xref: /linux/drivers/infiniband/hw/mlx4/mcg.c (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
1 /*
2  * Copyright (c) 2012 Mellanox Technologies. 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 <rdma/ib_mad.h>
34 #include <rdma/ib_smi.h>
35 #include <rdma/ib_cache.h>
36 #include <rdma/ib_sa.h>
37 
38 #include <linux/mlx4/cmd.h>
39 #include <linux/rbtree.h>
40 #include <linux/delay.h>
41 
42 #include "mlx4_ib.h"
43 
44 #define MAX_VFS		80
45 #define MAX_PEND_REQS_PER_FUNC 4
46 #define MAD_TIMEOUT_MS	2000
47 
48 #define mcg_warn(fmt, arg...)	pr_warn("MCG WARNING: " fmt, ##arg)
49 #define mcg_error(fmt, arg...)	pr_err(fmt, ##arg)
50 #define mcg_warn_group(group, format, arg...) \
51 	pr_warn("%s-%d: %16s (port %d): WARNING: " format, __func__, __LINE__,\
52 	(group)->name, group->demux->port, ## arg)
53 
54 #define mcg_error_group(group, format, arg...) \
55 	pr_err("  %16s: " format, (group)->name, ## arg)
56 
57 
58 static union ib_gid mgid0;
59 
60 static struct workqueue_struct *clean_wq;
61 
62 enum mcast_state {
63 	MCAST_NOT_MEMBER = 0,
64 	MCAST_MEMBER,
65 };
66 
67 enum mcast_group_state {
68 	MCAST_IDLE,
69 	MCAST_JOIN_SENT,
70 	MCAST_LEAVE_SENT,
71 	MCAST_RESP_READY
72 };
73 
74 struct mcast_member {
75 	enum mcast_state state;
76 	uint8_t			join_state;
77 	int			num_pend_reqs;
78 	struct list_head	pending;
79 };
80 
81 struct ib_sa_mcmember_data {
82 	union ib_gid	mgid;
83 	union ib_gid	port_gid;
84 	__be32		qkey;
85 	__be16		mlid;
86 	u8		mtusel_mtu;
87 	u8		tclass;
88 	__be16		pkey;
89 	u8		ratesel_rate;
90 	u8		lifetmsel_lifetm;
91 	__be32		sl_flowlabel_hoplimit;
92 	u8		scope_join_state;
93 	u8		proxy_join;
94 	u8		reserved[2];
95 };
96 
97 struct mcast_group {
98 	struct ib_sa_mcmember_data rec;
99 	struct rb_node		node;
100 	struct list_head	mgid0_list;
101 	struct mlx4_ib_demux_ctx *demux;
102 	struct mcast_member	func[MAX_VFS];
103 	struct mutex		lock;
104 	struct work_struct	work;
105 	struct list_head	pending_list;
106 	int			members[3];
107 	enum mcast_group_state	state;
108 	enum mcast_group_state	prev_state;
109 	struct ib_sa_mad	response_sa_mad;
110 	__be64			last_req_tid;
111 
112 	char			name[33]; /* MGID string */
113 	struct device_attribute	dentry;
114 
115 	/* refcount is the reference count for the following:
116 	   1. Each queued request
117 	   2. Each invocation of the worker thread
118 	   3. Membership of the port at the SA
119 	*/
120 	atomic_t		refcount;
121 
122 	/* delayed work to clean pending SM request */
123 	struct delayed_work	timeout_work;
124 	struct list_head	cleanup_list;
125 };
126 
127 struct mcast_req {
128 	int			func;
129 	struct ib_sa_mad	sa_mad;
130 	struct list_head	group_list;
131 	struct list_head	func_list;
132 	struct mcast_group	*group;
133 	int			clean;
134 };
135 
136 
137 #define safe_atomic_dec(ref) \
138 	do {\
139 		if (atomic_dec_and_test(ref)) \
140 			mcg_warn_group(group, "did not expect to reach zero\n"); \
141 	} while (0)
142 
143 static const char *get_state_string(enum mcast_group_state state)
144 {
145 	switch (state) {
146 	case MCAST_IDLE:
147 		return "MCAST_IDLE";
148 	case MCAST_JOIN_SENT:
149 		return "MCAST_JOIN_SENT";
150 	case MCAST_LEAVE_SENT:
151 		return "MCAST_LEAVE_SENT";
152 	case MCAST_RESP_READY:
153 		return "MCAST_RESP_READY";
154 	}
155 	return "Invalid State";
156 }
157 
158 static struct mcast_group *mcast_find(struct mlx4_ib_demux_ctx *ctx,
159 				      union ib_gid *mgid)
160 {
161 	struct rb_node *node = ctx->mcg_table.rb_node;
162 	struct mcast_group *group;
163 	int ret;
164 
165 	while (node) {
166 		group = rb_entry(node, struct mcast_group, node);
167 		ret = memcmp(mgid->raw, group->rec.mgid.raw, sizeof *mgid);
168 		if (!ret)
169 			return group;
170 
171 		if (ret < 0)
172 			node = node->rb_left;
173 		else
174 			node = node->rb_right;
175 	}
176 	return NULL;
177 }
178 
179 static struct mcast_group *mcast_insert(struct mlx4_ib_demux_ctx *ctx,
180 					struct mcast_group *group)
181 {
182 	struct rb_node **link = &ctx->mcg_table.rb_node;
183 	struct rb_node *parent = NULL;
184 	struct mcast_group *cur_group;
185 	int ret;
186 
187 	while (*link) {
188 		parent = *link;
189 		cur_group = rb_entry(parent, struct mcast_group, node);
190 
191 		ret = memcmp(group->rec.mgid.raw, cur_group->rec.mgid.raw,
192 			     sizeof group->rec.mgid);
193 		if (ret < 0)
194 			link = &(*link)->rb_left;
195 		else if (ret > 0)
196 			link = &(*link)->rb_right;
197 		else
198 			return cur_group;
199 	}
200 	rb_link_node(&group->node, parent, link);
201 	rb_insert_color(&group->node, &ctx->mcg_table);
202 	return NULL;
203 }
204 
205 static int send_mad_to_wire(struct mlx4_ib_demux_ctx *ctx, struct ib_mad *mad)
206 {
207 	struct mlx4_ib_dev *dev = ctx->dev;
208 	struct ib_ah_attr	ah_attr;
209 
210 	spin_lock(&dev->sm_lock);
211 	if (!dev->sm_ah[ctx->port - 1]) {
