aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ide/ide-probe.c
blob: e0316869eb6fc2a6996b915f38dba30fb2d6795b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
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
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
/*
 *  Copyright (C) 1994-1998   Linus Torvalds & authors (see below)
 *  Copyright (C) 2005, 2007  Bartlomiej Zolnierkiewicz
 */

/*
 *  Mostly written by Mark Lord <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 *  See linux/MAINTAINERS for address of current maintainer.
 *
 * This is the IDE probe module, as evolved from hd.c and ide.c.
 *
 * -- increase WAIT_PIDENTIFY to avoid CD-ROM locking at boot
 *	 by Andrea Arcangeli
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/spinlock.h>
#include <linux/kmod.h>
#include <linux/pci.h>
#include <linux/scatterlist.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/**
 *	generic_id		-	add a generic drive id
 *	@drive:	drive to make an ID block for
 *	
 *	Add a fake id field to the drive we are passed. This allows
 *	use to skip a ton of NULL checks (which people always miss) 
 *	and make drive properties unconditional outside of this file
 */
 
static void generic_id(ide_drive_t *drive)
{
	drive->id->cyls = drive->cyl;
	drive->id->heads = drive->head;
	drive->id->sectors = drive->sect;
	drive->id->cur_cyls = drive->cyl;
	drive->id->cur_heads = drive->head;
	drive->id->cur_sectors = drive->sect;
}

static void ide_disk_init_chs(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;

	/* Extract geometry if we did not already have one for the drive */
	if (!drive->cyl || !drive->head || !drive->sect) {
		drive->cyl  = drive->bios_cyl  = id->cyls;
		drive->head = drive->bios_head = id->heads;
		drive->sect = drive->bios_sect = id->sectors;
	}

	/* Handle logical geometry translation by the drive */
	if ((id->field_valid & 1) && id->cur_cyls &&
	    id->cur_heads && (id->cur_heads <= 16) && id->cur_sectors) {
		drive->cyl  = id->cur_cyls;
		drive->head = id->cur_heads;
		drive->sect = id->cur_sectors;
	}

	/* Use physical geometry if what we have still makes no sense */
	if (drive->head > 16 && id->heads && id->heads <= 16) {
		drive->cyl  = id->cyls;
		drive->head = id->heads;
		drive->sect = id->sectors;
	}
}

static void ide_disk_init_mult_count(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;

	drive->mult_count = 0;
	if (id->max_multsect) {
#ifdef CONFIG_IDEDISK_MULTI_MODE
		id->multsect = ((id->max_multsect/2) > 1) ? id->max_multsect : 0;
		id->multsect_valid = id->multsect ? 1 : 0;
		drive->mult_req = id->multsect_valid ? id->max_multsect : 0;
		drive->special.b.set_multmode = drive->mult_req ? 1 : 0;
#else	/* original, pre IDE-NFG, per request of AC */
		drive->mult_req = 0;
		if (drive->mult_req > id->max_multsect)
			drive->mult_req = id->max_multsect;
		if (drive->mult_req || ((id->multsect_valid & 1) && id->multsect))
			drive->special.b.set_multmode = 1;
#endif
	}
}

/**
 *	do_identify	-	identify a drive
 *	@drive: drive to identify 
 *	@cmd: command used
 *
 *	Called when we have issued a drive identify command to
 *	read and parse the results. This function is run with
 *	interrupts disabled. 
 */
 
static inline void do_identify (ide_drive_t *drive, u8 cmd)
{
	ide_hwif_t *hwif = HWIF(drive);
	int bswap = 1;
	struct hd_driveid *id;

	id = drive->id;
	/* read 512 bytes of id info */
	hwif->ata_input_data(drive, id, SECTOR_WORDS);

	drive->id_read = 1;
	local_irq_enable();
#ifdef DEBUG
	printk(KERN_INFO "%s: dumping identify data\n", drive->name);
	ide_dump_identify((u8 *)id);
#endif
	ide_fix_driveid(id);

#if defined (CONFIG_SCSI_EATA_PIO) || defined (CONFIG_SCSI_EATA)
	/*
	 * EATA SCSI controllers do a hardware ATA emulation:
	 * Ignore them if there is a driver for them available.
	 */
	if ((id->model[0] == 'P' && id->model[1] == 'M') ||
	    (id->model[0] == 'S' && id->model[1] == 'K')) {
		printk("%s: EATA SCSI HBA %.10s\n", drive->name, id->model);
		goto err_misc;
	}
#endif /* CONFIG_SCSI_EATA || CONFIG_SCSI_EATA_PIO */

	/*
	 *  WIN_IDENTIFY returns little-endian info,
	 *  WIN_PIDENTIFY *usually* returns little-endian info.
	 */
	if (cmd == WIN_PIDENTIFY) {
		if ((id->model[0] == 'N' && id->model[1] == 'E') /* NEC */
		 || (id->model[0] == 'F' && id->model[1] == 'X') /* Mitsumi */
		 || (id->model[0] == 'P' && id->model[1] == 'i'))/* Pioneer */
			/* Vertos drives may still be weird */
			bswap ^= 1;	
	}
	ide_fixstring(id->model,     sizeof(id->model),     bswap);
	ide_fixstring(id->fw_rev,    sizeof(id->fw_rev),    bswap);
	ide_fixstring(id->serial_no, sizeof(id->serial_no), bswap);

	/* we depend on this a lot! */
	id->model[sizeof(id->model)-1] = '\0';

	if (strstr(id->model, "E X A B Y T E N E S T"))
		goto err_misc;

	printk("%s: %s, ", drive->name, id->model);
	drive->present = 1;
	drive->dead = 0;

	/*
	 * Check for an ATAPI device
	 */
	if (cmd == WIN_PIDENTIFY) {
		u8 type = (id->config >> 8) & 0x1f;
		printk("ATAPI ");
		switch (type) {
			case ide_floppy:
				if (!strstr(id->model, "CD-ROM")) {
					if (!strstr(id->model, "oppy") &&
					    !strstr(id->model, "poyp") &&
					    !strstr(id->model, "ZIP"))
						printk("cdrom or floppy?, assuming ");
					if (drive->media != ide_cdrom) {
						printk ("FLOPPY");
						drive->removable = 1;
						break;
					}
				}
				/* Early cdrom models used zero */
				type = ide_cdrom;
			case ide_cdrom:
				drive->removable = 1;
#ifdef CONFIG_PPC
				/* kludge for Apple PowerBook internal zip */
				if (!strstr(id->model, "CD-ROM") &&
				    strstr(id->model, "ZIP")) {
					printk ("FLOPPY");
					type = ide_floppy;
					break;
				}
#endif
				printk ("CD/DVD-ROM");
				break;
			case ide_tape:
				printk ("TAPE");
				break;
			case ide_optical:
				printk ("OPTICAL");
				drive->removable = 1;
				break;
			default:
				printk("UNKNOWN (type %d)", type);
				break;
		}
		printk (" drive\n");
		drive->media = type;
		/* an ATAPI device ignores DRDY */
		drive->ready_stat = 0;
		return;
	}

