summaryrefslogtreecommitdiff
path: root/drivers/ata/libata-sata.c
blob: 4e88597aa9df3fa022d2475a8d27b51d1a49e801 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  SATA specific part of ATA helper library
 *
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *  Copyright 2006 Tejun Heo <htejun@gmail.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <linux/libata.h>

#include "libata.h"
#include "libata-transport.h"

/* debounce timing parameters in msecs { interval, duration, timeout } */
const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
EXPORT_SYMBOL_GPL(sata_deb_timing_long);

/**
 *	sata_scr_valid - test whether SCRs are accessible
 *	@link: ATA link to test SCR accessibility for
 *
 *	Test whether SCRs are accessible for @link.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	1 if SCRs are accessible, 0 otherwise.
 */
int sata_scr_valid(struct ata_link *link)
{
	struct ata_port *ap = link->ap;

	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
}
EXPORT_SYMBOL_GPL(sata_scr_valid);

/**
 *	sata_scr_read - read SCR register of the specified port
 *	@link: ATA link to read SCR for
 *	@reg: SCR to read
 *	@val: Place to store read value
 *
 *	Read SCR register @reg of @link into *@val.  This function is
 *	guaranteed to succeed if @link is ap->link, the cable type of
 *	the port is SATA and the port implements ->scr_read.
 *
 *	LOCKING:
 *	None if @link is ap->link.  Kernel thread context otherwise.
 *
 *	RETURNS:
 *	0 on success, negative errno on failure.
 */
int sata_scr_read(struct ata_link *link, int reg, u32 *val)
{
	if (ata_is_host_link(link)) {
		if (sata_scr_valid(link))
			return link->ap->ops->scr_read(link, reg, val);
		return -EOPNOTSUPP;
	}

	return sata_pmp_scr_read(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_read);

/**
 *	sata_scr_write - write SCR register of the specified port
 *	@link: ATA link to write SCR for
 *	@reg: SCR to write
 *	@val: value to write
 *
 *	Write @val to SCR register @reg of @link.  This function is
 *	guaranteed to succeed if @link is ap->link, the cable type of
 *	the port is SATA and the port implements ->scr_read.
 *
 *	LOCKING:
 *	None if @link is ap->link.  Kernel thread context otherwise.
 *
 *	RETURNS:
 *	0 on success, negative errno on failure.
 */
int sata_scr_write(struct ata_link *link, int reg, u32 val)
{
	if (ata_is_host_link(link)) {
		if (sata_scr_valid(link))
			return link->ap->ops->scr_write(link, reg, val);
		return -EOPNOTSUPP;
	}

	return sata_pmp_scr_write(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_write);

/**
 *	sata_scr_write_flush - write SCR register of the specified port and flush
 *	@link: ATA link to write SCR for
 *	@reg: SCR to write
 *	@val: value to write
 *
 *	This function is identical to sata_scr_write() except that this
 *	function performs flush after writing to the register.
 *
 *	LOCKING:
 *	None if @link is ap->link.  Kernel thread context otherwise.
 *
 *	RETURNS:
 *	0 on success, negative errno on failure.
 */
int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
{
	if (ata_is_host_link(link)) {
		int rc;

		if (sata_scr_valid(link)) {
			rc = link->ap->ops->scr_write(link, reg, val);
			if (rc == 0)
				rc = link->ap->ops->scr_read(link, reg, &val);
			return rc;
		}
		return -EOPNOTSUPP;
	}

	return sata_pmp_scr_write(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_write_flush);

/**
 *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
 *	@tf: Taskfile to convert
 *	@pmp: Port multiplier port
 *	@is_cmd: This FIS is for command
 *	@fis: Buffer into which data will output
 *
 *	Converts a standard ATA taskfile to a Serial ATA
 *	FIS structure (Register - Host to Device).
 *
 *	LOCKING:
 *	Inherited from caller.
 */
void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
{
	fis[0] = 0x27;			/* Register - Host to Device FIS */
	fis[1] = pmp & 0xf;		/* Port multiplier number*/
	if (is_cmd)
		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */

	fis[2] = tf->command;
	fis[3] = tf->feature;

	fis[4] = tf->lbal;
	fis[5] = tf->lbam;
	fis[6] = tf->lbah;
	fis[7] = tf->device;

	fis[8] = tf->hob_lbal;
	fis[9] = tf->hob_lbam;
	fis[10] = tf->hob_lbah;
	fis[11] = tf->hob_feature;

	fis[12] = tf->nsect;
	fis[13] = tf->hob_nsect;
	fis[14] = 0;
	fis[15] = tf->ctl;

	fis[16] = tf->auxiliary & 0xff;
	fis[17] = (tf->auxiliary >> 8) & 0xff;
	fis[18] = (tf->auxiliary >> 16) & 0xff;
	fis[19] = (tf->auxiliary >> 24) & 0xff;
}
EXPORT_SYMBOL_GPL(ata_tf_to_fis);

