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/slab.h>
38 #include <linux/bitops.h>
39 #include <linux/random.h>
40 
41 #include <rdma/ib_cache.h>
42 #include "sa.h"
43 
44 static void mcast_add_one(struct ib_device *device);
45 static void mcast_remove_one(struct ib_device *device);
46 
47 static struct ib_client mcast_client = {
48 	.name   = "ib_multicast",
49 	.add    = mcast_add_one,
50 	.remove = mcast_remove_one
51 };
52 
53 static struct ib_sa_client	sa_client;
54 static struct workqueue_struct	*mcast_wq;
55 static union ib_gid mgid0;
56 
57 struct mcast_device;
58 
59 struct mcast_port {
60 	struct mcast_device	*dev;
61 	spinlock_t		lock;
62 	struct rb_root		table;
63 	atomic_t		refcount;
64 	struct completion	comp;
65 	u8			port_num;
66 };
67 
68 struct mcast_device {
69 	struct ib_device	*device;
70 	struct ib_event_handler	event_handler;
71 	int			start_port;
72 	int			end_port;
73 	struct mcast_port	port[0];
74 };
75 
76 enum mcast_state {
77 	MCAST_JOINING,
78 	MCAST_MEMBER,
79 	MCAST_ERROR,
80 };
81 
82 enum mcast_group_state {
83 	MCAST_IDLE,
84 	MCAST_BUSY,
85 	MCAST_GROUP_ERROR,
86 	MCAST_PKEY_EVENT
87 };
88 
89 enum {
90 	MCAST_INVALID_PKEY_INDEX = 0xFFFF
91 };
92 
93 struct mcast_member;
94 
95 struct mcast_group {
96 	struct ib_sa_mcmember_rec rec;
97 	struct rb_node		node;
98 	struct mcast_port	*port;
99 	spinlock_t		lock;
100 	struct work_struct	work;
101 	struct list_head	pending_list;
102 	struct list_head	active_list;
103 	struct mcast_member	*last_join;
104 	int			members[3];
105 	atomic_t		refcount;
106 	enum mcast_group_state	state;
107 	struct ib_sa_query	*query;
108 	int			query_id;
109 	u16			pkey_index;
110 	u8			leave_state;
111 	int			retries;
112 };
113 
114 struct mcast_member {
115 	struct ib_sa_multicast	multicast;
116 	struct ib_sa_client	*client;
117 	struct mcast_group	*group;
118 	struct list_head	list;
119 	enum mcast_state	state;
120 	atomic_t		refcount;
121 	struct completion	comp;
122 };
123 
124 static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
125 			 void *context);
126 static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
127 			  void *context);
128 
129 static struct mcast_group *mcast_find(struct mcast_port *port,
130 				      union ib_gid *mgid)
131 {
132 	struct rb_node *node = port->table.rb_node;
133 	struct mcast_group *group;
134 	int ret;
135 
136 	while (node) {
137 		group = rb_entry(node, struct mcast_group, node);
138 		ret = memcmp(mgid->raw, group->rec.mgid.raw, sizeof *mgid);
139 		if (!ret)
140 			return group;
141 
142 		if (ret < 0)
143 			node = node->rb_left;
144 		else
145 			node = node->rb_right;
146 	}
147 	return NULL;
148 }
149 
150 static struct mcast_group *mcast_insert(struct mcast_port *port,
151 					struct mcast_group *group,
152 					int allow_duplicates)
153 {
154 	struct rb_node **link = &port->table.rb_node;
155 	struct rb_node *parent = NULL;
156 	struct mcast_group *cur_group;
157 	int ret;
158 
159 	while (*link) {
160 		parent = *link;
161 		cur_group = rb_entry(parent, struct mcast_group, node);
162 
163 		ret = memcmp(group->rec.mgid.raw, cur_group->rec.mgid.raw,
164 			     sizeof group->rec.mgid);
165 		if (ret < 0)
166 			link = &(*link)->rb_left;
167 		else if (ret > 0)
168 			link = &(*link)->rb_right;
169 		else if (allow_duplicates)
170 			link = &(*link)->rb_left;
171 		else
172 			return cur_group;
173 	}
174 	rb_link_node(&group->node, parent, link);
175 	rb_insert_color(&group->node, &port->table);
176 	return NULL;
177 }
178 
179 static void deref_port(struct mcast_port *port)
180 {
181 	if (atomic_dec_and_test(&port->refcount))
