aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/wd33c93.c
blob: 41883a87931d1d68d4336478b4cc5c5c6ab8f967 (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
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
/*
 * Copyright (c) 1996 John Shifflett, GeoLog Consulting
 *    john@geolog.com
 *    jshiffle@netcom.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/*
 * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC
 * provided much of the inspiration and some of the code for this
 * driver. Everything I know about Amiga DMA was gleaned from careful
 * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I
 * borrowed shamelessly from all over that source. Thanks Hamish!
 *
 * _This_ driver is (I feel) an improvement over the old one in
 * several respects:
 *
 *    -  Target Disconnection/Reconnection  is now supported. Any
 *          system with more than one device active on the SCSI bus
 *          will benefit from this. The driver defaults to what I
 *          call 'adaptive disconnect' - meaning that each command
 *          is evaluated individually as to whether or not it should
 *          be run with the option to disconnect/reselect (if the
 *          device chooses), or as a "SCSI-bus-hog".
 *
 *    -  Synchronous data transfers are now supported. Because of
 *          a few devices that choke after telling the driver that
 *          they can do sync transfers, we don't automatically use
 *          this faster protocol - it can be enabled via the command-
 *          line on a device-by-device basis.
 *
 *    -  Runtime operating parameters can now be specified through
 *       the 'amiboot' or the 'insmod' command line. For amiboot do:
 *          "amiboot [usual stuff] wd33c93=blah,blah,blah"
 *       The defaults should be good for most people. See the comment
 *       for 'setup_strings' below for more details.
 *
 *    -  The old driver relied exclusively on what the Western Digital
 *          docs call "Combination Level 2 Commands", which are a great
 *          idea in that the CPU is relieved of a lot of interrupt
 *          overhead. However, by accepting a certain (user-settable)
 *          amount of additional interrupts, this driver achieves
 *          better control over the SCSI bus, and data transfers are
 *          almost as fast while being much easier to define, track,
 *          and debug.
 *
 *
 * TODO:
 *       more speed. linked commands.
 *
 *
 * People with bug reports, wish-lists, complaints, comments,
 * or improvements are asked to pah-leeez email me (John Shifflett)
 * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get
 * this thing into as good a shape as possible, and I'm positive
 * there are lots of lurking bugs and "Stupid Places".
 *
 * Updates:
 *
 * Added support for pre -A chips, which don't have advanced features
 * and will generate CSR_RESEL rather than CSR_RESEL_AM.
 *	Richard Hirst <richard@sleepie.demon.co.uk>  August 2000
 *
 * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of
 * default_sx_per for asynchronous data transfers. Added adjustment
 * of transfer periods in sx_table to the actual input-clock.
 *  peter fuerst <post@pfrst.de>  February 2007
 */

#include <linux/module.h>

#include <linux/string.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>

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

#include <asm/irq.h>

#include "wd33c93.h"

#define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns


#define WD33C93_VERSION    "1.26++"
#define WD33C93_DATE       "10/Feb/2007"

MODULE_AUTHOR("John Shifflett");
MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
MODULE_LICENSE("GPL");

/*
 * 'setup_strings' is a single string used to pass operating parameters and
 * settings from the kernel/module command-line to the driver. 'setup_args[]'
 * is an array of strings that define the compile-time default values for
 * these settings. If Linux boots with an amiboot or insmod command-line,
 * those settings are combined with 'setup_args[]'. Note that amiboot
 * command-lines are prefixed with "wd33c93=" while insmod uses a
 * "setup_strings=" prefix. The driver recognizes the following keywords
 * (lower case required) and arguments:
 *
 * -  nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with
 *                    the 7 possible SCSI devices. Set a bit to negotiate for
 *                    asynchronous transfers on that device. To maintain
 *                    backwards compatibility, a command-line such as
 *                    "wd33c93=255" will be automatically translated to
 *                    "wd33c93=nosync:0xff".
 * -  nodma:x        -x = 1 to disable DMA, x = 0 to enable it. Argument is
 *                    optional - if not present, same as "nodma:1".
 * -  period:ns      -ns is the minimum # of nanoseconds in a SCSI data transfer
 *                    period. Default is 500; acceptable values are 250 - 1000.
 * -  disconnect:x   -x = 0 to never allow disconnects, 2 to always allow them.
 *                    x = 1 does 'adaptive' disconnects, which is the default
 *                    and generally the best choice.
 * -  debug:x        -If 'DEBUGGING_ON' is defined, x is a bit mask that causes
 *                    various types of debug output to printed - see the DB_xxx
 *                    defines in wd33c93.h
 * -  clock:x        -x = clock input in MHz for WD33c93 chip. Normal values
 *                    would be from 8 through 20. Default is 8.
 * -  burst:x        -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use
 *                    Single Byte DMA, which is the default. Argument is
 *                    optional - if not present, same as "burst:1".
 * -  fast:x         -x = 1 to enable Fast SCSI, which is only effective with
 *                    input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable
 *                    it, which is the default.  Argument is optional - if not
 *                    present, same as "fast:1".
 * -  next           -No argument. Used to separate blocks of keywords when
 *                    there's more than one host adapter in the system.
 *
 * Syntax Notes:
 * -  Numeric arguments can be decimal or the '0x' form of hex notation. There
 *    _must_ be a colon between a keyword and its numeric argument, with no
 *    spaces.
 * -  Keywords are separated by commas, no spaces, in the standard kernel
 *    command-line manner.
 * -  A keyword in the 'nth' comma-separated command-line member will overwrite
 *    the 'nth' element of setup_args[]. A blank command-line member (in
 *    other words, a comma with no preceding keyword) will _not_ overwrite
 *    the corresponding setup_args[] element.
 * -  If a keyword is used more than once, the first one applies to the first
 *    SCSI host found, the second to the second card, etc, unless the 'next'
 *    keyword is used to change the order.
 *
 * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'):
 * -  wd33c93=nosync:255
 * -  wd33c93=nodma
 * -  wd33c93=nodma:1
 * -  wd33c93=disconnect:2,nosync:0x08,period:250
 * -  wd33c93=debug:0x1c
 */

/* Normally, no defaults are specified */
static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };

static char *setup_strings;
module_param(setup_strings, charp, 0);

static void wd33c93_execute(struct Scsi_Host *instance);

#ifdef CONFIG_WD33C93_PIO
static inline uchar
read_wd33c93(const wd33c93_regs regs, uchar reg_num)
{
	uchar data;

	outb(reg_num, regs.SASR);
	data = inb(regs.SCMD);
	return data;
}

static inline unsigned long
read_wd33c93_count(const wd33c93_regs regs)
{
	unsigned long value;

	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
	value = inb(regs.SCMD) << 16;
	value |= inb(regs.SCMD) << 8;
	value |= inb(regs.SCMD);
	return value;
}

static inline uchar
read_aux_stat(const wd33c93_regs regs)
{
	return inb(regs.SASR);
}

static inline void
write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
{
      outb(reg_num, regs.SASR);
      outb(value, regs.SCMD);
}

static inline void
write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
{
	outb(WD_TRANSFER_COUNT_MSB, regs.SASR);
	outb((value >> 16) & 0xff, regs.SCMD);
	outb((value >> 8) & 0xff, regs.SCMD);
	outb( value & 0xff, regs.SCMD);
}

#define write_wd33c93_cmd(regs, cmd) \
	write_wd33c93((regs), WD_COMMAND, (cmd))

static inline void
write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
{
	int i;

	outb(WD_CDB_1, regs.SASR);
	for (i=0; i<len; i++)
		outb(cmnd[i], regs.SCMD);
}

#else /* CONFIG_WD33C93_PIO */
static inline uchar
read_wd33c93(const wd33c93_regs regs, uchar reg_num)
{
	*regs.SASR = reg_num;
	mb();
	return (*regs.SCMD);
}

static unsigned long
read_wd33c93_count(const wd33c93_regs regs)
{
	unsigned long value;

	*regs.SASR = WD_TRANSFER_COUNT_MSB;
	mb();
	value = *regs.SCMD << 16;
	value |= *regs.SCMD << 8;
	value |= *regs.SCMD;
	mb();
	return value;
}

static inline uchar
read_aux_stat(const wd33c93_regs regs)
{
	return *regs.SASR;
}

static inline void
write_wd33c93(const wd33c93_regs regs, uchar reg_num, uchar value)
{
	*regs.SASR = reg_num;
	mb();
	*regs.SCMD = value;
	mb();
}

static void
write_wd33c93_count(const wd33c93_regs regs, unsigned long value)
{
	*regs.SASR = WD_TRANSFER_COUNT_MSB;
	mb();
	*regs.SCMD = value >> 16;
	*regs.SCMD = value >> 8;
	*regs.SCMD = value;
	mb();
}

static inline void
write_wd33c93_cmd(const wd33c93_regs regs, uchar cmd)
{
	*regs.SASR = WD_COMMAND;
	mb();
	*regs.SCMD = cmd;
	mb();
}

static inline void
write_wd33c93_cdb(const wd33c93_regs regs, uint len, uchar cmnd[])
{
	int i;