/**
 *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
 *	@fis: Buffer from which data will be input
 *	@tf: Taskfile to output
 *
 *	Converts a serial ATA FIS structure to a standard ATA taskfile.
 *
 *	LOCKING:
 *	Inherited from caller.
 */

void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
{
	tf->command	= fis[2];	/* status */
	tf->feature	= fis[3];	/* error */

	tf->lbal	= fis[4];
	tf->lbam	= fis[5];
	tf->lbah	= fis[6];
	tf->device	= fis[7];

	tf->hob_lbal	= fis[8];
	tf->hob_lbam	= fis[9];
	tf->hob_lbah	= fis[10];

	tf->nsect	= fis[12];
	tf->hob_nsect	= fis[13];
}
EXPORT_SYMBOL_GPL(ata_tf_from_fis);

/**
 *	sata_link_debounce - debounce SATA phy status
 *	@link: ATA link to debounce SATA phy status for
 *	@params: timing parameters { interval, duration, timeout } in msec
 *	@deadline: deadline jiffies for the operation
 *
 *	Make sure SStatus of @link reaches stable state, determined by
 *	holding the same value where DET is not 1 for @duration polled
 *	every @interval, before @timeout.  Timeout constraints the
 *	beginning of the stable state.  Because DET gets stuck at 1 on
 *	some controllers after hot unplugging, this functions waits
 *	until timeout then returns 0 if DET is stable at 1.
 *
 *	@timeout is further limited by @deadline.  The sooner of the
 *	two is used.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep)
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
int sata_link_debounce(struct ata_link *link, const unsigned long *params,
		       unsigned long deadline)
{
	unsigned long interval = params[0];
	unsigned long duration = params[1];
	unsigned long last_jiffies, t;
	u32 last, cur;
	int rc;

	t = ata_deadline(jiffies, params[2]);
	if (time_before(t, deadline))
		deadline = t;

	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
		return rc;
	cur &= 0xf;

	last = cur;
	last_jiffies = jiffies;

	while (1) {
		ata_msleep(link->ap, interval);
		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
			return rc;
		cur &= 0xf;

		/* DET stable? */
		if (cur == last) {
			if (cur == 1 && time_before(jiffies, deadline))
				continue;
			if (time_after(jiffies,
				       ata_deadline(last_jiffies, duration)))
				return 0;
			continue;
		}

		/* unstable, start over */
		last = cur;
		last_jiffies = jiffies;

		/* Check deadline.  If debouncing failed, return
		 * -EPIPE to tell upper layer to lower link speed.
		 */
		if (time_after(jiffies, deadline))
			return -EPIPE;
	}
}
EXPORT_SYMBOL_GPL(sata_link_debounce);

/**
 *	sata_link_resume - resume SATA link
 *	@link: ATA link to resume SATA
 *	@params: timing parameters { interval, duration, timeout } in msec
 *	@deadline: deadline jiffies for the operation
 *
 *	Resume SATA phy @link and debounce it.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep)
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
int sata_link_resume(struct ata_link *link, const unsigned long *params,
		     unsigned long deadline)
{
	int tries = ATA_LINK_RESUME_TRIES;
	u32 scontrol, serror;
	int rc;

	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
		return rc;

	/*
	 * Writes to SControl sometimes get ignored under certain
	 * controllers (ata_piix SIDPR).  Make sure DET actually is
	 * cleared.
	 */
	do {
		scontrol = (scontrol & 0x0f0) | 0x300;
		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
			return rc;
		/*
		 * Some PHYs react badly if SStatus is pounded
		 * immediately after resuming.  Delay 200ms before
		 * debouncing.
		 */
		if (!(link->flags & ATA_LFLAG_NO_DB_DELAY))
			ata_msleep(link->ap, 200);

		/* is SControl restored correctly? */
		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
			return rc;
	} while ((scontrol & 0xf0f) != 0x300 && --tries);

	if ((scontrol & 0xf0f) != 0x300) {
		ata_link_warn(link, "failed to resume link (SControl %X)\n",
			     scontrol);
		return 0;
	}

	if (tries < ATA_LINK_RESUME_TRIES)
		ata_link_warn(link, "link resume succeeded after %d retries\n",
			      ATA_LINK_RESUME_TRIES - tries);

	if ((rc = sata_link_debounce(link, params, deadline)))
		return rc;

	/* clear SError, some PHYs require this even for SRST to work */
	if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
		rc = sata_scr_write(link, SCR_ERROR, serror);

	return rc != -EINVAL ? rc : 0;
}
EXPORT_SYMBOL_GPL(sata_link_resume);

/**
 *	sata_link_scr_lpm - manipulate SControl IPM and SPM fields
 *	@link: ATA link to manipulate SControl for
 *	@policy: LPM policy to configure
 *	@spm_wakeup: initiate LPM transition to active state
 *
 *	Manipulate the IPM field of the SControl register of @link
 *	according to @policy.  If @policy is ATA_LPM_MAX_POWER and
 *	@spm_wakeup is %true, the SPM field is manipulated to wake up
 *	the link.  This function also clears PHYRDY_CHG before
 *	returning.
 *
 *	LOCKING:
 *	EH context.
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
		      bool spm_wakeup)
{
	struct ata_eh_context *ehc = &link->eh_context;
	bool woken_up = false;
	u32 scontrol;
	int rc;

