On 2019-10-11 4:46 am, Nicolin Chen wrote:
This series of patches add an optional DT property to allow an SoC to
specify how many bits being physically connected to its SMMU instance,
depending on the SoC design.

This has come up before, and it doesn't work in general because a single SMMU instance can have many master interfaces, with potentially different sizes of address bus wired up to each. It's also a conceptually-wrong approach anyway, since this isn't a property of the SMMU; it's a property of the interconnect(s) upstream of the SMMU.

IIRC you were working on Tegra - if so, Thierry already has a plan, see this thread: https://lore.kernel.org/linux-arm-kernel/20190930133510.GA1904140@ulmo/


Nicolin Chen (2):
   dt-bindings: arm-smmu: Add an optional "input-address-size" property
   iommu/arm-smmu: Read optional "input-address-size" property

  Documentation/devicetree/bindings/iommu/arm,smmu.txt |  7 +++++++
  drivers/iommu/arm-smmu.c                             | 10 ++++++++--
  2 files changed, 15 insertions(+), 2 deletions(-)

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