net/smc: Add diagnostic information to smc ib-device

During smc ib-device creation, add network device ifindex to smc
ib-device structure. Register for netdevice changes and update ib-device
accordingly. This is needed for diagnostic purposes.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/smc/smc_ib.c

@@ -557,6 +557,49 @@ static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 
 static struct ib_client smc_ib_client;
 
+static void smc_copy_netdev_ifindex(struct smc_ib_device *smcibdev, int port)
+{
+	struct ib_device *ibdev = smcibdev->ibdev;
+	struct net_device *ndev;
+
+	if (!ibdev->ops.get_netdev)
+		return;
+	ndev = ibdev->ops.get_netdev(ibdev, port + 1);
+	if (ndev) {
+		smcibdev->ndev_ifidx[port] = ndev->ifindex;
+		dev_put(ndev);
+	}
+}
+
+void smc_ib_ndev_change(struct net_device *ndev, unsigned long event)
+{
+	struct smc_ib_device *smcibdev;
+	struct ib_device *libdev;
+	struct net_device *lndev;
+	u8 port_cnt;
+	int i;
+
+	mutex_lock(&smc_ib_devices.mutex);
+	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
+		port_cnt = smcibdev->ibdev->phys_port_cnt;
+		for (i = 0; i < min_t(size_t, port_cnt, SMC_MAX_PORTS); i++) {
+			libdev = smcibdev->ibdev;
+			if (!libdev->ops.get_netdev)
+				continue;
+			lndev = libdev->ops.get_netdev(libdev, i + 1);
+			if (lndev)
+				dev_put(lndev);
+			if (lndev != ndev)
+				continue;
+			if (event == NETDEV_REGISTER)
+				smcibdev->ndev_ifidx[i] = ndev->ifindex;
+			if (event == NETDEV_UNREGISTER)
+				smcibdev->ndev_ifidx[i] = 0;
+		}
+	}
+	mutex_unlock(&smc_ib_devices.mutex);
+}
+
 /* callback function for ib_register_client() */
 static int smc_ib_add_dev(struct ib_device *ibdev)
 {
@@ -596,6 +639,7 @@ static int smc_ib_add_dev(struct ib_device *ibdev)
 		if (smc_pnetid_by_dev_port(ibdev->dev.parent, i,
 					   smcibdev->pnetid[i]))
 			smc_pnetid_by_table_ib(smcibdev, i + 1);
+		smc_copy_netdev_ifindex(smcibdev, i);
 		pr_warn_ratelimited("smc:    ib device %s port %d has pnetid "
 				    "%.16s%s\n",
 				    smcibdev->ibdev->name, i + 1,

net/smc/smc_ib.h

@@ -55,11 +55,13 @@ struct smc_ib_device {				/* ib-device infos for smc */
 	struct mutex		mutex;		/* protect dev setup+cleanup */
 	atomic_t		lnk_cnt_by_port[SMC_MAX_PORTS];
 						/* number of links per port */
+	int			ndev_ifidx[SMC_MAX_PORTS]; /* ndev if indexes */
 };
 
 struct smc_buf_desc;
 struct smc_link;
 
+void smc_ib_ndev_change(struct net_device *ndev, unsigned long event);
 int smc_ib_register_client(void) __init;
 void smc_ib_unregister_client(void);
 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport);

net/smc/smc_pnet.c

@@ -827,9 +827,11 @@ static int smc_pnet_netdev_event(struct notifier_block *this,
 	case NETDEV_REBOOT:
 	case NETDEV_UNREGISTER:
 		smc_pnet_remove_by_ndev(event_dev);
+		smc_ib_ndev_change(event_dev, event);
 		return NOTIFY_OK;
 	case NETDEV_REGISTER:
 		smc_pnet_add_by_ndev(event_dev);
+		smc_ib_ndev_change(event_dev, event);
 		return NOTIFY_OK;
 	case NETDEV_UP:
 		smc_pnet_add_base_pnetid(net, event_dev, ndev_pnetid);