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>

4 files changed, 69 insertions, 0 deletions

diff --git a/Documentation/ABI/stable/sysfs-devices-cpu-events b/Documentation/ABI/stable/sysfs-devices-cpu-events
new file mode 100644
index 000000000000..e69de29bb2d1
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-devices-cpu-events
diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index 9710be3a2d17..b9b6c557bd0c 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -11,6 +11,7 @@
 
 #include <linux/types.h>
 #include <asm/hw_irq.h>
+#include <linux/device.h>
 
 #define MAX_HWEVENTS            8
 #define MAX_EVENT_ALTERNATIVES  8
@@ -35,6 +36,7 @@ struct power_pmu {
         void            (*disable_pmc)(unsigned int pmc, unsigned long mmcr[]);
         int             (*limited_pmc_event)(u64 event_id);
         u32             flags;
+        const struct attribute_group    **attr_groups;
         int             n_generic;
         int             *generic_events;
         int             (*cache_events)[PERF_COUNT_HW_CACHE_MAX]
@@ -109,3 +111,24 @@ extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
  * If an event_id is not subject to the constraint expressed by a particular
  * field, then it will have 0 in both the mask and value for that field.
  */
+
+extern ssize_t power_events_sysfs_show(struct device *dev,
+                                struct device_attribute *attr, char *page);
+
+/*
+ * EVENT_VAR() is same as PMU_EVENT_VAR with a suffix.
+ *
+ * Having a suffix allows us to have aliases in sysfs - eg: the generic
+ * event 'cpu-cycles' can have two entries in sysfs: 'cpu-cycles' and
+ * 'PM_CYC' where the latter is the name by which the event is known in
+ * POWER CPU specification.
+ */
+#define EVENT_VAR(_id, _suffix)         event_attr_##_id##_suffix
+#define EVENT_PTR(_id, _suffix)         &EVENT_VAR(_id, _suffix)
+
+#define EVENT_ATTR(_name, _id, _suffix)                                 \
+        PMU_EVENT_ATTR(_name, EVENT_VAR(_id, _suffix), PME_PM_##_id,    \
+                        power_events_sysfs_show)
+
+#define GENERIC_EVENT_ATTR(_name, _id)  EVENT_ATTR(_name, _id, _g)
+#define GENERIC_EVENT_PTR(_id)          EVENT_PTR(_id, _g)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index aa2465e21f1a..fa476d50791f 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1305,6 +1305,16 @@ static int power_pmu_event_idx(struct perf_event *event)
         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 @@ int __cpuinit register_power_pmu(struct power_pmu *pmu)
         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.
diff --git a/arch/powerpc/perf/power7-pmu.c b/arch/powerpc/perf/power7-pmu.c
index eebb36de429f..269bf2464a36 100644
--- a/arch/powerpc/perf/power7-pmu.c
+++ b/arch/powerpc/perf/power7-pmu.c
@@ -374,6 +374,39 @@ static int power7_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
         },
 };
 
+
+GENERIC_EVENT_ATTR(cpu-cycles,                  CYC);
+GENERIC_EVENT_ATTR(stalled-cycles-frontend,     GCT_NOSLOT_CYC);
+GENERIC_EVENT_ATTR(stalled-cycles-backend,      CMPLU_STALL);
+GENERIC_EVENT_ATTR(instructions,                INST_CMPL);
+GENERIC_EVENT_ATTR(cache-references,            LD_REF_L1);
+GENERIC_EVENT_ATTR(cache-misses,                LD_MISS_L1);
+GENERIC_EVENT_ATTR(branch-instructions,         BRU_FIN);
+GENERIC_EVENT_ATTR(branch-misses,               BRU_MPRED);
+
+static struct attribute *power7_events_attr[] = {
+        GENERIC_EVENT_PTR(CYC),
+        GENERIC_EVENT_PTR(GCT_NOSLOT_CYC),
+        GENERIC_EVENT_PTR(CMPLU_STALL),
+        GENERIC_EVENT_PTR(INST_CMPL),
+        GENERIC_EVENT_PTR(LD_REF_L1),
+        GENERIC_EVENT_PTR(LD_MISS_L1),
+        GENERIC_EVENT_PTR(BRU_FIN),
+        GENERIC_EVENT_PTR(BRU_MPRED),
+        NULL
+};
+
+
+static struct attribute_group power7_pmu_events_group = {
+        .name = "events",
+        .attrs = power7_events_attr,
+};
+
+static const struct attribute_group *power7_pmu_attr_groups[] = {
+        &power7_pmu_events_group,
+        NULL,
+};
+
 static struct power_pmu power7_pmu = {
         .name                   = "POWER7",
         .n_counter              = 6,
@@ -385,6 +418,7 @@ static struct power_pmu power7_pmu = {
         .get_alternatives       = power7_get_alternatives,
         .disable_pmc            = power7_disable_pmc,
         .flags                  = PPMU_ALT_SIPR,
+        .attr_groups            = power7_pmu_attr_groups,
         .n_generic              = ARRAY_SIZE(power7_generic_events),
         .generic_events         = power7_generic_events,
         .cache_events           = &power7_cache_events,