Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 98e3fe10c1dcfe8d6be2c12f9c8da461afcae710 (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
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
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
/* sun3_NCR5380.c -- adapted from atari_NCR5380.c for the sun3 by 
   Sam Creasey. */ 
/* 
 * 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
 *
 * DISTRIBUTION RELEASE 6. 
 *
 * 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
 */

/*
 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
 * this file, too:
 *
 *  - Some of the debug statements were incorrect (undefined variables and the
 *    like). I fixed that.
 *
 *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
 *    possible DMA transfer size should also happen for REAL_DMA. I added this
 *    in the #if statement.
 *
 *  - When using real DMA, information_transfer() should return in a DATAOUT
 *    phase after starting the DMA. It has nothing more to do.
 *
 *  - The interrupt service routine should run main after end of DMA, too (not
 *    only after RESELECTION interrupts). Additionally, it should _not_ test
 *    for more interrupts after running main, since a DMA process may have
 *    been started and interrupts are turned on now. The new int could happen
 *    inside the execution of NCR5380_intr(), leading to recursive
 *    calls.
 *
 *  - I've added a function merge_contiguous_buffers() that tries to
 *    merge scatter-gather buffers that are located at contiguous
 *    physical addresses and can be processed with the same DMA setup.
 *    Since most scatter-gather operations work on a page (4K) of
 *    4 buffers (1K), in more than 90% of all cases three interrupts and
 *    DMA setup actions are saved.
 *
 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
 *    and USLEEP, because these were messing up readability and will never be
 *    needed for Atari SCSI.
 * 
 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
 *   stuff), and 'main' is executed in a bottom half if awoken by an
 *   interrupt.
 *
 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
 *   constructs. In my eyes, this made the source rather unreadable, so I
 *   finally replaced that by the *_PRINTK() macros.
 *
 */
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_transport_spi.h>

/*
 * Further development / testing that should be done : 
 * 1.  Test linked command handling code after Eric is ready with 
 *     the high level code.
 */

#if (NDEBUG & NDEBUG_LISTS)
#define LIST(x,y) \
  { printk("LINE:%d   Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); \
    if ((x)==(y)) udelay(5); }
#define REMOVE(w,x,y,z) \
  { printk("LINE:%d   Removing: %p->%p  %p->%p \n", __LINE__, \
	   (void*)(w), (void*)(x), (void*)(y), (void*)(z)); \
    if ((x)==(y)) udelay(5); }
#else
#define LIST(x,y)
#define REMOVE(w,x,y,z)
#endif

#ifndef notyet
#undef LINKED
#endif

/*
 * Design
 * Issues :
 *
 * The other Linux SCSI drivers were written when Linux was Intel PC-only,
 * and specifically for each board rather than each chip.  This makes their
 * adaptation to platforms like the Mac (Some of which use NCR5380's)
 * more difficult than it has to be.
 *
 * Also, many of the SCSI drivers were written before the command queuing
 * routines were implemented, meaning their implementations of queued 
 * commands were hacked on rather than designed in from the start.
 *
 * When I designed the Linux SCSI drivers I figured that 
 * while having two different SCSI boards in a system might be useful
 * for debugging things, two of the same type wouldn't be used.
 * Well, I was wrong and a number of users have mailed me about running
 * multiple high-performance SCSI boards in a server.
 *
 * Finally, when I get questions from users, I have no idea what 
 * revision of my driver they are running.
 *
 * This driver attempts to address these problems :
 * 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.
 *
 * To solve the multiple-boards-in-the-same-system problem, 
 * there is a separate instance structure for each instance
 * of a 5380 in the system.  So, multiple NCR5380 drivers will
 * be able to coexist with appropriate changes to the high level
 * SCSI code.  
 *
 * A NCR5380_PUBLIC_REVISION macro is provided, with the release
 * number (updated for each public release) printed by the 
 * NCR5380_print_options command, which should be called from the 
 * wrapper detect function, so that I know what release of the driver
 * users are using.
 *
 * 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.
 * 
 * The workaround for this is to keep track of devices that have
 * disconnected.  If the device hasn't disconnected, for commands that
 * should disconnect, we do something like 
 *
 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
 * 
 * Some tweaking of N and M needs to be done.  An algorithm based 
 * on "time to data" would give the best results as long as short time
 * to datas (ie, on the same track) were considered, however 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 when not running by the interrupt handler,
 * timer, and queue command function.  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 USLEEP
 * was defined, and 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 control options : 
 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
 *	for commands that return with a CHECK CONDITION status. 
 *
 * LINKED - if defined, linked commands are supported.
 *
 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 *
 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 *
 * These macros MUST be defined :
 * 
 * NCR5380_read(register)  - read from the specified register
 *
 * NCR5380_write(register, value) - write to the specific register 
 *
 * Either real DMA *or* pseudo DMA may be implemented
 * REAL functions : 
 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
 * Note that the DMA setup functions should return the number of bytes 
 *	that they were able to program the controller for.
 *
 * Also note that generic i386/PC versions of these macros are 
 *	available as NCR5380_i386_dma_write_setup,
 *	NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 *
 * NCR5380_dma_write_setup(instance, src, count) - initialize
 * NCR5380_dma_read_setup(instance, dst, count) - initialize
 * NCR5380_dma_residual(instance); - residual count
 *
 * PSEUDO functions :
 * NCR5380_pwrite(instance, src, count)
 * NCR5380_pread(instance, dst, count);
 *
 * If nothing specific to this implementation needs doing (ie, with external
 * hardware), you must also define 
 *  
 * NCR5380_queue_command
 * NCR5380_reset
 * NCR5380_abort
 * NCR5380_proc_info
 *
 * to be the global entry points into the specific driver, ie 
 * #define NCR5380_queue_command t128_queue_command.
 *
 * If this is not done, the routines will be defined as static functions
 * with the NCR5380* names and the user must provide a globally
 * accessible wrapper function.
 *
 * The generic driver is initialized by calling NCR5380_init(instance),
 * after setting the appropriate host specific fields and ID.  If the 
 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 * possible) function may be used.  Before the specific driver initialization
 * code finishes, NCR5380_print_options should be called.
 */

static struct Scsi_Host *first_instance = NULL;
static struct scsi_host_template *the_template = NULL;

/* Macros ease life... :-) */
#define	SETUP_HOSTDATA(in)				\
    struct NCR5380_hostdata *hostdata =			\
	(struct NCR5380_hostdata *)(in)->hostdata
#define	HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)

#define	NEXT(cmd)	(*(struct scsi_cmnd **)&((cmd)->host_scribble))
#define	NEXTADDR(cmd)	((struct scsi_cmnd **)&((cmd)->host_scribble))

#define	HOSTNO		instance->host_no
#define	H_NO(cmd)	(cmd)->device->host->host_no

#define SGADDR(buffer) (void *)(((unsigned long)page_address((buffer)->page)) + \
			(buffer)->offset)

#ifdef SUPPORT_TAGS

/*
 * Functions for handling tagged queuing
 * =====================================
 *
 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 *
 * Using consecutive numbers for the tags is no good idea in my eyes. There
 * could be wrong re-usings if the counter (8 bit!) wraps and some early
 * command has been preempted for a long time. My solution: a bitfield for
 * remembering used tags.
 *
 * There's also the problem that each target has a certain queue size, but we
 * cannot know it in advance :-( We just see a QUEUE_FULL status being
 * returned. So, in this case, the driver internal queue size assumption is
 * reduced to the number of active tags if QUEUE_FULL is returned by the
 * target. The command is returned to the mid-level, but with status changed
 * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 * correctly.
 *
 * We're also not allowed running tagged commands as long as an untagged
 * command is active. And REQUEST SENSE commands after a contingent allegiance
 * condition _must_ be untagged. To keep track whether an untagged command has
 * been issued, the host->busy array is still employed, as it is without
 * support for tagged queuing.
 *
 * One could suspect that there are possible race conditions between
 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 * which already guaranteed to be running at most once. It is also the only
 * place where tags/LUNs are allocated. So no other allocation can slip
 * between that pair, there could only happen a reselection, which can free a
 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 */

/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
#undef TAG_NONE
#define TAG_NONE 0xff

