aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/target/target_core_pscsi.c
blob: 7ff6a35f26ac338e93e4867e8c8d9fd4de40e143 (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
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
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
/*******************************************************************************
 * Filename:  target_core_pscsi.c
 *
 * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
 *
 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/version.h>
#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
#include <linux/blk_types.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/genhd.h>
#include <linux/cdrom.h>
#include <linux/file.h>
#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <scsi/libsas.h> /* For TASK_ATTR_* */

#include <target/target_core_base.h>
#include <target/target_core_device.h>
#include <target/target_core_transport.h>

#include "target_core_pscsi.h"

#define ISPRINT(a)  ((a >= ' ') && (a <= '~'))

static struct se_subsystem_api pscsi_template;

static void pscsi_req_done(struct request *, int);

/*	pscsi_get_sh():
 *
 *
 */
static struct Scsi_Host *pscsi_get_sh(u32 host_no)
{
	struct Scsi_Host *sh = NULL;

	sh = scsi_host_lookup(host_no);
	if (IS_ERR(sh)) {
		printk(KERN_ERR "Unable to locate SCSI HBA with Host ID:"
				" %u\n", host_no);
		return NULL;
	}

	return sh;
}

/*	pscsi_attach_hba():
 *
 * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
 *	from the passed SCSI Host ID.
 */
static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
{
	int hba_depth;
	struct pscsi_hba_virt *phv;

	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
	if (!(phv)) {
		printk(KERN_ERR "Unable to allocate struct pscsi_hba_virt\n");
		return -1;
	}
	phv->phv_host_id = host_id;
	phv->phv_mode = PHV_VIRUTAL_HOST_ID;
	hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
	atomic_set(&hba->left_queue_depth, hba_depth);
	atomic_set(&hba->max_queue_depth, hba_depth);

	hba->hba_ptr = (void *)phv;

	printk(KERN_INFO "CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
		" Generic Target Core Stack %s\n", hba->hba_id,
		PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
	printk(KERN_INFO "CORE_HBA[%d] - Attached SCSI HBA to Generic"
		" Target Core with TCQ Depth: %d\n", hba->hba_id,
		atomic_read(&hba->max_queue_depth));

	return 0;
}

static void pscsi_detach_hba(struct se_hba *hba)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	struct Scsi_Host *scsi_host = phv->phv_lld_host;

	if (scsi_host) {
		scsi_host_put(scsi_host);

		printk(KERN_INFO "CORE_HBA[%d] - Detached SCSI HBA: %s from"
			" Generic Target Core\n", hba->hba_id,
			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
			"Unknown");
	} else
		printk(KERN_INFO "CORE_HBA[%d] - Detached Virtual SCSI HBA"
			" from Generic Target Core\n", hba->hba_id);

	kfree(phv);
	hba->hba_ptr = NULL;
}

static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
{
	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
	struct Scsi_Host *sh = phv->phv_lld_host;
	int hba_depth = PSCSI_VIRTUAL_HBA_DEPTH;
	/*
	 * Release the struct Scsi_Host
	 */
	if (!(mode_flag)) {
		if (!(sh))
			return 0;

		phv->phv_lld_host = NULL;
		phv->phv_mode = PHV_VIRUTAL_HOST_ID;
		atomic_set(&hba->left_queue_depth, hba_depth);
		atomic_set(&hba->max_queue_depth, hba_depth);

		printk(KERN_INFO "CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
			" %s\n", hba->hba_id, (sh->hostt->name) ?
			(sh->hostt->name) : "Unknown");

		scsi_host_put(sh);
		return 0;
	}
	/*
	 * Otherwise, locate struct Scsi_Host from the original passed
	 * pSCSI Host ID and enable for phba mode
	 */
	sh = pscsi_get_sh(phv->phv_host_id);
	if (!(sh)) {
		printk(KERN_ERR "pSCSI: Unable to locate SCSI Host for"
			" phv_host_id: %d\n", phv->phv_host_id);
		return -1;
	}
	/*
	 * Usually the SCSI LLD will use the hostt->can_queue value to define
	 * its HBA TCQ depth.  Some other drivers (like 2.6 megaraid) don't set
	 * this at all and set sh->can_queue at runtime.
	 */
	hba_depth = (sh->hostt->can_queue > sh->can_queue) ?
		sh->hostt->can_queue : sh->can_queue;

	atomic_set(&hba->left_queue_depth, hba_depth);
	atomic_set(&hba->max_queue_depth, hba_depth);

	phv->phv_lld_host = sh;
	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;

	printk(KERN_INFO "CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");

	return 1;
}

static void pscsi_tape_read_blocksize(struct se_device *dev,
		struct scsi_device *sdev)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
	int ret;

	buf = kzalloc(12, GFP_KERNEL);
	if (!buf)
		return;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = MODE_SENSE;
	cdb[4] = 0x0c; /* 12 bytes */

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
			HZ, 1, NULL);
	if (ret)
		goto out_free;

	/*
	 * If MODE_SENSE still returns zero, set the default value to 1024.
	 */
	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
	if (!sdev->sector_size)
		sdev->sector_size = 1024;
out_free:
	kfree(buf);
}

static void
pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
{
	unsigned char *buf;

	if (sdev->inquiry_len < INQUIRY_LEN)
		return;

	buf = sdev->inquiry;
	if (!buf)
		return;
	/*
	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
	 */
	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
}

static int
pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
	int ret;

