// SPDX-License-Identifier: GPL-2.0
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <net/flow_dissector.h>
#include "enic_res.h"
#include "enic_clsf.h"

/* enic_addfltr_5t - Add ipv4 5tuple filter
 *      @enic: enic struct of vnic
 *      @keys: flow_keys of ipv4 5tuple
 *      @rq: rq number to steer to
 *
 * This function returns filter_id(hardware_id) of the filter
 * added. In case of error it returns a negative number.
 */
int enic_addfltr_5t(struct enic *enic, struct flow_keys *keys, u16 rq)
{
        int res;
        struct filter data;

        switch (keys->basic.ip_proto) {
        case IPPROTO_TCP:
                data.u.ipv4.protocol = PROTO_TCP;
                break;
        case IPPROTO_UDP:
                data.u.ipv4.protocol = PROTO_UDP;
                break;
        default:
                return -EPROTONOSUPPORT;
        }

        data.type = FILTER_IPV4_5TUPLE;
        data.u.ipv4.src_addr = ntohl(keys->addrs.v4addrs.src);
        data.u.ipv4.dst_addr = ntohl(keys->addrs.v4addrs.dst);
        data.u.ipv4.src_port = ntohs(keys->ports.src);
        data.u.ipv4.dst_port = ntohs(keys->ports.dst);
        data.u.ipv4.flags = FILTER_FIELDS_IPV4_5TUPLE;

        spin_lock_bh(&enic->devcmd_lock);
        res = vnic_dev_classifier(enic->vdev, CLSF_ADD, &rq, &data);
        spin_unlock_bh(&enic->devcmd_lock);
        res = (res == 0) ? rq : res;

        return res;
}

/* enic_delfltr - Delete clsf filter
 *      @enic: enic struct of vnic
 *      @filter_id: filter_is(hardware_id) of filter to be deleted
 *
 * This function returns zero in case of success, negative number incase of
 * error.
 */
int enic_delfltr(struct enic *enic, u16 filter_id)
{
        int ret;

        spin_lock_bh(&enic->devcmd_lock);
        ret = vnic_dev_classifier(enic->vdev, CLSF_DEL, &filter_id, NULL);
        spin_unlock_bh(&enic->devcmd_lock);

        return ret;
}

/* enic_rfs_flw_tbl_init - initialize enic->rfs_h members
 *      @enic: enic data
 */
void enic_rfs_flw_tbl_init(struct enic *enic)
{
        int i;

        spin_lock_init(&enic->rfs_h.lock);
        for (i = 0; i <= ENIC_RFS_FLW_MASK; i++)
                INIT_HLIST_HEAD(&enic->rfs_h.ht_head[i]);
        enic->rfs_h.max = enic->config.num_arfs;
        enic->rfs_h.free = enic->rfs_h.max;
        enic->rfs_h.toclean = 0;
}

void enic_rfs_flw_tbl_free(struct enic *enic)
{
        int i;

        enic_rfs_timer_stop(enic);
        spin_lock_bh(&enic->rfs_h.lock);
        for (i = 0; i < (1 << ENIC_RFS_FLW_BITSHIFT); i++) {
                struct hlist_head *hhead;
                struct hlist_node *tmp;
                struct enic_rfs_fltr_node *n;

                hhead = &enic->rfs_h.ht_head[i];
                hlist_for_each_entry_safe(n, tmp, hhead, node) {
                        enic_delfltr(enic, n->fltr_id);
                        hlist_del(&n->node);
                        kfree(n);
                        enic->rfs_h.free++;
                }
        }
        spin_unlock_bh(&enic->rfs_h.lock);
}

struct enic_rfs_fltr_node *htbl_fltr_search(struct enic *enic, u16 fltr_id)
{
        int i;

        for (i = 0; i < (1 << ENIC_RFS_FLW_BITSHIFT); i++) {
                struct hlist_head *hhead;
                struct hlist_node *tmp;
                struct enic_rfs_fltr_node *n;

                hhead = &enic->rfs_h.ht_head[i];
                hlist_for_each_entry_safe(n, tmp, hhead, node)
                        if (n->fltr_id == fltr_id)
                                return n;
        }

        return NULL;
}

#ifdef CONFIG_RFS_ACCEL
void enic_flow_may_expire(struct timer_list *t)
{
        struct enic *enic = timer_container_of(enic, t, rfs_h.rfs_may_expire);
        bool res;
        int j;

        spin_lock_bh(&enic->rfs_h.lock);
        for (j = 0; j < ENIC_CLSF_EXPIRE_COUNT; j++) {
                struct hlist_head *hhead;
                struct hlist_node *tmp;
                struct enic_rfs_fltr_node *n;

