Soft RoCE driver

Soft RoCE (RXE) - The software RoCE driver

ib_rxe implements the RDMA transport and registers to the RDMA core
device as a kernel verbs provider. It also implements the packet IO
layer. On the other hand ib_rxe registers to the Linux netdev stack
as a udp encapsulating protocol, in that case RDMA, for sending and
receiving packets over any Ethernet device.  This yields a RDMA
transport over the UDP/Ethernet network layer forming a RoCEv2
compatible device.

The configuration procedure of the Soft RoCE drivers requires
binding to any existing Ethernet network device. This is done with
/sys interface.

A userspace Soft RoCE library (librxe) provides user applications
the ability to run with Soft RoCE devices.  The use of rxe verbs ins
user space requires the inclusion of librxe as a device specifics
plug-in to libibverbs. librxe is packaged separately.

Architecture:

     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
+---------------------------------------------------------------+
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Soft RoCE resources:

[1[ https://github.com/SoftRoCE/librxe-dev librxe - source code in
Github
[2] https://github.com/SoftRoCE/rxe-dev/wiki/rxe-dev:-Home - Soft RoCE
Wiki page
[3] https://github.com/SoftRoCE/librxe-dev - Soft RoCE userspace library

Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 851 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
new file mode 100644
index 000000000000..22ba24f2a2c1
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -0,0 +1,851 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *	   Redistribution and use in source and binary forms, with or
+ *	   without modification, are permitted provided that the following
+ *	   conditions are met:
+ *
+ *		- Redistributions of source code must retain the above
+ *		  copyright notice, this list of conditions and the following
+ *		  disclaimer.
+ *
+ *		- Redistributions in binary form must reproduce the above
+ *		  copyright notice, this list of conditions and the following
+ *		  disclaimer in the documentation and/or other materials
+ *		  provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+
+#include "rxe.h"
+#include "rxe_loc.h"
+#include "rxe_queue.h"
+#include "rxe_task.h"
+
+char *rxe_qp_state_name[] = {
+	[QP_STATE_RESET]	= "RESET",
+	[QP_STATE_INIT]		= "INIT",
+	[QP_STATE_READY]	= "READY",
+	[QP_STATE_DRAIN]	= "DRAIN",
+	[QP_STATE_DRAINED]	= "DRAINED",
+	[QP_STATE_ERROR]	= "ERROR",
+};
+
+static int rxe_qp_chk_cap(struct rxe_dev *rxe, struct ib_qp_cap *cap,
+			  int has_srq)
+{
+	if (cap->max_send_wr > rxe->attr.max_qp_wr) {
+		pr_warn("invalid send wr = %d > %d\n",
+			cap->max_send_wr, rxe->attr.max_qp_wr);
+		goto err1;
+	}
+
+	if (cap->max_send_sge > rxe->attr.max_sge) {
