diff mbox

[v3,06/13] SoftiWarp connection management

Message ID 20180114223603.19961-7-bmt@zurich.ibm.com (mailing list archive)
State RFC
Headers show

Commit Message

Bernard Metzler Jan. 14, 2018, 10:35 p.m. UTC
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
---
 drivers/infiniband/sw/siw/siw_cm.c | 2184 ++++++++++++++++++++++++++++++++++++
 drivers/infiniband/sw/siw/siw_cm.h |  156 +++
 2 files changed, 2340 insertions(+)
 create mode 100644 drivers/infiniband/sw/siw/siw_cm.c
 create mode 100644 drivers/infiniband/sw/siw/siw_cm.h

Comments

Steve Wise Jan. 30, 2018, 9:27 p.m. UTC | #1
> 
> Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
> ---
>  drivers/infiniband/sw/siw/siw_cm.c | 2184
> ++++++++++++++++++++++++++++++++++++
>  drivers/infiniband/sw/siw/siw_cm.h |  156 +++
>  2 files changed, 2340 insertions(+)
>  create mode 100644 drivers/infiniband/sw/siw/siw_cm.c
>  create mode 100644 drivers/infiniband/sw/siw/siw_cm.h

<snip>

> diff --git a/drivers/infiniband/sw/siw/siw_cm.h
> b/drivers/infiniband/sw/siw/siw_cm.h
> new file mode 100644
> index 000000000000..36a8d15d793a
> --- /dev/null
> +++ b/drivers/infiniband/sw/siw/siw_cm.h
> @@ -0,0 +1,156 @@
> +/*
> + * Software iWARP device driver
> + *
> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
> + *          Greg Joyce <greg@opengridcomputing.com>
> + *
> + * Copyright (c) 2008-2017, IBM Corporation
> + * Copyright (c) 2017, Open Grid Computing, Inc.
> + *
> + * 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
> + * 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.
> + *
> + *   - Neither the name of IBM nor the names of its contributors may be
> + *     used to endorse or promote products derived from this software
without
> + *     specific prior written permission.
> + *
> + * 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.
> + */
> +
> +#ifndef _SIW_CM_H
> +#define _SIW_CM_H
> +
> +#include <net/sock.h>
> +#include <linux/tcp.h>
> +
> +#include <rdma/iw_cm.h>
> +
> +
> +enum siw_cep_state {
> +	SIW_EPSTATE_IDLE = 1,
> +	SIW_EPSTATE_LISTENING,
> +	SIW_EPSTATE_CONNECTING,
> +	SIW_EPSTATE_AWAIT_MPAREQ,
> +	SIW_EPSTATE_RECVD_MPAREQ,
> +	SIW_EPSTATE_AWAIT_MPAREP,
> +	SIW_EPSTATE_RDMA_MODE,
> +	SIW_EPSTATE_CLOSED
> +};
> +
> +struct siw_mpa_info {
> +	struct mpa_rr		hdr;	/* peer mpa hdr in host byte order
*/
> +	struct mpa_v2_data	v2_ctrl;
> +	struct mpa_v2_data	v2_ctrl_req;
> +	char			*pdata;
> +	int			bytes_rcvd;
> +};
> +
> +struct siw_llp_info {
> +	struct socket		*sock;
> +	struct sockaddr_in	laddr;	/* redundant with socket info above
*/
> +	struct sockaddr_in	raddr;	/* dito, consider removal */
> +	struct siw_sk_upcalls	sk_def_upcalls;
> +};
> +
> +struct siw_device;
> +
> +struct siw_cep {
> +	struct iw_cm_id		*cm_id;
> +	struct siw_device	*sdev;
> +
> +	struct list_head	devq;
> +	/*
> +	 * The provider_data element of a listener IWCM ID
> +	 * refers to a list of one or more listener CEPs
> +	 */
> +	struct list_head	listenq;
> +	struct siw_cep		*listen_cep;
> +	struct siw_qp		*qp;
> +	spinlock_t		lock;
> +	wait_queue_head_t	waitq;
> +	struct kref		ref;
> +	enum siw_cep_state	state;
> +	short			in_use;
> +	struct siw_cm_work	*mpa_timer;
> +	struct list_head	work_freelist;
> +	struct siw_llp_info	llp;
> +	struct siw_mpa_info	mpa;
> +	int			ord;
> +	int			ird;
> +	bool			enhanced_rdma_conn_est;
> +	int			sk_error; /* not (yet) used XXX */
> +
> +	/* Saved upcalls of socket llp.sock */
> +	void	(*sk_state_change)(struct sock *sk);
> +	void	(*sk_data_ready)(struct sock *sk);
> +	void	(*sk_write_space)(struct sock *sk);
> +	void	(*sk_error_report)(struct sock *sk);
> +};
> +
> +/*
> + * Connection initiator waits 10 seconds to receive an
> + * MPA reply after sending out MPA request. Reponder waits for
> + * 5 seconds for MPA request to arrive if new TCP connection
> + * was set up.
> + */
> +#define MPAREQ_TIMEOUT	(HZ*10)
> +#define MPAREP_TIMEOUT	(HZ*5)
> +

These timeout times seem pretty low for a WAN link or even a brief network
down event during MPA negotiation connection.   Any particular reason for 10
and 5?


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Bernard Metzler Jan. 31, 2018, 5:28 p.m. UTC | #2
-----"Steve Wise" <swise@opengridcomputing.com> wrote: -----

>To: "'Bernard Metzler'" <bmt@zurich.ibm.com>,
><linux-rdma@vger.kernel.org>
>From: "Steve Wise" <swise@opengridcomputing.com>
>Date: 01/30/2018 10:27PM
>Subject: RE: [PATCH v3 06/13] SoftiWarp connection management
>
>> 
>> Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
>> ---
>>  drivers/infiniband/sw/siw/siw_cm.c | 2184
>> ++++++++++++++++++++++++++++++++++++
>>  drivers/infiniband/sw/siw/siw_cm.h |  156 +++
>>  2 files changed, 2340 insertions(+)
>>  create mode 100644 drivers/infiniband/sw/siw/siw_cm.c
>>  create mode 100644 drivers/infiniband/sw/siw/siw_cm.h
>
><snip>
>
>> diff --git a/drivers/infiniband/sw/siw/siw_cm.h


<snip>

>> +
>> +/*
>> + * Connection initiator waits 10 seconds to receive an
>> + * MPA reply after sending out MPA request. Reponder waits for
>> + * 5 seconds for MPA request to arrive if new TCP connection
>> + * was set up.
>> + */
>> +#define MPAREQ_TIMEOUT	(HZ*10)
>> +#define MPAREP_TIMEOUT	(HZ*5)
>> +
>
>These timeout times seem pretty low for a WAN link or even a brief
>network
>down event during MPA negotiation connection.   Any particular reason
>for 10
>and 5?
>
>
>
i picked those rather small numbers since it covers basically
only the latency after the TCP connection went up, so the
timer gets started only after the TCP connection was
established. at client side, we wait 5 seconds after sending the MPA
request to get the reply. on server side, we wait 10 seconds
for the MPA request, after we have accepted a new TCP connection.

maybe i shall make that longer? but the only real delay we have to
deal with is the server side application which thinks too long
if it shall 'accept' or 'reject' (maybe that is very artifical,
but i had to deal with cases of an application which never rejected/
accepted).

thanks
Bernard.

