sunvnet.c

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/* sunvnet.c: Sun LDOM Virtual Network Driver.
 *
 * Copyright (C) 2007, 2008 David S. Miller <[email protected]>
 */

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

#include "sunvnet.h"

#define DRV_MODULE_NAME     "sunvnet"
#define DRV_MODULE_VERSION  "1.0"
#define DRV_MODULE_RELDATE  "June 25, 2007"

static char version[] __devinitdata =
    DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
MODULE_AUTHOR("David S. Miller ([email protected])");
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 = 0 },
};

static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
{
    return vio_dring_avail(dr, VNET_TX_RING_SIZE);
}

static int vnet_handle_unknown(struct vnet_port *port, void *arg)
{
    struct vio_msg_tag *pkt = arg;

    pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
           pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
    pr_err("Resetting connection\n");

    ldc_disconnect(port->vio.lp);

    return -ECONNRESET;
}

static int vnet_send_attr(struct vio_driver_state *vio)
{
    struct vnet_port *port = to_vnet_port(vio);
    struct net_device *dev = port->vp->dev;
    struct vio_net_attr_info pkt;
    int i;

    memset(&pkt, 0, sizeof(pkt));
    pkt.tag.type = VIO_TYPE_CTRL;
    pkt.tag.stype = VIO_SUBTYPE_INFO;
    pkt.tag.stype_env = VIO_ATTR_INFO;
    pkt.tag.sid = vio_send_sid(vio);
    pkt.xfer_mode = VIO_DRING_MODE;
    pkt.addr_type = VNET_ADDR_ETHERMAC;
    pkt.ack_freq = 0;
    for (i = 0; i < 6; i++)
        pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
    pkt.mtu = ETH_FRAME_LEN;

    viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
           "ackfreq[%u] mtu[%llu]\n",
           pkt.xfer_mode, pkt.addr_type,
           (unsigned long long) pkt.addr,
           pkt.ack_freq,
           (unsigned long long) pkt.mtu);

    return vio_ldc_send(vio, &pkt, sizeof(pkt));
}

static int handle_attr_info(struct vio_driver_state *vio,
                struct vio_net_attr_info *pkt)
{
    viodbg(HS, "GOT NET ATTR INFO xmode[0x%x] atype[0x%x] addr[%llx] "
           "ackfreq[%u] mtu[%llu]\n",
           pkt->xfer_mode, pkt->addr_type,
           (unsigned long long) pkt->addr,
           pkt->ack_freq,
           (unsigned long long) pkt->mtu);

    pkt->tag.sid = vio_send_sid(vio);

    if (pkt->xfer_mode != VIO_DRING_MODE ||
        pkt->addr_type != VNET_ADDR_ETHERMAC ||
        pkt->mtu != ETH_FRAME_LEN) {
        viodbg(HS, "SEND NET ATTR NACK\n");

        pkt->tag.stype = VIO_SUBTYPE_NACK;

        (void) vio_ldc_send(vio, pkt, sizeof(*pkt));

        return -ECONNRESET;
    } else {
        viodbg(HS, "SEND NET ATTR ACK\n");

        pkt->tag.stype = VIO_SUBTYPE_ACK;

        return vio_ldc_send(vio, pkt, sizeof(*pkt));
    }

}

static int handle_attr_ack(struct vio_driver_state *vio,
               struct vio_net_attr_info *pkt)
{
    viodbg(HS, "GOT NET ATTR ACK\n");

    return 0;
}

static int handle_attr_nack(struct vio_driver_state *vio,
                struct vio_net_attr_info *pkt)
{
    viodbg(HS, "GOT NET ATTR NACK\n");

    return -ECONNRESET;
}

static int vnet_handle_attr(struct vio_driver_state *vio, void *arg)
{
    struct vio_net_attr_info *pkt = arg;

    switch (pkt->tag.stype) {
    case VIO_SUBTYPE_INFO:
        return handle_attr_info(vio, pkt);

    case VIO_SUBTYPE_ACK:
        return handle_attr_ack(vio, pkt);

    case VIO_SUBTYPE_NACK:
        return handle_attr_nack(vio, pkt);

    default:
        return -ECONNRESET;
    }
}

static void vnet_handshake_complete(struct vio_driver_state *vio)
{
    struct vio_dring_state *dr;

