/*-
 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
 *
 * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2004 Voltaire, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <sys/cdefs.h>
#include "ipoib.h"

#include <linux/delay.h>
#include <linux/completion.h>

#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
static int mcast_debug_level = 1;

module_param(mcast_debug_level, int, 0644);
MODULE_PARM_DESC(mcast_debug_level,
                 "Enable multicast debug tracing if > 0");
#endif

static DEFINE_MUTEX(mcast_mutex);

struct ipoib_mcast_iter {
        struct ipoib_dev_priv *priv;
        union ib_gid       mgid;
        unsigned long      created;
        unsigned int       queuelen;
        unsigned int       complete;
        unsigned int       send_only;
};

static void ipoib_mcast_free(struct ipoib_mcast *mcast)
{
        if_t dev = mcast->priv->dev;
        int tx_dropped = 0;

        ipoib_dbg_mcast(mcast->priv, "deleting multicast group %16D\n",
                        mcast->mcmember.mgid.raw, ":");

        if (mcast->ah)
                ipoib_put_ah(mcast->ah);

        tx_dropped = mcast->pkt_queue.ifq_len;
        _IF_DRAIN(&mcast->pkt_queue);   /* XXX Locking. */

        if_inc_counter(dev, IFCOUNTER_OERRORS, tx_dropped);

        kfree(mcast);
}

static struct ipoib_mcast *ipoib_mcast_alloc(struct ipoib_dev_priv *priv,
                                             int can_sleep)
{
        struct ipoib_mcast *mcast;

        mcast = kzalloc(sizeof *mcast, can_sleep ? GFP_KERNEL : GFP_ATOMIC);
        if (!mcast)
                return NULL;

        mcast->priv = priv;
        mcast->created = jiffies;
        mcast->backoff = 1;

        INIT_LIST_HEAD(&mcast->list);
        bzero(&mcast->pkt_queue, sizeof(mcast->pkt_queue));

        return mcast;
}

static struct ipoib_mcast *__ipoib_mcast_find(struct ipoib_dev_priv *priv,
    void *mgid)
{
        struct rb_node *n = priv->multicast_tree.rb_node;

        while (n) {
                struct ipoib_mcast *mcast;
                int ret;

                mcast = rb_entry(n, struct ipoib_mcast, rb_node);

                ret = memcmp(mgid, mcast->mcmember.mgid.raw,
                             sizeof (union ib_gid));
                if (ret < 0)
                        n = n->rb_left;
                else if (ret > 0)
                        n = n->rb_right;
                else
                        return mcast;
        }

        return NULL;
}

static int __ipoib_mcast_add(struct ipoib_dev_priv *priv,
    struct ipoib_mcast *mcast)
{
        struct rb_node **n = &priv->multicast_tree.rb_node, *pn = NULL;

        while (*n) {
                struct ipoib_mcast *tmcast;
                int ret;

                pn = *n;
                tmcast = rb_entry(pn, struct ipoib_mcast, rb_node);

                ret = memcmp(mcast->mcmember.mgid.raw, tmcast->mcmember.mgid.raw,
                             sizeof (union ib_gid));
                if (ret < 0)
                        n = &pn->rb_left;
                else if (ret > 0)
                        n = &pn->rb_right;
                else
                        return -EEXIST;
        }

        rb_link_node(&mcast->rb_node, pn, n);
        rb_insert_color(&mcast->rb_node, &priv->multicast_tree);

        return 0;
}

static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
                                   struct ib_sa_mcmember_rec *mcmember)
{
        struct ipoib_dev_priv *priv = mcast->priv;
        if_t dev = priv->dev;
        struct ipoib_ah *ah;
        struct epoch_tracker et;
        int ret;
        int set_qkey = 0;

        mcast->mcmember = *mcmember;

        /* Set the cached Q_Key before we attach if it's the broadcast group */
        if (!memcmp(mcast->mcmember.mgid.raw, if_getbroadcastaddr(dev) + 4,
                    sizeof (union ib_gid))) {
                spin_lock_irq(&priv->lock);
                if (!priv->broadcast) {
                        spin_unlock_irq(&priv->lock);
                        return -EAGAIN;
                }
                priv->qkey = be32_to_cpu(priv->broadcast->mcmember.qkey);
                spin_unlock_irq(&priv->lock);
                priv->tx_wr.remote_qkey = priv->qkey;
                set_qkey = 1;
        }

        if (!test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
                if (test_and_set_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags)) {
                        ipoib_warn(priv, "multicast group %16D already attached\n",
                                   mcast->mcmember.mgid.raw, ":");