	/*
	 * Not an ATAPI device: looks like a "regular" hard disk
	 */

	/*
	 * 0x848a = CompactFlash device
	 * These are *not* removable in Linux definition of the term
	 */

	if ((id->config != 0x848a) && (id->config & (1<<7)))
		drive->removable = 1;

	drive->media = ide_disk;
	printk("%s DISK drive\n", (id->config == 0x848a) ? "CFA" : "ATA" );

	return;

err_misc:
	kfree(id);
	drive->present = 0;
	return;
}

/**
 *	actual_try_to_identify	-	send ata/atapi identify
 *	@drive: drive to identify
 *	@cmd: command to use
 *
 *	try_to_identify() sends an ATA(PI) IDENTIFY request to a drive
 *	and waits for a response.  It also monitors irqs while this is
 *	happening, in hope of automatically determining which one is
 *	being used by the interface.
 *
 *	Returns:	0  device was identified
 *			1  device timed-out (no response to identify request)
 *			2  device aborted the command (refused to identify itself)
 */

static int actual_try_to_identify (ide_drive_t *drive, u8 cmd)
{
	ide_hwif_t *hwif = HWIF(drive);
	int use_altstatus = 0, rc;
	unsigned long timeout;
	u8 s = 0, a = 0;

	/* take a deep breath */
	msleep(50);

	if (hwif->io_ports[IDE_CONTROL_OFFSET]) {
		a = ide_read_altstatus(drive);
		s = ide_read_status(drive);
		if ((a ^ s) & ~INDEX_STAT)
			/* ancient Seagate drives, broken interfaces */
			printk(KERN_INFO "%s: probing with STATUS(0x%02x) "
					 "instead of ALTSTATUS(0x%02x)\n",
					 drive->name, s, a);
		else
			/* use non-intrusive polling */
			use_altstatus = 1;
	}

	/* set features register for atapi
	 * identify command to be sure of reply
	 */
	if ((cmd == WIN_PIDENTIFY))
		/* disable dma & overlap */
		hwif->OUTB(0, hwif->io_ports[IDE_FEATURE_OFFSET]);

	/* ask drive for ID */
	hwif->OUTB(cmd, hwif->io_ports[IDE_COMMAND_OFFSET]);

	timeout = ((cmd == WIN_IDENTIFY) ? WAIT_WORSTCASE : WAIT_PIDENTIFY) / 2;
	timeout += jiffies;
	do {
		if (time_after(jiffies, timeout)) {
			/* drive timed-out */
			return 1;
		}
		/* give drive a breather */
		msleep(50);
		s = use_altstatus ? ide_read_altstatus(drive)
				  : ide_read_status(drive);
	} while (s & BUSY_STAT);

	/* wait for IRQ and DRQ_STAT */
	msleep(50);
	s = ide_read_status(drive);

	if (OK_STAT(s, DRQ_STAT, BAD_R_STAT)) {
		unsigned long flags;

		/* local CPU only; some systems need this */
		local_irq_save(flags);
		/* drive returned ID */
		do_identify(drive, cmd);
		/* drive responded with ID */
		rc = 0;
		/* clear drive IRQ */
		(void)ide_read_status(drive);
		local_irq_restore(flags);
	} else {
		/* drive refused ID */
		rc = 2;
	}
	return rc;
}

/**
 *	try_to_identify	-	try to identify a drive
 *	@drive: drive to probe
 *	@cmd: command to use
 *
 *	Issue the identify command and then do IRQ probing to
 *	complete the identification when needed by finding the
 *	IRQ the drive is attached to
 */
 
static int try_to_identify (ide_drive_t *drive, u8 cmd)
{
	ide_hwif_t *hwif = HWIF(drive);
	int retval;
	int autoprobe = 0;
	unsigned long cookie = 0;

	/*
	 * Disable device irq unless we need to
	 * probe for it. Otherwise we'll get spurious
	 * interrupts during the identify-phase that
	 * the irq handler isn't expecting.
	 */
	if (hwif->io_ports[IDE_CONTROL_OFFSET]) {
		if (!hwif->irq) {
			autoprobe = 1;
			cookie = probe_irq_on();
		}
		ide_set_irq(drive, autoprobe);
	}

	retval = actual_try_to_identify(drive, cmd);

	if (autoprobe) {
		int irq;

		ide_set_irq(drive, 0);
		/* clear drive IRQ */
		(void)ide_read_status(drive);
		udelay(5);
		irq = probe_irq_off(cookie);
		if (!hwif->irq) {
			if (irq > 0) {
				hwif->irq = irq;
			} else {
				/* Mmmm.. multiple IRQs..
				 * don't know which was ours
				 */
				printk("%s: IRQ probe failed (0x%lx)\n",
					drive->name, cookie);
			}
		}
	}
	return retval;
}

static int ide_busy_sleep(ide_hwif_t *hwif)
{
	unsigned long timeout = jiffies + WAIT_WORSTCASE;
	u8 stat;

	do {
		msleep(50);
		stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
		if ((stat & BUSY_STAT) == 0)
			return 0;
	} while (time_before(jiffies, timeout));

	return 1;
}

/**
 *	do_probe		-	probe an IDE device
 *	@drive: drive to probe
 *	@cmd: command to use
 *
 *	do_probe() has the difficult job of finding a drive if it exists,
 *	without getting hung up if it doesn't exist, without trampling on
 *	ethernet cards, and without leaving any IRQs dangling to haunt us later.
 *
 *	If a drive is "known" to exist (from CMOS or kernel parameters),
 *	but does not respond right away, the probe will "hang in there"
 *	for the maximum wait time (about 30 seconds), otherwise it will
 *	exit much more quickly.
 *
 * Returns:	0  device was identified
 *		1  device timed-out (no response to identify request)
 *		2  device aborted the command (refused to identify itself)
 *		3  bad status from device (possible for ATAPI drives)
 *		4  probe was not attempted because failure was obvious
 */

static int do_probe (ide_drive_t *drive, u8 cmd)
{
	ide_hwif_t *hwif = HWIF(drive);
	int rc;
	u8 stat;

	if (drive->present) {
		/* avoid waiting for inappropriate probes */
		if ((drive->media != ide_disk) && (cmd == WIN_IDENTIFY))
			return 4;
	}
#ifdef DEBUG
	printk("probing for %s: present=%d, media=%d, probetype=%s\n",
		drive->name, drive->present, drive->media,
		(cmd == WIN_IDENTIFY) ? "ATA" : "ATAPI");
#endif

