[PATCH 4/5] swiotlb: map_page fix for highmem systems

[Becky Bruce <beckyb@kernel.crashing.org>]

The current code calls virt_to_phys() on address that might
be in highmem, which is bad.  This wasn't needed, anyway, because
we already have the physical address we need. Get rid of the
now-unused virtual address as well.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
---
 lib/swiotlb.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index c152f17..b33180e 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -640,7 +640,6 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 			    struct dma_attrs *attrs)
 {
 	phys_addr_t phys = page_to_phys(page) + offset;
-	void *ptr = page_address(page) + offset;
 	dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
 	void *map;
 
@@ -651,7 +650,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 	 * buffering it.
 	 */
 	if (!address_needs_mapping(dev, dev_addr, size) &&
-	    !range_needs_mapping(virt_to_phys(ptr), size))
+	    !range_needs_mapping(phys, size))
 		return dev_addr;
 
 	/*
-- 
1.5.6.6