212 		/* port is not yet Active, sm_ah not ready */
213 		spin_unlock(&dev->sm_lock);
214 		return -EAGAIN;
215 	}
216 	mlx4_ib_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);
217 	spin_unlock(&dev->sm_lock);
218 	return mlx4_ib_send_to_wire(dev, mlx4_master_func_num(dev->dev), ctx->port,
219 				    IB_QPT_GSI, 0, 1, IB_QP1_QKEY, &ah_attr, mad);
220 }
221 
222 static int send_mad_to_slave(int slave, struct mlx4_ib_demux_ctx *ctx,
223 			     struct ib_mad *mad)
224 {
225 	struct mlx4_ib_dev *dev = ctx->dev;
226 	struct ib_mad_agent *agent = dev->send_agent[ctx->port - 1][1];
227 	struct ib_wc wc;
228 	struct ib_ah_attr ah_attr;
229 
230 	/* Our agent might not yet be registered when mads start to arrive */
231 	if (!agent)
232 		return -EAGAIN;
233 
234 	ib_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);
235 
236 	wc.pkey_index = 0;
237 	wc.sl = 0;
238 	wc.dlid_path_bits = 0;
239 	wc.port_num = ctx->port;
240 	wc.slid = ah_attr.dlid;  /* opensm lid */
241 	wc.src_qp = 1;
242 	return mlx4_ib_send_to_slave(dev, slave, ctx->port, IB_QPT_GSI, &wc, NULL, mad);
243 }
244 
245 static int send_join_to_wire(struct mcast_group *group, struct ib_sa_mad *sa_mad)
246 {
247 	struct ib_sa_mad mad;
248 	struct ib_sa_mcmember_data *sa_mad_data = (struct ib_sa_mcmember_data *)&mad.data;
249 	int ret;
250 
251 	/* we rely on a mad request as arrived from a VF */
252 	memcpy(&mad, sa_mad, sizeof mad);
253 
254 	/* fix port GID to be the real one (slave 0) */
255 	sa_mad_data->port_gid.global.interface_id = group->demux->guid_cache[0];
256 
257 	/* assign our own TID */
258 	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
259 	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */
260 
261 	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
262 	/* set timeout handler */
263 	if (!ret) {
264 		/* calls mlx4_ib_mcg_timeout_handler */
265 		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
266 				msecs_to_jiffies(MAD_TIMEOUT_MS));
267 	}
268 
269 	return ret;
270 }
271 
272 static int send_leave_to_wire(struct mcast_group *group, u8 join_state)
273 {
274 	struct ib_sa_mad mad;
275 	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
276 	int ret;
277 
278 	memset(&mad, 0, sizeof mad);
279 	mad.mad_hdr.base_version = 1;
280 	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
281 	mad.mad_hdr.class_version = 2;
282 	mad.mad_hdr.method = IB_SA_METHOD_DELETE;
283 	mad.mad_hdr.status = cpu_to_be16(0);
284 	mad.mad_hdr.class_specific = cpu_to_be16(0);
285 	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
286 	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */
287 	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
288 	mad.mad_hdr.attr_mod = cpu_to_be32(0);
289 	mad.sa_hdr.sm_key = 0x0;
290 	mad.sa_hdr.attr_offset = cpu_to_be16(7);
291 	mad.sa_hdr.comp_mask = IB_SA_MCMEMBER_REC_MGID |
292 		IB_SA_MCMEMBER_REC_PORT_GID | IB_SA_MCMEMBER_REC_JOIN_STATE;
293 
294 	*sa_data = group->rec;
295 	sa_data->scope_join_state = join_state;
296 
297 	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
298 	if (ret)
299 		group->state = MCAST_IDLE;
300 
301 	/* set timeout handler */
302 	if (!ret) {
303 		/* calls mlx4_ib_mcg_timeout_handler */
304 		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
305 				msecs_to_jiffies(MAD_TIMEOUT_MS));
306 	}
307 
308 	return ret;
309 }
310 
311 static int send_reply_to_slave(int slave, struct mcast_group *group,
312 		struct ib_sa_mad *req_sa_mad, u16 status)
313 {
314 	struct ib_sa_mad mad;
315 	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
316 	struct ib_sa_mcmember_data *req_sa_data = (struct ib_sa_mcmember_data *)&req_sa_mad->data;
317 	int ret;
318 
319 	memset(&mad, 0, sizeof mad);
320 	mad.mad_hdr.base_version = 1;
321 	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
322 	mad.mad_hdr.class_version = 2;
323 	mad.mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
324 	mad.mad_hdr.status = cpu_to_be16(status);
325 	mad.mad_hdr.class_specific = cpu_to_be16(0);
326 	mad.mad_hdr.tid = req_sa_mad->mad_hdr.tid;
327 	*(u8 *)&mad.mad_hdr.tid = 0; /* resetting tid to 0 */
328 	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
329 	mad.mad_hdr.attr_mod = cpu_to_be32(0);
330 	mad.sa_hdr.sm_key = req_sa_mad->sa_hdr.sm_key;
331 	mad.sa_hdr.attr_offset = cpu_to_be16(7);
332 	mad.sa_hdr.comp_mask = 0; /* ignored on responses, see IBTA spec */
333 
334 	*sa_data = group->rec;
335 
336 	/* reconstruct VF's requested join_state and port_gid */
337 	sa_data->scope_join_state &= 0xf0;
338 	sa_data->scope_join_state |= (group->func[slave].join_state & 0x0f);
339 	memcpy(&sa_data->port_gid, &req_sa_data->port_gid, sizeof req_sa_data->port_gid);
340 
341 	ret = send_mad_to_slave(slave, group->demux, (struct ib_mad *)&mad);
342 	return ret;
343 }
344 
345 static int check_selector(ib_sa_comp_mask comp_mask,
346 			  ib_sa_comp_mask selector_mask,