    dr = &vio->drings[VIO_DRIVER_RX_RING];
    dr->snd_nxt = dr->rcv_nxt = 1;

    dr = &vio->drings[VIO_DRIVER_TX_RING];
    dr->snd_nxt = dr->rcv_nxt = 1;
}

/* The hypervisor interface that implements copying to/from imported
 * memory from another domain requires that copies are done to 8-byte
 * aligned buffers, and that the lengths of such copies are also 8-byte
 * multiples.
 *
 * So we align skb->data to an 8-byte multiple and pad-out the data
 * area so we can round the copy length up to the next multiple of
 * 8 for the copy.
 *
 * The transmitter puts the actual start of the packet 6 bytes into
 * the buffer it sends over, so that the IP headers after the ethernet
 * header are aligned properly.  These 6 bytes are not in the descriptor
 * length, they are simply implied.  This offset is represented using
 * the VNET_PACKET_SKIP macro.
 */
static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
                       unsigned int len)
{
    struct sk_buff *skb = netdev_alloc_skb(dev, len+VNET_PACKET_SKIP+8+8);
    unsigned long addr, off;

    if (unlikely(!skb))
        return NULL;

    addr = (unsigned long) skb->data;
    off = ((addr + 7UL) & ~7UL) - addr;
    if (off)
        skb_reserve(skb, off);

    return skb;
}

static int vnet_rx_one(struct vnet_port *port, unsigned int len,
               struct ldc_trans_cookie *cookies, int ncookies)
{
    struct net_device *dev = port->vp->dev;
    unsigned int copy_len;
    struct sk_buff *skb;
    int err;

    err = -EMSGSIZE;
    if (unlikely(len < ETH_ZLEN || len > ETH_FRAME_LEN)) {
        dev->stats.rx_length_errors++;
        goto out_dropped;
    }

    skb = alloc_and_align_skb(dev, len);
    err = -ENOMEM;
    if (unlikely(!skb)) {
        dev->stats.rx_missed_errors++;
        goto out_dropped;
    }

    copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
    skb_put(skb, copy_len);
    err = ldc_copy(port->vio.lp, LDC_COPY_IN,
               skb->data, copy_len, 0,
               cookies, ncookies);
    if (unlikely(err < 0)) {
        dev->stats.rx_frame_errors++;
        goto out_free_skb;
    }

    skb_pull(skb, VNET_PACKET_SKIP);
    skb_trim(skb, len);
    skb->protocol = eth_type_trans(skb, dev);

    dev->stats.rx_packets++;
    dev->stats.rx_bytes += len;

    netif_rx(skb);

    return 0;

out_free_skb:
    kfree_skb(skb);

out_dropped:
    dev->stats.rx_dropped++;
    return err;
}

static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
             u32 start, u32 end, u8 vio_dring_state)
{
    struct vio_dring_data hdr = {
        .tag = {
            .type       = VIO_TYPE_DATA,
            .stype      = VIO_SUBTYPE_ACK,
            .stype_env  = VIO_DRING_DATA,
            .sid        = vio_send_sid(&port->vio),
        },
        .dring_ident        = dr->ident,
        .start_idx      = start,
        .end_idx        = end,
        .state          = vio_dring_state,
    };
    int err, delay;

    hdr.seq = dr->snd_nxt;
    delay = 1;
    do {
        err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
        if (err > 0) {
            dr->snd_nxt++;
            break;
        }
        udelay(delay);
        if ((delay <<= 1) > 128)
            delay = 128;
    } while (err == -EAGAIN);

    return err;
}

static u32 next_idx(u32 idx, struct vio_dring_state *dr)
{
    if (++idx == dr->num_entries)
        idx = 0;
    return idx;
}

static u32 prev_idx(u32 idx, struct vio_dring_state *dr)
{
    if (idx == 0)
        idx = dr->num_entries - 1;
    else
        idx--;

    return idx;
}

static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
                    struct vio_dring_state *dr,
                    u32 index)
{
    struct vio_net_desc *desc = port->vio.desc_buf;
    int err;

    err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
                  (index * dr->entry_size),
                  dr->cookies, dr->ncookies);
    if (err < 0)
        return ERR_PTR(err);

