/*
 * 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/netdevice.h>
#include <linux/mlx5/driver.h>
#include <linux/mlx5/vport.h>
#include "mlx5_core.h"

enum {
        MLX5_LAG_FLAG_BONDED = 1 << 0,
};

struct lag_func {
        struct mlx5_core_dev *dev;
        struct net_device    *netdev;
};

/* Used for collection of netdev event info. */
struct lag_tracker {
        enum   netdev_lag_tx_type           tx_type;
        struct netdev_lag_lower_state_info  netdev_state[MLX5_MAX_PORTS];
        bool is_bonded;
};

/* LAG data of a ConnectX card.
 * It serves both its phys functions.
 */
struct mlx5_lag {
        u8                        flags;
        u8                        v2p_map[MLX5_MAX_PORTS];
        struct lag_func           pf[MLX5_MAX_PORTS];
        struct lag_tracker        tracker;
        struct delayed_work       bond_work;
        struct notifier_block     nb;
};

/* General purpose, use for short periods of time.
 * Beware of lock dependencies (preferably, no locks should be acquired
 * under it).
 */
static DEFINE_MUTEX(lag_mutex);

static int mlx5_cmd_create_lag(struct mlx5_core_dev *dev, u8 remap_port1,
                               u8 remap_port2)
{
        u32   in[MLX5_ST_SZ_DW(create_lag_in)]   = {0};
        u32   out[MLX5_ST_SZ_DW(create_lag_out)] = {0};
        void *lag_ctx = MLX5_ADDR_OF(create_lag_in, in, ctx);

        MLX5_SET(create_lag_in, in, opcode, MLX5_CMD_OP_CREATE_LAG);

        MLX5_SET(lagc, lag_ctx, tx_remap_affinity_1, remap_port1);
        MLX5_SET(lagc, lag_ctx, tx_remap_affinity_2, remap_port2);

        return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
}

static int mlx5_cmd_modify_lag(struct mlx5_core_dev *dev, u8 remap_port1,
                               u8 remap_port2)
{
        u32   in[MLX5_ST_SZ_DW(modify_lag_in)]   = {0};
        u32   out[MLX5_ST_SZ_DW(modify_lag_out)] = {0};
        void *lag_ctx = MLX5_ADDR_OF(modify_lag_in, in, ctx);

        MLX5_SET(modify_lag_in, in, opcode, MLX5_CMD_OP_MODIFY_LAG);
        MLX5_SET(modify_lag_in, in, field_select, 0x1);

        MLX5_SET(lagc, lag_ctx, tx_remap_affinity_1, remap_port1);
        MLX5_SET(lagc, lag_ctx, tx_remap_affinity_2, remap_port2);

        return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
}

static int mlx5_cmd_destroy_lag(struct mlx5_core_dev *dev)
{
        u32  in[MLX5_ST_SZ_DW(destroy_lag_in)]  = {0};
        u32 out[MLX5_ST_SZ_DW(destroy_lag_out)] = {0};

        MLX5_SET(destroy_lag_in, in, opcode, MLX5_CMD_OP_DESTROY_LAG);

        return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
}

int mlx5_cmd_create_vport_lag(struct mlx5_core_dev *dev)
{
        u32  in[MLX5_ST_SZ_DW(create_vport_lag_in)]  = {0};
        u32 out[MLX5_ST_SZ_DW(create_vport_lag_out)] = {0};

        MLX5_SET(create_vport_lag_in, in, opcode, MLX5_CMD_OP_CREATE_VPORT_LAG);

        return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
}
EXPORT_SYMBOL(mlx5_cmd_create_vport_lag);

int mlx5_cmd_destroy_vport_lag(struct mlx5_core_dev *dev)
{
        u32  in[MLX5_ST_SZ_DW(destroy_vport_lag_in)]  = {0};
        u32 out[MLX5_ST_SZ_DW(destroy_vport_lag_out)] = {0};

        MLX5_SET(destroy_vport_lag_in, in, opcode, MLX5_CMD_OP_DESTROY_VPORT_LAG);

        return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
}
EXPORT_SYMBOL(mlx5_cmd_destroy_vport_lag);

static struct mlx5_lag *mlx5_lag_dev_get(struct mlx5_core_dev *dev)
{
        return dev->priv.lag;
}

static int mlx5_lag_dev_get_netdev_idx(struct mlx5_lag *ldev,
                                       struct net_device *ndev)
{
        int i;

        for (i = 0; i < MLX5_MAX_PORTS; i++)
                if (ldev->pf[i].netdev == ndev)
                        return i;

        return -1;
}

static bool mlx5_lag_is_bonded(struct mlx5_lag *ldev)
{
        return !!(ldev->flags & MLX5_LAG_FLAG_BONDED);
}

