[net-next-2.6.git] / drivers / infiniband / hw / mlx4 / srq.c

/*
 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2007, 2008 Mellanox Technologies. 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/mlx4/qp.h>
#include <linux/mlx4/srq.h>
#include <linux/slab.h>

#include "mlx4_ib.h"
#include "user.h"

static void *get_wqe(struct mlx4_ib_srq *srq, int n)
{
	return mlx4_buf_offset(&srq->buf, n << srq->msrq.wqe_shift);
}

static void mlx4_ib_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
{
	struct ib_event event;
	struct ib_srq *ibsrq = &to_mibsrq(srq)->ibsrq;

	if (ibsrq->event_handler) {
		event.device      = ibsrq->device;
		event.element.srq = ibsrq;
		switch (type) {
		case MLX4_EVENT_TYPE_SRQ_LIMIT:
			event.event = IB_EVENT_SRQ_LIMIT_REACHED;
			break;
		case MLX4_EVENT_TYPE_SRQ_CATAS_ERROR:
			event.event = IB_EVENT_SRQ_ERR;
			break;
		default:
			printk(KERN_WARNING "mlx4_ib: Unexpected event type %d "
			       "on SRQ %06x\n", type, srq->srqn);
			return;
		}

		ibsrq->event_handler(&event, ibsrq->srq_context);
	}
}

struct ib_srq *mlx4_ib_create_srq(struct ib_pd *pd,
				  struct ib_srq_init_attr *init_attr,
				  struct ib_udata *udata)
{
	struct mlx4_ib_dev *dev = to_mdev(pd->device);
	struct mlx4_ib_srq *srq;
	struct mlx4_wqe_srq_next_seg *next;
	struct mlx4_wqe_data_seg *scatter;
	int desc_size;
	int buf_size;
	int err;
	int i;

	/* Sanity check SRQ size before proceeding */
	if (init_attr->attr.max_wr  >= dev->dev->caps.max_srq_wqes ||
	    init_attr->attr.max_sge >  dev->dev->caps.max_srq_sge)
		return ERR_PTR(-EINVAL);

	srq = kmalloc(sizeof *srq, GFP_KERNEL);
	if (!srq)
		return ERR_PTR(-ENOMEM);

	mutex_init(&srq->mutex);
	spin_lock_init(&srq->lock);
	srq->msrq.max    = roundup_pow_of_two(init_attr->attr.max_wr + 1);
	srq->msrq.max_gs = init_attr->attr.max_sge;

	desc_size = max(32UL,
			roundup_pow_of_two(sizeof (struct mlx4_wqe_srq_next_seg) +
					   srq->msrq.max_gs *
					   sizeof (struct mlx4_wqe_data_seg)));
	srq->msrq.wqe_shift = ilog2(desc_size);

	buf_size = srq->msrq.max * desc_size;

	if (pd->uobject) {
		struct mlx4_ib_create_srq ucmd;

		if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) {
			err = -EFAULT;
			goto err_srq;
		}

		srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr,
					buf_size, 0, 0);
		if (IS_ERR(srq->umem)) {
			err = PTR_ERR(srq->umem);
			goto err_srq;
		}

		err = mlx4_mtt_init(dev->dev, ib_umem_page_count(srq->umem),
				    ilog2(srq->umem->page_size), &srq->mtt);
		if (err)
			goto err_buf;

		err = mlx4_ib_umem_write_mtt(dev, &srq->mtt, srq->umem);
		if (err)
			goto err_mtt;

		err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
					  ucmd.db_addr, &srq->db);
		if (err)
			goto err_mtt;
	} else {
		err = mlx4_db_alloc(dev->dev, &srq->db, 0);
		if (err)
			goto err_srq;

		*srq->db.db = 0;

		if (mlx4_buf_alloc(dev->dev, buf_size, PAGE_SIZE * 2, &srq->buf)) {
			err = -ENOMEM;
			goto err_db;
		}

		srq->head    = 0;
		srq->tail    = srq->msrq.max - 1;
		srq->wqe_ctr = 0;

		for (i = 0; i < srq->msrq.max; ++i) {
			next = get_wqe(srq, i);
			next->next_wqe_index =
				cpu_to_be16((i + 1) & (srq->msrq.max - 1));

			for (scatter = (void *) (next + 1);
			     (void *) scatter < (void *) next + desc_size;
			     ++scatter)
				scatter->lkey = cpu_to_be32(MLX4_INVALID_LKEY);
		}