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diff mbox

Patch

diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c
new file mode 100644
index 000000000000..6e80ac002ddb
--- /dev/null
+++ b/drivers/infiniband/sw/siw/siw_cm.c
@@ -0,0 +1,2184 @@ 
+/*
+ * Software iWARP device driver
+ *
+ * Authors: Bernard Metzler <bmt@zurich.ibm.com>
+ *          Fredy Neeser <nfd@zurich.ibm.com>
+ *          Greg Joyce <greg@opengridcomputing.com>
+ *
+ * Copyright (c) 2008-2017, IBM Corporation
+ * Copyright (c) 2017, Open Grid Computing, Inc.
+ *
+ * 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
+ * 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.
+ *
+ *   - Neither the name of IBM nor the names of its contributors may be
+ *     used to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * 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/errno.h>
+#include <linux/types.h>
+#include <linux/net.h>
+#include <linux/inetdevice.h>
+#include <linux/workqueue.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <linux/tcp.h>
+
+#include <rdma/iw_cm.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_smi.h>
+#include <rdma/ib_user_verbs.h>
+
+#include "siw.h"
+#include "siw_cm.h"
+#include "siw_obj.h"
+
+/*
+ * Set to any combination of
+ * MPA_V2_RDMA_NO_RTR, MPA_V2_RDMA_READ_RTR, MPA_V2_RDMA_WRITE_RTR
+ */
+static __be16 rtr_type = MPA_V2_RDMA_READ_RTR|MPA_V2_RDMA_WRITE_RTR;
+static const bool relaxed_ird_negotiation = 1;
+
+/*
+ * siw_sock_nodelay() - Disable Nagle algorithm and/or set pingpong
+ */
+static int siw_sock_nodelay(struct socket *sock)
+{
+	int val = 1, rv = 0;
+
+	if (siw_lowdelay)
+		rv = kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
+				       (char *)&val, sizeof(val));
+
+	if (!rv && tcp_quickack)
+		rv =  kernel_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
+					(char *)&val, sizeof(val));
+	return rv;
+}
+
+static void siw_cm_llp_state_change(struct sock *s);
+static void siw_cm_llp_data_ready(struct sock *s);
+static void siw_cm_llp_write_space(struct sock *s);
+static void siw_cm_llp_error_report(struct sock *s);
+static int siw_cm_upcall(struct siw_cep *cep, enum iw_cm_event_type reson,
+			 int status);
+
+static void siw_sk_assign_cm_upcalls(struct sock *sk)
+{
+	write_lock_bh(&sk->sk_callback_lock);
+	sk->sk_state_change = siw_cm_llp_state_change;
+	sk->sk_data_ready   = siw_cm_llp_data_ready;
+	sk->sk_write_space  = siw_cm_llp_write_space;
+	sk->sk_error_report = siw_cm_llp_error_report;
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void siw_sk_save_upcalls(struct sock *sk)
+{
+	struct siw_cep *cep = sk_to_cep(sk);
+
+	write_lock_bh(&sk->sk_callback_lock);
+	cep->sk_state_change = sk->sk_state_change;
+	cep->sk_data_ready   = sk->sk_data_ready;
+	cep->sk_write_space  = sk->sk_write_space;
+	cep->sk_error_report = sk->sk_error_report;
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void siw_sk_restore_upcalls(struct sock *sk, struct siw_cep *cep)
+{
+	sk->sk_state_change	= cep->sk_state_change;
+	sk->sk_data_ready	= cep->sk_data_ready;
+	sk->sk_write_space	= cep->sk_write_space;
+	sk->sk_error_report	= cep->sk_error_report;
+	sk->sk_user_data	= NULL;
+}
+
+static void siw_qp_socket_assoc(struct siw_cep *cep, struct siw_qp *qp)
+{
+	struct socket *s = cep->llp.sock;
+	struct sock *sk = s->sk;
+
+	write_lock_bh(&sk->sk_callback_lock);
+
+	qp->attrs.llp_stream_handle = s;
+	sk->sk_data_ready = siw_qp_llp_data_ready;
+	sk->sk_write_space = siw_qp_llp_write_space;
+
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void siw_socket_disassoc(struct socket *s)
+{
+	struct sock	*sk = s->sk;
+	struct siw_cep	*cep;
+
+	if (sk) {
+		write_lock_bh(&sk->sk_callback_lock);
+		cep = sk_to_cep(sk);
+		if (cep) {
+			siw_sk_restore_upcalls(sk, cep);
+			siw_cep_put(cep);
+		} else
+			pr_warn("SIW: cannot restore sk callbacks: no ep\n");
+		write_unlock_bh(&sk->sk_callback_lock);
+	} else {
+		pr_warn("SIW: cannot restore sk callbacks: no sk\n");
+	}
+}
+
+static void siw_rtr_data_ready(struct sock *sk)
+{
+	struct siw_cep		*cep;
+	struct siw_qp		*qp = NULL;
+	read_descriptor_t	rd_desc;
+
+	read_lock(&sk->sk_callback_lock);
+
+	cep = sk_to_cep(sk);
+	if (!cep) {
+		WARN(1, "No connection endpoint\n");
+		goto out;
+	}
+	qp = sk_to_qp(sk);
+
+	memset(&rd_desc, 0, sizeof(rd_desc));
+	rd_desc.arg.data = qp;
+	rd_desc.count = 1;
+
+	tcp_read_sock(sk, &rd_desc, siw_tcp_rx_data);
+	/*
+	 * Check if first frame was successfully processed.
+	 * Signal connection full establishment if yes.
+	 * Failed data processing would have already scheduled
+	 * connection drop.
+	 */
+	if (!qp->rx_ctx.rx_suspend)
+		siw_cm_upcall(cep, IW_CM_EVENT_ESTABLISHED, 0);
+out:
+	read_unlock(&sk->sk_callback_lock);
+	if (qp)
+		siw_qp_socket_assoc(cep, qp);
+}
+
+static void siw_sk_assign_rtr_upcalls(struct siw_cep *cep)
+{
+	struct sock *sk = cep->llp.sock->sk;
+
+	write_lock_bh(&sk->sk_callback_lock);
+	sk->sk_data_ready = siw_rtr_data_ready;
+	sk->sk_write_space = siw_qp_llp_write_space;
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static inline int kernel_peername(struct socket *s, struct sockaddr_in *addr)
+{
+	int addr_len;
+
+	return s->ops->getname(s, (struct sockaddr *)addr, &addr_len, 1);
+}
+
+static inline int kernel_localname(struct socket *s, struct sockaddr_in *addr)
+{
+	int addr_len;
+
+	return s->ops->getname(s, (struct sockaddr *)addr, &addr_len, 0);
+}
+
+static void siw_cep_socket_assoc(struct siw_cep *cep, struct socket *s)
+{
+	cep->llp.sock = s;
+	siw_cep_get(cep);
+	s->sk->sk_user_data = cep;
+
+	siw_sk_save_upcalls(s->sk);
+	siw_sk_assign_cm_upcalls(s->sk);
+}
+
+static struct siw_cep *siw_cep_alloc(struct siw_device  *sdev)
+{
+	struct siw_cep *cep = kzalloc(sizeof(*cep), GFP_KERNEL);
+
+	if (cep) {
+		unsigned long flags;
+
+		INIT_LIST_HEAD(&cep->listenq);
+		INIT_LIST_HEAD(&cep->devq);
+		INIT_LIST_HEAD(&cep->work_freelist);
+
+		kref_init(&cep->ref);
+		cep->state = SIW_EPSTATE_IDLE;
+		init_waitqueue_head(&cep->waitq);
+		spin_lock_init(&cep->lock);
+		cep->sdev = sdev;
+		cep->enhanced_rdma_conn_est = false;
+
+		spin_lock_irqsave(&sdev->idr_lock, flags);
+		list_add_tail(&cep->devq, &sdev->cep_list);
+		spin_unlock_irqrestore(&sdev->idr_lock, flags);
+		atomic_inc(&sdev->num_cep);
+
+		siw_dbg_cep(cep, "new object\n");
+	}
+	return cep;
+}
+
+static void siw_cm_free_work(struct siw_cep *cep)
+{
+	struct list_head	*w, *tmp;
+	struct siw_cm_work	*work;
+
+	list_for_each_safe(w, tmp, &cep->work_freelist) {
+		work = list_entry(w, struct siw_cm_work, list);
+		list_del(&work->list);
+		kfree(work);
+	}
+}
+
+static void siw_cancel_mpatimer(struct siw_cep *cep)
+{
+	spin_lock_bh(&cep->lock);
+	if (cep->mpa_timer) {
+		if (cancel_delayed_work(&cep->mpa_timer->work)) {
+			siw_cep_put(cep);
+			kfree(cep->mpa_timer); /* not needed again */
+		}
+		cep->mpa_timer = NULL;
+	}
+	spin_unlock_bh(&cep->lock);
+}
+
+static void siw_put_work(struct siw_cm_work *work)
+{
+	INIT_LIST_HEAD(&work->list);
+	spin_lock_bh(&work->cep->lock);
+	list_add(&work->list, &work->cep->work_freelist);
+	spin_unlock_bh(&work->cep->lock);
+}
+
+static void siw_cep_set_inuse(struct siw_cep *cep)
+{
+	unsigned long flags;
+	int rv;
+retry:
+	siw_dbg_cep(cep, "current in_use %d\n", cep->in_use);
+
+	spin_lock_irqsave(&cep->lock, flags);
+
+	if (cep->in_use) {
+		spin_unlock_irqrestore(&cep->lock, flags);
+		rv = wait_event_interruptible(cep->waitq, !cep->in_use);
+		if (signal_pending(current))
+			flush_signals(current);
+		goto retry;
+	} else {
+		cep->in_use = 1;
+		spin_unlock_irqrestore(&cep->lock, flags);
+	}
+}
+
+static void siw_cep_set_free(struct siw_cep *cep)
+{
+	unsigned long flags;
+
+	siw_dbg_cep(cep, "current in_use %d\n", cep->in_use);
+
+	spin_lock_irqsave(&cep->lock, flags);
+	cep->in_use = 0;
+	spin_unlock_irqrestore(&cep->lock, flags);
+
+	wake_up(&cep->waitq);
+}
+
+static void __siw_cep_dealloc(struct kref *ref)
+{
+	struct siw_cep *cep = container_of(ref, struct siw_cep, ref);
+	struct siw_device *sdev = cep->sdev;
+	unsigned long flags;
+
+	siw_dbg_cep(cep, "free object\n");
+
+	WARN_ON(cep->listen_cep);
+
+	/* kfree(NULL) is safe */
+	kfree(cep->mpa.pdata);
+	spin_lock_bh(&cep->lock);
+	if (!list_empty(&cep->work_freelist))
