mlxsw: core_acl_flex_actions: Allow the first set to be dummy

In Spectrum-2, the real action sets are always in KVD linear. The first
set is always empty and contains only pointer to the first real set in
KVD linear. So provide possibility to specify the first set is the dummy
one.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c

@@ -351,9 +351,24 @@ struct mlxsw_afa_block *mlxsw_afa_block_create(struct mlxsw_afa *mlxsw_afa)
 	block->first_set = mlxsw_afa_set_create(true);
 	if (!block->first_set)
 		goto err_first_set_create;
-	block->cur_set = block->first_set;
+
+	/* In case user instructs to have dummy first set, we leave it
+	 * empty here and create another, real, set right away.
+	 */
+	if (mlxsw_afa->ops->dummy_first_set) {
+		block->cur_set = mlxsw_afa_set_create(false);
+		if (!block->cur_set)
+			goto err_second_set_create;
+		block->cur_set->prev = block->first_set;
+		block->first_set->next = block->cur_set;
+	} else {
+		block->cur_set = block->first_set;
+	}
+
 	return block;
 
+err_second_set_create:
+	mlxsw_afa_set_destroy(block->first_set);
 err_first_set_create:
 	kfree(block);
 	return NULL;

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.h

@@ -54,6 +54,7 @@ struct mlxsw_afa_ops {
 			  bool ingress, int *p_span_id);
 	void (*mirror_del)(void *priv, u8 local_in_port, int span_id,
 			   bool ingress);
+	bool dummy_first_set;
 };
 
 struct mlxsw_afa *mlxsw_afa_create(unsigned int max_acts_per_set,