Merge branch 's390-qeth'

Karsten Graul says:

====================
s390/qeth: Add bridge to switchdev LEARNING_SYNC

The netlink bridgeport attribute LEARNING_SYNC can be used to enable
qeth interfaces to report MAC addresses that are reachable via this
qeth interface to the attached software bridge via switchdev
notifiers SWITCHDEV_FDB_ADD_TO_BRIDGE and SWITCHDEV_FDB_DEL_TO_BRIDGE.

Extend this support of LEARNING_SYNC to the bridge to switchdev notifiers
SWITCHDEV_FDB_ADD_TO_DEVICE and SWITCHDEV_FDB_DEL_TO_DEVICE.

Add the capability to sync MAC addresses that are learned by a
north-facing, non-isolated bridgeport of a software bridge to
south-facing, isolated bridgeports. This enables the software bridge to
influence south to north traffic steering in hardware.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 237 insertions, 3 deletions

diff --git a/drivers/s390/net/Kconfig b/drivers/s390/net/Kconfig
index cff91b4f1a76..9c67b97faba2 100644
--- a/drivers/s390/net/Kconfig
+++ b/drivers/s390/net/Kconfig
@@ -74,6 +74,7 @@ config QETH_L2
 	def_tristate y
 	prompt "qeth layer 2 device support"
 	depends on QETH
+	depends on BRIDGE || BRIDGE=n
 	help
 	  Select this option to be able to run qeth devices in layer 2 mode.
 	  To compile as a module, choose M. The module name is qeth_l2.
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 69afc0311dd1..4871f712b874 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -717,6 +717,227 @@ static int qeth_l2_dev2br_an_set(struct qeth_card *card, bool enable)
 	return rc;
 }
 