	*regs.SASR = WD_CDB_1;
	for (i = 0; i < len; i++)
		*regs.SCMD = cmnd[i];
}
#endif /* CONFIG_WD33C93_PIO */

static inline uchar
read_1_byte(const wd33c93_regs regs)
{
	uchar asr;
	uchar x = 0;

	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO | 0x80);
	do {
		asr = read_aux_stat(regs);
		if (asr & ASR_DBR)
			x = read_wd33c93(regs, WD_DATA);
	} while (!(asr & ASR_INT));
	return x;
}

static int
round_period(unsigned int period, const struct sx_period *sx_table)
{
	int x;

	for (x = 1; sx_table[x].period_ns; x++) {
		if ((period <= sx_table[x - 0].period_ns) &&
		    (period > sx_table[x - 1].period_ns)) {
			return x;
		}
	}
	return 7;
}

/*
 * Calculate Synchronous Transfer Register value from SDTR code.
 */
static uchar
calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
               const struct sx_period *sx_table)
{
	/* When doing Fast SCSI synchronous data transfers, the corresponding
	 * value in 'sx_table' is two times the actually used transfer period.
	 */
	uchar result;

	if (offset && fast) {
		fast = STR_FSS;
		period *= 2;
	} else {
		fast = 0;
	}
	period *= 4;		/* convert SDTR code to ns */
	result = sx_table[round_period(period,sx_table)].reg_value;
	result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
	result |= fast;
	return result;
}

/*
 * Calculate SDTR code bytes [3],[4] from period and offset.
 */
static inline void
calc_sync_msg(unsigned int period, unsigned int offset, unsigned int fast,
                uchar  msg[2])
{
	/* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The
	 * actually used transfer period for Fast SCSI synchronous data
	 * transfers is half that value.
	 */
	period /= 4;
	if (offset && fast)
		period /= 2;
	msg[0] = period;
	msg[1] = offset;
}

static int
wd33c93_queuecommand_lck(struct scsi_cmnd *cmd,
		void (*done)(struct scsi_cmnd *))
{
	struct WD33C93_hostdata *hostdata;
	struct scsi_cmnd *tmp;

	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;

	DB(DB_QUEUE_COMMAND,
	   printk("Q-%d-%02x( ", cmd->device->id, cmd->cmnd[0]))

/* Set up a few fields in the scsi_cmnd structure for our own use:
 *  - host_scribble is the pointer to the next cmd in the input queue
 *  - scsi_done points to the routine we call when a cmd is finished
 *  - result is what you'd expect
 */
	cmd->host_scribble = NULL;
	cmd->scsi_done = done;
	cmd->result = 0;

/* We use the Scsi_Pointer structure that's included with each command
 * as a scratchpad (as it's intended to be used!). The handy thing about
 * the SCp.xxx fields is that they're always associated with a given
 * cmd, and are preserved across disconnect-reselect. This means we
 * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages
 * if we keep all the critical pointers and counters in SCp:
 *  - SCp.ptr is the pointer into the RAM buffer
 *  - SCp.this_residual is the size of that buffer
 *  - SCp.buffer points to the current scatter-gather buffer
 *  - SCp.buffers_residual tells us how many S.G. buffers there are
 *  - SCp.have_data_in is not used
 *  - SCp.sent_command is not used
 *  - SCp.phase records this command's SRCID_ER bit setting
 */

	if (scsi_bufflen(cmd)) {
		cmd->SCp.buffer = scsi_sglist(cmd);
		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
		cmd->SCp.this_residual = cmd->SCp.buffer->length;
	} else {
		cmd->SCp.buffer = NULL;
		cmd->SCp.buffers_residual = 0;
		cmd->SCp.ptr = NULL;
		cmd->SCp.this_residual = 0;
	}

/* WD docs state that at the conclusion of a "LEVEL2" command, the
 * status byte can be retrieved from the LUN register. Apparently,
 * this is the case only for *uninterrupted* LEVEL2 commands! If
 * there are any unexpected phases entered, even if they are 100%
 * legal (different devices may choose to do things differently),
 * the LEVEL2 command sequence is exited. This often occurs prior
 * to receiving the status byte, in which case the driver does a
 * status phase interrupt and gets the status byte on its own.
 * While such a command can then be "resumed" (ie restarted to
 * finish up as a LEVEL2 command), the LUN register will NOT be
 * a valid status byte at the command's conclusion, and we must
 * use the byte obtained during the earlier interrupt. Here, we
 * preset SCp.Status to an illegal value (0xff) so that when
 * this command finally completes, we can tell where the actual
 * status byte is stored.
 */

	cmd->SCp.Status = ILLEGAL_STATUS_BYTE;

	/*
	 * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE
	 * commands are added to the head of the queue so that the desired
	 * sense data is not lost before REQUEST_SENSE executes.
	 */

	spin_lock_irq(&hostdata->lock);

	if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
		cmd->host_scribble = (uchar *) hostdata->input_Q;
		hostdata->input_Q = cmd;
	} else {		/* find the end of the queue */
		for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
		     tmp->host_scribble;
		     tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
		tmp->host_scribble = (uchar *) cmd;
	}

/* We know that there's at least one command in 'input_Q' now.
 * Go see if any of them are runnable!
 */

	wd33c93_execute(cmd->device->host);

	DB(DB_QUEUE_COMMAND, printk(")Q "))

	spin_unlock_irq(&hostdata->lock);
	return 0;
}

DEF_SCSI_QCMD(wd33c93_queuecommand)

/*
 * This routine attempts to start a scsi command. If the host_card is
 * already connected, we give up immediately. Otherwise, look through
 * the input_Q, using the first command we find that's intended
 * for a currently non-busy target/lun.
 *
 * wd33c93_execute() is always called with interrupts disabled or from
 * the wd33c93_intr itself, which means that a wd33c93 interrupt
 * cannot occur while we are in here.
 */
static void
wd33c93_execute(struct Scsi_Host *instance)
{
	struct WD33C93_hostdata *hostdata =
	    (struct WD33C93_hostdata *) instance->hostdata;
	const wd33c93_regs regs = hostdata->regs;
	struct scsi_cmnd *cmd, *prev;

	DB(DB_EXECUTE, printk("EX("))
	if (hostdata->selecting || hostdata->connected) {
		DB(DB_EXECUTE, printk(")EX-0 "))
		return;
	}

	/*
	 * Search through the input_Q for a command destined
	 * for an idle target/lun.
	 */

	cmd = (struct scsi_cmnd *) hostdata->input_Q;
	prev = NULL;
	while (cmd) {
		if (!(hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)))
			break;
		prev = cmd;
		cmd = (struct scsi_cmnd *) cmd->host_scribble;
	}

	/* quit if queue empty or all possible targets are busy */

	if (!cmd) {
		DB(DB_EXECUTE, printk(")EX-1 "))
		return;
	}

	/*  remove command from queue */

	if (prev)
		prev->host_scribble = cmd->host_scribble;
	else
		hostdata->input_Q = (struct scsi_cmnd *) cmd->host_scribble;

#ifdef PROC_STATISTICS
	hostdata->cmd_cnt[cmd->device->id]++;
#endif

	/*
	 * Start the selection process
	 */

	if (cmd->sc_data_direction == DMA_TO_DEVICE)
		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
	else
		write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD);

/* Now we need to figure out whether or not this command is a good
 * candidate for disconnect/reselect. We guess to the best of our
 * ability, based on a set of hierarchical rules. When several
 * devices are operating simultaneously, disconnects are usually
 * an advantage. In a single device system, or if only 1 device
 * is being accessed, transfers usually go faster if disconnects
 * are not allowed:
 *
 * + Commands should NEVER disconnect if hostdata->disconnect =
 *   DIS_NEVER (this holds for tape drives also), and ALWAYS
 *   disconnect if hostdata->disconnect = DIS_ALWAYS.
 * + Tape drive commands should always be allowed to disconnect.
 * + Disconnect should be allowed if disconnected_Q isn't empty.
 * + Commands should NOT disconnect if input_Q is empty.
 * + Disconnect should be allowed if there are commands in input_Q
 *   for a different target/lun. In this case, the other commands
 *   should be made disconnect-able, if not already.
 *
 * I know, I know - this code would flunk me out of any
 * "C Programming 101" class ever offered. But it's easy
 * to change around and experiment with for now.
 */

	cmd->SCp.phase = 0;	/* assume no disconnect */
	if (hostdata->disconnect == DIS_NEVER)
		goto no;
	if (hostdata->disconnect == DIS_ALWAYS)
		goto yes;
	if (cmd->device->type == 1)	/* tape drive? */
		goto yes;
	if (hostdata->disconnected_Q)	/* other commands disconnected? */
		goto yes;
	if (!(hostdata->input_Q))	/* input_Q empty? */
		goto no;
	for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
	     prev = (struct scsi_cmnd *) prev->host_scribble) {
		if ((prev->device->id != cmd->device->id) ||
		    (prev->device->lun != cmd->device->lun)) {
			for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
			     prev = (struct scsi_cmnd *) prev->host_scribble)
				prev->SCp.phase = 1;
			goto yes;
		}
	}

	goto no;

 yes:
	cmd->SCp.phase = 1;