	/* needed for some systems
	 * (e.g. crw9624 as drive0 with disk as slave)
	 */
	msleep(50);
	SELECT_DRIVE(drive);
	msleep(50);
	if (hwif->INB(hwif->io_ports[IDE_SELECT_OFFSET]) != drive->select.all &&
	    !drive->present) {
		if (drive->select.b.unit != 0) {
			/* exit with drive0 selected */
			SELECT_DRIVE(&hwif->drives[0]);
			/* allow BUSY_STAT to assert & clear */
			msleep(50);
		}
		/* no i/f present: mmm.. this should be a 4 -ml */
		return 3;
	}

	stat = ide_read_status(drive);

	if (OK_STAT(stat, READY_STAT, BUSY_STAT) ||
	    drive->present || cmd == WIN_PIDENTIFY) {
		/* send cmd and wait */
		if ((rc = try_to_identify(drive, cmd))) {
			/* failed: try again */
			rc = try_to_identify(drive,cmd);
		}

		stat = ide_read_status(drive);

		if (stat == (BUSY_STAT | READY_STAT))
			return 4;

		if ((rc == 1 && cmd == WIN_PIDENTIFY) &&
			((drive->autotune == IDE_TUNE_DEFAULT) ||
			(drive->autotune == IDE_TUNE_AUTO))) {
			printk(KERN_ERR "%s: no response (status = 0x%02x), "
					"resetting drive\n", drive->name, stat);
			msleep(50);
			hwif->OUTB(drive->select.all,
				   hwif->io_ports[IDE_SELECT_OFFSET]);
			msleep(50);
			hwif->OUTB(WIN_SRST,
				   hwif->io_ports[IDE_COMMAND_OFFSET]);
			(void)ide_busy_sleep(hwif);
			rc = try_to_identify(drive, cmd);
		}

		/* ensure drive IRQ is clear */
		stat = ide_read_status(drive);

		if (rc == 1)
			printk(KERN_ERR "%s: no response (status = 0x%02x)\n",
					drive->name, stat);
	} else {
		/* not present or maybe ATAPI */
		rc = 3;
	}
	if (drive->select.b.unit != 0) {
		/* exit with drive0 selected */
		SELECT_DRIVE(&hwif->drives[0]);
		msleep(50);
		/* ensure drive irq is clear */
		(void)ide_read_status(drive);
	}
	return rc;
}

/*
 *
 */
static void enable_nest (ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	u8 stat;

	printk("%s: enabling %s -- ", hwif->name, drive->id->model);
	SELECT_DRIVE(drive);
	msleep(50);
	hwif->OUTB(EXABYTE_ENABLE_NEST, hwif->io_ports[IDE_COMMAND_OFFSET]);

	if (ide_busy_sleep(hwif)) {
		printk(KERN_CONT "failed (timeout)\n");
		return;
	}

	msleep(50);

	stat = ide_read_status(drive);

	if (!OK_STAT(stat, 0, BAD_STAT))
		printk(KERN_CONT "failed (status = 0x%02x)\n", stat);
	else
		printk(KERN_CONT "success\n");

	/* if !(success||timed-out) */
	if (do_probe(drive, WIN_IDENTIFY) >= 2) {
		/* look for ATAPI device */
		(void) do_probe(drive, WIN_PIDENTIFY);
	}
}

/**
 *	probe_for_drives	-	upper level drive probe
 *	@drive: drive to probe for
 *
 *	probe_for_drive() tests for existence of a given drive using do_probe()
 *	and presents things to the user as needed.
 *
 *	Returns:	0  no device was found
 *			1  device was found (note: drive->present might
 *			   still be 0)
 */
 
static inline u8 probe_for_drive (ide_drive_t *drive)
{
	/*
	 *	In order to keep things simple we have an id
	 *	block for all drives at all times. If the device
	 *	is pre ATA or refuses ATA/ATAPI identify we
	 *	will add faked data to this.
	 *
	 *	Also note that 0 everywhere means "can't do X"
	 */
 
	drive->id = kzalloc(SECTOR_WORDS *4, GFP_KERNEL);
	drive->id_read = 0;
	if(drive->id == NULL)
	{
		printk(KERN_ERR "ide: out of memory for id data.\n");
		return 0;
	}
	strcpy(drive->id->model, "UNKNOWN");
	
	/* skip probing? */
	if (!drive->noprobe)
	{
		/* if !(success||timed-out) */
		if (do_probe(drive, WIN_IDENTIFY) >= 2) {
			/* look for ATAPI device */
			(void) do_probe(drive, WIN_PIDENTIFY);
		}
		if (!drive->present)
			/* drive not found */
			return 0;
		if (strstr(drive->id->model, "E X A B Y T E N E S T"))
			enable_nest(drive);
	
		/* identification failed? */
		if (!drive->id_read) {
			if (drive->media == ide_disk) {
				printk(KERN_INFO "%s: non-IDE drive, CHS=%d/%d/%d\n",
					drive->name, drive->cyl,
					drive->head, drive->sect);
			} else if (drive->media == ide_cdrom) {
				printk(KERN_INFO "%s: ATAPI cdrom (?)\n", drive->name);
			} else {
				/* nuke it */
				printk(KERN_WARNING "%s: Unknown device on bus refused identification. Ignoring.\n", drive->name);
				drive->present = 0;
			}
		}
		/* drive was found */
	}
	if(!drive->present)
		return 0;
	/* The drive wasn't being helpful. Add generic info only */
	if (drive->id_read == 0) {
		generic_id(drive);
		return 1;
	}

	if (drive->media == ide_disk) {
		ide_disk_init_chs(drive);
		ide_disk_init_mult_count(drive);
	}

	return drive->present;
}

static void hwif_release_dev (struct device *dev)
{
	ide_hwif_t *hwif = container_of(dev, ide_hwif_t, gendev);

	complete(&hwif->gendev_rel_comp);
}

static int ide_register_port(ide_hwif_t *hwif)
{
	int ret;

