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iommu/vt-d: Preset A/D bits for user space DMA usage
authorLu Baolu <baolu.lu@linux.intel.com>
Wed, 18 Aug 2021 13:48:48 +0000 (21:48 +0800)
committerJoerg Roedel <jroedel@suse.de>
Thu, 19 Aug 2021 08:41:08 +0000 (10:41 +0200)
commit289b3b005cb9d9dd6b30297b52c2b4596bc878b2
treefbbfa6ceb84862eeeb8be20af160039658b14b24
parent792fb43ce2c98878f1539c1d3fdecc1d7a7d78fd
iommu/vt-d: Preset A/D bits for user space DMA usage

We preset the access and dirty bits for IOVA over first level usage only
for the kernel DMA (i.e., when domain type is IOMMU_DOMAIN_DMA). We should
also preset the FL A/D for user space DMA usage. The idea is that even the
user space A/D bit memory write is unnecessary. We should avoid it to
minimize the overhead.

Suggested-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210720013856.4143880-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210818134852.1847070-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
drivers/iommu/intel/iommu.c