[PATCH 3/6] ARM: perf-events: allow modules to query the number of hardware counters
Will Deacon
will.deacon at arm.com
Mon Apr 19 12:42:38 EDT 2010
For OProfile to initialise oprofilefs correctly, it needs to know
the number of counters it can represent.
This patch adds a function to the ARM perf-events backend to return
the number of hardware counters available for the current PMU.
Cc: Jamie Iles <jamie.iles at picochip.com>
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
arch/arm/include/asm/perf_event.h | 3 +++
arch/arm/kernel/perf_event.c | 12 ++++++++++++
2 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/perf_event.h b/arch/arm/include/asm/perf_event.h
index fa4b326..48837e6 100644
--- a/arch/arm/include/asm/perf_event.h
+++ b/arch/arm/include/asm/perf_event.h
@@ -42,4 +42,7 @@ enum arm_perf_pmu_ids {
extern enum arm_perf_pmu_ids
armpmu_get_pmu_id(void);
+extern int
+armpmu_get_max_events(void);
+
#endif /* __ARM_PERF_EVENT_H__ */
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 381f121..c457686 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -111,6 +111,18 @@ armpmu_get_pmu_id(void)
}
EXPORT_SYMBOL_GPL(armpmu_get_pmu_id);
+int
+armpmu_get_max_events(void)
+{
+ int max_events = 0;
+
+ if (armpmu != NULL)
+ max_events = armpmu->num_events;
+
+ return max_events;
+}
+EXPORT_SYMBOL_GPL(armpmu_get_max_events);
+
#define HW_OP_UNSUPPORTED 0xFFFF
#define C(_x) \
--
1.6.3.3
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