xref: /linux/drivers/infiniband/ulp/ipoib/ipoib_main.c (revision 643d1f7fe3aa12c8bdea6fa5b4ba874ff6dd601d)
1 /*
2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
4  * Copyright (c) 2004 Voltaire, Inc. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  *
34  * $Id: ipoib_main.c 1377 2004-12-23 19:57:12Z roland $
35  */
36 
37 #include "ipoib.h"
38 
39 #include <linux/module.h>
40 
41 #include <linux/init.h>
42 #include <linux/slab.h>
43 #include <linux/kernel.h>
44 
45 #include <linux/if_arp.h>	/* For ARPHRD_xxx */
46 
47 #include <linux/ip.h>
48 #include <linux/in.h>
49 
50 #include <net/dst.h>
51 
52 MODULE_AUTHOR("Roland Dreier");
53 MODULE_DESCRIPTION("IP-over-InfiniBand net driver");
54 MODULE_LICENSE("Dual BSD/GPL");
55 
56 int ipoib_sendq_size __read_mostly = IPOIB_TX_RING_SIZE;
57 int ipoib_recvq_size __read_mostly = IPOIB_RX_RING_SIZE;
58 
59 module_param_named(send_queue_size, ipoib_sendq_size, int, 0444);
60 MODULE_PARM_DESC(send_queue_size, "Number of descriptors in send queue");
61 module_param_named(recv_queue_size, ipoib_recvq_size, int, 0444);
62 MODULE_PARM_DESC(recv_queue_size, "Number of descriptors in receive queue");
63 
64 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
65 int ipoib_debug_level;
66 
67 module_param_named(debug_level, ipoib_debug_level, int, 0644);
68 MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0");
69 #endif
70 
71 struct ipoib_path_iter {
72 	struct net_device *dev;
73 	struct ipoib_path  path;
74 };
75 
76 static const u8 ipv4_bcast_addr[] = {
77 	0x00, 0xff, 0xff, 0xff,
78 	0xff, 0x12, 0x40, 0x1b,	0x00, 0x00, 0x00, 0x00,
79 	0x00, 0x00, 0x00, 0x00,	0xff, 0xff, 0xff, 0xff
80 };
81 
82 struct workqueue_struct *ipoib_workqueue;
83 
84 struct ib_sa_client ipoib_sa_client;
85 
86 static void ipoib_add_one(struct ib_device *device);
87 static void ipoib_remove_one(struct ib_device *device);
88 
89 static struct ib_client ipoib_client = {
90 	.name   = "ipoib",
91 	.add    = ipoib_add_one,
92 	.remove = ipoib_remove_one
93 };
94 
95 int ipoib_open(struct net_device *dev)
96 {
97 	struct ipoib_dev_priv *priv = netdev_priv(dev);
98 
99 	ipoib_dbg(priv, "bringing up interface\n");
100 
101 	napi_enable(&priv->napi);
102 	set_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);
103 
104 	if (ipoib_pkey_dev_delay_open(dev))
105 		return 0;
106 
107 	if (ipoib_ib_dev_open(dev)) {
108 		napi_disable(&priv->napi);
109 		return -EINVAL;
110 	}
111 
112 	if (ipoib_ib_dev_up(dev)) {
113 		ipoib_ib_dev_stop(dev, 1);
114 		napi_disable(&priv->napi);
115 		return -EINVAL;
116 	}
117 
118 	if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
119 		struct ipoib_dev_priv *cpriv;
120 
121 		/* Bring up any child interfaces too */
122 		mutex_lock(&priv->vlan_mutex);
123 		list_for_each_entry(cpriv, &priv->child_intfs, list) {
124 			int flags;
125 
126 			flags = cpriv->dev->flags;
127 			if (flags & IFF_UP)
128 				continue;
129 
130 			dev_change_flags(cpriv->dev, flags | IFF_UP);
131 		}
132 		mutex_unlock(&priv->vlan_mutex);
133 	}
134 
135 	netif_start_queue(dev);
136 
137 	return 0;
138 }
139 
140 static int ipoib_stop(struct net_device *dev)
141 {
142 	struct ipoib_dev_priv *priv = netdev_priv(dev);
143 
144 	ipoib_dbg(priv, "stopping interface\n");
145 
146 	clear_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags);
147 	napi_disable(&priv->napi);
148 
149 	netif_stop_queue(dev);
150 
151 	/*
152 	 * Now flush workqueue to make sure a scheduled task doesn't
153 	 * bring our internal state back up.
