/*
 * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/hash.h>
#include <linux/mlx5/fs.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <net/rps.h>
#include "en.h"

#define ARFS_HASH_SHIFT BITS_PER_BYTE
#define ARFS_HASH_SIZE BIT(BITS_PER_BYTE)

struct arfs_table {
        struct mlx5e_flow_table  ft;
        struct mlx5_flow_handle  *default_rule;
        struct hlist_head        rules_hash[ARFS_HASH_SIZE];
};

enum {
        MLX5E_ARFS_STATE_ENABLED,
};

enum arfs_type {
        ARFS_IPV4_TCP,
        ARFS_IPV6_TCP,
        ARFS_IPV4_UDP,
        ARFS_IPV6_UDP,
        ARFS_NUM_TYPES,
};

struct mlx5e_arfs_tables {
        struct arfs_table arfs_tables[ARFS_NUM_TYPES];
        /* Protect aRFS rules list */
        spinlock_t                     arfs_lock;
        int                            last_filter_id;
        struct workqueue_struct        *wq;
        unsigned long                  state;
};

struct arfs_tuple {
        __be16 etype;
        u8     ip_proto;
        union {
                __be32 src_ipv4;
                struct in6_addr src_ipv6;
        };
        union {
                __be32 dst_ipv4;
                struct in6_addr dst_ipv6;
        };
        __be16 src_port;
        __be16 dst_port;
};

struct arfs_rule {
        struct mlx5e_priv       *priv;
        struct work_struct      arfs_work;
        struct mlx5_flow_handle *rule;
        struct hlist_node       hlist;
        int                     rxq;
        /* Flow ID passed to ndo_rx_flow_steer */
        int                     flow_id;
        /* Filter ID returned by ndo_rx_flow_steer */
        int                     filter_id;
        struct arfs_tuple       tuple;
};

#define mlx5e_for_each_arfs_rule(hn, tmp, arfs_tables, i, j) \
        for (i = 0; i < ARFS_NUM_TYPES; i++) \
                mlx5e_for_each_hash_arfs_rule(hn, tmp, arfs_tables[i].rules_hash, j)

#define mlx5e_for_each_hash_arfs_rule(hn, tmp, hash, j) \
        for (j = 0; j < ARFS_HASH_SIZE; j++) \
                hlist_for_each_entry_safe(hn, tmp, &hash[j], hlist)

static enum mlx5_traffic_types arfs_get_tt(enum arfs_type type)
{
        switch (type) {
        case ARFS_IPV4_TCP:
                return MLX5_TT_IPV4_TCP;
        case ARFS_IPV4_UDP:
                return MLX5_TT_IPV4_UDP;
        case ARFS_IPV6_TCP:
                return MLX5_TT_IPV6_TCP;
        case ARFS_IPV6_UDP:
                return MLX5_TT_IPV6_UDP;
        default:
                return -EINVAL;
        }
}

static int arfs_disable(struct mlx5e_flow_steering *fs)
{
        struct mlx5_ttc_table *ttc = mlx5e_fs_get_ttc(fs, false);
        int err, i;

        for (i = 0; i < ARFS_NUM_TYPES; i++) {
                /* Modify ttc rules destination back to their default */
                err = mlx5_ttc_fwd_default_dest(ttc, arfs_get_tt(i));
                if (err) {
                        fs_err(fs,
                               "%s: modify ttc[%d] default destination failed, err(%d)\n",
                               __func__, arfs_get_tt(i), err);
                        return err;
                }
        }
        return 0;
}

static void arfs_del_rules(struct mlx5e_flow_steering *fs);

int mlx5e_arfs_disable(struct mlx5e_flow_steering *fs)
{
        /* Moving to switchdev mode, fs->arfs is freed by mlx5e_nic_profile
         * cleanup_rx callback and it is not recreated when
         * mlx5e_uplink_rep_profile is loaded as mlx5e_create_flow_steering()
         * is not called by the uplink_rep profile init_rx callback. Thus, if
         * ntuple is set, moving to switchdev flow will enter this function
         * with fs->arfs nullified.
         */
        if (!mlx5e_fs_get_arfs(fs))
                return 0;

        arfs_del_rules(fs);

