summaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/mlx4/mcg.c
blob: d844831179cf7c200e7d9ce15493b63557ad0193 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
/*
 * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <rdma/ib_mad.h>
#include <rdma/ib_smi.h>
#include <rdma/ib_cache.h>
#include <rdma/ib_sa.h>

#include <linux/mlx4/cmd.h>
#include <linux/rbtree.h>
#include <linux/delay.h>

#include "mlx4_ib.h"

#define MAX_VFS		80
#define MAX_PEND_REQS_PER_FUNC 4
#define MAD_TIMEOUT_MS	2000

#define mcg_warn(fmt, arg...)	pr_warn("MCG WARNING: " fmt, ##arg)
#define mcg_error(fmt, arg...)	pr_err(fmt, ##arg)
#define mcg_warn_group(group, format, arg...) \
	pr_warn("%s-%d: %16s (port %d): WARNING: " format, __func__, __LINE__,\
	(group)->name, group->demux->port, ## arg)

#define mcg_debug_group(group, format, arg...) \
	pr_debug("%s-%d: %16s (port %d): WARNING: " format, __func__, __LINE__,\
		 (group)->name, (group)->demux->port, ## arg)

#define mcg_error_group(group, format, arg...) \
	pr_err("  %16s: " format, (group)->name, ## arg)


static union ib_gid mgid0;

static struct workqueue_struct *clean_wq;

enum mcast_state {
	MCAST_NOT_MEMBER = 0,
	MCAST_MEMBER,
};

enum mcast_group_state {
	MCAST_IDLE,
	MCAST_JOIN_SENT,
	MCAST_LEAVE_SENT,
	MCAST_RESP_READY
};

struct mcast_member {
	enum mcast_state state;
	uint8_t			join_state;
	int			num_pend_reqs;
	struct list_head	pending;
};

struct ib_sa_mcmember_data {
	union ib_gid	mgid;
	union ib_gid	port_gid;
	__be32		qkey;
	__be16		mlid;
	u8		mtusel_mtu;
	u8		tclass;
	__be16		pkey;
	u8		ratesel_rate;
	u8		lifetmsel_lifetm;
	__be32		sl_flowlabel_hoplimit;
	u8		scope_join_state;
	u8		proxy_join;
	u8		reserved[2];
} __packed __aligned(4);

struct mcast_group {
	struct ib_sa_mcmember_data rec;
	struct rb_node		node;
	struct list_head	mgid0_list;
	struct mlx4_ib_demux_ctx *demux;
	struct mcast_member	func[MAX_VFS];
	struct mutex		lock;
	struct work_struct	work;
	struct list_head	pending_list;
	int			members[3];
	enum mcast_group_state	state;
	enum mcast_group_state	prev_state;
	struct ib_sa_mad	response_sa_mad;
	__be64			last_req_tid;

	char			name[33]; /* MGID string */
	struct device_attribute	dentry;

	/* refcount is the reference count for the following:
	   1. Each queued request
	   2. Each invocation of the worker thread
	   3. Membership of the port at the SA
	*/
	atomic_t		refcount;

	/* delayed work to clean pending SM request */
	struct delayed_work	timeout_work;
	struct list_head	cleanup_list;
};

struct mcast_req {
	int			func;
	struct ib_sa_mad	sa_mad;
	struct list_head	group_list;
	struct list_head	func_list;
	struct mcast_group	*group;
	int			clean;
};


#define safe_atomic_dec(ref) \
	do {\
		if (atomic_dec_and_test(ref)) \
			mcg_warn_group(group, "did not expect to reach zero\n"); \
	} while (0)

static const char *get_state_string(enum mcast_group_state state)
{
	switch (state) {
	case MCAST_IDLE:
		return "MCAST_IDLE";
	case MCAST_JOIN_SENT:
		return "MCAST_JOIN_SENT";
	case MCAST_LEAVE_SENT:
		return "MCAST_LEAVE_SENT";
	case MCAST_RESP_READY:
		return "MCAST_RESP_READY";
	}
	return "Invalid State";
}

static struct mcast_group *mcast_find(struct mlx4_ib_demux_ctx *ctx,
				      union ib_gid *mgid)
{
	struct rb_node *node = ctx->mcg_table.rb_node;
	struct mcast_group *group;
	int ret;

	while (node) {
		group = rb_entry(node, struct mcast_group, node);
		ret = memcmp(mgid->raw, group->rec.mgid.raw, sizeof *mgid);
		if (!ret)
			return group;

		if (ret < 0)
			node = node->rb_left;
		else
			node = node->rb_right;
	}
	return NULL;
}

static struct mcast_group *mcast_insert(struct mlx4_ib_demux_ctx *ctx,
					struct mcast_group *group)
{
	struct rb_node **link = &ctx->mcg_table.rb_node;
	struct rb_node *parent = NULL;
	struct mcast_group *cur_group;
	int ret;

	while (*link) {
		parent = *link;
		cur_group = rb_entry(parent, struct mcast_group, node);

		ret = memcmp(group->rec.mgid.raw, cur_group->rec.mgid.raw,
			     sizeof group->rec.mgid);
		if (ret < 0)
			link = &(*link)->rb_left;
		else if (ret > 0)
			link = &(*link)->rb_right;
		else
			return cur_group;
	}
	rb_link_node(&group->node, parent, link);
	rb_insert_color(&group->node, &ctx->mcg_table);
	return NULL;
}