                hhead = &enic->rfs_h.ht_head[enic->rfs_h.toclean++];
                hlist_for_each_entry_safe(n, tmp, hhead, node) {
                        res = rps_may_expire_flow(enic->netdev, n->rq_id,
                                                  n->flow_id, n->fltr_id);
                        if (res) {
                                res = enic_delfltr(enic, n->fltr_id);
                                if (unlikely(res))
                                        continue;
                                hlist_del(&n->node);
                                kfree(n);
                                enic->rfs_h.free++;
                        }
                }
        }
        spin_unlock_bh(&enic->rfs_h.lock);
        mod_timer(&enic->rfs_h.rfs_may_expire, jiffies + HZ/4);
}

static struct enic_rfs_fltr_node *htbl_key_search(struct hlist_head *h,
                                                  struct flow_keys *k)
{
        struct enic_rfs_fltr_node *tpos;

        hlist_for_each_entry(tpos, h, node)
                if (tpos->keys.addrs.v4addrs.src == k->addrs.v4addrs.src &&
                    tpos->keys.addrs.v4addrs.dst == k->addrs.v4addrs.dst &&
                    tpos->keys.ports.ports == k->ports.ports &&
                    tpos->keys.basic.ip_proto == k->basic.ip_proto &&
                    tpos->keys.basic.n_proto == k->basic.n_proto)
                        return tpos;
        return NULL;
}

int enic_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
                       u16 rxq_index, u32 flow_id)
{
        struct flow_keys keys;
        struct enic_rfs_fltr_node *n;
        struct enic *enic;
        u16 tbl_idx;
        int res, i;

        enic = netdev_priv(dev);
        res = skb_flow_dissect_flow_keys(skb, &keys, 0);
        if (!res || keys.basic.n_proto != htons(ETH_P_IP) ||
            (keys.basic.ip_proto != IPPROTO_TCP &&
             keys.basic.ip_proto != IPPROTO_UDP))
                return -EPROTONOSUPPORT;

        tbl_idx = skb_get_hash_raw(skb) & ENIC_RFS_FLW_MASK;
        spin_lock_bh(&enic->rfs_h.lock);
        n = htbl_key_search(&enic->rfs_h.ht_head[tbl_idx], &keys);

        if (n) { /* entry already present  */
                if (rxq_index == n->rq_id) {
                        res = -EEXIST;
                        goto ret_unlock;
                }

                /* desired rq changed for the flow, we need to delete
                 * old fltr and add new one
                 *
                 * The moment we delete the fltr, the upcoming pkts
                 * are put it default rq based on rss. When we add
                 * new filter, upcoming pkts are put in desired queue.
                 * This could cause ooo pkts.
                 *
                 * Lets 1st try adding new fltr and then del old one.
                 */
                i = --enic->rfs_h.free;
                /* clsf tbl is full, we have to del old fltr first*/
                if (unlikely(i < 0)) {
                        enic->rfs_h.free++;
                        res = enic_delfltr(enic, n->fltr_id);
                        if (unlikely(res < 0))
                                goto ret_unlock;
                        res = enic_addfltr_5t(enic, &keys, rxq_index);
                        if (res < 0) {
                                hlist_del(&n->node);
                                enic->rfs_h.free++;
                                goto ret_unlock;
                        }
                /* add new fltr 1st then del old fltr */
                } else {
                        int ret;

                        res = enic_addfltr_5t(enic, &keys, rxq_index);
                        if (res < 0) {
                                enic->rfs_h.free++;
                                goto ret_unlock;
                        }
                        ret = enic_delfltr(enic, n->fltr_id);
                        /* deleting old fltr failed. Add old fltr to list.
                         * enic_flow_may_expire() will try to delete it later.
                         */
                        if (unlikely(ret < 0)) {
                                struct enic_rfs_fltr_node *d;
                                struct hlist_head *head;

                                head = &enic->rfs_h.ht_head[tbl_idx];
                                d = kmalloc_obj(*d, GFP_ATOMIC);
                                if (d) {
                                        d->fltr_id = n->fltr_id;
                                        INIT_HLIST_NODE(&d->node);
                                        hlist_add_head(&d->node, head);
                                }
                        } else {
                                enic->rfs_h.free++;
                        }
                }
                n->rq_id = rxq_index;
                n->fltr_id = res;
                n->flow_id = flow_id;
        /* entry not present */
        } else {
                i = --enic->rfs_h.free;
                if (i <= 0) {
                        enic->rfs_h.free++;
                        res = -EBUSY;
                        goto ret_unlock;
                }

                n = kmalloc_obj(*n, GFP_ATOMIC);
                if (!n) {
                        res = -ENOMEM;
                        enic->rfs_h.free++;
                        goto ret_unlock;
                }

                res = enic_addfltr_5t(enic, &keys, rxq_index);
                if (res < 0) {
                        kfree(n);
                        enic->rfs_h.free++;
                        goto ret_unlock;
                }
                n->rq_id = rxq_index;
                n->fltr_id = res;
                n->flow_id = flow_id;
                n->keys = keys;
                INIT_HLIST_NODE(&n->node);
                hlist_add_head(&n->node, &enic->rfs_h.ht_head[tbl_idx]);
        }

ret_unlock:
        spin_unlock_bh(&enic->rfs_h.lock);
        return res;
}

#endif /* CONFIG_RFS_ACCEL */