        return arfs_disable(fs);
}

int mlx5e_arfs_enable(struct mlx5e_flow_steering *fs)
{
        struct mlx5_ttc_table *ttc = mlx5e_fs_get_ttc(fs, false);
        struct mlx5e_arfs_tables *arfs =  mlx5e_fs_get_arfs(fs);
        struct mlx5_flow_destination dest = {};
        int err, i;

        dest.type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
        for (i = 0; i < ARFS_NUM_TYPES; i++) {
                dest.ft = arfs->arfs_tables[i].ft.t;
                /* Modify ttc rules destination to point on the aRFS FTs */
                err = mlx5_ttc_fwd_dest(ttc, arfs_get_tt(i), &dest);
                if (err) {
                        fs_err(fs, "%s: modify ttc[%d] dest to arfs, failed err(%d)\n",
                               __func__, arfs_get_tt(i), err);
                        arfs_disable(fs);
                        return err;
                }
        }
        set_bit(MLX5E_ARFS_STATE_ENABLED, &arfs->state);

        return 0;
}

static void arfs_destroy_table(struct arfs_table *arfs_t)
{
        mlx5_del_flow_rules(arfs_t->default_rule);
        mlx5e_destroy_flow_table(&arfs_t->ft);
}

static void _mlx5e_cleanup_tables(struct mlx5e_flow_steering *fs)
{
        struct mlx5e_arfs_tables *arfs =  mlx5e_fs_get_arfs(fs);
        int i;

        arfs_del_rules(fs);
        destroy_workqueue(arfs->wq);
        for (i = 0; i < ARFS_NUM_TYPES; i++) {
                if (!IS_ERR_OR_NULL(arfs->arfs_tables[i].ft.t))
                        arfs_destroy_table(&arfs->arfs_tables[i]);
        }
}

void mlx5e_arfs_destroy_tables(struct mlx5e_flow_steering *fs, bool ntuple)
{
        struct mlx5e_arfs_tables *arfs =  mlx5e_fs_get_arfs(fs);

        if (!ntuple)
                return;

        _mlx5e_cleanup_tables(fs);
        mlx5e_fs_set_arfs(fs, NULL);
        kvfree(arfs);
}

static int arfs_add_default_rule(struct mlx5e_flow_steering *fs,
                                 struct mlx5e_rx_res *rx_res,
                                 enum arfs_type type)
{
        struct mlx5e_arfs_tables *arfs =  mlx5e_fs_get_arfs(fs);
        struct arfs_table *arfs_t = &arfs->arfs_tables[type];
        struct mlx5_flow_destination dest = {};
        MLX5_DECLARE_FLOW_ACT(flow_act);
        enum mlx5_traffic_types tt;
        int err = 0;

        dest.type = MLX5_FLOW_DESTINATION_TYPE_TIR;
        tt = arfs_get_tt(type);
        if (tt == -EINVAL) {
                fs_err(fs, "%s: bad arfs_type: %d\n", __func__, type);
                return -EINVAL;
        }

        /* FIXME: Must use mlx5_ttc_get_default_dest(),
         * but can't since TTC default is not setup yet !
         */
        dest.tir_num = mlx5e_rx_res_get_tirn_rss(rx_res, tt);
        arfs_t->default_rule = mlx5_add_flow_rules(arfs_t->ft.t, NULL,
                                                   &flow_act,
                                                   &dest, 1);
        if (IS_ERR(arfs_t->default_rule)) {
                err = PTR_ERR(arfs_t->default_rule);
                arfs_t->default_rule = NULL;
                fs_err(fs, "%s: add rule failed, arfs type=%d\n", __func__, type);
        }

        return err;
}

#define MLX5E_ARFS_NUM_GROUPS   2
#define MLX5E_ARFS_GROUP1_SIZE  (BIT(16) - 1)
#define MLX5E_ARFS_GROUP2_SIZE  BIT(0)
#define MLX5E_ARFS_TABLE_SIZE   (MLX5E_ARFS_GROUP1_SIZE +\
                                 MLX5E_ARFS_GROUP2_SIZE)
static int arfs_create_groups(struct mlx5e_flow_table *ft,
                              enum  arfs_type type)
{
        int inlen = MLX5_ST_SZ_BYTES(create_flow_group_in);
        void *outer_headers_c;
        int ix = 0;
        u32 *in;
        int err;
        u8 *mc;