+		pr_warn("invalid send sge = %d > %d\n",
+			cap->max_send_sge, rxe->attr.max_sge);
+		goto err1;
+	}
+
+	if (!has_srq) {
+		if (cap->max_recv_wr > rxe->attr.max_qp_wr) {
+			pr_warn("invalid recv wr = %d > %d\n",
+				cap->max_recv_wr, rxe->attr.max_qp_wr);
+			goto err1;
+		}
+
+		if (cap->max_recv_sge > rxe->attr.max_sge) {
+			pr_warn("invalid recv sge = %d > %d\n",
+				cap->max_recv_sge, rxe->attr.max_sge);
+			goto err1;
+		}
+	}
+
+	if (cap->max_inline_data > rxe->max_inline_data) {
+		pr_warn("invalid max inline data = %d > %d\n",
+			cap->max_inline_data, rxe->max_inline_data);
+		goto err1;
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+int rxe_qp_chk_init(struct rxe_dev *rxe, struct ib_qp_init_attr *init)
+{
+	struct ib_qp_cap *cap = &init->cap;
+	struct rxe_port *port;
+	int port_num = init->port_num;
+
+	if (!init->recv_cq || !init->send_cq) {
+		pr_warn("missing cq\n");
+		goto err1;
+	}
+
+	if (rxe_qp_chk_cap(rxe, cap, !!init->srq))
+		goto err1;
+
+	if (init->qp_type == IB_QPT_SMI || init->qp_type == IB_QPT_GSI) {
+		if (port_num != 1) {
+			pr_warn("invalid port = %d\n", port_num);
+			goto err1;
+		}
+
+		port = &rxe->port;
+
+		if (init->qp_type == IB_QPT_SMI && port->qp_smi_index) {
+			pr_warn("SMI QP exists for port %d\n", port_num);
+			goto err1;
+		}
+
+		if (init->qp_type == IB_QPT_GSI && port->qp_gsi_index) {
+			pr_warn("GSI QP exists for port %d\n", port_num);
+			goto err1;
+		}
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+static int alloc_rd_atomic_resources(struct rxe_qp *qp, unsigned int n)
+{
+	qp->resp.res_head = 0;
+	qp->resp.res_tail = 0;
+	qp->resp.resources = kcalloc(n, sizeof(struct resp_res), GFP_KERNEL);
+
+	if (!qp->resp.resources)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void free_rd_atomic_resources(struct rxe_qp *qp)
+{
+	if (qp->resp.resources) {
+		int i;
+
+		for (i = 0; i < qp->attr.max_rd_atomic; i++) {
+			struct resp_res *res = &qp->resp.resources[i];
+
+			free_rd_atomic_resource(qp, res);
+		}
+		kfree(qp->resp.resources);
+		qp->resp.resources = NULL;
+	}
+}
+
+void free_rd_atomic_resource(struct rxe_qp *qp, struct resp_res *res)
+{
+	if (res->type == RXE_ATOMIC_MASK) {
+		rxe_drop_ref(qp);
+		kfree_skb(res->atomic.skb);
+	} else if (res->type == RXE_READ_MASK) {
+		if (res->read.mr)
+			rxe_drop_ref(res->read.mr);
+	}
+	res->type = 0;
+}
+
+static void cleanup_rd_atomic_resources(struct rxe_qp *qp)
+{
+	int i;
+	struct resp_res *res;
+
+	if (qp->resp.resources) {
+		for (i = 0; i < qp->attr.max_rd_atomic; i++) {
+			res = &qp->resp.resources[i];
+			free_rd_atomic_resource(qp, res);
+		}
+	}
+}
+
+static void rxe_qp_init_misc(struct rxe_dev *rxe, struct rxe_qp *qp,
+			     struct ib_qp_init_attr *init)
+{
+	struct rxe_port *port;
+	u32 qpn;
+
+	qp->sq_sig_type		= init->sq_sig_type;
