iommu/vt-d: Cache PCI ATS state and Invalidate Queue Depth
We check the ATS state (enabled/disabled) and fetch the PCI ATS Invalidate
Queue Depth in performance-sensitive paths. It's easy to cache these,
which removes dependencies on PCI.
Remember the ATS enabled state. When enabling, read the queue depth once
and cache it in the device_domain_info struct. This is similar to what
amd_iommu.c does.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
1 file changed