182 		complete(&port->comp);
183 }
184 
185 static void release_group(struct mcast_group *group)
186 {
187 	struct mcast_port *port = group->port;
188 	unsigned long flags;
189 
190 	spin_lock_irqsave(&port->lock, flags);
191 	if (atomic_dec_and_test(&group->refcount)) {
192 		rb_erase(&group->node, &port->table);
193 		spin_unlock_irqrestore(&port->lock, flags);
194 		kfree(group);
195 		deref_port(port);
196 	} else
197 		spin_unlock_irqrestore(&port->lock, flags);
198 }
199 
200 static void deref_member(struct mcast_member *member)
201 {
202 	if (atomic_dec_and_test(&member->refcount))
203 		complete(&member->comp);
204 }
205 
206 static void queue_join(struct mcast_member *member)
207 {
208 	struct mcast_group *group = member->group;
209 	unsigned long flags;
210 
211 	spin_lock_irqsave(&group->lock, flags);
212 	list_add_tail(&member->list, &group->pending_list);
213 	if (group->state == MCAST_IDLE) {
214 		group->state = MCAST_BUSY;
215 		atomic_inc(&group->refcount);
216 		queue_work(mcast_wq, &group->work);
217 	}
218 	spin_unlock_irqrestore(&group->lock, flags);
219 }
220 
221 /*
222  * A multicast group has three types of members: full member, non member, and
223  * send only member.  We need to keep track of the number of members of each
224  * type based on their join state.  Adjust the number of members the belong to
225  * the specified join states.
226  */
227 static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
228 {
229 	int i;
230 
231 	for (i = 0; i < 3; i++, join_state >>= 1)
232 		if (join_state & 0x1)
233 			group->members[i] += inc;
234 }
235 
236 /*
237  * If a multicast group has zero members left for a particular join state, but
238  * the group is still a member with the SA, we need to leave that join state.
239  * Determine which join states we still belong to, but that do not have any
240  * active members.
241  */
242 static u8 get_leave_state(struct mcast_group *group)
243 {
244 	u8 leave_state = 0;
245 	int i;
246 
247 	for (i = 0; i < 3; i++)
248 		if (!group->members[i])
249 			leave_state |= (0x1 << i);
250 
251 	return leave_state & group->rec.join_state;
252 }
253 
254 static int check_selector(ib_sa_comp_mask comp_mask,
255 			  ib_sa_comp_mask selector_mask,
256 			  ib_sa_comp_mask value_mask,
257 			  u8 selector, u8 src_value, u8 dst_value)
258 {
259 	int err;
260 
261 	if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
262 		return 0;
263 
264 	switch (selector) {
265 	case IB_SA_GT:
266 		err = (src_value <= dst_value);
267 		break;
268 	case IB_SA_LT:
269 		err = (src_value >= dst_value);
270 		break;
271 	case IB_SA_EQ:
272 		err = (src_value != dst_value);
273 		break;
274 	default:
275 		err = 0;
276 		break;
277 	}
278 
279 	return err;
280 }
281 
282 static int cmp_rec(struct ib_sa_mcmember_rec *src,
283 		   struct ib_sa_mcmember_rec *dst, ib_sa_comp_mask comp_mask)
284 {
285 	/* MGID must already match */
286 
287 	if (comp_mask & IB_SA_MCMEMBER_REC_PORT_GID &&
288 	    memcmp(&src->port_gid, &dst->port_gid, sizeof src->port_gid))
289 		return -EINVAL;
290 	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
291 		return -EINVAL;
292 	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
293 		return -EINVAL;
294 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
295 			   IB_SA_MCMEMBER_REC_MTU, dst->mtu_selector,
296 			   src->mtu, dst->mtu))
297 		return -EINVAL;
298 	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
299 	    src->traffic_class != dst->traffic_class)
300 		return -EINVAL;
301 	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
302 		return -EINVAL;
