Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / core / multicast.c
diff --git a/kernel/drivers/infiniband/core/multicast.c b/kernel/drivers/infiniband/core/multicast.c
new file mode 100644 (file)
index 0000000..fa17b55
--- /dev/null
@@ -0,0 +1,903 @@
+/*
+ * Copyright (c) 2006 Intel Corporation.  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 <linux/completion.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/random.h>
+
+#include <rdma/ib_cache.h>
+#include "sa.h"
+
+static void mcast_add_one(struct ib_device *device);
+static void mcast_remove_one(struct ib_device *device);
+
+static struct ib_client mcast_client = {
+       .name   = "ib_multicast",
+       .add    = mcast_add_one,
+       .remove = mcast_remove_one
+};
+
+static struct ib_sa_client     sa_client;
+static struct workqueue_struct *mcast_wq;
+static union ib_gid mgid0;
+
+struct mcast_device;
+
+struct mcast_port {
+       struct mcast_device     *dev;
+       spinlock_t              lock;
+       struct rb_root          table;
+       atomic_t                refcount;
+       struct completion       comp;
+       u8                      port_num;
+};
+
+struct mcast_device {
+       struct ib_device        *device;
+       struct ib_event_handler event_handler;
+       int                     start_port;
+       int                     end_port;
+       struct mcast_port       port[0];
+};
+
+enum mcast_state {
+       MCAST_JOINING,
+       MCAST_MEMBER,
+       MCAST_ERROR,
+};
+
+enum mcast_group_state {
+       MCAST_IDLE,
+       MCAST_BUSY,
+       MCAST_GROUP_ERROR,
+       MCAST_PKEY_EVENT
+};
+
+enum {
+       MCAST_INVALID_PKEY_INDEX = 0xFFFF
+};
+
+struct mcast_member;
+
+struct mcast_group {
+       struct ib_sa_mcmember_rec rec;
+       struct rb_node          node;
+       struct mcast_port       *port;
+       spinlock_t              lock;
+       struct work_struct      work;
+       struct list_head        pending_list;
+       struct list_head        active_list;
+       struct mcast_member     *last_join;
+       int                     members[3];
+       atomic_t                refcount;
+       enum mcast_group_state  state;
+       struct ib_sa_query      *query;
+       int                     query_id;
+       u16                     pkey_index;
+       u8                      leave_state;
+       int                     retries;
+};
+
+struct mcast_member {
+       struct ib_sa_multicast  multicast;
+       struct ib_sa_client     *client;
+       struct mcast_group      *group;
+       struct list_head        list;
+       enum mcast_state        state;
+       atomic_t                refcount;
+       struct completion       comp;
+};
+
+static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
+                        void *context);
+static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
+                         void *context);
+
+static struct mcast_group *mcast_find(struct mcast_port *port,
+                                     union ib_gid *mgid)
+{
+       struct rb_node *node = port->table.rb_node;
+       struct mcast_group *group;
+       int ret;
+
+       while (node) {
+               group = rb_entry(node, struct mcast_group, node);
+               ret = memcmp(mgid->raw, group->rec.mgid.raw, sizeof *mgid);
+               if (!ret)
+                       return group;
+
+               if (ret < 0)
+                       node = node->rb_left;
+               else
+                       node = node->rb_right;
+       }
+       return NULL;
+}
+
+static struct mcast_group *mcast_insert(struct mcast_port *port,
+                                       struct mcast_group *group,
+                                       int allow_duplicates)
+{
+       struct rb_node **link = &port->table.rb_node;
+       struct rb_node *parent = NULL;
+       struct mcast_group *cur_group;
+       int ret;
+
+       while (*link) {
+               parent = *link;
+               cur_group = rb_entry(parent, struct mcast_group, node);
+
+               ret = memcmp(group->rec.mgid.raw, cur_group->rec.mgid.raw,
+                            sizeof group->rec.mgid);
+               if (ret < 0)
+                       link = &(*link)->rb_left;
+               else if (ret > 0)
+                       link = &(*link)->rb_right;