#ifdef PROC_STATISTICS
	hostdata->disc_allowed_cnt[cmd->device->id]++;
#endif

 no:

	write_wd33c93(regs, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0));

	write_wd33c93(regs, WD_TARGET_LUN, cmd->device->lun);
	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
		      hostdata->sync_xfer[cmd->device->id]);
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);

	if ((hostdata->level2 == L2_NONE) ||
	    (hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {

		/*
		 * Do a 'Select-With-ATN' command. This will end with
		 * one of the following interrupts:
		 *    CSR_RESEL_AM:  failure - can try again later.
		 *    CSR_TIMEOUT:   failure - give up.
		 *    CSR_SELECT:    success - proceed.
		 */

		hostdata->selecting = cmd;

/* Every target has its own synchronous transfer setting, kept in the
 * sync_xfer array, and a corresponding status byte in sync_stat[].
 * Each target's sync_stat[] entry is initialized to SX_UNSET, and its
 * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET
 * means that the parameters are undetermined as yet, and that we
 * need to send an SDTR message to this device after selection is
 * complete: We set SS_FIRST to tell the interrupt routine to do so.
 * If we've been asked not to try synchronous transfers on this
 * target (and _all_ luns within it), we'll still send the SDTR message
 * later, but at that time we'll negotiate for async by specifying a
 * sync fifo depth of 0.
 */
		if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
			hostdata->sync_stat[cmd->device->id] = SS_FIRST;
		hostdata->state = S_SELECTING;
		write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
	} else {

		/*
		 * Do a 'Select-With-ATN-Xfer' command. This will end with
		 * one of the following interrupts:
		 *    CSR_RESEL_AM:  failure - can try again later.
		 *    CSR_TIMEOUT:   failure - give up.
		 *    anything else: success - proceed.
		 */

		hostdata->connected = cmd;
		write_wd33c93(regs, WD_COMMAND_PHASE, 0);

		/* copy command_descriptor_block into WD chip
		 * (take advantage of auto-incrementing)
		 */

		write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);

		/* The wd33c93 only knows about Group 0, 1, and 5 commands when
		 * it's doing a 'select-and-transfer'. To be safe, we write the
		 * size of the CDB into the OWN_ID register for every case. This
		 * way there won't be problems with vendor-unique, audio, etc.
		 */

		write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);

		/* When doing a non-disconnect command with DMA, we can save
		 * ourselves a DATA phase interrupt later by setting everything
		 * up ahead of time.
		 */

		if ((cmd->SCp.phase == 0) && (hostdata->no_dma == 0)) {
			if (hostdata->dma_setup(cmd,
			    (cmd->sc_data_direction == DMA_TO_DEVICE) ?
			     DATA_OUT_DIR : DATA_IN_DIR))
				write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */
			else {
				write_wd33c93_count(regs,
						    cmd->SCp.this_residual);
				write_wd33c93(regs, WD_CONTROL,
					      CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
				hostdata->dma = D_DMA_RUNNING;
			}
		} else
			write_wd33c93_count(regs, 0);	/* guarantee a DATA_PHASE interrupt */

		hostdata->state = S_RUNNING_LEVEL2;
		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
	}

	/*
	 * Since the SCSI bus can handle only 1 connection at a time,
	 * we get out of here now. If the selection fails, or when
	 * the command disconnects, we'll come back to this routine
	 * to search the input_Q again...
	 */

	DB(DB_EXECUTE,
	   printk("%s)EX-2 ", (cmd->SCp.phase) ? "d:" : ""))
}

static void
transfer_pio(const wd33c93_regs regs, uchar * buf, int cnt,
	     int data_in_dir, struct WD33C93_hostdata *hostdata)
{
	uchar asr;

	DB(DB_TRANSFER,
	   printk("(%p,%d,%s:", buf, cnt, data_in_dir ? "in" : "out"))

	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
	write_wd33c93_count(regs, cnt);
	write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);
	if (data_in_dir) {
		do {
			asr = read_aux_stat(regs);
			if (asr & ASR_DBR)
				*buf++ = read_wd33c93(regs, WD_DATA);
		} while (!(asr & ASR_INT));
	} else {
		do {
			asr = read_aux_stat(regs);
			if (asr & ASR_DBR)
				write_wd33c93(regs, WD_DATA, *buf++);
		} while (!(asr & ASR_INT));
	}

	/* Note: we are returning with the interrupt UN-cleared.
	 * Since (presumably) an entire I/O operation has
	 * completed, the bus phase is probably different, and
	 * the interrupt routine will discover this when it
	 * responds to the uncleared int.
	 */

}

static void
transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
		int data_in_dir)
{
	struct WD33C93_hostdata *hostdata;
	unsigned long length;

	hostdata = (struct WD33C93_hostdata *) cmd->device->host->hostdata;

/* Normally, you'd expect 'this_residual' to be non-zero here.
 * In a series of scatter-gather transfers, however, this
 * routine will usually be called with 'this_residual' equal
 * to 0 and 'buffers_residual' non-zero. This means that a
 * previous transfer completed, clearing 'this_residual', and
 * now we need to setup the next scatter-gather buffer as the
 * source or destination for THIS transfer.
 */
	if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
		++cmd->SCp.buffer;
		--cmd->SCp.buffers_residual;
		cmd->SCp.this_residual = cmd->SCp.buffer->length;
		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
	}
	if (!cmd->SCp.this_residual) /* avoid bogus setups */
		return;

	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
		      hostdata->sync_xfer[cmd->device->id]);

/* 'hostdata->no_dma' is TRUE if we don't even want to try DMA.
 * Update 'this_residual' and 'ptr' after 'transfer_pio()' returns.
 */

	if (hostdata->no_dma || hostdata->dma_setup(cmd, data_in_dir)) {
#ifdef PROC_STATISTICS
		hostdata->pio_cnt++;
#endif
		transfer_pio(regs, (uchar *) cmd->SCp.ptr,
			     cmd->SCp.this_residual, data_in_dir, hostdata);
		length = cmd->SCp.this_residual;
		cmd->SCp.this_residual = read_wd33c93_count(regs);
		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
	}

/* We are able to do DMA (in fact, the Amiga hardware is
 * already going!), so start up the wd33c93 in DMA mode.
 * We set 'hostdata->dma' = D_DMA_RUNNING so that when the
 * transfer completes and causes an interrupt, we're
 * reminded to tell the Amiga to shut down its end. We'll
 * postpone the updating of 'this_residual' and 'ptr'
 * until then.
 */

	else {
#ifdef PROC_STATISTICS
		hostdata->dma_cnt++;
#endif
		write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
		write_wd33c93_count(regs, cmd->SCp.this_residual);

		if ((hostdata->level2 >= L2_DATA) ||
		    (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) {
			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
			hostdata->state = S_RUNNING_LEVEL2;
		} else
			write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO);

		hostdata->dma = D_DMA_RUNNING;
	}
}

void
wd33c93_intr(struct Scsi_Host *instance)
{
	struct WD33C93_hostdata *hostdata =
	    (struct WD33C93_hostdata *) instance->hostdata;
	const wd33c93_regs regs = hostdata->regs;
	struct scsi_cmnd *patch, *cmd;
	uchar asr, sr, phs, id, lun, *ucp, msg;
	unsigned long length, flags;

	asr = read_aux_stat(regs);
	if (!(asr & ASR_INT) || (asr & ASR_BSY))
		return;

	spin_lock_irqsave(&hostdata->lock, flags);

#ifdef PROC_STATISTICS
	hostdata->int_cnt++;
#endif

	cmd = (struct scsi_cmnd *) hostdata->connected;	/* assume we're connected */
	sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear the interrupt */
	phs = read_wd33c93(regs, WD_COMMAND_PHASE);

	DB(DB_INTR, printk("{%02x:%02x-", asr, sr))

/* After starting a DMA transfer, the next interrupt
 * is guaranteed to be in response to completion of
 * the transfer. Since the Amiga DMA hardware runs in
 * in an open-ended fashion, it needs to be told when
 * to stop; do that here if D_DMA_RUNNING is true.
 * Also, we have to update 'this_residual' and 'ptr'
 * based on the contents of the TRANSFER_COUNT register,
 * in case the device decided to do an intermediate
 * disconnect (a device may do this if it has to do a
 * seek, or just to be nice and let other devices have
 * some bus time during long transfers). After doing
 * whatever is needed, we go on and service the WD3393
 * interrupt normally.
 */
	    if (hostdata->dma == D_DMA_RUNNING) {
		DB(DB_TRANSFER,
		   printk("[%p/%d:", cmd->SCp.ptr, cmd->SCp.this_residual))
		    hostdata->dma_stop(cmd->device->host, cmd, 1);
		hostdata->dma = D_DMA_OFF;
		length = cmd->SCp.this_residual;
		cmd->SCp.this_residual = read_wd33c93_count(regs);
		cmd->SCp.ptr += (length - cmd->SCp.this_residual);
		DB(DB_TRANSFER,
		   printk("%p/%d]", cmd->SCp.ptr, cmd->SCp.this_residual))
	}

