[mirror_ubuntu-zesty-kernel.git] / drivers / infiniband / hw / ipath / ipath_srq.c

/*
 * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, 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/err.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include "ipath_verbs.h"

/**
 * ipath_post_srq_receive - post a receive on a shared receive queue
 * @ibsrq: the SRQ to post the receive on
 * @wr: the list of work requests to post
 * @bad_wr: the first WR to cause a problem is put here
 *
 * This may be called from interrupt context.
 */
int ipath_post_srq_receive(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
			   struct ib_recv_wr **bad_wr)
{
	struct ipath_srq *srq = to_isrq(ibsrq);
	struct ipath_rwq *wq;
	unsigned long flags;
	int ret;

	for (; wr; wr = wr->next) {
		struct ipath_rwqe *wqe;
		u32 next;
		int i;

		if ((unsigned) wr->num_sge > srq->rq.max_sge) {
			*bad_wr = wr;
			ret = -EINVAL;
			goto bail;
		}

		spin_lock_irqsave(&srq->rq.lock, flags);
		wq = srq->rq.wq;
		next = wq->head + 1;
		if (next >= srq->rq.size)
			next = 0;
		if (next == wq->tail) {
			spin_unlock_irqrestore(&srq->rq.lock, flags);
			*bad_wr = wr;
			ret = -ENOMEM;
			goto bail;
		}

		wqe = get_rwqe_ptr(&srq->rq, wq->head);
		wqe->wr_id = wr->wr_id;
		wqe->num_sge = wr->num_sge;
		for (i = 0; i < wr->num_sge; i++)
			wqe->sg_list[i] = wr->sg_list[i];
		/* Make sure queue entry is written before the head index. */
		smp_wmb();
		wq->head = next;
		spin_unlock_irqrestore(&srq->rq.lock, flags);
	}
	ret = 0;

bail:
	return ret;
}

/**
 * ipath_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 libipathverbs when creating a user SRQ
 */
struct ib_srq *ipath_create_srq(struct ib_pd *ibpd,
				struct ib_srq_init_attr *srq_init_attr,
				struct ib_udata *udata)
{
	struct ipath_ibdev *dev = to_idev(ibpd->device);
	struct ipath_srq *srq;
	u32 sz;
	struct ib_srq *ret;

	if (srq_init_attr->attr.max_wr == 0) {
		ret = ERR_PTR(-EINVAL);
		goto done;
	}

	if ((srq_init_attr->attr.max_sge > ib_ipath_max_srq_sges) ||
	    (srq_init_attr->attr.max_wr > ib_ipath_max_srq_wrs)) {
		ret = ERR_PTR(-EINVAL);
		goto done;
	}

	srq = kmalloc(sizeof(*srq), GFP_KERNEL);
	if (!srq) {
		ret = ERR_PTR(-ENOMEM);
		goto done;
	}

	/*
	 * 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 ipath_rwqe);
	srq->rq.wq = vmalloc_user(sizeof(struct ipath_rwq) + srq->rq.size * sz);
	if (!srq->rq.wq) {
		ret = ERR_PTR(-ENOMEM);
		goto bail_srq;
	}

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

		srq->ip =
		    ipath_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;
		}
	} else
		srq->ip = NULL;

	/*
	 * ib_create_srq() will initialize srq->ibsrq.
	 */
	spin_lock_init(&srq->rq.lock);
	srq->rq.wq->head = 0;
	srq->rq.wq->tail = 0;
	srq->limit = srq_init_attr->attr.srq_limit;

	spin_lock(&dev->n_srqs_lock);
	if (dev->n_srqs_allocated == ib_ipath_max_srqs) {
		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);
	}

	ret = &srq->ibsrq;
	goto done;

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

/**
 * ipath_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 ipathverbs.so
 */
int ipath_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
		     enum ib_srq_attr_mask attr_mask,
		     struct ib_udata *udata)
{
	struct ipath_srq *srq = to_isrq(ibsrq);
	struct ipath_rwq *wq;
	int ret = 0;

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

		/* Check that the requested sizes are below the limits. */
		if ((attr->max_wr > ib_ipath_max_srq_wrs) ||
		    ((attr_mask & IB_SRQ_LIMIT) ?
		     attr->srq_limit : srq->limit) > attr->max_wr) {
			ret = -EINVAL;
			goto bail;
		}

		sz = sizeof(struct ipath_rwqe) +
			srq->rq.max_sge * sizeof(struct ib_sge);
		size = attr->max_wr + 1;
		wq = vmalloc_user(sizeof(struct ipath_rwq) + size * sz);
		if (!wq) {
			ret = -ENOMEM;
			goto bail;
		}