154 	 */
155 	flush_workqueue(ipoib_workqueue);
156 
157 	ipoib_ib_dev_down(dev, 1);
158 	ipoib_ib_dev_stop(dev, 1);
159 
160 	if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
161 		struct ipoib_dev_priv *cpriv;
162 
163 		/* Bring down any child interfaces too */
164 		mutex_lock(&priv->vlan_mutex);
165 		list_for_each_entry(cpriv, &priv->child_intfs, list) {
166 			int flags;
167 
168 			flags = cpriv->dev->flags;
169 			if (!(flags & IFF_UP))
170 				continue;
171 
172 			dev_change_flags(cpriv->dev, flags & ~IFF_UP);
173 		}
174 		mutex_unlock(&priv->vlan_mutex);
175 	}
176 
177 	return 0;
178 }
179 
180 static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
181 {
182 	struct ipoib_dev_priv *priv = netdev_priv(dev);
183 
184 	/* dev->mtu > 2K ==> connected mode */
185 	if (ipoib_cm_admin_enabled(dev)) {
186 		if (new_mtu > ipoib_cm_max_mtu(dev))
187 			return -EINVAL;
188 
189 		if (new_mtu > priv->mcast_mtu)
190 			ipoib_warn(priv, "mtu > %d will cause multicast packet drops.\n",
191 				   priv->mcast_mtu);
192 
193 		dev->mtu = new_mtu;
194 		return 0;
195 	}
196 
197 	if (new_mtu > IPOIB_PACKET_SIZE - IPOIB_ENCAP_LEN)
198 		return -EINVAL;
199 
200 	priv->admin_mtu = new_mtu;
201 
202 	dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);
203 
204 	return 0;
205 }
206 
207 static struct ipoib_path *__path_find(struct net_device *dev, void *gid)
208 {
209 	struct ipoib_dev_priv *priv = netdev_priv(dev);
210 	struct rb_node *n = priv->path_tree.rb_node;
211 	struct ipoib_path *path;
212 	int ret;
213 
214 	while (n) {
215 		path = rb_entry(n, struct ipoib_path, rb_node);
216 
217 		ret = memcmp(gid, path->pathrec.dgid.raw,
218 			     sizeof (union ib_gid));
219 
220 		if (ret < 0)
221 			n = n->rb_left;
222 		else if (ret > 0)
223 			n = n->rb_right;
224 		else
225 			return path;
226 	}
227 
228 	return NULL;
229 }
230 
231 static int __path_add(struct net_device *dev, struct ipoib_path *path)
232 {
233 	struct ipoib_dev_priv *priv = netdev_priv(dev);
234 	struct rb_node **n = &priv->path_tree.rb_node;
235 	struct rb_node *pn = NULL;
236 	struct ipoib_path *tpath;
237 	int ret;
238 
239 	while (*n) {
240 		pn = *n;
241 		tpath = rb_entry(pn, struct ipoib_path, rb_node);
242 
243 		ret = memcmp(path->pathrec.dgid.raw, tpath->pathrec.dgid.raw,
244 			     sizeof (union ib_gid));
245 		if (ret < 0)
246 			n = &pn->rb_left;
247 		else if (ret > 0)
248 			n = &pn->rb_right;
249 		else
250 			return -EEXIST;
251 	}
252 
253 	rb_link_node(&path->rb_node, pn, n);
254 	rb_insert_color(&path->rb_node, &priv->path_tree);
255 
256 	list_add_tail(&path->list, &priv->path_list);
257 
258 	return 0;
259 }
260 
261 static void path_free(struct net_device *dev, struct ipoib_path *path)
262 {
263 	struct ipoib_dev_priv *priv = netdev_priv(dev);
264 	struct ipoib_neigh *neigh, *tn;
265 	struct sk_buff *skb;
266 	unsigned long flags;
267 
268 	while ((skb = __skb_dequeue(&path->queue)))
269 		dev_kfree_skb_irq(skb);
270 
271 	spin_lock_irqsave(&priv->lock, flags);
272 
273 	list_for_each_entry_safe(neigh, tn, &path->neigh_list, list) {
274 		/*
275 		 * It's safe to call ipoib_put_ah() inside priv->lock
276 		 * here, because we know that path->ah will always
277 		 * hold one more reference, so ipoib_put_ah() will
278 		 * never do more than decrement the ref count.
279 		 */
280 		if (neigh->ah)
281 			ipoib_put_ah(neigh->ah);
282 
283 		ipoib_neigh_free(dev, neigh);
284 	}
285 
286 	spin_unlock_irqrestore(&priv->lock, flags);
287 
288 	if (path->ah)
289 		ipoib_put_ah(path->ah);
290 
291 	kfree(path);
292 }
293 
294 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
295 
296 struct ipoib_path_iter *ipoib_path_iter_init(struct net_device *dev)
297 {
298 	struct ipoib_path_iter *iter;
299 
300 	iter = kmalloc(sizeof *iter, GFP_KERNEL);
301 	if (!iter)
302 		return NULL;
303 
304 	iter->dev = dev;
305 	memset(iter->path.pathrec.dgid.raw, 0, 16);
306 
307 	if (ipoib_path_iter_next(iter)) {
308 		kfree(iter);
309 		return NULL;
310 	}
311 
312 	return iter;
313 }
314 
315 int ipoib_path_iter_next(struct ipoib_path_iter *iter)
316 {
317 	struct ipoib_dev_priv *priv = netdev_priv(iter->dev);
318 	struct rb_node *n;
319 	struct ipoib_path *path;
320 	int ret = 1;
321 
322 	spin_lock_irq(&priv->lock);
323 
324 	n = rb_first(&priv->path_tree);
325 
326 	while (n) {
327 		path = rb_entry(n, struct ipoib_path, rb_node);
328 
329 		if (memcmp(iter->path.pathrec.dgid.raw, path->pathrec.dgid.raw,
330 			   sizeof (union ib_gid)) < 0) {
331 			iter->path = *path;
332 			ret = 0;
333 			break;
334 		}
335 
336 		n = rb_next(n);
337 	}
338 
339 	spin_unlock_irq(&priv->lock);
340 
341 	return ret;
342 }
343 
344 void ipoib_path_iter_read(struct ipoib_path_iter *iter,
345 			  struct ipoib_path *path)
346 {
347 	*path = iter->path;
348 }
349 
350 #endif /* CONFIG_INFINIBAND_IPOIB_DEBUG */
351 
352 void ipoib_flush_paths(struct net_device *dev)
353 {
354 	struct ipoib_dev_priv *priv = netdev_priv(dev);
355 	struct ipoib_path *path, *tp;
356 	LIST_HEAD(remove_list);
357 
358 	spin_lock_irq(&priv->tx_lock);
359 	spin_lock(&priv->lock);
360 