+		siw_cm_free_work(cep);
+	spin_unlock_bh(&cep->lock);
+
+	spin_lock_irqsave(&sdev->idr_lock, flags);
+	list_del(&cep->devq);
+	spin_unlock_irqrestore(&sdev->idr_lock, flags);
+	atomic_dec(&sdev->num_cep);
+	kfree(cep);
+}
+
+static struct siw_cm_work *siw_get_work(struct siw_cep *cep)
+{
+	struct siw_cm_work	*work = NULL;
+
+	spin_lock_bh(&cep->lock);
+	if (!list_empty(&cep->work_freelist)) {
+		work = list_entry(cep->work_freelist.next, struct siw_cm_work,
+				  list);
+		list_del_init(&work->list);
+	}
+	spin_unlock_bh(&cep->lock);
+	return work;
+}
+
+static int siw_cm_alloc_work(struct siw_cep *cep, int num)
+{
+	struct siw_cm_work	*work;
+
+	while (num--) {
+		work = kmalloc(sizeof(*work), GFP_KERNEL);
+		if (!work) {
+			if (!(list_empty(&cep->work_freelist)))
+				siw_cm_free_work(cep);
+			return -ENOMEM;
+		}
+		work->cep = cep;
+		INIT_LIST_HEAD(&work->list);
+		list_add(&work->list, &cep->work_freelist);
+	}
+	return 0;
+}
+
+/*
+ * siw_cm_upcall()
+ *
+ * Upcall to IWCM to inform about async connection events
+ */
+static int siw_cm_upcall(struct siw_cep *cep, enum iw_cm_event_type reason,
+			 int status)
+{
+	struct iw_cm_event	event;
+	struct iw_cm_id		*cm_id;
+
+	memset(&event, 0, sizeof(event));
+	event.status = status;
+	event.event = reason;
+
+	if (reason == IW_CM_EVENT_CONNECT_REQUEST) {
+		event.provider_data = cep;
+		cm_id = cep->listen_cep->cm_id;
+	} else {
+		cm_id = cep->cm_id;
+	}
+	/* Signal private data and address information */
+	if (reason == IW_CM_EVENT_CONNECT_REQUEST ||
+	    reason == IW_CM_EVENT_CONNECT_REPLY) {
+		u16 pd_len = be16_to_cpu(cep->mpa.hdr.params.pd_len);
+
+		if (pd_len && cep->enhanced_rdma_conn_est)
+			pd_len -= sizeof(struct mpa_v2_data);
+
+		if (pd_len) {
+			/*
+			 * hand over MPA private data
+			 */
+			event.private_data_len = pd_len;
+			event.private_data = cep->mpa.pdata;
+			/* Hide MPA V2 IRD/ORD control */
+			if (cep->enhanced_rdma_conn_est)
+				event.private_data +=
+					sizeof(struct mpa_v2_data);
+		}
+		to_sockaddr_in(event.local_addr) = cep->llp.laddr;
+		to_sockaddr_in(event.remote_addr) = cep->llp.raddr;
+	}
+	/* Signal IRD and ORD */
+	if (reason == IW_CM_EVENT_ESTABLISHED ||
+	    reason == IW_CM_EVENT_CONNECT_REPLY) {
+		/* Signal negotiated IRD/ORD values we will use */
+		event.ird = cep->ird;
+		event.ord = cep->ord;
+	} else if (reason == IW_CM_EVENT_CONNECT_REQUEST) {
+		event.ird = cep->ord;
+		event.ord = cep->ird;
+	}
+	siw_dbg_cep(cep, "[QP %d]: id 0x%p, reason=%d, status=%d\n",
+		    cep->qp ? QP_ID(cep->qp) : -1, cm_id, reason, status);
+
+	return cm_id->event_handler(cm_id, &event);
+}
+
+/*
+ * siw_qp_cm_drop()
+ *
+ * Drops established LLP connection if present and not already
+ * scheduled for dropping. Called from user context, SQ workqueue
+ * or receive IRQ. Caller signals if socket can be immediately
+ * closed (basically, if not in IRQ).
+ */
+void siw_qp_cm_drop(struct siw_qp *qp, int schedule)
+{
+	struct siw_cep *cep = qp->cep;
+
+	qp->rx_ctx.rx_suspend = 1;
+	qp->tx_ctx.tx_suspend = 1;
+
+	if (!qp->cep)
+		return;
+
+	if (schedule) {
+		siw_cm_queue_work(cep, SIW_CM_WORK_CLOSE_LLP);
+	} else {
+		siw_cep_set_inuse(cep);
+
+		if (cep->state == SIW_EPSTATE_CLOSED) {
+			siw_dbg_cep(cep, "already closed\n");
+			goto out;
+		}
+		siw_dbg_cep(cep, "immediate close, state %d\n", cep->state);
+
+		if (qp->term_info.valid)
+			siw_send_terminate(qp);
+
+		if (cep->cm_id) {
+			switch (cep->state) {
+
+			case SIW_EPSTATE_AWAIT_MPAREP:
+				siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+					      -EINVAL);
+				break;
+
+			case SIW_EPSTATE_RDMA_MODE:
+				siw_cm_upcall(cep, IW_CM_EVENT_CLOSE, 0);
+
+				break;
+
+			case SIW_EPSTATE_IDLE:
+			case SIW_EPSTATE_LISTENING:
+			case SIW_EPSTATE_CONNECTING:
+			case SIW_EPSTATE_AWAIT_MPAREQ:
+			case SIW_EPSTATE_RECVD_MPAREQ:
+			case SIW_EPSTATE_CLOSED:
+			default:
+
+				break;
+			}
+			cep->cm_id->rem_ref(cep->cm_id);
+			cep->cm_id = NULL;
+			siw_cep_put(cep);
+		}
+		cep->state = SIW_EPSTATE_CLOSED;
+
+		if (cep->llp.sock) {
+			siw_socket_disassoc(cep->llp.sock);
+			/*
+			 * Immediately close socket
+			 */
+			sock_release(cep->llp.sock);
+			cep->llp.sock = NULL;
+		}
+		if (cep->qp) {
+			cep->qp = NULL;
+			siw_qp_put(qp);
+		}
+out:
+		siw_cep_set_free(cep);
+	}
+}
+
+void siw_cep_put(struct siw_cep *cep)
+{
+	siw_dbg_cep(cep, "new refcount: %d\n", refcount_read(&cep->ref) - 1);
+
+	WARN_ON(refcount_read(&cep->ref) < 1);
+	kref_put(&cep->ref, __siw_cep_dealloc);
+}
+
+void siw_cep_get(struct siw_cep *cep)
+{
+	kref_get(&cep->ref);
+	siw_dbg_cep(cep, "new refcount: %d\n", refcount_read(&cep->ref));
+}
+
+static inline int ksock_recv(struct socket *sock, char *buf, size_t size,
+			     int flags)
+{
+	struct kvec iov = {buf, size};
+	struct msghdr msg = {.msg_name = NULL, .msg_flags = flags};
+
+	return kernel_recvmsg(sock, &msg, &iov, 1, size, flags);
+}
+
+/*
+ * Expects params->pd_len in host byte order
+ */
+static int siw_send_mpareqrep(struct siw_cep *cep, const void *pdata,
+			      u8 pd_len)
+{
+	struct socket	*s = cep->llp.sock;
+	struct mpa_rr	*rr = &cep->mpa.hdr;
+	struct kvec	iov[3];
+	struct msghdr	msg;
+	int		rv;
+	int		iovec_num = 0;
+	int		mpa_len;
+
+	memset(&msg, 0, sizeof(msg));
+
+	iov[iovec_num].iov_base = rr;
+	iov[iovec_num].iov_len = sizeof(*rr);
+	mpa_len = sizeof(*rr);
+
+	if (cep->enhanced_rdma_conn_est) {
+		iovec_num++;
+		iov[iovec_num].iov_base = &cep->mpa.v2_ctrl;
+		iov[iovec_num].iov_len = sizeof(cep->mpa.v2_ctrl);
+		mpa_len += sizeof(cep->mpa.v2_ctrl);
+	}
+	if (pd_len) {
+		iovec_num++;
+		iov[iovec_num].iov_base = (char *)pdata;
+		iov[iovec_num].iov_len = pd_len;
+		mpa_len += pd_len;
+	}
+	if (cep->enhanced_rdma_conn_est)
+		pd_len += sizeof(cep->mpa.v2_ctrl);
+
+	rr->params.pd_len = cpu_to_be16(pd_len);
+
+	rv = kernel_sendmsg(s, &msg, iov, iovec_num + 1, mpa_len);
+
+	return rv < 0 ? rv : 0;
+}
+
+/*
+ * Receive MPA Request/Reply header.
+ *
+ * Returns 0 if complete MPA Request/Reply haeder including
+ * eventual private data was received. Returns -EAGAIN if
+ * header was partially received or negative error code otherwise.
+ *
+ * Context: May be called in process context only
+ */
+static int siw_recv_mpa_rr(struct siw_cep *cep)
+{
+	struct mpa_rr	*hdr = &cep->mpa.hdr;
+	struct socket	*s = cep->llp.sock;
+	u16		pd_len;
+	int		rcvd, to_rcv;
+
+	if (cep->mpa.bytes_rcvd < sizeof(struct mpa_rr)) {
+
+		rcvd = ksock_recv(s, (char *)hdr + cep->mpa.bytes_rcvd,
+				  sizeof(struct mpa_rr) -
+				  cep->mpa.bytes_rcvd, 0);
+
+		if (rcvd <= 0)
+			return -ECONNABORTED;
+
+		cep->mpa.bytes_rcvd += rcvd;
+
+		if (cep->mpa.bytes_rcvd < sizeof(struct mpa_rr))
+			return -EAGAIN;
+
+		if (be16_to_cpu(hdr->params.pd_len) > MPA_MAX_PRIVDATA)
+			return -EPROTO;
+	}
+	pd_len = be16_to_cpu(hdr->params.pd_len);
+
+	/*
+	 * At least the MPA Request/Reply header (frame not including
+	 * private data) has been received.
+	 * Receive (or continue receiving) any private data.
+	 */
+	to_rcv = pd_len - (cep->mpa.bytes_rcvd - sizeof(struct mpa_rr));
+
+	if (!to_rcv) {
+		/*
+		 * We must have hdr->params.pd_len == 0 and thus received a
+		 * complete MPA Request/Reply frame.
+		 * Check against peer protocol violation.
+		 */
+		u32 word;
+
+		rcvd = ksock_recv(s, (char *)&word, sizeof(word), MSG_DONTWAIT);
+		if (rcvd == -EAGAIN)
+			return 0;
+
+		if (rcvd == 0) {
+			siw_dbg_cep(cep, "peer EOF\n");
+			return -EPIPE;
+		}
+		if (rcvd < 0) {
+			siw_dbg_cep(cep, "error: %d\n", rcvd);
+			return rcvd;
+		}
+		siw_dbg_cep(cep, "peer sent extra data: %d\n", rcvd);
+
+		return -EPROTO;
+	}
+
+	/*
+	 * At this point, we must have hdr->params.pd_len != 0.
+	 * A private data buffer gets allocated if hdr->params.pd_len != 0.
+	 */
+	if (!cep->mpa.pdata) {
+		cep->mpa.pdata = kmalloc(pd_len + 4, GFP_KERNEL);
+		if (!cep->mpa.pdata)
+			return -ENOMEM;
+	}
+	rcvd = ksock_recv(s, cep->mpa.pdata + cep->mpa.bytes_rcvd
+			  - sizeof(struct mpa_rr), to_rcv + 4, MSG_DONTWAIT);
+
+	if (rcvd < 0)
+		return rcvd;
+
+	if (rcvd > to_rcv)
+		return -EPROTO;
+
+	cep->mpa.bytes_rcvd += rcvd;
+
+	if (to_rcv == rcvd) {
+		siw_dbg_cep(cep, "%d bytes private data received\n", pd_len);
+		return 0;
+	}