	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
	if (!buf)
		return -1;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = INQUIRY;
	cdb[1] = 0x01; /* Query VPD */
	cdb[2] = 0x80; /* Unit Serial Number */
	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
	if (ret)
		goto out_free;

	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);

	wwn->t10_sub_dev->su_dev_flags |= SDF_FIRMWARE_VPD_UNIT_SERIAL;

	kfree(buf);
	return 0;

out_free:
	kfree(buf);
	return -1;
}

static void
pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
		struct t10_wwn *wwn)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
	int ident_len, page_len, off = 4, ret;
	struct t10_vpd *vpd;

	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
	if (!buf)
		return;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = INQUIRY;
	cdb[1] = 0x01; /* Query VPD */
	cdb[2] = 0x83; /* Device Identifier */
	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
			      NULL, HZ, 1, NULL);
	if (ret)
		goto out;

	page_len = (buf[2] << 8) | buf[3];
	while (page_len > 0) {
		/* Grab a pointer to the Identification descriptor */
		page_83 = &buf[off];
		ident_len = page_83[3];
		if (!ident_len) {
			printk(KERN_ERR "page_83[3]: identifier"
					" length zero!\n");
			break;
		}
		printk(KERN_INFO "T10 VPD Identifer Length: %d\n", ident_len);

		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
		if (!vpd) {
			printk(KERN_ERR "Unable to allocate memory for"
					" struct t10_vpd\n");
			goto out;
		}
		INIT_LIST_HEAD(&vpd->vpd_list);

		transport_set_vpd_proto_id(vpd, page_83);
		transport_set_vpd_assoc(vpd, page_83);

		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
			off += (ident_len + 4);
			page_len -= (ident_len + 4);
			kfree(vpd);
			continue;
		}
		if (transport_set_vpd_ident(vpd, page_83) < 0) {
			off += (ident_len + 4);
			page_len -= (ident_len + 4);
			kfree(vpd);
			continue;
		}

		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
		off += (ident_len + 4);
		page_len -= (ident_len + 4);
	}

out:
	kfree(buf);
}

/*	pscsi_add_device_to_list():
 *
 *
 */
static struct se_device *pscsi_add_device_to_list(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	struct pscsi_dev_virt *pdv,
	struct scsi_device *sd,
	int dev_flags)
{
	struct se_device *dev;
	struct se_dev_limits dev_limits;
	struct request_queue *q;
	struct queue_limits *limits;

	memset(&dev_limits, 0, sizeof(struct se_dev_limits));

	if (!sd->queue_depth) {
		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;

		printk(KERN_ERR "Set broken SCSI Device %d:%d:%d"
			" queue_depth to %d\n", sd->channel, sd->id,
				sd->lun, sd->queue_depth);
	}
	/*
	 * Setup the local scope queue_limits from struct request_queue->limits
	 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
	 */
	q = sd->request_queue;
	limits = &dev_limits.limits;
	limits->logical_block_size = sd->sector_size;
	limits->max_hw_sectors = (sd->host->max_sectors > queue_max_hw_sectors(q)) ?
				  queue_max_hw_sectors(q) : sd->host->max_sectors;
	limits->max_sectors = (sd->host->max_sectors > queue_max_sectors(q)) ?
				  queue_max_sectors(q) : sd->host->max_sectors;
	dev_limits.hw_queue_depth = sd->queue_depth;
	dev_limits.queue_depth = sd->queue_depth;
	/*
	 * Setup our standard INQUIRY info into se_dev->t10_wwn
	 */
	pscsi_set_inquiry_info(sd, &se_dev->t10_wwn);

	/*
	 * Set the pointer pdv->pdv_sd to from passed struct scsi_device,
	 * which has already been referenced with Linux SCSI code with
	 * scsi_device_get() in this file's pscsi_create_virtdevice().
	 *
	 * The passthrough operations called by the transport_add_device_*
	 * function below will require this pointer to be set for passthroug
	 *  ops.
	 *
	 * For the shutdown case in pscsi_free_device(), this struct
	 * scsi_device  reference is released with Linux SCSI code
	 * scsi_device_put() and the pdv->pdv_sd cleared.
	 */
	pdv->pdv_sd = sd;

	dev = transport_add_device_to_core_hba(hba, &pscsi_template,
				se_dev, dev_flags, (void *)pdv,
				&dev_limits, NULL, NULL);
	if (!(dev)) {
		pdv->pdv_sd = NULL;
		return NULL;
	}

	/*
	 * Locate VPD WWN Information used for various purposes within
	 * the Storage Engine.
	 */
	if (!pscsi_get_inquiry_vpd_serial(sd, &se_dev->t10_wwn)) {
		/*
		 * If VPD Unit Serial returned GOOD status, try
		 * VPD Device Identification page (0x83).
		 */
		pscsi_get_inquiry_vpd_device_ident(sd, &se_dev->t10_wwn);
	}