361 	list_splice(&priv->path_list, &remove_list);
362 	INIT_LIST_HEAD(&priv->path_list);
363 
364 	list_for_each_entry(path, &remove_list, list)
365 		rb_erase(&path->rb_node, &priv->path_tree);
366 
367 	list_for_each_entry_safe(path, tp, &remove_list, list) {
368 		if (path->query)
369 			ib_sa_cancel_query(path->query_id, path->query);
370 		spin_unlock(&priv->lock);
371 		spin_unlock_irq(&priv->tx_lock);
372 		wait_for_completion(&path->done);
373 		path_free(dev, path);
374 		spin_lock_irq(&priv->tx_lock);
375 		spin_lock(&priv->lock);
376 	}
377 	spin_unlock(&priv->lock);
378 	spin_unlock_irq(&priv->tx_lock);
379 }
380 
381 static void path_rec_completion(int status,
382 				struct ib_sa_path_rec *pathrec,
383 				void *path_ptr)
384 {
385 	struct ipoib_path *path = path_ptr;
386 	struct net_device *dev = path->dev;
387 	struct ipoib_dev_priv *priv = netdev_priv(dev);
388 	struct ipoib_ah *ah = NULL;
389 	struct ipoib_neigh *neigh, *tn;
390 	struct sk_buff_head skqueue;
391 	struct sk_buff *skb;
392 	unsigned long flags;
393 
394 	if (!status)
395 		ipoib_dbg(priv, "PathRec LID 0x%04x for GID " IPOIB_GID_FMT "\n",
396 			  be16_to_cpu(pathrec->dlid), IPOIB_GID_ARG(pathrec->dgid));
397 	else
398 		ipoib_dbg(priv, "PathRec status %d for GID " IPOIB_GID_FMT "\n",
399 			  status, IPOIB_GID_ARG(path->pathrec.dgid));
400 
401 	skb_queue_head_init(&skqueue);
402 
403 	if (!status) {
404 		struct ib_ah_attr av;
405 
406 		if (!ib_init_ah_from_path(priv->ca, priv->port, pathrec, &av))
407 			ah = ipoib_create_ah(dev, priv->pd, &av);
408 	}
409 
410 	spin_lock_irqsave(&priv->lock, flags);
411 
412 	path->ah = ah;
413 
414 	if (ah) {
415 		path->pathrec = *pathrec;
416 
417 		ipoib_dbg(priv, "created address handle %p for LID 0x%04x, SL %d\n",
418 			  ah, be16_to_cpu(pathrec->dlid), pathrec->sl);
419 
420 		while ((skb = __skb_dequeue(&path->queue)))
421 			__skb_queue_tail(&skqueue, skb);
422 
423 		list_for_each_entry_safe(neigh, tn, &path->neigh_list, list) {
424 			kref_get(&path->ah->ref);
425 			neigh->ah = path->ah;
426 			memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw,
427 			       sizeof(union ib_gid));
428 
429 			if (ipoib_cm_enabled(dev, neigh->neighbour)) {
430 				if (!ipoib_cm_get(neigh))
431 					ipoib_cm_set(neigh, ipoib_cm_create_tx(dev,
432 									       path,
433 									       neigh));
434 				if (!ipoib_cm_get(neigh)) {
435 					list_del(&neigh->list);
436 					if (neigh->ah)
437 						ipoib_put_ah(neigh->ah);
438 					ipoib_neigh_free(dev, neigh);
439 					continue;
440 				}
441 			}
442 
443 			while ((skb = __skb_dequeue(&neigh->queue)))
444 				__skb_queue_tail(&skqueue, skb);
445 		}
446 	}
447 
448 	path->query = NULL;
449 	complete(&path->done);
450 
451 	spin_unlock_irqrestore(&priv->lock, flags);
452 
453 	while ((skb = __skb_dequeue(&skqueue))) {
454 		skb->dev = dev;
455 		if (dev_queue_xmit(skb))
456 			ipoib_warn(priv, "dev_queue_xmit failed "
457 				   "to requeue packet\n");
458 	}
459 }
460 
461 static struct ipoib_path *path_rec_create(struct net_device *dev, void *gid)
462 {
463 	struct ipoib_dev_priv *priv = netdev_priv(dev);
464 	struct ipoib_path *path;
465 
466 	if (!priv->broadcast)
467 		return NULL;
468 
469 	path = kzalloc(sizeof *path, GFP_ATOMIC);
470 	if (!path)
471 		return NULL;
472 
473 	path->dev = dev;
474 
475 	skb_queue_head_init(&path->queue);
476 
477 	INIT_LIST_HEAD(&path->neigh_list);
478 
479 	memcpy(path->pathrec.dgid.raw, gid, sizeof (union ib_gid));
480 	path->pathrec.sgid	    = priv->local_gid;
481 	path->pathrec.pkey	    = cpu_to_be16(priv->pkey);
482 	path->pathrec.numb_path     = 1;
483 	path->pathrec.traffic_class = priv->broadcast->mcmember.traffic_class;
484 
485 	return path;
486 }
487 
488 static int path_rec_start(struct net_device *dev,
489 			  struct ipoib_path *path)
490 {
491 	struct ipoib_dev_priv *priv = netdev_priv(dev);
492 
493 	ipoib_dbg(priv, "Start path record lookup for " IPOIB_GID_FMT "\n",
494 		  IPOIB_GID_ARG(path->pathrec.dgid));
495 
496 	init_completion(&path->done);
497 
498 	path->query_id =
499 		ib_sa_path_rec_get(&ipoib_sa_client, priv->ca, priv->port,
500 				   &path->pathrec,
501 				   IB_SA_PATH_REC_DGID		|
502 				   IB_SA_PATH_REC_SGID		|
503 				   IB_SA_PATH_REC_NUMB_PATH	|
504 				   IB_SA_PATH_REC_TRAFFIC_CLASS |
505 				   IB_SA_PATH_REC_PKEY,
506 				   1000, GFP_ATOMIC,
507 				   path_rec_completion,
508 				   path, &path->query);
509 	if (path->query_id < 0) {
510 		ipoib_warn(priv, "ib_sa_path_rec_get failed\n");
511 		path->query = NULL;
512 		return path->query_id;
513 	}
514 
515 	return 0;
516 }
517 
518 static void neigh_add_path(struct sk_buff *skb, struct net_device *dev)
519 {
520 	struct ipoib_dev_priv *priv = netdev_priv(dev);
521 	struct ipoib_path *path;
522 	struct ipoib_neigh *neigh;
523 
524 	neigh = ipoib_neigh_alloc(skb->dst->neighbour, skb->dev);
525 	if (!neigh) {
526 		++dev->stats.tx_dropped;
527 		dev_kfree_skb_any(skb);
528 		return;
529 	}
530 
531 	/*
532 	 * We can only be called from ipoib_start_xmit, so we're
533 	 * inside tx_lock -- no need to save/restore flags.
534 	 */
535 	spin_lock(&priv->lock);
536 
537 	path = __path_find(dev, skb->dst->neighbour->ha + 4);
538 	if (!path) {
539 		path = path_rec_create(dev, skb->dst->neighbour->ha + 4);
540 		if (!path)
541 			goto err_path;
542 
543 		__path_add(dev, path);
544 	}
545 
546 	list_add_tail(&neigh->list, &path->neigh_list);
547 
548 	if (path->ah) {
549 		kref_get(&path->ah->ref);
550 		neigh->ah = path->ah;
551 		memcpy(&neigh->dgid.raw, &path->pathrec.dgid.raw,
552 		       sizeof(union ib_gid));
553 
554 		if (ipoib_cm_enabled(dev, neigh->neighbour)) {
555 			if (!ipoib_cm_get(neigh))
556 				ipoib_cm_set(neigh, ipoib_cm_create_tx(dev, path, neigh));
557 			if (!ipoib_cm_get(neigh)) {
558 				list_del(&neigh->list);
559 				if (neigh->ah)
560 					ipoib_put_ah(neigh->ah);
561 				ipoib_neigh_free(dev, neigh);
562 				goto err_drop;
563 			}
564 			if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE)
565 				__skb_queue_tail(&neigh->queue, skb);
566 			else {
567 				ipoib_warn(priv, "queue length limit %d. Packet drop.\n",
568 					   skb_queue_len(&neigh->queue));
569 				goto err_drop;
570 			}
571 		} else
572 			ipoib_send(dev, skb, path->ah, IPOIB_QPN(skb->dst->neighbour->ha));
573 	} else {
574 		neigh->ah  = NULL;
575 
576 		if (!path->query && path_rec_start(dev, path))
577 			goto err_list;
578 
579 		__skb_queue_tail(&neigh->queue, skb);
580 	}
581 
582 	spin_unlock(&priv->lock);
583 	return;
584 
585 err_list:
586 	list_del(&neigh->list);
587 
588 err_path:
589 	ipoib_neigh_free(dev, neigh);
590 err_drop:
591 	++dev->stats.tx_dropped;
592 	dev_kfree_skb_any(skb);
593 
594 	spin_unlock(&priv->lock);
595 }
596 
597 static void ipoib_path_lookup(struct sk_buff *skb, struct net_device *dev)
598 {
599 	struct ipoib_dev_priv *priv = netdev_priv(skb->dev);
600 
601 	/* Look up path record for unicasts */
602 	if (skb->dst->neighbour->ha[4] != 0xff) {
603 		neigh_add_path(skb, dev);
604 		return;
605 	}
606 
607 	/* Add in the P_Key for multicasts */
608 	skb->dst->neighbour->ha[8] = (priv->pkey >> 8) & 0xff;
609 	skb->dst->neighbour->ha[9] = priv->pkey & 0xff;
610 	ipoib_mcast_send(dev, skb->dst->neighbour->ha + 4, skb);
611 }
612 
613 static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
614 			     struct ipoib_pseudoheader *phdr)
615 {
616 	struct ipoib_dev_priv *priv = netdev_priv(dev);
617 	struct ipoib_path *path;
618 
619 	/*
620 	 * We can only be called from ipoib_start_xmit, so we're
621 	 * inside tx_lock -- no need to save/restore flags.
622 	 */
623 	spin_lock(&priv->lock);
624 
625 	path = __path_find(dev, phdr->hwaddr + 4);
626 	if (!path) {
627 		path = path_rec_create(dev, phdr->hwaddr + 4);
628 		if (path) {
629 			/* put pseudoheader back on for next time */
630 			skb_push(skb, sizeof *phdr);
631 			__skb_queue_tail(&path->queue, skb);
632 
633 			if (path_rec_start(dev, path)) {
634 				spin_unlock(&priv->lock);
635 				path_free(dev, path);
636 				return;
637 			} else
638 				__path_add(dev, path);
639 		} else {
640 			++dev->stats.tx_dropped;
641 			dev_kfree_skb_any(skb);
642 		}
643 
644 		spin_unlock(&priv->lock);
645 		return;
646 	}
647 
648 	if (path->ah) {
649 		ipoib_dbg(priv, "Send unicast ARP to %04x\n",
650 			  be16_to_cpu(path->pathrec.dlid));
651 
652 		ipoib_send(dev, skb, path->ah, IPOIB_QPN(phdr->hwaddr));
653 	} else if ((path->query || !path_rec_start(dev, path)) &&
654 		   skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
655 		/* put pseudoheader back on for next time */
656 		skb_push(skb, sizeof *phdr);
657 		__skb_queue_tail(&path->queue, skb);
658 	} else {
659 		++dev->stats.tx_dropped;
660 		dev_kfree_skb_any(skb);
661 	}
662 
663 	spin_unlock(&priv->lock);
664 }
665 
666 static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
667 {
668 	struct ipoib_dev_priv *priv = netdev_priv(dev);
669 	struct ipoib_neigh *neigh;
670 	unsigned long flags;
671 
672 	if (unlikely(!spin_trylock_irqsave(&priv->tx_lock, flags)))
673 		return NETDEV_TX_LOCKED;
674 
675 	if (likely(skb->dst && skb->dst->neighbour)) {
676 		if (unlikely(!*to_ipoib_neigh(skb->dst->neighbour))) {
677 			ipoib_path_lookup(skb, dev);
678 			goto out;
679 		}
680 
681 		neigh = *to_ipoib_neigh(skb->dst->neighbour);
682 
683 		if (ipoib_cm_get(neigh)) {
684 			if (ipoib_cm_up(neigh)) {
685 				ipoib_cm_send(dev, skb, ipoib_cm_get(neigh));
686 				goto out;
687 			}
688 		} else if (neigh->ah) {
689 			if (unlikely((memcmp(&neigh->dgid.raw,
690 					    skb->dst->neighbour->ha + 4,
691 					    sizeof(union ib_gid))) ||
692 					 (neigh->dev != dev))) {
693 				spin_lock(&priv->lock);
694 				/*
695 				 * It's safe to call ipoib_put_ah() inside
696 				 * priv->lock here, because we know that
697 				 * path->ah will always hold one more reference,
698 				 * so ipoib_put_ah() will never do more than
699 				 * decrement the ref count.