		/* 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 pointer value and compute
		 * the number of remaining WQEs.
		 */
		owq = srq->rq.wq;
		head = owq->head;
		if (head >= srq->rq.size)
			head = 0;
		tail = owq->tail;
		if (tail >= srq->rq.size)
			tail = 0;
		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 ipath_rwqe *wqe;
			int i;

			wqe = 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 ipath_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 ipath_mmap_info *ip = srq->ip;
			struct ipath_ibdev *dev = to_idev(srq->ibsrq.device);
			u32 s = sizeof(struct ipath_rwq) + size * sz;

			ipath_update_mmap_info(dev, ip, s, wq);

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

			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);
	}
	goto bail;

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

int ipath_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
{
	struct ipath_srq *srq = to_isrq(ibsrq);

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

/**
 * ipath_destroy_srq - destroy a shared receive queue
 * @ibsrq: the SRQ to destroy
 */
int ipath_destroy_srq(struct ib_srq *ibsrq)
{
	struct ipath_srq *srq = to_isrq(ibsrq);
	struct ipath_ibdev *dev = to_idev(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, ipath_release_mmap_info);
	else
		vfree(srq->rq.wq);
	kfree(srq);

	return 0;
}
Commit	Line	Data
cef1cce5	1	/*
e7eacd36	2	* Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
cef1cce5 BS	3	* Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
	4	*
	5	* This software is available to you under a choice of one of two
	6	* licenses. You may choose to be licensed under the terms of the GNU
	7	* General Public License (GPL) Version 2, available from the file
	8	* COPYING in the main directory of this source tree, or the
	9	* OpenIB.org BSD license below:
	10	*
	11	* Redistribution and use in source and binary forms, with or
	12	* without modification, are permitted provided that the following
	13	* conditions are met:
	14	*
	15	* - Redistributions of source code must retain the above
	16	* copyright notice, this list of conditions and the following
	17	* disclaimer.
	18	*
	19	* - Redistributions in binary form must reproduce the above
	20	* copyright notice, this list of conditions and the following
	21	* disclaimer in the documentation and/or other materials
	22	* provided with the distribution.
	23	*
	24	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	25	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	26	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	27	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	28	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	29	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	30	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	31	* SOFTWARE.
	32	*/
	33
	34	#include <linux/err.h>
5a0e3ad6	35	#include <linux/slab.h>
cef1cce5 BS	36	#include <linux/vmalloc.h>
	37
	38	#include "ipath_verbs.h"
	39
	40	/**
	41	* ipath_post_srq_receive - post a receive on a shared receive queue
	42	* @ibsrq: the SRQ to post the receive on
	43	* @wr: the list of work requests to post
	44	* @bad_wr: the first WR to cause a problem is put here
	45	*
	46	* This may be called from interrupt context.
	47	*/