347 			  ib_sa_comp_mask value_mask,
348 			  u8 src_value, u8 dst_value)
349 {
350 	int err;
351 	u8 selector = dst_value >> 6;
352 	dst_value &= 0x3f;
353 	src_value &= 0x3f;
354 
355 	if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
356 		return 0;
357 
358 	switch (selector) {
359 	case IB_SA_GT:
360 		err = (src_value <= dst_value);
361 		break;
362 	case IB_SA_LT:
363 		err = (src_value >= dst_value);
364 		break;
365 	case IB_SA_EQ:
366 		err = (src_value != dst_value);
367 		break;
368 	default:
369 		err = 0;
370 		break;
371 	}
372 
373 	return err;
374 }
375 
376 static u16 cmp_rec(struct ib_sa_mcmember_data *src,
377 		   struct ib_sa_mcmember_data *dst, ib_sa_comp_mask comp_mask)
378 {
379 	/* src is group record, dst is request record */
380 	/* MGID must already match */
381 	/* Port_GID we always replace to our Port_GID, so it is a match */
382 
383 #define MAD_STATUS_REQ_INVALID 0x0200
384 	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
385 		return MAD_STATUS_REQ_INVALID;
386 	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
387 		return MAD_STATUS_REQ_INVALID;
388 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
389 				 IB_SA_MCMEMBER_REC_MTU,
390 				 src->mtusel_mtu, dst->mtusel_mtu))
391 		return MAD_STATUS_REQ_INVALID;
392 	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
393 	    src->tclass != dst->tclass)
394 		return MAD_STATUS_REQ_INVALID;
395 	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
396 		return MAD_STATUS_REQ_INVALID;
397 	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
398 				 IB_SA_MCMEMBER_REC_RATE,
399 				 src->ratesel_rate, dst->ratesel_rate))
400 		return MAD_STATUS_REQ_INVALID;
401 	if (check_selector(comp_mask,
402 				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
403 				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
404 				 src->lifetmsel_lifetm, dst->lifetmsel_lifetm))
405 		return MAD_STATUS_REQ_INVALID;
406 	if (comp_mask & IB_SA_MCMEMBER_REC_SL &&
407 			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0xf0000000) !=
408 			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0xf0000000))
409 		return MAD_STATUS_REQ_INVALID;
410 	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
411 			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x0fffff00) !=
412 			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x0fffff00))
413 		return MAD_STATUS_REQ_INVALID;
414 	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
415 			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x000000ff) !=
416 			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x000000ff))
417 		return MAD_STATUS_REQ_INVALID;
418 	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE &&
419 			(src->scope_join_state & 0xf0) !=
420 			(dst->scope_join_state & 0xf0))
421 		return MAD_STATUS_REQ_INVALID;
422 
423 	/* join_state checked separately, proxy_join ignored */
424 
425 	return 0;
426 }
427 
428 /* release group, return 1 if this was last release and group is destroyed
429  * timout work is canceled sync */
430 static int release_group(struct mcast_group *group, int from_timeout_handler)
431 {
432 	struct mlx4_ib_demux_ctx *ctx = group->demux;
433 	int nzgroup;
434 
435 	mutex_lock(&ctx->mcg_table_lock);
436 	mutex_lock(&group->lock);
437 	if (atomic_dec_and_test(&group->refcount)) {
438 		if (!from_timeout_handler) {
439 			if (group->state != MCAST_IDLE &&
440 			    !cancel_delayed_work(&group->timeout_work)) {
441 				atomic_inc(&group->refcount);
442 				mutex_unlock(&group->lock);
443 				mutex_unlock(&ctx->mcg_table_lock);
444 				return 0;
445 			}
446 		}
447 
448 		nzgroup = memcmp(&group->rec.mgid, &mgid0, sizeof mgid0);
449 		if (nzgroup)
450 			del_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
451 		if (!list_empty(&group->pending_list))
452 			mcg_warn_group(group, "releasing a group with non empty pending list\n");
453 		if (nzgroup)
454 			rb_erase(&group->node, &ctx->mcg_table);
455 		list_del_init(&group->mgid0_list);
456 		mutex_unlock(&group->lock);
457 		mutex_unlock(&ctx->mcg_table_lock);
458 		kfree(group);
459 		return 1;
460 	} else {
461 		mutex_unlock(&group->lock);
462 		mutex_unlock(&ctx->mcg_table_lock);
463 	}
464 	return 0;
465 }
466 
467 static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
468 {
469 	int i;
470 
471 	for (i = 0; i < 3; i++, join_state >>= 1)
472 		if (join_state & 0x1)
473 			group->members[i] += inc;
474 }
475 
476 static u8 get_leave_state(struct mcast_group *group)
477 {
478 	u8 leave_state = 0;
479 	int i;
480 
481 	for (i = 0; i < 3; i++)
482 		if (!group->members[i])
483 			leave_state |= (1 << i);
484 
485 	return leave_state & (group->rec.scope_join_state & 7);
486 }
487 
488 static int join_group(struct mcast_group *group, int slave, u8 join_mask)
489 {
490 	int ret = 0;
491 	u8 join_state;
492 
