linux-kernel - [PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

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Message-ID: <1413980209-14913-1-git-send-email-chaiw.fnst@cn.fujitsu.com>
Date:	Wed, 22 Oct 2014 20:16:49 +0800
From:	chai wen <chaiw.fnst@...fujitsu.com>
To:	<will.deacon@....com>
CC:	<mark.rutland@....com>, <linux@....linux.org.uk>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>, <yuichi.kusakabe@...fujitsu.com>,
	chai wen <chaiw.fnst@...fujitsu.com>
Subject: [PATCH resend] ARM: perf: remove useless return and check of idx in counter handling

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, as idx validation check was moved
out all these functions by commit 7279adbd9bb8ef8f(ARM: perf: check ARMv7
counter validity on a per-pmu basis).
Let's remove the useless return of idx from these functions.

Acked-by: Mark Rutland <mark.rutland@....com>
Signed-off-by: chai wen <chaiw.fnst@...fujitsu.com>
---
 arch/arm/kernel/perf_event_v7.c |   40 +++++++++++++++++---------------------
 1 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index 116758b..aaf5314 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)
@@ -580,13 +578,15 @@ static inline u32 armv7pmu_read_counter(struct perf_event *event)
 	int idx = hwc->idx;
 	u32 value = 0;
 
-	if (!armv7_pmnc_counter_valid(cpu_pmu, idx))
+	if (!armv7_pmnc_counter_valid(cpu_pmu, idx)) {
 		pr_err("CPU%u reading wrong counter %d\n",
 			smp_processor_id(), idx);
-	else if (idx == ARMV7_IDX_CYCLE_COUNTER)
+	} 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;
 }
@@ -597,45 +597,43 @@ static inline void armv7pmu_write_counter(struct perf_event *event, u32 value)
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
-	if (!armv7_pmnc_counter_valid(cpu_pmu, idx))
+	if (!armv7_pmnc_counter_valid(cpu_pmu, idx)) {
 		pr_err("CPU%u writing wrong counter %d\n",
 			smp_processor_id(), idx);
-	else if (idx == ARMV7_IDX_CYCLE_COUNTER)
+	} 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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