iommu/arm-smmu: Allow implementation specific write_s2cr

stable inclusion
from stable-5.10.4
commit 3192e184ad9476938d8fb797731dfd1ac25ffa09
bugzilla: 46903

--------------------------------

commit 56b75b51 upstream.

The firmware found in some Qualcomm platforms intercepts writes to the
S2CR register in order to replace the BYPASS type with FAULT. Further
more it treats faults at this level as catastrophic and restarts the
device.

Add support for providing implementation specific versions of the S2CR
write function, to allow the Qualcomm driver to work around this
behavior.

Cc: <stable@vger.kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20201019182323.3162386-2-bjorn.andersson@linaro.org


Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>