net/mlx4_en: Manage hash of MAC addresses per port

As a preparation step for supporting multiple unicast addresses, store MAC addresses in hash table.
Remove the radix tree for MAC addresses per QP, as it's not in use.
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

@@ -545,13 +545,10 @@ static int mlx4_en_get_qp(struct mlx4_en_priv *priv)
 	memcpy(entry->mac, priv->dev->dev_addr, sizeof(entry->mac));
 	entry->reg_id = reg_id;
 
-	err = radix_tree_insert(&priv->mac_tree, *qpn, entry);
-	if (err)
-		goto insert_err;
-	return 0;
+	hlist_add_head_rcu(&entry->hlist,
+			   &priv->mac_hash[entry->mac[MLX4_EN_MAC_HASH_IDX]]);
 
-insert_err:
-	kfree(entry);
+	return 0;
 
 alloc_err:
 	mlx4_en_uc_steer_release(priv, priv->dev->dev_addr, *qpn, reg_id);
@@ -568,7 +565,6 @@ static void mlx4_en_put_qp(struct mlx4_en_priv *priv)
 {
 	struct mlx4_en_dev *mdev = priv->mdev;
 	struct mlx4_dev *dev = mdev->dev;
-	struct mlx4_mac_entry *entry;
 	int qpn = priv->base_qpn;
 	u64 mac = mlx4_en_mac_to_u64(priv->dev->dev_addr);
 
@@ -577,15 +573,26 @@ static void mlx4_en_put_qp(struct mlx4_en_priv *priv)
 	mlx4_unregister_mac(dev, priv->port, mac);
 
 	if (dev->caps.steering_mode != MLX4_STEERING_MODE_A0) {
-		entry = radix_tree_lookup(&priv->mac_tree, qpn);
-		if (entry) {
+		struct mlx4_mac_entry *entry;
+		struct hlist_node *n, *tmp;
+		struct hlist_head *bucket;
+		unsigned int mac_hash;
+
+		mac_hash = priv->dev->dev_addr[MLX4_EN_MAC_HASH_IDX];
+		bucket = &priv->mac_hash[mac_hash];
+		hlist_for_each_entry_safe(entry, n, tmp, bucket, hlist) {
+			if (ether_addr_equal_64bits(entry->mac,
+						    priv->dev->dev_addr)) {
 				en_dbg(DRV, priv, "Releasing qp: port %d, MAC %pM, qpn %d\n",
-			       priv->port, entry->mac, qpn);
+				       priv->port, priv->dev->dev_addr, qpn);
 				mlx4_en_uc_steer_release(priv, entry->mac,
 							 qpn, entry->reg_id);
 				mlx4_qp_release_range(dev, qpn, 1);
-			radix_tree_delete(&priv->mac_tree, qpn);
-			kfree(entry);
+
+				hlist_del_rcu(&entry->hlist);
+				kfree_rcu(entry, rcu);
+				break;
+			}
 		}
 	}
 }
@@ -595,27 +602,39 @@ static int mlx4_en_replace_mac(struct mlx4_en_priv *priv, int qpn,
 {
 	struct mlx4_en_dev *mdev = priv->mdev;
 	struct mlx4_dev *dev = mdev->dev;
-	struct mlx4_mac_entry *entry;
 	int err = 0;
 	u64 new_mac_u64 = mlx4_en_mac_to_u64(new_mac);
 
 	if (dev->caps.steering_mode != MLX4_STEERING_MODE_A0) {
-		u64 prev_mac_u64;
+		struct hlist_head *bucket;
+		unsigned int mac_hash;
+		struct mlx4_mac_entry *entry;
+		struct hlist_node *n, *tmp;
+		u64 prev_mac_u64 = mlx4_en_mac_to_u64(prev_mac);
 