	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
	if (rc)
		return rc;

	switch (policy) {
	case ATA_LPM_MAX_POWER:
		/* disable all LPM transitions */
		scontrol |= (0x7 << 8);
		/* initiate transition to active state */
		if (spm_wakeup) {
			scontrol |= (0x4 << 12);
			woken_up = true;
		}
		break;
	case ATA_LPM_MED_POWER:
		/* allow LPM to PARTIAL */
		scontrol &= ~(0x1 << 8);
		scontrol |= (0x6 << 8);
		break;
	case ATA_LPM_MED_POWER_WITH_DIPM:
	case ATA_LPM_MIN_POWER_WITH_PARTIAL:
	case ATA_LPM_MIN_POWER:
		if (ata_link_nr_enabled(link) > 0)
			/* no restrictions on LPM transitions */
			scontrol &= ~(0x7 << 8);
		else {
			/* empty port, power off */
			scontrol &= ~0xf;
			scontrol |= (0x1 << 2);
		}
		break;
	default:
		WARN_ON(1);
	}

	rc = sata_scr_write(link, SCR_CONTROL, scontrol);
	if (rc)
		return rc;

	/* give the link time to transit out of LPM state */
	if (woken_up)
		msleep(10);

	/* clear PHYRDY_CHG from SError */
	ehc->i.serror &= ~SERR_PHYRDY_CHG;
	return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
}
EXPORT_SYMBOL_GPL(sata_link_scr_lpm);

static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
{
	struct ata_link *host_link = &link->ap->link;
	u32 limit, target, spd;

	limit = link->sata_spd_limit;

	/* Don't configure downstream link faster than upstream link.
	 * It doesn't speed up anything and some PMPs choke on such
	 * configuration.
	 */
	if (!ata_is_host_link(link) && host_link->sata_spd)
		limit &= (1 << host_link->sata_spd) - 1;

	if (limit == UINT_MAX)
		target = 0;
	else
		target = fls(limit);

	spd = (*scontrol >> 4) & 0xf;
	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);

	return spd != target;
}

/**
 *	sata_set_spd_needed - is SATA spd configuration needed
 *	@link: Link in question
 *
 *	Test whether the spd limit in SControl matches
 *	@link->sata_spd_limit.  This function is used to determine
 *	whether hardreset is necessary to apply SATA spd
 *	configuration.
 *
 *	LOCKING:
 *	Inherited from caller.
 *
 *	RETURNS:
 *	1 if SATA spd configuration is needed, 0 otherwise.
 */
static int sata_set_spd_needed(struct ata_link *link)
{
	u32 scontrol;

	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
		return 1;

	return __sata_set_spd_needed(link, &scontrol);
}

/**
 *	sata_set_spd - set SATA spd according to spd limit
 *	@link: Link to set SATA spd for
 *
 *	Set SATA spd of @link according to sata_spd_limit.
 *
 *	LOCKING:
 *	Inherited from caller.
 *
 *	RETURNS:
 *	0 if spd doesn't need to be changed, 1 if spd has been
 *	changed.  Negative errno if SCR registers are inaccessible.
 */
int sata_set_spd(struct ata_link *link)
{
	u32 scontrol;
	int rc;

	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
		return rc;

	if (!__sata_set_spd_needed(link, &scontrol))
		return 0;

	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
		return rc;

	return 1;
}
EXPORT_SYMBOL_GPL(sata_set_spd);

/**
 *	sata_link_hardreset - reset link via SATA phy reset
 *	@link: link to reset
 *	@timing: timing parameters { interval, duration, timeout } in msec
 *	@deadline: deadline jiffies for the operation
 *	@online: optional out parameter indicating link onlineness
 *	@check_ready: optional callback to check link readiness
 *
 *	SATA phy-reset @link using DET bits of SControl register.
 *	After hardreset, link readiness is waited upon using
 *	ata_wait_ready() if @check_ready is specified.  LLDs are
 *	allowed to not specify @check_ready and wait itself after this
 *	function returns.  Device classification is LLD's
 *	responsibility.
 *
 *	*@online is set to one iff reset succeeded and @link is online
 *	after reset.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep)
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
			unsigned long deadline,
			bool *online, int (*check_ready)(struct ata_link *))
{
	u32 scontrol;
	int rc;

	DPRINTK("ENTER\n");

	if (online)
		*online = false;

	if (sata_set_spd_needed(link)) {
		/* SATA spec says nothing about how to reconfigure
		 * spd.  To be on the safe side, turn off phy during
		 * reconfiguration.  This works for at least ICH7 AHCI
		 * and Sil3124.
		 */
		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
			goto out;

		scontrol = (scontrol & 0x0f0) | 0x304;

