[PATCH 2/2][Eoan][SRU Disco] dma-contiguous: page-align the size in dma_free_contiguous()

[dann frazier]

From: Nicolin Chen <nicoleotsuka at gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1839395

According to the original dma_direct_alloc_pages() code:
{
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	if (!dma_release_from_contiguous(dev, page, count))
		__free_pages(page, get_order(size));
}

The count parameter for dma_release_from_contiguous() was page
aligned before the right-shifting operation, while the new API
dma_free_contiguous() forgets to have PAGE_ALIGN() at the size.

So this patch simply adds it to prevent any corner case.

Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Signed-off-by: Nicolin Chen <nicoleotsuka at gmail.com>
Reviewed-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Christoph Hellwig <hch at lst.de>
(cherry picked from commit f46cc0152501e46d1b3aa5e7eade61145070eab0)
Signed-off-by: dann frazier <dann.frazier at canonical.com>
---
 kernel/dma/contiguous.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index ea8259f53eda7..2bd410f934b32 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -267,7 +267,8 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
  */
 void dma_free_contiguous(struct device *dev, struct page *page, size_t size)
 {
-	if (!cma_release(dev_get_cma_area(dev), page, size >> PAGE_SHIFT))
+	if (!cma_release(dev_get_cma_area(dev), page,
+			 PAGE_ALIGN(size) >> PAGE_SHIFT))
 		__free_pages(page, get_order(size));
 }
 
-- 
2.23.0.rc1