+               else if (allow_duplicates)
+                       link = &(*link)->rb_left;
+               else
+                       return cur_group;
+       }
+       rb_link_node(&group->node, parent, link);
+       rb_insert_color(&group->node, &port->table);
+       return NULL;
+}
+
+static void deref_port(struct mcast_port *port)
+{
+       if (atomic_dec_and_test(&port->refcount))
+               complete(&port->comp);
+}
+
+static void release_group(struct mcast_group *group)
+{
+       struct mcast_port *port = group->port;
+       unsigned long flags;
+
+       spin_lock_irqsave(&port->lock, flags);
+       if (atomic_dec_and_test(&group->refcount)) {
+               rb_erase(&group->node, &port->table);
+               spin_unlock_irqrestore(&port->lock, flags);
+               kfree(group);
+               deref_port(port);
+       } else
+               spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void deref_member(struct mcast_member *member)
+{
+       if (atomic_dec_and_test(&member->refcount))
+               complete(&member->comp);
+}
+
+static void queue_join(struct mcast_member *member)
+{
+       struct mcast_group *group = member->group;
+       unsigned long flags;
+
+       spin_lock_irqsave(&group->lock, flags);
+       list_add_tail(&member->list, &group->pending_list);
+       if (group->state == MCAST_IDLE) {
+               group->state = MCAST_BUSY;
+               atomic_inc(&group->refcount);
+               queue_work(mcast_wq, &group->work);
+       }
+       spin_unlock_irqrestore(&group->lock, flags);
+}
+
+/*
+ * A multicast group has three types of members: full member, non member, and
+ * send only member.  We need to keep track of the number of members of each
+ * type based on their join state.  Adjust the number of members the belong to
+ * the specified join states.
+ */
+static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
+{
+       int i;
+
+       for (i = 0; i < 3; i++, join_state >>= 1)
+               if (join_state & 0x1)
+                       group->members[i] += inc;
+}
+
+/*
+ * If a multicast group has zero members left for a particular join state, but
+ * the group is still a member with the SA, we need to leave that join state.
+ * Determine which join states we still belong to, but that do not have any
+ * active members.
+ */
+static u8 get_leave_state(struct mcast_group *group)
+{
+       u8 leave_state = 0;
+       int i;
+
+       for (i = 0; i < 3; i++)
+               if (!group->members[i])
+                       leave_state |= (0x1 << i);
+
+       return leave_state & group->rec.join_state;
+}
+
+static int check_selector(ib_sa_comp_mask comp_mask,
+                         ib_sa_comp_mask selector_mask,
+                         ib_sa_comp_mask value_mask,
+                         u8 selector, u8 src_value, u8 dst_value)
+{
+       int err;
+
+       if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
+               return 0;
+
+       switch (selector) {
+       case IB_SA_GT:
+               err = (src_value <= dst_value);
+               break;
+       case IB_SA_LT:
+               err = (src_value >= dst_value);
+               break;
+       case IB_SA_EQ:
+               err = (src_value != dst_value);
+               break;
+       default:
+               err = 0;
+               break;
+       }
+
+       return err;
+}
+
+static int cmp_rec(struct ib_sa_mcmember_rec *src,
+                  struct ib_sa_mcmember_rec *dst, ib_sa_comp_mask comp_mask)
+{
+       /* MGID must already match */
+
+       if (comp_mask & IB_SA_MCMEMBER_REC_PORT_GID &&
+           memcmp(&src->port_gid, &dst->port_gid, sizeof src->port_gid))
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
+               return -EINVAL;
+       if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
+                          IB_SA_MCMEMBER_REC_MTU, dst->mtu_selector,
+                          src->mtu, dst->mtu))
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
+           src->traffic_class != dst->traffic_class)
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
+               return -EINVAL;
+       if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
+                          IB_SA_MCMEMBER_REC_RATE, dst->rate_selector,