	48	int ipath_post_srq_receive(struct ib_srq ibsrq, struct ib_recv_wr wr,
	49	struct ib_recv_wr **bad_wr)
	50	{
	51	struct ipath_srq *srq = to_isrq(ibsrq);
373d9915	52	struct ipath_rwq *wq;
cef1cce5 BS	53	unsigned long flags;
	54	int ret;
	55
	56	for (; wr; wr = wr->next) {
	57	struct ipath_rwqe *wqe;
	58	u32 next;
373d9915	59	int i;
cef1cce5	60
373d9915	61	if ((unsigned) wr->num_sge > srq->rq.max_sge) {
cef1cce5	62	*bad_wr = wr;
4187b915	63	ret = -EINVAL;
cef1cce5 BS	64	goto bail;
	65	}
	66
	67	spin_lock_irqsave(&srq->rq.lock, flags);
373d9915 RC	68	wq = srq->rq.wq;
373d9915 RC	69	next = wq->head + 1;
cef1cce5 BS	70	if (next >= srq->rq.size)
cef1cce5 BS	71	next = 0;
373d9915	72	if (next == wq->tail) {
cef1cce5 BS	73	spin_unlock_irqrestore(&srq->rq.lock, flags);
	74	*bad_wr = wr;
	75	ret = -ENOMEM;
	76	goto bail;
	77	}
	78
373d9915	79	wqe = get_rwqe_ptr(&srq->rq, wq->head);
cef1cce5	80	wqe->wr_id = wr->wr_id;
373d9915 RC	81	wqe->num_sge = wr->num_sge;
	82	for (i = 0; i < wr->num_sge; i++)
	83	wqe->sg_list[i] = wr->sg_list[i];
4fc570bc RC	84	/* Make sure queue entry is written before the head index. */
4fc570bc RC	85	smp_wmb();
373d9915	86	wq->head = next;
cef1cce5 BS	87	spin_unlock_irqrestore(&srq->rq.lock, flags);
	88	}
	89	ret = 0;
	90
	91	bail:
	92	return ret;
	93	}
	94
	95	/**
	96	* ipath_create_srq - create a shared receive queue
	97	* @ibpd: the protection domain of the SRQ to create
62769801 RC	98	* @srq_init_attr: the attributes of the SRQ
62769801 RC	99	* @udata: data from libipathverbs when creating a user SRQ
cef1cce5 BS	100	*/
	101	struct ib_srq ipath_create_srq(struct ib_pd ibpd,
	102	struct ib_srq_init_attr *srq_init_attr,
	103	struct ib_udata *udata)
	104	{
fe62546a	105	struct ipath_ibdev *dev = to_idev(ibpd->device);
cef1cce5 BS	106	struct ipath_srq *srq;
	107	u32 sz;
	108	struct ib_srq *ret;
	109
fe62546a BS	110	if (srq_init_attr->attr.max_wr == 0) {
fe62546a BS	111	ret = ERR_PTR(-EINVAL);
373d9915	112	goto done;
fe62546a BS	113	}
	114
	115	if ((srq_init_attr->attr.max_sge > ib_ipath_max_srq_sges) \|\|
	116	(srq_init_attr->attr.max_wr > ib_ipath_max_srq_wrs)) {
cef1cce5	117	ret = ERR_PTR(-EINVAL);
373d9915	118	goto done;
cef1cce5 BS	119	}
	120
	121	srq = kmalloc(sizeof(*srq), GFP_KERNEL);
	122	if (!srq) {
	123	ret = ERR_PTR(-ENOMEM);
373d9915	124	goto done;
cef1cce5 BS	125	}
	126
	127	/*
	128	* Need to use vmalloc() if we want to support large #s of entries.
	129	*/
	130	srq->rq.size = srq_init_attr->attr.max_wr + 1;
373d9915 RC	131	srq->rq.max_sge = srq_init_attr->attr.max_sge;
373d9915 RC	132	sz = sizeof(struct ib_sge) * srq->rq.max_sge +
cef1cce5	133	sizeof(struct ipath_rwqe);
373d9915	134	srq->rq.wq = vmalloc_user(sizeof(struct ipath_rwq) + srq->rq.size * sz);
cef1cce5	135	if (!srq->rq.wq) {
cef1cce5	136	ret = ERR_PTR(-ENOMEM);
373d9915	137	goto bail_srq;
cef1cce5 BS	138	}
cef1cce5 BS	139
373d9915 RC	140	/*
	141	* Return the address of the RWQ as the offset to mmap.
	142	* See ipath_mmap() for details.
	143	*/
	144	if (udata && udata->outlen >= sizeof(__u64)) {
373d9915	145	int err;
6b66b2da	146	u32 s = sizeof(struct ipath_rwq) + srq->rq.size * sz;
373d9915	147
6b66b2da RW	148	srq->ip =
	149	ipath_create_mmap_info(dev, s,
	150	ibpd->uobject->context,
	151	srq->rq.wq);
	152	if (!srq->ip) {
