summaryrefslogtreecommitdiffstats
path: root/drivers/ata/libata-scsi.c
blob: 72691fd939483af322e4460d8d168b2bf5899b46 (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
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
/*
 *  libata-scsi.c - helper library for ATA
 *
 *  Maintained by:  Tejun Heo <tj@kernel.org>
 *    		    Please ALWAYS copy linux-ide@vger.kernel.org
 *		    on emails.
 *
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/DocBook/libata.*
 *
 *  Hardware documentation available from
 *  - http://www.t10.org/
 *  - http://www.t13.org/
 *
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
#include <linux/libata.h>
#include <linux/hdreg.h>
#include <linux/uaccess.h>
#include <linux/suspend.h>
#include <asm/unaligned.h>

#include "libata.h"
#include "libata-transport.h"

#define ATA_SCSI_RBUF_SIZE	4096

static DEFINE_SPINLOCK(ata_scsi_rbuf_lock);
static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];

typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);

static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
					const struct scsi_device *scsidev);
static struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
					    const struct scsi_device *scsidev);

#define RW_RECOVERY_MPAGE 0x1
#define RW_RECOVERY_MPAGE_LEN 12
#define CACHE_MPAGE 0x8
#define CACHE_MPAGE_LEN 20
#define CONTROL_MPAGE 0xa
#define CONTROL_MPAGE_LEN 12
#define ALL_MPAGES 0x3f
#define ALL_SUB_MPAGES 0xff


static const u8 def_rw_recovery_mpage[RW_RECOVERY_MPAGE_LEN] = {
	RW_RECOVERY_MPAGE,
	RW_RECOVERY_MPAGE_LEN - 2,
	(1 << 7),	/* AWRE */
	0,		/* read retry count */
	0, 0, 0, 0,
	0,		/* write retry count */
	0, 0, 0
};

static const u8 def_cache_mpage[CACHE_MPAGE_LEN] = {
	CACHE_MPAGE,
	CACHE_MPAGE_LEN - 2,
	0,		/* contains WCE, needs to be 0 for logic */
	0, 0, 0, 0, 0, 0, 0, 0, 0,
	0,		/* contains DRA, needs to be 0 for logic */
	0, 0, 0, 0, 0, 0, 0
};

static const u8 def_control_mpage[CONTROL_MPAGE_LEN] = {
	CONTROL_MPAGE,
	CONTROL_MPAGE_LEN - 2,
	2,	/* DSENSE=0, GLTSD=1 */
	0,	/* [QAM+QERR may be 1, see 05-359r1] */
	0, 0, 0, 0, 0xff, 0xff,
	0, 30	/* extended self test time, see 05-359r1 */
};

static const char *ata_lpm_policy_names[] = {
	[ATA_LPM_UNKNOWN]	= "max_performance",
	[ATA_LPM_MAX_POWER]	= "max_performance",
	[ATA_LPM_MED_POWER]	= "medium_power",
	[ATA_LPM_MIN_POWER]	= "min_power",
};

static ssize_t ata_scsi_lpm_store(struct device *device,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct Scsi_Host *shost = class_to_shost(device);
	struct ata_port *ap = ata_shost_to_port(shost);
	struct ata_link *link;
	struct ata_device *dev;
	enum ata_lpm_policy policy;
	unsigned long flags;

	/* UNKNOWN is internal state, iterate from MAX_POWER */
	for (policy = ATA_LPM_MAX_POWER;
	     policy < ARRAY_SIZE(ata_lpm_policy_names); policy++) {
		const char *name = ata_lpm_policy_names[policy];

		if (strncmp(name, buf, strlen(name)) == 0)
			break;
	}
	if (policy == ARRAY_SIZE(ata_lpm_policy_names))
		return -EINVAL;

	spin_lock_irqsave(ap->lock, flags);

