aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/infiniband/core/ucma.c
blob: 7972bae2e9b3da9584caf20c2268f02bb00e53b8 (plain) (blame)
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
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
/*
 * Copyright (c) 2005-2006 Intel Corporation.  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 <linux/completion.h>
#include <linux/file.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/idr.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/module.h>

#include <rdma/rdma_user_cm.h>
#include <rdma/ib_marshall.h>
#include <rdma/rdma_cm.h>
#include <rdma/rdma_cm_ib.h>

MODULE_AUTHOR("Sean Hefty");
MODULE_DESCRIPTION("RDMA Userspace Connection Manager Access");
MODULE_LICENSE("Dual BSD/GPL");

static unsigned int max_backlog = 1024;

static struct ctl_table_header *ucma_ctl_table_hdr;
static ctl_table ucma_ctl_table[] = {
	{
		.procname	= "max_backlog",
		.data		= &max_backlog,
		.maxlen		= sizeof max_backlog,
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{ }
};

struct ucma_file {
	struct mutex		mut;
	struct file		*filp;
	struct list_head	ctx_list;
	struct list_head	event_list;
	wait_queue_head_t	poll_wait;
};

struct ucma_context {
	int			id;
	struct completion	comp;
	atomic_t		ref;
	int			events_reported;
	int			backlog;

	struct ucma_file	*file;
	struct rdma_cm_id	*cm_id;
	u64			uid;

	struct list_head	list;
	struct list_head	mc_list;
};

struct ucma_multicast {
	struct ucma_context	*ctx;
	int			id;
	int			events_reported;

	u64			uid;
	struct list_head	list;
	struct sockaddr_storage	addr;
};

struct ucma_event {
	struct ucma_context	*ctx;
	struct ucma_multicast	*mc;
	struct list_head	list;
	struct rdma_cm_id	*cm_id;
	struct rdma_ucm_event_resp resp;
};

static DEFINE_MUTEX(mut);
static DEFINE_IDR(ctx_idr);
static DEFINE_IDR(multicast_idr);

static inline struct ucma_context *_ucma_find_context(int id,
						      struct ucma_file *file)
{
	struct ucma_context *ctx;

	ctx = idr_find(&ctx_idr, id);
	if (!ctx)
		ctx = ERR_PTR(-ENOENT);
	else if (ctx->file != file)
		ctx = ERR_PTR(-EINVAL);
	return ctx;
}

static struct ucma_context *ucma_get_ctx(struct ucma_file *file, int id)
{
	struct ucma_context *ctx;

	mutex_lock(&mut);
	ctx = _ucma_find_context(id, file);
	if (!IS_ERR(ctx))
		atomic_inc(&ctx->ref);
	mutex_unlock(&mut);
	return ctx;
}

static void ucma_put_ctx(struct ucma_context *ctx)
{
	if (atomic_dec_and_test(&ctx->ref))
		complete(&ctx->comp);
}

static struct ucma_context *ucma_alloc_ctx(struct ucma_file *file)
{
	struct ucma_context *ctx;
	int ret;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return NULL;

	atomic_set(&ctx->ref, 1);
	init_completion(&ctx->comp);
	INIT_LIST_HEAD(&ctx->mc_list);
	ctx->file = file;

	do {
		ret = idr_pre_get(&ctx_idr, GFP_KERNEL);
		if (!ret)
			goto error;

		mutex_lock(&mut);
		ret = idr_get_new(&ctx_idr, ctx, &ctx->id);
		mutex_unlock(&mut);
	} while (ret == -EAGAIN);

	if (ret)
		goto error;

	list_add_tail(&ctx->list, &file->ctx_list);
	return ctx;

error:
	kfree(ctx);
	return NULL;
}

static struct ucma_multicast* ucma_alloc_multicast(struct ucma_context *ctx)
{
	struct ucma_multicast *mc;
	int ret;

	mc = kzalloc(sizeof(*mc), GFP_KERNEL);
	if (!mc)
		return NULL;

	do {
		ret = idr_pre_get(&multicast_idr, GFP_KERNEL);
		if (!ret)
			goto error;

		mutex_lock(&mut);
		ret = idr_get_new(&multicast_idr, mc, &mc->id);
		mutex_unlock(&mut);
	} while (ret == -EAGAIN);

	if (ret)
		goto error;

	mc->ctx = ctx;
	list_add_tail(&mc->list, &ctx->mc_list);
	return mc;

