net/ethtool: Introduce link_ksettings API for virtual network devices

With the ethtool_virtdev_set_link_ksettings function in core/ethtool.c,
ibmveth, netvsc, and virtio now use the core's helper function.

Funtionality changes that pertain to ibmveth driver include:

  1. Changed the initial hardcoded link speed to 1GB.

  2. Added support for allowing a user to change the reported link
  speed via ethtool.

Functionality changes to the netvsc driver include:

  1. When netvsc_get_link_ksettings is called, it will defer to the VF
  device if it exists to pull accelerated networking values, otherwise
  pull default or user-defined values.

  2. Similarly, if netvsc_set_link_ksettings called and a VF device
  exists, the real values of speed and duplex are changed.
Signed-off-by: Cris Forno <cforno12@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmveth.c

@@ -712,29 +712,36 @@ static int ibmveth_close(struct net_device *netdev)
 	return 0;
 }
 
-static int netdev_get_link_ksettings(struct net_device *dev,
+static int ibmveth_set_link_ksettings(struct net_device *dev,
+				      const struct ethtool_link_ksettings *cmd)
+{
+	struct ibmveth_adapter *adapter = netdev_priv(dev);
+
+	return ethtool_virtdev_set_link_ksettings(dev, cmd,
+						  &adapter->speed,
+						  &adapter->duplex);
+}
+
+static int ibmveth_get_link_ksettings(struct net_device *dev,
 				      struct ethtool_link_ksettings *cmd)
 {
-	u32 supported, advertising;
-
-	supported = (SUPPORTED_1000baseT_Full | SUPPORTED_Autoneg |
-				SUPPORTED_FIBRE);
-	advertising = (ADVERTISED_1000baseT_Full | ADVERTISED_Autoneg |
-				ADVERTISED_FIBRE);
-	cmd->base.speed = SPEED_1000;
-	cmd->base.duplex = DUPLEX_FULL;
-	cmd->base.port = PORT_FIBRE;
-	cmd->base.phy_address = 0;
-	cmd->base.autoneg = AUTONEG_ENABLE;
-
-	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported,
-						supported);
-	ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising,
-						advertising);
+	struct ibmveth_adapter *adapter = netdev_priv(dev);
+
+	cmd->base.speed = adapter->speed;
+	cmd->base.duplex = adapter->duplex;
+	cmd->base.port = PORT_OTHER;
 
 	return 0;
 }
 
+static void ibmveth_init_link_settings(struct net_device *dev)
+{
+	struct ibmveth_adapter *adapter = netdev_priv(dev);
+
+	adapter->speed = SPEED_1000;
+	adapter->duplex = DUPLEX_FULL;
+}
+
 static void netdev_get_drvinfo(struct net_device *dev,
 			       struct ethtool_drvinfo *info)
 {
@@ -970,7 +977,8 @@ static const struct ethtool_ops netdev_ethtool_ops = {
 	.get_strings		         = ibmveth_get_strings,
 	.get_sset_count		         = ibmveth_get_sset_count,
 	.get_ethtool_stats	         = ibmveth_get_ethtool_stats,
-	.get_link_ksettings	= netdev_get_link_ksettings,
+	.get_link_ksettings	         = ibmveth_get_link_ksettings,
+	.set_link_ksettings              = ibmveth_set_link_ksettings,
 };
 
 static int ibmveth_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
@@ -1674,6 +1682,7 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
 	adapter->netdev = netdev;
 	adapter->mcastFilterSize = be32_to_cpu(*mcastFilterSize_p);
 	adapter->pool_config = 0;
+	ibmveth_init_link_settings(netdev);
 
 	netif_napi_add(netdev, &adapter->napi, ibmveth_poll, 16);
 

drivers/net/ethernet/ibm/ibmveth.h

@@ -162,6 +162,9 @@ struct ibmveth_adapter {
     u64 tx_send_failed;
     u64 tx_large_packets;
     u64 rx_large_packets;
+    /* Ethtool settings */
+	u8 duplex;
+	u32 speed;
 };
 
 /*

drivers/net/hyperv/netvsc_drv.c

@@ -1140,23 +1140,6 @@ static int netvsc_set_channels(struct net_device *net,
 	return ret;
 }
 