303 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
304 			   IB_SA_MCMEMBER_REC_RATE, dst->rate_selector,
305 			   src->rate, dst->rate))
306 		return -EINVAL;
307 	if (check_selector(comp_mask,
308 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
309 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
310 			   dst->packet_life_time_selector,
311 			   src->packet_life_time, dst->packet_life_time))
312 		return -EINVAL;
313 	if (comp_mask & IB_SA_MCMEMBER_REC_SL && src->sl != dst->sl)
314 		return -EINVAL;
315 	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
316 	    src->flow_label != dst->flow_label)
317 		return -EINVAL;
318 	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
319 	    src->hop_limit != dst->hop_limit)
320 		return -EINVAL;
321 	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE && src->scope != dst->scope)
322 		return -EINVAL;
323 
324 	/* join_state checked separately, proxy_join ignored */
325 
326 	return 0;
327 }
328 
329 static int send_join(struct mcast_group *group, struct mcast_member *member)
330 {
331 	struct mcast_port *port = group->port;
332 	int ret;
333 
334 	group->last_join = member;
335 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
336 				       port->port_num, IB_MGMT_METHOD_SET,
337 				       &member->multicast.rec,
338 				       member->multicast.comp_mask,
339 				       3000, GFP_KERNEL, join_handler, group,
340 				       &group->query);
341 	if (ret >= 0) {
342 		group->query_id = ret;
343 		ret = 0;
344 	}
345 	return ret;
346 }
347 
348 static int send_leave(struct mcast_group *group, u8 leave_state)
349 {
350 	struct mcast_port *port = group->port;
351 	struct ib_sa_mcmember_rec rec;
352 	int ret;
353 
354 	rec = group->rec;
355 	rec.join_state = leave_state;
356 	group->leave_state = leave_state;
357 
358 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
359 				       port->port_num, IB_SA_METHOD_DELETE, &rec,
360 				       IB_SA_MCMEMBER_REC_MGID     |
361 				       IB_SA_MCMEMBER_REC_PORT_GID |
362 				       IB_SA_MCMEMBER_REC_JOIN_STATE,
363 				       3000, GFP_KERNEL, leave_handler,
364 				       group, &group->query);
365 	if (ret >= 0) {
366 		group->query_id = ret;
367 		ret = 0;
368 	}
369 	return ret;
370 }
371 
372 static void join_group(struct mcast_group *group, struct mcast_member *member,
373 		       u8 join_state)
374 {
375 	member->state = MCAST_MEMBER;
376 	adjust_membership(group, join_state, 1);
377 	group->rec.join_state |= join_state;
378 	member->multicast.rec = group->rec;
379 	member->multicast.rec.join_state = join_state;
380 	list_move(&member->list, &group->active_list);
381 }
382 
383 static int fail_join(struct mcast_group *group, struct mcast_member *member,
384 		     int status)
385 {
386 	spin_lock_irq(&group->lock);
387 	list_del_init(&member->list);
388 	spin_unlock_irq(&group->lock);
389 	return member->multicast.callback(status, &member->multicast);
390 }
391 
392 static void process_group_error(struct mcast_group *group)
393 {
394 	struct mcast_member *member;
395 	int ret = 0;
396 	u16 pkey_index;
397 
398 	if (group->state == MCAST_PKEY_EVENT)
399 		ret = ib_find_pkey(group->port->dev->device,
400 				   group->port->port_num,
401 				   be16_to_cpu(group->rec.pkey), &pkey_index);
402 
403 	spin_lock_irq(&group->lock);
404 	if (group->state == MCAST_PKEY_EVENT && !ret &&
405 	    group->pkey_index == pkey_index)
406 		goto out;
407 
408 	while (!list_empty(&group->active_list)) {
409 		member = list_entry(group->active_list.next,
410 				    struct mcast_member, list);
411 		atomic_inc(&member->refcount);
412 		list_del_init(&member->list);