+	qp->attr.path_mtu	= 1;
+	qp->mtu			= ib_mtu_enum_to_int(qp->attr.path_mtu);
+
+	qpn			= qp->pelem.index;
+	port			= &rxe->port;
+
+	switch (init->qp_type) {
+	case IB_QPT_SMI:
+		qp->ibqp.qp_num		= 0;
+		port->qp_smi_index	= qpn;
+		qp->attr.port_num	= init->port_num;
+		break;
+
+	case IB_QPT_GSI:
+		qp->ibqp.qp_num		= 1;
+		port->qp_gsi_index	= qpn;
+		qp->attr.port_num	= init->port_num;
+		break;
+
+	default:
+		qp->ibqp.qp_num		= qpn;
+		break;
+	}
+
+	INIT_LIST_HEAD(&qp->grp_list);
+
+	skb_queue_head_init(&qp->send_pkts);
+
+	spin_lock_init(&qp->grp_lock);
+	spin_lock_init(&qp->state_lock);
+
+	atomic_set(&qp->ssn, 0);
+	atomic_set(&qp->skb_out, 0);
+}
+
+static int rxe_qp_init_req(struct rxe_dev *rxe, struct rxe_qp *qp,
+			   struct ib_qp_init_attr *init,
+			   struct ib_ucontext *context, struct ib_udata *udata)
+{
+	int err;
+	int wqe_size;
+
+	err = sock_create_kern(&init_net, AF_INET, SOCK_DGRAM, 0, &qp->sk);
+	if (err < 0)
+		return err;
+	qp->sk->sk->sk_user_data = qp;
+
+	qp->sq.max_wr		= init->cap.max_send_wr;
+	qp->sq.max_sge		= init->cap.max_send_sge;
+	qp->sq.max_inline	= init->cap.max_inline_data;
+
+	wqe_size = max_t(int, sizeof(struct rxe_send_wqe) +
+			 qp->sq.max_sge * sizeof(struct ib_sge),
+			 sizeof(struct rxe_send_wqe) +
+			 qp->sq.max_inline);
+
+	qp->sq.queue = rxe_queue_init(rxe,
+				      &qp->sq.max_wr,
+				      wqe_size);
+	if (!qp->sq.queue)
+		return -ENOMEM;
+
+	err = do_mmap_info(rxe, udata, true,
+			   context, qp->sq.queue->buf,
+			   qp->sq.queue->buf_size, &qp->sq.queue->ip);
+
+	if (err) {
+		kvfree(qp->sq.queue->buf);
+		kfree(qp->sq.queue);
+		return err;
+	}
+
+	qp->req.wqe_index	= producer_index(qp->sq.queue);
+	qp->req.state		= QP_STATE_RESET;
+	qp->req.opcode		= -1;
+	qp->comp.opcode		= -1;
+
+	spin_lock_init(&qp->sq.sq_lock);
+	skb_queue_head_init(&qp->req_pkts);
+
+	rxe_init_task(rxe, &qp->req.task, qp,
+		      rxe_requester, "req");
+	rxe_init_task(rxe, &qp->comp.task, qp,
+		      rxe_completer, "comp");
+
+	init_timer(&qp->rnr_nak_timer);
+	qp->rnr_nak_timer.function = rnr_nak_timer;
+	qp->rnr_nak_timer.data = (unsigned long)qp;
+
+	init_timer(&qp->retrans_timer);
+	qp->retrans_timer.function = retransmit_timer;
+	qp->retrans_timer.data = (unsigned long)qp;
+	qp->qp_timeout_jiffies = 0; /* Can't be set for UD/UC in modify_qp */
+
+	return 0;
+}
+
+static int rxe_qp_init_resp(struct rxe_dev *rxe, struct rxe_qp *qp,
+			    struct ib_qp_init_attr *init,
+			    struct ib_ucontext *context, struct ib_udata *udata)
+{
+	int err;
+	int wqe_size;
+
+	if (!qp->srq) {
+		qp->rq.max_wr		= init->cap.max_recv_wr;
+		qp->rq.max_sge		= init->cap.max_recv_sge;
+
+		wqe_size = rcv_wqe_size(qp->rq.max_sge);
+
+		pr_debug("max_wr = %d, max_sge = %d, wqe_size = %d\n",
+			 qp->rq.max_wr, qp->rq.max_sge, wqe_size);
