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

/*
 * Copyright (c) 2007 Cisco Systems, 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/mlx4/qp.h>
#include <linux/mlx4/srq.h>

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

static void *get_wqe(struct mlx4_ib_srq *srq, int n)
{
	int offset = n << srq->msrq.wqe_shift;

	if (srq->buf.nbufs == 1)
		return srq->buf.u.direct.buf + offset;
	else
		return srq->buf.u.page_list[offset >> PAGE_SHIFT].buf +
			(offset & (PAGE_SIZE - 1));
}

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;
	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);
		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_ib_db_alloc(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));
		}

		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_ib_db_free(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 = be16_to_cpu(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_ib_db_free(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	/*
	2	* Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
	3	*
	4	* This software is available to you under a choice of one of two
	5	* licenses. You may choose to be licensed under the terms of the GNU
	6	* General Public License (GPL) Version 2, available from the file
	7	* COPYING in the main directory of this source tree, or the
	8	* OpenIB.org BSD license below:
	9	*
	10	* Redistribution and use in source and binary forms, with or
	11	* without modification, are permitted provided that the following
	12	* conditions are met:
	13	*
	14	* - Redistributions of source code must retain the above
	15	* copyright notice, this list of conditions and the following
	16	* disclaimer.
	17	*
	18	* - Redistributions in binary form must reproduce the above
	19	* copyright notice, this list of conditions and the following
	20	* disclaimer in the documentation and/or other materials
	21	* provided with the distribution.
	22	*
	23	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	24	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	25	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	26	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	27	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	28	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	29	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	30	* SOFTWARE.
	31	*/
	32
	33	#include <linux/mlx4/qp.h>
	34	#include <linux/mlx4/srq.h>
	35
	36	#include "mlx4_ib.h"
	37	#include "user.h"
	38
	39	static void get_wqe(struct mlx4_ib_srq srq, int n)
	40	{
	41	int offset = n << srq->msrq.wqe_shift;
	42
	43	if (srq->buf.nbufs == 1)
	44	return srq->buf.u.direct.buf + offset;
	45	else
	46	return srq->buf.u.page_list[offset >> PAGE_SHIFT].buf +
	47	(offset & (PAGE_SIZE - 1));
	48	}
	49
	50	static void mlx4_ib_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
	51	{
	52	struct ib_event event;
	53	struct ib_srq *ibsrq = &to_mibsrq(srq)->ibsrq;
	54
	55	if (ibsrq->event_handler) {
	56	event.device = ibsrq->device;
	57	event.element.srq = ibsrq;
	58	switch (type) {
	59	case MLX4_EVENT_TYPE_SRQ_LIMIT:
	60	event.event = IB_EVENT_SRQ_LIMIT_REACHED;
	61	break;
	62	case MLX4_EVENT_TYPE_SRQ_CATAS_ERROR:
	63	event.event = IB_EVENT_SRQ_ERR;
	64	break;
65	default:
66	printk(KERN_WARNING "mlx4_ib: Unexpected event type %d "
67	"on SRQ %06x\n", type, srq->srqn);
68	return;
69	}
70
71	ibsrq->event_handler(&event, ibsrq->srq_context);
72	}
73	}
74
75	struct ib_srq mlx4_ib_create_srq(struct ib_pd pd,
76	struct ib_srq_init_attr *init_attr,
