// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2018 Netronome Systems, Inc. */

#include "main.h"

/* LAG group config flags. */
#define NFP_FL_LAG_LAST                 BIT(1)
#define NFP_FL_LAG_FIRST                BIT(2)
#define NFP_FL_LAG_DATA                 BIT(3)
#define NFP_FL_LAG_XON                  BIT(4)
#define NFP_FL_LAG_SYNC                 BIT(5)
#define NFP_FL_LAG_SWITCH               BIT(6)
#define NFP_FL_LAG_RESET                BIT(7)

/* LAG port state flags. */
#define NFP_PORT_LAG_LINK_UP            BIT(0)
#define NFP_PORT_LAG_TX_ENABLED         BIT(1)
#define NFP_PORT_LAG_CHANGED            BIT(2)

enum nfp_fl_lag_batch {
        NFP_FL_LAG_BATCH_FIRST,
        NFP_FL_LAG_BATCH_MEMBER,
        NFP_FL_LAG_BATCH_FINISHED
};

/**
 * struct nfp_flower_cmsg_lag_config - control message payload for LAG config
 * @ctrl_flags: Configuration flags
 * @reserved:   Reserved for future use
 * @ttl:        Time to live of packet - host always sets to 0xff
 * @pkt_number: Config message packet number - increment for each message
 * @batch_ver:  Batch version of messages - increment for each batch of messages
 * @group_id:   Group ID applicable
 * @group_inst: Group instance number - increment when group is reused
 * @members:    Array of 32-bit words listing all active group members
 */
struct nfp_flower_cmsg_lag_config {
        u8 ctrl_flags;
        u8 reserved[2];
        u8 ttl;
        __be32 pkt_number;
        __be32 batch_ver;
        __be32 group_id;
        __be32 group_inst;
        __be32 members[];
};

/**
 * struct nfp_fl_lag_group - list entry for each LAG group
 * @group_id:           Assigned group ID for host/kernel sync
 * @group_inst:         Group instance in case of ID reuse
 * @list:               List entry
 * @master_ndev:        Group master Netdev
 * @dirty:              Marked if the group needs synced to HW
 * @offloaded:          Marked if the group is currently offloaded to NIC
 * @to_remove:          Marked if the group should be removed from NIC
 * @to_destroy:         Marked if the group should be removed from driver
 * @slave_cnt:          Number of slaves in group
 */
struct nfp_fl_lag_group {
        unsigned int group_id;
        u8 group_inst;
        struct list_head list;
        struct net_device *master_ndev;
        bool dirty;
        bool offloaded;
        bool to_remove;
        bool to_destroy;
        unsigned int slave_cnt;
};

#define NFP_FL_LAG_PKT_NUMBER_MASK      GENMASK(30, 0)
#define NFP_FL_LAG_VERSION_MASK         GENMASK(22, 0)
#define NFP_FL_LAG_HOST_TTL             0xff

/* Use this ID with zero members to ack a batch config */
#define NFP_FL_LAG_SYNC_ID              0
#define NFP_FL_LAG_GROUP_MIN            1 /* ID 0 reserved */
#define NFP_FL_LAG_GROUP_MAX            32 /* IDs 1 to 31 are valid */

/* wait for more config */
#define NFP_FL_LAG_DELAY                (msecs_to_jiffies(2))

#define NFP_FL_LAG_RETRANS_LIMIT        100 /* max retrans cmsgs to store */

static unsigned int nfp_fl_get_next_pkt_number(struct nfp_fl_lag *lag)
{
        lag->pkt_num++;
        lag->pkt_num &= NFP_FL_LAG_PKT_NUMBER_MASK;

        return lag->pkt_num;
}

static void nfp_fl_increment_version(struct nfp_fl_lag *lag)
{
        /* LSB is not considered by firmware so add 2 for each increment. */
        lag->batch_ver += 2;
        lag->batch_ver &= NFP_FL_LAG_VERSION_MASK;