+
+		qp->rq.queue = rxe_queue_init(rxe,
+					      &qp->rq.max_wr,
+					      wqe_size);
+		if (!qp->rq.queue)
+			return -ENOMEM;
+
+		err = do_mmap_info(rxe, udata, false, context,
+				   qp->rq.queue->buf,
+				   qp->rq.queue->buf_size,
+				   &qp->rq.queue->ip);
+		if (err) {
+			kvfree(qp->rq.queue->buf);
+			kfree(qp->rq.queue);
+			return err;
+		}
+	}
+
+	spin_lock_init(&qp->rq.producer_lock);
+	spin_lock_init(&qp->rq.consumer_lock);
+
+	skb_queue_head_init(&qp->resp_pkts);
+
+	rxe_init_task(rxe, &qp->resp.task, qp,
+		      rxe_responder, "resp");
+
+	qp->resp.opcode		= OPCODE_NONE;
+	qp->resp.msn		= 0;
+	qp->resp.state		= QP_STATE_RESET;
+
+	return 0;
+}
+
+/* called by the create qp verb */
+int rxe_qp_from_init(struct rxe_dev *rxe, struct rxe_qp *qp, struct rxe_pd *pd,
+		     struct ib_qp_init_attr *init, struct ib_udata *udata,
+		     struct ib_pd *ibpd)
+{
+	int err;
+	struct rxe_cq *rcq = to_rcq(init->recv_cq);
+	struct rxe_cq *scq = to_rcq(init->send_cq);
+	struct rxe_srq *srq = init->srq ? to_rsrq(init->srq) : NULL;
+	struct ib_ucontext *context = udata ? ibpd->uobject->context : NULL;
+
+	rxe_add_ref(pd);
+	rxe_add_ref(rcq);
+	rxe_add_ref(scq);
+	if (srq)
+		rxe_add_ref(srq);
+
+	qp->pd			= pd;
+	qp->rcq			= rcq;
+	qp->scq			= scq;
+	qp->srq			= srq;
+
+	rxe_qp_init_misc(rxe, qp, init);
+
+	err = rxe_qp_init_req(rxe, qp, init, context, udata);
+	if (err)
+		goto err1;
+
+	err = rxe_qp_init_resp(rxe, qp, init, context, udata);
+	if (err)
+		goto err2;
+
+	qp->attr.qp_state = IB_QPS_RESET;
+	qp->valid = 1;
+
+	return 0;
+
+err2:
+	rxe_queue_cleanup(qp->sq.queue);
+err1:
+	if (srq)
+		rxe_drop_ref(srq);
+	rxe_drop_ref(scq);
+	rxe_drop_ref(rcq);
+	rxe_drop_ref(pd);
+
+	return err;
+}
+
+/* called by the query qp verb */
+int rxe_qp_to_init(struct rxe_qp *qp, struct ib_qp_init_attr *init)
+{
+	init->event_handler		= qp->ibqp.event_handler;
+	init->qp_context		= qp->ibqp.qp_context;
+	init->send_cq			= qp->ibqp.send_cq;
+	init->recv_cq			= qp->ibqp.recv_cq;
+	init->srq			= qp->ibqp.srq;
+
+	init->cap.max_send_wr		= qp->sq.max_wr;
+	init->cap.max_send_sge		= qp->sq.max_sge;
+	init->cap.max_inline_data	= qp->sq.max_inline;
+
+	if (!qp->srq) {
+		init->cap.max_recv_wr		= qp->rq.max_wr;
+		init->cap.max_recv_sge		= qp->rq.max_sge;
+	}
+
+	init->sq_sig_type		= qp->sq_sig_type;
+
+	init->qp_type			= qp->ibqp.qp_type;
+	init->port_num			= 1;
+
+	return 0;
+}
+
+/* called by the modify qp verb, this routine checks all the parameters before
+ * making any changes
+ */
+int rxe_qp_chk_attr(struct rxe_dev *rxe, struct rxe_qp *qp,
+		    struct ib_qp_attr *attr, int mask)
+{
+	enum ib_qp_state cur_state = (mask & IB_QP_CUR_STATE) ?
+					attr->cur_qp_state : qp->attr.qp_state;
+	enum ib_qp_state new_state = (mask & IB_QP_STATE) ?
