From: David Woodhouse Date: Wed, 12 Mar 2014 00:10:29 +0000 (-0700) Subject: iommu/vt-d: Be less pessimistic about domain coherency where possible X-Git-Tag: v3.15-rc1~70^2^6~37 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d05019608746240d86a406fbf8d8c1fc71a87101;p=pandora-kernel.git iommu/vt-d: Be less pessimistic about domain coherency where possible In commit 2e12bc29 ("intel-iommu: Default to non-coherent for domains unattached to iommus") we decided to err on the side of caution and always assume that it's possible that a device will be attached which is behind a non-coherent IOMMU. In some cases, however, that just *cannot* happen. If there *are* no IOMMUs in the system which are non-coherent, then we don't need to do it. And flushing the dcache is a *significant* performance hit. Signed-off-by: David Woodhouse --- Reading git-diff-tree failed