    return desc;
}

static int put_rx_desc(struct vnet_port *port,
               struct vio_dring_state *dr,
               struct vio_net_desc *desc,
               u32 index)
{
    int err;

    err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
                  (index * dr->entry_size),
                  dr->cookies, dr->ncookies);
    if (err < 0)
        return err;

    return 0;
}

static int vnet_walk_rx_one(struct vnet_port *port,
                struct vio_dring_state *dr,
                u32 index, int *needs_ack)
{
    struct vio_net_desc *desc = get_rx_desc(port, dr, index);
    struct vio_driver_state *vio = &port->vio;
    int err;

    if (IS_ERR(desc))
        return PTR_ERR(desc);

    viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
           desc->hdr.state, desc->hdr.ack,
           desc->size, desc->ncookies,
           desc->cookies[0].cookie_addr,
           desc->cookies[0].cookie_size);

    if (desc->hdr.state != VIO_DESC_READY)
        return 1;
    err = vnet_rx_one(port, desc->size, desc->cookies, desc->ncookies);
    if (err == -ECONNRESET)
        return err;
    desc->hdr.state = VIO_DESC_DONE;
    err = put_rx_desc(port, dr, desc, index);
    if (err < 0)
        return err;
    *needs_ack = desc->hdr.ack;
    return 0;
}

static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
            u32 start, u32 end)
{
    struct vio_driver_state *vio = &port->vio;
    int ack_start = -1, ack_end = -1;

    end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);

    viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);

    while (start != end) {
        int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
        if (err == -ECONNRESET)
            return err;
        if (err != 0)
            break;
        if (ack_start == -1)
            ack_start = start;
        ack_end = start;
        start = next_idx(start, dr);
        if (ack && start != end) {
            err = vnet_send_ack(port, dr, ack_start, ack_end,
                        VIO_DRING_ACTIVE);
            if (err == -ECONNRESET)
                return err;
            ack_start = -1;
        }
    }
    if (unlikely(ack_start == -1))
        ack_start = ack_end = prev_idx(start, dr);
    return vnet_send_ack(port, dr, ack_start, ack_end, VIO_DRING_STOPPED);
}

static int vnet_rx(struct vnet_port *port, void *msgbuf)
{
    struct vio_dring_data *pkt = msgbuf;
    struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
    struct vio_driver_state *vio = &port->vio;

    viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
           pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);

    if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
        return 0;
    if (unlikely(pkt->seq != dr->rcv_nxt)) {
        pr_err("RX out of sequence seq[0x%llx] rcv_nxt[0x%llx]\n",
               pkt->seq, dr->rcv_nxt);
        return 0;
    }

    dr->rcv_nxt++;

    /* XXX Validate pkt->start_idx and pkt->end_idx XXX */

    return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx);
}

static int idx_is_pending(struct vio_dring_state *dr, u32 end)
{
    u32 idx = dr->cons;
    int found = 0;

    while (idx != dr->prod) {
        if (idx == end) {
            found = 1;
            break;
        }
        idx = next_idx(idx, dr);
    }
    return found;
}

static int vnet_ack(struct vnet_port *port, void *msgbuf)
{
    struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
    struct vio_dring_data *pkt = msgbuf;
    struct net_device *dev;
    struct vnet *vp;
    u32 end;

    if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
        return 0;

    end = pkt->end_idx;
    if (unlikely(!idx_is_pending(dr, end)))
        return 0;

    dr->cons = next_idx(end, dr);

    vp = port->vp;
    dev = vp->dev;
    if (unlikely(netif_queue_stopped(dev) &&
             vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
        return 1;

    return 0;
}

static int vnet_nack(struct vnet_port *port, void *msgbuf)
{
    /* XXX just reset or similar XXX */
    return 0;
}

static int handle_mcast(struct vnet_port *port, void *msgbuf)
{
    struct vio_net_mcast_info *pkt = msgbuf;

    if (pkt->tag.stype != VIO_SUBTYPE_ACK)
        pr_err("%s: Got unexpected MCAST reply [%02x:%02x:%04x:%08x]\n",
               port->vp->dev->name,
               pkt->tag.type,
               pkt->tag.stype,
               pkt->tag.stype_env,
               pkt->tag.sid);

