arm64: perf: Add support caps under sysfs

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ARMv8.4-PMU introduces the PMMIR_EL1 registers and some new PMU events,
like STALL_SLOT etc, are related to it. Let's add a caps directory to
/sys/bus/event_source/devices/armv8_pmuv3_0/ and support slots from
PMMIR_EL1 registers in this entry. The user programs can get the slots
from sysfs directly.

/sys/bus/event_source/devices/armv8_pmuv3_0/caps/slots is exposed
under sysfs. Both ARMv8.4-PMU and STALL_SLOT event are implemented,
it returns the slots from PMMIR_EL1, otherwise it will return 0.

Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/1600754025-53535-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>

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Shaokun Zhang 2020-09-22 13:53:45 +08:00 • committed by Will Deacon

parent 688494a407

commit f5be3a61fd

4 changed files with 78 additions and 33 deletions

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3

arch/arm64/include/asm/perf_event.h

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2

arch/arm64/include/asm/sysreg.h

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103

arch/arm64/kernel/perf_event.c

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3

include/linux/perf/arm_pmu.h

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