drivers/infiniband/hw/amso1100/c2_cq.c - kernel/prism - Git at Google

 /*
  * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
  * Copyright (c) 2005 Cisco Systems, Inc. All rights reserved.
  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
  * Copyright (c) 2004 Voltaire, Inc. All rights reserved.
  * Copyright (c) 2005 Open Grid Computing, 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 "c2.h"
 #include "c2_vq.h"
 #include "c2_status.h"

 #define C2_CQ_MSG_SIZE ((sizeof(struct c2wr_ce) + 32-1) & ~(32-1))

 static struct c2_cq *c2_cq_get(struct c2_dev *c2dev, int cqn)
 {
 	struct c2_cq *cq;
 	unsigned long flags;

 	spin_lock_irqsave(&c2dev->lock, flags);
 	cq = c2dev->qptr_array[cqn];
 	if (!cq) {
 		spin_unlock_irqrestore(&c2dev->lock, flags);
 		return NULL;
 	}
 	atomic_inc(&cq->refcount);
 	spin_unlock_irqrestore(&c2dev->lock, flags);
 	return cq;
 }

 static void c2_cq_put(struct c2_cq *cq)
 {
 	if (atomic_dec_and_test(&cq->refcount))
 		wake_up(&cq->wait);
 }

 void c2_cq_event(struct c2_dev *c2dev, u32 mq_index)
 {
 	struct c2_cq *cq;

 	cq = c2_cq_get(c2dev, mq_index);
 	if (!cq) {
 		printk("discarding events on destroyed CQN=%d\n", mq_index);
 		return;
 	}

 	(*cq->ibcq.comp_handler) (&cq->ibcq, cq->ibcq.cq_context);
 	c2_cq_put(cq);
 }

 void c2_cq_clean(struct c2_dev *c2dev, struct c2_qp *qp, u32 mq_index)
 {
 	struct c2_cq *cq;
 	struct c2_mq *q;

 	cq = c2_cq_get(c2dev, mq_index);
 	if (!cq)
 		return;

 	spin_lock_irq(&cq->lock);
 	q = &cq->mq;
 	if (q && !c2_mq_empty(q)) {
 		u16 priv = q->priv;
 		struct c2wr_ce *msg;

 		while (priv != be16_to_cpu(*q->shared)) {
 			msg = (struct c2wr_ce *)
 				(q->msg_pool.host + priv * q->msg_size);
 			if (msg->qp_user_context == (u64) (unsigned long) qp) {
 				msg->qp_user_context = (u64) 0;
 			}
 			priv = (priv + 1) % q->q_size;
 		}
 	}
 	spin_unlock_irq(&cq->lock);
 	c2_cq_put(cq);
 }

 static inline enum ib_wc_status c2_cqe_status_to_openib(u8 status)
 {
 	switch (status) {
 	case C2_OK:
 		return IB_WC_SUCCESS;
 	case CCERR_FLUSHED:
 		return IB_WC_WR_FLUSH_ERR;
 	case CCERR_BASE_AND_BOUNDS_VIOLATION:
 		return IB_WC_LOC_PROT_ERR;
 	case CCERR_ACCESS_VIOLATION:
 		return IB_WC_LOC_ACCESS_ERR;
 	case CCERR_TOTAL_LENGTH_TOO_BIG:
 		return IB_WC_LOC_LEN_ERR;
 	case CCERR_INVALID_WINDOW:
 		return IB_WC_MW_BIND_ERR;
 	default:
 		return IB_WC_GENERAL_ERR;
 	}
 }


 static inline int c2_poll_one(struct c2_dev *c2dev,
 			      struct c2_cq *cq, struct ib_wc *entry)
 {
 	struct c2wr_ce *ce;
 	struct c2_qp *qp;
 	int is_recv = 0;

