Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 1257 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx4/mcg.c b/drivers/infiniband/hw/mlx4/mcg.c
new file mode 100644
index 000000000..5e4ec9786
--- /dev/null
+++ b/drivers/infiniband/hw/mlx4/mcg.c
@@ -0,0 +1,1257 @@
+/*
+ * Copyright (c) 2012 Mellanox Technologies. 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 <rdma/ib_mad.h>
+#include <rdma/ib_smi.h>
+#include <rdma/ib_cache.h>
+#include <rdma/ib_sa.h>
+
+#include <linux/mlx4/cmd.h>
+#include <linux/rbtree.h>
+#include <linux/delay.h>
+
+#include "mlx4_ib.h"
+
+#define MAX_VFS		80
+#define MAX_PEND_REQS_PER_FUNC 4
+#define MAD_TIMEOUT_MS	2000
+
+#define mcg_warn(fmt, arg...)	pr_warn("MCG WARNING: " fmt, ##arg)
+#define mcg_error(fmt, arg...)	pr_err(fmt, ##arg)
+#define mcg_warn_group(group, format, arg...) \
+	pr_warn("%s-%d: %16s (port %d): WARNING: " format, __func__, __LINE__,\
+	(group)->name, group->demux->port, ## arg)
+
+#define mcg_debug_group(group, format, arg...) \
+	pr_debug("%s-%d: %16s (port %d): WARNING: " format, __func__, __LINE__,\
+		 (group)->name, (group)->demux->port, ## arg)
+
+#define mcg_error_group(group, format, arg...) \
+	pr_err("  %16s: " format, (group)->name, ## arg)
+
+
+static union ib_gid mgid0;
+
+static struct workqueue_struct *clean_wq;
+
+enum mcast_state {
+	MCAST_NOT_MEMBER = 0,
+	MCAST_MEMBER,
+};
+
+enum mcast_group_state {
+	MCAST_IDLE,
+	MCAST_JOIN_SENT,
+	MCAST_LEAVE_SENT,
+	MCAST_RESP_READY
+};
+
+struct mcast_member {
+	enum mcast_state state;
+	uint8_t			join_state;
+	int			num_pend_reqs;
+	struct list_head	pending;
+};
+
+struct ib_sa_mcmember_data {
+	union ib_gid	mgid;
+	union ib_gid	port_gid;
+	__be32		qkey;
+	__be16		mlid;
+	u8		mtusel_mtu;
+	u8		tclass;
+	__be16		pkey;
+	u8		ratesel_rate;
+	u8		lifetmsel_lifetm;
+	__be32		sl_flowlabel_hoplimit;
+	u8		scope_join_state;
+	u8		proxy_join;
+	u8		reserved[2];
+} __packed __aligned(4);
+
+struct mcast_group {
+	struct ib_sa_mcmember_data rec;
+	struct rb_node		node;
+	struct list_head	mgid0_list;
+	struct mlx4_ib_demux_ctx *demux;
+	struct mcast_member	func[MAX_VFS];
+	struct mutex		lock;
+	struct work_struct	work;
+	struct list_head	pending_list;
+	int			members[3];
+	enum mcast_group_state	state;
+	enum mcast_group_state	prev_state;
+	struct ib_sa_mad	response_sa_mad;
+	__be64			last_req_tid;
+
+	char			name[33]; /* MGID string */
+	struct device_attribute	dentry;
+
+	/* refcount is the reference count for the following:
+	   1. Each queued request
+	   2. Each invocation of the worker thread
+	   3. Membership of the port at the SA
+	*/
+	atomic_t		refcount;
+
+	/* delayed work to clean pending SM request */
+	struct delayed_work	timeout_work;
+	struct list_head	cleanup_list;
+};
+
+struct mcast_req {
+	int			func;
+	struct ib_sa_mad	sa_mad;
+	struct list_head	group_list;
+	struct list_head	func_list;
+	struct mcast_group	*group;
+	int			clean;
+};
+
+
+#define safe_atomic_dec(ref) \
+	do {\
+		if (atomic_dec_and_test(ref)) \
+			mcg_warn_group(group, "did not expect to reach zero\n"); \
+	} while (0)
+
+static const char *get_state_string(enum mcast_group_state state)
+{
+	switch (state) {
+	case MCAST_IDLE:
+		return "MCAST_IDLE";
+	case MCAST_JOIN_SENT:
+		return "MCAST_JOIN_SENT";
+	case MCAST_LEAVE_SENT:
+		return "MCAST_LEAVE_SENT";
+	case MCAST_RESP_READY:
+		return "MCAST_RESP_READY";
+	}
+	return "Invalid State";
+}
+
+static struct mcast_group *mcast_find(struct mlx4_ib_demux_ctx *ctx,
+				      union ib_gid *mgid)
+{
+	struct rb_node *node = ctx->mcg_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 mlx4_ib_demux_ctx *ctx,
+					struct mcast_group *group)
+{
+	struct rb_node **link = &ctx->mcg_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
+			return cur_group;
+	}
+	rb_link_node(&group->node, parent, link);
+	rb_insert_color(&group->node, &ctx->mcg_table);
+	return NULL;
+}
+
+static int send_mad_to_wire(struct mlx4_ib_demux_ctx *ctx, struct ib_mad *mad)
+{
+	struct mlx4_ib_dev *dev = ctx->dev;
+	struct rdma_ah_attr	ah_attr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->sm_lock, flags);
+	if (!dev->sm_ah[ctx->port - 1]) {
+		/* port is not yet Active, sm_ah not ready */
+		spin_unlock_irqrestore(&dev->sm_lock, flags);
