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/export.h>
38 #include <linux/slab.h>
39 #include <linux/bitops.h>
40 #include <linux/random.h>
41 
42 #include <rdma/ib_cache.h>
43 #include "sa.h"
44 
45 static void mcast_add_one(struct ib_device *device);
46 static void mcast_remove_one(struct ib_device *device, void *client_data);
47 
48 static struct ib_client mcast_client = {
49 	.name   = "ib_multicast",
50 	.add    = mcast_add_one,
51 	.remove = mcast_remove_one
52 };
53 
54 static struct ib_sa_client	sa_client;
55 static struct workqueue_struct	*mcast_wq;
56 static union ib_gid mgid0;
57 
58 struct mcast_device;
59 
60 struct mcast_port {
61 	struct mcast_device	*dev;
62 	spinlock_t		lock;
63 	struct rb_root		table;
64 	atomic_t		refcount;
65 	struct completion	comp;
66 	u8			port_num;
67 };
68 
69 struct mcast_device {
70 	struct ib_device	*device;
71 	struct ib_event_handler	event_handler;
72 	int			start_port;
73 	int			end_port;
74 	struct mcast_port	port[0];
75 };
76 
77 enum mcast_state {
78 	MCAST_JOINING,
79 	MCAST_MEMBER,
80 	MCAST_ERROR,
81 };
82 
83 enum mcast_group_state {
84 	MCAST_IDLE,
85 	MCAST_BUSY,
86 	MCAST_GROUP_ERROR,
87 	MCAST_PKEY_EVENT
88 };
89 
90 enum {
91 	MCAST_INVALID_PKEY_INDEX = 0xFFFF
92 };
93 
94 struct mcast_member;
95 
96 struct mcast_group {
97 	struct ib_sa_mcmember_rec rec;
98 	struct rb_node		node;
99 	struct mcast_port	*port;
100 	spinlock_t		lock;
101 	struct work_struct	work;
102 	struct list_head	pending_list;
103 	struct list_head	active_list;
104 	struct mcast_member	*last_join;
105 	int			members[NUM_JOIN_MEMBERSHIP_TYPES];
106 	atomic_t		refcount;
107 	enum mcast_group_state	state;
108 	struct ib_sa_query	*query;
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 four types of members: full member, non member,
223  * sendonly non member and sendonly full member.
224  * We need to keep track of the number of members of each
225  * type based on their join state.  Adjust the number of members the belong to
226  * the specified join states.
227  */
228 static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
229 {
230 	int i;
231 
232 	for (i = 0; i < NUM_JOIN_MEMBERSHIP_TYPES; i++, join_state >>= 1)
233 		if (join_state & 0x1)
234 			group->members[i] += inc;
235 }
236 
237 /*
238  * If a multicast group has zero members left for a particular join state, but
239  * the group is still a member with the SA, we need to leave that join state.
240  * Determine which join states we still belong to, but that do not have any
241  * active members.
242  */
243 static u8 get_leave_state(struct mcast_group *group)
244 {
245 	u8 leave_state = 0;
246 	int i;
247 
248 	for (i = 0; i < NUM_JOIN_MEMBERSHIP_TYPES; i++)
249 		if (!group->members[i])
250 			leave_state |= (0x1 << i);
251 
252 	return leave_state & group->rec.join_state;
253 }
254 
255 static int check_selector(ib_sa_comp_mask comp_mask,
256 			  ib_sa_comp_mask selector_mask,
257 			  ib_sa_comp_mask value_mask,
258 			  u8 selector, u8 src_value, u8 dst_value)
259 {
260 	int err;
261 
262 	if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
263 		return 0;
264 
265 	switch (selector) {
266 	case IB_SA_GT:
267 		err = (src_value <= dst_value);
268 		break;
269 	case IB_SA_LT:
270 		err = (src_value >= dst_value);
271 		break;
272 	case IB_SA_EQ:
273 		err = (src_value != dst_value);
274 		break;
275 	default:
276 		err = 0;
277 		break;
278 	}
279 
280 	return err;
281 }
282 
283 static int cmp_rec(struct ib_sa_mcmember_rec *src,
284 		   struct ib_sa_mcmember_rec *dst, ib_sa_comp_mask comp_mask)
285 {
286 	/* MGID must already match */
287 
288 	if (comp_mask & IB_SA_MCMEMBER_REC_PORT_GID &&
289 	    memcmp(&src->port_gid, &dst->port_gid, sizeof src->port_gid))
290 		return -EINVAL;
291 	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
292 		return -EINVAL;
