aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/wd7000.c
blob: 333580bf37c5a7d6cbccf6587d55ad7a2b3b3b2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
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
/* $Id: $
 *  linux/drivers/scsi/wd7000.c
 *
 *  Copyright (C) 1992  Thomas Wuensche
 *	closely related to the aha1542 driver from Tommy Thorn
 *	( as close as different hardware allows on a lowlevel-driver :-) )
 *
 *  Revised (and renamed) by John Boyd <boyd@cis.ohio-state.edu> to
 *  accommodate Eric Youngdale's modifications to scsi.c.  Nov 1992.
 *
 *  Additional changes to support scatter/gather.  Dec. 1992.  tw/jb
 *
 *  No longer tries to reset SCSI bus at boot (it wasn't working anyway).
 *  Rewritten to support multiple host adapters.
 *  Miscellaneous cleanup.
 *  So far, still doesn't do reset or abort correctly, since I have no idea
 *  how to do them with this board (8^(.                      Jan 1994 jb
 *
 * This driver now supports both of the two standard configurations (per
 * the 3.36 Owner's Manual, my latest reference) by the same method as
 * before; namely, by looking for a BIOS signature.  Thus, the location of
 * the BIOS signature determines the board configuration.  Until I have
 * time to do something more flexible, users should stick to one of the
 * following:
 *
 * Standard configuration for single-adapter systems:
 *    - BIOS at CE00h
 *    - I/O base address 350h
 *    - IRQ level 15
 *    - DMA channel 6
 * Standard configuration for a second adapter in a system:
 *    - BIOS at C800h
 *    - I/O base address 330h
 *    - IRQ level 11
 *    - DMA channel 5
 *
 * Anyone who can recompile the kernel is welcome to add others as need
 * arises, but unpredictable results may occur if there are conflicts.
 * In any event, if there are multiple adapters in a system, they MUST
 * use different I/O bases, IRQ levels, and DMA channels, since they will be
 * indistinguishable (and in direct conflict) otherwise.
 *
 *   As a point of information, the NO_OP command toggles the CMD_RDY bit
 * of the status port, and this fact could be used as a test for the I/O
 * base address (or more generally, board detection).  There is an interrupt
 * status port, so IRQ probing could also be done.  I suppose the full
 * DMA diagnostic could be used to detect the DMA channel being used.  I
 * haven't done any of this, though, because I think there's too much of
 * a chance that such explorations could be destructive, if some other
 * board's resources are used inadvertently.  So, call me a wimp, but I
 * don't want to try it.  The only kind of exploration I trust is memory
 * exploration, since it's more certain that reading memory won't be
 * destructive.
 *
 * More to my liking would be a LILO boot command line specification, such
 * as is used by the aha152x driver (and possibly others).  I'll look into
 * it, as I have time...
 *
 *   I get mail occasionally from people who either are using or are
 * considering using a WD7000 with Linux.  There is a variety of
 * nomenclature describing WD7000's.  To the best of my knowledge, the
 * following is a brief summary (from an old WD doc - I don't work for
 * them or anything like that):
 *
 * WD7000-FASST2: This is a WD7000 board with the real-mode SST ROM BIOS
 *        installed.  Last I heard, the BIOS was actually done by Columbia
 *        Data Products.  The BIOS is only used by this driver (and thus
 *        by Linux) to identify the board; none of it can be executed under
 *        Linux.
 *
 * WD7000-ASC: This is the original adapter board, with or without BIOS.
 *        The board uses a WD33C93 or WD33C93A SBIC, which in turn is
 *        controlled by an onboard Z80 processor.  The board interface
 *        visible to the host CPU is defined effectively by the Z80's
 *        firmware, and it is this firmware's revision level that is
 *        determined and reported by this driver.  (The version of the
 *        on-board BIOS is of no interest whatsoever.)  The host CPU has
 *        no access to the SBIC; hence the fact that it is a WD33C93 is
 *        also of no interest to this driver.
 *
 * WD7000-AX:
 * WD7000-MX:
 * WD7000-EX: These are newer versions of the WD7000-ASC.  The -ASC is
 *        largely built from discrete components; these boards use more
 *        integration.  The -AX is an ISA bus board (like the -ASC),
 *        the -MX is an MCA (i.e., PS/2) bus board), and the -EX is an
 *        EISA bus board.
 *
 *  At the time of my documentation, the -?X boards were "future" products,
 *  and were not yet available.  However, I vaguely recall that Thomas
 *  Wuensche had an -AX, so I believe at least it is supported by this
 *  driver.  I have no personal knowledge of either -MX or -EX boards.
 *
 *  P.S. Just recently, I've discovered (directly from WD and Future
 *  Domain) that all but the WD7000-EX have been out of production for
 *  two years now.  FD has production rights to the 7000-EX, and are
 *  producing it under a new name, and with a new BIOS.  If anyone has
 *  one of the FD boards, it would be nice to come up with a signature
 *  for it.
 *                                                           J.B. Jan 1994.
 *
 *
 *  Revisions by Miroslav Zagorac <zaga@fly.cc.fer.hr>
 *
 *  08/24/1996.
 *
 *  Enhancement for wd7000_detect function has been made, so you don't have
 *  to enter BIOS ROM address in initialisation data (see struct Config).
 *  We cannot detect IRQ, DMA and I/O base address for now, so we have to
 *  enter them as arguments while wd_7000 is detected. If someone has IRQ,
 *  DMA or I/O base address set to some other value, he can enter them in
 *  configuration without any problem. Also I wrote a function wd7000_setup,
 *  so now you can enter WD-7000 definition as kernel arguments,
 *  as in lilo.conf:
 *
 *     append="wd7000=IRQ,DMA,IO"
 *
 *  PS: If card BIOS ROM is disabled, function wd7000_detect now will recognize
 *      adapter, unlike the old one. Anyway, BIOS ROM from WD7000 adapter is
 *      useless for Linux. B^)
 *
 *
 *  09/06/1996.
 *
 *  Autodetecting of I/O base address from wd7000_detect function is removed,
 *  some little bugs removed, etc...
 *
 *  Thanks to Roger Scott for driver debugging.
 *
 *  06/07/1997
 *
 *  Added support for /proc file system (/proc/scsi/wd7000/[0...] files).
 *  Now, driver can handle hard disks with capacity >1GB.
 *
 *  01/15/1998
 *
 *  Added support for BUS_ON and BUS_OFF parameters in config line.
 *  Miscellaneous cleanup.
 *
 *  03/01/1998
 *
 *  WD7000 driver now work on kernels >= 2.1.x
 *
 *
 * 12/31/2001 - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 * use host->host_lock, not io_request_lock, cleanups
 *
 * 2002/10/04 - Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * Use dev_id for interrupts, kill __func__ pasting
 * Add a lock for the scb pool, clean up all other cli/sti usage stuff
 * Use the adapter lock for the other places we had the cli's
 *
 * 2002/10/06 - Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 * Switch to new style error handling
 * Clean up delay to udelay, and yielding sleeps
 * Make host reset actually reset the card
 * Make everything static
 *
 * 2003/02/12 - Christoph Hellwig <hch@infradead.org>
 *
 * Cleaned up host template definition
 * Removed now obsolete wd7000.h
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/io.h>

#include <asm/system.h>
#include <asm/dma.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsicam.h>


#undef  WD7000_DEBUG		/* general debug                */
#ifdef WD7000_DEBUG
#define dprintk printk
#else
#define dprintk(format,args...)
#endif

/*
 *  Mailbox structure sizes.
 *  I prefer to keep the number of ICMBs much larger than the number of
 *  OGMBs.  OGMBs are used very quickly by the driver to start one or
 *  more commands, while ICMBs are used by the host adapter per command.
 */
#define OGMB_CNT	16
#define ICMB_CNT	32