        /* Zero is reserved by firmware. */
        if (!lag->batch_ver)
                lag->batch_ver += 2;
}

static struct nfp_fl_lag_group *
nfp_fl_lag_group_create(struct nfp_fl_lag *lag, struct net_device *master)
{
        struct nfp_fl_lag_group *group;
        struct nfp_flower_priv *priv;
        int id;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);

        id = ida_simple_get(&lag->ida_handle, NFP_FL_LAG_GROUP_MIN,
                            NFP_FL_LAG_GROUP_MAX, GFP_KERNEL);
        if (id < 0) {
                nfp_flower_cmsg_warn(priv->app,
                                     "No more bonding groups available\n");
                return ERR_PTR(id);
        }

        group = kmalloc(sizeof(*group), GFP_KERNEL);
        if (!group) {
                ida_simple_remove(&lag->ida_handle, id);
                return ERR_PTR(-ENOMEM);
        }

        group->group_id = id;
        group->master_ndev = master;
        group->dirty = true;
        group->offloaded = false;
        group->to_remove = false;
        group->to_destroy = false;
        group->slave_cnt = 0;
        group->group_inst = ++lag->global_inst;
        list_add_tail(&group->list, &lag->group_list);

        return group;
}

static struct nfp_fl_lag_group *
nfp_fl_lag_find_group_for_master_with_lag(struct nfp_fl_lag *lag,
                                          struct net_device *master)
{
        struct nfp_fl_lag_group *entry;

        if (!master)
                return NULL;

        list_for_each_entry(entry, &lag->group_list, list)
                if (entry->master_ndev == master)
                        return entry;

        return NULL;
}

int nfp_flower_lag_populate_pre_action(struct nfp_app *app,
                                       struct net_device *master,
                                       struct nfp_fl_pre_lag *pre_act,
                                       struct netlink_ext_ack *extack)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_fl_lag_group *group = NULL;
        __be32 temp_vers;

        mutex_lock(&priv->nfp_lag.lock);
        group = nfp_fl_lag_find_group_for_master_with_lag(&priv->nfp_lag,
                                                          master);
        if (!group) {
                mutex_unlock(&priv->nfp_lag.lock);
                NL_SET_ERR_MSG_MOD(extack, "invalid entry: group does not exist for LAG action");
                return -ENOENT;
        }

        pre_act->group_id = cpu_to_be16(group->group_id);
        temp_vers = cpu_to_be32(priv->nfp_lag.batch_ver <<
                                NFP_FL_PRE_LAG_VER_OFF);
        memcpy(pre_act->lag_version, &temp_vers, 3);
        pre_act->instance = group->group_inst;
        mutex_unlock(&priv->nfp_lag.lock);

        return 0;
}

int nfp_flower_lag_get_output_id(struct nfp_app *app, struct net_device *master)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_fl_lag_group *group = NULL;
        int group_id = -ENOENT;

        mutex_lock(&priv->nfp_lag.lock);
        group = nfp_fl_lag_find_group_for_master_with_lag(&priv->nfp_lag,
                                                          master);
        if (group)
                group_id = group->group_id;
        mutex_unlock(&priv->nfp_lag.lock);

        return group_id;
}

static int
nfp_fl_lag_config_group(struct nfp_fl_lag *lag, struct nfp_fl_lag_group *group,
                        struct net_device **active_members,
                        unsigned int member_cnt, enum nfp_fl_lag_batch *batch)
{
        struct nfp_flower_cmsg_lag_config *cmsg_payload;
        struct nfp_flower_priv *priv;
        unsigned long int flags;
        unsigned int size, i;
        struct sk_buff *skb;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);
        size = sizeof(*cmsg_payload) + sizeof(__be32) * member_cnt;
        skb = nfp_flower_cmsg_alloc(priv->app, size,
                                    NFP_FLOWER_CMSG_TYPE_LAG_CONFIG,
                                    GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        cmsg_payload = nfp_flower_cmsg_get_data(skb);
        flags = 0;

        /* Increment batch version for each new batch of config messages. */
        if (*batch == NFP_FL_LAG_BATCH_FIRST) {
                flags |= NFP_FL_LAG_FIRST;
                nfp_fl_increment_version(lag);
                *batch = NFP_FL_LAG_BATCH_MEMBER;
        }