293 	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
294 		return -EINVAL;
295 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
296 			   IB_SA_MCMEMBER_REC_MTU, dst->mtu_selector,
297 			   src->mtu, dst->mtu))
298 		return -EINVAL;
299 	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
300 	    src->traffic_class != dst->traffic_class)
301 		return -EINVAL;
302 	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
303 		return -EINVAL;
304 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
305 			   IB_SA_MCMEMBER_REC_RATE, dst->rate_selector,
306 			   src->rate, dst->rate))
307 		return -EINVAL;
308 	if (check_selector(comp_mask,
309 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
310 			   IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
311 			   dst->packet_life_time_selector,
312 			   src->packet_life_time, dst->packet_life_time))
313 		return -EINVAL;
314 	if (comp_mask & IB_SA_MCMEMBER_REC_SL && src->sl != dst->sl)
315 		return -EINVAL;
316 	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
317 	    src->flow_label != dst->flow_label)
318 		return -EINVAL;
319 	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
320 	    src->hop_limit != dst->hop_limit)
321 		return -EINVAL;
322 	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE && src->scope != dst->scope)
323 		return -EINVAL;
324 
325 	/* join_state checked separately, proxy_join ignored */
326 
327 	return 0;
328 }
329 
330 static int send_join(struct mcast_group *group, struct mcast_member *member)
331 {
332 	struct mcast_port *port = group->port;
333 	int ret;
334 
335 	group->last_join = member;
336 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
337 				       port->port_num, IB_MGMT_METHOD_SET,
338 				       &member->multicast.rec,
339 				       member->multicast.comp_mask,
340 				       3000, GFP_KERNEL, join_handler, group,
341 				       &group->query);
342 	return (ret > 0) ? 0 : ret;
343 }
344 
345 static int send_leave(struct mcast_group *group, u8 leave_state)
346 {
347 	struct mcast_port *port = group->port;
348 	struct ib_sa_mcmember_rec rec;
349 	int ret;
350 
351 	rec = group->rec;
352 	rec.join_state = leave_state;
353 	group->leave_state = leave_state;
354 
355 	ret = ib_sa_mcmember_rec_query(&sa_client, port->dev->device,
356 				       port->port_num, IB_SA_METHOD_DELETE, &rec,
357 				       IB_SA_MCMEMBER_REC_MGID     |
358 				       IB_SA_MCMEMBER_REC_PORT_GID |
359 				       IB_SA_MCMEMBER_REC_JOIN_STATE,
360 				       3000, GFP_KERNEL, leave_handler,
361 				       group, &group->query);
362 	return (ret > 0) ? 0 : ret;
363 }
364 
365 static void join_group(struct mcast_group *group, struct mcast_member *member,
366 		       u8 join_state)
367 {
368 	member->state = MCAST_MEMBER;
369 	adjust_membership(group, join_state, 1);
370 	group->rec.join_state |= join_state;
371 	member->multicast.rec = group->rec;
372 	member->multicast.rec.join_state = join_state;
373 	list_move(&member->list, &group->active_list);
374 }
375 
376 static int fail_join(struct mcast_group *group, struct mcast_member *member,
377 		     int status)
378 {
379 	spin_lock_irq(&group->lock);
380 	list_del_init(&member->list);
381 	spin_unlock_irq(&group->lock);
382 	return member->multicast.callback(status, &member->multicast);
383 }
384 
385 static void process_group_error(struct mcast_group *group)
386 {
387 	struct mcast_member *member;
388 	int ret = 0;
389 	u16 pkey_index;
390 
391 	if (group->state == MCAST_PKEY_EVENT)
392 		ret = ib_find_pkey(group->port->dev->device,
393 				   group->port->port_num,
394 				   be16_to_cpu(group->rec.pkey), &pkey_index);
395 
396 	spin_lock_irq(&group->lock);
397 	if (group->state == MCAST_PKEY_EVENT && !ret &&
398 	    group->pkey_index == pkey_index)
399 		goto out;
400 
401 	while (!list_empty(&group->active_list)) {