static int send_mad_to_wire(struct mlx4_ib_demux_ctx *ctx, struct ib_mad *mad)
{
	struct mlx4_ib_dev *dev = ctx->dev;
	struct rdma_ah_attr	ah_attr;
	unsigned long flags;

	spin_lock_irqsave(&dev->sm_lock, flags);
	if (!dev->sm_ah[ctx->port - 1]) {
		/* port is not yet Active, sm_ah not ready */
		spin_unlock_irqrestore(&dev->sm_lock, flags);
		return -EAGAIN;
	}
	mlx4_ib_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);
	spin_unlock_irqrestore(&dev->sm_lock, flags);
	return mlx4_ib_send_to_wire(dev, mlx4_master_func_num(dev->dev),
				    ctx->port, IB_QPT_GSI, 0, 1, IB_QP1_QKEY,
				    &ah_attr, NULL, 0xffff, mad);
}

static int send_mad_to_slave(int slave, struct mlx4_ib_demux_ctx *ctx,
			     struct ib_mad *mad)
{
	struct mlx4_ib_dev *dev = ctx->dev;
	struct ib_mad_agent *agent = dev->send_agent[ctx->port - 1][1];
	struct ib_wc wc;
	struct rdma_ah_attr ah_attr;

	/* Our agent might not yet be registered when mads start to arrive */
	if (!agent)
		return -EAGAIN;

	rdma_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr);

	if (ib_find_cached_pkey(&dev->ib_dev, ctx->port, IB_DEFAULT_PKEY_FULL, &wc.pkey_index))
		return -EINVAL;
	wc.sl = 0;
	wc.dlid_path_bits = 0;
	wc.port_num = ctx->port;
	wc.slid = rdma_ah_get_dlid(&ah_attr);  /* opensm lid */
	wc.src_qp = 1;
	return mlx4_ib_send_to_slave(dev, slave, ctx->port, IB_QPT_GSI, &wc, NULL, mad);
}

static int send_join_to_wire(struct mcast_group *group, struct ib_sa_mad *sa_mad)
{
	struct ib_sa_mad mad;
	struct ib_sa_mcmember_data *sa_mad_data = (struct ib_sa_mcmember_data *)&mad.data;
	int ret;

	/* we rely on a mad request as arrived from a VF */
	memcpy(&mad, sa_mad, sizeof mad);

	/* fix port GID to be the real one (slave 0) */
	sa_mad_data->port_gid.global.interface_id = group->demux->guid_cache[0];

	/* assign our own TID */
	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */

	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
	/* set timeout handler */
	if (!ret) {
		/* calls mlx4_ib_mcg_timeout_handler */
		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
				msecs_to_jiffies(MAD_TIMEOUT_MS));
	}

	return ret;
}

static int send_leave_to_wire(struct mcast_group *group, u8 join_state)
{
	struct ib_sa_mad mad;
	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
	int ret;

	memset(&mad, 0, sizeof mad);
	mad.mad_hdr.base_version = 1;
	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
	mad.mad_hdr.class_version = 2;
	mad.mad_hdr.method = IB_SA_METHOD_DELETE;
	mad.mad_hdr.status = cpu_to_be16(0);
	mad.mad_hdr.class_specific = cpu_to_be16(0);
	mad.mad_hdr.tid = mlx4_ib_get_new_demux_tid(group->demux);
	group->last_req_tid = mad.mad_hdr.tid; /* keep it for later validation */
	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
	mad.mad_hdr.attr_mod = cpu_to_be32(0);
	mad.sa_hdr.sm_key = 0x0;
	mad.sa_hdr.attr_offset = cpu_to_be16(7);
	mad.sa_hdr.comp_mask = IB_SA_MCMEMBER_REC_MGID |
		IB_SA_MCMEMBER_REC_PORT_GID | IB_SA_MCMEMBER_REC_JOIN_STATE;

	*sa_data = group->rec;
	sa_data->scope_join_state = join_state;

	ret = send_mad_to_wire(group->demux, (struct ib_mad *)&mad);
	if (ret)
		group->state = MCAST_IDLE;

	/* set timeout handler */
	if (!ret) {
		/* calls mlx4_ib_mcg_timeout_handler */
		queue_delayed_work(group->demux->mcg_wq, &group->timeout_work,
				msecs_to_jiffies(MAD_TIMEOUT_MS));
	}

	return ret;
}

static int send_reply_to_slave(int slave, struct mcast_group *group,
		struct ib_sa_mad *req_sa_mad, u16 status)
{
	struct ib_sa_mad mad;
	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)&mad.data;
	struct ib_sa_mcmember_data *req_sa_data = (struct ib_sa_mcmember_data *)&req_sa_mad->data;
	int ret;

	memset(&mad, 0, sizeof mad);
	mad.mad_hdr.base_version = 1;
	mad.mad_hdr.mgmt_class = IB_MGMT_CLASS_SUBN_ADM;
	mad.mad_hdr.class_version = 2;
	mad.mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
	mad.mad_hdr.status = cpu_to_be16(status);
	mad.mad_hdr.class_specific = cpu_to_be16(0);
	mad.mad_hdr.tid = req_sa_mad->mad_hdr.tid;
	*(u8 *)&mad.mad_hdr.tid = 0; /* resetting tid to 0 */
	mad.mad_hdr.attr_id = cpu_to_be16(IB_SA_ATTR_MC_MEMBER_REC);
	mad.mad_hdr.attr_mod = cpu_to_be32(0);
	mad.sa_hdr.sm_key = req_sa_mad->sa_hdr.sm_key;
	mad.sa_hdr.attr_offset = cpu_to_be16(7);
	mad.sa_hdr.comp_mask = 0; /* ignored on responses, see IBTA spec */

