RDMA/core: Support link status events dispatching

JIRA: https://issues.redhat.com/browse/RHEL-78090

commit 1fb0644
Author: Yuyu Li <liyuyu6@huawei.com>
Date:   Fri Nov 22 18:52:58 2024 +0800

    RDMA/core: Support link status events dispatching

    Currently the dispatching of link status events is implemented by
    each RDMA driver independently, and most of them have very similar
    patterns. Add support for this in ib_core so that we can get rid
    of duplicate codes in each driver.

    A new last_port_state is added in ib_port_cache to cache the port
    state of the last link status events dispatching. The original
    port_state in ib_port_cache is not used here because it will be
    updated when ib_dispatch_event() is called, which means it may
    be changed between two link status events, and may lead to a loss
    of event dispatching.

    Some drivers currently have some private stuff in their link status
    events handler in addition to event dispatching, and cannot be
    perfectly integrated into the ib_core handling process. For these
    drivers, add a new ops report_port_event() so that they can keep
    their current processing.

    Finally, events of LAG devices are not supported yet in this patch
    as currently there is no way to obtain ibdev from upper netdev in
    ib_core. This can be a TODO work after the core have more support
    for LAG.

    Signed-off-by: Yuyu Li <liyuyu6@huawei.com>
    Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
    Signed-off-by: Leon Romanovsky <leon@kernel.org>

Signed-off-by: Kamal Heib <kheib@redhat.com>

Author: Kamalheib

drivers/infiniband/core/device.c

@@ -2771,6 +2771,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, set_vf_guid);
 	SET_DEVICE_OP(dev_ops, set_vf_link_state);
 	SET_DEVICE_OP(dev_ops, ufile_hw_cleanup);
+	SET_DEVICE_OP(dev_ops, report_port_event);
 
 	SET_OBJ_SIZE(dev_ops, ib_ah);
 	SET_OBJ_SIZE(dev_ops, ib_counters);
@@ -2864,6 +2865,58 @@ static const struct rdma_nl_cbs ibnl_ls_cb_table[RDMA_NL_LS_NUM_OPS] = {
 	},
 };
 
+void ib_dispatch_port_state_event(struct ib_device *ibdev, struct net_device *ndev)
+{
+	enum ib_port_state curr_state;
+	struct ib_event ibevent = {};
+	u32 port;
+
+	if (ib_query_netdev_port(ibdev, ndev, &port))
+		return;
+
+	curr_state = ib_get_curr_port_state(ndev);
+
+	write_lock_irq(&ibdev->cache_lock);
+	if (ibdev->port_data[port].cache.last_port_state == curr_state) {
+		write_unlock_irq(&ibdev->cache_lock);
+		return;
+	}
+	ibdev->port_data[port].cache.last_port_state = curr_state;
+	write_unlock_irq(&ibdev->cache_lock);
+
+	ibevent.event = (curr_state == IB_PORT_DOWN) ?
+					IB_EVENT_PORT_ERR : IB_EVENT_PORT_ACTIVE;
+	ibevent.device = ibdev;
+	ibevent.element.port_num = port;
+	ib_dispatch_event(&ibevent);
+}
+EXPORT_SYMBOL(ib_dispatch_port_state_event);
+
+static void handle_port_event(struct net_device *ndev, unsigned long event)
+{
+	struct ib_device *ibdev;
+
+	/* Currently, link events in bonding scenarios are still
+	 * reported by drivers that support bonding.
+	 */
+	if (netif_is_lag_master(ndev) || netif_is_lag_port(ndev))
+		return;
+
+	ibdev = ib_device_get_by_netdev(ndev, RDMA_DRIVER_UNKNOWN);
+	if (!ibdev)
+		return;
+
+	if (ibdev->ops.report_port_event) {
+		ibdev->ops.report_port_event(ibdev, ndev, event);
+		goto put_ibdev;
+	}
+
+	ib_dispatch_port_state_event(ibdev, ndev);
+
+put_ibdev:
+	ib_device_put(ibdev);
+};
+
 static int ib_netdevice_event(struct notifier_block *this,
 			      unsigned long event, void *ptr)
 {
@@ -2885,6 +2938,13 @@ static int ib_netdevice_event(struct notifier_block *this,
 		rdma_nl_notify_event(ibdev, port, RDMA_NETDEV_RENAME_EVENT);
 		ib_device_put(ibdev);
 		break;
+
+	case NETDEV_UP:
+	case NETDEV_CHANGE:
+	case NETDEV_DOWN:
+		handle_port_event(ndev, event);
+		break;
+
 	default:
 		break;
 	}

include/rdma/ib_verbs.h

@@ -2174,6 +2174,7 @@ struct ib_port_cache {
 	struct ib_gid_table   *gid;
 	u8                     lmc;
 	enum ib_port_state     port_state;
+	enum ib_port_state     last_port_state;
 };
 
 struct ib_port_immutable {
@@ -2678,6 +2679,13 @@ struct ib_device_ops {
 	 */
 	void (*ufile_hw_cleanup)(struct ib_uverbs_file *ufile);
 
+	/**
+	 * report_port_event - Drivers need to implement this if they have
+	 * some private stuff to handle when link status changes.
+	 */
+	void (*report_port_event)(struct ib_device *ibdev,
+				  struct net_device *ndev, unsigned long event);
+
 	DECLARE_RDMA_OBJ_SIZE(ib_ah);
 	DECLARE_RDMA_OBJ_SIZE(ib_counters);
 	DECLARE_RDMA_OBJ_SIZE(ib_cq);
@@ -4468,6 +4476,15 @@ struct net_device *ib_device_get_netdev(struct ib_device *ib_dev,
 					u32 port);
 int ib_query_netdev_port(struct ib_device *ibdev, struct net_device *ndev,
 			 u32 *port);
+
+static inline enum ib_port_state ib_get_curr_port_state(struct net_device *net_dev)
+{
+	return (netif_running(net_dev) && netif_carrier_ok(net_dev)) ?
+		IB_PORT_ACTIVE : IB_PORT_DOWN;
+}
+
+void ib_dispatch_port_state_event(struct ib_device *ibdev,
+				  struct net_device *ndev);
 struct ib_wq *ib_create_wq(struct ib_pd *pd,
 			   struct ib_wq_init_attr *init_attr);
 int ib_destroy_wq_user(struct ib_wq *wq, struct ib_udata *udata);