Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 906 insertions, 0 deletions

diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c
new file mode 100644
index 000000000..a236532a9
--- /dev/null
+++ b/drivers/infiniband/core/multicast.c
@@ -0,0 +1,906 @@
+/*
+ * 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 int mcast_add_one(struct ib_device *device);
+static void mcast_remove_one(struct ib_device *device, void *client_data);
+
+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;
+	refcount_t		refcount;
+	struct completion	comp;
+	u32			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[];
+};
+
+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[NUM_JOIN_MEMBERSHIP_TYPES];
+	atomic_t		refcount;
+	enum mcast_group_state	state;
+	struct ib_sa_query	*query;
+	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;
+	refcount_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 (refcount_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 (refcount_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 four types of members: full member, non member,
+ * sendonly non member and sendonly full 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 < NUM_JOIN_MEMBERSHIP_TYPES; 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 < NUM_JOIN_MEMBERSHIP_TYPES; 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);
+	return (ret > 0) ? 0 : 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);
+	return (ret > 0) ? 0 : 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);
+		refcount_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;
+		refcount_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) {
+		refcount_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;
+
+		if (ib_find_pkey(group->port->dev->device,
+				 group->port->port_num, be16_to_cpu(rec->pkey),
+				 &pkey_index))
+			pkey_index = MCAST_INVALID_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
+		refcount_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, u32 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);
+	refcount_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, u32 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);
+
+/**
+ * ib_init_ah_from_mcmember - Initialize AH attribute from multicast
+ * member record and gid of the device.
+ * @device:	RDMA device
+ * @port_num:	Port of the rdma device to consider
+ * @rec:	Multicast member record to use
+ * @ndev:	Optional netdevice, applicable only for RoCE
+ * @gid_type:	GID type to consider
+ * @ah_attr:	AH attribute to fillup on successful completion
+ *
+ * ib_init_ah_from_mcmember() initializes AH attribute based on multicast
+ * member record and other device properties. On success the caller is
+ * responsible to call rdma_destroy_ah_attr on the ah_attr. Returns 0 on
+ * success or appropriate error code.
+ *
+ */
+int ib_init_ah_from_mcmember(struct ib_device *device, u32 port_num,
+			     struct ib_sa_mcmember_rec *rec,
+			     struct net_device *ndev,
+			     enum ib_gid_type gid_type,
+			     struct rdma_ah_attr *ah_attr)
+{
+	const struct ib_gid_attr *sgid_attr;
+
+	/* GID table is not based on the netdevice for IB link layer,
+	 * so ignore ndev during search.
+	 */
+	if (rdma_protocol_ib(device, port_num))
+		ndev = NULL;
+	else if (!rdma_protocol_roce(device, port_num))
+		return -EINVAL;
+
+	sgid_attr = rdma_find_gid_by_port(device, &rec->port_gid,
+					  gid_type, port_num, ndev);
+	if (IS_ERR(sgid_attr))
+		return PTR_ERR(sgid_attr);
+
+	memset(ah_attr, 0, sizeof(*ah_attr));
+	ah_attr->type = rdma_ah_find_type(device, port_num);
+
+	rdma_ah_set_dlid(ah_attr, be16_to_cpu(rec->mlid));
+	rdma_ah_set_sl(ah_attr, rec->sl);
+	rdma_ah_set_port_num(ah_attr, port_num);
+	rdma_ah_set_static_rate(ah_attr, rec->rate);
+	rdma_move_grh_sgid_attr(ah_attr, &rec->mgid,
+				be32_to_cpu(rec->flow_label),
+				rec->hop_limit,	rec->traffic_class,
+				sgid_attr);
+	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_cap_ib_mcast(dev->device, event->element.port_num))
+		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_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 int mcast_add_one(struct ib_device *device)
+{
+	struct mcast_device *dev;
+	struct mcast_port *port;
+	int i;
+	int count = 0;
+
+	dev = kmalloc(struct_size(dev, port, device->phys_port_cnt),
+		      GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->start_port = rdma_start_port(device);
+	dev->end_port = rdma_end_port(device);
+
+	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
+		if (!rdma_cap_ib_mcast(device, dev->start_port + i))
+			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);
+		refcount_set(&port->refcount, 1);
+		++count;
+	}
+
+	if (!count) {
+		kfree(dev);
+		return -EOPNOTSUPP;
+	}
+
+	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);
+	return 0;
+}
+
+static void mcast_remove_one(struct ib_device *device, void *client_data)
+{
+	struct mcast_device *dev = client_data;
+	struct mcast_port *port;
+	int i;
+
+	ib_unregister_event_handler(&dev->event_handler);
+	flush_workqueue(mcast_wq);
+
+	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
+		if (rdma_cap_ib_mcast(device, dev->start_port + i)) {
+			port = &dev->port[i];
+			deref_port(port);
+			wait_for_completion(&port->comp);
+		}
+	}
+
+	kfree(dev);
+}
+
+int mcast_init(void)
+{
+	int ret;
+
+	mcast_wq = alloc_ordered_workqueue("ib_mcast", WQ_MEM_RECLAIM);
+	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);
+}