+                          src->rate, dst->rate))
+               return -EINVAL;
+       if (check_selector(comp_mask,
+                          IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
+                          IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
+                          dst->packet_life_time_selector,
+                          src->packet_life_time, dst->packet_life_time))
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_SL && src->sl != dst->sl)
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
+           src->flow_label != dst->flow_label)
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
+           src->hop_limit != dst->hop_limit)
+               return -EINVAL;
+       if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE && src->scope != dst->scope)
+               return -EINVAL;
+
+       /* join_state checked separately, proxy_join ignored */
+
+       return 0;
+}
+
+static int send_join(struct mcast_group *group, struct mcast_member *member)
+{
+       struct mcast_port *port = group->port;
+       int ret;
+
+       group->last_join = member;
+       ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
+                                      port->port_num, IB_MGMT_METHOD_SET,
+                                      &member->multicast.rec,
+                                      member->multicast.comp_mask,
+                                      3000, GFP_KERNEL, join_handler, group,
+                                      &group->query);
+       if (ret >= 0) {
+               group->query_id = ret;
+               ret = 0;
+       }
+       return ret;
+}
+
+static int send_leave(struct mcast_group *group, u8 leave_state)
+{
+       struct mcast_port *port = group->port;
+       struct ib_sa_mcmember_rec rec;
+       int ret;
+
+       rec = group->rec;
+       rec.join_state = leave_state;
+       group->leave_state = leave_state;
+
+       ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
+                                      port->port_num, IB_SA_METHOD_DELETE, &rec,
+                                      IB_SA_MCMEMBER_REC_MGID     |
+                                      IB_SA_MCMEMBER_REC_PORT_GID |
+                                      IB_SA_MCMEMBER_REC_JOIN_STATE,
+                                      3000, GFP_KERNEL, leave_handler,
+                                      group, &group->query);
+       if (ret >= 0) {
+               group->query_id = ret;
+               ret = 0;
+       }
+       return ret;
+}
+
+static void join_group(struct mcast_group *group, struct mcast_member *member,
+                      u8 join_state)
+{
+       member->state = MCAST_MEMBER;
+       adjust_membership(group, join_state, 1);
+       group->rec.join_state |= join_state;
+       member->multicast.rec = group->rec;
+       member->multicast.rec.join_state = join_state;
+       list_move(&member->list, &group->active_list);
+}
+
+static int fail_join(struct mcast_group *group, struct mcast_member *member,
+                    int status)
+{
+       spin_lock_irq(&group->lock);
+       list_del_init(&member->list);
+       spin_unlock_irq(&group->lock);
+       return member->multicast.callback(status, &member->multicast);
+}
+
+static void process_group_error(struct mcast_group *group)
+{
+       struct mcast_member *member;
+       int ret = 0;
+       u16 pkey_index;
+
+       if (group->state == MCAST_PKEY_EVENT)
+               ret = ib_find_pkey(group->port->dev->device,
+                                  group->port->port_num,
+                                  be16_to_cpu(group->rec.pkey), &pkey_index);
+
+       spin_lock_irq(&group->lock);
+       if (group->state == MCAST_PKEY_EVENT && !ret &&
+           group->pkey_index == pkey_index)
+               goto out;
+
+       while (!list_empty(&group->active_list)) {
+               member = list_entry(group->active_list.next,
+                                   struct mcast_member, list);
+               atomic_inc(&member->refcount);
+               list_del_init(&member->list);
+               adjust_membership(group, member->multicast.rec.join_state, -1);
+               member->state = MCAST_ERROR;
+               spin_unlock_irq(&group->lock);
+
+               ret = member->multicast.callback(-ENETRESET,