402 		member = list_entry(group->active_list.next,
403 				    struct mcast_member, list);
404 		atomic_inc(&member->refcount);
405 		list_del_init(&member->list);
406 		adjust_membership(group, member->multicast.rec.join_state, -1);
407 		member->state = MCAST_ERROR;
408 		spin_unlock_irq(&group->lock);
409 
410 		ret = member->multicast.callback(-ENETRESET,
411 						 &member->multicast);
412 		deref_member(member);
413 		if (ret)
414 			ib_sa_free_multicast(&member->multicast);
415 		spin_lock_irq(&group->lock);
416 	}
417 
418 	group->rec.join_state = 0;
419 out:
420 	group->state = MCAST_BUSY;
421 	spin_unlock_irq(&group->lock);
422 }
423 
424 static void mcast_work_handler(struct work_struct *work)
425 {
426 	struct mcast_group *group;
427 	struct mcast_member *member;
428 	struct ib_sa_multicast *multicast;
429 	int status, ret;
430 	u8 join_state;
431 
432 	group = container_of(work, typeof(*group), work);
433 retest:
434 	spin_lock_irq(&group->lock);
435 	while (!list_empty(&group->pending_list) ||
436 	       (group->state != MCAST_BUSY)) {
437 
438 		if (group->state != MCAST_BUSY) {
439 			spin_unlock_irq(&group->lock);
440 			process_group_error(group);
441 			goto retest;
442 		}
443 
444 		member = list_entry(group->pending_list.next,
445 				    struct mcast_member, list);
446 		multicast = &member->multicast;
447 		join_state = multicast->rec.join_state;
448 		atomic_inc(&member->refcount);
449 
450 		if (join_state == (group->rec.join_state & join_state)) {
451 			status = cmp_rec(&group->rec, &multicast->rec,
452 					 multicast->comp_mask);
453 			if (!status)
454 				join_group(group, member, join_state);
455 			else
456 				list_del_init(&member->list);
457 			spin_unlock_irq(&group->lock);
458 			ret = multicast->callback(status, multicast);
459 		} else {
460 			spin_unlock_irq(&group->lock);
461 			status = send_join(group, member);
462 			if (!status) {
463 				deref_member(member);
464 				return;
465 			}
466 			ret = fail_join(group, member, status);
467 		}
468 
469 		deref_member(member);
470 		if (ret)
471 			ib_sa_free_multicast(&member->multicast);
472 		spin_lock_irq(&group->lock);
473 	}
474 
475 	join_state = get_leave_state(group);
476 	if (join_state) {
477 		group->rec.join_state &= ~join_state;
478 		spin_unlock_irq(&group->lock);
479 		if (send_leave(group, join_state))
480 			goto retest;
481 	} else {
482 		group->state = MCAST_IDLE;
483 		spin_unlock_irq(&group->lock);
484 		release_group(group);
485 	}
486 }
487 
488 /*
489  * Fail a join request if it is still active - at the head of the pending queue.
490  */
491 static void process_join_error(struct mcast_group *group, int status)
492 {
493 	struct mcast_member *member;
494 	int ret;
495 
496 	spin_lock_irq(&group->lock);
497 	member = list_entry(group->pending_list.next,
498 			    struct mcast_member, list);
499 	if (group->last_join == member) {
500 		atomic_inc(&member->refcount);
501 		list_del_init(&member->list);
502 		spin_unlock_irq(&group->lock);
503 		ret = member->multicast.callback(status, &member->multicast);
504 		deref_member(member);
505 		if (ret)
506 			ib_sa_free_multicast(&member->multicast);
507 	} else
508 		spin_unlock_irq(&group->lock);
509 }
510 
511 static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
512 			 void *context)
513 {
514 	struct mcast_group *group = context;
515 	u16 pkey_index = MCAST_INVALID_PKEY_INDEX;
516 
517 	if (status)
518 		process_join_error(group, status);
519 	else {
520 		int mgids_changed, is_mgid0;
521 
522 		if (ib_find_pkey(group->port->dev->device,
523 				 group->port->port_num, be16_to_cpu(rec->pkey),
524 				 &pkey_index))
525 			pkey_index = MCAST_INVALID_PKEY_INDEX;
526 
527 		spin_lock_irq(&group->port->lock);
528 		if (group->state == MCAST_BUSY &&
529 		    group->pkey_index == MCAST_INVALID_PKEY_INDEX)