	/*
	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
	 */
	if (sd->type == TYPE_TAPE)
		pscsi_tape_read_blocksize(dev, sd);
	return dev;
}

static void *pscsi_allocate_virtdevice(struct se_hba *hba, const char *name)
{
	struct pscsi_dev_virt *pdv;

	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
	if (!(pdv)) {
		printk(KERN_ERR "Unable to allocate memory for struct pscsi_dev_virt\n");
		return NULL;
	}
	pdv->pdv_se_hba = hba;

	printk(KERN_INFO "PSCSI: Allocated pdv: %p for %s\n", pdv, name);
	return (void *)pdv;
}

/*
 * Called with struct Scsi_Host->host_lock called.
 */
static struct se_device *pscsi_create_type_disk(
	struct scsi_device *sd,
	struct pscsi_dev_virt *pdv,
	struct se_subsystem_dev *se_dev,
	struct se_hba *hba)
	__releases(sh->host_lock)
{
	struct se_device *dev;
	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
	struct Scsi_Host *sh = sd->host;
	struct block_device *bd;
	u32 dev_flags = 0;

	if (scsi_device_get(sd)) {
		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
			sh->host_no, sd->channel, sd->id, sd->lun);
		spin_unlock_irq(sh->host_lock);
		return NULL;
	}
	spin_unlock_irq(sh->host_lock);
	/*
	 * Claim exclusive struct block_device access to struct scsi_device
	 * for TYPE_DISK using supplied udev_path
	 */
	bd = blkdev_get_by_path(se_dev->se_dev_udev_path,
				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
	if (IS_ERR(bd)) {
		printk(KERN_ERR "pSCSI: blkdev_get_by_path() failed\n");
		scsi_device_put(sd);
		return NULL;
	}
	pdv->pdv_bd = bd;

	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
	if (!(dev)) {
		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
		scsi_device_put(sd);
		return NULL;
	}
	printk(KERN_INFO "CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%d\n",
		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);

	return dev;
}

/*
 * Called with struct Scsi_Host->host_lock called.
 */
static struct se_device *pscsi_create_type_rom(
	struct scsi_device *sd,
	struct pscsi_dev_virt *pdv,
	struct se_subsystem_dev *se_dev,
	struct se_hba *hba)
	__releases(sh->host_lock)
{
	struct se_device *dev;
	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
	struct Scsi_Host *sh = sd->host;
	u32 dev_flags = 0;

	if (scsi_device_get(sd)) {
		printk(KERN_ERR "scsi_device_get() failed for %d:%d:%d:%d\n",
			sh->host_no, sd->channel, sd->id, sd->lun);
		spin_unlock_irq(sh->host_lock);
		return NULL;
	}
	spin_unlock_irq(sh->host_lock);

	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
	if (!(dev)) {
		scsi_device_put(sd);
		return NULL;
	}
	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
		sd->channel, sd->id, sd->lun);

	return dev;
}

/*
 *Called with struct Scsi_Host->host_lock called.
 */
static struct se_device *pscsi_create_type_other(
	struct scsi_device *sd,
	struct pscsi_dev_virt *pdv,
	struct se_subsystem_dev *se_dev,
	struct se_hba *hba)
	__releases(sh->host_lock)
{
	struct se_device *dev;
	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)pdv->pdv_se_hba->hba_ptr;
	struct Scsi_Host *sh = sd->host;
	u32 dev_flags = 0;

	spin_unlock_irq(sh->host_lock);
	dev = pscsi_add_device_to_list(hba, se_dev, pdv, sd, dev_flags);
	if (!(dev))
		return NULL;

	printk(KERN_INFO "CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%d\n",
		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
		sd->channel, sd->id, sd->lun);

	return dev;
}

static struct se_device *pscsi_create_virtdevice(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	void *p)
{
	struct pscsi_dev_virt *pdv = (struct pscsi_dev_virt *)p;
	struct se_device *dev;
	struct scsi_device *sd;
	struct pscsi_hba_virt *phv = (struct pscsi_hba_virt *)hba->hba_ptr;
	struct Scsi_Host *sh = phv->phv_lld_host;
	int legacy_mode_enable = 0;

	if (!(pdv)) {
		printk(KERN_ERR "Unable to locate struct pscsi_dev_virt"
				" parameter\n");
		return ERR_PTR(-EINVAL);
	}
	/*
	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
	 */
	if (!(sh)) {
		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
			printk(KERN_ERR "pSCSI: Unable to locate struct"
				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
			return ERR_PTR(-ENODEV);
		}
		/*
		 * For the newer PHV_VIRUTAL_HOST_ID struct scsi_device
		 * reference, we enforce that udev_path has been set
		 */
		if (!(se_dev->su_dev_flags & SDF_USING_UDEV_PATH)) {
			printk(KERN_ERR "pSCSI: udev_path attribute has not"
				" been set before ENABLE=1\n");
			return ERR_PTR(-EINVAL);
		}
		/*
		 * If no scsi_host_id= was passed for PHV_VIRUTAL_HOST_ID,
		 * use the original TCM hba ID to reference Linux/SCSI Host No
		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
		 */
		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
			spin_lock(&hba->device_lock);
			if (!(list_empty(&hba->hba_dev_list))) {
				printk(KERN_ERR "pSCSI: Unable to set hba_mode"
					" with active devices\n");
				spin_unlock(&hba->device_lock);
				return ERR_PTR(-EEXIST);
			}
			spin_unlock(&hba->device_lock);

