drivers/infiniband/sw/rdmavt/srq.c - third_party/linux - Git at Google

 /*
  * Copyright(c) 2016 Intel Corporation.
  *
  * This file is provided under a dual BSD/GPLv2 license.  When using or
  * redistributing this file, you may do so under either license.
  *
  * GPL LICENSE SUMMARY
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  *
  * 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 for more details.
  *
  * BSD 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.
  *  - Neither the name of Intel Corporation nor the names of its
  *    contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * 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
  * OWNER 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 <linux/err.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>

 #include "srq.h"
 #include "vt.h"

 /**
  * rvt_driver_srq_init - init srq resources on a per driver basis
  * @rdi: rvt dev structure
  *
  * Do any initialization needed when a driver registers with rdmavt.
  */
 void rvt_driver_srq_init(struct rvt_dev_info *rdi)
 {
 	spin_lock_init(&rdi->n_srqs_lock);
 	rdi->n_srqs_allocated = 0;
 }

 /**
  * rvt_create_srq - create a shared receive queue
  * @ibpd: the protection domain of the SRQ to create
  * @srq_init_attr: the attributes of the SRQ
  * @udata: data from libibverbs when creating a user SRQ
  *
  * Return: Allocated srq object
  */
 struct ib_srq *rvt_create_srq(struct ib_pd *ibpd,
 			      struct ib_srq_init_attr *srq_init_attr,
 			      struct ib_udata *udata)
 {
 	struct rvt_dev_info *dev = ib_to_rvt(ibpd->device);
 	struct rvt_srq *srq;
 	u32 sz;
 	struct ib_srq *ret;

 	if (srq_init_attr->srq_type != IB_SRQT_BASIC)
 		return ERR_PTR(-ENOSYS);

 	if (srq_init_attr->attr.max_sge == 0 ||
 	    srq_init_attr->attr.max_sge > dev->dparms.props.max_srq_sge ||
 	    srq_init_attr->attr.max_wr == 0 ||
 	    srq_init_attr->attr.max_wr > dev->dparms.props.max_srq_wr)
 		return ERR_PTR(-EINVAL);

 	srq = kzalloc_node(sizeof(*srq), GFP_KERNEL, dev->dparms.node);
 	if (!srq)
 		return ERR_PTR(-ENOMEM);

 	/*
 	 * Need to use vmalloc() if we want to support large #s of entries.
 	 */
 	srq->rq.size = srq_init_attr->attr.max_wr + 1;
 	srq->rq.max_sge = srq_init_attr->attr.max_sge;
 	sz = sizeof(struct ib_sge) * srq->rq.max_sge +
 		sizeof(struct rvt_rwqe);
 	srq->rq.wq = udata ?
 		vmalloc_user(sizeof(struct rvt_rwq) + srq->rq.size * sz) :
 		vzalloc_node(sizeof(struct rvt_rwq) + srq->rq.size * sz,
 			     dev->dparms.node);
 	if (!srq->rq.wq) {
 		ret = ERR_PTR(-ENOMEM);
 		goto bail_srq;
 	}

 	/*
 	 * Return the address of the RWQ as the offset to mmap.
 	 * See rvt_mmap() for details.
 	 */
 	if (udata && udata->outlen >= sizeof(__u64)) {
 		int err;
 		u32 s = sizeof(struct rvt_rwq) + srq->rq.size * sz;

 		srq->ip =
 		    rvt_create_mmap_info(dev, s, ibpd->uobject->context,
 					 srq->rq.wq);
 		if (!srq->ip) {
 			ret = ERR_PTR(-ENOMEM);
 			goto bail_wq;
 		}

 		err = ib_copy_to_udata(udata, &srq->ip->offset,
 				       sizeof(srq->ip->offset));
 		if (err) {
 			ret = ERR_PTR(err);
 			goto bail_ip;
 		}
 	}