/* Respond to the specific WD3393 interrupt - there are quite a few! */
	switch (sr) {
	case CSR_TIMEOUT:
		DB(DB_INTR, printk("TIMEOUT"))

		    if (hostdata->state == S_RUNNING_LEVEL2)
			hostdata->connected = NULL;
		else {
			cmd = (struct scsi_cmnd *) hostdata->selecting;	/* get a valid cmd */
			hostdata->selecting = NULL;
		}

		cmd->result = DID_NO_CONNECT << 16;
		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
		hostdata->state = S_UNCONNECTED;
		cmd->scsi_done(cmd);

		/* From esp.c:
		 * There is a window of time within the scsi_done() path
		 * of execution where interrupts are turned back on full
		 * blast and left that way.  During that time we could
		 * reconnect to a disconnected command, then we'd bomb
		 * out below.  We could also end up executing two commands
		 * at _once_.  ...just so you know why the restore_flags()
		 * is here...
		 */

		spin_unlock_irqrestore(&hostdata->lock, flags);

/* We are not connected to a target - check to see if there
 * are commands waiting to be executed.
 */

		wd33c93_execute(instance);
		break;

/* Note: this interrupt should not occur in a LEVEL2 command */

	case CSR_SELECT:
		DB(DB_INTR, printk("SELECT"))
		    hostdata->connected = cmd =
		    (struct scsi_cmnd *) hostdata->selecting;
		hostdata->selecting = NULL;

		/* construct an IDENTIFY message with correct disconnect bit */

		hostdata->outgoing_msg[0] = (0x80 | 0x00 | cmd->device->lun);
		if (cmd->SCp.phase)
			hostdata->outgoing_msg[0] |= 0x40;

		if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {

			hostdata->sync_stat[cmd->device->id] = SS_WAITING;

/* Tack on a 2nd message to ask about synchronous transfers. If we've
 * been asked to do only asynchronous transfers on this device, we
 * request a fifo depth of 0, which is equivalent to async - should
 * solve the problems some people have had with GVP's Guru ROM.
 */

			hostdata->outgoing_msg[1] = EXTENDED_MESSAGE;
			hostdata->outgoing_msg[2] = 3;
			hostdata->outgoing_msg[3] = EXTENDED_SDTR;
			if (hostdata->no_sync & (1 << cmd->device->id)) {
				calc_sync_msg(hostdata->default_sx_per, 0,
						0, hostdata->outgoing_msg + 4);
			} else {
				calc_sync_msg(optimum_sx_per(hostdata),
						OPTIMUM_SX_OFF,
						hostdata->fast,
						hostdata->outgoing_msg + 4);
			}
			hostdata->outgoing_len = 6;
#ifdef SYNC_DEBUG
			ucp = hostdata->outgoing_msg + 1;
			printk(" sending SDTR %02x03%02x%02x%02x ",
				ucp[0], ucp[2], ucp[3], ucp[4]);
#endif
		} else
			hostdata->outgoing_len = 1;

		hostdata->state = S_CONNECTED;
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_XFER_DONE | PHS_DATA_IN:
	case CSR_UNEXP | PHS_DATA_IN:
	case CSR_SRV_REQ | PHS_DATA_IN:
		DB(DB_INTR,
		   printk("IN-%d.%d", cmd->SCp.this_residual,
			  cmd->SCp.buffers_residual))
		    transfer_bytes(regs, cmd, DATA_IN_DIR);
		if (hostdata->state != S_RUNNING_LEVEL2)
			hostdata->state = S_CONNECTED;
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_XFER_DONE | PHS_DATA_OUT:
	case CSR_UNEXP | PHS_DATA_OUT:
	case CSR_SRV_REQ | PHS_DATA_OUT:
		DB(DB_INTR,
		   printk("OUT-%d.%d", cmd->SCp.this_residual,
			  cmd->SCp.buffers_residual))
		    transfer_bytes(regs, cmd, DATA_OUT_DIR);
		if (hostdata->state != S_RUNNING_LEVEL2)
			hostdata->state = S_CONNECTED;
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

/* Note: this interrupt should not occur in a LEVEL2 command */

	case CSR_XFER_DONE | PHS_COMMAND:
	case CSR_UNEXP | PHS_COMMAND:
	case CSR_SRV_REQ | PHS_COMMAND:
		DB(DB_INTR, printk("CMND-%02x", cmd->cmnd[0]))
		    transfer_pio(regs, cmd->cmnd, cmd->cmd_len, DATA_OUT_DIR,
				 hostdata);
		hostdata->state = S_CONNECTED;
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_XFER_DONE | PHS_STATUS:
	case CSR_UNEXP | PHS_STATUS:
	case CSR_SRV_REQ | PHS_STATUS:
		DB(DB_INTR, printk("STATUS="))
		cmd->SCp.Status = read_1_byte(regs);
		DB(DB_INTR, printk("%02x", cmd->SCp.Status))
		    if (hostdata->level2 >= L2_BASIC) {
			sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
			udelay(7);
			hostdata->state = S_RUNNING_LEVEL2;
			write_wd33c93(regs, WD_COMMAND_PHASE, 0x50);
			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
		} else {
			hostdata->state = S_CONNECTED;
		}
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_XFER_DONE | PHS_MESS_IN:
	case CSR_UNEXP | PHS_MESS_IN:
	case CSR_SRV_REQ | PHS_MESS_IN:
		DB(DB_INTR, printk("MSG_IN="))

		msg = read_1_byte(regs);
		sr = read_wd33c93(regs, WD_SCSI_STATUS);	/* clear interrupt */
		udelay(7);

		hostdata->incoming_msg[hostdata->incoming_ptr] = msg;
		if (hostdata->incoming_msg[0] == EXTENDED_MESSAGE)
			msg = EXTENDED_MESSAGE;
		else
			hostdata->incoming_ptr = 0;

		cmd->SCp.Message = msg;
		switch (msg) {

		case COMMAND_COMPLETE:
			DB(DB_INTR, printk("CCMP"))
			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			hostdata->state = S_PRE_CMP_DISC;
			break;

		case SAVE_POINTERS:
			DB(DB_INTR, printk("SDP"))
			    write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			hostdata->state = S_CONNECTED;
			break;

		case RESTORE_POINTERS:
			DB(DB_INTR, printk("RDP"))
			    if (hostdata->level2 >= L2_BASIC) {
				write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
				write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
				hostdata->state = S_RUNNING_LEVEL2;
			} else {
				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
				hostdata->state = S_CONNECTED;
			}
			break;

		case DISCONNECT:
			DB(DB_INTR, printk("DIS"))
			    cmd->device->disconnect = 1;
			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			hostdata->state = S_PRE_TMP_DISC;
			break;

		case MESSAGE_REJECT:
			DB(DB_INTR, printk("REJ"))
#ifdef SYNC_DEBUG
			    printk("-REJ-");
#endif
			if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
				hostdata->sync_stat[cmd->device->id] = SS_SET;
				/* we want default_sx_per, not DEFAULT_SX_PER */
				hostdata->sync_xfer[cmd->device->id] =
					calc_sync_xfer(hostdata->default_sx_per
						/ 4, 0, 0, hostdata->sx_table);
			}
			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			hostdata->state = S_CONNECTED;
			break;

		case EXTENDED_MESSAGE:
			DB(DB_INTR, printk("EXT"))

			    ucp = hostdata->incoming_msg;

#ifdef SYNC_DEBUG
			printk("%02x", ucp[hostdata->incoming_ptr]);
#endif
			/* Is this the last byte of the extended message? */

			if ((hostdata->incoming_ptr >= 2) &&
			    (hostdata->incoming_ptr == (ucp[1] + 1))) {

				switch (ucp[2]) {	/* what's the EXTENDED code? */
				case EXTENDED_SDTR:
					/* default to default async period */
					id = calc_sync_xfer(hostdata->
							default_sx_per / 4, 0,
							0, hostdata->sx_table);
					if (hostdata->sync_stat[cmd->device->id] !=
					    SS_WAITING) {

/* A device has sent an unsolicited SDTR message; rather than go
 * through the effort of decoding it and then figuring out what
 * our reply should be, we're just gonna say that we have a
 * synchronous fifo depth of 0. This will result in asynchronous
 * transfers - not ideal but so much easier.
 * Actually, this is OK because it assures us that if we don't
 * specifically ask for sync transfers, we won't do any.
 */

						write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
						hostdata->outgoing_msg[0] =
						    EXTENDED_MESSAGE;
						hostdata->outgoing_msg[1] = 3;
						hostdata->outgoing_msg[2] =
						    EXTENDED_SDTR;
						calc_sync_msg(hostdata->
							default_sx_per, 0,
							0, hostdata->outgoing_msg + 3);
						hostdata->outgoing_len = 5;
					} else {
						if (ucp[4]) /* well, sync transfer */
							id = calc_sync_xfer(ucp[3], ucp[4],
									hostdata->fast,
									hostdata->sx_table);
						else if (ucp[3]) /* very unlikely... */
							id = calc_sync_xfer(ucp[3], ucp[4],
									0, hostdata->sx_table);
					}
					hostdata->sync_xfer[cmd->device->id] = id;
#ifdef SYNC_DEBUG
					printk(" sync_xfer=%02x\n",
					       hostdata->sync_xfer[cmd->device->id]);
#endif
					hostdata->sync_stat[cmd->device->id] =
					    SS_SET;
					write_wd33c93_cmd(regs,
							  WD_CMD_NEGATE_ACK);
					hostdata->state = S_CONNECTED;
					break;
				case EXTENDED_WDTR:
					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
					printk("sending WDTR ");
					hostdata->outgoing_msg[0] =
					    EXTENDED_MESSAGE;
					hostdata->outgoing_msg[1] = 2;
					hostdata->outgoing_msg[2] =
					    EXTENDED_WDTR;
					hostdata->outgoing_msg[3] = 0;	/* 8 bit transfer width */
					hostdata->outgoing_len = 4;
					write_wd33c93_cmd(regs,
							  WD_CMD_NEGATE_ACK);
					hostdata->state = S_CONNECTED;
					break;
				default:
					write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
					printk
					    ("Rejecting Unknown Extended Message(%02x). ",
					     ucp[2]);
					hostdata->outgoing_msg[0] =
					    MESSAGE_REJECT;
					hostdata->outgoing_len = 1;
					write_wd33c93_cmd(regs,
							  WD_CMD_NEGATE_ACK);
					hostdata->state = S_CONNECTED;
					break;
				}
				hostdata->incoming_ptr = 0;
			}

