// SPDX-License-Identifier: GPL-2.0
/* sunvnet.c: Sun LDOM Virtual Network Driver.
 *
 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
 * Copyright (C) 2016-2017 Oracle. All rights reserved.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/mutex.h>
#include <linux/highmem.h>
#include <linux/if_vlan.h>

#if IS_ENABLED(CONFIG_IPV6)
#include <linux/icmpv6.h>
#endif

#include <net/ip.h>
#include <net/icmp.h>
#include <net/route.h>

#include <asm/vio.h>
#include <asm/ldc.h>

#include "sunvnet_common.h"

/* length of time before we decide the hardware is borked,
 * and dev->tx_timeout() should be called to fix the problem
 */
#define VNET_TX_TIMEOUT                 (5 * HZ)

#define DRV_MODULE_NAME         "sunvnet"
#define DRV_MODULE_VERSION      "2.0"
#define DRV_MODULE_RELDATE      "February 3, 2017"

static char version[] =
        DRV_MODULE_NAME " " DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")";
MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
MODULE_DESCRIPTION("Sun LDOM virtual network driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

/* Ordered from largest major to lowest */
static struct vio_version vnet_versions[] = {
        { .major = 1, .minor = 8 },
        { .major = 1, .minor = 7 },
        { .major = 1, .minor = 6 },
        { .major = 1, .minor = 0 },
};

static void vnet_get_drvinfo(struct net_device *dev,
                             struct ethtool_drvinfo *info)
{
        strscpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
        strscpy(info->version, DRV_MODULE_VERSION, sizeof(info->version));
}

static u32 vnet_get_msglevel(struct net_device *dev)
{
        struct vnet *vp = netdev_priv(dev);

        return vp->msg_enable;
}

static void vnet_set_msglevel(struct net_device *dev, u32 value)
{
        struct vnet *vp = netdev_priv(dev);

        vp->msg_enable = value;
}

static const struct {
        const char string[ETH_GSTRING_LEN];
} ethtool_stats_keys[] = {
        { "rx_packets" },
        { "tx_packets" },
        { "rx_bytes" },
        { "tx_bytes" },
        { "rx_errors" },
        { "tx_errors" },
        { "rx_dropped" },
        { "tx_dropped" },
        { "multicast" },
        { "rx_length_errors" },
        { "rx_frame_errors" },
        { "rx_missed_errors" },
        { "tx_carrier_errors" },
        { "nports" },
};

static int vnet_get_sset_count(struct net_device *dev, int sset)
{
        struct vnet *vp = (struct vnet *)netdev_priv(dev);

        switch (sset) {
        case ETH_SS_STATS:
                return ARRAY_SIZE(ethtool_stats_keys)
                        + (NUM_VNET_PORT_STATS * vp->nports);
        default:
                return -EOPNOTSUPP;
        }
}

static void vnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
{
        struct vnet *vp = (struct vnet *)netdev_priv(dev);
        struct vnet_port *port;

        switch (stringset) {
        case ETH_SS_STATS:
                memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
                buf += sizeof(ethtool_stats_keys);

                rcu_read_lock();
                list_for_each_entry_rcu(port, &vp->port_list, list) {
                        ethtool_sprintf(&buf, "p%u.%s-%pM", port->q_index,
                                        port->switch_port ? "s" : "q",
                                        port->raddr);
                        ethtool_sprintf(&buf, "p%u.rx_packets", port->q_index);
                        ethtool_sprintf(&buf, "p%u.tx_packets", port->q_index);
                        ethtool_sprintf(&buf, "p%u.rx_bytes", port->q_index);
                        ethtool_sprintf(&buf, "p%u.tx_bytes", port->q_index);
                        ethtool_sprintf(&buf, "p%u.event_up", port->q_index);
                        ethtool_sprintf(&buf, "p%u.event_reset", port->q_index);
                }
                rcu_read_unlock();
                break;
        default:
                WARN_ON(1);
                break;
        }
}

static void vnet_get_ethtool_stats(struct net_device *dev,
                                   struct ethtool_stats *estats, u64 *data)
{
        struct vnet *vp = (struct vnet *)netdev_priv(dev);
        struct vnet_port *port;
        int i = 0;

