net/mlx5e: Rewrite IPsec vs. TC block interface

In the commit 366e46242b8e ("net/mlx5e: Make IPsec offload work together
with eswitch and TC"), new API to block IPsec vs. TC creation was introduced.

Internally, that API used devlink lock to avoid races with userspace, but it is
not really needed as dev->priv.eswitch is stable and can't be changed. So remove
dependency on devlink lock and move block encap code back to its original place.

Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Saeed Mahameed <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c

···
 	mlx5_del_flow_rules(rx->sa.rule);
 	mlx5_destroy_flow_group(rx->sa.group);
 	mlx5_destroy_flow_table(rx->ft.sa);
+	if (rx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	if (rx == ipsec->rx_esw) {
 		mlx5_esw_ipsec_rx_status_destroy(ipsec, rx);
 	} else {
···
 		goto err_add;
 
 	/* Create FT */
+	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
+		rx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
 	if (rx->allow_tunnel_mode)
 		flags = MLX5_FLOW_TABLE_TUNNEL_EN_REFORMAT;
 	ft = ipsec_ft_create(attr.ns, attr.sa_level, attr.prio, 2, flags);
···
 err_fs:
 	mlx5_destroy_flow_table(rx->ft.sa);
 err_fs_ft:
+	if (rx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(rx->status.rule);
 	mlx5_modify_header_dealloc(mdev, rx->status.modify_hdr);
 err_add:
···
 	if (rx->ft.refcnt)
 		goto skip;
 
-	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
-		rx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
-
-	err = mlx5_eswitch_block_mode_trylock(mdev);
+	err = mlx5_eswitch_block_mode(mdev);
 	if (err)
-		goto err_out;
+		return err;
 
 	err = rx_create(mdev, ipsec, rx, family);
-	mlx5_eswitch_block_mode_unlock(mdev, err);
-	if (err)
-		goto err_out;
+	if (err) {
+		mlx5_eswitch_unblock_mode(mdev);
+		return err;
+	}
 
 skip:
 	rx->ft.refcnt++;
 	return 0;
-
-err_out:
-	if (rx->allow_tunnel_mode)
-		mlx5_eswitch_unblock_encap(mdev);
-	return err;
 }
 
 static void rx_put(struct mlx5e_ipsec *ipsec, struct mlx5e_ipsec_rx *rx,
···
 	if (--rx->ft.refcnt)
 		return;
 
-	mlx5_eswitch_unblock_mode_lock(ipsec->mdev);
 	rx_destroy(ipsec->mdev, ipsec, rx, family);
-	mlx5_eswitch_unblock_mode_unlock(ipsec->mdev);
-
-	if (rx->allow_tunnel_mode)
-		mlx5_eswitch_unblock_encap(ipsec->mdev);
+	mlx5_eswitch_unblock_mode(ipsec->mdev);
 }
 
 static struct mlx5e_ipsec_rx *rx_ft_get(struct mlx5_core_dev *mdev,
···
 		mlx5_destroy_flow_group(tx->sa.group);
 	}
 	mlx5_destroy_flow_table(tx->ft.sa);
+	if (tx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(ipsec->mdev);
 	mlx5_del_flow_rules(tx->status.rule);
 	mlx5_destroy_flow_table(tx->ft.status);
 }
···
 	if (err)
 		goto err_status_rule;
 
+	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
+		tx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
 	if (tx->allow_tunnel_mode)
 		flags = MLX5_FLOW_TABLE_TUNNEL_EN_REFORMAT;
 	ft = ipsec_ft_create(tx->ns, attr.sa_level, attr.prio, 4, flags);
···
 err_sa_miss:
 	mlx5_destroy_flow_table(tx->ft.sa);
 err_sa_ft:
+	if (tx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(tx->status.rule);
 err_status_rule:
 	mlx5_destroy_flow_table(tx->ft.status);
···
 	if (tx->ft.refcnt)
 		goto skip;
 
-	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
-		tx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
-
-	err = mlx5_eswitch_block_mode_trylock(mdev);
+	err = mlx5_eswitch_block_mode(mdev);
 	if (err)
-		goto err_out;
+		return err;
 
 	err = tx_create(ipsec, tx, ipsec->roce);
 	if (err) {
-		mlx5_eswitch_block_mode_unlock(mdev, err);
-		goto err_out;
+		mlx5_eswitch_unblock_mode(mdev);
+		return err;
 	}
 
 	if (tx == ipsec->tx_esw)
 		ipsec_esw_tx_ft_policy_set(mdev, tx->ft.pol);
 
-	mlx5_eswitch_block_mode_unlock(mdev, err);
-
 skip:
 	tx->ft.refcnt++;
 	return 0;
-
-err_out:
-	if (tx->allow_tunnel_mode)
-		mlx5_eswitch_unblock_encap(mdev);
-	return err;
 }
 
 static void tx_put(struct mlx5e_ipsec *ipsec, struct mlx5e_ipsec_tx *tx)
···
 	if (--tx->ft.refcnt)
 		return;
 