		err = mlx4_mtt_init(dev->dev, srq->buf.npages, srq->buf.page_shift,
				    &srq->mtt);
		if (err)
			goto err_buf;

		err = mlx4_buf_write_mtt(dev->dev, &srq->mtt, &srq->buf);
		if (err)
			goto err_mtt;

		srq->wrid = kmalloc(srq->msrq.max * sizeof (u64), GFP_KERNEL);
		if (!srq->wrid) {
			err = -ENOMEM;
			goto err_mtt;
		}
	}

	err = mlx4_srq_alloc(dev->dev, to_mpd(pd)->pdn, &srq->mtt,
			     srq->db.dma, &srq->msrq);
	if (err)
		goto err_wrid;

	srq->msrq.event = mlx4_ib_srq_event;

	if (pd->uobject)
		if (ib_copy_to_udata(udata, &srq->msrq.srqn, sizeof (__u32))) {
			err = -EFAULT;
			goto err_wrid;
		}

	init_attr->attr.max_wr = srq->msrq.max - 1;

	return &srq->ibsrq;

err_wrid:
	if (pd->uobject)
		mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &srq->db);
	else
		kfree(srq->wrid);

err_mtt:
	mlx4_mtt_cleanup(dev->dev, &srq->mtt);

err_buf:
	if (pd->uobject)
		ib_umem_release(srq->umem);
	else
		mlx4_buf_free(dev->dev, buf_size, &srq->buf);

err_db:
	if (!pd->uobject)
		mlx4_db_free(dev->dev, &srq->db);

err_srq:
	kfree(srq);

	return ERR_PTR(err);
}

int mlx4_ib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
		       enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
{
	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	int ret;

	/* We don't support resizing SRQs (yet?) */
	if (attr_mask & IB_SRQ_MAX_WR)
		return -EINVAL;

	if (attr_mask & IB_SRQ_LIMIT) {
		if (attr->srq_limit >= srq->msrq.max)
			return -EINVAL;

		mutex_lock(&srq->mutex);
		ret = mlx4_srq_arm(dev->dev, &srq->msrq, attr->srq_limit);
		mutex_unlock(&srq->mutex);

		if (ret)
			return ret;
	}

	return 0;
}

int mlx4_ib_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
{
	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	int ret;
	int limit_watermark;

	ret = mlx4_srq_query(dev->dev, &srq->msrq, &limit_watermark);
	if (ret)
		return ret;

	srq_attr->srq_limit = limit_watermark;
	srq_attr->max_wr    = srq->msrq.max - 1;
	srq_attr->max_sge   = srq->msrq.max_gs;

	return 0;
}

int mlx4_ib_destroy_srq(struct ib_srq *srq)
{
	struct mlx4_ib_dev *dev = to_mdev(srq->device);
	struct mlx4_ib_srq *msrq = to_msrq(srq);

	mlx4_srq_free(dev->dev, &msrq->msrq);
	mlx4_mtt_cleanup(dev->dev, &msrq->mtt);

	if (srq->uobject) {
		mlx4_ib_db_unmap_user(to_mucontext(srq->uobject->context), &msrq->db);
		ib_umem_release(msrq->umem);
	} else {
		kfree(msrq->wrid);
		mlx4_buf_free(dev->dev, msrq->msrq.max << msrq->msrq.wqe_shift,
			      &msrq->buf);
		mlx4_db_free(dev->dev, &msrq->db);
	}

	kfree(msrq);

	return 0;
}

void mlx4_ib_free_srq_wqe(struct mlx4_ib_srq *srq, int wqe_index)
{
	struct mlx4_wqe_srq_next_seg *next;

	/* always called with interrupts disabled. */
	spin_lock(&srq->lock);

	next = get_wqe(srq, srq->tail);
	next->next_wqe_index = cpu_to_be16(wqe_index);
	srq->tail = wqe_index;

	spin_unlock(&srq->lock);
}

int mlx4_ib_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
			  struct ib_recv_wr **bad_wr)
{
	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	struct mlx4_wqe_srq_next_seg *next;
	struct mlx4_wqe_data_seg *scat;
	unsigned long flags;
	int err = 0;
	int nreq;
	int i;

	spin_lock_irqsave(&srq->lock, flags);

	for (nreq = 0; wr; ++nreq, wr = wr->next) {
		if (unlikely(wr->num_sge > srq->msrq.max_gs)) {
			err = -EINVAL;
			*bad_wr = wr;
			break;
		}

		if (unlikely(srq->head == srq->tail)) {
			err = -ENOMEM;
			*bad_wr = wr;
			break;
		}

		srq->wrid[srq->head] = wr->wr_id;

