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.
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"
"Arm PMU"
Suzuki
Will