                        return 0;
                }

                ret = ipoib_mcast_attach(priv, be16_to_cpu(mcast->mcmember.mlid),
                                         &mcast->mcmember.mgid, set_qkey);
                if (ret < 0) {
                        ipoib_warn(priv, "couldn't attach QP to multicast group %16D\n",
                                   mcast->mcmember.mgid.raw, ":");

                        clear_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags);
                        return ret;
                }
        }

        {
                struct ib_ah_attr av = {
                        .dlid          = be16_to_cpu(mcast->mcmember.mlid),
                        .port_num      = priv->port,
                        .sl            = mcast->mcmember.sl,
                        .ah_flags      = IB_AH_GRH,
                        .static_rate   = mcast->mcmember.rate,
                        .grh           = {
                                .flow_label    = be32_to_cpu(mcast->mcmember.flow_label),
                                .hop_limit     = mcast->mcmember.hop_limit,
                                .sgid_index    = 0,
                                .traffic_class = mcast->mcmember.traffic_class
                        }
                };
                av.grh.dgid = mcast->mcmember.mgid;

                ah = ipoib_create_ah(priv, priv->pd, &av);
                if (!ah) {
                        ipoib_warn(priv, "ib_address_create failed\n");
                } else {
                        spin_lock_irq(&priv->lock);
                        mcast->ah = ah;
                        spin_unlock_irq(&priv->lock);

                        ipoib_dbg_mcast(priv, "MGID %16D AV %p, LID 0x%04x, SL %d\n",
                                        mcast->mcmember.mgid.raw, ":",
                                        mcast->ah->ah,
                                        be16_to_cpu(mcast->mcmember.mlid),
                                        mcast->mcmember.sl);
                }
        }

        NET_EPOCH_ENTER(et);

        /* actually send any queued packets */
        while (mcast->pkt_queue.ifq_len) {
                struct mbuf *mb;
                _IF_DEQUEUE(&mcast->pkt_queue, mb);
                mb->m_pkthdr.rcvif = dev;

                if (if_transmit(dev, mb))
                        ipoib_warn(priv, "dev_queue_xmit failed to requeue packet\n");
        }

        NET_EPOCH_EXIT(et);
        return 0;
}

static int
ipoib_mcast_sendonly_join_complete(int status,
                                   struct ib_sa_multicast *multicast)
{
        struct ipoib_mcast *mcast = multicast->context;
        struct ipoib_dev_priv *priv = mcast->priv;

        /* We trap for port events ourselves. */
        if (status == -ENETRESET)
                return 0;

        if (!status)
                status = ipoib_mcast_join_finish(mcast, &multicast->rec);

        if (status) {
                if (mcast->logcount++ < 20)
                        ipoib_dbg_mcast(priv, "multicast join failed for %16D, status %d\n",
                                        mcast->mcmember.mgid.raw, ":", status);

                /* Flush out any queued packets */
                if_inc_counter(priv->dev, IFCOUNTER_OERRORS, mcast->pkt_queue.ifq_len);
                _IF_DRAIN(&mcast->pkt_queue);

                /* Clear the busy flag so we try again */
                status = test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY,
                                            &mcast->flags);
        }
        return status;
}

static int ipoib_mcast_sendonly_join(struct ipoib_mcast *mcast)
{
        struct ipoib_dev_priv *priv = mcast->priv;
        struct ib_sa_mcmember_rec rec = {
#if 0                           /* Some SMs don't support send-only yet */
                .join_state = 4
#else
                .join_state = 1
#endif
        };
        int ret = 0;

        if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) {
                ipoib_dbg_mcast(priv, "device shutting down, no multicast joins\n");
                return -ENODEV;
        }

        if (test_and_set_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags)) {
                ipoib_dbg_mcast(priv, "multicast entry busy, skipping\n");
                return -EBUSY;
        }

        rec.mgid     = mcast->mcmember.mgid;
        rec.port_gid = priv->local_gid;
        rec.pkey     = cpu_to_be16(priv->pkey);

