This series makes ETM TRCCCCTRL based 'cc_threshold' user configurable via the perf event attribute. But first, this implements an errata work around affecting ETM TRCIDR3.CCITMIN value on certain cpus, overriding the field.
This series applies on coresight/for-next/queue.
Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Mike Leach mike.leach@linaro.org Cc: James Clark james.clark@arm.com Cc: Leo Yan leo.yan@linaro.org Cc: Jonathan Corbet corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org
Changes in V5:
https://lore.kernel.org/all/20230821045216.641499-1-anshuman.khandual@arm.co...
- Replaced 'where as' with single word 'whereas' - Reworked 'cc_threshold' fallback to ETM_CYC_THRESHOLD_DEFAULT
Changes in V4:
https://lore.kernel.org/all/20230818112051.594986-1-anshuman.khandual@arm.co...
- Fixed a typo s/rangess/ranges, - Renamed etm4_work_around_wrong_ccitmin() as etm4_core_reads_wrong_ccitmin() - Moved drvdata->ccitmin value check for 256 inside etm4_core_reads_wrong_ccitmin() - Moved the comment inside etm4_core_reads_wrong_ccitmin()
Changes in V3:
https://lore.kernel.org/all/20230811034600.944386-1-anshuman.khandual@arm.co...
- Added errata work around affecting TRCIDR3.CCITMIN - Split the document update into a separate patch
Changes in V2:
https://lore.kernel.org/all/20230808074533.380537-1-anshuman.khandual@arm.co...
- s/treshhold/threshold
Changes in V1:
https://lore.kernel.org/all/20230804044720.1478900-1-anshuman.khandual@arm.c...
Anshuman Khandual (3): coresight: etm: Override TRCIDR3.CCITMIN on errata affected cpus coresight: etm: Make cycle count threshold user configurable Documentation: coresight: Add cc_threshold tunable
Documentation/arch/arm64/silicon-errata.rst | 10 +++++ Documentation/trace/coresight/coresight.rst | 4 ++ .../hwtracing/coresight/coresight-etm-perf.c | 2 + .../coresight/coresight-etm4x-core.c | 45 ++++++++++++++++++- 4 files changed, 59 insertions(+), 2 deletions(-)