/*
 *  Scb's are shared by all active adapters.  So, if they all become busy,
 *  callers may be made to wait in alloc_scbs for them to free.  That can
 *  be avoided by setting MAX_SCBS to NUM_CONFIG * WD7000_Q.  If you'd
 *  rather conserve memory, use a smaller number (> 0, of course) - things
 *  will should still work OK.
 */
#define MAX_SCBS        32

/*
 *  In this version, sg_tablesize now defaults to WD7000_SG, and will
 *  be set to SG_NONE for older boards.  This is the reverse of the
 *  previous default, and was changed so that the driver-level
 *  scsi_host_template would reflect the driver's support for scatter/
 *  gather.
 *
 *  Also, it has been reported that boards at Revision 6 support scatter/
 *  gather, so the new definition of an "older" board has been changed
 *  accordingly.
 */
#define WD7000_Q	16
#define WD7000_SG	16


/*
 *  WD7000-specific mailbox structure
 *
 */
typedef volatile struct mailbox {
	unchar status;
	unchar scbptr[3];	/* SCSI-style - MSB first (big endian) */
} Mailbox;

/*
 *  This structure should contain all per-adapter global data.  I.e., any
 *  new global per-adapter data should put in here.
 */
typedef struct adapter {
	struct Scsi_Host *sh;	/* Pointer to Scsi_Host structure    */
	int iobase;		/* This adapter's I/O base address   */
	int irq;		/* This adapter's IRQ level          */
	int dma;		/* This adapter's DMA channel        */
	int int_counter;	/* This adapter's interrupt counter  */
	int bus_on;		/* This adapter's BUS_ON time        */
	int bus_off;		/* This adapter's BUS_OFF time       */
	struct {		/* This adapter's mailboxes          */
		Mailbox ogmb[OGMB_CNT];	/* Outgoing mailboxes                */
		Mailbox icmb[ICMB_CNT];	/* Incoming mailboxes                */
	} mb;
	int next_ogmb;		/* to reduce contention at mailboxes */
	unchar control;		/* shadows CONTROL port value        */
	unchar rev1, rev2;	/* filled in by wd7000_revision      */
} Adapter;

/*
 * (linear) base address for ROM BIOS
 */
static const long wd7000_biosaddr[] = {
	0xc0000, 0xc2000, 0xc4000, 0xc6000, 0xc8000, 0xca000, 0xcc000, 0xce000,
	0xd0000, 0xd2000, 0xd4000, 0xd6000, 0xd8000, 0xda000, 0xdc000, 0xde000
};
#define NUM_ADDRS ARRAY_SIZE(wd7000_biosaddr)

static const unsigned short wd7000_iobase[] = {
	0x0300, 0x0308, 0x0310, 0x0318, 0x0320, 0x0328, 0x0330, 0x0338,
	0x0340, 0x0348, 0x0350, 0x0358, 0x0360, 0x0368, 0x0370, 0x0378,
	0x0380, 0x0388, 0x0390, 0x0398, 0x03a0, 0x03a8, 0x03b0, 0x03b8,
	0x03c0, 0x03c8, 0x03d0, 0x03d8, 0x03e0, 0x03e8, 0x03f0, 0x03f8
};
#define NUM_IOPORTS ARRAY_SIZE(wd7000_iobase)

static const short wd7000_irq[] = { 3, 4, 5, 7, 9, 10, 11, 12, 14, 15 };
#define NUM_IRQS ARRAY_SIZE(wd7000_irq)

static const short wd7000_dma[] = { 5, 6, 7 };
#define NUM_DMAS ARRAY_SIZE(wd7000_dma)

/*
 * The following is set up by wd7000_detect, and used thereafter for
 * proc and other global ookups
 */

#define UNITS	8
static struct Scsi_Host *wd7000_host[UNITS];

#define BUS_ON    64		/* x 125ns = 8000ns (BIOS default) */
#define BUS_OFF   15		/* x 125ns = 1875ns (BIOS default) */

/*
 *  Standard Adapter Configurations - used by wd7000_detect
 */
typedef struct {
	short irq;		/* IRQ level                                  */
	short dma;		/* DMA channel                                */
	unsigned iobase;	/* I/O base address                           */
	short bus_on;		/* Time that WD7000 spends on the AT-bus when */
	/* transferring data. BIOS default is 8000ns. */
	short bus_off;		/* Time that WD7000 spends OFF THE BUS after  */
	/* while it is transferring data.             */
	/* BIOS default is 1875ns                     */
} Config;

/*
 * Add here your configuration...
 */
static Config configs[] = {
	{15, 6, 0x350, BUS_ON, BUS_OFF},	/* defaults for single adapter */
	{11, 5, 0x320, BUS_ON, BUS_OFF},	/* defaults for second adapter */
	{7, 6, 0x350, BUS_ON, BUS_OFF},	/* My configuration (Zaga)     */
	{-1, -1, 0x0, BUS_ON, BUS_OFF}	/* Empty slot                  */
};
#define NUM_CONFIGS ARRAY_SIZE(configs)

/*
 *  The following list defines strings to look for in the BIOS that identify
 *  it as the WD7000-FASST2 SST BIOS.  I suspect that something should be
 *  added for the Future Domain version.
 */
typedef struct signature {
	const char *sig;	/* String to look for            */
	unsigned long ofs;	/* offset from BIOS base address */
	unsigned len;		/* length of string              */
} Signature;

static const Signature signatures[] = {
	{"SSTBIOS", 0x0000d, 7}	/* "SSTBIOS" @ offset 0x0000d */
};
#define NUM_SIGNATURES ARRAY_SIZE(signatures)


/*
 *  I/O Port Offsets and Bit Definitions
 *  4 addresses are used.  Those not defined here are reserved.
 */
#define ASC_STAT        0	/* Status,  Read          */
#define ASC_COMMAND     0	/* Command, Write         */
#define ASC_INTR_STAT   1	/* Interrupt Status, Read */
#define ASC_INTR_ACK    1	/* Acknowledge, Write     */
#define ASC_CONTROL     2	/* Control, Write         */

/*
 * ASC Status Port
 */
#define INT_IM		0x80	/* Interrupt Image Flag           */
#define CMD_RDY		0x40	/* Command Port Ready             */
#define CMD_REJ		0x20	/* Command Port Byte Rejected     */
#define ASC_INIT        0x10	/* ASC Initialized Flag           */
#define ASC_STATMASK    0xf0	/* The lower 4 Bytes are reserved */

/*
 * COMMAND opcodes
 *
 *  Unfortunately, I have no idea how to properly use some of these commands,
 *  as the OEM manual does not make it clear.  I have not been able to use
 *  enable/disable unsolicited interrupts or the reset commands with any
 *  discernible effect whatsoever.  I think they may be related to certain
 *  ICB commands, but again, the OEM manual doesn't make that clear.
 */
#define NO_OP             0	/* NO-OP toggles CMD_RDY bit in ASC_STAT  */
#define INITIALIZATION    1	/* initialization (10 bytes)              */
#define DISABLE_UNS_INTR  2	/* disable unsolicited interrupts         */
#define ENABLE_UNS_INTR   3	/* enable unsolicited interrupts          */
#define INTR_ON_FREE_OGMB 4	/* interrupt on free OGMB                 */
#define SOFT_RESET        5	/* SCSI bus soft reset                    */
#define HARD_RESET_ACK    6	/* SCSI bus hard reset acknowledge        */
#define START_OGMB        0x80	/* start command in OGMB (n)              */
#define SCAN_OGMBS        0xc0	/* start multiple commands, signature (n) */
				/*    where (n) = lower 6 bits            */
/*
 * For INITIALIZATION:
 */
typedef struct initCmd {
	unchar op;		/* command opcode (= 1)                    */
	unchar ID;		/* Adapter's SCSI ID                       */
	unchar bus_on;		/* Bus on time, x 125ns (see below)        */
	unchar bus_off;		/* Bus off time, ""         ""             */
	unchar rsvd;		/* Reserved                                */
	unchar mailboxes[3];	/* Address of Mailboxes, MSB first         */
	unchar ogmbs;		/* Number of outgoing MBs, max 64, 0,1 = 1 */
	unchar icmbs;		/* Number of incoming MBs,   ""       ""   */
} InitCmd;