+		return -EAGAIN;
+	}
+	mlx4_ib_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);
+	spin_unlock_irqrestore(&dev->sm_lock, flags);
+	return mlx4_ib_send_to_wire(dev, mlx4_master_func_num(dev->dev),
+				    ctx->port, IB_QPT_GSI, 0, 1, IB_QP1_QKEY,
+				    &ah_attr, NULL, 0xffff, mad);
+}
+
+static int send_mad_to_slave(int slave, struct mlx4_ib_demux_ctx *ctx,
+			     struct ib_mad *mad)
+{
+	struct mlx4_ib_dev *dev = ctx->dev;
+	struct ib_mad_agent *agent = dev->send_agent[ctx->port - 1][1];
+	struct ib_wc wc;
+	struct rdma_ah_attr ah_attr;
+
+	/* Our agent might not yet be registered when mads start to arrive */
+	if (!agent)
+		return -EAGAIN;
+
+	rdma_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);
+
+	if (ib_find_cached_pkey(&dev->ib_dev, ctx->port, IB_DEFAULT_PKEY_FULL, &wc.pkey_index))
+		return -EINVAL;
+	wc.sl = 0;
+	wc.dlid_path_bits = 0;
+	wc.port_num = ctx->port;
+	wc.slid = rdma_ah_get_dlid(&ah_attr);  /* opensm lid */
+	wc.src_qp = 1;
+	return mlx4_ib_send_to_slave(dev, slave, ctx->port, IB_QPT_GSI, &wc, NULL, mad);
+}
+
+static int send_join_to_wire(struct mcast_group *group, struct ib_sa_mad *sa_mad)
+{
+	struct ib_sa_mad mad;
+	struct ib_sa_mcmember_data *sa_mad_data = (struct ib_sa_mcmember_data *)&mad.data;
+	int ret;
+
+	/* we rely on a mad request as arrived from a VF */
+	memcpy(&mad, sa_mad, sizeof mad);
+
+	/* fix port GID to be the real one (slave 0) */
+	sa_mad_data->port_gid.global.interface_id = group->demux->guid_cache[0];
+
+	/* assign our own TID */
+	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
+	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */
+
+	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
+	/* set timeout handler */
+	if (!ret) {
+		/* calls mlx4_ib_mcg_timeout_handler */
+		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
+				msecs_to_jiffies(MAD_TIMEOUT_MS));
+	}
+
+	return ret;
+}
+
+static int send_leave_to_wire(struct mcast_group *group, u8 join_state)
+{
+	struct ib_sa_mad mad;
+	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
+	int ret;
+
+	memset(&mad, 0, sizeof mad);
+	mad.mad_hdr.base_version = 1;
+	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
+	mad.mad_hdr.class_version = 2;
+	mad.mad_hdr.method = IB_SA_METHOD_DELETE;
+	mad.mad_hdr.status = cpu_to_be16(0);
+	mad.mad_hdr.class_specific = cpu_to_be16(0);
+	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
+	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */
+	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
+	mad.mad_hdr.attr_mod = cpu_to_be32(0);
+	mad.sa_hdr.sm_key = 0x0;
+	mad.sa_hdr.attr_offset = cpu_to_be16(7);
+	mad.sa_hdr.comp_mask = IB_SA_MCMEMBER_REC_MGID |
+		IB_SA_MCMEMBER_REC_PORT_GID | IB_SA_MCMEMBER_REC_JOIN_STATE;
+
+	*sa_data = group->rec;
+	sa_data->scope_join_state = join_state;
+
+	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
+	if (ret)
+		group->state = MCAST_IDLE;
+
+	/* set timeout handler */
+	if (!ret) {
+		/* calls mlx4_ib_mcg_timeout_handler */
+		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
+				msecs_to_jiffies(MAD_TIMEOUT_MS));
+	}
+
+	return ret;
+}
+
+static int send_reply_to_slave(int slave, struct mcast_group *group,
+		struct ib_sa_mad *req_sa_mad, u16 status)
+{
+	struct ib_sa_mad mad;
+	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
+	struct ib_sa_mcmember_data *req_sa_data = (struct ib_sa_mcmember_data *)&req_sa_mad->data;
+	int ret;
+
+	memset(&mad, 0, sizeof mad);
+	mad.mad_hdr.base_version = 1;
+	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
+	mad.mad_hdr.class_version = 2;
+	mad.mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
+	mad.mad_hdr.status = cpu_to_be16(status);
+	mad.mad_hdr.class_specific = cpu_to_be16(0);
+	mad.mad_hdr.tid = req_sa_mad->mad_hdr.tid;
+	*(u8 *)&mad.mad_hdr.tid = 0; /* resetting tid to 0 */
+	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
+	mad.mad_hdr.attr_mod = cpu_to_be32(0);
+	mad.sa_hdr.sm_key = req_sa_mad->sa_hdr.sm_key;
+	mad.sa_hdr.attr_offset = cpu_to_be16(7);
+	mad.sa_hdr.comp_mask = 0; /* ignored on responses, see IBTA spec */
+
+	*sa_data = group->rec;
+
+	/* reconstruct VF's requested join_state and port_gid */
+	sa_data->scope_join_state &= 0xf0;
