summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/NCR5380.c
blob: 90ea0f5d9bdbbfc78da0b474a1490b184f3bde25 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
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
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
// SPDX-License-Identifier: GPL-2.0
/*
 * NCR 5380 generic driver routines.  These should make it *trivial*
 * to implement 5380 SCSI drivers under Linux with a non-trantor
 * architecture.
 *
 * Note that these routines also work with NR53c400 family chips.
 *
 * Copyright 1993, Drew Eckhardt
 * Visionary Computing
 * (Unix and Linux consulting and custom programming)
 * drew@colorado.edu
 * +1 (303) 666-5836
 *
 * For more information, please consult
 *
 * NCR 5380 Family
 * SCSI Protocol Controller
 * Databook
 *
 * NCR Microelectronics
 * 1635 Aeroplaza Drive
 * Colorado Springs, CO 80916
 * 1+ (719) 578-3400
 * 1+ (800) 334-5454
 */

/*
 * With contributions from Ray Van Tassle, Ingmar Baumgart,
 * Ronald van Cuijlenborg, Alan Cox and others.
 */

/* Ported to Atari by Roman Hodek and others. */

/* Adapted for the Sun 3 by Sam Creasey. */

/*
 * Design
 *
 * This is a generic 5380 driver.  To use it on a different platform,
 * one simply writes appropriate system specific macros (ie, data
 * transfer - some PC's will use the I/O bus, 68K's must use
 * memory mapped) and drops this file in their 'C' wrapper.
 *
 * As far as command queueing, two queues are maintained for
 * each 5380 in the system - commands that haven't been issued yet,
 * and commands that are currently executing.  This means that an
 * unlimited number of commands may be queued, letting
 * more commands propagate from the higher driver levels giving higher
 * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
 * allowing multiple commands to propagate all the way to a SCSI-II device
 * while a command is already executing.
 *
 *
 * Issues specific to the NCR5380 :
 *
 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
 * piece of hardware that requires you to sit in a loop polling for
 * the REQ signal as long as you are connected.  Some devices are
 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
 * while doing long seek operations. [...] These
 * broken devices are the exception rather than the rule and I'd rather
 * spend my time optimizing for the normal case.
 *
 * Architecture :
 *
 * At the heart of the design is a coroutine, NCR5380_main,
 * which is started from a workqueue for each NCR5380 host in the
 * system.  It attempts to establish I_T_L or I_T_L_Q nexuses by
 * removing the commands from the issue queue and calling
 * NCR5380_select() if a nexus is not established.
 *
 * Once a nexus is established, the NCR5380_information_transfer()
 * phase goes through the various phases as instructed by the target.
 * if the target goes into MSG IN and sends a DISCONNECT message,
 * the command structure is placed into the per instance disconnected
 * queue, and NCR5380_main tries to find more work.  If the target is
 * idle for too long, the system will try to sleep.
 *
 * If a command has disconnected, eventually an interrupt will trigger,
 * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 * to reestablish a nexus.  This will run main if necessary.
 *
 * On command termination, the done function will be called as
 * appropriate.
 *
 * SCSI pointers are maintained in the SCp field of SCSI command
 * structures, being initialized after the command is connected
 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 * Note that in violation of the standard, an implicit SAVE POINTERS operation
 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 */

/*
 * Using this file :
 * This file a skeleton Linux SCSI driver for the NCR 5380 series
 * of chips.  To use it, you write an architecture specific functions
 * and macros and include this file in your driver.
 *
 * These macros MUST be defined :
 *
 * NCR5380_read(register)  - read from the specified register
 *
 * NCR5380_write(register, value) - write to the specific register
 *
 * NCR5380_implementation_fields  - additional fields needed for this
 * specific implementation of the NCR5380
 *
 * Either real DMA *or* pseudo DMA may be implemented
 *
 * NCR5380_dma_xfer_len   - determine size of DMA/PDMA transfer
 * NCR5380_dma_send_setup - execute DMA/PDMA from memory to 5380
 * NCR5380_dma_recv_setup - execute DMA/PDMA from 5380 to memory
 * NCR5380_dma_residual   - residual byte count
 *
 * The generic driver is initialized by calling NCR5380_init(instance),
 * after setting the appropriate host specific fields and ID.
 */

#ifndef NCR5380_io_delay
#define NCR5380_io_delay(x)
#endif

#ifndef NCR5380_acquire_dma_irq
#define NCR5380_acquire_dma_irq(x)	(1)
#endif

#ifndef NCR5380_release_dma_irq
#define NCR5380_release_dma_irq(x)
#endif

static int do_abort(struct Scsi_Host *);
static void do_reset(struct Scsi_Host *);

/**
 * initialize_SCp - init the scsi pointer field
 * @cmd: command block to set up
 *
 * Set up the internal fields in the SCSI command.
 */

static inline void initialize_SCp(struct scsi_cmnd *cmd)
{
	/*
	 * Initialize the Scsi Pointer field so that all of the commands in the
	 * various queues are valid.
	 */

	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;
	}

	cmd->SCp.Status = 0;
	cmd->SCp.Message = 0;
}

/**
 * NCR5380_poll_politely2 - wait for two chip register values
 * @hostdata: host private data
 * @reg1: 5380 register to poll
 * @bit1: Bitmask to check
 * @val1: Expected value
 * @reg2: Second 5380 register to poll
 * @bit2: Second bitmask to check
 * @val2: Second expected value
 * @wait: Time-out in jiffies
 *
 * Polls the chip in a reasonably efficient manner waiting for an
 * event to occur. After a short quick poll we begin to yield the CPU
 * (if possible). In irq contexts the time-out is arbitrarily limited.
 * Callers may hold locks as long as they are held in irq mode.
 *
 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
 */

static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,
                                  unsigned int reg1, u8 bit1, u8 val1,
                                  unsigned int reg2, u8 bit2, u8 val2,
                                  unsigned long wait)
{
	unsigned long n = hostdata->poll_loops;
	unsigned long deadline = jiffies + wait;

	do {
		if ((NCR5380_read(reg1) & bit1) == val1)
			return 0;
		if ((NCR5380_read(reg2) & bit2) == val2)
			return 0;
		cpu_relax();
	} while (n--);

	if (irqs_disabled() || in_interrupt())
		return -ETIMEDOUT;

	/* Repeatedly sleep for 1 ms until deadline */
	while (time_is_after_jiffies(deadline)) {
		schedule_timeout_uninterruptible(1);
		if ((NCR5380_read(reg1) & bit1) == val1)
			return 0;
		if ((NCR5380_read(reg2) & bit2) == val2)
			return 0;
	}

	return -ETIMEDOUT;
}

#if NDEBUG
static struct {
	unsigned char mask;
	const char *name;
} signals[] = {
	{SR_DBP, "PARITY"},
	{SR_RST, "RST"},
	{SR_BSY, "BSY"},
	{SR_REQ, "REQ"},
	{SR_MSG, "MSG"},
	{SR_CD, "CD"},
	{SR_IO, "IO"},
	{SR_SEL, "SEL"},
	{0, NULL}
},
basrs[] = {
	{BASR_END_DMA_TRANSFER, "END OF DMA"},
	{BASR_DRQ, "DRQ"},
	{BASR_PARITY_ERROR, "PARITY ERROR"},
	{BASR_IRQ, "IRQ"},
	{BASR_PHASE_MATCH, "PHASE MATCH"},
	{BASR_BUSY_ERROR, "BUSY ERROR"},
	{BASR_ATN, "ATN"},
	{BASR_ACK, "ACK"},
	{0, NULL}
},
icrs[] = {
	{ICR_ASSERT_RST, "ASSERT RST"},
	{ICR_ARBITRATION_PROGRESS, "ARB. IN PROGRESS"},
	{ICR_ARBITRATION_LOST, "LOST ARB."},
	{ICR_ASSERT_ACK, "ASSERT ACK"},
	{ICR_ASSERT_BSY, "ASSERT BSY"},
	{ICR_ASSERT_SEL, "ASSERT SEL"},
	{ICR_ASSERT_ATN, "ASSERT ATN"},
	{ICR_ASSERT_DATA, "ASSERT DATA"},
	{0, NULL}
},
mrs[] = {
	{MR_BLOCK_DMA_MODE, "BLOCK DMA MODE"},
	{MR_TARGET, "TARGET"},
	{MR_ENABLE_PAR_CHECK, "PARITY CHECK"},
	{MR_ENABLE_PAR_INTR, "PARITY INTR"},
	{MR_ENABLE_EOP_INTR, "EOP INTR"},
	{MR_MONITOR_BSY, "MONITOR BSY"},
	{MR_DMA_MODE, "DMA MODE"},
	{MR_ARBITRATE, "ARBITRATE"},
	{0, NULL}
};