 	/*
 	 * ib_create_srq() will initialize srq->ibsrq.
 	 */
 	spin_lock_init(&srq->rq.lock);
 	srq->limit = srq_init_attr->attr.srq_limit;

 	spin_lock(&dev->n_srqs_lock);
 	if (dev->n_srqs_allocated == dev->dparms.props.max_srq) {
 		spin_unlock(&dev->n_srqs_lock);
 		ret = ERR_PTR(-ENOMEM);
 		goto bail_ip;
 	}

 	dev->n_srqs_allocated++;
 	spin_unlock(&dev->n_srqs_lock);

 	if (srq->ip) {
 		spin_lock_irq(&dev->pending_lock);
 		list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
 		spin_unlock_irq(&dev->pending_lock);
 	}

 	return &srq->ibsrq;

 bail_ip:
 	kfree(srq->ip);
 bail_wq:
 	vfree(srq->rq.wq);
 bail_srq:
 	kfree(srq);
 	return ret;
 }

 /**
  * rvt_modify_srq - modify a shared receive queue
  * @ibsrq: the SRQ to modify
  * @attr: the new attributes of the SRQ
  * @attr_mask: indicates which attributes to modify
  * @udata: user data for libibverbs.so
  *
  * Return: 0 on success
  */
 int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 		   enum ib_srq_attr_mask attr_mask,
 		   struct ib_udata *udata)
 {
 	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
 	struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
 	struct rvt_rwq *wq;
 	int ret = 0;

 	if (attr_mask & IB_SRQ_MAX_WR) {
 		struct rvt_rwq *owq;
 		struct rvt_rwqe *p;
 		u32 sz, size, n, head, tail;

 		/* Check that the requested sizes are below the limits. */
 		if ((attr->max_wr > dev->dparms.props.max_srq_wr) ||
 		    ((attr_mask & IB_SRQ_LIMIT) ?
 		     attr->srq_limit : srq->limit) > attr->max_wr)
 			return -EINVAL;

 		sz = sizeof(struct rvt_rwqe) +
 			srq->rq.max_sge * sizeof(struct ib_sge);
 		size = attr->max_wr + 1;
 		wq = udata ?
 			vmalloc_user(sizeof(struct rvt_rwq) + size * sz) :
 			vzalloc_node(sizeof(struct rvt_rwq) + size * sz,
 				     dev->dparms.node);
 		if (!wq)
 			return -ENOMEM;

 		/* Check that we can write the offset to mmap. */
 		if (udata && udata->inlen >= sizeof(__u64)) {
 			__u64 offset_addr;
 			__u64 offset = 0;

 			ret = ib_copy_from_udata(&offset_addr, udata,
 						 sizeof(offset_addr));
 			if (ret)
 				goto bail_free;
 			udata->outbuf = (void __user *)
 					(unsigned long)offset_addr;
 			ret = ib_copy_to_udata(udata, &offset,
 					       sizeof(offset));
 			if (ret)
 				goto bail_free;
 		}

 		spin_lock_irq(&srq->rq.lock);
 		/*
 		 * validate head and tail pointer values and compute
 		 * the number of remaining WQEs.
 		 */
 		owq = srq->rq.wq;
 		head = owq->head;
 		tail = owq->tail;
 		if (head >= srq->rq.size || tail >= srq->rq.size) {
 			ret = -EINVAL;
 			goto bail_unlock;
 		}
 		n = head;
 		if (n < tail)
 			n += srq->rq.size - tail;
 		else
 			n -= tail;
 		if (size <= n) {
 			ret = -EINVAL;
 			goto bail_unlock;
 		}
 		n = 0;
 		p = wq->wq;
 		while (tail != head) {
 			struct rvt_rwqe *wqe;
 			int i;

 			wqe = rvt_get_rwqe_ptr(&srq->rq, tail);
 			p->wr_id = wqe->wr_id;
 			p->num_sge = wqe->num_sge;
 			for (i = 0; i < wqe->num_sge; i++)
 				p->sg_list[i] = wqe->sg_list[i];
 			n++;
 			p = (struct rvt_rwqe *)((char *)p + sz);
 			if (++tail >= srq->rq.size)
 				tail = 0;
 		}
 		srq->rq.wq = wq;
 		srq->rq.size = size;
 		wq->head = n;
 		wq->tail = 0;
 		if (attr_mask & IB_SRQ_LIMIT)
 			srq->limit = attr->srq_limit;
 		spin_unlock_irq(&srq->rq.lock);

 		vfree(owq);

 		if (srq->ip) {
 			struct rvt_mmap_info *ip = srq->ip;
 			struct rvt_dev_info *dev = ib_to_rvt(srq->ibsrq.device);
 			u32 s = sizeof(struct rvt_rwq) + size * sz;

 			rvt_update_mmap_info(dev, ip, s, wq);