493 	/* remove bits that slave is already member of, and adjust */
494 	join_state = join_mask & (~group->func[slave].join_state);
495 	adjust_membership(group, join_state, 1);
496 	group->func[slave].join_state |= join_state;
497 	if (group->func[slave].state != MCAST_MEMBER && join_state) {
498 		group->func[slave].state = MCAST_MEMBER;
499 		ret = 1;
500 	}
501 	return ret;
502 }
503 
504 static int leave_group(struct mcast_group *group, int slave, u8 leave_state)
505 {
506 	int ret = 0;
507 
508 	adjust_membership(group, leave_state, -1);
509 	group->func[slave].join_state &= ~leave_state;
510 	if (!group->func[slave].join_state) {
511 		group->func[slave].state = MCAST_NOT_MEMBER;
512 		ret = 1;
513 	}
514 	return ret;
515 }
516 
517 static int check_leave(struct mcast_group *group, int slave, u8 leave_mask)
518 {
519 	if (group->func[slave].state != MCAST_MEMBER)
520 		return MAD_STATUS_REQ_INVALID;
521 
522 	/* make sure we're not deleting unset bits */
523 	if (~group->func[slave].join_state & leave_mask)
524 		return MAD_STATUS_REQ_INVALID;
525 
526 	if (!leave_mask)
527 		return MAD_STATUS_REQ_INVALID;
528 
529 	return 0;
530 }
531 
532 static void mlx4_ib_mcg_timeout_handler(struct work_struct *work)
533 {
534 	struct delayed_work *delay = to_delayed_work(work);
535 	struct mcast_group *group;
536 	struct mcast_req *req = NULL;
537 
538 	group = container_of(delay, typeof(*group), timeout_work);
539 
540 	mutex_lock(&group->lock);
541 	if (group->state == MCAST_JOIN_SENT) {
542 		if (!list_empty(&group->pending_list)) {
543 			req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
544 			list_del(&req->group_list);
545 			list_del(&req->func_list);
546 			--group->func[req->func].num_pend_reqs;
547 			mutex_unlock(&group->lock);
548 			kfree(req);
549 			if (memcmp(&group->rec.mgid, &mgid0, sizeof mgid0)) {
550 				if (release_group(group, 1))
551 					return;
552 			} else {
553 				kfree(group);
554 				return;
555 			}
556 			mutex_lock(&group->lock);
557 		} else
558 			mcg_warn_group(group, "DRIVER BUG\n");
559 	} else if (group->state == MCAST_LEAVE_SENT) {
560 		if (group->rec.scope_join_state & 7)
561 			group->rec.scope_join_state &= 0xf8;
562 		group->state = MCAST_IDLE;
563 		mutex_unlock(&group->lock);
564 		if (release_group(group, 1))
565 			return;
566 		mutex_lock(&group->lock);
567 	} else
568 		mcg_warn_group(group, "invalid state %s\n", get_state_string(group->state));
569 	group->state = MCAST_IDLE;
570 	atomic_inc(&group->refcount);
571 	if (!queue_work(group->demux->mcg_wq, &group->work))
572 		safe_atomic_dec(&group->refcount);
573 
574 	mutex_unlock(&group->lock);
575 }
576 
577 static int handle_leave_req(struct mcast_group *group, u8 leave_mask,
578 			    struct mcast_req *req)
579 {
580 	u16 status;
581 
582 	if (req->clean)
583 		leave_mask = group->func[req->func].join_state;
584 
585 	status = check_leave(group, req->func, leave_mask);
586 	if (!status)
587 		leave_group(group, req->func, leave_mask);
588 
589 	if (!req->clean)
590 		send_reply_to_slave(req->func, group, &req->sa_mad, status);
591 	--group->func[req->func].num_pend_reqs;
592 	list_del(&req->group_list);
593 	list_del(&req->func_list);
594 	kfree(req);
595 	return 1;
596 }
597 
598 static int handle_join_req(struct mcast_group *group, u8 join_mask,
599 			   struct mcast_req *req)
600 {
601 	u8 group_join_state = group->rec.scope_join_state & 7;
602 	int ref = 0;
603 	u16 status;
604 	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;
605 
606 	if (join_mask == (group_join_state & join_mask)) {
607 		/* port's membership need not change */
608 		status = cmp_rec(&group->rec, sa_data, req->sa_mad.sa_hdr.comp_mask);
609 		if (!status)
610 			join_group(group, req->func, join_mask);
611 
612 		--group->func[req->func].num_pend_reqs;
613 		send_reply_to_slave(req->func, group, &req->sa_mad, status);
614 		list_del(&req->group_list);
615 		list_del(&req->func_list);
616 		kfree(req);
617 		++ref;
618 	} else {
619 		/* port's membership needs to be updated */
620 		group->prev_state = group->state;
621 		if (send_join_to_wire(group, &req->sa_mad)) {
622 			--group->func[req->func].num_pend_reqs;
623 			list_del(&req->group_list);
624 			list_del(&req->func_list);
625 			kfree(req);
626 			ref = 1;
627 			group->state = group->prev_state;
628 		} else
629 			group->state = MCAST_JOIN_SENT;
630 	}
631 
632 	return ref;
633 }
634 
635 static void mlx4_ib_mcg_work_handler(struct work_struct *work)
636 {
637 	struct mcast_group *group;
638 	struct mcast_req *req = NULL;
639 	struct ib_sa_mcmember_data *sa_data;
640 	u8 req_join_state;
641 	int rc = 1; /* release_count - this is for the scheduled work */
642 	u16 status;
643 	u8 method;
644 
645 	group = container_of(work, typeof(*group), work);
646 
647 	mutex_lock(&group->lock);
648 
649 	/* First, let's see if a response from SM is waiting regarding this group.