/*
 * Interrupt Status Port - also returns diagnostic codes at ASC reset
 *
 * if msb is zero, the lower bits are diagnostic status
 * Diagnostics:
 * 01   No diagnostic error occurred
 * 02   RAM failure
 * 03   FIFO R/W failed
 * 04   SBIC register read/write failed
 * 05   Initialization D-FF failed
 * 06   Host IRQ D-FF failed
 * 07   ROM checksum error
 * Interrupt status (bitwise):
 * 10NNNNNN   outgoing mailbox NNNNNN is free
 * 11NNNNNN   incoming mailbox NNNNNN needs service
 */
#define MB_INTR    0xC0		/* Mailbox Service possible/required */
#define IMB_INTR   0x40		/* 1 Incoming / 0 Outgoing           */
#define MB_MASK    0x3f		/* mask for mailbox number           */

/*
 * CONTROL port bits
 */
#define INT_EN     0x08		/* Interrupt Enable */
#define DMA_EN     0x04		/* DMA Enable       */
#define SCSI_RES   0x02		/* SCSI Reset       */
#define ASC_RES    0x01		/* ASC Reset        */

/*
 * Driver data structures:
 *   - mb and scbs are required for interfacing with the host adapter.
 *     An SCB has extra fields not visible to the adapter; mb's
 *     _cannot_ do this, since the adapter assumes they are contiguous in
 *     memory, 4 bytes each, with ICMBs following OGMBs, and uses this fact
 *     to access them.
 *   - An icb is for host-only (non-SCSI) commands.  ICBs are 16 bytes each;
 *     the additional bytes are used only by the driver.
 *   - For now, a pool of SCBs are kept in global storage by this driver,
 *     and are allocated and freed as needed.
 *
 *  The 7000-FASST2 marks OGMBs empty as soon as it has _started_ a command,
 *  not when it has finished.  Since the SCB must be around for completion,
 *  problems arise when SCBs correspond to OGMBs, which may be reallocated
 *  earlier (or delayed unnecessarily until a command completes).
 *  Mailboxes are used as transient data structures, simply for
 *  carrying SCB addresses to/from the 7000-FASST2.
 *
 *  Note also since SCBs are not "permanently" associated with mailboxes,
 *  there is no need to keep a global list of scsi_cmnd pointers indexed
 *  by OGMB.   Again, SCBs reference their scsi_cmnds directly, so mailbox
 *  indices need not be involved.
 */

/*
 *  WD7000-specific scatter/gather element structure
 */
typedef struct sgb {
	unchar len[3];
	unchar ptr[3];		/* Also SCSI-style - MSB first */
} Sgb;

typedef struct scb {		/* Command Control Block 5.4.1               */
	unchar op;		/* Command Control Block Operation Code      */
	unchar idlun;		/* op=0,2:Target Id, op=1:Initiator Id       */
	/* Outbound data transfer, length is checked */
	/* Inbound data transfer, length is checked  */
	/* Logical Unit Number                       */
	unchar cdb[12];		/* SCSI Command Block                        */
	volatile unchar status;	/* SCSI Return Status                        */
	volatile unchar vue;	/* Vendor Unique Error Code                  */
	unchar maxlen[3];	/* Maximum Data Transfer Length              */
	unchar dataptr[3];	/* SCSI Data Block Pointer                   */
	unchar linkptr[3];	/* Next Command Link Pointer                 */
	unchar direc;		/* Transfer Direction                        */
	unchar reserved2[6];	/* SCSI Command Descriptor Block             */
	/* end of hardware SCB                       */
	struct scsi_cmnd *SCpnt;/* scsi_cmnd using this SCB                  */
	Sgb sgb[WD7000_SG];	/* Scatter/gather list for this SCB          */
	Adapter *host;		/* host adapter                              */
	struct scb *next;	/* for lists of scbs                         */
} Scb;

/*
 *  This driver is written to allow host-only commands to be executed.
 *  These use a 16-byte block called an ICB.  The format is extended by the
 *  driver to 18 bytes, to support the status returned in the ICMB and
 *  an execution phase code.
 *
 *  There are other formats besides these; these are the ones I've tried
 *  to use.  Formats for some of the defined ICB opcodes are not defined
 *  (notably, get/set unsolicited interrupt status) in my copy of the OEM
 *  manual, and others are ambiguous/hard to follow.
 */
#define ICB_OP_MASK           0x80	/* distinguishes scbs from icbs        */
#define ICB_OP_OPEN_RBUF      0x80	/* open receive buffer                 */
#define ICB_OP_RECV_CMD       0x81	/* receive command from initiator      */
#define ICB_OP_RECV_DATA      0x82	/* receive data from initiator         */
#define ICB_OP_RECV_SDATA     0x83	/* receive data with status from init. */
#define ICB_OP_SEND_DATA      0x84	/* send data with status to initiator  */
#define ICB_OP_SEND_STAT      0x86	/* send command status to initiator    */
					/* 0x87 is reserved                    */
#define ICB_OP_READ_INIT      0x88	/* read initialization bytes           */
#define ICB_OP_READ_ID        0x89	/* read adapter's SCSI ID              */
#define ICB_OP_SET_UMASK      0x8A	/* set unsolicited interrupt mask      */
#define ICB_OP_GET_UMASK      0x8B	/* read unsolicited interrupt mask     */
#define ICB_OP_GET_REVISION   0x8C	/* read firmware revision level        */
#define ICB_OP_DIAGNOSTICS    0x8D	/* execute diagnostics                 */
#define ICB_OP_SET_EPARMS     0x8E	/* set execution parameters            */
#define ICB_OP_GET_EPARMS     0x8F	/* read execution parameters           */

typedef struct icbRecvCmd {
	unchar op;
	unchar IDlun;		/* Initiator SCSI ID/lun     */
	unchar len[3];		/* command buffer length     */
	unchar ptr[3];		/* command buffer address    */
	unchar rsvd[7];		/* reserved                  */
	volatile unchar vue;	/* vendor-unique error code  */
	volatile unchar status;	/* returned (icmb) status    */
	volatile unchar phase;	/* used by interrupt handler */
} IcbRecvCmd;

typedef struct icbSendStat {
	unchar op;
	unchar IDlun;		/* Target SCSI ID/lun                  */
	unchar stat;		/* (outgoing) completion status byte 1 */
	unchar rsvd[12];	/* reserved                            */
	volatile unchar vue;	/* vendor-unique error code            */
	volatile unchar status;	/* returned (icmb) status              */
	volatile unchar phase;	/* used by interrupt handler           */
} IcbSendStat;

typedef struct icbRevLvl {
	unchar op;
	volatile unchar primary;	/* primary revision level (returned)   */
	volatile unchar secondary;	/* secondary revision level (returned) */
	unchar rsvd[12];	/* reserved                            */
	volatile unchar vue;	/* vendor-unique error code            */
	volatile unchar status;	/* returned (icmb) status              */
	volatile unchar phase;	/* used by interrupt handler           */
} IcbRevLvl;

typedef struct icbUnsMask {	/* I'm totally guessing here */
	unchar op;
	volatile unchar mask[14];	/* mask bits                 */
#if 0
	unchar rsvd[12];	/* reserved                  */
#endif
	volatile unchar vue;	/* vendor-unique error code  */
	volatile unchar status;	/* returned (icmb) status    */
	volatile unchar phase;	/* used by interrupt handler */
} IcbUnsMask;

typedef struct icbDiag {
	unchar op;
	unchar type;		/* diagnostics type code (0-3) */
	unchar len[3];		/* buffer length               */
	unchar ptr[3];		/* buffer address              */
	unchar rsvd[7];		/* reserved                    */
	volatile unchar vue;	/* vendor-unique error code    */
	volatile unchar status;	/* returned (icmb) status      */
	volatile unchar phase;	/* used by interrupt handler   */
} IcbDiag;

