[PATCH 5/6][v3] perf: Create a sysfs entry for Power event format

[sukadev at linux.vnet.ibm.com]

Create a sysfs entry, '/sys/bus/event_source/devices/cpu/format/event'
which describes the format of a POWER cpu.

The format of the event is the same for all POWER cpus at least in
(Power6, Power7), so bulk of this change is common in the code common
to POWER cpus.

This code is based on corresponding code in x86.

Changelog[v2]: [Jiri Olsa] Use PMU_FORMAT_ATTR() rather than duplicating it.

Signed-off-by: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/perf_event_server.h |    6 ++++++
 arch/powerpc/perf/core-book3s.c              |   12 ++++++++++++
 arch/powerpc/perf/power7-pmu.c               |    1 +
 3 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index b29fcc6..ee63205 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -135,3 +135,9 @@ extern ssize_t power_events_sysfs_show(struct device *dev,
 
 #define	POWER_EVENT_ATTR(_name, _id)	EVENT_ATTR(PM_##_name, _id, _p)
 #define	POWER_EVENT_PTR(_id)		EVENT_PTR(_id, _p)
+
+/*
+ * Format of a perf event is the same on all POWER cpus. Declare a
+ * common sysfs attribute group that individual POWER cpus can share.
+ */
+extern struct attribute_group power_pmu_format_group;
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index fa476d5..4ae044b 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1315,6 +1315,18 @@ ssize_t power_events_sysfs_show(struct device *dev,
 	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
 }
 
+PMU_FORMAT_ATTR(event, "config:0-20");
+
+static struct attribute *power_pmu_format_attr[] = {
+	&format_attr_event.attr,
+	NULL,
+};
+
+struct attribute_group power_pmu_format_group = {
+	.name = "format",
+	.attrs = power_pmu_format_attr,
+};
+
 struct pmu power_pmu = {
 	.pmu_enable	= power_pmu_enable,
 	.pmu_disable	= power_pmu_disable,
diff --git a/arch/powerpc/perf/power7-pmu.c b/arch/powerpc/perf/power7-pmu.c
index 5627940..5fb3c9b 100644
--- a/arch/powerpc/perf/power7-pmu.c
+++ b/arch/powerpc/perf/power7-pmu.c
@@ -410,6 +410,7 @@ static struct attribute_group power7_pmu_events_group = {
 };
 
 static const struct attribute_group *power7_pmu_attr_groups[] = {
+	&power_pmu_format_group,
 	&power7_pmu_events_group,
 	NULL,
 };
-- 
1.7.1