			if (pscsi_pmode_enable_hba(hba, 1) != 1)
				return ERR_PTR(-ENODEV);

			legacy_mode_enable = 1;
			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
			sh = phv->phv_lld_host;
		} else {
			sh = pscsi_get_sh(pdv->pdv_host_id);
			if (!(sh)) {
				printk(KERN_ERR "pSCSI: Unable to locate"
					" pdv_host_id: %d\n", pdv->pdv_host_id);
				return ERR_PTR(-ENODEV);
			}
		}
	} else {
		if (phv->phv_mode == PHV_VIRUTAL_HOST_ID) {
			printk(KERN_ERR "pSCSI: PHV_VIRUTAL_HOST_ID set while"
				" struct Scsi_Host exists\n");
			return ERR_PTR(-EEXIST);
		}
	}

	spin_lock_irq(sh->host_lock);
	list_for_each_entry(sd, &sh->__devices, siblings) {
		if ((pdv->pdv_channel_id != sd->channel) ||
		    (pdv->pdv_target_id != sd->id) ||
		    (pdv->pdv_lun_id != sd->lun))
			continue;
		/*
		 * Functions will release the held struct scsi_host->host_lock
		 * before calling calling pscsi_add_device_to_list() to register
		 * struct scsi_device with target_core_mod.
		 */
		switch (sd->type) {
		case TYPE_DISK:
			dev = pscsi_create_type_disk(sd, pdv, se_dev, hba);
			break;
		case TYPE_ROM:
			dev = pscsi_create_type_rom(sd, pdv, se_dev, hba);
			break;
		default:
			dev = pscsi_create_type_other(sd, pdv, se_dev, hba);
			break;
		}

		if (!(dev)) {
			if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
				scsi_host_put(sh);
			else if (legacy_mode_enable) {
				pscsi_pmode_enable_hba(hba, 0);
				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
			}
			pdv->pdv_sd = NULL;
			return ERR_PTR(-ENODEV);
		}
		return dev;
	}
	spin_unlock_irq(sh->host_lock);

	printk(KERN_ERR "pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);

	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
		scsi_host_put(sh);
	else if (legacy_mode_enable) {
		pscsi_pmode_enable_hba(hba, 0);
		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
	}

	return ERR_PTR(-ENODEV);
}

/*	pscsi_free_device(): (Part of se_subsystem_api_t template)
 *
 *
 */
static void pscsi_free_device(void *p)
{
	struct pscsi_dev_virt *pdv = p;
	struct pscsi_hba_virt *phv = pdv->pdv_se_hba->hba_ptr;
	struct scsi_device *sd = pdv->pdv_sd;

	if (sd) {
		/*
		 * Release exclusive pSCSI internal struct block_device claim for
		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
		 */
		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
			blkdev_put(pdv->pdv_bd,
				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
			pdv->pdv_bd = NULL;
		}
		/*
		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
		 * to struct Scsi_Host now.
		 */
		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
		    (phv->phv_lld_host != NULL))
			scsi_host_put(phv->phv_lld_host);

		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
			scsi_device_put(sd);

		pdv->pdv_sd = NULL;
	}

	kfree(pdv);
}

static inline struct pscsi_plugin_task *PSCSI_TASK(struct se_task *task)
{
	return container_of(task, struct pscsi_plugin_task, pscsi_task);
}


/*	pscsi_transport_complete():
 *
 *
 */
static int pscsi_transport_complete(struct se_task *task)
{
	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
	struct scsi_device *sd = pdv->pdv_sd;
	int result;
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	unsigned char *cdb = &pt->pscsi_cdb[0];

	result = pt->pscsi_result;
	/*
	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
	 * forced.
	 */
	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
		if (!TASK_CMD(task)->se_deve)
			goto after_mode_sense;

		if (TASK_CMD(task)->se_deve->lun_flags &
				TRANSPORT_LUNFLAGS_READ_ONLY) {
			unsigned char *buf = (unsigned char *)
				T_TASK(task->task_se_cmd)->t_task_buf;

			if (cdb[0] == MODE_SENSE_10) {
				if (!(buf[3] & 0x80))
					buf[3] |= 0x80;
			} else {
				if (!(buf[2] & 0x80))
					buf[2] |= 0x80;
			}
		}
	}
after_mode_sense:

	if (sd->type != TYPE_TAPE)
		goto after_mode_select;

