summaryrefslogtreecommitdiffstats
path: root/drivers/target/loopback/tcm_loop.c
blob: 4fb0eca86857e2f3229603397138d4c793b57eff (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
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
/*******************************************************************************
 *
 * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
 * for emulated SAS initiator ports
 *
 * © Copyright 2011-2013 Datera, Inc.
 *
 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
 *
 * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 ****************************************************************************/

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/configfs.h>
#include <scsi/scsi.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>

#include <target/target_core_base.h>
#include <target/target_core_fabric.h>

#include "tcm_loop.h"

#define to_tcm_loop_hba(hba)	container_of(hba, struct tcm_loop_hba, dev)

static struct workqueue_struct *tcm_loop_workqueue;
static struct kmem_cache *tcm_loop_cmd_cache;

static int tcm_loop_hba_no_cnt;

static int tcm_loop_queue_status(struct se_cmd *se_cmd);

/*
 * Called from struct target_core_fabric_ops->check_stop_free()
 */
static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
{
	/*
	 * Do not release struct se_cmd's containing a valid TMR
	 * pointer.  These will be released directly in tcm_loop_device_reset()
	 * with transport_generic_free_cmd().
	 */
	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
		return 0;
	/*
	 * Release the struct se_cmd, which will make a callback to release
	 * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
	 */
	transport_generic_free_cmd(se_cmd, 0);
	return 1;
}

static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
{
	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
				struct tcm_loop_cmd, tl_se_cmd);

	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
}

static int tcm_loop_show_info(struct seq_file *m, struct Scsi_Host *host)
{
	seq_printf(m, "tcm_loop_proc_info()\n");
	return 0;
}

static int tcm_loop_driver_probe(struct device *);
static int tcm_loop_driver_remove(struct device *);

static int pseudo_lld_bus_match(struct device *dev,
				struct device_driver *dev_driver)
{
	return 1;
}

static struct bus_type tcm_loop_lld_bus = {
	.name			= "tcm_loop_bus",
	.match			= pseudo_lld_bus_match,
	.probe			= tcm_loop_driver_probe,
	.remove			= tcm_loop_driver_remove,
};

static struct device_driver tcm_loop_driverfs = {
	.name			= "tcm_loop",
	.bus			= &tcm_loop_lld_bus,
};
/*
 * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 */
static struct device *tcm_loop_primary;

static void tcm_loop_submission_work(struct work_struct *work)
{
	struct tcm_loop_cmd *tl_cmd =
		container_of(work, struct tcm_loop_cmd, work);
	struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
	struct scsi_cmnd *sc = tl_cmd->sc;
	struct tcm_loop_nexus *tl_nexus;
	struct tcm_loop_hba *tl_hba;
	struct tcm_loop_tpg *tl_tpg;
	struct scatterlist *sgl_bidi = NULL;
	u32 sgl_bidi_count = 0, transfer_length;
	int rc;

	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];

	/*
	 * Ensure that this tl_tpg reference from the incoming sc->device->id
	 * has already been configured via tcm_loop_make_naa_tpg().
	 */
	if (!tl_tpg->tl_hba) {
		set_host_byte(sc, DID_NO_CONNECT);
		goto out_done;
	}
	if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
		set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
		goto out_done;
	}
	tl_nexus = tl_tpg->tl_nexus;
	if (!tl_nexus) {
		scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
				" does not exist\n");
		set_host_byte(sc, DID_ERROR);
		goto out_done;
	}
	if (scsi_bidi_cmnd(sc)) {
		struct scsi_data_buffer *sdb = scsi_in(sc);

		sgl_bidi = sdb->table.sgl;
		sgl_bidi_count = sdb->table.nents;
		se_cmd->se_cmd_flags |= SCF_BIDI;

	}

	transfer_length = scsi_transfer_length(sc);
	if (!scsi_prot_sg_count(sc) &&
	    scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
		se_cmd->prot_pto = true;
		/*
		 * loopback transport doesn't support
		 * WRITE_GENERATE, READ_STRIP protection
		 * information operations, go ahead unprotected.
		 */
		transfer_length = scsi_bufflen(sc);
	}

	se_cmd->tag = tl_cmd->sc_cmd_tag;
	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
			transfer_length, TCM_SIMPLE_TAG,
			sc->sc_data_direction, 0,
			scsi_sglist(sc), scsi_sg_count(sc),
			sgl_bidi, sgl_bidi_count,
			scsi_prot_sglist(sc), scsi_prot_sg_count(sc));
	if (rc < 0) {
		set_host_byte(sc, DID_NO_CONNECT);
		goto out_done;
	}
	return;

out_done:
	kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
	sc->scsi_done(sc);
	return;
}