413 		adjust_membership(group, member->multicast.rec.join_state, -1);
414 		member->state = MCAST_ERROR;
415 		spin_unlock_irq(&group->lock);
416 
417 		ret = member->multicast.callback(-ENETRESET,
418 						 &member->multicast);
419 		deref_member(member);
420 		if (ret)
421 			ib_sa_free_multicast(&member->multicast);
422 		spin_lock_irq(&group->lock);
423 	}
424 
425 	group->rec.join_state = 0;
426 out:
427 	group->state = MCAST_BUSY;
428 	spin_unlock_irq(&group->lock);
429 }
430 
431 static void mcast_work_handler(struct work_struct *work)
432 {
433 	struct mcast_group *group;
434 	struct mcast_member *member;
435 	struct ib_sa_multicast *multicast;
436 	int status, ret;
437 	u8 join_state;
438 
439 	group = container_of(work, typeof(*group), work);
440 retest:
441 	spin_lock_irq(&group->lock);
442 	while (!list_empty(&group->pending_list) ||
443 	       (group->state != MCAST_BUSY)) {
444 
445 		if (group->state != MCAST_BUSY) {
446 			spin_unlock_irq(&group->lock);
447 			process_group_error(group);
448 			goto retest;
449 		}
450 
451 		member = list_entry(group->pending_list.next,
452 				    struct mcast_member, list);
453 		multicast = &member->multicast;
454 		join_state = multicast->rec.join_state;
455 		atomic_inc(&member->refcount);
456 
457 		if (join_state == (group->rec.join_state & join_state)) {
458 			status = cmp_rec(&group->rec, &multicast->rec,
459 					 multicast->comp_mask);
460 			if (!status)
461 				join_group(group, member, join_state);
462 			else
463 				list_del_init(&member->list);
464 			spin_unlock_irq(&group->lock);
465 			ret = multicast->callback(status, multicast);
466 		} else {
467 			spin_unlock_irq(&group->lock);
468 			status = send_join(group, member);
469 			if (!status) {
470 				deref_member(member);
471 				return;
472 			}
473 			ret = fail_join(group, member, status);
474 		}
475 
476 		deref_member(member);
477 		if (ret)
478 			ib_sa_free_multicast(&member->multicast);
479 		spin_lock_irq(&group->lock);
480 	}
481 
482 	join_state = get_leave_state(group);
483 	if (join_state) {
484 		group->rec.join_state &= ~join_state;
485 		spin_unlock_irq(&group->lock);
486 		if (send_leave(group, join_state))
487 			goto retest;
488 	} else {
489 		group->state = MCAST_IDLE;
490 		spin_unlock_irq(&group->lock);
491 		release_group(group);
492 	}
493 }
494 
495 /*
496  * Fail a join request if it is still active - at the head of the pending queue.
497  */
498 static void process_join_error(struct mcast_group *group, int status)
499 {
500 	struct mcast_member *member;
501 	int ret;
502 
503 	spin_lock_irq(&group->lock);
504 	member = list_entry(group->pending_list.next,
505 			    struct mcast_member, list);
506 	if (group->last_join == member) {
507 		atomic_inc(&member->refcount);
508 		list_del_init(&member->list);
509 		spin_unlock_irq(&group->lock);
510 		ret = member->multicast.callback(status, &member->multicast);
511 		deref_member(member);
512 		if (ret)
513 			ib_sa_free_multicast(&member->multicast);
514 	} else
515 		spin_unlock_irq(&group->lock);
516 }
517 
518 static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
519 			 void *context)
520 {
521 	struct mcast_group *group = context;
522 	u16 pkey_index = MCAST_INVALID_PKEY_INDEX;
523 
524 	if (status)
525 		process_join_error(group, status);
526 	else {
527 		ib_find_pkey(group->port->dev->device, group->port->port_num,
528 			     be16_to_cpu(rec->pkey), &pkey_index);
529 
530 		spin_lock_irq(&group->port->lock);
531 		group->rec = *rec;
532 		if (group->state == MCAST_BUSY &&
533 		    group->pkey_index == MCAST_INVALID_PKEY_INDEX)
