aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/isci/remote_device.c
blob: d1c2a2294a3262c512b9d8781b541b62d2693492 (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
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * 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.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <scsi/sas.h>
#include <linux/bitops.h>
#include "isci.h"
#include "port.h"
#include "remote_device.h"
#include "request.h"
#include "remote_node_context.h"
#include "scu_event_codes.h"
#include "task.h"

#undef C
#define C(a) (#a)
const char *dev_state_name(enum sci_remote_device_states state)
{
	static const char * const strings[] = REMOTE_DEV_STATES;

	return strings[state];
}
#undef C

static enum sci_status sci_remote_device_suspend(struct isci_remote_device *idev,
						 enum sci_remote_node_suspension_reasons reason)
{
	return sci_remote_node_context_suspend(&idev->rnc, reason,
					       SCI_SOFTWARE_SUSPEND_EXPECTED_EVENT);
}

/**
 * isci_remote_device_ready() - This function is called by the ihost when the
 *    remote device is ready. We mark the isci device as ready and signal the
 *    waiting proccess.
 * @ihost: our valid isci_host
 * @idev: remote device
 *
 */
static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote_device *idev)
{
	dev_dbg(&ihost->pdev->dev,
		"%s: idev = %p\n", __func__, idev);

	clear_bit(IDEV_IO_NCQERROR, &idev->flags);
	set_bit(IDEV_IO_READY, &idev->flags);
	if (test_and_clear_bit(IDEV_START_PENDING, &idev->flags))
		wake_up(&ihost->eventq);
}

static enum sci_status sci_remote_device_terminate_req(
	struct isci_host *ihost,
	struct isci_remote_device *idev,
	int check_abort,
	struct isci_request *ireq)
{
	dev_dbg(&ihost->pdev->dev,
		"%s: idev=%p; flags=%lx; req=%p; req target=%p\n",
		__func__, idev, idev->flags, ireq, ireq->target_device);

	if (!test_bit(IREQ_ACTIVE, &ireq->flags) ||
	    (ireq->target_device != idev) ||
	    (check_abort && !test_bit(IREQ_PENDING_ABORT, &ireq->flags)))
		return SCI_SUCCESS;

	set_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags);

	return sci_controller_terminate_request(ihost, idev, ireq);
}

static enum sci_status sci_remote_device_terminate_reqs_checkabort(
	struct isci_remote_device *idev,
	int chk)
{
	struct isci_host *ihost = idev->owning_port->owning_controller;
	enum sci_status status  = SCI_SUCCESS;
	u32 i;

	for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
		struct isci_request *ireq = ihost->reqs[i];
		enum sci_status s;

		s = sci_remote_device_terminate_req(ihost, idev, chk, ireq);
		if (s != SCI_SUCCESS)
			status = s;
	}
	return status;
}

static bool isci_compare_suspendcount(
	struct isci_remote_device *idev,
	u32 localcount)
{
	smp_rmb();
	return localcount != idev->rnc.suspend_count;
}

enum sci_status isci_remote_device_terminate_requests(
	struct isci_host *ihost,
	struct isci_remote_device *idev,
	struct isci_request *ireq)
{
	enum sci_status status = SCI_SUCCESS;
	unsigned long flags;
	u32 rnc_suspend_count;

	spin_lock_irqsave(&ihost->scic_lock, flags);

	if (isci_get_device(idev) == NULL) {
		dev_dbg(&ihost->pdev->dev, "%s: failed isci_get_device(idev=%p)\n",
			__func__, idev);
		spin_unlock_irqrestore(&ihost->scic_lock, flags);
		status = SCI_FAILURE;
	} else {
		/* If already suspended, don't wait for another suspension. */
		smp_rmb();
		rnc_suspend_count
			= sci_remote_node_context_is_suspended(&idev->rnc)
				? 0 : idev->rnc.suspend_count;

		dev_dbg(&ihost->pdev->dev,
			"%s: idev=%p, ireq=%p; started_request_count=%d, "
				"rnc_suspend_count=%d, rnc.suspend_count=%d"
				"about to wait\n",
			__func__, idev, ireq, idev->started_request_count,
			rnc_suspend_count, idev->rnc.suspend_count);
		if (ireq) {
			/* Terminate a specific TC. */
			sci_remote_device_terminate_req(ihost, idev, 0, ireq);
			spin_unlock_irqrestore(&ihost->scic_lock, flags);
			wait_event(ihost->eventq,
				   (isci_compare_suspendcount(idev,
							      rnc_suspend_count)
				    && !test_bit(IREQ_ACTIVE, &ireq->flags)));
		} else {
			/* Terminate all TCs. */
			sci_remote_device_terminate_requests(idev);
			spin_unlock_irqrestore(&ihost->scic_lock, flags);
			wait_event(ihost->eventq,
				   (isci_compare_suspendcount(idev,
							      rnc_suspend_count)
				    && idev->started_request_count == 0));
		}
		dev_dbg(&ihost->pdev->dev, "%s: idev=%p, wait done\n",
			__func__, idev);
		isci_put_device(idev);
	}
	return status;
}

/**
* isci_remote_device_not_ready() - This function is called by the ihost when
*    the remote device is not ready. We mark the isci device as ready (not
*    "ready_for_io") and signal the waiting proccess.
* @isci_host: This parameter specifies the isci host object.
* @isci_device: This parameter specifies the remote device
*
* sci_lock is held on entrance to this function.
*/
static void isci_remote_device_not_ready(struct isci_host *ihost,
					 struct isci_remote_device *idev,
					 u32 reason)
{
	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p; reason = %d\n", __func__, idev, reason);

	switch (reason) {
	case SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED:
		set_bit(IDEV_IO_NCQERROR, &idev->flags);