/*
 * ->queuecommand can be and usually is called from interrupt context, so
 * defer the actual submission to a workqueue.
 */
static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
{
	struct tcm_loop_cmd *tl_cmd;

	pr_debug("tcm_loop_queuecommand() %d:%d:%d:%llu got CDB: 0x%02x"
		" scsi_buf_len: %u\n", sc->device->host->host_no,
		sc->device->id, sc->device->channel, sc->device->lun,
		sc->cmnd[0], scsi_bufflen(sc));

	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
	if (!tl_cmd) {
		pr_err("Unable to allocate struct tcm_loop_cmd\n");
		set_host_byte(sc, DID_ERROR);
		sc->scsi_done(sc);
		return 0;
	}

	tl_cmd->sc = sc;
	tl_cmd->sc_cmd_tag = sc->request->tag;
	INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
	queue_work(tcm_loop_workqueue, &tl_cmd->work);
	return 0;
}

/*
 * Called from SCSI EH process context to issue a LUN_RESET TMR
 * to struct scsi_device
 */
static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
			      u64 lun, int task, enum tcm_tmreq_table tmr)
{
	struct se_cmd *se_cmd = NULL;
	struct se_session *se_sess;
	struct se_portal_group *se_tpg;
	struct tcm_loop_nexus *tl_nexus;
	struct tcm_loop_cmd *tl_cmd = NULL;
	struct tcm_loop_tmr *tl_tmr = NULL;
	int ret = TMR_FUNCTION_FAILED, rc;

	/*
	 * Locate the tl_nexus and se_sess pointers
	 */
	tl_nexus = tl_tpg->tl_nexus;
	if (!tl_nexus) {
		pr_err("Unable to perform device reset without"
				" active I_T Nexus\n");
		return ret;
	}

	tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
	if (!tl_cmd) {
		pr_err("Unable to allocate memory for tl_cmd\n");
		return ret;
	}

	tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
	if (!tl_tmr) {
		pr_err("Unable to allocate memory for tl_tmr\n");
		goto release;
	}
	init_waitqueue_head(&tl_tmr->tl_tmr_wait);

	se_cmd = &tl_cmd->tl_se_cmd;
	se_tpg = &tl_tpg->tl_se_tpg;
	se_sess = tl_tpg->tl_nexus->se_sess;
	/*
	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
	 */
	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
				DMA_NONE, TCM_SIMPLE_TAG,
				&tl_cmd->tl_sense_buf[0]);

	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
	if (rc < 0)
		goto release;

	if (tmr == TMR_ABORT_TASK)
		se_cmd->se_tmr_req->ref_task_tag = task;

	/*
	 * Locate the underlying TCM struct se_lun
	 */
	if (transport_lookup_tmr_lun(se_cmd, lun) < 0) {
		ret = TMR_LUN_DOES_NOT_EXIST;
		goto release;
	}
	/*
	 * Queue the TMR to TCM Core and sleep waiting for
	 * tcm_loop_queue_tm_rsp() to wake us up.
	 */
	transport_generic_handle_tmr(se_cmd);
	wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
	/*
	 * The TMR LUN_RESET has completed, check the response status and
	 * then release allocations.
	 */
	ret = se_cmd->se_tmr_req->response;
release:
	if (se_cmd)
		transport_generic_free_cmd(se_cmd, 1);
	else
		kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
	kfree(tl_tmr);
	return ret;
}

static int tcm_loop_abort_task(struct scsi_cmnd *sc)
{
	struct tcm_loop_hba *tl_hba;
	struct tcm_loop_tpg *tl_tpg;
	int ret = FAILED;

	/*
	 * Locate the tcm_loop_hba_t pointer
	 */
	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
				 sc->request->tag, TMR_ABORT_TASK);
	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
}

/*
 * Called from SCSI EH process context to issue a LUN_RESET TMR
 * to struct scsi_device
 */
static int tcm_loop_device_reset(struct scsi_cmnd *sc)
{
	struct tcm_loop_hba *tl_hba;
	struct tcm_loop_tpg *tl_tpg;
	int ret = FAILED;

	/*
	 * Locate the tcm_loop_hba_t pointer
	 */
	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];

	ret = tcm_loop_issue_tmr(tl_tpg, sc->device->lun,
				 0, TMR_LUN_RESET);
	return (ret == TMR_FUNCTION_COMPLETE) ? SUCCESS : FAILED;
}

static int tcm_loop_target_reset(struct scsi_cmnd *sc)
{
	struct tcm_loop_hba *tl_hba;
	struct tcm_loop_tpg *tl_tpg;