/**
 * NCR5380_print - print scsi bus signals
 * @instance: adapter state to dump
 *
 * Print the SCSI bus signals for debugging purposes
 */

static void NCR5380_print(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char status, data, basr, mr, icr, i;

	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
	status = NCR5380_read(STATUS_REG);
	mr = NCR5380_read(MODE_REG);
	icr = NCR5380_read(INITIATOR_COMMAND_REG);
	basr = NCR5380_read(BUS_AND_STATUS_REG);

	printk(KERN_DEBUG "SR =   0x%02x : ", status);
	for (i = 0; signals[i].mask; ++i)
		if (status & signals[i].mask)
			printk(KERN_CONT "%s, ", signals[i].name);
	printk(KERN_CONT "\nBASR = 0x%02x : ", basr);
	for (i = 0; basrs[i].mask; ++i)
		if (basr & basrs[i].mask)
			printk(KERN_CONT "%s, ", basrs[i].name);
	printk(KERN_CONT "\nICR =  0x%02x : ", icr);
	for (i = 0; icrs[i].mask; ++i)
		if (icr & icrs[i].mask)
			printk(KERN_CONT "%s, ", icrs[i].name);
	printk(KERN_CONT "\nMR =   0x%02x : ", mr);
	for (i = 0; mrs[i].mask; ++i)
		if (mr & mrs[i].mask)
			printk(KERN_CONT "%s, ", mrs[i].name);
	printk(KERN_CONT "\n");
}

static struct {
	unsigned char value;
	const char *name;
} phases[] = {
	{PHASE_DATAOUT, "DATAOUT"},
	{PHASE_DATAIN, "DATAIN"},
	{PHASE_CMDOUT, "CMDOUT"},
	{PHASE_STATIN, "STATIN"},
	{PHASE_MSGOUT, "MSGOUT"},
	{PHASE_MSGIN, "MSGIN"},
	{PHASE_UNKNOWN, "UNKNOWN"}
};

/**
 * NCR5380_print_phase - show SCSI phase
 * @instance: adapter to dump
 *
 * Print the current SCSI phase for debugging purposes
 */

static void NCR5380_print_phase(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char status;
	int i;

	status = NCR5380_read(STATUS_REG);
	if (!(status & SR_REQ))
		shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
	else {
		for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
		     (phases[i].value != (status & PHASE_MASK)); ++i)
			;
		shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
	}
}
#endif

/**
 * NCR5380_info - report driver and host information
 * @instance: relevant scsi host instance
 *
 * For use as the host template info() handler.
 */

static const char *NCR5380_info(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	return hostdata->info;
}

/**
 * NCR5380_init - initialise an NCR5380
 * @instance: adapter to configure
 * @flags: control flags
 *
 * Initializes *instance and corresponding 5380 chip,
 * with flags OR'd into the initial flags value.
 *
 * Notes : I assume that the host, hostno, and id bits have been
 * set correctly. I don't care about the irq and other fields.
 *
 * Returns 0 for success
 */

static int NCR5380_init(struct Scsi_Host *instance, int flags)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int i;
	unsigned long deadline;
	unsigned long accesses_per_ms;

	instance->max_lun = 7;

	hostdata->host = instance;
	hostdata->id_mask = 1 << instance->this_id;
	hostdata->id_higher_mask = 0;
	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
		if (i > hostdata->id_mask)
			hostdata->id_higher_mask |= i;
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
	hostdata->dma_len = 0;

	spin_lock_init(&hostdata->lock);
	hostdata->connected = NULL;
	hostdata->sensing = NULL;
	INIT_LIST_HEAD(&hostdata->autosense);
	INIT_LIST_HEAD(&hostdata->unissued);
	INIT_LIST_HEAD(&hostdata->disconnected);

	hostdata->flags = flags;

	INIT_WORK(&hostdata->main_task, NCR5380_main);
	hostdata->work_q = alloc_workqueue("ncr5380_%d",
	                        WQ_UNBOUND | WQ_MEM_RECLAIM,
	                        1, instance->host_no);
	if (!hostdata->work_q)
		return -ENOMEM;

	snprintf(hostdata->info, sizeof(hostdata->info),
		"%s, irq %d, io_port 0x%lx, base 0x%lx, can_queue %d, cmd_per_lun %d, sg_tablesize %d, this_id %d, flags { %s%s%s}",
		instance->hostt->name, instance->irq, hostdata->io_port,
		hostdata->base, instance->can_queue, instance->cmd_per_lun,
		instance->sg_tablesize, instance->this_id,
		hostdata->flags & FLAG_DMA_FIXUP     ? "DMA_FIXUP "     : "",
		hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
		hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "");

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(TARGET_COMMAND_REG, 0);
	NCR5380_write(SELECT_ENABLE_REG, 0);

	/* Calibrate register polling loop */
	i = 0;
	deadline = jiffies + 1;
	do {
		cpu_relax();
	} while (time_is_after_jiffies(deadline));
	deadline += msecs_to_jiffies(256);
	do {
		NCR5380_read(STATUS_REG);
		++i;
		cpu_relax();
	} while (time_is_after_jiffies(deadline));
	accesses_per_ms = i / 256;
	hostdata->poll_loops = NCR5380_REG_POLL_TIME * accesses_per_ms / 2;

	return 0;
}

/**
 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 * @instance: adapter to check
 *
 * If the system crashed, it may have crashed with a connected target and
 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 * currently established nexus, which we know nothing about. Failing that
 * do a bus reset.
 *
 * Note that a bus reset will cause the chip to assert IRQ.
 *
 * Returns 0 if successful, otherwise -ENXIO.
 */

static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int pass;

	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
		switch (pass) {
		case 1:
		case 3:
		case 5:
			shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
			NCR5380_poll_politely(hostdata,
			                      STATUS_REG, SR_BSY, 0, 5 * HZ);
			break;
		case 2:
			shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
			do_abort(instance);
			break;
		case 4:
			shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
			do_reset(instance);
			/* Wait after a reset; the SCSI standard calls for
			 * 250ms, we wait 500ms to be on the safe side.
			 * But some Toshiba CD-ROMs need ten times that.
			 */
			if (hostdata->flags & FLAG_TOSHIBA_DELAY)
				msleep(2500);
			else
				msleep(500);
			break;
		case 6:
			shost_printk(KERN_ERR, instance, "bus locked solid\n");
			return -ENXIO;
		}
	}
	return 0;
}

/**
 * NCR5380_exit - remove an NCR5380
 * @instance: adapter to remove
 *
 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 */

static void NCR5380_exit(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	cancel_work_sync(&hostdata->main_task);
	destroy_workqueue(hostdata->work_q);
}

/**
 * complete_cmd - finish processing a command and return it to the SCSI ML
 * @instance: the host instance
 * @cmd: command to complete
 */

static void complete_cmd(struct Scsi_Host *instance,
                         struct scsi_cmnd *cmd)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);

	if (hostdata->sensing == cmd) {
		/* Autosense processing ends here */
		if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
			scsi_eh_restore_cmnd(cmd, &hostdata->ses);
			set_host_byte(cmd, DID_ERROR);
		} else
			scsi_eh_restore_cmnd(cmd, &hostdata->ses);
		hostdata->sensing = NULL;
	}

	hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);

	cmd->scsi_done(cmd);
}

/**
 * NCR5380_queue_command - queue a command
 * @instance: the relevant SCSI adapter
 * @cmd: SCSI command
 *
 * cmd is added to the per-instance issue queue, with minor
 * twiddling done to the host specific fields of cmd.  If the
 * main coroutine is not running, it is restarted.
 */

static int NCR5380_queue_command(struct Scsi_Host *instance,
                                 struct scsi_cmnd *cmd)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
	unsigned long flags;