 	ce = c2_mq_consume(&cq->mq);
 	if (!ce) {
 		return -EAGAIN;
 	}

 	/*
 	 * if the qp returned is null then this qp has already
 	 * been freed and we are unable process the completion.
 	 * try pulling the next message
 	 */
 	while ((qp =
 		(struct c2_qp *) (unsigned long) ce->qp_user_context) == NULL) {
 		c2_mq_free(&cq->mq);
 		ce = c2_mq_consume(&cq->mq);
 		if (!ce)
 			return -EAGAIN;
 	}

 	entry->status = c2_cqe_status_to_openib(c2_wr_get_result(ce));
 	entry->wr_id = ce->hdr.context;
 	entry->qp = &qp->ibqp;
 	entry->wc_flags = 0;
 	entry->slid = 0;
 	entry->sl = 0;
 	entry->src_qp = 0;
 	entry->dlid_path_bits = 0;
 	entry->pkey_index = 0;

 	switch (c2_wr_get_id(ce)) {
 	case C2_WR_TYPE_SEND:
 		entry->opcode = IB_WC_SEND;
 		break;
 	case C2_WR_TYPE_RDMA_WRITE:
 		entry->opcode = IB_WC_RDMA_WRITE;
 		break;
 	case C2_WR_TYPE_RDMA_READ:
 		entry->opcode = IB_WC_RDMA_READ;
 		break;
 	case C2_WR_TYPE_BIND_MW:
 		entry->opcode = IB_WC_BIND_MW;
 		break;
 	case C2_WR_TYPE_RECV:
 		entry->byte_len = be32_to_cpu(ce->bytes_rcvd);
 		entry->opcode = IB_WC_RECV;
 		is_recv = 1;
 		break;
 	default:
 		break;
 	}

 	/* consume the WQEs */
 	if (is_recv)
 		c2_mq_lconsume(&qp->rq_mq, 1);
 	else
 		c2_mq_lconsume(&qp->sq_mq,
 			       be32_to_cpu(c2_wr_get_wqe_count(ce)) + 1);

 	/* free the message */
 	c2_mq_free(&cq->mq);

 	return 0;
 }

 int c2_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
 {
 	struct c2_dev *c2dev = to_c2dev(ibcq->device);
 	struct c2_cq *cq = to_c2cq(ibcq);
 	unsigned long flags;
 	int npolled, err;

 	spin_lock_irqsave(&cq->lock, flags);

 	for (npolled = 0; npolled < num_entries; ++npolled) {

 		err = c2_poll_one(c2dev, cq, entry + npolled);
 		if (err)
 			break;
 	}

 	spin_unlock_irqrestore(&cq->lock, flags);

 	return npolled;
 }

 int c2_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
 {
 	struct c2_mq_shared __iomem *shared;
 	struct c2_cq *cq;
 	unsigned long flags;
 	int ret = 0;

 	cq = to_c2cq(ibcq);
 	shared = cq->mq.peer;

 	if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_NEXT_COMP)
 		writeb(C2_CQ_NOTIFICATION_TYPE_NEXT, &shared->notification_type);
 	else if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED)
 		writeb(C2_CQ_NOTIFICATION_TYPE_NEXT_SE, &shared->notification_type);
 	else
 		return -EINVAL;

 	writeb(CQ_WAIT_FOR_DMA | CQ_ARMED, &shared->armed);

 	/*
 	 * Now read back shared->armed to make the PCI
 	 * write synchronous.  This is necessary for
 	 * correct cq notification semantics.
 	 */
 	readb(&shared->armed);

 	if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
 		spin_lock_irqsave(&cq->lock, flags);
 		ret = !c2_mq_empty(&cq->mq);
 		spin_unlock_irqrestore(&cq->lock, flags);
 	}

 	return ret;
 }

 static void c2_free_cq_buf(struct c2_dev *c2dev, struct c2_mq *mq)
 {
 	dma_free_coherent(&c2dev->pcidev->dev, mq->q_size * mq->msg_size,
 			  mq->msg_pool.host, pci_unmap_addr(mq, mapping));
 }