	*sa_data = group->rec;

	/* reconstruct VF's requested join_state and port_gid */
	sa_data->scope_join_state &= 0xf0;
	sa_data->scope_join_state |= (group->func[slave].join_state & 0x0f);
	memcpy(&sa_data->port_gid, &req_sa_data->port_gid, sizeof req_sa_data->port_gid);

	ret = send_mad_to_slave(slave, group->demux, (struct ib_mad *)&mad);
	return ret;
}

static int check_selector(ib_sa_comp_mask comp_mask,
			  ib_sa_comp_mask selector_mask,
			  ib_sa_comp_mask value_mask,
			  u8 src_value, u8 dst_value)
{
	int err;
	u8 selector = dst_value >> 6;
	dst_value &= 0x3f;
	src_value &= 0x3f;

	if (!(comp_mask & selector_mask) || !(comp_mask & value_mask))
		return 0;

	switch (selector) {
	case IB_SA_GT:
		err = (src_value <= dst_value);
		break;
	case IB_SA_LT:
		err = (src_value >= dst_value);
		break;
	case IB_SA_EQ:
		err = (src_value != dst_value);
		break;
	default:
		err = 0;
		break;
	}

	return err;
}

static u16 cmp_rec(struct ib_sa_mcmember_data *src,
		   struct ib_sa_mcmember_data *dst, ib_sa_comp_mask comp_mask)
{
	/* src is group record, dst is request record */
	/* MGID must already match */
	/* Port_GID we always replace to our Port_GID, so it is a match */

#define MAD_STATUS_REQ_INVALID 0x0200
	if (comp_mask & IB_SA_MCMEMBER_REC_QKEY && src->qkey != dst->qkey)
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_MLID && src->mlid != dst->mlid)
		return MAD_STATUS_REQ_INVALID;
	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_MTU_SELECTOR,
				 IB_SA_MCMEMBER_REC_MTU,
				 src->mtusel_mtu, dst->mtusel_mtu))
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_TRAFFIC_CLASS &&
	    src->tclass != dst->tclass)
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_PKEY && src->pkey != dst->pkey)
		return MAD_STATUS_REQ_INVALID;
	if (check_selector(comp_mask, IB_SA_MCMEMBER_REC_RATE_SELECTOR,
				 IB_SA_MCMEMBER_REC_RATE,
				 src->ratesel_rate, dst->ratesel_rate))
		return MAD_STATUS_REQ_INVALID;
	if (check_selector(comp_mask,
				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME_SELECTOR,
				 IB_SA_MCMEMBER_REC_PACKET_LIFE_TIME,
				 src->lifetmsel_lifetm, dst->lifetmsel_lifetm))
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_SL &&
			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0xf0000000) !=
			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0xf0000000))
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_FLOW_LABEL &&
			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x0fffff00) !=
			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x0fffff00))
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_HOP_LIMIT &&
			(be32_to_cpu(src->sl_flowlabel_hoplimit) & 0x000000ff) !=
			(be32_to_cpu(dst->sl_flowlabel_hoplimit) & 0x000000ff))
		return MAD_STATUS_REQ_INVALID;
	if (comp_mask & IB_SA_MCMEMBER_REC_SCOPE &&
			(src->scope_join_state & 0xf0) !=
			(dst->scope_join_state & 0xf0))
		return MAD_STATUS_REQ_INVALID;

	/* join_state checked separately, proxy_join ignored */

	return 0;
}

/* release group, return 1 if this was last release and group is destroyed
 * timout work is canceled sync */
static int release_group(struct mcast_group *group, int from_timeout_handler)
{
	struct mlx4_ib_demux_ctx *ctx = group->demux;
	int nzgroup;

	mutex_lock(&ctx->mcg_table_lock);
	mutex_lock(&group->lock);
	if (atomic_dec_and_test(&group->refcount)) {
		if (!from_timeout_handler) {
			if (group->state != MCAST_IDLE &&
			    !cancel_delayed_work(&group->timeout_work)) {
				atomic_inc(&group->refcount);
				mutex_unlock(&group->lock);
				mutex_unlock(&ctx->mcg_table_lock);
				return 0;
			}
		}

		nzgroup = memcmp(&group->rec.mgid, &mgid0, sizeof mgid0);
		if (nzgroup)
			del_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
		if (!list_empty(&group->pending_list))
			mcg_warn_group(group, "releasing a group with non empty pending list\n");
		if (nzgroup)
			rb_erase(&group->node, &ctx->mcg_table);
		list_del_init(&group->mgid0_list);
		mutex_unlock(&group->lock);
		mutex_unlock(&ctx->mcg_table_lock);
		kfree(group);
		return 1;
	} else {
		mutex_unlock(&group->lock);
		mutex_unlock(&ctx->mcg_table_lock);
	}
	return 0;
}

static void adjust_membership(struct mcast_group *group, u8 join_state, int inc)
{
	int i;

	for (i = 0; i < 3; i++, join_state >>= 1)
		if (join_state & 0x1)
			group->members[i] += inc;
}

static u8 get_leave_state(struct mcast_group *group)
{
	u8 leave_state = 0;
	int i;

	for (i = 0; i < 3; i++)
		if (!group->members[i])
			leave_state |= (1 << i);

	return leave_state & (group->rec.scope_join_state & 0xf);
}

static int join_group(struct mcast_group *group, int slave, u8 join_mask)
{
	int ret = 0;
	u8 join_state;

