[PATCH 1/2] ARM: perf: armv7 remove useless return and check of idx in counter handling

From: chai wen
Date: Wed Oct 22 2014 - 04:26:47 EST


Idx sanity check was once implemented separately in these counter handling
functions and then return value was treated as a judgement.
armv7_pmnc_select_counter()
armv7_pmnc_enable_counter()
armv7_pmnc_disable_counter()
armv7_pmnc_enable_intens()
armv7_pmnc_disable_intens()
But we do not need to do this now, and the return of idx is useless.

Signed-off-by: chai wen <chaiw.fnst@xxxxxxxxxxxxxx>
---
arch/arm/kernel/perf_event_v7.c | 32 ++++++++++++++------------------
1 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index 116758b..f66a9b8 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c
@@ -564,13 +564,11 @@ static inline int armv7_pmnc_counter_has_overflowed(u32 pmnc, int idx)
return pmnc & BIT(ARMV7_IDX_TO_COUNTER(idx));
}

-static inline int armv7_pmnc_select_counter(int idx)
+static inline void armv7_pmnc_select_counter(int idx)
{
u32 counter = ARMV7_IDX_TO_COUNTER(idx);
asm volatile("mcr p15, 0, %0, c9, c12, 5" : : "r" (counter));
isb();
-
- return idx;
}

static inline u32 armv7pmu_read_counter(struct perf_event *event)
@@ -585,8 +583,10 @@ static inline u32 armv7pmu_read_counter(struct perf_event *event)
smp_processor_id(), idx);
else if (idx == ARMV7_IDX_CYCLE_COUNTER)
asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (value));
- else if (armv7_pmnc_select_counter(idx) == idx)
+ else {
+ armv7_pmnc_select_counter(idx);
asm volatile("mrc p15, 0, %0, c9, c13, 2" : "=r" (value));
+ }

return value;
}
@@ -602,40 +602,38 @@ static inline void armv7pmu_write_counter(struct perf_event *event, u32 value)
smp_processor_id(), idx);
else if (idx == ARMV7_IDX_CYCLE_COUNTER)
asm volatile("mcr p15, 0, %0, c9, c13, 0" : : "r" (value));
- else if (armv7_pmnc_select_counter(idx) == idx)
+ else {
+ armv7_pmnc_select_counter(idx);
asm volatile("mcr p15, 0, %0, c9, c13, 2" : : "r" (value));
+ }
}

static inline void armv7_pmnc_write_evtsel(int idx, u32 val)
{
- if (armv7_pmnc_select_counter(idx) == idx) {
- val &= ARMV7_EVTYPE_MASK;
- asm volatile("mcr p15, 0, %0, c9, c13, 1" : : "r" (val));
- }
+ armv7_pmnc_select_counter(idx);
+ val &= ARMV7_EVTYPE_MASK;
+ asm volatile("mcr p15, 0, %0, c9, c13, 1" : : "r" (val));
}

-static inline int armv7_pmnc_enable_counter(int idx)
+static inline void armv7_pmnc_enable_counter(int idx)
{
u32 counter = ARMV7_IDX_TO_COUNTER(idx);
asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r" (BIT(counter)));
- return idx;
}

-static inline int armv7_pmnc_disable_counter(int idx)
+static inline void armv7_pmnc_disable_counter(int idx)
{
u32 counter = ARMV7_IDX_TO_COUNTER(idx);
asm volatile("mcr p15, 0, %0, c9, c12, 2" : : "r" (BIT(counter)));
- return idx;
}

-static inline int armv7_pmnc_enable_intens(int idx)
+static inline void armv7_pmnc_enable_intens(int idx)
{
u32 counter = ARMV7_IDX_TO_COUNTER(idx);
asm volatile("mcr p15, 0, %0, c9, c14, 1" : : "r" (BIT(counter)));
- return idx;
}

-static inline int armv7_pmnc_disable_intens(int idx)
+static inline void armv7_pmnc_disable_intens(int idx)
{
u32 counter = ARMV7_IDX_TO_COUNTER(idx);
asm volatile("mcr p15, 0, %0, c9, c14, 2" : : "r" (BIT(counter)));
@@ -643,8 +641,6 @@ static inline int armv7_pmnc_disable_intens(int idx)
/* Clear the overflow flag in case an interrupt is pending. */
asm volatile("mcr p15, 0, %0, c9, c12, 3" : : "r" (BIT(counter)));
isb();
-
- return idx;
}

static inline u32 armv7_pmnc_getreset_flags(void)
--
1.7.1

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