 			/*
 			 * Return the offset to mmap.
 			 * See rvt_mmap() for details.
 			 */
 			if (udata && udata->inlen >= sizeof(__u64)) {
 				ret = ib_copy_to_udata(udata, &ip->offset,
 						       sizeof(ip->offset));
 				if (ret)
 					return ret;
 			}

 			/*
 			 * Put user mapping info onto the pending list
 			 * unless it already is on the list.
 			 */
 			spin_lock_irq(&dev->pending_lock);
 			if (list_empty(&ip->pending_mmaps))
 				list_add(&ip->pending_mmaps,
 					 &dev->pending_mmaps);
 			spin_unlock_irq(&dev->pending_lock);
 		}
 	} else if (attr_mask & IB_SRQ_LIMIT) {
 		spin_lock_irq(&srq->rq.lock);
 		if (attr->srq_limit >= srq->rq.size)
 			ret = -EINVAL;
 		else
 			srq->limit = attr->srq_limit;
 		spin_unlock_irq(&srq->rq.lock);
 	}
 	return ret;

 bail_unlock:
 	spin_unlock_irq(&srq->rq.lock);
 bail_free:
 	vfree(wq);
 	return ret;
 }

 /** rvt_query_srq - query srq data
  * @ibsrq: srq to query
  * @attr: return info in attr
  *
  * Return: always 0
  */
 int rvt_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
 {
 	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);

 	attr->max_wr = srq->rq.size - 1;
 	attr->max_sge = srq->rq.max_sge;
 	attr->srq_limit = srq->limit;
 	return 0;
 }

 /**
  * rvt_destroy_srq - destory an srq
  * @ibsrq: srq object to destroy
  *
  * Return always 0
  */
 int rvt_destroy_srq(struct ib_srq *ibsrq)
 {
 	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
 	struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);

 	spin_lock(&dev->n_srqs_lock);
 	dev->n_srqs_allocated--;
 	spin_unlock(&dev->n_srqs_lock);
 	if (srq->ip)
 		kref_put(&srq->ip->ref, rvt_release_mmap_info);
 	else
 		vfree(srq->rq.wq);
 	kfree(srq);

 	return 0;
 }
	/*
	* Copyright(c) 2016 Intel Corporation.
	*
	* This file is provided under a dual BSD/GPLv2 license. When using or
	* redistributing this file, you may do so under either license.
	*
	* GPL LICENSE SUMMARY
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of version 2 of the GNU General Public License as
	* published by the Free Software Foundation.
	*
	* 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 for more details.
	*
	* BSD 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.
	* - Neither the name of Intel Corporation nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* 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
	* OWNER 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 <linux/err.h>
	#include <linux/slab.h>
	#include <linux/vmalloc.h>

	#include "srq.h"
	#include "vt.h"

	/**
	* rvt_driver_srq_init - init srq resources on a per driver basis
	* @rdi: rvt dev structure
	*
	* Do any initialization needed when a driver registers with rdmavt.
	*/
	void rvt_driver_srq_init(struct rvt_dev_info *rdi)
	{
	spin_lock_init(&rdi->n_srqs_lock);
	rdi->n_srqs_allocated = 0;
	}

	/**
	* rvt_create_srq - create a shared receive queue
	* @ibpd: the protection domain of the SRQ to create
	* @srq_init_attr: the attributes of the SRQ
	* @udata: data from libibverbs when creating a user SRQ
	*
	* Return: Allocated srq object
	*/
	struct ib_srq rvt_create_srq(struct ib_pd ibpd,
	struct ib_srq_init_attr *srq_init_attr,
	struct ib_udata *udata)
	{
	struct rvt_dev_info *dev = ib_to_rvt(ibpd->device);
	struct rvt_srq *srq;
	u32 sz;
	struct ib_srq *ret;

	if (srq_init_attr->srq_type != IB_SRQT_BASIC)
	return ERR_PTR(-ENOSYS);

	if (srq_init_attr->attr.max_sge == 0 \|\|
	srq_init_attr->attr.max_sge > dev->dparms.props.max_srq_sge \|\|
	srq_init_attr->attr.max_wr == 0 \|\|
	srq_init_attr->attr.max_wr > dev->dparms.props.max_srq_wr)
	return ERR_PTR(-EINVAL);

	srq = kzalloc_node(sizeof(*srq), GFP_KERNEL, dev->dparms.node);
	if (!srq)
	return ERR_PTR(-ENOMEM);

