From: Mike Travis <travis@sgi.com>
Date: Sat, 28 May 2011 18:15:03 +0000 (-0500)
Subject: intel-iommu: Speed up processing of the identity_mapping function
X-Git-Tag: v3.0-rc2~18^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb452a4040bb051d92e85d6e7eb60c11734c1781;p=pandora-kernel.git

intel-iommu: Speed up processing of the identity_mapping function

When there are a large count of PCI devices, and the pass through
option for iommu is set, much time is spent in the identity_mapping
function hunting though the iommu domains to check if a specific
device is "identity mapped".

Speed up the function by checking the cached info to see if
it's mapped to the static identity domain.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---

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