	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, &ap->link, ENABLED) {
			if (dev->horkage & ATA_HORKAGE_NOLPM) {
				count = -EOPNOTSUPP;
				goto out_unlock;
			}
		}
	}

	ap->target_lpm_policy = policy;
	ata_port_schedule_eh(ap);
out_unlock:
	spin_unlock_irqrestore(ap->lock, flags);
	return count;
}

static ssize_t ata_scsi_lpm_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	if (ap->target_lpm_policy >= ARRAY_SIZE(ata_lpm_policy_names))
		return -EINVAL;

	return snprintf(buf, PAGE_SIZE, "%s\n",
			ata_lpm_policy_names[ap->target_lpm_policy]);
}
DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
	    ata_scsi_lpm_show, ata_scsi_lpm_store);
EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);

static ssize_t ata_scsi_park_show(struct device *device,
				  struct device_attribute *attr, char *buf)
{
	struct scsi_device *sdev = to_scsi_device(device);
	struct ata_port *ap;
	struct ata_link *link;
	struct ata_device *dev;
	unsigned long flags, now;
	unsigned int uninitialized_var(msecs);
	int rc = 0;

	ap = ata_shost_to_port(sdev->host);

	spin_lock_irqsave(ap->lock, flags);
	dev = ata_scsi_find_dev(ap, sdev);
	if (!dev) {
		rc = -ENODEV;
		goto unlock;
	}
	if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
		rc = -EOPNOTSUPP;
		goto unlock;
	}

	link = dev->link;
	now = jiffies;
	if (ap->pflags & ATA_PFLAG_EH_IN_PROGRESS &&
	    link->eh_context.unloaded_mask & (1 << dev->devno) &&
	    time_after(dev->unpark_deadline, now))
		msecs = jiffies_to_msecs(dev->unpark_deadline - now);
	else
		msecs = 0;

unlock:
	spin_unlock_irq(ap->lock);

	return rc ? rc : snprintf(buf, 20, "%u\n", msecs);
}

static ssize_t ata_scsi_park_store(struct device *device,
				   struct device_attribute *attr,
				   const char *buf, size_t len)
{
	struct scsi_device *sdev = to_scsi_device(device);
	struct ata_port *ap;
	struct ata_device *dev;
	long int input;
	unsigned long flags;
	int rc;

	rc = kstrtol(buf, 10, &input);
	if (rc)
		return rc;
	if (input < -2)
		return -EINVAL;
	if (input > ATA_TMOUT_MAX_PARK) {
		rc = -EOVERFLOW;
		input = ATA_TMOUT_MAX_PARK;
	}

	ap = ata_shost_to_port(sdev->host);

	spin_lock_irqsave(ap->lock, flags);
	dev = ata_scsi_find_dev(ap, sdev);
	if (unlikely(!dev)) {
		rc = -ENODEV;
		goto unlock;
	}
	if (dev->class != ATA_DEV_ATA) {
		rc = -EOPNOTSUPP;
		goto unlock;
	}

	if (input >= 0) {
		if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
			rc = -EOPNOTSUPP;
			goto unlock;
		}

		dev->unpark_deadline = ata_deadline(jiffies, input);
		dev->link->eh_info.dev_action[dev->devno] |= ATA_EH_PARK;
		ata_port_schedule_eh(ap);
		complete(&ap->park_req_pending);
	} else {
		switch (input) {
		case -1:
			dev->flags &= ~ATA_DFLAG_NO_UNLOAD;
			break;
		case -2:
			dev->flags |= ATA_DFLAG_NO_UNLOAD;
			break;
		}
	}
unlock:
	spin_unlock_irqrestore(ap->lock, flags);

	return rc ? rc : len;
}
DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
	    ata_scsi_park_show, ata_scsi_park_store);
EXPORT_SYMBOL_GPL(dev_attr_unload_heads);

static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
{
	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

	scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
}

static ssize_t
ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);
	if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
		return ap->ops->em_store(ap, buf, count);
	return -EINVAL;
}

static ssize_t
ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
		return ap->ops->em_show(ap, buf);
	return -EINVAL;
}
DEVICE_ATTR(em_message, S_IRUGO | S_IWUSR,
		ata_scsi_em_message_show, ata_scsi_em_message_store);
EXPORT_SYMBOL_GPL(dev_attr_em_message);

static ssize_t
ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct ata_port *ap = ata_shost_to_port(shost);

