ocelot: Handle SWITCHDEV_PORT_OBJ_ADD/_DEL

Following patches will change the way of distributing port object
changes from a switchdev operation to a switchdev notifier. The
switchdev code currently recursively descends through layers of lower
devices, eventually calling the op on a front-panel port device. The
notifier will instead be sent referencing the bridge port device, which
may be a stacking device that's one of front-panel ports uppers, or a
completely unrelated device.

Dispatch the new events to ocelot_port_obj_add() resp. _del() to
maintain the same behavior that the switchdev operation based code
currently has. Pass through switchdev_handle_port_obj_add() / _del() to
handle the recursive descend, because Ocelot supports LAG uppers.

Register to the new switchdev blocking notifier chain to get the new
events when they start getting distributed.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot.c

@@ -1595,6 +1595,34 @@ struct notifier_block ocelot_netdevice_nb __read_mostly = {
 };
 EXPORT_SYMBOL(ocelot_netdevice_nb);
 
+static int ocelot_switchdev_blocking_event(struct notifier_block *unused,
+					   unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	int err;
+
+	switch (event) {
+		/* Blocking events. */
+	case SWITCHDEV_PORT_OBJ_ADD:
+		err = switchdev_handle_port_obj_add(dev, ptr,
+						    ocelot_netdevice_dev_check,
+						    ocelot_port_obj_add);
+		return notifier_from_errno(err);
+	case SWITCHDEV_PORT_OBJ_DEL:
+		err = switchdev_handle_port_obj_del(dev, ptr,
+						    ocelot_netdevice_dev_check,
+						    ocelot_port_obj_del);
+		return notifier_from_errno(err);
+	}
+
+	return NOTIFY_DONE;
+}
+
+struct notifier_block ocelot_switchdev_blocking_nb __read_mostly = {
+	.notifier_call = ocelot_switchdev_blocking_event,
+};
+EXPORT_SYMBOL(ocelot_switchdev_blocking_nb);
+
 int ocelot_probe_port(struct ocelot *ocelot, u8 port,
 		      void __iomem *regs,
 		      struct phy_device *phy)

drivers/net/ethernet/mscc/ocelot.h

@@ -499,5 +499,6 @@ int ocelot_probe_port(struct ocelot *ocelot, u8 port,
 		      struct phy_device *phy);
 
 extern struct notifier_block ocelot_netdevice_nb;
+extern struct notifier_block ocelot_switchdev_blocking_nb;
 
 #endif

drivers/net/ethernet/mscc/ocelot_board.c

@@ -12,6 +12,7 @@
 #include <linux/of_platform.h>
 #include <linux/mfd/syscon.h>
 #include <linux/skbuff.h>
+#include <net/switchdev.h>
 
 #include "ocelot.h"
 
@@ -328,6 +329,7 @@ static int mscc_ocelot_probe(struct platform_device *pdev)
 	}
 
 	register_netdevice_notifier(&ocelot_netdevice_nb);
+	register_switchdev_blocking_notifier(&ocelot_switchdev_blocking_nb);
 
 	dev_info(&pdev->dev, "Ocelot switch probed\n");
 
@@ -342,6 +344,7 @@ static int mscc_ocelot_remove(struct platform_device *pdev)
 	struct ocelot *ocelot = platform_get_drvdata(pdev);
 
 	ocelot_deinit(ocelot);
+	unregister_switchdev_blocking_notifier(&ocelot_switchdev_blocking_nb);
 	unregister_netdevice_notifier(&ocelot_netdevice_nb);
 
 	return 0;