PCI/ATS: Add pci_pri_supported() to check device or associated PF
authorAshok Raj <ashok.raj@intel.com>
Thu, 23 Jul 2020 22:37:29 +0000 (15:37 -0700)
committerBjorn Helgaas <bhelgaas@google.com>
Fri, 24 Jul 2020 14:50:41 +0000 (09:50 -0500)
commit3f9a7a13fe4cb6e119e4e4745fbf975d30bfac9b
tree35ee302aafcea3a116d369053c878bcbfbb4b09f
parent1c026a18d40bdd904d3ae1f7737cd08b376286d6
PCI/ATS: Add pci_pri_supported() to check device or associated PF

For SR-IOV, the PF PRI is shared between the PF and any associated VFs, and
the PRI Capability is allowed for PFs but not for VFs.  Searching for the
PRI Capability on a VF always fails, even if its associated PF supports
PRI.

Add pci_pri_supported() to check whether device or its associated PF
supports PRI.

[bhelgaas: commit log, avoid "!!"]
Fixes: b16d0cb9e2fc ("iommu/vt-d: Always enable PASID/PRI PCI capabilities before ATS")
Link: https://lore.kernel.org/r/1595543849-19692-1-git-send-email-ashok.raj@intel.com
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org # v4.4+
drivers/iommu/intel/iommu.c
drivers/pci/ats.c
include/linux/pci-ats.h