// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2018 Mellanox Technologies. */

#include <net/gre.h>
#include "en/tc_tun.h"

static bool mlx5e_tc_tun_can_offload_gretap(struct mlx5e_priv *priv)
{
        return !!MLX5_CAP_ESW(priv->mdev, nvgre_encap_decap);
}

static int mlx5e_tc_tun_calc_hlen_gretap(struct mlx5e_encap_entry *e)
{
        return gre_calc_hlen(e->tun_info->key.tun_flags);
}

static int mlx5e_tc_tun_init_encap_attr_gretap(struct net_device *tunnel_dev,
                                               struct mlx5e_priv *priv,
                                               struct mlx5e_encap_entry *e,
                                               struct netlink_ext_ack *extack)
{
        e->tunnel = &gre_tunnel;
        e->reformat_type = MLX5_REFORMAT_TYPE_L2_TO_NVGRE;
        return 0;
}

static int mlx5e_gen_ip_tunnel_header_gretap(char buf[],
                                             __u8 *ip_proto,
                                             struct mlx5e_encap_entry *e)
{
        const struct ip_tunnel_key *tun_key  = &e->tun_info->key;
        struct gre_base_hdr *greh = (struct gre_base_hdr *)(buf);
        __be32 tun_id = tunnel_id_to_key32(tun_key->tun_id);
        IP_TUNNEL_DECLARE_FLAGS(unsupp) = { };
        int hdr_len;

        *ip_proto = IPPROTO_GRE;

        /* the HW does not calculate GRE csum or sequences */
        __set_bit(IP_TUNNEL_CSUM_BIT, unsupp);
        __set_bit(IP_TUNNEL_SEQ_BIT, unsupp);

        if (ip_tunnel_flags_intersect(tun_key->tun_flags, unsupp))
                return -EOPNOTSUPP;

        greh->protocol = htons(ETH_P_TEB);

        /* GRE key */
        hdr_len = mlx5e_tc_tun_calc_hlen_gretap(e);
        greh->flags = gre_tnl_flags_to_gre_flags(tun_key->tun_flags);
        if (test_bit(IP_TUNNEL_KEY_BIT, tun_key->tun_flags)) {
                __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
                *ptr = tun_id;
        }

        return 0;
}

static int mlx5e_tc_tun_parse_gretap(struct mlx5e_priv *priv,
                                     struct mlx5_flow_spec *spec,
                                     struct flow_cls_offload *f,
                                     void *headers_c,
                                     void *headers_v)
{
        void *misc_c = MLX5_ADDR_OF(fte_match_param, spec->match_criteria, misc_parameters);
        void *misc_v = MLX5_ADDR_OF(fte_match_param, spec->match_value, misc_parameters);
        struct flow_rule *rule = flow_cls_offload_flow_rule(f);

        MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, headers_c, ip_protocol);
        MLX5_SET(fte_match_set_lyr_2_4, headers_v, ip_protocol, IPPROTO_GRE);

        /* gre protocol */
        MLX5_SET_TO_ONES(fte_match_set_misc, misc_c, gre_protocol);
        MLX5_SET(fte_match_set_misc, misc_v, gre_protocol, ETH_P_TEB);

        /* gre key */
        if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
                struct flow_match_enc_keyid enc_keyid;

                flow_rule_match_enc_keyid(rule, &enc_keyid);
                MLX5_SET(fte_match_set_misc, misc_c,
                         gre_key.key, be32_to_cpu(enc_keyid.mask->keyid));
                MLX5_SET(fte_match_set_misc, misc_v,
                         gre_key.key, be32_to_cpu(enc_keyid.key->keyid));
        }

        spec->match_criteria_enable |= MLX5_MATCH_MISC_PARAMETERS;

        return 0;
}

struct mlx5e_tc_tunnel gre_tunnel = {
        .tunnel_type          = MLX5E_TC_TUNNEL_TYPE_GRETAP,
        .match_level          = MLX5_MATCH_L3,
        .can_offload          = mlx5e_tc_tun_can_offload_gretap,
        .calc_hlen            = mlx5e_tc_tun_calc_hlen_gretap,
        .init_encap_attr      = mlx5e_tc_tun_init_encap_attr_gretap,
        .generate_ip_tun_hdr  = mlx5e_gen_ip_tunnel_header_gretap,
        .parse_udp_ports      = NULL,
        .parse_tunnel         = mlx5e_tc_tun_parse_gretap,
        .encap_info_equal     = mlx5e_tc_tun_encap_info_equal_generic,
};