+struct qeth_l2_br2dev_event_work {
+	struct work_struct work;
+	struct net_device *br_dev;
+	struct net_device *lsync_dev;
+	struct net_device *dst_dev;
+	unsigned long event;
+	unsigned char addr[ETH_ALEN];
+};
+
+static const struct net_device_ops qeth_l2_netdev_ops;
+
+static bool qeth_l2_must_learn(struct net_device *netdev,
+			       struct net_device *dstdev)
+{
+	struct qeth_priv *priv;
+
+	priv = netdev_priv(netdev);
+	return (netdev != dstdev &&
+		(priv->brport_features & BR_LEARNING_SYNC) &&
+		!(br_port_flag_is_set(netdev, BR_ISOLATED) &&
+		  br_port_flag_is_set(dstdev, BR_ISOLATED)) &&
+		netdev->netdev_ops == &qeth_l2_netdev_ops);
+}
+
+/**
+ *	qeth_l2_br2dev_worker() - update local MACs
+ *	@work: bridge to device FDB update
+ *
+ *	Update local MACs of a learning_sync bridgeport so it can receive
+ *	messages for a destination port.
+ *	In case of an isolated learning_sync port, also update its isolated
+ *	siblings.
+ */
+static void qeth_l2_br2dev_worker(struct work_struct *work)
+{
+	struct qeth_l2_br2dev_event_work *br2dev_event_work =
+		container_of(work, struct qeth_l2_br2dev_event_work, work);
+	struct net_device *lsyncdev = br2dev_event_work->lsync_dev;
+	struct net_device *dstdev = br2dev_event_work->dst_dev;
+	struct net_device *brdev = br2dev_event_work->br_dev;
+	unsigned long event = br2dev_event_work->event;
+	unsigned char *addr = br2dev_event_work->addr;
+	struct qeth_card *card = lsyncdev->ml_priv;
+	struct net_device *lowerdev;
+	struct list_head *iter;
+	int err = 0;
+
+	kfree(br2dev_event_work);
+	QETH_CARD_TEXT_(card, 4, "b2dw%04x", event);
+	QETH_CARD_TEXT_(card, 4, "ma%012lx", ether_addr_to_u64(addr));
+
+	rcu_read_lock();
+	/* Verify preconditions are still valid: */
+	if (!netif_is_bridge_port(lsyncdev) ||
+	    brdev != netdev_master_upper_dev_get_rcu(lsyncdev))
+		goto unlock;
+	if (!qeth_l2_must_learn(lsyncdev, dstdev))
+		goto unlock;
+
+	if (br_port_flag_is_set(lsyncdev, BR_ISOLATED)) {
+		/* Update lsyncdev and its isolated sibling(s): */
+		iter = &brdev->adj_list.lower;
+		lowerdev = netdev_next_lower_dev_rcu(brdev, &iter);
+		while (lowerdev) {
+			if (br_port_flag_is_set(lowerdev, BR_ISOLATED)) {
+				switch (event) {
+				case SWITCHDEV_FDB_ADD_TO_DEVICE:
+					err = dev_uc_add(lowerdev, addr);
+					break;
+				case SWITCHDEV_FDB_DEL_TO_DEVICE:
+					err = dev_uc_del(lowerdev, addr);
+					break;
+				default:
+					break;
+				}
+				if (err) {
+					QETH_CARD_TEXT(card, 2, "b2derris");
+					QETH_CARD_TEXT_(card, 2,
+							"err%02x%03d", event,
+							lowerdev->ifindex);
+				}
+			}
+			lowerdev = netdev_next_lower_dev_rcu(brdev, &iter);
+		}
+	} else {
+		switch (event) {
+		case SWITCHDEV_FDB_ADD_TO_DEVICE:
+			err = dev_uc_add(lsyncdev, addr);
+			break;
+		case SWITCHDEV_FDB_DEL_TO_DEVICE:
+			err = dev_uc_del(lsyncdev, addr);
+			break;
+		default:
+			break;
+		}
+		if (err)
+			QETH_CARD_TEXT_(card, 2, "b2derr%02x", event);
+	}
+
+unlock:
+	rcu_read_unlock();
+	dev_put(brdev);
+	dev_put(lsyncdev);
+	dev_put(dstdev);
+}
+
+static int qeth_l2_br2dev_queue_work(struct net_device *brdev,
+				     struct net_device *lsyncdev,
+				     struct net_device *dstdev,
+				     unsigned long event,
+				     const unsigned char *addr)
+{
+	struct qeth_l2_br2dev_event_work *worker_data;
+	struct qeth_card *card;
+
+	worker_data = kzalloc(sizeof(*worker_data), GFP_ATOMIC);
+	if (!worker_data)
+		return -ENOMEM;
+	INIT_WORK(&worker_data->work, qeth_l2_br2dev_worker);
+	worker_data->br_dev = brdev;
+	worker_data->lsync_dev = lsyncdev;
+	worker_data->dst_dev = dstdev;
+	worker_data->event = event;
+	ether_addr_copy(worker_data->addr, addr);
+
+	card = lsyncdev->ml_priv;
+	/* Take a reference on the sw port devices and the bridge */
+	dev_hold(brdev);
+	dev_hold(lsyncdev);
+	dev_hold(dstdev);
+	queue_work(card->event_wq, &worker_data->work);
+	return 0;
+}
+
+/* Called under rtnl_lock */
+static int qeth_l2_switchdev_event(struct notifier_block *unused,
+				   unsigned long event, void *ptr)
+{
+	struct net_device *dstdev, *brdev, *lowerdev;
+	struct switchdev_notifier_fdb_info *fdb_info;