#if (NDEBUG & NDEBUG_NO_WRITE)
	switch (cmd->cmnd[0]) {
	case WRITE_6:
	case WRITE_10:
		shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
		cmd->result = (DID_ERROR << 16);
		cmd->scsi_done(cmd);
		return 0;
	}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */

	cmd->result = 0;

	if (!NCR5380_acquire_dma_irq(instance))
		return SCSI_MLQUEUE_HOST_BUSY;

	spin_lock_irqsave(&hostdata->lock, flags);

	/*
	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
	 * commands are added to the head of the queue since any command will
	 * clear the contingent allegiance condition that exists and the
	 * sense data is only guaranteed to be valid while the condition exists.
	 */

	if (cmd->cmnd[0] == REQUEST_SENSE)
		list_add(&ncmd->list, &hostdata->unissued);
	else
		list_add_tail(&ncmd->list, &hostdata->unissued);

	spin_unlock_irqrestore(&hostdata->lock, flags);

	dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
	         cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");

	/* Kick off command processing */
	queue_work(hostdata->work_q, &hostdata->main_task);
	return 0;
}

static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	/* Caller does the locking needed to set & test these data atomically */
	if (list_empty(&hostdata->disconnected) &&
	    list_empty(&hostdata->unissued) &&
	    list_empty(&hostdata->autosense) &&
	    !hostdata->connected &&
	    !hostdata->selecting) {
		NCR5380_release_dma_irq(instance);
	}
}

/**
 * dequeue_next_cmd - dequeue a command for processing
 * @instance: the scsi host instance
 *
 * Priority is given to commands on the autosense queue. These commands
 * need autosense because of a CHECK CONDITION result.
 *
 * Returns a command pointer if a command is found for a target that is
 * not already busy. Otherwise returns NULL.
 */

static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	struct NCR5380_cmd *ncmd;
	struct scsi_cmnd *cmd;

	if (hostdata->sensing || list_empty(&hostdata->autosense)) {
		list_for_each_entry(ncmd, &hostdata->unissued, list) {
			cmd = NCR5380_to_scmd(ncmd);
			dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
			         cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);

			if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
				list_del(&ncmd->list);
				dsprintk(NDEBUG_QUEUES, instance,
				         "dequeue: removed %p from issue queue\n", cmd);
				return cmd;
			}
		}
	} else {
		/* Autosense processing begins here */
		ncmd = list_first_entry(&hostdata->autosense,
		                        struct NCR5380_cmd, list);
		list_del(&ncmd->list);
		cmd = NCR5380_to_scmd(ncmd);
		dsprintk(NDEBUG_QUEUES, instance,
		         "dequeue: removed %p from autosense queue\n", cmd);
		scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
		hostdata->sensing = cmd;
		return cmd;
	}
	return NULL;
}

static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);

	if (hostdata->sensing == cmd) {
		scsi_eh_restore_cmnd(cmd, &hostdata->ses);
		list_add(&ncmd->list, &hostdata->autosense);
		hostdata->sensing = NULL;
	} else
		list_add(&ncmd->list, &hostdata->unissued);
}

/**
 * NCR5380_main - NCR state machines
 *
 * NCR5380_main is a coroutine that runs as long as more work can
 * be done on the NCR5380 host adapters in a system.  Both
 * NCR5380_queue_command() and NCR5380_intr() will try to start it
 * in case it is not running.
 */

static void NCR5380_main(struct work_struct *work)
{
	struct NCR5380_hostdata *hostdata =
		container_of(work, struct NCR5380_hostdata, main_task);
	struct Scsi_Host *instance = hostdata->host;
	int done;

	do {
		done = 1;

		spin_lock_irq(&hostdata->lock);
		while (!hostdata->connected && !hostdata->selecting) {
			struct scsi_cmnd *cmd = dequeue_next_cmd(instance);

			if (!cmd)
				break;

			dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);

			/*
			 * Attempt to establish an I_T_L nexus here.
			 * On success, instance->hostdata->connected is set.
			 * On failure, we must add the command back to the
			 * issue queue so we can keep trying.
			 */
			/*
			 * REQUEST SENSE commands are issued without tagged
			 * queueing, even on SCSI-II devices because the
			 * contingent allegiance condition exists for the
			 * entire unit.
			 */

			if (!NCR5380_select(instance, cmd)) {
				dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
				maybe_release_dma_irq(instance);
			} else {
				dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
				         "main: select failed, returning %p to queue\n", cmd);
				requeue_cmd(instance, cmd);
			}
		}
		if (hostdata->connected && !hostdata->dma_len) {
			dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
			NCR5380_information_transfer(instance);
			done = 0;
		}
		spin_unlock_irq(&hostdata->lock);
		if (!done)
			cond_resched();
	} while (!done);
}

/*
 * NCR5380_dma_complete - finish DMA transfer
 * @instance: the scsi host instance
 *
 * Called by the interrupt handler when DMA finishes or a phase
 * mismatch occurs (which would end the DMA transfer).
 */

static void NCR5380_dma_complete(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int transferred;
	unsigned char **data;
	int *count;
	int saved_data = 0, overrun = 0;
	unsigned char p;

	if (hostdata->read_overruns) {
		p = hostdata->connected->SCp.phase;
		if (p & SR_IO) {
			udelay(10);
			if ((NCR5380_read(BUS_AND_STATUS_REG) &
			     (BASR_PHASE_MATCH | BASR_ACK)) ==
			    (BASR_PHASE_MATCH | BASR_ACK)) {
				saved_data = NCR5380_read(INPUT_DATA_REG);
				overrun = 1;
				dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
			}
		}
	}

#ifdef CONFIG_SUN3
	if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
		pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
		       instance->host_no);
		BUG();
	}

	if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
	    (BASR_PHASE_MATCH | BASR_ACK)) {
		pr_err("scsi%d: BASR %02x\n", instance->host_no,
		       NCR5380_read(BUS_AND_STATUS_REG));
		pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
		       instance->host_no);
		BUG();
	}
#endif

	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	NCR5380_read(RESET_PARITY_INTERRUPT_REG);

	transferred = hostdata->dma_len - NCR5380_dma_residual(hostdata);
	hostdata->dma_len = 0;

	data = (unsigned char **)&hostdata->connected->SCp.ptr;
	count = &hostdata->connected->SCp.this_residual;
	*data += transferred;
	*count -= transferred;

	if (hostdata->read_overruns) {
		int cnt, toPIO;

		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
			cnt = toPIO = hostdata->read_overruns;
			if (overrun) {
				dsprintk(NDEBUG_DMA, instance,
				         "Got an input overrun, using saved byte\n");
				*(*data)++ = saved_data;
				(*count)--;
				cnt--;
				toPIO--;
			}
			if (toPIO > 0) {
				dsprintk(NDEBUG_DMA, instance,
				         "Doing %d byte PIO to 0x%p\n", cnt, *data);
				NCR5380_transfer_pio(instance, &p, &cnt, data);
				*count -= toPIO - cnt;
			}
		}
	}
}