error:
	kfree(mc);
	return NULL;
}

static void ucma_copy_conn_event(struct rdma_ucm_conn_param *dst,
				 struct rdma_conn_param *src)
{
	if (src->private_data_len)
		memcpy(dst->private_data, src->private_data,
		       src->private_data_len);
	dst->private_data_len = src->private_data_len;
	dst->responder_resources =src->responder_resources;
	dst->initiator_depth = src->initiator_depth;
	dst->flow_control = src->flow_control;
	dst->retry_count = src->retry_count;
	dst->rnr_retry_count = src->rnr_retry_count;
	dst->srq = src->srq;
	dst->qp_num = src->qp_num;
}

static void ucma_copy_ud_event(struct rdma_ucm_ud_param *dst,
			       struct rdma_ud_param *src)
{
	if (src->private_data_len)
		memcpy(dst->private_data, src->private_data,
		       src->private_data_len);
	dst->private_data_len = src->private_data_len;
	ib_copy_ah_attr_to_user(&dst->ah_attr, &src->ah_attr);
	dst->qp_num = src->qp_num;
	dst->qkey = src->qkey;
}

static void ucma_set_event_context(struct ucma_context *ctx,
				   struct rdma_cm_event *event,
				   struct ucma_event *uevent)
{
	uevent->ctx = ctx;
	switch (event->event) {
	case RDMA_CM_EVENT_MULTICAST_JOIN:
	case RDMA_CM_EVENT_MULTICAST_ERROR:
		uevent->mc = (struct ucma_multicast *)
			     event->param.ud.private_data;
		uevent->resp.uid = uevent->mc->uid;
		uevent->resp.id = uevent->mc->id;
		break;
	default:
		uevent->resp.uid = ctx->uid;
		uevent->resp.id = ctx->id;
		break;
	}
}

static int ucma_event_handler(struct rdma_cm_id *cm_id,
			      struct rdma_cm_event *event)
{
	struct ucma_event *uevent;
	struct ucma_context *ctx = cm_id->context;
	int ret = 0;

	uevent = kzalloc(sizeof(*uevent), GFP_KERNEL);
	if (!uevent)
		return event->event == RDMA_CM_EVENT_CONNECT_REQUEST;

	mutex_lock(&ctx->file->mut);
	uevent->cm_id = cm_id;
	ucma_set_event_context(ctx, event, uevent);
	uevent->resp.event = event->event;
	uevent->resp.status = event->status;
	if (cm_id->qp_type == IB_QPT_UD)
		ucma_copy_ud_event(&uevent->resp.param.ud, &event->param.ud);
	else
		ucma_copy_conn_event(&uevent->resp.param.conn,
				     &event->param.conn);

	if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST) {
		if (!ctx->backlog) {
			ret = -ENOMEM;
			kfree(uevent);
			goto out;
		}
		ctx->backlog--;
	} else if (!ctx->uid) {
		/*
		 * We ignore events for new connections until userspace has set
		 * their context.  This can only happen if an error occurs on a
		 * new connection before the user accepts it.  This is okay,
		 * since the accept will just fail later.
		 */
		kfree(uevent);
		goto out;
	}

	list_add_tail(&uevent->list, &ctx->file->event_list);
	wake_up_interruptible(&ctx->file->poll_wait);
out:
	mutex_unlock(&ctx->file->mut);
	return ret;
}

static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf,
			      int in_len, int out_len)
{
	struct ucma_context *ctx;
	struct rdma_ucm_get_event cmd;
	struct ucma_event *uevent;
	int ret = 0;

	if (out_len < sizeof uevent->resp)
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	mutex_lock(&file->mut);
	while (list_empty(&file->event_list)) {
		mutex_unlock(&file->mut);

		if (file->filp->f_flags & O_NONBLOCK)
			return -EAGAIN;

		if (wait_event_interruptible(file->poll_wait,
					     !list_empty(&file->event_list)))
			return -ERESTARTSYS;

		mutex_lock(&file->mut);
	}

	uevent = list_entry(file->event_list.next, struct ucma_event, list);

	if (uevent->resp.event == RDMA_CM_EVENT_CONNECT_REQUEST) {
		ctx = ucma_alloc_ctx(file);
		if (!ctx) {
			ret = -ENOMEM;
			goto done;
		}
		uevent->ctx->backlog++;
		ctx->cm_id = uevent->cm_id;
		ctx->cm_id->context = ctx;
		uevent->resp.id = ctx->id;
	}