-		entry = radix_tree_lookup(&priv->mac_tree, qpn);
-		if (!entry)
-			return -EINVAL;
-		prev_mac_u64 = mlx4_en_mac_to_u64(entry->mac);
+		bucket = &priv->mac_hash[prev_mac[MLX4_EN_MAC_HASH_IDX]];
+		hlist_for_each_entry_safe(entry, n, tmp, bucket, hlist) {
+			if (ether_addr_equal_64bits(entry->mac, prev_mac)) {
 				mlx4_en_uc_steer_release(priv, entry->mac,
 							 qpn, entry->reg_id);
-		mlx4_unregister_mac(dev, priv->port, prev_mac_u64);
+				mlx4_unregister_mac(dev, priv->port,
+						    prev_mac_u64);
+				hlist_del_rcu(&entry->hlist);
+				synchronize_rcu();
 				memcpy(entry->mac, new_mac, ETH_ALEN);
 				entry->reg_id = 0;
+				mac_hash = new_mac[MLX4_EN_MAC_HASH_IDX];
+				hlist_add_head_rcu(&entry->hlist,
+						   &priv->mac_hash[mac_hash]);
 				mlx4_register_mac(dev, priv->port, new_mac_u64);
 				err = mlx4_en_uc_steer_add(priv, new_mac,
-					   &qpn, &entry->reg_id);
+							   &qpn,
+							   &entry->reg_id);
 				return err;
 			}
+		}
+		return -EINVAL;
+	}
 
 	return __mlx4_replace_mac(dev, priv->port, qpn, new_mac_u64);
 }
@@ -1816,6 +1835,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 {
 	struct net_device *dev;
 	struct mlx4_en_priv *priv;
+	int i;
 	int err;
 
 	dev = alloc_etherdev_mqs(sizeof(struct mlx4_en_priv),
@@ -1874,7 +1894,8 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 		dev->dcbnl_ops = &mlx4_en_dcbnl_ops;
 #endif
 
-	INIT_RADIX_TREE(&priv->mac_tree, GFP_KERNEL);
+	for (i = 0; i < MLX4_EN_MAC_HASH_SIZE; ++i)
+		INIT_HLIST_HEAD(&priv->mac_hash[i]);
 
 	/* Query for default mac and max mtu */
 	priv->max_mtu = mdev->dev->caps.eth_mtu_cap[priv->port];

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

@@ -615,11 +615,26 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			ethh = (struct ethhdr *)(page_address(frags[0].page) +
 						 frags[0].offset);
 
+			if (is_multicast_ether_addr(ethh->h_dest)) {
+				struct mlx4_mac_entry *entry;
+				struct hlist_node *n;
+				struct hlist_head *bucket;
+				unsigned int mac_hash;
+
 				/* Drop the packet, since HW loopback-ed it */
-			if (ether_addr_equal_64bits(dev->dev_addr,
-						    ethh->h_source))
+				mac_hash = ethh->h_source[MLX4_EN_MAC_HASH_IDX];
+				bucket = &priv->mac_hash[mac_hash];
+				rcu_read_lock();
+				hlist_for_each_entry_rcu(entry, n, bucket, hlist) {
+					if (ether_addr_equal_64bits(entry->mac,
+								    ethh->h_source)) {
+						rcu_read_unlock();
 						goto next;
 					}
+				}
+				rcu_read_unlock();
+			}
+		}
 
 		/*
 		 * Packet is OK - process it.

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

@@ -442,6 +442,9 @@ enum {
 	MLX4_EN_FLAG_RX_FILTER_NEEDED	= (1 << 3)
 };
 
+#define MLX4_EN_MAC_HASH_SIZE (1 << BITS_PER_BYTE)
+#define MLX4_EN_MAC_HASH_IDX 5
+
 struct mlx4_en_priv {
 	struct mlx4_en_dev *mdev;
 	struct mlx4_en_port_profile *prof;
@@ -521,7 +524,7 @@ struct mlx4_en_priv {
 	bool wol;
 	struct device *ddev;
 	int base_tx_qpn;
-	struct radix_tree_root mac_tree;
+	struct hlist_head mac_hash[MLX4_EN_MAC_HASH_SIZE];
 
 #ifdef CONFIG_MLX4_EN_DCB
 	struct ieee_ets ets;
@@ -542,8 +545,10 @@ enum mlx4_en_wol {
 };
 
 struct mlx4_mac_entry {
+	struct hlist_node hlist;
 	unsigned char mac[ETH_ALEN + 2];
 	u64 reg_id;
+	struct rcu_head rcu;
 };
 
 #define MLX4_EN_WOL_DO_MODIFY (1ULL << 63)