700 				 */
701 				ipoib_put_ah(neigh->ah);
702 				list_del(&neigh->list);
703 				ipoib_neigh_free(dev, neigh);
704 				spin_unlock(&priv->lock);
705 				ipoib_path_lookup(skb, dev);
706 				goto out;
707 			}
708 
709 			ipoib_send(dev, skb, neigh->ah, IPOIB_QPN(skb->dst->neighbour->ha));
710 			goto out;
711 		}
712 
713 		if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
714 			spin_lock(&priv->lock);
715 			__skb_queue_tail(&neigh->queue, skb);
716 			spin_unlock(&priv->lock);
717 		} else {
718 			++dev->stats.tx_dropped;
719 			dev_kfree_skb_any(skb);
720 		}
721 	} else {
722 		struct ipoib_pseudoheader *phdr =
723 			(struct ipoib_pseudoheader *) skb->data;
724 		skb_pull(skb, sizeof *phdr);
725 
726 		if (phdr->hwaddr[4] == 0xff) {
727 			/* Add in the P_Key for multicast*/
728 			phdr->hwaddr[8] = (priv->pkey >> 8) & 0xff;
729 			phdr->hwaddr[9] = priv->pkey & 0xff;
730 
731 			ipoib_mcast_send(dev, phdr->hwaddr + 4, skb);
732 		} else {
733 			/* unicast GID -- should be ARP or RARP reply */
734 
735 			if ((be16_to_cpup((__be16 *) skb->data) != ETH_P_ARP) &&
736 			    (be16_to_cpup((__be16 *) skb->data) != ETH_P_RARP)) {
737 				ipoib_warn(priv, "Unicast, no %s: type %04x, QPN %06x "
738 					   IPOIB_GID_FMT "\n",
739 					   skb->dst ? "neigh" : "dst",
740 					   be16_to_cpup((__be16 *) skb->data),
741 					   IPOIB_QPN(phdr->hwaddr),
742 					   IPOIB_GID_RAW_ARG(phdr->hwaddr + 4));
743 				dev_kfree_skb_any(skb);
744 				++dev->stats.tx_dropped;
745 				goto out;
746 			}
747 
748 			unicast_arp_send(skb, dev, phdr);
749 		}
750 	}
751 
752 out:
753 	spin_unlock_irqrestore(&priv->tx_lock, flags);
754 
755 	return NETDEV_TX_OK;
756 }
757 
758 static void ipoib_timeout(struct net_device *dev)
759 {
760 	struct ipoib_dev_priv *priv = netdev_priv(dev);
761 
762 	ipoib_warn(priv, "transmit timeout: latency %d msecs\n",
763 		   jiffies_to_msecs(jiffies - dev->trans_start));
764 	ipoib_warn(priv, "queue stopped %d, tx_head %u, tx_tail %u\n",
765 		   netif_queue_stopped(dev),
766 		   priv->tx_head, priv->tx_tail);
767 	/* XXX reset QP, etc. */
768 }
769 
770 static int ipoib_hard_header(struct sk_buff *skb,
771 			     struct net_device *dev,
772 			     unsigned short type,
773 			     const void *daddr, const void *saddr, unsigned len)
774 {
775 	struct ipoib_header *header;
776 
777 	header = (struct ipoib_header *) skb_push(skb, sizeof *header);
778 
779 	header->proto = htons(type);
780 	header->reserved = 0;
781 
782 	/*
783 	 * If we don't have a neighbour structure, stuff the
784 	 * destination address onto the front of the skb so we can
785 	 * figure out where to send the packet later.
786 	 */
787 	if ((!skb->dst || !skb->dst->neighbour) && daddr) {
788 		struct ipoib_pseudoheader *phdr =
789 			(struct ipoib_pseudoheader *) skb_push(skb, sizeof *phdr);
790 		memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
791 	}
792 
793 	return 0;
794 }
795 
796 static void ipoib_set_mcast_list(struct net_device *dev)
797 {
798 	struct ipoib_dev_priv *priv = netdev_priv(dev);
799 
800 	if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) {
801 		ipoib_dbg(priv, "IPOIB_FLAG_OPER_UP not set");
802 		return;
803 	}
804 
805 	queue_work(ipoib_workqueue, &priv->restart_task);
806 }
807 
808 static void ipoib_neigh_cleanup(struct neighbour *n)
809 {
810 	struct ipoib_neigh *neigh;
811 	struct ipoib_dev_priv *priv = netdev_priv(n->dev);
812 	unsigned long flags;
813 	struct ipoib_ah *ah = NULL;
814 
815 	neigh = *to_ipoib_neigh(n);
816 	if (neigh) {
817 		priv = netdev_priv(neigh->dev);
818 		ipoib_dbg(priv, "neigh_destructor for bonding device: %s\n",
819 			  n->dev->name);
820 	} else
821 		return;
822 	ipoib_dbg(priv,
823 		  "neigh_cleanup for %06x " IPOIB_GID_FMT "\n",
824 		  IPOIB_QPN(n->ha),
825 		  IPOIB_GID_RAW_ARG(n->ha + 4));
826 
827 	spin_lock_irqsave(&priv->lock, flags);
828 
829 	if (neigh->ah)
830 		ah = neigh->ah;
831 	list_del(&neigh->list);
832 	ipoib_neigh_free(n->dev, neigh);
833 
834 	spin_unlock_irqrestore(&priv->lock, flags);
835 
836 	if (ah)
837 		ipoib_put_ah(ah);
838 }
839 
