[PATCH v4 00/26] iommu: Shared Virtual Addressing and SMMUv3 support

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

Shared Virtual Addressing (SVA) allows to share process page tables with
devices using the IOMMU. Add a generic implementation of the IOMMU SVA
API, and add support in the Arm SMMUv3 driver.

Previous versions of this patchset were sent over a year ago [1][2] but
we've made a lot of progress since then:

* ATS support for SMMUv3 was merged in v5.2.
* The bind() and fault reporting APIs have been merged in v5.3.
* IOASID were added in v5.5.
* SMMUv3 PASID was added in v5.6, with some pending for v5.7.

* The first user of the bind() API will be merged in v5.7 [3]. The zip
  accelerator is also the first piece of hardware that I've been able to
  use for testing (previous versions were developed with software models)
  and I now have tools for evaluating SVA performance. Unfortunately I
  still don't have hardware that supports ATS and PRI; the zip accelerator
  uses stall.

These are the remaining changes for SVA support in SMMUv3. Since v3 [1]
I fixed countless bugs and - I think - addressed everyone's comments.
Thanks to recent MMU notifier rework, iommu-sva.c is a lot more
straightforward. I'm still unhappy with the complicated locking in the
SMMUv3 driver resulting from patch 12 (Seize private ASID), but I
haven't found anything better.

Please find all SVA patches on branches sva/current and sva/zip-devel at
https://jpbrucker.net/git/linux

[1] https://lore.kernel.org/linux-iommu/20180920170046.20154-1-jean-philippe.brucker@arm.com/
[2] https://lore.kernel.org/linux-iommu/20180511190641.23008-1-jean-philippe.brucker@arm.com/
[3] https://lore.kernel.org/linux-iommu/1581407665-13504-1-git-send-email-zhangfei.gao@linaro.org/

Jean-Philippe Brucker (26):
  mm/mmu_notifiers: pass private data down to alloc_notifier()
  iommu/sva: Manage process address spaces
  iommu: Add a page fault handler
  iommu/sva: Search mm by PASID
  iommu/iopf: Handle mm faults
  iommu/sva: Register page fault handler
  arm64: mm: Pin down ASIDs for sharing mm with devices
  iommu/io-pgtable-arm: Move some definitions to a header
  iommu/arm-smmu-v3: Manage ASIDs with xarray
  arm64: cpufeature: Export symbol read_sanitised_ftr_reg()
  iommu/arm-smmu-v3: Share process page tables
  iommu/arm-smmu-v3: Seize private ASID
  iommu/arm-smmu-v3: Add support for VHE
  iommu/arm-smmu-v3: Enable broadcast TLB maintenance
  iommu/arm-smmu-v3: Add SVA feature checking
  iommu/arm-smmu-v3: Add dev_to_master() helper
  iommu/arm-smmu-v3: Implement mm operations
  iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops
  iommu/arm-smmu-v3: Add support for Hardware Translation Table Update
  iommu/arm-smmu-v3: Maintain a SID->device structure
  iommu/arm-smmu-v3: Ratelimit event dump
  dt-bindings: document stall property for IOMMU masters
  iommu/arm-smmu-v3: Add stall support for platform devices
  PCI/ATS: Add PRI stubs
  PCI/ATS: Export symbols of PRI functions
  iommu/arm-smmu-v3: Add support for PRI

 .../devicetree/bindings/iommu/iommu.txt       |   18 +
 arch/arm64/include/asm/mmu.h                  |    1 +
 arch/arm64/include/asm/mmu_context.h          |   11 +-
 arch/arm64/kernel/cpufeature.c                |    1 +
 arch/arm64/mm/context.c                       |  103 +-
 drivers/iommu/Kconfig                         |   13 +
 drivers/iommu/Makefile                        |    2 +
 drivers/iommu/arm-smmu-v3.c                   | 1354 +++++++++++++++--
 drivers/iommu/io-pgfault.c                    |  533 +++++++
 drivers/iommu/io-pgtable-arm.c                |   27 +-
 drivers/iommu/io-pgtable-arm.h                |   30 +
 drivers/iommu/iommu-sva.c                     |  596 ++++++++
 drivers/iommu/iommu-sva.h                     |   64 +
 drivers/iommu/iommu.c                         |    1 +
 drivers/iommu/of_iommu.c                      |    5 +-
 drivers/misc/sgi-gru/grutlbpurge.c            |    4 +-
 drivers/pci/ats.c                             |    4 +
 include/linux/iommu.h                         |   73 +
 include/linux/mmu_notifier.h                  |   10 +-
 include/linux/pci-ats.h                       |    8 +
 mm/mmu_notifier.c                             |    6 +-
 21 files changed, 2699 insertions(+), 165 deletions(-)
 create mode 100644 drivers/iommu/io-pgfault.c
 create mode 100644 drivers/iommu/io-pgtable-arm.h
 create mode 100644 drivers/iommu/iommu-sva.c
 create mode 100644 drivers/iommu/iommu-sva.h

-- 
2.25.0