	/* remove bits that slave is already member of, and adjust */
	join_state = join_mask & (~group->func[slave].join_state);
	adjust_membership(group, join_state, 1);
	group->func[slave].join_state |= join_state;
	if (group->func[slave].state != MCAST_MEMBER && join_state) {
		group->func[slave].state = MCAST_MEMBER;
		ret = 1;
	}
	return ret;
}

static int leave_group(struct mcast_group *group, int slave, u8 leave_state)
{
	int ret = 0;

	adjust_membership(group, leave_state, -1);
	group->func[slave].join_state &= ~leave_state;
	if (!group->func[slave].join_state) {
		group->func[slave].state = MCAST_NOT_MEMBER;
		ret = 1;
	}
	return ret;
}

static int check_leave(struct mcast_group *group, int slave, u8 leave_mask)
{
	if (group->func[slave].state != MCAST_MEMBER)
		return MAD_STATUS_REQ_INVALID;

	/* make sure we're not deleting unset bits */
	if (~group->func[slave].join_state & leave_mask)
		return MAD_STATUS_REQ_INVALID;

	if (!leave_mask)
		return MAD_STATUS_REQ_INVALID;

	return 0;
}

static void mlx4_ib_mcg_timeout_handler(struct work_struct *work)
{
	struct delayed_work *delay = to_delayed_work(work);
	struct mcast_group *group;
	struct mcast_req *req = NULL;

	group = container_of(delay, typeof(*group), timeout_work);

	mutex_lock(&group->lock);
	if (group->state == MCAST_JOIN_SENT) {
		if (!list_empty(&group->pending_list)) {
			req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
			list_del(&req->group_list);
			list_del(&req->func_list);
			--group->func[req->func].num_pend_reqs;
			mutex_unlock(&group->lock);
			kfree(req);
			if (memcmp(&group->rec.mgid, &mgid0, sizeof mgid0)) {
				if (release_group(group, 1))
					return;
			} else {
				kfree(group);
				return;
			}
			mutex_lock(&group->lock);
		} else
			mcg_warn_group(group, "DRIVER BUG\n");
	} else if (group->state == MCAST_LEAVE_SENT) {
		if (group->rec.scope_join_state & 0xf)
			group->rec.scope_join_state &= 0xf0;
		group->state = MCAST_IDLE;
		mutex_unlock(&group->lock);
		if (release_group(group, 1))
			return;
		mutex_lock(&group->lock);
	} else
		mcg_warn_group(group, "invalid state %s\n", get_state_string(group->state));
	group->state = MCAST_IDLE;
	atomic_inc(&group->refcount);
	if (!queue_work(group->demux->mcg_wq, &group->work))
		safe_atomic_dec(&group->refcount);

	mutex_unlock(&group->lock);
}

static int handle_leave_req(struct mcast_group *group, u8 leave_mask,
			    struct mcast_req *req)
{
	u16 status;

	if (req->clean)
		leave_mask = group->func[req->func].join_state;

	status = check_leave(group, req->func, leave_mask);
	if (!status)
		leave_group(group, req->func, leave_mask);

	if (!req->clean)
		send_reply_to_slave(req->func, group, &req->sa_mad, status);
	--group->func[req->func].num_pend_reqs;
	list_del(&req->group_list);
	list_del(&req->func_list);
	kfree(req);
	return 1;
}

static int handle_join_req(struct mcast_group *group, u8 join_mask,
			   struct mcast_req *req)
{
	u8 group_join_state = group->rec.scope_join_state & 0xf;
	int ref = 0;
	u16 status;
	struct ib_sa_mcmember_data *sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;

	if (join_mask == (group_join_state & join_mask)) {
		/* port's membership need not change */
		status = cmp_rec(&group->rec, sa_data, req->sa_mad.sa_hdr.comp_mask);
		if (!status)
			join_group(group, req->func, join_mask);

		--group->func[req->func].num_pend_reqs;
		send_reply_to_slave(req->func, group, &req->sa_mad, status);
		list_del(&req->group_list);
		list_del(&req->func_list);
		kfree(req);
		++ref;
	} else {
		/* port's membership needs to be updated */
		group->prev_state = group->state;
		if (send_join_to_wire(group, &req->sa_mad)) {
			--group->func[req->func].num_pend_reqs;
			list_del(&req->group_list);
			list_del(&req->func_list);
			kfree(req);
			ref = 1;
			group->state = group->prev_state;
		} else
			group->state = MCAST_JOIN_SENT;
	}

	return ref;
}

static void mlx4_ib_mcg_work_handler(struct work_struct *work)
{
	struct mcast_group *group;
	struct mcast_req *req = NULL;
	struct ib_sa_mcmember_data *sa_data;
	u8 req_join_state;
	int rc = 1; /* release_count - this is for the scheduled work */
	u16 status;
	u8 method;

	group = container_of(work, typeof(*group), work);

	mutex_lock(&group->lock);