        /* If it is a reset msg then it is also the end of the batch. */
        if (lag->rst_cfg) {
                flags |= NFP_FL_LAG_RESET;
                *batch = NFP_FL_LAG_BATCH_FINISHED;
        }

        /* To signal the end of a batch, both the switch and last flags are set
         * and the the reserved SYNC group ID is used.
         */
        if (*batch == NFP_FL_LAG_BATCH_FINISHED) {
                flags |= NFP_FL_LAG_SWITCH | NFP_FL_LAG_LAST;
                lag->rst_cfg = false;
                cmsg_payload->group_id = cpu_to_be32(NFP_FL_LAG_SYNC_ID);
                cmsg_payload->group_inst = 0;
        } else {
                cmsg_payload->group_id = cpu_to_be32(group->group_id);
                cmsg_payload->group_inst = cpu_to_be32(group->group_inst);
        }

        cmsg_payload->reserved[0] = 0;
        cmsg_payload->reserved[1] = 0;
        cmsg_payload->ttl = NFP_FL_LAG_HOST_TTL;
        cmsg_payload->ctrl_flags = flags;
        cmsg_payload->batch_ver = cpu_to_be32(lag->batch_ver);
        cmsg_payload->pkt_number = cpu_to_be32(nfp_fl_get_next_pkt_number(lag));

        for (i = 0; i < member_cnt; i++)
                cmsg_payload->members[i] =
                        cpu_to_be32(nfp_repr_get_port_id(active_members[i]));

        nfp_ctrl_tx(priv->app->ctrl, skb);
        return 0;
}

static void nfp_fl_lag_do_work(struct work_struct *work)
{
        enum nfp_fl_lag_batch batch = NFP_FL_LAG_BATCH_FIRST;
        struct nfp_fl_lag_group *entry, *storage;
        struct delayed_work *delayed_work;
        struct nfp_flower_priv *priv;
        struct nfp_fl_lag *lag;
        int err;

        delayed_work = to_delayed_work(work);
        lag = container_of(delayed_work, struct nfp_fl_lag, work);
        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);

        mutex_lock(&lag->lock);
        list_for_each_entry_safe(entry, storage, &lag->group_list, list) {
                struct net_device *iter_netdev, **acti_netdevs;
                struct nfp_flower_repr_priv *repr_priv;
                int active_count = 0, slaves = 0;
                struct nfp_repr *repr;
                unsigned long *flags;

                if (entry->to_remove) {
                        /* Active count of 0 deletes group on hw. */
                        err = nfp_fl_lag_config_group(lag, entry, NULL, 0,
                                                      &batch);
                        if (!err) {
                                entry->to_remove = false;
                                entry->offloaded = false;
                        } else {
                                nfp_flower_cmsg_warn(priv->app,
                                                     "group delete failed\n");
                                schedule_delayed_work(&lag->work,
                                                      NFP_FL_LAG_DELAY);
                                continue;
                        }

                        if (entry->to_destroy) {
                                ida_simple_remove(&lag->ida_handle,
                                                  entry->group_id);
                                list_del(&entry->list);
                                kfree(entry);
                        }
                        continue;
                }

                acti_netdevs = kmalloc_array(entry->slave_cnt,
                                             sizeof(*acti_netdevs), GFP_KERNEL);

                /* Include sanity check in the loop. It may be that a bond has
                 * changed between processing the last notification and the
                 * work queue triggering. If the number of slaves has changed
                 * or it now contains netdevs that cannot be offloaded, ignore
                 * the group until pending notifications are processed.
                 */
                rcu_read_lock();
                for_each_netdev_in_bond_rcu(entry->master_ndev, iter_netdev) {
                        if (!nfp_netdev_is_nfp_repr(iter_netdev)) {
                                slaves = 0;
                                break;
                        }

                        repr = netdev_priv(iter_netdev);

                        if (repr->app != priv->app) {
                                slaves = 0;
                                break;
                        }