+                                                &member->multicast);
+               deref_member(member);
+               if (ret)
+                       ib_sa_free_multicast(&member->multicast);
+               spin_lock_irq(&group->lock);
+       }
+
+       group->rec.join_state = 0;
+out:
+       group->state = MCAST_BUSY;
+       spin_unlock_irq(&group->lock);
+}
+
+static void mcast_work_handler(struct work_struct *work)
+{
+       struct mcast_group *group;
+       struct mcast_member *member;
+       struct ib_sa_multicast *multicast;
+       int status, ret;
+       u8 join_state;
+
+       group = container_of(work, typeof(*group), work);
+retest:
+       spin_lock_irq(&group->lock);
+       while (!list_empty(&group->pending_list) ||
+              (group->state != MCAST_BUSY)) {
+
+               if (group->state != MCAST_BUSY) {
+                       spin_unlock_irq(&group->lock);
+                       process_group_error(group);
+                       goto retest;
+               }
+
+               member = list_entry(group->pending_list.next,
+                                   struct mcast_member, list);
+               multicast = &member->multicast;
+               join_state = multicast->rec.join_state;
+               atomic_inc(&member->refcount);
+
+               if (join_state == (group->rec.join_state & join_state)) {
+                       status = cmp_rec(&group->rec, &multicast->rec,
+                                        multicast->comp_mask);
+                       if (!status)
+                               join_group(group, member, join_state);
+                       else
+                               list_del_init(&member->list);
+                       spin_unlock_irq(&group->lock);
+                       ret = multicast->callback(status, multicast);
+               } else {
+                       spin_unlock_irq(&group->lock);
+                       status = send_join(group, member);
+                       if (!status) {
+                               deref_member(member);
+                               return;
+                       }
+                       ret = fail_join(group, member, status);
+               }
+
+               deref_member(member);
+               if (ret)
+                       ib_sa_free_multicast(&member->multicast);
+               spin_lock_irq(&group->lock);
+       }
+
+       join_state = get_leave_state(group);
+       if (join_state) {
+               group->rec.join_state &= ~join_state;
+               spin_unlock_irq(&group->lock);
+               if (send_leave(group, join_state))
+                       goto retest;
+       } else {
+               group->state = MCAST_IDLE;
+               spin_unlock_irq(&group->lock);
+               release_group(group);
+       }
+}
+
+/*
+ * Fail a join request if it is still active - at the head of the pending queue.
+ */
+static void process_join_error(struct mcast_group *group, int status)
+{
+       struct mcast_member *member;
+       int ret;
+
+       spin_lock_irq(&group->lock);
+       member = list_entry(group->pending_list.next,
+                           struct mcast_member, list);
+       if (group->last_join == member) {
+               atomic_inc(&member->refcount);
+               list_del_init(&member->list);
+               spin_unlock_irq(&group->lock);
+               ret = member->multicast.callback(status, &member->multicast);
+               deref_member(member);
+               if (ret)
+                       ib_sa_free_multicast(&member->multicast);
+       } else
+               spin_unlock_irq(&group->lock);
+}
+
+static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
+                        void *context)
+{
+       struct mcast_group *group = context;
+       u16 pkey_index = MCAST_INVALID_PKEY_INDEX;
+
+       if (status)
+               process_join_error(group, status);
+       else {
+               int mgids_changed, is_mgid0;
+               ib_find_pkey(group->port->dev->device, group->port->port_num,
+                            be16_to_cpu(rec->pkey), &pkey_index);
+
+               spin_lock_irq(&group->port->lock);
+               if (group->state == MCAST_BUSY &&
+                   group->pkey_index == MCAST_INVALID_PKEY_INDEX)