        ft->g = kzalloc_objs(*ft->g, MLX5E_ARFS_NUM_GROUPS);
        if (!ft->g)
                return -ENOMEM;

        in = kvzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_free_g;
        }

        mc = MLX5_ADDR_OF(create_flow_group_in, in, match_criteria);
        outer_headers_c = MLX5_ADDR_OF(fte_match_param, mc,
                                       outer_headers);
        MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c, ethertype);
        switch (type) {
        case ARFS_IPV4_TCP:
        case ARFS_IPV6_TCP:
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c, tcp_dport);
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c, tcp_sport);
                break;
        case ARFS_IPV4_UDP:
        case ARFS_IPV6_UDP:
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c, udp_dport);
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c, udp_sport);
                break;
        default:
                err = -EINVAL;
                goto err_free_in;
        }

        switch (type) {
        case ARFS_IPV4_TCP:
        case ARFS_IPV4_UDP:
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c,
                                 src_ipv4_src_ipv6.ipv4_layout.ipv4);
                MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, outer_headers_c,
                                 dst_ipv4_dst_ipv6.ipv4_layout.ipv4);
                break;
        case ARFS_IPV6_TCP:
        case ARFS_IPV6_UDP:
                memset(MLX5_ADDR_OF(fte_match_set_lyr_2_4, outer_headers_c,
                                    src_ipv4_src_ipv6.ipv6_layout.ipv6),
                       0xff, 16);
                memset(MLX5_ADDR_OF(fte_match_set_lyr_2_4, outer_headers_c,
                                    dst_ipv4_dst_ipv6.ipv6_layout.ipv6),
                       0xff, 16);
                break;
        default:
                err = -EINVAL;
                goto err_free_in;
        }

        MLX5_SET_CFG(in, match_criteria_enable, MLX5_MATCH_OUTER_HEADERS);
        MLX5_SET_CFG(in, start_flow_index, ix);
        ix += MLX5E_ARFS_GROUP1_SIZE;
        MLX5_SET_CFG(in, end_flow_index, ix - 1);
        ft->g[ft->num_groups] = mlx5_create_flow_group(ft->t, in);
        if (IS_ERR(ft->g[ft->num_groups]))
                goto err_clean_group;
        ft->num_groups++;

        memset(in, 0, inlen);
        MLX5_SET_CFG(in, start_flow_index, ix);
        ix += MLX5E_ARFS_GROUP2_SIZE;
        MLX5_SET_CFG(in, end_flow_index, ix - 1);
        ft->g[ft->num_groups] = mlx5_create_flow_group(ft->t, in);
        if (IS_ERR(ft->g[ft->num_groups]))
                goto err_clean_group;
        ft->num_groups++;

        kvfree(in);
        return 0;

err_clean_group:
        err = PTR_ERR(ft->g[ft->num_groups]);
        ft->g[ft->num_groups] = NULL;
err_free_in:
        kvfree(in);
err_free_g:
        kfree(ft->g);
        ft->g = NULL;
        return err;
}

static int arfs_create_table(struct mlx5e_flow_steering *fs,
                             struct mlx5e_rx_res *rx_res,
                             enum arfs_type type)
{
        struct mlx5_flow_namespace *ns = mlx5e_fs_get_ns(fs, false);
        struct mlx5e_arfs_tables *arfs = mlx5e_fs_get_arfs(fs);
        struct mlx5e_flow_table *ft = &arfs->arfs_tables[type].ft;
        struct mlx5_flow_table_attr ft_attr = {};
        int err;

        ft->num_groups = 0;

        ft_attr.max_fte = MLX5E_ARFS_TABLE_SIZE;
        ft_attr.level = MLX5E_ARFS_FT_LEVEL;
        ft_attr.prio = MLX5E_NIC_PRIO;

        ft->t = mlx5_create_flow_table(ns, &ft_attr);
        if (IS_ERR(ft->t)) {
                err = PTR_ERR(ft->t);
                ft->t = NULL;
                return err;
        }