+	sa_data->scope_join_state |= (group->func[slave].join_state & 0x0f);
+	memcpy(&sa_data->port_gid, &req_sa_data->port_gid, sizeof req_sa_data->port_gid);
+
+	ret = send_mad_to_slave(slave, group->demux, (struct ib_mad *)&mad);
+	return ret;
+}
+
+static int check_selector(ib_sa_comp_mask comp_mask,
+			  ib_sa_comp_mask selector_mask,
+			  ib_sa_comp_mask value_mask,
+			  u8 src_value, u8 dst_value)
+{
+	int err;
+	u8 selector = dst_value >> 6;
+	dst_value &= 0x3f;
+	src_value &= 0x3f;
+
+	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 u16 cmp_rec(struct ib_sa_mcmember_data *src,
+		   struct ib_sa_mcmember_data *dst, ib_sa_comp_mask comp_mask)
+{
+	/* src is group record, dst is request record */
+	/* MGID must already match */
+	/* Port_GID we always replace to our Port_GID, so it is a match */
+
+#define MAD_STATUS_REQ_INVALID 0x0200
+	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
+		return MAD_STATUS_REQ_INVALID;
+	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
+				 IB_SA_MCMEMBER_REC_MTU,
+				 src->mtusel_mtu, dst->mtusel_mtu))
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
+	    src->tclass != dst->tclass)
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
+		return MAD_STATUS_REQ_INVALID;
+	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
+				 IB_SA_MCMEMBER_REC_RATE,
+				 src->ratesel_rate, dst->ratesel_rate))
+		return MAD_STATUS_REQ_INVALID;
+	if (check_selector(comp_mask,
+				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
+				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
+				 src->lifetmsel_lifetm, dst->lifetmsel_lifetm))
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_SL &&
+			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0xf0000000) !=
+			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0xf0000000))
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
+			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x0fffff00) !=
+			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x0fffff00))
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
+			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x000000ff) !=
+			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x000000ff))
+		return MAD_STATUS_REQ_INVALID;
+	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE &&
+			(src->scope_join_state & 0xf0) !=
+			(dst->scope_join_state & 0xf0))
+		return MAD_STATUS_REQ_INVALID;
+
+	/* join_state checked separately, proxy_join ignored */
+
+	return 0;
+}
+
+/* release group, return 1 if this was last release and group is destroyed
+ * timout work is canceled sync */
+static int release_group(struct mcast_group *group, int from_timeout_handler)
+{
+	struct mlx4_ib_demux_ctx *ctx = group->demux;
+	int nzgroup;
+
+	mutex_lock(&ctx->mcg_table_lock);
+	mutex_lock(&group->lock);
+	if (atomic_dec_and_test(&group->refcount)) {
+		if (!from_timeout_handler) {
+			if (group->state != MCAST_IDLE &&
+			    !cancel_delayed_work(&group->timeout_work)) {
+				atomic_inc(&group->refcount);
+				mutex_unlock(&group->lock);
+				mutex_unlock(&ctx->mcg_table_lock);
+				return 0;
+			}
+		}
+
+		nzgroup = memcmp(&group->rec.mgid, &mgid0, sizeof mgid0);
+		if (nzgroup)
+			del_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
+		if (!list_empty(&group->pending_list))
+			mcg_warn_group(group, "releasing a group with non empty pending list\n");
+		if (nzgroup)
+			rb_erase(&group->node, &ctx->mcg_table);
+		list_del_init(&group->mgid0_list);
+		mutex_unlock(&group->lock);
+		mutex_unlock(&ctx->mcg_table_lock);
+		kfree(group);
+		return 1;
+	} else {
+		mutex_unlock(&group->lock);
+		mutex_unlock(&ctx->mcg_table_lock);
+	}
+	return 0;
+}
+
+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;
+}
+
+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 |= (1 << i);
+
+	return leave_state & (group->rec.scope_join_state & 0xf);
+}
+
+static int join_group(struct mcast_group *group, int slave, u8 join_mask)
+{
+	int ret = 0;
+	u8 join_state;
+
+	/* remove bits that slave is already member of, and adjust */
+	join_state = join_mask & (~group->func[slave].join_state);
+	adjust_membership(group, join_state, 1);
+	group->func[slave].join_state |= join_state;
