PM / QoS: Add dev_pm_qos_request tracepoints

Adds tracepoints to dev_pm_qos_add_request, dev_pm_qos_update_request,
and dev_pm_qos_remove_request. It's useful for checking device name,
dev_pm_qos_request_type, and value.

Signed-off-by: Sahara <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/base/power/qos.c

···
 #include <linux/export.h>
 #include <linux/pm_runtime.h>
 #include <linux/err.h>
+#include <trace/events/power.h>
 
 #include "power.h"
 
···
 	else if (!dev->power.qos)
 		ret = dev_pm_qos_constraints_allocate(dev);
 
+	trace_dev_pm_qos_add_request(dev_name(dev), type, value);
 	if (!ret) {
 		req->dev = dev;
 		req->type = type;
···
 		return -EINVAL;
 	}
 
+	trace_dev_pm_qos_update_request(dev_name(req->dev), req->type,
+					new_value);
 	if (curr_value != new_value)
 		ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value);
 
···
 	if (IS_ERR_OR_NULL(req->dev->power.qos))
 		return -ENODEV;
 
+	trace_dev_pm_qos_remove_request(dev_name(req->dev), req->type,
+					PM_QOS_DEFAULT_VALUE);
 	ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
 	memset(req, 0, sizeof(*req));
 	return ret;

include/trace/events/power.h

···
 			{ PM_QOS_REMOVE_REQ,	"REMOVE_REQ" }),
 		  __entry->prev_value, __entry->curr_value)
 );
+
+DECLARE_EVENT_CLASS(dev_pm_qos_request,
+
+	TP_PROTO(const char *name, enum dev_pm_qos_req_type type,
+		 s32 new_value),
+
+	TP_ARGS(name, type, new_value),
+
+	TP_STRUCT__entry(
+		__string( name,                    name         )
+		__field( enum dev_pm_qos_req_type, type         )
+		__field( s32,                      new_value    )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->type = type;
+		__entry->new_value = new_value;
+	),
+
+	TP_printk("device=%s type=%s new_value=%d",
+		  __get_str(name),
+		  __print_symbolic(__entry->type,
+			{ DEV_PM_QOS_LATENCY,	"DEV_PM_QOS_LATENCY" },
+			{ DEV_PM_QOS_FLAGS,	"DEV_PM_QOS_FLAGS" }),
+		  __entry->new_value)
+);
+
+DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_add_request,
+
+	TP_PROTO(const char *name, enum dev_pm_qos_req_type type,
+		 s32 new_value),
+
+	TP_ARGS(name, type, new_value)
+);
+
+DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_update_request,
+
+	TP_PROTO(const char *name, enum dev_pm_qos_req_type type,
+		 s32 new_value),
+
+	TP_ARGS(name, type, new_value)
+);
+
+DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_remove_request,
+
+	TP_PROTO(const char *name, enum dev_pm_qos_req_type type,
+		 s32 new_value),
+
+	TP_ARGS(name, type, new_value)
+);
 #endif /* _TRACE_POWER_H */
 
 /* This part must be outside protection */