	/* register with global device tree */
	strlcpy(hwif->gendev.bus_id,hwif->name,BUS_ID_SIZE);
	hwif->gendev.driver_data = hwif;
	if (hwif->gendev.parent == NULL) {
		if (hwif->dev)
			hwif->gendev.parent = hwif->dev;
		else
			/* Would like to do = &device_legacy */
			hwif->gendev.parent = NULL;
	}
	hwif->gendev.release = hwif_release_dev;
	ret = device_register(&hwif->gendev);
	if (ret < 0) {
		printk(KERN_WARNING "IDE: %s: device_register error: %d\n",
			__func__, ret);
		goto out;
	}

	get_device(&hwif->gendev);

	hwif->portdev = device_create(ide_port_class, &hwif->gendev,
				      MKDEV(0, 0), hwif->name);
	if (IS_ERR(hwif->portdev)) {
		ret = PTR_ERR(hwif->portdev);
		device_unregister(&hwif->gendev);
	}
	dev_set_drvdata(hwif->portdev, hwif);
out:
	return ret;
}

/**
 *	ide_port_wait_ready	-	wait for port to become ready
 *	@hwif: IDE port
 *
 *	This is needed on some PPCs and a bunch of BIOS-less embedded
 *	platforms.  Typical cases are:
 *
 *	- The firmware hard reset the disk before booting the kernel,
 *	  the drive is still doing it's poweron-reset sequence, that
 *	  can take up to 30 seconds.
 *
 *	- The firmware does nothing (or no firmware), the device is
 *	  still in POST state (same as above actually).
 *
 *	- Some CD/DVD/Writer combo drives tend to drive the bus during
 *	  their reset sequence even when they are non-selected slave
 *	  devices, thus preventing discovery of the main HD.
 *
 *	Doing this wait-for-non-busy should not harm any existing
 *	configuration and fix some issues like the above.
 *
 *	BenH.
 *
 *	Returns 0 on success, error code (< 0) otherwise.
 */

static int ide_port_wait_ready(ide_hwif_t *hwif)
{
	int unit, rc;

	printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name);

	/* Let HW settle down a bit from whatever init state we
	 * come from */
	mdelay(2);

	/* Wait for BSY bit to go away, spec timeout is 30 seconds,
	 * I know of at least one disk who takes 31 seconds, I use 35
	 * here to be safe
	 */
	rc = ide_wait_not_busy(hwif, 35000);
	if (rc)
		return rc;

	/* Now make sure both master & slave are ready */
	for (unit = 0; unit < MAX_DRIVES; unit++) {
		ide_drive_t *drive = &hwif->drives[unit];

		/* Ignore disks that we will not probe for later. */
		if (!drive->noprobe || drive->present) {
			SELECT_DRIVE(drive);
			ide_set_irq(drive, 1);
			mdelay(2);
			rc = ide_wait_not_busy(hwif, 35000);
			if (rc)
				goto out;
		} else
			printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n",
					  drive->name);
	}
out:
	/* Exit function with master reselected (let's be sane) */
	if (unit)
		SELECT_DRIVE(&hwif->drives[0]);

	return rc;
}

/**
 *	ide_undecoded_slave	-	look for bad CF adapters
 *	@drive1: drive
 *
 *	Analyse the drives on the interface and attempt to decide if we
 *	have the same drive viewed twice. This occurs with crap CF adapters
 *	and PCMCIA sometimes.
 */

void ide_undecoded_slave(ide_drive_t *drive1)
{
	ide_drive_t *drive0 = &drive1->hwif->drives[0];

	if ((drive1->dn & 1) == 0 || drive0->present == 0)
		return;

	/* If the models don't match they are not the same product */
	if (strcmp(drive0->id->model, drive1->id->model))
		return;

	/* Serial numbers do not match */
	if (strncmp(drive0->id->serial_no, drive1->id->serial_no, 20))
		return;

	/* No serial number, thankfully very rare for CF */
	if (drive0->id->serial_no[0] == 0)
		return;

	/* Appears to be an IDE flash adapter with decode bugs */
	printk(KERN_WARNING "ide-probe: ignoring undecoded slave\n");

	drive1->present = 0;
}

EXPORT_SYMBOL_GPL(ide_undecoded_slave);

static int ide_probe_port(ide_hwif_t *hwif)
{
	unsigned long flags;
	unsigned int irqd;
	int unit, rc = -ENODEV;

	BUG_ON(hwif->present);

	if (hwif->drives[0].noprobe && hwif->drives[1].noprobe)
		return -EACCES;

	/*
	 * We must always disable IRQ, as probe_for_drive will assert IRQ, but
	 * we'll install our IRQ driver much later...
	 */
	irqd = hwif->irq;
	if (irqd)
		disable_irq(hwif->irq);

	local_irq_set(flags);

	if (ide_port_wait_ready(hwif) == -EBUSY)
		printk(KERN_DEBUG "%s: Wait for ready failed before probe !\n", hwif->name);

	/*
	 * Second drive should only exist if first drive was found,
	 * but a lot of cdrom drives are configured as single slaves.
	 */
	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];
		drive->dn = (hwif->channel ? 2 : 0) + unit;
		(void) probe_for_drive(drive);
		if (drive->present)
			rc = 0;
	}
	if (hwif->io_ports[IDE_CONTROL_OFFSET] && hwif->reset) {
		printk(KERN_WARNING "%s: reset\n", hwif->name);
		hwif->OUTB(12, hwif->io_ports[IDE_CONTROL_OFFSET]);
		udelay(10);
		hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
		(void)ide_busy_sleep(hwif);
	}
	local_irq_restore(flags);
	/*
	 * Use cached IRQ number. It might be (and is...) changed by probe
	 * code above
	 */
	if (irqd)
		enable_irq(irqd);

	return rc;
}

static void ide_port_tune_devices(ide_hwif_t *hwif)
{
	const struct ide_port_ops *port_ops = hwif->port_ops;
	int unit;

	for (unit = 0; unit < MAX_DRIVES; unit++) {
		ide_drive_t *drive = &hwif->drives[unit];

		if (drive->present && port_ops && port_ops->quirkproc)
			port_ops->quirkproc(drive);
	}