                        slaves++;
                        if (slaves > entry->slave_cnt)
                                break;

                        /* Check the ports for state changes. */
                        repr_priv = repr->app_priv;
                        flags = &repr_priv->lag_port_flags;

                        if (*flags & NFP_PORT_LAG_CHANGED) {
                                *flags &= ~NFP_PORT_LAG_CHANGED;
                                entry->dirty = true;
                        }

                        if ((*flags & NFP_PORT_LAG_TX_ENABLED) &&
                            (*flags & NFP_PORT_LAG_LINK_UP))
                                acti_netdevs[active_count++] = iter_netdev;
                }
                rcu_read_unlock();

                if (slaves != entry->slave_cnt || !entry->dirty) {
                        kfree(acti_netdevs);
                        continue;
                }

                err = nfp_fl_lag_config_group(lag, entry, acti_netdevs,
                                              active_count, &batch);
                if (!err) {
                        entry->offloaded = true;
                        entry->dirty = false;
                } else {
                        nfp_flower_cmsg_warn(priv->app,
                                             "group offload failed\n");
                        schedule_delayed_work(&lag->work, NFP_FL_LAG_DELAY);
                }

                kfree(acti_netdevs);
        }

        /* End the config batch if at least one packet has been batched. */
        if (batch == NFP_FL_LAG_BATCH_MEMBER) {
                batch = NFP_FL_LAG_BATCH_FINISHED;
                err = nfp_fl_lag_config_group(lag, NULL, NULL, 0, &batch);
                if (err)
                        nfp_flower_cmsg_warn(priv->app,
                                             "group batch end cmsg failed\n");
        }

        mutex_unlock(&lag->lock);
}

static int
nfp_fl_lag_put_unprocessed(struct nfp_fl_lag *lag, struct sk_buff *skb)
{
        struct nfp_flower_cmsg_lag_config *cmsg_payload;

        cmsg_payload = nfp_flower_cmsg_get_data(skb);
        if (be32_to_cpu(cmsg_payload->group_id) >= NFP_FL_LAG_GROUP_MAX)
                return -EINVAL;

        /* Drop cmsg retrans if storage limit is exceeded to prevent
         * overloading. If the fw notices that expected messages have not been
         * received in a given time block, it will request a full resync.
         */
        if (skb_queue_len(&lag->retrans_skbs) >= NFP_FL_LAG_RETRANS_LIMIT)
                return -ENOSPC;

        __skb_queue_tail(&lag->retrans_skbs, skb);

        return 0;
}

static void nfp_fl_send_unprocessed(struct nfp_fl_lag *lag)
{
        struct nfp_flower_priv *priv;
        struct sk_buff *skb;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);

        while ((skb = __skb_dequeue(&lag->retrans_skbs)))
                nfp_ctrl_tx(priv->app->ctrl, skb);
}

bool nfp_flower_lag_unprocessed_msg(struct nfp_app *app, struct sk_buff *skb)
{
        struct nfp_flower_cmsg_lag_config *cmsg_payload;
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_fl_lag_group *group_entry;
        unsigned long int flags;
        bool store_skb = false;
        int err;

        cmsg_payload = nfp_flower_cmsg_get_data(skb);
        flags = cmsg_payload->ctrl_flags;

        /* Note the intentional fall through below. If DATA and XON are both
         * set, the message will stored and sent again with the rest of the
         * unprocessed messages list.
         */

        /* Store */
        if (flags & NFP_FL_LAG_DATA)
                if (!nfp_fl_lag_put_unprocessed(&priv->nfp_lag, skb))
                        store_skb = true;

        /* Send stored */
        if (flags & NFP_FL_LAG_XON)
                nfp_fl_send_unprocessed(&priv->nfp_lag);

        /* Resend all */
        if (flags & NFP_FL_LAG_SYNC) {
                /* To resend all config:
                 * 1) Clear all unprocessed messages
                 * 2) Mark all groups dirty
                 * 3) Reset NFP group config
                 * 4) Schedule a LAG config update
                 */

