// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
// Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.

#include "act.h"
#include "en/tc_priv.h"
#include "eswitch.h"

static int
validate_goto_chain(struct mlx5e_priv *priv,
                    struct mlx5e_tc_flow *flow,
                    struct mlx5_flow_attr *attr,
                    const struct flow_action_entry *act,
                    struct netlink_ext_ack *extack)
{
        struct mlx5e_tc_table *tc = mlx5e_fs_get_tc(priv->fs);
        bool is_esw = mlx5e_is_eswitch_flow(flow);
        bool ft_flow = mlx5e_is_ft_flow(flow);
        u32 dest_chain = act->chain_index;
        struct mlx5_fs_chains *chains;
        struct mlx5_eswitch *esw;
        u32 reformat_and_fwd;
        u32 max_chain;

        esw = priv->mdev->priv.eswitch;
        chains = is_esw ? esw_chains(esw) : mlx5e_nic_chains(tc);
        max_chain = mlx5_chains_get_chain_range(chains);
        reformat_and_fwd = is_esw ?
                           MLX5_CAP_ESW_FLOWTABLE_FDB(priv->mdev, reformat_and_fwd_to_table) :
                           MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, reformat_and_fwd_to_table);

        if (ft_flow) {
                NL_SET_ERR_MSG_MOD(extack, "Goto action is not supported");
                return -EOPNOTSUPP;
        }

        if (!mlx5_chains_backwards_supported(chains) &&
            dest_chain <= attr->chain) {
                NL_SET_ERR_MSG_MOD(extack, "Goto lower numbered chain isn't supported");
                return -EOPNOTSUPP;
        }

        if (dest_chain > max_chain) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Requested destination chain is out of supported range");
                return -EOPNOTSUPP;
        }

        if (attr->action & (MLX5_FLOW_CONTEXT_ACTION_PACKET_REFORMAT |
                            MLX5_FLOW_CONTEXT_ACTION_DECAP) &&
            !reformat_and_fwd) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Goto chain is not allowed if action has reformat or decap");
                return -EOPNOTSUPP;
        }

        return 0;
}

static bool
tc_act_can_offload_goto(struct mlx5e_tc_act_parse_state *parse_state,
                        const struct flow_action_entry *act,
                        int act_index,
                        struct mlx5_flow_attr *attr)
{
        struct netlink_ext_ack *extack = parse_state->extack;
        struct mlx5e_tc_flow *flow = parse_state->flow;

        if (validate_goto_chain(flow->priv, flow, attr, act, extack))
                return false;

        return true;
}

static int
tc_act_parse_goto(struct mlx5e_tc_act_parse_state *parse_state,
                  const struct flow_action_entry *act,
                  struct mlx5e_priv *priv,
                  struct mlx5_flow_attr *attr)
{
        attr->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
        attr->dest_chain = act->chain_index;

        return 0;
}

static int
tc_act_post_parse_goto(struct mlx5e_tc_act_parse_state *parse_state,
                       struct mlx5e_priv *priv,
                       struct mlx5_flow_attr *attr)
{
        struct mlx5e_tc_flow_parse_attr *parse_attr = attr->parse_attr;
        struct netlink_ext_ack *extack = parse_state->extack;
        struct mlx5e_tc_flow *flow = parse_state->flow;

        if (!attr->dest_chain)
                return 0;

        if (parse_state->decap) {
                /* It can be supported if we'll create a mapping for
                 * the tunnel device only (without tunnel), and set
                 * this tunnel id with this decap flow.
                 *
                 * On restore (miss), we'll just set this saved tunnel
                 * device.
                 */

                NL_SET_ERR_MSG_MOD(extack, "Decap with goto isn't supported");
                netdev_warn(priv->netdev, "Decap with goto isn't supported");
                return -EOPNOTSUPP;
        }

        if (!mlx5e_is_eswitch_flow(flow) && parse_attr->mirred_ifindex[0]) {
                NL_SET_ERR_MSG_MOD(extack, "Mirroring goto chain rules isn't supported");
                return -EOPNOTSUPP;
        }

        return 0;
}

struct mlx5e_tc_act mlx5e_tc_act_goto = {
        .can_offload = tc_act_can_offload_goto,
        .parse_action = tc_act_parse_goto,
        .post_parse = tc_act_post_parse_goto,
        .is_terminating_action = true,
};