Re: [PATCH 07/10] arm64: Add erratum detection for TRBE overwrite in FILL mode

From: Catalin Marinas
Date: Mon Aug 02 2021 - 07:22:41 EST

On Wed, Jul 28, 2021 at 02:52:14PM +0100, Suzuki K Poulose wrote:
> Arm Neoverse-N2 and the Cortex-A710 cores are affected
> by a CPU erratum where the TRBE will overwrite the trace buffer
> in FILL mode. The TRBE doesn't stop (as expected in FILL mode)
> when it reaches the limit and wraps to the base to continue
> writing upto 3 cache lines. This will overwrite any trace that
> was written previously.
> Add the Neoverse-N2 erratumi(#2139208) and Cortex-A710 erratum
> (#2119858) to the detection logic.
> This will be used by the TRBE driver in later patches to work
> around the issue. The detection has been kept with the core
> arm64 errata framework list to make sure :
> - We don't duplicate the framework in TRBE driver
> - The errata detection is advertised like the rest
> of the CPU errata.
> Note that the Kconfig entries will be added after we have added
> the work around in the TRBE driver, which depends on the cpucap
> from here.
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Cc: Mike Leach <mike.leach@xxxxxxxxxx>
> cc: Leo Yan <leo.yan@xxxxxxxxxx>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>