	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];

		if (drive->present) {
			if (drive->autotune == IDE_TUNE_AUTO)
				ide_set_max_pio(drive);

			if (drive->autotune != IDE_TUNE_DEFAULT &&
			    drive->autotune != IDE_TUNE_AUTO)
				continue;

			drive->nice1 = 1;

			if (hwif->dma_host_set)
				ide_set_dma(drive);
		}
	}

	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];

		if (hwif->host_flags & IDE_HFLAG_NO_IO_32BIT)
			drive->no_io_32bit = 1;
		else
			drive->no_io_32bit = drive->id->dword_io ? 1 : 0;
	}
}

#if MAX_HWIFS > 1
/*
 * save_match() is used to simplify logic in init_irq() below.
 *
 * A loophole here is that we may not know about a particular
 * hwif's irq until after that hwif is actually probed/initialized..
 * This could be a problem for the case where an hwif is on a
 * dual interface that requires serialization (eg. cmd640) and another
 * hwif using one of the same irqs is initialized beforehand.
 *
 * This routine detects and reports such situations, but does not fix them.
 */
static void save_match(ide_hwif_t *hwif, ide_hwif_t *new, ide_hwif_t **match)
{
	ide_hwif_t *m = *match;

	if (m && m->hwgroup && m->hwgroup != new->hwgroup) {
		if (!new->hwgroup)
			return;
		printk("%s: potential irq problem with %s and %s\n",
			hwif->name, new->name, m->name);
	}
	if (!m || m->irq != hwif->irq) /* don't undo a prior perfect match */
		*match = new;
}
#endif /* MAX_HWIFS > 1 */

/*
 * init request queue
 */
static int ide_init_queue(ide_drive_t *drive)
{
	struct request_queue *q;
	ide_hwif_t *hwif = HWIF(drive);
	int max_sectors = 256;
	int max_sg_entries = PRD_ENTRIES;

	/*
	 *	Our default set up assumes the normal IDE case,
	 *	that is 64K segmenting, standard PRD setup
	 *	and LBA28. Some drivers then impose their own
	 *	limits and LBA48 we could raise it but as yet
	 *	do not.
	 */

	q = blk_init_queue_node(do_ide_request, &ide_lock, hwif_to_node(hwif));
	if (!q)
		return 1;

	q->queuedata = drive;
	blk_queue_segment_boundary(q, 0xffff);

	if (hwif->rqsize < max_sectors)
		max_sectors = hwif->rqsize;
	blk_queue_max_sectors(q, max_sectors);

#ifdef CONFIG_PCI
	/* When we have an IOMMU, we may have a problem where pci_map_sg()
	 * creates segments that don't completely match our boundary
	 * requirements and thus need to be broken up again. Because it
	 * doesn't align properly either, we may actually have to break up
	 * to more segments than what was we got in the first place, a max
	 * worst case is twice as many.
	 * This will be fixed once we teach pci_map_sg() about our boundary
	 * requirements, hopefully soon. *FIXME*
	 */
	if (!PCI_DMA_BUS_IS_PHYS)
		max_sg_entries >>= 1;
#endif /* CONFIG_PCI */

	blk_queue_max_hw_segments(q, max_sg_entries);
	blk_queue_max_phys_segments(q, max_sg_entries);

	/* assign drive queue */
	drive->queue = q;

	/* needs drive->queue to be set */
	ide_toggle_bounce(drive, 1);

	return 0;
}

static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	spin_lock_irq(&ide_lock);
	if (!hwgroup->drive) {
		/* first drive for hwgroup. */
		drive->next = drive;
		hwgroup->drive = drive;
		hwgroup->hwif = HWIF(hwgroup->drive);
	} else {
		drive->next = hwgroup->drive->next;
		hwgroup->drive->next = drive;
	}
	spin_unlock_irq(&ide_lock);
}

/*
 * For any present drive:
 * - allocate the block device queue
 * - link drive into the hwgroup
 */
static void ide_port_setup_devices(ide_hwif_t *hwif)
{
	int i;

	mutex_lock(&ide_cfg_mtx);
	for (i = 0; i < MAX_DRIVES; i++) {
		ide_drive_t *drive = &hwif->drives[i];

		if (!drive->present)
			continue;

		if (ide_init_queue(drive)) {
			printk(KERN_ERR "ide: failed to init %s\n",
					drive->name);
			continue;
		}

		ide_add_drive_to_hwgroup(drive);
	}
	mutex_unlock(&ide_cfg_mtx);
}

/*
 * This routine sets up the irq for an ide interface, and creates a new
 * hwgroup for the irq/hwif if none was previously assigned.
 *
 * Much of the code is for correctly detecting/handling irq sharing
 * and irq serialization situations.  This is somewhat complex because
 * it handles static as well as dynamic (PCMCIA) IDE interfaces.
 */
static int init_irq (ide_hwif_t *hwif)
{
	unsigned int index;
	ide_hwgroup_t *hwgroup;
	ide_hwif_t *match = NULL;


	BUG_ON(in_interrupt());
	BUG_ON(irqs_disabled());	
	BUG_ON(hwif == NULL);

	mutex_lock(&ide_cfg_mtx);
	hwif->hwgroup = NULL;
#if MAX_HWIFS > 1
	/*
	 * Group up with any other hwifs that share our irq(s).
	 */
	for (index = 0; index < MAX_HWIFS; index++) {
		ide_hwif_t *h = &ide_hwifs[index];
		if (h->hwgroup) {  /* scan only initialized hwif's */
			if (hwif->irq == h->irq) {
				hwif->sharing_irq = h->sharing_irq = 1;
				if (hwif->chipset != ide_pci ||
				    h->chipset != ide_pci) {
					save_match(hwif, h, &match);
				}
			}
			if (hwif->serialized) {
				if (hwif->mate && hwif->mate->irq == h->irq)
					save_match(hwif, h, &match);
			}
			if (h->serialized) {
				if (h->mate && hwif->irq == h->mate->irq)
					save_match(hwif, h, &match);
			}
		}
	}
#endif /* MAX_HWIFS > 1 */
	/*
	 * If we are still without a hwgroup, then form a new one
	 */
	if (match) {
		hwgroup = match->hwgroup;
		hwif->hwgroup = hwgroup;
		/*
		 * Link us into the hwgroup.
		 * This must be done early, do ensure that unexpected_intr
		 * can find the hwif and prevent irq storms.
		 * No drives are attached to the new hwif, choose_drive
		 * can't do anything stupid (yet).
		 * Add ourself as the 2nd entry to the hwgroup->hwif
		 * linked list, the first entry is the hwif that owns
		 * hwgroup->handler - do not change that.
		 */
		spin_lock_irq(&ide_lock);
		hwif->next = hwgroup->hwif->next;
		hwgroup->hwif->next = hwif;
		BUG_ON(hwif->next == hwif);
		spin_unlock_irq(&ide_lock);
	} else {
		hwgroup = kmalloc_node(sizeof(*hwgroup), GFP_KERNEL|__GFP_ZERO,
				       hwif_to_node(hwif));
		if (hwgroup == NULL)
			goto out_up;

		hwif->hwgroup = hwgroup;
		hwgroup->hwif = hwif->next = hwif;

		init_timer(&hwgroup->timer);
		hwgroup->timer.function = &ide_timer_expiry;
		hwgroup->timer.data = (unsigned long) hwgroup;
	}