840 struct ipoib_neigh *ipoib_neigh_alloc(struct neighbour *neighbour,
841 				      struct net_device *dev)
842 {
843 	struct ipoib_neigh *neigh;
844 
845 	neigh = kmalloc(sizeof *neigh, GFP_ATOMIC);
846 	if (!neigh)
847 		return NULL;
848 
849 	neigh->neighbour = neighbour;
850 	neigh->dev = dev;
851 	*to_ipoib_neigh(neighbour) = neigh;
852 	skb_queue_head_init(&neigh->queue);
853 	ipoib_cm_set(neigh, NULL);
854 
855 	return neigh;
856 }
857 
858 void ipoib_neigh_free(struct net_device *dev, struct ipoib_neigh *neigh)
859 {
860 	struct sk_buff *skb;
861 	*to_ipoib_neigh(neigh->neighbour) = NULL;
862 	while ((skb = __skb_dequeue(&neigh->queue))) {
863 		++dev->stats.tx_dropped;
864 		dev_kfree_skb_any(skb);
865 	}
866 	if (ipoib_cm_get(neigh))
867 		ipoib_cm_destroy_tx(ipoib_cm_get(neigh));
868 	kfree(neigh);
869 }
870 
871 static int ipoib_neigh_setup_dev(struct net_device *dev, struct neigh_parms *parms)
872 {
873 	parms->neigh_cleanup = ipoib_neigh_cleanup;
874 
875 	return 0;
876 }
877 
878 int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
879 {
880 	struct ipoib_dev_priv *priv = netdev_priv(dev);
881 
882 	/* Allocate RX/TX "rings" to hold queued skbs */
883 	priv->rx_ring =	kzalloc(ipoib_recvq_size * sizeof *priv->rx_ring,
884 				GFP_KERNEL);
885 	if (!priv->rx_ring) {
886 		printk(KERN_WARNING "%s: failed to allocate RX ring (%d entries)\n",
887 		       ca->name, ipoib_recvq_size);
888 		goto out;
889 	}
890 
891 	priv->tx_ring = kzalloc(ipoib_sendq_size * sizeof *priv->tx_ring,
892 				GFP_KERNEL);
893 	if (!priv->tx_ring) {
894 		printk(KERN_WARNING "%s: failed to allocate TX ring (%d entries)\n",
895 		       ca->name, ipoib_sendq_size);
896 		goto out_rx_ring_cleanup;
897 	}
898 
899 	/* priv->tx_head, tx_tail & tx_outstanding are already 0 */
900 
901 	if (ipoib_ib_dev_init(dev, ca, port))
902 		goto out_tx_ring_cleanup;
903 
904 	return 0;
905 
906 out_tx_ring_cleanup:
907 	kfree(priv->tx_ring);
908 
909 out_rx_ring_cleanup:
910 	kfree(priv->rx_ring);
911 
912 out:
913 	return -ENOMEM;
914 }
915 
916 void ipoib_dev_cleanup(struct net_device *dev)
917 {
918 	struct ipoib_dev_priv *priv = netdev_priv(dev), *cpriv, *tcpriv;
919 
920 	ipoib_delete_debug_files(dev);
921 
922 	/* Delete any child interfaces first */
923 	list_for_each_entry_safe(cpriv, tcpriv, &priv->child_intfs, list) {
924 		unregister_netdev(cpriv->dev);
925 		ipoib_dev_cleanup(cpriv->dev);
926 		free_netdev(cpriv->dev);
927 	}
928 
929 	ipoib_ib_dev_cleanup(dev);
930 
931 	kfree(priv->rx_ring);
932 	kfree(priv->tx_ring);
933 
934 	priv->rx_ring = NULL;
935 	priv->tx_ring = NULL;
936 }
937 
938 static const struct header_ops ipoib_header_ops = {
939 	.create	= ipoib_hard_header,
940 };
941 
942 static void ipoib_setup(struct net_device *dev)
943 {
944 	struct ipoib_dev_priv *priv = netdev_priv(dev);
945 
946 	dev->open		 = ipoib_open;
947 	dev->stop		 = ipoib_stop;
948 	dev->change_mtu		 = ipoib_change_mtu;
949 	dev->hard_start_xmit	 = ipoib_start_xmit;
950 	dev->tx_timeout		 = ipoib_timeout;
951 	dev->header_ops		 = &ipoib_header_ops;
952 	dev->set_multicast_list	 = ipoib_set_mcast_list;
953 	dev->neigh_setup	 = ipoib_neigh_setup_dev;
954 
955 	netif_napi_add(dev, &priv->napi, ipoib_poll, 100);
956 
957 	dev->watchdog_timeo	 = HZ;
958 
959 	dev->flags		|= IFF_BROADCAST | IFF_MULTICAST;
960 
961 	/*
962 	 * We add in INFINIBAND_ALEN to allow for the destination
963 	 * address "pseudoheader" for skbs without neighbour struct.
964 	 */
965 	dev->hard_header_len	 = IPOIB_ENCAP_LEN + INFINIBAND_ALEN;
966 	dev->addr_len		 = INFINIBAND_ALEN;
967 	dev->type		 = ARPHRD_INFINIBAND;
968 	dev->tx_queue_len	 = ipoib_sendq_size * 2;
969 	dev->features		 = NETIF_F_VLAN_CHALLENGED | NETIF_F_LLTX;
970 
971 	/* MTU will be reset when mcast join happens */
972 	dev->mtu		 = IPOIB_PACKET_SIZE - IPOIB_ENCAP_LEN;
973 	priv->mcast_mtu		 = priv->admin_mtu = dev->mtu;
974 
975 	memcpy(dev->broadcast, ipv4_bcast_addr, INFINIBAND_ALEN);
976 
977 	netif_carrier_off(dev);
978 
979 	priv->dev = dev;
980 
981 	spin_lock_init(&priv->lock);
982 	spin_lock_init(&priv->tx_lock);
983 
984 	mutex_init(&priv->mcast_mutex);
