1 /*
2  * Copyright (c) 2006 Intel Corporation.  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/completion.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/err.h>
36 #include <linux/interrupt.h>
37 #include <linux/bitops.h>
38 #include <linux/random.h>
39 
40 #include <rdma/ib_cache.h>
41 #include "sa.h"
42 
43 static void mcast_add_one(struct ib_device *device);
44 static void mcast_remove_one(struct ib_device *device);
45 
46 static struct ib_client mcast_client = {
47 	.name   = "ib_multicast",
48 	.add    = mcast_add_one,
49 	.remove = mcast_remove_one
50 };
51 
52 static struct ib_sa_client	sa_client;
53 static struct workqueue_struct	*mcast_wq;
54 static union ib_gid mgid0;
55 
56 struct mcast_device;
57 
58 struct mcast_port {
59 	struct mcast_device	*dev;
60 	spinlock_t		lock;
61 	struct rb_root		table;
62 	atomic_t		refcount;
63 	struct completion	comp;
64 	u8			port_num;
65 };
66 
67 struct mcast_device {
68 	struct ib_device	*device;
69 	struct ib_event_handler	event_handler;
70 	int			start_port;
71 	int			end_port;
72 	struct mcast_port	port[0];
73 };
74 
75 enum mcast_state {
76 	MCAST_JOINING,
77 	MCAST_MEMBER,
78 	MCAST_ERROR,
79 };
80 
81 enum mcast_group_state {
82 	MCAST_IDLE,
83 	MCAST_BUSY,
84 	MCAST_GROUP_ERROR,
85 	MCAST_PKEY_EVENT
86 };
87 
88 enum {
89 	MCAST_INVALID_PKEY_INDEX = 0xFFFF
90 };
91 
92 struct mcast_member;
93 
94 struct mcast_group {
95 	struct ib_sa_mcmember_rec rec;
96 	struct rb_node		node;
97 	struct mcast_port	*port;
98 	spinlock_t		lock;
99 	struct work_struct	work;
100 	struct list_head	pending_list;
101 	struct list_head	active_list;
102 	struct mcast_member	*last_join;
103 	int			members[3];
104 	atomic_t		refcount;
105 	enum mcast_group_state	state;
106 	struct ib_sa_query	*query;
107 	int			query_id;
108 	u16			pkey_index;
109 	u8			leave_state;
110 	int			retries;
111 };
112 
113 struct mcast_member {
114 	struct ib_sa_multicast	multicast;
115 	struct ib_sa_client	*client;
116 	struct mcast_group	*group;
117 	struct list_head	list;
118 	enum mcast_state	state;
119 	atomic_t		refcount;
120 	struct completion	comp;
121 };
122 
123 static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
124 			 void *context);
125 static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
126 			  void *context);
127 
128 static struct mcast_group *mcast_find(struct mcast_port *port,
129 				      union ib_gid *mgid)
130 {
131 	struct rb_node *node = port->table.rb_node;
132 	struct mcast_group *group;
133 	int ret;
134 
135 	while (node) {
136 		group = rb_entry(node, struct mcast_group, node);
137 		ret = memcmp(mgid->raw, group->rec.mgid.raw, sizeof *mgid);
138 		if (!ret)
139 			return group;
140 
141 		if (ret < 0)
142 			node = node->rb_left;
143 		else
144 			node = node->rb_right;
145 	}
146 	return NULL;
147 }
148 
149 static struct mcast_group *mcast_insert(struct mcast_port *port,
150 					struct mcast_group *group,
151 					int allow_duplicates)
152 {
153 	struct rb_node **link = &port->table.rb_node;
154 	struct rb_node *parent = NULL;
155 	struct mcast_group *cur_group;
156 	int ret;
157 
158 	while (*link) {
159 		parent = *link;
160 		cur_group = rb_entry(parent, struct mcast_group, node);
161 
162 		ret = memcmp(group->rec.mgid.raw, cur_group->rec.mgid.raw,
163 			     sizeof group->rec.mgid);
164 		if (ret < 0)
165 			link = &(*link)->rb_left;
166 		else if (ret > 0)
167 			link = &(*link)->rb_right;
168 		else if (allow_duplicates)
169 			link = &(*link)->rb_left;
170 		else
171 			return cur_group;
172 	}
173 	rb_link_node(&group->node, parent, link);
174 	rb_insert_color(&group->node, &port->table);
175 	return NULL;