	153	ret = ERR_PTR(-ENOMEM);
373d9915 RC	154	goto bail_wq;
	155	}
	156
6b66b2da RW	157	err = ib_copy_to_udata(udata, &srq->ip->offset,
	158	sizeof(srq->ip->offset));
	159	if (err) {
	160	ret = ERR_PTR(err);
	161	goto bail_ip;
373d9915	162	}
373d9915 RC	163	} else
	164	srq->ip = NULL;
	165
cef1cce5 BS	166	/*
	167	* ib_create_srq() will initialize srq->ibsrq.
	168	*/
	169	spin_lock_init(&srq->rq.lock);
373d9915 RC	170	srq->rq.wq->head = 0;
373d9915 RC	171	srq->rq.wq->tail = 0;
cef1cce5 BS	172	srq->limit = srq_init_attr->attr.srq_limit;
cef1cce5 BS	173
f3e93c77 BS	174	spin_lock(&dev->n_srqs_lock);
	175	if (dev->n_srqs_allocated == ib_ipath_max_srqs) {
	176	spin_unlock(&dev->n_srqs_lock);
	177	ret = ERR_PTR(-ENOMEM);
6b66b2da	178	goto bail_ip;
f3e93c77 BS	179	}
	180
	181	dev->n_srqs_allocated++;
	182	spin_unlock(&dev->n_srqs_lock);
373d9915	183
6b66b2da RW	184	if (srq->ip) {
	185	spin_lock_irq(&dev->pending_lock);
	186	list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
	187	spin_unlock_irq(&dev->pending_lock);
	188	}
	189
cef1cce5	190	ret = &srq->ibsrq;
373d9915	191	goto done;
cef1cce5	192
6b66b2da RW	193	bail_ip:
6b66b2da RW	194	kfree(srq->ip);
373d9915 RC	195	bail_wq:
373d9915 RC	196	vfree(srq->rq.wq);
373d9915 RC	197	bail_srq:
373d9915 RC	198	kfree(srq);
373d9915	199	done:
cef1cce5 BS	200	return ret;
	201	}
	202
	203	/**
	204	* ipath_modify_srq - modify a shared receive queue
	205	* @ibsrq: the SRQ to modify
	206	* @attr: the new attributes of the SRQ
	207	* @attr_mask: indicates which attributes to modify
9bc57e2d	208	* @udata: user data for ipathverbs.so
cef1cce5 BS	209	*/
cef1cce5 BS	210	int ipath_modify_srq(struct ib_srq ibsrq, struct ib_srq_attr attr,
9bc57e2d RC	211	enum ib_srq_attr_mask attr_mask,
9bc57e2d RC	212	struct ib_udata *udata)
cef1cce5 BS	213	{
cef1cce5 BS	214	struct ipath_srq *srq = to_isrq(ibsrq);
14de986a	215	struct ipath_rwq *wq;
373d9915	216	int ret = 0;
cef1cce5	217
373d9915 RC	218	if (attr_mask & IB_SRQ_MAX_WR) {
373d9915 RC	219	struct ipath_rwq *owq;
373d9915 RC	220	struct ipath_rwqe *p;
373d9915 RC	221	u32 sz, size, n, head, tail;
cef1cce5	222
373d9915 RC	223	/* Check that the requested sizes are below the limits. */
	224	if ((attr->max_wr > ib_ipath_max_srq_wrs) \|\|
	225	((attr_mask & IB_SRQ_LIMIT) ?
	226	attr->srq_limit : srq->limit) > attr->max_wr) {
cef1cce5 BS	227	ret = -EINVAL;
	228	goto bail;
	229	}
	230
	231	sz = sizeof(struct ipath_rwqe) +
373d9915	232	srq->rq.max_sge * sizeof(struct ib_sge);
fe62546a	233	size = attr->max_wr + 1;
373d9915	234	wq = vmalloc_user(sizeof(struct ipath_rwq) + size * sz);
cef1cce5 BS	235	if (!wq) {
	236	ret = -ENOMEM;
	237	goto bail;
	238	}
	239
14de986a	240	/* Check that we can write the offset to mmap. */
373d9915 RC	241	if (udata && udata->inlen >= sizeof(__u64)) {
373d9915 RC	242	__u64 offset_addr;
14de986a	243	__u64 offset = 0;
373d9915 RC	244
	245	ret = ib_copy_from_udata(&offset_addr, udata,
	246	sizeof(offset_addr));
14de986a RC	247	if (ret)
14de986a RC	248	goto bail_free;
3dd59e22 AJ	249	udata->outbuf =
3dd59e22 AJ	250	(void __user *) (unsigned long) offset_addr;
373d9915 RC	251	ret = ib_copy_to_udata(udata, &offset,
373d9915 RC	252	sizeof(offset));
14de986a RC	253	if (ret)
14de986a RC	254	goto bail_free;
373d9915 RC	255	}
	256