	/*
	 * Allocate the irq, if not already obtained for another hwif
	 */
	if (!match || match->irq != hwif->irq) {
		int sa = 0;
#if defined(__mc68000__)
		sa = IRQF_SHARED;
#endif /* __mc68000__ */

		if (IDE_CHIPSET_IS_PCI(hwif->chipset))
			sa = IRQF_SHARED;

		if (hwif->io_ports[IDE_CONTROL_OFFSET])
			/* clear nIEN */
			hwif->OUTB(0x08, hwif->io_ports[IDE_CONTROL_OFFSET]);

		if (request_irq(hwif->irq,&ide_intr,sa,hwif->name,hwgroup))
	       		goto out_unlink;
	}

	if (!hwif->rqsize) {
		if ((hwif->host_flags & IDE_HFLAG_NO_LBA48) ||
		    (hwif->host_flags & IDE_HFLAG_NO_LBA48_DMA))
			hwif->rqsize = 256;
		else
			hwif->rqsize = 65536;
	}

#if !defined(__mc68000__)
	printk("%s at 0x%03lx-0x%03lx,0x%03lx on irq %d", hwif->name,
		hwif->io_ports[IDE_DATA_OFFSET],
		hwif->io_ports[IDE_DATA_OFFSET]+7,
		hwif->io_ports[IDE_CONTROL_OFFSET], hwif->irq);
#else
	printk("%s at 0x%08lx on irq %d", hwif->name,
		hwif->io_ports[IDE_DATA_OFFSET], hwif->irq);
#endif /* __mc68000__ */
	if (match)
		printk(" (%sed with %s)",
			hwif->sharing_irq ? "shar" : "serializ", match->name);
	printk("\n");

	mutex_unlock(&ide_cfg_mtx);
	return 0;
out_unlink:
	ide_remove_port_from_hwgroup(hwif);
out_up:
	mutex_unlock(&ide_cfg_mtx);
	return 1;
}

static int ata_lock(dev_t dev, void *data)
{
	/* FIXME: we want to pin hwif down */
	return 0;
}

static struct kobject *ata_probe(dev_t dev, int *part, void *data)
{
	ide_hwif_t *hwif = data;
	int unit = *part >> PARTN_BITS;
	ide_drive_t *drive = &hwif->drives[unit];
	if (!drive->present)
		return NULL;

	if (drive->media == ide_disk)
		request_module("ide-disk");
	if (drive->scsi)
		request_module("ide-scsi");
	if (drive->media == ide_cdrom || drive->media == ide_optical)
		request_module("ide-cd");
	if (drive->media == ide_tape)
		request_module("ide-tape");
	if (drive->media == ide_floppy)
		request_module("ide-floppy");

	return NULL;
}

static struct kobject *exact_match(dev_t dev, int *part, void *data)
{
	struct gendisk *p = data;
	*part &= (1 << PARTN_BITS) - 1;
	return &p->dev.kobj;
}

static int exact_lock(dev_t dev, void *data)
{
	struct gendisk *p = data;

	if (!get_disk(p))
		return -1;
	return 0;
}

void ide_register_region(struct gendisk *disk)
{
	blk_register_region(MKDEV(disk->major, disk->first_minor),
			    disk->minors, NULL, exact_match, exact_lock, disk);
}

EXPORT_SYMBOL_GPL(ide_register_region);

void ide_unregister_region(struct gendisk *disk)
{
	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
			      disk->minors);
}

EXPORT_SYMBOL_GPL(ide_unregister_region);

void ide_init_disk(struct gendisk *disk, ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	unsigned int unit = (drive->select.all >> 4) & 1;

	disk->major = hwif->major;
	disk->first_minor = unit << PARTN_BITS;
	sprintf(disk->disk_name, "hd%c", 'a' + hwif->index * MAX_DRIVES + unit);
	disk->queue = drive->queue;
}

EXPORT_SYMBOL_GPL(ide_init_disk);

static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	if (drive == drive->next) {
		/* special case: last drive from hwgroup. */
		BUG_ON(hwgroup->drive != drive);
		hwgroup->drive = NULL;
	} else {
		ide_drive_t *walk;

		walk = hwgroup->drive;
		while (walk->next != drive)
			walk = walk->next;
		walk->next = drive->next;
		if (hwgroup->drive == drive) {
			hwgroup->drive = drive->next;
			hwgroup->hwif = hwgroup->drive->hwif;
		}
	}
	BUG_ON(hwgroup->drive == drive);
}

static void drive_release_dev (struct device *dev)
{
	ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);

	ide_proc_unregister_device(drive);

	spin_lock_irq(&ide_lock);
	ide_remove_drive_from_hwgroup(drive);
	kfree(drive->id);
	drive->id = NULL;
	drive->present = 0;
	/* Messed up locking ... */
	spin_unlock_irq(&ide_lock);
	blk_cleanup_queue(drive->queue);
	spin_lock_irq(&ide_lock);
	drive->queue = NULL;
	spin_unlock_irq(&ide_lock);

	complete(&drive->gendev_rel_comp);
}

#ifndef ide_default_irq
#define ide_default_irq(irq) 0
#endif

static int hwif_init(ide_hwif_t *hwif)
{
	int old_irq;

	if (!hwif->irq) {
		if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET])))
		{
			printk("%s: DISABLED, NO IRQ\n", hwif->name);
			return 0;
		}
	}

	if (register_blkdev(hwif->major, hwif->name))
		return 0;

	if (!hwif->sg_max_nents)
		hwif->sg_max_nents = PRD_ENTRIES;

	hwif->sg_table = kmalloc(sizeof(struct scatterlist)*hwif->sg_max_nents,
				 GFP_KERNEL);
	if (!hwif->sg_table) {
		printk(KERN_ERR "%s: unable to allocate SG table.\n", hwif->name);
		goto out;
	}