+	return -EAGAIN;
+}
+
+/*
+ * siw_proc_mpareq()
+ *
+ * Read MPA Request from socket and signal new connection to IWCM
+ * if success. Caller must hold lock on corresponding listening CEP.
+ */
+static int siw_proc_mpareq(struct siw_cep *cep)
+{
+	struct mpa_rr	*req;
+	int		version, rv;
+	u16		pd_len;
+
+	rv = siw_recv_mpa_rr(cep);
+	if (rv)
+		return rv;
+
+	req = &cep->mpa.hdr;
+
+	version = __mpa_rr_revision(req->params.bits);
+	pd_len = be16_to_cpu(req->params.pd_len);
+
+	if (version > MPA_REVISION_2)
+		/* allow for 0, 1, and 2 only */
+		return -EPROTO;
+
+	if (memcmp(req->key, MPA_KEY_REQ, 16))
+		return -EPROTO;
+
+	/* Prepare for sending MPA reply */
+	memcpy(req->key, MPA_KEY_REP, 16);
+
+	if (version == MPA_REVISION_2 &&
+	    (req->params.bits & MPA_RR_FLAG_ENHANCED)) {
+		/*
+		 * MPA version 2 must signal IRD/ORD values and P2P mode
+		 * in private data if header flag MPA_RR_FLAG_ENHANCED
+		 * is set.
+		 */
+		if (pd_len < sizeof(struct mpa_v2_data))
+			goto reject_conn;
+
+		cep->enhanced_rdma_conn_est = true;
+	}
+
+	/* MPA Markers: currently not supported. Marker TX to be added. */
+	if (req->params.bits & MPA_RR_FLAG_MARKERS)
+		goto reject_conn;
+
+	if (req->params.bits & MPA_RR_FLAG_CRC) {
+		/*
+		 * RFC 5044, page 27: CRC MUST be used if peer requests it.
+		 * siw specific: 'mpa_crc_strict' parameter to reject
+		 * connection with CRC if local CRC off enforced by
+		 * 'mpa_crc_strict' module parameter.
+		 */
+		if (!mpa_crc_required && mpa_crc_strict)
+			goto reject_conn;
+
+		/* Enable CRC if requested by module parameter */
+		if (mpa_crc_required)
+			req->params.bits |= MPA_RR_FLAG_CRC;
+	}
+
+	if (cep->enhanced_rdma_conn_est) {
+		struct mpa_v2_data *v2 = (struct mpa_v2_data *)cep->mpa.pdata;
+
+		/*
+		 * Peer requested ORD becomes requested local IRD,
+		 * peer requested IRD becomes requested local ORD.
+		 * IRD and ORD get limited by global maximum values.
+		 */
+		cep->ord = ntohs(v2->ird) & MPA_IRD_ORD_MASK;
+		cep->ord = min(cep->ord, SIW_MAX_ORD_QP);
+		cep->ird = ntohs(v2->ord) & MPA_IRD_ORD_MASK;
+		cep->ird = min(cep->ird, SIW_MAX_IRD_QP);
+
+		/* May get overwritten by locally negotiated values */
+		cep->mpa.v2_ctrl.ird = htons(cep->ird);
+		cep->mpa.v2_ctrl.ord = htons(cep->ord);
+
+		/*
+		 * Support for peer sent zero length Write or Read to
+		 * let local side enter RTS. Writes are preferred.
+		 * Sends would require pre-posting a Receive and are
+		 * not supported.
+		 * Propose zero length Write if none of Read and Write
+		 * is indicated.
+		 */
+		if (v2->ird & MPA_V2_PEER_TO_PEER) {
+			cep->mpa.v2_ctrl.ird |= MPA_V2_PEER_TO_PEER;
+
+			if (v2->ord & MPA_V2_RDMA_WRITE_RTR)
+				cep->mpa.v2_ctrl.ord |= MPA_V2_RDMA_WRITE_RTR;
+			else if (v2->ord & MPA_V2_RDMA_READ_RTR)
+				cep->mpa.v2_ctrl.ord |= MPA_V2_RDMA_READ_RTR;
+			else
+				cep->mpa.v2_ctrl.ord |= MPA_V2_RDMA_WRITE_RTR;
+		}
+	}
+
+	cep->state = SIW_EPSTATE_RECVD_MPAREQ;
+
+	/* Keep reference until IWCM accepts/rejects */
+	siw_cep_get(cep);
+	rv = siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REQUEST, 0);
+	if (rv)
+		siw_cep_put(cep);
+
+	return rv;
+
+reject_conn:
+	siw_dbg_cep(cep, "reject: crc %d:%d:%d, m %d:%d\n",
+		    req->params.bits & MPA_RR_FLAG_CRC ? 1 : 0,
+		    mpa_crc_required, mpa_crc_strict,
+		    req->params.bits & MPA_RR_FLAG_MARKERS ? 1 : 0, 0);
+
+	req->params.bits &= ~MPA_RR_FLAG_MARKERS;
+	req->params.bits |= MPA_RR_FLAG_REJECT;
+
+	if (!mpa_crc_required && mpa_crc_strict)
+		req->params.bits &= ~MPA_RR_FLAG_CRC;
+
+	if (pd_len)
+		kfree(cep->mpa.pdata);
+
+	cep->mpa.pdata = NULL;
+
+	(void)siw_send_mpareqrep(cep, NULL, 0);
+
+	return -EOPNOTSUPP;
+}
+
+static int siw_proc_mpareply(struct siw_cep *cep)
+{
+	struct siw_qp_attrs	qp_attrs;
+	enum siw_qp_attr_mask	qp_attr_mask;
+	struct siw_qp		*qp = cep->qp;
+	struct mpa_rr		*rep;
+	int			rv;
+	u16			rep_ord;
+	u16			rep_ird;
+	bool			ird_insufficient = false;
+	enum mpa_v2_ctrl	mpa_p2p_mode = MPA_V2_RDMA_NO_RTR;
+
+	rv = siw_recv_mpa_rr(cep);
+	if (rv != -EAGAIN)
+		siw_cancel_mpatimer(cep);
+	if (rv)
+		goto out_err;
+
+	rep = &cep->mpa.hdr;
+
+	if (__mpa_rr_revision(rep->params.bits) > MPA_REVISION_2) {
+		/* allow for 0, 1,  and 2 only */
+		rv = -EPROTO;
+		goto out_err;
+	}
+	if (memcmp(rep->key, MPA_KEY_REP, 16)) {
+		siw_init_terminate(qp, TERM_ERROR_LAYER_LLP,
+				   LLP_ETYPE_MPA,
+				   LLP_ECODE_INVALID_REQ_RESP, 0);
+		siw_send_terminate(qp);
+		rv = -EPROTO;
+		goto out_err;
+	}
+	if (rep->params.bits & MPA_RR_FLAG_REJECT) {
+		siw_dbg_cep(cep, "got mpa reject\n");
+		(void)siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+				    -ECONNRESET);
+
+		return -ECONNRESET;
+	}
+	if ((rep->params.bits & MPA_RR_FLAG_MARKERS)
+		|| (mpa_crc_required && !(rep->params.bits & MPA_RR_FLAG_CRC))
+		|| (mpa_crc_strict && !mpa_crc_required
+			&& (rep->params.bits & MPA_RR_FLAG_CRC))) {
+
+		siw_dbg_cep(cep, "reply unsupp: crc %d:%d:%d, m %d:%d\n",
+			    rep->params.bits & MPA_RR_FLAG_CRC ? 1 : 0,
+			    mpa_crc_required, mpa_crc_strict,
+			    rep->params.bits & MPA_RR_FLAG_MARKERS ? 1 : 0, 0);
+
+		(void)siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+				    -ECONNREFUSED);
+		return -EINVAL;
+	}
+
+	if (cep->enhanced_rdma_conn_est) {
+		struct mpa_v2_data *v2;
+
+		if (__mpa_rr_revision(rep->params.bits) < MPA_REVISION_2 ||
+		    !(rep->params.bits & MPA_RR_FLAG_ENHANCED)) {
+			/*
+			 * Protocol failure: The responder MUST reply with
+			 * MPA version 2 and MUST set MPA_RR_FLAG_ENHANCED.
+			 */
+			siw_dbg_cep(cep, "mpa reply error: vers %d, enhcd %d\n",
+				__mpa_rr_revision(rep->params.bits),
+				rep->params.bits & MPA_RR_FLAG_ENHANCED ? 1:0);
+
+			(void)siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+					    -ECONNRESET);
+			return -EINVAL;
+		}
+		v2 = (struct mpa_v2_data *)cep->mpa.pdata;
+		rep_ird = ntohs(v2->ird) & MPA_IRD_ORD_MASK;
+		rep_ord = ntohs(v2->ord) & MPA_IRD_ORD_MASK;
+
+		if (cep->ird < rep_ord &&
+		    (relaxed_ird_negotiation == false ||
+		     rep_ord > cep->sdev->attrs.max_ird)) {
+			siw_dbg_cep(cep, "ird %d, rep_ord %d, max_ord %d\n",
+				    cep->ird, rep_ord,
+				    cep->sdev->attrs.max_ord);
+			ird_insufficient = true;
+		}
+		if (cep->ord > rep_ird && relaxed_ird_negotiation == false) {
+			siw_dbg_cep(cep, "ord %d, rep_ird %d\n",
+				    cep->ord, rep_ird);
+			ird_insufficient = true;
+		}
+		/*
+		 * Always report negotiated peer values to user,
+		 * even if IRD/ORD negotiation failed
+		 */
+		cep->ird = rep_ord;
+		cep->ord = rep_ird;
+
+		if (ird_insufficient) {
+			/*
+			 * If the initiator IRD is insuffient for the
+			 * responder ORD, send a TERM.
+			 */
+			siw_init_terminate(qp, TERM_ERROR_LAYER_LLP,
+					   LLP_ETYPE_MPA,
+					   LLP_ECODE_INSUFFICIENT_IRD, 0);
+			siw_send_terminate(qp);
+			rv = -ENOMEM;
+			goto out_err;
+		}
+
+		if (cep->mpa.v2_ctrl_req.ird & MPA_V2_PEER_TO_PEER)
+			mpa_p2p_mode = cep->mpa.v2_ctrl_req.ord &
+				(MPA_V2_RDMA_WRITE_RTR | MPA_V2_RDMA_READ_RTR);
+
+		/*
+		 * Check if we requested P2P mode, and if peer agrees
+		 */
+		if (mpa_p2p_mode != MPA_V2_RDMA_NO_RTR) {
+			if ((mpa_p2p_mode & v2->ord) == 0) {
+				/*
+				 * We requested RTR mode(s), but the peer
+				 * did not pick any mode we support.
+				 */
+				siw_dbg_cep(cep,
+					"rtr mode:  req %2x, got %2x\n",
+					mpa_p2p_mode,
+					v2->ord & (MPA_V2_RDMA_WRITE_RTR |
+						   MPA_V2_RDMA_READ_RTR));
+
+				siw_init_terminate(qp, TERM_ERROR_LAYER_LLP,
+						   LLP_ETYPE_MPA,
+						   LLP_ECODE_NO_MATCHING_RTR,
+						   0);
+				siw_send_terminate(qp);
+				rv = -EPROTO;
+				goto out_err;
+			}
+			mpa_p2p_mode = v2->ord &
+				(MPA_V2_RDMA_WRITE_RTR | MPA_V2_RDMA_READ_RTR);
+		}
+	}
+
+	memset(&qp_attrs, 0, sizeof(qp_attrs));
+
+	if (rep->params.bits & MPA_RR_FLAG_CRC)
+		qp_attrs.flags = SIW_MPA_CRC;
+
+	qp_attrs.irq_size = cep->ird;
+	qp_attrs.orq_size = cep->ord;
+	qp_attrs.llp_stream_handle = cep->llp.sock;
+	qp_attrs.state = SIW_QP_STATE_RTS;
+
+	qp_attr_mask = SIW_QP_ATTR_STATE | SIW_QP_ATTR_LLP_HANDLE |
+		       SIW_QP_ATTR_ORD | SIW_QP_ATTR_IRD | SIW_QP_ATTR_MPA;
+
+	/* Move socket RX/TX under QP control */
+	down_write(&qp->state_lock);
+	if (qp->attrs.state > SIW_QP_STATE_RTR) {