 static int c2_alloc_cq_buf(struct c2_dev *c2dev, struct c2_mq *mq, int q_size,
 			   int msg_size)
 {
 	u8 *pool_start;

 	pool_start = dma_alloc_coherent(&c2dev->pcidev->dev, q_size * msg_size,
 					&mq->host_dma, GFP_KERNEL);
 	if (!pool_start)
 		return -ENOMEM;

 	c2_mq_rep_init(mq,
 		       0,		/* index (currently unknown) */
 		       q_size,
 		       msg_size,
 		       pool_start,
 		       NULL,	/* peer (currently unknown) */
 		       C2_MQ_HOST_TARGET);

 	pci_unmap_addr_set(mq, mapping, mq->host_dma);

 	return 0;
 }

 int c2_init_cq(struct c2_dev *c2dev, int entries,
 	       struct c2_ucontext *ctx, struct c2_cq *cq)
 {
 	struct c2wr_cq_create_req wr;
 	struct c2wr_cq_create_rep *reply;
 	unsigned long peer_pa;
 	struct c2_vq_req *vq_req;
 	int err;

 	might_sleep();

 	cq->ibcq.cqe = entries - 1;
 	cq->is_kernel = !ctx;

 	/* Allocate a shared pointer */
 	cq->mq.shared = c2_alloc_mqsp(c2dev, c2dev->kern_mqsp_pool,
 				      &cq->mq.shared_dma, GFP_KERNEL);
 	if (!cq->mq.shared)
 		return -ENOMEM;

 	/* Allocate pages for the message pool */
 	err = c2_alloc_cq_buf(c2dev, &cq->mq, entries + 1, C2_CQ_MSG_SIZE);
 	if (err)
 		goto bail0;

 	vq_req = vq_req_alloc(c2dev);
 	if (!vq_req) {
 		err = -ENOMEM;
 		goto bail1;
 	}

 	memset(&wr, 0, sizeof(wr));
 	c2_wr_set_id(&wr, CCWR_CQ_CREATE);
 	wr.hdr.context = (unsigned long) vq_req;
 	wr.rnic_handle = c2dev->adapter_handle;
 	wr.msg_size = cpu_to_be32(cq->mq.msg_size);
 	wr.depth = cpu_to_be32(cq->mq.q_size);
 	wr.shared_ht = cpu_to_be64(cq->mq.shared_dma);
 	wr.msg_pool = cpu_to_be64(cq->mq.host_dma);
 	wr.user_context = (u64) (unsigned long) (cq);

 	vq_req_get(c2dev, vq_req);

 	err = vq_send_wr(c2dev, (union c2wr *) & wr);
 	if (err) {
 		vq_req_put(c2dev, vq_req);
 		goto bail2;
 	}

 	err = vq_wait_for_reply(c2dev, vq_req);
 	if (err)
 		goto bail2;

 	reply = (struct c2wr_cq_create_rep *) (unsigned long) (vq_req->reply_msg);
 	if (!reply) {
 		err = -ENOMEM;
 		goto bail2;
 	}

 	if ((err = c2_errno(reply)) != 0)
 		goto bail3;

 	cq->adapter_handle = reply->cq_handle;
 	cq->mq.index = be32_to_cpu(reply->mq_index);

 	peer_pa = c2dev->pa + be32_to_cpu(reply->adapter_shared);
 	cq->mq.peer = ioremap_nocache(peer_pa, PAGE_SIZE);
 	if (!cq->mq.peer) {
 		err = -ENOMEM;
 		goto bail3;
 	}

 	vq_repbuf_free(c2dev, reply);
 	vq_req_free(c2dev, vq_req);

 	spin_lock_init(&cq->lock);
 	atomic_set(&cq->refcount, 1);
 	init_waitqueue_head(&cq->wait);