	sg_init_table(hwif->sg_table, hwif->sg_max_nents);
	
	if (init_irq(hwif) == 0)
		goto done;

	old_irq = hwif->irq;
	/*
	 *	It failed to initialise. Find the default IRQ for 
	 *	this port and try that.
	 */
	if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET]))) {
		printk("%s: Disabled unable to get IRQ %d.\n",
			hwif->name, old_irq);
		goto out;
	}
	if (init_irq(hwif)) {
		printk("%s: probed IRQ %d and default IRQ %d failed.\n",
			hwif->name, old_irq, hwif->irq);
		goto out;
	}
	printk("%s: probed IRQ %d failed, using default.\n",
		hwif->name, hwif->irq);

done:
	blk_register_region(MKDEV(hwif->major, 0), MAX_DRIVES << PARTN_BITS,
			    THIS_MODULE, ata_probe, ata_lock, hwif);
	return 1;

out:
	unregister_blkdev(hwif->major, hwif->name);
	return 0;
}

static void hwif_register_devices(ide_hwif_t *hwif)
{
	unsigned int i;

	for (i = 0; i < MAX_DRIVES; i++) {
		ide_drive_t *drive = &hwif->drives[i];
		struct device *dev = &drive->gendev;
		int ret;

		if (!drive->present)
			continue;

		ide_add_generic_settings(drive);

		snprintf(dev->bus_id, BUS_ID_SIZE, "%u.%u", hwif->index, i);
		dev->parent = &hwif->gendev;
		dev->bus = &ide_bus_type;
		dev->driver_data = drive;
		dev->release = drive_release_dev;

		ret = device_register(dev);
		if (ret < 0)
			printk(KERN_WARNING "IDE: %s: device_register error: "
					    "%d\n", __func__, ret);
	}
}

static void ide_port_init_devices(ide_hwif_t *hwif)
{
	const struct ide_port_ops *port_ops = hwif->port_ops;
	int i;

	for (i = 0; i < MAX_DRIVES; i++) {
		ide_drive_t *drive = &hwif->drives[i];

		if (hwif->host_flags & IDE_HFLAG_IO_32BIT)
			drive->io_32bit = 1;
		if (hwif->host_flags & IDE_HFLAG_UNMASK_IRQS)
			drive->unmask = 1;
		if (hwif->host_flags & IDE_HFLAG_NO_UNMASK_IRQS)
			drive->no_unmask = 1;
		if ((hwif->host_flags & IDE_HFLAG_NO_AUTOTUNE) == 0)
			drive->autotune = 1;
	}

	if (port_ops && port_ops->port_init_devs)
		port_ops->port_init_devs(hwif);
}

static void ide_init_port(ide_hwif_t *hwif, unsigned int port,
			  const struct ide_port_info *d)
{
	if (d->chipset != ide_etrax100)
		hwif->channel = port;

	if (d->chipset)
		hwif->chipset = d->chipset;

	if (d->init_iops)
		d->init_iops(hwif);

	if ((!hwif->irq && (d->host_flags & IDE_HFLAG_LEGACY_IRQS)) ||
	    (d->host_flags & IDE_HFLAG_FORCE_LEGACY_IRQS))
		hwif->irq = port ? 15 : 14;

	hwif->host_flags = d->host_flags;
	hwif->pio_mask = d->pio_mask;

	/* ->set_pio_mode for DTC2278 is currently limited to port 0 */
	if (hwif->chipset != ide_dtc2278 || hwif->channel == 0)
		hwif->port_ops = d->port_ops;

	if ((d->host_flags & IDE_HFLAG_SERIALIZE) && hwif->mate)
		hwif->mate->serialized = hwif->serialized = 1;

	hwif->swdma_mask = d->swdma_mask;
	hwif->mwdma_mask = d->mwdma_mask;
	hwif->ultra_mask = d->udma_mask;

	if ((d->host_flags & IDE_HFLAG_NO_DMA) == 0) {
		int rc;

		if (d->init_dma)
			rc = d->init_dma(hwif, d);
		else
			rc = ide_hwif_setup_dma(hwif, d);

		if (rc < 0) {
			printk(KERN_INFO "%s: DMA disabled\n", hwif->name);
			hwif->swdma_mask = 0;
			hwif->mwdma_mask = 0;
			hwif->ultra_mask = 0;
		}
	}

	if (d->host_flags & IDE_HFLAG_RQSIZE_256)
		hwif->rqsize = 256;

	/* call chipset specific routine for each enabled port */
	if (d->init_hwif)
		d->init_hwif(hwif);
}

static void ide_port_cable_detect(ide_hwif_t *hwif)
{
	const struct ide_port_ops *port_ops = hwif->port_ops;

	if (port_ops && port_ops->cable_detect && (hwif->ultra_mask & 0x78)) {
		if (hwif->cbl != ATA_CBL_PATA40_SHORT)
			hwif->cbl = port_ops->cable_detect(hwif);
	}
}

static ssize_t store_delete_devices(struct device *portdev,
				    struct device_attribute *attr,
				    const char *buf, size_t n)
{
	ide_hwif_t *hwif = dev_get_drvdata(portdev);

	if (strncmp(buf, "1", n))
		return -EINVAL;

	ide_port_unregister_devices(hwif);

	return n;
};

static DEVICE_ATTR(delete_devices, S_IWUSR, NULL, store_delete_devices);

static ssize_t store_scan(struct device *portdev,
			  struct device_attribute *attr,
			  const char *buf, size_t n)
{
	ide_hwif_t *hwif = dev_get_drvdata(portdev);

	if (strncmp(buf, "1", n))
		return -EINVAL;

	ide_port_unregister_devices(hwif);
	ide_port_scan(hwif);

	return n;
};

static DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);

static struct device_attribute *ide_port_attrs[] = {
	&dev_attr_delete_devices,
	&dev_attr_scan,
	NULL
};

static int ide_sysfs_register_port(ide_hwif_t *hwif)
{
	int i, rc;

	for (i = 0; ide_port_attrs[i]; i++) {
		rc = device_create_file(hwif->portdev, ide_port_attrs[i]);
		if (rc)
			break;
	}

	return rc;
}

/**
 *	ide_find_port_slot	-	find free ide_hwifs[] slot
 *	@d: IDE port info
 *
 *	Return the new hwif.  If we are out of free slots return NULL.
 */

ide_hwif_t *ide_find_port_slot(const struct ide_port_info *d)
{
	ide_hwif_t *hwif;
	int i;
	u8 bootable = (d && (d->host_flags & IDE_HFLAG_NON_BOOTABLE)) ? 0 : 1;