650 	 * If so, we need to update the group's REC. If this is a bad response, we
651 	 * may need to send a bad response to a VF waiting for it. If VF is waiting
652 	 * and this is a good response, the VF will be answered later in this func. */
653 	if (group->state == MCAST_RESP_READY) {
654 		/* cancels mlx4_ib_mcg_timeout_handler */
655 		cancel_delayed_work(&group->timeout_work);
656 		status = be16_to_cpu(group->response_sa_mad.mad_hdr.status);
657 		method = group->response_sa_mad.mad_hdr.method;
658 		if (group->last_req_tid != group->response_sa_mad.mad_hdr.tid) {
659 			mcg_warn_group(group, "Got MAD response to existing MGID but wrong TID, dropping. Resp TID=%llx, group TID=%llx\n",
660 				be64_to_cpu(group->response_sa_mad.mad_hdr.tid),
661 				be64_to_cpu(group->last_req_tid));
662 			group->state = group->prev_state;
663 			goto process_requests;
664 		}
665 		if (status) {
666 			if (!list_empty(&group->pending_list))
667 				req = list_first_entry(&group->pending_list,
668 						struct mcast_req, group_list);
669 			if ((method == IB_MGMT_METHOD_GET_RESP)) {
670 					if (req) {
671 						send_reply_to_slave(req->func, group, &req->sa_mad, status);
672 						--group->func[req->func].num_pend_reqs;
673 						list_del(&req->group_list);
674 						list_del(&req->func_list);
675 						kfree(req);
676 						++rc;
677 					} else
678 						mcg_warn_group(group, "no request for failed join\n");
679 			} else if (method == IB_SA_METHOD_DELETE_RESP && group->demux->flushing)
680 				++rc;
681 		} else {
682 			u8 resp_join_state;
683 			u8 cur_join_state;
684 
685 			resp_join_state = ((struct ib_sa_mcmember_data *)
686 						group->response_sa_mad.data)->scope_join_state & 7;
687 			cur_join_state = group->rec.scope_join_state & 7;
688 
689 			if (method == IB_MGMT_METHOD_GET_RESP) {
690 				/* successfull join */
691 				if (!cur_join_state && resp_join_state)
692 					--rc;
693 			} else if (!resp_join_state)
694 					++rc;
695 			memcpy(&group->rec, group->response_sa_mad.data, sizeof group->rec);
696 		}
697 		group->state = MCAST_IDLE;
698 	}
699 
700 process_requests:
701 	/* We should now go over pending join/leave requests, as long as we are idle. */
702 	while (!list_empty(&group->pending_list) && group->state == MCAST_IDLE) {
703 		req = list_first_entry(&group->pending_list, struct mcast_req,
704 				       group_list);
705 		sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;
706 		req_join_state = sa_data->scope_join_state & 0x7;
707 
708 		/* For a leave request, we will immediately answer the VF, and
709 		 * update our internal counters. The actual leave will be sent
710 		 * to SM later, if at all needed. We dequeue the request now. */
711 		if (req->sa_mad.mad_hdr.method == IB_SA_METHOD_DELETE)
712 			rc += handle_leave_req(group, req_join_state, req);
713 		else
714 			rc += handle_join_req(group, req_join_state, req);
715 	}
716 
717 	/* Handle leaves */
718 	if (group->state == MCAST_IDLE) {
719 		req_join_state = get_leave_state(group);
720 		if (req_join_state) {
721 			group->rec.scope_join_state &= ~req_join_state;
722 			group->prev_state = group->state;
723 			if (send_leave_to_wire(group, req_join_state)) {
724 				group->state = group->prev_state;
725 				++rc;
726 			} else
727 				group->state = MCAST_LEAVE_SENT;
728 		}
729 	}
730 
731 	if (!list_empty(&group->pending_list) && group->state == MCAST_IDLE)
732 		goto process_requests;
733 	mutex_unlock(&group->lock);
734 
735 	while (rc--)
736 		release_group(group, 0);
737 }
738 
739 static struct mcast_group *search_relocate_mgid0_group(struct mlx4_ib_demux_ctx *ctx,
740 						       __be64 tid,
741 						       union ib_gid *new_mgid)
742 {
743 	struct mcast_group *group = NULL, *cur_group;
744 	struct mcast_req *req;
745 	struct list_head *pos;
746 	struct list_head *n;
747 
748 	mutex_lock(&ctx->mcg_table_lock);
749 	list_for_each_safe(pos, n, &ctx->mcg_mgid0_list) {
750 		group = list_entry(pos, struct mcast_group, mgid0_list);
751 		mutex_lock(&group->lock);
752 		if (group->last_req_tid == tid) {
753 			if (memcmp(new_mgid, &mgid0, sizeof mgid0)) {
754 				group->rec.mgid = *new_mgid;
755 				sprintf(group->name, "%016llx%016llx",
756 						be64_to_cpu(group->rec.mgid.global.subnet_prefix),
757 						be64_to_cpu(group->rec.mgid.global.interface_id));
758 				list_del_init(&group->mgid0_list);
759 				cur_group = mcast_insert(ctx, group);
760 				if (cur_group) {
761 					/* A race between our code and SM. Silently cleaning the new one */
762 					req = list_first_entry(&group->pending_list,
763 							       struct mcast_req, group_list);
764 					--group->func[req->func].num_pend_reqs;
765 					list_del(&req->group_list);
766 					list_del(&req->func_list);
767 					kfree(req);
768 					mutex_unlock(&group->lock);
769 					mutex_unlock(&ctx->mcg_table_lock);
770 					release_group(group, 0);
771 					return NULL;
772 				}
773 
774 				atomic_inc(&group->refcount);