/* For the m68k, the number of bits in 'allocated' must be a multiple of 32! */
#if (MAX_TAGS % 32) != 0
#error "MAX_TAGS must be a multiple of 32!"
#endif

typedef struct {
    char	allocated[MAX_TAGS/8];
    int		nr_allocated;
    int		queue_size;
} TAG_ALLOC;

static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */


static void __init init_tags( void )
{
    int target, lun;
    TAG_ALLOC *ta;
    
    if (!setup_use_tagged_queuing)
	return;
    
    for( target = 0; target < 8; ++target ) {
	for( lun = 0; lun < 8; ++lun ) {
	    ta = &TagAlloc[target][lun];
	    memset( &ta->allocated, 0, MAX_TAGS/8 );
	    ta->nr_allocated = 0;
	    /* At the beginning, assume the maximum queue size we could
	     * support (MAX_TAGS). This value will be decreased if the target
	     * returns QUEUE_FULL status.
	     */
	    ta->queue_size = MAX_TAGS;
	}
    }
}


/* Check if we can issue a command to this LUN: First see if the LUN is marked
 * busy by an untagged command. If the command should use tagged queuing, also
 * check that there is a free tag and the target's queue won't overflow. This
 * function should be called with interrupts disabled to avoid race
 * conditions.
 */ 

static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
{
    SETUP_HOSTDATA(cmd->device->host);

    if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
	return( 1 );
    if (!should_be_tagged ||
	!setup_use_tagged_queuing || !cmd->device->tagged_supported)
	return( 0 );
    if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
	TagAlloc[cmd->device->id][cmd->device->lun].queue_size ) {
	TAG_PRINTK( "scsi%d: target %d lun %d: no free tags\n",
		    H_NO(cmd), cmd->device->id, cmd->device->lun );
	return( 1 );
    }
    return( 0 );
}


/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 * must be called before!), or reserve the LUN in 'busy' if the command is
 * untagged.
 */

static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
{
    SETUP_HOSTDATA(cmd->device->host);

    /* If we or the target don't support tagged queuing, allocate the LUN for
     * an untagged command.
     */
    if (!should_be_tagged ||
	!setup_use_tagged_queuing || !cmd->device->tagged_supported) {
	cmd->tag = TAG_NONE;
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
	TAG_PRINTK( "scsi%d: target %d lun %d now allocated by untagged "
		    "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun );
    }
    else {
	TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];

	cmd->tag = find_first_zero_bit( &ta->allocated, MAX_TAGS );
	set_bit( cmd->tag, &ta->allocated );
	ta->nr_allocated++;
	TAG_PRINTK( "scsi%d: using tag %d for target %d lun %d "
		    "(now %d tags in use)\n",
		    H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun,
		    ta->nr_allocated );
    }
}


/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 * unlock the LUN.
 */

static void cmd_free_tag(struct scsi_cmnd *cmd)
{
    SETUP_HOSTDATA(cmd->device->host);

    if (cmd->tag == TAG_NONE) {
	hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
	TAG_PRINTK( "scsi%d: target %d lun %d untagged cmd finished\n",
		    H_NO(cmd), cmd->device->id, cmd->device->lun );
    }
    else if (cmd->tag >= MAX_TAGS) {
	printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
		H_NO(cmd), cmd->tag );
    }
    else {
	TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
	clear_bit( cmd->tag, &ta->allocated );
	ta->nr_allocated--;
	TAG_PRINTK( "scsi%d: freed tag %d for target %d lun %d\n",
		    H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun );
    }
}


static void free_all_tags( void )
{
    int target, lun;
    TAG_ALLOC *ta;

    if (!setup_use_tagged_queuing)
	return;
    
    for( target = 0; target < 8; ++target ) {
	for( lun = 0; lun < 8; ++lun ) {
	    ta = &TagAlloc[target][lun];
	    memset( &ta->allocated, 0, MAX_TAGS/8 );
	    ta->nr_allocated = 0;
	}
    }
}

#endif /* SUPPORT_TAGS */


/*
 * Function: void merge_contiguous_buffers(struct scsi_cmnd *cmd)
 *
 * Purpose: Try to merge several scatter-gather requests into one DMA
 *    transfer. This is possible if the scatter buffers lie on
 *    physical contiguous addresses.
 *
 * Parameters: struct scsi_cmnd *cmd
 *    The command to work on. The first scatter buffer's data are
 *    assumed to be already transfered into ptr/this_residual.
 */

static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
{
    unsigned long endaddr;
#if (NDEBUG & NDEBUG_MERGING)
    unsigned long oldlen = cmd->SCp.this_residual;
    int		  cnt = 1;
#endif

    for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
	 cmd->SCp.buffers_residual &&
	 virt_to_phys(SGADDR(&(cmd->SCp.buffer[1]))) == endaddr; ) {
	
	MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
		   SGADDR(&(cmd->SCp.buffer[1])), endaddr);
#if (NDEBUG & NDEBUG_MERGING)
	++cnt;
#endif
	++cmd->SCp.buffer;
	--cmd->SCp.buffers_residual;
	cmd->SCp.this_residual += cmd->SCp.buffer->length;
	endaddr += cmd->SCp.buffer->length;
    }
#if (NDEBUG & NDEBUG_MERGING)
    if (oldlen != cmd->SCp.this_residual)
	MER_PRINTK("merged %d buffers from %p, new length %08x\n",
		   cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
#endif
}

/*
 * Function : void initialize_SCp(struct scsi_cmnd *cmd)
 *
 * Purpose : initialize the saved data pointers for cmd to point to the 
 *	start of the buffer.
 *
 * Inputs : cmd - struct scsi_cmnd structure to have pointers reset.
 */

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 (cmd->use_sg) {
	cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
	cmd->SCp.buffers_residual = cmd->use_sg - 1;
	cmd->SCp.ptr = (char *) SGADDR(cmd->SCp.buffer);
	cmd->SCp.this_residual = cmd->SCp.buffer->length;

	/* ++roman: Try to merge some scatter-buffers if they are at
	 * contiguous physical addresses.
	 */
//	merge_contiguous_buffers( cmd );
    } else {
	cmd->SCp.buffer = NULL;
	cmd->SCp.buffers_residual = 0;
	cmd->SCp.ptr = (char *) cmd->request_buffer;
	cmd->SCp.this_residual = cmd->request_bufflen;
    }
    
}

#include <linux/delay.h>

#if 1
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_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}},
icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{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, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, 
    {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, 
    "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
    {MR_MONITOR_BSY, "MODE MONITOR BSY"},
    {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, 
    {0, NULL}};

/*
 * Function : void NCR5380_print(struct Scsi_Host *instance)
 *
 * Purpose : print the SCSI bus signals for debugging purposes
 *
 * Input : instance - which NCR5380
 */

static void NCR5380_print(struct Scsi_Host *instance) {
    unsigned char status, data, basr, mr, icr, i;
    unsigned long flags;

    local_irq_save(flags);
    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);
    local_irq_restore(flags);
    printk("STATUS_REG: %02x ", status);
    for (i = 0; signals[i].mask ; ++i) 
	if (status & signals[i].mask)
	    printk(",%s", signals[i].name);
    printk("\nBASR: %02x ", basr);
    for (i = 0; basrs[i].mask ; ++i) 
	if (basr & basrs[i].mask)
	    printk(",%s", basrs[i].name);
    printk("\nICR: %02x ", icr);
    for (i = 0; icrs[i].mask; ++i) 
	if (icr & icrs[i].mask)
	    printk(",%s", icrs[i].name);
    printk("\nMODE: %02x ", mr);
    for (i = 0; mrs[i].mask; ++i) 
	if (mr & mrs[i].mask)
	    printk(",%s", mrs[i].name);
    printk("\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"}};

/* 
 * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
 *
 * Purpose : print the current SCSI phase for debugging purposes
 *
 * Input : instance - which NCR5380
 */

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

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

#else /* !NDEBUG */

/* dummies... */
__inline__ void NCR5380_print(struct Scsi_Host *instance) { };
__inline__ void NCR5380_print_phase(struct Scsi_Host *instance) { };

#endif

/*
 * ++roman: New scheme of calling NCR5380_main()
 * 
 * If we're not in an interrupt, we can call our main directly, it cannot be
 * already running. Else, we queue it on a task queue, if not 'main_running'
 * tells us that a lower level is already executing it. This way,
 * 'main_running' needs not be protected in a special way.
 *
 * queue_main() is a utility function for putting our main onto the task
 * queue, if main_running is false. It should be called only from a
 * interrupt or bottom half.
 */