	/*
	 * Claim an unassigned slot.
	 *
	 * Give preference to claiming other slots before claiming ide0/ide1,
	 * just in case there's another interface yet-to-be-scanned
	 * which uses ports 0x1f0/0x170 (the ide0/ide1 defaults).
	 *
	 * Unless there is a bootable card that does not use the standard
	 * ports 0x1f0/0x170 (the ide0/ide1 defaults).
	 */
	if (bootable) {
		i = (d && (d->host_flags & IDE_HFLAG_QD_2ND_PORT)) ? 1 : 0;

		for (; i < MAX_HWIFS; i++) {
			hwif = &ide_hwifs[i];
			if (hwif->chipset == ide_unknown)
				return hwif;
		}
	} else {
		for (i = 2; i < MAX_HWIFS; i++) {
			hwif = &ide_hwifs[i];
			if (hwif->chipset == ide_unknown)
				return hwif;
		}
		for (i = 0; i < 2 && i < MAX_HWIFS; i++) {
			hwif = &ide_hwifs[i];
			if (hwif->chipset == ide_unknown)
				return hwif;
		}
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(ide_find_port_slot);

int ide_device_add_all(u8 *idx, const struct ide_port_info *d)
{
	ide_hwif_t *hwif, *mate = NULL;
	int i, rc = 0;

	for (i = 0; i < MAX_HWIFS; i++) {
		if (d == NULL || idx[i] == 0xff) {
			mate = NULL;
			continue;
		}

		hwif = &ide_hwifs[idx[i]];

		if (d->chipset != ide_etrax100 && (i & 1) && mate) {
			hwif->mate = mate;
			mate->mate = hwif;
		}

		mate = (i & 1) ? NULL : hwif;

		ide_init_port(hwif, i & 1, d);
		ide_port_cable_detect(hwif);
		ide_port_init_devices(hwif);
	}

	for (i = 0; i < MAX_HWIFS; i++) {
		if (idx[i] == 0xff)
			continue;

		hwif = &ide_hwifs[idx[i]];

		if (ide_probe_port(hwif) == 0)
			hwif->present = 1;

		if (hwif->chipset != ide_4drives || !hwif->mate ||
		    !hwif->mate->present)
			ide_register_port(hwif);

		if (hwif->present)
			ide_port_tune_devices(hwif);
	}

	for (i = 0; i < MAX_HWIFS; i++) {
		if (idx[i] == 0xff)
			continue;

		hwif = &ide_hwifs[idx[i]];

		if (hwif_init(hwif) == 0) {
			printk(KERN_INFO "%s: failed to initialize IDE "
					 "interface\n", hwif->name);
			hwif->present = 0;
			rc = -1;
			continue;
		}

		if (hwif->present)
			ide_port_setup_devices(hwif);

		ide_acpi_init(hwif);

		if (hwif->present)
			ide_acpi_port_init_devices(hwif);
	}

	for (i = 0; i < MAX_HWIFS; i++) {
		if (idx[i] == 0xff)
			continue;

		hwif = &ide_hwifs[idx[i]];

		if (hwif->chipset == ide_unknown)
			hwif->chipset = ide_generic;

		if (hwif->present)
			hwif_register_devices(hwif);
	}

	for (i = 0; i < MAX_HWIFS; i++) {
		if (idx[i] == 0xff)
			continue;

		hwif = &ide_hwifs[idx[i]];

		ide_sysfs_register_port(hwif);
		ide_proc_register_port(hwif);

		if (hwif->present)
			ide_proc_port_register_devices(hwif);
	}

	return rc;
}
EXPORT_SYMBOL_GPL(ide_device_add_all);

int ide_device_add(u8 idx[4], const struct ide_port_info *d)
{
	u8 idx_all[MAX_HWIFS];
	int i;

	for (i = 0; i < MAX_HWIFS; i++)
		idx_all[i] = (i < 4) ? idx[i] : 0xff;

	return ide_device_add_all(idx_all, d);
}
EXPORT_SYMBOL_GPL(ide_device_add);

void ide_port_scan(ide_hwif_t *hwif)
{
	ide_port_cable_detect(hwif);
	ide_port_init_devices(hwif);

	if (ide_probe_port(hwif) < 0)
		return;

	hwif->present = 1;

	ide_port_tune_devices(hwif);
	ide_acpi_port_init_devices(hwif);
	ide_port_setup_devices(hwif);
	hwif_register_devices(hwif);
	ide_proc_port_register_devices(hwif);
}
EXPORT_SYMBOL_GPL(ide_port_scan);

static void ide_legacy_init_one(u8 *idx, hw_regs_t *hw, u8 port_no,
				const struct ide_port_info *d,
				unsigned long config)
{
	ide_hwif_t *hwif;
	unsigned long base, ctl;
	int irq;

	if (port_no == 0) {
		base = 0x1f0;
		ctl  = 0x3f6;
		irq  = 14;
	} else {
		base = 0x170;
		ctl  = 0x376;
		irq  = 15;
	}

	if (!request_region(base, 8, d->name)) {
		printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.\n",
				d->name, base, base + 7);
		return;
	}

	if (!request_region(ctl, 1, d->name)) {
		printk(KERN_ERR "%s: I/O resource 0x%lX not free.\n",
				d->name, ctl);
		release_region(base, 8);
		return;
	}

	ide_std_init_ports(hw, base, ctl);
	hw->irq = irq;

	hwif = ide_find_port_slot(d);
	if (hwif) {
		ide_init_port_hw(hwif, hw);
		if (config)
			hwif->config_data = config;
		idx[port_no] = hwif->index;
	}
}

int ide_legacy_device_add(const struct ide_port_info *d, unsigned long config)
{
	u8 idx[4] = { 0xff, 0xff, 0xff, 0xff };
	hw_regs_t hw[2];

	memset(&hw, 0, sizeof(hw));

	if ((d->host_flags & IDE_HFLAG_QD_2ND_PORT) == 0)
		ide_legacy_init_one(idx, &hw[0], 0, d, config);
	ide_legacy_init_one(idx, &hw[1], 1, d, config);

	if (idx[0] == 0xff && idx[1] == 0xff &&
	    (d->host_flags & IDE_HFLAG_SINGLE))
		return -ENOENT;

	ide_device_add(idx, d);

	return 0;
}
EXPORT_SYMBOL_GPL(ide_legacy_device_add);