	257	spin_lock_irq(&srq->rq.lock);
	258	/*
	259	* validate head pointer value and compute
	260	* the number of remaining WQEs.
	261	*/
	262	owq = srq->rq.wq;
	263	head = owq->head;
	264	if (head >= srq->rq.size)
	265	head = 0;
	266	tail = owq->tail;
	267	if (tail >= srq->rq.size)
	268	tail = 0;
	269	n = head;
	270	if (n < tail)
	271	n += srq->rq.size - tail;
cef1cce5	272	else
373d9915 RC	273	n -= tail;
373d9915 RC	274	if (size <= n) {
cef1cce5	275	ret = -EINVAL;
14de986a	276	goto bail_unlock;
cef1cce5 BS	277	}
cef1cce5 BS	278	n = 0;
373d9915 RC	279	p = wq->wq;
373d9915 RC	280	while (tail != head) {
cef1cce5 BS	281	struct ipath_rwqe *wqe;
	282	int i;
	283
373d9915	284	wqe = get_rwqe_ptr(&srq->rq, tail);
cef1cce5	285	p->wr_id = wqe->wr_id;
cef1cce5 BS	286	p->num_sge = wqe->num_sge;
	287	for (i = 0; i < wqe->num_sge; i++)
	288	p->sg_list[i] = wqe->sg_list[i];
	289	n++;
	290	p = (struct ipath_rwqe )((char ) p + sz);
373d9915 RC	291	if (++tail >= srq->rq.size)
373d9915 RC	292	tail = 0;
cef1cce5	293	}
cef1cce5 BS	294	srq->rq.wq = wq;
cef1cce5 BS	295	srq->rq.size = size;
373d9915 RC	296	wq->head = n;
	297	wq->tail = 0;
	298	if (attr_mask & IB_SRQ_LIMIT)
	299	srq->limit = attr->srq_limit;
	300	spin_unlock_irq(&srq->rq.lock);
	301
	302	vfree(owq);
	303
	304	if (srq->ip) {
	305	struct ipath_mmap_info *ip = srq->ip;
	306	struct ipath_ibdev *dev = to_idev(srq->ibsrq.device);
6b66b2da	307	u32 s = sizeof(struct ipath_rwq) + size * sz;
373d9915	308
6b66b2da	309	ipath_update_mmap_info(dev, ip, s, wq);
14de986a RC	310
	311	/*
	312	* Return the offset to mmap.
	313	* See ipath_mmap() for details.
	314	*/
	315	if (udata && udata->inlen >= sizeof(__u64)) {
	316	ret = ib_copy_to_udata(udata, &ip->offset,
	317	sizeof(ip->offset));
	318	if (ret)
	319	goto bail;
	320	}
	321
373d9915	322	spin_lock_irq(&dev->pending_lock);
6b66b2da RW	323	if (list_empty(&ip->pending_mmaps))
	324	list_add(&ip->pending_mmaps,
	325	&dev->pending_mmaps);
373d9915 RC	326	spin_unlock_irq(&dev->pending_lock);
	327	}
	328	} else if (attr_mask & IB_SRQ_LIMIT) {
	329	spin_lock_irq(&srq->rq.lock);
	330	if (attr->srq_limit >= srq->rq.size)
	331	ret = -EINVAL;
	332	else
	333	srq->limit = attr->srq_limit;
	334	spin_unlock_irq(&srq->rq.lock);
fe62546a	335	}
14de986a	336	goto bail;
cef1cce5	337
14de986a RC	338	bail_unlock:
	339	spin_unlock_irq(&srq->rq.lock);
	340	bail_free:
	341	vfree(wq);
cef1cce5 BS	342	bail:
	343	return ret;
	344	}
	345
	346	int ipath_query_srq(struct ib_srq ibsrq, struct ib_srq_attr attr)
	347	{
	348	struct ipath_srq *srq = to_isrq(ibsrq);
	349
	350	attr->max_wr = srq->rq.size - 1;
	351	attr->max_sge = srq->rq.max_sge;
	352	attr->srq_limit = srq->limit;
	353	return 0;
	354	}
	355
	356	/**
	357	* ipath_destroy_srq - destroy a shared receive queue
	358	* @ibsrq: the SRQ to destroy
	359	*/
	360	int ipath_destroy_srq(struct ib_srq *ibsrq)
	361	{
	362	struct ipath_srq *srq = to_isrq(ibsrq);
fe62546a	363	struct ipath_ibdev *dev = to_idev(ibsrq->device);
cef1cce5	364
f3e93c77	365	spin_lock(&dev->n_srqs_lock);
fe62546a	366	dev->n_srqs_allocated--;
f3e93c77 BS	367	spin_unlock(&dev->n_srqs_lock);
	368	if (srq->ip)
	369	kref_put(&srq->ip->ref, ipath_release_mmap_info);
	370	else
	371	vfree(srq->rq.wq);
cef1cce5 BS	372	kfree(srq);
	373
	374	return 0;
	375	}