+	if (group->func[slave].state != MCAST_MEMBER && join_state) {
+		group->func[slave].state = MCAST_MEMBER;
+		ret = 1;
+	}
+	return ret;
+}
+
+static int leave_group(struct mcast_group *group, int slave, u8 leave_state)
+{
+	int ret = 0;
+
+	adjust_membership(group, leave_state, -1);
+	group->func[slave].join_state &= ~leave_state;
+	if (!group->func[slave].join_state) {
+		group->func[slave].state = MCAST_NOT_MEMBER;
+		ret = 1;
+	}
+	return ret;
+}
+
+static int check_leave(struct mcast_group *group, int slave, u8 leave_mask)
+{
+	if (group->func[slave].state != MCAST_MEMBER)
+		return MAD_STATUS_REQ_INVALID;
+
+	/* make sure we're not deleting unset bits */
+	if (~group->func[slave].join_state & leave_mask)
+		return MAD_STATUS_REQ_INVALID;
+
+	if (!leave_mask)
+		return MAD_STATUS_REQ_INVALID;
+
+	return 0;
+}
+
+static void mlx4_ib_mcg_timeout_handler(struct work_struct *work)
+{
+	struct delayed_work *delay = to_delayed_work(work);
+	struct mcast_group *group;
+	struct mcast_req *req = NULL;
+
+	group = container_of(delay, typeof(*group), timeout_work);
+
+	mutex_lock(&group->lock);
+	if (group->state == MCAST_JOIN_SENT) {
+		if (!list_empty(&group->pending_list)) {
+			req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
+			list_del(&req->group_list);
+			list_del(&req->func_list);
+			--group->func[req->func].num_pend_reqs;
+			mutex_unlock(&group->lock);
+			kfree(req);
+			if (memcmp(&group->rec.mgid, &mgid0, sizeof mgid0)) {
+				if (release_group(group, 1))
+					return;
+			} else {
+				kfree(group);
+				return;
+			}
+			mutex_lock(&group->lock);
+		} else
+			mcg_warn_group(group, "DRIVER BUG\n");
+	} else if (group->state == MCAST_LEAVE_SENT) {
+		if (group->rec.scope_join_state & 0xf)
+			group->rec.scope_join_state &= 0xf0;
+		group->state = MCAST_IDLE;
+		mutex_unlock(&group->lock);
+		if (release_group(group, 1))
+			return;
+		mutex_lock(&group->lock);
+	} else
+		mcg_warn_group(group, "invalid state %s\n", get_state_string(group->state));
+	group->state = MCAST_IDLE;
+	atomic_inc(&group->refcount);
+	if (!queue_work(group->demux->mcg_wq, &group->work))
+		safe_atomic_dec(&group->refcount);
+
+	mutex_unlock(&group->lock);
+}
+
+static int handle_leave_req(struct mcast_group *group, u8 leave_mask,
+			    struct mcast_req *req)
+{
+	u16 status;
+
+	if (req->clean)
+		leave_mask = group->func[req->func].join_state;
+
+	status = check_leave(group, req->func, leave_mask);
+	if (!status)
+		leave_group(group, req->func, leave_mask);
+
+	if (!req->clean)
+		send_reply_to_slave(req->func, group, &req->sa_mad, status);
+	--group->func[req->func].num_pend_reqs;
+	list_del(&req->group_list);
+	list_del(&req->func_list);
+	kfree(req);
+	return 1;
+}
+
+static int handle_join_req(struct mcast_group *group, u8 join_mask,
+			   struct mcast_req *req)
+{
+	u8 group_join_state = group->rec.scope_join_state & 0xf;
+	int ref = 0;
+	u16 status;
+	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;
+
+	if (join_mask == (group_join_state & join_mask)) {
+		/* port's membership need not change */
+		status = cmp_rec(&group->rec, sa_data, req->sa_mad.sa_hdr.comp_mask);
+		if (!status)
+			join_group(group, req->func, join_mask);
+
+		--group->func[req->func].num_pend_reqs;
+		send_reply_to_slave(req->func, group, &req->sa_mad, status);
+		list_del(&req->group_list);
+		list_del(&req->func_list);
+		kfree(req);
+		++ref;
+	} else {
+		/* port's membership needs to be updated */
+		group->prev_state = group->state;
+		if (send_join_to_wire(group, &req->sa_mad)) {
+			--group->func[req->func].num_pend_reqs;
+			list_del(&req->group_list);
+			list_del(&req->func_list);
+			kfree(req);
+			ref = 1;
+			group->state = group->prev_state;
+		} else
+			group->state = MCAST_JOIN_SENT;
+	}
+
+	return ref;
+}
+
+static void mlx4_ib_mcg_work_handler(struct work_struct *work)
+{
+	struct mcast_group *group;
+	struct mcast_req *req = NULL;
+	struct ib_sa_mcmember_data *sa_data;
+	u8 req_join_state;
+	int rc = 1; /* release_count - this is for the scheduled work */
+	u16 status;
+	u8 method;
+
+	group = container_of(work, typeof(*group), work);
+
+	mutex_lock(&group->lock);
+
+	/* First, let's see if a response from SM is waiting regarding this group.