	/*
	 * Hack to correctly obtain the initiator requested blocksize for
	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
	 * struct scsi_device->sector_size will not contain the correct value
	 * by default, so we go ahead and set it so
	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
	 * storage engine.
	 */
	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
		unsigned char *buf;
		struct scatterlist *sg = task->task_sg;
		u16 bdl;
		u32 blocksize;

		buf = sg_virt(&sg[0]);
		if (!(buf)) {
			printk(KERN_ERR "Unable to get buf for scatterlist\n");
			goto after_mode_select;
		}

		if (cdb[0] == MODE_SELECT)
			bdl = (buf[3]);
		else
			bdl = (buf[6] << 8) | (buf[7]);

		if (!bdl)
			goto after_mode_select;

		if (cdb[0] == MODE_SELECT)
			blocksize = (buf[9] << 16) | (buf[10] << 8) |
					(buf[11]);
		else
			blocksize = (buf[13] << 16) | (buf[14] << 8) |
					(buf[15]);

		sd->sector_size = blocksize;
	}
after_mode_select:

	if (status_byte(result) & CHECK_CONDITION)
		return 1;

	return 0;
}

static struct se_task *
pscsi_alloc_task(struct se_cmd *cmd)
{
	struct pscsi_plugin_task *pt;
	unsigned char *cdb = T_TASK(cmd)->t_task_cdb;

	pt = kzalloc(sizeof(struct pscsi_plugin_task), GFP_KERNEL);
	if (!pt) {
		printk(KERN_ERR "Unable to allocate struct pscsi_plugin_task\n");
		return NULL;
	}

	/*
	 * If TCM Core is signaling a > TCM_MAX_COMMAND_SIZE allocation,
	 * allocate the extended CDB buffer for per struct se_task context
	 * pt->pscsi_cdb now.
	 */
	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb) {

		pt->pscsi_cdb = kzalloc(scsi_command_size(cdb), GFP_KERNEL);
		if (!(pt->pscsi_cdb)) {
			printk(KERN_ERR "pSCSI: Unable to allocate extended"
					" pt->pscsi_cdb\n");
			kfree(pt);
			return NULL;
		}
	} else
		pt->pscsi_cdb = &pt->__pscsi_cdb[0];

	return &pt->pscsi_task;
}

static inline void pscsi_blk_init_request(
	struct se_task *task,
	struct pscsi_plugin_task *pt,
	struct request *req,
	int bidi_read)
{
	/*
	 * Defined as "scsi command" in include/linux/blkdev.h.
	 */
	req->cmd_type = REQ_TYPE_BLOCK_PC;
	/*
	 * For the extra BIDI-COMMAND READ struct request we do not
	 * need to setup the remaining structure members
	 */
	if (bidi_read)
		return;
	/*
	 * Setup the done function pointer for struct request,
	 * also set the end_io_data pointer.to struct se_task.
	 */
	req->end_io = pscsi_req_done;
	req->end_io_data = (void *)task;
	/*
	 * Load the referenced struct se_task's SCSI CDB into
	 * include/linux/blkdev.h:struct request->cmd
	 */
	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
	req->cmd = &pt->pscsi_cdb[0];
	/*
	 * Setup pointer for outgoing sense data.
	 */
	req->sense = (void *)&pt->pscsi_sense[0];
	req->sense_len = 0;
}

/*
 * Used for pSCSI data payloads for all *NON* SCF_SCSI_DATA_SG_IO_CDB
*/
static int pscsi_blk_get_request(struct se_task *task)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;

	pt->pscsi_req = blk_get_request(pdv->pdv_sd->request_queue,
			(task->task_data_direction == DMA_TO_DEVICE),
			GFP_KERNEL);
	if (!(pt->pscsi_req) || IS_ERR(pt->pscsi_req)) {
		printk(KERN_ERR "PSCSI: blk_get_request() failed: %ld\n",
				IS_ERR(pt->pscsi_req));
		return PYX_TRANSPORT_LU_COMM_FAILURE;
	}
	/*
	 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
	 * and setup rq callback, CDB and sense.
	 */
	pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);
	return 0;
}

/*      pscsi_do_task(): (Part of se_subsystem_api_t template)
 *
 *
 */
static int pscsi_do_task(struct se_task *task)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
	/*
	 * Set the struct request->timeout value based on peripheral
	 * device type from SCSI.
	 */
	if (pdv->pdv_sd->type == TYPE_DISK)
		pt->pscsi_req->timeout = PS_TIMEOUT_DISK;
	else
		pt->pscsi_req->timeout = PS_TIMEOUT_OTHER;

	pt->pscsi_req->retries = PS_RETRY;
	/*
	 * Queue the struct request into the struct scsi_device->request_queue.
	 * Also check for HEAD_OF_QUEUE SAM TASK attr from received se_cmd
	 * descriptor
	 */
	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, pt->pscsi_req,
			(task->task_se_cmd->sam_task_attr == TASK_ATTR_HOQ),
			pscsi_req_done);

	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
}

static void pscsi_free_task(struct se_task *task)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	struct se_cmd *cmd = task->task_se_cmd;

	/*
	 * Release the extended CDB allocation from pscsi_alloc_task()
	 * if one exists.
	 */
	if (T_TASK(cmd)->t_task_cdb != T_TASK(cmd)->__t_task_cdb)
		kfree(pt->pscsi_cdb);
	/*
	 * We do not release the bio(s) here associated with this task, as
	 * this is handled by bio_put() and pscsi_bi_endio().
	 */
	kfree(pt);
}

enum {
	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
	Opt_scsi_lun_id, Opt_err
};

static match_table_t tokens = {
	{Opt_scsi_host_id, "scsi_host_id=%d"},
	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
	{Opt_scsi_target_id, "scsi_target_id=%d"},
	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
	{Opt_err, NULL}
};