        err = arfs_create_groups(ft, type);
        if (err)
                goto err;

        err = arfs_add_default_rule(fs, rx_res,  type);
        if (err)
                goto err;

        return 0;
err:
        mlx5e_destroy_flow_table(ft);
        return err;
}

int mlx5e_arfs_create_tables(struct mlx5e_flow_steering *fs,
                             struct mlx5e_rx_res *rx_res, bool ntuple)
{
        struct mlx5e_arfs_tables *arfs;
        int err = -ENOMEM;
        int i;

        if (!ntuple)
                return 0;

        arfs = kvzalloc_obj(*arfs);
        if (!arfs)
                return -ENOMEM;

        spin_lock_init(&arfs->arfs_lock);
        arfs->wq = create_singlethread_workqueue("mlx5e_arfs");
        if (!arfs->wq)
                goto err;

        mlx5e_fs_set_arfs(fs, arfs);

        for (i = 0; i < ARFS_NUM_TYPES; i++) {
                err = arfs_create_table(fs, rx_res, i);
                if (err)
                        goto err_des;
        }
        return 0;

err_des:
        _mlx5e_cleanup_tables(fs);
err:
        mlx5e_fs_set_arfs(fs, NULL);
        kvfree(arfs);
        return err;
}

#define MLX5E_ARFS_EXPIRY_QUOTA 60

static void arfs_may_expire_flow(struct mlx5e_priv *priv)
{
        struct mlx5e_arfs_tables *arfs = mlx5e_fs_get_arfs(priv->fs);
        struct arfs_rule *arfs_rule;
        struct hlist_node *htmp;
        HLIST_HEAD(del_list);
        int quota = 0;
        int i;
        int j;

        spin_lock_bh(&arfs->arfs_lock);
        mlx5e_for_each_arfs_rule(arfs_rule, htmp, arfs->arfs_tables, i, j) {
                if (!work_pending(&arfs_rule->arfs_work) &&
                    rps_may_expire_flow(priv->netdev,
                                        arfs_rule->rxq, arfs_rule->flow_id,
                                        arfs_rule->filter_id)) {
                        hlist_del_init(&arfs_rule->hlist);
                        hlist_add_head(&arfs_rule->hlist, &del_list);
                        if (quota++ > MLX5E_ARFS_EXPIRY_QUOTA)
                                break;
                }
        }
        spin_unlock_bh(&arfs->arfs_lock);
        hlist_for_each_entry_safe(arfs_rule, htmp, &del_list, hlist) {
                if (arfs_rule->rule) {
                        mlx5_del_flow_rules(arfs_rule->rule);
                        priv->channel_stats[arfs_rule->rxq]->rq.arfs_expired++;
                }
                hlist_del(&arfs_rule->hlist);
                kfree(arfs_rule);
        }
}

static void arfs_del_rules(struct mlx5e_flow_steering *fs)
{
        struct mlx5e_arfs_tables *arfs = mlx5e_fs_get_arfs(fs);
        struct hlist_node *htmp;
        struct arfs_rule *rule;
        HLIST_HEAD(del_list);
        int i;
        int j;

        clear_bit(MLX5E_ARFS_STATE_ENABLED, &arfs->state);

        spin_lock_bh(&arfs->arfs_lock);
        mlx5e_for_each_arfs_rule(rule, htmp, arfs->arfs_tables, i, j) {
                hlist_del_init(&rule->hlist);
                hlist_add_head(&rule->hlist, &del_list);
        }
        spin_unlock_bh(&arfs->arfs_lock);

        hlist_for_each_entry_safe(rule, htmp, &del_list, hlist) {
                cancel_work_sync(&rule->arfs_work);
                if (rule->rule)
                        mlx5_del_flow_rules(rule->rule);
                hlist_del(&rule->hlist);
                kfree(rule);
        }
}

static struct hlist_head *
arfs_hash_bucket(struct arfs_table *arfs_t, __be16 src_port,
                 __be16 dst_port)
{
        unsigned long l;
        int bucket_idx;

        l = (__force unsigned long)src_port |
            ((__force unsigned long)dst_port << 2);

        bucket_idx = hash_long(l, ARFS_HASH_SHIFT);