-	mlx5_eswitch_unblock_mode_lock(ipsec->mdev);
-
 	if (tx == ipsec->tx_esw) {
 		mlx5_esw_ipsec_restore_dest_uplink(ipsec->mdev);
 		ipsec_esw_tx_ft_policy_set(ipsec->mdev, NULL);
 	}
 
 	tx_destroy(ipsec, tx, ipsec->roce);
-
-	mlx5_eswitch_unblock_mode_unlock(ipsec->mdev);
-
-	if (tx->allow_tunnel_mode)
-		mlx5_eswitch_unblock_encap(ipsec->mdev);
+	mlx5_eswitch_unblock_mode(ipsec->mdev);
 }
 
 static struct mlx5_flow_table *tx_ft_get_policy(struct mlx5_core_dev *mdev,

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

···
 bool mlx5_eswitch_block_encap(struct mlx5_core_dev *dev);
 void mlx5_eswitch_unblock_encap(struct mlx5_core_dev *dev);
 
-int mlx5_eswitch_block_mode_trylock(struct mlx5_core_dev *dev);
-void mlx5_eswitch_block_mode_unlock(struct mlx5_core_dev *dev, int err);
-void mlx5_eswitch_unblock_mode_lock(struct mlx5_core_dev *dev);
-void mlx5_eswitch_unblock_mode_unlock(struct mlx5_core_dev *dev);
+int mlx5_eswitch_block_mode(struct mlx5_core_dev *dev);
+void mlx5_eswitch_unblock_mode(struct mlx5_core_dev *dev);
 
 static inline int mlx5_eswitch_num_vfs(struct mlx5_eswitch *esw)
 {
···
 {
 }
 
-static inline int mlx5_eswitch_block_mode_trylock(struct mlx5_core_dev *dev) { return 0; }
-
-static inline void mlx5_eswitch_block_mode_unlock(struct mlx5_core_dev *dev, int err) {}
-
-static inline void mlx5_eswitch_unblock_mode_lock(struct mlx5_core_dev *dev) {}
-
-static inline void mlx5_eswitch_unblock_mode_unlock(struct mlx5_core_dev *dev) {}
+static inline int mlx5_eswitch_block_mode(struct mlx5_core_dev *dev) { return 0; }
+static inline void mlx5_eswitch_unblock_mode(struct mlx5_core_dev *dev) {}
 #endif /* CONFIG_MLX5_ESWITCH */
 
 #endif /* __MLX5_ESWITCH_H__ */

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

···
 	return net_eq(devl_net, netdev_net);
 }
 
-int mlx5_eswitch_block_mode_trylock(struct mlx5_core_dev *dev)
+int mlx5_eswitch_block_mode(struct mlx5_core_dev *dev)
 {
-	struct devlink *devlink = priv_to_devlink(dev);
-	struct mlx5_eswitch *esw;
+	struct mlx5_eswitch *esw = dev->priv.eswitch;
 	int err;
 
-	devl_lock(devlink);
-	esw = mlx5_devlink_eswitch_get(devlink);
-	if (IS_ERR(esw)) {
-		/* Failure means no eswitch => not possible to change eswitch mode */
-		devl_unlock(devlink);
+	if (!mlx5_esw_allowed(esw))
 		return 0;
-	}
 
+	/* Take TC into account */
 	err = mlx5_esw_try_lock(esw);
-	if (err < 0) {
-		devl_unlock(devlink);
+	if (err < 0)
 		return err;
-	}
 
+	esw->offloads.num_block_mode++;
+	mlx5_esw_unlock(esw);
 	return 0;
 }
 
-void mlx5_eswitch_block_mode_unlock(struct mlx5_core_dev *dev, int err)
+void mlx5_eswitch_unblock_mode(struct mlx5_core_dev *dev)
 {
-	struct devlink *devlink = priv_to_devlink(dev);
-	struct mlx5_eswitch *esw;
+	struct mlx5_eswitch *esw = dev->priv.eswitch;
 
-	esw = mlx5_devlink_eswitch_get(devlink);
-	if (IS_ERR(esw))
-		return;
-
-	if (!err)
-		esw->offloads.num_block_mode++;
-	mlx5_esw_unlock(esw);
-	devl_unlock(devlink);
-}
-
-void mlx5_eswitch_unblock_mode_lock(struct mlx5_core_dev *dev)
-{
-	struct devlink *devlink = priv_to_devlink(dev);
-	struct mlx5_eswitch *esw;
-
-	esw = mlx5_devlink_eswitch_get(devlink);
-	if (IS_ERR(esw))
+	if (!mlx5_esw_allowed(esw))
 		return;
 
 	down_write(&esw->mode_lock);
-}
-
-void mlx5_eswitch_unblock_mode_unlock(struct mlx5_core_dev *dev)
-{
-	struct devlink *devlink = priv_to_devlink(dev);
-	struct mlx5_eswitch *esw;
-
-	esw = mlx5_devlink_eswitch_get(devlink);
-	if (IS_ERR(esw))
-		return;
-
 	esw->offloads.num_block_mode--;
 	up_write(&esw->mode_lock);
 }