176 }
177 
178 static void deref_port(struct mcast_port *port)
179 {
180 	if (atomic_dec_and_test(&port->refcount))
181 		complete(&port->comp);
182 }
183 
184 static void release_group(struct mcast_group *group)
185 {
186 	struct mcast_port *port = group->port;
187 	unsigned long flags;
188 
189 	spin_lock_irqsave(&port->lock, flags);
190 	if (atomic_dec_and_test(&group->refcount)) {
191 		rb_erase(&group->node, &port->table);
192 		spin_unlock_irqrestore(&port->lock, flags);
193 		kfree(group);
194 		deref_port(port);
195 	} else
196 		spin_unlock_irqrestore(&port->lock, flags);
197 }
198 
199 static void deref_member(struct mcast_member *member)
200 {
201 	if (atomic_dec_and_test(&member->refcount))
202 		complete(&member->comp);
203 }
204 
205 static void queue_join(struct mcast_member *member)
206 {
207 	struct mcast_group *group = member->group;
208 	unsigned long flags;
209 
210 	spin_lock_irqsave(&group->lock, flags);
211 	list_add_tail(&member->list, &group->pending_list);
212 	if (group->state == MCAST_IDLE) {
213 		group->state = MCAST_BUSY;
214 		atomic_inc(&group->refcount);
215 		queue_work(mcast_wq, &group->work);
216 	}
217 	spin_unlock_irqrestore(&group->lock, flags);
218 }
219 
220 /*
221  * A multicast group has three types of members: full member, non member, and
222  * send only member.  We need to keep track of the number of members of each
223  * type based on their join state.  Adjust the number of members the belong to
224  * the specified join states.
225  */
226 static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
227 {
228 	int i;
229 
230 	for (i = 0; i < 3; i++, join_state >>= 1)
231 		if (join_state & 0x1)
232 			group->members[i] += inc;
233 }
234 
235 /*
236  * If a multicast group has zero members left for a particular join state, but
237  * the group is still a member with the SA, we need to leave that join state.
238  * Determine which join states we still belong to, but that do not have any
239  * active members.
240  */
241 static u8 get_leave_state(struct mcast_group *group)
242 {
243 	u8 leave_state = 0;
244 	int i;
245 
246 	for (i = 0; i < 3; i++)
247 		if (!group->members[i])
248 			leave_state |= (0x1 << i);
249 
250 	return leave_state & group->rec.join_state;
251 }
252 
253 static int check_selector(ib_sa_comp_mask comp_mask,
254 			  ib_sa_comp_mask selector_mask,
255 			  ib_sa_comp_mask value_mask,
256 			  u8 selector, u8 src_value, u8 dst_value)
257 {
258 	int err;
259 
260 	if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
261 		return 0;
262 
263 	switch (selector) {
264 	case IB_SA_GT:
265 		err = (src_value <= dst_value);
266 		break;
267 	case IB_SA_LT:
268 		err = (src_value >= dst_value);
269 		break;
270 	case IB_SA_EQ:
271 		err = (src_value != dst_value);
272 		break;
273 	default:
274 		err = 0;
275 		break;
276 	}
277 
278 	return err;
279 }
280 
281 static int cmp_rec(struct ib_sa_mcmember_rec *src,
282 		   struct ib_sa_mcmember_rec *dst, ib_sa_comp_mask comp_mask)
283 {
284 	/* MGID must already match */
285 
286 	if (comp_mask & IB_SA_MCMEMBER_REC_PORT_GID &&
287 	    memcmp(&src->port_gid, &dst->port_gid, sizeof src->port_gid))
288 		return -EINVAL;
289 	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
290 		return -EINVAL;
291 	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
292 		return -EINVAL;
293 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
294 			   IB_SA_MCMEMBER_REC_MTU, dst->mtu_selector,
295 			   src->mtu, dst->mtu))
296 		return -EINVAL;
297 	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
298 	    src->traffic_class != dst->traffic_class)
299 		return -EINVAL;