#define ICB_DIAG_POWERUP   0	/* Power-up diags only       */
#define ICB_DIAG_WALKING   1	/* walking 1's pattern       */
#define ICB_DIAG_DMA       2	/* DMA - system memory diags */
#define ICB_DIAG_FULL      3	/* do both 1 & 2             */

typedef struct icbParms {
	unchar op;
	unchar rsvd1;		/* reserved                  */
	unchar len[3];		/* parms buffer length       */
	unchar ptr[3];		/* parms buffer address      */
	unchar idx[2];		/* index (MSB-LSB)           */
	unchar rsvd2[5];	/* reserved                  */
	volatile unchar vue;	/* vendor-unique error code  */
	volatile unchar status;	/* returned (icmb) status    */
	volatile unchar phase;	/* used by interrupt handler */
} IcbParms;

typedef struct icbAny {
	unchar op;
	unchar data[14];	/* format-specific data      */
	volatile unchar vue;	/* vendor-unique error code  */
	volatile unchar status;	/* returned (icmb) status    */
	volatile unchar phase;	/* used by interrupt handler */
} IcbAny;

typedef union icb {
	unchar op;		/* ICB opcode                     */
	IcbRecvCmd recv_cmd;	/* format for receive command     */
	IcbSendStat send_stat;	/* format for send status         */
	IcbRevLvl rev_lvl;	/* format for get revision level  */
	IcbDiag diag;		/* format for execute diagnostics */
	IcbParms eparms;	/* format for get/set exec parms  */
	IcbAny icb;		/* generic format                 */
	unchar data[18];
} Icb;

#ifdef MODULE
static char *wd7000;
module_param(wd7000, charp, 0);
#endif

/*
 *  Driver SCB structure pool.
 *
 *  The SCBs declared here are shared by all host adapters; hence, this
 *  structure is not part of the Adapter structure.
 */
static Scb scbs[MAX_SCBS];
static Scb *scbfree;		/* free list         */
static int freescbs = MAX_SCBS;	/* free list counter */
static spinlock_t scbpool_lock;	/* guards the scb free list and count */

/*
 *  END of data/declarations - code follows.
 */
static void __init setup_error(char *mesg, int *ints)
{
	if (ints[0] == 3)
		printk(KERN_ERR "wd7000_setup: \"wd7000=%d,%d,0x%x\" -> %s\n", ints[1], ints[2], ints[3], mesg);
	else if (ints[0] == 4)
		printk(KERN_ERR "wd7000_setup: \"wd7000=%d,%d,0x%x,%d\" -> %s\n", ints[1], ints[2], ints[3], ints[4], mesg);
	else
		printk(KERN_ERR "wd7000_setup: \"wd7000=%d,%d,0x%x,%d,%d\" -> %s\n", ints[1], ints[2], ints[3], ints[4], ints[5], mesg);
}


/*
 * Note: You can now set these options from the kernel's "command line".
 * The syntax is:
 *
 *     wd7000=<IRQ>,<DMA>,<IO>[,<BUS_ON>[,<BUS_OFF>]]
 *
 * , where BUS_ON and BUS_OFF are in nanoseconds. BIOS default values
 * are 8000ns for BUS_ON and 1875ns for BUS_OFF.
 * eg:
 *     wd7000=7,6,0x350
 *
 * will configure the driver for a WD-7000 controller
 * using IRQ 15 with a DMA channel 6, at IO base address 0x350.
 */
static int __init wd7000_setup(char *str)
{
	static short wd7000_card_num;	/* .bss will zero this */
	short i;
	int ints[6];

	(void) get_options(str, ARRAY_SIZE(ints), ints);

	if (wd7000_card_num >= NUM_CONFIGS) {
		printk(KERN_ERR "%s: Too many \"wd7000=\" configurations in " "command line!\n", __func__);
		return 0;
	}

	if ((ints[0] < 3) || (ints[0] > 5)) {
		printk(KERN_ERR "%s: Error in command line!  " "Usage: wd7000=<IRQ>,<DMA>,IO>[,<BUS_ON>" "[,<BUS_OFF>]]\n", __func__);
	} else {
		for (i = 0; i < NUM_IRQS; i++)
			if (ints[1] == wd7000_irq[i])
				break;

		if (i == NUM_IRQS) {
			setup_error("invalid IRQ.", ints);
			return 0;
		} else
			configs[wd7000_card_num].irq = ints[1];

		for (i = 0; i < NUM_DMAS; i++)
			if (ints[2] == wd7000_dma[i])
				break;

		if (i == NUM_DMAS) {
			setup_error("invalid DMA channel.", ints);
			return 0;
		} else
			configs[wd7000_card_num].dma = ints[2];

		for (i = 0; i < NUM_IOPORTS; i++)
			if (ints[3] == wd7000_iobase[i])
				break;

		if (i == NUM_IOPORTS) {
			setup_error("invalid I/O base address.", ints);
			return 0;
		} else
			configs[wd7000_card_num].iobase = ints[3];

		if (ints[0] > 3) {
			if ((ints[4] < 500) || (ints[4] > 31875)) {
				setup_error("BUS_ON value is out of range (500" " to 31875 nanoseconds)!", ints);
				configs[wd7000_card_num].bus_on = BUS_ON;
			} else
				configs[wd7000_card_num].bus_on = ints[4] / 125;
		} else
			configs[wd7000_card_num].bus_on = BUS_ON;

		if (ints[0] > 4) {
			if ((ints[5] < 500) || (ints[5] > 31875)) {
				setup_error("BUS_OFF value is out of range (500" " to 31875 nanoseconds)!", ints);
				configs[wd7000_card_num].bus_off = BUS_OFF;
			} else
				configs[wd7000_card_num].bus_off = ints[5] / 125;
		} else
			configs[wd7000_card_num].bus_off = BUS_OFF;

		if (wd7000_card_num) {
			for (i = 0; i < (wd7000_card_num - 1); i++) {
				int j = i + 1;

				for (; j < wd7000_card_num; j++)
					if (configs[i].irq == configs[j].irq) {
						setup_error("duplicated IRQ!", ints);
						return 0;
					}
				if (configs[i].dma == configs[j].dma) {
					setup_error("duplicated DMA " "channel!", ints);
					return 0;
				}
				if (configs[i].iobase == configs[j].iobase) {
					setup_error("duplicated I/O " "base address!", ints);
					return 0;
				}
			}
		}

		dprintk(KERN_DEBUG "wd7000_setup: IRQ=%d, DMA=%d, I/O=0x%x, "
			"BUS_ON=%dns, BUS_OFF=%dns\n", configs[wd7000_card_num].irq, configs[wd7000_card_num].dma, configs[wd7000_card_num].iobase, configs[wd7000_card_num].bus_on * 125, configs[wd7000_card_num].bus_off * 125);

		wd7000_card_num++;
	}
	return 1;
}

__setup("wd7000=", wd7000_setup);

static inline void any2scsi(unchar * scsi, int any)
{
	*scsi++ = (unsigned)any >> 16;
	*scsi++ = (unsigned)any >> 8;
	*scsi++ = any;
}

static inline int scsi2int(unchar * scsi)
{
	return (scsi[0] << 16) | (scsi[1] << 8) | scsi[2];
}

static inline void wd7000_enable_intr(Adapter * host)
{
	host->control |= INT_EN;
	outb(host->control, host->iobase + ASC_CONTROL);
}


static inline void wd7000_enable_dma(Adapter * host)
{
	unsigned long flags;
	host->control |= DMA_EN;
	outb(host->control, host->iobase + ASC_CONTROL);

	flags = claim_dma_lock();
	set_dma_mode(host->dma, DMA_MODE_CASCADE);
	enable_dma(host->dma);
	release_dma_lock(flags);

