[PATCH v3 2/7] arm_pmu: Change API to support 64bit counter values

From: suzuki.poulose@arm.com (Suzuki K Poulose)
Date: 2018-06-19 10:17:26
Also in: lkml
Subsystem: arm pmu profiling and debugging, arm port, arm64 port (aarch64 architecture), performance events subsystem, the rest · Maintainers: Will Deacon, Mark Rutland, Russell King, Catalin Marinas, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds

Convert the {read/write}_counter APIs to handle 64bit values
to enable supporting chained event counters.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <redacted>
Reviewed-by: Julien Thierry <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 - No changes since v2
---
 arch/arm/kernel/perf_event_v6.c     | 4 ++--
 arch/arm/kernel/perf_event_v7.c     | 4 ++--
 arch/arm/kernel/perf_event_xscale.c | 8 ++++----
 arch/arm64/kernel/perf_event.c      | 9 ++++-----
 include/linux/perf/arm_pmu.h        | 4 ++--
 5 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c
index f64a6bf..0729f98 100644
--- a/arch/arm/kernel/perf_event_v6.c
+++ b/arch/arm/kernel/perf_event_v6.c

@@ -233,7 +233,7 @@ armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
 	return ret;
 }
 
-static inline u32 armv6pmu_read_counter(struct perf_event *event)
+static inline u64 armv6pmu_read_counter(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

@@ -251,7 +251,7 @@ static inline u32 armv6pmu_read_counter(struct perf_event *event)
 	return value;
 }
 
-static inline void armv6pmu_write_counter(struct perf_event *event, u32 value)
+static inline void armv6pmu_write_counter(struct perf_event *event, u64 value)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index ecca4cd..fd7ce01 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c

@@ -743,7 +743,7 @@ static inline void armv7_pmnc_select_counter(int idx)
 	isb();
 }
 
-static inline u32 armv7pmu_read_counter(struct perf_event *event)
+static inline u64 armv7pmu_read_counter(struct perf_event *event)
 {
 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;

@@ -763,7 +763,7 @@ static inline u32 armv7pmu_read_counter(struct perf_event *event)
 	return value;
 }
 
-static inline void armv7pmu_write_counter(struct perf_event *event, u32 value)
+static inline void armv7pmu_write_counter(struct perf_event *event, u64 value)
 {
 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;

diff --git a/arch/arm/kernel/perf_event_xscale.c b/arch/arm/kernel/perf_event_xscale.c
index c4f0294..942230f 100644
--- a/arch/arm/kernel/perf_event_xscale.c
+++ b/arch/arm/kernel/perf_event_xscale.c

@@ -316,7 +316,7 @@ static void xscale1pmu_stop(struct arm_pmu *cpu_pmu)
 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 }
 
-static inline u32 xscale1pmu_read_counter(struct perf_event *event)
+static inline u64 xscale1pmu_read_counter(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

@@ -337,7 +337,7 @@ static inline u32 xscale1pmu_read_counter(struct perf_event *event)
 	return val;
 }
 
-static inline void xscale1pmu_write_counter(struct perf_event *event, u32 val)
+static inline void xscale1pmu_write_counter(struct perf_event *event, u64 val)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

@@ -678,7 +678,7 @@ static void xscale2pmu_stop(struct arm_pmu *cpu_pmu)
 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 }
 
-static inline u32 xscale2pmu_read_counter(struct perf_event *event)
+static inline u64 xscale2pmu_read_counter(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

@@ -705,7 +705,7 @@ static inline u32 xscale2pmu_read_counter(struct perf_event *event)
 	return val;
 }
 
-static inline void xscale2pmu_write_counter(struct perf_event *event, u32 val)
+static inline void xscale2pmu_write_counter(struct perf_event *event, u64 val)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	int counter = hwc->idx;

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 678ecff..66a2ffd 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c

@@ -512,7 +512,7 @@ static inline int armv8pmu_select_counter(int idx)
 	return idx;
 }
 
-static inline u32 armv8pmu_read_counter(struct perf_event *event)
+static inline u64 armv8pmu_read_counter(struct perf_event *event)
 {
 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;

@@ -530,7 +530,7 @@ static inline u32 armv8pmu_read_counter(struct perf_event *event)
 	return value;
 }
 
-static inline void armv8pmu_write_counter(struct perf_event *event, u32 value)
+static inline void armv8pmu_write_counter(struct perf_event *event, u64 value)
 {
 	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 	struct hw_perf_event *hwc = &event->hw;

@@ -545,9 +545,8 @@ static inline void armv8pmu_write_counter(struct perf_event *event, u32 value)
 		 * count using the lower 32bits and we want an interrupt when
 		 * it overflows.
 		 */
-		u64 value64 = 0xffffffff00000000ULL | value;
-
-		write_sysreg(value64, pmccntr_el0);
+		value |= 0xffffffff00000000ULL;
+		write_sysreg(value, pmccntr_el0);
 	} else if (armv8pmu_select_counter(idx) == idx)
 		write_sysreg(value, pmxevcntr_el0);
 }

diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 12c30a2..f7126a2 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h

@@ -87,8 +87,8 @@ struct arm_pmu {
 					 struct perf_event *event);
 	int		(*set_event_filter)(struct hw_perf_event *evt,
 					    struct perf_event_attr *attr);
-	u32		(*read_counter)(struct perf_event *event);
-	void		(*write_counter)(struct perf_event *event, u32 val);
+	u64		(*read_counter)(struct perf_event *event);
+	void		(*write_counter)(struct perf_event *event, u64 val);
 	void		(*start)(struct arm_pmu *);
 	void		(*stop)(struct arm_pmu *);
 	void		(*reset)(void *);

-- 
2.7.4

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