; - } + if (!dev) + return 0; + mem = dev->dma_mem; + if (!mem) + return 0; + + pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); + if (pageno >= 0) { + /* + * Memory was found in the per-device arena. + */ + *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); + *ret = mem->virt_base + (pageno << PAGE_SHIFT); + memset(*ret, 0, size); + } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) { + /* + * The per-device arena is exhausted and we are not + * permitted to fall back to generic memory. + */ + *ret = NULL; + } else { + /* + * The per-device arena is exhausted and we are + * permitted to fall back to generic memory. + */ + return 0; } - return (mem != NULL); + return 1; } EXPORT_SYMBOL(dma_alloc_from_coherent); |