net: consolidate and fix ethtool_ops->get_settings calling

This patch does several things:
- introduces __ethtool_get_settings which is called from ethtool code and
  from drivers as well. Put ASSERT_RTNL there.
- dev_ethtool_get_settings() is replaced by __ethtool_get_settings()
- changes calling in drivers so rtnl locking is respected. In
  iboe_get_rate was previously ->get_settings() called unlocked. This
  fixes it. Also prb_calc_retire_blk_tmo() in af_packet.c had the same
  problem. Also fixed by calling __dev_get_by_index() instead of
  dev_get_by_index() and holding rtnl_lock for both calls.
- introduces rtnl_lock in bnx2fc_vport_create() and fcoe_vport_create()
  so bnx2fc_if_create() and fcoe_if_create() are called locked as they
  are from other places.
- use __ethtool_get_settings() in bonding code

Signed-off-by: Jiri Pirko <jpirko@redhat.com>

v2->v3:
	-removed dev_ethtool_get_settings()
	-added ASSERT_RTNL into __ethtool_get_settings()
	-prb_calc_retire_blk_tmo - use __dev_get_by_index() and lock
	 around it and __ethtool_get_settings() call
v1->v2:
        add missing export_symbol
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> [except FCoE bits]
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2ea3d63..25e68f5 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -530,33 +530,35 @@
 {
 	struct net_device *dev;
 	unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
+	struct ethtool_cmd ecmd;
+	int err;
 
-	dev = dev_get_by_index(sock_net(&po->sk), po->ifindex);
-	if (unlikely(dev == NULL))
+	rtnl_lock();
+	dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
+	if (unlikely(!dev)) {
+		rtnl_unlock();
 		return DEFAULT_PRB_RETIRE_TOV;
-
-	if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
-		struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
-
-		if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
-			switch (ecmd.speed) {
-			case SPEED_10000:
-				msec = 1;
-				div = 10000/1000;
-				break;
-			case SPEED_1000:
-				msec = 1;
-				div = 1000/1000;
-				break;
-			/*
-			 * If the link speed is so slow you don't really
-			 * need to worry about perf anyways
-			 */
-			case SPEED_100:
-			case SPEED_10:
-			default:
-				return DEFAULT_PRB_RETIRE_TOV;
-			}
+	}
+	err = __ethtool_get_settings(dev, &ecmd);
+	rtnl_unlock();
+	if (!err) {
+		switch (ecmd.speed) {
+		case SPEED_10000:
+			msec = 1;
+			div = 10000/1000;
+			break;
+		case SPEED_1000:
+			msec = 1;
+			div = 1000/1000;
+			break;
+		/*
+		 * If the link speed is so slow you don't really
+		 * need to worry about perf anyways
+		 */
+		case SPEED_100:
+		case SPEED_10:
+		default:
+			return DEFAULT_PRB_RETIRE_TOV;
 		}
 	}