From: Alexandra Winter <wintera@linux.ibm.com>
Date: Fri, 6 Aug 2021 17:26:03 +0200
Subject: s390/qeth: Update MACs of LEARNING_SYNC device
Git-commit: f7936b7b2663c99a096a5c432ba96ab1e91a6c0f
Patch-mainline: v5.15-rc1
References: jsc#SLE-18329 jsc#SLE-18330 jsc#SLE-18516 bsc#1191738 LTC#193282

Update the MAC addresses that are registered with a LEARNING_SYNC qeth
device with the events announced by the attached software bridge.

Typically the LEARNING_SYNC qeth bridge port has an isolated sibling (the
default interface of an 'HiperSockets Converged Interface' (HSCI)). Update
the MACs of isolated siblings as well, to avoid unnecessary flooding in
the attached virtualized switches.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/net/qeth_l2_main.c |  131 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 127 insertions(+), 4 deletions(-)

--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -760,6 +760,15 @@ static int qeth_l2_dev2br_an_set(struct
 	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,
@@ -775,6 +784,116 @@ static bool qeth_l2_must_learn(struct ne
 		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)
@@ -784,6 +903,7 @@ static int qeth_l2_switchdev_event(struc
 	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))
@@ -802,10 +922,13 @@ static int qeth_l2_switchdev_event(struc
 		if (qeth_l2_must_learn(lowerdev, dstdev)) {
 			card = lowerdev->ml_priv;
 			QETH_CARD_TEXT_(card, 4, "b2dqw%03x", event);
-			/* tbd: rc = qeth_l2_br2dev_queue_work(brdev, lowerdev,
-			 *				       dstdev, event,
-			 *				       fdb_info->addr);
-			 */
+			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);
 	}