		next      = get_wqe(srq, srq->head);
		srq->head = be16_to_cpu(next->next_wqe_index);
		scat      = (struct mlx4_wqe_data_seg *) (next + 1);

		for (i = 0; i < wr->num_sge; ++i) {
			scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length);
			scat[i].lkey       = cpu_to_be32(wr->sg_list[i].lkey);
			scat[i].addr       = cpu_to_be64(wr->sg_list[i].addr);
		}

		if (i < srq->msrq.max_gs) {
			scat[i].byte_count = 0;
			scat[i].lkey       = cpu_to_be32(MLX4_INVALID_LKEY);
			scat[i].addr       = 0;
		}
	}

	if (likely(nreq)) {
		srq->wqe_ctr += nreq;

		/*
		 * Make sure that descriptors are written before
		 * doorbell record.
		 */
		wmb();

		*srq->db.db = cpu_to_be32(srq->wqe_ctr);
	}

	spin_unlock_irqrestore(&srq->lock, flags);

	return err;
}
Commit	Line	Data
225c7b1f RD	1	/*
225c7b1f RD	2	* Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
51a379d0	3	* Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
225c7b1f RD	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/mlx4/qp.h>
	35	#include <linux/mlx4/srq.h>
5a0e3ad6	36	#include <linux/slab.h>
225c7b1f RD	37
	38	#include "mlx4_ib.h"
	39	#include "user.h"
	40
	41	static void get_wqe(struct mlx4_ib_srq srq, int n)
	42	{
1c69fc2a	43	return mlx4_buf_offset(&srq->buf, n << srq->msrq.wqe_shift);
225c7b1f RD	44	}
	45
	46	static void mlx4_ib_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
	47	{
	48	struct ib_event event;
	49	struct ib_srq *ibsrq = &to_mibsrq(srq)->ibsrq;
	50
	51	if (ibsrq->event_handler) {
	52	event.device = ibsrq->device;
	53	event.element.srq = ibsrq;
	54	switch (type) {
	55	case MLX4_EVENT_TYPE_SRQ_LIMIT:
	56	event.event = IB_EVENT_SRQ_LIMIT_REACHED;
	57	break;
	58	case MLX4_EVENT_TYPE_SRQ_CATAS_ERROR:
	59	event.event = IB_EVENT_SRQ_ERR;
	60	break;
	61	default:
	62	printk(KERN_WARNING "mlx4_ib: Unexpected event type %d "
	63	"on SRQ %06x\n", type, srq->srqn);
	64	return;
	65	}
	66
	67	ibsrq->event_handler(&event, ibsrq->srq_context);
	68	}
	69	}
	70
	71	struct ib_srq mlx4_ib_create_srq(struct ib_pd pd,
	72	struct ib_srq_init_attr *init_attr,
	73	struct ib_udata *udata)
	74	{
	75	struct mlx4_ib_dev *dev = to_mdev(pd->device);
	76	struct mlx4_ib_srq *srq;
	77	struct mlx4_wqe_srq_next_seg *next;
4c425588	78	struct mlx4_wqe_data_seg *scatter;
225c7b1f RD	79	int desc_size;
	80	int buf_size;
	81	int err;
	82	int i;
	83
	84	/* Sanity check SRQ size before proceeding */
	85	if (init_attr->attr.max_wr >= dev->dev->caps.max_srq_wqes \|\|
	86	init_attr->attr.max_sge > dev->dev->caps.max_srq_sge)
	87	return ERR_PTR(-EINVAL);
	88
	89	srq = kmalloc(sizeof *srq, GFP_KERNEL);
	90	if (!srq)
	91	return ERR_PTR(-ENOMEM);
	92
	93	mutex_init(&srq->mutex);
	94	spin_lock_init(&srq->lock);
	95	srq->msrq.max = roundup_pow_of_two(init_attr->attr.max_wr + 1);
	96	srq->msrq.max_gs = init_attr->attr.max_sge;
	97
	98	desc_size = max(32UL,
	99	roundup_pow_of_two(sizeof (struct mlx4_wqe_srq_next_seg) +
	100	srq->msrq.max_gs *
	101	sizeof (struct mlx4_wqe_data_seg)));
	102	srq->msrq.wqe_shift = ilog2(desc_size);
	103
	104	buf_size = srq->msrq.max * desc_size;
	105
	106	if (pd->uobject) {
	107	struct mlx4_ib_create_srq ucmd;
	108
	109	if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) {