+		rv = -EINVAL;
+		up_write(&qp->state_lock);
+		goto out_err;
+	}
+	rv = siw_qp_modify(qp, &qp_attrs, qp_attr_mask);
+
+	siw_qp_socket_assoc(cep, qp);
+
+	up_write(&qp->state_lock);
+
+	/* Send extra RDMA frame to trigger peer RTS if negotiated */
+	if (mpa_p2p_mode != MPA_V2_RDMA_NO_RTR) {
+		rv = siw_qp_mpa_rts(qp, mpa_p2p_mode);
+		if (rv)
+			goto out_err;
+	}
+
+	if (!rv) {
+		rv = siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY, 0);
+		if (!rv)
+			cep->state = SIW_EPSTATE_RDMA_MODE;
+
+		return 0;
+	}
+
+out_err:
+	(void)siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY, -EINVAL);
+
+	return rv;
+}
+
+/*
+ * siw_accept_newconn - accept an incoming pending connection
+ *
+ */
+static void siw_accept_newconn(struct siw_cep *cep)
+{
+	struct socket		*s = cep->llp.sock;
+	struct socket		*new_s = NULL;
+	struct siw_cep		*new_cep = NULL;
+	int			rv = 0; /* debug only. should disappear */
+
+	if (cep->state != SIW_EPSTATE_LISTENING)
+		goto error;
+
+	new_cep = siw_cep_alloc(cep->sdev);
+	if (!new_cep)
+		goto error;
+
+	/*
+	 * 4: Allocate a sufficient number of work elements
+	 * to allow concurrent handling of local + peer close
+	 * events, MPA header processing + MPA timeout.
+	 */
+	if (siw_cm_alloc_work(new_cep, 4) != 0)
+		goto error;
+
+	/*
+	 * Copy saved socket callbacks from listening CEP
+	 * and assign new socket with new CEP
+	 */
+	new_cep->sk_state_change = cep->sk_state_change;
+	new_cep->sk_data_ready   = cep->sk_data_ready;
+	new_cep->sk_write_space  = cep->sk_write_space;
+	new_cep->sk_error_report = cep->sk_error_report;
+
+	rv = kernel_accept(s, &new_s, O_NONBLOCK);
+	if (rv != 0) {
+		/*
+		 * Connection already aborted by peer..?
+		 */
+		siw_dbg_cep(cep, "kernel_accept() error: %d\n", rv);
+		goto error;
+	}
+	new_cep->llp.sock = new_s;
+	siw_cep_get(new_cep);
+	new_s->sk->sk_user_data = new_cep;
+
+	siw_dbg_cep(cep, "listen socket 0x%p, new 0x%p\n", s, new_s);
+
+	rv = siw_sock_nodelay(new_s);
+	if (rv) {
+		siw_dbg_cep(cep, "siw_sock_nodelay() error: %d\n", rv);
+		goto error;
+	}
+
+	rv = kernel_peername(new_s, &new_cep->llp.raddr);
+	if (rv) {
+		siw_dbg_cep(cep, "kernel_peername() error: %d\n", rv);
+		goto error;
+	}
+	rv = kernel_localname(new_s, &new_cep->llp.laddr);
+	if (rv) {
+		siw_dbg_cep(cep, "kernel_localname() error: %d\n", rv);
+		goto error;
+	}
+
+	new_cep->state = SIW_EPSTATE_AWAIT_MPAREQ;
+
+	rv = siw_cm_queue_work(new_cep, SIW_CM_WORK_MPATIMEOUT);
+	if (rv)
+		goto error;
+	/*
+	 * See siw_proc_mpareq() etc. for the use of new_cep->listen_cep.
+	 */
+	new_cep->listen_cep = cep;
+	siw_cep_get(cep);
+
+	if (atomic_read(&new_s->sk->sk_rmem_alloc)) {
+		/*
+		 * MPA REQ already queued
+		 */
+		siw_dbg_cep(cep, "immediate mpa request\n");
+
+		siw_cep_set_inuse(new_cep);
+		rv = siw_proc_mpareq(new_cep);
+		siw_cep_set_free(new_cep);
+
+		if (rv != -EAGAIN) {
+			siw_cep_put(cep);
+			new_cep->listen_cep = NULL;
+			if (rv)
+				goto error;
+		}
+	}
+	return;
+
+error:
+	if (new_cep)
+		siw_cep_put(new_cep);
+
+	if (new_s) {
+		siw_socket_disassoc(new_s);
+		sock_release(new_s);
+		new_cep->llp.sock = NULL;
+	}
+	siw_dbg_cep(cep, "error %d\n", rv);
+}
+
+static void siw_cm_work_handler(struct work_struct *w)
+{
+	struct siw_cm_work	*work;
+	struct siw_cep		*cep;
+	int release_cep = 0, rv = 0;
+
+	work = container_of(w, struct siw_cm_work, work.work);
+	cep = work->cep;
+
+	siw_dbg_cep(cep, "[QP %d]: work type: %d, state %d\n",
+		    cep->qp ? QP_ID(cep->qp) : -1, work->type, cep->state);
+
+	siw_cep_set_inuse(cep);
+
+	switch (work->type) {
+
+	case SIW_CM_WORK_ACCEPT:
+
+		siw_accept_newconn(cep);
+		break;
+
+	case SIW_CM_WORK_READ_MPAHDR:
+
+		switch (cep->state) {
+
+		case SIW_EPSTATE_AWAIT_MPAREQ:
+
+			if (cep->listen_cep) {
+				siw_cep_set_inuse(cep->listen_cep);
+
+				if (cep->listen_cep->state ==
+				    SIW_EPSTATE_LISTENING)
+					rv = siw_proc_mpareq(cep);
+				else
+					rv = -EFAULT;
+
+				siw_cep_set_free(cep->listen_cep);
+
+				if (rv != -EAGAIN) {
+					siw_cep_put(cep->listen_cep);
+					cep->listen_cep = NULL;
+					if (rv)
+						siw_cep_put(cep);
+				}
+			}
+			break;
+
+		case SIW_EPSTATE_AWAIT_MPAREP:
+
+			rv = siw_proc_mpareply(cep);
+			break;
+
+		default:
+			/*
+			 * CEP already moved out of MPA handshake.
+			 * any connection management already done.
+			 * silently ignore the mpa packet.
+			 */
+			if (cep->state == SIW_EPSTATE_RDMA_MODE) {
+				cep->llp.sock->sk->sk_data_ready(
+					cep->llp.sock->sk);
+				siw_dbg_cep(cep, "already in RDMA mode");
+			} else {
+				siw_dbg_cep(cep, "out of state: %d\n",
+					    cep->state);
+			}
+		}
+		if (rv && rv != EAGAIN)
+			release_cep = 1;
+
+		break;
+
+	case SIW_CM_WORK_CLOSE_LLP:
+		/*
+		 * QP scheduled LLP close
+		 */
+		siw_dbg_cep(cep, "work close_llp, state=%d\n", cep->state);
+
+		if (cep->qp && cep->qp->term_info.valid)
+			siw_send_terminate(cep->qp);
+
+		if (cep->cm_id)
+			siw_cm_upcall(cep, IW_CM_EVENT_CLOSE, 0);
+
+		release_cep = 1;
+
+		break;
+
+	case SIW_CM_WORK_PEER_CLOSE:
+
+		siw_dbg_cep(cep, "work peer_close, state=%d\n", cep->state);
+
+		if (cep->cm_id) {
+			switch (cep->state) {
+
+			case SIW_EPSTATE_AWAIT_MPAREP:
+				/*
+				 * MPA reply not received, but connection drop
+				 */
+				siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+					      -ECONNRESET);
+				break;
+
+			case SIW_EPSTATE_RDMA_MODE:
+				/*
+				 * NOTE: IW_CM_EVENT_DISCONNECT is given just
+				 *       to transition IWCM into CLOSING.
+				 */
+				siw_cm_upcall(cep, IW_CM_EVENT_DISCONNECT, 0);
+				siw_cm_upcall(cep, IW_CM_EVENT_CLOSE, 0);
+
+				break;
+
+			default:
+
+				break;
+				/*
+				 * for these states there is no connection
+				 * known to the IWCM.
+				 */
+			}
+		} else {
+			switch (cep->state) {
+
+			case SIW_EPSTATE_RECVD_MPAREQ:
+				/*
+				 * Wait for the ulp/CM to call accept/reject
+				 */
+				siw_dbg_cep(cep,
+					    "mpa req recvd, wait for ULP\n");
+				break;
+
+			case SIW_EPSTATE_AWAIT_MPAREQ:
+				/*
+				 * Socket close before MPA request received.
+				 */
+				siw_dbg_cep(cep, "no mpareq: drop listener\n");
+				siw_cep_put(cep->listen_cep);
+				cep->listen_cep = NULL;
+
+				break;
+
+			default:
+				break;
+			}
+		}
+		release_cep = 1;
+
+		break;
+
+	case SIW_CM_WORK_MPATIMEOUT:
+
+		cep->mpa_timer = NULL;
+
+		if (cep->state == SIW_EPSTATE_AWAIT_MPAREP) {
+			/*
+			 * MPA request timed out:
+			 * Hide any partially received private data and signal
+			 * timeout
+			 */
+			cep->mpa.hdr.params.pd_len = 0;
+
+			if (cep->cm_id)
+				siw_cm_upcall(cep, IW_CM_EVENT_CONNECT_REPLY,
+					      -ETIMEDOUT);
+			release_cep = 1;
+
+		} else if (cep->state == SIW_EPSTATE_AWAIT_MPAREQ) {
+			/*
+			 * No MPA request received after peer TCP stream setup.
+			 */
+			if (cep->listen_cep) {
+				siw_cep_put(cep->listen_cep);
+				cep->listen_cep = NULL;
+			}
+			release_cep = 1;
+		}
+		break;
+
+	default:
+		WARN(1, "Undefined CM work type: %d\n", work->type);
+	}
+
+	if (release_cep) {
+		siw_dbg_cep(cep,
+			    "release: timer=%s, sock=0x%p, QP %d, id 0x%p\n",
+			    cep->mpa_timer ? "y" : "n", cep->llp.sock,
+			    cep->qp ? QP_ID(cep->qp) : -1, cep->cm_id);
+
+		siw_cancel_mpatimer(cep);
+
+		cep->state = SIW_EPSTATE_CLOSED;
+
+		if (cep->qp) {
+			struct siw_qp *qp = cep->qp;
+			/*
+			 * Serialize a potential race with application
+			 * closing the QP and calling siw_qp_cm_drop()
+			 */
+			siw_qp_get(qp);
+			siw_cep_set_free(cep);
+
+			siw_qp_llp_close(qp);
+			siw_qp_put(qp);
+
+			siw_cep_set_inuse(cep);
+			cep->qp = NULL;
+			siw_qp_put(qp);
+		}
+		if (cep->llp.sock) {
+			siw_socket_disassoc(cep->llp.sock);
+			sock_release(cep->llp.sock);
+			cep->llp.sock = NULL;
+		}
+		if (cep->cm_id) {
+			cep->cm_id->rem_ref(cep->cm_id);
+			cep->cm_id = NULL;
+			siw_cep_put(cep);
+		}
+	}
+
+	siw_cep_set_free(cep);
+	siw_dbg_cep(cep, "Exit: work type: %d\n", work->type);
+
+	siw_put_work(work);
+	siw_cep_put(cep);
+}
+
+static struct workqueue_struct *siw_cm_wq;
+
+int siw_cm_queue_work(struct siw_cep *cep, enum siw_work_type type)
+{
+	struct siw_cm_work *work = siw_get_work(cep);
+	unsigned long delay = 0;
+
+	if (!work) {
+		siw_dbg_cep(cep, "failed with no work available\n");