	return snprintf(buf, 23, "%d\n", ap->em_message_type);
}
DEVICE_ATTR(em_message_type, S_IRUGO,
		  ata_scsi_em_message_type_show, NULL);
EXPORT_SYMBOL_GPL(dev_attr_em_message_type);

static ssize_t
ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);

	if (atadev && ap->ops->sw_activity_show &&
	    (ap->flags & ATA_FLAG_SW_ACTIVITY))
		return ap->ops->sw_activity_show(atadev, buf);
	return -EINVAL;
}

static ssize_t
ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
	const char *buf, size_t count)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
	enum sw_activity val;
	int rc;

	if (atadev && ap->ops->sw_activity_store &&
	    (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
		val = simple_strtoul(buf, NULL, 0);
		switch (val) {
		case OFF: case BLINK_ON: case BLINK_OFF:
			rc = ap->ops->sw_activity_store(atadev, val);
			if (!rc)
				return count;
			else
				return rc;
		}
	}
	return -EINVAL;
}
DEVICE_ATTR(sw_activity, S_IWUSR | S_IRUGO, ata_scsi_activity_show,
			ata_scsi_activity_store);
EXPORT_SYMBOL_GPL(dev_attr_sw_activity);

struct device_attribute *ata_common_sdev_attrs[] = {
	&dev_attr_unload_heads,
	NULL
};
EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);

static void ata_scsi_invalid_field(struct scsi_cmnd *cmd)
{
	ata_scsi_set_sense(cmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	cmd->scsi_done(cmd);
}

/**
 *	ata_std_bios_param - generic bios head/sector/cylinder calculator used by sd.
 *	@sdev: SCSI device for which BIOS geometry is to be determined
 *	@bdev: block device associated with @sdev
 *	@capacity: capacity of SCSI device
 *	@geom: location to which geometry will be output
 *
 *	Generic bios head/sector/cylinder calculator
 *	used by sd. Most BIOSes nowadays expect a XXX/255/16  (CHS)
 *	mapping. Some situations may arise where the disk is not
 *	bootable if this is not used.
 *
 *	LOCKING:
 *	Defined by the SCSI layer.  We don't really care.
 *
 *	RETURNS:
 *	Zero.
 */
int ata_std_bios_param(struct scsi_device *sdev, struct block_device *bdev,
		       sector_t capacity, int geom[])
{
	geom[0] = 255;
	geom[1] = 63;
	sector_div(capacity, 255*63);
	geom[2] = capacity;

	return 0;
}

/**
 *	ata_scsi_unlock_native_capacity - unlock native capacity
 *	@sdev: SCSI device to adjust device capacity for
 *
 *	This function is called if a partition on @sdev extends beyond
 *	the end of the device.  It requests EH to unlock HPA.
 *
 *	LOCKING:
 *	Defined by the SCSI layer.  Might sleep.
 */
void ata_scsi_unlock_native_capacity(struct scsi_device *sdev)
{
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *dev;
	unsigned long flags;

	spin_lock_irqsave(ap->lock, flags);

	dev = ata_scsi_find_dev(ap, sdev);
	if (dev && dev->n_sectors < dev->n_native_sectors) {
		dev->flags |= ATA_DFLAG_UNLOCK_HPA;
		dev->link->eh_info.action |= ATA_EH_RESET;
		ata_port_schedule_eh(ap);
	}

	spin_unlock_irqrestore(ap->lock, flags);
	ata_port_wait_eh(ap);
}

/**
 *	ata_get_identity - Handler for HDIO_GET_IDENTITY ioctl
 *	@ap: target port
 *	@sdev: SCSI device to get identify data for
 *	@arg: User buffer area for identify data
 *
 *	LOCKING:
 *	Defined by the SCSI layer.  We don't really care.
 *
 *	RETURNS:
 *	Zero on success, negative errno on error.
 */
static int ata_get_identity(struct ata_port *ap, struct scsi_device *sdev,
			    void __user *arg)
{
	struct ata_device *dev = ata_scsi_find_dev(ap, sdev);
	u16 __user *dst = arg;
	char buf[40];

	if (!dev)
		return -ENOMSG;

