s390/qeth: Register switchdev event handler

Conditionally register a qeth_l2 switchdev_event handler to handle bridge
to device switchdev events, when at least one qeth interface has the
bridgeport attribute LEARNING_SYNC enabled.

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>

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 69afc03..3d02d35 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -717,6 +717,31 @@ static int qeth_l2_dev2br_an_set(struct qeth_card *card, bool enable)
        return rc;
 }
 
+static refcount_t qeth_l2_switchdev_notify_refcnt;
+
+/* Called under rtnl_lock */
+static void qeth_l2_br2dev_get(void)
+{
+       if (!refcount_inc_not_zero(&qeth_l2_switchdev_notify_refcnt)) {
+               /* tbd: register_switchdev_notifier(&qeth_l2_sw_notifier); */
+               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)
+{
+       if (refcount_dec_and_test(&qeth_l2_switchdev_notify_refcnt)) {
+               /* tbd: unregister_switchdev_notifier(&qeth_l2_sw_notifier); */
+               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 +835,19 @@ 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 +2100,7 @@ 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 +2112,15 @@ 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 +2243,7 @@ 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;
 }