	/*
	* Need to use vmalloc() if we want to support large #s of entries.
	*/
	srq->rq.size = srq_init_attr->attr.max_wr + 1;
	srq->rq.max_sge = srq_init_attr->attr.max_sge;
	sz = sizeof(struct ib_sge) * srq->rq.max_sge +
	sizeof(struct rvt_rwqe);
	srq->rq.wq = udata ?
	vmalloc_user(sizeof(struct rvt_rwq) + srq->rq.size * sz) :
	vzalloc_node(sizeof(struct rvt_rwq) + srq->rq.size * sz,
	dev->dparms.node);
	if (!srq->rq.wq) {
	ret = ERR_PTR(-ENOMEM);
	goto bail_srq;
	}

	/*
	* Return the address of the RWQ as the offset to mmap.
	* See rvt_mmap() for details.
	*/
	if (udata && udata->outlen >= sizeof(__u64)) {
	int err;
	u32 s = sizeof(struct rvt_rwq) + srq->rq.size * sz;

	srq->ip =
	rvt_create_mmap_info(dev, s, ibpd->uobject->context,
	srq->rq.wq);
	if (!srq->ip) {
	ret = ERR_PTR(-ENOMEM);
	goto bail_wq;
	}

	err = ib_copy_to_udata(udata, &srq->ip->offset,
	sizeof(srq->ip->offset));
	if (err) {
	ret = ERR_PTR(err);
	goto bail_ip;
	}
	}

	/*
	* ib_create_srq() will initialize srq->ibsrq.
	*/
	spin_lock_init(&srq->rq.lock);
	srq->limit = srq_init_attr->attr.srq_limit;

	spin_lock(&dev->n_srqs_lock);
	if (dev->n_srqs_allocated == dev->dparms.props.max_srq) {
	spin_unlock(&dev->n_srqs_lock);
	ret = ERR_PTR(-ENOMEM);
	goto bail_ip;
	}

	dev->n_srqs_allocated++;
	spin_unlock(&dev->n_srqs_lock);

	if (srq->ip) {
	spin_lock_irq(&dev->pending_lock);
	list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
	spin_unlock_irq(&dev->pending_lock);
	}

	return &srq->ibsrq;

	bail_ip:
	kfree(srq->ip);
	bail_wq:
	vfree(srq->rq.wq);
	bail_srq:
	kfree(srq);
	return ret;
	}

	/**
	* rvt_modify_srq - modify a shared receive queue
	* @ibsrq: the SRQ to modify
	* @attr: the new attributes of the SRQ
	* @attr_mask: indicates which attributes to modify
	* @udata: user data for libibverbs.so
	*
	* Return: 0 on success
	*/
	int rvt_modify_srq(struct ib_srq ibsrq, struct ib_srq_attr attr,
	enum ib_srq_attr_mask attr_mask,
	struct ib_udata *udata)
	{
	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
	struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
	struct rvt_rwq *wq;
	int ret = 0;

	if (attr_mask & IB_SRQ_MAX_WR) {
	struct rvt_rwq *owq;
	struct rvt_rwqe *p;
	u32 sz, size, n, head, tail;

	/* Check that the requested sizes are below the limits. */
	if ((attr->max_wr > dev->dparms.props.max_srq_wr) \|\|
	((attr_mask & IB_SRQ_LIMIT) ?
	attr->srq_limit : srq->limit) > attr->max_wr)
	return -EINVAL;

	sz = sizeof(struct rvt_rwqe) +
	srq->rq.max_sge * sizeof(struct ib_sge);
	size = attr->max_wr + 1;
	wq = udata ?
	vmalloc_user(sizeof(struct rvt_rwq) + size * sz) :
	vzalloc_node(sizeof(struct rvt_rwq) + size * sz,
	dev->dparms.node);
	if (!wq)
	return -ENOMEM;