	/* First, let's see if a response from SM is waiting regarding this group.
	 * If so, we need to update the group's REC. If this is a bad response, we
	 * may need to send a bad response to a VF waiting for it. If VF is waiting
	 * and this is a good response, the VF will be answered later in this func. */
	if (group->state == MCAST_RESP_READY) {
		/* cancels mlx4_ib_mcg_timeout_handler */
		cancel_delayed_work(&group->timeout_work);
		status = be16_to_cpu(group->response_sa_mad.mad_hdr.status);
		method = group->response_sa_mad.mad_hdr.method;
		if (group->last_req_tid != group->response_sa_mad.mad_hdr.tid) {
			mcg_warn_group(group, "Got MAD response to existing MGID but wrong TID, dropping. Resp TID=%llx, group TID=%llx\n",
				be64_to_cpu(group->response_sa_mad.mad_hdr.tid),
				be64_to_cpu(group->last_req_tid));
			group->state = group->prev_state;
			goto process_requests;
		}
		if (status) {
			if (!list_empty(&group->pending_list))
				req = list_first_entry(&group->pending_list,
						struct mcast_req, group_list);
			if (method == IB_MGMT_METHOD_GET_RESP) {
					if (req) {
						send_reply_to_slave(req->func, group, &req->sa_mad, status);
						--group->func[req->func].num_pend_reqs;
						list_del(&req->group_list);
						list_del(&req->func_list);
						kfree(req);
						++rc;
					} else
						mcg_warn_group(group, "no request for failed join\n");
			} else if (method == IB_SA_METHOD_DELETE_RESP && group->demux->flushing)
				++rc;
		} else {
			u8 resp_join_state;
			u8 cur_join_state;

			resp_join_state = ((struct ib_sa_mcmember_data *)
						group->response_sa_mad.data)->scope_join_state & 0xf;
			cur_join_state = group->rec.scope_join_state & 0xf;

			if (method == IB_MGMT_METHOD_GET_RESP) {
				/* successfull join */
				if (!cur_join_state && resp_join_state)
					--rc;
			} else if (!resp_join_state)
					++rc;
			memcpy(&group->rec, group->response_sa_mad.data, sizeof group->rec);
		}
		group->state = MCAST_IDLE;
	}

process_requests:
	/* We should now go over pending join/leave requests, as long as we are idle. */
	while (!list_empty(&group->pending_list) && group->state == MCAST_IDLE) {
		req = list_first_entry(&group->pending_list, struct mcast_req,
				       group_list);
		sa_data = (struct ib_sa_mcmember_data *)req->sa_mad.data;
		req_join_state = sa_data->scope_join_state & 0xf;

		/* For a leave request, we will immediately answer the VF, and
		 * update our internal counters. The actual leave will be sent
		 * to SM later, if at all needed. We dequeue the request now. */
		if (req->sa_mad.mad_hdr.method == IB_SA_METHOD_DELETE)
			rc += handle_leave_req(group, req_join_state, req);
		else
			rc += handle_join_req(group, req_join_state, req);
	}

	/* Handle leaves */
	if (group->state == MCAST_IDLE) {
		req_join_state = get_leave_state(group);
		if (req_join_state) {
			group->rec.scope_join_state &= ~req_join_state;
			group->prev_state = group->state;
			if (send_leave_to_wire(group, req_join_state)) {
				group->state = group->prev_state;
				++rc;
			} else
				group->state = MCAST_LEAVE_SENT;
		}
	}

	if (!list_empty(&group->pending_list) && group->state == MCAST_IDLE)
		goto process_requests;
	mutex_unlock(&group->lock);

	while (rc--)
		release_group(group, 0);
}

static struct mcast_group *search_relocate_mgid0_group(struct mlx4_ib_demux_ctx *ctx,
						       __be64 tid,
						       union ib_gid *new_mgid)
{
	struct mcast_group *group = NULL, *cur_group, *n;
	struct mcast_req *req;

	mutex_lock(&ctx->mcg_table_lock);
	list_for_each_entry_safe(group, n, &ctx->mcg_mgid0_list, mgid0_list) {
		mutex_lock(&group->lock);
		if (group->last_req_tid == tid) {
			if (memcmp(new_mgid, &mgid0, sizeof mgid0)) {
				group->rec.mgid = *new_mgid;
				sprintf(group->name, "%016llx%016llx",
						be64_to_cpu(group->rec.mgid.global.subnet_prefix),
						be64_to_cpu(group->rec.mgid.global.interface_id));
				list_del_init(&group->mgid0_list);
				cur_group = mcast_insert(ctx, group);
				if (cur_group) {
					/* A race between our code and SM. Silently cleaning the new one */
					req = list_first_entry(&group->pending_list,
							       struct mcast_req, group_list);
					--group->func[req->func].num_pend_reqs;
					list_del(&req->group_list);
					list_del(&req->func_list);
					kfree(req);
					mutex_unlock(&group->lock);
					mutex_unlock(&ctx->mcg_table_lock);
					release_group(group, 0);
					return NULL;
				}

				atomic_inc(&group->refcount);
				add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);
				mutex_unlock(&group->lock);
				mutex_unlock(&ctx->mcg_table_lock);
				return group;
			} else {
				struct mcast_req *tmp1, *tmp2;

				list_del(&group->mgid0_list);
				if (!list_empty(&group->pending_list) && group->state != MCAST_IDLE)
					cancel_delayed_work_sync(&group->timeout_work);