+	 * If so, we need to update the group's REC. If this is a bad response, we
+	 * may need to send a bad response to a VF waiting for it. If VF is waiting
+	 * and this is a good response, the VF will be answered later in this func. */
+	if (group->state == MCAST_RESP_READY) {
+		/* cancels mlx4_ib_mcg_timeout_handler */
+		cancel_delayed_work(&group->timeout_work);
+		status = be16_to_cpu(group->response_sa_mad.mad_hdr.status);
+		method = group->response_sa_mad.mad_hdr.method;
+		if (group->last_req_tid != group->response_sa_mad.mad_hdr.tid) {
+			mcg_warn_group(group, "Got MAD response to existing MGID but wrong TID, dropping. Resp TID=%llx, group TID=%llx\n",
+				be64_to_cpu(group->response_sa_mad.mad_hdr.tid),
+				be64_to_cpu(group->last_req_tid));
+			group->state = group->prev_state;
+			goto process_requests;
+		}
+		if (status) {
+			if (!list_empty(&group->pending_list))
+				req = list_first_entry(&group->pending_list,
+						struct mcast_req, group_list);
+			if (method == IB_MGMT_METHOD_GET_RESP) {
+					if (req) {
+						send_reply_to_slave(req->func, group, &req->sa_mad, status);
+						--group->func[req->func].num_pend_reqs;
+						list_del(&req->group_list);
+						list_del(&req->func_list);
+						kfree(req);
+						++rc;
+					} else
+						mcg_warn_group(group, "no request for failed join\n");
+			} else if (method == IB_SA_METHOD_DELETE_RESP && group->demux->flushing)
+				++rc;
+		} else {
+			u8 resp_join_state;
+			u8 cur_join_state;
+
+			resp_join_state = ((struct ib_sa_mcmember_data *)
+						group->response_sa_mad.data)->scope_join_state & 0xf;
+			cur_join_state = group->rec.scope_join_state & 0xf;
+
+			if (method == IB_MGMT_METHOD_GET_RESP) {
+				/* successfull join */
+				if (!cur_join_state && resp_join_state)
+					--rc;
+			} else if (!resp_join_state)
+					++rc;
+			memcpy(&group->rec, group->response_sa_mad.data, sizeof group->rec);
+		}
+		group->state = MCAST_IDLE;
+	}
+
+process_requests:
+	/* We should now go over pending join/leave requests, as long as we are idle. */
+	while (!list_empty(&group->pending_list) && group->state == MCAST_IDLE) {
+		req = list_first_entry(&group->pending_list, struct mcast_req,
+				       group_list);
+		sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;
+		req_join_state = sa_data->scope_join_state & 0xf;
+
+		/* For a leave request, we will immediately answer the VF, and
+		 * update our internal counters. The actual leave will be sent
+		 * to SM later, if at all needed. We dequeue the request now. */
+		if (req->sa_mad.mad_hdr.method == IB_SA_METHOD_DELETE)
+			rc += handle_leave_req(group, req_join_state, req);
+		else
+			rc += handle_join_req(group, req_join_state, req);
+	}
+
+	/* Handle leaves */
+	if (group->state == MCAST_IDLE) {
+		req_join_state = get_leave_state(group);
+		if (req_join_state) {
+			group->rec.scope_join_state &= ~req_join_state;
+			group->prev_state = group->state;
+			if (send_leave_to_wire(group, req_join_state)) {
+				group->state = group->prev_state;
+				++rc;
+			} else
+				group->state = MCAST_LEAVE_SENT;
+		}
+	}
+
+	if (!list_empty(&group->pending_list) && group->state == MCAST_IDLE)
+		goto process_requests;
+	mutex_unlock(&group->lock);
+
+	while (rc--)
+		release_group(group, 0);
+}
+
+static struct mcast_group *search_relocate_mgid0_group(struct mlx4_ib_demux_ctx *ctx,
+						       __be64 tid,
+						       union ib_gid *new_mgid)
+{
+	struct mcast_group *group = NULL, *cur_group, *n;
+	struct mcast_req *req;
+
+	mutex_lock(&ctx->mcg_table_lock);
+	list_for_each_entry_safe(group, n, &ctx->mcg_mgid0_list, mgid0_list) {
+		mutex_lock(&group->lock);
+		if (group->last_req_tid == tid) {
+			if (memcmp(new_mgid, &mgid0, sizeof mgid0)) {
+				group->rec.mgid = *new_mgid;
+				sprintf(group->name, "%016llx%016llx",
+						be64_to_cpu(group->rec.mgid.global.subnet_prefix),
+						be64_to_cpu(group->rec.mgid.global.interface_id));
+				list_del_init(&group->mgid0_list);
+				cur_group = mcast_insert(ctx, group);
+				if (cur_group) {
+					/* A race between our code and SM. Silently cleaning the new one */
+					req = list_first_entry(&group->pending_list,
+							       struct mcast_req, group_list);
+					--group->func[req->func].num_pend_reqs;
+					list_del(&req->group_list);
+					list_del(&req->func_list);
+					kfree(req);
+					mutex_unlock(&group->lock);
+					mutex_unlock(&ctx->mcg_table_lock);