+		return -ENOMEM;
+	}
+	work->type = type;
+	work->cep = cep;
+
+	siw_cep_get(cep);
+
+	INIT_DELAYED_WORK(&work->work, siw_cm_work_handler);
+
+	if (type == SIW_CM_WORK_MPATIMEOUT) {
+		cep->mpa_timer = work;
+
+		if (cep->state == SIW_EPSTATE_AWAIT_MPAREP)
+			delay = MPAREQ_TIMEOUT;
+		else
+			delay = MPAREP_TIMEOUT;
+	}
+	siw_dbg_cep(cep, "[QP %d]: work type: %d, work 0x%p, timeout %lu\n",
+		    cep->qp ? QP_ID(cep->qp) : -1, type, work, delay);
+
+	queue_delayed_work(siw_cm_wq, &work->work, delay);
+
+	return 0;
+}
+
+static void siw_cm_llp_data_ready(struct sock *sk)
+{
+	struct siw_cep	*cep;
+
+	read_lock(&sk->sk_callback_lock);
+
+	cep = sk_to_cep(sk);
+	if (!cep) {
+		WARN_ON(1);
+		goto out;
+	}
+
+	siw_dbg_cep(cep, "state: %d\n", cep->state);
+
+	switch (cep->state) {
+
+	case SIW_EPSTATE_RDMA_MODE:
+		/* fall through */
+	case SIW_EPSTATE_LISTENING:
+
+		break;
+
+	case SIW_EPSTATE_AWAIT_MPAREQ:
+		/* fall through */
+	case SIW_EPSTATE_AWAIT_MPAREP:
+
+		siw_cm_queue_work(cep, SIW_CM_WORK_READ_MPAHDR);
+		break;
+
+	default:
+		siw_dbg_cep(cep, "unexpected data, state %d\n", cep->state);
+		break;
+	}
+out:
+	read_unlock(&sk->sk_callback_lock);
+}
+
+static void siw_cm_llp_write_space(struct sock *sk)
+{
+	struct siw_cep	*cep = sk_to_cep(sk);
+
+	if (cep)
+		siw_dbg_cep(cep, "state: %d\n", cep->state);
+}
+
+static void siw_cm_llp_error_report(struct sock *sk)
+{
+	struct siw_cep	*cep = sk_to_cep(sk);
+
+	if (cep) {
+		siw_dbg_cep(cep, "error %d, socket state: %d, cep state: %d\n",
+			    sk->sk_err, sk->sk_state, cep->state);
+		cep->sk_error = sk->sk_err;
+		cep->sk_error_report(sk);
+	}
+}
+
+static void siw_cm_llp_state_change(struct sock *sk)
+{
+	struct siw_cep	*cep;
+	struct socket	*s;
+	void (*orig_state_change)(struct sock *);
+
+	read_lock(&sk->sk_callback_lock);
+
+	cep = sk_to_cep(sk);
+	if (!cep) {
+		/* endpoint already disassociated */
+		read_unlock(&sk->sk_callback_lock);
+		return;
+	}
+	orig_state_change = cep->sk_state_change;
+
+	s = sk->sk_socket;
+
+	siw_dbg_cep(cep, "state: %d\n", cep->state);
+
+	switch (sk->sk_state) {
+
+	case TCP_ESTABLISHED:
+		/*
+		 * handle accepting socket as special case where only
+		 * new connection is possible
+		 */
+		siw_cm_queue_work(cep, SIW_CM_WORK_ACCEPT);
+
+		break;
+
+	case TCP_CLOSE:
+	case TCP_CLOSE_WAIT:
+
+		if (cep->qp)
+			cep->qp->tx_ctx.tx_suspend = 1;
+		siw_cm_queue_work(cep, SIW_CM_WORK_PEER_CLOSE);
+
+		break;
+
+	default:
+		siw_dbg_cep(cep, "unexpected socket state %d\n", sk->sk_state);
+	}
+	read_unlock(&sk->sk_callback_lock);
+	orig_state_change(sk);
+}
+
+static int kernel_bindconnect(struct socket *s,
+			      struct sockaddr *laddr, int laddrlen,
+			      struct sockaddr *raddr, int raddrlen, int flags)
+{
+	int rv, s_val = 1;
+
+	/*
+	 * Make address available again asap.
+	 */
+	rv = kernel_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&s_val,
+				sizeof(s_val));
+	if (rv < 0)
+		return rv;
+
+	rv = s->ops->bind(s, laddr, laddrlen);
+	if (rv < 0)
+		return rv;
+
+	rv = s->ops->connect(s, raddr, raddrlen, flags);
+	if (rv < 0)
+		return rv;
+
+	return s->ops->getname(s, laddr, &s_val, 0);
+}
+
+int siw_connect(struct iw_cm_id *id, struct iw_cm_conn_param *params)
+{
+	struct siw_device *sdev = siw_dev_base2siw(id->device);
+	struct siw_qp *qp;
+	struct siw_cep *cep = NULL;
+	struct socket *s = NULL;
+	struct sockaddr	*laddr, *raddr;
+	bool p2p_mode = peer_to_peer;
+
+	u16 pd_len = params->private_data_len;
+	int version = mpa_version, rv;
+
+	if (pd_len > MPA_MAX_PRIVDATA)
+		return -EINVAL;
+
+	if (params->ird > sdev->attrs.max_ird ||
+	    params->ord > sdev->attrs.max_ord)
+		return -ENOMEM;
+
+	qp = siw_qp_id2obj(sdev, params->qpn);
+	if (!qp) {
+		WARN(1, "[QP %u] does not exist\n", params->qpn);
+		rv = -EINVAL;
+		goto error;
+	}
+
+	siw_dbg_qp(qp, "id 0x%p, pd_len %d, laddr 0x%x:%d, raddr 0x%x:%d\n",
+		   id, pd_len,
+		   ntohl(to_sockaddr_in(id->local_addr).sin_addr.s_addr),
+		   ntohs(to_sockaddr_in(id->local_addr).sin_port),
+		   ntohl(to_sockaddr_in(id->remote_addr).sin_addr.s_addr),
+		   ntohs(to_sockaddr_in(id->remote_addr).sin_port));
+
+	laddr = (struct sockaddr *)&id->local_addr;
+	raddr = (struct sockaddr *)&id->remote_addr;
+
+	rv = sock_create(AF_INET, SOCK_STREAM, IPPROTO_TCP, &s);
+	if (rv < 0)
+		goto error;
+
+	/*
+	 * NOTE: For simplification, connect() is called in blocking
+	 * mode. Might be reconsidered for async connection setup at
+	 * TCP level.
+	 */
+	rv = kernel_bindconnect(s, laddr, sizeof(*laddr), raddr,
+				sizeof(*raddr), 0);
+	if (rv != 0) {
+		siw_dbg_qp(qp, "id 0x%p: kernel_bindconnect: rv %d\n", id, rv);
+		goto error;
+	}
+	rv = siw_sock_nodelay(s);
+	if (rv != 0) {
+		siw_dbg_qp(qp, "siw_sock_nodelay() error: %d\n", rv);
+		goto error;
+	}
+	cep = siw_cep_alloc(sdev);
+	if (!cep) {
+		rv =  -ENOMEM;
+		goto error;
+	}
+	siw_cep_set_inuse(cep);
+
+	/* Associate QP with CEP */
+	siw_cep_get(cep);
+	qp->cep = cep;
+
+	/* siw_qp_get(qp) already done by QP lookup */
+	cep->qp = qp;
+
+	id->add_ref(id);
+	cep->cm_id = id;
+
+	/*
+	 * 4: Allocate a sufficient number of work elements
+	 * to allow concurrent handling of local + peer close
+	 * events, MPA header processing + MPA timeout.
+	 */
+	rv = siw_cm_alloc_work(cep, 4);
+	if (rv != 0) {
+		rv = -ENOMEM;
+		goto error;
+	}
+	cep->ird = params->ird;
+	cep->ord = params->ord;
+
+	if (p2p_mode && cep->ord == 0)
+		cep->ord = 1;
+
+	cep->state = SIW_EPSTATE_CONNECTING;
+
+	rv = kernel_peername(s, &cep->llp.raddr);
+	if (rv)
+		goto error;
+
+	rv = kernel_localname(s, &cep->llp.laddr);
+	if (rv)
+		goto error;
+
+	/*
+	 * Associate CEP with socket
+	 */
+	siw_cep_socket_assoc(cep, s);
+
+	cep->state = SIW_EPSTATE_AWAIT_MPAREP;
+
+	/*
+	 * Set MPA Request bits: CRC if required, no MPA Markers,
+	 * MPA Rev. according to module parameter 'mpa_version', Key 'Request'.
+	 */
+	cep->mpa.hdr.params.bits = 0;
+	if (version > MPA_REVISION_2) {
+		pr_warn("Setting MPA version to %u\n", MPA_REVISION_2);
+		version = MPA_REVISION_2;
+		/* Adjust also module parameter */
+		mpa_version = MPA_REVISION_2;
+	}
+	__mpa_rr_set_revision(&cep->mpa.hdr.params.bits, version);
+
+	if (mpa_crc_required)
+		cep->mpa.hdr.params.bits |= MPA_RR_FLAG_CRC;
+
+	/*
+	 * If MPA version == 2:
+	 * o Include ORD and IRD.
+	 * o Indicate peer-to-peer mode, if required by module
+	 *   parameter 'peer_to_peer'.
+	 */
+	if (version == MPA_REVISION_2) {
+		cep->enhanced_rdma_conn_est = true;
+		cep->mpa.hdr.params.bits |= MPA_RR_FLAG_ENHANCED;
+
+		cep->mpa.v2_ctrl.ird = htons(cep->ird);
+		cep->mpa.v2_ctrl.ord = htons(cep->ord);
+
+		if (p2p_mode) {
+			cep->mpa.v2_ctrl.ird |= MPA_V2_PEER_TO_PEER;
+			cep->mpa.v2_ctrl.ord |= rtr_type;
+		}
+		/* Remember own P2P mode requested */
+		cep->mpa.v2_ctrl_req.ird = cep->mpa.v2_ctrl.ird;
+		cep->mpa.v2_ctrl_req.ord = cep->mpa.v2_ctrl.ord;
+	}
+
+	memcpy(cep->mpa.hdr.key, MPA_KEY_REQ, 16);
+
+	rv = siw_send_mpareqrep(cep, params->private_data, pd_len);
+	/*
+	 * Reset private data.
+	 */
+	cep->mpa.hdr.params.pd_len = 0;
+
+	if (rv >= 0) {
+		rv = siw_cm_queue_work(cep, SIW_CM_WORK_MPATIMEOUT);
+		if (!rv) {
+			siw_dbg_cep(cep, "id 0x%p, [QP %d]: exit\n",
+				    id, QP_ID(qp));
+			siw_cep_set_free(cep);
+			return 0;
+		}
+	}
+error:
+	siw_dbg_qp(qp, "failed: %d\n", rv);
+
+	if (cep) {
+		siw_socket_disassoc(s);
+		sock_release(s);
+		cep->llp.sock = NULL;
+
+		cep->qp = NULL;
+
+		cep->cm_id = NULL;
+		id->rem_ref(id);
+		siw_cep_put(cep);
+
+		qp->cep = NULL;
+		siw_cep_put(cep);
+
+		cep->state = SIW_EPSTATE_CLOSED;
+
+		siw_cep_set_free(cep);
+
+		siw_cep_put(cep);
+
+	} else if (s) {
+		sock_release(s);
+	}
+	siw_qp_put(qp);
+
+	return rv;
+}
+
+/*
+ * siw_accept - Let SoftiWARP accept an RDMA connection request
+ *
+ * @id:		New connection management id to be used for accepted
+ *		connection request
+ * @params:	Connection parameters provided by ULP for accepting connection
+ *
+ * Transition QP to RTS state, associate new CM id @id with accepted CEP
+ * and get prepared for TCP input by installing socket callbacks.
+ * Then send MPA Reply and generate the "connection established" event.
+ * Socket callbacks must be installed before sending MPA Reply, because