		/* Suspend the remote device so the I/O can be terminated. */
		sci_remote_device_suspend(idev, SCI_SW_SUSPEND_NORMAL);

		/* Kill all outstanding requests for the device. */
		sci_remote_device_terminate_requests(idev);

		/* Fall through into the default case... */
	default:
		clear_bit(IDEV_IO_READY, &idev->flags);
		break;
	}
}

/* called once the remote node context is ready to be freed.
 * The remote device can now report that its stop operation is complete. none
 */
static void rnc_destruct_done(void *_dev)
{
	struct isci_remote_device *idev = _dev;

	BUG_ON(idev->started_request_count != 0);
	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
}

enum sci_status sci_remote_device_terminate_requests(
	struct isci_remote_device *idev)
{
	return sci_remote_device_terminate_reqs_checkabort(idev, 0);
}

enum sci_status sci_remote_device_stop(struct isci_remote_device *idev,
					u32 timeout)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_FAILED:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	case SCI_DEV_STOPPED:
		return SCI_SUCCESS;
	case SCI_DEV_STARTING:
		/* device not started so there had better be no requests */
		BUG_ON(idev->started_request_count != 0);
		sci_remote_node_context_destruct(&idev->rnc,
						      rnc_destruct_done, idev);
		/* Transition to the stopping state and wait for the
		 * remote node to complete being posted and invalidated.
		 */
		sci_change_state(sm, SCI_DEV_STOPPING);
		return SCI_SUCCESS;
	case SCI_DEV_READY:
	case SCI_STP_DEV_IDLE:
	case SCI_STP_DEV_CMD:
	case SCI_STP_DEV_NCQ:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_AWAIT_RESET:
	case SCI_SMP_DEV_IDLE:
	case SCI_SMP_DEV_CMD:
		sci_change_state(sm, SCI_DEV_STOPPING);
		if (idev->started_request_count == 0)
			sci_remote_node_context_destruct(&idev->rnc,
							 rnc_destruct_done,
							 idev);
		else {
			sci_remote_device_suspend(
				idev, SCI_SW_SUSPEND_LINKHANG_DETECT);
			sci_remote_device_terminate_requests(idev);
		}
		return SCI_SUCCESS;
	case SCI_DEV_STOPPING:
		/* All requests should have been terminated, but if there is an
		 * attempt to stop a device already in the stopping state, then
		 * try again to terminate.
		 */
		return sci_remote_device_terminate_requests(idev);
	case SCI_DEV_RESETTING:
		sci_change_state(sm, SCI_DEV_STOPPING);
		return SCI_SUCCESS;
	}
}

enum sci_status sci_remote_device_reset(struct isci_remote_device *idev)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_STOPPED:
	case SCI_DEV_STARTING:
	case SCI_SMP_DEV_IDLE:
	case SCI_SMP_DEV_CMD:
	case SCI_DEV_STOPPING:
	case SCI_DEV_FAILED:
	case SCI_DEV_RESETTING:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	case SCI_DEV_READY:
	case SCI_STP_DEV_IDLE:
	case SCI_STP_DEV_CMD:
	case SCI_STP_DEV_NCQ:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_AWAIT_RESET:
		sci_change_state(sm, SCI_DEV_RESETTING);
		return SCI_SUCCESS;
	}
}

enum sci_status sci_remote_device_reset_complete(struct isci_remote_device *idev)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;

	if (state != SCI_DEV_RESETTING) {
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	}

	sci_change_state(sm, SCI_DEV_READY);
	return SCI_SUCCESS;
}

enum sci_status sci_remote_device_frame_handler(struct isci_remote_device *idev,
						     u32 frame_index)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	struct isci_host *ihost = idev->owning_port->owning_controller;
	enum sci_status status;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_STOPPED:
	case SCI_DEV_STARTING:
	case SCI_STP_DEV_IDLE:
	case SCI_SMP_DEV_IDLE:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		/* Return the frame back to the controller */
		sci_controller_release_frame(ihost, frame_index);
		return SCI_FAILURE_INVALID_STATE;
	case SCI_DEV_READY:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_AWAIT_RESET:
	case SCI_DEV_STOPPING:
	case SCI_DEV_FAILED:
	case SCI_DEV_RESETTING: {
		struct isci_request *ireq;
		struct ssp_frame_hdr hdr;
		void *frame_header;
		ssize_t word_cnt;

		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
								       frame_index,
								       &frame_header);
		if (status != SCI_SUCCESS)
			return status;

		word_cnt = sizeof(hdr) / sizeof(u32);
		sci_swab32_cpy(&hdr, frame_header, word_cnt);

		ireq = sci_request_by_tag(ihost, be16_to_cpu(hdr.tag));
		if (ireq && ireq->target_device == idev) {
			/* The IO request is now in charge of releasing the frame */
			status = sci_io_request_frame_handler(ireq, frame_index);
		} else {
			/* We could not map this tag to a valid IO
			 * request Just toss the frame and continue
			 */
			sci_controller_release_frame(ihost, frame_index);
		}
		break;
	}
	case SCI_STP_DEV_NCQ: {
		struct dev_to_host_fis *hdr;

		status = sci_unsolicited_frame_control_get_header(&ihost->uf_control,
								       frame_index,
								       (void **)&hdr);
		if (status != SCI_SUCCESS)
			return status;

		if (hdr->fis_type == FIS_SETDEVBITS &&
		    (hdr->status & ATA_ERR)) {
			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;