+					release_group(group, 0);
+					return NULL;
+				}
+
+				atomic_inc(&group->refcount);
+				add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
+				mutex_unlock(&group->lock);
+				mutex_unlock(&ctx->mcg_table_lock);
+				return group;
+			} else {
+				struct mcast_req *tmp1, *tmp2;
+
+				list_del(&group->mgid0_list);
+				if (!list_empty(&group->pending_list) && group->state != MCAST_IDLE)
+					cancel_delayed_work_sync(&group->timeout_work);
+
+				list_for_each_entry_safe(tmp1, tmp2, &group->pending_list, group_list) {
+					list_del(&tmp1->group_list);
+					kfree(tmp1);
+				}
+				mutex_unlock(&group->lock);
+				mutex_unlock(&ctx->mcg_table_lock);
+				kfree(group);
+				return NULL;
+			}
+		}
+		mutex_unlock(&group->lock);
+	}
+	mutex_unlock(&ctx->mcg_table_lock);
+
+	return NULL;
+}
+
+static ssize_t sysfs_show_group(struct device *dev,
+		struct device_attribute *attr, char *buf);
+
+static struct mcast_group *acquire_group(struct mlx4_ib_demux_ctx *ctx,
+					 union ib_gid *mgid, int create)
+{
+	struct mcast_group *group, *cur_group;
+	int is_mgid0;
+	int i;
+
+	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
+	if (!is_mgid0) {
+		group = mcast_find(ctx, mgid);
+		if (group)
+			goto found;
+	}
+
+	if (!create)
+		return ERR_PTR(-ENOENT);
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return ERR_PTR(-ENOMEM);
+
+	group->demux = ctx;
+	group->rec.mgid = *mgid;
+	INIT_LIST_HEAD(&group->pending_list);
+	INIT_LIST_HEAD(&group->mgid0_list);
+	for (i = 0; i < MAX_VFS; ++i)
+		INIT_LIST_HEAD(&group->func[i].pending);
+	INIT_WORK(&group->work, mlx4_ib_mcg_work_handler);
+	INIT_DELAYED_WORK(&group->timeout_work, mlx4_ib_mcg_timeout_handler);
+	mutex_init(&group->lock);
+	sprintf(group->name, "%016llx%016llx",
+			be64_to_cpu(group->rec.mgid.global.subnet_prefix),
+			be64_to_cpu(group->rec.mgid.global.interface_id));
+	sysfs_attr_init(&group->dentry.attr);
+	group->dentry.show = sysfs_show_group;
+	group->dentry.store = NULL;
+	group->dentry.attr.name = group->name;
+	group->dentry.attr.mode = 0400;
+	group->state = MCAST_IDLE;
+
+	if (is_mgid0) {
+		list_add(&group->mgid0_list, &ctx->mcg_mgid0_list);
+		goto found;
+	}
+
+	cur_group = mcast_insert(ctx, group);
+	if (cur_group) {
+		mcg_warn("group just showed up %s - confused\n", cur_group->name);
+		kfree(group);
+		return ERR_PTR(-EINVAL);
+	}
+
+	add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
+
+found:
+	atomic_inc(&group->refcount);
+	return group;
+}
+
+static void queue_req(struct mcast_req *req)
+{
+	struct mcast_group *group = req->group;
+
+	atomic_inc(&group->refcount); /* for the request */
+	atomic_inc(&group->refcount); /* for scheduling the work */
+	list_add_tail(&req->group_list, &group->pending_list);
+	list_add_tail(&req->func_list, &group->func[req->func].pending);
+	/* calls mlx4_ib_mcg_work_handler */
+	if (!queue_work(group->demux->mcg_wq, &group->work))
+		safe_atomic_dec(&group->refcount);
+}
+
+int mlx4_ib_mcg_demux_handler(struct ib_device *ibdev, int port, int slave,
+			      struct ib_sa_mad *mad)
+{
+	struct mlx4_ib_dev *dev = to_mdev(ibdev);
+	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)mad->data;
+	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
+	struct mcast_group *group;
+
+	switch (mad->mad_hdr.method) {
+	case IB_MGMT_METHOD_GET_RESP:
+	case IB_SA_METHOD_DELETE_RESP:
+		mutex_lock(&ctx->mcg_table_lock);
+		group = acquire_group(ctx, &rec->mgid, 0);
+		mutex_unlock(&ctx->mcg_table_lock);
+		if (IS_ERR(group)) {
+			if (mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP) {
+				__be64 tid = mad->mad_hdr.tid;
+				*(u8 *)(&tid) = (u8)slave; /* in group we kept the modified TID */
+				group = search_relocate_mgid0_group(ctx, tid, &rec->mgid);
+			} else
+				group = NULL;
+		}
+
+		if (!group)
+			return 1;
+
+		mutex_lock(&group->lock);
+		group->response_sa_mad = *mad;
+		group->prev_state = group->state;
+		group->state = MCAST_RESP_READY;
+		/* calls mlx4_ib_mcg_work_handler */
+		atomic_inc(&group->refcount);
+		if (!queue_work(ctx->mcg_wq, &group->work))
+			safe_atomic_dec(&group->refcount);
+		mutex_unlock(&group->lock);
+		release_group(group, 0);
+		return 1; /* consumed */
+	case IB_MGMT_METHOD_SET:
+	case IB_SA_METHOD_GET_TABLE:
+	case IB_SA_METHOD_GET_TABLE_RESP:
+	case IB_SA_METHOD_DELETE:
+		return 0; /* not consumed, pass-through to guest over tunnel */