}


#define WAITnexttimeout 200	/* 2 seconds */

static inline short WAIT(unsigned port, unsigned mask, unsigned allof, unsigned noneof)
{
	unsigned WAITbits;
	unsigned long WAITtimeout = jiffies + WAITnexttimeout;

	while (time_before_eq(jiffies, WAITtimeout)) {
		WAITbits = inb(port) & mask;

		if (((WAITbits & allof) == allof) && ((WAITbits & noneof) == 0))
			return (0);
	}

	return (1);
}


static inline int command_out(Adapter * host, unchar * cmd, int len)
{
	if (!WAIT(host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0)) {
		while (len--) {
			do {
				outb(*cmd, host->iobase + ASC_COMMAND);
				WAIT(host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0);
			} while (inb(host->iobase + ASC_STAT) & CMD_REJ);

			cmd++;
		}

		return (1);
	}

	printk(KERN_WARNING "wd7000 command_out: WAIT failed(%d)\n", len + 1);

	return (0);
}


/*
 *  This version of alloc_scbs is in preparation for supporting multiple
 *  commands per lun and command chaining, by queueing pending commands.
 *  We will need to allocate Scbs in blocks since they will wait to be
 *  executed so there is the possibility of deadlock otherwise.
 *  Also, to keep larger requests from being starved by smaller requests,
 *  we limit access to this routine with an internal busy flag, so that
 *  the satisfiability of a request is not dependent on the size of the
 *  request.
 */
static inline Scb *alloc_scbs(struct Scsi_Host *host, int needed)
{
	Scb *scb, *p = NULL;
	unsigned long flags;
	unsigned long timeout = jiffies + WAITnexttimeout;
	unsigned long now;
	int i;

	if (needed <= 0)
		return (NULL);	/* sanity check */

	spin_unlock_irq(host->host_lock);

      retry:
	while (freescbs < needed) {
		timeout = jiffies + WAITnexttimeout;
		do {
			/* FIXME: can we actually just yield here ?? */
			for (now = jiffies; now == jiffies;)
				cpu_relax();	/* wait a jiffy */
		} while (freescbs < needed && time_before_eq(jiffies, timeout));
		/*
		 *  If we get here with enough free Scbs, we can take them.
		 *  Otherwise, we timed out and didn't get enough.
		 */
		if (freescbs < needed) {
			printk(KERN_ERR "wd7000: can't get enough free SCBs.\n");
			return (NULL);
		}
	}

	/* Take the lock, then check we didnt get beaten, if so try again */
	spin_lock_irqsave(&scbpool_lock, flags);
	if (freescbs < needed) {
		spin_unlock_irqrestore(&scbpool_lock, flags);
		goto retry;
	}

	scb = scbfree;
	freescbs -= needed;
	for (i = 0; i < needed; i++) {
		p = scbfree;
		scbfree = p->next;
	}
	p->next = NULL;

	spin_unlock_irqrestore(&scbpool_lock, flags);

	spin_lock_irq(host->host_lock);
	return (scb);
}


static inline void free_scb(Scb * scb)
{
	unsigned long flags;

	spin_lock_irqsave(&scbpool_lock, flags);

	memset(scb, 0, sizeof(Scb));
	scb->next = scbfree;
	scbfree = scb;
	freescbs++;

	spin_unlock_irqrestore(&scbpool_lock, flags);
}


static inline void init_scbs(void)
{
	int i;

	spin_lock_init(&scbpool_lock);

	/* This is only ever called before the SCB pool is active */

	scbfree = &(scbs[0]);
	memset(scbs, 0, sizeof(scbs));
	for (i = 0; i < MAX_SCBS - 1; i++) {
		scbs[i].next = &(scbs[i + 1]);
		scbs[i].SCpnt = NULL;
	}
	scbs[MAX_SCBS - 1].next = NULL;
	scbs[MAX_SCBS - 1].SCpnt = NULL;
}


static int mail_out(Adapter * host, Scb * scbptr)
/*
 *  Note: this can also be used for ICBs; just cast to the parm type.
 */
{
	int i, ogmb;
	unsigned long flags;
	unchar start_ogmb;
	Mailbox *ogmbs = host->mb.ogmb;
	int *next_ogmb = &(host->next_ogmb);

	dprintk("wd7000_mail_out: 0x%06lx", (long) scbptr);

	/* We first look for a free outgoing mailbox */
	spin_lock_irqsave(host->sh->host_lock, flags);
	ogmb = *next_ogmb;
	for (i = 0; i < OGMB_CNT; i++) {
		if (ogmbs[ogmb].status == 0) {
			dprintk(" using OGMB 0x%x", ogmb);
			ogmbs[ogmb].status = 1;
			any2scsi((unchar *) ogmbs[ogmb].scbptr, (int) scbptr);

			*next_ogmb = (ogmb + 1) % OGMB_CNT;
			break;
		} else
			ogmb = (ogmb + 1) % OGMB_CNT;
	}
	spin_unlock_irqrestore(host->sh->host_lock, flags);

	dprintk(", scb is 0x%06lx", (long) scbptr);

	if (i >= OGMB_CNT) {
		/*
		 *  Alternatively, we might issue the "interrupt on free OGMB",
		 *  and sleep, but it must be ensured that it isn't the init
		 *  task running.  Instead, this version assumes that the caller
		 *  will be persistent, and try again.  Since it's the adapter
		 *  that marks OGMB's free, waiting even with interrupts off
		 *  should work, since they are freed very quickly in most cases.
		 */
		dprintk(", no free OGMBs.\n");
		return (0);
	}

	wd7000_enable_intr(host);

	start_ogmb = START_OGMB | ogmb;
	command_out(host, &start_ogmb, 1);

	dprintk(", awaiting interrupt.\n");

	return (1);
}


static int make_code(unsigned hosterr, unsigned scsierr)
{
#ifdef WD7000_DEBUG
	int in_error = hosterr;
#endif

	switch ((hosterr >> 8) & 0xff) {
	case 0:		/* Reserved */
		hosterr = DID_ERROR;
		break;
	case 1:		/* Command Complete, no errors */
		hosterr = DID_OK;
		break;
	case 2:		/* Command complete, error logged in scb status (scsierr) */
		hosterr = DID_OK;
		break;
	case 4:		/* Command failed to complete - timeout */
		hosterr = DID_TIME_OUT;
		break;
	case 5:		/* Command terminated; Bus reset by external device */
		hosterr = DID_RESET;
		break;
	case 6:		/* Unexpected Command Received w/ host as target */
		hosterr = DID_BAD_TARGET;
		break;
	case 80:		/* Unexpected Reselection */
	case 81:		/* Unexpected Selection */
		hosterr = DID_BAD_INTR;
		break;
	case 82:		/* Abort Command Message  */
		hosterr = DID_ABORT;
		break;
	case 83:		/* SCSI Bus Software Reset */
	case 84:		/* SCSI Bus Hardware Reset */
		hosterr = DID_RESET;
		break;
	default:		/* Reserved */
		hosterr = DID_ERROR;
	}
#ifdef WD7000_DEBUG
	if (scsierr || hosterr)
		dprintk("\nSCSI command error: SCSI 0x%02x host 0x%04x return %d\n", scsierr, in_error, hosterr);
#endif
	return (scsierr | (hosterr << 16));
}