			/* We need to read more MESS_IN bytes for the extended message */

			else {
				hostdata->incoming_ptr++;
				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
				hostdata->state = S_CONNECTED;
			}
			break;

		default:
			printk("Rejecting Unknown Message(%02x) ", msg);
			write_wd33c93_cmd(regs, WD_CMD_ASSERT_ATN);	/* want MESS_OUT */
			hostdata->outgoing_msg[0] = MESSAGE_REJECT;
			hostdata->outgoing_len = 1;
			write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			hostdata->state = S_CONNECTED;
		}
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

/* Note: this interrupt will occur only after a LEVEL2 command */

	case CSR_SEL_XFER_DONE:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
		if (phs == 0x60) {
			DB(DB_INTR, printk("SX-DONE"))
			    cmd->SCp.Message = COMMAND_COMPLETE;
			lun = read_wd33c93(regs, WD_TARGET_LUN);
			DB(DB_INTR, printk(":%d.%d", cmd->SCp.Status, lun))
			    hostdata->connected = NULL;
			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
			hostdata->state = S_UNCONNECTED;
			if (cmd->SCp.Status == ILLEGAL_STATUS_BYTE)
				cmd->SCp.Status = lun;
			if (cmd->cmnd[0] == REQUEST_SENSE
			    && cmd->SCp.Status != GOOD)
				cmd->result =
				    (cmd->
				     result & 0x00ffff) | (DID_ERROR << 16);
			else
				cmd->result =
				    cmd->SCp.Status | (cmd->SCp.Message << 8);
			cmd->scsi_done(cmd);

/* We are no longer  connected to a target - check to see if
 * there are commands waiting to be executed.
 */
			spin_unlock_irqrestore(&hostdata->lock, flags);
			wd33c93_execute(instance);
		} else {
			printk
			    ("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
			     asr, sr, phs);
			spin_unlock_irqrestore(&hostdata->lock, flags);
		}
		break;

/* Note: this interrupt will occur only after a LEVEL2 command */

	case CSR_SDP:
		DB(DB_INTR, printk("SDP"))
		    hostdata->state = S_RUNNING_LEVEL2;
		write_wd33c93(regs, WD_COMMAND_PHASE, 0x41);
		write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_XFER_DONE | PHS_MESS_OUT:
	case CSR_UNEXP | PHS_MESS_OUT:
	case CSR_SRV_REQ | PHS_MESS_OUT:
		DB(DB_INTR, printk("MSG_OUT="))

/* To get here, we've probably requested MESSAGE_OUT and have
 * already put the correct bytes in outgoing_msg[] and filled
 * in outgoing_len. We simply send them out to the SCSI bus.
 * Sometimes we get MESSAGE_OUT phase when we're not expecting
 * it - like when our SDTR message is rejected by a target. Some
 * targets send the REJECT before receiving all of the extended
 * message, and then seem to go back to MESSAGE_OUT for a byte
 * or two. Not sure why, or if I'm doing something wrong to
 * cause this to happen. Regardless, it seems that sending
 * NOP messages in these situations results in no harm and
 * makes everyone happy.
 */
		    if (hostdata->outgoing_len == 0) {
			hostdata->outgoing_len = 1;
			hostdata->outgoing_msg[0] = NOP;
		}
		transfer_pio(regs, hostdata->outgoing_msg,
			     hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
		DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
		    hostdata->outgoing_len = 0;
		hostdata->state = S_CONNECTED;
		spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	case CSR_UNEXP_DISC:

/* I think I've seen this after a request-sense that was in response
 * to an error condition, but not sure. We certainly need to do
 * something when we get this interrupt - the question is 'what?'.
 * Let's think positively, and assume some command has finished
 * in a legal manner (like a command that provokes a request-sense),
 * so we treat it as a normal command-complete-disconnect.
 */

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
		if (cmd == NULL) {
			printk(" - Already disconnected! ");
			hostdata->state = S_UNCONNECTED;
			spin_unlock_irqrestore(&hostdata->lock, flags);
			return;
		}
		DB(DB_INTR, printk("UNEXP_DISC"))
		    hostdata->connected = NULL;
		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
		hostdata->state = S_UNCONNECTED;
		if (cmd->cmnd[0] == REQUEST_SENSE && cmd->SCp.Status != GOOD)
			cmd->result =
			    (cmd->result & 0x00ffff) | (DID_ERROR << 16);
		else
			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
		cmd->scsi_done(cmd);

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */
		/* look above for comments on scsi_done() */
		spin_unlock_irqrestore(&hostdata->lock, flags);
		wd33c93_execute(instance);
		break;

	case CSR_DISC:

/* Make sure that reselection is enabled at this point - it may
 * have been turned off for the command that just completed.
 */

		write_wd33c93(regs, WD_SOURCE_ID, SRCID_ER);
		DB(DB_INTR, printk("DISC"))
		    if (cmd == NULL) {
			printk(" - Already disconnected! ");
			hostdata->state = S_UNCONNECTED;
		}
		switch (hostdata->state) {
		case S_PRE_CMP_DISC:
			hostdata->connected = NULL;
			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
			hostdata->state = S_UNCONNECTED;
			DB(DB_INTR, printk(":%d", cmd->SCp.Status))
			    if (cmd->cmnd[0] == REQUEST_SENSE
				&& cmd->SCp.Status != GOOD)
				cmd->result =
				    (cmd->
				     result & 0x00ffff) | (DID_ERROR << 16);
			else
				cmd->result =
				    cmd->SCp.Status | (cmd->SCp.Message << 8);
			cmd->scsi_done(cmd);
			break;
		case S_PRE_TMP_DISC:
		case S_RUNNING_LEVEL2:
			cmd->host_scribble = (uchar *) hostdata->disconnected_Q;
			hostdata->disconnected_Q = cmd;
			hostdata->connected = NULL;
			hostdata->state = S_UNCONNECTED;

#ifdef PROC_STATISTICS
			hostdata->disc_done_cnt[cmd->device->id]++;
#endif

			break;
		default:
			printk("*** Unexpected DISCONNECT interrupt! ***");
			hostdata->state = S_UNCONNECTED;
		}

/* We are no longer connected to a target - check to see if
 * there are commands waiting to be executed.
 */
		spin_unlock_irqrestore(&hostdata->lock, flags);
		wd33c93_execute(instance);
		break;

	case CSR_RESEL_AM:
	case CSR_RESEL:
		DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))

		    /* Old chips (pre -A ???) don't have advanced features and will
		     * generate CSR_RESEL.  In that case we have to extract the LUN the
		     * hard way (see below).
		     * First we have to make sure this reselection didn't
		     * happen during Arbitration/Selection of some other device.
		     * If yes, put losing command back on top of input_Q.
		     */
		    if (hostdata->level2 <= L2_NONE) {

			if (hostdata->selecting) {
				cmd = (struct scsi_cmnd *) hostdata->selecting;
				hostdata->selecting = NULL;
				hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
				cmd->host_scribble =
				    (uchar *) hostdata->input_Q;
				hostdata->input_Q = cmd;
			}
		}

		else {

			if (cmd) {
				if (phs == 0x00) {
					hostdata->busy[cmd->device->id] &=
					    ~(1 << cmd->device->lun);
					cmd->host_scribble =
					    (uchar *) hostdata->input_Q;
					hostdata->input_Q = cmd;
				} else {
					printk
					    ("---%02x:%02x:%02x-TROUBLE: Intrusive ReSelect!---",
					     asr, sr, phs);
					while (1)
						printk("\r");
				}
			}

		}

		/* OK - find out which device reselected us. */

		id = read_wd33c93(regs, WD_SOURCE_ID);
		id &= SRCID_MASK;

