diff mbox

[v4,09/16] IB/pvrdma: Add support for Completion Queues

Message ID 1473655766-31628-10-git-send-email-aditr@vmware.com
State Not Applicable
Headers show

Commit Message

Adit Ranadive Sept. 12, 2016, 4:49 a.m. UTC
This patch adds the support for creating and destroying completion queues
on the paravirtual RDMA device.

Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Reviewed-by: George Zhang <georgezhang@vmware.com>
Reviewed-by: Aditya Sarwade <asarwade@vmware.com>
Reviewed-by: Bryan Tan <bryantan@vmware.com>
Signed-off-by: Adit Ranadive <aditr@vmware.com>
---
Changes v3->v4:
 - Added a pvrdma_destroy_cq in the error path.
 - Renamed pvrdma_flush_cqe to _pvrdma_flush_cqe since we need a lock to
 be held while calling this.
 - Updated to use wrapper for UAR write for CQ.
 - Ensure that poll_cq does not return error values.

Changes v2->v3:
 - Removed boolean from pvrdma_cmd_post.
 - Return -EAGAIN if qp retrieved from CQE is bogus.
 - Check for invalid index of ring.
---
 drivers/infiniband/hw/pvrdma/pvrdma_cq.c | 428 +++++++++++++++++++++++++++++++
 1 file changed, 428 insertions(+)
 create mode 100644 drivers/infiniband/hw/pvrdma/pvrdma_cq.c

Comments

Yuval Shaia Sept. 14, 2016, 12:43 p.m. UTC | #1
On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> +
> +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp **cur_qp,
> +			   struct ib_wc *wc)
> +{
> +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> +	int has_data;
> +	unsigned int head;
> +	bool tried = false;
> +	struct pvrdma_cqe *cqe;
> +
> +retry:
> +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> +					    cq->ibcq.cqe, &head);
> +	if (has_data == 0) {
> +		if (tried)
> +			return -EAGAIN;
> +
> +		/* Pass down POLL to give physical HCA a chance to poll. */
> +		pvrdma_write_uar_cq(dev, cq->cq_handle | PVRDMA_UAR_CQ_POLL);
> +
> +		tried = true;
> +		goto retry;
> +	} else if (has_data == PVRDMA_INVALID_IDX) {

I didn't went throw the entire life cycle of RX-ring's head and tail but
you need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
there is probability that in the next call to pvrdma_poll_one it will be
fine. Otherwise it is an endless loop.