	if (copy_to_user(dst, dev->id, ATA_ID_WORDS * sizeof(u16)))
		return -EFAULT;

	ata_id_string(dev->id, buf, ATA_ID_PROD, ATA_ID_PROD_LEN);
	if (copy_to_user(dst + ATA_ID_PROD, buf, ATA_ID_PROD_LEN))
		return -EFAULT;

	ata_id_string(dev->id, buf, ATA_ID_FW_REV, ATA_ID_FW_REV_LEN);
	if (copy_to_user(dst + ATA_ID_FW_REV, buf, ATA_ID_FW_REV_LEN))
		return -EFAULT;

	ata_id_string(dev->id, buf, ATA_ID_SERNO, ATA_ID_SERNO_LEN);
	if (copy_to_user(dst + ATA_ID_SERNO, buf, ATA_ID_SERNO_LEN))
		return -EFAULT;

	return 0;
}

/**
 *	ata_cmd_ioctl - Handler for HDIO_DRIVE_CMD ioctl
 *	@scsidev: Device to which we are issuing command
 *	@arg: User provided data for issuing command
 *
 *	LOCKING:
 *	Defined by the SCSI layer.  We don't really care.
 *
 *	RETURNS:
 *	Zero on success, negative errno on error.
 */
int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
{
	int rc = 0;
	u8 scsi_cmd[MAX_COMMAND_SIZE];
	u8 args[4], *argbuf = NULL, *sensebuf = NULL;
	int argsize = 0;
	enum dma_data_direction data_dir;
	int cmd_result;

	if (arg == NULL)
		return -EINVAL;

	if (copy_from_user(args, arg, sizeof(args)))
		return -EFAULT;

	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
	if (!sensebuf)
		return -ENOMEM;

	memset(scsi_cmd, 0, sizeof(scsi_cmd));

	if (args[3]) {
		argsize = ATA_SECT_SIZE * args[3];
		argbuf = kmalloc(argsize, GFP_KERNEL);
		if (argbuf == NULL) {
			rc = -ENOMEM;
			goto error;
		}

		scsi_cmd[1]  = (4 << 1); /* PIO Data-in */
		scsi_cmd[2]  = 0x0e;     /* no off.line or cc, read from dev,
					    block count in sector count field */
		data_dir = DMA_FROM_DEVICE;
	} else {
		scsi_cmd[1]  = (3 << 1); /* Non-data */
		scsi_cmd[2]  = 0x20;     /* cc but no off.line or data xfer */
		data_dir = DMA_NONE;
	}

	scsi_cmd[0] = ATA_16;

	scsi_cmd[4] = args[2];
	if (args[0] == ATA_CMD_SMART) { /* hack -- ide driver does this too */
		scsi_cmd[6]  = args[3];
		scsi_cmd[8]  = args[1];
		scsi_cmd[10] = 0x4f;
		scsi_cmd[12] = 0xc2;
	} else {
		scsi_cmd[6]  = args[1];
	}
	scsi_cmd[14] = args[0];

	/* Good values for timeout and retries?  Values below
	   from scsi_ioctl_send_command() for default case... */
	cmd_result = scsi_execute(scsidev, scsi_cmd, data_dir, argbuf, argsize,
				  sensebuf, (10*HZ), 5, 0, NULL);

	if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
		u8 *desc = sensebuf + 8;
		cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */

		/* If we set cc then ATA pass-through will cause a
		 * check condition even if no error. Filter that. */
		if (cmd_result & SAM_STAT_CHECK_CONDITION) {
			struct scsi_sense_hdr sshdr;
			scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,
					     &sshdr);
			if (sshdr.sense_key == RECOVERED_ERROR &&
			    sshdr.asc == 0 && sshdr.ascq == 0x1d)
				cmd_result &= ~SAM_STAT_CHECK_CONDITION;
		}