 	/*
 	 * Use the MQ index allocated by the adapter to
 	 * store the CQ in the qptr_array
 	 */
 	cq->cqn = cq->mq.index;
 	c2dev->qptr_array[cq->cqn] = cq;

 	return 0;

       bail3:
 	vq_repbuf_free(c2dev, reply);
       bail2:
 	vq_req_free(c2dev, vq_req);
       bail1:
 	c2_free_cq_buf(c2dev, &cq->mq);
       bail0:
 	c2_free_mqsp(cq->mq.shared);

 	return err;
 }

 void c2_free_cq(struct c2_dev *c2dev, struct c2_cq *cq)
 {
 	int err;
 	struct c2_vq_req *vq_req;
 	struct c2wr_cq_destroy_req wr;
 	struct c2wr_cq_destroy_rep *reply;

 	might_sleep();

 	/* Clear CQ from the qptr array */
 	spin_lock_irq(&c2dev->lock);
 	c2dev->qptr_array[cq->mq.index] = NULL;
 	atomic_dec(&cq->refcount);
 	spin_unlock_irq(&c2dev->lock);

 	wait_event(cq->wait, !atomic_read(&cq->refcount));

 	vq_req = vq_req_alloc(c2dev);
 	if (!vq_req) {
 		goto bail0;
 	}

 	memset(&wr, 0, sizeof(wr));
 	c2_wr_set_id(&wr, CCWR_CQ_DESTROY);
 	wr.hdr.context = (unsigned long) vq_req;
 	wr.rnic_handle = c2dev->adapter_handle;
 	wr.cq_handle = cq->adapter_handle;

 	vq_req_get(c2dev, vq_req);

 	err = vq_send_wr(c2dev, (union c2wr *) & wr);
 	if (err) {
 		vq_req_put(c2dev, vq_req);
 		goto bail1;
 	}

 	err = vq_wait_for_reply(c2dev, vq_req);
 	if (err)
 		goto bail1;

 	reply = (struct c2wr_cq_destroy_rep *) (unsigned long) (vq_req->reply_msg);
 	if (reply)
 		vq_repbuf_free(c2dev, reply);
       bail1:
 	vq_req_free(c2dev, vq_req);
       bail0:
 	if (cq->is_kernel) {
 		c2_free_cq_buf(c2dev, &cq->mq);
 	}

 	return;
 }
	/*
	* Copyright (c) 2004, 2005 Topspin Communications. All rights reserved.
	* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
	* Copyright (c) 2005 Cisco Systems, Inc. All rights reserved.
	* Copyright (c) 2005 Mellanox Technologies. All rights reserved.
	* Copyright (c) 2004 Voltaire, Inc. All rights reserved.
	* Copyright (c) 2005 Open Grid Computing, 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 "c2.h"
	#include "c2_vq.h"
	#include "c2_status.h"

	#define C2_CQ_MSG_SIZE ((sizeof(struct c2wr_ce) + 32-1) & ~(32-1))

	static struct c2_cq c2_cq_get(struct c2_dev c2dev, int cqn)
	{
	struct c2_cq *cq;
	unsigned long flags;

	spin_lock_irqsave(&c2dev->lock, flags);
	cq = c2dev->qptr_array[cqn];
	if (!cq) {
	spin_unlock_irqrestore(&c2dev->lock, flags);
	return NULL;
	}
	atomic_inc(&cq->refcount);
	spin_unlock_irqrestore(&c2dev->lock, flags);
	return cq;
	}

	static void c2_cq_put(struct c2_cq *cq)
	{
	if (atomic_dec_and_test(&cq->refcount))
	wake_up(&cq->wait);
	}

	void c2_cq_event(struct c2_dev *c2dev, u32 mq_index)
	{
	struct c2_cq *cq;

	cq = c2_cq_get(c2dev, mq_index);
	if (!cq) {
	printk("discarding events on destroyed CQN=%d\n", mq_index);
	return;
	}