530 			group->pkey_index = pkey_index;
531 		mgids_changed = memcmp(&rec->mgid, &group->rec.mgid,
532 				       sizeof(group->rec.mgid));
533 		group->rec = *rec;
534 		if (mgids_changed) {
535 			rb_erase(&group->node, &group->port->table);
536 			is_mgid0 = !memcmp(&mgid0, &group->rec.mgid,
537 					   sizeof(mgid0));
538 			mcast_insert(group->port, group, is_mgid0);
539 		}
540 		spin_unlock_irq(&group->port->lock);
541 	}
542 	mcast_work_handler(&group->work);
543 }
544 
545 static void leave_handler(int status, struct ib_sa_mcmember_rec *rec,
546 			  void *context)
547 {
548 	struct mcast_group *group = context;
549 
550 	if (status && group->retries > 0 &&
551 	    !send_leave(group, group->leave_state))
552 		group->retries--;
553 	else
554 		mcast_work_handler(&group->work);
555 }
556 
557 static struct mcast_group *acquire_group(struct mcast_port *port,
558 					 union ib_gid *mgid, gfp_t gfp_mask)
559 {
560 	struct mcast_group *group, *cur_group;
561 	unsigned long flags;
562 	int is_mgid0;
563 
564 	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
565 	if (!is_mgid0) {
566 		spin_lock_irqsave(&port->lock, flags);
567 		group = mcast_find(port, mgid);
568 		if (group)
569 			goto found;
570 		spin_unlock_irqrestore(&port->lock, flags);
571 	}
572 
573 	group = kzalloc(sizeof *group, gfp_mask);
574 	if (!group)
575 		return NULL;
576 
577 	group->retries = 3;
578 	group->port = port;
579 	group->rec.mgid = *mgid;
580 	group->pkey_index = MCAST_INVALID_PKEY_INDEX;
581 	INIT_LIST_HEAD(&group->pending_list);
582 	INIT_LIST_HEAD(&group->active_list);
583 	INIT_WORK(&group->work, mcast_work_handler);
584 	spin_lock_init(&group->lock);
585 
586 	spin_lock_irqsave(&port->lock, flags);
587 	cur_group = mcast_insert(port, group, is_mgid0);
588 	if (cur_group) {
589 		kfree(group);
590 		group = cur_group;
591 	} else
592 		atomic_inc(&port->refcount);
593 found:
594 	atomic_inc(&group->refcount);
595 	spin_unlock_irqrestore(&port->lock, flags);
596 	return group;
597 }
598 
599 /*
600  * We serialize all join requests to a single group to make our lives much
601  * easier.  Otherwise, two users could try to join the same group
602  * simultaneously, with different configurations, one could leave while the
603  * join is in progress, etc., which makes locking around error recovery
604  * difficult.
605  */
606 struct ib_sa_multicast *
607 ib_sa_join_multicast(struct ib_sa_client *client,
608 		     struct ib_device *device, u8 port_num,
609 		     struct ib_sa_mcmember_rec *rec,
610 		     ib_sa_comp_mask comp_mask, gfp_t gfp_mask,
611 		     int (*callback)(int status,
612 				     struct ib_sa_multicast *multicast),
613 		     void *context)
614 {
615 	struct mcast_device *dev;
616 	struct mcast_member *member;
617 	struct ib_sa_multicast *multicast;
618 	int ret;
619 
620 	dev = ib_get_client_data(device, &mcast_client);
621 	if (!dev)
622 		return ERR_PTR(-ENODEV);
623 
624 	member = kmalloc(sizeof *member, gfp_mask);
625 	if (!member)
626 		return ERR_PTR(-ENOMEM);
627 
628 	ib_sa_client_get(client);
629 	member->client = client;
630 	member->multicast.rec = *rec;
631 	member->multicast.comp_mask = comp_mask;
632 	member->multicast.callback = callback;
633 	member->multicast.context = context;
634 	init_completion(&member->comp);
635 	atomic_set(&member->refcount, 1);
636 	member->state = MCAST_JOINING;
637 
638 	member->group = acquire_group(&dev->port[port_num - dev->start_port],
639 				      &rec->mgid, gfp_mask);
640 	if (!member->group) {
641 		ret = -ENOMEM;
642 		goto err;
643 	}
644 
645 	/*
646 	 * The user will get the multicast structure in their callback.  They
647 	 * could then free the multicast structure before we can return from
648 	 * this routine.  So we save the pointer to return before queuing
649 	 * any callback.
