[PATCH v3 5/7] arm64: perf: Clean up armv8pmu_select_counter

From: Suzuki K Poulose
Date: Tue Jun 19 2018 - 06:16:50 EST


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@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
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