#define wd7000_intr_ack(host)   outb (0, host->iobase + ASC_INTR_ACK)


static irqreturn_t wd7000_intr(int irq, void *dev_id)
{
	Adapter *host = (Adapter *) dev_id;
	int flag, icmb, errstatus, icmb_status;
	int host_error, scsi_error;
	Scb *scb;	/* for SCSI commands */
	IcbAny *icb;	/* for host commands */
	struct scsi_cmnd *SCpnt;
	Mailbox *icmbs = host->mb.icmb;
	unsigned long flags;

	spin_lock_irqsave(host->sh->host_lock, flags);
	host->int_counter++;

	dprintk("wd7000_intr: irq = %d, host = 0x%06lx\n", irq, (long) host);

	flag = inb(host->iobase + ASC_INTR_STAT);

	dprintk("wd7000_intr: intr stat = 0x%02x\n", flag);

	if (!(inb(host->iobase + ASC_STAT) & INT_IM)) {
		/* NB: these are _very_ possible if IRQ 15 is being used, since
		 * it's the "garbage collector" on the 2nd 8259 PIC.  Specifically,
		 * any interrupt signal into the 8259 which can't be identified
		 * comes out as 7 from the 8259, which is 15 to the host.  Thus, it
		 * is a good thing the WD7000 has an interrupt status port, so we
		 * can sort these out.  Otherwise, electrical noise and other such
		 * problems would be indistinguishable from valid interrupts...
		 */
		dprintk("wd7000_intr: phantom interrupt...\n");
		goto ack;
	}

	if (!(flag & MB_INTR))
		goto ack;

	/* The interrupt is for a mailbox */
	if (!(flag & IMB_INTR)) {
		dprintk("wd7000_intr: free outgoing mailbox\n");
		/*
		 * If sleep_on() and the "interrupt on free OGMB" command are
		 * used in mail_out(), wake_up() should correspondingly be called
		 * here.  For now, we don't need to do anything special.
		 */
		goto ack;
	}

	/* The interrupt is for an incoming mailbox */
	icmb = flag & MB_MASK;
	icmb_status = icmbs[icmb].status;
	if (icmb_status & 0x80) {	/* unsolicited - result in ICMB */
		dprintk("wd7000_intr: unsolicited interrupt 0x%02x\n", icmb_status);
		goto ack;
	}

	/* Aaaargh! (Zaga) */
	scb = isa_bus_to_virt(scsi2int((unchar *) icmbs[icmb].scbptr));
	icmbs[icmb].status = 0;
	if (scb->op & ICB_OP_MASK) {	/* an SCB is done */
		icb = (IcbAny *) scb;
		icb->status = icmb_status;
		icb->phase = 0;
		goto ack;
	}

	SCpnt = scb->SCpnt;
	if (--(SCpnt->SCp.phase) <= 0) {	/* all scbs are done */
		host_error = scb->vue | (icmb_status << 8);
		scsi_error = scb->status;
		errstatus = make_code(host_error, scsi_error);
		SCpnt->result = errstatus;

		free_scb(scb);

		SCpnt->scsi_done(SCpnt);
	}

 ack:
	dprintk("wd7000_intr: return from interrupt handler\n");
	wd7000_intr_ack(host);

	spin_unlock_irqrestore(host->sh->host_lock, flags);
	return IRQ_HANDLED;
}

static int wd7000_queuecommand(struct scsi_cmnd *SCpnt,
		void (*done)(struct scsi_cmnd *))
{
	Scb *scb;
	Sgb *sgb;
	unchar *cdb = (unchar *) SCpnt->cmnd;
	unchar idlun;
	short cdblen;
	int nseg;
	Adapter *host = (Adapter *) SCpnt->device->host->hostdata;

	cdblen = SCpnt->cmd_len;
	idlun = ((SCpnt->device->id << 5) & 0xe0) | (SCpnt->device->lun & 7);
	SCpnt->scsi_done = done;
	SCpnt->SCp.phase = 1;
	scb = alloc_scbs(SCpnt->device->host, 1);
	scb->idlun = idlun;
	memcpy(scb->cdb, cdb, cdblen);
	scb->direc = 0x40;	/* Disable direction check */

	scb->SCpnt = SCpnt;	/* so we can find stuff later */
	SCpnt->host_scribble = (unchar *) scb;
	scb->host = host;

	nseg = scsi_sg_count(SCpnt);
	if (nseg > 1) {
		struct scatterlist *sg;
		unsigned i;

		dprintk("Using scatter/gather with %d elements.\n", nseg);

		sgb = scb->sgb;
		scb->op = 1;
		any2scsi(scb->dataptr, (int) sgb);
		any2scsi(scb->maxlen, nseg * sizeof(Sgb));

		scsi_for_each_sg(SCpnt, sg, nseg, i) {
			any2scsi(sgb[i].ptr, isa_page_to_bus(sg_page(sg)) + sg->offset);
			any2scsi(sgb[i].len, sg->length);
		}
	} else {
		scb->op = 0;
		if (nseg) {
			struct scatterlist *sg = scsi_sglist(SCpnt);
			any2scsi(scb->dataptr, isa_page_to_bus(sg_page(sg)) + sg->offset);
		}
		any2scsi(scb->maxlen, scsi_bufflen(SCpnt));
	}

	/* FIXME: drop lock and yield here ? */

	while (!mail_out(host, scb))
		cpu_relax();	/* keep trying */

	return 0;
}

static int wd7000_diagnostics(Adapter * host, int code)
{
	static IcbDiag icb = { ICB_OP_DIAGNOSTICS };
	static unchar buf[256];
	unsigned long timeout;

	icb.type = code;
	any2scsi(icb.len, sizeof(buf));
	any2scsi(icb.ptr, (int) &buf);
	icb.phase = 1;
	/*
	 * This routine is only called at init, so there should be OGMBs
	 * available.  I'm assuming so here.  If this is going to
	 * fail, I can just let the timeout catch the failure.
	 */
	mail_out(host, (struct scb *) &icb);
	timeout = jiffies + WAITnexttimeout;	/* wait up to 2 seconds */
	while (icb.phase && time_before(jiffies, timeout)) {
		cpu_relax();	/* wait for completion */
		barrier();
	}

	if (icb.phase) {
		printk("wd7000_diagnostics: timed out.\n");
		return (0);
	}
	if (make_code(icb.vue | (icb.status << 8), 0)) {
		printk("wd7000_diagnostics: failed (0x%02x,0x%02x)\n", icb.vue, icb.status);
		return (0);
	}

	return (1);
}


static int wd7000_adapter_reset(Adapter * host)
{
	InitCmd init_cmd = {
		INITIALIZATION,
		7,
		host->bus_on,
		host->bus_off,
		0,
		{0, 0, 0},
		OGMB_CNT,
		ICMB_CNT
	};
	int diag;
	/*
	 *  Reset the adapter - only.  The SCSI bus was initialized at power-up,
	 *  and we need to do this just so we control the mailboxes, etc.
	 */
	outb(ASC_RES, host->iobase + ASC_CONTROL);
	udelay(40);		/* reset pulse: this is 40us, only need 25us */
	outb(0, host->iobase + ASC_CONTROL);
	host->control = 0;	/* this must always shadow ASC_CONTROL */

	if (WAIT(host->iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0)) {
		printk(KERN_ERR "wd7000_init: WAIT timed out.\n");
		return -1;	/* -1 = not ok */
	}

	if ((diag = inb(host->iobase + ASC_INTR_STAT)) != 1) {
		printk("wd7000_init: ");

		switch (diag) {
		case 2:
			printk(KERN_ERR "RAM failure.\n");
			break;
		case 3:
			printk(KERN_ERR "FIFO R/W failed\n");
			break;
		case 4:
			printk(KERN_ERR "SBIC register R/W failed\n");
			break;
		case 5:
			printk(KERN_ERR "Initialization D-FF failed.\n");
			break;
		case 6:
			printk(KERN_ERR "Host IRQ D-FF failed.\n");
			break;
		case 7:
			printk(KERN_ERR "ROM checksum error.\n");
			break;
		default:
			printk(KERN_ERR "diagnostic code 0x%02Xh received.\n", diag);
		}
		return -1;
	}
	/* Clear mailboxes */
	memset(&(host->mb), 0, sizeof(host->mb));