775 				add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
776 				mutex_unlock(&group->lock);
777 				mutex_unlock(&ctx->mcg_table_lock);
778 				return group;
779 			} else {
780 				struct mcast_req *tmp1, *tmp2;
781 
782 				list_del(&group->mgid0_list);
783 				if (!list_empty(&group->pending_list) && group->state != MCAST_IDLE)
784 					cancel_delayed_work_sync(&group->timeout_work);
785 
786 				list_for_each_entry_safe(tmp1, tmp2, &group->pending_list, group_list) {
787 					list_del(&tmp1->group_list);
788 					kfree(tmp1);
789 				}
790 				mutex_unlock(&group->lock);
791 				mutex_unlock(&ctx->mcg_table_lock);
792 				kfree(group);
793 				return NULL;
794 			}
795 		}
796 		mutex_unlock(&group->lock);
797 	}
798 	mutex_unlock(&ctx->mcg_table_lock);
799 
800 	return NULL;
801 }
802 
803 static ssize_t sysfs_show_group(struct device *dev,
804 		struct device_attribute *attr, char *buf);
805 
806 static struct mcast_group *acquire_group(struct mlx4_ib_demux_ctx *ctx,
807 					 union ib_gid *mgid, int create,
808 					 gfp_t gfp_mask)
809 {
810 	struct mcast_group *group, *cur_group;
811 	int is_mgid0;
812 	int i;
813 
814 	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
815 	if (!is_mgid0) {
816 		group = mcast_find(ctx, mgid);
817 		if (group)
818 			goto found;
819 	}
820 
821 	if (!create)
822 		return ERR_PTR(-ENOENT);
823 
824 	group = kzalloc(sizeof *group, gfp_mask);
825 	if (!group)
826 		return ERR_PTR(-ENOMEM);
827 
828 	group->demux = ctx;
829 	group->rec.mgid = *mgid;
830 	INIT_LIST_HEAD(&group->pending_list);
831 	INIT_LIST_HEAD(&group->mgid0_list);
832 	for (i = 0; i < MAX_VFS; ++i)
833 		INIT_LIST_HEAD(&group->func[i].pending);
834 	INIT_WORK(&group->work, mlx4_ib_mcg_work_handler);
835 	INIT_DELAYED_WORK(&group->timeout_work, mlx4_ib_mcg_timeout_handler);
836 	mutex_init(&group->lock);
837 	sprintf(group->name, "%016llx%016llx",
838 			be64_to_cpu(group->rec.mgid.global.subnet_prefix),
839 			be64_to_cpu(group->rec.mgid.global.interface_id));
840 	sysfs_attr_init(&group->dentry.attr);
841 	group->dentry.show = sysfs_show_group;
842 	group->dentry.store = NULL;
843 	group->dentry.attr.name = group->name;
844 	group->dentry.attr.mode = 0400;
845 	group->state = MCAST_IDLE;
846 
847 	if (is_mgid0) {
848 		list_add(&group->mgid0_list, &ctx->mcg_mgid0_list);
849 		goto found;
850 	}
851 
852 	cur_group = mcast_insert(ctx, group);
853 	if (cur_group) {
854 		mcg_warn("group just showed up %s - confused\n", cur_group->name);
855 		kfree(group);
856 		return ERR_PTR(-EINVAL);
857 	}
858 
859 	add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
860 
861 found:
862 	atomic_inc(&group->refcount);
863 	return group;
864 }
865 
866 static void queue_req(struct mcast_req *req)
867 {
868 	struct mcast_group *group = req->group;
869 
870 	atomic_inc(&group->refcount); /* for the request */
871 	atomic_inc(&group->refcount); /* for scheduling the work */
872 	list_add_tail(&req->group_list, &group->pending_list);
873 	list_add_tail(&req->func_list, &group->func[req->func].pending);
874 	/* calls mlx4_ib_mcg_work_handler */
875 	if (!queue_work(group->demux->mcg_wq, &group->work))
876 		safe_atomic_dec(&group->refcount);
877 }
878 
879 int mlx4_ib_mcg_demux_handler(struct ib_device *ibdev, int port, int slave,
880 			      struct ib_sa_mad *mad)
881 {
882 	struct mlx4_ib_dev *dev = to_mdev(ibdev);
883 	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)mad->data;
884 	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
885 	struct mcast_group *group;
886 
887 	switch (mad->mad_hdr.method) {
888 	case IB_MGMT_METHOD_GET_RESP:
889 	case IB_SA_METHOD_DELETE_RESP:
890 		mutex_lock(&ctx->mcg_table_lock);
891 		group = acquire_group(ctx, &rec->mgid, 0, GFP_KERNEL);
892 		mutex_unlock(&ctx->mcg_table_lock);
893 		if (IS_ERR(group)) {
894 			if (mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP) {
895 				__be64 tid = mad->mad_hdr.tid;
896 				*(u8 *)(&tid) = (u8)slave; /* in group we kept the modified TID */
897 				group = search_relocate_mgid0_group(ctx, tid, &rec->mgid);
898 			} else
899 				group = NULL;
900 		}
901 
902 		if (!group)
903 			return 1;
904 
905 		mutex_lock(&group->lock);
906 		group->response_sa_mad = *mad;
907 		group->prev_state = group->state;
908 		group->state = MCAST_RESP_READY;
909 		/* calls mlx4_ib_mcg_work_handler */
910 		atomic_inc(&group->refcount);
911 		if (!queue_work(ctx->mcg_wq, &group->work))
912 			safe_atomic_dec(&group->refcount);
913 		mutex_unlock(&group->lock);
914 		release_group(group, 0);
915 		return 1; /* consumed */
916 	case IB_MGMT_METHOD_SET:
917 	case IB_SA_METHOD_GET_TABLE:
918 	case IB_SA_METHOD_GET_TABLE_RESP:
919 	case IB_SA_METHOD_DELETE:
920 		return 0; /* not consumed, pass-through to guest over tunnel */
921 	default:
922 		mcg_warn("In demux, port %d: unexpected MCMember method: 0x%x, dropping\n",
923 			port, mad->mad_hdr.method);
924 		return 1; /* consumed */
925 	}
926 }
927 
