linux-imx

// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2018, Intel Corporation. */

​

/* This provides a net_failover interface for paravirtual drivers to

 * provide an alternate datapath by exporting APIs to create and

 * destroy a upper 'net_failover' netdev. The upper dev manages the

 * original paravirtual interface as a 'standby' netdev and uses the

 * generic failover infrastructure to register and manage a direct

 * attached VF as a 'primary' netdev. This enables live migration of

 * a VM with direct attached VF by failing over to the paravirtual

 * datapath when the VF is unplugged.

 *

 * Some of the netdev management routines are based on bond/team driver as

 * this driver provides active-backup functionality similar to those drivers.

 */

​

#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/ethtool.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/netpoll.h>

#include <linux/rtnetlink.h>

#include <linux/if_vlan.h>

#include <linux/pci.h>

#include <net/sch_generic.h>

#include <uapi/linux/if_arp.h>

#include <net/net_failover.h>

​

static bool net_failover_xmit_ready(struct net_device *dev)

{

    return netif_running(dev) && netif_carrier_ok(dev);

}

​

static int net_failover_open(struct net_device *dev)

{

    struct net_failover_info *nfo_info = netdev_priv(dev);

    struct net_device *primary_dev, *standby_dev;

    int err;

​

    primary_dev = rtnl_dereference(nfo_info->primary_dev);

    if (primary_dev) {

        err = dev_open(primary_dev, NULL);

        if (err)

            goto err_primary_open;

    }

​

    standby_dev = rtnl_dereference(nfo_info->standby_dev);

    if (standby_dev) {

        err = dev_open(standby_dev, NULL);

        if (err)

            goto err_standby_open;

    }

​

    if ((primary_dev && net_failover_xmit_ready(primary_dev)) ||

        (standby_dev && net_failover_xmit_ready(standby_dev))) {

        netif_carrier_on(dev);

        netif_tx_wake_all_queues(dev);

    }

​

    return 0;

​

err_standby_open: