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1/*
2 * Copyright (c) 2005 Cisco Systems. 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 * $Id: mthca_srq.c,v 1.1.1.1 2007/08/03 18:52:32 Exp $
33 */
34
35#include <linux/slab.h>
36#include <linux/string.h>
37#include <linux/sched.h>
38
39#include <asm/io.h>
40
41#include "mthca_dev.h"
42#include "mthca_cmd.h"
43#include "mthca_memfree.h"
44#include "mthca_wqe.h"
45
46enum {
47	MTHCA_MAX_DIRECT_SRQ_SIZE = 4 * PAGE_SIZE
48};
49
50struct mthca_tavor_srq_context {
51	__be64 wqe_base_ds;	/* low 6 bits is descriptor size */
52	__be32 state_pd;
53	__be32 lkey;
54	__be32 uar;
55	__be16 limit_watermark;
56	__be16 wqe_cnt;
57	u32    reserved[2];
58};
59
60struct mthca_arbel_srq_context {
61	__be32 state_logsize_srqn;
62	__be32 lkey;
63	__be32 db_index;
64	__be32 logstride_usrpage;
65	__be64 wqe_base;
66	__be32 eq_pd;
67	__be16 limit_watermark;
68	__be16 wqe_cnt;
69	u16    reserved1;
70	__be16 wqe_counter;
71	u32    reserved2[3];
72};
73
74static void *get_wqe(struct mthca_srq *srq, int n)
75{
76	if (srq->is_direct)
77		return srq->queue.direct.buf + (n << srq->wqe_shift);
78	else
79		return srq->queue.page_list[(n << srq->wqe_shift) >> PAGE_SHIFT].buf +
80			((n << srq->wqe_shift) & (PAGE_SIZE - 1));
81}
82
83/*
84 * Return a pointer to the location within a WQE that we're using as a
85 * link when the WQE is in the free list.  We use the imm field
86 * because in the Tavor case, posting a WQE may overwrite the next
87 * segment of the previous WQE, but a receive WQE will never touch the
88 * imm field.  This avoids corrupting our free list if the previous
89 * WQE has already completed and been put on the free list when we
90 * post the next WQE.
91 */
92static inline int *wqe_to_link(void *wqe)
93{
94	return (int *) (wqe + offsetof(struct mthca_next_seg, imm));
95}
96
97static void mthca_tavor_init_srq_context(struct mthca_dev *dev,
98					 struct mthca_pd *pd,
99					 struct mthca_srq *srq,
100					 struct mthca_tavor_srq_context *context)
101{
102	memset(context, 0, sizeof *context);
103
104	context->wqe_base_ds = cpu_to_be64(1 << (srq->wqe_shift - 4));
105	context->state_pd    = cpu_to_be32(pd->pd_num);
106	context->lkey        = cpu_to_be32(srq->mr.ibmr.lkey);
107
108	if (pd->ibpd.uobject)
109		context->uar =
110			cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
111	else
112		context->uar = cpu_to_be32(dev->driver_uar.index);
113}
114
115static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
116					 struct mthca_pd *pd,
117					 struct mthca_srq *srq,
118					 struct mthca_arbel_srq_context *context)
119{
120	int logsize, max;
121
122	memset(context, 0, sizeof *context);
123
124	max = srq->max;
125	logsize = ilog2(max);
126	context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
127	context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
128	context->db_index = cpu_to_be32(srq->db_index);
129	context->logstride_usrpage = cpu_to_be32((srq->wqe_shift - 4) << 29);
130	if (pd->ibpd.uobject)
131		context->logstride_usrpage |=
132			cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
133	else
134		context->logstride_usrpage |= cpu_to_be32(dev->driver_uar.index);
135	context->eq_pd = cpu_to_be32(MTHCA_EQ_ASYNC << 24 | pd->pd_num);
136}
137
138static void mthca_free_srq_buf(struct mthca_dev *dev, struct mthca_srq *srq)
139{
140	mthca_buf_free(dev, srq->max << srq->wqe_shift, &srq->queue,
141		       srq->is_direct, &srq->mr);
142	kfree(srq->wrid);
143}
144
145static int mthca_alloc_srq_buf(struct mthca_dev *dev, struct mthca_pd *pd,
146			       struct mthca_srq *srq)
147{
148	struct mthca_data_seg *scatter;
149	void *wqe;
150	int err;
151	int i;
152
153	if (pd->ibpd.uobject)
154		return 0;
155
156	srq->wrid = kmalloc(srq->max * sizeof (u64), GFP_KERNEL);
157	if (!srq->wrid)
158		return -ENOMEM;
159
160	err = mthca_buf_alloc(dev, srq->max << srq->wqe_shift,
161			      MTHCA_MAX_DIRECT_SRQ_SIZE,
162			      &srq->queue, &srq->is_direct, pd, 1, &srq->mr);
163	if (err) {
164		kfree(srq->wrid);
165		return err;
166	}
167
168	/*
169	 * Now initialize the SRQ buffer so that all of the WQEs are
170	 * linked into the list of free WQEs.  In addition, set the
171	 * scatter list L_Keys to the sentry value of 0x100.
172	 */
173	for (i = 0; i < srq->max; ++i) {
174		wqe = get_wqe(srq, i);
175
176		*wqe_to_link(wqe) = i < srq->max - 1 ? i + 1 : -1;
177
178		for (scatter = wqe + sizeof (struct mthca_next_seg);
179		     (void *) scatter < wqe + (1 << srq->wqe_shift);
180		     ++scatter)
181			scatter->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
182	}
183
184	srq->last = get_wqe(srq, srq->max - 1);
185
186	return 0;
187}
188
189int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
190		    struct ib_srq_attr *attr, struct mthca_srq *srq)
191{
192	struct mthca_mailbox *mailbox;
193	u8 status;
194	int ds;
195	int err;
196
197	/* Sanity check SRQ size before proceeding */
198	if (attr->max_wr  > dev->limits.max_srq_wqes ||
199	    attr->max_sge > dev->limits.max_srq_sge)
200		return -EINVAL;
201
202	srq->max      = attr->max_wr;
203	srq->max_gs   = attr->max_sge;
204	srq->counter  = 0;
205
206	if (mthca_is_memfree(dev))
207		srq->max = roundup_pow_of_two(srq->max + 1);
208	else
209		srq->max = srq->max + 1;
210
211	ds = max(64UL,
212		 roundup_pow_of_two(sizeof (struct mthca_next_seg) +
213				    srq->max_gs * sizeof (struct mthca_data_seg)));
214
215	if (!mthca_is_memfree(dev) && (ds > dev->limits.max_desc_sz))
216		return -EINVAL;
217
218	srq->wqe_shift = ilog2(ds);
219
220	srq->srqn = mthca_alloc(&dev->srq_table.alloc);
221	if (srq->srqn == -1)
222		return -ENOMEM;
223
224	if (mthca_is_memfree(dev)) {
225		err = mthca_table_get(dev, dev->srq_table.table, srq->srqn);
226		if (err)
227			goto err_out;
228
229		if (!pd->ibpd.uobject) {
230			srq->db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_SRQ,
231						       srq->srqn, &srq->db);
232			if (srq->db_index < 0) {
233				err = -ENOMEM;
234				goto err_out_icm;
235			}
236		}
237	}
238
239	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
240	if (IS_ERR(mailbox)) {
241		err = PTR_ERR(mailbox);
242		goto err_out_db;
243	}
244
245	err = mthca_alloc_srq_buf(dev, pd, srq);
246	if (err)
247		goto err_out_mailbox;
248
249	spin_lock_init(&srq->lock);
250	srq->refcount = 1;
251	init_waitqueue_head(&srq->wait);
252	mutex_init(&srq->mutex);
253
254	if (mthca_is_memfree(dev))
255		mthca_arbel_init_srq_context(dev, pd, srq, mailbox->buf);
256	else
257		mthca_tavor_init_srq_context(dev, pd, srq, mailbox->buf);
258
259	err = mthca_SW2HW_SRQ(dev, mailbox, srq->srqn, &status);
260
261	if (err) {
262		mthca_warn(dev, "SW2HW_SRQ failed (%d)\n", err);
263		goto err_out_free_buf;
264	}
265	if (status) {
266		mthca_warn(dev, "SW2HW_SRQ returned status 0x%02x\n",
267			   status);
268		err = -EINVAL;
269		goto err_out_free_buf;
270	}
271
272	spin_lock_irq(&dev->srq_table.lock);
273	if (mthca_array_set(&dev->srq_table.srq,
274			    srq->srqn & (dev->limits.num_srqs - 1),
275			    srq)) {
276		spin_unlock_irq(&dev->srq_table.lock);
277		goto err_out_free_srq;
278	}
279	spin_unlock_irq(&dev->srq_table.lock);
280
281	mthca_free_mailbox(dev, mailbox);
282
283	srq->first_free = 0;
284	srq->last_free  = srq->max - 1;
285
286	attr->max_wr    = srq->max - 1;
287	attr->max_sge   = srq->max_gs;
288
289	return 0;
290
291err_out_free_srq:
292	err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
293	if (err)
294		mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
295	else if (status)
296		mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
297
298err_out_free_buf:
299	if (!pd->ibpd.uobject)
300		mthca_free_srq_buf(dev, srq);
301
302err_out_mailbox:
303	mthca_free_mailbox(dev, mailbox);
304
305err_out_db:
306	if (!pd->ibpd.uobject && mthca_is_memfree(dev))
307		mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
308
309err_out_icm:
310	mthca_table_put(dev, dev->srq_table.table, srq->srqn);
311
312err_out:
313	mthca_free(&dev->srq_table.alloc, srq->srqn);
314
315	return err;
316}
317
318static inline int get_srq_refcount(struct mthca_dev *dev, struct mthca_srq *srq)
319{
320	int c;
321
322	spin_lock_irq(&dev->srq_table.lock);
323	c = srq->refcount;
324	spin_unlock_irq(&dev->srq_table.lock);
325
326	return c;
327}
328
329void mthca_free_srq(struct mthca_dev *dev, struct mthca_srq *srq)
330{
331	struct mthca_mailbox *mailbox;
332	int err;
333	u8 status;
334
335	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
336	if (IS_ERR(mailbox)) {
337		mthca_warn(dev, "No memory for mailbox to free SRQ.\n");
338		return;
339	}
340
341	err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
342	if (err)
343		mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
344	else if (status)
345		mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
346
347	spin_lock_irq(&dev->srq_table.lock);
348	mthca_array_clear(&dev->srq_table.srq,
349			  srq->srqn & (dev->limits.num_srqs - 1));
350	--srq->refcount;
351	spin_unlock_irq(&dev->srq_table.lock);
352
353	wait_event(srq->wait, !get_srq_refcount(dev, srq));
354
355	if (!srq->ibsrq.uobject) {
356		mthca_free_srq_buf(dev, srq);
357		if (mthca_is_memfree(dev))
358			mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
359	}
360
361	mthca_table_put(dev, dev->srq_table.table, srq->srqn);
362	mthca_free(&dev->srq_table.alloc, srq->srqn);
363	mthca_free_mailbox(dev, mailbox);
364}
365
366int mthca_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
367		     enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
368{
369	struct mthca_dev *dev = to_mdev(ibsrq->device);
370	struct mthca_srq *srq = to_msrq(ibsrq);
371	int ret;
372	u8 status;
373
374	/* We don't support resizing SRQs (yet?) */
375	if (attr_mask & IB_SRQ_MAX_WR)
376		return -EINVAL;
377
378	if (attr_mask & IB_SRQ_LIMIT) {
379		u32 max_wr = mthca_is_memfree(dev) ? srq->max - 1 : srq->max;
380		if (attr->srq_limit > max_wr)
381			return -EINVAL;
382
383		mutex_lock(&srq->mutex);
384		ret = mthca_ARM_SRQ(dev, srq->srqn, attr->srq_limit, &status);
385		mutex_unlock(&srq->mutex);
386
387		if (ret)
388			return ret;
389		if (status)
390			return -EINVAL;
391	}
392
393	return 0;
394}
395
396int mthca_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
397{
398	struct mthca_dev *dev = to_mdev(ibsrq->device);
399	struct mthca_srq *srq = to_msrq(ibsrq);
400	struct mthca_mailbox *mailbox;
401	struct mthca_arbel_srq_context *arbel_ctx;