	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &uevent->resp, sizeof uevent->resp)) {
		ret = -EFAULT;
		goto done;
	}

	list_del(&uevent->list);
	uevent->ctx->events_reported++;
	if (uevent->mc)
		uevent->mc->events_reported++;
	kfree(uevent);
done:
	mutex_unlock(&file->mut);
	return ret;
}

static int ucma_get_qp_type(struct rdma_ucm_create_id *cmd, enum ib_qp_type *qp_type)
{
	switch (cmd->ps) {
	case RDMA_PS_TCP:
		*qp_type = IB_QPT_RC;
		return 0;
	case RDMA_PS_UDP:
	case RDMA_PS_IPOIB:
		*qp_type = IB_QPT_UD;
		return 0;
	case RDMA_PS_IB:
		*qp_type = cmd->qp_type;
		return 0;
	default:
		return -EINVAL;
	}
}

static ssize_t ucma_create_id(struct ucma_file *file, const char __user *inbuf,
			      int in_len, int out_len)
{
	struct rdma_ucm_create_id cmd;
	struct rdma_ucm_create_id_resp resp;
	struct ucma_context *ctx;
	enum ib_qp_type qp_type;
	int ret;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ret = ucma_get_qp_type(&cmd, &qp_type);
	if (ret)
		return ret;

	mutex_lock(&file->mut);
	ctx = ucma_alloc_ctx(file);
	mutex_unlock(&file->mut);
	if (!ctx)
		return -ENOMEM;

	ctx->uid = cmd.uid;
	ctx->cm_id = rdma_create_id(ucma_event_handler, ctx, cmd.ps, qp_type);
	if (IS_ERR(ctx->cm_id)) {
		ret = PTR_ERR(ctx->cm_id);
		goto err1;
	}

	resp.id = ctx->id;
	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp))) {
		ret = -EFAULT;
		goto err2;
	}
	return 0;

err2:
	rdma_destroy_id(ctx->cm_id);
err1:
	mutex_lock(&mut);
	idr_remove(&ctx_idr, ctx->id);
	mutex_unlock(&mut);
	kfree(ctx);
	return ret;
}

static void ucma_cleanup_multicast(struct ucma_context *ctx)
{
	struct ucma_multicast *mc, *tmp;

	mutex_lock(&mut);
	list_for_each_entry_safe(mc, tmp, &ctx->mc_list, list) {
		list_del(&mc->list);
		idr_remove(&multicast_idr, mc->id);
		kfree(mc);
	}
	mutex_unlock(&mut);
}

static void ucma_cleanup_mc_events(struct ucma_multicast *mc)
{
	struct ucma_event *uevent, *tmp;

	list_for_each_entry_safe(uevent, tmp, &mc->ctx->file->event_list, list) {
		if (uevent->mc != mc)
			continue;

		list_del(&uevent->list);
		kfree(uevent);
	}
}

/*
 * We cannot hold file->mut when calling rdma_destroy_id() or we can
 * deadlock.  We also acquire file->mut in ucma_event_handler(), and
 * rdma_destroy_id() will wait until all callbacks have completed.
 */
static int ucma_free_ctx(struct ucma_context *ctx)
{
	int events_reported;
	struct ucma_event *uevent, *tmp;
	LIST_HEAD(list);

	/* No new events will be generated after destroying the id. */
	rdma_destroy_id(ctx->cm_id);

	ucma_cleanup_multicast(ctx);

	/* Cleanup events not yet reported to the user. */
	mutex_lock(&ctx->file->mut);
	list_for_each_entry_safe(uevent, tmp, &ctx->file->event_list, list) {
		if (uevent->ctx == ctx)
			list_move_tail(&uevent->list, &list);
	}
	list_del(&ctx->list);
	mutex_unlock(&ctx->file->mut);

	list_for_each_entry_safe(uevent, tmp, &list, list) {
		list_del(&uevent->list);
		if (uevent->resp.event == RDMA_CM_EVENT_CONNECT_REQUEST)
			rdma_destroy_id(uevent->cm_id);
		kfree(uevent);
	}

	events_reported = ctx->events_reported;
	kfree(ctx);
	return events_reported;
}

static ssize_t ucma_destroy_id(struct ucma_file *file, const char __user *inbuf,
			       int in_len, int out_len)
{
	struct rdma_ucm_destroy_id cmd;
	struct rdma_ucm_destroy_id_resp resp;
	struct ucma_context *ctx;
	int ret = 0;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	mutex_lock(&mut);
	ctx = _ucma_find_context(cmd.id, file);
	if (!IS_ERR(ctx))
		idr_remove(&ctx_idr, ctx->id);
	mutex_unlock(&mut);

	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ucma_put_ctx(ctx);
	wait_for_completion(&ctx->comp);
	resp.events_reported = ucma_free_ctx(ctx);

