// SPDX-License-Identifier: GPL-2.0
/* ldmvsw.c: Sun4v LDOM Virtual Switch Driver.
 *
 * Copyright (C) 2016-2017 Oracle. All rights reserved.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

#if defined(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>

/* This driver makes use of the common code in sunvnet_common.c */
#include "sunvnet_common.h"

/* Length of time before we decide the hardware is hung,
 * and dev->tx_timeout() should be called to fix the problem.
 */
#define VSW_TX_TIMEOUT                  (10 * HZ)

/* Static HW Addr used for the network interfaces representing vsw ports */
static u8 vsw_port_hwaddr[ETH_ALEN] = {0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

#define DRV_MODULE_NAME         "ldmvsw"
#define DRV_MODULE_VERSION      "1.2"
#define DRV_MODULE_RELDATE      "March 4, 2017"

static char version[] =
        DRV_MODULE_NAME " " DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")";
MODULE_AUTHOR("Oracle");
MODULE_DESCRIPTION("Sun4v LDOM Virtual Switch Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

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

static void vsw_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 vsw_get_msglevel(struct net_device *dev)
{
        struct vnet_port *port = netdev_priv(dev);

        return port->vp->msg_enable;
}

static void vsw_set_msglevel(struct net_device *dev, u32 value)
{
        struct vnet_port *port = netdev_priv(dev);

        port->vp->msg_enable = value;
}

static const struct ethtool_ops vsw_ethtool_ops = {
        .get_drvinfo            = vsw_get_drvinfo,
        .get_msglevel           = vsw_get_msglevel,
        .set_msglevel           = vsw_set_msglevel,
        .get_link               = ethtool_op_get_link,
};

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

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

        return port;
}

static u16 vsw_select_queue(struct net_device *dev, struct sk_buff *skb,
                            struct net_device *sb_dev)
{
        struct vnet_port *port = netdev_priv(dev);

        if (!port)
                return 0;

        return port->q_index;
}

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

static void vsw_set_rx_mode(struct net_device *dev)
{
        struct vnet_port *port = netdev_priv(dev);

        return sunvnet_set_rx_mode_common(dev, port->vp);
}

static int ldmvsw_open(struct net_device *dev)
{
        struct vnet_port *port = netdev_priv(dev);
        struct vio_driver_state *vio = &port->vio;

        /* reset the channel */
        vio_link_state_change(vio, LDC_EVENT_RESET);
        vnet_port_reset(port);
        vio_port_up(vio);

        return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void vsw_poll_controller(struct net_device *dev)
{
        struct vnet_port *port = netdev_priv(dev);

        return sunvnet_poll_controller_common(dev, port->vp);
}
#endif

static const struct net_device_ops vsw_ops = {
        .ndo_open               = ldmvsw_open,
        .ndo_stop               = sunvnet_close_common,
        .ndo_set_rx_mode        = vsw_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         = vsw_start_xmit,
        .ndo_select_queue       = vsw_select_queue,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = vsw_poll_controller,
#endif
};

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

static struct vnet *vsw_get_vnet(struct mdesc_handle *hp,
                                 u64 port_node,
                                 u64 *handle)
{
        struct vnet *vp;
        struct vnet *iter;
        const u64 *local_mac = NULL;
        const u64 *cfghandle = NULL;
        u64 a;

        /* Get the parent virtual-network-switch macaddr and cfghandle */
        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, "virtual-network-switch"))
                        continue;

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

        /* find or create associated vnet */
        vp = NULL;
        mutex_lock(&vnet_list_mutex);
        list_for_each_entry(iter, &vnet_list, list) {
                if (iter->local_mac == *local_mac) {
                        vp = iter;
                        break;
                }
        }

        if (!vp) {
                vp = kzalloc_obj(*vp);
                if (unlikely(!vp)) {
                        mutex_unlock(&vnet_list_mutex);
                        return ERR_PTR(-ENOMEM);
                }

                spin_lock_init(&vp->lock);
                INIT_LIST_HEAD(&vp->port_list);
                INIT_LIST_HEAD(&vp->list);
                vp->local_mac = *local_mac;
                list_add(&vp->list, &vnet_list);
        }

        mutex_unlock(&vnet_list_mutex);

        *handle = (u64)*cfghandle;

        return vp;
}

static struct net_device *vsw_alloc_netdev(u8 hwaddr[],
                                           struct vio_dev *vdev,
                                           u64 handle,
                                           u64 port_id)
{
        struct net_device *dev;
        struct vnet_port *port;

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

        eth_hw_addr_set(dev, hwaddr);
        ether_addr_copy(dev->perm_addr, dev->dev_addr);

        sprintf(dev->name, "vif%d.%d", (int)handle, (int)port_id);

        dev->netdev_ops = &vsw_ops;
        dev->ethtool_ops = &vsw_ethtool_ops;
        dev->watchdog_timeo = VSW_TX_TIMEOUT;

        dev->hw_features = 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);

        return dev;
}

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

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

static const char *remote_macaddr_prop = "remote-mac-address";
static const char *id_prop = "id";

static int vsw_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;
        struct net_device *dev;
        const u64 *rmac;
        int len, i, err;
        const u64 *port_id;
        u64 handle;

        hp = mdesc_grab();

        if (!hp)
                return -ENODEV;

