perf/POWER7: Make generic event translations available in sysfs

Make the generic perf events in POWER7 available via sysfs.

	$ ls /sys/bus/event_source/devices/cpu/events
	branch-instructions
	branch-misses
	cache-misses
	cache-references
	cpu-cycles
	instructions
	stalled-cycles-backend
	stalled-cycles-frontend

	$ cat /sys/bus/event_source/devices/cpu/events/cache-misses
	event=0x400f0

This patch is based on commits that implement this functionality on x86.
Eg:
	commit a47473939db20e3961b200eb00acf5fcf084d755
	Author: Jiri Olsa <jolsa@redhat.com>
	Date:   Wed Oct 10 14:53:11 2012 +0200

	    perf/x86: Make hardware event translations available in sysfs

Changelog:[v2]
	[Jiri Osla] Drop EVENT_ID() macro since it is only used once.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/20130123062454.GD13720@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index aa2465e..fa476d5 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1305,6 +1305,16 @@
 	return event->hw.idx;
 }
 
+ssize_t power_events_sysfs_show(struct device *dev,
+				struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+
+	return sprintf(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
 struct pmu power_pmu = {
 	.pmu_enable	= power_pmu_enable,
 	.pmu_disable	= power_pmu_disable,
@@ -1537,6 +1547,8 @@
 	pr_info("%s performance monitor hardware support registered\n",
 		pmu->name);
 
+	power_pmu.attr_groups = ppmu->attr_groups;
+
 #ifdef MSR_HV
 	/*
 	 * Use FCHV to ignore kernel events if MSR.HV is set.