net/mlx4_en: Add support for drop action through ethtool

The drop action is implemented by allocating a QP and keeping it in a reset state
such that the HW drops any packets which are steered to that QP. When a drop action
is requested, we attach the relevant flow to that QP.

Sign-off-by: Hadar Hen Zion <hadarh@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 42 insertions, 2 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index 3e72a2076fb5..dd6a77b21149 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -821,7 +821,7 @@ static int mlx4_en_flow_replace(struct net_device *dev,
 
         /* Allow direct QP attaches if the EN_ETHTOOL_QP_ATTACH flag is set */
         if (cmd->fs.ring_cookie == RX_CLS_FLOW_DISC)
-                return -EINVAL;
+                qpn = priv->drop_qp.qpn;
         else if (cmd->fs.ring_cookie & EN_ETHTOOL_QP_ATTACH) {
                 qpn = cmd->fs.ring_cookie & (EN_ETHTOOL_QP_ATTACH - 1);
         } else {
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index b7945a80ad15..94375a8c6d42 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -796,6 +796,10 @@ int mlx4_en_start_port(struct net_device *dev)
                 goto mac_err;
         }
 
+        err = mlx4_en_create_drop_qp(priv);
+        if (err)
+                goto rss_err;
+
         /* Configure tx cq's and rings */
         for (i = 0; i < priv->tx_ring_num; i++) {
                 /* Configure cq */
@@ -895,7 +899,8 @@ tx_err:
                 mlx4_en_deactivate_tx_ring(priv, &priv->tx_ring[tx_index]);
                 mlx4_en_deactivate_cq(priv, &priv->tx_cq[tx_index]);
         }
-
+        mlx4_en_destroy_drop_qp(priv);
+rss_err:
         mlx4_en_release_rss_steer(priv);
 mac_err:
         mlx4_put_eth_qp(mdev->dev, priv->port, priv->mac, priv->base_qpn);
@@ -950,6 +955,8 @@ void mlx4_en_stop_port(struct net_device *dev)
         /* Flush multicast filter */
         mlx4_SET_MCAST_FLTR(mdev->dev, priv->port, 0, 1, MLX4_MCAST_CONFIG);
 
+        mlx4_en_destroy_drop_qp(priv);
+
         /* Free TX Rings */
         for (i = 0; i < priv->tx_ring_num; i++) {
                 mlx4_en_deactivate_tx_ring(priv, &priv->tx_ring[i]);
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index d49a7ac3187d..a04cbf767eb5 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -844,6 +844,36 @@ out:
         return err;
 }
 
+int mlx4_en_create_drop_qp(struct mlx4_en_priv *priv)
+{
+        int err;
+        u32 qpn;
+
+        err = mlx4_qp_reserve_range(priv->mdev->dev, 1, 1, &qpn);
+        if (err) {
+                en_err(priv, "Failed reserving drop qpn\n");
+                return err;
+        }
+        err = mlx4_qp_alloc(priv->mdev->dev, qpn, &priv->drop_qp);
+        if (err) {
+                en_err(priv, "Failed allocating drop qp\n");
+                mlx4_qp_release_range(priv->mdev->dev, qpn, 1);
+                return err;
+        }
+
+        return 0;
+}
+
+void mlx4_en_destroy_drop_qp(struct mlx4_en_priv *priv)
+{
+        u32 qpn;
+
+        qpn = priv->drop_qp.qpn;
+        mlx4_qp_remove(priv->mdev->dev, &priv->drop_qp);
+        mlx4_qp_free(priv->mdev->dev, &priv->drop_qp);
+        mlx4_qp_release_range(priv->mdev->dev, qpn, 1);
+}
+
 /* Allocate rx qp's and configure them according to rss map */
 int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv)
 {
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 8882e70493fe..a12632150b34 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -500,6 +500,7 @@ struct mlx4_en_priv {
         struct mlx4_en_rx_ring rx_ring[MAX_RX_RINGS];
         struct mlx4_en_cq *tx_cq;
         struct mlx4_en_cq rx_cq[MAX_RX_RINGS];
+        struct mlx4_qp drop_qp;
         struct work_struct mcast_task;
         struct work_struct mac_task;
         struct work_struct watchdog_task;
@@ -586,6 +587,8 @@ void mlx4_en_unmap_buffer(struct mlx4_buf *buf);
 void mlx4_en_calc_rx_buf(struct net_device *dev);
 int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv);
 void mlx4_en_release_rss_steer(struct mlx4_en_priv *priv);
+int mlx4_en_create_drop_qp(struct mlx4_en_priv *priv);
+void mlx4_en_destroy_drop_qp(struct mlx4_en_priv *priv);
 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring);
 void mlx4_en_rx_irq(struct mlx4_cq *mcq);