	/*
	 * Locate the tcm_loop_hba_t pointer
	 */
	tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
	if (!tl_hba) {
		pr_err("Unable to perform device reset without"
				" active I_T Nexus\n");
		return FAILED;
	}
	/*
	 * Locate the tl_tpg pointer from TargetID in sc->device->id
	 */
	tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
	if (tl_tpg) {
		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
		return SUCCESS;
	}
	return FAILED;
}

static int tcm_loop_slave_alloc(struct scsi_device *sd)
{
	set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
	return 0;
}

static struct scsi_host_template tcm_loop_driver_template = {
	.show_info		= tcm_loop_show_info,
	.proc_name		= "tcm_loopback",
	.name			= "TCM_Loopback",
	.queuecommand		= tcm_loop_queuecommand,
	.change_queue_depth	= scsi_change_queue_depth,
	.eh_abort_handler = tcm_loop_abort_task,
	.eh_device_reset_handler = tcm_loop_device_reset,
	.eh_target_reset_handler = tcm_loop_target_reset,
	.can_queue		= 1024,
	.this_id		= -1,
	.sg_tablesize		= 256,
	.cmd_per_lun		= 1024,
	.max_sectors		= 0xFFFF,
	.use_clustering		= DISABLE_CLUSTERING,
	.slave_alloc		= tcm_loop_slave_alloc,
	.module			= THIS_MODULE,
	.track_queue_depth	= 1,
};

static int tcm_loop_driver_probe(struct device *dev)
{
	struct tcm_loop_hba *tl_hba;
	struct Scsi_Host *sh;
	int error, host_prot;

	tl_hba = to_tcm_loop_hba(dev);

	sh = scsi_host_alloc(&tcm_loop_driver_template,
			sizeof(struct tcm_loop_hba));
	if (!sh) {
		pr_err("Unable to allocate struct scsi_host\n");
		return -ENODEV;
	}
	tl_hba->sh = sh;

	/*
	 * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
	 */
	*((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
	/*
	 * Setup single ID, Channel and LUN for now..
	 */
	sh->max_id = 2;
	sh->max_lun = 0;
	sh->max_channel = 0;
	sh->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;

	host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION |
		    SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION |
		    SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION;

	scsi_host_set_prot(sh, host_prot);
	scsi_host_set_guard(sh, SHOST_DIX_GUARD_CRC);

	error = scsi_add_host(sh, &tl_hba->dev);
	if (error) {
		pr_err("%s: scsi_add_host failed\n", __func__);
		scsi_host_put(sh);
		return -ENODEV;
	}
	return 0;
}

static int tcm_loop_driver_remove(struct device *dev)
{
	struct tcm_loop_hba *tl_hba;
	struct Scsi_Host *sh;

	tl_hba = to_tcm_loop_hba(dev);
	sh = tl_hba->sh;

	scsi_remove_host(sh);
	scsi_host_put(sh);
	return 0;
}

static void tcm_loop_release_adapter(struct device *dev)
{
	struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);

	kfree(tl_hba);
}

/*
 * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 */
static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
{
	int ret;

	tl_hba->dev.bus = &tcm_loop_lld_bus;
	tl_hba->dev.parent = tcm_loop_primary;
	tl_hba->dev.release = &tcm_loop_release_adapter;
	dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);

	ret = device_register(&tl_hba->dev);
	if (ret) {
		pr_err("device_register() failed for"
				" tl_hba->dev: %d\n", ret);
		return -ENODEV;
	}

	return 0;
}

/*
 * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 * tcm_loop SCSI bus.
 */
static int tcm_loop_alloc_core_bus(void)
{
	int ret;

	tcm_loop_primary = root_device_register("tcm_loop_0");
	if (IS_ERR(tcm_loop_primary)) {
		pr_err("Unable to allocate tcm_loop_primary\n");
		return PTR_ERR(tcm_loop_primary);
	}

	ret = bus_register(&tcm_loop_lld_bus);
	if (ret) {
		pr_err("bus_register() failed for tcm_loop_lld_bus\n");
		goto dev_unreg;
	}

	ret = driver_register(&tcm_loop_driverfs);
	if (ret) {
		pr_err("driver_register() failed for"
				"tcm_loop_driverfs\n");
		goto bus_unreg;
	}

	pr_debug("Initialized TCM Loop Core Bus\n");
	return ret;

bus_unreg:
	bus_unregister(&tcm_loop_lld_bus);
dev_unreg:
	root_device_unregister(tcm_loop_primary);
	return ret;
}