			/* TODO Check sactive and complete associated IO if any. */
			sci_change_state(sm, SCI_STP_DEV_NCQ_ERROR);
		} else if (hdr->fis_type == FIS_REGD2H &&
			   (hdr->status & ATA_ERR)) {
			/*
			 * Some devices return D2H FIS when an NCQ error is detected.
			 * Treat this like an SDB error FIS ready reason.
			 */
			idev->not_ready_reason = SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED;
			sci_change_state(&idev->sm, SCI_STP_DEV_NCQ_ERROR);
		} else
			status = SCI_FAILURE;

		sci_controller_release_frame(ihost, frame_index);
		break;
	}
	case SCI_STP_DEV_CMD:
	case SCI_SMP_DEV_CMD:
		/* The device does not process any UF received from the hardware while
		 * in this state.  All unsolicited frames are forwarded to the io request
		 * object.
		 */
		status = sci_io_request_frame_handler(idev->working_request, frame_index);
		break;
	}

	return status;
}

static bool is_remote_device_ready(struct isci_remote_device *idev)
{

	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;

	switch (state) {
	case SCI_DEV_READY:
	case SCI_STP_DEV_IDLE:
	case SCI_STP_DEV_CMD:
	case SCI_STP_DEV_NCQ:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_AWAIT_RESET:
	case SCI_SMP_DEV_IDLE:
	case SCI_SMP_DEV_CMD:
		return true;
	default:
		return false;
	}
}

/*
 * called once the remote node context has transisitioned to a ready
 * state (after suspending RX and/or TX due to early D2H fis)
 */
static void atapi_remote_device_resume_done(void *_dev)
{
	struct isci_remote_device *idev = _dev;
	struct isci_request *ireq = idev->working_request;

	sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
}

enum sci_status sci_remote_device_event_handler(struct isci_remote_device *idev,
						     u32 event_code)
{
	enum sci_status status;

	switch (scu_get_event_type(event_code)) {
	case SCU_EVENT_TYPE_RNC_OPS_MISC:
	case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
	case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
		status = sci_remote_node_context_event_handler(&idev->rnc, event_code);
		break;
	case SCU_EVENT_TYPE_PTX_SCHEDULE_EVENT:
		if (scu_get_event_code(event_code) == SCU_EVENT_IT_NEXUS_TIMEOUT) {
			status = SCI_SUCCESS;

			/* Suspend the associated RNC */
			sci_remote_device_suspend(idev, SCI_SW_SUSPEND_NORMAL);

			dev_dbg(scirdev_to_dev(idev),
				"%s: device: %p event code: %x: %s\n",
				__func__, idev, event_code,
				is_remote_device_ready(idev)
				? "I_T_Nexus_Timeout event"
				: "I_T_Nexus_Timeout event in wrong state");

			break;
		}
	/* Else, fall through and treat as unhandled... */
	default:
		dev_dbg(scirdev_to_dev(idev),
			"%s: device: %p event code: %x: %s\n",
			__func__, idev, event_code,
			is_remote_device_ready(idev)
			? "unexpected event"
			: "unexpected event in wrong state");
		status = SCI_FAILURE_INVALID_STATE;
		break;
	}

	if (status != SCI_SUCCESS)
		return status;

	return status;
}

static void sci_remote_device_start_request(struct isci_remote_device *idev,
						 struct isci_request *ireq,
						 enum sci_status status)
{
	struct isci_port *iport = idev->owning_port;

	/* cleanup requests that failed after starting on the port */
	if (status != SCI_SUCCESS)
		sci_port_complete_io(iport, idev, ireq);
	else {
		kref_get(&idev->kref);
		idev->started_request_count++;
	}
}

enum sci_status sci_remote_device_start_io(struct isci_host *ihost,
						struct isci_remote_device *idev,
						struct isci_request *ireq)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	struct isci_port *iport = idev->owning_port;
	enum sci_status status;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_STOPPED:
	case SCI_DEV_STARTING:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_DEV_STOPPING:
	case SCI_DEV_FAILED:
	case SCI_DEV_RESETTING:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	case SCI_DEV_READY:
		/* attempt to start an io request for this device object. The remote
		 * device object will issue the start request for the io and if
		 * successful it will start the request for the port object then
		 * increment its own request count.
		 */
		status = sci_port_start_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			return status;

		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
		if (status != SCI_SUCCESS)
			break;

		status = sci_request_start(ireq);
		break;
	case SCI_STP_DEV_IDLE: {
		/* handle the start io operation for a sata device that is in
		 * the command idle state. - Evalute the type of IO request to
		 * be started - If its an NCQ request change to NCQ substate -
		 * If its any other command change to the CMD substate
		 *
		 * If this is a softreset we may want to have a different
		 * substate.
		 */
		enum sci_remote_device_states new_state;
		struct sas_task *task = isci_request_access_task(ireq);

		status = sci_port_start_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			return status;

		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
		if (status != SCI_SUCCESS)
			break;

		status = sci_request_start(ireq);
		if (status != SCI_SUCCESS)
			break;

		if (task->ata_task.use_ncq)
			new_state = SCI_STP_DEV_NCQ;
		else {
			idev->working_request = ireq;
			new_state = SCI_STP_DEV_CMD;
		}
		sci_change_state(sm, new_state);
		break;
	}
	case SCI_STP_DEV_NCQ: {
		struct sas_task *task = isci_request_access_task(ireq);

		if (task->ata_task.use_ncq) {
			status = sci_port_start_io(iport, idev, ireq);
			if (status != SCI_SUCCESS)
				return status;

			status = sci_remote_node_context_start_io(&idev->rnc, ireq);
			if (status != SCI_SUCCESS)
				break;

			status = sci_request_start(ireq);
		} else
			return SCI_FAILURE_INVALID_STATE;
		break;
	}
	case SCI_STP_DEV_AWAIT_RESET:
		return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;
	case SCI_SMP_DEV_IDLE:
		status = sci_port_start_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			return status;

		status = sci_remote_node_context_start_io(&idev->rnc, ireq);
		if (status != SCI_SUCCESS)
			break;

