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authorRonny Hegewald <ronny.hegewald@online.de>2012-08-31 09:57:52 +0000
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-09-05 10:50:27 -0400
commitb5031ed1be0aa419250557123633453753181643 (patch)
treea1c23701bda262f1576d2c1a8d3833110c9f0916
parentce7184bdbd38d920fb515266fbbdc585ad2e5493 (diff)
downloadlinux-linaro-stable-b5031ed1be0aa419250557123633453753181643.tar.gz
xen: Use correct masking in xen_swiotlb_alloc_coherent.
When running 32-bit pvops-dom0 and a driver tries to allocate a coherent DMA-memory the xen swiotlb-implementation returned memory beyond 4GB. The underlaying reason is that if the supplied driver passes in a DMA_BIT_MASK(64) ( hwdev->coherent_dma_mask is set to 0xffffffffffffffff) our dma_mask will be u64 set to 0xffffffffffffffff even if we set it to DMA_BIT_MASK(32) previously. Meaning we do not reset the upper bits. By using the dma_alloc_coherent_mask function - it does the proper casting and we get 0xfffffffff. This caused not working sound on a system with 4 GB and a 64-bit compatible sound-card with sets the DMA-mask to 64bit. On bare-metal and the forward-ported xen-dom0 patches from OpenSuse a coherent DMA-memory is always allocated inside the 32-bit address-range by calling dma_alloc_coherent_mask. This patch adds the same functionality to xen swiotlb and is a rebase of the original patch from Ronny Hegewald which never got upstream b/c the underlaying reason was not understood until now. The original email with the original patch is in: http://old-list-archives.xen.org/archives/html/xen-devel/2010-02/msg00038.html the original thread from where the discussion started is in: http://old-list-archives.xen.org/archives/html/xen-devel/2010-01/msg00928.html Signed-off-by: Ronny Hegewald <ronny.hegewald@online.de> Signed-off-by: Stefano Panella <stefano.panella@citrix.com> Acked-By: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: stable@vger.kernel.org
-rw-r--r--drivers/xen/swiotlb-xen.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 1afb4fba11b4..4d519488d304 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -232,7 +232,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
return ret;
if (hwdev && hwdev->coherent_dma_mask)
- dma_mask = hwdev->coherent_dma_mask;
+ dma_mask = dma_alloc_coherent_mask(hwdev, flags);
phys = virt_to_phys(ret);
dev_addr = xen_phys_to_bus(phys);