Re: [PATCH v6 00/15] arm64: Self-hosted trace related errata workarounds

From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: will@kernel.org, catalin.marinas@arm.com,
	anshuman.khandual@arm.com, mike.leach@linaro.org,
	leo.yan@linaro.org, maz@kernel.org, coresight@lists.linaro.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 00/15] arm64: Self-hosted trace related errata workarounds
Date: Wed, 20 Oct 2021 09:42:07 -0600	[thread overview]
Message-ID: <20211020154207.GA3456574@p14s> (raw)
In-Reply-To: <20211019163153.3692640-1-suzuki.poulose@arm.com>

On Tue, Oct 19, 2021 at 05:31:38PM +0100, Suzuki K Poulose wrote:
> 
> This series adds CPU erratum work arounds related to the self-hosted
> tracing. The list of affected errata handled in this series are :
> 
>  * TRBE may overwrite trace in FILL mode
>    - Arm Neoverse-N2	#2139208
>    - Cortex-A710	#211985
> 
>  * A TSB instruction may not flush the trace completely when executed
>    in trace prohibited region.
> 
>    - Arm Neoverse-N2	#2067961
>    - Cortex-A710	#2054223
> 
>  * TRBE may write to out-of-range address
>    - Arm Neoverse-N2	#2253138
>    - Cortex-A710	#2224489
> 
> The series applies on coresight/next. The series has been reordered
> to make it easier to merge the patches via arm64 tree and the coresight
> tree.
> 
> Patches 1-4 are could be picked up via arm64 tree. The rest can go via
> the coresight tree. The Kconfig items for the TRBE errata are initially
> dropped in with dependency on COMPILE_TEST. These are dropped only after
> the driver is equipped with the work around in later patches.
> 
> 
> A tree is available here :
> 
> git@git.gitlab.arm.com:linux-arm/linux-skp.git  coresight/errata/trbe-tsb-n2-a710/v6
> 
> Changes since v5:
>  * https://lkml.kernel.org/r/20211014223125.2605031-1-suzuki.poulose@arm.com
>  - Fix typo in the Kconfig symbol usage in errata listing (Will)
>  - Fix typo in commit description for 
>    "arm64: errata: Add detection for TRBE overwrite in FILL mode"
>  - Fix commit description checkpatch warnings on column length for:
>     "arm64: errata: Add detection for TRBE write to out-of-range"
>  - Collected Reviews/Acks from Mathieu/Anshuman/Will
> 
> Changes since v4:
>  * https://lkml.kernel.org/r/20211012131743.2040596-1-suzuki.poulose@arm.com
> 
>  - Fix WARN on trbe driver probe on a hotplugged CPU, by making
>    sure that the arm_trbe_probe_cpu() is called from non-premptible
>    context. this_cpu_has_cap() doesn't like to be called from a
>    preemptible() context.
> 
>  - Fix Kconfig text issues pointed out by Randy
> 
> Changes since v3:
>  
>  - Fix missing Kconfig selection for TSB flush failure erratum (Will)
>    Merged the Kconfig changes to the core patch for TSB.
>  - Use COMPILE_TEST dependency for the TRBE work arounds instead of
>    delaying the Kconfig entries.
> 
> Changes since v2:
>  * https://lkml.kernel.org/r/20210921134121.2423546-1-suzuki.poulose@arm.com 
>  - Dropped patch adding a helper to reach cpudata from perf handle
>  - Split the TSB erratum work around patch to split the Kconfig/erratum
>    list update changes(pushed to the end of the series).
>  - Added wrappers to check the erratum :
>     trbe_has_erratum(cpudata, TRBE_ERRATUM_<TITLE>) -> trbe_may_<title>
>  - More ASCII art explanation on workaround.
> 
> Changes since v1:
>  * https://lkml.kernel.org/r/20210728135217.591173-1-suzuki.poulose@arm.com
>  - Added a fix to the TRBE driver handling of sink_specific data
>  - Added more description and ASCII art for overwrite in FILL mode
>    work around 
>  - Added another TRBE erratum to the list.
>   "TRBE may write to out-of-range address"
>   Patches from 12-17
>  - Added comment to list the expectations around TSB erratum workaround.
> 
> 
> 
> Suzuki K Poulose (15):
>   arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
>   arm64: errata: Add detection for TRBE overwrite in FILL mode
>   arm64: errata: Add workaround for TSB flush failures
>   arm64: errata: Add detection for TRBE write to out-of-range
>   coresight: trbe: Add a helper to calculate the trace generated
>   coresight: trbe: Add a helper to pad a given buffer area
>   coresight: trbe: Decouple buffer base from the hardware base
>   coresight: trbe: Allow driver to choose a different alignment
>   coresight: trbe: Add infrastructure for Errata handling
>   coresight: trbe: Workaround TRBE errata overwrite in FILL mode
>   coresight: trbe: Add a helper to determine the minimum buffer size
>   coresight: trbe: Make sure we have enough space
>   coresight: trbe: Work around write to out of range
>   arm64: errata: Enable workaround for TRBE overwrite in FILL mode
>   arm64: errata: Enable TRBE workaround for write to out-of-range
>     address
> 
>  Documentation/arm64/silicon-errata.rst       |  12 +
>  arch/arm64/Kconfig                           | 111 ++++++
>  arch/arm64/include/asm/barrier.h             |  16 +-
>  arch/arm64/include/asm/cputype.h             |   4 +
>  arch/arm64/kernel/cpu_errata.c               |  64 +++
>  arch/arm64/tools/cpucaps                     |   3 +
>  drivers/hwtracing/coresight/coresight-trbe.c | 394 +++++++++++++++++--
>  7 files changed, 567 insertions(+), 37 deletions(-)

I have applied this set.

Thanks,
Mathieu

> 
> -- 
> 2.25.4
> 

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