static void tcm_loop_release_core_bus(void)
{
	driver_unregister(&tcm_loop_driverfs);
	bus_unregister(&tcm_loop_lld_bus);
	root_device_unregister(tcm_loop_primary);

	pr_debug("Releasing TCM Loop Core BUS\n");
}

static char *tcm_loop_get_fabric_name(void)
{
	return "loopback";
}

static inline struct tcm_loop_tpg *tl_tpg(struct se_portal_group *se_tpg)
{
	return container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
}

static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
{
	/*
	 * Return the passed NAA identifier for the Target Port
	 */
	return &tl_tpg(se_tpg)->tl_hba->tl_wwn_address[0];
}

static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
{
	/*
	 * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
	 * to represent the SCSI Target Port.
	 */
	return tl_tpg(se_tpg)->tl_tpgt;
}

/*
 * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 * based upon the incoming fabric dependent SCSI Initiator Port
 */
static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
{
	return 1;
}

static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
{
	return 0;
}

/*
 * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 */
static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
{
	return 0;
}

/*
 * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 * It has been added here as a nop for target_fabric_tf_ops_check()
 */
static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
{
	return 0;
}

static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
{
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
						   tl_se_tpg);
	return tl_tpg->tl_fabric_prot_type;
}

static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
{
	return 1;
}

static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
{
	return 1;
}

static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
{
	return;
}

static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
{
	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
			struct tcm_loop_cmd, tl_se_cmd);

	return tl_cmd->sc_cmd_state;
}

static int tcm_loop_shutdown_session(struct se_session *se_sess)
{
	return 0;
}

static void tcm_loop_close_session(struct se_session *se_sess)
{
	return;
};

static int tcm_loop_write_pending(struct se_cmd *se_cmd)
{
	/*
	 * Since Linux/SCSI has already sent down a struct scsi_cmnd
	 * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
	 * memory, and memory has already been mapped to struct se_cmd->t_mem_list
	 * format with transport_generic_map_mem_to_cmd().
	 *
	 * We now tell TCM to add this WRITE CDB directly into the TCM storage
	 * object execution queue.
	 */
	target_execute_cmd(se_cmd);
	return 0;
}

static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
{
	return 0;
}

static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
{
	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
				struct tcm_loop_cmd, tl_se_cmd);
	struct scsi_cmnd *sc = tl_cmd->sc;

	pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
		     " cdb: 0x%02x\n", sc, sc->cmnd[0]);

	sc->result = SAM_STAT_GOOD;
	set_host_byte(sc, DID_OK);
	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
		scsi_set_resid(sc, se_cmd->residual_count);
	sc->scsi_done(sc);
	return 0;
}

static int tcm_loop_queue_status(struct se_cmd *se_cmd)
{
	struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
				struct tcm_loop_cmd, tl_se_cmd);
	struct scsi_cmnd *sc = tl_cmd->sc;

	pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
			" cdb: 0x%02x\n", sc, sc->cmnd[0]);

	if (se_cmd->sense_buffer &&
	   ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
	    (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {

		memcpy(sc->sense_buffer, se_cmd->sense_buffer,
				SCSI_SENSE_BUFFERSIZE);
		sc->result = SAM_STAT_CHECK_CONDITION;
		set_driver_byte(sc, DRIVER_SENSE);
	} else
		sc->result = se_cmd->scsi_status;

	set_host_byte(sc, DID_OK);
	if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
	    (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
		scsi_set_resid(sc, se_cmd->residual_count);
	sc->scsi_done(sc);
	return 0;
}

static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
{
	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
	struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
	/*
	 * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
	 * and wake up the wait_queue_head_t in tcm_loop_device_reset()
	 */
	atomic_set(&tl_tmr->tmr_complete, 1);
	wake_up(&tl_tmr->tl_tmr_wait);
}

static void tcm_loop_aborted_task(struct se_cmd *se_cmd)
{
	return;
}

static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
{
	switch (tl_hba->tl_proto_id) {
	case SCSI_PROTOCOL_SAS:
		return "SAS";
	case SCSI_PROTOCOL_FCP:
		return "FCP";
	case SCSI_PROTOCOL_ISCSI:
		return "iSCSI";
	default:
		break;
	}

	return "Unknown";
}

/* Start items for tcm_loop_port_cit */

static int tcm_loop_port_link(
	struct se_portal_group *se_tpg,
	struct se_lun *lun)
{
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
				struct tcm_loop_tpg, tl_se_tpg);
	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;