> +		dev_err(&dev->pdev->dev, "CQ ring state invalid\n");
> +		return -EAGAIN;
> +	}
> +
> +	cqe = get_cqe(cq, head);
> +
> +	/* Ensure cqe is valid. */
> +	rmb();
> +	if (dev->qp_tbl[cqe->qp & 0xffff])
> +		*cur_qp = (struct pvrdma_qp *)dev->qp_tbl[cqe->qp & 0xffff];
> +	else
> +		return -EAGAIN;
> +
> +	wc->opcode = pvrdma_wc_opcode_to_ib(cqe->opcode);
> +	wc->status = pvrdma_wc_status_to_ib(cqe->status);
> +	wc->wr_id = cqe->wr_id;
> +	wc->qp = &(*cur_qp)->ibqp;
> +	wc->byte_len = cqe->byte_len;
> +	wc->ex.imm_data = cqe->imm_data;
> +	wc->src_qp = cqe->src_qp;
> +	wc->wc_flags = pvrdma_wc_flags_to_ib(cqe->wc_flags);
> +	wc->pkey_index = cqe->pkey_index;
> +	wc->slid = cqe->slid;
> +	wc->sl = cqe->sl;
> +	wc->dlid_path_bits = cqe->dlid_path_bits;
> +	wc->port_num = cqe->port_num;
> +	wc->vendor_err = 0;
> +
> +	/* Update shared ring state */
> +	pvrdma_idx_ring_inc(&cq->ring_state->rx.cons_head, cq->ibcq.cqe);
> +
> +	return 0;
> +}
> +
> +/**
> + * pvrdma_poll_cq - poll for work completion queue entries
> + * @ibcq: completion queue
> + * @num_entries: the maximum number of entries
> + * @entry: pointer to work completion array
> + *
> + * @return: number of polled completion entries
> + */
> +int pvrdma_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
> +{
> +	struct pvrdma_cq *cq = to_vcq(ibcq);
> +	struct pvrdma_qp *cur_qp = NULL;
> +	unsigned long flags;
> +	int npolled;
> +
> +	if (num_entries < 1 || wc == NULL)
> +		return 0;
> +
> +	spin_lock_irqsave(&cq->cq_lock, flags);
> +	for (npolled = 0; npolled < num_entries; ++npolled) {
> +		if (pvrdma_poll_one(cq, &cur_qp, wc + npolled))
> +			break;
> +	}
> +
> +	spin_unlock_irqrestore(&cq->cq_lock, flags);
> +
> +	/* Ensure we do not return errors from poll_cq */
> +	return npolled;
> +}
> +
> +/**
> + * pvrdma_resize_cq - resize CQ
> + * @ibcq: the completion queue
> + * @entries: CQ entries
> + * @udata: user data
> + *
> + * @return: -EOPNOTSUPP as CQ resize is not supported.
> + */
> +int pvrdma_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
> +{
> +	return -EOPNOTSUPP;
> +}
> -- 
> 2.7.4
> 
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Adit Ranadive Sept. 15, 2016, 12:07 a.m. UTC | #2
On Wed, Sep 14, 2016 at 05:43:37 -0700, Yuval Shaia wrote:
> On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> > +
> > +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp
> **cur_qp,
> > +			   struct ib_wc *wc)
> > +{
> > +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> > +	int has_data;
> > +	unsigned int head;
> > +	bool tried = false;
> > +	struct pvrdma_cqe *cqe;
> > +
> > +retry:
> > +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > +					    cq->ibcq.cqe, &head);
> > +	if (has_data == 0) {
> > +		if (tried)
> > +			return -EAGAIN;
> > +
> > +		/* Pass down POLL to give physical HCA a chance to poll. */
> > +		pvrdma_write_uar_cq(dev, cq->cq_handle |
> PVRDMA_UAR_CQ_POLL);
> > +
> > +		tried = true;
> > +		goto retry;
> > +	} else if (has_data == PVRDMA_INVALID_IDX) {
> 
> I didn't went throw the entire life cycle of RX-ring's head and tail but you
> need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
> there is probability that in the next call to pvrdma_poll_one it will be fine.
> Otherwise it is an endless loop.

We have never run into this issue internally but I don't think we can recover here 
in the driver. The only way to recover would be to destroy and recreate the CQ 
which we shouldn't do since it could be used by multiple QPs. 
We don't have a way yet to recover in the device. Once we add that this check
should go away.

The reason I returned an error value from poll_cq in v3 was to break the possible 
loop so that it might give clients a chance to recover. But since poll_cq is not expected
to fail I just log the device error here. I can revert to that version if you want to break
the possible loop.
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Yuval Shaia Sept. 15, 2016, 7:36 a.m. UTC | #3
Hi Adit,
Please see my comments inline.

Besides that I have no more comment for this patch.

Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>

Yuval

On Thu, Sep 15, 2016 at 12:07:29AM +0000, Adit Ranadive wrote:
> On Wed, Sep 14, 2016 at 05:43:37 -0700, Yuval Shaia wrote:
> > On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> > > +
> > > +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp
> > **cur_qp,
> > > +			   struct ib_wc *wc)
> > > +{
> > > +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> > > +	int has_data;
> > > +	unsigned int head;
> > > +	bool tried = false;
> > > +	struct pvrdma_cqe *cqe;
> > > +
> > > +retry:
> > > +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > > +					    cq->ibcq.cqe, &head);
> > > +	if (has_data == 0) {
> > > +		if (tried)
> > > +			return -EAGAIN;
> > > +
> > > +		/* Pass down POLL to give physical HCA a chance to poll. */
> > > +		pvrdma_write_uar_cq(dev, cq->cq_handle |
> > PVRDMA_UAR_CQ_POLL);
> > > +
> > > +		tried = true;
> > > +		goto retry;
> > > +	} else if (has_data == PVRDMA_INVALID_IDX) {
> > 
> > I didn't went throw the entire life cycle of RX-ring's head and tail but you
> > need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
> > there is probability that in the next call to pvrdma_poll_one it will be fine.
> > Otherwise it is an endless loop.
> 
> We have never run into this issue internally but I don't think we can recover here 

I briefly reviewed the life cycle of RX-ring's head and tail and didn't
caught any suspicious place that might corrupt it.
So glad to see that you never encountered this case.

