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/v5
Changes since v4: - 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 | 395 +++++++++++++++++-- 7 files changed, 567 insertions(+), 38 deletions(-)