		status = sci_request_start(ireq);
		if (status != SCI_SUCCESS)
			break;

		idev->working_request = ireq;
		sci_change_state(&idev->sm, SCI_SMP_DEV_CMD);
		break;
	case SCI_STP_DEV_CMD:
	case SCI_SMP_DEV_CMD:
		/* device is already handling a command it can not accept new commands
		 * until this one is complete.
		 */
		return SCI_FAILURE_INVALID_STATE;
	}

	sci_remote_device_start_request(idev, ireq, status);
	return status;
}

static enum sci_status common_complete_io(struct isci_port *iport,
					  struct isci_remote_device *idev,
					  struct isci_request *ireq)
{
	enum sci_status status;

	status = sci_request_complete(ireq);
	if (status != SCI_SUCCESS)
		return status;

	status = sci_port_complete_io(iport, idev, ireq);
	if (status != SCI_SUCCESS)
		return status;

	sci_remote_device_decrement_request_count(idev);
	return status;
}

enum sci_status sci_remote_device_complete_io(struct isci_host *ihost,
						   struct isci_remote_device *idev,
						   struct isci_request *ireq)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	struct isci_port *iport = idev->owning_port;
	enum sci_status status;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_STOPPED:
	case SCI_DEV_STARTING:
	case SCI_STP_DEV_IDLE:
	case SCI_SMP_DEV_IDLE:
	case SCI_DEV_FAILED:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	case SCI_DEV_READY:
	case SCI_STP_DEV_AWAIT_RESET:
	case SCI_DEV_RESETTING:
		status = common_complete_io(iport, idev, ireq);
		break;
	case SCI_STP_DEV_CMD:
	case SCI_STP_DEV_NCQ:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_ATAPI_ERROR:
		status = common_complete_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			break;

		if (ireq->sci_status == SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED) {
			/* This request causes hardware error, device needs to be Lun Reset.
			 * So here we force the state machine to IDLE state so the rest IOs
			 * can reach RNC state handler, these IOs will be completed by RNC with
			 * status of "DEVICE_RESET_REQUIRED", instead of "INVALID STATE".
			 */
			sci_change_state(sm, SCI_STP_DEV_AWAIT_RESET);
		} else if (idev->started_request_count == 0)
			sci_change_state(sm, SCI_STP_DEV_IDLE);
		break;
	case SCI_SMP_DEV_CMD:
		status = common_complete_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			break;
		sci_change_state(sm, SCI_SMP_DEV_IDLE);
		break;
	case SCI_DEV_STOPPING:
		status = common_complete_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			break;

		if (idev->started_request_count == 0)
			sci_remote_node_context_destruct(&idev->rnc,
							 rnc_destruct_done,
							 idev);
		break;
	}

	if (status != SCI_SUCCESS)
		dev_err(scirdev_to_dev(idev),
			"%s: Port:0x%p Device:0x%p Request:0x%p Status:0x%x "
			"could not complete\n", __func__, iport,
			idev, ireq, status);
	else
		isci_put_device(idev);

	return status;
}

static void sci_remote_device_continue_request(void *dev)
{
	struct isci_remote_device *idev = dev;

	/* we need to check if this request is still valid to continue. */
	if (idev->working_request)
		sci_controller_continue_io(idev->working_request);
}

enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
						  struct isci_remote_device *idev,
						  struct isci_request *ireq)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	struct isci_port *iport = idev->owning_port;
	enum sci_status status;

	switch (state) {
	case SCI_DEV_INITIAL:
	case SCI_DEV_STOPPED:
	case SCI_DEV_STARTING:
	case SCI_SMP_DEV_IDLE:
	case SCI_SMP_DEV_CMD:
	case SCI_DEV_STOPPING:
	case SCI_DEV_FAILED:
	case SCI_DEV_RESETTING:
	case SCI_DEV_FINAL:
	default:
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	case SCI_STP_DEV_IDLE:
	case SCI_STP_DEV_CMD:
	case SCI_STP_DEV_NCQ:
	case SCI_STP_DEV_NCQ_ERROR:
	case SCI_STP_DEV_AWAIT_RESET:
		status = sci_port_start_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			return status;

		status = sci_request_start(ireq);
		if (status != SCI_SUCCESS)
			goto out;

		/* Note: If the remote device state is not IDLE this will
		 * replace the request that probably resulted in the task
		 * management request.
		 */
		idev->working_request = ireq;
		sci_change_state(sm, SCI_STP_DEV_CMD);

		/* The remote node context must cleanup the TCi to NCQ mapping
		 * table.  The only way to do this correctly is to either write
		 * to the TLCR register or to invalidate and repost the RNC. In
		 * either case the remote node context state machine will take
		 * the correct action when the remote node context is suspended
		 * and later resumed.
		 */
		sci_remote_device_suspend(idev,
					  SCI_SW_SUSPEND_LINKHANG_DETECT);

		status = sci_remote_node_context_start_task(&idev->rnc, ireq,
				sci_remote_device_continue_request, idev);

	out:
		sci_remote_device_start_request(idev, ireq, status);
		/* We need to let the controller start request handler know that
		 * it can't post TC yet. We will provide a callback function to
		 * post TC when RNC gets resumed.
		 */
		return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
	case SCI_DEV_READY:
		status = sci_port_start_io(iport, idev, ireq);
		if (status != SCI_SUCCESS)
			return status;