	/* Execute init command */
	any2scsi((unchar *) & (init_cmd.mailboxes), (int) &(host->mb));
	if (!command_out(host, (unchar *) & init_cmd, sizeof(init_cmd))) {
		printk(KERN_ERR "wd7000_adapter_reset: adapter initialization failed.\n");
		return -1;
	}

	if (WAIT(host->iobase + ASC_STAT, ASC_STATMASK, ASC_INIT, 0)) {
		printk("wd7000_adapter_reset: WAIT timed out.\n");
		return -1;
	}
	return 0;
}

static int wd7000_init(Adapter * host)
{
	if (wd7000_adapter_reset(host) == -1)
		return 0;


	if (request_irq(host->irq, wd7000_intr, IRQF_DISABLED, "wd7000", host)) {
		printk("wd7000_init: can't get IRQ %d.\n", host->irq);
		return (0);
	}
	if (request_dma(host->dma, "wd7000")) {
		printk("wd7000_init: can't get DMA channel %d.\n", host->dma);
		free_irq(host->irq, host);
		return (0);
	}
	wd7000_enable_dma(host);
	wd7000_enable_intr(host);

	if (!wd7000_diagnostics(host, ICB_DIAG_FULL)) {
		free_dma(host->dma);
		free_irq(host->irq, NULL);
		return (0);
	}

	return (1);
}


static void wd7000_revision(Adapter * host)
{
	static IcbRevLvl icb = { ICB_OP_GET_REVISION };

	icb.phase = 1;
	/*
	 * Like diagnostics, this is only done at init time, in fact, from
	 * wd7000_detect, so there should be OGMBs available.  If it fails,
	 * the only damage will be that the revision will show up as 0.0,
	 * which in turn means that scatter/gather will be disabled.
	 */
	mail_out(host, (struct scb *) &icb);
	while (icb.phase) {
		cpu_relax();	/* wait for completion */
		barrier();
	}
	host->rev1 = icb.primary;
	host->rev2 = icb.secondary;
}


#undef SPRINTF
#define SPRINTF(args...) { if (pos < (buffer + length)) pos += sprintf (pos, ## args); }

static int wd7000_set_info(char *buffer, int length, struct Scsi_Host *host)
{
	dprintk("Buffer = <%.*s>, length = %d\n", length, buffer, length);

	/*
	 * Currently this is a no-op
	 */
	dprintk("Sorry, this function is currently out of order...\n");
	return (length);
}


static int wd7000_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length,  int inout)
{
	Adapter *adapter = (Adapter *)host->hostdata;
	unsigned long flags;
	char *pos = buffer;
#ifdef WD7000_DEBUG
	Mailbox *ogmbs, *icmbs;
	short count;
#endif

	/*
	 * Has data been written to the file ?
	 */
	if (inout)
		return (wd7000_set_info(buffer, length, host));

	spin_lock_irqsave(host->host_lock, flags);
	SPRINTF("Host scsi%d: Western Digital WD-7000 (rev %d.%d)\n", host->host_no, adapter->rev1, adapter->rev2);
	SPRINTF("  IO base:      0x%x\n", adapter->iobase);
	SPRINTF("  IRQ:          %d\n", adapter->irq);
	SPRINTF("  DMA channel:  %d\n", adapter->dma);
	SPRINTF("  Interrupts:   %d\n", adapter->int_counter);
	SPRINTF("  BUS_ON time:  %d nanoseconds\n", adapter->bus_on * 125);
	SPRINTF("  BUS_OFF time: %d nanoseconds\n", adapter->bus_off * 125);

#ifdef WD7000_DEBUG
	ogmbs = adapter->mb.ogmb;
	icmbs = adapter->mb.icmb;

	SPRINTF("\nControl port value: 0x%x\n", adapter->control);
	SPRINTF("Incoming mailbox:\n");
	SPRINTF("  size: %d\n", ICMB_CNT);
	SPRINTF("  queued messages: ");

	for (i = count = 0; i < ICMB_CNT; i++)
		if (icmbs[i].status) {
			count++;
			SPRINTF("0x%x ", i);
		}

	SPRINTF(count ? "\n" : "none\n");

	SPRINTF("Outgoing mailbox:\n");
	SPRINTF("  size: %d\n", OGMB_CNT);
	SPRINTF("  next message: 0x%x\n", adapter->next_ogmb);
	SPRINTF("  queued messages: ");

	for (i = count = 0; i < OGMB_CNT; i++)
		if (ogmbs[i].status) {
			count++;
			SPRINTF("0x%x ", i);
		}

	SPRINTF(count ? "\n" : "none\n");
#endif

	spin_unlock_irqrestore(host->host_lock, flags);

	/*
	 * Calculate start of next buffer, and return value.
	 */
	*start = buffer + offset;

	if ((pos - buffer) < offset)
		return (0);
	else if ((pos - buffer - offset) < length)
		return (pos - buffer - offset);
	else
		return (length);
}


/*
 *  Returns the number of adapters this driver is supporting.
 *
 *  The source for hosts.c says to wait to call scsi_register until 100%
 *  sure about an adapter.  We need to do it a little sooner here; we
 *  need the storage set up by scsi_register before wd7000_init, and
 *  changing the location of an Adapter structure is more trouble than
 *  calling scsi_unregister.
 *
 */

static __init int wd7000_detect(struct scsi_host_template *tpnt)
{
	short present = 0, biosaddr_ptr, sig_ptr, i, pass;
	short biosptr[NUM_CONFIGS];
	unsigned iobase;
	Adapter *host = NULL;
	struct Scsi_Host *sh;
	int unit = 0;

	dprintk("wd7000_detect: started\n");

#ifdef MODULE
	if (wd7000)
		wd7000_setup(wd7000);
#endif

	for (i = 0; i < UNITS; wd7000_host[i++] = NULL);
	for (i = 0; i < NUM_CONFIGS; biosptr[i++] = -1);

	tpnt->proc_name = "wd7000";
	tpnt->proc_info = &wd7000_proc_info;