77	struct ib_udata *udata)
78	{
79	struct mlx4_ib_dev *dev = to_mdev(pd->device);
80	struct mlx4_ib_srq *srq;
81	struct mlx4_wqe_srq_next_seg *next;
82	int desc_size;
83	int buf_size;
84	int err;
85	int i;
86
87	/* Sanity check SRQ size before proceeding */
88	if (init_attr->attr.max_wr >= dev->dev->caps.max_srq_wqes \|\|
89	init_attr->attr.max_sge > dev->dev->caps.max_srq_sge)
90	return ERR_PTR(-EINVAL);
91
92	srq = kmalloc(sizeof *srq, GFP_KERNEL);
93	if (!srq)
94	return ERR_PTR(-ENOMEM);
95
96	mutex_init(&srq->mutex);
97	spin_lock_init(&srq->lock);
98	srq->msrq.max = roundup_pow_of_two(init_attr->attr.max_wr + 1);
99	srq->msrq.max_gs = init_attr->attr.max_sge;
100
101	desc_size = max(32UL,
102	roundup_pow_of_two(sizeof (struct mlx4_wqe_srq_next_seg) +
103	srq->msrq.max_gs *
104	sizeof (struct mlx4_wqe_data_seg)));
105	srq->msrq.wqe_shift = ilog2(desc_size);
106
107	buf_size = srq->msrq.max * desc_size;
108
109	if (pd->uobject) {
110	struct mlx4_ib_create_srq ucmd;
111
112	if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) {
113	err = -EFAULT;
114	goto err_srq;
115	}
116
117	srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr,
118	buf_size, 0);
119	if (IS_ERR(srq->umem)) {
120	err = PTR_ERR(srq->umem);
121	goto err_srq;
122	}
123
124	err = mlx4_mtt_init(dev->dev, ib_umem_page_count(srq->umem),
125	ilog2(srq->umem->page_size), &srq->mtt);
126	if (err)
127	goto err_buf;
128
129	err = mlx4_ib_umem_write_mtt(dev, &srq->mtt, srq->umem);
130	if (err)
131	goto err_mtt;
132
133	err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
134	ucmd.db_addr, &srq->db);
135	if (err)
136	goto err_mtt;
137	} else {
138	err = mlx4_ib_db_alloc(dev, &srq->db, 0);
139	if (err)
140	goto err_srq;
141
142	*srq->db.db = 0;
143
144	if (mlx4_buf_alloc(dev->dev, buf_size, PAGE_SIZE * 2, &srq->buf)) {
145	err = -ENOMEM;
146	goto err_db;
147	}
148
149	srq->head = 0;
150	srq->tail = srq->msrq.max - 1;
151	srq->wqe_ctr = 0;
152
153	for (i = 0; i < srq->msrq.max; ++i) {
154	next = get_wqe(srq, i);
155	next->next_wqe_index =
156	cpu_to_be16((i + 1) & (srq->msrq.max - 1));
157	}
158
159	err = mlx4_mtt_init(dev->dev, srq->buf.npages, srq->buf.page_shift,
160	&srq->mtt);
161	if (err)
162	goto err_buf;
163
164	err = mlx4_buf_write_mtt(dev->dev, &srq->mtt, &srq->buf);
165	if (err)
166	goto err_mtt;
167
168	srq->wrid = kmalloc(srq->msrq.max * sizeof (u64), GFP_KERNEL);
169	if (!srq->wrid) {
170	err = -ENOMEM;
171	goto err_mtt;
172	}
173	}
174
175	err = mlx4_srq_alloc(dev->dev, to_mpd(pd)->pdn, &srq->mtt,
176	srq->db.dma, &srq->msrq);
177	if (err)
178	goto err_wrid;
179
180	srq->msrq.event = mlx4_ib_srq_event;
181
182	if (pd->uobject)
183	if (ib_copy_to_udata(udata, &srq->msrq.srqn, sizeof (__u32))) {
184	err = -EFAULT;
185	goto err_wrid;
186	}
187
188	init_attr->attr.max_wr = srq->msrq.max - 1;
189
190	return &srq->ibsrq;
191
192	err_wrid:
193	if (pd->uobject)
194	mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &srq->db);
195	else
196	kfree(srq->wrid);
197
198	err_mtt:
199	mlx4_mtt_cleanup(dev->dev, &srq->mtt);
200
201	err_buf:
202	if (pd->uobject)
203	ib_umem_release(srq->umem);
204	else
205	mlx4_buf_free(dev->dev, buf_size, &srq->buf);
206
207	err_db:
208	if (!pd->uobject)
209	mlx4_ib_db_free(dev, &srq->db);
210
211	err_srq:
212	kfree(srq);
213
214	return ERR_PTR(err);
215	}
216
217	int mlx4_ib_modify_srq(struct ib_srq ibsrq, struct ib_srq_attr attr,
218	enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
219	{
220	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
