From: Mark Rutland <mark.rutland@arm.com>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, will.deacon@arm.com,
robin.murphy@arm.com, julien.thierry@arm.com
Subject: Re: [PATCH v3 5/7] arm64: perf: Clean up armv8pmu_select_counter
Date: Fri, 29 Jun 2018 14:29:23 +0100 [thread overview]
Message-ID: <20180629132922.la6lntd54kut5c4y@lakrids.cambridge.arm.com> (raw)
In-Reply-To: <1529403342-17899-6-git-send-email-suzuki.poulose@arm.com>
On Tue, Jun 19, 2018 at 11:15:40AM +0100, Suzuki K Poulose wrote:
> armv8pmu_select_counter always returns the passed idx. So
> let us make that void and get rid of the pointless checks.
>
> Suggested-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/kernel/perf_event.c | 29 +++++++++++++++++++----------
> 1 file changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
> index 66a2ffd..9ce3729 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -503,13 +503,17 @@ static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx)
> return pmnc & BIT(ARMV8_IDX_TO_COUNTER(idx));
> }
>
> -static inline int armv8pmu_select_counter(int idx)
> +static inline void armv8pmu_select_counter(int idx)
> {
> u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> write_sysreg(counter, pmselr_el0);
> isb();
> +}
>
> - return idx;
> +static inline u32 armv8pmu_read_evcntr(int idx)
> +{
> + armv8pmu_select_counter(idx);
> + return read_sysreg(pmxevcntr_el0);
> }
>
> static inline u64 armv8pmu_read_counter(struct perf_event *event)
> @@ -524,12 +528,18 @@ static inline u64 armv8pmu_read_counter(struct perf_event *event)
> smp_processor_id(), idx);
> else if (idx == ARMV8_IDX_CYCLE_COUNTER)
> value = read_sysreg(pmccntr_el0);
> - else if (armv8pmu_select_counter(idx) == idx)
> - value = read_sysreg(pmxevcntr_el0);
> + else
> + value = armv8pmu_read_evcntr(idx);
>
> return value;
> }
>
> +static inline void armv8pmu_write_evcntr(int idx, u32 value)
> +{
> + armv8pmu_select_counter(idx);
> + write_sysreg(value, pmxevcntr_el0);
> +}
> +
> static inline void armv8pmu_write_counter(struct perf_event *event, u64 value)
> {
> struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
> @@ -547,16 +557,15 @@ static inline void armv8pmu_write_counter(struct perf_event *event, u64 value)
> */
> value |= 0xffffffff00000000ULL;
> write_sysreg(value, pmccntr_el0);
> - } else if (armv8pmu_select_counter(idx) == idx)
> - write_sysreg(value, pmxevcntr_el0);
> + } else
> + armv8pmu_write_evcntr(idx, value);
> }
>
> static inline void armv8pmu_write_evtype(int idx, u32 val)
> {
> - if (armv8pmu_select_counter(idx) == idx) {
> - val &= ARMV8_PMU_EVTYPE_MASK;
> - write_sysreg(val, pmxevtyper_el0);
> - }
> + armv8pmu_select_counter(idx);
> + val &= ARMV8_PMU_EVTYPE_MASK;
> + write_sysreg(val, pmxevtyper_el0);
> }
>
> static inline int armv8pmu_enable_counter(int idx)
> --
> 2.7.4
>
next prev parent reply other threads:[~2018-06-29 13:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-19 10:15 [PATCH v3 0/7] arm64: perf: Support for chained counters Suzuki K Poulose
2018-06-19 10:15 ` [PATCH v3 1/7] arm_pmu: Clean up maximum period handling Suzuki K Poulose
2018-06-19 10:45 ` Mark Rutland
2018-06-19 10:15 ` [PATCH v3 2/7] arm_pmu: Change API to support 64bit counter values Suzuki K Poulose
2018-06-19 10:52 ` Mark Rutland
2018-06-19 10:15 ` [PATCH v3 3/7] arm_pmu: Add support for 64bit event counters Suzuki K Poulose
2018-06-19 10:57 ` Mark Rutland
2018-06-19 10:15 ` [PATCH v3 4/7] arm_pmu: Tidy up clear_event_idx call backs Suzuki K Poulose
2018-06-29 13:27 ` Mark Rutland
2018-06-29 13:40 ` Mark Rutland
2018-06-29 14:18 ` Suzuki K Poulose
2018-06-29 14:29 ` Mark Rutland
2018-06-19 10:15 ` [PATCH v3 5/7] arm64: perf: Clean up armv8pmu_select_counter Suzuki K Poulose
2018-06-29 13:29 ` Mark Rutland [this message]
2018-06-19 10:15 ` [PATCH v3 6/7] arm64: perf: Disable PMU while processing counter overflows Suzuki K Poulose
2018-06-19 10:43 ` Mark Rutland
2018-06-19 10:15 ` [PATCH v3 7/7] arm64: perf: Add support for chaining event counters Suzuki K Poulose
2018-06-29 14:01 ` Mark Rutland
2018-06-29 14:29 ` Suzuki K Poulose
2018-06-29 14:39 ` Mark Rutland
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