	atomic_inc_mb(&tl_tpg->tl_tpg_port_count);
	/*
	 * Add Linux/SCSI struct scsi_device by HCTL
	 */
	scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);

	pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
	return 0;
}

static void tcm_loop_port_unlink(
	struct se_portal_group *se_tpg,
	struct se_lun *se_lun)
{
	struct scsi_device *sd;
	struct tcm_loop_hba *tl_hba;
	struct tcm_loop_tpg *tl_tpg;

	tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
	tl_hba = tl_tpg->tl_hba;

	sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
				se_lun->unpacked_lun);
	if (!sd) {
		pr_err("Unable to locate struct scsi_device for %d:%d:"
			"%llu\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
		return;
	}
	/*
	 * Remove Linux/SCSI struct scsi_device by HCTL
	 */
	scsi_remove_device(sd);
	scsi_device_put(sd);

	atomic_dec_mb(&tl_tpg->tl_tpg_port_count);

	pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
}

/* End items for tcm_loop_port_cit */

static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_show(
		struct config_item *item, char *page)
{
	struct se_portal_group *se_tpg = attrib_to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
						   tl_se_tpg);

	return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
}

static ssize_t tcm_loop_tpg_attrib_fabric_prot_type_store(
		struct config_item *item, const char *page, size_t count)
{
	struct se_portal_group *se_tpg = attrib_to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
						   tl_se_tpg);
	unsigned long val;
	int ret = kstrtoul(page, 0, &val);

	if (ret) {
		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
		return ret;
	}
	if (val != 0 && val != 1 && val != 3) {
		pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
		return -EINVAL;
	}
	tl_tpg->tl_fabric_prot_type = val;

	return count;
}

CONFIGFS_ATTR(tcm_loop_tpg_attrib_, fabric_prot_type);

static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
	&tcm_loop_tpg_attrib_attr_fabric_prot_type,
	NULL,
};

/* Start items for tcm_loop_nexus_cit */

static int tcm_loop_make_nexus(
	struct tcm_loop_tpg *tl_tpg,
	const char *name)
{
	struct se_portal_group *se_tpg;
	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
	struct tcm_loop_nexus *tl_nexus;
	int ret = -ENOMEM;

	if (tl_tpg->tl_nexus) {
		pr_debug("tl_tpg->tl_nexus already exists\n");
		return -EEXIST;
	}
	se_tpg = &tl_tpg->tl_se_tpg;

	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
	if (!tl_nexus) {
		pr_err("Unable to allocate struct tcm_loop_nexus\n");
		return -ENOMEM;
	}
	/*
	 * Initialize the struct se_session pointer
	 */
	tl_nexus->se_sess = transport_init_session(
				TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
	if (IS_ERR(tl_nexus->se_sess)) {
		ret = PTR_ERR(tl_nexus->se_sess);
		goto out;
	}
	/*
	 * Since we are running in 'demo mode' this call with generate a
	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
	 * Initiator port name of the passed configfs group 'name'.
	 */
	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
				se_tpg, (unsigned char *)name);
	if (!tl_nexus->se_sess->se_node_acl) {
		transport_free_session(tl_nexus->se_sess);
		goto out;
	}
	/* Now, register the I_T Nexus as active. */
	transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
			tl_nexus->se_sess, tl_nexus);
	tl_tpg->tl_nexus = tl_nexus;
	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
		name);
	return 0;

out:
	kfree(tl_nexus);
	return ret;
}

static int tcm_loop_drop_nexus(
	struct tcm_loop_tpg *tpg)
{
	struct se_session *se_sess;
	struct tcm_loop_nexus *tl_nexus;

	tl_nexus = tpg->tl_nexus;
	if (!tl_nexus)
		return -ENODEV;

	se_sess = tl_nexus->se_sess;
	if (!se_sess)
		return -ENODEV;

	if (atomic_read(&tpg->tl_tpg_port_count)) {
		pr_err("Unable to remove TCM_Loop I_T Nexus with"
			" active TPG port count: %d\n",
			atomic_read(&tpg->tl_tpg_port_count));
		return -EPERM;
	}

	pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tpg->tl_hba),
		tl_nexus->se_sess->se_node_acl->initiatorname);
	/*
	 * Release the SCSI I_T Nexus to the emulated Target Port
	 */
	transport_deregister_session(tl_nexus->se_sess);
	tpg->tl_nexus = NULL;
	kfree(tl_nexus);
	return 0;
}