985 	mutex_init(&priv->vlan_mutex);
986 
987 	INIT_LIST_HEAD(&priv->path_list);
988 	INIT_LIST_HEAD(&priv->child_intfs);
989 	INIT_LIST_HEAD(&priv->dead_ahs);
990 	INIT_LIST_HEAD(&priv->multicast_list);
991 
992 	INIT_DELAYED_WORK(&priv->pkey_poll_task, ipoib_pkey_poll);
993 	INIT_WORK(&priv->pkey_event_task, ipoib_pkey_event);
994 	INIT_DELAYED_WORK(&priv->mcast_task,   ipoib_mcast_join_task);
995 	INIT_WORK(&priv->flush_task,   ipoib_ib_dev_flush);
996 	INIT_WORK(&priv->restart_task, ipoib_mcast_restart_task);
997 	INIT_DELAYED_WORK(&priv->ah_reap_task, ipoib_reap_ah);
998 }
999 
1000 struct ipoib_dev_priv *ipoib_intf_alloc(const char *name)
1001 {
1002 	struct net_device *dev;
1003 
1004 	dev = alloc_netdev((int) sizeof (struct ipoib_dev_priv), name,
1005 			   ipoib_setup);
1006 	if (!dev)
1007 		return NULL;
1008 
1009 	return netdev_priv(dev);
1010 }
1011 
1012 static ssize_t show_pkey(struct device *dev,
1013 			 struct device_attribute *attr, char *buf)
1014 {
1015 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));
1016 
1017 	return sprintf(buf, "0x%04x\n", priv->pkey);
1018 }
1019 static DEVICE_ATTR(pkey, S_IRUGO, show_pkey, NULL);
1020 
1021 static ssize_t show_umcast(struct device *dev,
1022 			   struct device_attribute *attr, char *buf)
1023 {
1024 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));
1025 
1026 	return sprintf(buf, "%d\n", test_bit(IPOIB_FLAG_UMCAST, &priv->flags));
1027 }
1028 
1029 static ssize_t set_umcast(struct device *dev,
1030 			  struct device_attribute *attr,
1031 			  const char *buf, size_t count)
1032 {
1033 	struct ipoib_dev_priv *priv = netdev_priv(to_net_dev(dev));
1034 	unsigned long umcast_val = simple_strtoul(buf, NULL, 0);
1035 
1036 	if (umcast_val > 0) {
1037 		set_bit(IPOIB_FLAG_UMCAST, &priv->flags);
1038 		ipoib_warn(priv, "ignoring multicast groups joined directly "
1039 				"by userspace\n");
1040 	} else
1041 		clear_bit(IPOIB_FLAG_UMCAST, &priv->flags);
1042 
1043 	return count;
1044 }
1045 static DEVICE_ATTR(umcast, S_IWUSR | S_IRUGO, show_umcast, set_umcast);
1046 
1047 int ipoib_add_umcast_attr(struct net_device *dev)
1048 {
1049 	return device_create_file(&dev->dev, &dev_attr_umcast);
1050 }
1051 
1052 static ssize_t create_child(struct device *dev,
1053 			    struct device_attribute *attr,
1054 			    const char *buf, size_t count)
1055 {
1056 	int pkey;
1057 	int ret;
1058 
1059 	if (sscanf(buf, "%i", &pkey) != 1)
1060 		return -EINVAL;
1061 
1062 	if (pkey < 0 || pkey > 0xffff)
1063 		return -EINVAL;
1064 
1065 	/*
1066 	 * Set the full membership bit, so that we join the right
1067 	 * broadcast group, etc.
1068 	 */
1069 	pkey |= 0x8000;
1070 
1071 	ret = ipoib_vlan_add(to_net_dev(dev), pkey);
1072 
1073 	return ret ? ret : count;
1074 }
1075 static DEVICE_ATTR(create_child, S_IWUGO, NULL, create_child);
1076 
1077 static ssize_t delete_child(struct device *dev,
1078 			    struct device_attribute *attr,
1079 			    const char *buf, size_t count)
1080 {
1081 	int pkey;
1082 	int ret;
1083 
1084 	if (sscanf(buf, "%i", &pkey) != 1)
1085 		return -EINVAL;
1086 
1087 	if (pkey < 0 || pkey > 0xffff)
1088 		return -EINVAL;
1089 
1090 	ret = ipoib_vlan_delete(to_net_dev(dev), pkey);
1091 
1092 	return ret ? ret : count;
1093 
1094 }
1095 static DEVICE_ATTR(delete_child, S_IWUGO, NULL, delete_child);
1096 
1097 int ipoib_add_pkey_attr(struct net_device *dev)
1098 {
1099 	return device_create_file(&dev->dev, &dev_attr_pkey);
1100 }
1101 
1102 static struct net_device *ipoib_add_port(const char *format,
1103 					 struct ib_device *hca, u8 port)
1104 {
1105 	struct ipoib_dev_priv *priv;
1106 	int result = -ENOMEM;
1107 
1108 	priv = ipoib_intf_alloc(format);
1109 	if (!priv)
1110 		goto alloc_mem_failed;
1111 
1112 	SET_NETDEV_DEV(priv->dev, hca->dma_device);
1113 
1114 	result = ib_query_pkey(hca, port, 0, &priv->pkey);
1115 	if (result) {
1116 		printk(KERN_WARNING "%s: ib_query_pkey port %d failed (ret = %d)\n",
1117 		       hca->name, port, result);
1118 		goto device_init_failed;
1119 	}
1120 
1121 	/*
1122 	 * Set the full membership bit, so that we join the right
1123 	 * broadcast group, etc.