static ssize_t pscsi_set_configfs_dev_params(struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	const char *page,
	ssize_t count)
{
	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	char *orig, *ptr, *opts;
	substring_t args[MAX_OPT_ARGS];
	int ret = 0, arg, token;

	opts = kstrdup(page, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;

	orig = opts;

	while ((ptr = strsep(&opts, ",")) != NULL) {
		if (!*ptr)
			continue;

		token = match_token(ptr, tokens, args);
		switch (token) {
		case Opt_scsi_host_id:
			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
				printk(KERN_ERR "PSCSI[%d]: Unable to accept"
					" scsi_host_id while phv_mode =="
					" PHV_LLD_SCSI_HOST_NO\n",
					phv->phv_host_id);
				ret = -EINVAL;
				goto out;
			}
			match_int(args, &arg);
			pdv->pdv_host_id = arg;
			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Host ID:"
				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
			break;
		case Opt_scsi_channel_id:
			match_int(args, &arg);
			pdv->pdv_channel_id = arg;
			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Channel"
				" ID: %d\n",  phv->phv_host_id,
				pdv->pdv_channel_id);
			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
			break;
		case Opt_scsi_target_id:
			match_int(args, &arg);
			pdv->pdv_target_id = arg;
			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI Target"
				" ID: %d\n", phv->phv_host_id,
				pdv->pdv_target_id);
			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
			break;
		case Opt_scsi_lun_id:
			match_int(args, &arg);
			pdv->pdv_lun_id = arg;
			printk(KERN_INFO "PSCSI[%d]: Referencing SCSI LUN ID:"
				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
			pdv->pdv_flags |= PDF_HAS_LUN_ID;
			break;
		default:
			break;
		}
	}

out:
	kfree(orig);
	return (!ret) ? count : ret;
}

static ssize_t pscsi_check_configfs_dev_params(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev)
{
	struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;

	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
		printk(KERN_ERR "Missing scsi_channel_id=, scsi_target_id= and"
			" scsi_lun_id= parameters\n");
		return -1;
	}

	return 0;
}

static ssize_t pscsi_show_configfs_dev_params(struct se_hba *hba,
					      struct se_subsystem_dev *se_dev,
					      char *b)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
        struct pscsi_dev_virt *pdv = se_dev->se_dev_su_ptr;
	struct scsi_device *sd = pdv->pdv_sd;
	unsigned char host_id[16];
	ssize_t bl;
	int i;

	if (phv->phv_mode == PHV_VIRUTAL_HOST_ID)
		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
	else
		snprintf(host_id, 16, "PHBA Mode");

	bl = sprintf(b, "SCSI Device Bus Location:"
		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
		host_id);

	if (sd) {
		bl += sprintf(b + bl, "        ");
		bl += sprintf(b + bl, "Vendor: ");
		for (i = 0; i < 8; i++) {
			if (ISPRINT(sd->vendor[i]))   /* printable character? */
				bl += sprintf(b + bl, "%c", sd->vendor[i]);
			else
				bl += sprintf(b + bl, " ");
		}
		bl += sprintf(b + bl, " Model: ");
		for (i = 0; i < 16; i++) {
			if (ISPRINT(sd->model[i]))   /* printable character ? */
				bl += sprintf(b + bl, "%c", sd->model[i]);
			else
				bl += sprintf(b + bl, " ");
		}
		bl += sprintf(b + bl, " Rev: ");
		for (i = 0; i < 4; i++) {
			if (ISPRINT(sd->rev[i]))   /* printable character ? */
				bl += sprintf(b + bl, "%c", sd->rev[i]);
			else
				bl += sprintf(b + bl, " ");
		}
		bl += sprintf(b + bl, "\n");
	}
	return bl;
}

static void pscsi_bi_endio(struct bio *bio, int error)
{
	bio_put(bio);
}

static inline struct bio *pscsi_get_bio(struct pscsi_dev_virt *pdv, int sg_num)
{
	struct bio *bio;
	/*
	 * Use bio_malloc() following the comment in for bio -> struct request
	 * in block/blk-core.c:blk_make_request()
	 */
	bio = bio_kmalloc(GFP_KERNEL, sg_num);
	if (!(bio)) {
		printk(KERN_ERR "PSCSI: bio_kmalloc() failed\n");
		return NULL;
	}
	bio->bi_end_io = pscsi_bi_endio;

	return bio;
}

#if 0
#define DEBUG_PSCSI(x...) printk(x)
#else
#define DEBUG_PSCSI(x...)
#endif

static int __pscsi_map_task_SG(
	struct se_task *task,
	struct scatterlist *task_sg,
	u32 task_sg_num,
	int bidi_read)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
	struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
	struct page *page;
	struct scatterlist *sg;
	u32 data_len = task->task_size, i, len, bytes, off;
	int nr_pages = (task->task_size + task_sg[0].offset +
			PAGE_SIZE - 1) >> PAGE_SHIFT;
	int nr_vecs = 0, rc, ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
	int rw = (task->task_data_direction == DMA_TO_DEVICE);

	if (!task->task_size)
		return 0;
	/*
	 * For SCF_SCSI_DATA_SG_IO_CDB, Use fs/bio.c:bio_add_page() to setup
	 * the bio_vec maplist from TC< struct se_mem -> task->task_sg ->
	 * struct scatterlist memory.  The struct se_task->task_sg[] currently needs
	 * to be attached to struct bios for submission to Linux/SCSI using
	 * struct request to struct scsi_device->request_queue.
	 *
	 * Note that this will be changing post v2.6.28 as Target_Core_Mod/pSCSI
	 * is ported to upstream SCSI passthrough functionality that accepts
	 * struct scatterlist->page_link or struct page as a paraemeter.
	 */
	DEBUG_PSCSI("PSCSI: nr_pages: %d\n", nr_pages);

	for_each_sg(task_sg, sg, task_sg_num, i) {
		page = sg_page(sg);
		off = sg->offset;
		len = sg->length;

