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).
I'm looking at allowing the perf userspace tool to load the event
descriptions at runtime, which would probably help.
* From v4 [4]:
- More DT binding tweaks
- Collected RB from Rob
- Rebased on 5.17-rc3
* From v3 [3]:
- DT binding fixes
- Typo fixes (and probably more added)
- Rebased on 5.17-rc1
* From v2 [2]:
- Reworked the way the FIQ virtual affinity is exposed (now coming
from the DT instead of being internal to the irqchip driver)
- Dropped the locking from the PMU driver after Mark's review
- Required the exclude_guest flag to be set, as the PMU doesn't seem
to be able to count guest events, at least by default
- Dropped the counter-stop on interrupt and instead stop the whole
PMU on interrupt
- Dropped the kernel taint, as I couldn't find a good way to do that
on first use
- Collected RBs from Hector
* 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@xxxxxxxxxx
[2] https://lore.kernel.org/r/20211201134909.390490-1-maz@xxxxxxxxxx
[3] https://lore.kernel.org/r/20211214182634.727330-1-maz@xxxxxxxxxx
[4] https://lore.kernel.org/r/20220124201231.298961-1-maz@xxxxxxxxxx
Marc Zyngier (10):
dt-bindings: arm-pmu: Document Apple PMU compatible strings
dt-bindings: apple,aic: Add CPU PMU per-cpu pseudo-interrupts
dt-bindings: apple,aic: Add affinity description for per-cpu
pseudo-interrupts
irqchip/apple-aic: Parse FIQ affinities from device-tree
irqchip/apple-aic: Wire PMU interrupts
arm64: dts: apple: Add t8103 PMU interrupt affinities
arm64: dts: apple: Add t8303 PMU nodes
irqchip/apple-aic: Move PMU-specific registers to their own include
file
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 | 31 +
arch/arm64/boot/dts/apple/t8103.dtsi | 24 +
arch/arm64/include/asm/apple_m1_pmu.h | 64 ++
drivers/irqchip/irq-apple-aic.c | 94 ++-
drivers/perf/Kconfig | 7 +
drivers/perf/Makefile | 1 +
drivers/perf/apple_m1_cpu_pmu.c | 584 ++++++++++++++++++
drivers/perf/arm_pmu.c | 2 +
.../interrupt-controller/apple-aic.h | 2 +
include/linux/perf/arm_pmu.h | 2 +
11 files changed, 791 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