		/* Resume the RNC as needed: */
		status = sci_remote_node_context_start_task(&idev->rnc, ireq,
							    NULL, NULL);
		if (status != SCI_SUCCESS)
			break;

		status = sci_request_start(ireq);
		break;
	}
	sci_remote_device_start_request(idev, ireq, status);

	return status;
}

void sci_remote_device_post_request(struct isci_remote_device *idev, u32 request)
{
	struct isci_port *iport = idev->owning_port;
	u32 context;

	context = request |
		  (ISCI_PEG << SCU_CONTEXT_COMMAND_PROTOCOL_ENGINE_GROUP_SHIFT) |
		  (iport->physical_port_index << SCU_CONTEXT_COMMAND_LOGICAL_PORT_SHIFT) |
		  idev->rnc.remote_node_index;

	sci_controller_post_request(iport->owning_controller, context);
}

/* called once the remote node context has transisitioned to a
 * ready state.  This is the indication that the remote device object can also
 * transition to ready.
 */
static void remote_device_resume_done(void *_dev)
{
	struct isci_remote_device *idev = _dev;

	if (is_remote_device_ready(idev))
		return;

	/* go 'ready' if we are not already in a ready state */
	sci_change_state(&idev->sm, SCI_DEV_READY);
}

static void sci_stp_remote_device_ready_idle_substate_resume_complete_handler(void *_dev)
{
	struct isci_remote_device *idev = _dev;
	struct isci_host *ihost = idev->owning_port->owning_controller;

	/* For NCQ operation we do not issue a isci_remote_device_not_ready().
	 * As a result, avoid sending the ready notification.
	 */
	if (idev->sm.previous_state_id != SCI_STP_DEV_NCQ)
		isci_remote_device_ready(ihost, idev);
}

static void sci_remote_device_initial_state_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);

	/* Initial state is a transitional state to the stopped state */
	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
}

/**
 * sci_remote_device_destruct() - free remote node context and destruct
 * @remote_device: This parameter specifies the remote device to be destructed.
 *
 * Remote device objects are a limited resource.  As such, they must be
 * protected.  Thus calls to construct and destruct are mutually exclusive and
 * non-reentrant. The return value shall indicate if the device was
 * successfully destructed or if some failure occurred. enum sci_status This value
 * is returned if the device is successfully destructed.
 * SCI_FAILURE_INVALID_REMOTE_DEVICE This value is returned if the supplied
 * device isn't valid (e.g. it's already been destoryed, the handle isn't
 * valid, etc.).
 */
static enum sci_status sci_remote_device_destruct(struct isci_remote_device *idev)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	struct isci_host *ihost;

	if (state != SCI_DEV_STOPPED) {
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	}

	ihost = idev->owning_port->owning_controller;
	sci_controller_free_remote_node_context(ihost, idev,
						     idev->rnc.remote_node_index);
	idev->rnc.remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
	sci_change_state(sm, SCI_DEV_FINAL);

	return SCI_SUCCESS;
}

/**
 * isci_remote_device_deconstruct() - This function frees an isci_remote_device.
 * @ihost: This parameter specifies the isci host object.
 * @idev: This parameter specifies the remote device to be freed.
 *
 */
static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_remote_device *idev)
{
	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p\n", __func__, idev);

	/* There should not be any outstanding io's. All paths to
	 * here should go through isci_remote_device_nuke_requests.
	 * If we hit this condition, we will need a way to complete
	 * io requests in process */
	BUG_ON(idev->started_request_count > 0);

	sci_remote_device_destruct(idev);
	list_del_init(&idev->node);
	isci_put_device(idev);
}

static void sci_remote_device_stopped_state_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;
	u32 prev_state;

	/* If we are entering from the stopping state let the SCI User know that
	 * the stop operation has completed.
	 */
	prev_state = idev->sm.previous_state_id;
	if (prev_state == SCI_DEV_STOPPING)
		isci_remote_device_deconstruct(ihost, idev);

	sci_controller_remote_device_stopped(ihost, idev);
}

static void sci_remote_device_starting_state_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	isci_remote_device_not_ready(ihost, idev,
				     SCIC_REMOTE_DEVICE_NOT_READY_START_REQUESTED);
}

static void sci_remote_device_ready_state_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;
	struct domain_device *dev = idev->domain_dev;

	if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_SATA)) {
		sci_change_state(&idev->sm, SCI_STP_DEV_IDLE);
	} else if (dev_is_expander(dev)) {
		sci_change_state(&idev->sm, SCI_SMP_DEV_IDLE);
	} else
		isci_remote_device_ready(ihost, idev);
}

static void sci_remote_device_ready_state_exit(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct domain_device *dev = idev->domain_dev;

	if (dev->dev_type == SAS_END_DEV) {
		struct isci_host *ihost = idev->owning_port->owning_controller;

		isci_remote_device_not_ready(ihost, idev,
					     SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED);
	}
}

static void sci_remote_device_resetting_state_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p\n", __func__, idev);

	sci_remote_device_suspend(idev, SCI_SW_SUSPEND_LINKHANG_DETECT);
}

static void sci_remote_device_resetting_state_exit(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p\n", __func__, idev);

	sci_remote_node_context_resume(&idev->rnc, NULL, NULL);
}

static void sci_stp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);

	idev->working_request = NULL;
	if (sci_remote_node_context_is_ready(&idev->rnc)) {
		/*
		 * Since the RNC is ready, it's alright to finish completion
		 * processing (e.g. signal the remote device is ready). */
		sci_stp_remote_device_ready_idle_substate_resume_complete_handler(idev);
	} else {
		sci_remote_node_context_resume(&idev->rnc,
			sci_stp_remote_device_ready_idle_substate_resume_complete_handler,
			idev);
	}
}

static void sci_stp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	BUG_ON(idev->working_request == NULL);

	isci_remote_device_not_ready(ihost, idev,
				     SCIC_REMOTE_DEVICE_NOT_READY_SATA_REQUEST_STARTED);
}

static void sci_stp_remote_device_ready_ncq_error_substate_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	if (idev->not_ready_reason == SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED)
		isci_remote_device_not_ready(ihost, idev,
					     idev->not_ready_reason);
}

static void sci_stp_remote_device_atapi_error_substate_enter(
	struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);

