[PATCH v3 0/7] arm64: Add support for Armv9.4 PMU fixed instruction counter

From: Rob Herring (Arm)
Date: Wed Jul 31 2024 - 12:51:46 EST


This series adds support for the optional fixed instruction counter
added in Armv9.4 PMU. Most of the series is a refactoring to remove the
index to counter number conversion which dates back to the Armv7 PMU
driver. Removing it is necessary in order to support more than 32
counters without a bunch of conditional code further complicating the
conversion.

Patch 1 changes struct arm_pmu.num_events to a bitmap of events, and
updates all the users. This removes the index to counter conversion
on the PMUv3 and Armv7 drivers.

Patch 2 updates various register accessors to use 64-bit values matching
the register size.

Patches 3-4 update KVM PMU register accesses to use shared accessors
from asm/arm_pmuv3.h.

Patches 5-6 rework KVM and perf PMU defines for counter indexes and
number of counters.

Patch 7 finally adds support for the fixed instruction counter.

I tested this on FVP with VHE host and a guest. Also ran kvm-unittests
in Arm's kernelCI.

Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
---
Changes in v3:
- Fix using 64-bit counters in pre-Armv8.5. The chained event check
for cycle counter in armv8pmu_event_is_chained() was returning the
cycle counter needed chaining which is never true. Separate fix is
here: https://lore.kernel.org/all/20240710182357.3701635-1-robh@xxxxxxxxxx/
- Rebase to v6.11-rc1 and dropped already applied patches
- Link to v2: https://lore.kernel.org/r/20240626-arm-pmu-3-9-icntr-v2-0-c9784b4f4065@xxxxxxxxxx

Changes in v2:
- Include threshold fix patches and account for threshold support in
counter assignment.
- Add patch including asm/arm_pmuv3.h from linux/perf/arm_pmuv3.h
- Fix compile error for Apple PMU
- Minor review comments detailed in individual patches
- Link to v1: https://lore.kernel.org/r/20240607-arm-pmu-3-9-icntr-v1-0-c7bd2dceff3b@xxxxxxxxxx

---
Rob Herring (Arm) (7):
perf: arm_pmu: Remove event index to counter remapping
perf: arm_pmuv3: Prepare for more than 32 counters
KVM: arm64: pmu: Use arm_pmuv3.h register accessors
KVM: arm64: pmu: Use generated define for PMSELR_EL0.SEL access
arm64: perf/kvm: Use a common PMU cycle counter define
KVM: arm64: Refine PMU defines for number of counters
perf: arm_pmuv3: Add support for Armv9.4 PMU instruction counter

arch/arm/include/asm/arm_pmuv3.h | 20 ++++++
arch/arm64/include/asm/arm_pmuv3.h | 53 ++++++++++++--
arch/arm64/include/asm/kvm_host.h | 8 +--
arch/arm64/include/asm/sysreg.h | 1 -
arch/arm64/kvm/pmu-emul.c | 14 ++--
arch/arm64/kvm/pmu.c | 87 ++++++-----------------
arch/arm64/kvm/sys_regs.c | 11 +--
arch/arm64/tools/sysreg | 30 ++++++++
drivers/perf/apple_m1_cpu_pmu.c | 4 +-
drivers/perf/arm_pmu.c | 11 +--
drivers/perf/arm_pmuv3.c | 140 +++++++++++++++++++------------------
drivers/perf/arm_v6_pmu.c | 6 +-
drivers/perf/arm_v7_pmu.c | 77 ++++++++------------
drivers/perf/arm_xscale_pmu.c | 12 ++--
include/kvm/arm_pmu.h | 8 +--
include/linux/perf/arm_pmu.h | 10 ++-
include/linux/perf/arm_pmuv3.h | 9 ++-
17 files changed, 272 insertions(+), 229 deletions(-)
---
base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
change-id: 20240607-arm-pmu-3-9-icntr-04375ddd0082

Best regards,
--
Rob Herring (Arm) <robh@xxxxxxxxxx>