534 			group->pkey_index = pkey_index;
535 		if (!memcmp(&mgid0, &group->rec.mgid, sizeof mgid0)) {
536 			rb_erase(&group->node, &group->port->table);
537 			mcast_insert(group->port, group, 1);
538 		}
539 		spin_unlock_irq(&group->port->lock);
540 	}
541 	mcast_work_handler(&group->work);
542 }
543 
544 static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
545 			  void *context)
546 {
547 	struct mcast_group *group = context;
548 
549 	if (status && group->retries > 0 &&
550 	    !send_leave(group, group->leave_state))
551 		group->retries--;
552 	else
553 		mcast_work_handler(&group->work);
554 }
555 
556 static struct mcast_group *acquire_group(struct mcast_port *port,
557 					 union ib_gid *mgid, gfp_t gfp_mask)
558 {
559 	struct mcast_group *group, *cur_group;
560 	unsigned long flags;
561 	int is_mgid0;
562 
563 	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
564 	if (!is_mgid0) {
565 		spin_lock_irqsave(&port->lock, flags);
566 		group = mcast_find(port, mgid);
567 		if (group)
568 			goto found;
569 		spin_unlock_irqrestore(&port->lock, flags);
570 	}
571 
572 	group = kzalloc(sizeof *group, gfp_mask);
573 	if (!group)
574 		return NULL;
575 
576 	group->retries = 3;
577 	group->port = port;
578 	group->rec.mgid = *mgid;
579 	group->pkey_index = MCAST_INVALID_PKEY_INDEX;
580 	INIT_LIST_HEAD(&group->pending_list);
581 	INIT_LIST_HEAD(&group->active_list);
582 	INIT_WORK(&group->work, mcast_work_handler);
583 	spin_lock_init(&group->lock);
584 
585 	spin_lock_irqsave(&port->lock, flags);
586 	cur_group = mcast_insert(port, group, is_mgid0);
587 	if (cur_group) {
588 		kfree(group);
589 		group = cur_group;
590 	} else
591 		atomic_inc(&port->refcount);
592 found:
593 	atomic_inc(&group->refcount);
594 	spin_unlock_irqrestore(&port->lock, flags);
595 	return group;
596 }
597 
598 /*
599  * We serialize all join requests to a single group to make our lives much
600  * easier.  Otherwise, two users could try to join the same group
601  * simultaneously, with different configurations, one could leave while the
602  * join is in progress, etc., which makes locking around error recovery
603  * difficult.
604  */
605 struct ib_sa_multicast *
606 ib_sa_join_multicast(struct ib_sa_client *client,
607 		     struct ib_device *device, u8 port_num,
608 		     struct ib_sa_mcmember_rec *rec,
609 		     ib_sa_comp_mask comp_mask, gfp_t gfp_mask,
610 		     int (*callback)(int status,
611 				     struct ib_sa_multicast *multicast),
612 		     void *context)
613 {
614 	struct mcast_device *dev;
615 	struct mcast_member *member;
616 	struct ib_sa_multicast *multicast;
617 	int ret;
618 
619 	dev = ib_get_client_data(device, &mcast_client);
620 	if (!dev)
621 		return ERR_PTR(-ENODEV);
622 
623 	member = kmalloc(sizeof *member, gfp_mask);
624 	if (!member)
625 		return ERR_PTR(-ENOMEM);
626 
627 	ib_sa_client_get(client);
628 	member->client = client;
629 	member->multicast.rec = *rec;
630 	member->multicast.comp_mask = comp_mask;
631 	member->multicast.callback = callback;
632 	member->multicast.context = context;
633 	init_completion(&member->comp);
634 	atomic_set(&member->refcount, 1);
635 	member->state = MCAST_JOINING;
636 
637 	member->group = acquire_group(&dev->port[port_num - dev->start_port],
638 				      &rec->mgid, gfp_mask);
639 	if (!member->group) {
640 		ret = -ENOMEM;
641 		goto err;
642 	}
643 
644 	/*
645 	 * The user will get the multicast structure in their callback.  They
646 	 * could then free the multicast structure before we can return from
647 	 * this routine.  So we save the pointer to return before queuing
648 	 * any callback.