928 int mlx4_ib_mcg_multiplex_handler(struct ib_device *ibdev, int port,
929 				  int slave, struct ib_sa_mad *sa_mad)
930 {
931 	struct mlx4_ib_dev *dev = to_mdev(ibdev);
932 	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)sa_mad->data;
933 	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
934 	struct mcast_group *group;
935 	struct mcast_req *req;
936 	int may_create = 0;
937 
938 	if (ctx->flushing)
939 		return -EAGAIN;
940 
941 	switch (sa_mad->mad_hdr.method) {
942 	case IB_MGMT_METHOD_SET:
943 		may_create = 1;
944 	case IB_SA_METHOD_DELETE:
945 		req = kzalloc(sizeof *req, GFP_KERNEL);
946 		if (!req)
947 			return -ENOMEM;
948 
949 		req->func = slave;
950 		req->sa_mad = *sa_mad;
951 
952 		mutex_lock(&ctx->mcg_table_lock);
953 		group = acquire_group(ctx, &rec->mgid, may_create, GFP_KERNEL);
954 		mutex_unlock(&ctx->mcg_table_lock);
955 		if (IS_ERR(group)) {
956 			kfree(req);
957 			return PTR_ERR(group);
958 		}
959 		mutex_lock(&group->lock);
960 		if (group->func[slave].num_pend_reqs > MAX_PEND_REQS_PER_FUNC) {
961 			mutex_unlock(&group->lock);
962 			mcg_warn_group(group, "Port %d, Func %d has too many pending requests (%d), dropping\n",
963 				       port, slave, MAX_PEND_REQS_PER_FUNC);
964 			release_group(group, 0);
965 			kfree(req);
966 			return -ENOMEM;
967 		}
968 		++group->func[slave].num_pend_reqs;
969 		req->group = group;
970 		queue_req(req);
971 		mutex_unlock(&group->lock);
972 		release_group(group, 0);
973 		return 1; /* consumed */
974 	case IB_SA_METHOD_GET_TABLE:
975 	case IB_MGMT_METHOD_GET_RESP:
976 	case IB_SA_METHOD_GET_TABLE_RESP:
977 	case IB_SA_METHOD_DELETE_RESP:
978 		return 0; /* not consumed, pass-through */
979 	default:
980 		mcg_warn("In multiplex, port %d, func %d: unexpected MCMember method: 0x%x, dropping\n",
981 			port, slave, sa_mad->mad_hdr.method);
982 		return 1; /* consumed */
983 	}
984 }
985 
986 static ssize_t sysfs_show_group(struct device *dev,
987 		struct device_attribute *attr, char *buf)
988 {
989 	struct mcast_group *group =
990 		container_of(attr, struct mcast_group, dentry);
991 	struct mcast_req *req = NULL;
992 	char pending_str[40];
993 	char state_str[40];
994 	ssize_t len = 0;
995 	int f;
996 
997 	if (group->state == MCAST_IDLE)
998 		sprintf(state_str, "%s", get_state_string(group->state));
999 	else
1000 		sprintf(state_str, "%s(TID=0x%llx)",
1001 				get_state_string(group->state),
1002 				be64_to_cpu(group->last_req_tid));
1003 	if (list_empty(&group->pending_list)) {
1004 		sprintf(pending_str, "No");
1005 	} else {
1006 		req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
1007 		sprintf(pending_str, "Yes(TID=0x%llx)",
1008 				be64_to_cpu(req->sa_mad.mad_hdr.tid));
1009 	}
1010 	len += sprintf(buf + len, "%1d [%02d,%02d,%02d] %4d %4s %5s     ",
1011 			group->rec.scope_join_state & 0xf,
1012 			group->members[2], group->members[1], group->members[0],
1013 			atomic_read(&group->refcount),
1014 			pending_str,
1015 			state_str);
1016 	for (f = 0; f < MAX_VFS; ++f)
1017 		if (group->func[f].state == MCAST_MEMBER)
1018 			len += sprintf(buf + len, "%d[%1x] ",
1019 					f, group->func[f].join_state);
1020 
1021 	len += sprintf(buf + len, "\t\t(%4hx %4x %2x %2x %2x %2x %2x "
1022 		"%4x %4x %2x %2x)\n",
1023 		be16_to_cpu(group->rec.pkey),
1024 		be32_to_cpu(group->rec.qkey),
1025 		(group->rec.mtusel_mtu & 0xc0) >> 6,
1026 		group->rec.mtusel_mtu & 0x3f,
1027 		group->rec.tclass,
1028 		(group->rec.ratesel_rate & 0xc0) >> 6,
1029 		group->rec.ratesel_rate & 0x3f,
1030 		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0xf0000000) >> 28,
1031 		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x0fffff00) >> 8,
1032 		be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x000000ff,
1033 		group->rec.proxy_join);
1034 
1035 	return len;
1036 }
1037 
1038 int mlx4_ib_mcg_port_init(struct mlx4_ib_demux_ctx *ctx)
1039 {
1040 	char name[20];
1041 
1042 	atomic_set(&ctx->tid, 0);
1043 	sprintf(name, "mlx4_ib_mcg%d", ctx->port);
1044 	ctx->mcg_wq = create_singlethread_workqueue(name);
1045 	if (!ctx->mcg_wq)
1046 		return -ENOMEM;
1047 
1048 	mutex_init(&ctx->mcg_table_lock);
1049 	ctx->mcg_table = RB_ROOT;
1050 	INIT_LIST_HEAD(&ctx->mcg_mgid0_list);
1051 	ctx->flushing = 0;
1052 
1053 	return 0;
1054 }
1055 
1056 static void force_clean_group(struct mcast_group *group)
1057 {
1058 	struct mcast_req *req, *tmp
1059 		;
1060 	list_for_each_entry_safe(req, tmp, &group->pending_list, group_list) {
1061 		list_del(&req->group_list);
1062 		kfree(req);
1063 	}
1064 	del_sysfs_port_mcg_attr(group->demux->dev, group->demux->port, &group->dentry.attr);
1065 	rb_erase(&group->node, &group->demux->mcg_table);
1066 	kfree(group);
1067 }
1068 
1069 static void _mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
1070 {
1071 	int i;
1072 	struct rb_node *p;
1073 	struct mcast_group *group;
1074 	unsigned long end;
1075 	int count;
1076 
1077 	if (ctx->flushing)
1078 		return;
1079 