221	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
222	int ret;
223
224	/* We don't support resizing SRQs (yet?) */
225	if (attr_mask & IB_SRQ_MAX_WR)
226	return -EINVAL;
227
228	if (attr_mask & IB_SRQ_LIMIT) {
229	if (attr->srq_limit >= srq->msrq.max)
230	return -EINVAL;
231
232	mutex_lock(&srq->mutex);
233	ret = mlx4_srq_arm(dev->dev, &srq->msrq, attr->srq_limit);
234	mutex_unlock(&srq->mutex);
235
236	if (ret)
237	return ret;
238	}
239
240	return 0;
241	}
242
65541cb7 JM	243	int mlx4_ib_query_srq(struct ib_srq ibsrq, struct ib_srq_attr srq_attr)
	244	{
	245	struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
	246	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	247	int ret;
	248	int limit_watermark;
	249
	250	ret = mlx4_srq_query(dev->dev, &srq->msrq, &limit_watermark);
	251	if (ret)
	252	return ret;
	253
	254	srq_attr->srq_limit = be16_to_cpu(limit_watermark);
	255	srq_attr->max_wr = srq->msrq.max - 1;
	256	srq_attr->max_sge = srq->msrq.max_gs;
	257
	258	return 0;
	259	}
	260
225c7b1f RD	261	int mlx4_ib_destroy_srq(struct ib_srq *srq)
	262	{
	263	struct mlx4_ib_dev *dev = to_mdev(srq->device);
	264	struct mlx4_ib_srq *msrq = to_msrq(srq);
	265
	266	mlx4_srq_free(dev->dev, &msrq->msrq);
	267	mlx4_mtt_cleanup(dev->dev, &msrq->mtt);
	268
	269	if (srq->uobject) {
	270	mlx4_ib_db_unmap_user(to_mucontext(srq->uobject->context), &msrq->db);
	271	ib_umem_release(msrq->umem);
	272	} else {
	273	kfree(msrq->wrid);
	274	mlx4_buf_free(dev->dev, msrq->msrq.max << msrq->msrq.wqe_shift,
	275	&msrq->buf);
	276	mlx4_ib_db_free(dev, &msrq->db);
	277	}
	278
	279	kfree(msrq);
	280
	281	return 0;
	282	}
	283
	284	void mlx4_ib_free_srq_wqe(struct mlx4_ib_srq *srq, int wqe_index)
	285	{
	286	struct mlx4_wqe_srq_next_seg *next;
	287
	288	/* always called with interrupts disabled. */
	289	spin_lock(&srq->lock);
	290
	291	next = get_wqe(srq, srq->tail);
	292	next->next_wqe_index = cpu_to_be16(wqe_index);
	293	srq->tail = wqe_index;
	294
	295	spin_unlock(&srq->lock);
	296	}
	297
	298	int mlx4_ib_post_srq_recv(struct ib_srq ibsrq, struct ib_recv_wr wr,
	299	struct ib_recv_wr **bad_wr)
	300	{
	301	struct mlx4_ib_srq *srq = to_msrq(ibsrq);
	302	struct mlx4_wqe_srq_next_seg *next;
	303	struct mlx4_wqe_data_seg *scat;
	304	unsigned long flags;
	305	int err = 0;
	306	int nreq;
	307	int i;
	308
	309	spin_lock_irqsave(&srq->lock, flags);
	310
	311	for (nreq = 0; wr; ++nreq, wr = wr->next) {
	312	if (unlikely(wr->num_sge > srq->msrq.max_gs)) {
	313	err = -EINVAL;
	314	*bad_wr = wr;
	315	break;
	316	}
	317
56a8c8b6 RD	318	if (unlikely(srq->head == srq->tail)) {
	319	err = -ENOMEM;
	320	*bad_wr = wr;
	321	break;
	322	}
	323
225c7b1f RD	324	srq->wrid[srq->head] = wr->wr_id;
	325
	326	next = get_wqe(srq, srq->head);
	327	srq->head = be16_to_cpu(next->next_wqe_index);
	328	scat = (struct mlx4_wqe_data_seg *) (next + 1);
	329
	330	for (i = 0; i < wr->num_sge; ++i) {
	331	scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length);
	332	scat[i].lkey = cpu_to_be32(wr->sg_list[i].lkey);
	333	scat[i].addr = cpu_to_be64(wr->sg_list[i].addr);
	334	}
	335
	336	if (i < srq->msrq.max_gs) {
	337	scat[i].byte_count = 0;
	338	scat[i].lkey = cpu_to_be32(MLX4_INVALID_LKEY);
	339	scat[i].addr = 0;
	340	}
	341	}
	342
	343	if (likely(nreq)) {
	344	srq->wqe_ctr += nreq;
	345
	346	/*
	347	* Make sure that descriptors are written before
	348	* doorbell record.
	349	*/
	350	wmb();
	351
	352	*srq->db.db = cpu_to_be32(srq->wqe_ctr);
	353	}
	354
	355	spin_unlock_irqrestore(&srq->lock, flags);
	356
	357	return err;
	358	}