1124 	 */
1125 	priv->pkey |= 0x8000;
1126 
1127 	priv->dev->broadcast[8] = priv->pkey >> 8;
1128 	priv->dev->broadcast[9] = priv->pkey & 0xff;
1129 
1130 	result = ib_query_gid(hca, port, 0, &priv->local_gid);
1131 	if (result) {
1132 		printk(KERN_WARNING "%s: ib_query_gid port %d failed (ret = %d)\n",
1133 		       hca->name, port, result);
1134 		goto device_init_failed;
1135 	} else
1136 		memcpy(priv->dev->dev_addr + 4, priv->local_gid.raw, sizeof (union ib_gid));
1137 
1138 
1139 	result = ipoib_dev_init(priv->dev, hca, port);
1140 	if (result < 0) {
1141 		printk(KERN_WARNING "%s: failed to initialize port %d (ret = %d)\n",
1142 		       hca->name, port, result);
1143 		goto device_init_failed;
1144 	}
1145 
1146 	INIT_IB_EVENT_HANDLER(&priv->event_handler,
1147 			      priv->ca, ipoib_event);
1148 	result = ib_register_event_handler(&priv->event_handler);
1149 	if (result < 0) {
1150 		printk(KERN_WARNING "%s: ib_register_event_handler failed for "
1151 		       "port %d (ret = %d)\n",
1152 		       hca->name, port, result);
1153 		goto event_failed;
1154 	}
1155 
1156 	result = register_netdev(priv->dev);
1157 	if (result) {
1158 		printk(KERN_WARNING "%s: couldn't register ipoib port %d; error %d\n",
1159 		       hca->name, port, result);
1160 		goto register_failed;
1161 	}
1162 
1163 	ipoib_create_debug_files(priv->dev);
1164 
1165 	if (ipoib_cm_add_mode_attr(priv->dev))
1166 		goto sysfs_failed;
1167 	if (ipoib_add_pkey_attr(priv->dev))
1168 		goto sysfs_failed;
1169 	if (ipoib_add_umcast_attr(priv->dev))
1170 		goto sysfs_failed;
1171 	if (device_create_file(&priv->dev->dev, &dev_attr_create_child))
1172 		goto sysfs_failed;
1173 	if (device_create_file(&priv->dev->dev, &dev_attr_delete_child))
1174 		goto sysfs_failed;
1175 
1176 	return priv->dev;
1177 
1178 sysfs_failed:
1179 	ipoib_delete_debug_files(priv->dev);
1180 	unregister_netdev(priv->dev);
1181 
1182 register_failed:
1183 	ib_unregister_event_handler(&priv->event_handler);
1184 	flush_scheduled_work();
1185 
1186 event_failed:
1187 	ipoib_dev_cleanup(priv->dev);
1188 
1189 device_init_failed:
1190 	free_netdev(priv->dev);
1191 
1192 alloc_mem_failed:
1193 	return ERR_PTR(result);
1194 }
1195 
1196 static void ipoib_add_one(struct ib_device *device)
1197 {
1198 	struct list_head *dev_list;
1199 	struct net_device *dev;
1200 	struct ipoib_dev_priv *priv;
1201 	int s, e, p;
1202 
1203 	if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
1204 		return;
1205 
1206 	dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
1207 	if (!dev_list)
1208 		return;
1209 
1210 	INIT_LIST_HEAD(dev_list);
1211 
1212 	if (device->node_type == RDMA_NODE_IB_SWITCH) {
1213 		s = 0;
1214 		e = 0;
1215 	} else {
1216 		s = 1;
1217 		e = device->phys_port_cnt;
1218 	}
1219 
1220 	for (p = s; p <= e; ++p) {
1221 		dev = ipoib_add_port("ib%d", device, p);
1222 		if (!IS_ERR(dev)) {
1223 			priv = netdev_priv(dev);
1224 			list_add_tail(&priv->list, dev_list);
1225 		}
1226 	}
1227 
1228 	ib_set_client_data(device, &ipoib_client, dev_list);
1229 }
1230 
1231 static void ipoib_remove_one(struct ib_device *device)
1232 {
1233 	struct ipoib_dev_priv *priv, *tmp;
1234 	struct list_head *dev_list;
1235 
1236 	if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
1237 		return;
1238 
1239 	dev_list = ib_get_client_data(device, &ipoib_client);
1240 
1241 	list_for_each_entry_safe(priv, tmp, dev_list, list) {
1242 		ib_unregister_event_handler(&priv->event_handler);
1243 		flush_scheduled_work();
1244 
1245 		unregister_netdev(priv->dev);
1246 		ipoib_dev_cleanup(priv->dev);
1247 		free_netdev(priv->dev);
1248 	}
1249 
1250 	kfree(dev_list);
1251 }
1252 
1253 static int __init ipoib_init_module(void)
1254 {
1255 	int ret;
1256 
1257 	ipoib_recvq_size = roundup_pow_of_two(ipoib_recvq_size);
1258 	ipoib_recvq_size = min(ipoib_recvq_size, IPOIB_MAX_QUEUE_SIZE);
1259 	ipoib_recvq_size = max(ipoib_recvq_size, IPOIB_MIN_QUEUE_SIZE);
1260 
1261 	ipoib_sendq_size = roundup_pow_of_two(ipoib_sendq_size);
1262 	ipoib_sendq_size = min(ipoib_sendq_size, IPOIB_MAX_QUEUE_SIZE);
1263 	ipoib_sendq_size = max(ipoib_sendq_size, IPOIB_MIN_QUEUE_SIZE);
1264 #ifdef CONFIG_INFINIBAND_IPOIB_CM
1265 	ipoib_max_conn_qp = min(ipoib_max_conn_qp, IPOIB_CM_MAX_CONN_QP);
1266 #endif
1267 
1268 	ret = ipoib_register_debugfs();
1269 	if (ret)
1270 		return ret;
1271 
1272 	/*
1273 	 * We create our own workqueue mainly because we want to be
1274 	 * able to flush it when devices are being removed.  We can't
1275 	 * use schedule_work()/flush_scheduled_work() because both
1276 	 * unregister_netdev() and linkwatch_event take the rtnl lock,
1277 	 * so flush_scheduled_work() can deadlock during device
1278 	 * removal.
1279 	 */
1280 	ipoib_workqueue = create_singlethread_workqueue("ipoib");
1281 	if (!ipoib_workqueue) {
1282 		ret = -ENOMEM;
1283 		goto err_fs;
1284 	}
1285 
1286 	ib_sa_register_client(&ipoib_sa_client);
1287 
1288 	ret = ib_register_client(&ipoib_client);
1289 	if (ret)
1290 		goto err_sa;
1291 
1292 	return 0;
1293 
1294 err_sa:
1295 	ib_sa_unregister_client(&ipoib_sa_client);
1296 	destroy_workqueue(ipoib_workqueue);
1297 
1298 err_fs:
1299 	ipoib_unregister_debugfs();
1300 
1301 	return ret;
1302 }
1303 
1304 static void __exit ipoib_cleanup_module(void)
1305 {
1306 	ib_unregister_client(&ipoib_client);
1307 	ib_sa_unregister_client(&ipoib_sa_client);
1308 	ipoib_unregister_debugfs();
1309 	destroy_workqueue(ipoib_workqueue);
1310 }
1311 
1312 module_init(ipoib_init_module);
1313 module_exit(ipoib_cleanup_module);
1314