	/*
	 * Set up SCB free list, which is shared by all adapters
	 */
	init_scbs();

	for (pass = 0; pass < NUM_CONFIGS; pass++) {
		/*
		 * First, search for BIOS SIGNATURE...
		 */
		for (biosaddr_ptr = 0; biosaddr_ptr < NUM_ADDRS; biosaddr_ptr++)
			for (sig_ptr = 0; sig_ptr < NUM_SIGNATURES; sig_ptr++) {
				for (i = 0; i < pass; i++)
					if (biosptr[i] == biosaddr_ptr)
						break;

				if (i == pass) {
					void __iomem *biosaddr = ioremap(wd7000_biosaddr[biosaddr_ptr] + signatures[sig_ptr].ofs,
								 signatures[sig_ptr].len);
					short bios_match = 1;

					if (biosaddr)
						bios_match = check_signature(biosaddr, signatures[sig_ptr].sig, signatures[sig_ptr].len);

					iounmap(biosaddr);

					if (bios_match)
						goto bios_matched;
				}
			}

	      bios_matched:
		/*
		 * BIOS SIGNATURE has been found.
		 */
#ifdef WD7000_DEBUG
		dprintk("wd7000_detect: pass %d\n", pass + 1);

		if (biosaddr_ptr == NUM_ADDRS)
			dprintk("WD-7000 SST BIOS not detected...\n");
		else
			dprintk("WD-7000 SST BIOS detected at 0x%lx: checking...\n", wd7000_biosaddr[biosaddr_ptr]);
#endif

		if (configs[pass].irq < 0)
			continue;

		if (unit == UNITS)
			continue;

		iobase = configs[pass].iobase;

		dprintk("wd7000_detect: check IO 0x%x region...\n", iobase);

		if (request_region(iobase, 4, "wd7000")) {

			dprintk("wd7000_detect: ASC reset (IO 0x%x) ...", iobase);
			/*
			 * ASC reset...
			 */
			outb(ASC_RES, iobase + ASC_CONTROL);
			msleep(10);
			outb(0, iobase + ASC_CONTROL);

			if (WAIT(iobase + ASC_STAT, ASC_STATMASK, CMD_RDY, 0)) {
				dprintk("failed!\n");
				goto err_release;
			} else
				dprintk("ok!\n");

			if (inb(iobase + ASC_INTR_STAT) == 1) {
				/*
				 *  We register here, to get a pointer to the extra space,
				 *  which we'll use as the Adapter structure (host) for
				 *  this adapter.  It is located just after the registered
				 *  Scsi_Host structure (sh), and is located by the empty
				 *  array hostdata.
				 */
				sh = scsi_register(tpnt, sizeof(Adapter));
				if (sh == NULL)
					goto err_release;

				host = (Adapter *) sh->hostdata;

				dprintk("wd7000_detect: adapter allocated at 0x%x\n", (int) host);
				memset(host, 0, sizeof(Adapter));

				host->irq = configs[pass].irq;
				host->dma = configs[pass].dma;
				host->iobase = iobase;
				host->int_counter = 0;
				host->bus_on = configs[pass].bus_on;
				host->bus_off = configs[pass].bus_off;
				host->sh = wd7000_host[unit] = sh;
				unit++;

				dprintk("wd7000_detect: Trying init WD-7000 card at IO " "0x%x, IRQ %d, DMA %d...\n", host->iobase, host->irq, host->dma);

				if (!wd7000_init(host))	/* Initialization failed */
					goto err_unregister;

				/*
				 *  OK from here - we'll use this adapter/configuration.
				 */
				wd7000_revision(host);	/* important for scatter/gather */

				/*
				 *  For boards before rev 6.0, scatter/gather isn't supported.
				 */
				if (host->rev1 < 6)
					sh->sg_tablesize = 1;

				present++;	/* count it */

				if (biosaddr_ptr != NUM_ADDRS)
					biosptr[pass] = biosaddr_ptr;

				printk(KERN_INFO "Western Digital WD-7000 (rev %d.%d) ", host->rev1, host->rev2);
				printk("using IO 0x%x, IRQ %d, DMA %d.\n", host->iobase, host->irq, host->dma);
				printk("  BUS_ON time: %dns, BUS_OFF time: %dns\n", host->bus_on * 125, host->bus_off * 125);
			}
		} else
			dprintk("wd7000_detect: IO 0x%x region already allocated!\n", iobase);

		continue;

	      err_unregister:
		scsi_unregister(sh);
	      err_release:
		release_region(iobase, 4);

	}

	if (!present)
		printk("Failed initialization of WD-7000 SCSI card!\n");

	return (present);
}

static int wd7000_release(struct Scsi_Host *shost)
{
	if (shost->irq)
		free_irq(shost->irq, NULL);
	if (shost->io_port && shost->n_io_port)
		release_region(shost->io_port, shost->n_io_port);
	scsi_unregister(shost);
	return 0;
}

#if 0
/*
 *  I have absolutely NO idea how to do an abort with the WD7000...
 */
static int wd7000_abort(Scsi_Cmnd * SCpnt)
{
	Adapter *host = (Adapter *) SCpnt->device->host->hostdata;

	if (inb(host->iobase + ASC_STAT) & INT_IM) {
		printk("wd7000_abort: lost interrupt\n");
		wd7000_intr_handle(host->irq, NULL, NULL);
		return FAILED;
	}
	return FAILED;
}
#endif

/*
 *  Last resort. Reinitialize the board.
 */

static int wd7000_host_reset(struct scsi_cmnd *SCpnt)
{
	Adapter *host = (Adapter *) SCpnt->device->host->hostdata;

	spin_lock_irq(SCpnt->device->host->host_lock);

	if (wd7000_adapter_reset(host) < 0) {
		spin_unlock_irq(SCpnt->device->host->host_lock);
		return FAILED;
	}

	wd7000_enable_intr(host);

	spin_unlock_irq(SCpnt->device->host->host_lock);
	return SUCCESS;
}

/*
 *  This was borrowed directly from aha1542.c. (Zaga)
 */

static int wd7000_biosparam(struct scsi_device *sdev,
		struct block_device *bdev, sector_t capacity, int *ip)
{
	char b[BDEVNAME_SIZE];

	dprintk("wd7000_biosparam: dev=%s, size=%d, ",
		bdevname(bdev, b), capacity);
	(void)b;	/* unused var warning? */

	/*
	 * try default translation
	 */
	ip[0] = 64;
	ip[1] = 32;
	ip[2] = capacity >> 11;

	/*
	 * for disks >1GB do some guessing
	 */
	if (ip[2] >= 1024) {
		int info[3];

		/*
		 * try to figure out the geometry from the partition table
		 */
		if ((scsicam_bios_param(bdev, capacity, info) < 0) || !(((info[0] == 64) && (info[1] == 32)) || ((info[0] == 255) && (info[1] == 63)))) {
			printk("wd7000_biosparam: unable to verify geometry for disk with >1GB.\n" "                  using extended translation.\n");

			ip[0] = 255;
			ip[1] = 63;
			ip[2] = (unsigned long) capacity / (255 * 63);
		} else {
			ip[0] = info[0];
			ip[1] = info[1];
			ip[2] = info[2];

			if (info[0] == 255)
				printk(KERN_INFO "%s: current partition table is " "using extended translation.\n", __func__);
		}
	}

	dprintk("bios geometry: head=%d, sec=%d, cyl=%d\n", ip[0], ip[1], ip[2]);
	dprintk("WARNING: check, if the bios geometry is correct.\n");

	return (0);
}

MODULE_AUTHOR("Thomas Wuensche, John Boyd, Miroslav Zagorac");
MODULE_DESCRIPTION("Driver for the WD7000 series ISA controllers");
MODULE_LICENSE("GPL");

static struct scsi_host_template driver_template = {
	.proc_name		= "wd7000",
	.proc_info		= wd7000_proc_info,
	.name			= "Western Digital WD-7000",
	.detect			= wd7000_detect,
	.release		= wd7000_release,
	.queuecommand		= wd7000_queuecommand,
	.eh_host_reset_handler	= wd7000_host_reset,
	.bios_param		= wd7000_biosparam,
	.can_queue		= WD7000_Q,
	.this_id		= 7,
	.sg_tablesize		= WD7000_SG,
	.cmd_per_lun		= 1,
	.unchecked_isa_dma	= 1,
	.use_clustering		= ENABLE_CLUSTERING,
};

#include "scsi_module.c"