/**
 * NCR5380_intr - generic NCR5380 irq handler
 * @irq: interrupt number
 * @dev_id: device info
 *
 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 * from the disconnected queue, and restarting NCR5380_main()
 * as required.
 *
 * The chip can assert IRQ in any of six different conditions. The IRQ flag
 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 * Three of these six conditions are latched in the Bus and Status Register:
 * - End of DMA (cleared by ending DMA Mode)
 * - Parity error (cleared by reading RPIR)
 * - Loss of BSY (cleared by reading RPIR)
 * Two conditions have flag bits that are not latched:
 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 * - Bus reset (non-maskable)
 * The remaining condition has no flag bit at all:
 * - Selection/reselection
 *
 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 * claimed that "the design of the [DP8490] interrupt logic ensures
 * interrupts will not be lost (they can be on the DP5380)."
 * The L5380/53C80 datasheet from LOGIC Devices has more details.
 *
 * Checking for bus reset by reading RST is futile because of interrupt
 * latency, but a bus reset will reset chip logic. Checking for parity error
 * is unnecessary because that interrupt is never enabled. A Loss of BSY
 * condition will clear DMA Mode. We can tell when this occurs because the
 * the Busy Monitor interrupt is enabled together with DMA Mode.
 */

static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
{
	struct Scsi_Host *instance = dev_id;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int handled = 0;
	unsigned char basr;
	unsigned long flags;

	spin_lock_irqsave(&hostdata->lock, flags);

	basr = NCR5380_read(BUS_AND_STATUS_REG);
	if (basr & BASR_IRQ) {
		unsigned char mr = NCR5380_read(MODE_REG);
		unsigned char sr = NCR5380_read(STATUS_REG);

		dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
		         irq, basr, sr, mr);

		if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
			/* Probably End of DMA, Phase Mismatch or Loss of BSY.
			 * We ack IRQ after clearing Mode Register. Workarounds
			 * for End of DMA errata need to happen in DMA Mode.
			 */

			dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");

			if (hostdata->connected) {
				NCR5380_dma_complete(instance);
				queue_work(hostdata->work_q, &hostdata->main_task);
			} else {
				NCR5380_write(MODE_REG, MR_BASE);
				NCR5380_read(RESET_PARITY_INTERRUPT_REG);
			}
		} else if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
		    (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
			/* Probably reselected */
			NCR5380_write(SELECT_ENABLE_REG, 0);
			NCR5380_read(RESET_PARITY_INTERRUPT_REG);

			dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");

			if (!hostdata->connected) {
				NCR5380_reselect(instance);
				queue_work(hostdata->work_q, &hostdata->main_task);
			}
			if (!hostdata->connected)
				NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		} else {
			/* Probably Bus Reset */
			NCR5380_read(RESET_PARITY_INTERRUPT_REG);

			dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
#ifdef SUN3_SCSI_VME
			dregs->csr |= CSR_DMA_ENABLE;
#endif
		}
		handled = 1;
	} else {
		dsprintk(NDEBUG_INTR, instance, "interrupt without IRQ bit\n");
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
	}

	spin_unlock_irqrestore(&hostdata->lock, flags);

	return IRQ_RETVAL(handled);
}

/*
 * Function : int NCR5380_select(struct Scsi_Host *instance,
 * struct scsi_cmnd *cmd)
 *
 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
 * including ARBITRATION, SELECTION, and initial message out for
 * IDENTIFY and queue messages.
 *
 * Inputs : instance - instantiation of the 5380 driver on which this
 * target lives, cmd - SCSI command to execute.
 *
 * Returns cmd if selection failed but should be retried,
 * NULL if selection failed and should not be retried, or
 * NULL if selection succeeded (hostdata->connected == cmd).
 *
 * Side effects :
 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
 * with registers as they should have been on entry - ie
 * SELECT_ENABLE will be set appropriately, the NCR5380
 * will cease to drive any SCSI bus signals.
 *
 * If successful : I_T_L or I_T_L_Q nexus will be established,
 * instance->connected will be set to cmd.
 * SELECT interrupt will be disabled.
 *
 * If failed (no target) : cmd->scsi_done() will be called, and the
 * cmd->result host byte set to DID_BAD_TARGET.
 */

static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
                                        struct scsi_cmnd *cmd)
	__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char tmp[3], phase;
	unsigned char *data;
	int len;
	int err;

	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
	dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
	         instance->this_id);

	/*
	 * Arbitration and selection phases are slow and involve dropping the
	 * lock, so we have to watch out for EH. An exception handler may
	 * change 'selecting' to NULL. This function will then return NULL
	 * so that the caller will forget about 'cmd'. (During information
	 * transfer phases, EH may change 'connected' to NULL.)
	 */
	hostdata->selecting = cmd;

	/*
	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
	 * data bus during SELECTION.
	 */

	NCR5380_write(TARGET_COMMAND_REG, 0);

	/*
	 * Start arbitration.
	 */

	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
	NCR5380_write(MODE_REG, MR_ARBITRATE);

	/* The chip now waits for BUS FREE phase. Then after the 800 ns
	 * Bus Free Delay, arbitration will begin.
	 */

	spin_unlock_irq(&hostdata->lock);
	err = NCR5380_poll_politely2(hostdata, MODE_REG, MR_ARBITRATE, 0,
	                INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
	                                       ICR_ARBITRATION_PROGRESS, HZ);
	spin_lock_irq(&hostdata->lock);
	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
		/* Reselection interrupt */
		goto out;
	}
	if (!hostdata->selecting) {
		/* Command was aborted */
		NCR5380_write(MODE_REG, MR_BASE);
		goto out;
	}
	if (err < 0) {
		NCR5380_write(MODE_REG, MR_BASE);
		shost_printk(KERN_ERR, instance,
		             "select: arbitration timeout\n");
		goto out;
	}
	spin_unlock_irq(&hostdata->lock);

	/* The SCSI-2 arbitration delay is 2.4 us */
	udelay(3);

	/* Check for lost arbitration */
	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	    (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
		NCR5380_write(MODE_REG, MR_BASE);
		dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
		spin_lock_irq(&hostdata->lock);
		goto out;
	}

	/* After/during arbitration, BSY should be asserted.
	 * IBM DPES-31080 Version S31Q works now
	 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
	 */
	NCR5380_write(INITIATOR_COMMAND_REG,
		      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);

	/*
	 * Again, bus clear + bus settle time is 1.2us, however, this is
	 * a minimum so we'll udelay ceil(1.2)
	 */

	if (hostdata->flags & FLAG_TOSHIBA_DELAY)
		udelay(15);
	else
		udelay(2);

	spin_lock_irq(&hostdata->lock);

	/* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
		goto out;

	if (!hostdata->selecting) {
		NCR5380_write(MODE_REG, MR_BASE);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		goto out;
	}

	dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");

	/*
	 * Now that we have won arbitration, start Selection process, asserting
	 * the host and target ID's on the SCSI bus.
	 */

	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));

	/*
	 * Raise ATN while SEL is true before BSY goes false from arbitration,
	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
	 * phase immediately after selection.
	 */

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
	              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
	NCR5380_write(MODE_REG, MR_BASE);

	/*
	 * Reselect interrupts must be turned off prior to the dropping of BSY,
	 * otherwise we will trigger an interrupt.
	 */
	NCR5380_write(SELECT_ENABLE_REG, 0);

	spin_unlock_irq(&hostdata->lock);

	/*
	 * The initiator shall then wait at least two deskew delays and release
	 * the BSY signal.
	 */
	udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */

	/* Reset BSY */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
	              ICR_ASSERT_ATN | ICR_ASSERT_SEL);

	/*
	 * Something weird happens when we cease to drive BSY - looks
	 * like the board/chip is letting us do another read before the
	 * appropriate propagation delay has expired, and we're confusing
	 * a BSY signal from ourselves as the target's response to SELECTION.
	 *
	 * A small delay (the 'C++' frontend breaks the pipeline with an
	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
	 * tighter 'C' code breaks and requires this) solves the problem -
	 * the 1 us delay is arbitrary, and only used because this delay will
	 * be the same on other platforms and since it works here, it should
	 * work there.
	 *
	 * wingel suggests that this could be due to failing to wait
	 * one deskew delay.
	 */

	udelay(1);

	dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));

	/*
	 * The SCSI specification calls for a 250 ms timeout for the actual
	 * selection.
	 */

	err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_BSY, SR_BSY,
	                            msecs_to_jiffies(250));

	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
		spin_lock_irq(&hostdata->lock);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_reselect(instance);
		if (!hostdata->connected)
			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
		goto out;
	}

	if (err < 0) {
		spin_lock_irq(&hostdata->lock);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		/* Can't touch cmd if it has been reclaimed by the scsi ML */
		if (hostdata->selecting) {
			cmd->result = DID_BAD_TARGET << 16;
			complete_cmd(instance, cmd);
			dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
			cmd = NULL;
		}
		goto out;
	}