> in the driver. The only way to recover would be to destroy and recreate the CQ 
> which we shouldn't do since it could be used by multiple QPs. 

Agree.
But don't they hit the same problem too?

> We don't have a way yet to recover in the device. Once we add that this check
> should go away.

To be honest i have no idea how to do that - i was expecting driver's vendors
to come up with an ideas :)
I once came up with an idea to force restart of the driver but it was
rejected.

> 
> The reason I returned an error value from poll_cq in v3 was to break the possible 
> loop so that it might give clients a chance to recover. But since poll_cq is not expected
> to fail I just log the device error here. I can revert to that version if you want to break
> the possible loop.

Clients (ULPs) cannot recover from this case. They even do not check the
reason of the error and treats any error as -EAGAIN.

> --
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Leon Romanovsky Sept. 18, 2016, 5:07 p.m. UTC | #4
On Thu, Sep 15, 2016 at 10:36:12AM +0300, Yuval Shaia wrote:
> Hi Adit,
> Please see my comments inline.
>
> Besides that I have no more comment for this patch.
>
> Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
>
> Yuval
>
> On Thu, Sep 15, 2016 at 12:07:29AM +0000, Adit Ranadive wrote:
> > On Wed, Sep 14, 2016 at 05:43:37 -0700, Yuval Shaia wrote:
> > > On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> > > > +
> > > > +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp
> > > **cur_qp,
> > > > +			   struct ib_wc *wc)
> > > > +{
> > > > +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> > > > +	int has_data;
> > > > +	unsigned int head;
> > > > +	bool tried = false;
> > > > +	struct pvrdma_cqe *cqe;
> > > > +
> > > > +retry:
> > > > +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > > > +					    cq->ibcq.cqe, &head);
> > > > +	if (has_data == 0) {
> > > > +		if (tried)
> > > > +			return -EAGAIN;
> > > > +
> > > > +		/* Pass down POLL to give physical HCA a chance to poll. */
> > > > +		pvrdma_write_uar_cq(dev, cq->cq_handle |
> > > PVRDMA_UAR_CQ_POLL);
> > > > +
> > > > +		tried = true;
> > > > +		goto retry;
> > > > +	} else if (has_data == PVRDMA_INVALID_IDX) {
> > >
> > > I didn't went throw the entire life cycle of RX-ring's head and tail but you
> > > need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
> > > there is probability that in the next call to pvrdma_poll_one it will be fine.
> > > Otherwise it is an endless loop.
> >
> > We have never run into this issue internally but I don't think we can recover here
>
> I briefly reviewed the life cycle of RX-ring's head and tail and didn't
> caught any suspicious place that might corrupt it.
> So glad to see that you never encountered this case.
>
> > in the driver. The only way to recover would be to destroy and recreate the CQ
> > which we shouldn't do since it could be used by multiple QPs.
>
> Agree.
> But don't they hit the same problem too?
>
> > We don't have a way yet to recover in the device. Once we add that this check
> > should go away.
>
> To be honest i have no idea how to do that - i was expecting driver's vendors
> to come up with an ideas :)
> I once came up with an idea to force restart of the driver but it was
> rejected.
>
> >
> > The reason I returned an error value from poll_cq in v3 was to break the possible
> > loop so that it might give clients a chance to recover. But since poll_cq is not expected
> > to fail I just log the device error here. I can revert to that version if you want to break
> > the possible loop.
>
> Clients (ULPs) cannot recover from this case. They even do not check the
> reason of the error and treats any error as -EAGAIN.

It is because poll_one is not expected to fall.