		/* and extract the lun from the ID message. (Note that we don't
		 * bother to check for a valid message here - I guess this is
		 * not the right way to go, but...)
		 */

		if (sr == CSR_RESEL_AM) {
			lun = read_wd33c93(regs, WD_DATA);
			if (hostdata->level2 < L2_RESELECT)
				write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
			lun &= 7;
		} else {
			/* Old chip; wait for msgin phase to pick up the LUN. */
			for (lun = 255; lun; lun--) {
				if ((asr = read_aux_stat(regs)) & ASR_INT)
					break;
				udelay(10);
			}
			if (!(asr & ASR_INT)) {
				printk
				    ("wd33c93: Reselected without IDENTIFY\n");
				lun = 0;
			} else {
				/* Verify this is a change to MSG_IN and read the message */
				sr = read_wd33c93(regs, WD_SCSI_STATUS);
				udelay(7);
				if (sr == (CSR_ABORT | PHS_MESS_IN) ||
				    sr == (CSR_UNEXP | PHS_MESS_IN) ||
				    sr == (CSR_SRV_REQ | PHS_MESS_IN)) {
					/* Got MSG_IN, grab target LUN */
					lun = read_1_byte(regs);
					/* Now we expect a 'paused with ACK asserted' int.. */
					asr = read_aux_stat(regs);
					if (!(asr & ASR_INT)) {
						udelay(10);
						asr = read_aux_stat(regs);
						if (!(asr & ASR_INT))
							printk
							    ("wd33c93: No int after LUN on RESEL (%02x)\n",
							     asr);
					}
					sr = read_wd33c93(regs, WD_SCSI_STATUS);
					udelay(7);
					if (sr != CSR_MSGIN)
						printk
						    ("wd33c93: Not paused with ACK on RESEL (%02x)\n",
						     sr);
					lun &= 7;
					write_wd33c93_cmd(regs,
							  WD_CMD_NEGATE_ACK);
				} else {
					printk
					    ("wd33c93: Not MSG_IN on reselect (%02x)\n",
					     sr);
					lun = 0;
				}
			}
		}

		/* Now we look for the command that's reconnecting. */

		cmd = (struct scsi_cmnd *) hostdata->disconnected_Q;
		patch = NULL;
		while (cmd) {
			if (id == cmd->device->id && lun == cmd->device->lun)
				break;
			patch = cmd;
			cmd = (struct scsi_cmnd *) cmd->host_scribble;
		}

		/* Hmm. Couldn't find a valid command.... What to do? */

		if (!cmd) {
			printk
			    ("---TROUBLE: target %d.%d not in disconnect queue---",
			     id, lun);
			spin_unlock_irqrestore(&hostdata->lock, flags);
			return;
		}

		/* Ok, found the command - now start it up again. */

		if (patch)
			patch->host_scribble = cmd->host_scribble;
		else
			hostdata->disconnected_Q =
			    (struct scsi_cmnd *) cmd->host_scribble;
		hostdata->connected = cmd;

		/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]'
		 * because these things are preserved over a disconnect.
		 * But we DO need to fix the DPD bit so it's correct for this command.
		 */

		if (cmd->sc_data_direction == DMA_TO_DEVICE)
			write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id);
		else
			write_wd33c93(regs, WD_DESTINATION_ID,
				      cmd->device->id | DSTID_DPD);
		if (hostdata->level2 >= L2_RESELECT) {
			write_wd33c93_count(regs, 0);	/* we want a DATA_PHASE interrupt */
			write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
			write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
			hostdata->state = S_RUNNING_LEVEL2;
		} else
			hostdata->state = S_CONNECTED;

		    spin_unlock_irqrestore(&hostdata->lock, flags);
		break;

	default:
		printk("--UNKNOWN INTERRUPT:%02x:%02x:%02x--", asr, sr, phs);
		spin_unlock_irqrestore(&hostdata->lock, flags);
	}

	DB(DB_INTR, printk("} "))

}

static void
reset_wd33c93(struct Scsi_Host *instance)
{
	struct WD33C93_hostdata *hostdata =
	    (struct WD33C93_hostdata *) instance->hostdata;
	const wd33c93_regs regs = hostdata->regs;
	uchar sr;

#ifdef CONFIG_SGI_IP22
	{
		int busycount = 0;
		extern void sgiwd93_reset(unsigned long);
		/* wait 'til the chip gets some time for us */
		while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
			udelay (10);
	/*
 	 * there are scsi devices out there, which manage to lock up
	 * the wd33c93 in a busy condition. In this state it won't
	 * accept the reset command. The only way to solve this is to
 	 * give the chip a hardware reset (if possible). The code below
	 * does this for the SGI Indy, where this is possible
	 */
	/* still busy ? */
	if (read_aux_stat(regs) & ASR_BSY)
		sgiwd93_reset(instance->base); /* yeah, give it the hard one */
	}
#endif

	write_wd33c93(regs, WD_OWN_ID, OWNID_EAF | OWNID_RAF |
		      instance->this_id | hostdata->clock_freq);
	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
	write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
		      calc_sync_xfer(hostdata->default_sx_per / 4,
				     DEFAULT_SX_OFF, 0, hostdata->sx_table));
	write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);


#ifdef CONFIG_MVME147_SCSI
	udelay(25);		/* The old wd33c93 on MVME147 needs this, at least */
#endif

	while (!(read_aux_stat(regs) & ASR_INT))
		;
	sr = read_wd33c93(regs, WD_SCSI_STATUS);

	hostdata->microcode = read_wd33c93(regs, WD_CDB_1);
	if (sr == 0x00)
		hostdata->chip = C_WD33C93;
	else if (sr == 0x01) {
		write_wd33c93(regs, WD_QUEUE_TAG, 0xa5);	/* any random number */
		sr = read_wd33c93(regs, WD_QUEUE_TAG);
		if (sr == 0xa5) {
			hostdata->chip = C_WD33C93B;
			write_wd33c93(regs, WD_QUEUE_TAG, 0);
		} else
			hostdata->chip = C_WD33C93A;
	} else
		hostdata->chip = C_UNKNOWN_CHIP;

	if (hostdata->chip != C_WD33C93B)	/* Fast SCSI unavailable */
		hostdata->fast = 0;

	write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
	write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
}

int
wd33c93_host_reset(struct scsi_cmnd * SCpnt)
{
	struct Scsi_Host *instance;
	struct WD33C93_hostdata *hostdata;
	int i;

	instance = SCpnt->device->host;
	hostdata = (struct WD33C93_hostdata *) instance->hostdata;

	printk("scsi%d: reset. ", instance->host_no);
	disable_irq(instance->irq);

	hostdata->dma_stop(instance, NULL, 0);
	for (i = 0; i < 8; i++) {
		hostdata->busy[i] = 0;
		hostdata->sync_xfer[i] =
			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
					0, hostdata->sx_table);
		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
	}
	hostdata->input_Q = NULL;
	hostdata->selecting = NULL;
	hostdata->connected = NULL;
	hostdata->disconnected_Q = NULL;
	hostdata->state = S_UNCONNECTED;
	hostdata->dma = D_DMA_OFF;
	hostdata->incoming_ptr = 0;
	hostdata->outgoing_len = 0;

	reset_wd33c93(instance);
	SCpnt->result = DID_RESET << 16;
	enable_irq(instance->irq);
	return SUCCESS;
}

int
wd33c93_abort(struct scsi_cmnd * cmd)
{
	struct Scsi_Host *instance;
	struct WD33C93_hostdata *hostdata;
	wd33c93_regs regs;
	struct scsi_cmnd *tmp, *prev;

	disable_irq(cmd->device->host->irq);

	instance = cmd->device->host;
	hostdata = (struct WD33C93_hostdata *) instance->hostdata;
	regs = hostdata->regs;

/*
 * Case 1 : If the command hasn't been issued yet, we simply remove it
 *     from the input_Q.
 */

	tmp = (struct scsi_cmnd *) hostdata->input_Q;
	prev = NULL;
	while (tmp) {
		if (tmp == cmd) {
			if (prev)
				prev->host_scribble = cmd->host_scribble;
			else
				hostdata->input_Q =
				    (struct scsi_cmnd *) cmd->host_scribble;
			cmd->host_scribble = NULL;
			cmd->result = DID_ABORT << 16;
			printk
			    ("scsi%d: Abort - removing command from input_Q. ",
			     instance->host_no);
			enable_irq(cmd->device->host->irq);
			cmd->scsi_done(cmd);
			return SUCCESS;
		}
		prev = tmp;
		tmp = (struct scsi_cmnd *) tmp->host_scribble;
	}

/*
 * Case 2 : If the command is connected, we're going to fail the abort
 *     and let the high level SCSI driver retry at a later time or
 *     issue a reset.
 *
 *     Timeouts, and therefore aborted commands, will be highly unlikely
 *     and handling them cleanly in this situation would make the common
 *     case of noresets less efficient, and would pollute our code.  So,
 *     we fail.
 */

	if (hostdata->connected == cmd) {
		uchar sr, asr;
		unsigned long timeout;

		printk("scsi%d: Aborting connected command - ",
		       instance->host_no);

		printk("stopping DMA - ");
		if (hostdata->dma == D_DMA_RUNNING) {
			hostdata->dma_stop(instance, cmd, 0);
			hostdata->dma = D_DMA_OFF;
		}

		printk("sending wd33c93 ABORT command - ");
		write_wd33c93(regs, WD_CONTROL,
			      CTRL_IDI | CTRL_EDI | CTRL_POLLED);
		write_wd33c93_cmd(regs, WD_CMD_ABORT);

