[v2,0/4] Add system mmu support for Armada-806

Message

Gregory CLEMENT July 11, 2019, 3:02 p.m. UTC

Hello,

last year a first version of this series was submitted to add support
for IOMMU for AP806, including workaround for accessing ARM SMMU 64bit
registers[1].

For the record, AP-806 can't access SMMU registers with 64bit width,
this patches split the readq/writeq for 32bit access, due to erratanum
#582743.

Based on the feedback from Robin Murphy, I also add code ensuring that
we won't try to use AArch64 format with 32 bits acces.

It was also discussed to not use compatible but propertu to support
this workaround. I agree to make this change if needed, but for now I
would like to have a feedback on the current code to know if it is
acceptable if there is still potential issue.

The series was tested on a vanilla v5.1 kernel, and without the
series, an USB stick was not detected under QEMU whereas with this
series it worked as expected.

Greogry

[1]: https://lkml.org/lkml/2018/10/15/373

Gregory CLEMENT (1):
  arm64: dts: marvell: armada-ap806: add smmu support

Hanna Hawa (3):
  iommu/arm-smmu: Introduce wrapper for writeq/readq
  iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum
    #582743
  dt-bindings: iommu/arm,smmu: add compatible string for Marvell

 Documentation/arm64/silicon-errata.txt        |  2 +
 .../devicetree/bindings/iommu/arm,smmu.txt    |  1 +
 arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 17 +++++
 drivers/iommu/arm-smmu.c                      | 74 ++++++++++++++++---
 4 files changed, 83 insertions(+), 11 deletions(-)