300 	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
301 		return -EINVAL;
302 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
303 			   IB_SA_MCMEMBER_REC_RATE, dst->rate_selector,
304 			   src->rate, dst->rate))
305 		return -EINVAL;
306 	if (check_selector(comp_mask,
307 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
308 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
309 			   dst->packet_life_time_selector,
310 			   src->packet_life_time, dst->packet_life_time))
311 		return -EINVAL;
312 	if (comp_mask & IB_SA_MCMEMBER_REC_SL && src->sl != dst->sl)
313 		return -EINVAL;
314 	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
315 	    src->flow_label != dst->flow_label)
316 		return -EINVAL;
317 	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
318 	    src->hop_limit != dst->hop_limit)
319 		return -EINVAL;
320 	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE && src->scope != dst->scope)
321 		return -EINVAL;
322 
323 	/* join_state checked separately, proxy_join ignored */
324 
325 	return 0;
326 }
327 
328 static int send_join(struct mcast_group *group, struct mcast_member *member)
329 {
330 	struct mcast_port *port = group->port;
331 	int ret;
332 
333 	group->last_join = member;
334 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
335 				       port->port_num, IB_MGMT_METHOD_SET,
336 				       &member->multicast.rec,
337 				       member->multicast.comp_mask,
338 				       3000, GFP_KERNEL, join_handler, group,
339 				       &group->query);
340 	if (ret >= 0) {
341 		group->query_id = ret;
342 		ret = 0;
343 	}
344 	return ret;
345 }
346 
347 static int send_leave(struct mcast_group *group, u8 leave_state)
348 {
349 	struct mcast_port *port = group->port;
350 	struct ib_sa_mcmember_rec rec;
351 	int ret;
352 
353 	rec = group->rec;
354 	rec.join_state = leave_state;
355 	group->leave_state = leave_state;
356 
357 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
358 				       port->port_num, IB_SA_METHOD_DELETE, &rec,
359 				       IB_SA_MCMEMBER_REC_MGID     |
360 				       IB_SA_MCMEMBER_REC_PORT_GID |
361 				       IB_SA_MCMEMBER_REC_JOIN_STATE,
362 				       3000, GFP_KERNEL, leave_handler,
363 				       group, &group->query);
364 	if (ret >= 0) {
365 		group->query_id = ret;
366 		ret = 0;
367 	}
368 	return ret;
369 }
370 
371 static void join_group(struct mcast_group *group, struct mcast_member *member,
372 		       u8 join_state)
373 {
374 	member->state = MCAST_MEMBER;
375 	adjust_membership(group, join_state, 1);
376 	group->rec.join_state |= join_state;
377 	member->multicast.rec = group->rec;
378 	member->multicast.rec.join_state = join_state;
379 	list_move(&member->list, &group->active_list);
380 }
381 
382 static int fail_join(struct mcast_group *group, struct mcast_member *member,
383 		     int status)
384 {
385 	spin_lock_irq(&group->lock);
386 	list_del_init(&member->list);
387 	spin_unlock_irq(&group->lock);
388 	return member->multicast.callback(status, &member->multicast);
389 }
390 
391 static void process_group_error(struct mcast_group *group)
392 {
393 	struct mcast_member *member;
394 	int ret = 0;
395 	u16 pkey_index;
396 
397 	if (group->state == MCAST_PKEY_EVENT)
398 		ret = ib_find_pkey(group->port->dev->device,
399 				   group->port->port_num,
400 				   be16_to_cpu(group->rec.pkey), &pkey_index);
401 
402 	spin_lock_irq(&group->lock);
403 	if (group->state == MCAST_PKEY_EVENT && !ret &&
404 	    group->pkey_index == pkey_index)
405 		goto out;
406 
407 	while (!list_empty(&group->active_list)) {
408 		member = list_entry(group->active_list.next,
409 				    struct mcast_member, list);