#include <linux/workqueue.h>
#include <linux/interrupt.h>

static volatile int main_running = 0;
static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);

static __inline__ void queue_main(void)
{
    if (!main_running) {
	/* If in interrupt and NCR5380_main() not already running,
	   queue it on the 'immediate' task queue, to be processed
	   immediately after the current interrupt processing has
	   finished. */
	schedule_work(&NCR5380_tqueue);
    }
    /* else: nothing to do: the running NCR5380_main() will pick up
       any newly queued command. */
}


static inline void NCR5380_all_init (void)
{
    static int done = 0;
    if (!done) {
	INI_PRINTK("scsi : NCR5380_all_init()\n");
	done = 1;
    }
}

 
/*
 * Function : void NCR58380_print_options (struct Scsi_Host *instance)
 *
 * Purpose : called by probe code indicating the NCR5380 driver
 *	     options that were selected.
 *
 * Inputs : instance, pointer to this instance.  Unused.
 */

static void __init NCR5380_print_options (struct Scsi_Host *instance)
{
    printk(" generic options"
#ifdef AUTOSENSE 
    " AUTOSENSE"
#endif
#ifdef REAL_DMA
    " REAL DMA"
#endif
#ifdef PARITY
    " PARITY"
#endif
#ifdef SUPPORT_TAGS
    " SCSI-2 TAGGED QUEUING"
#endif
    );
    printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
}

/*
 * Function : void NCR5380_print_status (struct Scsi_Host *instance)
 *
 * Purpose : print commands in the various queues, called from
 *	NCR5380_abort and NCR5380_debug to aid debugging.
 *
 * Inputs : instance, pointer to this instance.  
 */

static void NCR5380_print_status (struct Scsi_Host *instance)
{
    char *pr_bfr;
    char *start;
    int len;

    NCR_PRINT(NDEBUG_ANY);
    NCR_PRINT_PHASE(NDEBUG_ANY);

    pr_bfr = (char *) __get_free_page(GFP_ATOMIC);
    if (!pr_bfr) {
	printk("NCR5380_print_status: no memory for print buffer\n");
	return;
    }
    len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
    pr_bfr[len] = 0;
    printk("\n%s\n", pr_bfr);
    free_page((unsigned long) pr_bfr);
}


/******************************************/
/*
 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
 *
 * *buffer: I/O buffer
 * **start: if inout == FALSE pointer into buffer where user read should start
 * offset: current offset
 * length: length of buffer
 * hostno: Scsi_Host host_no
 * inout: TRUE - user is writing; FALSE - user is reading
 *
 * Return the number of bytes read from or written
*/

#undef SPRINTF
#define SPRINTF(fmt,args...) \
  do { if (pos + strlen(fmt) + 20 /* slop */ < buffer + length) \
	 pos += sprintf(pos, fmt , ## args); } while(0)
static
char *lprint_Scsi_Cmnd(struct scsi_cmnd *cmd, char *pos, char *buffer,
		       int length);

static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
			     char **start, off_t offset, int length, int inout)
{
    char *pos = buffer;
    struct NCR5380_hostdata *hostdata;
    struct scsi_cmnd *ptr;
    unsigned long flags;
    off_t begin = 0;
#define check_offset()				\
    do {					\
	if (pos - buffer < offset - begin) {	\
	    begin += pos - buffer;		\
	    pos = buffer;			\
	}					\
    } while (0)

    hostdata = (struct NCR5380_hostdata *)instance->hostdata;

    if (inout) { /* Has data been written to the file ? */
	return(-ENOSYS);  /* Currently this is a no-op */
    }
    SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
    check_offset();
    local_irq_save(flags);
    SPRINTF("NCR5380: coroutine is%s running.\n", main_running ? "" : "n't");
    check_offset();
    if (!hostdata->connected)
	SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
    else
	pos = lprint_Scsi_Cmnd ((struct scsi_cmnd *) hostdata->connected,
				pos, buffer, length);
    SPRINTF("scsi%d: issue_queue\n", HOSTNO);
    check_offset();
    for (ptr = (struct scsi_cmnd *) hostdata->issue_queue; ptr; ptr = NEXT(ptr))
    {
	pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length);
	check_offset();
    }

    SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
    check_offset();
    for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
	 ptr = NEXT(ptr)) {
	pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length);
	check_offset();
    }

    local_irq_restore(flags);
    *start = buffer + (offset - begin);
    if (pos - buffer < offset - begin)
	return 0;
    else if (pos - buffer - (offset - begin) < length)
	return pos - buffer - (offset - begin);
    return length;
}

static char *lprint_Scsi_Cmnd(struct scsi_cmnd *cmd, char *pos, char *buffer,
			      int length)
{
    int i, s;
    unsigned char *command;
    SPRINTF("scsi%d: destination target %d, lun %d\n",
	    H_NO(cmd), cmd->device->id, cmd->device->lun);
    SPRINTF("        command = ");
    command = cmd->cmnd;
    SPRINTF("%2d (0x%02x)", command[0], command[0]);
    for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
	SPRINTF(" %02x", command[i]);
    SPRINTF("\n");
    return pos;
}


/* 
 * Function : void NCR5380_init (struct Scsi_Host *instance)
 *
 * Purpose : initializes *instance and corresponding 5380 chip.
 *
 * Inputs : instance - instantiation of the 5380 driver.  
 *
 * Notes : I assume that the host, hostno, and id bits have been
 * 	set correctly.  I don't care about the irq and other fields. 
 * 
 */

static int NCR5380_init (struct Scsi_Host *instance, int flags)
{
    int i;
    SETUP_HOSTDATA(instance);

    NCR5380_all_init();

    hostdata->aborted = 0;
    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;
#ifdef SUPPORT_TAGS
    init_tags();
#endif
#if defined (REAL_DMA)
    hostdata->dma_len = 0;
#endif
    hostdata->targets_present = 0;
    hostdata->connected = NULL;
    hostdata->issue_queue = NULL;
    hostdata->disconnected_queue = NULL;
    hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;

    if (!the_template) {
	the_template = instance->hostt;
	first_instance = instance;
    }
	

#ifndef AUTOSENSE
    if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
	 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
	        "        without AUTOSENSE option, contingent allegiance conditions may\n"
	        "        be incorrectly cleared.\n", HOSTNO);
#endif /* def AUTOSENSE */

    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);

    return 0;
}

/* 
 * Function : int NCR5380_queue_command (struct scsi_cmnd *cmd,
 *	void (*done)(struct scsi_cmnd *))
 *
 * Purpose :  enqueues a SCSI command
 *
 * Inputs : cmd - SCSI command, done - function called on completion, with
 *	a pointer to the command descriptor.
 * 
 * Returns : 0
 *
 * Side effects : 
 *      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.
 *
 */

/* Only make static if a wrapper function is used */
static int NCR5380_queue_command(struct scsi_cmnd *cmd,
				 void (*done)(struct scsi_cmnd *))
{
    SETUP_HOSTDATA(cmd->device->host);
    struct scsi_cmnd *tmp;
    unsigned long flags;

#if (NDEBUG & NDEBUG_NO_WRITE)
    switch (cmd->cmnd[0]) {
    case WRITE_6:
    case WRITE_10:
	printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
	       H_NO(cmd));
	cmd->result = (DID_ERROR << 16);
	done(cmd);
	return 0;
    }
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */


#ifdef NCR5380_STATS
# if 0
    if (!hostdata->connected && !hostdata->issue_queue &&
	!hostdata->disconnected_queue) {
	hostdata->timebase = jiffies;
    }
# endif
# ifdef NCR5380_STAT_LIMIT
    if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
# endif
	switch (cmd->cmnd[0])
	{
	    case WRITE:
	    case WRITE_6:
	    case WRITE_10:
		hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
		hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;
		hostdata->pendingw++;
		break;
	    case READ:
	    case READ_6:
	    case READ_10:
		hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
		hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;
		hostdata->pendingr++;
		break;
	}
#endif

    /* 
     * We use the host_scribble field as a pointer to the next command  
     * in a queue 
     */

    NEXT(cmd) = NULL;
    cmd->scsi_done = done;

    cmd->result = 0;


    /* 
     * 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.
     */

    local_irq_save(flags);
    /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
     * Otherwise a running NCR5380_main may steal the lock.
     * Lock before actually inserting due to fairness reasons explained in
     * atari_scsi.c. If we insert first, then it's impossible for this driver
     * to release the lock.
     * Stop timer for this command while waiting for the lock, or timeouts
     * may happen (and they really do), and it's no good if the command doesn't
     * appear in any of the queues.
     * ++roman: Just disabling the NCR interrupt isn't sufficient here,
     * because also a timer int can trigger an abort or reset, which would
     * alter queues and touch the lock.
     */
    if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
	LIST(cmd, hostdata->issue_queue);
	NEXT(cmd) = hostdata->issue_queue;
	hostdata->issue_queue = cmd;
    } else {
	for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
	     NEXT(tmp); tmp = NEXT(tmp))
	    ;
	LIST(cmd, tmp);
	NEXT(tmp) = cmd;
    }

    local_irq_restore(flags);

    QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
	      (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");

    /* If queue_command() is called from an interrupt (real one or bottom
     * half), we let queue_main() do the job of taking care about main. If it
     * is already running, this is a no-op, else main will be queued.
     *
     * If we're not in an interrupt, we can call NCR5380_main()
     * unconditionally, because it cannot be already running.
     */
    if (in_interrupt() || ((flags >> 8) & 7) >= 6)
	queue_main();
    else
	NCR5380_main(NULL);
    return 0;
}

/*
 * Function : NCR5380_main (void) 
 *
 * Purpose : 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.
 * 
 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should 
 *  reenable them.  This prevents reentrancy and kernel stack overflow.
 */ 	
    
static void NCR5380_main (struct work_struct *bl)
{
    struct scsi_cmnd *tmp, *prev;
    struct Scsi_Host *instance = first_instance;
    struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
    int done;
    unsigned long flags;
    
    /*
     * We run (with interrupts disabled) until we're sure that none of 
     * the host adapters have anything that can be done, at which point 
     * we set main_running to 0 and exit.
     *
     * Interrupts are enabled before doing various other internal 
     * instructions, after we've decided that we need to run through
     * the loop again.
     *
     * this should prevent any race conditions.
     * 
     * ++roman: Just disabling the NCR interrupt isn't sufficient here,
     * because also a timer int can trigger an abort or reset, which can
     * alter queues and touch the Falcon lock.
     */

    /* Tell int handlers main() is now already executing.  Note that
       no races are possible here. If an int comes in before
       'main_running' is set here, and queues/executes main via the
       task queue, it doesn't do any harm, just this instance of main
       won't find any work left to do. */
    if (main_running)
    	return;
    main_running = 1;

    local_save_flags(flags);
    do {
	local_irq_disable(); /* Freeze request queues */
	done = 1;
	
	if (!hostdata->connected) {
	    MAIN_PRINTK( "scsi%d: not connected\n", HOSTNO );
	    /*
	     * Search through the issue_queue for a command destined
	     * for a target that's not busy.
	     */
#if (NDEBUG & NDEBUG_LISTS)
	    for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
		 tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
		;
	    if ((tmp == prev) && tmp) printk(" LOOP\n");/* else printk("\n");*/
#endif
	    for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
		 prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp) ) {

#if (NDEBUG & NDEBUG_LISTS)
		if (prev != tmp)
		    printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
			   tmp, tmp->target, hostdata->busy[tmp->target],
			   tmp->lun);
#endif
		/*  When we find one, remove it from the issue queue. */
		/* ++guenther: possible race with Falcon locking */
		if (
#ifdef SUPPORT_TAGS
		    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
#else
		    !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
#endif
		    ) {
		    /* ++guenther: just to be sure, this must be atomic */
		    local_irq_disable();
		    if (prev) {
		        REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
			NEXT(prev) = NEXT(tmp);
		    } else {
		        REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
			hostdata->issue_queue = NEXT(tmp);
		    }
		    NEXT(tmp) = NULL;
		    
		    /* reenable interrupts after finding one */
		    local_irq_restore(flags);
		    
		    /* 
		     * 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.	
		     */
		    MAIN_PRINTK("scsi%d: main(): command for target %d "
				"lun %d removed from issue_queue\n",
				HOSTNO, tmp->target, tmp->lun);
		    /* 
		     * REQUEST SENSE commands are issued without tagged
		     * queueing, even on SCSI-II devices because the 
		     * contingent allegiance condition exists for the 
		     * entire unit.
		     */
		    /* ++roman: ...and the standard also requires that
		     * REQUEST SENSE command are untagged.
		     */
		    
#ifdef SUPPORT_TAGS
		    cmd_get_tag( tmp, tmp->cmnd[0] != REQUEST_SENSE );
#endif
		    if (!NCR5380_select(instance, tmp, 
			    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : 
			    TAG_NEXT)) {
			break;
		    } else {
			local_irq_disable();
			LIST(tmp, hostdata->issue_queue);
			NEXT(tmp) = hostdata->issue_queue;
			hostdata->issue_queue = tmp;
#ifdef SUPPORT_TAGS
			cmd_free_tag( tmp );
#endif
			local_irq_restore(flags);
			MAIN_PRINTK("scsi%d: main(): select() failed, "
				    "returned to issue_queue\n", HOSTNO);
			if (hostdata->connected)
			    break;
		    }
		} /* if target/lun/target queue is not busy */
	    } /* for issue_queue */
	} /* if (!hostdata->connected) */
	if (hostdata->connected 
#ifdef REAL_DMA
	    && !hostdata->dma_len
#endif
	    ) {
	    local_irq_restore(flags);
	    MAIN_PRINTK("scsi%d: main: performing information transfer\n",
			HOSTNO);
	    NCR5380_information_transfer(instance);
	    MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
	    done = 0;
	}
    } while (!done);

    /* Better allow ints _after_ 'main_running' has been cleared, else
       an interrupt could believe we'll pick up the work it left for
       us, but we won't see it anymore here... */
    main_running = 0;
    local_irq_restore(flags);
}


#ifdef REAL_DMA
/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : Called by interrupt handler when DMA finishes or a phase
 *	mismatch occurs (which would finish the DMA transfer).  
 *
 * Inputs : instance - this instance of the NCR5380.
 *
 */

static void NCR5380_dma_complete( struct Scsi_Host *instance )
{
    SETUP_HOSTDATA(instance);
    int           transfered;
    unsigned char **data;
    volatile int  *count;

    if (!hostdata->connected) {
	printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
	       "no connected cmd\n", HOSTNO);
	return;
    }

    DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
	       HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
	       NCR5380_read(STATUS_REG));

    if((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
	    printk("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n", HOSTNO);
	    printk("please e-mail sammy@sammy.net with a description of how this\n");
	    printk("error was produced.\n");
	    BUG();
    }

    /* make sure we're not stuck in a data phase */
    if((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH |
					    BASR_ACK)) ==
       (BASR_PHASE_MATCH | BASR_ACK)) {
	    printk("scsi%d: BASR %02x\n", HOSTNO, NCR5380_read(BUS_AND_STATUS_REG));
	    printk("scsi%d: bus stuck in data phase -- probably a single byte "
		   "overrun!\n", HOSTNO);
	    printk("not prepared for this error!\n");
	    printk("please e-mail sammy@sammy.net with a description of how this\n");
	    printk("error was produced.\n");
	    BUG();
    }



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

    transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
    hostdata->dma_len = 0;

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

}
#endif /* REAL_DMA */


/*
 * Function : void NCR5380_intr (int irq)
 * 
 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 *	from the disconnected queue, and restarting NCR5380_main() 
 *	as required.
 *
 * Inputs : int irq, irq that caused this interrupt.
 *
 */

static irqreturn_t NCR5380_intr (int irq, void *dev_id)
{
    struct Scsi_Host *instance = first_instance;
    int done = 1, handled = 0;
    unsigned char basr;

    INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);

    /* Look for pending interrupts */
    basr = NCR5380_read(BUS_AND_STATUS_REG);
    INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
    /* dispatch to appropriate routine if found and done=0 */
    if (basr & BASR_IRQ) {
	NCR_PRINT(NDEBUG_INTR);
	if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
	    done = 0;
//	    ENABLE_IRQ();
	    INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
	    NCR5380_reselect(instance);
	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else if (basr & BASR_PARITY_ERROR) {
	    INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
	    (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
	    INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
	    (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}
	else {
	    /*  
	     * The rest of the interrupt conditions can occur only during a
	     * DMA transfer
	     */

#if defined(REAL_DMA)
	    /*
	     * We should only get PHASE MISMATCH and EOP interrupts if we have
	     * DMA enabled, so do a sanity check based on the current setting
	     * of the MODE register.
	     */

	    if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
		((basr & BASR_END_DMA_TRANSFER) || 
		 !(basr & BASR_PHASE_MATCH))) {
		    
		INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
		NCR5380_dma_complete( instance );
		done = 0;
//		ENABLE_IRQ();
	    } else
#endif /* REAL_DMA */
	    {
/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
		if (basr & BASR_PHASE_MATCH)
		   INT_PRINTK("scsi%d: unknown interrupt, "
			   "BASR 0x%x, MR 0x%x, SR 0x%x\n",
			   HOSTNO, basr, NCR5380_read(MODE_REG),
			   NCR5380_read(STATUS_REG));
		(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
	    }
	} /* if !(SELECTION || PARITY) */
	handled = 1;
    } /* BASR & IRQ */
    else {

	printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
	       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
	       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
	(void) NCR5380_read(RESET_PARITY_INTERRUPT_REG);
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
    }
    
    if (!done) {
	INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
	/* Put a call to NCR5380_main() on the queue... */
	queue_main();
    }
    return IRQ_RETVAL(handled);
}

#ifdef NCR5380_STATS
static void collect_stats(struct NCR5380_hostdata *hostdata,
			  struct scsi_cmnd *cmd)
{
# ifdef NCR5380_STAT_LIMIT
    if (cmd->request_bufflen > NCR5380_STAT_LIMIT)
# endif
	switch (cmd->cmnd[0])
	{
	    case WRITE:
	    case WRITE_6:
	    case WRITE_10:
		hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
		/*hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;*/
		hostdata->pendingw--;
		break;
	    case READ:
	    case READ_6:
	    case READ_10:
		hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
		/*hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;*/
		hostdata->pendingr--;
		break;
	}
}
#endif

/* 
 * Function : int NCR5380_select(struct Scsi_Host *instance,
 * 				 struct scsi_cmnd *cmd,	int tag);
 *
 * 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, tag - set to TAG_NEXT for 
 *	new tag, TAG_NONE for untagged queueing, otherwise set to the tag for 
 *	the command that is presently connected.
 * 
 * Returns : -1 if selection could not execute for some reason,
 *	0 if selection succeeded or failed because the target 
 * 	did not respond.
 *
 * 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 int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd,
			  int tag)
{
    SETUP_HOSTDATA(instance);
    unsigned char tmp[3], phase;
    unsigned char *data;
    int len;
    unsigned long timeout;
    unsigned long flags;

    hostdata->restart_select = 0;
    NCR_PRINT(NDEBUG_ARBITRATION);
    ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
	       instance->this_id);

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

    local_irq_save(flags);
    if (hostdata->connected) {
	local_irq_restore(flags);
	return -1;
    }
    NCR5380_write(TARGET_COMMAND_REG, 0);


    /* 
     * Start arbitration.
     */
    
    NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
    NCR5380_write(MODE_REG, MR_ARBITRATE);

    local_irq_restore(flags);

    /* Wait for arbitration logic to complete */
#if NCR_TIMEOUT
    {
      unsigned long timeout = jiffies + 2*NCR_TIMEOUT;

      while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
	   && time_before(jiffies, timeout) && !hostdata->connected)
	;
      if (time_after_eq(jiffies, timeout))
      {
	printk("scsi : arbitration timeout at %d\n", __LINE__);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	return -1;
      }
    }
#else /* NCR_TIMEOUT */
    while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
	 && !hostdata->connected);
#endif

    ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);

    if (hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE); 
	return -1;
    }
    /* 
     * The arbitration delay is 2.2us, but this is a minimum and there is 
     * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
     * the integral nature of udelay().
     *
     */

    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) ||
	hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE); 
	ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
		   HOSTNO);
	return -1;
    }

     /* 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 ) ;
    
    if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
		   HOSTNO);
	return -1;
    }

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

#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
    /* ++roman: But some targets (see above :-) seem to need a bit more... */
    udelay(15);
#else
    udelay(2);
#endif
    
    if (hostdata->connected) {
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
    }

    ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);

    /* 
     * 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 << cmd->device->id)));

    /* 
     * 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.
     */

    if (hostdata->connected) {
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
    }

    NCR5380_write(SELECT_ENABLE_REG, 0);

    /*
     * 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);

    SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);

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

    timeout = jiffies + 25; 

    /* 
     * XXX very interesting - we're seeing a bounce where the BSY we 
     * asserted is being reflected / still asserted (propagation delay?)
     * and it's detecting as true.  Sigh.
     */

#if 0
    /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
     * IO while SEL is true. But again, there are some disks out the in the
     * world that do that nevertheless. (Somebody claimed that this announces
     * reselection capability of the target.) So we better skip that test and
     * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
     */

    while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & 
	(SR_BSY | SR_IO)));

    if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == 
	    (SR_SEL | SR_IO)) {
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	    NCR5380_reselect(instance);
	    printk (KERN_ERR "scsi%d: reselection after won arbitration?\n",
		    HOSTNO);
	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	    return -1;
    }
#else
    while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY));
#endif

    /* 
     * 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);

    if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	if (hostdata->targets_present & (1 << cmd->device->id)) {
	    printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
	    if (hostdata->restart_select)
		printk(KERN_NOTICE "\trestart select\n");
	    NCR_PRINT(NDEBUG_ANY);
	    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	    return -1;
	}
	cmd->result = DID_BAD_TARGET << 16;
#ifdef NCR5380_STATS
	collect_stats(hostdata, cmd);
#endif
#ifdef SUPPORT_TAGS
	cmd_free_tag( cmd );
#endif
	cmd->scsi_done(cmd);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
	NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
	return 0;
    } 

    hostdata->targets_present |= (1 << cmd->device->id);

    /*
     * 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.
     * 
     * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
     * message (2 bytes) with a tag ID that we increment with every command
     * until it wraps back to 0.
     *
     * XXX - it turns out that there are some broken SCSI-II devices,
     *	     which claim to support tagged queuing but fail when more than
     *	     some number of commands are issued at once.
     */

    /* Wait for start of REQ/ACK handshake */
    while (!(NCR5380_read(STATUS_REG) & SR_REQ));

    SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
	       HOSTNO, cmd->device->id);
    tmp[0] = IDENTIFY(1, cmd->device->lun);

#ifdef SUPPORT_TAGS
    if (cmd->tag != TAG_NONE) {
	tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
	tmp[2] = cmd->tag;
	len = 3;
    } else 
	len = 1;
#else
    len = 1;
    cmd->tag=0;
#endif /* SUPPORT_TAGS */

    /* Send message(s) */
    data = tmp;
    phase = PHASE_MSGOUT;
    NCR5380_transfer_pio(instance, &phase, &len, &data);
    SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
    /* XXX need to handle errors here */
    hostdata->connected = cmd;
#ifndef SUPPORT_TAGS
    hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif    
#ifdef SUN3_SCSI_VME
    dregs->csr |= CSR_INTR;
#endif
    initialize_SCp(cmd);


    return 0;
}

/* 
 * 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 transfered 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)
{
    register unsigned char p = *phase, tmp;
    register int c = *count;
    register 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 
	 */
	while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ));

	HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);

	/* Check for phase mismatch */	
	if ((tmp & PHASE_MASK) != p) {
	    PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
	    NCR_PRINT_PHASE(NDEBUG_PIO);
	    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);
		NCR_PRINT(NDEBUG_PIO);
		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);
		NCR_PRINT(NDEBUG_PIO);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
		    ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
	    }
	} else {
	    NCR_PRINT(NDEBUG_PIO);
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
	}

	while (NCR5380_read(STATUS_REG) & SR_REQ);

	HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);

/*
 * 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);

    PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, 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 is the case if
     * we're in MSGIN and all wanted bytes have been received. */
    if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
	*phase = tmp & PHASE_MASK;
    else 
	*phase = PHASE_UNKNOWN;

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

/*
 * Function : do_abort (Scsi_Host *host)
 * 
 * Purpose : abort the currently established nexus.  Should only be 
 * 	called from a routine which can drop into a 
 * 
 * Returns : 0 on success, -1 on failure.
 */

static int do_abort (struct Scsi_Host *host) 
{
    unsigned char tmp, *msgptr, phase;
    int len;

    /* 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.
     */
    
    while (!(tmp = NCR5380_read(STATUS_REG)) & SR_REQ);

    NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

    if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
	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);
    }
   
    tmp = ABORT;
    msgptr = &tmp;
    len = 1;
    phase = PHASE_MSGOUT;
    NCR5380_transfer_pio (host, &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;
}

#if defined(REAL_DMA)
/* 
 * 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 transfered 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)
{
    SETUP_HOSTDATA(instance);
    register int c = *count;
    register unsigned char p = *phase;
    unsigned long flags;

