tree ef19298ec70274c9c199fa74a4f08e77cc69080b
parent 8fcc5372fbac085199d84a880503ed67aba3fe49
author Mike Travis <travis@sgi.com> 1306606503 -0500
committer David Woodhouse <David.Woodhouse@intel.com> 1306928856 +0100

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>