>
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
Adit Ranadive Sept. 18, 2016, 8:36 p.m. UTC | #5
On Sun, Sep 18, 2016 at 10:07:18 -0700, Leon Romanovsky wrote: 
> On Thu, Sep 15, 2016 at 10:36:12AM +0300, Yuval Shaia wrote:
> > Hi Adit,
> > Please see my comments inline.
> >
> > Besides that I have no more comment for this patch.
> >
> > Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
> >
> > Yuval
> >
> > On Thu, Sep 15, 2016 at 12:07:29AM +0000, Adit Ranadive wrote:
> > > On Wed, Sep 14, 2016 at 05:43:37 -0700, Yuval Shaia wrote:
> > > > On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> > > > > +
> > > > > +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp
> > > > **cur_qp,
> > > > > +			   struct ib_wc *wc)
> > > > > +{
> > > > > +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> > > > > +	int has_data;
> > > > > +	unsigned int head;
> > > > > +	bool tried = false;
> > > > > +	struct pvrdma_cqe *cqe;
> > > > > +
> > > > > +retry:
> > > > > +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > > > > +					    cq->ibcq.cqe, &head);
> > > > > +	if (has_data == 0) {
> > > > > +		if (tried)
> > > > > +			return -EAGAIN;
> > > > > +
> > > > > +		/* Pass down POLL to give physical HCA a chance to poll. */
> > > > > +		pvrdma_write_uar_cq(dev, cq->cq_handle |
> > > > PVRDMA_UAR_CQ_POLL);
> > > > > +
> > > > > +		tried = true;
> > > > > +		goto retry;
> > > > > +	} else if (has_data == PVRDMA_INVALID_IDX) {
> > > >
> > > > I didn't went throw the entire life cycle of RX-ring's head and tail but you
> > > > need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
> > > > there is probability that in the next call to pvrdma_poll_one it will be fine.
> > > > Otherwise it is an endless loop.
> > >
> > > We have never run into this issue internally but I don't think we can recover here
> >
> > I briefly reviewed the life cycle of RX-ring's head and tail and didn't
> > caught any suspicious place that might corrupt it.
> > So glad to see that you never encountered this case.
> >
> > > in the driver. The only way to recover would be to destroy and recreate the CQ
> > > which we shouldn't do since it could be used by multiple QPs.
> >
> > Agree.
> > But don't they hit the same problem too?
> >
> > > We don't have a way yet to recover in the device. Once we add that this check
> > > should go away.
> >
> > To be honest i have no idea how to do that - i was expecting driver's vendors
> > to come up with an ideas :)
> > I once came up with an idea to force restart of the driver but it was
> > rejected.
> >
> > >
> > > The reason I returned an error value from poll_cq in v3 was to break the possible
> > > loop so that it might give clients a chance to recover. But since poll_cq is not expected
> > > to fail I just log the device error here. I can revert to that version if you want to break
> > > the possible loop.
> >
> > Clients (ULPs) cannot recover from this case. They even do not check the
> > reason of the error and treats any error as -EAGAIN.
> 
> It is because poll_one is not expected to fall.