/* End items for tcm_loop_nexus_cit */

static ssize_t tcm_loop_tpg_nexus_show(struct config_item *item, char *page)
{
	struct se_portal_group *se_tpg = to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
			struct tcm_loop_tpg, tl_se_tpg);
	struct tcm_loop_nexus *tl_nexus;
	ssize_t ret;

	tl_nexus = tl_tpg->tl_nexus;
	if (!tl_nexus)
		return -ENODEV;

	ret = snprintf(page, PAGE_SIZE, "%s\n",
		tl_nexus->se_sess->se_node_acl->initiatorname);

	return ret;
}

static ssize_t tcm_loop_tpg_nexus_store(struct config_item *item,
		const char *page, size_t count)
{
	struct se_portal_group *se_tpg = to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
			struct tcm_loop_tpg, tl_se_tpg);
	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
	unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
	int ret;
	/*
	 * Shutdown the active I_T nexus if 'NULL' is passed..
	 */
	if (!strncmp(page, "NULL", 4)) {
		ret = tcm_loop_drop_nexus(tl_tpg);
		return (!ret) ? count : ret;
	}
	/*
	 * Otherwise make sure the passed virtual Initiator port WWN matches
	 * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
	 * tcm_loop_make_nexus()
	 */
	if (strlen(page) >= TL_WWN_ADDR_LEN) {
		pr_err("Emulated NAA Sas Address: %s, exceeds"
				" max: %d\n", page, TL_WWN_ADDR_LEN);
		return -EINVAL;
	}
	snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);

	ptr = strstr(i_port, "naa.");
	if (ptr) {
		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
			pr_err("Passed SAS Initiator Port %s does not"
				" match target port protoid: %s\n", i_port,
				tcm_loop_dump_proto_id(tl_hba));
			return -EINVAL;
		}
		port_ptr = &i_port[0];
		goto check_newline;
	}
	ptr = strstr(i_port, "fc.");
	if (ptr) {
		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
			pr_err("Passed FCP Initiator Port %s does not"
				" match target port protoid: %s\n", i_port,
				tcm_loop_dump_proto_id(tl_hba));
			return -EINVAL;
		}
		port_ptr = &i_port[3]; /* Skip over "fc." */
		goto check_newline;
	}
	ptr = strstr(i_port, "iqn.");
	if (ptr) {
		if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
			pr_err("Passed iSCSI Initiator Port %s does not"
				" match target port protoid: %s\n", i_port,
				tcm_loop_dump_proto_id(tl_hba));
			return -EINVAL;
		}
		port_ptr = &i_port[0];
		goto check_newline;
	}
	pr_err("Unable to locate prefix for emulated Initiator Port:"
			" %s\n", i_port);
	return -EINVAL;
	/*
	 * Clear any trailing newline for the NAA WWN
	 */
check_newline:
	if (i_port[strlen(i_port)-1] == '\n')
		i_port[strlen(i_port)-1] = '\0';

	ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
	if (ret < 0)
		return ret;

	return count;
}

static ssize_t tcm_loop_tpg_transport_status_show(struct config_item *item,
		char *page)
{
	struct se_portal_group *se_tpg = to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
			struct tcm_loop_tpg, tl_se_tpg);
	const char *status = NULL;
	ssize_t ret = -EINVAL;

	switch (tl_tpg->tl_transport_status) {
	case TCM_TRANSPORT_ONLINE:
		status = "online";
		break;
	case TCM_TRANSPORT_OFFLINE:
		status = "offline";
		break;
	default:
		break;
	}

	if (status)
		ret = snprintf(page, PAGE_SIZE, "%s\n", status);

	return ret;
}

static ssize_t tcm_loop_tpg_transport_status_store(struct config_item *item,
		const char *page, size_t count)
{
	struct se_portal_group *se_tpg = to_tpg(item);
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
			struct tcm_loop_tpg, tl_se_tpg);

	if (!strncmp(page, "online", 6)) {
		tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
		return count;
	}
	if (!strncmp(page, "offline", 7)) {
		tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
		if (tl_tpg->tl_nexus) {
			struct se_session *tl_sess = tl_tpg->tl_nexus->se_sess;

			core_allocate_nexus_loss_ua(tl_sess->se_node_acl);
		}
		return count;
	}
	return -EINVAL;
}

CONFIGFS_ATTR(tcm_loop_tpg_, nexus);
CONFIGFS_ATTR(tcm_loop_tpg_, transport_status);

static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
	&tcm_loop_tpg_attr_nexus,
	&tcm_loop_tpg_attr_transport_status,
	NULL,
};

