[PATCH 2/7] perf: New helper function for pmu name

[Matt Fleming]

Introduce perf_pmu_name() helper function that returns the name of the
pmu. This gives us a generic way to get the name of a pmu regardless of
how an architecture identifies it internally, e.g. ARM uses an id
whereas SH currently uses a string.

Signed-off-by: Matt Fleming <matt at console-pimps.org>
---
 arch/arm/kernel/perf_event.c |   23 +++++++++++++++++++++++
 arch/arm/oprofile/common.c   |   22 +---------------------
 arch/sh/kernel/perf_event.c  |   14 ++++++++++++++
 include/linux/perf_event.h   |    1 +
 kernel/perf_event.c          |    5 +++++
 5 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index ef3bc33..3bff24d 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -123,6 +123,29 @@ armpmu_get_max_events(void)
 }
 EXPORT_SYMBOL_GPL(armpmu_get_max_events);
 
+const char *perf_pmu_name(void)
+{
+	enum arm_perf_pmu_ids id = armpmu_get_pmu_id();
+
+	switch (id) {
+	case ARM_PERF_PMU_ID_XSCALE1:
+		return "arm/xscale1";
+	case ARM_PERF_PMU_ID_XSCALE2:
+		return "arm/xscale2";
+	case ARM_PERF_PMU_ID_V6:
+		return "arm/armv6";
+	case ARM_PERF_PMU_ID_V6MP:
+		return "arm/mpcore";
+	case ARM_PERF_PMU_ID_CA8:
+		return "arm/armv7";
+	case ARM_PERF_PMU_ID_CA9:
+		return "arm/armv7-ca9";
+	default:
+		return NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(perf_pmu_name);
+
 int perf_num_counters(void)
 {
 	return armpmu_get_max_events();
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index 23f18a0..cb224ee 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -155,26 +155,6 @@ static void op_perf_stop(void)
 }
 
 
-static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
-{
-	switch (id) {
-	case ARM_PERF_PMU_ID_XSCALE1:
-		return "arm/xscale1";
-	case ARM_PERF_PMU_ID_XSCALE2:
-		return "arm/xscale2";
-	case ARM_PERF_PMU_ID_V6:
-		return "arm/armv6";
-	case ARM_PERF_PMU_ID_V6MP:
-		return "arm/mpcore";
-	case ARM_PERF_PMU_ID_CA8:
-		return "arm/armv7";
-	case ARM_PERF_PMU_ID_CA9:
-		return "arm/armv7-ca9";
-	default:
-		return NULL;
-	}
-}
-
 static int op_arm_create_files(struct super_block *sb, struct dentry *root)
 {
 	unsigned int i;
@@ -391,7 +371,7 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
 	ops->start		= op_arm_start;
 	ops->stop		= op_arm_stop;
 	ops->shutdown		= op_arm_stop;
-	ops->cpu_type		= op_name_from_perf_id(armpmu_get_pmu_id());
+	ops->cpu_type		= perf_pmu_name();
 
 	if (!ops->cpu_type)
 		ret = -ENODEV;
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 2cb9ad5..e065a1d 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -59,6 +59,20 @@ static inline int sh_pmu_initialized(void)
 	return !!sh_pmu;
 }
 
+const char *perf_pmu_name(void)
+{
+	if (!sh_pmu)
+		return NULL;
+
+	if (!strcmp(sh_pmu->name, "SH7750"))
+		return "sh/sh7750";
+	if (!strcmp(sh_pmu->name, "SH-4A"))
+		return "sh/sh4a";
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(perf_pmu_name);
+
 int perf_num_counters(void)
 {
 	if (!sh_pmu)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 1a02192..33f08da 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -850,6 +850,7 @@ extern int perf_max_events;
 extern const struct pmu *hw_perf_event_init(struct perf_event *event);
 
 extern int perf_num_counters(void);
+extern const char *perf_pmu_name(void);
 extern void perf_event_task_sched_in(struct task_struct *task);
 extern void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
 extern void perf_event_task_tick(struct task_struct *task);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index db5b560..fc51268 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -85,6 +85,11 @@ void __weak hw_perf_enable(void)		{ barrier(); }
 
 void __weak perf_event_print_debug(void)	{ }
 
+extern __weak const char *perf_pmu_name(void)
+{
+	return "pmu";
+}
+
 static DEFINE_PER_CPU(int, perf_disable_count);
 
 void perf_disable(void)
-- 
1.7.1