		/* Send userspace a few ATA registers (same as drivers/ide) */
		if (sensebuf[0] == 0x72 &&	/* format is "descriptor" */
		    desc[0] == 0x09) {		/* code is "ATA Descriptor" */
			args[0] = desc[13];	/* status */
			args[1] = desc[3];	/* error */
			args[2] = desc[5];	/* sector count (0:7) */
			if (copy_to_user(arg, args, sizeof(args)))
				rc = -EFAULT;
		}
	}


	if (cmd_result) {
		rc = -EIO;
		goto error;
	}

	if ((argbuf)
	 && copy_to_user(arg + sizeof(args), argbuf, argsize))
		rc = -EFAULT;
error:
	kfree(sensebuf);
	kfree(argbuf);
	return rc;
}

/**
 *	ata_task_ioctl - Handler for HDIO_DRIVE_TASK ioctl
 *	@scsidev: Device to which we are issuing command
 *	@arg: User provided data for issuing command
 *
 *	LOCKING:
 *	Defined by the SCSI layer.  We don't really care.
 *
 *	RETURNS:
 *	Zero on success, negative errno on error.
 */
int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
{
	int rc = 0;
	u8 scsi_cmd[MAX_COMMAND_SIZE];
	u8 args[7], *sensebuf = NULL;
	int cmd_result;

	if (arg == NULL)
		return -EINVAL;

	if (copy_from_user(args, arg, sizeof(args)))
		return -EFAULT;

	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
	if (!sensebuf)
		return -ENOMEM;

	memset(scsi_cmd, 0, sizeof(scsi_cmd));
	scsi_cmd[0]  = ATA_16;
	scsi_cmd[1]  = (3 << 1); /* Non-data */
	scsi_cmd[2]  = 0x20;     /* cc but no off.line or data xfer */
	scsi_cmd[4]  = args[1];
	scsi_cmd[6]  = args[2];
	scsi_cmd[8]  = args[3];
	scsi_cmd[10] = args[4];
	scsi_cmd[12] = args[5];
	scsi_cmd[13] = args[6] & 0x4f;
	scsi_cmd[14] = args[0];

	/* Good values for timeout and retries?  Values below
	   from scsi_ioctl_send_command() for default case... */
	cmd_result = scsi_execute(scsidev, scsi_cmd, DMA_NONE, NULL, 0,
				sensebuf, (10*HZ), 5, 0, NULL);

	if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
		u8 *desc = sensebuf + 8;
		cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */

		/* If we set cc then ATA pass-through will cause a
		 * check condition even if no error. Filter that. */
		if (cmd_result & SAM_STAT_CHECK_CONDITION) {
			struct scsi_sense_hdr sshdr;
			scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,
						&sshdr);
			if (sshdr.sense_key == RECOVERED_ERROR &&
			    sshdr.asc == 0 && sshdr.ascq == 0x1d)
				cmd_result &= ~SAM_STAT_CHECK_CONDITION;
		}

		/* Send userspace ATA registers */
		if (sensebuf[0] == 0x72 &&	/* format is "descriptor" */
				desc[0] == 0x09) {/* code is "ATA Descriptor" */
			args[0] = desc[13];	/* status */
			args[1] = desc[3];	/* error */
			args[2] = desc[5];	/* sector count (0:7) */
			args[3] = desc[7];	/* lbal */
			args[4] = desc[9];	/* lbam */
			args[5] = desc[11];	/* lbah */
			args[6] = desc[12];	/* select */
			if (copy_to_user(arg, args, sizeof(args)))
				rc = -EFAULT;
		}
	}

	if (cmd_result) {
		rc = -EIO;
		goto error;
	}

 error:
	kfree(sensebuf);
	return rc;
}

static int ata_ioc32(struct ata_port *ap)
{
	if (ap->flags & ATA_FLAG_PIO_DMA)
		return 1;
	if (ap->pflags & ATA_PFLAG_PIO32)
		return 1;
	return 0;
}

int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
		     int cmd, void __user *arg)
{
	int val = -EINVAL, rc = -EINVAL;
	unsigned long flags;

	switch (cmd) {
	case ATA_IOC_GET_IO32:
		spin_lock_irqsave(ap->lock, flags);
		val = ata_ioc32(ap);
		spin_unlock_irqrestore(ap->lock, flags);
		if (copy_to_user(arg, &val, 1))
			return -EFAULT;
		return 0;