Poll_one is an internal function in our driver. ULPs should still be okay I think as long as poll_cq
does not fail, no?
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Leon Romanovsky Sept. 19, 2016, 3:24 a.m. UTC | #6
On Sun, Sep 18, 2016 at 08:36:55PM +0000, Adit Ranadive wrote:
> On Sun, Sep 18, 2016 at 10:07:18 -0700, Leon Romanovsky wrote:
> > On Thu, Sep 15, 2016 at 10:36:12AM +0300, Yuval Shaia wrote:
> > > Hi Adit,
> > > Please see my comments inline.
> > >
> > > Besides that I have no more comment for this patch.
> > >
> > > Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
> > >
> > > Yuval
> > >
> > > On Thu, Sep 15, 2016 at 12:07:29AM +0000, Adit Ranadive wrote:
> > > > On Wed, Sep 14, 2016 at 05:43:37 -0700, Yuval Shaia wrote:
> > > > > On Sun, Sep 11, 2016 at 09:49:19PM -0700, Adit Ranadive wrote:
> > > > > > +
> > > > > > +static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp
> > > > > **cur_qp,
> > > > > > +			   struct ib_wc *wc)
> > > > > > +{
> > > > > > +	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
> > > > > > +	int has_data;
> > > > > > +	unsigned int head;
> > > > > > +	bool tried = false;
> > > > > > +	struct pvrdma_cqe *cqe;
> > > > > > +
> > > > > > +retry:
> > > > > > +	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
> > > > > > +					    cq->ibcq.cqe, &head);
> > > > > > +	if (has_data == 0) {
> > > > > > +		if (tried)
> > > > > > +			return -EAGAIN;
> > > > > > +
> > > > > > +		/* Pass down POLL to give physical HCA a chance to poll. */
> > > > > > +		pvrdma_write_uar_cq(dev, cq->cq_handle |
> > > > > PVRDMA_UAR_CQ_POLL);
> > > > > > +
> > > > > > +		tried = true;
> > > > > > +		goto retry;
> > > > > > +	} else if (has_data == PVRDMA_INVALID_IDX) {
> > > > >
> > > > > I didn't went throw the entire life cycle of RX-ring's head and tail but you
> > > > > need to make sure that PVRDMA_INVALID_IDX error is recoverable one, i.e
> > > > > there is probability that in the next call to pvrdma_poll_one it will be fine.
> > > > > Otherwise it is an endless loop.
> > > >
> > > > We have never run into this issue internally but I don't think we can recover here
> > >
> > > I briefly reviewed the life cycle of RX-ring's head and tail and didn't
> > > caught any suspicious place that might corrupt it.
> > > So glad to see that you never encountered this case.
> > >
> > > > in the driver. The only way to recover would be to destroy and recreate the CQ
> > > > which we shouldn't do since it could be used by multiple QPs.
> > >
> > > Agree.
> > > But don't they hit the same problem too?
> > >
> > > > We don't have a way yet to recover in the device. Once we add that this check
> > > > should go away.
> > >
> > > To be honest i have no idea how to do that - i was expecting driver's vendors
> > > to come up with an ideas :)
> > > I once came up with an idea to force restart of the driver but it was
> > > rejected.
> > >
> > > >
> > > > The reason I returned an error value from poll_cq in v3 was to break the possible
> > > > loop so that it might give clients a chance to recover. But since poll_cq is not expected
> > > > to fail I just log the device error here. I can revert to that version if you want to break
> > > > the possible loop.
> > >
> > > Clients (ULPs) cannot recover from this case. They even do not check the
> > > reason of the error and treats any error as -EAGAIN.
> >
> > It is because poll_one is not expected to fall.
>
> Poll_one is an internal function in our driver. ULPs should still be okay I think as long as poll_cq
> does not fail, no?

Yes, I think so.

