net/mlx5: E-Switch, Enable restore table only if reg_c1 is supported

Reg c0/c1 matching, rewrite of regs c0/c1, and copy header of regs c1,B
is needed for the restore table to function, might not be supported by
firmware, and creation of the restore table or the copy header will
fail.

Check reg_c1 loopback support, as firmware which supports this,
should have all of the above.

Fixes: 11b717d6 ("net/mlx5: E-Switch, Get reg_c0 value on CQE")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -1069,6 +1069,9 @@ esw_add_restore_rule(struct mlx5_eswitch *esw, u32 tag)
 	struct mlx5_flow_spec *spec;
 	void *misc;
 
+	if (!mlx5_eswitch_reg_c1_loopback_supported(esw))
+		return ERR_PTR(-EOPNOTSUPP);
+
 	spec = kzalloc(sizeof(*spec), GFP_KERNEL);
 	if (!spec)
 		return ERR_PTR(-ENOMEM);
@@ -1477,6 +1480,9 @@ static void esw_destroy_restore_table(struct mlx5_eswitch *esw)
 {
 	struct mlx5_esw_offload *offloads = &esw->offloads;
 
+	if (!mlx5_eswitch_reg_c1_loopback_supported(esw))
+		return;
+
 	mlx5_modify_header_dealloc(esw->dev, offloads->restore_copy_hdr_id);
 	mlx5_destroy_flow_group(offloads->restore_group);
 	mlx5_destroy_flow_table(offloads->ft_offloads_restore);
@@ -1496,6 +1502,9 @@ static int esw_create_restore_table(struct mlx5_eswitch *esw)
 	u32 *flow_group_in;
 	int err = 0;
 
+	if (!mlx5_eswitch_reg_c1_loopback_supported(esw))
+		return 0;
+
 	ns = mlx5_get_flow_namespace(dev, MLX5_FLOW_NAMESPACE_OFFLOADS);
 	if (!ns) {
 		esw_warn(esw->dev, "Failed to get offloads flow namespace\n");