/* Now we have to attempt to flush out the FIFO... */

		printk("flushing fifo - ");
		timeout = 1000000;
		do {
			asr = read_aux_stat(regs);
			if (asr & ASR_DBR)
				read_wd33c93(regs, WD_DATA);
		} while (!(asr & ASR_INT) && timeout-- > 0);
		sr = read_wd33c93(regs, WD_SCSI_STATUS);
		printk
		    ("asr=%02x, sr=%02x, %ld bytes un-transferred (timeout=%ld) - ",
		     asr, sr, read_wd33c93_count(regs), timeout);

		/*
		 * Abort command processed.
		 * Still connected.
		 * We must disconnect.
		 */

		printk("sending wd33c93 DISCONNECT command - ");
		write_wd33c93_cmd(regs, WD_CMD_DISCONNECT);

		timeout = 1000000;
		asr = read_aux_stat(regs);
		while ((asr & ASR_CIP) && timeout-- > 0)
			asr = read_aux_stat(regs);
		sr = read_wd33c93(regs, WD_SCSI_STATUS);
		printk("asr=%02x, sr=%02x.", asr, sr);

		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
		hostdata->connected = NULL;
		hostdata->state = S_UNCONNECTED;
		cmd->result = DID_ABORT << 16;

/*      sti();*/
		wd33c93_execute(instance);

		enable_irq(cmd->device->host->irq);
		cmd->scsi_done(cmd);
		return SUCCESS;
	}

/*
 * Case 3: If the command is currently disconnected from the bus,
 * we're not going to expend much effort here: Let's just return
 * an ABORT_SNOOZE and hope for the best...
 */

	tmp = (struct scsi_cmnd *) hostdata->disconnected_Q;
	while (tmp) {
		if (tmp == cmd) {
			printk
			    ("scsi%d: Abort - command found on disconnected_Q - ",
			     instance->host_no);
			printk("Abort SNOOZE. ");
			enable_irq(cmd->device->host->irq);
			return FAILED;
		}
		tmp = (struct scsi_cmnd *) tmp->host_scribble;
	}

/*
 * Case 4 : If we reached this point, the command was not found in any of
 *     the queues.
 *
 * We probably reached this point because of an unlikely race condition
 * between the command completing successfully and the abortion code,
 * so we won't panic, but we will notify the user in case something really
 * broke.
 */

/*   sti();*/
	wd33c93_execute(instance);

	enable_irq(cmd->device->host->irq);
	printk("scsi%d: warning : SCSI command probably completed successfully"
	       "         before abortion. ", instance->host_no);
	return FAILED;
}

#define MAX_WD33C93_HOSTS 4
#define MAX_SETUP_ARGS ARRAY_SIZE(setup_args)
#define SETUP_BUFFER_SIZE 200
static char setup_buffer[SETUP_BUFFER_SIZE];
static char setup_used[MAX_SETUP_ARGS];
static int done_setup = 0;

static int
wd33c93_setup(char *str)
{
	int i;
	char *p1, *p2;

	/* The kernel does some processing of the command-line before calling
	 * this function: If it begins with any decimal or hex number arguments,
	 * ints[0] = how many numbers found and ints[1] through [n] are the values
	 * themselves. str points to where the non-numeric arguments (if any)
	 * start: We do our own parsing of those. We construct synthetic 'nosync'
	 * keywords out of numeric args (to maintain compatibility with older
	 * versions) and then add the rest of the arguments.
	 */

	p1 = setup_buffer;
	*p1 = '\0';
	if (str)
		strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
	setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
	p1 = setup_buffer;
	i = 0;
	while (*p1 && (i < MAX_SETUP_ARGS)) {
		p2 = strchr(p1, ',');
		if (p2) {
			*p2 = '\0';
			if (p1 != p2)
				setup_args[i] = p1;
			p1 = p2 + 1;
			i++;
		} else {
			setup_args[i] = p1;
			break;
		}
	}
	for (i = 0; i < MAX_SETUP_ARGS; i++)
		setup_used[i] = 0;
	done_setup = 1;

	return 1;
}
__setup("wd33c93=", wd33c93_setup);

/* check_setup_args() returns index if key found, 0 if not
 */
static int
check_setup_args(char *key, int *flags, int *val, char *buf)
{
	int x;
	char *cp;

	for (x = 0; x < MAX_SETUP_ARGS; x++) {
		if (setup_used[x])
			continue;
		if (!strncmp(setup_args[x], key, strlen(key)))
			break;
		if (!strncmp(setup_args[x], "next", strlen("next")))
			return 0;
	}
	if (x == MAX_SETUP_ARGS)
		return 0;
	setup_used[x] = 1;
	cp = setup_args[x] + strlen(key);
	*val = -1;
	if (*cp != ':')
		return ++x;
	cp++;
	if ((*cp >= '0') && (*cp <= '9')) {
		*val = simple_strtoul(cp, NULL, 0);
	}
	return ++x;
}

/*
 * Calculate internal data-transfer-clock cycle from input-clock
 * frequency (/MHz) and fill 'sx_table'.
 *
 * The original driver used to rely on a fixed sx_table, containing periods
 * for (only) the lower limits of the respective input-clock-frequency ranges
 * (8-10/12-15/16-20 MHz). Although it seems, that no problems occurred with
 * this setting so far, it might be desirable to adjust the transfer periods
 * closer to the really attached, possibly 25% higher, input-clock, since
 * - the wd33c93 may really use a significant shorter period, than it has
 *   negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz
 *   instead).
 * - the wd33c93 may ask the target for a lower transfer rate, than the target
 *   is capable of (eg. negotiating for an assumed minimum of 252ns instead of
 *   possible 200ns, which indeed shows up in tests as an approx. 10% lower
 *   transfer rate).
 */
static inline unsigned int
round_4(unsigned int x)
{
	switch (x & 3) {
		case 1: --x;
			break;
		case 2: ++x;
		case 3: ++x;
	}
	return x;
}

static void
calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
{
	unsigned int d, i;
	if (mhz < 11)
		d = 2;	/* divisor for  8-10 MHz input-clock */
	else if (mhz < 16)
		d = 3;	/* divisor for 12-15 MHz input-clock */
	else
		d = 4;	/* divisor for 16-20 MHz input-clock */

	d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */

	sx_table[0].period_ns = 1;
	sx_table[0].reg_value = 0x20;
	for (i = 1; i < 8; i++) {
		sx_table[i].period_ns = round_4((i+1)*d / 100);
		sx_table[i].reg_value = (i+1)*0x10;
	}
	sx_table[7].reg_value = 0;
	sx_table[8].period_ns = 0;
	sx_table[8].reg_value = 0;
}

/*
 * check and, maybe, map an init- or "clock:"- argument.
 */
static uchar
set_clk_freq(int freq, int *mhz)
{
	int x = freq;
	if (WD33C93_FS_8_10 == freq)
		freq = 8;
	else if (WD33C93_FS_12_15 == freq)
		freq = 12;
	else if (WD33C93_FS_16_20 == freq)
		freq = 16;
	else if (freq > 7 && freq < 11)
		x = WD33C93_FS_8_10;
		else if (freq > 11 && freq < 16)
		x = WD33C93_FS_12_15;
		else if (freq > 15 && freq < 21)
		x = WD33C93_FS_16_20;
	else {
			/* Hmm, wouldn't it be safer to assume highest freq here? */
		x = WD33C93_FS_8_10;
		freq = 8;
	}
	*mhz = freq;
	return x;
}

/*
 * to be used with the resync: fast: ... options
 */
static inline void set_resync ( struct WD33C93_hostdata *hd, int mask )
{
	int i;
	for (i = 0; i < 8; i++)
		if (mask & (1 << i))
			hd->sync_stat[i] = SS_UNSET;
}

void
wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
	     dma_setup_t setup, dma_stop_t stop, int clock_freq)
{
	struct WD33C93_hostdata *hostdata;
	int i;
	int flags;
	int val;
	char buf[32];

	if (!done_setup && setup_strings)
		wd33c93_setup(setup_strings);

	hostdata = (struct WD33C93_hostdata *) instance->hostdata;

	hostdata->regs = regs;
	hostdata->clock_freq = set_clk_freq(clock_freq, &i);
	calc_sx_table(i, hostdata->sx_table);
	hostdata->dma_setup = setup;
	hostdata->dma_stop = stop;
	hostdata->dma_bounce_buffer = NULL;
	hostdata->dma_bounce_len = 0;
	for (i = 0; i < 8; i++) {
		hostdata->busy[i] = 0;
		hostdata->sync_xfer[i] =
			calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
					0, hostdata->sx_table);
		hostdata->sync_stat[i] = SS_UNSET;	/* using default sync values */
#ifdef PROC_STATISTICS
		hostdata->cmd_cnt[i] = 0;
		hostdata->disc_allowed_cnt[i] = 0;
		hostdata->disc_done_cnt[i] = 0;
#endif
	}
	hostdata->input_Q = NULL;
	hostdata->selecting = NULL;
	hostdata->connected = NULL;
	hostdata->disconnected_Q = NULL;
	hostdata->state = S_UNCONNECTED;
	hostdata->dma = D_DMA_OFF;
	hostdata->level2 = L2_BASIC;
	hostdata->disconnect = DIS_ADAPTIVE;
	hostdata->args = DEBUG_DEFAULTS;
	hostdata->incoming_ptr = 0;
	hostdata->outgoing_len = 0;
	hostdata->default_sx_per = DEFAULT_SX_PER;
	hostdata->no_dma = 0;	/* default is DMA enabled */