402	struct mthca_tavor_srq_context *tavor_ctx;
403	u8 status;
404	int err;
405
406	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
407	if (IS_ERR(mailbox))
408		return PTR_ERR(mailbox);
409
410	err = mthca_QUERY_SRQ(dev, srq->srqn, mailbox, &status);
411	if (err)
412		goto out;
413
414	if (mthca_is_memfree(dev)) {
415		arbel_ctx = mailbox->buf;
416		srq_attr->srq_limit = be16_to_cpu(arbel_ctx->limit_watermark);
417	} else {
418		tavor_ctx = mailbox->buf;
419		srq_attr->srq_limit = be16_to_cpu(tavor_ctx->limit_watermark);
420	}
421
422	srq_attr->max_wr  = srq->max - 1;
423	srq_attr->max_sge = srq->max_gs;
424
425out:
426	mthca_free_mailbox(dev, mailbox);
427
428	return err;
429}
430
431void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
432		     enum ib_event_type event_type)
433{
434	struct mthca_srq *srq;
435	struct ib_event event;
436
437	spin_lock(&dev->srq_table.lock);
438	srq = mthca_array_get(&dev->srq_table.srq, srqn & (dev->limits.num_srqs - 1));
439	if (srq)
440		++srq->refcount;
441	spin_unlock(&dev->srq_table.lock);
442
443	if (!srq) {
444		mthca_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
445		return;
446	}
447
448	if (!srq->ibsrq.event_handler)
449		goto out;
450
451	event.device      = &dev->ib_dev;
452	event.event       = event_type;
453	event.element.srq = &srq->ibsrq;
454	srq->ibsrq.event_handler(&event, srq->ibsrq.srq_context);
455
456out:
457	spin_lock(&dev->srq_table.lock);
458	if (!--srq->refcount)
459		wake_up(&srq->wait);
460	spin_unlock(&dev->srq_table.lock);
461}
462
463/*
464 * This function must be called with IRQs disabled.
465 */
466void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr)
467{
468	int ind;
469
470	ind = wqe_addr >> srq->wqe_shift;
471
472	spin_lock(&srq->lock);
473
474	if (likely(srq->first_free >= 0))
475		*wqe_to_link(get_wqe(srq, srq->last_free)) = ind;
476	else
477		srq->first_free = ind;
478
479	*wqe_to_link(get_wqe(srq, ind)) = -1;
480	srq->last_free = ind;
481
482	spin_unlock(&srq->lock);
483}
484
485int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
486			      struct ib_recv_wr **bad_wr)
487{
488	struct mthca_dev *dev = to_mdev(ibsrq->device);
489	struct mthca_srq *srq = to_msrq(ibsrq);
490	__be32 doorbell[2];
491	unsigned long flags;
492	int err = 0;
493	int first_ind;
494	int ind;
495	int next_ind;
496	int nreq;
497	int i;
498	void *wqe;
499	void *prev_wqe;
500
501	spin_lock_irqsave(&srq->lock, flags);
502
503	first_ind = srq->first_free;
504
505	for (nreq = 0; wr; wr = wr->next) {
506		ind = srq->first_free;
507
508		if (ind < 0) {
509			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
510			err = -ENOMEM;
511			*bad_wr = wr;
512			break;
513		}
514
515		wqe       = get_wqe(srq, ind);
516		next_ind  = *wqe_to_link(wqe);
517
518		if (next_ind < 0) {
519			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
520			err = -ENOMEM;
521			*bad_wr = wr;
522			break;
523		}
524
525		prev_wqe  = srq->last;
526		srq->last = wqe;
527
528		((struct mthca_next_seg *) wqe)->nda_op = 0;
529		((struct mthca_next_seg *) wqe)->ee_nds = 0;