	/*
	 * No less than two deskew delays after the initiator detects the
	 * BSY signal is true, it shall release the SEL signal and may
	 * change the DATA BUS.                                     -wingel
	 */

	udelay(1);

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);

	/*
	 * Since we followed the SCSI spec, and raised ATN while SEL
	 * was true but before BSY was false during selection, the information
	 * transfer phase should be a MESSAGE OUT phase so that we can send the
	 * IDENTIFY message.
	 */

	/* Wait for start of REQ/ACK handshake */

	err = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
	spin_lock_irq(&hostdata->lock);
	if (err < 0) {
		shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		goto out;
	}
	if (!hostdata->selecting) {
		do_abort(instance);
		goto out;
	}

	dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
	         scmd_id(cmd));
	tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);

	len = 1;
	data = tmp;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
	if (len) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		cmd->result = DID_ERROR << 16;
		complete_cmd(instance, cmd);
		dsprintk(NDEBUG_SELECTION, instance, "IDENTIFY message transfer failed\n");
		cmd = NULL;
		goto out;
	}

	dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");

	hostdata->connected = cmd;
	hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;

#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif

	initialize_SCp(cmd);

	cmd = NULL;

out:
	if (!hostdata->selecting)
		return NULL;
	hostdata->selecting = NULL;
	return cmd;
}

/*
 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
 * unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using polled I/O
 *
 * Inputs : instance - instance of driver, *phase - pointer to
 * what phase is expected, *count - pointer to number of
 * bytes to transfer, **data - pointer to data pointer.
 *
 * Returns : -1 when different phase is entered without transferring
 * maximum number of bytes, 0 if all bytes are transferred or exit
 * is in same phase.
 *
 * Also, *phase, *count, *data are modified in place.
 *
 * XXX Note : handling for bus free may be useful.
 */

/*
 * Note : this code is not as quick as it could be, however it
 * IS 100% reliable, and for the actual data transfer where speed
 * counts, we will always do a pseudo DMA or DMA transfer.
 */

static int NCR5380_transfer_pio(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char p = *phase, tmp;
	int c = *count;
	unsigned char *d = *data;

	/*
	 * The NCR5380 chip will only drive the SCSI bus when the
	 * phase specified in the appropriate bits of the TARGET COMMAND
	 * REGISTER match the STATUS REGISTER
	 */

	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));

	do {
		/*
		 * Wait for assertion of REQ, after which the phase bits will be
		 * valid
		 */

		if (NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
			break;

		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");

		/* Check for phase mismatch */
		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
			dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
			NCR5380_dprint_phase(NDEBUG_PIO, instance);
			break;
		}

		/* Do actual transfer from SCSI bus to / from memory */
		if (!(p & SR_IO))
			NCR5380_write(OUTPUT_DATA_REG, *d);
		else
			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);

		++d;

		/*
		 * The SCSI standard suggests that in MSGOUT phase, the initiator
		 * should drop ATN on the last byte of the message phase
		 * after REQ has been asserted for the handshake but before
		 * the initiator raises ACK.
		 */

		if (!(p & SR_IO)) {
			if (!((p & SR_MSG) && c > 1)) {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
				NCR5380_dprint(NDEBUG_PIO, instance);
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
				              ICR_ASSERT_DATA | ICR_ASSERT_ACK);
			} else {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
				              ICR_ASSERT_DATA | ICR_ASSERT_ATN);
				NCR5380_dprint(NDEBUG_PIO, instance);
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
				              ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
			}
		} else {
			NCR5380_dprint(NDEBUG_PIO, instance);
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
		}

		if (NCR5380_poll_politely(hostdata,
		                          STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
			break;

		dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");

/*
 * We have several special cases to consider during REQ/ACK handshaking :
 * 1.  We were in MSGOUT phase, and we are on the last byte of the
 * message.  ATN must be dropped as ACK is dropped.
 *
 * 2.  We are in a MSGIN phase, and we are on the last byte of the
 * message.  We must exit with ACK asserted, so that the calling
 * code may raise ATN before dropping ACK to reject the message.
 *
 * 3.  ACK and ATN are clear and the target may proceed as normal.
 */
		if (!(p == PHASE_MSGIN && c == 1)) {
			if (p == PHASE_MSGOUT && c > 1)
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
			else
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		}
	} while (--c);

	dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);

	*count = c;
	*data = d;
	tmp = NCR5380_read(STATUS_REG);
	/* The phase read from the bus is valid if either REQ is (already)
	 * asserted or if ACK hasn't been released yet. The latter applies if
	 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
	 */
	if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
		*phase = tmp & PHASE_MASK;
	else
		*phase = PHASE_UNKNOWN;

	if (!c || (*phase == p))
		return 0;
	else
		return -1;
}

/**
 * do_reset - issue a reset command
 * @instance: adapter to reset
 *
 * Issue a reset sequence to the NCR5380 and try and get the bus
 * back into sane shape.
 *
 * This clears the reset interrupt flag because there may be no handler for
 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
 * been installed. And when in EH we may have released the ST DMA interrupt.
 */

static void do_reset(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata __maybe_unused *hostdata = shost_priv(instance);
	unsigned long flags;

	local_irq_save(flags);
	NCR5380_write(TARGET_COMMAND_REG,
	              PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
	udelay(50);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	local_irq_restore(flags);
}

/**
 * do_abort - abort the currently established nexus by going to
 * MESSAGE OUT phase and sending an ABORT message.
 * @instance: relevant scsi host instance
 *
 * Returns 0 on success, -1 on failure.
 */

static int do_abort(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char *msgptr, phase, tmp;
	int len;
	int rc;

	/* Request message out phase */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);

	/*
	 * Wait for the target to indicate a valid phase by asserting
	 * REQ.  Once this happens, we'll have either a MSGOUT phase
	 * and can immediately send the ABORT message, or we'll have some
	 * other phase and will have to source/sink data.
	 *
	 * We really don't care what value was on the bus or what value
	 * the target sees, so we just handshake.
	 */

	rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
	if (rc < 0)
		goto timeout;

	tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;

	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

	if (tmp != PHASE_MSGOUT) {
		NCR5380_write(INITIATOR_COMMAND_REG,
		              ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
		rc = NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, 0, 3 * HZ);
		if (rc < 0)
			goto timeout;
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
	}

	tmp = ABORT;
	msgptr = &tmp;
	len = 1;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(instance, &phase, &len, &msgptr);

	/*
	 * If we got here, and the command completed successfully,
	 * we're about to go into bus free state.
	 */

	return len ? -1 : 0;

timeout:
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
}

/*
 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
 * unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using either real
 * or pseudo DMA.
 *
 * Inputs : instance - instance of driver, *phase - pointer to
 * what phase is expected, *count - pointer to number of
 * bytes to transfer, **data - pointer to data pointer.
 *
 * Returns : -1 when different phase is entered without transferring
 * maximum number of bytes, 0 if all bytes or transferred or exit
 * is in same phase.
 *
 * Also, *phase, *count, *data are modified in place.
 */


static int NCR5380_transfer_dma(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int c = *count;
	unsigned char p = *phase;
	unsigned char *d = *data;
	unsigned char tmp;
	int result = 0;

	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
		*phase = tmp;
		return -1;
	}

	hostdata->connected->SCp.phase = p;

	if (p & SR_IO) {
		if (hostdata->read_overruns)
			c -= hostdata->read_overruns;
		else if (hostdata->flags & FLAG_DMA_FIXUP)
			--c;
	}

	dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
	         (p & SR_IO) ? "receive" : "send", c, d);

#ifdef CONFIG_SUN3
	/* send start chain */
	sun3scsi_dma_start(c, *data);
#endif

	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
	                        MR_ENABLE_EOP_INTR);

	if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
		/* On the Medusa, it is a must to initialize the DMA before
		 * starting the NCR. This is also the cleaner way for the TT.
		 */
		if (p & SR_IO)
			result = NCR5380_dma_recv_setup(hostdata, d, c);
		else
			result = NCR5380_dma_send_setup(hostdata, d, c);
	}