                __skb_queue_purge(&priv->nfp_lag.retrans_skbs);

                mutex_lock(&priv->nfp_lag.lock);
                list_for_each_entry(group_entry, &priv->nfp_lag.group_list,
                                    list)
                        group_entry->dirty = true;

                err = nfp_flower_lag_reset(&priv->nfp_lag);
                if (err)
                        nfp_flower_cmsg_warn(priv->app,
                                             "mem err in group reset msg\n");
                mutex_unlock(&priv->nfp_lag.lock);

                schedule_delayed_work(&priv->nfp_lag.work, 0);
        }

        return store_skb;
}

static void
nfp_fl_lag_schedule_group_remove(struct nfp_fl_lag *lag,
                                 struct nfp_fl_lag_group *group)
{
        group->to_remove = true;

        schedule_delayed_work(&lag->work, NFP_FL_LAG_DELAY);
}

static void
nfp_fl_lag_schedule_group_delete(struct nfp_fl_lag *lag,
                                 struct net_device *master)
{
        struct nfp_fl_lag_group *group;
        struct nfp_flower_priv *priv;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);

        if (!netif_is_bond_master(master))
                return;

        mutex_lock(&lag->lock);
        group = nfp_fl_lag_find_group_for_master_with_lag(lag, master);
        if (!group) {
                mutex_unlock(&lag->lock);
                nfp_warn(priv->app->cpp, "untracked bond got unregistered %s\n",
                         netdev_name(master));
                return;
        }

        group->to_remove = true;
        group->to_destroy = true;
        mutex_unlock(&lag->lock);

        schedule_delayed_work(&lag->work, NFP_FL_LAG_DELAY);
}

static int
nfp_fl_lag_changeupper_event(struct nfp_fl_lag *lag,
                             struct netdev_notifier_changeupper_info *info)
{
        struct net_device *upper = info->upper_dev, *iter_netdev;
        struct netdev_lag_upper_info *lag_upper_info;
        struct nfp_fl_lag_group *group;
        struct nfp_flower_priv *priv;
        unsigned int slave_count = 0;
        bool can_offload = true;
        struct nfp_repr *repr;

        if (!netif_is_lag_master(upper))
                return 0;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);

        rcu_read_lock();
        for_each_netdev_in_bond_rcu(upper, iter_netdev) {
                if (!nfp_netdev_is_nfp_repr(iter_netdev)) {
                        can_offload = false;
                        break;
                }
                repr = netdev_priv(iter_netdev);

                /* Ensure all ports are created by the same app/on same card. */
                if (repr->app != priv->app) {
                        can_offload = false;
                        break;
                }

                slave_count++;
        }
        rcu_read_unlock();

        lag_upper_info = info->upper_info;

        /* Firmware supports active/backup and L3/L4 hash bonds. */
        if (lag_upper_info &&
            lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_ACTIVEBACKUP &&
            (lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH ||
             (lag_upper_info->hash_type != NETDEV_LAG_HASH_L34 &&
              lag_upper_info->hash_type != NETDEV_LAG_HASH_E34 &&
              lag_upper_info->hash_type != NETDEV_LAG_HASH_UNKNOWN))) {
                can_offload = false;
                nfp_flower_cmsg_warn(priv->app,
                                     "Unable to offload tx_type %u hash %u\n",
                                     lag_upper_info->tx_type,
                                     lag_upper_info->hash_type);
        }

        mutex_lock(&lag->lock);
        group = nfp_fl_lag_find_group_for_master_with_lag(lag, upper);

        if (slave_count == 0 || !can_offload) {
                /* Cannot offload the group - remove if previously offloaded. */
                if (group && group->offloaded)
                        nfp_fl_lag_schedule_group_remove(lag, group);

                mutex_unlock(&lag->lock);
                return 0;
        }

        if (!group) {
                group = nfp_fl_lag_group_create(lag, upper);
                if (IS_ERR(group)) {
                        mutex_unlock(&lag->lock);
                        return PTR_ERR(group);
                }
        }

        group->dirty = true;
        group->slave_cnt = slave_count;

