On Mon, May 09, 2022 at 11:02:23AM +0100, Suzuki K Poulose wrote: > Cc: Mike Williams, Mathieu Poirier > > On 09/05/2022 10:28, Will Deacon wrote: > > On Sun, May 08, 2022 at 07:28:08PM -0500, Besar Wicaksono wrote: > > > Add driver support for ARM CoreSight PMU device and event attributes for NVIDIA > > > implementation. The code is based on ARM Coresight PMU architecture and ACPI ARM > > > Performance Monitoring Unit table (APMT) specification below: > > > * ARM Coresight PMU: > > > https://developer.arm.com/documentation/ihi0091/latest > > > * APMT: https://developer.arm.com/documentation/den0117/latest > > > > > > Notes: > > > * There is a concern on the naming of the PMU device. > > > Currently the driver is probing "arm-coresight-pmu" device, however the APMT > > > spec supports different kinds of CoreSight PMU based implementation. So it is > > > open for discussion if the name can stay or a "generic" name is required. > > > Please see the following thread: > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2022-May/740485.html > > > > > > Besar Wicaksono (2): > > > perf: coresight_pmu: Add support for ARM CoreSight PMU driver > > > perf: coresight_pmu: Add support for NVIDIA SCF and MCF attribute > > > > > > arch/arm64/configs/defconfig | 1 + > > > drivers/perf/Kconfig | 2 + > > > drivers/perf/Makefile | 1 + > > > drivers/perf/coresight_pmu/Kconfig | 10 + > > > drivers/perf/coresight_pmu/Makefile | 7 + > > > .../perf/coresight_pmu/arm_coresight_pmu.c | 1317 +++++++++++++++++ > > > .../perf/coresight_pmu/arm_coresight_pmu.h | 147 ++ > > > .../coresight_pmu/arm_coresight_pmu_nvidia.c | 300 ++++ > > > .../coresight_pmu/arm_coresight_pmu_nvidia.h | 17 + > > > 9 files changed, 1802 insertions(+) > > > > How does this interact with all the stuff we have under > > drivers/hwtracing/coresight/? > > Absolutely zero, except for the name. The standard > is named "CoreSight PMU" which is a bit unfortunate, > given the only link, AFAIU, with the "CoreSight" architecture > is the Lock Access Register(LAR). For reference, the > drivers/hwtracing/coresight/ is purely "CoreSight" self-hosted > tracing and the PMU is called "cs_etm" (expands to coresight etm). > Otherwise the standard doesn't have anything to do with what > exists already in the kernel. > > That said, I am concerned that the "coresight_pmu" is easily confused > with what exists today. Given that this is more of a "PMU" standard > for the IPs in the Arm world, it would be better to name it as such > avoiding any confusion with the existing PMUs. > Thanks Suzuki. I did suggest something similar[1] but asked to retain it so that it can be discussed in the bigger and right forum. > One potential recommendation for the name is, "Arm PMU" (The ACPI table is > named Arm PMU Table). But then that could be clashing with the armv8_pmu > :-(. > > Some of the other options are : > > "Arm Generic PMU" > "Arm Uncore PMU" I wasn't sure on this if there is any restriction on usage of this on Arm and hence didn't make the suggestion. But if allowed, this would be my choice too. -- Regards, Sudeep [1] https://lore.kernel.org/lkml/20220504182633.a3mwuiohfqtjvpep@bogus
