[3.16.y-ckt stable] Patch "Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bcbde6546f5122e34ddaeb455d2fa30da9634d4c Mon Sep 17 00:00:00 2001
From: David Vrabel <david.vrabel at citrix.com>
Date: Wed, 10 Dec 2014 14:48:43 +0000
Subject: Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"

commit dbdd74763f1faf799fbb9ed30423182e92919378 upstream.

This reverts commit 2c3fc8d26dd09b9d7069687eead849ee81c78e46.

This commit broke on x86 PV because entries in the generic SWIOTLB are
indexed using (pseudo-)physical address not DMA address and these are
not the same in a x86 PV guest.

Signed-off-by: David Vrabel <david.vrabel at citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell at citrix.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/xen/swiotlb-xen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index de37cc22b9a5..c9d0d5a0e662 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -451,7 +451,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,

 	/* NOTE: We use dev_addr here, not paddr! */
 	if (is_xen_swiotlb_buffer(dev_addr)) {
-		swiotlb_tbl_unmap_single(hwdev, dev_addr, size, dir);
+		swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
 		return;
 	}

--
2.1.4