net/mlx5e: E-Switch, Add a check that log_max_l2_table is valid

If log_max_l2_table is 0 there is no really room for one L2 address.
and should be treated as not supported.
Do the check in MPFS init and for vport context events which
both used to update L2 address.
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -712,6 +712,9 @@ void esw_vport_change_handle_locked(struct mlx5_vport *vport)
 	struct mlx5_eswitch *esw = dev->priv.eswitch;
 	u8 mac[ETH_ALEN];
 
+	if (!MLX5_CAP_GEN(dev, log_max_l2_table))
+		return;
+
 	mlx5_query_nic_vport_mac_address(dev, vport->vport, true, mac);
 	esw_debug(dev, "vport[%d] Context Changed: perm mac: %pM\n",
 		  vport->vport, mac);
@@ -948,7 +951,8 @@ void mlx5_esw_vport_disable(struct mlx5_eswitch *esw, u16 vport_num)
 	vport->enabled = false;
 
 	/* Disable events from this vport */
-	arm_vport_context_events_cmd(esw->dev, vport->vport, 0);
+	if (MLX5_CAP_GEN(esw->dev, log_max_l2_table))
+		arm_vport_context_events_cmd(esw->dev, vport->vport, 0);
 
 	if (!mlx5_esw_is_manager_vport(esw, vport->vport) &&
 	    MLX5_CAP_GEN(esw->dev, vhca_resource_manager))

drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c

@@ -99,7 +99,7 @@ int mlx5_mpfs_init(struct mlx5_core_dev *dev)
 	int l2table_size = 1 << MLX5_CAP_GEN(dev, log_max_l2_table);
 	struct mlx5_mpfs *mpfs;
 
-	if (!MLX5_ESWITCH_MANAGER(dev))
+	if (!MLX5_ESWITCH_MANAGER(dev) || l2table_size == 1)
 		return 0;
 
 	mpfs = kzalloc(sizeof(*mpfs), GFP_KERNEL);