410 		atomic_inc(&member->refcount);
411 		list_del_init(&member->list);
412 		adjust_membership(group, member->multicast.rec.join_state, -1);
413 		member->state = MCAST_ERROR;
414 		spin_unlock_irq(&group->lock);
415 
416 		ret = member->multicast.callback(-ENETRESET,
417 						 &member->multicast);
418 		deref_member(member);
419 		if (ret)
420 			ib_sa_free_multicast(&member->multicast);
421 		spin_lock_irq(&group->lock);
422 	}
423 
424 	group->rec.join_state = 0;
425 out:
426 	group->state = MCAST_BUSY;
427 	spin_unlock_irq(&group->lock);
428 }
429 
430 static void mcast_work_handler(struct work_struct *work)
431 {
432 	struct mcast_group *group;
433 	struct mcast_member *member;
434 	struct ib_sa_multicast *multicast;
435 	int status, ret;
436 	u8 join_state;
437 
438 	group = container_of(work, typeof(*group), work);
439 retest:
440 	spin_lock_irq(&group->lock);
441 	while (!list_empty(&group->pending_list) ||
442 	       (group->state != MCAST_BUSY)) {
443 
444 		if (group->state != MCAST_BUSY) {
445 			spin_unlock_irq(&group->lock);
446 			process_group_error(group);
447 			goto retest;
448 		}
449 
450 		member = list_entry(group->pending_list.next,
451 				    struct mcast_member, list);
452 		multicast = &member->multicast;
453 		join_state = multicast->rec.join_state;
454 		atomic_inc(&member->refcount);
455 
456 		if (join_state == (group->rec.join_state & join_state)) {
457 			status = cmp_rec(&group->rec, &multicast->rec,
458 					 multicast->comp_mask);
459 			if (!status)
460 				join_group(group, member, join_state);
461 			else
462 				list_del_init(&member->list);
463 			spin_unlock_irq(&group->lock);
464 			ret = multicast->callback(status, multicast);
465 		} else {
466 			spin_unlock_irq(&group->lock);
467 			status = send_join(group, member);
468 			if (!status) {
469 				deref_member(member);
470 				return;
471 			}
472 			ret = fail_join(group, member, status);
473 		}
474 
475 		deref_member(member);
476 		if (ret)
477 			ib_sa_free_multicast(&member->multicast);
478 		spin_lock_irq(&group->lock);
479 	}
480 
481 	join_state = get_leave_state(group);
482 	if (join_state) {
483 		group->rec.join_state &= ~join_state;
484 		spin_unlock_irq(&group->lock);
485 		if (send_leave(group, join_state))
486 			goto retest;
487 	} else {
488 		group->state = MCAST_IDLE;
489 		spin_unlock_irq(&group->lock);
490 		release_group(group);
491 	}
492 }
493 
494 /*
495  * Fail a join request if it is still active - at the head of the pending queue.
496  */
497 static void process_join_error(struct mcast_group *group, int status)
498 {
499 	struct mcast_member *member;
500 	int ret;
501 
502 	spin_lock_irq(&group->lock);
503 	member = list_entry(group->pending_list.next,
504 			    struct mcast_member, list);
505 	if (group->last_join == member) {
506 		atomic_inc(&member->refcount);
507 		list_del_init(&member->list);
508 		spin_unlock_irq(&group->lock);
509 		ret = member->multicast.callback(status, &member->multicast);
510 		deref_member(member);
511 		if (ret)
512 			ib_sa_free_multicast(&member->multicast);
513 	} else
514 		spin_unlock_irq(&group->lock);
515 }
516 
517 static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
518 			 void *context)
519 {
520 	struct mcast_group *group = context;
521 	u16 pkey_index = MCAST_INVALID_PKEY_INDEX;
522 
523 	if (status)
524 		process_join_error(group, status);
525 	else {
526 		ib_find_pkey(group->port->dev->device, group->port->port_num,
527 			     be16_to_cpu(rec->pkey), &pkey_index);
528 
529 		spin_lock_irq(&group->port->lock);
530 		group->rec = *rec;
531 		if (group->state == MCAST_BUSY &&
532 		    group->pkey_index == MCAST_INVALID_PKEY_INDEX)