	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp)))
		ret = -EFAULT;

	return ret;
}

static ssize_t ucma_bind_addr(struct ucma_file *file, const char __user *inbuf,
			      int in_len, int out_len)
{
	struct rdma_ucm_bind_addr cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_bind_addr(ctx->cm_id, (struct sockaddr *) &cmd.addr);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_resolve_addr(struct ucma_file *file,
				 const char __user *inbuf,
				 int in_len, int out_len)
{
	struct rdma_ucm_resolve_addr cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_resolve_addr(ctx->cm_id, (struct sockaddr *) &cmd.src_addr,
				(struct sockaddr *) &cmd.dst_addr,
				cmd.timeout_ms);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_resolve_route(struct ucma_file *file,
				  const char __user *inbuf,
				  int in_len, int out_len)
{
	struct rdma_ucm_resolve_route cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_resolve_route(ctx->cm_id, cmd.timeout_ms);
	ucma_put_ctx(ctx);
	return ret;
}

static void ucma_copy_ib_route(struct rdma_ucm_query_route_resp *resp,
			       struct rdma_route *route)
{
	struct rdma_dev_addr *dev_addr;

	resp->num_paths = route->num_paths;
	switch (route->num_paths) {
	case 0:
		dev_addr = &route->addr.dev_addr;
		rdma_addr_get_dgid(dev_addr,
				   (union ib_gid *) &resp->ib_route[0].dgid);
		rdma_addr_get_sgid(dev_addr,
				   (union ib_gid *) &resp->ib_route[0].sgid);
		resp->ib_route[0].pkey = cpu_to_be16(ib_addr_get_pkey(dev_addr));
		break;
	case 2:
		ib_copy_path_rec_to_user(&resp->ib_route[1],
					 &route->path_rec[1]);
		/* fall through */
	case 1:
		ib_copy_path_rec_to_user(&resp->ib_route[0],
					 &route->path_rec[0]);
		break;
	default:
		break;
	}
}

static void ucma_copy_iboe_route(struct rdma_ucm_query_route_resp *resp,
				 struct rdma_route *route)
{
	struct rdma_dev_addr *dev_addr;
	struct net_device *dev;
	u16 vid = 0;

	resp->num_paths = route->num_paths;
	switch (route->num_paths) {
	case 0:
		dev_addr = &route->addr.dev_addr;
		dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
			if (dev) {
				vid = rdma_vlan_dev_vlan_id(dev);
				dev_put(dev);
			}

		iboe_mac_vlan_to_ll((union ib_gid *) &resp->ib_route[0].dgid,
				    dev_addr->dst_dev_addr, vid);
		iboe_addr_get_sgid(dev_addr,
				   (union ib_gid *) &resp->ib_route[0].sgid);
		resp->ib_route[0].pkey = cpu_to_be16(0xffff);
		break;
	case 2:
		ib_copy_path_rec_to_user(&resp->ib_route[1],
					 &route->path_rec[1]);
		/* fall through */
	case 1:
		ib_copy_path_rec_to_user(&resp->ib_route[0],
					 &route->path_rec[0]);
		break;
	default:
		break;
	}
}

static void ucma_copy_iw_route(struct rdma_ucm_query_route_resp *resp,
			       struct rdma_route *route)
{
	struct rdma_dev_addr *dev_addr;

	dev_addr = &route->addr.dev_addr;
	rdma_addr_get_dgid(dev_addr, (union ib_gid *) &resp->ib_route[0].dgid);
	rdma_addr_get_sgid(dev_addr, (union ib_gid *) &resp->ib_route[0].sgid);
}

static ssize_t ucma_query_route(struct ucma_file *file,
				const char __user *inbuf,
				int in_len, int out_len)
{
	struct rdma_ucm_query_route cmd;
	struct rdma_ucm_query_route_resp resp;
	struct ucma_context *ctx;
	struct sockaddr *addr;
	int ret = 0;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	memset(&resp, 0, sizeof resp);
	addr = (struct sockaddr *) &ctx->cm_id->route.addr.src_addr;
	memcpy(&resp.src_addr, addr, addr->sa_family == AF_INET ?
				     sizeof(struct sockaddr_in) :
				     sizeof(struct sockaddr_in6));
	addr = (struct sockaddr *) &ctx->cm_id->route.addr.dst_addr;
	memcpy(&resp.dst_addr, addr, addr->sa_family == AF_INET ?
				     sizeof(struct sockaddr_in) :
				     sizeof(struct sockaddr_in6));
	if (!ctx->cm_id->device)
		goto out;