    /* sanity check */
    if(!sun3_dma_setup_done) {
	 printk("scsi%d: transfer_dma without setup!\n", HOSTNO);
	 BUG();
    }
    hostdata->dma_len = c;

    DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
	       HOSTNO, (p & SR_IO) ? "reading" : "writing",
	       c, (p & SR_IO) ? "to" : "from", *data);

    /* netbsd turns off ints here, why not be safe and do it too */
    local_irq_save(flags);
    
    /* send start chain */
    sun3scsi_dma_start(c, *data);
    
    if (p & SR_IO) {
	    NCR5380_write(TARGET_COMMAND_REG, 1);
	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	    NCR5380_write(INITIATOR_COMMAND_REG, 0);
	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
	    NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
    } else {
	    NCR5380_write(TARGET_COMMAND_REG, 0);
	    NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	    NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
	    NCR5380_write(MODE_REG, (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
	    NCR5380_write(START_DMA_SEND_REG, 0);
    }

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

    local_irq_restore(flags);

    sun3_dma_active = 1;
    return 0;
}
#endif /* defined(REAL_DMA) */

/*
 * 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)
{
    SETUP_HOSTDATA(instance);
    unsigned long flags;
    unsigned char msgout = NOP;
    int sink = 0;
    int len;
#if defined(REAL_DMA)
    int transfersize;
#endif
    unsigned char *data;
    unsigned char phase, tmp, extended_msg[10], old_phase=0xff;
    struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;

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

    while (1) {
	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;
		NCR_PRINT_PHASE(NDEBUG_INFORMATION);
	    }

	    if(phase == PHASE_CMDOUT) {
		    void *d;
		    unsigned long count;

		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
			count = cmd->SCp.buffer->length;
			d = SGADDR(cmd->SCp.buffer);
		} else {
			count = cmd->SCp.this_residual;
			d = cmd->SCp.ptr;
		}
#ifdef REAL_DMA
		/* this command setup for dma yet? */
		if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done
						  != cmd))
		{
			if(blk_fs_request(cmd->request)) {
				sun3scsi_dma_setup(d, count,
						   rq_data_dir(cmd->request));
				sun3_dma_setup_done = cmd;
			}
		}
#endif
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_INTR;
#endif
	    }

	    
	    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)
		printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
		       "aborted\n", HOSTNO);
		sink = 1;
		do_abort(instance);
		cmd->result = DID_ERROR  << 16;
		cmd->done(cmd);
		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 = SGADDR(cmd->SCp.buffer);

		    /* ++roman: Try to merge some scatter-buffers if
		     * they are at contiguous physical addresses.
		     */
//		    merge_contiguous_buffers( cmd );
		    INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
			       HOSTNO, 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.
		 */

/* ++roman: I suggest, this should be
 *   #if def(REAL_DMA)
 * instead of leaving REAL_DMA out.
 */

#if defined(REAL_DMA)
//		if (!cmd->device->borken &&
		if((transfersize =
		    NCR5380_dma_xfer_len(instance,cmd,phase)) > SUN3_DMA_MINSIZE) {
		    len = transfersize;
		    cmd->SCp.phase = phase;

		    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. */ 
			printk(KERN_NOTICE "scsi%d: switching target %d "
			       "lun %d to slow handshake\n", HOSTNO,
			       cmd->device->id, cmd->device->lun);
			cmd->device->borken = 1;
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			    ICR_ASSERT_ATN);
			sink = 1;
			do_abort(instance);
			cmd->result = DID_ERROR  << 16;
			cmd->done(cmd);
			/* XXX - need to source or sink data here, as appropriate */
		    } else {
#ifdef REAL_DMA
			/* ++roman: When using real DMA,
			 * information_transfer() should return after
			 * starting DMA since it has nothing more to
			 * do.
			 */
				    return;
#else			
			cmd->SCp.this_residual -= transfersize - len;
#endif
		    }
		} else 
#endif /* defined(REAL_DMA) */
		  NCR5380_transfer_pio(instance, &phase, 
		    (int *) &cmd->SCp.this_residual, (unsigned char **)
		    &cmd->SCp.ptr);
#ifdef REAL_DMA
		/* if we had intended to dma that command clear it */
		if(sun3_dma_setup_done == cmd)
			sun3_dma_setup_done = NULL;
#endif

		break;
	    case PHASE_MSGIN:
		len = 1;
		data = &tmp;
		NCR5380_write(SELECT_ENABLE_REG, 0); 	/* disable reselects */
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		cmd->SCp.Message = tmp;
		
		switch (tmp) {
		/*
		 * Linking lets us reduce the time required to get the 
		 * next command out to the device, hopefully this will
		 * mean we don't waste another revolution due to the delays
		 * required by ARBITRATION and another SELECTION.
		 *
		 * In the current implementation proposal, low level drivers
		 * merely have to start the next command, pointed to by 
		 * next_link, done() is called as with unlinked commands.
		 */
#ifdef LINKED
		case LINKED_CMD_COMPLETE:
		case LINKED_FLG_CMD_COMPLETE:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    
		    LNK_PRINTK("scsi%d: target %d lun %d linked command "
			       "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);

		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /*
		     * Sanity check : A linked command should only terminate
		     * with one of these messages if there are more linked
		     * commands available.
		     */

		    if (!cmd->next_link) {
			 printk(KERN_NOTICE "scsi%d: target %d lun %d "
				"linked command complete, no next_link\n",
				HOSTNO, cmd->device->id, cmd->device->lun);
			    sink = 1;
			    do_abort (instance);
			    return;
		    }

		    initialize_SCp(cmd->next_link);
		    /* The next command is still part of this process; copy it
		     * and don't free it! */
		    cmd->next_link->tag = cmd->tag;
		    cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    LNK_PRINTK("scsi%d: target %d lun %d linked request "
			       "done, calling scsi_done().\n",
			       HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    cmd = hostdata->connected;
		    break;
#endif /* def LINKED */
		case ABORT:
		case COMMAND_COMPLETE: 
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    hostdata->connected = NULL;
		    QU_PRINTK("scsi%d: command for target %d, lun %d "
			      "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
		    if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
			/* Turn a QUEUE FULL status into BUSY, I think the
			 * mid level cannot handle QUEUE FULL :-( (The
			 * command is retried after BUSY). Also update our
			 * queue size to the number of currently issued
			 * commands now.
			 */
			/* ++Andreas: the mid level code knows about
			   QUEUE_FULL now. */
			TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
			TAG_PRINTK("scsi%d: target %d lun %d returned "
				   "QUEUE_FULL after %d commands\n",
				   HOSTNO, cmd->device->id, cmd->device->lun,
				   ta->nr_allocated);
			if (ta->queue_size > ta->nr_allocated)
			    ta->nr_allocated = ta->queue_size;
		    }
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

		    /* 
		     * I'm not sure what the correct thing to do here is : 
		     * 
		     * If the command that just executed is NOT a request 
		     * sense, the obvious thing to do is to set the result
		     * code to the values of the stored parameters.
		     * 
		     * If it was a REQUEST SENSE command, we need some way to
		     * differentiate between the failure code of the original
		     * and the failure code of the REQUEST sense - the obvious
		     * case is success, where we fall through and leave the
		     * result code unchanged.
		     * 
		     * The non-obvious place is where the REQUEST SENSE failed
		     */

		    if (cmd->cmnd[0] != REQUEST_SENSE) 
			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    else if (status_byte(cmd->SCp.Status) != GOOD)
			cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
		    
#ifdef AUTOSENSE
		    if ((cmd->cmnd[0] != REQUEST_SENSE) && 
			(status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
			ASEN_PRINTK("scsi%d: performing request sense\n",
				    HOSTNO);
			cmd->cmnd[0] = REQUEST_SENSE;
			cmd->cmnd[1] &= 0xe0;
			cmd->cmnd[2] = 0;
			cmd->cmnd[3] = 0;
			cmd->cmnd[4] = sizeof(cmd->sense_buffer);
			cmd->cmnd[5] = 0;
			cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);

			cmd->use_sg = 0;
			/* this is initialized from initialize_SCp 
			cmd->SCp.buffer = NULL;
			cmd->SCp.buffers_residual = 0;
			*/
			cmd->request_buffer = (char *) cmd->sense_buffer;
			cmd->request_bufflen = sizeof(cmd->sense_buffer);

			local_irq_save(flags);
			LIST(cmd,hostdata->issue_queue);
			NEXT(cmd) = hostdata->issue_queue;
		        hostdata->issue_queue = (struct scsi_cmnd *) cmd;
		        local_irq_restore(flags);
			QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
				  "issue queue\n", H_NO(cmd));
		   } else
#endif /* def AUTOSENSE */
		   {
#ifdef NCR5380_STATS
		       collect_stats(hostdata, cmd);
#endif
		       cmd->scsi_done(cmd);
		    }