				list_for_each_entry_safe(tmp1, tmp2, &group->pending_list, group_list) {
					list_del(&tmp1->group_list);
					kfree(tmp1);
				}
				mutex_unlock(&group->lock);
				mutex_unlock(&ctx->mcg_table_lock);
				kfree(group);
				return NULL;
			}
		}
		mutex_unlock(&group->lock);
	}
	mutex_unlock(&ctx->mcg_table_lock);

	return NULL;
}

static ssize_t sysfs_show_group(struct device *dev,
		struct device_attribute *attr, char *buf);

static struct mcast_group *acquire_group(struct mlx4_ib_demux_ctx *ctx,
					 union ib_gid *mgid, int create)
{
	struct mcast_group *group, *cur_group;
	int is_mgid0;
	int i;

	is_mgid0 = !memcmp(&mgid0, mgid, sizeof mgid0);
	if (!is_mgid0) {
		group = mcast_find(ctx, mgid);
		if (group)
			goto found;
	}

	if (!create)
		return ERR_PTR(-ENOENT);

	group = kzalloc(sizeof(*group), GFP_KERNEL);
	if (!group)
		return ERR_PTR(-ENOMEM);

	group->demux = ctx;
	group->rec.mgid = *mgid;
	INIT_LIST_HEAD(&group->pending_list);
	INIT_LIST_HEAD(&group->mgid0_list);
	for (i = 0; i < MAX_VFS; ++i)
		INIT_LIST_HEAD(&group->func[i].pending);
	INIT_WORK(&group->work, mlx4_ib_mcg_work_handler);
	INIT_DELAYED_WORK(&group->timeout_work, mlx4_ib_mcg_timeout_handler);
	mutex_init(&group->lock);
	sprintf(group->name, "%016llx%016llx",
			be64_to_cpu(group->rec.mgid.global.subnet_prefix),
			be64_to_cpu(group->rec.mgid.global.interface_id));
	sysfs_attr_init(&group->dentry.attr);
	group->dentry.show = sysfs_show_group;
	group->dentry.store = NULL;
	group->dentry.attr.name = group->name;
	group->dentry.attr.mode = 0400;
	group->state = MCAST_IDLE;

	if (is_mgid0) {
		list_add(&group->mgid0_list, &ctx->mcg_mgid0_list);
		goto found;
	}

	cur_group = mcast_insert(ctx, group);
	if (cur_group) {
		mcg_warn("group just showed up %s - confused\n", cur_group->name);
		kfree(group);
		return ERR_PTR(-EINVAL);
	}

	add_sysfs_port_mcg_attr(ctx->dev, ctx->port, &group->dentry.attr);

found:
	atomic_inc(&group->refcount);
	return group;
}

static void queue_req(struct mcast_req *req)
{
	struct mcast_group *group = req->group;

	atomic_inc(&group->refcount); /* for the request */
	atomic_inc(&group->refcount); /* for scheduling the work */
	list_add_tail(&req->group_list, &group->pending_list);
	list_add_tail(&req->func_list, &group->func[req->func].pending);
	/* calls mlx4_ib_mcg_work_handler */
	if (!queue_work(group->demux->mcg_wq, &group->work))
		safe_atomic_dec(&group->refcount);
}

int mlx4_ib_mcg_demux_handler(struct ib_device *ibdev, int port, int slave,
			      struct ib_sa_mad *mad)
{
	struct mlx4_ib_dev *dev = to_mdev(ibdev);
	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)mad->data;
	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
	struct mcast_group *group;

	switch (mad->mad_hdr.method) {
	case IB_MGMT_METHOD_GET_RESP:
	case IB_SA_METHOD_DELETE_RESP:
		mutex_lock(&ctx->mcg_table_lock);
		group = acquire_group(ctx, &rec->mgid, 0);
		mutex_unlock(&ctx->mcg_table_lock);
		if (IS_ERR(group)) {
			if (mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP) {
				__be64 tid = mad->mad_hdr.tid;
				*(u8 *)(&tid) = (u8)slave; /* in group we kept the modified TID */
				group = search_relocate_mgid0_group(ctx, tid, &rec->mgid);
			} else
				group = NULL;
		}

		if (!group)
			return 1;

		mutex_lock(&group->lock);
		group->response_sa_mad = *mad;
		group->prev_state = group->state;
		group->state = MCAST_RESP_READY;
		/* calls mlx4_ib_mcg_work_handler */
		atomic_inc(&group->refcount);
		if (!queue_work(ctx->mcg_wq, &group->work))
			safe_atomic_dec(&group->refcount);
		mutex_unlock(&group->lock);
		release_group(group, 0);
		return 1; /* consumed */
	case IB_MGMT_METHOD_SET:
	case IB_SA_METHOD_GET_TABLE:
	case IB_SA_METHOD_GET_TABLE_RESP:
	case IB_SA_METHOD_DELETE:
		return 0; /* not consumed, pass-through to guest over tunnel */
	default:
		mcg_warn("In demux, port %d: unexpected MCMember method: 0x%x, dropping\n",
			port, mad->mad_hdr.method);
		return 1; /* consumed */
	}
}

