iommu/arm-smmu-qcom: Implement S2CR quirk
The firmware found in some Qualcomm platforms intercepts writes to S2CR in order to replace bypass type streams with fault; and ignore S2CR updates of type fault. Detect this behavior and implement a custom write_s2cr function in order to trick the firmware into supporting bypass streams by the means of configuring the stream for translation using a reserved and disabled context bank. Also circumvent the problem of configuring faulting streams by configuring the stream as bypass. Cc: <stable@vger.kernel.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Tested-by: Steev Klimaszewski <steev@kali.org> Acked-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20201019182323.3162386-4-bjorn.andersson@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
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