+	default:
+		mcg_warn("In demux, port %d: unexpected MCMember method: 0x%x, dropping\n",
+			port, mad->mad_hdr.method);
+		return 1; /* consumed */
+	}
+}
+
+int mlx4_ib_mcg_multiplex_handler(struct ib_device *ibdev, int port,
+				  int slave, struct ib_sa_mad *sa_mad)
+{
+	struct mlx4_ib_dev *dev = to_mdev(ibdev);
+	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)sa_mad->data;
+	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
+	struct mcast_group *group;
+	struct mcast_req *req;
+	int may_create = 0;
+
+	if (ctx->flushing)
+		return -EAGAIN;
+
+	switch (sa_mad->mad_hdr.method) {
+	case IB_MGMT_METHOD_SET:
+		may_create = 1;
+		fallthrough;
+	case IB_SA_METHOD_DELETE:
+		req = kzalloc(sizeof *req, GFP_KERNEL);
+		if (!req)
+			return -ENOMEM;
+
+		req->func = slave;
+		req->sa_mad = *sa_mad;
+
+		mutex_lock(&ctx->mcg_table_lock);
+		group = acquire_group(ctx, &rec->mgid, may_create);
+		mutex_unlock(&ctx->mcg_table_lock);
+		if (IS_ERR(group)) {
+			kfree(req);
+			return PTR_ERR(group);
+		}
+		mutex_lock(&group->lock);
+		if (group->func[slave].num_pend_reqs > MAX_PEND_REQS_PER_FUNC) {
+			mutex_unlock(&group->lock);
+			mcg_debug_group(group, "Port %d, Func %d has too many pending requests (%d), dropping\n",
+					port, slave, MAX_PEND_REQS_PER_FUNC);
+			release_group(group, 0);
+			kfree(req);
+			return -ENOMEM;
+		}
+		++group->func[slave].num_pend_reqs;
+		req->group = group;
+		queue_req(req);
+		mutex_unlock(&group->lock);
+		release_group(group, 0);
+		return 1; /* consumed */
+	case IB_SA_METHOD_GET_TABLE:
+	case IB_MGMT_METHOD_GET_RESP:
+	case IB_SA_METHOD_GET_TABLE_RESP:
+	case IB_SA_METHOD_DELETE_RESP:
+		return 0; /* not consumed, pass-through */
+	default:
+		mcg_warn("In multiplex, port %d, func %d: unexpected MCMember method: 0x%x, dropping\n",
+			port, slave, sa_mad->mad_hdr.method);
+		return 1; /* consumed */
+	}
+}
+
+static ssize_t sysfs_show_group(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mcast_group *group =
+		container_of(attr, struct mcast_group, dentry);
+	struct mcast_req *req = NULL;
+	char pending_str[40];
+	char state_str[40];
+	ssize_t len = 0;
+	int f;
+
+	if (group->state == MCAST_IDLE)
+		sprintf(state_str, "%s", get_state_string(group->state));
+	else
+		sprintf(state_str, "%s(TID=0x%llx)",
+				get_state_string(group->state),
+				be64_to_cpu(group->last_req_tid));
+	if (list_empty(&group->pending_list)) {
+		sprintf(pending_str, "No");
+	} else {
+		req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
+		sprintf(pending_str, "Yes(TID=0x%llx)",
+				be64_to_cpu(req->sa_mad.mad_hdr.tid));
+	}
+	len += sprintf(buf + len, "%1d [%02d,%02d,%02d] %4d %4s %5s     ",
+			group->rec.scope_join_state & 0xf,
+			group->members[2], group->members[1], group->members[0],
+			atomic_read(&group->refcount),
+			pending_str,
+			state_str);
+	for (f = 0; f < MAX_VFS; ++f)
+		if (group->func[f].state == MCAST_MEMBER)
+			len += sprintf(buf + len, "%d[%1x] ",
+					f, group->func[f].join_state);
+
+	len += sprintf(buf + len, "\t\t(%4hx %4x %2x %2x %2x %2x %2x "
+		"%4x %4x %2x %2x)\n",
+		be16_to_cpu(group->rec.pkey),
+		be32_to_cpu(group->rec.qkey),
+		(group->rec.mtusel_mtu & 0xc0) >> 6,
+		group->rec.mtusel_mtu & 0x3f,
+		group->rec.tclass,
+		(group->rec.ratesel_rate & 0xc0) >> 6,
+		group->rec.ratesel_rate & 0x3f,
+		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0xf0000000) >> 28,
+		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x0fffff00) >> 8,
+		be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x000000ff,
+		group->rec.proxy_join);
+
+	return len;
+}
+
+int mlx4_ib_mcg_port_init(struct mlx4_ib_demux_ctx *ctx)
+{
+	char name[20];
+
+	atomic_set(&ctx->tid, 0);
+	sprintf(name, "mlx4_ib_mcg%d", ctx->port);
+	ctx->mcg_wq = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
+	if (!ctx->mcg_wq)
+		return -ENOMEM;
+
+	mutex_init(&ctx->mcg_table_lock);
+	ctx->mcg_table = RB_ROOT;
+	INIT_LIST_HEAD(&ctx->mcg_mgid0_list);
+	ctx->flushing = 0;
+
+	return 0;
+}
+
+static void force_clean_group(struct mcast_group *group)
+{
+	struct mcast_req *req, *tmp
+		;
+	list_for_each_entry_safe(req, tmp, &group->pending_list, group_list) {
+		list_del(&req->group_list);
+		kfree(req);
+	}
+	del_sysfs_port_mcg_attr(group->demux->dev, group->demux->port, &group->dentry.attr);
+	rb_erase(&group->node, &group->demux->mcg_table);
+	kfree(group);
+}
+