		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
			goto out;

		sata_set_spd(link);
	}

	/* issue phy wake/reset */
	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
		goto out;

	scontrol = (scontrol & 0x0f0) | 0x301;

	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
		goto out;

	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
	 * 10.4.2 says at least 1 ms.
	 */
	ata_msleep(link->ap, 1);

	/* bring link back */
	rc = sata_link_resume(link, timing, deadline);
	if (rc)
		goto out;
	/* if link is offline nothing more to do */
	if (ata_phys_link_offline(link))
		goto out;

	/* Link is online.  From this point, -ENODEV too is an error. */
	if (online)
		*online = true;

	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
		/* If PMP is supported, we have to do follow-up SRST.
		 * Some PMPs don't send D2H Reg FIS after hardreset if
		 * the first port is empty.  Wait only for
		 * ATA_TMOUT_PMP_SRST_WAIT.
		 */
		if (check_ready) {
			unsigned long pmp_deadline;

			pmp_deadline = ata_deadline(jiffies,
						    ATA_TMOUT_PMP_SRST_WAIT);
			if (time_after(pmp_deadline, deadline))
				pmp_deadline = deadline;
			ata_wait_ready(link, pmp_deadline, check_ready);
		}
		rc = -EAGAIN;
		goto out;
	}

	rc = 0;
	if (check_ready)
		rc = ata_wait_ready(link, deadline, check_ready);
 out:
	if (rc && rc != -EAGAIN) {
		/* online is set iff link is online && reset succeeded */
		if (online)
			*online = false;
		ata_link_err(link, "COMRESET failed (errno=%d)\n", rc);
	}
	DPRINTK("EXIT, rc=%d\n", rc);
	return rc;
}
EXPORT_SYMBOL_GPL(sata_link_hardreset);

/**
 *	ata_qc_complete_multiple - Complete multiple qcs successfully
 *	@ap: port in question
 *	@qc_active: new qc_active mask
 *
 *	Complete in-flight commands.  This functions is meant to be
 *	called from low-level driver's interrupt routine to complete
 *	requests normally.  ap->qc_active and @qc_active is compared
 *	and commands are completed accordingly.
 *
 *	Always use this function when completing multiple NCQ commands
 *	from IRQ handlers instead of calling ata_qc_complete()
 *	multiple times to keep IRQ expect status properly in sync.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Number of completed commands on success, -errno otherwise.
 */
int ata_qc_complete_multiple(struct ata_port *ap, u64 qc_active)
{
	u64 done_mask, ap_qc_active = ap->qc_active;
	int nr_done = 0;

	/*
	 * If the internal tag is set on ap->qc_active, then we care about
	 * bit0 on the passed in qc_active mask. Move that bit up to match
	 * the internal tag.
	 */
	if (ap_qc_active & (1ULL << ATA_TAG_INTERNAL)) {
		qc_active |= (qc_active & 0x01) << ATA_TAG_INTERNAL;
		qc_active ^= qc_active & 0x01;
	}

	done_mask = ap_qc_active ^ qc_active;

	if (unlikely(done_mask & qc_active)) {
		ata_port_err(ap, "illegal qc_active transition (%08llx->%08llx)\n",
			     ap->qc_active, qc_active);
		return -EINVAL;
	}

	while (done_mask) {
		struct ata_queued_cmd *qc;
		unsigned int tag = __ffs64(done_mask);

		qc = ata_qc_from_tag(ap, tag);
		if (qc) {
			ata_qc_complete(qc);
			nr_done++;
		}
		done_mask &= ~(1ULL << tag);
	}

	return nr_done;
}
EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);

/**
 *	ata_slave_link_init - initialize slave link
 *	@ap: port to initialize slave link for
 *
 *	Create and initialize slave link for @ap.  This enables slave
 *	link handling on the port.
 *
 *	In libata, a port contains links and a link contains devices.
 *	There is single host link but if a PMP is attached to it,
 *	there can be multiple fan-out links.  On SATA, there's usually
 *	a single device connected to a link but PATA and SATA
 *	controllers emulating TF based interface can have two - master
 *	and slave.
 *
 *	However, there are a few controllers which don't fit into this
 *	abstraction too well - SATA controllers which emulate TF
 *	interface with both master and slave devices but also have
 *	separate SCR register sets for each device.  These controllers
 *	need separate links for physical link handling
 *	(e.g. onlineness, link speed) but should be treated like a
 *	traditional M/S controller for everything else (e.g. command
 *	issue, softreset).
 *
 *	slave_link is libata's way of handling this class of
 *	controllers without impacting core layer too much.  For
 *	anything other than physical link handling, the default host
 *	link is used for both master and slave.  For physical link
 *	handling, separate @ap->slave_link is used.  All dirty details
 *	are implemented inside libata core layer.  From LLD's POV, the
 *	only difference is that prereset, hardreset and postreset are
 *	called once more for the slave link, so the reset sequence
 *	looks like the following.
 *
 *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
 *	softreset(M) -> postreset(M) -> postreset(S)
 *
 *	Note that softreset is called only for the master.  Softreset
 *	resets both M/S by definition, so SRST on master should handle
 *	both (the standard method will work just fine).
 *
 *	LOCKING:
 *	Should be called before host is registered.
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
int ata_slave_link_init(struct ata_port *ap)
{
	struct ata_link *link;