	resp.node_guid = (__force __u64) ctx->cm_id->device->node_guid;
	resp.port_num = ctx->cm_id->port_num;
	switch (rdma_node_get_transport(ctx->cm_id->device->node_type)) {
	case RDMA_TRANSPORT_IB:
		switch (rdma_port_get_link_layer(ctx->cm_id->device,
			ctx->cm_id->port_num)) {
		case IB_LINK_LAYER_INFINIBAND:
			ucma_copy_ib_route(&resp, &ctx->cm_id->route);
			break;
		case IB_LINK_LAYER_ETHERNET:
			ucma_copy_iboe_route(&resp, &ctx->cm_id->route);
			break;
		default:
			break;
		}
		break;
	case RDMA_TRANSPORT_IWARP:
		ucma_copy_iw_route(&resp, &ctx->cm_id->route);
		break;
	default:
		break;
	}

out:
	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp)))
		ret = -EFAULT;

	ucma_put_ctx(ctx);
	return ret;
}

static void ucma_copy_conn_param(struct rdma_conn_param *dst,
				 struct rdma_ucm_conn_param *src)
{
	dst->private_data = src->private_data;
	dst->private_data_len = src->private_data_len;
	dst->responder_resources =src->responder_resources;
	dst->initiator_depth = src->initiator_depth;
	dst->flow_control = src->flow_control;
	dst->retry_count = src->retry_count;
	dst->rnr_retry_count = src->rnr_retry_count;
	dst->srq = src->srq;
	dst->qp_num = src->qp_num;
}

static ssize_t ucma_connect(struct ucma_file *file, const char __user *inbuf,
			    int in_len, int out_len)
{
	struct rdma_ucm_connect cmd;
	struct rdma_conn_param conn_param;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	if (!cmd.conn_param.valid)
		return -EINVAL;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ucma_copy_conn_param(&conn_param, &cmd.conn_param);
	ret = rdma_connect(ctx->cm_id, &conn_param);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_listen(struct ucma_file *file, const char __user *inbuf,
			   int in_len, int out_len)
{
	struct rdma_ucm_listen cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ctx->backlog = cmd.backlog > 0 && cmd.backlog < max_backlog ?
		       cmd.backlog : max_backlog;
	ret = rdma_listen(ctx->cm_id, ctx->backlog);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_accept(struct ucma_file *file, const char __user *inbuf,
			   int in_len, int out_len)
{
	struct rdma_ucm_accept cmd;
	struct rdma_conn_param conn_param;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	if (cmd.conn_param.valid) {
		ucma_copy_conn_param(&conn_param, &cmd.conn_param);
		mutex_lock(&file->mut);
		ret = rdma_accept(ctx->cm_id, &conn_param);
		if (!ret)
			ctx->uid = cmd.uid;
		mutex_unlock(&file->mut);
	} else
		ret = rdma_accept(ctx->cm_id, NULL);

	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_reject(struct ucma_file *file, const char __user *inbuf,
			   int in_len, int out_len)
{
	struct rdma_ucm_reject cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_reject(ctx->cm_id, cmd.private_data, cmd.private_data_len);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_disconnect(struct ucma_file *file, const char __user *inbuf,
			       int in_len, int out_len)
{
	struct rdma_ucm_disconnect cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_disconnect(ctx->cm_id);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_init_qp_attr(struct ucma_file *file,
				 const char __user *inbuf,
				 int in_len, int out_len)
{
	struct rdma_ucm_init_qp_attr cmd;
	struct ib_uverbs_qp_attr resp;
	struct ucma_context *ctx;
	struct ib_qp_attr qp_attr;
	int ret;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	resp.qp_attr_mask = 0;
	memset(&qp_attr, 0, sizeof qp_attr);
	qp_attr.qp_state = cmd.qp_state;
	ret = rdma_init_qp_attr(ctx->cm_id, &qp_attr, &resp.qp_attr_mask);
	if (ret)
		goto out;

	ib_copy_qp_attr_to_user(&resp, &qp_attr);
	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp)))
		ret = -EFAULT;

out:
	ucma_put_ctx(ctx);
	return ret;
}

static int ucma_set_option_id(struct ucma_context *ctx, int optname,
			      void *optval, size_t optlen)
{
	int ret = 0;

	switch (optname) {
	case RDMA_OPTION_ID_TOS:
		if (optlen != sizeof(u8)) {
			ret = -EINVAL;
			break;
		}
		rdma_set_service_type(ctx->cm_id, *((u8 *) optval));
		break;
	case RDMA_OPTION_ID_REUSEADDR:
		if (optlen != sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		ret = rdma_set_reuseaddr(ctx->cm_id, *((int *) optval) ? 1 : 0);
		break;
	case RDMA_OPTION_ID_AFONLY:
		if (optlen != sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		ret = rdma_set_afonly(ctx->cm_id, *((int *) optval) ? 1 : 0);
		break;
	default:
		ret = -ENOSYS;
	}

	return ret;
}

static int ucma_set_ib_path(struct ucma_context *ctx,
			    struct ib_path_rec_data *path_data, size_t optlen)
{
	struct ib_sa_path_rec sa_path;
	struct rdma_cm_event event;
	int ret;