+                       group->pkey_index = pkey_index;
+               mgids_changed = memcmp(&rec->mgid, &group->rec.mgid,
+                                      sizeof(group->rec.mgid));
+               group->rec = *rec;
+               if (mgids_changed) {
+                       rb_erase(&group->node, &group->port->table);
+                       is_mgid0 = !memcmp(&mgid0, &group->rec.mgid,
+                                          sizeof(mgid0));
+                       mcast_insert(group->port, group, is_mgid0);
+               }
+               spin_unlock_irq(&group->port->lock);
+       }
+       mcast_work_handler(&group->work);
+}
+
+static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
+                         void *context)
+{
+       struct mcast_group *group = context;
+
+       if (status && group->retries > 0 &&
+           !send_leave(group, group->leave_state))
+               group->retries--;
+       else
+               mcast_work_handler(&group->work);
+}
+
+static struct mcast_group *acquire_group(struct mcast_port *port,
+                                        union ib_gid *mgid, gfp_t gfp_mask)
+{
+       struct mcast_group *group, *cur_group;
+       unsigned long flags;
+       int is_mgid0;
+
+       is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
+       if (!is_mgid0) {
+               spin_lock_irqsave(&port->lock, flags);
+               group = mcast_find(port, mgid);
+               if (group)
+                       goto found;
+               spin_unlock_irqrestore(&port->lock, flags);
+       }
+
+       group = kzalloc(sizeof *group, gfp_mask);
+       if (!group)
+               return NULL;
+
+       group->retries = 3;
+       group->port = port;
+       group->rec.mgid = *mgid;
+       group->pkey_index = MCAST_INVALID_PKEY_INDEX;
+       INIT_LIST_HEAD(&group->pending_list);
+       INIT_LIST_HEAD(&group->active_list);
+       INIT_WORK(&group->work, mcast_work_handler);
+       spin_lock_init(&group->lock);
+
+       spin_lock_irqsave(&port->lock, flags);
+       cur_group = mcast_insert(port, group, is_mgid0);
+       if (cur_group) {
+               kfree(group);
+               group = cur_group;
+       } else
+               atomic_inc(&port->refcount);
+found:
+       atomic_inc(&group->refcount);
+       spin_unlock_irqrestore(&port->lock, flags);
+       return group;
+}
+
+/*
+ * We serialize all join requests to a single group to make our lives much
+ * easier.  Otherwise, two users could try to join the same group
+ * simultaneously, with different configurations, one could leave while the
+ * join is in progress, etc., which makes locking around error recovery
+ * difficult.
+ */
+struct ib_sa_multicast *
+ib_sa_join_multicast(struct ib_sa_client *client,
+                    struct ib_device *device, u8 port_num,
+                    struct ib_sa_mcmember_rec *rec,
+                    ib_sa_comp_mask comp_mask, gfp_t gfp_mask,
+                    int (*callback)(int status,
+                                    struct ib_sa_multicast *multicast),
+                    void *context)
+{
+       struct mcast_device *dev;
+       struct mcast_member *member;
+       struct ib_sa_multicast *multicast;
+       int ret;
+
+       dev = ib_get_client_data(device, &mcast_client);
+       if (!dev)
+               return ERR_PTR(-ENODEV);
+
+       member = kmalloc(sizeof *member, gfp_mask);
+       if (!member)
+               return ERR_PTR(-ENOMEM);
+
+       ib_sa_client_get(client);
+       member->client = client;
+       member->multicast.rec = *rec;
+       member->multicast.comp_mask = comp_mask;
+       member->multicast.callback = callback;
+       member->multicast.context = context;
+       init_completion(&member->comp);
+       atomic_set(&member->refcount, 1);
+       member->state = MCAST_JOINING;
+
+       member->group = acquire_group(&dev->port[port_num - dev->start_port],
+                                     &rec->mgid, gfp_mask);
+       if (!member->group) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
+       /*
+        * The user will get the multicast structure in their callback.  They
+        * could then free the multicast structure before we can return from
+        * this routine.  So we save the pointer to return before queuing
+        * any callback.