	WARN_ON(ap->slave_link);
	WARN_ON(ap->flags & ATA_FLAG_PMP);

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

	ata_link_init(ap, link, 1);
	ap->slave_link = link;
	return 0;
}
EXPORT_SYMBOL_GPL(ata_slave_link_init);

/**
 *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
 *	@link: Link receiving the event
 *
 *	Test whether the received PHY event has to be ignored or not.
 *
 *	LOCKING:
 *	None:
 *
 *	RETURNS:
 *	True if the event has to be ignored.
 */
bool sata_lpm_ignore_phy_events(struct ata_link *link)
{
	unsigned long lpm_timeout = link->last_lpm_change +
				    msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);

	/* if LPM is enabled, PHYRDY doesn't mean anything */
	if (link->lpm_policy > ATA_LPM_MAX_POWER)
		return true;

	/* ignore the first PHY event after the LPM policy changed
	 * as it is might be spurious
	 */
	if ((link->flags & ATA_LFLAG_CHANGED) &&
	    time_before(jiffies, lpm_timeout))
		return true;

	return false;
}
EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);

static const char *ata_lpm_policy_names[] = {
	[ATA_LPM_UNKNOWN]		= "max_performance",
	[ATA_LPM_MAX_POWER]		= "max_performance",
	[ATA_LPM_MED_POWER]		= "medium_power",
	[ATA_LPM_MED_POWER_WITH_DIPM]	= "med_power_with_dipm",
	[ATA_LPM_MIN_POWER_WITH_PARTIAL] = "min_power_with_partial",
	[ATA_LPM_MIN_POWER]		= "min_power",
};

static ssize_t ata_scsi_lpm_store(struct device *device,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct Scsi_Host *shost = class_to_shost(device);
	struct ata_port *ap = ata_shost_to_port(shost);
	struct ata_link *link;
	struct ata_device *dev;
	enum ata_lpm_policy policy;
	unsigned long flags;

	/* UNKNOWN is internal state, iterate from MAX_POWER */
	for (policy = ATA_LPM_MAX_POWER;
	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
		const char *name = ata_lpm_policy_names[policy];

		if (strncmp(name, buf, strlen(name)) == 0)
			break;
	}
	if (policy == ARRAY_SIZE(ata_lpm_policy_names))
		return -EINVAL;

	spin_lock_irqsave(ap->lock, flags);

	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, &ap->link, ENABLED) {
			if (dev->horkage & ATA_HORKAGE_NOLPM) {
				count = -EOPNOTSUPP;
				goto out_unlock;
			}
		}
	}

	ap->target_lpm_policy = policy;
	ata_port_schedule_eh(ap);
out_unlock:
	spin_unlock_irqrestore(ap->lock, flags);
	return count;
}

static ssize_t ata_scsi_lpm_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))
		return -EINVAL;

	return snprintf(buf, PAGE_SIZE, "%s\n",
			ata_lpm_policy_names[ap->target_lpm_policy]);
}
DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
	    ata_scsi_lpm_show, ata_scsi_lpm_store);
EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);

static ssize_t ata_ncq_prio_supported_show(struct device *device,
					   struct device_attribute *attr,
					   char *buf)
{
	struct scsi_device *sdev = to_scsi_device(device);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *dev;
	bool ncq_prio_supported;
	int rc = 0;

	spin_lock_irq(ap->lock);
	dev = ata_scsi_find_dev(ap, sdev);
	if (!dev)
		rc = -ENODEV;
	else
		ncq_prio_supported = dev->flags & ATA_DFLAG_NCQ_PRIO;
	spin_unlock_irq(ap->lock);

	return rc ? rc : sysfs_emit(buf, "%u\n", ncq_prio_supported);
}

DEVICE_ATTR(ncq_prio_supported, S_IRUGO, ata_ncq_prio_supported_show, NULL);
EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_supported);

static ssize_t ata_ncq_prio_enable_show(struct device *device,
					struct device_attribute *attr,
					char *buf)
{
	struct scsi_device *sdev = to_scsi_device(device);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *dev;
	bool ncq_prio_enable;
	int rc = 0;

	spin_lock_irq(ap->lock);
	dev = ata_scsi_find_dev(ap, sdev);
	if (!dev)
		rc = -ENODEV;
	else
		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE;
	spin_unlock_irq(ap->lock);

	return rc ? rc : snprintf(buf, 20, "%u\n", ncq_prio_enable);
}

static ssize_t ata_ncq_prio_enable_store(struct device *device,
					 struct device_attribute *attr,
					 const char *buf, size_t len)
{
	struct scsi_device *sdev = to_scsi_device(device);
	struct ata_port *ap;
	struct ata_device *dev;
	long int input;
	int rc = 0;

	rc = kstrtol(buf, 10, &input);
	if (rc)
		return rc;
	if ((input < 0) || (input > 1))
		return -EINVAL;

	ap = ata_shost_to_port(sdev->host);
	dev = ata_scsi_find_dev(ap, sdev);
	if (unlikely(!dev))
		return  -ENODEV;

	spin_lock_irq(ap->lock);

