[tip:core/iommu] swiotlb: map_page fix for highmem systems

[Becky Bruce]

Commit-ID:  dd6b02fe427f30520d0adc94aa52352367227873
Gitweb:     http://git.kernel.org/tip/dd6b02fe427f30520d0adc94aa52352367227873
Author:     Becky Bruce <beckyb@xxxxxxxxxxxxxxxxxxx>
AuthorDate: Wed, 8 Apr 2009 09:09:17 -0500
Committer:  Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 8 Apr 2009 16:18:36 +0200

swiotlb: map_page fix for highmem systems

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@xxxxxxxxxxxxxxxxxxx>
Acked-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Cc: jeremy@xxxxxxxx
Cc: ian.campbell@xxxxxxxxxx
LKML-Reference: <1239199761-22886-4-git-send-email-galak@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
 lib/swiotlb.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 4fd6a76..e8a47c8 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;
 
 	/*
--
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