@@ -134,6 +134,113 @@ void cpumask_chip(void)
 	cpu_notifier_register_done();
 }
 
+PMU_FORMAT_ATTR(event, "config:0-20");
+struct attribute *p8_nest_format_attrs[] = {
+	&format_attr_event.attr,
+	NULL,
+};
+
+struct attribute_group p8_nest_format_group = {
+	.name = "format",
+	.attrs = p8_nest_format_attrs,
+};
+
+int p8_nest_event_init(struct perf_event *event)
+{
+	int chip_id;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/* Sampling not supported yet */
+	if (event->hw.sample_period)
+		return -EINVAL;
+
+	/* unsupported modes and filters */
+	if (event->attr.exclude_user   ||
+	    event->attr.exclude_kernel ||
+	    event->attr.exclude_hv     ||
+	    event->attr.exclude_idle   ||
+	    event->attr.exclude_host   ||
+	    event->attr.exclude_guest  ||
+	    event->attr.sample_period) /* no sampling */
+		return -EINVAL;
+
+	if (event->cpu < 0)
+		return -EINVAL;
+
+	chip_id = topology_physical_package_id(event->cpu);
+	event->hw.event_base = event->attr.config +
+				p8_perchip_nest_info[chip_id].vbase;
+
+	return 0;
+}
+
+void p8_nest_read_counter(struct perf_event *event)
+{
+	u64 *addr;
+	u64 data = 0;
+
+	addr = (u64 *)event->hw.event_base;
+	data = __be64_to_cpu((uint64_t)*addr);
+	local64_set(&event->hw.prev_count, data);
+}
+
+void p8_nest_perf_event_update(struct perf_event *event)
+{
+	u64 counter_prev, counter_new, final_count;
+	uint64_t *addr;
+
+	addr = (u64 *)event->hw.event_base;
+	counter_prev = local64_read(&event->hw.prev_count);
+	counter_new = __be64_to_cpu((uint64_t)*addr);
+	final_count = counter_new - counter_prev;
+
+	local64_set(&event->hw.prev_count, counter_new);
+	local64_add(final_count, &event->count);
+}
+
+void p8_nest_event_start(struct perf_event *event, int flags)
+{
+	event->hw.state = 0;
+	p8_nest_read_counter(event);
+}
+
+void p8_nest_event_stop(struct perf_event *event, int flags)
+{
+	p8_nest_perf_event_update(event);
+}
+
+int p8_nest_event_add(struct perf_event *event, int flags)
+{
+	p8_nest_event_start(event, flags);
+	return 0;
+}
+
+void p8_nest_event_del(struct perf_event *event, int flags)
+{
+	p8_nest_event_stop(event, flags);
+}
+
+/*
+ * Populate pmu ops in the structure
+ */
+static int update_pmu_ops(struct nest_pmu *pmu)
+{
+	if (!pmu)
+		return -EINVAL;
+
+	pmu->pmu.task_ctx_nr = perf_invalid_context;
+	pmu->pmu.event_init = p8_nest_event_init;
+	pmu->pmu.add = p8_nest_event_add;
+	pmu->pmu.del = p8_nest_event_del;
+	pmu->pmu.start = p8_nest_event_start;
+	pmu->pmu.stop = p8_nest_event_stop;
+	pmu->pmu.read = p8_nest_perf_event_update;
+	pmu->pmu.attr_groups = pmu->attr_groups;
+
+	return 0;
+}
 
 static int __init nest_pmu_init(void)
 {