        mcast->mc = ib_sa_join_multicast(&ipoib_sa_client, priv->ca,
                                         priv->port, &rec,
                                         IB_SA_MCMEMBER_REC_MGID        |
                                         IB_SA_MCMEMBER_REC_PORT_GID    |
                                         IB_SA_MCMEMBER_REC_PKEY        |
                                         IB_SA_MCMEMBER_REC_JOIN_STATE,
                                         GFP_ATOMIC,
                                         ipoib_mcast_sendonly_join_complete,
                                         mcast);
        if (IS_ERR(mcast->mc)) {
                ret = PTR_ERR(mcast->mc);
                clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
                ipoib_warn(priv, "ib_sa_join_multicast failed (ret = %d)\n",
                           ret);
        } else {
                ipoib_dbg_mcast(priv, "no multicast record for %16D, starting join\n",
                                mcast->mcmember.mgid.raw, ":");
        }

        return ret;
}

void ipoib_mcast_carrier_on_task(struct work_struct *work)
{
        struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
                                                   carrier_on_task);
        struct ib_port_attr attr;

        /*
         * Take rtnl_lock to avoid racing with ipoib_stop() and
         * turning the carrier back on while a device is being
         * removed.
         */
        if (ib_query_port(priv->ca, priv->port, &attr) ||
            attr.state != IB_PORT_ACTIVE) {
                ipoib_dbg(priv, "Keeping carrier off until IB port is active\n");
                return;
        }
        if_link_state_change(priv->dev, LINK_STATE_UP);
}

static int ipoib_mcast_join_complete(int status,
                                     struct ib_sa_multicast *multicast)
{
        struct ipoib_mcast *mcast = multicast->context;
        struct ipoib_dev_priv *priv = mcast->priv;

        ipoib_dbg_mcast(priv, "join completion for %16D (status %d)\n",
                        mcast->mcmember.mgid.raw, ":", status);

        /* We trap for port events ourselves. */
        if (status == -ENETRESET)
                return 0;

        if (!status)
                status = ipoib_mcast_join_finish(mcast, &multicast->rec);

        if (!status) {
                mcast->backoff = 1;
                mutex_lock(&mcast_mutex);
                if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
                        queue_delayed_work(ipoib_workqueue,
                                           &priv->mcast_task, 0);
                mutex_unlock(&mcast_mutex);

                /*
                 * Defer carrier on work to ipoib_workqueue to avoid a
                 * deadlock on rtnl_lock here.
                 */
                if (mcast == priv->broadcast)
                        queue_work(ipoib_workqueue, &priv->carrier_on_task);

                return 0;
        }

        if (mcast->logcount++ < 20) {
                if (status == -ETIMEDOUT || status == -EAGAIN) {
                        ipoib_dbg_mcast(priv, "multicast join failed for %16D, status %d\n",
                                        mcast->mcmember.mgid.raw, ":", status);
                } else {
                        ipoib_warn(priv, "multicast join failed for %16D, status %d\n",
                                   mcast->mcmember.mgid.raw, ":", status);
                }
        }

        mcast->backoff *= 2;
        if (mcast->backoff > IPOIB_MAX_BACKOFF_SECONDS)
                mcast->backoff = IPOIB_MAX_BACKOFF_SECONDS;

        /* Clear the busy flag so we try again */
        status = test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);

        mutex_lock(&mcast_mutex);
        spin_lock_irq(&priv->lock);
        if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
                queue_delayed_work(ipoib_workqueue, &priv->mcast_task,
                                   mcast->backoff * HZ);
        spin_unlock_irq(&priv->lock);
        mutex_unlock(&mcast_mutex);

        return status;
}

static void ipoib_mcast_join(struct ipoib_dev_priv *priv,
    struct ipoib_mcast *mcast, int create)
{
        struct ib_sa_mcmember_rec rec = {
                .join_state = 1
        };
        ib_sa_comp_mask comp_mask;
        int ret = 0;

        ipoib_dbg_mcast(priv, "joining MGID %16D\n",
            mcast->mcmember.mgid.raw, ":");

        rec.mgid     = mcast->mcmember.mgid;
        rec.port_gid = priv->local_gid;
        rec.pkey     = cpu_to_be16(priv->pkey);

        comp_mask =
                IB_SA_MCMEMBER_REC_MGID         |
                IB_SA_MCMEMBER_REC_PORT_GID     |
                IB_SA_MCMEMBER_REC_PKEY         |
                IB_SA_MCMEMBER_REC_JOIN_STATE;

