arm: mm: fix DMA pool affiliation check

The __free_from_pool() function was changed in
e9da6e9905e639b0f842a244bc770b48ad0523e9. Unfortunately, the test that
checks whether the provided (start,size) is within the DMA pool has
been improperly modified. It used to be:

  if (start < coherent_head.vm_start || end > coherent_head.vm_end)

Where coherent_head.vm_end was non-inclusive (i.e, it did not include
the first byte after the pool). The test has been changed to:

  if (start < pool->vaddr || start > pool->vaddr + pool->size)

So now pool->vaddr + pool->size is inclusive (i.e, it includes the
first byte after the pool), so the test should be >= instead of >.

This bug causes the following message when freeing the *first* DMA
coherent buffer that has been allocated, because its virtual address
is exactly equal to pool->vaddr + pool->size :

WARNING: at /home/thomas/projets/linux-2.6/arch/arm/mm/dma-mapping.c:463 __free_from_pool+0xa4/0xc0()
freeing wrong coherent size from pool

Signed-off-by: Thomas Petazzoni <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Russell King <[email protected]>
Cc: Lior Amsalem <[email protected]>
Cc: Maen Suleiman <[email protected]>
Cc: Tawfik Bayouk <[email protected]>
Cc: Shadi Ammouri <[email protected]>
Cc: Eran Ben-Avi <[email protected]>
Cc: Yehuda Yitschak <[email protected]>
Cc: Nadav Haklai <[email protected]>
[m.szyprowski: rebased onto v3.6-rc5 and resolved conflict]
Signed-off-by: Marek Szyprowski <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 051204fc4617..e59c4ab71bcb 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -489,7 +489,7 @@ static bool __in_atomic_pool(void *start, size_t size)
 	void *pool_start = pool->vaddr;
 	void *pool_end = pool->vaddr + pool->size;
 
-	if (start < pool_start || start > pool_end)
+	if (start < pool_start || start >= pool_end)
 		return false;
 
 	if (end <= pool_end)