	/*
	 * On the PAS16 at least I/O recovery delays are not needed here.
	 * Everyone else seems to want them.
	 */

	if (p & SR_IO) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_io_delay(1);
		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
	} else {
		NCR5380_io_delay(1);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
		NCR5380_io_delay(1);
		NCR5380_write(START_DMA_SEND_REG, 0);
		NCR5380_io_delay(1);
	}

#ifdef CONFIG_SUN3
#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_DMA_ENABLE;
#endif
	sun3_dma_active = 1;
#endif

	if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
		/* On the Falcon, the DMA setup must be done after the last
		 * NCR access, else the DMA setup gets trashed!
		 */
		if (p & SR_IO)
			result = NCR5380_dma_recv_setup(hostdata, d, c);
		else
			result = NCR5380_dma_send_setup(hostdata, d, c);
	}

	/* On failure, NCR5380_dma_xxxx_setup() returns a negative int. */
	if (result < 0)
		return result;

	/* For real DMA, result is the byte count. DMA interrupt is expected. */
	if (result > 0) {
		hostdata->dma_len = result;
		return 0;
	}

	/* The result is zero iff pseudo DMA send/receive was completed. */
	hostdata->dma_len = c;

/*
 * A note regarding the DMA errata workarounds for early NMOS silicon.
 *
 * For DMA sends, we want to wait until the last byte has been
 * transferred out over the bus before we turn off DMA mode.  Alas, there
 * seems to be no terribly good way of doing this on a 5380 under all
 * conditions.  For non-scatter-gather operations, we can wait until REQ
 * and ACK both go false, or until a phase mismatch occurs.  Gather-sends
 * are nastier, since the device will be expecting more data than we
 * are prepared to send it, and REQ will remain asserted.  On a 53C8[01] we
 * could test Last Byte Sent to assure transfer (I imagine this is precisely
 * why this signal was added to the newer chips) but on the older 538[01]
 * this signal does not exist.  The workaround for this lack is a watchdog;
 * we bail out of the wait-loop after a modest amount of wait-time if
 * the usual exit conditions are not met.  Not a terribly clean or
 * correct solution :-%
 *
 * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
 * If the chip is in DMA receive mode, it will respond to a target's
 * REQ by latching the SCSI data into the INPUT DATA register and asserting
 * ACK, even if it has _already_ been notified by the DMA controller that
 * the current DMA transfer has completed!  If the NCR5380 is then taken
 * out of DMA mode, this already-acknowledged byte is lost. This is
 * not a problem for "one DMA transfer per READ command", because
 * the situation will never arise... either all of the data is DMA'ed
 * properly, or the target switches to MESSAGE IN phase to signal a
 * disconnection (either operation bringing the DMA to a clean halt).
 * However, in order to handle scatter-receive, we must work around the
 * problem.  The chosen fix is to DMA fewer bytes, then check for the
 * condition before taking the NCR5380 out of DMA mode.  One or two extra
 * bytes are transferred via PIO as necessary to fill out the original
 * request.
 */

	if (hostdata->flags & FLAG_DMA_FIXUP) {
		if (p & SR_IO) {
			/*
			 * The workaround was to transfer fewer bytes than we
			 * intended to with the pseudo-DMA read function, wait for
			 * the chip to latch the last byte, read it, and then disable
			 * pseudo-DMA mode.
			 *
			 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
			 * REQ is deasserted when ACK is asserted, and not reasserted
			 * until ACK goes false.  Since the NCR5380 won't lower ACK
			 * until DACK is asserted, which won't happen unless we twiddle
			 * the DMA port or we take the NCR5380 out of DMA mode, we
			 * can guarantee that we won't handshake another extra
			 * byte.
			 */

			if (NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
			                          BASR_DRQ, BASR_DRQ, HZ) < 0) {
				result = -1;
				shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
			}
			if (NCR5380_poll_politely(hostdata, STATUS_REG,
			                          SR_REQ, 0, HZ) < 0) {
				result = -1;
				shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
			}
			d[*count - 1] = NCR5380_read(INPUT_DATA_REG);
		} else {
			/*
			 * Wait for the last byte to be sent.  If REQ is being asserted for
			 * the byte we're interested, we'll ACK it and it will go false.
			 */
			if (NCR5380_poll_politely2(hostdata,
			     BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
			     BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
				result = -1;
				shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
			}
		}
	}

	NCR5380_dma_complete(instance);
	return result;
}

/*
 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
 *
 * Purpose : run through the various SCSI phases and do as the target
 * directs us to.  Operates on the currently connected command,
 * instance->connected.
 *
 * Inputs : instance, instance for which we are doing commands
 *
 * Side effects : SCSI things happen, the disconnected queue will be
 * modified if a command disconnects, *instance->connected will
 * change.
 *
 * XXX Note : we need to watch for bus free or a reset condition here
 * to recover from an unexpected bus free condition.
 */

static void NCR5380_information_transfer(struct Scsi_Host *instance)
	__releases(&hostdata->lock) __acquires(&hostdata->lock)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char msgout = NOP;
	int sink = 0;
	int len;
	int transfersize;
	unsigned char *data;
	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
	struct scsi_cmnd *cmd;

#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif

	while ((cmd = hostdata->connected)) {
		struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);

		tmp = NCR5380_read(STATUS_REG);
		/* We only have a valid SCSI phase when REQ is asserted */
		if (tmp & SR_REQ) {
			phase = (tmp & PHASE_MASK);
			if (phase != old_phase) {
				old_phase = phase;
				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
			}
#ifdef CONFIG_SUN3
			if (phase == PHASE_CMDOUT &&
			    sun3_dma_setup_done != cmd) {
				int count;

				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);
				}

				count = sun3scsi_dma_xfer_len(hostdata, cmd);

				if (count > 0) {
					if (rq_data_dir(cmd->request))
						sun3scsi_dma_send_setup(hostdata,
						                        cmd->SCp.ptr, count);
					else
						sun3scsi_dma_recv_setup(hostdata,
						                        cmd->SCp.ptr, count);
					sun3_dma_setup_done = cmd;
				}
#ifdef SUN3_SCSI_VME
				dregs->csr |= CSR_INTR;
#endif
			}
#endif /* CONFIG_SUN3 */

			if (sink && (phase != PHASE_MSGOUT)) {
				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
				              ICR_ASSERT_ACK);
				while (NCR5380_read(STATUS_REG) & SR_REQ)
					;
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
				              ICR_ASSERT_ATN);
				sink = 0;
				continue;
			}

			switch (phase) {
			case PHASE_DATAOUT:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
				shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
				sink = 1;
				do_abort(instance);
				cmd->result = DID_ERROR << 16;
				complete_cmd(instance, cmd);
				hostdata->connected = NULL;
				return;
#endif
			case PHASE_DATAIN:
				/*
				 * If there is no room left in the current buffer in the
				 * scatter-gather list, move onto the next one.
				 */

				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);
					dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
					         cmd->SCp.this_residual,
					         cmd->SCp.buffers_residual);
				}