        data[i++] = dev->stats.rx_packets;
        data[i++] = dev->stats.tx_packets;
        data[i++] = dev->stats.rx_bytes;
        data[i++] = dev->stats.tx_bytes;
        data[i++] = dev->stats.rx_errors;
        data[i++] = dev->stats.tx_errors;
        data[i++] = dev->stats.rx_dropped;
        data[i++] = dev->stats.tx_dropped;
        data[i++] = dev->stats.multicast;
        data[i++] = dev->stats.rx_length_errors;
        data[i++] = dev->stats.rx_frame_errors;
        data[i++] = dev->stats.rx_missed_errors;
        data[i++] = dev->stats.tx_carrier_errors;
        data[i++] = vp->nports;

        rcu_read_lock();
        list_for_each_entry_rcu(port, &vp->port_list, list) {
                data[i++] = port->q_index;
                data[i++] = port->stats.rx_packets;
                data[i++] = port->stats.tx_packets;
                data[i++] = port->stats.rx_bytes;
                data[i++] = port->stats.tx_bytes;
                data[i++] = port->stats.event_up;
                data[i++] = port->stats.event_reset;
        }
        rcu_read_unlock();
}

static const struct ethtool_ops vnet_ethtool_ops = {
        .get_drvinfo            = vnet_get_drvinfo,
        .get_msglevel           = vnet_get_msglevel,
        .set_msglevel           = vnet_set_msglevel,
        .get_link               = ethtool_op_get_link,
        .get_sset_count         = vnet_get_sset_count,
        .get_strings            = vnet_get_strings,
        .get_ethtool_stats      = vnet_get_ethtool_stats,
};

static LIST_HEAD(vnet_list);
static DEFINE_MUTEX(vnet_list_mutex);

static struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
{
        unsigned int hash = vnet_hashfn(skb->data);
        struct hlist_head *hp = &vp->port_hash[hash];
        struct vnet_port *port;

        hlist_for_each_entry_rcu(port, hp, hash) {
                if (!sunvnet_port_is_up_common(port))
                        continue;
                if (ether_addr_equal(port->raddr, skb->data))
                        return port;
        }
        list_for_each_entry_rcu(port, &vp->port_list, list) {
                if (!port->switch_port)
                        continue;
                if (!sunvnet_port_is_up_common(port))
                        continue;
                return port;
        }
        return NULL;
}

/* func arg to vnet_start_xmit_common() to get the proper tx port */
static struct vnet_port *vnet_tx_port_find(struct sk_buff *skb,
                                           struct net_device *dev)
{
        struct vnet *vp = netdev_priv(dev);

        return __tx_port_find(vp, skb);
}

static u16 vnet_select_queue(struct net_device *dev, struct sk_buff *skb,
                             struct net_device *sb_dev)
{
        struct vnet *vp = netdev_priv(dev);
        struct vnet_port *port = __tx_port_find(vp, skb);

        if (!port)
                return 0;

        return port->q_index;
}

/* Wrappers to common functions */
static netdev_tx_t vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        return sunvnet_start_xmit_common(skb, dev, vnet_tx_port_find);
}

static void vnet_set_rx_mode(struct net_device *dev)
{
        struct vnet *vp = netdev_priv(dev);

        return sunvnet_set_rx_mode_common(dev, vp);
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void vnet_poll_controller(struct net_device *dev)
{
        struct vnet *vp = netdev_priv(dev);

        return sunvnet_poll_controller_common(dev, vp);
}
#endif

static const struct net_device_ops vnet_ops = {
        .ndo_open               = sunvnet_open_common,
        .ndo_stop               = sunvnet_close_common,
        .ndo_set_rx_mode        = vnet_set_rx_mode,
        .ndo_set_mac_address    = sunvnet_set_mac_addr_common,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_tx_timeout         = sunvnet_tx_timeout_common,
        .ndo_start_xmit         = vnet_start_xmit,
        .ndo_select_queue       = vnet_select_queue,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = vnet_poll_controller,
#endif
};

static struct vnet *vnet_new(const u64 *local_mac,
                             struct vio_dev *vdev)
{
        struct net_device *dev;
        u8 addr[ETH_ALEN];
        struct vnet *vp;
        int err, i;

        dev = alloc_etherdev_mqs(sizeof(*vp), VNET_MAX_TXQS, 1);
        if (!dev)
                return ERR_PTR(-ENOMEM);
        dev->needed_headroom = VNET_PACKET_SKIP + 8;
        dev->needed_tailroom = 8;

        for (i = 0; i < ETH_ALEN; i++)
                addr[i] = (*local_mac >> (5 - i) * 8) & 0xff;
        eth_hw_addr_set(dev, addr);

        vp = netdev_priv(dev);

        spin_lock_init(&vp->lock);
        vp->dev = dev;