533 			group->pkey_index = pkey_index;
534 		if (!memcmp(&mgid0, &group->rec.mgid, sizeof mgid0)) {
535 			rb_erase(&group->node, &group->port->table);
536 			mcast_insert(group->port, group, 1);
537 		}
538 		spin_unlock_irq(&group->port->lock);
539 	}
540 	mcast_work_handler(&group->work);
541 }
542 
543 static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
544 			  void *context)
545 {
546 	struct mcast_group *group = context;
547 
548 	if (status && group->retries > 0 &&
549 	    !send_leave(group, group->leave_state))
550 		group->retries--;
551 	else
552 		mcast_work_handler(&group->work);
553 }
554 
555 static struct mcast_group *acquire_group(struct mcast_port *port,
556 					 union ib_gid *mgid, gfp_t gfp_mask)
557 {
558 	struct mcast_group *group, *cur_group;
559 	unsigned long flags;
560 	int is_mgid0;
561 
562 	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
563 	if (!is_mgid0) {
564 		spin_lock_irqsave(&port->lock, flags);
565 		group = mcast_find(port, mgid);
566 		if (group)
567 			goto found;
568 		spin_unlock_irqrestore(&port->lock, flags);
569 	}
570 
571 	group = kzalloc(sizeof *group, gfp_mask);
572 	if (!group)
573 		return NULL;
574 
575 	group->retries = 3;
576 	group->port = port;
577 	group->rec.mgid = *mgid;
578 	group->pkey_index = MCAST_INVALID_PKEY_INDEX;
579 	INIT_LIST_HEAD(&group->pending_list);
580 	INIT_LIST_HEAD(&group->active_list);
581 	INIT_WORK(&group->work, mcast_work_handler);
582 	spin_lock_init(&group->lock);
583 
584 	spin_lock_irqsave(&port->lock, flags);
585 	cur_group = mcast_insert(port, group, is_mgid0);
586 	if (cur_group) {
587 		kfree(group);
588 		group = cur_group;
589 	} else
590 		atomic_inc(&port->refcount);
591 found:
592 	atomic_inc(&group->refcount);
593 	spin_unlock_irqrestore(&port->lock, flags);
594 	return group;
595 }
596 
597 /*
598  * We serialize all join requests to a single group to make our lives much
599  * easier.  Otherwise, two users could try to join the same group
600  * simultaneously, with different configurations, one could leave while the
601  * join is in progress, etc., which makes locking around error recovery
602  * difficult.
603  */
604 struct ib_sa_multicast *
605 ib_sa_join_multicast(struct ib_sa_client *client,
606 		     struct ib_device *device, u8 port_num,
607 		     struct ib_sa_mcmember_rec *rec,
608 		     ib_sa_comp_mask comp_mask, gfp_t gfp_mask,
609 		     int (*callback)(int status,
610 				     struct ib_sa_multicast *multicast),
611 		     void *context)
612 {
613 	struct mcast_device *dev;
614 	struct mcast_member *member;
615 	struct ib_sa_multicast *multicast;
616 	int ret;
617 
618 	dev = ib_get_client_data(device, &mcast_client);
619 	if (!dev)
620 		return ERR_PTR(-ENODEV);
621 
622 	member = kmalloc(sizeof *member, gfp_mask);
623 	if (!member)
624 		return ERR_PTR(-ENOMEM);
625 
626 	ib_sa_client_get(client);
627 	member->client = client;
628 	member->multicast.rec = *rec;
629 	member->multicast.comp_mask = comp_mask;
630 	member->multicast.callback = callback;
631 	member->multicast.context = context;
632 	init_completion(&member->comp);
633 	atomic_set(&member->refcount, 1);
634 	member->state = MCAST_JOINING;
635 
636 	member->group = acquire_group(&dev->port[port_num - dev->start_port],
637 				      &rec->mgid, gfp_mask);
638 	if (!member->group) {
639 		ret = -ENOMEM;
640 		goto err;
641 	}
642 
643 	/*
644 	 * The user will get the multicast structure in their callback.  They
645 	 * could then free the multicast structure before we can return from
646 	 * this routine.  So we save the pointer to return before queuing
647 	 * any callback.