static void mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker,
                                           u8 *port1, u8 *port2)
{
        if (tracker->tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP) {
                if (tracker->netdev_state[0].tx_enabled) {
                        *port1 = 1;
                        *port2 = 1;
                } else {
                        *port1 = 2;
                        *port2 = 2;
                }
        } else {
                *port1 = 1;
                *port2 = 2;
                if (!tracker->netdev_state[0].link_up)
                        *port1 = 2;
                else if (!tracker->netdev_state[1].link_up)
                        *port2 = 1;
        }
}

static void mlx5_activate_lag(struct mlx5_lag *ldev,
                              struct lag_tracker *tracker)
{
        struct mlx5_core_dev *dev0 = ldev->pf[0].dev;
        int err;

        ldev->flags |= MLX5_LAG_FLAG_BONDED;

        mlx5_infer_tx_affinity_mapping(tracker, &ldev->v2p_map[0],
                                       &ldev->v2p_map[1]);

        err = mlx5_cmd_create_lag(dev0, ldev->v2p_map[0], ldev->v2p_map[1]);
        if (err)
                mlx5_core_err(dev0,
                              "Failed to create LAG (%d)\n",
                              err);
}

static void mlx5_deactivate_lag(struct mlx5_lag *ldev)
{
        struct mlx5_core_dev *dev0 = ldev->pf[0].dev;
        int err;

        ldev->flags &= ~MLX5_LAG_FLAG_BONDED;

        err = mlx5_cmd_destroy_lag(dev0);
        if (err)
                mlx5_core_err(dev0,
                              "Failed to destroy LAG (%d)\n",
                              err);
}

static void mlx5_do_bond(struct mlx5_lag *ldev)
{
        struct mlx5_core_dev *dev0 = ldev->pf[0].dev;
        struct mlx5_core_dev *dev1 = ldev->pf[1].dev;
        struct lag_tracker tracker;
        u8 v2p_port1, v2p_port2;
        int i, err;

        if (!dev0 || !dev1)
                return;

        mutex_lock(&lag_mutex);
        tracker = ldev->tracker;
        mutex_unlock(&lag_mutex);

        if (tracker.is_bonded && !mlx5_lag_is_bonded(ldev)) {
                if (mlx5_sriov_is_enabled(dev0) ||
                    mlx5_sriov_is_enabled(dev1)) {
                        mlx5_core_warn(dev0, "LAG is not supported with SRIOV");
                        return;
                }

                for (i = 0; i < MLX5_MAX_PORTS; i++)
                        mlx5_remove_dev_by_protocol(ldev->pf[i].dev,
                                                    MLX5_INTERFACE_PROTOCOL_IB);

                mlx5_activate_lag(ldev, &tracker);

                mlx5_add_dev_by_protocol(dev0, MLX5_INTERFACE_PROTOCOL_IB);
                mlx5_nic_vport_enable_roce(dev1);
        } else if (tracker.is_bonded && mlx5_lag_is_bonded(ldev)) {
                mlx5_infer_tx_affinity_mapping(&tracker, &v2p_port1,
                                               &v2p_port2);

                if ((v2p_port1 != ldev->v2p_map[0]) ||
                    (v2p_port2 != ldev->v2p_map[1])) {
                        ldev->v2p_map[0] = v2p_port1;
                        ldev->v2p_map[1] = v2p_port2;

                        err = mlx5_cmd_modify_lag(dev0, v2p_port1, v2p_port2);
                        if (err)
                                mlx5_core_err(dev0,
                                              "Failed to modify LAG (%d)\n",
                                              err);
                }
        } else if (!tracker.is_bonded && mlx5_lag_is_bonded(ldev)) {
                mlx5_remove_dev_by_protocol(dev0, MLX5_INTERFACE_PROTOCOL_IB);
                mlx5_nic_vport_disable_roce(dev1);

                mlx5_deactivate_lag(ldev);

                for (i = 0; i < MLX5_MAX_PORTS; i++)
                        if (ldev->pf[i].dev)
                                mlx5_add_dev_by_protocol(ldev->pf[i].dev,
                                                         MLX5_INTERFACE_PROTOCOL_IB);
        }
}

static void mlx5_queue_bond_work(struct mlx5_lag *ldev, unsigned long delay)
{
        schedule_delayed_work(&ldev->bond_work, delay);
}

static void mlx5_do_bond_work(struct work_struct *work)
{
        struct delayed_work *delayed_work = to_delayed_work(work);
        struct mlx5_lag *ldev = container_of(delayed_work, struct mlx5_lag,
                                             bond_work);
        int status;

        status = mlx5_dev_list_trylock();
        if (!status) {
                /* 1 sec delay. */
                mlx5_queue_bond_work(ldev, HZ);
                return;
        }

        mlx5_do_bond(ldev);
        mlx5_dev_list_unlock();
}

static int mlx5_handle_changeupper_event(struct mlx5_lag *ldev,
                                         struct lag_tracker *tracker,
                                         struct net_device *ndev,
                                         struct netdev_notifier_changeupper_info *info)
{
        struct net_device *upper = info->upper_dev, *ndev_tmp;
        struct netdev_lag_upper_info *lag_upper_info;
        bool is_bonded;
        int bond_status = 0;
        int num_slaves = 0;
        int idx;

        if (!netif_is_lag_master(upper))
                return 0;

        lag_upper_info = info->upper_info;