	/* This state is entered when an I/O is decoded with an error
	 * condition.  By this point the RNC expected suspension state is set.
	 * The error conditions suspend the device, so unsuspend here if
	 * possible.
	 */
	sci_remote_node_context_resume(&idev->rnc,
				       atapi_remote_device_resume_done,
				       idev);
}

static void sci_smp_remote_device_ready_idle_substate_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	isci_remote_device_ready(ihost, idev);
}

static void sci_smp_remote_device_ready_cmd_substate_enter(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);
	struct isci_host *ihost = idev->owning_port->owning_controller;

	BUG_ON(idev->working_request == NULL);

	isci_remote_device_not_ready(ihost, idev,
				     SCIC_REMOTE_DEVICE_NOT_READY_SMP_REQUEST_STARTED);
}

static void sci_smp_remote_device_ready_cmd_substate_exit(struct sci_base_state_machine *sm)
{
	struct isci_remote_device *idev = container_of(sm, typeof(*idev), sm);

	idev->working_request = NULL;
}

static const struct sci_base_state sci_remote_device_state_table[] = {
	[SCI_DEV_INITIAL] = {
		.enter_state = sci_remote_device_initial_state_enter,
	},
	[SCI_DEV_STOPPED] = {
		.enter_state = sci_remote_device_stopped_state_enter,
	},
	[SCI_DEV_STARTING] = {
		.enter_state = sci_remote_device_starting_state_enter,
	},
	[SCI_DEV_READY] = {
		.enter_state = sci_remote_device_ready_state_enter,
		.exit_state  = sci_remote_device_ready_state_exit
	},
	[SCI_STP_DEV_IDLE] = {
		.enter_state = sci_stp_remote_device_ready_idle_substate_enter,
	},
	[SCI_STP_DEV_CMD] = {
		.enter_state = sci_stp_remote_device_ready_cmd_substate_enter,
	},
	[SCI_STP_DEV_NCQ] = { },
	[SCI_STP_DEV_NCQ_ERROR] = {
		.enter_state = sci_stp_remote_device_ready_ncq_error_substate_enter,
	},
	[SCI_STP_DEV_ATAPI_ERROR] = {
		.enter_state = sci_stp_remote_device_atapi_error_substate_enter,
	},
	[SCI_STP_DEV_AWAIT_RESET] = { },
	[SCI_SMP_DEV_IDLE] = {
		.enter_state = sci_smp_remote_device_ready_idle_substate_enter,
	},
	[SCI_SMP_DEV_CMD] = {
		.enter_state = sci_smp_remote_device_ready_cmd_substate_enter,
		.exit_state  = sci_smp_remote_device_ready_cmd_substate_exit,
	},
	[SCI_DEV_STOPPING] = { },
	[SCI_DEV_FAILED] = { },
	[SCI_DEV_RESETTING] = {
		.enter_state = sci_remote_device_resetting_state_enter,
		.exit_state  = sci_remote_device_resetting_state_exit
	},
	[SCI_DEV_FINAL] = { },
};

/**
 * sci_remote_device_construct() - common construction
 * @sci_port: SAS/SATA port through which this device is accessed.
 * @sci_dev: remote device to construct
 *
 * This routine just performs benign initialization and does not
 * allocate the remote_node_context which is left to
 * sci_remote_device_[de]a_construct().  sci_remote_device_destruct()
 * frees the remote_node_context(s) for the device.
 */
static void sci_remote_device_construct(struct isci_port *iport,
				  struct isci_remote_device *idev)
{
	idev->owning_port = iport;
	idev->started_request_count = 0;

	sci_init_sm(&idev->sm, sci_remote_device_state_table, SCI_DEV_INITIAL);

	sci_remote_node_context_construct(&idev->rnc,
					       SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX);
}

/**
 * sci_remote_device_da_construct() - construct direct attached device.
 *
 * The information (e.g. IAF, Signature FIS, etc.) necessary to build
 * the device is known to the SCI Core since it is contained in the
 * sci_phy object.  Remote node context(s) is/are a global resource
 * allocated by this routine, freed by sci_remote_device_destruct().
 *
 * Returns:
 * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
 * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
 * sata-only controller instance.
 * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
 */
static enum sci_status sci_remote_device_da_construct(struct isci_port *iport,
						       struct isci_remote_device *idev)
{
	enum sci_status status;
	struct sci_port_properties properties;

	sci_remote_device_construct(iport, idev);

	sci_port_get_properties(iport, &properties);
	/* Get accurate port width from port's phy mask for a DA device. */
	idev->device_port_width = hweight32(properties.phy_mask);

	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
							     idev,
							     &idev->rnc.remote_node_index);

	if (status != SCI_SUCCESS)
		return status;

	idev->connection_rate = sci_port_get_max_allowed_speed(iport);

	return SCI_SUCCESS;
}

/**
 * sci_remote_device_ea_construct() - construct expander attached device
 *
 * Remote node context(s) is/are a global resource allocated by this
 * routine, freed by sci_remote_device_destruct().
 *
 * Returns:
 * SCI_FAILURE_DEVICE_EXISTS - device has already been constructed.
 * SCI_FAILURE_UNSUPPORTED_PROTOCOL - e.g. sas device attached to
 * sata-only controller instance.
 * SCI_FAILURE_INSUFFICIENT_RESOURCES - remote node contexts exhausted.
 */
static enum sci_status sci_remote_device_ea_construct(struct isci_port *iport,
						       struct isci_remote_device *idev)
{
	struct domain_device *dev = idev->domain_dev;
	enum sci_status status;

	sci_remote_device_construct(iport, idev);

	status = sci_controller_allocate_remote_node_context(iport->owning_controller,
								  idev,
								  &idev->rnc.remote_node_index);
	if (status != SCI_SUCCESS)
		return status;

