// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018-2021, Intel Corporation. */

/* Link Aggregation code */

#include "ice.h"
#include "ice_lib.h"
#include "ice_lag.h"

#define ICE_LAG_RES_SHARED	BIT(14)
#define ICE_LAG_RES_VALID	BIT(15)

/**
 * ice_lag_set_primary - set PF LAG state as Primary
 * @lag: LAG info struct
 */
static void ice_lag_set_primary(struct ice_lag *lag)
{
	struct ice_pf *pf = lag->pf;

	if (!pf)
		return;

	if (lag->role != ICE_LAG_UNSET && lag->role != ICE_LAG_BACKUP) {
		dev_warn(ice_pf_to_dev(pf), "%s: Attempt to be Primary, but incompatible state.\n",
			 netdev_name(lag->netdev));
		return;
	}

	lag->role = ICE_LAG_PRIMARY;
}

/**
 * ice_lag_set_backup - set PF LAG state to Backup
 * @lag: LAG info struct
 */
static void ice_lag_set_backup(struct ice_lag *lag)
{
	struct ice_pf *pf = lag->pf;

	if (!pf)
		return;

	if (lag->role != ICE_LAG_UNSET && lag->role != ICE_LAG_PRIMARY) {
		dev_dbg(ice_pf_to_dev(pf), "%s: Attempt to be Backup, but incompatible state\n",
			netdev_name(lag->netdev));
		return;
	}

	lag->role = ICE_LAG_BACKUP;
}

/**
 * ice_display_lag_info - print LAG info
 * @lag: LAG info struct
 */
static void ice_display_lag_info(struct ice_lag *lag)
{
	const char *name, *upper, *role, *bonded, *primary;
	struct device *dev = &lag->pf->pdev->dev;

	name = lag->netdev ? netdev_name(lag->netdev) : "unset";
	upper = lag->upper_netdev ? netdev_name(lag->upper_netdev) : "unset";
	primary = lag->primary ? "TRUE" : "FALSE";
	bonded = lag->bonded ? "BONDED" : "UNBONDED";

	switch (lag->role) {
	case ICE_LAG_NONE:
		role = "NONE";
		break;
	case ICE_LAG_PRIMARY:
		role = "PRIMARY";
		break;
	case ICE_LAG_BACKUP:
		role = "BACKUP";
		break;
	case ICE_LAG_UNSET:
		role = "UNSET";
		break;
	default:
		role = "ERROR";
	}

	dev_dbg(dev, "%s %s, upper:%s, role:%s, primary:%s\n", name, bonded,
		upper, role, primary);
}

/**
 * ice_lag_info_event - handle NETDEV_BONDING_INFO event
 * @lag: LAG info struct
 * @ptr: opaque data pointer
 *
 * ptr is to be cast to (netdev_notifier_bonding_info *)
 */
static void ice_lag_info_event(struct ice_lag *lag, void *ptr)
{
	struct netdev_notifier_bonding_info *info;
	struct netdev_bonding_info *bonding_info;
	struct net_device *event_netdev;
	const char *lag_netdev_name;

	event_netdev = netdev_notifier_info_to_dev(ptr);
	info = ptr;
	lag_netdev_name = netdev_name(lag->netdev);
	bonding_info = &info->bonding_info;

	if (event_netdev != lag->netdev || !lag->bonded || !lag->upper_netdev)
		return;

	if (bonding_info->master.bond_mode != BOND_MODE_ACTIVEBACKUP) {
		netdev_dbg(lag->netdev, "Bonding event recv, but mode not active/backup\n");
		goto lag_out;
	}

	if (strcmp(bonding_info->slave.slave_name, lag_netdev_name)) {
		netdev_dbg(lag->netdev, "Bonding event recv, but secondary info not for us\n");
		goto lag_out;
	}

	if (bonding_info->slave.state)
		ice_lag_set_backup(lag);
	else
		ice_lag_set_primary(lag);