Thanks
diff mbox

Patch

diff --git a/drivers/infiniband/hw/pvrdma/pvrdma_cq.c b/drivers/infiniband/hw/pvrdma/pvrdma_cq.c
new file mode 100644
index 0000000..8144b20
--- /dev/null
+++ b/drivers/infiniband/hw/pvrdma/pvrdma_cq.c
@@ -0,0 +1,428 @@ 
+/*
+ * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of EITHER the GNU General Public License
+ * version 2 as published by the Free Software Foundation or the BSD
+ * 2-Clause License. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License version 2 for more details at
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program available in the file COPYING in the main
+ * directory of this source tree.
+ *
+ * The BSD 2-Clause License
+ *
+ *     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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <asm/page.h>
+#include <linux/io.h>
+#include <linux/wait.h>
+#include <rdma/ib_addr.h>
+#include <rdma/ib_smi.h>
+#include <rdma/ib_user_verbs.h>
+
+#include "pvrdma.h"
+#include "pvrdma_user.h"
+
+/**
+ * pvrdma_req_notify_cq - request notification for a completion queue
+ * @ibcq: the completion queue
+ * @notify_flags: notification flags
+ *
+ * @return: 0 for success.
+ */
+int pvrdma_req_notify_cq(struct ib_cq *ibcq,
+			 enum ib_cq_notify_flags notify_flags)
+{
+	struct pvrdma_dev *dev = to_vdev(ibcq->device);
+	struct pvrdma_cq *cq = to_vcq(ibcq);
+	u32 val = cq->cq_handle;
+
+	val |= (notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
+		PVRDMA_UAR_CQ_ARM_SOL : PVRDMA_UAR_CQ_ARM;
+
+	pvrdma_write_uar_cq(dev, val);
+
+	return 0;
+}
+
+/**
+ * pvrdma_create_cq - create completion queue
+ * @ibdev: the device
+ * @attr: completion queue attributes
+ * @context: user context
+ * @udata: user data
+ *
+ * @return: ib_cq completion queue pointer on success,
+ *          otherwise returns negative errno.
+ */
+struct ib_cq *pvrdma_create_cq(struct ib_device *ibdev,
+			       const struct ib_cq_init_attr *attr,
+			       struct ib_ucontext *context,
+			       struct ib_udata *udata)
+{
+	int entries = attr->cqe;
+	struct pvrdma_dev *dev = to_vdev(ibdev);
+	struct pvrdma_cq *cq;
+	int ret;
+	int npages;
+	unsigned long flags;
+	union pvrdma_cmd_req req;
+	union pvrdma_cmd_resp rsp;
+	struct pvrdma_cmd_create_cq *cmd = &req.create_cq;
+	struct pvrdma_cmd_create_cq_resp *resp = &rsp.create_cq_resp;
+	struct pvrdma_create_cq ucmd;
+
+	BUILD_BUG_ON(sizeof(struct pvrdma_cqe) != 64);
+
+	entries = roundup_pow_of_two(entries);
+	if (entries < 1 || entries > dev->dsr->caps.max_cqe)
+		return ERR_PTR(-EINVAL);
+
+	if (!atomic_add_unless(&dev->num_cqs, 1, dev->dsr->caps.max_cq))
+		return ERR_PTR(-EINVAL);
+
+	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
+	if (!cq) {
+		atomic_dec(&dev->num_cqs);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	cq->ibcq.cqe = entries;
+
+	if (context) {
+		if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
+			ret = -EFAULT;
+			goto err_cq;
+		}
+
+		cq->umem = ib_umem_get(context, ucmd.buf_addr, ucmd.buf_size,
+				       IB_ACCESS_LOCAL_WRITE, 1);
+		if (IS_ERR(cq->umem)) {
+			ret = PTR_ERR(cq->umem);
+			goto err_cq;
+		}
+
+		npages = ib_umem_page_count(cq->umem);
+	} else {
+		cq->is_kernel = true;
+
+		/* One extra page for shared ring state */
+		npages = 1 + (entries * sizeof(struct pvrdma_cqe) +
+			      PAGE_SIZE - 1) / PAGE_SIZE;
+
+		/* Skip header page. */
+		cq->offset = PAGE_SIZE;
+	}
+
+	if (npages < 0 || npages > PVRDMA_PAGE_DIR_MAX_PAGES) {
+		dev_warn(&dev->pdev->dev,
