perf, x86: Move perfctr init code to x86_setup_perfctr()

Split __hw_perf_event_init() to configure pmu events other than
perfctrs. Perfctr code is moved to a separate function
x86_setup_perfctr(). This and the following patches refactor the code.

Split in multiple patches for better review.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1271190201-25705-2-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perf_event.c

@@ -426,6 +426,8 @@ set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event_attr *attr)
 	return 0;
 }
 
+static int x86_setup_perfctr(struct perf_event *event);
+
 static int x86_pmu_hw_config(struct perf_event *event)
 {
 	/*
@@ -453,9 +455,6 @@ static int x86_pmu_hw_config(struct perf_event *event)
  */
 static int __hw_perf_event_init(struct perf_event *event)
 {
-	struct perf_event_attr *attr = &event->attr;
-	struct hw_perf_event *hwc = &event->hw;
-	u64 config;
 	int err;
 
 	if (!x86_pmu_initialized())
@@ -482,15 +481,24 @@ static int __hw_perf_event_init(struct perf_event *event)
 
 	event->destroy = hw_perf_event_destroy;
 
-	hwc->idx = -1;
-	hwc->last_cpu = -1;
-	hwc->last_tag = ~0ULL;
+	event->hw.idx = -1;
+	event->hw.last_cpu = -1;
+	event->hw.last_tag = ~0ULL;
 
 	/* Processor specifics */
 	err = x86_pmu.hw_config(event);
 	if (err)
 		return err;
 
+	return x86_setup_perfctr(event);
+}
+
+static int x86_setup_perfctr(struct perf_event *event)
+{
+	struct perf_event_attr *attr = &event->attr;
+	struct hw_perf_event *hwc = &event->hw;
+	u64 config;
+
 	if (!hwc->sample_period) {
 		hwc->sample_period = x86_pmu.max_period;
 		hwc->last_period = hwc->sample_period;