tipc: add trace_events for tipc bearer

The commit adds the new trace_event for TIPC bearer, L2 device event:

trace_tipc_l2_device_event()

Also, it puts the trace at the tipc_l2_device_event() function, then
the device/bearer events and related info can be traced out during
runtime when needed.

Acked-by: Ying Xue <[e-mail]>
Tested-by: Ying Xue <[e-mail]>
Acked-by: Jon Maloy <[e-mail]>
Signed-off-by: Tuong Lien <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/tipc/bearer.c

···
 #include "bcast.h"
 #include "netlink.h"
 #include "udp_media.h"
+#include "trace.h"
 
 #define MAX_ADDR_STR 60
 
···
 	if (!b)
 		return NOTIFY_DONE;
 
+	trace_tipc_l2_device_event(dev, b, evt);
 	switch (evt) {
 	case NETDEV_CHANGE:
 		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {

net/tipc/trace.h

···
 			{(0xcbe),	"SYNCH_BEGIN_EVT"		},\
 			{(0xcee),	"SYNCH_END_EVT"			})
 
+/* Bearer, net device events: */
+#define dev_evt_sym(val)						  \
+	__print_symbolic(val,						  \
+			{(NETDEV_CHANGE),	"NETDEV_CHANGE"		},\
+			{(NETDEV_GOING_DOWN),	"NETDEV_GOING_DOWN"	},\
+			{(NETDEV_UP),		"NETDEV_UP"		},\
+			{(NETDEV_CHANGEMTU),	"NETDEV_CHANGEMTU"	},\
+			{(NETDEV_CHANGEADDR),	"NETDEV_CHANGEADDR"	},\
+			{(NETDEV_UNREGISTER),	"NETDEV_UNREGISTER"	},\
+			{(NETDEV_CHANGENAME),	"NETDEV_CHANGENAME"	})
+
 extern unsigned long sysctl_tipc_sk_filter[5] __read_mostly;
 
 int tipc_skb_dump(struct sk_buff *skb, bool more, char *buf);
···
 	TP_ARGS(name, os, ns, evt))
 DEFINE_FSM_EVENT(tipc_link_fsm);
 DEFINE_FSM_EVENT(tipc_node_fsm);
+
+TRACE_EVENT(tipc_l2_device_event,
+
+	TP_PROTO(struct net_device *dev, struct tipc_bearer *b,
+		 unsigned long evt),
+
+	TP_ARGS(dev, b, evt),
+
+	TP_STRUCT__entry(
+		__string(dev_name, dev->name)
+		__string(b_name, b->name)
+		__field(unsigned long, evt)
+		__field(u8, b_up)
+		__field(u8, carrier)
+		__field(u8, oper)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev_name, dev->name);
+		__assign_str(b_name, b->name);
+		__entry->evt = evt;
+		__entry->b_up = test_bit(0, &b->up);
+		__entry->carrier = netif_carrier_ok(dev);
+		__entry->oper = netif_oper_up(dev);
+	),
+
+	TP_printk("%s on: <%s>/<%s> oper: %s carrier: %s bearer: %s\n",
+		  dev_evt_sym(__entry->evt), __get_str(dev_name),
+		  __get_str(b_name), (__entry->oper) ? "up" : "down",
+		  (__entry->carrier) ? "ok" : "notok",
+		  (__entry->b_up) ? "up" : "down")
+);
 
 #endif /* _TIPC_TRACE_H */