	110	err = -EFAULT;
	111	goto err_srq;
	112	}
	113
	114	srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr,
cb9fbc5c	115	buf_size, 0, 0);
225c7b1f RD	116	if (IS_ERR(srq->umem)) {
	117	err = PTR_ERR(srq->umem);
	118	goto err_srq;
	119	}
	120
	121	err = mlx4_mtt_init(dev->dev, ib_umem_page_count(srq->umem),
	122	ilog2(srq->umem->page_size), &srq->mtt);
	123	if (err)
	124	goto err_buf;
	125
	126	err = mlx4_ib_umem_write_mtt(dev, &srq->mtt, srq->umem);
	127	if (err)
	128	goto err_mtt;
	129
	130	err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
	131	ucmd.db_addr, &srq->db);
	132	if (err)
	133	goto err_mtt;
	134	} else {
6296883c	135	err = mlx4_db_alloc(dev->dev, &srq->db, 0);
225c7b1f RD	136	if (err)
	137	goto err_srq;
	138
	139	*srq->db.db = 0;
	140
	141	if (mlx4_buf_alloc(dev->dev, buf_size, PAGE_SIZE * 2, &srq->buf)) {
	142	err = -ENOMEM;
	143	goto err_db;
	144	}
	145
	146	srq->head = 0;
	147	srq->tail = srq->msrq.max - 1;
	148	srq->wqe_ctr = 0;
	149
	150	for (i = 0; i < srq->msrq.max; ++i) {
	151	next = get_wqe(srq, i);
	152	next->next_wqe_index =
	153	cpu_to_be16((i + 1) & (srq->msrq.max - 1));
4c425588 JM	154
	155	for (scatter = (void *) (next + 1);
	156	(void ) scatter < (void ) next + desc_size;
	157	++scatter)
	158	scatter->lkey = cpu_to_be32(MLX4_INVALID_LKEY);
225c7b1f RD	159	}
	160
	161	err = mlx4_mtt_init(dev->dev, srq->buf.npages, srq->buf.page_shift,
	162	&srq->mtt);
	163	if (err)
	164	goto err_buf;
	165
	166	err = mlx4_buf_write_mtt(dev->dev, &srq->mtt, &srq->buf);
	167	if (err)
	168	goto err_mtt;
	169
	170	srq->wrid = kmalloc(srq->msrq.max * sizeof (u64), GFP_KERNEL);
	171	if (!srq->wrid) {
	172	err = -ENOMEM;
	173	goto err_mtt;
	174	}
	175	}
	176
	177	err = mlx4_srq_alloc(dev->dev, to_mpd(pd)->pdn, &srq->mtt,
	178	srq->db.dma, &srq->msrq);
	179	if (err)
	180	goto err_wrid;
	181
	182	srq->msrq.event = mlx4_ib_srq_event;
	183
	184	if (pd->uobject)
	185	if (ib_copy_to_udata(udata, &srq->msrq.srqn, sizeof (__u32))) {
	186	err = -EFAULT;
	187	goto err_wrid;
	188	}
	189
	190	init_attr->attr.max_wr = srq->msrq.max - 1;
	191
	192	return &srq->ibsrq;
	193
	194	err_wrid:
	195	if (pd->uobject)
	196	mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &srq->db);
	197	else
	198	kfree(srq->wrid);
	199
	200	err_mtt:
	201	mlx4_mtt_cleanup(dev->dev, &srq->mtt);
	202
	203	err_buf:
	204	if (pd->uobject)
	205	ib_umem_release(srq->umem);
	206	else
	207	mlx4_buf_free(dev->dev, buf_size, &srq->buf);
	208
	209	err_db:
	210	if (!pd->uobject)
6296883c	211	mlx4_db_free(dev->dev, &srq->db);
225c7b1f RD	212
	213	err_srq:
	214	kfree(srq);
	215
	216	return ERR_PTR(err);
	217	}
	218
	219	int mlx4_ib_modify_srq(struct ib_srq ibsrq, struct ib_srq_attr attr,
	220	enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
	221	{
	222	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
	223	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	224	int ret;
	225
	226	/* We don't support resizing SRQs (yet?) */
	227	if (attr_mask & IB_SRQ_MAX_WR)
	228	return -EINVAL;
	229
	230	if (attr_mask & IB_SRQ_LIMIT) {
	231	if (attr->srq_limit >= srq->msrq.max)
	232	return -EINVAL;
	233
	234	mutex_lock(&srq->mutex);
	235	ret = mlx4_srq_arm(dev->dev, &srq->msrq, attr->srq_limit);