        /* The event may still be of interest if the slave does not belong to
         * us, but is enslaved to a master which has one or more of our netdevs
         * as slaves (e.g., if a new slave is added to a master that bonds two
         * of our netdevs, we should unbond).
         */
        rcu_read_lock();
        for_each_netdev_in_bond_rcu(upper, ndev_tmp) {
                idx = mlx5_lag_dev_get_netdev_idx(ldev, ndev_tmp);
                if (idx > -1)
                        bond_status |= (1 << idx);

                num_slaves++;
        }
        rcu_read_unlock();

        /* None of this lagdev's netdevs are slaves of this master. */
        if (!(bond_status & 0x3))
                return 0;

        if (lag_upper_info)
                tracker->tx_type = lag_upper_info->tx_type;

        /* Determine bonding status:
         * A device is considered bonded if both its physical ports are slaves
         * of the same lag master, and only them.
         * Lag mode must be activebackup or hash.
         */
        is_bonded = (num_slaves == MLX5_MAX_PORTS) &&
                    (bond_status == 0x3) &&
                    ((tracker->tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP) ||
                     (tracker->tx_type == NETDEV_LAG_TX_TYPE_HASH));

        if (tracker->is_bonded != is_bonded) {
                tracker->is_bonded = is_bonded;
                return 1;
        }

        return 0;
}

static int mlx5_handle_changelowerstate_event(struct mlx5_lag *ldev,
                                              struct lag_tracker *tracker,
                                              struct net_device *ndev,
                                              struct netdev_notifier_changelowerstate_info *info)
{
        struct netdev_lag_lower_state_info *lag_lower_info;
        int idx;

        if (!netif_is_lag_port(ndev))
                return 0;

        idx = mlx5_lag_dev_get_netdev_idx(ldev, ndev);
        if (idx == -1)
                return 0;

        /* This information is used to determine virtual to physical
         * port mapping.
         */
        lag_lower_info = info->lower_state_info;
        if (!lag_lower_info)
                return 0;

        tracker->netdev_state[idx] = *lag_lower_info;

        return 1;
}

static int mlx5_lag_netdev_event(struct notifier_block *this,
                                 unsigned long event, void *ptr)
{
        struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
        struct lag_tracker tracker;
        struct mlx5_lag *ldev;
        int changed = 0;

        if (!net_eq(dev_net(ndev), &init_net))
                return NOTIFY_DONE;

        if ((event != NETDEV_CHANGEUPPER) && (event != NETDEV_CHANGELOWERSTATE))
                return NOTIFY_DONE;

        ldev    = container_of(this, struct mlx5_lag, nb);
        tracker = ldev->tracker;

        switch (event) {
        case NETDEV_CHANGEUPPER:
                changed = mlx5_handle_changeupper_event(ldev, &tracker, ndev,
                                                        ptr);
                break;
        case NETDEV_CHANGELOWERSTATE:
                changed = mlx5_handle_changelowerstate_event(ldev, &tracker,
                                                             ndev, ptr);
                break;
        }

        mutex_lock(&lag_mutex);
        ldev->tracker = tracker;
        mutex_unlock(&lag_mutex);

        if (changed)
                mlx5_queue_bond_work(ldev, 0);

        return NOTIFY_DONE;
}

static struct mlx5_lag *mlx5_lag_dev_alloc(void)
{
        struct mlx5_lag *ldev;

        ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
        if (!ldev)
                return NULL;