+			 "overflow pages in completion queue\n");
+		ret = -EINVAL;
+		goto err_umem;
+	}
+
+	ret = pvrdma_page_dir_init(dev, &cq->pdir, npages, cq->is_kernel);
+	if (ret) {
+		dev_warn(&dev->pdev->dev,
+			 "could not allocate page directory\n");
+		goto err_umem;
+	}
+
+	if (cq->is_kernel) {
+		/* Ring state is always the first page. */
+		cq->ring_state = cq->pdir.pages[0];
+	} else {
+		pvrdma_page_dir_insert_umem(&cq->pdir, cq->umem, 0);
+	}
+
+	atomic_set(&cq->refcnt, 1);
+	init_waitqueue_head(&cq->wait);
+	spin_lock_init(&cq->cq_lock);
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->hdr.cmd = PVRDMA_CMD_CREATE_CQ;
+	cmd->nchunks = npages;
+	cmd->ctx_handle = (context) ?
+		(u64)to_vucontext(context)->ctx_handle : 0;
+	cmd->cqe = entries;
+	cmd->pdir_dma = cq->pdir.dir_dma;
+	ret = pvrdma_cmd_post(dev, &req, &rsp);
+
+	if (ret < 0 || rsp.hdr.ack != PVRDMA_CMD_CREATE_CQ_RESP) {
+		dev_warn(&dev->pdev->dev,
+			 "could not create completion queue\n");
+		goto err_page_dir;
+	}
+
+	cq->ibcq.cqe = resp->cqe;
+	cq->cq_handle = resp->cq_handle;
+	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
+	dev->cq_tbl[cq->cq_handle % dev->dsr->caps.max_cq] = cq;
+	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
+
+	if (context) {
+		cq->uar = &(to_vucontext(context)->uar);
+
+		/* Copy udata back. */
+		if (ib_copy_to_udata(udata, &cq->cq_handle, sizeof(__u32))) {
+			dev_warn(&dev->pdev->dev,
+				 "failed to copy back udata\n");
+			pvrdma_destroy_cq(&cq->ibcq);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	return &cq->ibcq;
+
+err_page_dir:
+	pvrdma_page_dir_cleanup(dev, &cq->pdir);
+err_umem:
+	if (context)
+		ib_umem_release(cq->umem);
+err_cq:
+	atomic_dec(&dev->num_cqs);
+	kfree(cq);
+
+	return ERR_PTR(ret);
+}
+
+static void pvrdma_free_cq(struct pvrdma_dev *dev, struct pvrdma_cq *cq)
+{
+	atomic_dec(&cq->refcnt);
+	wait_event(cq->wait, !atomic_read(&cq->refcnt));
+
+	if (!cq->is_kernel)
+		ib_umem_release(cq->umem);
+
+	pvrdma_page_dir_cleanup(dev, &cq->pdir);
+	kfree(cq);
+}
+
+/**
+ * pvrdma_destroy_cq - destroy completion queue
+ * @cq: the completion queue to destroy.
+ *
+ * @return: 0 for success.
+ */
+int pvrdma_destroy_cq(struct ib_cq *cq)
+{
+	struct pvrdma_cq *vcq = to_vcq(cq);
+	union pvrdma_cmd_req req;
+	struct pvrdma_cmd_destroy_cq *cmd = &req.destroy_cq;
+	struct pvrdma_dev *dev = to_vdev(cq->device);
+	unsigned long flags;
+	int ret;
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->hdr.cmd = PVRDMA_CMD_DESTROY_CQ;
+	cmd->cq_handle = vcq->cq_handle;
+
+	ret = pvrdma_cmd_post(dev, &req, NULL);
+	if (ret < 0)
+		dev_warn(&dev->pdev->dev,
+			 "could not destroy completion queue\n");
+
+	/* free cq's resources */
+	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
+	dev->cq_tbl[vcq->cq_handle] = NULL;
+	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
+
+	pvrdma_free_cq(dev, vcq);
+	atomic_dec(&dev->num_cqs);
+
+	return ret;
+}
+
+/**
+ * pvrdma_modify_cq - modify the CQ moderation parameters
+ * @ibcq: the CQ to modify
+ * @cq_count: number of CQEs that will trigger an event
+ * @cq_period: max period of time in usec before triggering an event
+ *
+ * @return: -EOPNOTSUPP as CQ resize is not supported.
+ */
+int pvrdma_modify_cq(struct ib_cq *cq, u16 cq_count, u16 cq_period)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline struct pvrdma_cqe *get_cqe(struct pvrdma_cq *cq, int i)
+{
+	return (struct pvrdma_cqe *)pvrdma_page_dir_get_ptr(
+					&cq->pdir,
+					cq->offset +
+					sizeof(struct pvrdma_cqe) * i);
+}
+