/* Start items for tcm_loop_naa_cit */

static struct se_portal_group *tcm_loop_make_naa_tpg(
	struct se_wwn *wwn,
	struct config_group *group,
	const char *name)
{
	struct tcm_loop_hba *tl_hba = container_of(wwn,
			struct tcm_loop_hba, tl_hba_wwn);
	struct tcm_loop_tpg *tl_tpg;
	int ret;
	unsigned long tpgt;

	if (strstr(name, "tpgt_") != name) {
		pr_err("Unable to locate \"tpgt_#\" directory"
				" group\n");
		return ERR_PTR(-EINVAL);
	}
	if (kstrtoul(name+5, 10, &tpgt))
		return ERR_PTR(-EINVAL);

	if (tpgt >= TL_TPGS_PER_HBA) {
		pr_err("Passed tpgt: %lu exceeds TL_TPGS_PER_HBA:"
				" %u\n", tpgt, TL_TPGS_PER_HBA);
		return ERR_PTR(-EINVAL);
	}
	tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
	tl_tpg->tl_hba = tl_hba;
	tl_tpg->tl_tpgt = tpgt;
	/*
	 * Register the tl_tpg as a emulated TCM Target Endpoint
	 */
	ret = core_tpg_register(wwn, &tl_tpg->tl_se_tpg, tl_hba->tl_proto_id);
	if (ret < 0)
		return ERR_PTR(-ENOMEM);

	pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
		" Target Port %s,t,0x%04lx\n", tcm_loop_dump_proto_id(tl_hba),
		config_item_name(&wwn->wwn_group.cg_item), tpgt);

	return &tl_tpg->tl_se_tpg;
}

static void tcm_loop_drop_naa_tpg(
	struct se_portal_group *se_tpg)
{
	struct se_wwn *wwn = se_tpg->se_tpg_wwn;
	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
				struct tcm_loop_tpg, tl_se_tpg);
	struct tcm_loop_hba *tl_hba;
	unsigned short tpgt;

	tl_hba = tl_tpg->tl_hba;
	tpgt = tl_tpg->tl_tpgt;
	/*
	 * Release the I_T Nexus for the Virtual target link if present
	 */
	tcm_loop_drop_nexus(tl_tpg);
	/*
	 * Deregister the tl_tpg as a emulated TCM Target Endpoint
	 */
	core_tpg_deregister(se_tpg);

	tl_tpg->tl_hba = NULL;
	tl_tpg->tl_tpgt = 0;

	pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
		" Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
		config_item_name(&wwn->wwn_group.cg_item), tpgt);
}

/* End items for tcm_loop_naa_cit */

/* Start items for tcm_loop_cit */

static struct se_wwn *tcm_loop_make_scsi_hba(
	struct target_fabric_configfs *tf,
	struct config_group *group,
	const char *name)
{
	struct tcm_loop_hba *tl_hba;
	struct Scsi_Host *sh;
	char *ptr;
	int ret, off = 0;

	tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
	if (!tl_hba) {
		pr_err("Unable to allocate struct tcm_loop_hba\n");
		return ERR_PTR(-ENOMEM);
	}
	/*
	 * Determine the emulated Protocol Identifier and Target Port Name
	 * based on the incoming configfs directory name.
	 */
	ptr = strstr(name, "naa.");
	if (ptr) {
		tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
		goto check_len;
	}
	ptr = strstr(name, "fc.");
	if (ptr) {
		tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
		off = 3; /* Skip over "fc." */
		goto check_len;
	}
	ptr = strstr(name, "iqn.");
	if (!ptr) {
		pr_err("Unable to locate prefix for emulated Target "
				"Port: %s\n", name);
		ret = -EINVAL;
		goto out;
	}
	tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;

check_len:
	if (strlen(name) >= TL_WWN_ADDR_LEN) {
		pr_err("Emulated NAA %s Address: %s, exceeds"
			" max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
			TL_WWN_ADDR_LEN);
		ret = -EINVAL;
		goto out;
	}
	snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);

	/*
	 * Call device_register(tl_hba->dev) to register the emulated
	 * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
	 * device_register() callbacks in tcm_loop_driver_probe()
	 */
	ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
	if (ret)
		goto out;

	sh = tl_hba->sh;
	tcm_loop_hba_no_cnt++;
	pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
		" %s Address: %s at Linux/SCSI Host ID: %d\n",
		tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);

	return &tl_hba->tl_hba_wwn;
out:
	kfree(tl_hba);
	return ERR_PTR(ret);
}

static void tcm_loop_drop_scsi_hba(
	struct se_wwn *wwn)
{
	struct tcm_loop_hba *tl_hba = container_of(wwn,
				struct tcm_loop_hba, tl_hba_wwn);

	pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
		" %s Address: %s at Linux/SCSI Host ID: %d\n",
		tcm_loop_dump_proto_id(tl_hba), tl_hba->tl_wwn_address,
		tl_hba->sh->host_no);
	/*
	 * Call device_unregister() on the original tl_hba->dev.
	 * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
	 * release *tl_hba;
	 */
	device_unregister(&tl_hba->dev);
}

