From: Will Deacon <will.deacon@arm.com>
To: Andrew Murray <andrew.murray@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v8 4/6] arm64: perf: extract chain helper into header
Date: Mon, 10 Jun 2019 12:39:08 +0100 [thread overview]
Message-ID: <20190610113908.GE15979@fuggles.cambridge.arm.com> (raw)
In-Reply-To: <20190522153019.18645-5-andrew.murray@arm.com>
On Wed, May 22, 2019 at 04:30:17PM +0100, Andrew Murray wrote:
> The ARMv8 Performance Monitors Extension includes an architectural
> event type named CHAIN which allows for chaining counters together.
>
> Let's extract the test for this event into a header file such that
> other users, such as KVM (for PMU emulation) can make use of.
>
> Signed-off-by: Andrew Murray <andrew.murray@arm.com>
> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> arch/arm64/include/asm/perf_event.h | 5 +++++
> arch/arm64/kernel/perf_event.c | 2 +-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h
> index c593761ba61c..cd13f3fd1055 100644
> --- a/arch/arm64/include/asm/perf_event.h
> +++ b/arch/arm64/include/asm/perf_event.h
> @@ -219,6 +219,11 @@
> #define ARMV8_PMU_USERENR_CR (1 << 2) /* Cycle counter can be read at EL0 */
> #define ARMV8_PMU_USERENR_ER (1 << 3) /* Event counter can be read at EL0 */
>
> +static inline bool armv8pmu_evtype_is_chain(u64 evtype)
> +{
> + return (evtype == ARMV8_PMUV3_PERFCTR_CHAIN);
> +}
> +
> #ifdef CONFIG_PERF_EVENTS
> struct pt_regs;
> extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
> index 314b1adedf06..265bd835a724 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -879,7 +879,7 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event,
> static int armv8pmu_filter_match(struct perf_event *event)
> {
> unsigned long evtype = event->hw.config_base & ARMV8_PMU_EVTYPE_EVENT;
> - return evtype != ARMV8_PMUV3_PERFCTR_CHAIN;
> + return !armv8pmu_evtype_is_chain(evtype);
Acked-by: Will Deacon <will.deacon@arm.com>
Although if the definition of armv8pmu_evtype_is_chain() isn't going to
get any more complicated than a single evtype comparison, I'm not sure it's
worth this abstraction, to be honest.
Will
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next prev parent reply other threads:[~2019-06-10 11:39 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 15:30 [PATCH v8 0/6] KVM: arm/arm64: add support for chained counters Andrew Murray
2019-05-22 15:30 ` [PATCH v8 1/6] KVM: arm/arm64: rename kvm_pmu_{enable/disable}_counter functions Andrew Murray
2019-05-22 15:30 ` [PATCH v8 2/6] KVM: arm/arm64: extract duplicated code to own function Andrew Murray
2019-05-22 15:30 ` [PATCH v8 3/6] KVM: arm/arm64: re-create event when setting counter value Andrew Murray
2019-05-22 15:30 ` [PATCH v8 4/6] arm64: perf: extract chain helper into header Andrew Murray
2019-06-10 11:39 ` Will Deacon [this message]
2019-05-22 15:30 ` [PATCH v8 5/6] KVM: arm/arm64: remove pmc->bitmask Andrew Murray
2019-05-22 16:07 ` Marc Zyngier
2019-05-22 16:26 ` Andrew Murray
2019-06-10 12:54 ` Suzuki K Poulose
2019-06-12 14:30 ` Andrew Murray
2019-05-22 15:30 ` [PATCH v8 6/6] KVM: arm/arm64: support chained PMU counters Andrew Murray
2019-06-10 10:21 ` Julien Thierry
2019-06-10 16:05 ` Suzuki K Poulose
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