		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /* 
		     * Restore phase bits to 0 so an interrupted selection, 
		     * arbitration can resume.
		     */
		    NCR5380_write(TARGET_COMMAND_REG, 0);
		    
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
			barrier();

		    return;
		case MESSAGE_REJECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    switch (hostdata->last_message) {
		    case HEAD_OF_QUEUE_TAG:
		    case ORDERED_QUEUE_TAG:
		    case SIMPLE_QUEUE_TAG:
			/* The target obviously doesn't support tagged
			 * queuing, even though it announced this ability in
			 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
			 * clear 'tagged_supported' and lock the LUN, since
			 * the command is treated as untagged further on.
			 */
			cmd->device->tagged_supported = 0;
			hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
			cmd->tag = TAG_NONE;
			TAG_PRINTK("scsi%d: target %d lun %d rejected "
				   "QUEUE_TAG message; tagged queuing "
				   "disabled\n",
				   HOSTNO, cmd->device->id, cmd->device->lun);
			break;
		    }
		    break;
		case DISCONNECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    local_irq_save(flags);
		    cmd->device->disconnect = 1;
		    LIST(cmd,hostdata->disconnected_queue);
		    NEXT(cmd) = hostdata->disconnected_queue;
		    hostdata->connected = NULL;
		    hostdata->disconnected_queue = cmd;
		    local_irq_restore(flags);
		    QU_PRINTK("scsi%d: command for target %d lun %d was "
			      "moved from connected to the "
			      "disconnected_queue\n", HOSTNO, 
			      cmd->device->id, 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);
		    /* Wait for bus free to avoid nasty timeouts */
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
		    	barrier();
#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);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    break;
		case EXTENDED_MESSAGE:
/* 
 * Extended messages are sent in the following format :
 * Byte 	
 * 0		EXTENDED_MESSAGE == 1
 * 1		length (includes one byte for code, doesn't 
 *		include first two bytes)
 * 2 		code
 * 3..length+1	arguments
 *
 * Start the extended 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);

		    EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);

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

		    if (!len && extended_msg[1] <= 
			(sizeof (extended_msg) - 1)) {
			/* 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);
			EXT_PRINTK("scsi%d: message received, residual %d\n",
				   HOSTNO, len);

			switch (extended_msg[2]) {
			case EXTENDED_SDTR:
			case EXTENDED_WDTR:
			case EXTENDED_MODIFY_DATA_POINTER:
			case EXTENDED_EXTENDED_IDENTIFY:
			    tmp = 0;
			}
		    } else if (len) {
			printk(KERN_NOTICE "scsi%d: error receiving "
			       "extended message\n", HOSTNO);
			tmp = 0;
		    } else {
			printk(KERN_NOTICE "scsi%d: extended message "
			       "code %02x length %d is too long\n",
			       HOSTNO, extended_msg[2], extended_msg[1]);
			tmp = 0;
		    }
		/* Fall through to reject message */

		/* 
  		 * If we get something weird that we aren't expecting, 
 		 * reject it.
		 */
		default:
		    if (!tmp) {
			printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
			spi_print_msg(extended_msg);
			printk("\n");
		    } else if (tmp != EXTENDED_MESSAGE)
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "message %02x from target %d, lun %d\n",
			       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
		    else
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "extended message "
			       "code %02x, length %d from target %d, lun %d\n",
			       HOSTNO, extended_msg[1], extended_msg[0],
			       cmd->device->id, cmd->device->lun);
   

		    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) {
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    hostdata->connected = NULL;
		    cmd->result = DID_ERROR << 16;
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    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:
		printk("scsi%d: unknown phase\n", HOSTNO);
		NCR_PRINT(NDEBUG_ANY);
	    } /* switch(phase) */
	} /* if (tmp * SR_REQ) */ 
    } /* while (1) */
}

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

/* it might eventually prove necessary to do a dma setup on
   reselection, but it doesn't seem to be needed now -- sam */

static void NCR5380_reselect (struct Scsi_Host *instance)
{
    SETUP_HOSTDATA(instance);
    unsigned char target_mask;
    unsigned char lun;
#ifdef SUPPORT_TAGS
    unsigned char tag;
#endif
    unsigned char msg[3];
    struct scsi_cmnd *tmp = NULL, *prev;
/*    unsigned long flags; */

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

    NCR5380_write(MODE_REG, MR_BASE);
    hostdata->restart_select = 1;

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

    RSL_PRINTK("scsi%d: reselect\n", HOSTNO);

    /* 
     * 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);
    
    while (NCR5380_read(STATUS_REG) & SR_SEL);
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

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

    while (!(NCR5380_read(STATUS_REG) & SR_REQ));

#if 1
    // 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);
#endif

    if (!(msg[0] & 0x80)) {
	printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
	spi_print_msg(msg);
	do_abort(instance);
	return;
    }
    lun = (msg[0] & 0x07);

    /* 
     * 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.
     */

    for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
	 tmp; prev = tmp, tmp = NEXT(tmp) ) {
	if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
#ifdef SUPPORT_TAGS
	    && (tag == tmp->tag) 
#endif
	    ) {
	    if (prev) {
		REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
		NEXT(prev) = NEXT(tmp);
	    } else {
		REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
		hostdata->disconnected_queue = NEXT(tmp);
	    }
	    NEXT(tmp) = NULL;
	    break;
	}
    }
    
    if (!tmp) {
	printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
#ifdef SUPPORT_TAGS
		"tag %d "
#endif
		"not in disconnected_queue.\n",
		HOSTNO, target_mask, lun
#ifdef SUPPORT_TAGS
		, tag
#endif
		);
	/* 
	 * Since we have an established nexus that we can't do anything
	 * with, we must abort it.  
	 */
	do_abort(instance);
	return;
    }
#if 1
    /* engage dma setup for the command we just saw */
    {
	    void *d;
	    unsigned long count;

	    if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
		    count = tmp->SCp.buffer->length;
		    d = SGADDR(tmp->SCp.buffer);
	    } else {
		    count = tmp->SCp.this_residual;
		    d = tmp->SCp.ptr;
	    }
#ifdef REAL_DMA
	    /* setup this command for dma if not already */
	    if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done != tmp))
	    {
		    sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
		    sun3_dma_setup_done = tmp;
	    }
#endif
    }
#endif

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

#ifdef SUPPORT_TAGS
    /* If the phase is still MSGIN, the target wants to send some more
     * messages. In case it supports tagged queuing, this is probably a
     * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
     */
    tag = TAG_NONE;
    if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
	/* Accept previous IDENTIFY message by clearing ACK */
	NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
	len = 2;
	data = msg+1;
	if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
	    msg[1] == SIMPLE_QUEUE_TAG)
	    tag = msg[2];
	TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
		   "reselection\n", HOSTNO, target_mask, lun, tag);
    }
#endif
    
    hostdata->connected = tmp;
    RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
	       HOSTNO, tmp->target, tmp->lun, tmp->tag);
}


/*
 * Function : int NCR5380_abort(struct scsi_cmnd *cmd)
 *
 * Purpose : abort a command
 *
 * Inputs : cmd - the struct scsi_cmnd to abort, code - code to set the
 * 	host byte of the result field to, if zero DID_ABORTED is 
 *	used.
 *
 * Returns : 0 - success, -1 on failure.
 *
 * XXX - there is no way to abort the command that is currently 
 * 	 connected, you have to wait for it to complete.  If this is 
 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
 * 	 called where the loop started in NCR5380_main().
 */

static int NCR5380_abort(struct scsi_cmnd *cmd)
{
    struct Scsi_Host *instance = cmd->device->host;
    SETUP_HOSTDATA(instance);
    struct scsi_cmnd *tmp, **prev;
    unsigned long flags;

    printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
    scsi_print_command(cmd);

    NCR5380_print_status (instance);

    local_irq_save(flags);
    
    ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
		NCR5380_read(BUS_AND_STATUS_REG),
		NCR5380_read(STATUS_REG));

