net/mlx4_en: num cores tx rings for every UP

Change the TX ring scheme such that the number of rings for untagged packets
and for tagged packets (per each of the vlan priorities) is the same, unlike
the current situation where for tagged traffic there's one ring per priority
and for untagged rings as the number of core.

Queue selection is done as follows:

If the mqprio qdisc is operates on the interface, such that the core networking
code invoked the device setup_tc ndo callback, a mapping of skb->priority =>
queue set is forced - for both, tagged and untagged traffic.

Else, the egress map skb->priority =>  User priority is used for tagged traffic, and
all untagged traffic is sent through tx rings of UP 0.

The patch follows the convergence of discussing that issue with John Fastabend
over this thread http://comments.gmane.org/gmane.linux.network/229877

Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Liran Liss <liranl@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 11 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index eaa8fadf19c0..926d8aac941c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -47,9 +47,22 @@
 
 static int mlx4_en_setup_tc(struct net_device *dev, u8 up)
 {
-	if (up != MLX4_EN_NUM_UP)
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int i;
+	unsigned int q, offset = 0;
+
+	if (up && up != MLX4_EN_NUM_UP)
 		return -EINVAL;
 
+	netdev_set_num_tc(dev, up);
+
+	/* Partition Tx queues evenly amongst UP's */
+	q = priv->tx_ring_num / up;
+	for (i = 0; i < up; i++) {
+		netdev_set_tc_queue(dev, i, q, offset);
+		offset += q;
+	}
+
 	return 0;
 }
 
@@ -661,7 +674,7 @@ int mlx4_en_start_port(struct net_device *dev)
 		/* Configure ring */
 		tx_ring = &priv->tx_ring[i];
 		err = mlx4_en_activate_tx_ring(priv, tx_ring, cq->mcq.cqn,
-				max(0, i - MLX4_EN_NUM_TX_RINGS));
+			i / priv->mdev->profile.num_tx_rings_p_up);
 		if (err) {
 			en_err(priv, "Failed allocating Tx ring\n");
 			mlx4_en_deactivate_cq(priv, cq);
@@ -986,6 +999,9 @@ void mlx4_en_destroy_netdev(struct net_device *dev)
 
 	mlx4_en_free_resources(priv);
 
+	kfree(priv->tx_ring);
+	kfree(priv->tx_cq);
+
 	free_netdev(dev);
 }
 
@@ -1091,6 +1107,18 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	priv->ctrl_flags = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE |
 			MLX4_WQE_CTRL_SOLICITED);
 	priv->tx_ring_num = prof->tx_ring_num;
+	priv->tx_ring = kzalloc(sizeof(struct mlx4_en_tx_ring) *
+			priv->tx_ring_num, GFP_KERNEL);
+	if (!priv->tx_ring) {
+		err = -ENOMEM;
+		goto out;
+	}
+	priv->tx_cq = kzalloc(sizeof(struct mlx4_en_cq) * priv->tx_ring_num,
+			GFP_KERNEL);
+	if (!priv->tx_cq) {
+		err = -ENOMEM;
+		goto out;
+	}
 	priv->rx_ring_num = prof->rx_ring_num;
 	priv->mac_index = -1;
 	priv->msg_enable = MLX4_EN_MSG_LEVEL;
@@ -1138,15 +1166,6 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	netif_set_real_num_tx_queues(dev, priv->tx_ring_num);
 	netif_set_real_num_rx_queues(dev, priv->rx_ring_num);
 
-	netdev_set_num_tc(dev, MLX4_EN_NUM_UP);
-
-	/* First 9 rings are for UP 0 */
-	netdev_set_tc_queue(dev, 0, MLX4_EN_NUM_TX_RINGS + 1, 0);
-
-	/* Partition Tx queues evenly amongst UP's 1-7 */
-	for (i = 1; i < MLX4_EN_NUM_UP; i++)
-		netdev_set_tc_queue(dev, i, 1, MLX4_EN_NUM_TX_RINGS + i);
-
 	SET_ETHTOOL_OPS(dev, &mlx4_en_ethtool_ops);
 
 	/* Set defualt MAC */