net/mlx5e: TC, Skip redundant ct clear actions

Offload of ct clear action is just resetting the reg_c register.
It's done by allocating modify hdr resources which is limited.
Doing it multiple times is redundant and wasting modify hdr resources
and if resources depleted the driver will fail offloading the rule.
Ignore redundant ct clear actions after the first one.

Fixes: 806401c2 ("net/mlx5e: CT, Fix multiple allocations and memleak of mod acts")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Ariel Levkovich <lariel@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h

@@ -16,6 +16,7 @@ struct mlx5e_tc_act_parse_state {
 	unsigned int num_actions;
 	struct mlx5e_tc_flow *flow;
 	struct netlink_ext_ack *extack;
+	bool ct_clear;
 	bool encap;
 	bool decap;
 	bool mpls_push;

drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/ct.c

@@ -27,8 +27,13 @@ tc_act_parse_ct(struct mlx5e_tc_act_parse_state *parse_state,
 		struct mlx5e_priv *priv,
 		struct mlx5_flow_attr *attr)
 {
+	bool clear_action = act->ct.action & TCA_CT_ACT_CLEAR;
 	int err;
 
+	/* It's redundant to do ct clear more than once. */
+	if (clear_action && parse_state->ct_clear)
+		return 0;
+
 	err = mlx5_tc_ct_parse_action(parse_state->ct_priv, attr,
 				      &attr->parse_attr->mod_hdr_acts,
 				      act, parse_state->extack);
@@ -40,6 +45,8 @@ tc_act_parse_ct(struct mlx5e_tc_act_parse_state *parse_state,
 	if (mlx5e_is_eswitch_flow(parse_state->flow))
 		attr->esw_attr->split_count = attr->esw_attr->out_count;
 
+	parse_state->ct_clear = clear_action;
+
 	return 0;
 }