[PATCH v4 03/11] perf: provide a common perf_event_nop_0() for use with .event_idx

[Cody P Schafer <cody@linux.vnet.ibm.com>]

Rather an having every pmu that needs a function that just returns 0 for
.event_idx define their own copy, reuse the one in kernel/events/core.c.

Rename from perf_swevent_event_idx() because we're no longer using it
for just software events. Naming is based on the perf_pmu_nop_*()
functions.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
---
 include/linux/perf_event.h |  1 +
 kernel/events/core.c       | 10 +++++-----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 5c12009..23da668 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -560,6 +560,7 @@ extern void perf_pmu_migrate_context(struct pmu *pmu,
 extern u64 perf_event_read_value(struct perf_event *event,
 				 u64 *enabled, u64 *running);
 
+extern int perf_event_nop_0(struct perf_event *event);
 
 struct perf_sample_data {
 	u64				type;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index fa0b2d4..16bf7c2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5816,7 +5816,7 @@ static int perf_swevent_init(struct perf_event *event)
 	return 0;
 }
 
-static int perf_swevent_event_idx(struct perf_event *event)
+int perf_event_nop_0(struct perf_event *event)
 {
 	return 0;
 }
@@ -5831,7 +5831,7 @@ static struct pmu perf_swevent = {
 	.stop		= perf_swevent_stop,
 	.read		= perf_swevent_read,
 
-	.event_idx	= perf_swevent_event_idx,
+	.event_idx	= perf_event_nop_0,
 };
 
 #ifdef CONFIG_EVENT_TRACING
@@ -5950,7 +5950,7 @@ static struct pmu perf_tracepoint = {
 	.stop		= perf_swevent_stop,
 	.read		= perf_swevent_read,
 
-	.event_idx	= perf_swevent_event_idx,
+	.event_idx	= perf_event_nop_0,
 };
 
 static inline void perf_tp_register(void)
@@ -6177,7 +6177,7 @@ static struct pmu perf_cpu_clock = {
 	.stop		= cpu_clock_event_stop,
 	.read		= cpu_clock_event_read,
 
-	.event_idx	= perf_swevent_event_idx,
+	.event_idx	= perf_event_nop_0,
 };
 
 /*
@@ -6257,7 +6257,7 @@ static struct pmu perf_task_clock = {
 	.stop		= task_clock_event_stop,
 	.read		= task_clock_event_read,
 
-	.event_idx	= perf_swevent_event_idx,
+	.event_idx	= perf_event_nop_0,
 };
 
 static void perf_pmu_nop_void(struct pmu *pmu)
-- 
1.9.0