net/mlx4_en: Add unicast MAC filtering

Implement and advertise unicast MAC filtering, such that setting macvlan
instance over mlx4_en interfaces will not require the networking core
to put mlx4_en devices in promiscuous mode.

If for some reason adding a unicast address filter fails e.g as of missing space in
the HW mac table, the device forces itself into promiscuous mode (and out of this
forced state when enough space is available).
Signed-off-by: Yan Burman <yanb@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -1016,6 +1016,126 @@ static void mlx4_en_do_multicast(struct mlx4_en_priv *priv,
 	}
 }
 
+static void mlx4_en_do_uc_filter(struct mlx4_en_priv *priv,
+				 struct net_device *dev,
+				 struct mlx4_en_dev *mdev)
+{
+	struct netdev_hw_addr *ha;
+	struct mlx4_mac_entry *entry;
+	struct hlist_node *n, *tmp;
+	bool found;
+	u64 mac;
+	int err = 0;
+	struct hlist_head *bucket;
+	unsigned int i;
+	int removed = 0;
+	u32 prev_flags;
+
+	/* Note that we do not need to protect our mac_hash traversal with rcu,
+	 * since all modification code is protected by mdev->state_lock
+	 */
+
+	/* find what to remove */
+	for (i = 0; i < MLX4_EN_MAC_HASH_SIZE; ++i) {
+		bucket = &priv->mac_hash[i];
+		hlist_for_each_entry_safe(entry, n, tmp, bucket, hlist) {
+			found = false;
+			netdev_for_each_uc_addr(ha, dev) {
+				if (ether_addr_equal_64bits(entry->mac,
+							    ha->addr)) {
+					found = true;
+					break;
+				}
+			}
+
+			/* MAC address of the port is not in uc list */
+			if (ether_addr_equal_64bits(entry->mac, dev->dev_addr))
+				found = true;
+
+			if (!found) {
+				mac = mlx4_en_mac_to_u64(entry->mac);
+				mlx4_en_uc_steer_release(priv, entry->mac,
+							 priv->base_qpn,
+							 entry->reg_id);
+				mlx4_unregister_mac(mdev->dev, priv->port, mac);
+
+				hlist_del_rcu(&entry->hlist);
+				kfree_rcu(entry, rcu);
+				en_dbg(DRV, priv, "Removed MAC %pM on port:%d\n",
+				       entry->mac, priv->port);
+				++removed;
+			}
+		}
+	}
+
+	/* if we didn't remove anything, there is no use in trying to add
+	 * again once we are in a forced promisc mode state
+	 */
+	if ((priv->flags & MLX4_EN_FLAG_FORCE_PROMISC) && 0 == removed)
+		return;
+
+	prev_flags = priv->flags;
+	priv->flags &= ~MLX4_EN_FLAG_FORCE_PROMISC;
+
+	/* find what to add */
+	netdev_for_each_uc_addr(ha, dev) {
+		found = false;
+		bucket = &priv->mac_hash[ha->addr[MLX4_EN_MAC_HASH_IDX]];
+		hlist_for_each_entry(entry, n, bucket, hlist) {
+			if (ether_addr_equal_64bits(entry->mac, ha->addr)) {
+				found = true;
+				break;
+			}
+		}
+
+		if (!found) {
+			entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+			if (!entry) {
+				en_err(priv, "Failed adding MAC %pM on port:%d (out of memory)\n",
+				       ha->addr, priv->port);
+				priv->flags |= MLX4_EN_FLAG_FORCE_PROMISC;
+				break;
+			}
+			mac = mlx4_en_mac_to_u64(ha->addr);
+			memcpy(entry->mac, ha->addr, ETH_ALEN);
+			err = mlx4_register_mac(mdev->dev, priv->port, mac);
+			if (err < 0) {
+				en_err(priv, "Failed registering MAC %pM on port %d: %d\n",
+				       ha->addr, priv->port, err);
+				kfree(entry);
+				priv->flags |= MLX4_EN_FLAG_FORCE_PROMISC;
+				break;
+			}
+			err = mlx4_en_uc_steer_add(priv, ha->addr,
+						   &priv->base_qpn,
+						   &entry->reg_id);
+			if (err) {
+				en_err(priv, "Failed adding MAC %pM on port %d: %d\n",
+				       ha->addr, priv->port, err);
+				mlx4_unregister_mac(mdev->dev, priv->port, mac);
+				kfree(entry);
+				priv->flags |= MLX4_EN_FLAG_FORCE_PROMISC;
+				break;
+			} else {
+				unsigned int mac_hash;
+				en_dbg(DRV, priv, "Added MAC %pM on port:%d\n",
+				       ha->addr, priv->port);
+				mac_hash = ha->addr[MLX4_EN_MAC_HASH_IDX];
+				bucket = &priv->mac_hash[mac_hash];
+				hlist_add_head_rcu(&entry->hlist, bucket);
+			}
+		}
+	}
+
+	if (priv->flags & MLX4_EN_FLAG_FORCE_PROMISC) {
+		en_warn(priv, "Forcing promiscuous mode on port:%d\n",
+			priv->port);
+	} else if (prev_flags & MLX4_EN_FLAG_FORCE_PROMISC) {
+		en_warn(priv, "Stop forcing promiscuous mode on port:%d\n",
+			priv->port);
+	}
+}
+
 static void mlx4_en_do_set_rx_mode(struct work_struct *work)
 {
 	struct mlx4_en_priv *priv = container_of(work, struct mlx4_en_priv,
@@ -1043,8 +1163,12 @@ static void mlx4_en_do_set_rx_mode(struct work_struct *work)
 		}
 	}
 
+	if (dev->priv_flags & IFF_UNICAST_FLT)
+		mlx4_en_do_uc_filter(priv, dev, mdev);
+
 	/* Promsicuous mode: disable all filters */
-	if (dev->flags & IFF_PROMISC) {
+	if ((dev->flags & IFF_PROMISC) ||
+	    (priv->flags & MLX4_EN_FLAG_FORCE_PROMISC)) {
 		mlx4_en_set_promisc_mode(priv, mdev);
 		goto out;
 	}
@@ -1961,6 +2085,9 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	    MLX4_STEERING_MODE_DEVICE_MANAGED)
 		dev->hw_features |= NETIF_F_NTUPLE;
 
+	if (mdev->dev->caps.steering_mode != MLX4_STEERING_MODE_A0)
+		dev->priv_flags |= IFF_UNICAST_FLT;
+
 	mdev->pndev[port] = dev;
 
 	netif_carrier_off(dev);

drivers/net/ethernet/mellanox/mlx4/mlx4_en.h

@@ -439,7 +439,8 @@ enum {
 	 */
 	MLX4_EN_FLAG_ENABLE_HW_LOOPBACK	= (1 << 2),
 	/* whether we need to drop packets that hardware loopback-ed */
-	MLX4_EN_FLAG_RX_FILTER_NEEDED	= (1 << 3)
+	MLX4_EN_FLAG_RX_FILTER_NEEDED	= (1 << 3),
+	MLX4_EN_FLAG_FORCE_PROMISC	= (1 << 4)
 };
 
 #define MLX4_EN_MAC_HASH_SIZE (1 << BITS_PER_BYTE)