From: Stephen Hemminger <stephen@networkplumber.org>
Date: Thu, 31 Aug 2017 16:16:12 -0700
Patch-mainline: v4.14-rc1
Subject: netvsc: cleanup datapath switch
Git-commit: 9a0c48df0d77602da3958a4c8fc2abb9521b0ade
References: fate#323887

Use one routine for datapath up/down. Don't need to reopen
the rndis layer.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Olaf Hering <ohering@suse.de>
---
 drivers/net/hyperv/netvsc_drv.c | 38 +++++++-------------------------------
 1 file changed, 7 insertions(+), 31 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1847,11 +1847,13 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
 	return NOTIFY_OK;
 }
 
-static int netvsc_vf_up(struct net_device *vf_netdev)
+/* VF up/down change detected, schedule to change data path */
+static int netvsc_vf_changed(struct net_device *vf_netdev)
 {
 	struct net_device_context *net_device_ctx;
 	struct netvsc_device *netvsc_dev;
 	struct net_device *ndev;
+	bool vf_is_up = netif_running(vf_netdev);
 
 	ndev = get_netvsc_byref(vf_netdev);
 	if (!ndev)
@@ -1862,34 +1864,9 @@ static int netvsc_vf_up(struct net_device *vf_netdev)
 	if (!netvsc_dev)
 		return NOTIFY_DONE;
 
-	/* Bump refcount when datapath is acvive - Why? */
-	rndis_filter_open(netvsc_dev);
-
-	/* notify the host to switch the data path. */
-	netvsc_switch_datapath(ndev, true);
-	netdev_info(ndev, "Data path switched to VF: %s\n", vf_netdev->name);
-
-	return NOTIFY_OK;
-}
-
-static int netvsc_vf_down(struct net_device *vf_netdev)
-{
-	struct net_device_context *net_device_ctx;
-	struct netvsc_device *netvsc_dev;
-	struct net_device *ndev;
-
-	ndev = get_netvsc_byref(vf_netdev);
-	if (!ndev)
-		return NOTIFY_DONE;
-
-	net_device_ctx = netdev_priv(ndev);
-	netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
-	if (!netvsc_dev)
-		return NOTIFY_DONE;
-
-	netvsc_switch_datapath(ndev, false);
-	netdev_info(ndev, "Data path switched from VF: %s\n", vf_netdev->name);
-	rndis_filter_close(netvsc_dev);
+	netvsc_switch_datapath(ndev, vf_is_up);
+	netdev_info(ndev, "Data path switched %s VF: %s\n",
+		    vf_is_up ? "to" : "from", vf_netdev->name);
 
 	return NOTIFY_OK;
 }
@@ -2099,9 +2076,8 @@ static int netvsc_netdev_event(struct notifier_block *this,
 	case NETDEV_UNREGISTER:
 		return netvsc_unregister_vf(event_dev);
 	case NETDEV_UP:
-		return netvsc_vf_up(event_dev);
 	case NETDEV_DOWN:
-		return netvsc_vf_down(event_dev);
+		return netvsc_vf_changed(event_dev);
 	default:
 		return NOTIFY_DONE;
 	}