650 	 */
651 	multicast = &member->multicast;
652 	queue_join(member);
653 	return multicast;
654 
655 err:
656 	ib_sa_client_put(client);
657 	kfree(member);
658 	return ERR_PTR(ret);
659 }
660 EXPORT_SYMBOL(ib_sa_join_multicast);
661 
662 void ib_sa_free_multicast(struct ib_sa_multicast *multicast)
663 {
664 	struct mcast_member *member;
665 	struct mcast_group *group;
666 
667 	member = container_of(multicast, struct mcast_member, multicast);
668 	group = member->group;
669 
670 	spin_lock_irq(&group->lock);
671 	if (member->state == MCAST_MEMBER)
672 		adjust_membership(group, multicast->rec.join_state, -1);
673 
674 	list_del_init(&member->list);
675 
676 	if (group->state == MCAST_IDLE) {
677 		group->state = MCAST_BUSY;
678 		spin_unlock_irq(&group->lock);
679 		/* Continue to hold reference on group until callback */
680 		queue_work(mcast_wq, &group->work);
681 	} else {
682 		spin_unlock_irq(&group->lock);
683 		release_group(group);
684 	}
685 
686 	deref_member(member);
687 	wait_for_completion(&member->comp);
688 	ib_sa_client_put(member->client);
689 	kfree(member);
690 }
691 EXPORT_SYMBOL(ib_sa_free_multicast);
692 
693 int ib_sa_get_mcmember_rec(struct ib_device *device, u8 port_num,
694 			   union ib_gid *mgid, struct ib_sa_mcmember_rec *rec)
695 {
696 	struct mcast_device *dev;
697 	struct mcast_port *port;
698 	struct mcast_group *group;
699 	unsigned long flags;
700 	int ret = 0;
701 
702 	dev = ib_get_client_data(device, &mcast_client);
703 	if (!dev)
704 		return -ENODEV;
705 
706 	port = &dev->port[port_num - dev->start_port];
707 	spin_lock_irqsave(&port->lock, flags);
708 	group = mcast_find(port, mgid);
709 	if (group)
710 		*rec = group->rec;
711 	else
712 		ret = -EADDRNOTAVAIL;
713 	spin_unlock_irqrestore(&port->lock, flags);
714 
715 	return ret;
716 }
717 EXPORT_SYMBOL(ib_sa_get_mcmember_rec);
718 
719 /**
720  * ib_init_ah_from_mcmember - Initialize AH attribute from multicast
721  * member record and gid of the device.
722  * @device:	RDMA device
723  * @port_num:	Port of the rdma device to consider
724  * @ndev:	Optional netdevice, applicable only for RoCE
725  * @gid_type:	GID type to consider
726  * @ah_attr:	AH attribute to fillup on successful completion
727  *
728  * ib_init_ah_from_mcmember() initializes AH attribute based on multicast
729  * member record and other device properties. On success the caller is
730  * responsible to call rdma_destroy_ah_attr on the ah_attr. Returns 0 on
731  * success or appropriate error code.
732  *
733  */
734 int ib_init_ah_from_mcmember(struct ib_device *device, u8 port_num,
735 			     struct ib_sa_mcmember_rec *rec,
736 			     struct net_device *ndev,
737 			     enum ib_gid_type gid_type,
738 			     struct rdma_ah_attr *ah_attr)
739 {
740 	const struct ib_gid_attr *sgid_attr;
741 
742 	/* GID table is not based on the netdevice for IB link layer,
743 	 * so ignore ndev during search.
744 	 */
745 	if (rdma_protocol_ib(device, port_num))
746 		ndev = NULL;
747 	else if (!rdma_protocol_roce(device, port_num))
748 		return -EINVAL;
749 
750 	sgid_attr = rdma_find_gid_by_port(device, &rec->port_gid,
751 					  gid_type, port_num, ndev);
752 	if (IS_ERR(sgid_attr))
753 		return PTR_ERR(sgid_attr);
754 
755 	memset(ah_attr, 0, sizeof(*ah_attr));
756 	ah_attr->type = rdma_ah_find_type(device, port_num);
757 
758 	rdma_ah_set_dlid(ah_attr, be16_to_cpu(rec->mlid));
759 	rdma_ah_set_sl(ah_attr, rec->sl);
760 	rdma_ah_set_port_num(ah_attr, port_num);
761 	rdma_ah_set_static_rate(ah_attr, rec->rate);
762 	rdma_move_grh_sgid_attr(ah_attr, &rec->mgid,
763 				be32_to_cpu(rec->flow_label),
764 				rec->hop_limit,	rec->traffic_class,
765 				sgid_attr);
766 	return 0;
767 }