	236	mutex_unlock(&srq->mutex);
	237
	238	if (ret)
	239	return ret;
	240	}
	241
	242	return 0;
	243	}
	244
65541cb7 JM	245	int mlx4_ib_query_srq(struct ib_srq ibsrq, struct ib_srq_attr srq_attr)
	246	{
	247	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
	248	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	249	int ret;
	250	int limit_watermark;
	251
	252	ret = mlx4_srq_query(dev->dev, &srq->msrq, &limit_watermark);
	253	if (ret)
	254	return ret;
	255
d7dc3ccb	256	srq_attr->srq_limit = limit_watermark;
65541cb7 JM	257	srq_attr->max_wr = srq->msrq.max - 1;
	258	srq_attr->max_sge = srq->msrq.max_gs;
	259
	260	return 0;
	261	}
	262
225c7b1f RD	263	int mlx4_ib_destroy_srq(struct ib_srq *srq)
	264	{
	265	struct mlx4_ib_dev *dev = to_mdev(srq->device);
	266	struct mlx4_ib_srq *msrq = to_msrq(srq);
	267
	268	mlx4_srq_free(dev->dev, &msrq->msrq);
	269	mlx4_mtt_cleanup(dev->dev, &msrq->mtt);
	270
	271	if (srq->uobject) {
	272	mlx4_ib_db_unmap_user(to_mucontext(srq->uobject->context), &msrq->db);
	273	ib_umem_release(msrq->umem);
	274	} else {
	275	kfree(msrq->wrid);
	276	mlx4_buf_free(dev->dev, msrq->msrq.max << msrq->msrq.wqe_shift,
	277	&msrq->buf);
6296883c	278	mlx4_db_free(dev->dev, &msrq->db);
225c7b1f RD	279	}
	280
	281	kfree(msrq);
	282
	283	return 0;
	284	}
	285
	286	void mlx4_ib_free_srq_wqe(struct mlx4_ib_srq *srq, int wqe_index)
	287	{
	288	struct mlx4_wqe_srq_next_seg *next;
	289
	290	/* always called with interrupts disabled. */
	291	spin_lock(&srq->lock);
	292
	293	next = get_wqe(srq, srq->tail);
	294	next->next_wqe_index = cpu_to_be16(wqe_index);
	295	srq->tail = wqe_index;
	296
	297	spin_unlock(&srq->lock);
	298	}
	299
	300	int mlx4_ib_post_srq_recv(struct ib_srq ibsrq, struct ib_recv_wr wr,
	301	struct ib_recv_wr **bad_wr)
	302	{
	303	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	304	struct mlx4_wqe_srq_next_seg *next;
	305	struct mlx4_wqe_data_seg *scat;
	306	unsigned long flags;
	307	int err = 0;
	308	int nreq;
	309	int i;
	310
	311	spin_lock_irqsave(&srq->lock, flags);
	312
	313	for (nreq = 0; wr; ++nreq, wr = wr->next) {
	314	if (unlikely(wr->num_sge > srq->msrq.max_gs)) {
	315	err = -EINVAL;
	316	*bad_wr = wr;
	317	break;
	318	}
	319
56a8c8b6 RD	320	if (unlikely(srq->head == srq->tail)) {
	321	err = -ENOMEM;
	322	*bad_wr = wr;
	323	break;
	324	}
	325
225c7b1f RD	326	srq->wrid[srq->head] = wr->wr_id;
	327
	328	next = get_wqe(srq, srq->head);
	329	srq->head = be16_to_cpu(next->next_wqe_index);
	330	scat = (struct mlx4_wqe_data_seg *) (next + 1);
	331
	332	for (i = 0; i < wr->num_sge; ++i) {
	333	scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length);
	334	scat[i].lkey = cpu_to_be32(wr->sg_list[i].lkey);
	335	scat[i].addr = cpu_to_be64(wr->sg_list[i].addr);
	336	}
	337
	338	if (i < srq->msrq.max_gs) {
	339	scat[i].byte_count = 0;
	340	scat[i].lkey = cpu_to_be32(MLX4_INVALID_LKEY);
	341	scat[i].addr = 0;
	342	}
	343	}
	344
	345	if (likely(nreq)) {
	346	srq->wqe_ctr += nreq;
	347
	348	/*
	349	* Make sure that descriptors are written before
	350	* doorbell record.
	351	*/
	352	wmb();
	353
	354	*srq->db.db = cpu_to_be32(srq->wqe_ctr);
	355	}
	356
	357	spin_unlock_irqrestore(&srq->lock, flags);
	358
	359	return err;
	360	}