net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues

To save per-packet calculations, we use the following static mappings:
1) priv {channel, tc} to netdev txq (used @mlx5e_selec_queue())
2) netdev txq to priv sq (used @mlx5e_xmit())

Thanks to these static mappings, no more need for a separate implementation
of ndo_start_xmit when multiple TCs are configured.
We believe the performance improvement of such separation would be negligible, if any.
The previous way of dynamically calculating the above mappings required
allocating more TX queues than actually used (@alloc_etherdev_mqs()),
which is now no longer needed.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 14 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 9a48d8eac0fc..f5f5eb96059e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -496,6 +496,7 @@ static int mlx5e_create_sq(struct mlx5e_channel *c,
 
 	void *sqc = param->sqc;
 	void *sqc_wq = MLX5_ADDR_OF(sqc, sqc, wq);
+	int txq_ix;
 	int err;
 
 	err = mlx5_alloc_map_uar(mdev, &sq->uar);
@@ -515,14 +516,15 @@ static int mlx5e_create_sq(struct mlx5e_channel *c,
 	if (err)
 		goto err_sq_wq_destroy;
 
-	sq->txq = netdev_get_tx_queue(priv->netdev,
-				      c->ix + tc * priv->params.num_channels);
+	txq_ix = c->ix + tc * priv->params.num_channels;
+	sq->txq = netdev_get_tx_queue(priv->netdev, txq_ix);
 
 	sq->pdev    = c->pdev;
 	sq->mkey_be = c->mkey_be;
 	sq->channel = c;
 	sq->tc      = tc;
 	sq->edge    = (sq->wq.sz_m1 + 1) - MLX5_SEND_WQE_MAX_WQEBBS;
+	priv->txq_to_sq_map[txq_ix] = sq;
 
 	return 0;
 
@@ -902,6 +904,15 @@ static void mlx5e_close_sqs(struct mlx5e_channel *c)
 		mlx5e_close_sq(&c->sq[tc]);
 }
 
+static void mlx5e_build_tc_to_txq_map(struct mlx5e_channel *c,
+				      int num_channels)
+{
+	int i;
+
+	for (i = 0; i < MLX5E_MAX_NUM_TC; i++)
+		c->tc_to_txq_map[i] = c->ix + i * num_channels;
+}
+
 static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
 			      struct mlx5e_channel_param *cparam,
 			      struct mlx5e_channel **cp)
@@ -923,6 +934,8 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
 	c->mkey_be  = cpu_to_be32(priv->mr.key);
 	c->num_tc   = priv->num_tc;
 
+	mlx5e_build_tc_to_txq_map(c, priv->params.num_channels);
+
 	netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);
 
 	err = mlx5e_open_tx_cqs(c, cparam);
@@ -1050,14 +1063,18 @@ static void mlx5e_build_channel_param(struct mlx5e_priv *priv,
 static int mlx5e_open_channels(struct mlx5e_priv *priv)
 {
 	struct mlx5e_channel_param cparam;
-	int err;
+	int err = -ENOMEM;
 	int i;
 	int j;
 
 	priv->channel = kcalloc(priv->params.num_channels,
 				sizeof(struct mlx5e_channel *), GFP_KERNEL);
-	if (!priv->channel)
-		return -ENOMEM;
+
+	priv->txq_to_sq_map = kcalloc(priv->params.num_channels * priv->num_tc,
+				      sizeof(struct mlx5e_sq *), GFP_KERNEL);
+
+	if (!priv->channel || !priv->txq_to_sq_map)
+		goto err_free_txq_to_sq_map;
 
 	mlx5e_build_channel_param(priv, &cparam);
 	for (i = 0; i < priv->params.num_channels; i++) {
@@ -1078,6 +1095,8 @@ err_close_channels:
 	for (i--; i >= 0; i--)
 		mlx5e_close_channel(priv->channel[i]);
 
+err_free_txq_to_sq_map:
+	kfree(priv->txq_to_sq_map);
 	kfree(priv->channel);
 
 	return err;
@@ -1090,6 +1109,7 @@ static void mlx5e_close_channels(struct mlx5e_priv *priv)
 	for (i = 0; i < priv->params.num_channels; i++)
 		mlx5e_close_channel(priv->channel[i]);
 
+	kfree(priv->txq_to_sq_map);
 	kfree(priv->channel);
 }
 
@@ -1384,8 +1404,7 @@ int mlx5e_open_locked(struct net_device *netdev)
 	int num_txqs;
 	int err;
 
-	num_txqs = roundup_pow_of_two(priv->params.num_channels) *
-		   priv->params.num_tc;
+	num_txqs = priv->params.num_channels * priv->params.num_tc;
 	netif_set_real_num_tx_queues(netdev, num_txqs);
 	netif_set_real_num_rx_queues(netdev, priv->params.num_channels);
 
@@ -1693,9 +1712,6 @@ static void mlx5e_build_netdev_priv(struct mlx5_core_dev *mdev,
 	priv->mdev                         = mdev;
 	priv->netdev                       = netdev;
 	priv->params.num_channels          = num_comp_vectors;
-	priv->order_base_2_num_channels    = order_base_2(num_comp_vectors);
-	priv->queue_mapping_channel_mask   =
-		roundup_pow_of_two(num_comp_vectors) - 1;
 	priv->num_tc                       = priv->params.num_tc;
 	priv->default_vlan_prio            = priv->params.default_vlan_prio;
 
@@ -1723,7 +1739,6 @@ static void mlx5e_build_netdev(struct net_device *netdev)
 
 	if (priv->num_tc > 1) {
 		mlx5e_netdev_ops.ndo_select_queue = mlx5e_select_queue;
-		mlx5e_netdev_ops.ndo_start_xmit   = mlx5e_xmit_multi_tc;
 	}
 
 	netdev->netdev_ops        = &mlx5e_netdev_ops;
@@ -1793,9 +1808,7 @@ static void *mlx5e_create_netdev(struct mlx5_core_dev *mdev)
 	if (mlx5e_check_required_hca_cap(mdev))
 		return NULL;
 
-	netdev = alloc_etherdev_mqs(sizeof(struct mlx5e_priv),
-				    roundup_pow_of_two(ncv) * MLX5E_MAX_NUM_TC,
-				    ncv);
+	netdev = alloc_etherdev_mqs(sizeof(struct mlx5e_priv), ncv, ncv);
 	if (!netdev) {
 		mlx5_core_err(mdev, "alloc_etherdev_mqs() failed\n");
 		return NULL;