649 	 */
650 	multicast = &member->multicast;
651 	queue_join(member);
652 	return multicast;
653 
654 err:
655 	ib_sa_client_put(client);
656 	kfree(member);
657 	return ERR_PTR(ret);
658 }
659 EXPORT_SYMBOL(ib_sa_join_multicast);
660 
661 void ib_sa_free_multicast(struct ib_sa_multicast *multicast)
662 {
663 	struct mcast_member *member;
664 	struct mcast_group *group;
665 
666 	member = container_of(multicast, struct mcast_member, multicast);
667 	group = member->group;
668 
669 	spin_lock_irq(&group->lock);
670 	if (member->state == MCAST_MEMBER)
671 		adjust_membership(group, multicast->rec.join_state, -1);
672 
673 	list_del_init(&member->list);
674 
675 	if (group->state == MCAST_IDLE) {
676 		group->state = MCAST_BUSY;
677 		spin_unlock_irq(&group->lock);
678 		/* Continue to hold reference on group until callback */
679 		queue_work(mcast_wq, &group->work);
680 	} else {
681 		spin_unlock_irq(&group->lock);
682 		release_group(group);
683 	}
684 
685 	deref_member(member);
686 	wait_for_completion(&member->comp);
687 	ib_sa_client_put(member->client);
688 	kfree(member);
689 }
690 EXPORT_SYMBOL(ib_sa_free_multicast);
691 
692 int ib_sa_get_mcmember_rec(struct ib_device *device, u8 port_num,
693 			   union ib_gid *mgid, struct ib_sa_mcmember_rec *rec)
694 {
695 	struct mcast_device *dev;
696 	struct mcast_port *port;
697 	struct mcast_group *group;
698 	unsigned long flags;
699 	int ret = 0;
700 
701 	dev = ib_get_client_data(device, &mcast_client);
702 	if (!dev)
703 		return -ENODEV;
704 
705 	port = &dev->port[port_num - dev->start_port];
706 	spin_lock_irqsave(&port->lock, flags);
707 	group = mcast_find(port, mgid);
708 	if (group)
709 		*rec = group->rec;
710 	else
711 		ret = -EADDRNOTAVAIL;
712 	spin_unlock_irqrestore(&port->lock, flags);
713 
714 	return ret;
715 }
716 EXPORT_SYMBOL(ib_sa_get_mcmember_rec);
717 
718 int ib_init_ah_from_mcmember(struct ib_device *device, u8 port_num,
719 			     struct ib_sa_mcmember_rec *rec,
720 			     struct ib_ah_attr *ah_attr)
721 {
722 	int ret;
723 	u16 gid_index;
724 	u8 p;
725 
726 	ret = ib_find_cached_gid(device, &rec->port_gid, &p, &gid_index);
727 	if (ret)
728 		return ret;
729 
730 	memset(ah_attr, 0, sizeof *ah_attr);
731 	ah_attr->dlid = be16_to_cpu(rec->mlid);
732 	ah_attr->sl = rec->sl;
733 	ah_attr->port_num = port_num;
734 	ah_attr->static_rate = rec->rate;
735 
736 	ah_attr->ah_flags = IB_AH_GRH;
737 	ah_attr->grh.dgid = rec->mgid;
738 
739 	ah_attr->grh.sgid_index = (u8) gid_index;
740 	ah_attr->grh.flow_label = be32_to_cpu(rec->flow_label);
741 	ah_attr->grh.hop_limit = rec->hop_limit;
742 	ah_attr->grh.traffic_class = rec->traffic_class;
743 
744 	return 0;
745 }
746 EXPORT_SYMBOL(ib_init_ah_from_mcmember);
747 
748 static void mcast_groups_event(struct mcast_port *port,
749 			       enum mcast_group_state state)
750 {
751 	struct mcast_group *group;
752 	struct rb_node *node;
753 	unsigned long flags;
754 
755 	spin_lock_irqsave(&port->lock, flags);
756 	for (node = rb_first(&port->table); node; node = rb_next(node)) {
757 		group = rb_entry(node, struct mcast_group, node);
758 		spin_lock(&group->lock);
759 		if (group->state == MCAST_IDLE) {
760 			atomic_inc(&group->refcount);
761 			queue_work(mcast_wq, &group->work);
762 		}
763 		if (group->state != MCAST_GROUP_ERROR)
764 			group->state = state;
765 		spin_unlock(&group->lock);
