[PATCH 4.7 073/186] ARC: dma: fix address translation in arc_dma_free

4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vladimir Kondratiev <redacted>

commit b4dff2874006e54b60ce4f4dbcfec9ab81c6aff4 upstream.

page should be calculated using physical address.
If platform uses non-trivial dma-to-phys memory translation,
dma_handle should be converted to physicval address before
calculation of page.

Failing to do so results in struct page * pointing to
wrong or non-existent memory.

Fixes: f2e3d55397ff ("ARC: dma: reintroduce platform specific dma<->phys")
Signed-off-by: Vladimir Kondratiev <redacted>
Signed-off-by: Vineet Gupta <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arc/mm/dma.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c

@@ -92,7 +92,8 @@ static void *arc_dma_alloc(struct device
 static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle, struct dma_attrs *attrs)
 {
-	struct page *page = virt_to_page(dma_handle);
+	phys_addr_t paddr = plat_dma_to_phys(dev, dma_handle);
+	struct page *page = virt_to_page(paddr);
 	int is_non_coh = 1;
 
 	is_non_coh = dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) ||