530		/* flags field will always remain 0 */
531
532		wqe += sizeof (struct mthca_next_seg);
533
534		if (unlikely(wr->num_sge > srq->max_gs)) {
535			err = -EINVAL;
536			*bad_wr = wr;
537			srq->last = prev_wqe;
538			break;
539		}
540
541		for (i = 0; i < wr->num_sge; ++i) {
542			((struct mthca_data_seg *) wqe)->byte_count =
543				cpu_to_be32(wr->sg_list[i].length);
544			((struct mthca_data_seg *) wqe)->lkey =
545				cpu_to_be32(wr->sg_list[i].lkey);
546			((struct mthca_data_seg *) wqe)->addr =
547				cpu_to_be64(wr->sg_list[i].addr);
548			wqe += sizeof (struct mthca_data_seg);
549		}
550
551		if (i < srq->max_gs) {
552			((struct mthca_data_seg *) wqe)->byte_count = 0;
553			((struct mthca_data_seg *) wqe)->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
554			((struct mthca_data_seg *) wqe)->addr = 0;
555		}
556
557		((struct mthca_next_seg *) prev_wqe)->nda_op =
558			cpu_to_be32((ind << srq->wqe_shift) | 1);
559		wmb();
560		((struct mthca_next_seg *) prev_wqe)->ee_nds =
561			cpu_to_be32(MTHCA_NEXT_DBD);
562
563		srq->wrid[ind]  = wr->wr_id;
564		srq->first_free = next_ind;
565
566		++nreq;
567		if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
568			nreq = 0;
569
570			doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
571			doorbell[1] = cpu_to_be32(srq->srqn << 8);
572
573			/*
574			 * Make sure that descriptors are written
575			 * before doorbell is rung.
576			 */
577			wmb();
578
579			mthca_write64(doorbell,
580				      dev->kar + MTHCA_RECEIVE_DOORBELL,
581				      MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
582
583			first_ind = srq->first_free;
584		}
585	}
586
587	if (likely(nreq)) {
588		doorbell[0] = cpu_to_be32(first_ind << srq->wqe_shift);
589		doorbell[1] = cpu_to_be32((srq->srqn << 8) | nreq);
590
591		/*
592		 * Make sure that descriptors are written before
593		 * doorbell is rung.
594		 */
595		wmb();
596
597		mthca_write64(doorbell,
598			      dev->kar + MTHCA_RECEIVE_DOORBELL,
599			      MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
600	}
601
602	/*
603	 * Make sure doorbells don't leak out of SRQ spinlock and
604	 * reach the HCA out of order:
605	 */
606	mmiowb();
607
608	spin_unlock_irqrestore(&srq->lock, flags);
609	return err;
610}
611
612int mthca_arbel_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
613			      struct ib_recv_wr **bad_wr)
614{
615	struct mthca_dev *dev = to_mdev(ibsrq->device);
616	struct mthca_srq *srq = to_msrq(ibsrq);
617	unsigned long flags;
618	int err = 0;
619	int ind;
620	int next_ind;
621	int nreq;
622	int i;
623	void *wqe;
624
625	spin_lock_irqsave(&srq->lock, flags);
626
627	for (nreq = 0; wr; ++nreq, wr = wr->next) {
628		ind = srq->first_free;
629
630		if (ind < 0) {
631			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
632			err = -ENOMEM;
633			*bad_wr = wr;
634			break;
635		}
636
637		wqe       = get_wqe(srq, ind);
638		next_ind  = *wqe_to_link(wqe);
639
640		if (next_ind < 0) {
641			mthca_err(dev, "SRQ %06x full\n", srq->srqn);
642			err = -ENOMEM;
643			*bad_wr = wr;
644			break;
645		}
646