+					attr->qp_state : cur_state;
+
+	if (!ib_modify_qp_is_ok(cur_state, new_state, qp_type(qp), mask,
+				IB_LINK_LAYER_ETHERNET)) {
+		pr_warn("invalid mask or state for qp\n");
+		goto err1;
+	}
+
+	if (mask & IB_QP_STATE) {
+		if (cur_state == IB_QPS_SQD) {
+			if (qp->req.state == QP_STATE_DRAIN &&
+			    new_state != IB_QPS_ERR)
+				goto err1;
+		}
+	}
+
+	if (mask & IB_QP_PORT) {
+		if (attr->port_num != 1) {
+			pr_warn("invalid port %d\n", attr->port_num);
+			goto err1;
+		}
+	}
+
+	if (mask & IB_QP_CAP && rxe_qp_chk_cap(rxe, &attr->cap, !!qp->srq))
+		goto err1;
+
+	if (mask & IB_QP_AV && rxe_av_chk_attr(rxe, &attr->ah_attr))
+		goto err1;
+
+	if (mask & IB_QP_ALT_PATH) {
+		if (rxe_av_chk_attr(rxe, &attr->alt_ah_attr))
+			goto err1;
+		if (attr->alt_port_num != 1) {
+			pr_warn("invalid alt port %d\n", attr->alt_port_num);
+			goto err1;
+		}
+		if (attr->alt_timeout > 31) {
+			pr_warn("invalid QP alt timeout %d > 31\n",
+				attr->alt_timeout);
+			goto err1;
+		}
+	}
+
+	if (mask & IB_QP_PATH_MTU) {
+		struct rxe_port *port = &rxe->port;
+
+		enum ib_mtu max_mtu = port->attr.max_mtu;
+		enum ib_mtu mtu = attr->path_mtu;
+
+		if (mtu > max_mtu) {
+			pr_debug("invalid mtu (%d) > (%d)\n",
+				 ib_mtu_enum_to_int(mtu),
+				 ib_mtu_enum_to_int(max_mtu));
+			goto err1;
+		}
+	}
+
+	if (mask & IB_QP_MAX_QP_RD_ATOMIC) {
+		if (attr->max_rd_atomic > rxe->attr.max_qp_rd_atom) {
+			pr_warn("invalid max_rd_atomic %d > %d\n",
+				attr->max_rd_atomic,
+				rxe->attr.max_qp_rd_atom);
+			goto err1;
+		}
+	}
+
+	if (mask & IB_QP_TIMEOUT) {
+		if (attr->timeout > 31) {
+			pr_warn("invalid QP timeout %d > 31\n",
+				attr->timeout);
+			goto err1;
+		}
+	}
+
+	return 0;
+
+err1:
+	return -EINVAL;
+}
+
+/* move the qp to the reset state */
+static void rxe_qp_reset(struct rxe_qp *qp)
+{
+	/* stop tasks from running */
+	rxe_disable_task(&qp->resp.task);
+
+	/* stop request/comp */
+	if (qp->sq.queue) {
+		if (qp_type(qp) == IB_QPT_RC)
+			rxe_disable_task(&qp->comp.task);
+		rxe_disable_task(&qp->req.task);
+	}
+
+	/* move qp to the reset state */
+	qp->req.state = QP_STATE_RESET;
+	qp->resp.state = QP_STATE_RESET;
+
+	/* let state machines reset themselves drain work and packet queues
+	 * etc.