        if (create) {
                comp_mask |=
                        IB_SA_MCMEMBER_REC_QKEY                 |
                        IB_SA_MCMEMBER_REC_MTU_SELECTOR         |
                        IB_SA_MCMEMBER_REC_MTU                  |
                        IB_SA_MCMEMBER_REC_TRAFFIC_CLASS        |
                        IB_SA_MCMEMBER_REC_RATE_SELECTOR        |
                        IB_SA_MCMEMBER_REC_RATE                 |
                        IB_SA_MCMEMBER_REC_SL                   |
                        IB_SA_MCMEMBER_REC_FLOW_LABEL           |
                        IB_SA_MCMEMBER_REC_HOP_LIMIT;

                rec.qkey          = priv->broadcast->mcmember.qkey;
                rec.mtu_selector  = IB_SA_EQ;
                rec.mtu           = priv->broadcast->mcmember.mtu;
                rec.traffic_class = priv->broadcast->mcmember.traffic_class;
                rec.rate_selector = IB_SA_EQ;
                rec.rate          = priv->broadcast->mcmember.rate;
                rec.sl            = priv->broadcast->mcmember.sl;
                rec.flow_label    = priv->broadcast->mcmember.flow_label;
                rec.hop_limit     = priv->broadcast->mcmember.hop_limit;
        }

        set_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
        mcast->mc = ib_sa_join_multicast(&ipoib_sa_client, priv->ca, priv->port,
                                         &rec, comp_mask, GFP_KERNEL,
                                         ipoib_mcast_join_complete, mcast);
        if (IS_ERR(mcast->mc)) {
                clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags);
                ret = PTR_ERR(mcast->mc);
                ipoib_warn(priv, "ib_sa_join_multicast failed, status %d\n", ret);

                mcast->backoff *= 2;
                if (mcast->backoff > IPOIB_MAX_BACKOFF_SECONDS)
                        mcast->backoff = IPOIB_MAX_BACKOFF_SECONDS;

                mutex_lock(&mcast_mutex);
                if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
                        queue_delayed_work(ipoib_workqueue,
                                           &priv->mcast_task,
                                           mcast->backoff * HZ);
                mutex_unlock(&mcast_mutex);
        }
}

void ipoib_mcast_join_task(struct work_struct *work)
{
        struct ipoib_dev_priv *priv =
                container_of(work, struct ipoib_dev_priv, mcast_task.work);
        if_t dev = priv->dev;
        struct ib_port_attr attr;

        ipoib_dbg_mcast(priv, "Running join task. flags 0x%lX\n", priv->flags);

        if (!test_bit(IPOIB_MCAST_RUN, &priv->flags))
                return;

        if (ib_query_port(priv->ca, priv->port, &attr) ||
            attr.state != IB_PORT_ACTIVE) {
                ipoib_dbg(priv, "%s: port state is not ACTIVE (state = %d) suspend task.\n",
                          __func__, attr.state);
                return;
        }

        if (ib_query_gid(priv->ca, priv->port, 0, &priv->local_gid, NULL))
                ipoib_warn(priv, "ib_query_gid() failed\n");
        else
                memcpy(if_getlladdr(dev) + 4, priv->local_gid.raw, sizeof (union ib_gid));

        {
                struct ib_port_attr attr;

                if (!ib_query_port(priv->ca, priv->port, &attr))
                        priv->local_lid = attr.lid;
                else
                        ipoib_warn(priv, "ib_query_port failed\n");
        }

        if (!priv->broadcast) {
                struct ipoib_mcast *broadcast;

                if (!test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
                        return;

                broadcast = ipoib_mcast_alloc(priv, 1);
                if (!broadcast) {
                        ipoib_warn(priv, "failed to allocate broadcast group\n");
                        mutex_lock(&mcast_mutex);
                        if (test_bit(IPOIB_MCAST_RUN, &priv->flags))
                                queue_delayed_work(ipoib_workqueue,
                                                   &priv->mcast_task, HZ);
                        mutex_unlock(&mcast_mutex);
                        return;
                }

                spin_lock_irq(&priv->lock);
                memcpy(broadcast->mcmember.mgid.raw, if_getbroadcastaddr(dev) + 4,
                       sizeof (union ib_gid));
                priv->broadcast = broadcast;