        INIT_DELAYED_WORK(&ldev->bond_work, mlx5_do_bond_work);

        return ldev;
}

static void mlx5_lag_dev_free(struct mlx5_lag *ldev)
{
        kfree(ldev);
}

static void mlx5_lag_dev_add_pf(struct mlx5_lag *ldev,
                                struct mlx5_core_dev *dev,
                                struct net_device *netdev)
{
        unsigned int fn = PCI_FUNC(dev->pdev->devfn);

        if (fn >= MLX5_MAX_PORTS)
                return;

        mutex_lock(&lag_mutex);
        ldev->pf[fn].dev    = dev;
        ldev->pf[fn].netdev = netdev;
        ldev->tracker.netdev_state[fn].link_up = 0;
        ldev->tracker.netdev_state[fn].tx_enabled = 0;

        dev->priv.lag = ldev;
        mutex_unlock(&lag_mutex);
}

static void mlx5_lag_dev_remove_pf(struct mlx5_lag *ldev,
                                   struct mlx5_core_dev *dev)
{
        int i;

        for (i = 0; i < MLX5_MAX_PORTS; i++)
                if (ldev->pf[i].dev == dev)
                        break;

        if (i == MLX5_MAX_PORTS)
                return;

        mutex_lock(&lag_mutex);
        memset(&ldev->pf[i], 0, sizeof(*ldev->pf));

        dev->priv.lag = NULL;
        mutex_unlock(&lag_mutex);
}


/* Must be called with intf_mutex held */
void mlx5_lag_add(struct mlx5_core_dev *dev, struct net_device *netdev)
{
        struct mlx5_lag *ldev = NULL;
        struct mlx5_core_dev *tmp_dev;

        if (!MLX5_CAP_GEN(dev, vport_group_manager) ||
            !MLX5_CAP_GEN(dev, lag_master) ||
            (MLX5_CAP_GEN(dev, num_lag_ports) != MLX5_MAX_PORTS))
                return;

        tmp_dev = mlx5_get_next_phys_dev(dev);
        if (tmp_dev)
                ldev = tmp_dev->priv.lag;

        if (!ldev) {
                ldev = mlx5_lag_dev_alloc();
                if (!ldev) {
                        mlx5_core_err(dev, "Failed to alloc lag dev\n");
                        return;
                }
        }

        mlx5_lag_dev_add_pf(ldev, dev, netdev);

        if (!ldev->nb.notifier_call) {
                ldev->nb.notifier_call = mlx5_lag_netdev_event;
                if (register_netdevice_notifier(&ldev->nb)) {
                        ldev->nb.notifier_call = NULL;
                        mlx5_core_err(dev, "Failed to register LAG netdev notifier\n");
                }
        }
}

/* Must be called with intf_mutex held */
void mlx5_lag_remove(struct mlx5_core_dev *dev)
{
        struct mlx5_lag *ldev;
        int i;

        ldev = mlx5_lag_dev_get(dev);
        if (!ldev)
                return;

        if (mlx5_lag_is_bonded(ldev))
                mlx5_deactivate_lag(ldev);

        mlx5_lag_dev_remove_pf(ldev, dev);

        for (i = 0; i < MLX5_MAX_PORTS; i++)
                if (ldev->pf[i].dev)
                        break;

        if (i == MLX5_MAX_PORTS) {
                if (ldev->nb.notifier_call)
                        unregister_netdevice_notifier(&ldev->nb);
                cancel_delayed_work_sync(&ldev->bond_work);
                mlx5_lag_dev_free(ldev);
        }
}

bool mlx5_lag_is_active(struct mlx5_core_dev *dev)
{
        struct mlx5_lag *ldev;
        bool res;

        mutex_lock(&lag_mutex);
        ldev = mlx5_lag_dev_get(dev);
        res  = ldev && mlx5_lag_is_bonded(ldev);
        mutex_unlock(&lag_mutex);

        return res;
}
EXPORT_SYMBOL(mlx5_lag_is_active);

struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev)
{
        struct net_device *ndev = NULL;
        struct mlx5_lag *ldev;

        mutex_lock(&lag_mutex);
        ldev = mlx5_lag_dev_get(dev);

        if (!(ldev && mlx5_lag_is_bonded(ldev)))
                goto unlock;

        if (ldev->tracker.tx_type == NETDEV_LAG_TX_TYPE_ACTIVEBACKUP) {
                ndev = ldev->tracker.netdev_state[0].tx_enabled ?
                       ldev->pf[0].netdev : ldev->pf[1].netdev;
        } else {
                ndev = ldev->pf[0].netdev;
        }
        if (ndev)
                dev_hold(ndev);

unlock:
        mutex_unlock(&lag_mutex);

        return ndev;
}
EXPORT_SYMBOL(mlx5_lag_get_roce_netdev);

bool mlx5_lag_intf_add(struct mlx5_interface *intf, struct mlx5_priv *priv)
{
        struct mlx5_core_dev *dev = container_of(priv, struct mlx5_core_dev,
                                                 priv);
        struct mlx5_lag *ldev;

        if (intf->protocol != MLX5_INTERFACE_PROTOCOL_IB)
                return true;

        ldev = mlx5_lag_dev_get(dev);
        if (!ldev || !mlx5_lag_is_bonded(ldev) || ldev->pf[0].dev == dev)
                return true;

        /* If bonded, we do not add an IB device for PF1. */
        return false;
}