+void _pvrdma_flush_cqe(struct pvrdma_qp *qp, struct pvrdma_cq *cq)
+{
+	int head;
+	int has_data;
+
+	if (!cq->is_kernel)
+		return;
+
+	/* Lock held */
+	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
+					    cq->ibcq.cqe, &head);
+	if (unlikely(has_data > 0)) {
+		int items;
+		int curr;
+		int tail = pvrdma_idx(&cq->ring_state->rx.prod_tail,
+				      cq->ibcq.cqe);
+		struct pvrdma_cqe *cqe;
+		struct pvrdma_cqe *curr_cqe;
+
+		items = (tail > head) ? (tail - head) :
+			(cq->ibcq.cqe - head + tail);
+		curr = --tail;
+		while (items-- > 0) {
+			if (curr < 0)
+				curr = cq->ibcq.cqe - 1;
+			if (tail < 0)
+				tail = cq->ibcq.cqe - 1;
+			curr_cqe = get_cqe(cq, curr);
+			if ((curr_cqe->qp & 0xFFFF) != qp->qp_handle) {
+				if (curr != tail) {
+					cqe = get_cqe(cq, tail);
+					*cqe = *curr_cqe;
+				}
+				tail--;
+			} else {
+				pvrdma_idx_ring_inc(
+					&cq->ring_state->rx.cons_head,
+					cq->ibcq.cqe);
+			}
+			curr--;
+		}
+	}
+}
+
+static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp **cur_qp,
+			   struct ib_wc *wc)
+{
+	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
+	int has_data;
+	unsigned int head;
+	bool tried = false;
+	struct pvrdma_cqe *cqe;
+
+retry:
+	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
+					    cq->ibcq.cqe, &head);
+	if (has_data == 0) {
+		if (tried)
+			return -EAGAIN;
+
+		/* Pass down POLL to give physical HCA a chance to poll. */
+		pvrdma_write_uar_cq(dev, cq->cq_handle | PVRDMA_UAR_CQ_POLL);
+
+		tried = true;
+		goto retry;
+	} else if (has_data == PVRDMA_INVALID_IDX) {
+		dev_err(&dev->pdev->dev, "CQ ring state invalid\n");
+		return -EAGAIN;
+	}
+
+	cqe = get_cqe(cq, head);
+
+	/* Ensure cqe is valid. */
+	rmb();
+	if (dev->qp_tbl[cqe->qp & 0xffff])
+		*cur_qp = (struct pvrdma_qp *)dev->qp_tbl[cqe->qp & 0xffff];
+	else
+		return -EAGAIN;
+
+	wc->opcode = pvrdma_wc_opcode_to_ib(cqe->opcode);
+	wc->status = pvrdma_wc_status_to_ib(cqe->status);
+	wc->wr_id = cqe->wr_id;
+	wc->qp = &(*cur_qp)->ibqp;
+	wc->byte_len = cqe->byte_len;
+	wc->ex.imm_data = cqe->imm_data;
+	wc->src_qp = cqe->src_qp;
+	wc->wc_flags = pvrdma_wc_flags_to_ib(cqe->wc_flags);
+	wc->pkey_index = cqe->pkey_index;
+	wc->slid = cqe->slid;
+	wc->sl = cqe->sl;
+	wc->dlid_path_bits = cqe->dlid_path_bits;
+	wc->port_num = cqe->port_num;
+	wc->vendor_err = 0;
+
+	/* Update shared ring state */
+	pvrdma_idx_ring_inc(&cq->ring_state->rx.cons_head, cq->ibcq.cqe);
+
+	return 0;
+}
+
+/**
+ * pvrdma_poll_cq - poll for work completion queue entries
+ * @ibcq: completion queue
+ * @num_entries: the maximum number of entries
+ * @entry: pointer to work completion array
+ *
+ * @return: number of polled completion entries
+ */
+int pvrdma_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
+{
+	struct pvrdma_cq *cq = to_vcq(ibcq);
+	struct pvrdma_qp *cur_qp = NULL;
+	unsigned long flags;
+	int npolled;
+
+	if (num_entries < 1 || wc == NULL)
+		return 0;
+
+	spin_lock_irqsave(&cq->cq_lock, flags);
+	for (npolled = 0; npolled < num_entries; ++npolled) {
+		if (pvrdma_poll_one(cq, &cur_qp, wc + npolled))
+			break;
+	}
+
+	spin_unlock_irqrestore(&cq->cq_lock, flags);
+
+	/* Ensure we do not return errors from poll_cq */
+	return npolled;
+}
+
+/**
+ * pvrdma_resize_cq - resize CQ
+ * @ibcq: the completion queue
+ * @entries: CQ entries
+ * @udata: user data
+ *
+ * @return: -EOPNOTSUPP as CQ resize is not supported.
+ */
+int pvrdma_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *udata)
+{
+	return -EOPNOTSUPP;
+}