	case ATA_IOC_SET_IO32:
		val = (unsigned long) arg;
		rc = 0;
		spin_lock_irqsave(ap->lock, flags);
		if (ap->pflags & ATA_PFLAG_PIO32CHANGE) {
			if (val)
				ap->pflags |= ATA_PFLAG_PIO32;
			else
				ap->pflags &= ~ATA_PFLAG_PIO32;
		} else {
			if (val != ata_ioc32(ap))
				rc = -EINVAL;
		}
		spin_unlock_irqrestore(ap->lock, flags);
		return rc;

	case HDIO_GET_IDENTITY:
		return ata_get_identity(ap, scsidev, arg);

	case HDIO_DRIVE_CMD:
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
			return -EACCES;
		return ata_cmd_ioctl(scsidev, arg);

	case HDIO_DRIVE_TASK:
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
			return -EACCES;
		return ata_task_ioctl(scsidev, arg);

	default:
		rc = -ENOTTY;
		break;
	}

	return rc;
}
EXPORT_SYMBOL_GPL(ata_sas_scsi_ioctl);

int ata_scsi_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg)
{
	return ata_sas_scsi_ioctl(ata_shost_to_port(scsidev->host),
				scsidev, cmd, arg);
}
EXPORT_SYMBOL_GPL(ata_scsi_ioctl);

/**
 *	ata_scsi_qc_new - acquire new ata_queued_cmd reference
 *	@dev: ATA device to which the new command is attached
 *	@cmd: SCSI command that originated this ATA command
 *
 *	Obtain a reference to an unused ata_queued_cmd structure,
 *	which is the basic libata structure representing a single
 *	ATA command sent to the hardware.
 *
 *	If a command was available, fill in the SCSI-specific
 *	portions of the structure with information on the
 *	current command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Command allocated, or %NULL if none available.
 */
static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
					      struct scsi_cmnd *cmd)
{
	struct ata_queued_cmd *qc;

	qc = ata_qc_new_init(dev);
	if (qc) {
		qc->scsicmd = cmd;
		qc->scsidone = cmd->scsi_done;

		qc->sg = scsi_sglist(cmd);
		qc->n_elem = scsi_sg_count(cmd);
	} else {
		cmd->result = (DID_OK << 16) | (QUEUE_FULL << 1);
		cmd->scsi_done(cmd);
	}

	return qc;
}

static void ata_qc_set_pc_nbytes(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;

	qc->extrabytes = scmd->request->extra_len;
	qc->nbytes = scsi_bufflen(scmd) + qc->extrabytes;
}

/**
 *	ata_dump_status - user friendly display of error info
 *	@id: id of the port in question
 *	@tf: ptr to filled out taskfile
 *
 *	Decode and dump the ATA error/status registers for the user so
 *	that they have some idea what really happened at the non
 *	make-believe layer.
 *
 *	LOCKING:
 *	inherited from caller
 */
static void ata_dump_status(unsigned id, struct ata_taskfile *tf)
{
	u8 stat = tf->command, err = tf->feature;

	printk(KERN_WARNING "ata%u: status=0x%02x { ", id, stat);
	if (stat & ATA_BUSY) {
		printk("Busy }\n");	/* Data is not valid in this case */
	} else {
		if (stat & 0x40)	printk("DriveReady ");
		if (stat & 0x20)	printk("DeviceFault ");
		if (stat & 0x10)	printk("SeekComplete ");
		if (stat & 0x08)	printk("DataRequest ");
		if (stat & 0x04)	printk("CorrectedError ");
		if (stat & 0x02)	printk("Index ");
		if (stat & 0x01)	printk("Error ");
		printk("}\n");

		if (err) {
			printk(KERN_WARNING "ata%u: error=0x%02x { ", id, err);
			if (err & 0x04)		printk("DriveStatusError ");
			if (err & 0x80) {
				if (err & 0x04)	printk("BadCRC ");
				else		printk("Sector ");
			}
			if (err & 0x40)		printk("UncorrectableError ");
			if (err & 0x10)		printk("SectorIdNotFound ");
			if (err & 0x02)		printk("TrackZeroNotFound ");
			if (err & 0x01)		printk("AddrMarkNotFound ");
			printk("}\n");
		}
	}
}