    return 0;
}

static void maybe_tx_wakeup(struct vnet *vp)
{
    struct net_device *dev = vp->dev;

    netif_tx_lock(dev);
    if (likely(netif_queue_stopped(dev))) {
        struct vnet_port *port;
        int wake = 1;

        list_for_each_entry(port, &vp->port_list, list) {
            struct vio_dring_state *dr;

            dr = &port->vio.drings[VIO_DRIVER_TX_RING];
            if (vnet_tx_dring_avail(dr) <
                VNET_TX_WAKEUP_THRESH(dr)) {
                wake = 0;
                break;
            }
        }
        if (wake)
            netif_wake_queue(dev);
    }
    netif_tx_unlock(dev);
}

static void vnet_event(void *arg, int event)
{
    struct vnet_port *port = arg;
    struct vio_driver_state *vio = &port->vio;
    unsigned long flags;
    int tx_wakeup, err;

    spin_lock_irqsave(&vio->lock, flags);

    if (unlikely(event == LDC_EVENT_RESET ||
             event == LDC_EVENT_UP)) {
        vio_link_state_change(vio, event);
        spin_unlock_irqrestore(&vio->lock, flags);

        if (event == LDC_EVENT_RESET)
            vio_port_up(vio);
        return;
    }

    if (unlikely(event != LDC_EVENT_DATA_READY)) {
        pr_warning("Unexpected LDC event %d\n", event);
        spin_unlock_irqrestore(&vio->lock, flags);
        return;
    }

    tx_wakeup = err = 0;
    while (1) {
        union {
            struct vio_msg_tag tag;
            u64 raw[8];
        } msgbuf;

        err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
        if (unlikely(err < 0)) {
            if (err == -ECONNRESET)
                vio_conn_reset(vio);
            break;
        }
        if (err == 0)
            break;
        viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
               msgbuf.tag.type,
               msgbuf.tag.stype,
               msgbuf.tag.stype_env,
               msgbuf.tag.sid);
        err = vio_validate_sid(vio, &msgbuf.tag);
        if (err < 0)
            break;

        if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
            if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
                err = vnet_rx(port, &msgbuf);
            } else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
                err = vnet_ack(port, &msgbuf);
                if (err > 0)
                    tx_wakeup |= err;
            } else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
                err = vnet_nack(port, &msgbuf);
            }
        } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
            if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
                err = handle_mcast(port, &msgbuf);
            else
                err = vio_control_pkt_engine(vio, &msgbuf);
            if (err)
                break;
        } else {
            err = vnet_handle_unknown(port, &msgbuf);
        }
        if (err == -ECONNRESET)
            break;
    }
    spin_unlock(&vio->lock);
    if (unlikely(tx_wakeup && err != -ECONNRESET))
        maybe_tx_wakeup(port->vp);
    local_irq_restore(flags);
}

static int __vnet_tx_trigger(struct vnet_port *port)
{
    struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
    struct vio_dring_data hdr = {
        .tag = {
            .type       = VIO_TYPE_DATA,
            .stype      = VIO_SUBTYPE_INFO,
            .stype_env  = VIO_DRING_DATA,
            .sid        = vio_send_sid(&port->vio),
        },
        .dring_ident        = dr->ident,
        .start_idx      = dr->prod,
        .end_idx        = (u32) -1,
    };
    int err, delay;

    hdr.seq = dr->snd_nxt;
    delay = 1;
    do {
        err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
        if (err > 0) {
            dr->snd_nxt++;
            break;
        }
        udelay(delay);
        if ((delay <<= 1) > 128)
            delay = 128;
    } while (err == -EAGAIN);

    return err;
}

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 hlist_node *n;
    struct vnet_port *port;

    hlist_for_each_entry(port, n, hp, hash) {
        if (ether_addr_equal(port->raddr, skb->data))
            return port;
    }
    port = NULL;
    if (!list_empty(&vp->port_list))
        port = list_entry(vp->port_list.next, struct vnet_port, list);

    return port;
}

struct vnet_port *tx_port_find(struct vnet *vp, struct sk_buff *skb)
{
    struct vnet_port *ret;
    unsigned long flags;