	(*cq->ibcq.comp_handler) (&cq->ibcq, cq->ibcq.cq_context);
	c2_cq_put(cq);
	}

	void c2_cq_clean(struct c2_dev c2dev, struct c2_qp qp, u32 mq_index)
	{
	struct c2_cq *cq;
	struct c2_mq *q;

	cq = c2_cq_get(c2dev, mq_index);
	if (!cq)
	return;

	spin_lock_irq(&cq->lock);
	q = &cq->mq;
	if (q && !c2_mq_empty(q)) {
	u16 priv = q->priv;
	struct c2wr_ce *msg;

	while (priv != be16_to_cpu(*q->shared)) {
	msg = (struct c2wr_ce *)
	(q->msg_pool.host + priv * q->msg_size);
	if (msg->qp_user_context == (u64) (unsigned long) qp) {
	msg->qp_user_context = (u64) 0;
	}
	priv = (priv + 1) % q->q_size;
	}
	}
	spin_unlock_irq(&cq->lock);
	c2_cq_put(cq);
	}

	static inline enum ib_wc_status c2_cqe_status_to_openib(u8 status)
	{
	switch (status) {
	case C2_OK:
	return IB_WC_SUCCESS;
	case CCERR_FLUSHED:
	return IB_WC_WR_FLUSH_ERR;
	case CCERR_BASE_AND_BOUNDS_VIOLATION:
	return IB_WC_LOC_PROT_ERR;
	case CCERR_ACCESS_VIOLATION:
	return IB_WC_LOC_ACCESS_ERR;
	case CCERR_TOTAL_LENGTH_TOO_BIG:
	return IB_WC_LOC_LEN_ERR;
	case CCERR_INVALID_WINDOW:
	return IB_WC_MW_BIND_ERR;
	default:
	return IB_WC_GENERAL_ERR;
	}
	}


	static inline int c2_poll_one(struct c2_dev *c2dev,
	struct c2_cq cq, struct ib_wc entry)
	{
	struct c2wr_ce *ce;
	struct c2_qp *qp;
	int is_recv = 0;

	ce = c2_mq_consume(&cq->mq);
	if (!ce) {
	return -EAGAIN;
	}

	/*
	* if the qp returned is null then this qp has already
	* been freed and we are unable process the completion.
	* try pulling the next message
	*/
	while ((qp =
	(struct c2_qp *) (unsigned long) ce->qp_user_context) == NULL) {
	c2_mq_free(&cq->mq);
	ce = c2_mq_consume(&cq->mq);
	if (!ce)
	return -EAGAIN;
	}

	entry->status = c2_cqe_status_to_openib(c2_wr_get_result(ce));
	entry->wr_id = ce->hdr.context;
	entry->qp = &qp->ibqp;
	entry->wc_flags = 0;
	entry->slid = 0;
	entry->sl = 0;
	entry->src_qp = 0;
	entry->dlid_path_bits = 0;
	entry->pkey_index = 0;

	switch (c2_wr_get_id(ce)) {
	case C2_WR_TYPE_SEND:
	entry->opcode = IB_WC_SEND;
	break;
	case C2_WR_TYPE_RDMA_WRITE:
	entry->opcode = IB_WC_RDMA_WRITE;
	break;
	case C2_WR_TYPE_RDMA_READ:
	entry->opcode = IB_WC_RDMA_READ;
	break;
	case C2_WR_TYPE_BIND_MW:
	entry->opcode = IB_WC_BIND_MW;
	break;
	case C2_WR_TYPE_RECV:
	entry->byte_len = be32_to_cpu(ce->bytes_rcvd);
	entry->opcode = IB_WC_RECV;
	is_recv = 1;
	break;
	default:
	break;
	}

	/* consume the WQEs */
	if (is_recv)
	c2_mq_lconsume(&qp->rq_mq, 1);
	else
	c2_mq_lconsume(&qp->sq_mq,
	be32_to_cpu(c2_wr_get_wqe_count(ce)) + 1);