	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {
		rc = -EINVAL;
		goto unlock;
	}

	if (input)
		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLE;
	else
		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;

unlock:
	spin_unlock_irq(ap->lock);

	return rc ? rc : len;
}

DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
	    ata_ncq_prio_enable_show, ata_ncq_prio_enable_store);
EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_enable);

struct attribute *ata_ncq_sdev_attrs[] = {
	&dev_attr_unload_heads.attr,
	&dev_attr_ncq_prio_enable.attr,
	&dev_attr_ncq_prio_supported.attr,
	NULL
};

static const struct attribute_group ata_ncq_sdev_attr_group = {
	.attrs = ata_ncq_sdev_attrs
};

const struct attribute_group *ata_ncq_sdev_groups[] = {
	&ata_ncq_sdev_attr_group,
	NULL
};
EXPORT_SYMBOL_GPL(ata_ncq_sdev_groups);

static ssize_t
ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);
	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
		return ap->ops->em_store(ap, buf, count);
	return -EINVAL;
}

static ssize_t
ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
		return ap->ops->em_show(ap, buf);
	return -EINVAL;
}
DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,
		ata_scsi_em_message_show, ata_scsi_em_message_store);
EXPORT_SYMBOL_GPL(dev_attr_em_message);

static ssize_t
ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	return snprintf(buf, 23, "%d\n", ap->em_message_type);
}
DEVICE_ATTR(em_message_type, S_IRUGO,
		  ata_scsi_em_message_type_show, NULL);
EXPORT_SYMBOL_GPL(dev_attr_em_message_type);

static ssize_t
ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);

	if (atadev && ap->ops->sw_activity_show &&
	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
		return ap->ops->sw_activity_show(atadev, buf);
	return -EINVAL;
}

static ssize_t
ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
	const char *buf, size_t count)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
	enum sw_activity val;
	int rc;

	if (atadev && ap->ops->sw_activity_store &&
	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
		val = simple_strtoul(buf, NULL, 0);
		switch (val) {
		case OFF: case BLINK_ON: case BLINK_OFF:
			rc = ap->ops->sw_activity_store(atadev, val);
			if (!rc)
				return count;
			else
				return rc;
		}
	}
	return -EINVAL;
}
DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
			ata_scsi_activity_store);
EXPORT_SYMBOL_GPL(dev_attr_sw_activity);

/**
 *	__ata_change_queue_depth - helper for ata_scsi_change_queue_depth
 *	@ap: ATA port to which the device change the queue depth
 *	@sdev: SCSI device to configure queue depth for
 *	@queue_depth: new queue depth
 *
 *	libsas and libata have different approaches for associating a sdev to
 *	its ata_port.
 *
 */
int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
			     int queue_depth)
{
	struct ata_device *dev;
	unsigned long flags;

	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
		return sdev->queue_depth;

	dev = ata_scsi_find_dev(ap, sdev);
	if (!dev || !ata_dev_enabled(dev))
		return sdev->queue_depth;

	/* NCQ enabled? */
	spin_lock_irqsave(ap->lock, flags);
	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
		dev->flags |= ATA_DFLAG_NCQ_OFF;
		queue_depth = 1;
	}
	spin_unlock_irqrestore(ap->lock, flags);

	/* limit and apply queue depth */
	queue_depth = min(queue_depth, sdev->host->can_queue);
	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
	queue_depth = min(queue_depth, ATA_MAX_QUEUE);

	if (sdev->queue_depth == queue_depth)
		return -EINVAL;

	return scsi_change_queue_depth(sdev, queue_depth);
}
EXPORT_SYMBOL_GPL(__ata_change_queue_depth);

/**
 *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
 *	@sdev: SCSI device to configure queue depth for
 *	@queue_depth: new queue depth
 *
 *	This is libata standard hostt->change_queue_depth callback.
 *	SCSI will call into this callback when user tries to set queue
 *	depth via sysfs.
 *
 *	LOCKING:
 *	SCSI layer (we don't care)
 *
 *	RETURNS:
 *	Newly configured queue depth.
 */
int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
{
	struct ata_port *ap = ata_shost_to_port(sdev->host);

	return __ata_change_queue_depth(ap, sdev, queue_depth);
}
EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);