766 	}
767 	spin_unlock_irqrestore(&port->lock, flags);
768 }
769 
770 static void mcast_event_handler(struct ib_event_handler *handler,
771 				struct ib_event *event)
772 {
773 	struct mcast_device *dev;
774 	int index;
775 
776 	dev = container_of(handler, struct mcast_device, event_handler);
777 	if (rdma_port_get_link_layer(dev->device, event->element.port_num) !=
778 	    IB_LINK_LAYER_INFINIBAND)
779 		return;
780 
781 	index = event->element.port_num - dev->start_port;
782 
783 	switch (event->event) {
784 	case IB_EVENT_PORT_ERR:
785 	case IB_EVENT_LID_CHANGE:
786 	case IB_EVENT_SM_CHANGE:
787 	case IB_EVENT_CLIENT_REREGISTER:
788 		mcast_groups_event(&dev->port[index], MCAST_GROUP_ERROR);
789 		break;
790 	case IB_EVENT_PKEY_CHANGE:
791 		mcast_groups_event(&dev->port[index], MCAST_PKEY_EVENT);
792 		break;
793 	default:
794 		break;
795 	}
796 }
797 
798 static void mcast_add_one(struct ib_device *device)
799 {
800 	struct mcast_device *dev;
801 	struct mcast_port *port;
802 	int i;
803 	int count = 0;
804 
805 	if (rdma_node_get_transport(device->node_type) != RDMA_TRANSPORT_IB)
806 		return;
807 
808 	dev = kmalloc(sizeof *dev + device->phys_port_cnt * sizeof *port,
809 		      GFP_KERNEL);
810 	if (!dev)
811 		return;
812 
813 	if (device->node_type == RDMA_NODE_IB_SWITCH)
814 		dev->start_port = dev->end_port = 0;
815 	else {
816 		dev->start_port = 1;
817 		dev->end_port = device->phys_port_cnt;
818 	}
819 
820 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
821 		if (rdma_port_get_link_layer(device, dev->start_port + i) !=
822 		    IB_LINK_LAYER_INFINIBAND)
823 			continue;
824 		port = &dev->port[i];
825 		port->dev = dev;
826 		port->port_num = dev->start_port + i;
827 		spin_lock_init(&port->lock);
828 		port->table = RB_ROOT;
829 		init_completion(&port->comp);
830 		atomic_set(&port->refcount, 1);
831 		++count;
832 	}
833 
834 	if (!count) {
835 		kfree(dev);
836 		return;
837 	}
838 
839 	dev->device = device;
840 	ib_set_client_data(device, &mcast_client, dev);
841 
842 	INIT_IB_EVENT_HANDLER(&dev->event_handler, device, mcast_event_handler);
843 	ib_register_event_handler(&dev->event_handler);
844 }
845 
846 static void mcast_remove_one(struct ib_device *device)
847 {
848 	struct mcast_device *dev;
849 	struct mcast_port *port;
850 	int i;
851 
852 	dev = ib_get_client_data(device, &mcast_client);
853 	if (!dev)
854 		return;
855 
856 	ib_unregister_event_handler(&dev->event_handler);
857 	flush_workqueue(mcast_wq);
858 
859 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
860 		if (rdma_port_get_link_layer(device, dev->start_port + i) ==
861 		    IB_LINK_LAYER_INFINIBAND) {
862 			port = &dev->port[i];
863 			deref_port(port);
864 			wait_for_completion(&port->comp);
865 		}
866 	}
867 
868 	kfree(dev);
869 }
870 
871 int mcast_init(void)
872 {
873 	int ret;
874 
875 	mcast_wq = create_singlethread_workqueue("ib_mcast");
876 	if (!mcast_wq)
877 		return -ENOMEM;
878 
879 	ib_sa_register_client(&sa_client);
880 
881 	ret = ib_register_client(&mcast_client);
882 	if (ret)
883 		goto err;
884 	return 0;
885 
886 err:
887 	ib_sa_unregister_client(&sa_client);
888 	destroy_workqueue(mcast_wq);
889 	return ret;
890 }
891 
892 void mcast_cleanup(void)
893 {
894 	ib_unregister_client(&mcast_client);
895 	ib_sa_unregister_client(&sa_client);
896 	destroy_workqueue(mcast_wq);
897 }
898