        return &arfs_t->rules_hash[bucket_idx];
}

static struct arfs_table *arfs_get_table(struct mlx5e_arfs_tables *arfs,
                                         u8 ip_proto, __be16 etype)
{
        if (etype == htons(ETH_P_IP) && ip_proto == IPPROTO_TCP)
                return &arfs->arfs_tables[ARFS_IPV4_TCP];
        if (etype == htons(ETH_P_IP) && ip_proto == IPPROTO_UDP)
                return &arfs->arfs_tables[ARFS_IPV4_UDP];
        if (etype == htons(ETH_P_IPV6) && ip_proto == IPPROTO_TCP)
                return &arfs->arfs_tables[ARFS_IPV6_TCP];
        if (etype == htons(ETH_P_IPV6) && ip_proto == IPPROTO_UDP)
                return &arfs->arfs_tables[ARFS_IPV6_UDP];

        return NULL;
}

static struct mlx5_flow_handle *arfs_add_rule(struct mlx5e_priv *priv,
                                              struct arfs_rule *arfs_rule)
{
        struct mlx5e_arfs_tables *arfs = mlx5e_fs_get_arfs(priv->fs);
        struct arfs_tuple *tuple = &arfs_rule->tuple;
        struct mlx5_flow_handle *rule = NULL;
        struct mlx5_flow_destination dest = {};
        MLX5_DECLARE_FLOW_ACT(flow_act);
        struct arfs_table *arfs_table;
        struct mlx5_flow_spec *spec;
        struct mlx5_flow_table *ft;
        int err = 0;

        spec = kvzalloc_obj(*spec);
        if (!spec) {
                priv->channel_stats[arfs_rule->rxq]->rq.arfs_err++;
                err = -ENOMEM;
                goto out;
        }
        spec->match_criteria_enable = MLX5_MATCH_OUTER_HEADERS;
        MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                         outer_headers.ethertype);
        MLX5_SET(fte_match_param, spec->match_value, outer_headers.ethertype,
                 ntohs(tuple->etype));
        arfs_table = arfs_get_table(arfs, tuple->ip_proto, tuple->etype);
        if (!arfs_table) {
                WARN_ONCE(1, "arfs table does not exist for etype %u and ip_proto %u\n",
                          tuple->etype, tuple->ip_proto);
                err = -EINVAL;
                goto out;
        }

        ft = arfs_table->ft.t;
        if (tuple->ip_proto == IPPROTO_TCP) {
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.tcp_dport);
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.tcp_sport);
                MLX5_SET(fte_match_param, spec->match_value, outer_headers.tcp_dport,
                         ntohs(tuple->dst_port));
                MLX5_SET(fte_match_param, spec->match_value, outer_headers.tcp_sport,
                         ntohs(tuple->src_port));
        } else {
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.udp_dport);
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.udp_sport);
                MLX5_SET(fte_match_param, spec->match_value, outer_headers.udp_dport,
                         ntohs(tuple->dst_port));
                MLX5_SET(fte_match_param, spec->match_value, outer_headers.udp_sport,
                         ntohs(tuple->src_port));
        }
        if (tuple->etype == htons(ETH_P_IP)) {
                memcpy(MLX5_ADDR_OF(fte_match_param, spec->match_value,
                                    outer_headers.src_ipv4_src_ipv6.ipv4_layout.ipv4),
                       &tuple->src_ipv4,
                       4);
                memcpy(MLX5_ADDR_OF(fte_match_param, spec->match_value,
                                    outer_headers.dst_ipv4_dst_ipv6.ipv4_layout.ipv4),
                       &tuple->dst_ipv4,
                       4);
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.src_ipv4_src_ipv6.ipv4_layout.ipv4);
                MLX5_SET_TO_ONES(fte_match_param, spec->match_criteria,
                                 outer_headers.dst_ipv4_dst_ipv6.ipv4_layout.ipv4);
        } else {
                memcpy(MLX5_ADDR_OF(fte_match_param, spec->match_value,
                                    outer_headers.src_ipv4_src_ipv6.ipv6_layout.ipv6),
                       &tuple->src_ipv6,
                       16);
                memcpy(MLX5_ADDR_OF(fte_match_param, spec->match_value,
                                    outer_headers.dst_ipv4_dst_ipv6.ipv6_layout.ipv6),
                       &tuple->dst_ipv6,
                       16);
                memset(MLX5_ADDR_OF(fte_match_param, spec->match_criteria,
                                    outer_headers.src_ipv4_src_ipv6.ipv6_layout.ipv6),
                       0xff,
                       16);
                memset(MLX5_ADDR_OF(fte_match_param, spec->match_criteria,
                                    outer_headers.dst_ipv4_dst_ipv6.ipv6_layout.ipv6),
                       0xff,
                       16);
        }
        dest.type = MLX5_FLOW_DESTINATION_TYPE_TIR;
        dest.tir_num = mlx5e_rx_res_get_tirn_direct(priv->rx_res, arfs_rule->rxq);
        rule = mlx5_add_flow_rules(ft, spec, &flow_act, &dest, 1);
        if (IS_ERR(rule)) {
                err = PTR_ERR(rule);
                priv->channel_stats[arfs_rule->rxq]->rq.arfs_err++;
                netdev_dbg(priv->netdev,
                           "%s: add rule(filter id=%d, rq idx=%d, ip proto=0x%x) failed,err=%d\n",
                           __func__, arfs_rule->filter_id, arfs_rule->rxq,
                           tuple->ip_proto, err);
        }