768 EXPORT_SYMBOL(ib_init_ah_from_mcmember);
769 
770 static void mcast_groups_event(struct mcast_port *port,
771 			       enum mcast_group_state state)
772 {
773 	struct mcast_group *group;
774 	struct rb_node *node;
775 	unsigned long flags;
776 
777 	spin_lock_irqsave(&port->lock, flags);
778 	for (node = rb_first(&port->table); node; node = rb_next(node)) {
779 		group = rb_entry(node, struct mcast_group, node);
780 		spin_lock(&group->lock);
781 		if (group->state == MCAST_IDLE) {
782 			atomic_inc(&group->refcount);
783 			queue_work(mcast_wq, &group->work);
784 		}
785 		if (group->state != MCAST_GROUP_ERROR)
786 			group->state = state;
787 		spin_unlock(&group->lock);
788 	}
789 	spin_unlock_irqrestore(&port->lock, flags);
790 }
791 
792 static void mcast_event_handler(struct ib_event_handler *handler,
793 				struct ib_event *event)
794 {
795 	struct mcast_device *dev;
796 	int index;
797 
798 	dev = container_of(handler, struct mcast_device, event_handler);
799 	if (!rdma_cap_ib_mcast(dev->device, event->element.port_num))
800 		return;
801 
802 	index = event->element.port_num - dev->start_port;
803 
804 	switch (event->event) {
805 	case IB_EVENT_PORT_ERR:
806 	case IB_EVENT_LID_CHANGE:
807 	case IB_EVENT_SM_CHANGE:
808 	case IB_EVENT_CLIENT_REREGISTER:
809 		mcast_groups_event(&dev->port[index], MCAST_GROUP_ERROR);
810 		break;
811 	case IB_EVENT_PKEY_CHANGE:
812 		mcast_groups_event(&dev->port[index], MCAST_PKEY_EVENT);
813 		break;
814 	default:
815 		break;
816 	}
817 }
818 
819 static void mcast_add_one(struct ib_device *device)
820 {
821 	struct mcast_device *dev;
822 	struct mcast_port *port;
823 	int i;
824 	int count = 0;
825 
826 	dev = kmalloc(struct_size(dev, port, device->phys_port_cnt),
827 		      GFP_KERNEL);
828 	if (!dev)
829 		return;
830 
831 	dev->start_port = rdma_start_port(device);
832 	dev->end_port = rdma_end_port(device);
833 
834 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
835 		if (!rdma_cap_ib_mcast(device, dev->start_port + i))
836 			continue;
837 		port = &dev->port[i];
838 		port->dev = dev;
839 		port->port_num = dev->start_port + i;
840 		spin_lock_init(&port->lock);
841 		port->table = RB_ROOT;
842 		init_completion(&port->comp);
843 		atomic_set(&port->refcount, 1);
844 		++count;
845 	}
846 
847 	if (!count) {
848 		kfree(dev);
849 		return;
850 	}
851 
852 	dev->device = device;
853 	ib_set_client_data(device, &mcast_client, dev);
854 
855 	INIT_IB_EVENT_HANDLER(&dev->event_handler, device, mcast_event_handler);
856 	ib_register_event_handler(&dev->event_handler);
857 }
858 
859 static void mcast_remove_one(struct ib_device *device, void *client_data)
860 {
861 	struct mcast_device *dev = client_data;
862 	struct mcast_port *port;
863 	int i;
864 
865 	if (!dev)
866 		return;
867 
868 	ib_unregister_event_handler(&dev->event_handler);
869 	flush_workqueue(mcast_wq);
870 
871 	for (i = 0; i <= dev->end_port - dev->start_port; i++) {
872 		if (rdma_cap_ib_mcast(device, dev->start_port + i)) {
873 			port = &dev->port[i];
874 			deref_port(port);
875 			wait_for_completion(&port->comp);
876 		}
877 	}
878 
879 	kfree(dev);
880 }
881 
882 int mcast_init(void)
883 {
884 	int ret;
885 
886 	mcast_wq = alloc_ordered_workqueue("ib_mcast", WQ_MEM_RECLAIM);
887 	if (!mcast_wq)
888 		return -ENOMEM;
889 
890 	ib_sa_register_client(&sa_client);
891 
892 	ret = ib_register_client(&mcast_client);
893 	if (ret)
894 		goto err;
895 	return 0;
896 
897 err:
898 	ib_sa_unregister_client(&sa_client);
899 	destroy_workqueue(mcast_wq);
900 	return ret;
901 }
902 
903 void mcast_cleanup(void)
904 {
905 	ib_unregister_client(&mcast_client);
906 	ib_sa_unregister_client(&sa_client);
907 	destroy_workqueue(mcast_wq);
908 }
909