				/*
				 * The preferred transfer method is going to be
				 * PSEUDO-DMA for systems that are strictly PIO,
				 * since we can let the hardware do the handshaking.
				 *
				 * For this to work, we need to know the transfersize
				 * ahead of time, since the pseudo-DMA code will sit
				 * in an unconditional loop.
				 */

				transfersize = 0;
				if (!cmd->device->borken)
					transfersize = NCR5380_dma_xfer_len(hostdata, cmd);

				if (transfersize > 0) {
					len = transfersize;
					if (NCR5380_transfer_dma(instance, &phase,
					    &len, (unsigned char **)&cmd->SCp.ptr)) {
						/*
						 * If the watchdog timer fires, all future
						 * accesses to this device will use the
						 * polled-IO.
						 */
						scmd_printk(KERN_INFO, cmd,
							"switching to slow handshake\n");
						cmd->device->borken = 1;
						sink = 1;
						do_abort(instance);
						cmd->result = DID_ERROR << 16;
						/* XXX - need to source or sink data here, as appropriate */
					}
				} else {
					/* Transfer a small chunk so that the
					 * irq mode lock is not held too long.
					 */
					transfersize = min(cmd->SCp.this_residual,
							   NCR5380_PIO_CHUNK_SIZE);
					len = transfersize;
					NCR5380_transfer_pio(instance, &phase, &len,
					                     (unsigned char **)&cmd->SCp.ptr);
					cmd->SCp.this_residual -= transfersize - len;
				}
#ifdef CONFIG_SUN3
				if (sun3_dma_setup_done == cmd)
					sun3_dma_setup_done = NULL;
#endif
				return;
			case PHASE_MSGIN:
				len = 1;
				data = &tmp;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				cmd->SCp.Message = tmp;

				switch (tmp) {
				case ABORT:
				case COMMAND_COMPLETE:
					/* Accept message by clearing ACK */
					sink = 1;
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					dsprintk(NDEBUG_QUEUES, instance,
					         "COMMAND COMPLETE %p target %d lun %llu\n",
					         cmd, scmd_id(cmd), cmd->device->lun);

					hostdata->connected = NULL;

					cmd->result &= ~0xffff;
					cmd->result |= cmd->SCp.Status;
					cmd->result |= cmd->SCp.Message << 8;

					if (cmd->cmnd[0] == REQUEST_SENSE)
						complete_cmd(instance, cmd);
					else {
						if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
						    cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
							dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
							         cmd);
							list_add_tail(&ncmd->list,
							              &hostdata->autosense);
						} else
							complete_cmd(instance, cmd);
					}

					/*
					 * Restore phase bits to 0 so an interrupted selection,
					 * arbitration can resume.
					 */
					NCR5380_write(TARGET_COMMAND_REG, 0);

					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

					maybe_release_dma_irq(instance);
					return;
				case MESSAGE_REJECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					switch (hostdata->last_message) {
					case HEAD_OF_QUEUE_TAG:
					case ORDERED_QUEUE_TAG:
					case SIMPLE_QUEUE_TAG:
						cmd->device->simple_tags = 0;
						hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
						break;
					default:
						break;
					}
					break;
				case DISCONNECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					hostdata->connected = NULL;
					list_add(&ncmd->list, &hostdata->disconnected);
					dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
					         instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
					         cmd, scmd_id(cmd), cmd->device->lun);

					/*
					 * Restore phase bits to 0 so an interrupted selection,
					 * arbitration can resume.
					 */
					NCR5380_write(TARGET_COMMAND_REG, 0);

					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
#ifdef SUN3_SCSI_VME
					dregs->csr |= CSR_DMA_ENABLE;
#endif
					return;
					/*
					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
					 * operation, in violation of the SCSI spec so we can safely
					 * ignore SAVE/RESTORE pointers calls.
					 *
					 * Unfortunately, some disks violate the SCSI spec and
					 * don't issue the required SAVE_POINTERS message before
					 * disconnecting, and we have to break spec to remain
					 * compatible.
					 */
				case SAVE_POINTERS:
				case RESTORE_POINTERS:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					break;
				case EXTENDED_MESSAGE:
					/*
					 * Start the message buffer with the EXTENDED_MESSAGE
					 * byte, since spi_print_msg() wants the whole thing.
					 */
					extended_msg[0] = EXTENDED_MESSAGE;
					/* Accept first byte by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

					spin_unlock_irq(&hostdata->lock);

					dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");

					len = 2;
					data = extended_msg + 1;
					phase = PHASE_MSGIN;
					NCR5380_transfer_pio(instance, &phase, &len, &data);
					dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
					         (int)extended_msg[1],
					         (int)extended_msg[2]);

					if (!len && extended_msg[1] > 0 &&
					    extended_msg[1] <= sizeof(extended_msg) - 2) {
						/* Accept third byte by clearing ACK */
						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
						len = extended_msg[1] - 1;
						data = extended_msg + 3;
						phase = PHASE_MSGIN;

						NCR5380_transfer_pio(instance, &phase, &len, &data);
						dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
						         len);

						switch (extended_msg[2]) {
						case EXTENDED_SDTR:
						case EXTENDED_WDTR:
							tmp = 0;
						}
					} else if (len) {
						shost_printk(KERN_ERR, instance, "error receiving extended message\n");
						tmp = 0;
					} else {
						shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
						             extended_msg[2], extended_msg[1]);
						tmp = 0;
					}

					spin_lock_irq(&hostdata->lock);
					if (!hostdata->connected)
						return;

					/* Fall through to reject message */

					/*
					 * If we get something weird that we aren't expecting,
					 * reject it.
					 */
				default:
					if (tmp == EXTENDED_MESSAGE)
						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown extended message code %02x, length %d\n",
						            extended_msg[2], extended_msg[1]);
					else if (tmp)
						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown message code %02x\n",
						            tmp);

					msgout = MESSAGE_REJECT;
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
					break;
				} /* switch (tmp) */
				break;
			case PHASE_MSGOUT:
				len = 1;
				data = &msgout;
				hostdata->last_message = msgout;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				if (msgout == ABORT) {
					hostdata->connected = NULL;
					cmd->result = DID_ERROR << 16;
					complete_cmd(instance, cmd);
					maybe_release_dma_irq(instance);
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					return;
				}
				msgout = NOP;
				break;
			case PHASE_CMDOUT:
				len = cmd->cmd_len;
				data = cmd->cmnd;
				/*
				 * XXX for performance reasons, on machines with a
				 * PSEUDO-DMA architecture we should probably
				 * use the dma transfer function.
				 */
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				break;
			case PHASE_STATIN:
				len = 1;
				data = &tmp;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				cmd->SCp.Status = tmp;
				break;
			default:
				shost_printk(KERN_ERR, instance, "unknown phase\n");
				NCR5380_dprint(NDEBUG_ANY, instance);
			} /* switch(phase) */
		} else {
			spin_unlock_irq(&hostdata->lock);
			NCR5380_poll_politely(hostdata, STATUS_REG, SR_REQ, SR_REQ, HZ);
			spin_lock_irq(&hostdata->lock);
		}
	}
}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
 * Purpose : does reselection, initializing the instance->connected
 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
 * nexus has been reestablished,
 *
 * Inputs : instance - this instance of the NCR5380.
 */

static void NCR5380_reselect(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned char target_mask;
	unsigned char lun;
	unsigned char msg[3];
	struct NCR5380_cmd *ncmd;
	struct scsi_cmnd *tmp;

	/*
	 * Disable arbitration, etc. since the host adapter obviously
	 * lost, and tell an interrupted NCR5380_select() to restart.
	 */

	NCR5380_write(MODE_REG, MR_BASE);

	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);

	dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");

	/*
	 * At this point, we have detected that our SCSI ID is on the bus,
	 * SEL is true and BSY was false for at least one bus settle delay
	 * (400 ns).
	 *
	 * We must assert BSY ourselves, until the target drops the SEL
	 * signal.
	 */

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
	if (NCR5380_poll_politely(hostdata,
	                          STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		return;
	}
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	/*
	 * Wait for target to go into MSGIN.
	 */

	if (NCR5380_poll_politely(hostdata,
	                          STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
		do_abort(instance);
		return;
	}

#ifdef CONFIG_SUN3
	/* acknowledge toggle to MSGIN */
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));

	/* peek at the byte without really hitting the bus */
	msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
#else
	{
		int len = 1;
		unsigned char *data = msg;
		unsigned char phase = PHASE_MSGIN;

		NCR5380_transfer_pio(instance, &phase, &len, &data);

		if (len) {
			do_abort(instance);
			return;
		}
	}
#endif /* CONFIG_SUN3 */

	if (!(msg[0] & 0x80)) {
		shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
		spi_print_msg(msg);
		printk("\n");
		do_abort(instance);
		return;
	}
	lun = msg[0] & 0x07;

	/*
	 * We need to add code for SCSI-II to track which devices have
	 * I_T_L_Q nexuses established, and which have simple I_T_L
	 * nexuses so we can chose to do additional data transfer.
	 */