+	 */
+	__rxe_do_task(&qp->resp.task);
+
+	if (qp->sq.queue) {
+		__rxe_do_task(&qp->comp.task);
+		__rxe_do_task(&qp->req.task);
+	}
+
+	/* cleanup attributes */
+	atomic_set(&qp->ssn, 0);
+	qp->req.opcode = -1;
+	qp->req.need_retry = 0;
+	qp->req.noack_pkts = 0;
+	qp->resp.msn = 0;
+	qp->resp.opcode = -1;
+	qp->resp.drop_msg = 0;
+	qp->resp.goto_error = 0;
+	qp->resp.sent_psn_nak = 0;
+
+	if (qp->resp.mr) {
+		rxe_drop_ref(qp->resp.mr);
+		qp->resp.mr = NULL;
+	}
+
+	cleanup_rd_atomic_resources(qp);
+
+	/* reenable tasks */
+	rxe_enable_task(&qp->resp.task);
+
+	if (qp->sq.queue) {
+		if (qp_type(qp) == IB_QPT_RC)
+			rxe_enable_task(&qp->comp.task);
+
+		rxe_enable_task(&qp->req.task);
+	}
+}
+
+/* drain the send queue */
+static void rxe_qp_drain(struct rxe_qp *qp)
+{
+	if (qp->sq.queue) {
+		if (qp->req.state != QP_STATE_DRAINED) {
+			qp->req.state = QP_STATE_DRAIN;
+			if (qp_type(qp) == IB_QPT_RC)
+				rxe_run_task(&qp->comp.task, 1);
+			else
+				__rxe_do_task(&qp->comp.task);
+			rxe_run_task(&qp->req.task, 1);
+		}
+	}
+}
+
+/* move the qp to the error state */
+void rxe_qp_error(struct rxe_qp *qp)
+{
+	qp->req.state = QP_STATE_ERROR;
+	qp->resp.state = QP_STATE_ERROR;
+
+	/* drain work and packet queues */
+	rxe_run_task(&qp->resp.task, 1);
+
+	if (qp_type(qp) == IB_QPT_RC)
+		rxe_run_task(&qp->comp.task, 1);
+	else
+		__rxe_do_task(&qp->comp.task);
+	rxe_run_task(&qp->req.task, 1);
+}
+
+/* called by the modify qp verb */
+int rxe_qp_from_attr(struct rxe_qp *qp, struct ib_qp_attr *attr, int mask,
+		     struct ib_udata *udata)
+{
+	int err;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	union ib_gid sgid;
+	struct ib_gid_attr sgid_attr;
+
+	if (mask & IB_QP_MAX_QP_RD_ATOMIC) {
+		int max_rd_atomic = __roundup_pow_of_two(attr->max_rd_atomic);
+
+		free_rd_atomic_resources(qp);
+
+		err = alloc_rd_atomic_resources(qp, max_rd_atomic);
+		if (err)
+			return err;
+
+		qp->attr.max_rd_atomic = max_rd_atomic;
+		atomic_set(&qp->req.rd_atomic, max_rd_atomic);
+	}
+
+	if (mask & IB_QP_CUR_STATE)
+		qp->attr.cur_qp_state = attr->qp_state;
+
+	if (mask & IB_QP_EN_SQD_ASYNC_NOTIFY)
+		qp->attr.en_sqd_async_notify = attr->en_sqd_async_notify;
+
+	if (mask & IB_QP_ACCESS_FLAGS)
+		qp->attr.qp_access_flags = attr->qp_access_flags;
+
+	if (mask & IB_QP_PKEY_INDEX)
+		qp->attr.pkey_index = attr->pkey_index;
+
+	if (mask & IB_QP_PORT)
+		qp->attr.port_num = attr->port_num;
+
+	if (mask & IB_QP_QKEY)
+		qp->attr.qkey = attr->qkey;
+
+	if (mask & IB_QP_AV) {
+		ib_get_cached_gid(&rxe->ib_dev, 1,
+				  attr->ah_attr.grh.sgid_index, &sgid,
+				  &sgid_attr);
+		rxe_av_from_attr(rxe, attr->port_num, &qp->pri_av,
