iommu/arm-smmu-qcom: Limit the SMR groups to 128

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Some platforms support more than 128 stream matching groups than what is
defined by the ARM SMMU architecture specification. But due to some unknown
reasons, those additional groups don't exhibit the same behavior as the
architecture supported ones.

For instance, the additional groups will not detect the quirky behavior of
some firmware versions intercepting writes to S2CR register, thus skipping
the quirk implemented in the driver and causing boot crash.

So let's limit the groups to 128 for now until the issue with those groups
are fixed and issue a notice to users in that case.

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20230327080029.11584-1-manivannan.sadhasivam@linaro.org
[will: Reworded the comment slightly]
Signed-off-by: Will Deacon <will@kernel.org>

...

This commit is contained in:

Manivannan Sadhasivam 2023-03-27 13:30:29 +05:30 • committed by Will Deacon

parent 8c153645fa

commit 1226113473

1 changed files with 15 additions and 1 deletions

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drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

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