-static bool
-netvsc_validate_ethtool_ss_cmd(const struct ethtool_link_ksettings *cmd)
-{
-	struct ethtool_link_ksettings diff1 = *cmd;
-	struct ethtool_link_ksettings diff2 = {};
-
-	diff1.base.speed = 0;
-	diff1.base.duplex = 0;
-	/* advertising and cmd are usually set */
-	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
-	diff1.base.cmd = 0;
-	/* We set port to PORT_OTHER */
-	diff2.base.port = PORT_OTHER;
-
-	return !memcmp(&diff1, &diff2, sizeof(diff1));
-}
-
 static void netvsc_init_settings(struct net_device *dev)
 {
 	struct net_device_context *ndc = netdev_priv(dev);
@@ -1173,6 +1156,12 @@ static int netvsc_get_link_ksettings(struct net_device *dev,
 				     struct ethtool_link_ksettings *cmd)
 {
 	struct net_device_context *ndc = netdev_priv(dev);
+	struct net_device *vf_netdev;
+
+	vf_netdev = rtnl_dereference(ndc->vf_netdev);
+
+	if (vf_netdev)
+		return __ethtool_get_link_ksettings(vf_netdev, cmd);
 
 	cmd->base.speed = ndc->speed;
 	cmd->base.duplex = ndc->duplex;
@@ -1185,18 +1174,18 @@ static int netvsc_set_link_ksettings(struct net_device *dev,
 				     const struct ethtool_link_ksettings *cmd)
 {
 	struct net_device_context *ndc = netdev_priv(dev);
-	u32 speed;
+	struct net_device *vf_netdev = rtnl_dereference(ndc->vf_netdev);
 
-	speed = cmd->base.speed;
-	if (!ethtool_validate_speed(speed) ||
-	    !ethtool_validate_duplex(cmd->base.duplex) ||
-	    !netvsc_validate_ethtool_ss_cmd(cmd))
-		return -EINVAL;
+	if (vf_netdev) {
+		if (!vf_netdev->ethtool_ops->set_link_ksettings)
+			return -EOPNOTSUPP;
 
-	ndc->speed = speed;
-	ndc->duplex = cmd->base.duplex;
+		return vf_netdev->ethtool_ops->set_link_ksettings(vf_netdev,
+								  cmd);
+	}
 
-	return 0;
+	return ethtool_virtdev_set_link_ksettings(dev, cmd,
+						  &ndc->speed, &ndc->duplex);
 }
 
 static int netvsc_change_mtu(struct net_device *ndev, int mtu)

drivers/net/virtio_net.c

@@ -2178,48 +2178,13 @@ static void virtnet_get_channels(struct net_device *dev,
 	channels->other_count = 0;
 }
 
-/* Check if the user is trying to change anything besides speed/duplex */
-static bool
-virtnet_validate_ethtool_cmd(const struct ethtool_link_ksettings *cmd)
-{
-	struct ethtool_link_ksettings diff1 = *cmd;
-	struct ethtool_link_ksettings diff2 = {};
-
-	/* cmd is always set so we need to clear it, validate the port type
-	 * and also without autonegotiation we can ignore advertising
-	 */
-	diff1.base.speed = 0;
-	diff2.base.port = PORT_OTHER;
-	ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
-	diff1.base.duplex = 0;
-	diff1.base.cmd = 0;
-	diff1.base.link_mode_masks_nwords = 0;
-
-	return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
-		bitmap_empty(diff1.link_modes.supported,
-			     __ETHTOOL_LINK_MODE_MASK_NBITS) &&
-		bitmap_empty(diff1.link_modes.advertising,
-			     __ETHTOOL_LINK_MODE_MASK_NBITS) &&
-		bitmap_empty(diff1.link_modes.lp_advertising,
-			     __ETHTOOL_LINK_MODE_MASK_NBITS);
-}
-
 static int virtnet_set_link_ksettings(struct net_device *dev,
 				      const struct ethtool_link_ksettings *cmd)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
-	u32 speed;
 
-	speed = cmd->base.speed;
-	/* don't allow custom speed and duplex */
-	if (!ethtool_validate_speed(speed) ||
-	    !ethtool_validate_duplex(cmd->base.duplex) ||
-	    !virtnet_validate_ethtool_cmd(cmd))
-		return -EINVAL;
-	vi->speed = speed;
-	vi->duplex = cmd->base.duplex;
-
-	return 0;
+	return ethtool_virtdev_set_link_ksettings(dev, cmd,
+						  &vi->speed, &vi->duplex);
 }
 
 static int virtnet_get_link_ksettings(struct net_device *dev,