#ifdef PROC_INTERFACE
	hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
	    PR_CONNECTED | PR_INPUTQ | PR_DISCQ | PR_STOP;
#ifdef PROC_STATISTICS
	hostdata->dma_cnt = 0;
	hostdata->pio_cnt = 0;
	hostdata->int_cnt = 0;
#endif
#endif

	if (check_setup_args("clock", &flags, &val, buf)) {
		hostdata->clock_freq = set_clk_freq(val, &val);
		calc_sx_table(val, hostdata->sx_table);
	}

	if (check_setup_args("nosync", &flags, &val, buf))
		hostdata->no_sync = val;

	if (check_setup_args("nodma", &flags, &val, buf))
		hostdata->no_dma = (val == -1) ? 1 : val;

	if (check_setup_args("period", &flags, &val, buf))
		hostdata->default_sx_per =
		    hostdata->sx_table[round_period((unsigned int) val,
		                                    hostdata->sx_table)].period_ns;

	if (check_setup_args("disconnect", &flags, &val, buf)) {
		if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
			hostdata->disconnect = val;
		else
			hostdata->disconnect = DIS_ADAPTIVE;
	}

	if (check_setup_args("level2", &flags, &val, buf))
		hostdata->level2 = val;

	if (check_setup_args("debug", &flags, &val, buf))
		hostdata->args = val & DB_MASK;

	if (check_setup_args("burst", &flags, &val, buf))
		hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;

	if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
		&& check_setup_args("fast", &flags, &val, buf))
		hostdata->fast = !!val;

	if ((i = check_setup_args("next", &flags, &val, buf))) {
		while (i)
			setup_used[--i] = 1;
	}
#ifdef PROC_INTERFACE
	if (check_setup_args("proc", &flags, &val, buf))
		hostdata->proc = val;
#endif

	spin_lock_irq(&hostdata->lock);
	reset_wd33c93(instance);
	spin_unlock_irq(&hostdata->lock);

	printk("wd33c93-%d: chip=%s/%d no_sync=0x%x no_dma=%d",
	       instance->host_no,
	       (hostdata->chip == C_WD33C93) ? "WD33c93" : (hostdata->chip ==
							    C_WD33C93A) ?
	       "WD33c93A" : (hostdata->chip ==
			     C_WD33C93B) ? "WD33c93B" : "unknown",
	       hostdata->microcode, hostdata->no_sync, hostdata->no_dma);
#ifdef DEBUGGING_ON
	printk(" debug_flags=0x%02x\n", hostdata->args);
#else
	printk(" debugging=OFF\n");
#endif
	printk("           setup_args=");
	for (i = 0; i < MAX_SETUP_ARGS; i++)
		printk("%s,", setup_args[i]);
	printk("\n");
	printk("           Version %s - %s\n", WD33C93_VERSION, WD33C93_DATE);
}

int wd33c93_write_info(struct Scsi_Host *instance, char *buf, int len)
{
#ifdef PROC_INTERFACE
	char *bp;
	struct WD33C93_hostdata *hd;
	int x;

	hd = (struct WD33C93_hostdata *) instance->hostdata;

/* We accept the following
 * keywords (same format as command-line, but arguments are not optional):
 *    debug
 *    disconnect
 *    period
 *    resync
 *    proc
 *    nodma
 *    level2
 *    burst
 *    fast
 *    nosync
 */

	buf[len] = '\0';
	for (bp = buf; *bp; ) {
		while (',' == *bp || ' ' == *bp)
			++bp;
	if (!strncmp(bp, "debug:", 6)) {
			hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
	} else if (!strncmp(bp, "disconnect:", 11)) {
			x = simple_strtoul(bp+11, &bp, 0);
		if (x < DIS_NEVER || x > DIS_ALWAYS)
			x = DIS_ADAPTIVE;
		hd->disconnect = x;
	} else if (!strncmp(bp, "period:", 7)) {
		x = simple_strtoul(bp+7, &bp, 0);
		hd->default_sx_per =
			hd->sx_table[round_period((unsigned int) x,
						  hd->sx_table)].period_ns;
	} else if (!strncmp(bp, "resync:", 7)) {
			set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
	} else if (!strncmp(bp, "proc:", 5)) {
			hd->proc = simple_strtoul(bp+5, &bp, 0);
	} else if (!strncmp(bp, "nodma:", 6)) {
			hd->no_dma = simple_strtoul(bp+6, &bp, 0);
	} else if (!strncmp(bp, "level2:", 7)) {
			hd->level2 = simple_strtoul(bp+7, &bp, 0);
		} else if (!strncmp(bp, "burst:", 6)) {
			hd->dma_mode =
				simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
		} else if (!strncmp(bp, "fast:", 5)) {
			x = !!simple_strtol(bp+5, &bp, 0);
			if (x != hd->fast)
				set_resync(hd, 0xff);
			hd->fast = x;
		} else if (!strncmp(bp, "nosync:", 7)) {
			x = simple_strtoul(bp+7, &bp, 0);
			set_resync(hd, x ^ hd->no_sync);
			hd->no_sync = x;
		} else {
			break; /* unknown keyword,syntax-error,... */
		}
	}
	return len;
#else
	return 0;
#endif
}

int
wd33c93_show_info(struct seq_file *m, struct Scsi_Host *instance)
{
#ifdef PROC_INTERFACE
	struct WD33C93_hostdata *hd;
	struct scsi_cmnd *cmd;
	int x;

	hd = (struct WD33C93_hostdata *) instance->hostdata;

	spin_lock_irq(&hd->lock);
	if (hd->proc & PR_VERSION)
		seq_printf(m, "\nVersion %s - %s.",
			WD33C93_VERSION, WD33C93_DATE);

	if (hd->proc & PR_INFO) {
		seq_printf(m, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
			" dma_mode=%02x fast=%d",
			hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
		seq_printf(m, "\nsync_xfer[] =       ");
		for (x = 0; x < 7; x++)
			seq_printf(m, "\t%02x", hd->sync_xfer[x]);
		seq_printf(m, "\nsync_stat[] =       ");
		for (x = 0; x < 7; x++)
			seq_printf(m, "\t%02x", hd->sync_stat[x]);
	}
#ifdef PROC_STATISTICS
	if (hd->proc & PR_STATISTICS) {
		seq_printf(m, "\ncommands issued:    ");
		for (x = 0; x < 7; x++)
			seq_printf(m, "\t%ld", hd->cmd_cnt[x]);
		seq_printf(m, "\ndisconnects allowed:");
		for (x = 0; x < 7; x++)
			seq_printf(m, "\t%ld", hd->disc_allowed_cnt[x]);
		seq_printf(m, "\ndisconnects done:   ");
		for (x = 0; x < 7; x++)
			seq_printf(m, "\t%ld", hd->disc_done_cnt[x]);
		seq_printf(m,
			"\ninterrupts: %ld, DATA_PHASE ints: %ld DMA, %ld PIO",
			hd->int_cnt, hd->dma_cnt, hd->pio_cnt);
	}
#endif
	if (hd->proc & PR_CONNECTED) {
		seq_printf(m, "\nconnected:     ");
		if (hd->connected) {
			cmd = (struct scsi_cmnd *) hd->connected;
			seq_printf(m, " %d:%d(%02x)",
				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
		}
	}
	if (hd->proc & PR_INPUTQ) {
		seq_printf(m, "\ninput_Q:       ");
		cmd = (struct scsi_cmnd *) hd->input_Q;
		while (cmd) {
			seq_printf(m, " %d:%d(%02x)",
				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
			cmd = (struct scsi_cmnd *) cmd->host_scribble;
		}
	}
	if (hd->proc & PR_DISCQ) {
		seq_printf(m, "\ndisconnected_Q:");
		cmd = (struct scsi_cmnd *) hd->disconnected_Q;
		while (cmd) {
			seq_printf(m, " %d:%d(%02x)",
				cmd->device->id, cmd->device->lun, cmd->cmnd[0]);
			cmd = (struct scsi_cmnd *) cmd->host_scribble;
		}
	}
	seq_printf(m, "\n");
	spin_unlock_irq(&hd->lock);
#endif				/* PROC_INTERFACE */
	return 0;
}

EXPORT_SYMBOL(wd33c93_host_reset);
EXPORT_SYMBOL(wd33c93_init);
EXPORT_SYMBOL(wd33c93_abort);
EXPORT_SYMBOL(wd33c93_queuecommand);
EXPORT_SYMBOL(wd33c93_intr);
EXPORT_SYMBOL(wd33c93_show_info);
EXPORT_SYMBOL(wd33c93_write_info);