648 	 */
649 	multicast = &member->multicast;
650 	queue_join(member);
651 	return multicast;
652 
653 err:
654 	ib_sa_client_put(client);
655 	kfree(member);
656 	return ERR_PTR(ret);
657 }
658 EXPORT_SYMBOL(ib_sa_join_multicast);
659 
660 void ib_sa_free_multicast(struct ib_sa_multicast *multicast)
661 {
662 	struct mcast_member *member;
663 	struct mcast_group *group;
664 
665 	member = container_of(multicast, struct mcast_member, multicast);
666 	group = member->group;
667 
668 	spin_lock_irq(&group->lock);
669 	if (member->state == MCAST_MEMBER)
670 		adjust_membership(group, multicast->rec.join_state, -1);
671 
672 	list_del_init(&member->list);
673 
674 	if (group->state == MCAST_IDLE) {
675 		group->state = MCAST_BUSY;
676 		spin_unlock_irq(&group->lock);
677 		/* Continue to hold reference on group until callback */
678 		queue_work(mcast_wq, &group->work);
679 	} else {
680 		spin_unlock_irq(&group->lock);
681 		release_group(group);
682 	}
683 
684 	deref_member(member);
685 	wait_for_completion(&member->comp);
686 	ib_sa_client_put(member->client);
687 	kfree(member);
688 }
689 EXPORT_SYMBOL(ib_sa_free_multicast);
690 
691 int ib_sa_get_mcmember_rec(struct ib_device *device, u8 port_num,
692 			   union ib_gid *mgid, struct ib_sa_mcmember_rec *rec)
693 {
694 	struct mcast_device *dev;
695 	struct mcast_port *port;
696 	struct mcast_group *group;
697 	unsigned long flags;
698 	int ret = 0;
699 
700 	dev = ib_get_client_data(device, &mcast_client);
701 	if (!dev)
702 		return -ENODEV;
703 
704 	port = &dev->port[port_num - dev->start_port];
705 	spin_lock_irqsave(&port->lock, flags);
706 	group = mcast_find(port, mgid);
707 	if (group)
708 		*rec = group->rec;
709 	else
710 		ret = -EADDRNOTAVAIL;
711 	spin_unlock_irqrestore(&port->lock, flags);
712 
713 	return ret;
714 }
715 EXPORT_SYMBOL(ib_sa_get_mcmember_rec);
716 
717 int ib_init_ah_from_mcmember(struct ib_device *device, u8 port_num,
718 			     struct ib_sa_mcmember_rec *rec,
719 			     struct ib_ah_attr *ah_attr)
720 {
721 	int ret;
722 	u16 gid_index;
723 	u8 p;
724 
725 	ret = ib_find_cached_gid(device, &rec->port_gid, &p, &gid_index);
726 	if (ret)
727 		return ret;
728 
729 	memset(ah_attr, 0, sizeof *ah_attr);
730 	ah_attr->dlid = be16_to_cpu(rec->mlid);
731 	ah_attr->sl = rec->sl;
732 	ah_attr->port_num = port_num;
733 	ah_attr->static_rate = rec->rate;
734 
735 	ah_attr->ah_flags = IB_AH_GRH;
736 	ah_attr->grh.dgid = rec->mgid;
737 
738 	ah_attr->grh.sgid_index = (u8) gid_index;
739 	ah_attr->grh.flow_label = be32_to_cpu(rec->flow_label);
740 	ah_attr->grh.hop_limit = rec->hop_limit;
741 	ah_attr->grh.traffic_class = rec->traffic_class;
742 
743 	return 0;
744 }
745 EXPORT_SYMBOL(ib_init_ah_from_mcmember);
746 
747 static void mcast_groups_event(struct mcast_port *port,
748 			       enum mcast_group_state state)
749 {
750 	struct mcast_group *group;
751 	struct rb_node *node;
752 	unsigned long flags;
753 
754 	spin_lock_irqsave(&port->lock, flags);
755 	for (node = rb_first(&port->table); node; node = rb_next(node)) {
756 		group = rb_entry(node, struct mcast_group, node);
757 		spin_lock(&group->lock);