	/* For SAS-2 the physical link rate is actually a logical link
	 * rate that incorporates multiplexing.  The SCU doesn't
	 * incorporate multiplexing and for the purposes of the
	 * connection the logical link rate is that same as the
	 * physical.  Furthermore, the SAS-2 and SAS-1.1 fields overlay
	 * one another, so this code works for both situations.
	 */
	idev->connection_rate = min_t(u16, sci_port_get_max_allowed_speed(iport),
					 dev->linkrate);

	/* / @todo Should I assign the port width by reading all of the phys on the port? */
	idev->device_port_width = 1;

	return SCI_SUCCESS;
}

enum sci_status sci_remote_device_resume(
	struct isci_remote_device *idev,
	scics_sds_remote_node_context_callback cb_fn,
	void *cb_p)
{
	enum sci_status status;

	status = sci_remote_node_context_resume(&idev->rnc, cb_fn, cb_p);
	if (status != SCI_SUCCESS)
		dev_dbg(scirdev_to_dev(idev), "%s: failed to resume: %d\n",
			__func__, status);
	return status;
}

enum sci_status isci_remote_device_resume_from_abort(
	struct isci_host *ihost,
	struct isci_remote_device *idev)
{
	unsigned long flags;
	enum sci_status status;

	spin_lock_irqsave(&ihost->scic_lock, flags);
	/* Preserve any current resume callbacks, for instance from other
	 * resumptions.
	 */
	clear_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags);
	status = sci_remote_device_resume(idev, idev->rnc.user_callback,
					  idev->rnc.user_cookie);
	spin_unlock_irqrestore(&ihost->scic_lock, flags);
	return status;
}
/**
 * sci_remote_device_start() - This method will start the supplied remote
 *    device.  This method enables normal IO requests to flow through to the
 *    remote device.
 * @remote_device: This parameter specifies the device to be started.
 * @timeout: This parameter specifies the number of milliseconds in which the
 *    start operation should complete.
 *
 * An indication of whether the device was successfully started. SCI_SUCCESS
 * This value is returned if the device was successfully started.
 * SCI_FAILURE_INVALID_PHY This value is returned if the user attempts to start
 * the device when there have been no phys added to it.
 */
static enum sci_status sci_remote_device_start(struct isci_remote_device *idev,
					       u32 timeout)
{
	struct sci_base_state_machine *sm = &idev->sm;
	enum sci_remote_device_states state = sm->current_state_id;
	enum sci_status status;

	if (state != SCI_DEV_STOPPED) {
		dev_warn(scirdev_to_dev(idev), "%s: in wrong state: %s\n",
			 __func__, dev_state_name(state));
		return SCI_FAILURE_INVALID_STATE;
	}

	status = sci_remote_device_resume(idev, remote_device_resume_done,
					  idev);
	if (status != SCI_SUCCESS)
		return status;

	sci_change_state(sm, SCI_DEV_STARTING);

	return SCI_SUCCESS;
}

static enum sci_status isci_remote_device_construct(struct isci_port *iport,
						    struct isci_remote_device *idev)
{
	struct isci_host *ihost = iport->isci_host;
	struct domain_device *dev = idev->domain_dev;
	enum sci_status status;

	if (dev->parent && dev_is_expander(dev->parent))
		status = sci_remote_device_ea_construct(iport, idev);
	else
		status = sci_remote_device_da_construct(iport, idev);

	if (status != SCI_SUCCESS) {
		dev_dbg(&ihost->pdev->dev, "%s: construct failed: %d\n",
			__func__, status);

		return status;
	}

	/* start the device. */
	status = sci_remote_device_start(idev, ISCI_REMOTE_DEVICE_START_TIMEOUT);

	if (status != SCI_SUCCESS)
		dev_warn(&ihost->pdev->dev, "remote device start failed: %d\n",
			 status);

	return status;
}

/**
 * This function builds the isci_remote_device when a libsas dev_found message
 *    is received.
 * @isci_host: This parameter specifies the isci host object.
 * @port: This parameter specifies the isci_port conected to this device.
 *
 * pointer to new isci_remote_device.
 */
static struct isci_remote_device *
isci_remote_device_alloc(struct isci_host *ihost, struct isci_port *iport)
{
	struct isci_remote_device *idev;
	int i;

	for (i = 0; i < SCI_MAX_REMOTE_DEVICES; i++) {
		idev = &ihost->devices[i];
		if (!test_and_set_bit(IDEV_ALLOCATED, &idev->flags))
			break;
	}

	if (i >= SCI_MAX_REMOTE_DEVICES) {
		dev_warn(&ihost->pdev->dev, "%s: failed\n", __func__);
		return NULL;
	}
	if (WARN_ONCE(!list_empty(&idev->node), "found non-idle remote device\n"))
		return NULL;

	return idev;
}

void isci_remote_device_release(struct kref *kref)
{
	struct isci_remote_device *idev = container_of(kref, typeof(*idev), kref);
	struct isci_host *ihost = idev->isci_port->isci_host;

	idev->domain_dev = NULL;
	idev->isci_port = NULL;
	clear_bit(IDEV_START_PENDING, &idev->flags);
	clear_bit(IDEV_STOP_PENDING, &idev->flags);
	clear_bit(IDEV_IO_READY, &idev->flags);
	clear_bit(IDEV_GONE, &idev->flags);
	smp_mb__before_clear_bit();
	clear_bit(IDEV_ALLOCATED, &idev->flags);
	wake_up(&ihost->eventq);
}

