[PATCH v2 0/8] drivers/perf: CPU PMU driver for Apple M1

[Marc Zyngier]

The M1 SoC embeds a per-CPU PMU that has a very different programming
interface compared to the architected PMUv3 that is normally present
on standard implementations.

This small series adds a driver for this HW by leveraging the arm_pmu
infrastructure, resulting in a rather simple driver.

Of course, we know next to nothing about the actual events this PMU
counts, aside from CPU cycles and instructions. Everything else is
undocumented (though as Dougall pointed out, someone could extract the
relevant information from a macOS install if they wanted -- I don't).

My hope is that this driver will help people to explore the event
space and propose possible interpretations for these events using
reproducible test cases.

* From v1 [1]:
  - Added a few comments clarifying the event mapping to counters
  - Spelling fixes
  - Collected Acks from Rob

[1] https://lore.kernel.org/r/20211113115429.4027571-1-maz@kernel.org

Marc Zyngier (8):
  dt-bindings: arm-pmu: Document Apple PMU compatible strings
  dt-bindings: apple,aic: Add CPU PMU per-cpu pseudo-interrupts
  irqchip/apple-aic: Add cpumasks for E and P cores
  irqchip/apple-aic: Wire PMU interrupts
  irqchip/apple-aic: Move PMU-specific registers to their own include
    file
  arm64: apple: t8301: Add PMU nodes
  drivers/perf: arm_pmu: Handle 47 bit counters
  drivers/perf: Add Apple icestorm/firestorm CPU PMU driver

 .../devicetree/bindings/arm/pmu.yaml          |   2 +
 .../interrupt-controller/apple,aic.yaml       |   2 +
 arch/arm64/boot/dts/apple/t8103.dtsi          |  12 +
 arch/arm64/include/asm/apple_m1_pmu.h         |  64 ++
 drivers/irqchip/irq-apple-aic.c               |  59 +-
 drivers/perf/Kconfig                          |   7 +
 drivers/perf/Makefile                         |   1 +
 drivers/perf/apple_m1_cpu_pmu.c               | 637 ++++++++++++++++++
 drivers/perf/arm_pmu.c                        |   2 +
 .../interrupt-controller/apple-aic.h          |   2 +
 include/linux/perf/arm_pmu.h                  |   2 +
 11 files changed, 768 insertions(+), 22 deletions(-)
 create mode 100644 arch/arm64/include/asm/apple_m1_pmu.h
 create mode 100644 drivers/perf/apple_m1_cpu_pmu.c

-- 
2.30.2