lag_out:
	ice_display_lag_info(lag);
}

/**
 * ice_lag_link - handle LAG link event
 * @lag: LAG info struct
 * @info: info from the netdev notifier
 */
static void
ice_lag_link(struct ice_lag *lag, struct netdev_notifier_changeupper_info *info)
{
	struct net_device *netdev_tmp, *upper = info->upper_dev;
	struct ice_pf *pf = lag->pf;
	int peers = 0;

	if (lag->bonded)
		dev_warn(ice_pf_to_dev(pf), "%s Already part of a bond\n",
			 netdev_name(lag->netdev));

	rcu_read_lock();
	for_each_netdev_in_bond_rcu(upper, netdev_tmp)
		peers++;
	rcu_read_unlock();

	if (lag->upper_netdev != upper) {
		dev_hold(upper);
		lag->upper_netdev = upper;
	}

	ice_clear_rdma_cap(pf);

	lag->bonded = true;
	lag->role = ICE_LAG_UNSET;

	/* if this is the first element in an LAG mark as primary */
	lag->primary = !!(peers == 1);
}

/**
 * ice_lag_unlink - handle unlink event
 * @lag: LAG info struct
 * @info: info from netdev notification
 */
static void
ice_lag_unlink(struct ice_lag *lag,
	       struct netdev_notifier_changeupper_info *info)
{
	struct net_device *netdev_tmp, *upper = info->upper_dev;
	struct ice_pf *pf = lag->pf;
	bool found = false;

	if (!lag->bonded) {
		netdev_dbg(lag->netdev, "bonding unlink event on non-LAG netdev\n");
		return;
	}

	/* determine if we are in the new LAG config or not */
	rcu_read_lock();
	for_each_netdev_in_bond_rcu(upper, netdev_tmp) {
		if (netdev_tmp == lag->netdev) {
			found = true;
			break;
		}
	}
	rcu_read_unlock();

	if (found)
		return;

	if (lag->upper_netdev) {
		dev_put(lag->upper_netdev);
		lag->upper_netdev = NULL;
	}

	ice_set_rdma_cap(pf);
	lag->bonded = false;
	lag->role = ICE_LAG_NONE;
}

/**
 * ice_lag_unregister - handle netdev unregister events
 * @lag: LAG info struct
 * @netdev: netdev reporting the event
 */
static void ice_lag_unregister(struct ice_lag *lag, struct net_device *netdev)
{
	struct ice_pf *pf = lag->pf;

	/* check to see if this event is for this netdev
	 * check that we are in an aggregate
	 */
	if (netdev != lag->netdev || !lag->bonded)
		return;

	if (lag->upper_netdev) {
		dev_put(lag->upper_netdev);
		lag->upper_netdev = NULL;
		ice_set_rdma_cap(pf);
	}
	/* perform some cleanup in case we come back */
	lag->bonded = false;
	lag->role = ICE_LAG_NONE;
}

/**
 * ice_lag_init_feature_support_flag - Check for NVM support for LAG
 * @pf: PF struct
 */
static void ice_lag_init_feature_support_flag(struct ice_pf *pf)
{
	struct ice_hw_common_caps *caps;

	caps = &pf->hw.dev_caps.common_cap;
	if (caps->roce_lag)
		ice_set_feature_support(pf, ICE_F_ROCE_LAG);
	else
		ice_clear_feature_support(pf, ICE_F_ROCE_LAG);

	if (caps->sriov_lag)
		ice_set_feature_support(pf, ICE_F_SRIOV_LAG);
	else
		ice_clear_feature_support(pf, ICE_F_SRIOV_LAG);
}

/**
 * ice_lag_changeupper_event - handle LAG changeupper event
 * @lag: LAG info struct
 * @ptr: opaque pointer data
 *
 * ptr is to be cast into netdev_notifier_changeupper_info
 */
static void ice_lag_changeupper_event(struct ice_lag *lag, void *ptr)
{
	struct netdev_notifier_changeupper_info *info;
	struct net_device *netdev;

	info = ptr;
	netdev = netdev_notifier_info_to_dev(ptr);