        /* Group may have been on queue for removal but is now offfloable. */
        group->to_remove = false;
        mutex_unlock(&lag->lock);

        schedule_delayed_work(&lag->work, NFP_FL_LAG_DELAY);
        return 0;
}

static void
nfp_fl_lag_changels_event(struct nfp_fl_lag *lag, struct net_device *netdev,
                          struct netdev_notifier_changelowerstate_info *info)
{
        struct netdev_lag_lower_state_info *lag_lower_info;
        struct nfp_flower_repr_priv *repr_priv;
        struct nfp_flower_priv *priv;
        struct nfp_repr *repr;
        unsigned long *flags;

        if (!netif_is_lag_port(netdev) || !nfp_netdev_is_nfp_repr(netdev))
                return;

        lag_lower_info = info->lower_state_info;
        if (!lag_lower_info)
                return;

        priv = container_of(lag, struct nfp_flower_priv, nfp_lag);
        repr = netdev_priv(netdev);

        /* Verify that the repr is associated with this app. */
        if (repr->app != priv->app)
                return;

        repr_priv = repr->app_priv;
        flags = &repr_priv->lag_port_flags;

        mutex_lock(&lag->lock);
        if (lag_lower_info->link_up)
                *flags |= NFP_PORT_LAG_LINK_UP;
        else
                *flags &= ~NFP_PORT_LAG_LINK_UP;

        if (lag_lower_info->tx_enabled)
                *flags |= NFP_PORT_LAG_TX_ENABLED;
        else
                *flags &= ~NFP_PORT_LAG_TX_ENABLED;

        *flags |= NFP_PORT_LAG_CHANGED;
        mutex_unlock(&lag->lock);

        schedule_delayed_work(&lag->work, NFP_FL_LAG_DELAY);
}

int nfp_flower_lag_netdev_event(struct nfp_flower_priv *priv,
                                struct net_device *netdev,
                                unsigned long event, void *ptr)
{
        struct nfp_fl_lag *lag = &priv->nfp_lag;
        int err;

        switch (event) {
        case NETDEV_CHANGEUPPER:
                err = nfp_fl_lag_changeupper_event(lag, ptr);
                if (err)
                        return NOTIFY_BAD;
                return NOTIFY_OK;
        case NETDEV_CHANGELOWERSTATE:
                nfp_fl_lag_changels_event(lag, netdev, ptr);
                return NOTIFY_OK;
        case NETDEV_UNREGISTER:
                nfp_fl_lag_schedule_group_delete(lag, netdev);
                return NOTIFY_OK;
        }

        return NOTIFY_DONE;
}

int nfp_flower_lag_reset(struct nfp_fl_lag *lag)
{
        enum nfp_fl_lag_batch batch = NFP_FL_LAG_BATCH_FIRST;

        lag->rst_cfg = true;
        return nfp_fl_lag_config_group(lag, NULL, NULL, 0, &batch);
}

void nfp_flower_lag_init(struct nfp_fl_lag *lag)
{
        INIT_DELAYED_WORK(&lag->work, nfp_fl_lag_do_work);
        INIT_LIST_HEAD(&lag->group_list);
        mutex_init(&lag->lock);
        ida_init(&lag->ida_handle);

        __skb_queue_head_init(&lag->retrans_skbs);

        /* 0 is a reserved batch version so increment to first valid value. */
        nfp_fl_increment_version(lag);
}

void nfp_flower_lag_cleanup(struct nfp_fl_lag *lag)
{
        struct nfp_fl_lag_group *entry, *storage;

        cancel_delayed_work_sync(&lag->work);

        __skb_queue_purge(&lag->retrans_skbs);

        /* Remove all groups. */
        mutex_lock(&lag->lock);
        list_for_each_entry_safe(entry, storage, &lag->group_list, list) {
                list_del(&entry->list);
                kfree(entry);
        }
        mutex_unlock(&lag->lock);
        mutex_destroy(&lag->lock);
        ida_destroy(&lag->ida_handle);
}