coresight: trbe: Work around the trace data corruption
authorAnshuman Khandual <anshuman.khandual@arm.com>
Tue, 25 Jan 2022 14:20:37 +0000 (19:50 +0530)
committerMathieu Poirier <mathieu.poirier@linaro.org>
Thu, 27 Jan 2022 19:01:53 +0000 (12:01 -0700)
commitcc3154d9fe555f145131127ae0d2e375cdb90b3e
treee99edcc8948078d47139ef03851ca1a0c06f365d
parentf2629f4da4c70160fa3b8818f23b501a6be197f4
coresight: trbe: Work around the trace data corruption

TRBE implementations affected by Arm erratum #1902691 might corrupt trace
data or deadlock, when it's being written into the memory. Workaround this
problem in the driver, by preventing TRBE initialization on affected cpus.
The firmware must have disabled the access to TRBE for the kernel on such
implementations. This will cover the kernel for any firmware that doesn't
do this already. This just updates the TRBE driver as required.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-doc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/1643120437-14352-8-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
arch/arm64/Kconfig
drivers/hwtracing/coresight/coresight-trbe.c