/**
 * isci_remote_device_stop() - This function is called internally to stop the
 *    remote device.
 * @isci_host: This parameter specifies the isci host object.
 * @isci_device: This parameter specifies the remote device.
 *
 * The status of the ihost request to stop.
 */
enum sci_status isci_remote_device_stop(struct isci_host *ihost, struct isci_remote_device *idev)
{
	enum sci_status status;
	unsigned long flags;

	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p\n", __func__, idev);

	spin_lock_irqsave(&ihost->scic_lock, flags);
	idev->domain_dev->lldd_dev = NULL; /* disable new lookups */
	set_bit(IDEV_GONE, &idev->flags);

	set_bit(IDEV_STOP_PENDING, &idev->flags);
	status = sci_remote_device_stop(idev, 50);
	spin_unlock_irqrestore(&ihost->scic_lock, flags);

	/* Wait for the stop complete callback. */
	if (WARN_ONCE(status != SCI_SUCCESS, "failed to stop device\n"))
		/* nothing to wait for */;
	else
		wait_for_device_stop(ihost, idev);

	dev_dbg(&ihost->pdev->dev,
		"%s: isci_device = %p, waiting done.\n", __func__, idev);

	return status;
}

/**
 * isci_remote_device_gone() - This function is called by libsas when a domain
 *    device is removed.
 * @domain_device: This parameter specifies the libsas domain device.
 *
 */
void isci_remote_device_gone(struct domain_device *dev)
{
	struct isci_host *ihost = dev_to_ihost(dev);
	struct isci_remote_device *idev = dev->lldd_dev;

	dev_dbg(&ihost->pdev->dev,
		"%s: domain_device = %p, isci_device = %p, isci_port = %p\n",
		__func__, dev, idev, idev->isci_port);

	isci_remote_device_stop(ihost, idev);
}


/**
 * isci_remote_device_found() - This function is called by libsas when a remote
 *    device is discovered. A remote device object is created and started. the
 *    function then sleeps until the sci core device started message is
 *    received.
 * @domain_device: This parameter specifies the libsas domain device.
 *
 * status, zero indicates success.
 */
int isci_remote_device_found(struct domain_device *dev)
{
	struct isci_host *isci_host = dev_to_ihost(dev);
	struct isci_port *isci_port = dev->port->lldd_port;
	struct isci_remote_device *isci_device;
	enum sci_status status;

	dev_dbg(&isci_host->pdev->dev,
		"%s: domain_device = %p\n", __func__, dev);

	if (!isci_port)
		return -ENODEV;

	isci_device = isci_remote_device_alloc(isci_host, isci_port);
	if (!isci_device)
		return -ENODEV;

	kref_init(&isci_device->kref);
	INIT_LIST_HEAD(&isci_device->node);

	spin_lock_irq(&isci_host->scic_lock);
	isci_device->domain_dev = dev;
	isci_device->isci_port = isci_port;
	list_add_tail(&isci_device->node, &isci_port->remote_dev_list);

	set_bit(IDEV_START_PENDING, &isci_device->flags);
	status = isci_remote_device_construct(isci_port, isci_device);

	dev_dbg(&isci_host->pdev->dev,
		"%s: isci_device = %p\n",
		__func__, isci_device);

	if (status == SCI_SUCCESS) {
		/* device came up, advertise it to the world */
		dev->lldd_dev = isci_device;
	} else
		isci_put_device(isci_device);
	spin_unlock_irq(&isci_host->scic_lock);

	/* wait for the device ready callback. */
	wait_for_device_start(isci_host, isci_device);

	return status == SCI_SUCCESS ? 0 : -ENODEV;
}

enum sci_status isci_remote_device_suspend_terminate(
	struct isci_host *ihost,
	struct isci_remote_device *idev,
	struct isci_request *ireq)
{
	unsigned long flags;
	enum sci_status status;

	/* Put the device into suspension. */
	spin_lock_irqsave(&ihost->scic_lock, flags);
	set_bit(IDEV_ABORT_PATH_ACTIVE, &idev->flags);
	sci_remote_device_suspend(idev, SCI_SW_SUSPEND_LINKHANG_DETECT);
	spin_unlock_irqrestore(&ihost->scic_lock, flags);

	/* Terminate and wait for the completions. */
	status = isci_remote_device_terminate_requests(ihost, idev, ireq);
	if (status != SCI_SUCCESS)
		dev_dbg(&ihost->pdev->dev,
			"%s: isci_remote_device_terminate_requests(%p) "
				"returned %d!\n",
			__func__, idev, status);

	/* NOTE: RNC resumption is left to the caller! */
	return status;
}

int isci_remote_device_is_safe_to_abort(
	struct isci_remote_device *idev)
{
	return sci_remote_node_context_is_safe_to_abort(&idev->rnc);
}

enum sci_status sci_remote_device_abort_requests_pending_abort(
	struct isci_remote_device *idev)
{
	return sci_remote_device_terminate_reqs_checkabort(idev, 1);
}

enum sci_status isci_remote_device_reset_complete(
	struct isci_host *ihost,
	struct isci_remote_device *idev)
{
	unsigned long flags;
	enum sci_status status;

	spin_lock_irqsave(&ihost->scic_lock, flags);
	status = sci_remote_device_reset_complete(idev);
	spin_unlock_irqrestore(&ihost->scic_lock, flags);

	return status;
}

void isci_dev_set_hang_detection_timeout(
	struct isci_remote_device *idev,
	u32 timeout)
{
	if (dev_is_sata(idev->domain_dev)) {
		if (timeout) {
			if (test_and_set_bit(IDEV_RNC_LLHANG_ENABLED,
					     &idev->flags))
				return;  /* Already enabled. */
		} else if (!test_and_clear_bit(IDEV_RNC_LLHANG_ENABLED,
					       &idev->flags))
			return;  /* Not enabled. */

		sci_port_set_hang_detection_timeout(idev->owning_port,
						    timeout);
	}
}