out:
        kvfree(spec);
        return err ? ERR_PTR(err) : rule;
}

static void arfs_modify_rule_rq(struct mlx5e_priv *priv,
                                struct mlx5_flow_handle *rule, u16 rxq)
{
        struct mlx5_flow_destination dst = {};
        int err = 0;

        dst.type = MLX5_FLOW_DESTINATION_TYPE_TIR;
        dst.tir_num = mlx5e_rx_res_get_tirn_direct(priv->rx_res, rxq);
        err =  mlx5_modify_rule_destination(rule, &dst, NULL);
        if (err) {
                priv->channel_stats[rxq]->rq.arfs_err++;
                netdev_warn(priv->netdev,
                            "Failed to modify aRFS rule destination to rq=%d\n", rxq);
        }
}

static void arfs_handle_work(struct work_struct *work)
{
        struct arfs_rule *arfs_rule = container_of(work,
                                                   struct arfs_rule,
                                                   arfs_work);
        struct mlx5e_priv *priv = arfs_rule->priv;
        struct mlx5e_arfs_tables *arfs;
        struct mlx5_flow_handle *rule;

        arfs = mlx5e_fs_get_arfs(priv->fs);
        if (!test_bit(MLX5E_ARFS_STATE_ENABLED, &arfs->state))
                return;

        if (!arfs_rule->rule) {
                rule = arfs_add_rule(priv, arfs_rule);
                if (IS_ERR(rule))
                        goto out;
                arfs_rule->rule = rule;
                priv->channel_stats[arfs_rule->rxq]->rq.arfs_add++;
        } else {
                arfs_modify_rule_rq(priv, arfs_rule->rule,
                                    arfs_rule->rxq);
        }
out:
        arfs_may_expire_flow(priv);
}

static struct arfs_rule *arfs_alloc_rule(struct mlx5e_priv *priv,
                                         struct arfs_table *arfs_t,
                                         const struct flow_keys *fk,
                                         u16 rxq, u32 flow_id)
{
        struct mlx5e_arfs_tables *arfs =  mlx5e_fs_get_arfs(priv->fs);
        struct arfs_rule *rule;
        struct arfs_tuple *tuple;

        rule = kzalloc_obj(*rule, GFP_ATOMIC);
        if (!rule) {
                priv->channel_stats[rxq]->rq.arfs_err++;
                return NULL;
        }

        rule->priv = priv;
        rule->rxq = rxq;
        INIT_WORK(&rule->arfs_work, arfs_handle_work);