                __ipoib_mcast_add(priv, priv->broadcast);
                spin_unlock_irq(&priv->lock);
        }

        if (priv->broadcast &&
            !test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
                if (priv->broadcast &&
                    !test_bit(IPOIB_MCAST_FLAG_BUSY, &priv->broadcast->flags))
                        ipoib_mcast_join(priv, priv->broadcast, 0);
                return;
        }

        while (1) {
                struct ipoib_mcast *mcast = NULL;

                spin_lock_irq(&priv->lock);
                list_for_each_entry(mcast, &priv->multicast_list, list) {
                        if (!test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)
                            && !test_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags)
                            && !test_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags)) {
                                /* Found the next unjoined group */
                                break;
                        }
                }
                spin_unlock_irq(&priv->lock);

                if (&mcast->list == &priv->multicast_list) {
                        /* All done */
                        break;
                }

                ipoib_mcast_join(priv, mcast, 1);
                return;
        }

        spin_lock_irq(&priv->lock);
        if (priv->broadcast)
                priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
        else
                priv->mcast_mtu = priv->admin_mtu;
        spin_unlock_irq(&priv->lock);

        if (!ipoib_cm_admin_enabled(priv))
                ipoib_change_mtu(priv, min(priv->mcast_mtu, priv->admin_mtu),
                    true);

        ipoib_dbg_mcast(priv, "successfully joined all multicast groups\n");

        clear_bit(IPOIB_MCAST_RUN, &priv->flags);
}

int ipoib_mcast_start_thread(struct ipoib_dev_priv *priv)
{
        ipoib_dbg_mcast(priv, "starting multicast thread flags 0x%lX\n",
            priv->flags);

        mutex_lock(&mcast_mutex);
        if (!test_and_set_bit(IPOIB_MCAST_RUN, &priv->flags))
                queue_delayed_work(ipoib_workqueue, &priv->mcast_task, 0);
        mutex_unlock(&mcast_mutex);

        return 0;
}

int ipoib_mcast_stop_thread(struct ipoib_dev_priv *priv, int flush)
{

        ipoib_dbg_mcast(priv, "stopping multicast thread\n");

        mutex_lock(&mcast_mutex);
        clear_bit(IPOIB_MCAST_RUN, &priv->flags);
        cancel_delayed_work(&priv->mcast_task);
        mutex_unlock(&mcast_mutex);

        if (flush)
                flush_workqueue(ipoib_workqueue);

        return 0;
}

static int ipoib_mcast_leave(struct ipoib_dev_priv *priv, struct ipoib_mcast *mcast)
{
        int ret = 0;

        if (test_and_clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
                ib_sa_free_multicast(mcast->mc);

        if (test_and_clear_bit(IPOIB_MCAST_FLAG_ATTACHED, &mcast->flags)) {
                ipoib_dbg_mcast(priv, "leaving MGID %16D\n",
                                mcast->mcmember.mgid.raw, ":");

                /* Remove ourselves from the multicast group */
                ret = ib_detach_mcast(priv->qp, &mcast->mcmember.mgid,
                                      be16_to_cpu(mcast->mcmember.mlid));
                if (ret)
                        ipoib_warn(priv, "ib_detach_mcast failed (result = %d)\n", ret);
        }

        return 0;
}

void
ipoib_mcast_send(struct ipoib_dev_priv *priv, void *mgid, struct mbuf *mb)
{
        if_t dev = priv->dev;
        struct ipoib_mcast *mcast;

        if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)         ||
            !priv->broadcast                                    ||
            !test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
                if_inc_counter(dev, IFCOUNTER_OERRORS, 1);
                m_freem(mb);
                return;
        }

        mcast = __ipoib_mcast_find(priv, mgid);
        if (!mcast) {
                /* Let's create a new send only group now */
                ipoib_dbg_mcast(priv, "setting up send only multicast group for %16D\n",
                                mgid, ":");

                mcast = ipoib_mcast_alloc(priv, 0);
                if (!mcast) {
                        ipoib_warn(priv, "unable to allocate memory for "
                                   "multicast structure\n");
                        if_inc_counter(dev, IFCOUNTER_OERRORS, 1);
                        m_freem(mb);
                        goto out;
                }

                set_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags);
                memcpy(mcast->mcmember.mgid.raw, mgid, sizeof (union ib_gid));
                __ipoib_mcast_add(priv, mcast);
                list_add_tail(&mcast->list, &priv->multicast_list);
        }

        if (!mcast->ah) {
                if (mcast->pkt_queue.ifq_len < IPOIB_MAX_MCAST_QUEUE) {
                        _IF_ENQUEUE(&mcast->pkt_queue, mb);
                } else {
                        if_inc_counter(dev, IFCOUNTER_OERRORS, 1);
                        m_freem(mb);
                }

                if (test_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags))
                        ipoib_dbg_mcast(priv, "no address vector, "
                                        "but multicast join already started\n");
                else if (test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags))
                        ipoib_mcast_sendonly_join(mcast);