	if (optlen % sizeof(*path_data))
		return -EINVAL;

	for (; optlen; optlen -= sizeof(*path_data), path_data++) {
		if (path_data->flags == (IB_PATH_GMP | IB_PATH_PRIMARY |
					 IB_PATH_BIDIRECTIONAL))
			break;
	}

	if (!optlen)
		return -EINVAL;

	ib_sa_unpack_path(path_data->path_rec, &sa_path);
	ret = rdma_set_ib_paths(ctx->cm_id, &sa_path, 1);
	if (ret)
		return ret;

	memset(&event, 0, sizeof event);
	event.event = RDMA_CM_EVENT_ROUTE_RESOLVED;
	return ucma_event_handler(ctx->cm_id, &event);
}

static int ucma_set_option_ib(struct ucma_context *ctx, int optname,
			      void *optval, size_t optlen)
{
	int ret;

	switch (optname) {
	case RDMA_OPTION_IB_PATH:
		ret = ucma_set_ib_path(ctx, optval, optlen);
		break;
	default:
		ret = -ENOSYS;
	}

	return ret;
}

static int ucma_set_option_level(struct ucma_context *ctx, int level,
				 int optname, void *optval, size_t optlen)
{
	int ret;

	switch (level) {
	case RDMA_OPTION_ID:
		ret = ucma_set_option_id(ctx, optname, optval, optlen);
		break;
	case RDMA_OPTION_IB:
		ret = ucma_set_option_ib(ctx, optname, optval, optlen);
		break;
	default:
		ret = -ENOSYS;
	}

	return ret;
}

static ssize_t ucma_set_option(struct ucma_file *file, const char __user *inbuf,
			       int in_len, int out_len)
{
	struct rdma_ucm_set_option cmd;
	struct ucma_context *ctx;
	void *optval;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	optval = memdup_user((void __user *) (unsigned long) cmd.optval,
			     cmd.optlen);
	if (IS_ERR(optval)) {
		ret = PTR_ERR(optval);
		goto out;
	}

	ret = ucma_set_option_level(ctx, cmd.level, cmd.optname, optval,
				    cmd.optlen);
	kfree(optval);

out:
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_notify(struct ucma_file *file, const char __user *inbuf,
			   int in_len, int out_len)
{
	struct rdma_ucm_notify cmd;
	struct ucma_context *ctx;
	int ret;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	ret = rdma_notify(ctx->cm_id, (enum ib_event_type) cmd.event);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_join_multicast(struct ucma_file *file,
				   const char __user *inbuf,
				   int in_len, int out_len)
{
	struct rdma_ucm_join_mcast cmd;
	struct rdma_ucm_create_id_resp resp;
	struct ucma_context *ctx;
	struct ucma_multicast *mc;
	int ret;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	ctx = ucma_get_ctx(file, cmd.id);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);

	mutex_lock(&file->mut);
	mc = ucma_alloc_multicast(ctx);
	if (!mc) {
		ret = -ENOMEM;
		goto err1;
	}

	mc->uid = cmd.uid;
	memcpy(&mc->addr, &cmd.addr, sizeof cmd.addr);
	ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr, mc);
	if (ret)
		goto err2;

	resp.id = mc->id;
	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp))) {
		ret = -EFAULT;
		goto err3;
	}

	mutex_unlock(&file->mut);
	ucma_put_ctx(ctx);
	return 0;

err3:
	rdma_leave_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr);
	ucma_cleanup_mc_events(mc);
err2:
	mutex_lock(&mut);
	idr_remove(&multicast_idr, mc->id);
	mutex_unlock(&mut);
	list_del(&mc->list);
	kfree(mc);
err1:
	mutex_unlock(&file->mut);
	ucma_put_ctx(ctx);
	return ret;
}

static ssize_t ucma_leave_multicast(struct ucma_file *file,
				    const char __user *inbuf,
				    int in_len, int out_len)
{
	struct rdma_ucm_destroy_id cmd;
	struct rdma_ucm_destroy_id_resp resp;
	struct ucma_multicast *mc;
	int ret = 0;

	if (out_len < sizeof(resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	mutex_lock(&mut);
	mc = idr_find(&multicast_idr, cmd.id);
	if (!mc)
		mc = ERR_PTR(-ENOENT);
	else if (mc->ctx->file != file)
		mc = ERR_PTR(-EINVAL);
	else {
		idr_remove(&multicast_idr, mc->id);
		atomic_inc(&mc->ctx->ref);
	}
	mutex_unlock(&mut);

	if (IS_ERR(mc)) {
		ret = PTR_ERR(mc);
		goto out;
	}

	rdma_leave_multicast(mc->ctx->cm_id, (struct sockaddr *) &mc->addr);
	mutex_lock(&mc->ctx->file->mut);
	ucma_cleanup_mc_events(mc);
	list_del(&mc->list);
	mutex_unlock(&mc->ctx->file->mut);

	ucma_put_ctx(mc->ctx);
	resp.events_reported = mc->events_reported;
	kfree(mc);

