diff options
authorJan Beulich <jbeulich@novell.com>2008-08-05 13:01:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-05 14:33:49 -0700
commitd2dc1f4adb4b5b02d87e49e115e5107f4da790c0 (patch)
parent978cc90c469b38bcbbfd00a8c183d74e5b17bf45 (diff)
dma: fix order calculation in dma_mark_declared_memory_occupied()
get_order() takes byte-sized input, not a page-granular one. Irrespective of this fix I'm inclined to believe that this doesn't work right anyway - bitmap_allocate_region() has an implicit assumption of 'pos' being suitable for 'order', which this function doesn't seem to enforce (and since it's being called with a byte-granular value there's no reason to believe that the callers would make sure device_addr is passed accordingly - it's also not documented that way). Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
index 7517115a8cce..91e96950cd52 100644
--- a/kernel/dma-coherent.c
+++ b/kernel/dma-coherent.c
@@ -77,15 +77,14 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
struct dma_coherent_mem *mem = dev->dma_mem;
int pos, err;
- int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);
- pages >>= PAGE_SHIFT;
+ size += device_addr & ~PAGE_MASK;
if (!mem)
return ERR_PTR(-EINVAL);
pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
- err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
+ err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
if (err != 0)
return ERR_PTR(err);
return mem->virt_base + (pos << PAGE_SHIFT);

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