                /*
                 * If lookup completes between here and out:, don't
                 * want to send packet twice.
                 */
                mcast = NULL;
        }

out:
        if (mcast && mcast->ah)
                ipoib_send(priv, mb, mcast->ah, IB_MULTICAST_QPN);
}

void ipoib_mcast_dev_flush(struct ipoib_dev_priv *priv)
{
        LIST_HEAD(remove_list);
        struct ipoib_mcast *mcast, *tmcast;
        unsigned long flags;

        ipoib_dbg_mcast(priv, "flushing multicast list\n");

        spin_lock_irqsave(&priv->lock, flags);

        list_for_each_entry_safe(mcast, tmcast, &priv->multicast_list, list) {
                list_del(&mcast->list);
                rb_erase(&mcast->rb_node, &priv->multicast_tree);
                list_add_tail(&mcast->list, &remove_list);
        }

        if (priv->broadcast) {
                rb_erase(&priv->broadcast->rb_node, &priv->multicast_tree);
                list_add_tail(&priv->broadcast->list, &remove_list);
                priv->broadcast = NULL;
        }

        spin_unlock_irqrestore(&priv->lock, flags);

        list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {
                ipoib_mcast_leave(priv, mcast);
                ipoib_mcast_free(mcast);
        }
}

static int ipoib_mcast_addr_is_valid(const u8 *addr, unsigned int addrlen,
                                     const u8 *broadcast)
{
        if (addrlen != INFINIBAND_ALEN)
                return 0;
        /* reserved QPN, prefix, scope */
        if (memcmp(addr, broadcast, 6))
                return 0;
        /* signature lower, pkey */
        if (memcmp(addr + 7, broadcast + 7, 3))
                return 0;
        return 1;
}

void ipoib_mcast_restart_task(struct work_struct *work)
{
        struct ipoib_dev_priv *priv =
                container_of(work, struct ipoib_dev_priv, restart_task);
        ipoib_mcast_restart(priv);
}

struct ipoib_mcast_ctx {
        struct ipoib_dev_priv *priv;
        struct list_head remove_list;
};

static u_int
ipoib_process_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
{
        struct ipoib_mcast_ctx *ctx = arg;
        struct ipoib_dev_priv *priv = ctx->priv;
        struct ipoib_mcast *mcast;
        struct ib_sa_mcmember_rec rec;
        union ib_gid mgid;
        uint8_t *addr;
        int addrlen;

        addr = LLADDR(sdl);
        addrlen = sdl->sdl_alen;
        if (!ipoib_mcast_addr_is_valid(addr, addrlen,
            if_getbroadcastaddr(priv->dev)))
                return (0);

        memcpy(mgid.raw, addr + 4, sizeof mgid);

        mcast = __ipoib_mcast_find(priv, &mgid);
        if (!mcast || test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
                struct ipoib_mcast *nmcast;

                /* ignore group which is directly joined by userspace */
                if (test_bit(IPOIB_FLAG_UMCAST, &priv->flags) &&
                    !ib_sa_get_mcmember_rec(priv->ca, priv->port, &mgid, &rec)) {
                        ipoib_dbg_mcast(priv, "ignoring multicast entry for mgid %16D\n",
                                        mgid.raw, ":");
                        return (0);
                }

                /* Not found or send-only group, let's add a new entry */
                ipoib_dbg_mcast(priv, "adding multicast entry for mgid %16D\n",
                                mgid.raw, ":");

                nmcast = ipoib_mcast_alloc(priv, 0);
                if (!nmcast) {
                        ipoib_warn(priv, "unable to allocate memory for multicast structure\n");
                        return (0);
                }

                set_bit(IPOIB_MCAST_FLAG_FOUND, &nmcast->flags);

                nmcast->mcmember.mgid = mgid;

                if (mcast) {
                        /* Destroy the send only entry */
                        list_move_tail(&mcast->list, &ctx->remove_list);