		DEBUG_PSCSI("PSCSI: i: %d page: %p len: %d off: %d\n", i,
			page, len, off);

		while (len > 0 && data_len > 0) {
			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
			bytes = min(bytes, data_len);

			if (!(bio)) {
				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
				nr_pages -= nr_vecs;
				/*
				 * Calls bio_kmalloc() and sets bio->bi_end_io()
				 */
				bio = pscsi_get_bio(pdv, nr_vecs);
				if (!(bio))
					goto fail;

				if (rw)
					bio->bi_rw |= REQ_WRITE;

				DEBUG_PSCSI("PSCSI: Allocated bio: %p,"
					" dir: %s nr_vecs: %d\n", bio,
					(rw) ? "rw" : "r", nr_vecs);
				/*
				 * Set *hbio pointer to handle the case:
				 * nr_pages > BIO_MAX_PAGES, where additional
				 * bios need to be added to complete a given
				 * struct se_task
				 */
				if (!hbio)
					hbio = tbio = bio;
				else
					tbio = tbio->bi_next = bio;
			}

			DEBUG_PSCSI("PSCSI: Calling bio_add_pc_page() i: %d"
				" bio: %p page: %p len: %d off: %d\n", i, bio,
				page, len, off);

			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
					bio, page, bytes, off);
			if (rc != bytes)
				goto fail;

			DEBUG_PSCSI("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
				bio->bi_vcnt, nr_vecs);

			if (bio->bi_vcnt > nr_vecs) {
				DEBUG_PSCSI("PSCSI: Reached bio->bi_vcnt max:"
					" %d i: %d bio: %p, allocating another"
					" bio\n", bio->bi_vcnt, i, bio);
				/*
				 * Clear the pointer so that another bio will
				 * be allocated with pscsi_get_bio() above, the
				 * current bio has already been set *tbio and
				 * bio->bi_next.
				 */
				bio = NULL;
			}

			page++;
			len -= bytes;
			data_len -= bytes;
			off = 0;
		}
	}
	/*
	 * Setup the primary pt->pscsi_req used for non BIDI and BIDI-COMMAND
	 * primary SCSI WRITE poayload mapped for struct se_task->task_sg[]
	 */
	if (!(bidi_read)) {
		/*
		 * Starting with v2.6.31, call blk_make_request() passing in *hbio to
		 * allocate the pSCSI task a struct request.
		 */
		pt->pscsi_req = blk_make_request(pdv->pdv_sd->request_queue,
					hbio, GFP_KERNEL);
		if (!(pt->pscsi_req)) {
			printk(KERN_ERR "pSCSI: blk_make_request() failed\n");
			goto fail;
		}
		/*
		 * Setup the newly allocated struct request for REQ_TYPE_BLOCK_PC,
		 * and setup rq callback, CDB and sense.
		 */
		pscsi_blk_init_request(task, pt, pt->pscsi_req, 0);

		return task->task_sg_num;
	}
	/*
	 * Setup the secondary pt->pscsi_req->next_rq used for the extra BIDI-COMMAND
	 * SCSI READ paylaod mapped for struct se_task->task_sg_bidi[]
	 */
	pt->pscsi_req->next_rq = blk_make_request(pdv->pdv_sd->request_queue,
					hbio, GFP_KERNEL);
	if (!(pt->pscsi_req->next_rq)) {
		printk(KERN_ERR "pSCSI: blk_make_request() failed for BIDI\n");
		goto fail;
	}
	pscsi_blk_init_request(task, pt, pt->pscsi_req->next_rq, 1);

	return task->task_sg_num;
fail:
	while (hbio) {
		bio = hbio;
		hbio = hbio->bi_next;
		bio->bi_next = NULL;
		bio_endio(bio, 0);
	}
	return ret;
}

static int pscsi_map_task_SG(struct se_task *task)
{
	int ret;