+ * the latter may cause a first RDMA message to arrive from the RDMA Initiator
+ * side very quickly, at which time the socket callbacks must be ready.
+ */
+int siw_accept(struct iw_cm_id *id, struct iw_cm_conn_param *params)
+{
+	struct siw_device	*sdev = siw_dev_base2siw(id->device);
+	struct siw_cep		*cep = (struct siw_cep *)id->provider_data;
+	struct siw_qp		*qp;
+	struct siw_qp_attrs	qp_attrs;
+	int rv, max_priv_data = MPA_MAX_PRIVDATA;
+	bool wait_for_peer_rts = false;
+
+	siw_cep_set_inuse(cep);
+	siw_cep_put(cep);
+
+	/* Free lingering inbound private data */
+	if (cep->mpa.hdr.params.pd_len) {
+		cep->mpa.hdr.params.pd_len = 0;
+		kfree(cep->mpa.pdata);
+		cep->mpa.pdata = NULL;
+	}
+	siw_cancel_mpatimer(cep);
+
+	if (cep->state != SIW_EPSTATE_RECVD_MPAREQ) {
+		siw_dbg_cep(cep, "id 0x%p: out of state\n", id);
+
+		siw_cep_set_free(cep);
+		siw_cep_put(cep);
+
+		return -ECONNRESET;
+	}
+
+	qp = siw_qp_id2obj(sdev, params->qpn);
+	if (!qp) {
+		WARN(1, "[QP %d] does not exist\n", params->qpn);
+		siw_cep_set_free(cep);
+		siw_cep_put(cep);
+
+		return -EINVAL;
+	}
+
+	down_write(&qp->state_lock);
+	if (qp->attrs.state > SIW_QP_STATE_RTR) {
+		rv = -EINVAL;
+		up_write(&qp->state_lock);
+		goto error;
+	}
+
+	siw_dbg_cep(cep, "id 0x%p\n", id);
+
+	if (params->ord > sdev->attrs.max_ord ||
+	    params->ird > sdev->attrs.max_ird) {
+		siw_dbg_cep(cep,
+			"id 0x%p, [QP %d]: ord %d (max %d), ird %d (max %d)\n",
+			id, QP_ID(qp),
+			params->ord, sdev->attrs.max_ord,
+			params->ird, sdev->attrs.max_ird);
+		rv = -EINVAL;
+		up_write(&qp->state_lock);
+		goto error;
+	}
+	if (cep->enhanced_rdma_conn_est)
+		max_priv_data -= sizeof(struct mpa_v2_data);
+
+	if (params->private_data_len > max_priv_data) {
+		siw_dbg_cep(cep,
+			"id 0x%p, [QP %d]: private data length: %d (max %d)\n",
+			id, QP_ID(qp),
+			params->private_data_len, max_priv_data);
+		rv =  -EINVAL;
+		up_write(&qp->state_lock);
+		goto error;
+	}
+
+	if (cep->enhanced_rdma_conn_est) {
+		if (params->ord > cep->ord) {
+			if (relaxed_ird_negotiation)
+				params->ord = cep->ord;
+			else {
+				cep->ird = params->ird;
+				cep->ord = params->ord;
+				rv =  -EINVAL;
+				up_write(&qp->state_lock);
+				goto error;
+			}
+		}
+		if (params->ird < cep->ird) {
+			if (relaxed_ird_negotiation &&
+			    cep->ird <= sdev->attrs.max_ird)
+				params->ird = cep->ird;
+			else {
+				rv = -ENOMEM;
+				up_write(&qp->state_lock);
+				goto error;
+			}
+		}
+		if (cep->mpa.v2_ctrl.ord &
+		    (MPA_V2_RDMA_WRITE_RTR | MPA_V2_RDMA_READ_RTR))
+			wait_for_peer_rts = true;
+		/*
+		 * Signal back negotiated IRD and ORD values
+		 */
+		cep->mpa.v2_ctrl.ord = htons(params->ord & MPA_IRD_ORD_MASK) |
+				(cep->mpa.v2_ctrl.ord & ~MPA_V2_MASK_IRD_ORD);
+		cep->mpa.v2_ctrl.ird = htons(params->ird & MPA_IRD_ORD_MASK) |
+				(cep->mpa.v2_ctrl.ird & ~MPA_V2_MASK_IRD_ORD);
+	}
+	cep->ird = params->ird;
+	cep->ord = params->ord;
+
+	cep->cm_id = id;
+	id->add_ref(id);
+
+	memset(&qp_attrs, 0, sizeof(qp_attrs));
+	qp_attrs.orq_size = cep->ord;
+	qp_attrs.irq_size = cep->ird;
+	qp_attrs.llp_stream_handle = cep->llp.sock;
+	if (cep->mpa.hdr.params.bits & MPA_RR_FLAG_CRC)
+		qp_attrs.flags = SIW_MPA_CRC;
+	qp_attrs.state = SIW_QP_STATE_RTS;
+
+	siw_dbg_cep(cep, "id 0x%p, [QP%d]: moving to rts\n", id, QP_ID(qp));
+
+	/* Associate QP with CEP */
+	siw_cep_get(cep);
+	qp->cep = cep;
+
+	/* siw_qp_get(qp) already done by QP lookup */
+	cep->qp = qp;
+
+	cep->state = SIW_EPSTATE_RDMA_MODE;
+
+	/* Move socket RX/TX under QP control */
+	rv = siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE|
+					  SIW_QP_ATTR_LLP_HANDLE|
+					  SIW_QP_ATTR_ORD|
+					  SIW_QP_ATTR_IRD|
+					  SIW_QP_ATTR_MPA);
+	up_write(&qp->state_lock);
+
+	if (rv)
+		goto error;
+
+	siw_dbg_cep(cep, "id 0x%p, [QP %d]: send mpa reply, %d byte pdata\n",
+		    id, QP_ID(qp), params->private_data_len);
+
+	rv = siw_send_mpareqrep(cep, params->private_data,
+				params->private_data_len);
+	if (rv != 0)
+		goto error;
+
+	if (wait_for_peer_rts) {
+		siw_sk_assign_rtr_upcalls(cep);
+	} else {
+		siw_qp_socket_assoc(cep, qp);
+		rv = siw_cm_upcall(cep, IW_CM_EVENT_ESTABLISHED, 0);
+		if (rv)
+			goto error;
+	}
+	siw_cep_set_free(cep);
+
+	return 0;
+error:
+	siw_socket_disassoc(cep->llp.sock);
+	sock_release(cep->llp.sock);
+	cep->llp.sock = NULL;
+
+	cep->state = SIW_EPSTATE_CLOSED;
+
+	if (cep->cm_id) {
+		cep->cm_id->rem_ref(id);
+		cep->cm_id = NULL;
+	}
+	if (qp->cep) {
+		siw_cep_put(cep);
+		qp->cep = NULL;
+	}
+	cep->qp = NULL;
+	siw_qp_put(qp);
+
+	siw_cep_set_free(cep);
+	siw_cep_put(cep);
+
+	return rv;
+}
+
+/*
+ * siw_reject()
+ *
+ * Local connection reject case. Send private data back to peer,
+ * close connection and dereference connection id.
+ */
+int siw_reject(struct iw_cm_id *id, const void *pdata, u8 pd_len)
+{
+	struct siw_cep *cep = (struct siw_cep *)id->provider_data;
+
+	siw_cep_set_inuse(cep);
+	siw_cep_put(cep);
+
+	siw_cancel_mpatimer(cep);
+
+	if (cep->state != SIW_EPSTATE_RECVD_MPAREQ) {
+
+		siw_dbg_cep(cep, "id 0x%p: out of state\n", id);
+
+		siw_cep_set_free(cep);
+		siw_cep_put(cep); /* put last reference */
+
+		return -ECONNRESET;
+	}
+	siw_dbg_cep(cep, "id 0x%p, cep->state %d, pd_len %d\n",
+		    id, cep->state, pd_len);
+
+	if (__mpa_rr_revision(cep->mpa.hdr.params.bits) >= MPA_REVISION_1) {
+		cep->mpa.hdr.params.bits |= MPA_RR_FLAG_REJECT; /* reject */
+		(void)siw_send_mpareqrep(cep, pdata, pd_len);
+	}
+	siw_socket_disassoc(cep->llp.sock);
+	sock_release(cep->llp.sock);
+	cep->llp.sock = NULL;
+
+	cep->state = SIW_EPSTATE_CLOSED;
+
+	siw_cep_set_free(cep);
+	siw_cep_put(cep);
+
+	return 0;
+}
+
+static int siw_listen_address(struct iw_cm_id *id, int backlog,
+			      struct sockaddr *laddr)
+{
+	struct socket *s;
+	struct siw_cep *cep = NULL;
+	struct siw_device *sdev = siw_dev_base2siw(id->device);
+	int rv = 0, s_val;
+
+	rv = sock_create(AF_INET, SOCK_STREAM, IPPROTO_TCP, &s);
+	if (rv < 0)
+		return rv;
+
+	/*
+	 * Probably to be removed later. Allows binding
+	 * local port when still in TIME_WAIT from last close.
+	 */
+	s_val = 1;
+	rv = kernel_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&s_val,
+			       sizeof(s_val));
+	if (rv) {
+		siw_dbg(sdev, "id 0x%p: setsockopt error: %d\n", id, rv);
+		goto error;
+	}
+	rv = s->ops->bind(s, laddr, sizeof(*laddr));
+	if (rv != 0) {
+		siw_dbg(sdev, "id 0x%p: socket bind error: %d\n", id, rv);
+		goto error;
+	}
+	cep = siw_cep_alloc(sdev);
+	if (!cep) {
+		rv = -ENOMEM;
+		goto error;
+	}
+	siw_cep_socket_assoc(cep, s);
+
+	rv = siw_cm_alloc_work(cep, backlog);
+	if (rv != 0) {
+		siw_dbg(sdev, "id 0x%p: alloc_work error %d, backlog %d\n",
+			id, rv, backlog);
+		goto error;
+	}
+	rv = s->ops->listen(s, backlog);
+	if (rv != 0) {
+		siw_dbg(sdev, "id 0x%p: listen error %d\n", id, rv);
+		goto error;
+	}
+	memcpy(&cep->llp.laddr, &id->local_addr, sizeof(cep->llp.laddr));
+	memcpy(&cep->llp.raddr, &id->remote_addr, sizeof(cep->llp.raddr));
+
+	cep->cm_id = id;
+	id->add_ref(id);
+
+	/*
+	 * In case of a wildcard rdma_listen on a multi-homed device,
+	 * a listener's IWCM id is associated with more than one listening CEP.
+	 *
+	 * We currently use id->provider_data in three different ways:
+	 *
+	 * o For a listener's IWCM id, id->provider_data points to
+	 *   the list_head of the list of listening CEPs.
+	 *   Uses: siw_create_listen(), siw_destroy_listen()
+	 *
+	 * o For a passive-side IWCM id, id->provider_data points to
+	 *   the CEP itself. This is a consequence of
+	 *   - siw_cm_upcall() setting event.provider_data = cep and
+	 *   - the IWCM's cm_conn_req_handler() setting provider_data of the
+	 *     new passive-side IWCM id equal to event.provider_data
+	 *   Uses: siw_accept(), siw_reject()
+	 *
+	 * o For an active-side IWCM id, id->provider_data is not used at all.
+	 *
+	 */
+	if (!id->provider_data) {
+		id->provider_data = kmalloc(sizeof(struct list_head),
+					    GFP_KERNEL);
+		if (!id->provider_data) {
+			rv = -ENOMEM;
+			goto error;
+		}
+		INIT_LIST_HEAD((struct list_head *)id->provider_data);
+	}
+
+	siw_dbg(sdev, "id 0x%p: provider_data 0x%p, cep 0x%p\n",
+		id, id->provider_data, cep);
+