    spin_lock_irqsave(&vp->lock, flags);
    ret = __tx_port_find(vp, skb);
    spin_unlock_irqrestore(&vp->lock, flags);

    return ret;
}

static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
    struct vnet *vp = netdev_priv(dev);
    struct vnet_port *port = tx_port_find(vp, skb);
    struct vio_dring_state *dr;
    struct vio_net_desc *d;
    unsigned long flags;
    unsigned int len;
    void *tx_buf;
    int i, err;

    if (unlikely(!port))
        goto out_dropped;

    spin_lock_irqsave(&port->vio.lock, flags);

    dr = &port->vio.drings[VIO_DRIVER_TX_RING];
    if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
        if (!netif_queue_stopped(dev)) {
            netif_stop_queue(dev);

            /* This is a hard error, log it. */
            netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
            dev->stats.tx_errors++;
        }
        spin_unlock_irqrestore(&port->vio.lock, flags);
        return NETDEV_TX_BUSY;
    }

    d = vio_dring_cur(dr);

    tx_buf = port->tx_bufs[dr->prod].buf;
    skb_copy_from_linear_data(skb, tx_buf + VNET_PACKET_SKIP, skb->len);

    len = skb->len;
    if (len < ETH_ZLEN) {
        len = ETH_ZLEN;
        memset(tx_buf+VNET_PACKET_SKIP+skb->len, 0, len - skb->len);
    }

    d->hdr.ack = VIO_ACK_ENABLE;
    d->size = len;
    d->ncookies = port->tx_bufs[dr->prod].ncookies;
    for (i = 0; i < d->ncookies; i++)
        d->cookies[i] = port->tx_bufs[dr->prod].cookies[i];

    /* This has to be a non-SMP write barrier because we are writing
     * to memory which is shared with the peer LDOM.
     */
    wmb();

    d->hdr.state = VIO_DESC_READY;

    err = __vnet_tx_trigger(port);
    if (unlikely(err < 0)) {
        netdev_info(dev, "TX trigger error %d\n", err);
        d->hdr.state = VIO_DESC_FREE;
        dev->stats.tx_carrier_errors++;
        goto out_dropped_unlock;
    }

    dev->stats.tx_packets++;
    dev->stats.tx_bytes += skb->len;

    dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
    if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
        netif_stop_queue(dev);
        if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
            netif_wake_queue(dev);
    }

    spin_unlock_irqrestore(&port->vio.lock, flags);

    dev_kfree_skb(skb);

    return NETDEV_TX_OK;

out_dropped_unlock:
    spin_unlock_irqrestore(&port->vio.lock, flags);

out_dropped:
    dev_kfree_skb(skb);
    dev->stats.tx_dropped++;
    return NETDEV_TX_OK;
}

static void vnet_tx_timeout(struct net_device *dev)
{
    /* XXX Implement me XXX */
}

static int vnet_open(struct net_device *dev)
{
    netif_carrier_on(dev);
    netif_start_queue(dev);

    return 0;
}

static int vnet_close(struct net_device *dev)
{
    netif_stop_queue(dev);
    netif_carrier_off(dev);

    return 0;
}

static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
{
    struct vnet_mcast_entry *m;

    for (m = vp->mcast_list; m; m = m->next) {
        if (!memcmp(m->addr, addr, ETH_ALEN))
            return m;
    }
    return NULL;
}

static void __update_mc_list(struct vnet *vp, struct net_device *dev)
{
    struct netdev_hw_addr *ha;

    netdev_for_each_mc_addr(ha, dev) {
        struct vnet_mcast_entry *m;

        m = __vnet_mc_find(vp, ha->addr);
        if (m) {
            m->hit = 1;
            continue;
        }

        if (!m) {
            m = kzalloc(sizeof(*m), GFP_ATOMIC);
            if (!m)
                continue;
            memcpy(m->addr, ha->addr, ETH_ALEN);
            m->hit = 1;

            m->next = vp->mcast_list;
            vp->mcast_list = m;
        }
    }
}

static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
{
    struct vio_net_mcast_info info;
    struct vnet_mcast_entry *m, **pp;
    int n_addrs;

    memset(&info, 0, sizeof(info));

    info.tag.type = VIO_TYPE_CTRL;
    info.tag.stype = VIO_SUBTYPE_INFO;
    info.tag.stype_env = VNET_MCAST_INFO;
    info.tag.sid = vio_send_sid(&port->vio);
    info.set = 1;

    n_addrs = 0;
    for (m = vp->mcast_list; m; m = m->next) {
        if (m->sent)
            continue;
        m->sent = 1;
        memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
               m->addr, ETH_ALEN);
        if (++n_addrs == VNET_NUM_MCAST) {
            info.count = n_addrs;