	/*
	 * Setup the main struct request for the task->task_sg[] payload
	 */

	ret = __pscsi_map_task_SG(task, task->task_sg, task->task_sg_num, 0);
	if (ret >= 0 && task->task_sg_bidi) {
		/*
		 * If present, set up the extra BIDI-COMMAND SCSI READ
		 * struct request and payload.
		 */
		ret = __pscsi_map_task_SG(task, task->task_sg_bidi,
					task->task_sg_num, 1);
	}

	if (ret < 0)
		return PYX_TRANSPORT_LU_COMM_FAILURE;
	return 0;
}

/*	pscsi_map_task_non_SG():
 *
 *
 */
static int pscsi_map_task_non_SG(struct se_task *task)
{
	struct se_cmd *cmd = TASK_CMD(task);
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);
	struct pscsi_dev_virt *pdv = task->se_dev->dev_ptr;
	int ret = 0;

	if (pscsi_blk_get_request(task) < 0)
		return PYX_TRANSPORT_LU_COMM_FAILURE;

	if (!task->task_size)
		return 0;

	ret = blk_rq_map_kern(pdv->pdv_sd->request_queue,
			pt->pscsi_req, T_TASK(cmd)->t_task_buf,
			task->task_size, GFP_KERNEL);
	if (ret < 0) {
		printk(KERN_ERR "PSCSI: blk_rq_map_kern() failed: %d\n", ret);
		return PYX_TRANSPORT_LU_COMM_FAILURE;
	}
	return 0;
}

static int pscsi_CDB_none(struct se_task *task)
{
	return pscsi_blk_get_request(task);
}

/*	pscsi_get_cdb():
 *
 *
 */
static unsigned char *pscsi_get_cdb(struct se_task *task)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);

	return pt->pscsi_cdb;
}

/*	pscsi_get_sense_buffer():
 *
 *
 */
static unsigned char *pscsi_get_sense_buffer(struct se_task *task)
{
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);

	return (unsigned char *)&pt->pscsi_sense[0];
}

/*	pscsi_get_device_rev():
 *
 *
 */
static u32 pscsi_get_device_rev(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = dev->dev_ptr;
	struct scsi_device *sd = pdv->pdv_sd;

	return (sd->scsi_level - 1) ? sd->scsi_level - 1 : 1;
}

/*	pscsi_get_device_type():
 *
 *
 */
static u32 pscsi_get_device_type(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = dev->dev_ptr;
	struct scsi_device *sd = pdv->pdv_sd;

	return sd->type;
}

static sector_t pscsi_get_blocks(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = dev->dev_ptr;

	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
		return pdv->pdv_bd->bd_part->nr_sects;

	dump_stack();
	return 0;
}

/*	pscsi_handle_SAM_STATUS_failures():
 *
 *
 */
static inline void pscsi_process_SAM_status(
	struct se_task *task,
	struct pscsi_plugin_task *pt)
{
	task->task_scsi_status = status_byte(pt->pscsi_result);
	if ((task->task_scsi_status)) {
		task->task_scsi_status <<= 1;
		printk(KERN_INFO "PSCSI Status Byte exception at task: %p CDB:"
			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
			pt->pscsi_result);
	}

	switch (host_byte(pt->pscsi_result)) {
	case DID_OK:
		transport_complete_task(task, (!task->task_scsi_status));
		break;
	default:
		printk(KERN_INFO "PSCSI Host Byte exception at task: %p CDB:"
			" 0x%02x Result: 0x%08x\n", task, pt->pscsi_cdb[0],
			pt->pscsi_result);
		task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
		task->task_error_status = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
		TASK_CMD(task)->transport_error_status =
					PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
		transport_complete_task(task, 0);
		break;
	}

	return;
}

static void pscsi_req_done(struct request *req, int uptodate)
{
	struct se_task *task = req->end_io_data;
	struct pscsi_plugin_task *pt = PSCSI_TASK(task);

	pt->pscsi_result = req->errors;
	pt->pscsi_resid = req->resid_len;

	pscsi_process_SAM_status(task, pt);
	/*
	 * Release BIDI-READ if present
	 */
	if (req->next_rq != NULL)
		__blk_put_request(req->q, req->next_rq);

	__blk_put_request(req->q, req);
	pt->pscsi_req = NULL;
}

static struct se_subsystem_api pscsi_template = {
	.name			= "pscsi",
	.owner			= THIS_MODULE,
	.transport_type		= TRANSPORT_PLUGIN_PHBA_PDEV,
	.cdb_none		= pscsi_CDB_none,
	.map_task_non_SG	= pscsi_map_task_non_SG,
	.map_task_SG		= pscsi_map_task_SG,
	.attach_hba		= pscsi_attach_hba,
	.detach_hba		= pscsi_detach_hba,
	.pmode_enable_hba	= pscsi_pmode_enable_hba,
	.allocate_virtdevice	= pscsi_allocate_virtdevice,
	.create_virtdevice	= pscsi_create_virtdevice,
	.free_device		= pscsi_free_device,
	.transport_complete	= pscsi_transport_complete,
	.alloc_task		= pscsi_alloc_task,
	.do_task		= pscsi_do_task,
	.free_task		= pscsi_free_task,
	.check_configfs_dev_params = pscsi_check_configfs_dev_params,
	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
	.get_cdb		= pscsi_get_cdb,
	.get_sense_buffer	= pscsi_get_sense_buffer,
	.get_device_rev		= pscsi_get_device_rev,
	.get_device_type	= pscsi_get_device_type,
	.get_blocks		= pscsi_get_blocks,
};

static int __init pscsi_module_init(void)
{
	return transport_subsystem_register(&pscsi_template);
}

static void pscsi_module_exit(void)
{
	transport_subsystem_release(&pscsi_template);
}

MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");

module_init(pscsi_module_init);
module_exit(pscsi_module_exit);