[PATCH v2 0/7] iommu/vt-d: Add page request draining support

[Lu Baolu]

When a PASID is stopped or terminated, there can be pending PRQs
(requests that haven't received responses) in the software and
remapping hardware. The pending page requests must be drained
so that the pasid could be reused. The register level interface
for page request draining is defined in 7.11 of the VT-d spec.
This series adds the support for page requests draining.

This includes two parts:
 - PATCH 1/7 ~ 3/7: refactor the qi_submit_sync() to support
   multiple descriptors per submission which will be used by
   PATCH 6/7.
 - PATCH 4/7 ~ 7/7: add page request drain support after a
   pasid entry is torn down due to an unbind operation.

Please help to review.

Best regards,
baolu

Change log:
 v1->v2:
  - Fix race between multiple prq handling threads

Lu Baolu (7):
  iommu/vt-d: Refactor parameters for qi_submit_sync()
  iommu/vt-d: Multiple descriptors per qi_submit_sync()
  iommu/vt-d: debugfs: Add support to show inv queue internals
  iommu/vt-d: Refactor prq_event_thread()
  iommu/vt-d: Save prq descriptors in an internal list
  iommu/vt-d: Add page request draining support
  iommu/vt-d: Remove redundant IOTLB flush

 drivers/iommu/dmar.c                |  63 +++--
 drivers/iommu/intel-iommu-debugfs.c |  62 +++++
 drivers/iommu/intel-pasid.c         |   4 +-
 drivers/iommu/intel-svm.c           | 383 ++++++++++++++++++----------
 drivers/iommu/intel_irq_remapping.c |   2 +-
 include/linux/intel-iommu.h         |  12 +-
 6 files changed, 369 insertions(+), 157 deletions(-)

-- 
2.17.1