#if 1
/* 
 * Case 1 : If the command is the currently executing command, 
 * we'll set the aborted flag and return control so that 
 * information transfer routine can exit cleanly.
 */

    if (hostdata->connected == cmd) {

	ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
/*
 * We should perform BSY checking, and make sure we haven't slipped
 * into BUS FREE.
 */

/*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
/* 
 * Since we can't change phases until we've completed the current 
 * handshake, we have to source or sink a byte of data if the current
 * phase is not MSGOUT.
 */

/* 
 * Return control to the executing NCR drive so we can clear the
 * aborted flag and get back into our main loop.
 */ 

	if (do_abort(instance) == 0) {
	  hostdata->aborted = 1;
	  hostdata->connected = NULL;
	  cmd->result = DID_ABORT << 16;
#ifdef SUPPORT_TAGS
	  cmd_free_tag( cmd );
#else
	  hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
	  local_irq_restore(flags);
	  cmd->scsi_done(cmd);
	  return SCSI_ABORT_SUCCESS;
	} else {
/*	  local_irq_restore(flags); */
	  printk("scsi%d: abort of connected command failed!\n", HOSTNO);
	  return SCSI_ABORT_ERROR;
	} 
   }
#endif

/* 
 * Case 2 : If the command hasn't been issued yet, we simply remove it 
 * 	    from the issue queue.
 */
    for (prev = (struct scsi_cmnd **) &(hostdata->issue_queue),
	tmp = (struct scsi_cmnd *) hostdata->issue_queue;
	tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp))
	if (cmd == tmp) {
	    REMOVE(5, *prev, tmp, NEXT(tmp));
	    (*prev) = NEXT(tmp);
	    NEXT(tmp) = NULL;
	    tmp->result = DID_ABORT << 16;
	    local_irq_restore(flags);
	    ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
			HOSTNO);
	    /* Tagged queuing note: no tag to free here, hasn't been assigned
	     * yet... */
	    tmp->scsi_done(tmp);
	    return SCSI_ABORT_SUCCESS;
	}

/* 
 * Case 3 : If any commands are 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) {
	local_irq_restore(flags);
	ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
        return SCSI_ABORT_SNOOZE;
    }

/*
 * Case 4: If the command is currently disconnected from the bus, and 
 * 	there are no connected commands, we reconnect the I_T_L or 
 *	I_T_L_Q nexus associated with it, go into message out, and send 
 *      an abort message.
 *
 * This case is especially ugly. In order to reestablish the nexus, we
 * need to call NCR5380_select().  The easiest way to implement this 
 * function was to abort if the bus was busy, and let the interrupt
 * handler triggered on the SEL for reselect take care of lost arbitrations
 * where necessary, meaning interrupts need to be enabled.
 *
 * When interrupts are enabled, the queues may change - so we 
 * can't remove it from the disconnected queue before selecting it
 * because that could cause a failure in hashing the nexus if that 
 * device reselected.
 * 
 * Since the queues may change, we can't use the pointers from when we
 * first locate it.
 *
 * So, we must first locate the command, and if NCR5380_select()
 * succeeds, then issue the abort, relocate the command and remove
 * it from the disconnected queue.
 */

    for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
	 tmp = NEXT(tmp)) 
        if (cmd == tmp) {
            local_irq_restore(flags);
	    ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
  
            if (NCR5380_select (instance, cmd, (int) cmd->tag)) 
		return SCSI_ABORT_BUSY;

	    ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);

	    do_abort (instance);

	    local_irq_save(flags);
	    for (prev = (struct scsi_cmnd **) &(hostdata->disconnected_queue),
		tmp = (struct scsi_cmnd *) hostdata->disconnected_queue;
		tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp) )
		    if (cmd == tmp) {
		    REMOVE(5, *prev, tmp, NEXT(tmp));
		    *prev = NEXT(tmp);
		    NEXT(tmp) = NULL;
		    tmp->result = DID_ABORT << 16;
		    /* We must unlock the tag/LUN immediately here, since the
		     * target goes to BUS FREE and doesn't send us another
		     * message (COMMAND_COMPLETE or the like)
		     */
#ifdef SUPPORT_TAGS
		    cmd_free_tag( tmp );
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    local_irq_restore(flags);
		    tmp->scsi_done(tmp);
		    return SCSI_ABORT_SUCCESS;
		}
	}

/*
 * Case 5 : 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.
 */

    local_irq_restore(flags);
    printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully\n"
           KERN_INFO "        before abortion\n", HOSTNO); 

    return SCSI_ABORT_NOT_RUNNING;
}


/* 
 * Function : int NCR5380_bus_reset(struct scsi_cmnd *cmd)
 * 
 * Purpose : reset the SCSI bus.
 *
 * Returns : SCSI_RESET_WAKEUP
 *
 */ 

static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
{
    SETUP_HOSTDATA(cmd->device->host);
    int           i;
    unsigned long flags;
#if 1
    struct scsi_cmnd *connected, *disconnected_queue;
#endif


    NCR5380_print_status (cmd->device->host);

    /* get in phase */
    NCR5380_write( TARGET_COMMAND_REG,
		   PHASE_SR_TO_TCR( NCR5380_read(STATUS_REG) ));
    /* assert RST */
    NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST );
    udelay (40);
    /* reset NCR registers */
    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 );
    /* ++roman: reset interrupt condition! otherwise no interrupts don't get
     * through anymore ... */
    (void)NCR5380_read( RESET_PARITY_INTERRUPT_REG );

#if 1 /* XXX Should now be done by midlevel code, but it's broken XXX */
      /* XXX see below                                            XXX */

    /* MSch: old-style reset: actually abort all command processing here */

    /* After the reset, there are no more connected or disconnected commands
     * and no busy units; to avoid problems with re-inserting the commands
     * into the issue_queue (via scsi_done()), the aborted commands are
     * remembered in local variables first.
     */
    local_irq_save(flags);
    connected = (struct scsi_cmnd *)hostdata->connected;
    hostdata->connected = NULL;
    disconnected_queue = (struct scsi_cmnd *)hostdata->disconnected_queue;
    hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
    free_all_tags();
#endif
    for( i = 0; i < 8; ++i )
	hostdata->busy[i] = 0;
#ifdef REAL_DMA
    hostdata->dma_len = 0;
#endif
    local_irq_restore(flags);

    /* In order to tell the mid-level code which commands were aborted, 
     * set the command status to DID_RESET and call scsi_done() !!!
     * This ultimately aborts processing of these commands in the mid-level.
     */

    if ((cmd = connected)) {
	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
	cmd->scsi_done( cmd );
    }

    for (i = 0; (cmd = disconnected_queue); ++i) {
	disconnected_queue = NEXT(cmd);
	NEXT(cmd) = NULL;
	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
	cmd->scsi_done( cmd );
    }
    if (i > 0)
	ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);


    /* since all commands have been explicitly terminated, we need to tell
     * the midlevel code that the reset was SUCCESSFUL, and there is no 
     * need to 'wake up' the commands by a request_sense
     */
    return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
#else /* 1 */

    /* MSch: new-style reset handling: let the mid-level do what it can */

    /* ++guenther: MID-LEVEL IS STILL BROKEN.
     * Mid-level is supposed to requeue all commands that were active on the
     * various low-level queues. In fact it does this, but that's not enough
     * because all these commands are subject to timeout. And if a timeout
     * happens for any removed command, *_abort() is called but all queues
     * are now empty. Abort then gives up the falcon lock, which is fatal,
     * since the mid-level will queue more commands and must have the lock
     * (it's all happening inside timer interrupt handler!!).
     * Even worse, abort will return NOT_RUNNING for all those commands not
     * on any queue, so they won't be retried ...
     *
     * Conclusion: either scsi.c disables timeout for all resetted commands
     * immediately, or we lose!  As of linux-2.0.20 it doesn't.
     */

    /* 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 (hostdata->issue_queue)
	ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
    if (hostdata->connected) 
	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
    if (hostdata->disconnected_queue)
	ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));

    local_irq_save(flags);
    hostdata->issue_queue = NULL;
    hostdata->connected = NULL;
    hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
    free_all_tags();
#endif
    for( i = 0; i < 8; ++i )
	hostdata->busy[i] = 0;
#ifdef REAL_DMA
    hostdata->dma_len = 0;
#endif
    local_irq_restore(flags);

    /* we did no complete reset of all commands, so a wakeup is required */
    return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
#endif /* 1 */
}

/* Local Variables: */
/* tab-width: 8     */
/* End:             */