+				 &attr->ah_attr);
+		rxe_av_fill_ip_info(rxe, &qp->pri_av, &attr->ah_attr,
+				    &sgid_attr, &sgid);
+		if (sgid_attr.ndev)
+			dev_put(sgid_attr.ndev);
+	}
+
+	if (mask & IB_QP_ALT_PATH) {
+		ib_get_cached_gid(&rxe->ib_dev, 1,
+				  attr->alt_ah_attr.grh.sgid_index, &sgid,
+				  &sgid_attr);
+
+		rxe_av_from_attr(rxe, attr->alt_port_num, &qp->alt_av,
+				 &attr->alt_ah_attr);
+		rxe_av_fill_ip_info(rxe, &qp->alt_av, &attr->alt_ah_attr,
+				    &sgid_attr, &sgid);
+		if (sgid_attr.ndev)
+			dev_put(sgid_attr.ndev);
+
+		qp->attr.alt_port_num = attr->alt_port_num;
+		qp->attr.alt_pkey_index = attr->alt_pkey_index;
+		qp->attr.alt_timeout = attr->alt_timeout;
+	}
+
+	if (mask & IB_QP_PATH_MTU) {
+		qp->attr.path_mtu = attr->path_mtu;
+		qp->mtu = ib_mtu_enum_to_int(attr->path_mtu);
+	}
+
+	if (mask & IB_QP_TIMEOUT) {
+		qp->attr.timeout = attr->timeout;
+		if (attr->timeout == 0) {
+			qp->qp_timeout_jiffies = 0;
+		} else {
+			/* According to the spec, timeout = 4.096 * 2 ^ attr->timeout [us] */
+			int j = nsecs_to_jiffies(4096ULL << attr->timeout);
+
+			qp->qp_timeout_jiffies = j ? j : 1;
+		}
+	}
+
+	if (mask & IB_QP_RETRY_CNT) {
+		qp->attr.retry_cnt = attr->retry_cnt;
+		qp->comp.retry_cnt = attr->retry_cnt;
+		pr_debug("set retry count = %d\n", attr->retry_cnt);
+	}
+
+	if (mask & IB_QP_RNR_RETRY) {
+		qp->attr.rnr_retry = attr->rnr_retry;
+		qp->comp.rnr_retry = attr->rnr_retry;
+		pr_debug("set rnr retry count = %d\n", attr->rnr_retry);
+	}
+
+	if (mask & IB_QP_RQ_PSN) {
+		qp->attr.rq_psn = (attr->rq_psn & BTH_PSN_MASK);
+		qp->resp.psn = qp->attr.rq_psn;
+		pr_debug("set resp psn = 0x%x\n", qp->resp.psn);
+	}
+
+	if (mask & IB_QP_MIN_RNR_TIMER) {
+		qp->attr.min_rnr_timer = attr->min_rnr_timer;
+		pr_debug("set min rnr timer = 0x%x\n",
+			 attr->min_rnr_timer);
+	}
+
+	if (mask & IB_QP_SQ_PSN) {
+		qp->attr.sq_psn = (attr->sq_psn & BTH_PSN_MASK);
+		qp->req.psn = qp->attr.sq_psn;
+		qp->comp.psn = qp->attr.sq_psn;
+		pr_debug("set req psn = 0x%x\n", qp->req.psn);
+	}
+
+	if (mask & IB_QP_MAX_DEST_RD_ATOMIC) {
+		qp->attr.max_dest_rd_atomic =
+			__roundup_pow_of_two(attr->max_dest_rd_atomic);
+	}
+
+	if (mask & IB_QP_PATH_MIG_STATE)
+		qp->attr.path_mig_state = attr->path_mig_state;
+
+	if (mask & IB_QP_DEST_QPN)
+		qp->attr.dest_qp_num = attr->dest_qp_num;
+
+	if (mask & IB_QP_STATE) {
+		qp->attr.qp_state = attr->qp_state;
+
+		switch (attr->qp_state) {
+		case IB_QPS_RESET:
+			pr_debug("qp state -> RESET\n");
+			rxe_qp_reset(qp);
+			break;
+
+		case IB_QPS_INIT:
+			pr_debug("qp state -> INIT\n");
+			qp->req.state = QP_STATE_INIT;
