net: dsa: Add support for learning FDB through notification

Add support for learning FDB through notification. The driver defers
the hardware update via ordered work queue. In case of a successful
FDB add a notification is sent back to bridge.

In case of hw FDB del failure the static FDB will be deleted from
the bridge, thus, the interface is moved to down state in order to
indicate inconsistent situation.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 125 insertions, 2 deletions

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 6a1d4d6d212b..064f833a0422 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1332,19 +1332,142 @@ static int dsa_slave_netdevice_event(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+struct dsa_switchdev_event_work {
+	struct work_struct work;
+	struct switchdev_notifier_fdb_info fdb_info;
+	struct net_device *dev;
+	unsigned long event;
+};
+
+static void dsa_slave_switchdev_event_work(struct work_struct *work)
+{
+	struct dsa_switchdev_event_work *switchdev_work =
+		container_of(work, struct dsa_switchdev_event_work, work);
+	struct net_device *dev = switchdev_work->dev;
+	struct switchdev_notifier_fdb_info *fdb_info;
+	struct dsa_slave_priv *p = netdev_priv(dev);
+	int err;
+
+	rtnl_lock();
+	switch (switchdev_work->event) {
+	case SWITCHDEV_FDB_ADD_TO_DEVICE:
+		fdb_info = &switchdev_work->fdb_info;
+		err = dsa_port_fdb_add(p->dp, fdb_info->addr, fdb_info->vid);
+		if (err) {
+			netdev_dbg(dev, "fdb add failed err=%d\n", err);
+			break;
+		}
+		call_switchdev_notifiers(SWITCHDEV_FDB_OFFLOADED, dev,
+					 &fdb_info->info);
+		break;
+
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		fdb_info = &switchdev_work->fdb_info;
+		err = dsa_port_fdb_del(p->dp, fdb_info->addr, fdb_info->vid);
+		if (err) {
+			netdev_dbg(dev, "fdb del failed err=%d\n", err);
+			dev_close(dev);
+		}
+		break;
+	}
+	rtnl_unlock();
+
+	kfree(switchdev_work->fdb_info.addr);
+	kfree(switchdev_work);
+	dev_put(dev);
+}
+
+static int
+dsa_slave_switchdev_fdb_work_init(struct dsa_switchdev_event_work *
+				  switchdev_work,
+				  const struct switchdev_notifier_fdb_info *
+				  fdb_info)
+{
+	memcpy(&switchdev_work->fdb_info, fdb_info,
+	       sizeof(switchdev_work->fdb_info));
+	switchdev_work->fdb_info.addr = kzalloc(ETH_ALEN, GFP_ATOMIC);
+	if (!switchdev_work->fdb_info.addr)
+		return -ENOMEM;
+	ether_addr_copy((u8 *)switchdev_work->fdb_info.addr,
+			fdb_info->addr);
+	return 0;
+}
+
+/* Called under rcu_read_lock() */
+static int dsa_slave_switchdev_event(struct notifier_block *unused,
+				     unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	struct dsa_switchdev_event_work *switchdev_work;
+
+	if (!dsa_slave_dev_check(dev))
+		return NOTIFY_DONE;
+
+	switchdev_work = kzalloc(sizeof(*switchdev_work), GFP_ATOMIC);
+	if (!switchdev_work)
+		return NOTIFY_BAD;
+
+	INIT_WORK(&switchdev_work->work,
+		  dsa_slave_switchdev_event_work);
+	switchdev_work->dev = dev;
+	switchdev_work->event = event;
+
+	switch (event) {
+	case SWITCHDEV_FDB_ADD_TO_DEVICE: /* fall through */
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		if (dsa_slave_switchdev_fdb_work_init(switchdev_work,
+						      ptr))
+			goto err_fdb_work_init;
+		dev_hold(dev);
+		break;
+	default:
+		kfree(switchdev_work);
+		return NOTIFY_DONE;
+	}
+
+	dsa_schedule_work(&switchdev_work->work);
+	return NOTIFY_OK;
+
+err_fdb_work_init:
+	kfree(switchdev_work);
+	return NOTIFY_BAD;
+}
+
 static struct notifier_block dsa_slave_nb __read_mostly = {
-	.notifier_call	= dsa_slave_netdevice_event,
+	.notifier_call  = dsa_slave_netdevice_event,
+};
+
+static struct notifier_block dsa_slave_switchdev_notifier = {
+	.notifier_call = dsa_slave_switchdev_event,
 };
 
 int dsa_slave_register_notifier(void)
 {
-	return register_netdevice_notifier(&dsa_slave_nb);
+	int err;
+
+	err = register_netdevice_notifier(&dsa_slave_nb);
+	if (err)
+		return err;
+
+	err = register_switchdev_notifier(&dsa_slave_switchdev_notifier);
+	if (err)
+		goto err_switchdev_nb;
+
+	return 0;
+
+err_switchdev_nb:
+	unregister_netdevice_notifier(&dsa_slave_nb);
+	return err;
 }
 
 void dsa_slave_unregister_notifier(void)
 {
 	int err;
 
+	err = unregister_switchdev_notifier(&dsa_slave_switchdev_notifier);
+	if (err)
+		pr_err("DSA: failed to unregister switchdev notifier (%d)\n", err);
+
 	err = unregister_netdevice_notifier(&dsa_slave_nb);
 	if (err)
 		pr_err("DSA: failed to unregister slave notifier (%d)\n", err);