	/* free the message */
	c2_mq_free(&cq->mq);

	return 0;
	}

	int c2_poll_cq(struct ib_cq ibcq, int num_entries, struct ib_wc entry)
	{
	struct c2_dev *c2dev = to_c2dev(ibcq->device);
	struct c2_cq *cq = to_c2cq(ibcq);
	unsigned long flags;
	int npolled, err;

	spin_lock_irqsave(&cq->lock, flags);

	for (npolled = 0; npolled < num_entries; ++npolled) {

	err = c2_poll_one(c2dev, cq, entry + npolled);
	if (err)
	break;
	}

	spin_unlock_irqrestore(&cq->lock, flags);

	return npolled;
	}

	int c2_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
	{
	struct c2_mq_shared __iomem *shared;
	struct c2_cq *cq;
	unsigned long flags;
	int ret = 0;

	cq = to_c2cq(ibcq);
	shared = cq->mq.peer;

	if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_NEXT_COMP)
	writeb(C2_CQ_NOTIFICATION_TYPE_NEXT, &shared->notification_type);
	else if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED)
	writeb(C2_CQ_NOTIFICATION_TYPE_NEXT_SE, &shared->notification_type);
	else
	return -EINVAL;

	writeb(CQ_WAIT_FOR_DMA \| CQ_ARMED, &shared->armed);

	/*
	* Now read back shared->armed to make the PCI
	* write synchronous. This is necessary for
	* correct cq notification semantics.
	*/
	readb(&shared->armed);

	if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
	spin_lock_irqsave(&cq->lock, flags);
	ret = !c2_mq_empty(&cq->mq);
	spin_unlock_irqrestore(&cq->lock, flags);
	}

	return ret;
	}

	static void c2_free_cq_buf(struct c2_dev c2dev, struct c2_mq mq)
	{
	dma_free_coherent(&c2dev->pcidev->dev, mq->q_size * mq->msg_size,
	mq->msg_pool.host, pci_unmap_addr(mq, mapping));
	}

	static int c2_alloc_cq_buf(struct c2_dev c2dev, struct c2_mq mq, int q_size,
	int msg_size)
	{
	u8 *pool_start;

	pool_start = dma_alloc_coherent(&c2dev->pcidev->dev, q_size * msg_size,
	&mq->host_dma, GFP_KERNEL);
	if (!pool_start)
	return -ENOMEM;

	c2_mq_rep_init(mq,
	0, /* index (currently unknown) */
	q_size,
	msg_size,
	pool_start,
	NULL, /* peer (currently unknown) */
	C2_MQ_HOST_TARGET);

	pci_unmap_addr_set(mq, mapping, mq->host_dma);

	return 0;
	}

	int c2_init_cq(struct c2_dev *c2dev, int entries,
	struct c2_ucontext ctx, struct c2_cq cq)
	{
	struct c2wr_cq_create_req wr;
	struct c2wr_cq_create_rep *reply;
	unsigned long peer_pa;
	struct c2_vq_req *vq_req;
	int err;

	might_sleep();

	cq->ibcq.cqe = entries - 1;
	cq->is_kernel = !ctx;

	/* Allocate a shared pointer */
	cq->mq.shared = c2_alloc_mqsp(c2dev, c2dev->kern_mqsp_pool,
	&cq->mq.shared_dma, GFP_KERNEL);
	if (!cq->mq.shared)
	return -ENOMEM;

