linux/drivers/hwtracing
Anshuman Khandual ac0ba21002 coresight: trbe: Work around the ignored system register writes
TRBE implementations affected by Arm erratum #2064142 might fail to write
into certain system registers after the TRBE has been disabled. Under some
conditions after TRBE has been disabled, writes into certain TRBE registers
TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1 and TRBTRG_EL1 will be
ignored and not be effected.

Work around this problem in the TRBE driver by executing TSB CSYNC and DSB
just after the trace collection has stopped and before performing a system
register write to one of the affected registers. 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/1643120437-14352-6-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
2022-03-11 10:06:35 +00:00
..
coresight coresight: trbe: Work around the ignored system register writes 2022-03-11 10:06:35 +00:00
intel_th bus: Make remove callback return void 2021-07-21 11:53:42 +02:00
stm stm class: Use correct UUID APIs 2021-04-16 07:26:50 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00