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authorMichal Nazarewicz <mina86@mina86.com>2012-09-05 07:50:41 +0200
committerMarek Szyprowski <m.szyprowski@samsung.com>2012-10-02 08:57:45 +0200
commitbdd43cb39f1b1e897c5d7992d05d0b9f0dd786d1 (patch)
treeeec00a15f43da4bb55510a6d1542c038a877637e
parentLinux 3.6 (diff)
downloadlinux-dev-bdd43cb39f1b1e897c5d7992d05d0b9f0dd786d1.tar.xz
linux-dev-bdd43cb39f1b1e897c5d7992d05d0b9f0dd786d1.zip
drivers: dma-contiguous: refactor dma_alloc_from_contiguous()
The dma_alloc_from_contiguous() function returns either a valid pointer to a page structure or NULL, the error code set when pageno >= cma->count is not used at all and can be safely removed. This commit also changes the function to avoid goto and have only one exit path and one place where mutex is unlocked. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> [fixed compilation break caused by missing semicolon] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
-rw-r--r--drivers/base/dma-contiguous.c18
1 files changed, 7 insertions, 11 deletions
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 34d94c762a1e..9a1469474f55 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -315,6 +315,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
{
unsigned long mask, pfn, pageno, start = 0;
struct cma *cma = dev_get_cma_area(dev);
+ struct page *page = NULL;
int ret;
if (!cma || !cma->count)
@@ -336,18 +337,17 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
for (;;) {
pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
start, count, mask);
- if (pageno >= cma->count) {
- ret = -ENOMEM;
- goto error;
- }
+ if (pageno >= cma->count)
+ break;
pfn = cma->base_pfn + pageno;
ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
if (ret == 0) {
bitmap_set(cma->bitmap, pageno, count);
+ page = pfn_to_page(pfn);
break;
} else if (ret != -EBUSY) {
- goto error;
+ break;
}
pr_debug("%s(): memory range at %p is busy, retrying\n",
__func__, pfn_to_page(pfn));
@@ -356,12 +356,8 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
}
mutex_unlock(&cma_mutex);
-
- pr_debug("%s(): returned %p\n", __func__, pfn_to_page(pfn));
- return pfn_to_page(pfn);
-error:
- mutex_unlock(&cma_mutex);
- return NULL;
+ pr_debug("%s(): returned %p\n", __func__, page);
+ return page;
}
/**