1 files changed, 76 insertions, 23 deletions

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 3d21521453fe..e498c927c3d0 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_net.h>
 #include <net/devlink.h>
+#include <net/sch_generic.h>
 
 #include "dsa_priv.h"
 
@@ -1064,9 +1065,18 @@ static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
 
 	list_for_each_entry(dp, &dst->ports, list) {
 		if (dsa_port_is_cpu(dp)) {
-			err = dsa_master_setup(dp->master, dp);
+			struct net_device *master = dp->master;
+			bool admin_up = (master->flags & IFF_UP) &&
+					!qdisc_tx_is_noop(master);
+
+			err = dsa_master_setup(master, dp);
 			if (err)
 				return err;
+
+			/* Replay master state event */
+			dsa_tree_master_admin_state_change(dst, master, admin_up);
+			dsa_tree_master_oper_state_change(dst, master,
+							  netif_oper_up(master));
 		}
 	}
 
@@ -1081,9 +1091,19 @@ static void dsa_tree_teardown_master(struct dsa_switch_tree *dst)
 
 	rtnl_lock();
 
-	list_for_each_entry(dp, &dst->ports, list)
-		if (dsa_port_is_cpu(dp))
-			dsa_master_teardown(dp->master);
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_is_cpu(dp)) {
+			struct net_device *master = dp->master;
+
+			/* Synthesizing an "admin down" state is sufficient for
+			 * the switches to get a notification if the master is
+			 * currently up and running.
+			 */
+			dsa_tree_master_admin_state_change(dst, master, false);
+
+			dsa_master_teardown(master);
+		}
+	}
 
 	rtnl_unlock();
 }
@@ -1279,6 +1299,52 @@ out_unlock:
 	return err;
 }
 
+static void dsa_tree_master_state_change(struct dsa_switch_tree *dst,
+					 struct net_device *master)
+{
+	struct dsa_notifier_master_state_info info;
+	struct dsa_port *cpu_dp = master->dsa_ptr;
+
+	info.master = master;
+	info.operational = dsa_port_master_is_operational(cpu_dp);
+
+	dsa_tree_notify(dst, DSA_NOTIFIER_MASTER_STATE_CHANGE, &info);
+}
+
+void dsa_tree_master_admin_state_change(struct dsa_switch_tree *dst,
+					struct net_device *master,
+					bool up)
+{
+	struct dsa_port *cpu_dp = master->dsa_ptr;
+	bool notify = false;
+
+	if ((dsa_port_master_is_operational(cpu_dp)) !=
+	    (up && cpu_dp->master_oper_up))
+		notify = true;
+
+	cpu_dp->master_admin_up = up;
+
+	if (notify)
+		dsa_tree_master_state_change(dst, master);
+}
+
+void dsa_tree_master_oper_state_change(struct dsa_switch_tree *dst,
+				       struct net_device *master,
+				       bool up)
+{
+	struct dsa_port *cpu_dp = master->dsa_ptr;
+	bool notify = false;
+
+	if ((dsa_port_master_is_operational(cpu_dp)) !=
+	    (cpu_dp->master_admin_up && up))
+		notify = true;
+
+	cpu_dp->master_oper_up = up;
+
+	if (notify)
+		dsa_tree_master_state_change(dst, master);
+}
+
 static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
 {
 	struct dsa_switch_tree *dst = ds->dst;
@@ -1718,7 +1784,6 @@ EXPORT_SYMBOL_GPL(dsa_unregister_switch);
 void dsa_switch_shutdown(struct dsa_switch *ds)
 {
 	struct net_device *master, *slave_dev;
-	LIST_HEAD(unregister_list);
 	struct dsa_port *dp;
 
 	mutex_lock(&dsa2_mutex);
@@ -1729,25 +1794,13 @@ void dsa_switch_shutdown(struct dsa_switch *ds)
 		slave_dev = dp->slave;
 
 		netdev_upper_dev_unlink(master, slave_dev);
-		/* Just unlinking ourselves as uppers of the master is not
-		 * sufficient. When the master net device unregisters, that will
-		 * also call dev_close, which we will catch as NETDEV_GOING_DOWN
-		 * and trigger a dev_close on our own devices (dsa_slave_close).
-		 * In turn, that will call dev_mc_unsync on the master's net
-		 * device. If the master is also a DSA switch port, this will
-		 * trigger dsa_slave_set_rx_mode which will call dev_mc_sync on
-		 * its own master. Lockdep will complain about the fact that
-		 * all cascaded masters have the same dsa_master_addr_list_lock_key,
-		 * which it normally would not do if the cascaded masters would
-		 * be in a proper upper/lower relationship, which we've just
-		 * destroyed.
-		 * To suppress the lockdep warnings, let's actually unregister
-		 * the DSA slave interfaces too, to avoid the nonsensical
-		 * multicast address list synchronization on shutdown.
-		 */
-		unregister_netdevice_queue(slave_dev, &unregister_list);
 	}
-	unregister_netdevice_many(&unregister_list);
+
+	/* Disconnect from further netdevice notifiers on the master,
+	 * since netdev_uses_dsa() will now return false.
+	 */
+	dsa_switch_for_each_cpu_port(dp, ds)
+		dp->master->dsa_ptr = NULL;
 
 	rtnl_unlock();
 	mutex_unlock(&dsa2_mutex);