+static void _mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
+{
+	int i;
+	struct rb_node *p;
+	struct mcast_group *group;
+	unsigned long end;
+	int count;
+
+	for (i = 0; i < MAX_VFS; ++i)
+		clean_vf_mcast(ctx, i);
+
+	end = jiffies + msecs_to_jiffies(MAD_TIMEOUT_MS + 3000);
+	do {
+		count = 0;
+		mutex_lock(&ctx->mcg_table_lock);
+		for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p))
+			++count;
+		mutex_unlock(&ctx->mcg_table_lock);
+		if (!count)
+			break;
+
+		usleep_range(1000, 2000);
+	} while (time_after(end, jiffies));
+
+	flush_workqueue(ctx->mcg_wq);
+	if (destroy_wq)
+		destroy_workqueue(ctx->mcg_wq);
+
+	mutex_lock(&ctx->mcg_table_lock);
+	while ((p = rb_first(&ctx->mcg_table)) != NULL) {
+		group = rb_entry(p, struct mcast_group, node);
+		if (atomic_read(&group->refcount))
+			mcg_debug_group(group, "group refcount %d!!! (pointer %p)\n",
+					atomic_read(&group->refcount), group);
+
+		force_clean_group(group);
+	}
+	mutex_unlock(&ctx->mcg_table_lock);
+}
+
+struct clean_work {
+	struct work_struct work;
+	struct mlx4_ib_demux_ctx *ctx;
+	int destroy_wq;
+};
+
+static void mcg_clean_task(struct work_struct *work)
+{
+	struct clean_work *cw = container_of(work, struct clean_work, work);
+
+	_mlx4_ib_mcg_port_cleanup(cw->ctx, cw->destroy_wq);
+	cw->ctx->flushing = 0;
+	kfree(cw);
+}
+
+void mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
+{
+	struct clean_work *work;
+
+	if (ctx->flushing)
+		return;
+
+	ctx->flushing = 1;
+
+	if (destroy_wq) {
+		_mlx4_ib_mcg_port_cleanup(ctx, destroy_wq);
+		ctx->flushing = 0;
+		return;
+	}
+
+	work = kmalloc(sizeof *work, GFP_KERNEL);
+	if (!work) {
+		ctx->flushing = 0;
+		return;
+	}
+
+	work->ctx = ctx;
+	work->destroy_wq = destroy_wq;
+	INIT_WORK(&work->work, mcg_clean_task);
+	queue_work(clean_wq, &work->work);
+}
+
+static void build_leave_mad(struct mcast_req *req)
+{
+	struct ib_sa_mad *mad = &req->sa_mad;
+
+	mad->mad_hdr.method = IB_SA_METHOD_DELETE;
+}
+
+
+static void clear_pending_reqs(struct mcast_group *group, int vf)
+{
+	struct mcast_req *req, *tmp, *group_first = NULL;
+	int clear;
+	int pend = 0;
+
+	if (!list_empty(&group->pending_list))
+		group_first = list_first_entry(&group->pending_list, struct mcast_req, group_list);
+
+	list_for_each_entry_safe(req, tmp, &group->func[vf].pending, func_list) {
+		clear = 1;
+		if (group_first == req &&
+		    (group->state == MCAST_JOIN_SENT ||
+		     group->state == MCAST_LEAVE_SENT)) {
+			clear = cancel_delayed_work(&group->timeout_work);
+			pend = !clear;
+			group->state = MCAST_IDLE;
+		}
+		if (clear) {
+			--group->func[vf].num_pend_reqs;
+			list_del(&req->group_list);
+			list_del(&req->func_list);
+			kfree(req);
+			atomic_dec(&group->refcount);
+		}
+	}
+
+	if (!pend && (!list_empty(&group->func[vf].pending) || group->func[vf].num_pend_reqs)) {
+		mcg_warn_group(group, "DRIVER BUG: list_empty %d, num_pend_reqs %d\n",
+			       list_empty(&group->func[vf].pending), group->func[vf].num_pend_reqs);
+	}
+}
+
+static int push_deleteing_req(struct mcast_group *group, int slave)
+{
+	struct mcast_req *req;
+	struct mcast_req *pend_req;
+
+	if (!group->func[slave].join_state)
+		return 0;
+
+	req = kzalloc(sizeof *req, GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	if (!list_empty(&group->func[slave].pending)) {
+		pend_req = list_entry(group->func[slave].pending.prev, struct mcast_req, group_list);
+		if (pend_req->clean) {
+			kfree(req);
+			return 0;
+		}
+	}
+
+	req->clean = 1;
+	req->func = slave;
+	req->group = group;
+	++group->func[slave].num_pend_reqs;
+	build_leave_mad(req);
+	queue_req(req);
+	return 0;
+}
+
+void clean_vf_mcast(struct mlx4_ib_demux_ctx *ctx, int slave)
+{
+	struct mcast_group *group;
+	struct rb_node *p;
+
+	mutex_lock(&ctx->mcg_table_lock);
+	for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p)) {
+		group = rb_entry(p, struct mcast_group, node);
+		mutex_lock(&group->lock);
+		if (atomic_read(&group->refcount)) {
+			/* clear pending requests of this VF */
+			clear_pending_reqs(group, slave);
+			push_deleteing_req(group, slave);
+		}
+		mutex_unlock(&group->lock);
+	}
+	mutex_unlock(&ctx->mcg_table_lock);
+}
+
+
+int mlx4_ib_mcg_init(void)
+{
+	clean_wq = alloc_ordered_workqueue("mlx4_ib_mcg", WQ_MEM_RECLAIM);
+	if (!clean_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void mlx4_ib_mcg_destroy(void)
+{
+	destroy_workqueue(clean_wq);
+}