/**
 *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
 *	@host: ATA host container for all SAS ports
 *	@port_info: Information from low-level host driver
 *	@shost: SCSI host that the scsi device is attached to
 *
 *	LOCKING:
 *	PCI/etc. bus probe sem.
 *
 *	RETURNS:
 *	ata_port pointer on success / NULL on failure.
 */

struct ata_port *ata_sas_port_alloc(struct ata_host *host,
				    struct ata_port_info *port_info,
				    struct Scsi_Host *shost)
{
	struct ata_port *ap;

	ap = ata_port_alloc(host);
	if (!ap)
		return NULL;

	ap->port_no = 0;
	ap->lock = &host->lock;
	ap->pio_mask = port_info->pio_mask;
	ap->mwdma_mask = port_info->mwdma_mask;
	ap->udma_mask = port_info->udma_mask;
	ap->flags |= port_info->flags;
	ap->ops = port_info->port_ops;
	ap->cbl = ATA_CBL_SATA;

	return ap;
}
EXPORT_SYMBOL_GPL(ata_sas_port_alloc);

/**
 *	ata_sas_port_start - Set port up for dma.
 *	@ap: Port to initialize
 *
 *	Called just after data structures for each port are
 *	initialized.
 *
 *	May be used as the port_start() entry in ata_port_operations.
 *
 *	LOCKING:
 *	Inherited from caller.
 */
int ata_sas_port_start(struct ata_port *ap)
{
	/*
	 * the port is marked as frozen at allocation time, but if we don't
	 * have new eh, we won't thaw it
	 */
	if (!ap->ops->error_handler)
		ap->pflags &= ~ATA_PFLAG_FROZEN;
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_port_start);

/**
 *	ata_sas_port_stop - Undo ata_sas_port_start()
 *	@ap: Port to shut down
 *
 *	May be used as the port_stop() entry in ata_port_operations.
 *
 *	LOCKING:
 *	Inherited from caller.
 */

void ata_sas_port_stop(struct ata_port *ap)
{
}
EXPORT_SYMBOL_GPL(ata_sas_port_stop);

/**
 * ata_sas_async_probe - simply schedule probing and return
 * @ap: Port to probe
 *
 * For batch scheduling of probe for sas attached ata devices, assumes
 * the port has already been through ata_sas_port_init()
 */
void ata_sas_async_probe(struct ata_port *ap)
{
	__ata_port_probe(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_async_probe);

int ata_sas_sync_probe(struct ata_port *ap)
{
	return ata_port_probe(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_sync_probe);


/**
 *	ata_sas_port_init - Initialize a SATA device
 *	@ap: SATA port to initialize
 *
 *	LOCKING:
 *	PCI/etc. bus probe sem.
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */

int ata_sas_port_init(struct ata_port *ap)
{
	int rc = ap->ops->port_start(ap);

	if (rc)
		return rc;
	ap->print_id = atomic_inc_return(&ata_print_id);
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_port_init);

int ata_sas_tport_add(struct device *parent, struct ata_port *ap)
{
	return ata_tport_add(parent, ap);
}
EXPORT_SYMBOL_GPL(ata_sas_tport_add);

void ata_sas_tport_delete(struct ata_port *ap)
{
	ata_tport_delete(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_tport_delete);

/**
 *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
 *	@ap: SATA port to destroy
 *
 */

void ata_sas_port_destroy(struct ata_port *ap)
{
	if (ap->ops->port_stop)
		ap->ops->port_stop(ap);
	kfree(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_port_destroy);

/**
 *	ata_sas_slave_configure - Default slave_config routine for libata devices
 *	@sdev: SCSI device to configure
 *	@ap: ATA port to which SCSI device is attached
 *
 *	RETURNS:
 *	Zero.
 */

int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
{
	ata_scsi_sdev_config(sdev);
	ata_scsi_dev_config(sdev, ap->link.device);
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_slave_configure);

/**
 *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
 *	@cmd: SCSI command to be sent
 *	@ap:	ATA port to which the command is being sent
 *
 *	RETURNS:
 *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
 *	0 otherwise.
 */

int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
{
	int rc = 0;

	ata_scsi_dump_cdb(ap, cmd);

	if (likely(ata_dev_enabled(ap->link.device)))
		rc = __ata_scsi_queuecmd(cmd, ap->link.device);
	else {
		cmd->result = (DID_BAD_TARGET << 16);
		scsi_done(cmd);
	}
	return rc;
}
EXPORT_SYMBOL_GPL(ata_sas_queuecmd);

int ata_sas_allocate_tag(struct ata_port *ap)
{
	unsigned int max_queue = ap->host->n_tags;
	unsigned int i, tag;

	for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
		tag = tag < max_queue ? tag : 0;

		/* the last tag is reserved for internal command. */
		if (ata_tag_internal(tag))
			continue;

		if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
			ap->sas_last_tag = tag;
			return tag;
		}
	}
	return -1;
}

void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
{
	clear_bit(tag, &ap->sas_tag_allocated);
}

/**
 *	sata_async_notification - SATA async notification handler
 *	@ap: ATA port where async notification is received
 *
 *	Handler to be called when async notification via SDB FIS is
 *	received.  This function schedules EH if necessary.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	1 if EH is scheduled, 0 otherwise.
 */
int sata_async_notification(struct ata_port *ap)
{
	u32 sntf;
	int rc;

	if (!(ap->flags & ATA_FLAG_AN))
		return 0;