+			qp->resp.state = QP_STATE_INIT;
+			break;
+
+		case IB_QPS_RTR:
+			pr_debug("qp state -> RTR\n");
+			qp->resp.state = QP_STATE_READY;
+			break;
+
+		case IB_QPS_RTS:
+			pr_debug("qp state -> RTS\n");
+			qp->req.state = QP_STATE_READY;
+			break;
+
+		case IB_QPS_SQD:
+			pr_debug("qp state -> SQD\n");
+			rxe_qp_drain(qp);
+			break;
+
+		case IB_QPS_SQE:
+			pr_warn("qp state -> SQE !!?\n");
+			/* Not possible from modify_qp. */
+			break;
+
+		case IB_QPS_ERR:
+			pr_debug("qp state -> ERR\n");
+			rxe_qp_error(qp);
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/* called by the query qp verb */
+int rxe_qp_to_attr(struct rxe_qp *qp, struct ib_qp_attr *attr, int mask)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+
+	*attr = qp->attr;
+
+	attr->rq_psn				= qp->resp.psn;
+	attr->sq_psn				= qp->req.psn;
+
+	attr->cap.max_send_wr			= qp->sq.max_wr;
+	attr->cap.max_send_sge			= qp->sq.max_sge;
+	attr->cap.max_inline_data		= qp->sq.max_inline;
+
+	if (!qp->srq) {
+		attr->cap.max_recv_wr		= qp->rq.max_wr;
+		attr->cap.max_recv_sge		= qp->rq.max_sge;
+	}
+
+	rxe_av_to_attr(rxe, &qp->pri_av, &attr->ah_attr);
+	rxe_av_to_attr(rxe, &qp->alt_av, &attr->alt_ah_attr);
+
+	if (qp->req.state == QP_STATE_DRAIN) {
+		attr->sq_draining = 1;
+		/* applications that get this state
+		 * typically spin on it. yield the
+		 * processor
+		 */
+		cond_resched();
+	} else {
+		attr->sq_draining = 0;
+	}
+
+	pr_debug("attr->sq_draining = %d\n", attr->sq_draining);
+
+	return 0;
+}
+
+/* called by the destroy qp verb */
+void rxe_qp_destroy(struct rxe_qp *qp)
+{
+	qp->valid = 0;
+	qp->qp_timeout_jiffies = 0;
+	rxe_cleanup_task(&qp->resp.task);
+
+	del_timer_sync(&qp->retrans_timer);
+	del_timer_sync(&qp->rnr_nak_timer);
+
+	rxe_cleanup_task(&qp->req.task);
+	if (qp_type(qp) == IB_QPT_RC)
+		rxe_cleanup_task(&qp->comp.task);
+
+	/* flush out any receive wr's or pending requests */
+	__rxe_do_task(&qp->req.task);
+	if (qp->sq.queue) {
+		__rxe_do_task(&qp->comp.task);
+		__rxe_do_task(&qp->req.task);
+	}
+}
+
+/* called when the last reference to the qp is dropped */
+void rxe_qp_cleanup(void *arg)
+{
+	struct rxe_qp *qp = arg;
+
+	rxe_drop_all_mcast_groups(qp);
+
+	if (qp->sq.queue)
+		rxe_queue_cleanup(qp->sq.queue);
+
+	if (qp->srq)
+		rxe_drop_ref(qp->srq);
+
+	if (qp->rq.queue)
+		rxe_queue_cleanup(qp->rq.queue);
+
+	if (qp->scq)
+		rxe_drop_ref(qp->scq);
+	if (qp->rcq)
+		rxe_drop_ref(qp->rcq);
+	if (qp->pd)
+		rxe_drop_ref(qp->pd);
+
+	if (qp->resp.mr) {
+		rxe_drop_ref(qp->resp.mr);
+		qp->resp.mr = NULL;
+	}
+
+	free_rd_atomic_resources(qp);
+
+	kernel_sock_shutdown(qp->sk, SHUT_RDWR);
+}