        INIT_LIST_HEAD(&vp->port_list);
        for (i = 0; i < VNET_PORT_HASH_SIZE; i++)
                INIT_HLIST_HEAD(&vp->port_hash[i]);
        INIT_LIST_HEAD(&vp->list);
        vp->local_mac = *local_mac;

        dev->netdev_ops = &vnet_ops;
        dev->ethtool_ops = &vnet_ethtool_ops;
        dev->watchdog_timeo = VNET_TX_TIMEOUT;

        dev->hw_features = NETIF_F_TSO | NETIF_F_GSO | NETIF_F_ALL_TSO |
                           NETIF_F_HW_CSUM | NETIF_F_SG;
        dev->features = dev->hw_features;

        /* MTU range: 68 - 65535 */
        dev->min_mtu = ETH_MIN_MTU;
        dev->max_mtu = VNET_MAX_MTU;

        SET_NETDEV_DEV(dev, &vdev->dev);

        err = register_netdev(dev);
        if (err) {
                pr_err("Cannot register net device, aborting\n");
                goto err_out_free_dev;
        }

        netdev_info(dev, "Sun LDOM vnet %pM\n", dev->dev_addr);

        list_add(&vp->list, &vnet_list);

        return vp;

err_out_free_dev:
        free_netdev(dev);

        return ERR_PTR(err);
}

static struct vnet *vnet_find_or_create(const u64 *local_mac,
                                        struct vio_dev *vdev)
{
        struct vnet *iter, *vp;

        mutex_lock(&vnet_list_mutex);
        vp = NULL;
        list_for_each_entry(iter, &vnet_list, list) {
                if (iter->local_mac == *local_mac) {
                        vp = iter;
                        break;
                }
        }
        if (!vp)
                vp = vnet_new(local_mac, vdev);
        mutex_unlock(&vnet_list_mutex);

        return vp;
}

static void vnet_cleanup(void)
{
        struct vnet *vp;
        struct net_device *dev;

        mutex_lock(&vnet_list_mutex);
        while (!list_empty(&vnet_list)) {
                vp = list_first_entry(&vnet_list, struct vnet, list);
                list_del(&vp->list);
                dev = vp->dev;
                /* vio_unregister_driver() should have cleaned up port_list */
                BUG_ON(!list_empty(&vp->port_list));
                unregister_netdev(dev);
                free_netdev(dev);
        }
        mutex_unlock(&vnet_list_mutex);
}

static const char *local_mac_prop = "local-mac-address";

static struct vnet *vnet_find_parent(struct mdesc_handle *hp,
                                     u64 port_node,
                                     struct vio_dev *vdev)
{
        const u64 *local_mac = NULL;
        u64 a;

        mdesc_for_each_arc(a, hp, port_node, MDESC_ARC_TYPE_BACK) {
                u64 target = mdesc_arc_target(hp, a);
                const char *name;

                name = mdesc_get_property(hp, target, "name", NULL);
                if (!name || strcmp(name, "network"))
                        continue;

                local_mac = mdesc_get_property(hp, target,
                                               local_mac_prop, NULL);
                if (local_mac)
                        break;
        }
        if (!local_mac)
                return ERR_PTR(-ENODEV);

        return vnet_find_or_create(local_mac, vdev);
}

static struct ldc_channel_config vnet_ldc_cfg = {
        .event          = sunvnet_event_common,
        .mtu            = 64,
        .mode           = LDC_MODE_UNRELIABLE,
};

static struct vio_driver_ops vnet_vio_ops = {
        .send_attr              = sunvnet_send_attr_common,
        .handle_attr            = sunvnet_handle_attr_common,
        .handshake_complete     = sunvnet_handshake_complete_common,
};