	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp)))
		ret = -EFAULT;
out:
	return ret;
}

static void ucma_lock_files(struct ucma_file *file1, struct ucma_file *file2)
{
	/* Acquire mutex's based on pointer comparison to prevent deadlock. */
	if (file1 < file2) {
		mutex_lock(&file1->mut);
		mutex_lock(&file2->mut);
	} else {
		mutex_lock(&file2->mut);
		mutex_lock(&file1->mut);
	}
}

static void ucma_unlock_files(struct ucma_file *file1, struct ucma_file *file2)
{
	if (file1 < file2) {
		mutex_unlock(&file2->mut);
		mutex_unlock(&file1->mut);
	} else {
		mutex_unlock(&file1->mut);
		mutex_unlock(&file2->mut);
	}
}

static void ucma_move_events(struct ucma_context *ctx, struct ucma_file *file)
{
	struct ucma_event *uevent, *tmp;

	list_for_each_entry_safe(uevent, tmp, &ctx->file->event_list, list)
		if (uevent->ctx == ctx)
			list_move_tail(&uevent->list, &file->event_list);
}

static ssize_t ucma_migrate_id(struct ucma_file *new_file,
			       const char __user *inbuf,
			       int in_len, int out_len)
{
	struct rdma_ucm_migrate_id cmd;
	struct rdma_ucm_migrate_resp resp;
	struct ucma_context *ctx;
	struct file *filp;
	struct ucma_file *cur_file;
	int ret = 0;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;

	/* Get current fd to protect against it being closed */
	filp = fget(cmd.fd);
	if (!filp)
		return -ENOENT;

	/* Validate current fd and prevent destruction of id. */
	ctx = ucma_get_ctx(filp->private_data, cmd.id);
	if (IS_ERR(ctx)) {
		ret = PTR_ERR(ctx);
		goto file_put;
	}

	cur_file = ctx->file;
	if (cur_file == new_file) {
		resp.events_reported = ctx->events_reported;
		goto response;
	}

	/*
	 * Migrate events between fd's, maintaining order, and avoiding new
	 * events being added before existing events.
	 */
	ucma_lock_files(cur_file, new_file);
	mutex_lock(&mut);

	list_move_tail(&ctx->list, &new_file->ctx_list);
	ucma_move_events(ctx, new_file);
	ctx->file = new_file;
	resp.events_reported = ctx->events_reported;

	mutex_unlock(&mut);
	ucma_unlock_files(cur_file, new_file);

response:
	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &resp, sizeof(resp)))
		ret = -EFAULT;

	ucma_put_ctx(ctx);
file_put:
	fput(filp);
	return ret;
}

static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,
				   const char __user *inbuf,
				   int in_len, int out_len) = {
	[RDMA_USER_CM_CMD_CREATE_ID]	= ucma_create_id,
	[RDMA_USER_CM_CMD_DESTROY_ID]	= ucma_destroy_id,
	[RDMA_USER_CM_CMD_BIND_ADDR]	= ucma_bind_addr,
	[RDMA_USER_CM_CMD_RESOLVE_ADDR]	= ucma_resolve_addr,
	[RDMA_USER_CM_CMD_RESOLVE_ROUTE]= ucma_resolve_route,
	[RDMA_USER_CM_CMD_QUERY_ROUTE]	= ucma_query_route,
	[RDMA_USER_CM_CMD_CONNECT]	= ucma_connect,
	[RDMA_USER_CM_CMD_LISTEN]	= ucma_listen,
	[RDMA_USER_CM_CMD_ACCEPT]	= ucma_accept,
	[RDMA_USER_CM_CMD_REJECT]	= ucma_reject,
	[RDMA_USER_CM_CMD_DISCONNECT]	= ucma_disconnect,
	[RDMA_USER_CM_CMD_INIT_QP_ATTR]	= ucma_init_qp_attr,
	[RDMA_USER_CM_CMD_GET_EVENT]	= ucma_get_event,
	[RDMA_USER_CM_CMD_GET_OPTION]	= NULL,
	[RDMA_USER_CM_CMD_SET_OPTION]	= ucma_set_option,
	[RDMA_USER_CM_CMD_NOTIFY]	= ucma_notify,
	[RDMA_USER_CM_CMD_JOIN_MCAST]	= ucma_join_multicast,
	[RDMA_USER_CM_CMD_LEAVE_MCAST]	= ucma_leave_multicast,
	[RDMA_USER_CM_CMD_MIGRATE_ID]	= ucma_migrate_id
};