            (void) vio_ldc_send(&port->vio, &info,
                        sizeof(info));
            n_addrs = 0;
        }
    }
    if (n_addrs) {
        info.count = n_addrs;
        (void) vio_ldc_send(&port->vio, &info, sizeof(info));
    }

    info.set = 0;

    n_addrs = 0;
    pp = &vp->mcast_list;
    while ((m = *pp) != NULL) {
        if (m->hit) {
            m->hit = 0;
            pp = &m->next;
            continue;
        }

        memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
               m->addr, ETH_ALEN);
        if (++n_addrs == VNET_NUM_MCAST) {
            info.count = n_addrs;
            (void) vio_ldc_send(&port->vio, &info,
                        sizeof(info));
            n_addrs = 0;
        }

        *pp = m->next;
        kfree(m);
    }
    if (n_addrs) {
        info.count = n_addrs;
        (void) vio_ldc_send(&port->vio, &info, sizeof(info));
    }
}

static void vnet_set_rx_mode(struct net_device *dev)
{
    struct vnet *vp = netdev_priv(dev);
    struct vnet_port *port;
    unsigned long flags;

    spin_lock_irqsave(&vp->lock, flags);
    if (!list_empty(&vp->port_list)) {
        port = list_entry(vp->port_list.next, struct vnet_port, list);

        if (port->switch_port) {
            __update_mc_list(vp, dev);
            __send_mc_list(vp, port);
        }
    }
    spin_unlock_irqrestore(&vp->lock, flags);
}

static int vnet_change_mtu(struct net_device *dev, int new_mtu)
{
    if (new_mtu != ETH_DATA_LEN)
        return -EINVAL;

    dev->mtu = new_mtu;
    return 0;
}

static int vnet_set_mac_addr(struct net_device *dev, void *p)
{
    return -EINVAL;
}

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

static void vnet_port_free_tx_bufs(struct vnet_port *port)
{
    struct vio_dring_state *dr;
    int i;

    dr = &port->vio.drings[VIO_DRIVER_TX_RING];
    if (dr->base) {
        ldc_free_exp_dring(port->vio.lp, dr->base,
                   (dr->entry_size * dr->num_entries),
                   dr->cookies, dr->ncookies);
        dr->base = NULL;
        dr->entry_size = 0;
        dr->num_entries = 0;
        dr->pending = 0;
        dr->ncookies = 0;
    }

    for (i = 0; i < VNET_TX_RING_SIZE; i++) {
        void *buf = port->tx_bufs[i].buf;

        if (!buf)
            continue;

        ldc_unmap(port->vio.lp,
              port->tx_bufs[i].cookies,
              port->tx_bufs[i].ncookies);

        kfree(buf);
        port->tx_bufs[i].buf = NULL;
    }
}

static int __devinit vnet_port_alloc_tx_bufs(struct vnet_port *port)
{
    struct vio_dring_state *dr;
    unsigned long len;
    int i, err, ncookies;
    void *dring;

    for (i = 0; i < VNET_TX_RING_SIZE; i++) {
        void *buf = kzalloc(ETH_FRAME_LEN + 8, GFP_KERNEL);
        int map_len = (ETH_FRAME_LEN + 7) & ~7;

        err = -ENOMEM;
        if (!buf)
            goto err_out;

        err = -EFAULT;
        if ((unsigned long)buf & (8UL - 1)) {
            pr_err("TX buffer misaligned\n");
            kfree(buf);
            goto err_out;
        }

        err = ldc_map_single(port->vio.lp, buf, map_len,
                     port->tx_bufs[i].cookies, 2,
                     (LDC_MAP_SHADOW |
                      LDC_MAP_DIRECT |
                      LDC_MAP_RW));
        if (err < 0) {
            kfree(buf);
            goto err_out;
        }
        port->tx_bufs[i].buf = buf;
        port->tx_bufs[i].ncookies = err;
    }

