arm_pmu: Add support for 64bit event counters
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Tue, 10 Jul 2018 08:58:00 +0000 (09:58 +0100)
committerWill Deacon <will.deacon@arm.com>
Tue, 10 Jul 2018 17:19:02 +0000 (18:19 +0100)
commite2da97d328d4951d25f6634eda7213f7257417b6
tree720f1eb257839024079bd868eea080cc895be84e
parent3a95200d3f89afd8b67f39d88d36cc7ec96ce385
arm_pmu: Add support for 64bit event counters

Each PMU has a set of 32bit event counters. But in some
special cases, the events could be counted using counters
which are effectively 64bit wide.

e.g, Arm V8 PMUv3 has a 64 bit cycle counter which can count
only the CPU cycles. Also, the PMU can chain the event counters
to effectively count as a 64bit counter.

Add support for tracking the events that uses 64bit counters.
This only affects the periods set for each counter in the core
driver.

Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
drivers/perf/arm_pmu.c
include/linux/perf/arm_pmu.h