const char *remote_macaddr_prop = "remote-mac-address";

static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
        struct mdesc_handle *hp;
        struct vnet_port *port;
        unsigned long flags;
        struct vnet *vp;
        const u64 *rmac;
        int len, i, err, switch_port;

        hp = mdesc_grab();

        if (!hp)
                return -ENODEV;

        vp = vnet_find_parent(hp, vdev->mp, vdev);
        if (IS_ERR(vp)) {
                pr_err("Cannot find port parent vnet\n");
                err = PTR_ERR(vp);
                goto err_out_put_mdesc;
        }

        rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
        err = -ENODEV;
        if (!rmac) {
                pr_err("Port lacks %s property\n", remote_macaddr_prop);
                goto err_out_put_mdesc;
        }

        port = kzalloc_obj(*port);
        err = -ENOMEM;
        if (!port)
                goto err_out_put_mdesc;

        for (i = 0; i < ETH_ALEN; i++)
                port->raddr[i] = (*rmac >> (5 - i) * 8) & 0xff;

        port->vp = vp;

        err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
                              vnet_versions, ARRAY_SIZE(vnet_versions),
                              &vnet_vio_ops, vp->dev->name);
        if (err)
                goto err_out_free_port;

        err = vio_ldc_alloc(&port->vio, &vnet_ldc_cfg, port);
        if (err)
                goto err_out_free_port;

        netif_napi_add(port->vp->dev, &port->napi, sunvnet_poll_common);

        INIT_HLIST_NODE(&port->hash);
        INIT_LIST_HEAD(&port->list);

        switch_port = 0;
        if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL))
                switch_port = 1;
        port->switch_port = switch_port;
        port->tso = true;
        port->tsolen = 0;

        spin_lock_irqsave(&vp->lock, flags);
        if (switch_port)
                list_add_rcu(&port->list, &vp->port_list);
        else
                list_add_tail_rcu(&port->list, &vp->port_list);
        hlist_add_head_rcu(&port->hash,
                           &vp->port_hash[vnet_hashfn(port->raddr)]);
        sunvnet_port_add_txq_common(port);
        spin_unlock_irqrestore(&vp->lock, flags);

        dev_set_drvdata(&vdev->dev, port);

        pr_info("%s: PORT ( remote-mac %pM%s )\n",
                vp->dev->name, port->raddr, switch_port ? " switch-port" : "");

        timer_setup(&port->clean_timer, sunvnet_clean_timer_expire_common, 0);

        napi_enable(&port->napi);
        vio_port_up(&port->vio);

        mdesc_release(hp);

        return 0;

err_out_free_port:
        kfree(port);

err_out_put_mdesc:
        mdesc_release(hp);
        return err;
}

static void vnet_port_remove(struct vio_dev *vdev)
{
        struct vnet_port *port = dev_get_drvdata(&vdev->dev);

        if (port) {
                timer_delete_sync(&port->vio.timer);

                napi_disable(&port->napi);

                list_del_rcu(&port->list);
                hlist_del_rcu(&port->hash);

                synchronize_rcu();
                timer_shutdown_sync(&port->clean_timer);
                sunvnet_port_rm_txq_common(port);
                netif_napi_del(&port->napi);
                sunvnet_port_free_tx_bufs_common(port);
                vio_ldc_free(&port->vio);

                dev_set_drvdata(&vdev->dev, NULL);

                kfree(port);
        }
}

static const struct vio_device_id vnet_port_match[] = {
        {
                .type = "vnet-port",
        },
        {},
};
MODULE_DEVICE_TABLE(vio, vnet_port_match);

static struct vio_driver vnet_port_driver = {
        .id_table       = vnet_port_match,
        .probe          = vnet_port_probe,
        .remove         = vnet_port_remove,
        .name           = "vnet_port",
};

static int __init vnet_init(void)
{
        pr_info("%s\n", version);
        return vio_register_driver(&vnet_port_driver);
}

static void __exit vnet_exit(void)
{
        vio_unregister_driver(&vnet_port_driver);
        vnet_cleanup();
}

module_init(vnet_init);
module_exit(vnet_exit);