	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
	if (rc == 0)
		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);

	if (!sata_pmp_attached(ap) || rc) {
		/* PMP is not attached or SNTF is not available */
		if (!sata_pmp_attached(ap)) {
			/* PMP is not attached.  Check whether ATAPI
			 * AN is configured.  If so, notify media
			 * change.
			 */
			struct ata_device *dev = ap->link.device;

			if ((dev->class == ATA_DEV_ATAPI) &&
			    (dev->flags & ATA_DFLAG_AN))
				ata_scsi_media_change_notify(dev);
			return 0;
		} else {
			/* PMP is attached but SNTF is not available.
			 * ATAPI async media change notification is
			 * not used.  The PMP must be reporting PHY
			 * status change, schedule EH.
			 */
			ata_port_schedule_eh(ap);
			return 1;
		}
	} else {
		/* PMP is attached and SNTF is available */
		struct ata_link *link;

		/* check and notify ATAPI AN */
		ata_for_each_link(link, ap, EDGE) {
			if (!(sntf & (1 << link->pmp)))
				continue;

			if ((link->device->class == ATA_DEV_ATAPI) &&
			    (link->device->flags & ATA_DFLAG_AN))
				ata_scsi_media_change_notify(link->device);
		}

		/* If PMP is reporting that PHY status of some
		 * downstream ports has changed, schedule EH.
		 */
		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
			ata_port_schedule_eh(ap);
			return 1;
		}

		return 0;
	}
}
EXPORT_SYMBOL_GPL(sata_async_notification);

/**
 *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
 *	@dev: Device to read log page 10h from
 *	@tag: Resulting tag of the failed command
 *	@tf: Resulting taskfile registers of the failed command
 *
 *	Read log page 10h to obtain NCQ error details and clear error
 *	condition.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
static int ata_eh_read_log_10h(struct ata_device *dev,
			       int *tag, struct ata_taskfile *tf)
{
	u8 *buf = dev->link->ap->sector_buf;
	unsigned int err_mask;
	u8 csum;
	int i;

	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, 0, buf, 1);
	if (err_mask)
		return -EIO;

	csum = 0;
	for (i = 0; i < ATA_SECT_SIZE; i++)
		csum += buf[i];
	if (csum)
		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
			     csum);

	if (buf[0] & 0x80)
		return -ENOENT;

	*tag = buf[0] & 0x1f;

	tf->command = buf[2];
	tf->feature = buf[3];
	tf->lbal = buf[4];
	tf->lbam = buf[5];
	tf->lbah = buf[6];
	tf->device = buf[7];
	tf->hob_lbal = buf[8];
	tf->hob_lbam = buf[9];
	tf->hob_lbah = buf[10];
	tf->nsect = buf[12];
	tf->hob_nsect = buf[13];
	if (dev->class == ATA_DEV_ZAC && ata_id_has_ncq_autosense(dev->id))
		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];

	return 0;
}

/**
 *	ata_eh_analyze_ncq_error - analyze NCQ error
 *	@link: ATA link to analyze NCQ error for
 *
 *	Read log page 10h, determine the offending qc and acquire
 *	error status TF.  For NCQ device errors, all LLDDs have to do
 *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
 *	care of the rest.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_eh_analyze_ncq_error(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev = link->device;
	struct ata_queued_cmd *qc;
	struct ata_taskfile tf;
	int tag, rc;

	/* if frozen, we can't do much */
	if (ap->pflags & ATA_PFLAG_FROZEN)
		return;

	/* is it NCQ device error? */
	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
		return;

	/* has LLDD analyzed already? */
	ata_qc_for_each_raw(ap, qc, tag) {
		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		if (qc->err_mask)
			return;
	}

	/* okay, this error is ours */
	memset(&tf, 0, sizeof(tf));
	rc = ata_eh_read_log_10h(dev, &tag, &tf);
	if (rc) {
		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
			     rc);
		return;
	}

	if (!(link->sactive & (1 << tag))) {
		ata_link_err(link, "log page 10h reported inactive tag %d\n",
			     tag);
		return;
	}

	/* we've got the perpetrator, condemn it */
	qc = __ata_qc_from_tag(ap, tag);
	memcpy(&qc->result_tf, &tf, sizeof(tf));
	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
	if (dev->class == ATA_DEV_ZAC &&
	    ((qc->result_tf.command & ATA_SENSE) || qc->result_tf.auxiliary)) {
		char sense_key, asc, ascq;

		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
		asc = (qc->result_tf.auxiliary >> 8) & 0xff;
		ascq = qc->result_tf.auxiliary & 0xff;
		ata_scsi_set_sense(dev, qc->scsicmd, sense_key, asc, ascq);
		ata_scsi_set_sense_information(dev, qc->scsicmd,
					       &qc->result_tf);
		qc->flags |= ATA_QCFLAG_SENSE_VALID;
	}

	ehc->i.err_mask &= ~AC_ERR_DEV;
}
EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);