+	struct switchdev_notifier_info *info = ptr;
+	struct list_head *iter;
+	struct qeth_card *card;
+	int rc;
+
+	if (!(event == SWITCHDEV_FDB_ADD_TO_DEVICE ||
+	      event == SWITCHDEV_FDB_DEL_TO_DEVICE))
+		return NOTIFY_DONE;
+
+	dstdev = switchdev_notifier_info_to_dev(info);
+	brdev = netdev_master_upper_dev_get_rcu(dstdev);
+	if (!brdev || !netif_is_bridge_master(brdev))
+		return NOTIFY_DONE;
+	fdb_info = container_of(info,
+				struct switchdev_notifier_fdb_info,
+				info);
+	iter = &brdev->adj_list.lower;
+	lowerdev = netdev_next_lower_dev_rcu(brdev, &iter);
+	while (lowerdev) {
+		if (qeth_l2_must_learn(lowerdev, dstdev)) {
+			card = lowerdev->ml_priv;
+			QETH_CARD_TEXT_(card, 4, "b2dqw%03x", event);
+			rc = qeth_l2_br2dev_queue_work(brdev, lowerdev,
+						       dstdev, event,
+						       fdb_info->addr);
+			if (rc) {
+				QETH_CARD_TEXT(card, 2, "b2dqwerr");
+				return NOTIFY_BAD;
+			}
+		}
+		lowerdev = netdev_next_lower_dev_rcu(brdev, &iter);
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block qeth_l2_sw_notifier = {
+		.notifier_call = qeth_l2_switchdev_event,
+};
+
+static refcount_t qeth_l2_switchdev_notify_refcnt;
+
+/* Called under rtnl_lock */
+static void qeth_l2_br2dev_get(void)
+{
+	int rc;
+
+	if (!refcount_inc_not_zero(&qeth_l2_switchdev_notify_refcnt)) {
+		rc = register_switchdev_notifier(&qeth_l2_sw_notifier);
+		if (rc) {
+			QETH_DBF_MESSAGE(2,
+					 "failed to register qeth_l2_sw_notifier: %d\n",
+					 rc);
+		} else {
+			refcount_set(&qeth_l2_switchdev_notify_refcnt, 1);
+			QETH_DBF_MESSAGE(2, "qeth_l2_sw_notifier registered\n");
+		}
+	}
+	QETH_DBF_TEXT_(SETUP, 2, "b2d+%04d",
+		       qeth_l2_switchdev_notify_refcnt.refs.counter);
+}
+
+/* Called under rtnl_lock */
+static void qeth_l2_br2dev_put(void)
+{
+	int rc;
+
+	if (refcount_dec_and_test(&qeth_l2_switchdev_notify_refcnt)) {
+		rc = unregister_switchdev_notifier(&qeth_l2_sw_notifier);
+		if (rc) {
+			QETH_DBF_MESSAGE(2,
+					 "failed to unregister qeth_l2_sw_notifier: %d\n",
+					 rc);
+		} else {
+			QETH_DBF_MESSAGE(2,
+					 "qeth_l2_sw_notifier unregistered\n");
+		}
+	}
+	QETH_DBF_TEXT_(SETUP, 2, "b2d-%04d",
+		       qeth_l2_switchdev_notify_refcnt.refs.counter);
+}
+
 static int qeth_l2_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 				  struct net_device *dev, u32 filter_mask,
 				  int nlflags)
@@ -810,16 +1031,19 @@ static int qeth_l2_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	} else if (enable) {
 		qeth_l2_set_pnso_mode(card, QETH_PNSO_ADDR_INFO);
 		rc = qeth_l2_dev2br_an_set(card, true);
-		if (rc)
+		if (rc) {
 			qeth_l2_set_pnso_mode(card, QETH_PNSO_NONE);
-		else
+		} else {
 			priv->brport_features |= BR_LEARNING_SYNC;
+			qeth_l2_br2dev_get();
+		}
 	} else {
 		rc = qeth_l2_dev2br_an_set(card, false);
 		if (!rc) {
 			qeth_l2_set_pnso_mode(card, QETH_PNSO_NONE);
 			priv->brport_features ^= BR_LEARNING_SYNC;
 			qeth_l2_dev2br_fdb_flush(card);
+			qeth_l2_br2dev_put();
 		}
 	}
 	mutex_unlock(&card->sbp_lock);
@@ -2072,6 +2296,7 @@ static int qeth_l2_probe_device(struct ccwgroup_device *gdev)
 static void qeth_l2_remove_device(struct ccwgroup_device *gdev)
 {
 	struct qeth_card *card = dev_get_drvdata(&gdev->dev);
+	struct qeth_priv *priv;
 
 	if (gdev->dev.type != &qeth_l2_devtype)
 		device_remove_groups(&gdev->dev, qeth_l2_attr_groups);
@@ -2083,8 +2308,15 @@ static void qeth_l2_remove_device(struct ccwgroup_device *gdev)
 		qeth_set_offline(card, card->discipline, false);
 
 	cancel_work_sync(&card->close_dev_work);
-	if (card->dev->reg_state == NETREG_REGISTERED)
+	if (card->dev->reg_state == NETREG_REGISTERED) {
+		priv = netdev_priv(card->dev);
+		if (priv->brport_features & BR_LEARNING_SYNC) {
+			rtnl_lock();
+			qeth_l2_br2dev_put();
+			rtnl_unlock();
+		}
 		unregister_netdev(card->dev);
+	}
 }
 
 static int qeth_l2_set_online(struct qeth_card *card, bool carrier_ok)
@@ -2207,6 +2439,7 @@ EXPORT_SYMBOL_GPL(qeth_l2_discipline);
 static int __init qeth_l2_init(void)
 {
 	pr_info("register layer 2 discipline\n");
+	refcount_set(&qeth_l2_switchdev_notify_refcnt, 0);
 	return 0;
 }