1080 	ctx->flushing = 1;
1081 	for (i = 0; i < MAX_VFS; ++i)
1082 		clean_vf_mcast(ctx, i);
1083 
1084 	end = jiffies + msecs_to_jiffies(MAD_TIMEOUT_MS + 3000);
1085 	do {
1086 		count = 0;
1087 		mutex_lock(&ctx->mcg_table_lock);
1088 		for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p))
1089 			++count;
1090 		mutex_unlock(&ctx->mcg_table_lock);
1091 		if (!count)
1092 			break;
1093 
1094 		msleep(1);
1095 	} while (time_after(end, jiffies));
1096 
1097 	flush_workqueue(ctx->mcg_wq);
1098 	if (destroy_wq)
1099 		destroy_workqueue(ctx->mcg_wq);
1100 
1101 	mutex_lock(&ctx->mcg_table_lock);
1102 	while ((p = rb_first(&ctx->mcg_table)) != NULL) {
1103 		group = rb_entry(p, struct mcast_group, node);
1104 		if (atomic_read(&group->refcount))
1105 			mcg_warn_group(group, "group refcount %d!!! (pointer %p)\n", atomic_read(&group->refcount), group);
1106 
1107 		force_clean_group(group);
1108 	}
1109 	mutex_unlock(&ctx->mcg_table_lock);
1110 
1111 	if (!destroy_wq)
1112 		ctx->flushing = 0;
1113 }
1114 
1115 struct clean_work {
1116 	struct work_struct work;
1117 	struct mlx4_ib_demux_ctx *ctx;
1118 	int destroy_wq;
1119 };
1120 
1121 static void mcg_clean_task(struct work_struct *work)
1122 {
1123 	struct clean_work *cw = container_of(work, struct clean_work, work);
1124 
1125 	_mlx4_ib_mcg_port_cleanup(cw->ctx, cw->destroy_wq);
1126 	kfree(cw);
1127 }
1128 
1129 void mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
1130 {
1131 	struct clean_work *work;
1132 
1133 	if (destroy_wq) {
1134 		_mlx4_ib_mcg_port_cleanup(ctx, destroy_wq);
1135 		return;
1136 	}
1137 
1138 	work = kmalloc(sizeof *work, GFP_KERNEL);
1139 	if (!work) {
1140 		mcg_warn("failed allocating work for cleanup\n");
1141 		return;
1142 	}
1143 
1144 	work->ctx = ctx;
1145 	work->destroy_wq = destroy_wq;
1146 	INIT_WORK(&work->work, mcg_clean_task);
1147 	queue_work(clean_wq, &work->work);
1148 }
1149 
1150 static void build_leave_mad(struct mcast_req *req)
1151 {
1152 	struct ib_sa_mad *mad = &req->sa_mad;
1153 
1154 	mad->mad_hdr.method = IB_SA_METHOD_DELETE;
1155 }
1156 
1157 
1158 static void clear_pending_reqs(struct mcast_group *group, int vf)
1159 {
1160 	struct mcast_req *req, *tmp, *group_first = NULL;
1161 	int clear;
1162 	int pend = 0;
1163 
1164 	if (!list_empty(&group->pending_list))
1165 		group_first = list_first_entry(&group->pending_list, struct mcast_req, group_list);
1166 
1167 	list_for_each_entry_safe(req, tmp, &group->func[vf].pending, func_list) {
1168 		clear = 1;
1169 		if (group_first == req &&
1170 		    (group->state == MCAST_JOIN_SENT ||
1171 		     group->state == MCAST_LEAVE_SENT)) {
1172 			clear = cancel_delayed_work(&group->timeout_work);
1173 			pend = !clear;
1174 			group->state = MCAST_IDLE;
1175 		}
1176 		if (clear) {
1177 			--group->func[vf].num_pend_reqs;
1178 			list_del(&req->group_list);
1179 			list_del(&req->func_list);
1180 			kfree(req);
1181 			atomic_dec(&group->refcount);
1182 		}
1183 	}
1184 
1185 	if (!pend && (!list_empty(&group->func[vf].pending) || group->func[vf].num_pend_reqs)) {
1186 		mcg_warn_group(group, "DRIVER BUG: list_empty %d, num_pend_reqs %d\n",
1187 			       list_empty(&group->func[vf].pending), group->func[vf].num_pend_reqs);
1188 	}
1189 }
1190 
1191 static int push_deleteing_req(struct mcast_group *group, int slave)
1192 {
1193 	struct mcast_req *req;
1194 	struct mcast_req *pend_req;
1195 
1196 	if (!group->func[slave].join_state)
1197 		return 0;
1198 
1199 	req = kzalloc(sizeof *req, GFP_KERNEL);
1200 	if (!req) {
1201 		mcg_warn_group(group, "failed allocation - may leave stall groups\n");
1202 		return -ENOMEM;
1203 	}
1204 
1205 	if (!list_empty(&group->func[slave].pending)) {
1206 		pend_req = list_entry(group->func[slave].pending.prev, struct mcast_req, group_list);
1207 		if (pend_req->clean) {
1208 			kfree(req);
1209 			return 0;
1210 		}
1211 	}
1212 
1213 	req->clean = 1;
1214 	req->func = slave;
1215 	req->group = group;
1216 	++group->func[slave].num_pend_reqs;
1217 	build_leave_mad(req);
1218 	queue_req(req);
1219 	return 0;
1220 }
1221 
1222 void clean_vf_mcast(struct mlx4_ib_demux_ctx *ctx, int slave)
1223 {
1224 	struct mcast_group *group;
1225 	struct rb_node *p;
1226 
1227 	mutex_lock(&ctx->mcg_table_lock);
1228 	for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p)) {
1229 		group = rb_entry(p, struct mcast_group, node);
1230 		mutex_lock(&group->lock);
1231 		if (atomic_read(&group->refcount)) {
1232 			/* clear pending requests of this VF */
1233 			clear_pending_reqs(group, slave);
1234 			push_deleteing_req(group, slave);
1235 		}
1236 		mutex_unlock(&group->lock);
1237 	}
1238 	mutex_unlock(&ctx->mcg_table_lock);
1239 }
1240 
1241 
1242 int mlx4_ib_mcg_init(void)
1243 {
1244 	clean_wq = create_singlethread_workqueue("mlx4_ib_mcg");
1245 	if (!clean_wq)
1246 		return -ENOMEM;
1247 
1248 	return 0;
1249 }
1250 
1251 void mlx4_ib_mcg_destroy(void)
1252 {
1253 	destroy_workqueue(clean_wq);
1254 }
1255