647		((struct mthca_next_seg *) wqe)->nda_op =
648			cpu_to_be32((next_ind << srq->wqe_shift) | 1);
649		((struct mthca_next_seg *) wqe)->ee_nds = 0;
650		/* flags field will always remain 0 */
651
652		wqe += sizeof (struct mthca_next_seg);
653
654		if (unlikely(wr->num_sge > srq->max_gs)) {
655			err = -EINVAL;
656			*bad_wr = wr;
657			break;
658		}
659
660		for (i = 0; i < wr->num_sge; ++i) {
661			((struct mthca_data_seg *) wqe)->byte_count =
662				cpu_to_be32(wr->sg_list[i].length);
663			((struct mthca_data_seg *) wqe)->lkey =
664				cpu_to_be32(wr->sg_list[i].lkey);
665			((struct mthca_data_seg *) wqe)->addr =
666				cpu_to_be64(wr->sg_list[i].addr);
667			wqe += sizeof (struct mthca_data_seg);
668		}
669
670		if (i < srq->max_gs) {
671			((struct mthca_data_seg *) wqe)->byte_count = 0;
672			((struct mthca_data_seg *) wqe)->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
673			((struct mthca_data_seg *) wqe)->addr = 0;
674		}
675
676		srq->wrid[ind]  = wr->wr_id;
677		srq->first_free = next_ind;
678	}
679
680	if (likely(nreq)) {
681		srq->counter += nreq;
682
683		/*
684		 * Make sure that descriptors are written before
685		 * we write doorbell record.
686		 */
687		wmb();
688		*srq->db = cpu_to_be32(srq->counter);
689	}
690
691	spin_unlock_irqrestore(&srq->lock, flags);
692	return err;
693}
694
695int mthca_max_srq_sge(struct mthca_dev *dev)
696{
697	if (mthca_is_memfree(dev))
698		return dev->limits.max_sg;
699
700	/*
701	 * SRQ allocations are based on powers of 2 for Tavor,
702	 * (although they only need to be multiples of 16 bytes).
703	 *
704	 * Therefore, we need to base the max number of sg entries on
705	 * the largest power of 2 descriptor size that is <= to the
706	 * actual max WQE descriptor size, rather than return the
707	 * max_sg value given by the firmware (which is based on WQE
708	 * sizes as multiples of 16, not powers of 2).
709	 *
710	 * If SRQ implementation is changed for Tavor to be based on
711	 * multiples of 16, the calculation below can be deleted and
712	 * the FW max_sg value returned.
713	 */
714	return min_t(int, dev->limits.max_sg,
715		     ((1 << (fls(dev->limits.max_desc_sz) - 1)) -
716		      sizeof (struct mthca_next_seg)) /
717		     sizeof (struct mthca_data_seg));
718}
719
720int mthca_init_srq_table(struct mthca_dev *dev)
721{
722	int err;
723
724	if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
725		return 0;
726
727	spin_lock_init(&dev->srq_table.lock);
728
729	err = mthca_alloc_init(&dev->srq_table.alloc,
730			       dev->limits.num_srqs,
731			       dev->limits.num_srqs - 1,
732			       dev->limits.reserved_srqs);
733	if (err)
734		return err;
735
736	err = mthca_array_init(&dev->srq_table.srq,
737			       dev->limits.num_srqs);
738	if (err)
739		mthca_alloc_cleanup(&dev->srq_table.alloc);
740
741	return err;
742}
743
744void mthca_cleanup_srq_table(struct mthca_dev *dev)
745{
746	if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
747		return;
748
749	mthca_array_cleanup(&dev->srq_table.srq, dev->limits.num_srqs);
750	mthca_alloc_cleanup(&dev->srq_table.alloc);
751}
752