        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);
                mdesc_release(hp);
                return err;
        }

        port_id = mdesc_get_property(hp, vdev->mp, id_prop, NULL);
        err = -ENODEV;
        if (!port_id) {
                pr_err("Port lacks %s property\n", id_prop);
                mdesc_release(hp);
                return err;
        }

        /* Get (or create) the vnet associated with this port */
        vp = vsw_get_vnet(hp, vdev->mp, &handle);
        if (IS_ERR(vp)) {
                err = PTR_ERR(vp);
                pr_err("Failed to get vnet for vsw-port\n");
                mdesc_release(hp);
                return err;
        }

        mdesc_release(hp);

        dev = vsw_alloc_netdev(vsw_port_hwaddr, vdev, handle, *port_id);
        if (IS_ERR(dev)) {
                err = PTR_ERR(dev);
                pr_err("Failed to alloc netdev for vsw-port\n");
                return err;
        }

        port = netdev_priv(dev);

        INIT_LIST_HEAD(&port->list);

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

        port->vp = vp;
        port->dev = dev;
        port->switch_port = 1;
        port->tso = false; /* no tso in vsw, misbehaves in bridge */
        port->tsolen = 0;

        /* Mark the port as belonging to ldmvsw which directs the
         * common code to use the net_device in the vnet_port
         * rather than the net_device in the vnet (which is used
         * by sunvnet). This bit is used by the VNET_PORT_TO_NET_DEVICE
         * macro.
         */
        port->vsw = 1;

        err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
                              vsw_versions, ARRAY_SIZE(vsw_versions),
                              &vsw_vio_ops, dev->name);
        if (err)
                goto err_out_free_dev;

        err = vio_ldc_alloc(&port->vio, &vsw_ldc_cfg, port);
        if (err)
                goto err_out_free_dev;

        dev_set_drvdata(&vdev->dev, port);

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

        spin_lock_irqsave(&vp->lock, flags);
        list_add_rcu(&port->list, &vp->port_list);
        spin_unlock_irqrestore(&vp->lock, flags);

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

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

        spin_lock_irqsave(&vp->lock, flags);
        sunvnet_port_add_txq_common(port);
        spin_unlock_irqrestore(&vp->lock, flags);

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

        /* assure no carrier until we receive an LDC_EVENT_UP,
         * even if the vsw config script tries to force us up
         */
        netif_carrier_off(dev);

        netdev_info(dev, "LDOM vsw-port %pM\n", dev->dev_addr);

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

        return 0;

err_out_del_timer:
        timer_delete_sync(&port->clean_timer);
        list_del_rcu(&port->list);
        synchronize_rcu();
        netif_napi_del(&port->napi);
        dev_set_drvdata(&vdev->dev, NULL);
        vio_ldc_free(&port->vio);

err_out_free_dev:
        free_netdev(dev);
        return err;
}

static void vsw_port_remove(struct vio_dev *vdev)
{
        struct vnet_port *port = dev_get_drvdata(&vdev->dev);
        unsigned long flags;

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

                napi_disable(&port->napi);
                unregister_netdev(port->dev);

                list_del_rcu(&port->list);

                synchronize_rcu();
                spin_lock_irqsave(&port->vp->lock, flags);
                sunvnet_port_rm_txq_common(port);
                spin_unlock_irqrestore(&port->vp->lock, flags);
                netif_napi_del(&port->napi);
                sunvnet_port_free_tx_bufs_common(port);
                vio_ldc_free(&port->vio);

                dev_set_drvdata(&vdev->dev, NULL);

                free_netdev(port->dev);
        }
}

static void vsw_cleanup(void)
{
        struct vnet *vp;

        /* just need to free up the vnet list */
        mutex_lock(&vnet_list_mutex);
        while (!list_empty(&vnet_list)) {
                vp = list_first_entry(&vnet_list, struct vnet, list);
                list_del(&vp->list);
                /* vio_unregister_driver() should have cleaned up port_list */
                if (!list_empty(&vp->port_list))
                        pr_err("Ports not removed by VIO subsystem!\n");
                kfree(vp);
        }
        mutex_unlock(&vnet_list_mutex);
}

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

static struct vio_driver vsw_port_driver = {
        .id_table       = vsw_port_match,
        .probe          = vsw_port_probe,
        .remove         = vsw_port_remove,
        .name           = "vsw_port",
};

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

static void __exit vsw_exit(void)
{
        vio_unregister_driver(&vsw_port_driver);
        vsw_cleanup();
}

module_init(vsw_init);
module_exit(vsw_exit);