        tuple = &rule->tuple;
        tuple->etype = fk->basic.n_proto;
        tuple->ip_proto = fk->basic.ip_proto;
        if (tuple->etype == htons(ETH_P_IP)) {
                tuple->src_ipv4 = fk->addrs.v4addrs.src;
                tuple->dst_ipv4 = fk->addrs.v4addrs.dst;
        } else {
                memcpy(&tuple->src_ipv6, &fk->addrs.v6addrs.src,
                       sizeof(struct in6_addr));
                memcpy(&tuple->dst_ipv6, &fk->addrs.v6addrs.dst,
                       sizeof(struct in6_addr));
        }
        tuple->src_port = fk->ports.src;
        tuple->dst_port = fk->ports.dst;

        rule->flow_id = flow_id;
        rule->filter_id = arfs->last_filter_id++ % RPS_NO_FILTER;

        hlist_add_head(&rule->hlist,
                       arfs_hash_bucket(arfs_t, tuple->src_port,
                                        tuple->dst_port));
        return rule;
}

static bool arfs_cmp(const struct arfs_tuple *tuple, const struct flow_keys *fk)
{
        if (tuple->src_port != fk->ports.src || tuple->dst_port != fk->ports.dst)
                return false;
        if (tuple->etype != fk->basic.n_proto)
                return false;
        if (tuple->etype == htons(ETH_P_IP))
                return tuple->src_ipv4 == fk->addrs.v4addrs.src &&
                       tuple->dst_ipv4 == fk->addrs.v4addrs.dst;
        if (tuple->etype == htons(ETH_P_IPV6))
                return !memcmp(&tuple->src_ipv6, &fk->addrs.v6addrs.src,
                               sizeof(struct in6_addr)) &&
                       !memcmp(&tuple->dst_ipv6, &fk->addrs.v6addrs.dst,
                               sizeof(struct in6_addr));
        return false;
}

static struct arfs_rule *arfs_find_rule(struct arfs_table *arfs_t,
                                        const struct flow_keys *fk)
{
        struct arfs_rule *arfs_rule;
        struct hlist_head *head;

        head = arfs_hash_bucket(arfs_t, fk->ports.src, fk->ports.dst);
        hlist_for_each_entry(arfs_rule, head, hlist) {
                if (arfs_cmp(&arfs_rule->tuple, fk))
                        return arfs_rule;
        }

        return NULL;
}

int mlx5e_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
                        u16 rxq_index, u32 flow_id)
{
        struct mlx5e_priv *priv = netdev_priv(dev);
        struct mlx5e_arfs_tables *arfs;
        struct arfs_rule *arfs_rule;
        struct arfs_table *arfs_t;
        struct flow_keys fk;

        arfs =  mlx5e_fs_get_arfs(priv->fs);
        if (!skb_flow_dissect_flow_keys(skb, &fk, 0))
                return -EPROTONOSUPPORT;

        if (fk.basic.n_proto != htons(ETH_P_IP) &&
            fk.basic.n_proto != htons(ETH_P_IPV6))
                return -EPROTONOSUPPORT;

        if (skb->encapsulation)
                return -EPROTONOSUPPORT;

        arfs_t = arfs_get_table(arfs, fk.basic.ip_proto, fk.basic.n_proto);
        if (!arfs_t)
                return -EPROTONOSUPPORT;

        spin_lock_bh(&arfs->arfs_lock);
        if (!test_bit(MLX5E_ARFS_STATE_ENABLED, &arfs->state)) {
                spin_unlock_bh(&arfs->arfs_lock);
                return -EPERM;
        }

        arfs_rule = arfs_find_rule(arfs_t, &fk);
        if (arfs_rule) {
                if (arfs_rule->rxq == rxq_index || work_busy(&arfs_rule->arfs_work)) {
                        spin_unlock_bh(&arfs->arfs_lock);
                        return arfs_rule->filter_id;
                }

                priv->channel_stats[rxq_index]->rq.arfs_request_in++;
                priv->channel_stats[arfs_rule->rxq]->rq.arfs_request_out++;
                arfs_rule->rxq = rxq_index;
        } else {
                arfs_rule = arfs_alloc_rule(priv, arfs_t, &fk, rxq_index, flow_id);
                if (!arfs_rule) {
                        spin_unlock_bh(&arfs->arfs_lock);
                        return -ENOMEM;
                }
        }
        queue_work(arfs->wq, &arfs_rule->arfs_work);
        spin_unlock_bh(&arfs->arfs_lock);
        return arfs_rule->filter_id;
}