net: dsa: introduce bridge notifier

A slave device will now notify the switch fabric once its port is
bridged or unbridged, instead of calling directly its switch operations.

This code allows propagating cross-chip bridging events in the fabric.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dsa.h b/include/net/dsa.h
index ac4ea7c..e9c940c 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -268,6 +268,16 @@
 struct switchdev_obj_port_mdb;
 struct switchdev_obj_port_vlan;
 
+#define DSA_NOTIFIER_BRIDGE_JOIN		1
+#define DSA_NOTIFIER_BRIDGE_LEAVE		2
+
+/* DSA_NOTIFIER_BRIDGE_* */
+struct dsa_notifier_bridge_info {
+	struct net_device *br;
+	int sw_index;
+	int port;
+};
+
 struct dsa_switch_ops {
 	/*
 	 * Probing and setup.