+        */
+       multicast = &member->multicast;
+       queue_join(member);
+       return multicast;
+
+err:
+       ib_sa_client_put(client);
+       kfree(member);
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(ib_sa_join_multicast);
+
+void ib_sa_free_multicast(struct ib_sa_multicast *multicast)
+{
+       struct mcast_member *member;
+       struct mcast_group *group;
+
+       member = container_of(multicast, struct mcast_member, multicast);
+       group = member->group;
+
+       spin_lock_irq(&group->lock);
+       if (member->state == MCAST_MEMBER)
+               adjust_membership(group, multicast->rec.join_state, -1);
+
+       list_del_init(&member->list);
+
+       if (group->state == MCAST_IDLE) {
+               group->state = MCAST_BUSY;
+               spin_unlock_irq(&group->lock);
+               /* Continue to hold reference on group until callback */
+               queue_work(mcast_wq, &group->work);
+       } else {
+               spin_unlock_irq(&group->lock);
+               release_group(group);
+       }
+
+       deref_member(member);
+       wait_for_completion(&member->comp);
+       ib_sa_client_put(member->client);
+       kfree(member);
+}
+EXPORT_SYMBOL(ib_sa_free_multicast);
+
+int ib_sa_get_mcmember_rec(struct ib_device *device, u8 port_num,
+                          union ib_gid *mgid, struct ib_sa_mcmember_rec *rec)
+{
+       struct mcast_device *dev;
+       struct mcast_port *port;
+       struct mcast_group *group;
+       unsigned long flags;
+       int ret = 0;
+
+       dev = ib_get_client_data(device, &mcast_client);
+       if (!dev)
+               return -ENODEV;
+
+       port = &dev->port[port_num - dev->start_port];
+       spin_lock_irqsave(&port->lock, flags);
+       group = mcast_find(port, mgid);
+       if (group)
+               *rec = group->rec;
+       else
+               ret = -EADDRNOTAVAIL;
+       spin_unlock_irqrestore(&port->lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(ib_sa_get_mcmember_rec);
+
+int ib_init_ah_from_mcmember(struct ib_device *device, u8 port_num,
+                            struct ib_sa_mcmember_rec *rec,
+                            struct ib_ah_attr *ah_attr)
+{
+       int ret;
+       u16 gid_index;
+       u8 p;
+
+       ret = ib_find_cached_gid(device, &rec->port_gid, &p, &gid_index);
+       if (ret)
+               return ret;
+
+       memset(ah_attr, 0, sizeof *ah_attr);
+       ah_attr->dlid = be16_to_cpu(rec->mlid);
+       ah_attr->sl = rec->sl;
+       ah_attr->port_num = port_num;
+       ah_attr->static_rate = rec->rate;
+
+       ah_attr->ah_flags = IB_AH_GRH;
+       ah_attr->grh.dgid = rec->mgid;
+
+       ah_attr->grh.sgid_index = (u8) gid_index;
+       ah_attr->grh.flow_label = be32_to_cpu(rec->flow_label);
+       ah_attr->grh.hop_limit = rec->hop_limit;
+       ah_attr->grh.traffic_class = rec->traffic_class;
+
+       return 0;
+}
+EXPORT_SYMBOL(ib_init_ah_from_mcmember);
+
+static void mcast_groups_event(struct mcast_port *port,
+                              enum mcast_group_state state)
+{
+       struct mcast_group *group;
+       struct rb_node *node;
+       unsigned long flags;
+
+       spin_lock_irqsave(&port->lock, flags);
+       for (node = rb_first(&port->table); node; node = rb_next(node)) {
+               group = rb_entry(node, struct mcast_group, node);
+               spin_lock(&group->lock);
+               if (group->state == MCAST_IDLE) {
+                       atomic_inc(&group->refcount);
+                       queue_work(mcast_wq, &group->work);
+               }
+               if (group->state != MCAST_GROUP_ERROR)
+                       group->state = state;
+               spin_unlock(&group->lock);
+       }