static ssize_t ucma_write(struct file *filp, const char __user *buf,
			  size_t len, loff_t *pos)
{
	struct ucma_file *file = filp->private_data;
	struct rdma_ucm_cmd_hdr hdr;
	ssize_t ret;

	if (len < sizeof(hdr))
		return -EINVAL;

	if (copy_from_user(&hdr, buf, sizeof(hdr)))
		return -EFAULT;

	if (hdr.cmd >= ARRAY_SIZE(ucma_cmd_table))
		return -EINVAL;

	if (hdr.in + sizeof(hdr) > len)
		return -EINVAL;

	if (!ucma_cmd_table[hdr.cmd])
		return -ENOSYS;

	ret = ucma_cmd_table[hdr.cmd](file, buf + sizeof(hdr), hdr.in, hdr.out);
	if (!ret)
		ret = len;

	return ret;
}

static unsigned int ucma_poll(struct file *filp, struct poll_table_struct *wait)
{
	struct ucma_file *file = filp->private_data;
	unsigned int mask = 0;

	poll_wait(filp, &file->poll_wait, wait);

	if (!list_empty(&file->event_list))
		mask = POLLIN | POLLRDNORM;

	return mask;
}

/*
 * ucma_open() does not need the BKL:
 *
 *  - no global state is referred to;
 *  - there is no ioctl method to race against;
 *  - no further module initialization is required for open to work
 *    after the device is registered.
 */
static int ucma_open(struct inode *inode, struct file *filp)
{
	struct ucma_file *file;

	file = kmalloc(sizeof *file, GFP_KERNEL);
	if (!file)
		return -ENOMEM;

	INIT_LIST_HEAD(&file->event_list);
	INIT_LIST_HEAD(&file->ctx_list);
	init_waitqueue_head(&file->poll_wait);
	mutex_init(&file->mut);

	filp->private_data = file;
	file->filp = filp;

	return nonseekable_open(inode, filp);
}

static int ucma_close(struct inode *inode, struct file *filp)
{
	struct ucma_file *file = filp->private_data;
	struct ucma_context *ctx, *tmp;

	mutex_lock(&file->mut);
	list_for_each_entry_safe(ctx, tmp, &file->ctx_list, list) {
		mutex_unlock(&file->mut);

		mutex_lock(&mut);
		idr_remove(&ctx_idr, ctx->id);
		mutex_unlock(&mut);

		ucma_free_ctx(ctx);
		mutex_lock(&file->mut);
	}
	mutex_unlock(&file->mut);
	kfree(file);
	return 0;
}

static const struct file_operations ucma_fops = {
	.owner 	 = THIS_MODULE,
	.open 	 = ucma_open,
	.release = ucma_close,
	.write	 = ucma_write,
	.poll    = ucma_poll,
	.llseek	 = no_llseek,
};

static struct miscdevice ucma_misc = {
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= "rdma_cm",
	.nodename	= "infiniband/rdma_cm",
	.mode		= 0666,
	.fops		= &ucma_fops,
};

static ssize_t show_abi_version(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	return sprintf(buf, "%d\n", RDMA_USER_CM_ABI_VERSION);
}
static DEVICE_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);

static int __init ucma_init(void)
{
	int ret;

	ret = misc_register(&ucma_misc);
	if (ret)
		return ret;

	ret = device_create_file(ucma_misc.this_device, &dev_attr_abi_version);
	if (ret) {
		printk(KERN_ERR "rdma_ucm: couldn't create abi_version attr\n");
		goto err1;
	}

	ucma_ctl_table_hdr = register_net_sysctl(&init_net, "net/rdma_ucm", ucma_ctl_table);
	if (!ucma_ctl_table_hdr) {
		printk(KERN_ERR "rdma_ucm: couldn't register sysctl paths\n");
		ret = -ENOMEM;
		goto err2;
	}
	return 0;
err2:
	device_remove_file(ucma_misc.this_device, &dev_attr_abi_version);
err1:
	misc_deregister(&ucma_misc);
	return ret;
}

static void __exit ucma_cleanup(void)
{
	unregister_net_sysctl_table(ucma_ctl_table_hdr);
	device_remove_file(ucma_misc.this_device, &dev_attr_abi_version);
	misc_deregister(&ucma_misc);
	idr_destroy(&ctx_idr);
}

module_init(ucma_init);
module_exit(ucma_cleanup);