	/* Allocate pages for the message pool */
	err = c2_alloc_cq_buf(c2dev, &cq->mq, entries + 1, C2_CQ_MSG_SIZE);
	if (err)
	goto bail0;

	vq_req = vq_req_alloc(c2dev);
	if (!vq_req) {
	err = -ENOMEM;
	goto bail1;
	}

	memset(&wr, 0, sizeof(wr));
	c2_wr_set_id(&wr, CCWR_CQ_CREATE);
	wr.hdr.context = (unsigned long) vq_req;
	wr.rnic_handle = c2dev->adapter_handle;
	wr.msg_size = cpu_to_be32(cq->mq.msg_size);
	wr.depth = cpu_to_be32(cq->mq.q_size);
	wr.shared_ht = cpu_to_be64(cq->mq.shared_dma);
	wr.msg_pool = cpu_to_be64(cq->mq.host_dma);
	wr.user_context = (u64) (unsigned long) (cq);

	vq_req_get(c2dev, vq_req);

	err = vq_send_wr(c2dev, (union c2wr *) & wr);
	if (err) {
	vq_req_put(c2dev, vq_req);
	goto bail2;
	}

	err = vq_wait_for_reply(c2dev, vq_req);
	if (err)
	goto bail2;

	reply = (struct c2wr_cq_create_rep *) (unsigned long) (vq_req->reply_msg);
	if (!reply) {
	err = -ENOMEM;
	goto bail2;
	}

	if ((err = c2_errno(reply)) != 0)
	goto bail3;

	cq->adapter_handle = reply->cq_handle;
	cq->mq.index = be32_to_cpu(reply->mq_index);

	peer_pa = c2dev->pa + be32_to_cpu(reply->adapter_shared);
	cq->mq.peer = ioremap_nocache(peer_pa, PAGE_SIZE);
	if (!cq->mq.peer) {
	err = -ENOMEM;
	goto bail3;
	}

	vq_repbuf_free(c2dev, reply);
	vq_req_free(c2dev, vq_req);

	spin_lock_init(&cq->lock);
	atomic_set(&cq->refcount, 1);
	init_waitqueue_head(&cq->wait);

	/*
	* Use the MQ index allocated by the adapter to
	* store the CQ in the qptr_array
	*/
	cq->cqn = cq->mq.index;
	c2dev->qptr_array[cq->cqn] = cq;

	return 0;

	bail3:
	vq_repbuf_free(c2dev, reply);
	bail2:
	vq_req_free(c2dev, vq_req);
	bail1:
	c2_free_cq_buf(c2dev, &cq->mq);
	bail0:
	c2_free_mqsp(cq->mq.shared);

	return err;
	}

	void c2_free_cq(struct c2_dev c2dev, struct c2_cq cq)
	{
	int err;
	struct c2_vq_req *vq_req;
	struct c2wr_cq_destroy_req wr;
	struct c2wr_cq_destroy_rep *reply;

	might_sleep();

	/* Clear CQ from the qptr array */
	spin_lock_irq(&c2dev->lock);
	c2dev->qptr_array[cq->mq.index] = NULL;
	atomic_dec(&cq->refcount);
	spin_unlock_irq(&c2dev->lock);

	wait_event(cq->wait, !atomic_read(&cq->refcount));

	vq_req = vq_req_alloc(c2dev);
	if (!vq_req) {
	goto bail0;
	}

	memset(&wr, 0, sizeof(wr));
	c2_wr_set_id(&wr, CCWR_CQ_DESTROY);
	wr.hdr.context = (unsigned long) vq_req;
	wr.rnic_handle = c2dev->adapter_handle;
	wr.cq_handle = cq->adapter_handle;

	vq_req_get(c2dev, vq_req);

	err = vq_send_wr(c2dev, (union c2wr *) & wr);
	if (err) {
	vq_req_put(c2dev, vq_req);
	goto bail1;
	}

	err = vq_wait_for_reply(c2dev, vq_req);
	if (err)
	goto bail1;

	reply = (struct c2wr_cq_destroy_rep *) (unsigned long) (vq_req->reply_msg);
	if (reply)
	vq_repbuf_free(c2dev, reply);
	bail1:
	vq_req_free(c2dev, vq_req);
	bail0:
	if (cq->is_kernel) {
	c2_free_cq_buf(c2dev, &cq->mq);
	}

	return;
	}