RDMA/hns: support send link down event fastly

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

When the netdev port status changes, the roce driver sends a port down
event by parsing the netdev event dispatched by IB_CORE, which takes about
a few hundred milliseconds.
But,it is not fast enough for ULP sometimes.

The HNS NIC driver can directly notify the ROCE driver send port
event via callback function, this takes only a few milliseconds.
This patch implements this callback function.

Feature or Bugfix:Bugfix
Signed-off-by: NLang Cheng <chenglang@huawei.com>
Reviewed-by: Noulijun <oulijun@huawei.com>
Reviewed-by: Nliyangyang20 <liyangyang20@huawei.com>
Reviewed-by: Nwangxi <wangxi11@huawei.com>
Reviewed-by: Nliuyixian <liuyixian@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -7555,9 +7555,43 @@ static int hns_roce_hw_v2_reset_notify(struct hnae3_handle *handle,
 	return ret;
 }
 
+static void hns_roce_hw_v2_link_status_change(struct hnae3_handle *handle,
+					      bool linkup)
+{
+	struct hns_roce_dev *hr_dev = (struct hns_roce_dev *)handle->priv;
+	struct net_device *netdev = handle->rinfo.netdev;
+	struct ib_event event;
+	unsigned long flags;
+	u8 phy_port;
+
+	if (linkup || !hr_dev)
+		return;
+
+	for (phy_port = 0; phy_port < hr_dev->caps.num_ports; phy_port++)
+		if (netdev == hr_dev->iboe.netdevs[phy_port])
+			break;
+
+	if (phy_port == hr_dev->caps.num_ports)
+		return;
+
+	spin_lock_irqsave(&hr_dev->iboe.lock, flags);
+	if (hr_dev->iboe.last_port_state[phy_port] == IB_PORT_DOWN) {
+		spin_unlock_irqrestore(&hr_dev->iboe.lock, flags);
+		return;
+	}
+	hr_dev->iboe.last_port_state[phy_port] = IB_PORT_DOWN;
+	spin_unlock_irqrestore(&hr_dev->iboe.lock, flags);
+
+	event.device = &hr_dev->ib_dev;
+	event.element.port_num = to_rdma_port_num(phy_port);
+	event.event = IB_EVENT_PORT_ERR;
+	ib_dispatch_event(&event);
+}
+
 static const struct hnae3_client_ops hns_roce_hw_v2_ops = {
 	.init_instance = hns_roce_hw_v2_init_instance,
 	.uninit_instance = hns_roce_hw_v2_uninit_instance,
+	.link_status_change = hns_roce_hw_v2_link_status_change,
 	.reset_notify = hns_roce_hw_v2_reset_notify,
 };