int mlx4_ib_mcg_multiplex_handler(struct ib_device *ibdev, int port,
				  int slave, struct ib_sa_mad *sa_mad)
{
	struct mlx4_ib_dev *dev = to_mdev(ibdev);
	struct ib_sa_mcmember_data *rec = (struct ib_sa_mcmember_data *)sa_mad->data;
	struct mlx4_ib_demux_ctx *ctx = &dev->sriov.demux[port - 1];
	struct mcast_group *group;
	struct mcast_req *req;
	int may_create = 0;

	if (ctx->flushing)
		return -EAGAIN;

	switch (sa_mad->mad_hdr.method) {
	case IB_MGMT_METHOD_SET:
		may_create = 1;
		/* fall through */
	case IB_SA_METHOD_DELETE:
		req = kzalloc(sizeof *req, GFP_KERNEL);
		if (!req)
			return -ENOMEM;

		req->func = slave;
		req->sa_mad = *sa_mad;

		mutex_lock(&ctx->mcg_table_lock);
		group = acquire_group(ctx, &rec->mgid, may_create);
		mutex_unlock(&ctx->mcg_table_lock);
		if (IS_ERR(group)) {
			kfree(req);
			return PTR_ERR(group);
		}
		mutex_lock(&group->lock);
		if (group->func[slave].num_pend_reqs > MAX_PEND_REQS_PER_FUNC) {
			mutex_unlock(&group->lock);
			mcg_debug_group(group, "Port %d, Func %d has too many pending requests (%d), dropping\n",
					port, slave, MAX_PEND_REQS_PER_FUNC);
			release_group(group, 0);
			kfree(req);
			return -ENOMEM;
		}
		++group->func[slave].num_pend_reqs;
		req->group = group;
		queue_req(req);
		mutex_unlock(&group->lock);
		release_group(group, 0);
		return 1; /* consumed */
	case IB_SA_METHOD_GET_TABLE:
	case IB_MGMT_METHOD_GET_RESP:
	case IB_SA_METHOD_GET_TABLE_RESP:
	case IB_SA_METHOD_DELETE_RESP:
		return 0; /* not consumed, pass-through */
	default:
		mcg_warn("In multiplex, port %d, func %d: unexpected MCMember method: 0x%x, dropping\n",
			port, slave, sa_mad->mad_hdr.method);
		return 1; /* consumed */
	}
}

static ssize_t sysfs_show_group(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mcast_group *group =
		container_of(attr, struct mcast_group, dentry);
	struct mcast_req *req = NULL;
	char pending_str[40];
	char state_str[40];
	ssize_t len = 0;
	int f;

	if (group->state == MCAST_IDLE)
		sprintf(state_str, "%s", get_state_string(group->state));
	else
		sprintf(state_str, "%s(TID=0x%llx)",
				get_state_string(group->state),
				be64_to_cpu(group->last_req_tid));
	if (list_empty(&group->pending_list)) {
		sprintf(pending_str, "No");
	} else {
		req = list_first_entry(&group->pending_list, struct mcast_req, group_list);
		sprintf(pending_str, "Yes(TID=0x%llx)",
				be64_to_cpu(req->sa_mad.mad_hdr.tid));
	}
	len += sprintf(buf + len, "%1d [%02d,%02d,%02d] %4d %4s %5s     ",
			group->rec.scope_join_state & 0xf,
			group->members[2], group->members[1], group->members[0],
			atomic_read(&group->refcount),
			pending_str,
			state_str);
	for (f = 0; f < MAX_VFS; ++f)
		if (group->func[f].state == MCAST_MEMBER)
			len += sprintf(buf + len, "%d[%1x] ",
					f, group->func[f].join_state);

	len += sprintf(buf + len, "\t\t(%4hx %4x %2x %2x %2x %2x %2x "
		"%4x %4x %2x %2x)\n",
		be16_to_cpu(group->rec.pkey),
		be32_to_cpu(group->rec.qkey),
		(group->rec.mtusel_mtu & 0xc0) >> 6,
		group->rec.mtusel_mtu & 0x3f,
		group->rec.tclass,
		(group->rec.ratesel_rate & 0xc0) >> 6,
		group->rec.ratesel_rate & 0x3f,
		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0xf0000000) >> 28,
		(be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x0fffff00) >> 8,
		be32_to_cpu(group->rec.sl_flowlabel_hoplimit) & 0x000000ff,
		group->rec.proxy_join);

	return len;
}

int mlx4_ib_mcg_port_init(struct mlx4_ib_demux_ctx *ctx)
{
	char name[20];

	atomic_set(&ctx->tid, 0);
	sprintf(name, "mlx4_ib_mcg%d", ctx->port);
	ctx->mcg_wq = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
	if (!ctx->mcg_wq)
		return -ENOMEM;

	mutex_init(&ctx->mcg_table_lock);
	ctx->mcg_table = RB_ROOT;
	INIT_LIST_HEAD(&ctx->mcg_mgid0_list);
	ctx->flushing = 0;

	return 0;
}

static void force_clean_group(struct mcast_group *group)
{
	struct mcast_req *req, *tmp
		;
	list_for_each_entry_safe(req, tmp, &group->pending_list, group_list) {
		list_del(&req->group_list);
		kfree(req);
	}
	del_sysfs_port_mcg_attr(group->demux->dev, group->demux->port, &group->dentry.attr);
	rb_erase(&group->node, &group->demux->mcg_table);
	kfree(group);
}

static void _mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
{
	int i;
	struct rb_node *p;
	struct mcast_group *group;
	unsigned long end;
	int count;