	/*
	 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
	 * just reestablished, and remove it from the disconnected queue.
	 */

	tmp = NULL;
	list_for_each_entry(ncmd, &hostdata->disconnected, list) {
		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);

		if (target_mask == (1 << scmd_id(cmd)) &&
		    lun == (u8)cmd->device->lun) {
			list_del(&ncmd->list);
			tmp = cmd;
			break;
		}
	}

	if (tmp) {
		dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
		         "reselect: removed %p from disconnected queue\n", tmp);
	} else {
		shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
		             target_mask, lun);
		/*
		 * Since we have an established nexus that we can't do anything
		 * with, we must abort it.
		 */
		do_abort(instance);
		return;
	}

#ifdef CONFIG_SUN3
	if (sun3_dma_setup_done != tmp) {
		int count;

		if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
			++tmp->SCp.buffer;
			--tmp->SCp.buffers_residual;
			tmp->SCp.this_residual = tmp->SCp.buffer->length;
			tmp->SCp.ptr = sg_virt(tmp->SCp.buffer);
		}

		count = sun3scsi_dma_xfer_len(hostdata, tmp);

		if (count > 0) {
			if (rq_data_dir(tmp->request))
				sun3scsi_dma_send_setup(hostdata,
				                        tmp->SCp.ptr, count);
			else
				sun3scsi_dma_recv_setup(hostdata,
				                        tmp->SCp.ptr, count);
			sun3_dma_setup_done = tmp;
		}
	}

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
#endif /* CONFIG_SUN3 */

	/* Accept message by clearing ACK */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	hostdata->connected = tmp;
	dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu\n",
	         scmd_id(tmp), tmp->device->lun);
}

/**
 * list_find_cmd - test for presence of a command in a linked list
 * @haystack: list of commands
 * @needle: command to search for
 */

static bool list_find_cmd(struct list_head *haystack,
                          struct scsi_cmnd *needle)
{
	struct NCR5380_cmd *ncmd;

	list_for_each_entry(ncmd, haystack, list)
		if (NCR5380_to_scmd(ncmd) == needle)
			return true;
	return false;
}

/**
 * list_remove_cmd - remove a command from linked list
 * @haystack: list of commands
 * @needle: command to remove
 */

static bool list_del_cmd(struct list_head *haystack,
                         struct scsi_cmnd *needle)
{
	if (list_find_cmd(haystack, needle)) {
		struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);

		list_del(&ncmd->list);
		return true;
	}
	return false;
}

/**
 * NCR5380_abort - scsi host eh_abort_handler() method
 * @cmd: the command to be aborted
 *
 * Try to abort a given command by removing it from queues and/or sending
 * the target an abort message. This may not succeed in causing a target
 * to abort the command. Nonetheless, the low-level driver must forget about
 * the command because the mid-layer reclaims it and it may be re-issued.
 *
 * The normal path taken by a command is as follows. For EH we trace this
 * same path to locate and abort the command.
 *
 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
 * [disconnected -> connected ->]...
 * [autosense -> connected ->] done
 *
 * If cmd was not found at all then presumably it has already been completed,
 * in which case return SUCCESS to try to avoid further EH measures.
 *
 * If the command has not completed yet, we must not fail to find it.
 * We have no option but to forget the aborted command (even if it still
 * lacks sense data). The mid-layer may re-issue a command that is in error
 * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
 * this driver are such that a command can appear on one queue only.
 *
 * The lock protects driver data structures, but EH handlers also use it
 * to serialize their own execution and prevent their own re-entry.
 */

static int NCR5380_abort(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned long flags;
	int result = SUCCESS;

	spin_lock_irqsave(&hostdata->lock, flags);

#if (NDEBUG & NDEBUG_ANY)
	scmd_printk(KERN_INFO, cmd, __func__);
#endif
	NCR5380_dprint(NDEBUG_ANY, instance);
	NCR5380_dprint_phase(NDEBUG_ANY, instance);

	if (list_del_cmd(&hostdata->unissued, cmd)) {
		dsprintk(NDEBUG_ABORT, instance,
		         "abort: removed %p from issue queue\n", cmd);
		cmd->result = DID_ABORT << 16;
		cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
		goto out;
	}

	if (hostdata->selecting == cmd) {
		dsprintk(NDEBUG_ABORT, instance,
		         "abort: cmd %p == selecting\n", cmd);
		hostdata->selecting = NULL;
		cmd->result = DID_ABORT << 16;
		complete_cmd(instance, cmd);
		goto out;
	}

	if (list_del_cmd(&hostdata->disconnected, cmd)) {
		dsprintk(NDEBUG_ABORT, instance,
		         "abort: removed %p from disconnected list\n", cmd);
		/* Can't call NCR5380_select() and send ABORT because that
		 * means releasing the lock. Need a bus reset.
		 */
		set_host_byte(cmd, DID_ERROR);
		complete_cmd(instance, cmd);
		result = FAILED;
		goto out;
	}

	if (hostdata->connected == cmd) {
		dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
		hostdata->connected = NULL;
		hostdata->dma_len = 0;
		if (do_abort(instance)) {
			set_host_byte(cmd, DID_ERROR);
			complete_cmd(instance, cmd);
			result = FAILED;
			goto out;
		}
		set_host_byte(cmd, DID_ABORT);
		complete_cmd(instance, cmd);
		goto out;
	}

	if (list_del_cmd(&hostdata->autosense, cmd)) {
		dsprintk(NDEBUG_ABORT, instance,
		         "abort: removed %p from sense queue\n", cmd);
		set_host_byte(cmd, DID_ERROR);
		complete_cmd(instance, cmd);
	}

out:
	if (result == FAILED)
		dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
	else
		dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);

	queue_work(hostdata->work_q, &hostdata->main_task);
	maybe_release_dma_irq(instance);
	spin_unlock_irqrestore(&hostdata->lock, flags);

	return result;
}


/**
 * NCR5380_host_reset - reset the SCSI host
 * @cmd: SCSI command undergoing EH
 *
 * Returns SUCCESS
 */

static int NCR5380_host_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	int i;
	unsigned long flags;
	struct NCR5380_cmd *ncmd;

	spin_lock_irqsave(&hostdata->lock, flags);

#if (NDEBUG & NDEBUG_ANY)
	scmd_printk(KERN_INFO, cmd, __func__);
#endif
	NCR5380_dprint(NDEBUG_ANY, instance);
	NCR5380_dprint_phase(NDEBUG_ANY, instance);

	do_reset(instance);

	/* reset NCR registers */
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(TARGET_COMMAND_REG, 0);
	NCR5380_write(SELECT_ENABLE_REG, 0);

	/* After the reset, there are no more connected or disconnected commands
	 * and no busy units; so clear the low-level status here to avoid
	 * conflicts when the mid-level code tries to wake up the affected
	 * commands!
	 */

	if (list_del_cmd(&hostdata->unissued, cmd)) {
		cmd->result = DID_RESET << 16;
		cmd->scsi_done(cmd);
	}

	if (hostdata->selecting) {
		hostdata->selecting->result = DID_RESET << 16;
		complete_cmd(instance, hostdata->selecting);
		hostdata->selecting = NULL;
	}

	list_for_each_entry(ncmd, &hostdata->disconnected, list) {
		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);

		set_host_byte(cmd, DID_RESET);
		complete_cmd(instance, cmd);
	}
	INIT_LIST_HEAD(&hostdata->disconnected);

	list_for_each_entry(ncmd, &hostdata->autosense, list) {
		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);

		set_host_byte(cmd, DID_RESET);
		cmd->scsi_done(cmd);
	}
	INIT_LIST_HEAD(&hostdata->autosense);

	if (hostdata->connected) {
		set_host_byte(hostdata->connected, DID_RESET);
		complete_cmd(instance, hostdata->connected);
		hostdata->connected = NULL;
	}

	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
	hostdata->dma_len = 0;

	queue_work(hostdata->work_q, &hostdata->main_task);
	maybe_release_dma_irq(instance);
	spin_unlock_irqrestore(&hostdata->lock, flags);

	return SUCCESS;
}