/* Start items for tcm_loop_cit */
static ssize_t tcm_loop_wwn_version_show(struct config_item *item, char *page)
{
	return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
}

CONFIGFS_ATTR_RO(tcm_loop_wwn_, version);

static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
	&tcm_loop_wwn_attr_version,
	NULL,
};

/* End items for tcm_loop_cit */

static const struct target_core_fabric_ops loop_ops = {
	.module				= THIS_MODULE,
	.name				= "loopback",
	.get_fabric_name		= tcm_loop_get_fabric_name,
	.tpg_get_wwn			= tcm_loop_get_endpoint_wwn,
	.tpg_get_tag			= tcm_loop_get_tag,
	.tpg_check_demo_mode		= tcm_loop_check_demo_mode,
	.tpg_check_demo_mode_cache	= tcm_loop_check_demo_mode_cache,
	.tpg_check_demo_mode_write_protect =
				tcm_loop_check_demo_mode_write_protect,
	.tpg_check_prod_mode_write_protect =
				tcm_loop_check_prod_mode_write_protect,
	.tpg_check_prot_fabric_only	= tcm_loop_check_prot_fabric_only,
	.tpg_get_inst_index		= tcm_loop_get_inst_index,
	.check_stop_free		= tcm_loop_check_stop_free,
	.release_cmd			= tcm_loop_release_cmd,
	.shutdown_session		= tcm_loop_shutdown_session,
	.close_session			= tcm_loop_close_session,
	.sess_get_index			= tcm_loop_sess_get_index,
	.write_pending			= tcm_loop_write_pending,
	.write_pending_status		= tcm_loop_write_pending_status,
	.set_default_node_attributes	= tcm_loop_set_default_node_attributes,
	.get_cmd_state			= tcm_loop_get_cmd_state,
	.queue_data_in			= tcm_loop_queue_data_in,
	.queue_status			= tcm_loop_queue_status,
	.queue_tm_rsp			= tcm_loop_queue_tm_rsp,
	.aborted_task			= tcm_loop_aborted_task,
	.fabric_make_wwn		= tcm_loop_make_scsi_hba,
	.fabric_drop_wwn		= tcm_loop_drop_scsi_hba,
	.fabric_make_tpg		= tcm_loop_make_naa_tpg,
	.fabric_drop_tpg		= tcm_loop_drop_naa_tpg,
	.fabric_post_link		= tcm_loop_port_link,
	.fabric_pre_unlink		= tcm_loop_port_unlink,
	.tfc_wwn_attrs			= tcm_loop_wwn_attrs,
	.tfc_tpg_base_attrs		= tcm_loop_tpg_attrs,
	.tfc_tpg_attrib_attrs		= tcm_loop_tpg_attrib_attrs,
};

static int __init tcm_loop_fabric_init(void)
{
	int ret = -ENOMEM;

	tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
	if (!tcm_loop_workqueue)
		goto out;

	tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
				sizeof(struct tcm_loop_cmd),
				__alignof__(struct tcm_loop_cmd),
				0, NULL);
	if (!tcm_loop_cmd_cache) {
		pr_debug("kmem_cache_create() for"
			" tcm_loop_cmd_cache failed\n");
		goto out_destroy_workqueue;
	}

	ret = tcm_loop_alloc_core_bus();
	if (ret)
		goto out_destroy_cache;

	ret = target_register_template(&loop_ops);
	if (ret)
		goto out_release_core_bus;

	return 0;

out_release_core_bus:
	tcm_loop_release_core_bus();
out_destroy_cache:
	kmem_cache_destroy(tcm_loop_cmd_cache);
out_destroy_workqueue:
	destroy_workqueue(tcm_loop_workqueue);
out:
	return ret;
}

static void __exit tcm_loop_fabric_exit(void)
{
	target_unregister_template(&loop_ops);
	tcm_loop_release_core_bus();
	kmem_cache_destroy(tcm_loop_cmd_cache);
	destroy_workqueue(tcm_loop_workqueue);
}

MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
MODULE_LICENSE("GPL");
module_init(tcm_loop_fabric_init);
module_exit(tcm_loop_fabric_exit);
OpenPOWER on IntegriCloud