	for (i = 0; i < MAX_VFS; ++i)
		clean_vf_mcast(ctx, i);

	end = jiffies + msecs_to_jiffies(MAD_TIMEOUT_MS + 3000);
	do {
		count = 0;
		mutex_lock(&ctx->mcg_table_lock);
		for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p))
			++count;
		mutex_unlock(&ctx->mcg_table_lock);
		if (!count)
			break;

		usleep_range(1000, 2000);
	} while (time_after(end, jiffies));

	flush_workqueue(ctx->mcg_wq);
	if (destroy_wq)
		destroy_workqueue(ctx->mcg_wq);

	mutex_lock(&ctx->mcg_table_lock);
	while ((p = rb_first(&ctx->mcg_table)) != NULL) {
		group = rb_entry(p, struct mcast_group, node);
		if (atomic_read(&group->refcount))
			mcg_debug_group(group, "group refcount %d!!! (pointer %p)\n",
					atomic_read(&group->refcount), group);

		force_clean_group(group);
	}
	mutex_unlock(&ctx->mcg_table_lock);
}

struct clean_work {
	struct work_struct work;
	struct mlx4_ib_demux_ctx *ctx;
	int destroy_wq;
};

static void mcg_clean_task(struct work_struct *work)
{
	struct clean_work *cw = container_of(work, struct clean_work, work);

	_mlx4_ib_mcg_port_cleanup(cw->ctx, cw->destroy_wq);
	cw->ctx->flushing = 0;
	kfree(cw);
}

void mlx4_ib_mcg_port_cleanup(struct mlx4_ib_demux_ctx *ctx, int destroy_wq)
{
	struct clean_work *work;

	if (ctx->flushing)
		return;

	ctx->flushing = 1;

	if (destroy_wq) {
		_mlx4_ib_mcg_port_cleanup(ctx, destroy_wq);
		ctx->flushing = 0;
		return;
	}

	work = kmalloc(sizeof *work, GFP_KERNEL);
	if (!work) {
		ctx->flushing = 0;
		return;
	}

	work->ctx = ctx;
	work->destroy_wq = destroy_wq;
	INIT_WORK(&work->work, mcg_clean_task);
	queue_work(clean_wq, &work->work);
}

static void build_leave_mad(struct mcast_req *req)
{
	struct ib_sa_mad *mad = &req->sa_mad;

	mad->mad_hdr.method = IB_SA_METHOD_DELETE;
}


static void clear_pending_reqs(struct mcast_group *group, int vf)
{
	struct mcast_req *req, *tmp, *group_first = NULL;
	int clear;
	int pend = 0;

	if (!list_empty(&group->pending_list))
		group_first = list_first_entry(&group->pending_list, struct mcast_req, group_list);

	list_for_each_entry_safe(req, tmp, &group->func[vf].pending, func_list) {
		clear = 1;
		if (group_first == req &&
		    (group->state == MCAST_JOIN_SENT ||
		     group->state == MCAST_LEAVE_SENT)) {
			clear = cancel_delayed_work(&group->timeout_work);
			pend = !clear;
			group->state = MCAST_IDLE;
		}
		if (clear) {
			--group->func[vf].num_pend_reqs;
			list_del(&req->group_list);
			list_del(&req->func_list);
			kfree(req);
			atomic_dec(&group->refcount);
		}
	}

	if (!pend && (!list_empty(&group->func[vf].pending) || group->func[vf].num_pend_reqs)) {
		mcg_warn_group(group, "DRIVER BUG: list_empty %d, num_pend_reqs %d\n",
			       list_empty(&group->func[vf].pending), group->func[vf].num_pend_reqs);
	}
}

static int push_deleteing_req(struct mcast_group *group, int slave)
{
	struct mcast_req *req;
	struct mcast_req *pend_req;

	if (!group->func[slave].join_state)
		return 0;

	req = kzalloc(sizeof *req, GFP_KERNEL);
	if (!req)
		return -ENOMEM;

	if (!list_empty(&group->func[slave].pending)) {
		pend_req = list_entry(group->func[slave].pending.prev, struct mcast_req, group_list);
		if (pend_req->clean) {
			kfree(req);
			return 0;
		}
	}

	req->clean = 1;
	req->func = slave;
	req->group = group;
	++group->func[slave].num_pend_reqs;
	build_leave_mad(req);
	queue_req(req);
	return 0;
}

void clean_vf_mcast(struct mlx4_ib_demux_ctx *ctx, int slave)
{
	struct mcast_group *group;
	struct rb_node *p;

	mutex_lock(&ctx->mcg_table_lock);
	for (p = rb_first(&ctx->mcg_table); p; p = rb_next(p)) {
		group = rb_entry(p, struct mcast_group, node);
		mutex_lock(&group->lock);
		if (atomic_read(&group->refcount)) {
			/* clear pending requests of this VF */
			clear_pending_reqs(group, slave);
			push_deleteing_req(group, slave);
		}
		mutex_unlock(&group->lock);
	}
	mutex_unlock(&ctx->mcg_table_lock);
}


int mlx4_ib_mcg_init(void)
{
	clean_wq = alloc_ordered_workqueue("mlx4_ib_mcg", WQ_MEM_RECLAIM);
	if (!clean_wq)
		return -ENOMEM;

	return 0;
}

void mlx4_ib_mcg_destroy(void)
{
	destroy_workqueue(clean_wq);
}