+       spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void mcast_event_handler(struct ib_event_handler *handler,
+                               struct ib_event *event)
+{
+       struct mcast_device *dev;
+       int index;
+
+       dev = container_of(handler, struct mcast_device, event_handler);
+       if (rdma_port_get_link_layer(dev->device, event->element.port_num) !=
+           IB_LINK_LAYER_INFINIBAND)
+               return;
+
+       index = event->element.port_num - dev->start_port;
+
+       switch (event->event) {
+       case IB_EVENT_PORT_ERR:
+       case IB_EVENT_LID_CHANGE:
+       case IB_EVENT_SM_CHANGE:
+       case IB_EVENT_CLIENT_REREGISTER:
+               mcast_groups_event(&dev->port[index], MCAST_GROUP_ERROR);
+               break;
+       case IB_EVENT_PKEY_CHANGE:
+               mcast_groups_event(&dev->port[index], MCAST_PKEY_EVENT);
+               break;
+       default:
+               break;
+       }
+}
+
+static void mcast_add_one(struct ib_device *device)
+{
+       struct mcast_device *dev;
+       struct mcast_port *port;
+       int i;
+       int count = 0;
+
+       if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
+               return;
+
+       dev = kmalloc(sizeof *dev + device->phys_port_cnt * sizeof *port,
+                     GFP_KERNEL);
+       if (!dev)
+               return;
+
+       if (device->node_type == RDMA_NODE_IB_SWITCH)
+               dev->start_port = dev->end_port = 0;
+       else {
+               dev->start_port = 1;
+               dev->end_port = device->phys_port_cnt;
+       }
+
+       for (i = 0; i <= dev->end_port - dev->start_port; i++) {
+               if (rdma_port_get_link_layer(device, dev->start_port + i) !=
+                   IB_LINK_LAYER_INFINIBAND)
+                       continue;
+               port = &dev->port[i];
+               port->dev = dev;
+               port->port_num = dev->start_port + i;
+               spin_lock_init(&port->lock);
+               port->table = RB_ROOT;
+               init_completion(&port->comp);
+               atomic_set(&port->refcount, 1);
+               ++count;
+       }
+
+       if (!count) {
+               kfree(dev);
+               return;
+       }
+
+       dev->device = device;
+       ib_set_client_data(device, &mcast_client, dev);
+
+       INIT_IB_EVENT_HANDLER(&dev->event_handler, device, mcast_event_handler);
+       ib_register_event_handler(&dev->event_handler);
+}
+
+static void mcast_remove_one(struct ib_device *device)
+{
+       struct mcast_device *dev;
+       struct mcast_port *port;
+       int i;
+
+       dev = ib_get_client_data(device, &mcast_client);
+       if (!dev)
+               return;
+
+       ib_unregister_event_handler(&dev->event_handler);
+       flush_workqueue(mcast_wq);
+
+       for (i = 0; i <= dev->end_port - dev->start_port; i++) {
+               if (rdma_port_get_link_layer(device, dev->start_port + i) ==
+                   IB_LINK_LAYER_INFINIBAND) {
+                       port = &dev->port[i];
+                       deref_port(port);
+                       wait_for_completion(&port->comp);
+               }
+       }
+
+       kfree(dev);
+}
+
+int mcast_init(void)
+{
+       int ret;
+
+       mcast_wq = create_singlethread_workqueue("ib_mcast");
+       if (!mcast_wq)
+               return -ENOMEM;
+
+       ib_sa_register_client(&sa_client);
+
+       ret = ib_register_client(&mcast_client);
+       if (ret)
+               goto err;
+       return 0;
+
+err:
+       ib_sa_unregister_client(&sa_client);
+       destroy_workqueue(mcast_wq);
+       return ret;
+}
+
+void mcast_cleanup(void)
+{
+       ib_unregister_client(&mcast_client);
+       ib_sa_unregister_client(&sa_client);
+       destroy_workqueue(mcast_wq);
+}