                        rb_replace_node(&mcast->rb_node,
                                        &nmcast->rb_node,
                                        &priv->multicast_tree);
                } else
                        __ipoib_mcast_add(priv, nmcast);

                list_add_tail(&nmcast->list, &priv->multicast_list);
        }

        if (mcast)
                set_bit(IPOIB_MCAST_FLAG_FOUND, &mcast->flags);

        return (1);
}

void ipoib_mcast_restart(struct ipoib_dev_priv *priv)
{
        struct ipoib_mcast_ctx ctx = { priv,
            { &ctx.remove_list, &ctx.remove_list }};
        if_t dev = priv->dev;
        struct ipoib_mcast *mcast, *tmcast;

        ipoib_dbg_mcast(priv, "restarting multicast task flags 0x%lX\n",
            priv->flags);

        ipoib_mcast_stop_thread(priv, 0);

        spin_lock(&priv->lock);

        /*
         * Unfortunately, the networking core only gives us a list of all of
         * the multicast hardware addresses. We need to figure out which ones
         * are new and which ones have been removed
         */

        /* Clear out the found flag */
        list_for_each_entry(mcast, &priv->multicast_list, list)
                clear_bit(IPOIB_MCAST_FLAG_FOUND, &mcast->flags);

        /* Mark all of the entries that are found or don't exist */
        ctx.priv = priv;
        if_foreach_llmaddr(dev, ipoib_process_maddr, &ctx);

        /* Remove all of the entries don't exist anymore */
        list_for_each_entry_safe(mcast, tmcast, &priv->multicast_list, list) {
                if (!test_bit(IPOIB_MCAST_FLAG_FOUND, &mcast->flags) &&
                    !test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
                        ipoib_dbg_mcast(priv, "deleting multicast group %16D\n",
                                        mcast->mcmember.mgid.raw, ":");

                        rb_erase(&mcast->rb_node, &priv->multicast_tree);

                        /* Move to the remove list */
                        list_move_tail(&mcast->list, &ctx.remove_list);
                }
        }

        spin_unlock(&priv->lock);

        /* We have to cancel outside of the spinlock */
        list_for_each_entry_safe(mcast, tmcast, &ctx.remove_list, list) {
                ipoib_mcast_leave(mcast->priv, mcast);
                ipoib_mcast_free(mcast);
        }

        if (test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
                ipoib_mcast_start_thread(priv);
}

#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG

struct ipoib_mcast_iter *ipoib_mcast_iter_init(struct ipoib_dev_priv *priv)
{
        struct ipoib_mcast_iter *iter;

        iter = kmalloc(sizeof *iter, GFP_KERNEL);
        if (!iter)
                return NULL;

        iter->priv = priv;
        memset(iter->mgid.raw, 0, 16);

        if (ipoib_mcast_iter_next(iter)) {
                kfree(iter);
                return NULL;
        }

        return iter;
}

int ipoib_mcast_iter_next(struct ipoib_mcast_iter *iter)
{
        struct ipoib_dev_priv *priv = iter->priv;
        struct rb_node *n;
        struct ipoib_mcast *mcast;
        int ret = 1;

        spin_lock_irq(&priv->lock);

        n = rb_first(&priv->multicast_tree);

        while (n) {
                mcast = rb_entry(n, struct ipoib_mcast, rb_node);

                if (memcmp(iter->mgid.raw, mcast->mcmember.mgid.raw,
                           sizeof (union ib_gid)) < 0) {
                        iter->mgid      = mcast->mcmember.mgid;
                        iter->created   = mcast->created;
                        iter->queuelen  = mcast->pkt_queue.ifq_len;
                        iter->complete  = !!mcast->ah;
                        iter->send_only = !!(mcast->flags & (1 << IPOIB_MCAST_FLAG_SENDONLY));

                        ret = 0;

                        break;
                }

                n = rb_next(n);
        }

        spin_unlock_irq(&priv->lock);

        return ret;
}

void ipoib_mcast_iter_read(struct ipoib_mcast_iter *iter,
                           union ib_gid *mgid,
                           unsigned long *created,
                           unsigned int *queuelen,
                           unsigned int *complete,
                           unsigned int *send_only)
{
        *mgid      = iter->mgid;
        *created   = iter->created;
        *queuelen  = iter->queuelen;
        *complete  = iter->complete;
        *send_only = iter->send_only;
}

#endif /* CONFIG_INFINIBAND_IPOIB_DEBUG */