    dr = &port->vio.drings[VIO_DRIVER_TX_RING];

    len = (VNET_TX_RING_SIZE *
           (sizeof(struct vio_net_desc) +
        (sizeof(struct ldc_trans_cookie) * 2)));

    ncookies = VIO_MAX_RING_COOKIES;
    dring = ldc_alloc_exp_dring(port->vio.lp, len,
                    dr->cookies, &ncookies,
                    (LDC_MAP_SHADOW |
                     LDC_MAP_DIRECT |
                     LDC_MAP_RW));
    if (IS_ERR(dring)) {
        err = PTR_ERR(dring);
        goto err_out;
    }

    dr->base = dring;
    dr->entry_size = (sizeof(struct vio_net_desc) +
              (sizeof(struct ldc_trans_cookie) * 2));
    dr->num_entries = VNET_TX_RING_SIZE;
    dr->prod = dr->cons = 0;
    dr->pending = VNET_TX_RING_SIZE;
    dr->ncookies = ncookies;

    return 0;

err_out:
    vnet_port_free_tx_bufs(port);

    return err;
}

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

static const struct net_device_ops vnet_ops = {
    .ndo_open       = vnet_open,
    .ndo_stop       = vnet_close,
    .ndo_set_rx_mode    = vnet_set_rx_mode,
    .ndo_set_mac_address    = vnet_set_mac_addr,
    .ndo_validate_addr  = eth_validate_addr,
    .ndo_tx_timeout     = vnet_tx_timeout,
    .ndo_change_mtu     = vnet_change_mtu,
    .ndo_start_xmit     = vnet_start_xmit,
};

static struct vnet * __devinit vnet_new(const u64 *local_mac)
{
    struct net_device *dev;
    struct vnet *vp;
    int err, i;

    dev = alloc_etherdev(sizeof(*vp));
    if (!dev)
        return ERR_PTR(-ENOMEM);

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

    memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);

    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;

    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 * __devinit vnet_find_or_create(const u64 *local_mac)
{
    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);
    mutex_unlock(&vnet_list_mutex);

    return vp;
}

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

static struct vnet * __devinit vnet_find_parent(struct mdesc_handle *hp,
                        u64 port_node)
{
    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);
}

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

static struct vio_driver_ops vnet_vio_ops = {
    .send_attr      = vnet_send_attr,
    .handle_attr        = vnet_handle_attr,
    .handshake_complete = vnet_handshake_complete,
};

static void __devinit print_version(void)
{
    printk_once(KERN_INFO "%s", version);
}

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

static int __devinit 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;

    print_version();

    hp = mdesc_grab();

    vp = vnet_find_parent(hp, vdev->mp);
    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(sizeof(*port), GFP_KERNEL);
    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;

    err = vnet_port_alloc_tx_bufs(port);
    if (err)
        goto err_out_free_ldc;

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

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

    spin_lock_irqsave(&vp->lock, flags);
    if (switch_port)
        list_add(&port->list, &vp->port_list);
    else
        list_add_tail(&port->list, &vp->port_list);
    hlist_add_head(&port->hash, &vp->port_hash[vnet_hashfn(port->raddr)]);
    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" : "");

    vio_port_up(&port->vio);

    mdesc_release(hp);

    return 0;

err_out_free_ldc:
    vio_ldc_free(&port->vio);

err_out_free_port:
    kfree(port);

err_out_put_mdesc:
    mdesc_release(hp);
    return err;
}

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

    if (port) {
        struct vnet *vp = port->vp;
        unsigned long flags;

        del_timer_sync(&port->vio.timer);

        spin_lock_irqsave(&vp->lock, flags);
        list_del(&port->list);
        hlist_del(&port->hash);
        spin_unlock_irqrestore(&vp->lock, flags);

        vnet_port_free_tx_bufs(port);
        vio_ldc_free(&port->vio);

        dev_set_drvdata(&vdev->dev, NULL);

        kfree(port);
    }
    return 0;
}

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)
{
    return vio_register_driver(&vnet_port_driver);
}

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

module_init(vnet_init);
module_exit(vnet_exit);