	/* not for this netdev */
	if (netdev != lag->netdev)
		return;

	if (!info->upper_dev) {
		netdev_dbg(netdev, "changeupper rcvd, but no upper defined\n");
		return;
	}

	netdev_dbg(netdev, "bonding %s\n", info->linking ? "LINK" : "UNLINK");

	if (!netif_is_lag_master(info->upper_dev)) {
		netdev_dbg(netdev, "changeupper rcvd, but not primary. bail\n");
		return;
	}

	if (info->linking)
		ice_lag_link(lag, info);
	else
		ice_lag_unlink(lag, info);

	ice_display_lag_info(lag);
}

/**
 * ice_lag_process_event - process a task assigned to the lag_wq
 * @work: pointer to work_struct
 */
static void ice_lag_process_event(struct work_struct *work)
{
	struct netdev_notifier_changeupper_info *info;
	struct ice_lag_work *lag_work;
	struct net_device *netdev;
	struct list_head *tmp, *n;
	struct ice_pf *pf;

	lag_work = container_of(work, struct ice_lag_work, lag_task);
	pf = lag_work->lag->pf;

	mutex_lock(&pf->lag_mutex);
	lag_work->lag->netdev_head = &lag_work->netdev_list.node;

	switch (lag_work->event) {
	case NETDEV_CHANGEUPPER:
		info = &lag_work->info.changeupper_info;
		ice_lag_changeupper_event(lag_work->lag, info);
		break;
	case NETDEV_BONDING_INFO:
		ice_lag_info_event(lag_work->lag, &lag_work->info.bonding_info);
		break;
	case NETDEV_UNREGISTER:
		if (ice_is_feature_supported(pf, ICE_F_SRIOV_LAG)) {
			netdev = lag_work->info.bonding_info.info.dev;
			if ((netdev == lag_work->lag->netdev ||
			     lag_work->lag->primary) && lag_work->lag->bonded)
				ice_lag_unregister(lag_work->lag, netdev);
		}
		break;
	default:
		break;
	}

	/* cleanup resources allocated for this work item */
	list_for_each_safe(tmp, n, &lag_work->netdev_list.node) {
		struct ice_lag_netdev_list *entry;

		entry = list_entry(tmp, struct ice_lag_netdev_list, node);
		list_del(&entry->node);
		kfree(entry);
	}
	lag_work->lag->netdev_head = NULL;

	mutex_unlock(&pf->lag_mutex);

	kfree(lag_work);
}

/**
 * ice_lag_event_handler - handle LAG events from netdev
 * @notif_blk: notifier block registered by this netdev
 * @event: event type
 * @ptr: opaque data containing notifier event
 */
static int
ice_lag_event_handler(struct notifier_block *notif_blk, unsigned long event,
		      void *ptr)
{
	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
	struct net_device *upper_netdev;
	struct ice_lag_work *lag_work;
	struct ice_lag *lag;

	if (!netif_is_ice(netdev))
		return NOTIFY_DONE;

	if (event != NETDEV_CHANGEUPPER && event != NETDEV_BONDING_INFO &&
	    event != NETDEV_UNREGISTER)
		return NOTIFY_DONE;

	if (!(netdev->priv_flags & IFF_BONDING))
		return NOTIFY_DONE;

	lag = container_of(notif_blk, struct ice_lag, notif_block);
	if (!lag->netdev)
		return NOTIFY_DONE;

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

	/* This memory will be freed at the end of ice_lag_process_event */
	lag_work = kzalloc(sizeof(*lag_work), GFP_KERNEL);
	if (!lag_work)
		return -ENOMEM;

	lag_work->event_netdev = netdev;
	lag_work->lag = lag;
	lag_work->event = event;
	if (event == NETDEV_CHANGEUPPER) {
		struct netdev_notifier_changeupper_info *info;

		info = ptr;
		upper_netdev = info->upper_dev;
	} else {
		upper_netdev = netdev_master_upper_dev_get(netdev);
	}