758 		if (group->state == MCAST_IDLE) {
759 			atomic_inc(&group->refcount);
760 			queue_work(mcast_wq, &group->work);
761 		}
762 		if (group->state != MCAST_GROUP_ERROR)
763 			group->state = state;
764 		spin_unlock(&group->lock);
765 	}
766 	spin_unlock_irqrestore(&port->lock, flags);
767 }
768 
769 static void mcast_event_handler(struct ib_event_handler *handler,
770 				struct ib_event *event)
771 {
772 	struct mcast_device *dev;
773 	int index;
774 
775 	dev = container_of(handler, struct mcast_device, event_handler);
776 	index = event->element.port_num - dev->start_port;
777 
778 	switch (event->event) {
779 	case IB_EVENT_PORT_ERR:
780 	case IB_EVENT_LID_CHANGE:
781 	case IB_EVENT_SM_CHANGE:
782 	case IB_EVENT_CLIENT_REREGISTER:
783 		mcast_groups_event(&dev->port[index], MCAST_GROUP_ERROR);
784 		break;
785 	case IB_EVENT_PKEY_CHANGE:
786 		mcast_groups_event(&dev->port[index], MCAST_PKEY_EVENT);
787 		break;
788 	default:
789 		break;
790 	}
791 }
792 
793 static void mcast_add_one(struct ib_device *device)
794 {
795 	struct mcast_device *dev;
796 	struct mcast_port *port;
797 	int i;
798 
799 	if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
800 		return;
801 
802 	dev = kmalloc(sizeof *dev + device->phys_port_cnt * sizeof *port,
803 		      GFP_KERNEL);
804 	if (!dev)
805 		return;
806 
807 	if (device->node_type == RDMA_NODE_IB_SWITCH)
808 		dev->start_port = dev->end_port = 0;
809 	else {
810 		dev->start_port = 1;
811 		dev->end_port = device->phys_port_cnt;
812 	}
813 
814 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
815 		port = &dev->port[i];
816 		port->dev = dev;
817 		port->port_num = dev->start_port + i;
818 		spin_lock_init(&port->lock);
819 		port->table = RB_ROOT;
820 		init_completion(&port->comp);
821 		atomic_set(&port->refcount, 1);
822 	}
823 
824 	dev->device = device;
825 	ib_set_client_data(device, &mcast_client, dev);
826 
827 	INIT_IB_EVENT_HANDLER(&dev->event_handler, device, mcast_event_handler);
828 	ib_register_event_handler(&dev->event_handler);
829 }
830 
831 static void mcast_remove_one(struct ib_device *device)
832 {
833 	struct mcast_device *dev;
834 	struct mcast_port *port;
835 	int i;
836 
837 	dev = ib_get_client_data(device, &mcast_client);
838 	if (!dev)
839 		return;
840 
841 	ib_unregister_event_handler(&dev->event_handler);
842 	flush_workqueue(mcast_wq);
843 
844 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
845 		port = &dev->port[i];
846 		deref_port(port);
847 		wait_for_completion(&port->comp);
848 	}
849 
850 	kfree(dev);
851 }
852 
853 int mcast_init(void)
854 {
855 	int ret;
856 
857 	mcast_wq = create_singlethread_workqueue("ib_mcast");
858 	if (!mcast_wq)
859 		return -ENOMEM;
860 
861 	ib_sa_register_client(&sa_client);
862 
863 	ret = ib_register_client(&mcast_client);
864 	if (ret)
865 		goto err;
866 	return 0;
867 
868 err:
869 	ib_sa_unregister_client(&sa_client);
870 	destroy_workqueue(mcast_wq);
871 	return ret;
872 }
873 
874 void mcast_cleanup(void)
875 {
876 	ib_unregister_client(&mcast_client);
877 	ib_sa_unregister_client(&sa_client);
878 	destroy_workqueue(mcast_wq);
879 }
880