	/* Check that we can write the offset to mmap. */
	if (udata && udata->inlen >= sizeof(__u64)) {
	__u64 offset_addr;
	__u64 offset = 0;

	ret = ib_copy_from_udata(&offset_addr, udata,
	sizeof(offset_addr));
	if (ret)
	goto bail_free;
	udata->outbuf = (void __user *)
	(unsigned long)offset_addr;
	ret = ib_copy_to_udata(udata, &offset,
	sizeof(offset));
	if (ret)
	goto bail_free;
	}

	spin_lock_irq(&srq->rq.lock);
	/*
	* validate head and tail pointer values and compute
	* the number of remaining WQEs.
	*/
	owq = srq->rq.wq;
	head = owq->head;
	tail = owq->tail;
	if (head >= srq->rq.size \|\| tail >= srq->rq.size) {
	ret = -EINVAL;
	goto bail_unlock;
	}
	n = head;
	if (n < tail)
	n += srq->rq.size - tail;
	else
	n -= tail;
	if (size <= n) {
	ret = -EINVAL;
	goto bail_unlock;
	}
	n = 0;
	p = wq->wq;
	while (tail != head) {
	struct rvt_rwqe *wqe;
	int i;

	wqe = rvt_get_rwqe_ptr(&srq->rq, tail);
	p->wr_id = wqe->wr_id;
	p->num_sge = wqe->num_sge;
	for (i = 0; i < wqe->num_sge; i++)
	p->sg_list[i] = wqe->sg_list[i];
	n++;
	p = (struct rvt_rwqe )((char )p + sz);
	if (++tail >= srq->rq.size)
	tail = 0;
	}
	srq->rq.wq = wq;
	srq->rq.size = size;
	wq->head = n;
	wq->tail = 0;
	if (attr_mask & IB_SRQ_LIMIT)
	srq->limit = attr->srq_limit;
	spin_unlock_irq(&srq->rq.lock);

	vfree(owq);

	if (srq->ip) {
	struct rvt_mmap_info *ip = srq->ip;
	struct rvt_dev_info *dev = ib_to_rvt(srq->ibsrq.device);
	u32 s = sizeof(struct rvt_rwq) + size * sz;

	rvt_update_mmap_info(dev, ip, s, wq);

	/*
	* Return the offset to mmap.
	* See rvt_mmap() for details.
	*/
	if (udata && udata->inlen >= sizeof(__u64)) {
	ret = ib_copy_to_udata(udata, &ip->offset,
	sizeof(ip->offset));
	if (ret)
	return ret;
	}

	/*
	* Put user mapping info onto the pending list
	* unless it already is on the list.
	*/
	spin_lock_irq(&dev->pending_lock);
	if (list_empty(&ip->pending_mmaps))
	list_add(&ip->pending_mmaps,
	&dev->pending_mmaps);
	spin_unlock_irq(&dev->pending_lock);
	}
	} else if (attr_mask & IB_SRQ_LIMIT) {
	spin_lock_irq(&srq->rq.lock);
	if (attr->srq_limit >= srq->rq.size)
	ret = -EINVAL;
	else
	srq->limit = attr->srq_limit;
	spin_unlock_irq(&srq->rq.lock);
	}
	return ret;

	bail_unlock:
	spin_unlock_irq(&srq->rq.lock);
	bail_free:
	vfree(wq);
	return ret;
	}

	/** rvt_query_srq - query srq data
	* @ibsrq: srq to query
	* @attr: return info in attr
	*
	* Return: always 0
	*/
	int rvt_query_srq(struct ib_srq ibsrq, struct ib_srq_attr attr)
	{
	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);

	attr->max_wr = srq->rq.size - 1;
	attr->max_sge = srq->rq.max_sge;
	attr->srq_limit = srq->limit;
	return 0;
	}

	/**
	* rvt_destroy_srq - destory an srq
	* @ibsrq: srq object to destroy
	*
	* Return always 0
	*/
	int rvt_destroy_srq(struct ib_srq *ibsrq)
	{
	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
	struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);

	spin_lock(&dev->n_srqs_lock);
	dev->n_srqs_allocated--;
	spin_unlock(&dev->n_srqs_lock);
	if (srq->ip)
	kref_put(&srq->ip->ref, rvt_release_mmap_info);
	else
	vfree(srq->rq.wq);
	kfree(srq);

	return 0;
	}