	INIT_LIST_HEAD(&lag_work->netdev_list.node);
	if (upper_netdev) {
		struct ice_lag_netdev_list *nd_list;
		struct net_device *tmp_nd;

		rcu_read_lock();
		for_each_netdev_in_bond_rcu(upper_netdev, tmp_nd) {
			nd_list = kzalloc(sizeof(*nd_list), GFP_KERNEL);
			if (!nd_list)
				break;

			nd_list->netdev = tmp_nd;
			list_add(&nd_list->node, &lag_work->netdev_list.node);
		}
		rcu_read_unlock();
	}

	switch (event) {
	case NETDEV_CHANGEUPPER:
		lag_work->info.changeupper_info =
			*((struct netdev_notifier_changeupper_info *)ptr);
		break;
	case NETDEV_BONDING_INFO:
		lag_work->info.bonding_info =
			*((struct netdev_notifier_bonding_info *)ptr);
		break;
	default:
		lag_work->info.notifier_info =
			*((struct netdev_notifier_info *)ptr);
		break;
	}

	INIT_WORK(&lag_work->lag_task, ice_lag_process_event);
	queue_work(ice_lag_wq, &lag_work->lag_task);

	return NOTIFY_DONE;
}

/**
 * ice_register_lag_handler - register LAG handler on netdev
 * @lag: LAG struct
 */
static int ice_register_lag_handler(struct ice_lag *lag)
{
	struct device *dev = ice_pf_to_dev(lag->pf);
	struct notifier_block *notif_blk;

	notif_blk = &lag->notif_block;

	if (!notif_blk->notifier_call) {
		notif_blk->notifier_call = ice_lag_event_handler;
		if (register_netdevice_notifier(notif_blk)) {
			notif_blk->notifier_call = NULL;
			dev_err(dev, "FAIL register LAG event handler!\n");
			return -EINVAL;
		}
		dev_dbg(dev, "LAG event handler registered\n");
	}
	return 0;
}

/**
 * ice_unregister_lag_handler - unregister LAG handler on netdev
 * @lag: LAG struct
 */
static void ice_unregister_lag_handler(struct ice_lag *lag)
{
	struct device *dev = ice_pf_to_dev(lag->pf);
	struct notifier_block *notif_blk;

	notif_blk = &lag->notif_block;
	if (notif_blk->notifier_call) {
		unregister_netdevice_notifier(notif_blk);
		dev_dbg(dev, "LAG event handler unregistered\n");
	}
}

/**
 * ice_init_lag - initialize support for LAG
 * @pf: PF struct
 *
 * Alloc memory for LAG structs and initialize the elements.
 * Memory will be freed in ice_deinit_lag
 */
int ice_init_lag(struct ice_pf *pf)
{
	struct device *dev = ice_pf_to_dev(pf);
	struct ice_lag *lag;
	struct ice_vsi *vsi;
	int err;

	ice_lag_init_feature_support_flag(pf);

	pf->lag = kzalloc(sizeof(*lag), GFP_KERNEL);
	if (!pf->lag)
		return -ENOMEM;
	lag = pf->lag;

	vsi = ice_get_main_vsi(pf);
	if (!vsi) {
		dev_err(dev, "couldn't get main vsi, link aggregation init fail\n");
		err = -EIO;
		goto lag_error;
	}

	lag->pf = pf;
	lag->netdev = vsi->netdev;
	lag->role = ICE_LAG_NONE;
	lag->bonded = false;
	lag->upper_netdev = NULL;
	lag->notif_block.notifier_call = NULL;

	err = ice_register_lag_handler(lag);
	if (err) {
		dev_warn(dev, "INIT LAG: Failed to register event handler\n");
		goto lag_error;
	}

	ice_display_lag_info(lag);

	dev_dbg(dev, "INIT LAG complete\n");
	return 0;

lag_error:
	kfree(lag);
	pf->lag = NULL;
	return err;
}

/**
 * ice_deinit_lag - Clean up LAG
 * @pf: PF struct
 *
 * Clean up kernel LAG info and free memory
 * This function is meant to only be called on driver remove/shutdown
 */
void ice_deinit_lag(struct ice_pf *pf)
{
	struct ice_lag *lag;

	lag = pf->lag;

	if (!lag)
		return;

	if (lag->pf)
		ice_unregister_lag_handler(lag);

	flush_workqueue(ice_lag_wq);

	kfree(lag);

	pf->lag = NULL;
}