net/mlx5e: MPLSoUDP encap, support action vlan pop_eth explicitly

Currently the MPLSoUDP encap offload does the L2 pop implicitly
while adding such action explicitly (vlan eth_push) will cause
the rule to not be offloaded.

Solve it by adding offload support for vlan eth_push in case of
MPLSoUDP decap case.

Flow example:
filter root protocol ip pref 1 flower chain 0
filter root protocol ip pref 1 flower chain 0 handle 0x1
  eth_type ipv4
  dst_ip 2.2.2.22
  src_ip 2.2.2.21
  in_hw in_hw_count 1
        action order 1: vlan  pop_eth pipe
         index 1 ref 1 bind 1
        used_hw_stats delayed

        action order 2: mpls  push protocol mpls_uc label 555 tc 3 ttl 255 pipe
         index 1 ref 1 bind 1
        used_hw_stats delayed

        action order 3: tunnel_key  set
        src_ip 8.8.8.21
        dst_ip 8.8.8.22
        dst_port 6635
        csum
        tos 0x4
        ttl 6 pipe
         index 1 ref 1 bind 1
        used_hw_stats delayed

        action order 4: mirred (Egress Redirect to device bareudp0) stolen
        index 1 ref 1 bind 1
        used_hw_stats delayed
Signed-off-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -41,6 +41,7 @@ static struct mlx5e_tc_act *tc_acts_fdb[NUM_FLOW_ACTIONS] = {
 	NULL, /* FLOW_ACTION_JUMP, */
 	NULL, /* FLOW_ACTION_PIPE, */
 	&mlx5e_tc_act_vlan,
+	&mlx5e_tc_act_vlan,
 };
 
 /* Must be aligned with enum flow_action_id. */

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

@@ -23,6 +23,7 @@ struct mlx5e_tc_act_parse_state {
 	bool decap;
 	bool mpls_push;
 	bool eth_push;
+	bool eth_pop;
 	bool ptype_host;
 	const struct ip_tunnel_info *tun_info;
 	struct mlx5e_mpls_info mpls_info;

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

@@ -125,6 +125,11 @@ tc_act_can_offload_mirred(struct mlx5e_tc_act_parse_state *parse_state,
 		return false;
 	}
 
+	if (parse_state->eth_pop && !parse_state->mpls_push) {
+		NL_SET_ERR_MSG_MOD(extack, "vlan pop eth is supported only with mpls push");
+		return false;
+	}
+
 	if (flow_flag_test(parse_state->flow, L3_TO_L2_DECAP) && !parse_state->eth_push) {
 		NL_SET_ERR_MSG_MOD(extack, "mpls pop is only supported with vlan eth push");
 		return false;

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

@@ -85,6 +85,9 @@ parse_tc_vlan_action(struct mlx5e_priv *priv,
 			*action |= MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH;
 		}
 		break;
+	case FLOW_ACTION_VLAN_POP_ETH:
+		parse_state->eth_pop = true;
+		break;
 	case FLOW_ACTION_VLAN_PUSH_ETH:
 		if (!flow_flag_test(parse_state->flow, L3_TO_L2_DECAP))
 			return -EOPNOTSUPP;