+	list_add_tail(&cep->listenq, (struct list_head *)id->provider_data);
+	cep->state = SIW_EPSTATE_LISTENING;
+
+	return 0;
+
+error:
+	siw_dbg(sdev, "failed: %d\n", rv);
+
+	if (cep) {
+		siw_cep_set_inuse(cep);
+
+		if (cep->cm_id) {
+			cep->cm_id->rem_ref(cep->cm_id);
+			cep->cm_id = NULL;
+		}
+		cep->llp.sock = NULL;
+		siw_socket_disassoc(s);
+		cep->state = SIW_EPSTATE_CLOSED;
+
+		siw_cep_set_free(cep);
+		siw_cep_put(cep);
+	}
+	sock_release(s);
+
+	return rv;
+}
+
+static void siw_drop_listeners(struct iw_cm_id *id)
+{
+	struct list_head	*p, *tmp;
+
+	/*
+	 * In case of a wildcard rdma_listen on a multi-homed device,
+	 * a listener's IWCM id is associated with more than one listening CEP.
+	 */
+	list_for_each_safe(p, tmp, (struct list_head *)id->provider_data) {
+		struct siw_cep *cep = list_entry(p, struct siw_cep, listenq);
+
+		list_del(p);
+
+		siw_dbg_cep(cep, "id 0x%p: drop cep, state %d\n",
+			    id, cep->state);
+
+		siw_cep_set_inuse(cep);
+
+		if (cep->cm_id) {
+			cep->cm_id->rem_ref(cep->cm_id);
+			cep->cm_id = NULL;
+		}
+		if (cep->llp.sock) {
+			siw_socket_disassoc(cep->llp.sock);
+			sock_release(cep->llp.sock);
+			cep->llp.sock = NULL;
+		}
+		cep->state = SIW_EPSTATE_CLOSED;
+		siw_cep_set_free(cep);
+		siw_cep_put(cep);
+	}
+}
+
+/*
+ * siw_create_listen - Create resources for a listener's IWCM ID @id
+ *
+ * Listens on the socket addresses id->local_addr and id->remote_addr.
+ *
+ * If the listener's @id provides a specific local IP address, at most one
+ * listening socket is created and associated with @id.
+ *
+ * If the listener's @id provides the wildcard (zero) local IP address,
+ * a separate listen is performed for each local IP address of the device
+ * by creating a listening socket and binding to that local IP address.
+ *
+ */
+int siw_create_listen(struct iw_cm_id *id, int backlog)
+{
+	struct ib_device *base_dev = id->device;
+	struct siw_device *sdev = siw_dev_base2siw(base_dev);
+	int rv = 0;
+
+	siw_dbg(sdev, "id 0x%p: backlog %d\n", id, backlog);
+
+	if (to_sockaddr_in(id->local_addr).sin_family == AF_INET) {
+		/* IPv4 */
+		struct sockaddr_in	laddr = to_sockaddr_in(id->local_addr);
+		u8			*l_ip, *r_ip;
+		struct in_device	*in_dev;
+
+		l_ip = (u8 *) &to_sockaddr_in(id->local_addr).sin_addr.s_addr;
+		r_ip = (u8 *) &to_sockaddr_in(id->remote_addr).sin_addr.s_addr;
+		siw_dbg(sdev,
+			"id 0x%p: laddr %d.%d.%d.%d:%d, raddr %d.%d.%d.%d:%d\n",
+			id, l_ip[0], l_ip[1], l_ip[2], l_ip[3],
+			ntohs(to_sockaddr_in(id->local_addr).sin_port),
+			r_ip[0], r_ip[1], r_ip[2], r_ip[3],
+			ntohs(to_sockaddr_in(id->remote_addr).sin_port));
+
+		in_dev = in_dev_get(sdev->netdev);
+		if (!in_dev) {
+			siw_dbg(sdev, "id 0x%p: netdev w/o in_device\n", id);
+			return -ENODEV;
+		}
+
+		for_ifa(in_dev) {
+			/*
+			 * Create a listening socket if id->local_addr
+			 * contains the wildcard IP address OR
+			 * the IP address of the interface.
+			 */
+			if (ipv4_is_zeronet(
+			    to_sockaddr_in(id->local_addr).sin_addr.s_addr) ||
+			    to_sockaddr_in(id->local_addr).sin_addr.s_addr ==
+			    ifa->ifa_address) {
+				laddr.sin_addr.s_addr = ifa->ifa_address;
+
+				l_ip = (u8 *) &laddr.sin_addr.s_addr;
+				siw_dbg(sdev,
+					"id 0x%p: bind: %d.%d.%d.%d:%d\n",
+					id, l_ip[0], l_ip[1], l_ip[2],
+					l_ip[3], ntohs(laddr.sin_port));
+
+				rv = siw_listen_address(id, backlog,
+						(struct sockaddr *)&laddr);
+				if (rv)
+					break;
+			}
+		}
+		endfor_ifa(in_dev);
+		in_dev_put(in_dev);
+
+		if (rv && id->provider_data)
+			siw_drop_listeners(id);
+
+	} else {
+		/* IPv6 */
+		rv = -EAFNOSUPPORT;
+		siw_dbg(sdev, "id 0x%p: TODO: IPv6 support\n", id);
+	}
+	if (!rv)
+		siw_dbg(sdev, "id 0x%p: success\n", id);
+
+	return rv;
+}
+
+int siw_destroy_listen(struct iw_cm_id *id)
+{
+	struct siw_device *sdev = siw_dev_base2siw(id->device);
+
+	siw_dbg(sdev, "id 0x%p\n", id);
+
+	if (!id->provider_data) {
+		siw_dbg(sdev, "id 0x%p: no cep(s)\n", id);
+		return 0;
+	}
+	siw_drop_listeners(id);
+	kfree(id->provider_data);
+	id->provider_data = NULL;
+
+	return 0;
+}
+
+int siw_cm_init(void)
+{
+	/*
+	 * create_single_workqueue for strict ordering
+	 */
+	siw_cm_wq = create_singlethread_workqueue("siw_cm_wq");
+	if (!siw_cm_wq)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void siw_cm_exit(void)
+{
+	if (siw_cm_wq) {
+		flush_workqueue(siw_cm_wq);
+		destroy_workqueue(siw_cm_wq);
+	}
+}
diff --git a/drivers/infiniband/sw/siw/siw_cm.h b/drivers/infiniband/sw/siw/siw_cm.h
new file mode 100644
index 000000000000..36a8d15d793a
--- /dev/null
+++ b/drivers/infiniband/sw/siw/siw_cm.h
@@ -0,0 +1,156 @@ 
+/*
+ * Software iWARP device driver
+ *
+ * Authors: Bernard Metzler <bmt@zurich.ibm.com>
+ *          Greg Joyce <greg@opengridcomputing.com>
+ *
+ * Copyright (c) 2008-2017, IBM Corporation
+ * Copyright (c) 2017, Open Grid Computing, Inc.
+ *
+ * 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
+ * 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.
+ *
+ *   - Neither the name of IBM nor the names of its contributors may be
+ *     used to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * 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.
+ */
+
+#ifndef _SIW_CM_H
+#define _SIW_CM_H
+
+#include <net/sock.h>
+#include <linux/tcp.h>
+
+#include <rdma/iw_cm.h>
+
+
+enum siw_cep_state {
+	SIW_EPSTATE_IDLE = 1,
+	SIW_EPSTATE_LISTENING,
+	SIW_EPSTATE_CONNECTING,
+	SIW_EPSTATE_AWAIT_MPAREQ,
+	SIW_EPSTATE_RECVD_MPAREQ,
+	SIW_EPSTATE_AWAIT_MPAREP,
+	SIW_EPSTATE_RDMA_MODE,
+	SIW_EPSTATE_CLOSED
+};
+
+struct siw_mpa_info {
+	struct mpa_rr		hdr;	/* peer mpa hdr in host byte order */
+	struct mpa_v2_data	v2_ctrl;
+	struct mpa_v2_data	v2_ctrl_req;
+	char			*pdata;
+	int			bytes_rcvd;
+};
+
+struct siw_llp_info {
+	struct socket		*sock;
+	struct sockaddr_in	laddr;	/* redundant with socket info above */
+	struct sockaddr_in	raddr;	/* dito, consider removal */
+	struct siw_sk_upcalls	sk_def_upcalls;
+};
+
+struct siw_device;
+
+struct siw_cep {
+	struct iw_cm_id		*cm_id;
+	struct siw_device	*sdev;
+
+	struct list_head	devq;
+	/*
+	 * The provider_data element of a listener IWCM ID
+	 * refers to a list of one or more listener CEPs
+	 */
+	struct list_head	listenq;
+	struct siw_cep		*listen_cep;
+	struct siw_qp		*qp;
+	spinlock_t		lock;
+	wait_queue_head_t	waitq;
+	struct kref		ref;
+	enum siw_cep_state	state;
+	short			in_use;
+	struct siw_cm_work	*mpa_timer;
+	struct list_head	work_freelist;
+	struct siw_llp_info	llp;
+	struct siw_mpa_info	mpa;
+	int			ord;
+	int			ird;
+	bool			enhanced_rdma_conn_est;
+	int			sk_error; /* not (yet) used XXX */
+
+	/* Saved upcalls of socket llp.sock */
+	void	(*sk_state_change)(struct sock *sk);
+	void	(*sk_data_ready)(struct sock *sk);
+	void	(*sk_write_space)(struct sock *sk);
+	void	(*sk_error_report)(struct sock *sk);
+};
+
+/*
+ * Connection initiator waits 10 seconds to receive an
+ * MPA reply after sending out MPA request. Reponder waits for
+ * 5 seconds for MPA request to arrive if new TCP connection
+ * was set up.
+ */
+#define MPAREQ_TIMEOUT	(HZ*10)
+#define MPAREP_TIMEOUT	(HZ*5)
+
+enum siw_work_type {
+	SIW_CM_WORK_ACCEPT = 1,
+	SIW_CM_WORK_READ_MPAHDR,
+	SIW_CM_WORK_CLOSE_LLP,		/* close socket */
+	SIW_CM_WORK_PEER_CLOSE,		/* socket indicated peer close */
+	SIW_CM_WORK_MPATIMEOUT
+};
+
+struct siw_cm_work {
+	struct delayed_work	work;
+	struct list_head	list;
+	enum siw_work_type	type;
+	struct siw_cep	*cep;
+};
+
+#define to_sockaddr_in(a) (*(struct sockaddr_in *)(&(a)))
+
+extern int siw_connect(struct iw_cm_id *id, struct iw_cm_conn_param *parm);
+extern int siw_accept(struct iw_cm_id *id, struct iw_cm_conn_param *param);
+extern int siw_reject(struct iw_cm_id *id, const void *data, u8 len);
+extern int siw_create_listen(struct iw_cm_id *id, int backlog);
+extern int siw_destroy_listen(struct iw_cm_id *id);
+
+extern void siw_cep_get(struct siw_cep *cep);
+extern void siw_cep_put(struct siw_cep *cep);
+extern int siw_cm_queue_work(struct siw_cep *cep, enum siw_work_type type);
+
+extern int siw_cm_init(void);
+extern void siw_cm_exit(void);
+
+/*
+ * TCP socket interface
+ */
+#define sk_to_qp(sk)	(((struct siw_cep *)((sk)->sk_user_data))->qp)
+#define sk_to_cep(sk)	((struct siw_cep *)((sk)->sk_user_data))
+
+#endif