/**
 *	ata_to_sense_error - convert ATA error to SCSI error
 *	@id: ATA device number
 *	@drv_stat: value contained in ATA status register
 *	@drv_err: value contained in ATA error register
 *	@sk: the sense key we'll fill out
 *	@asc: the additional sense code we'll fill out
 *	@ascq: the additional sense code qualifier we'll fill out
 *	@verbose: be verbose
 *
 *	Converts an ATA error into a SCSI error.  Fill out pointers to
 *	SK, ASC, and ASCQ bytes for later use in fixed or descriptor
 *	format sense blocks.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk,
			       u8 *asc, u8 *ascq, int verbose)
{
	int i;

	/* Based on the 3ware driver translation table */
	static const unsigned char sense_table[][4] = {
		/* BBD|ECC|ID|MAR */
		{0xd1, 		ABORTED_COMMAND, 0x00, 0x00}, 	// Device busy                  Aborted command
		/* BBD|ECC|ID */
		{0xd0,  	ABORTED_COMMAND, 0x00, 0x00}, 	// Device busy                  Aborted command
		/* ECC|MC|MARK */
		{0x61, 		HARDWARE_ERROR, 0x00, 0x00}, 	// Device fault                 Hardware error
		/* ICRC|ABRT */		/* NB: ICRC & !ABRT is BBD */
		{0x84, 		ABORTED_COMMAND, 0x47, 0x00}, 	// Data CRC error               SCSI parity error
		/* MC|ID|ABRT|TRK0|MARK */
		{0x37, 		NOT_READY, 0x04, 0x00}, 	// Unit offline                 Not ready
		/* MCR|MARK */
		{0x09, 		NOT_READY, 0x04, 0x00}, 	// Unrecovered disk error       Not ready
		/*  Bad address mark */
		{0x01, 		MEDIUM_ERROR, 0x13, 0x00}, 	// Address mark not found       Address mark not found for data field
		/* TRK0 */
		{0x02, 		HARDWARE_ERROR, 0x00, 0x00}, 	// Track 0 not found		Hardware error
		/* Abort: 0x04 is not translated here, see below */
		/* Media change request */
		{0x08, 		NOT_READY, 0x04, 0x00}, 	// Media change request	  FIXME: faking offline
		/* SRV/IDNF */
		{0x10, 		ILLEGAL_REQUEST, 0x21, 0x00}, 	// ID not found                 Logical address out of range
		/* MC */
		{0x20, 		UNIT_ATTENTION, 0x28, 0x00}, 	// Media Changed		Not ready to ready change, medium may have changed
		/* ECC */
		{0x40, 		MEDIUM_ERROR, 0x11, 0x04}, 	// Uncorrectable ECC error      Unrecovered read error
		/* BBD - block marked bad */
		{0x80, 		MEDIUM_ERROR, 0x11, 0x04}, 	// Block marked bad		Medium error, unrecovered read error
		{0xFF, 0xFF, 0xFF, 0xFF}, // END mark
	};
	static const unsigned char stat_table[][4] = {
		/* Must be first because BUSY means no other bits valid */
		{0x80, 		ABORTED_COMMAND, 0x47, 0x00},	// Busy, fake parity for now
		{0x20, 		HARDWARE_ERROR,  0x44, 0x00}, 	// Device fault, internal target failure
		{0x08, 		ABORTED_COMMAND, 0x47, 0x00},	// Timed out in xfer, fake parity for now
		{0x04, 		RECOVERED_ERROR, 0x11, 0x00},	// Recovered ECC error	  Medium error, recovered
		{0xFF, 0xFF, 0xFF, 0xFF}, // END mark
	};

	/*
	 *	Is this an error we can process/parse
	 */
	if (drv_stat & ATA_BUSY) {
		drv_err = 0;	/* Ignore the err bits, they're invalid */
	}

	if (drv_err) {
		/* Look for drv_err */
		for (i = 0; sense_table[i][0] != 0xFF; i++) {
			/* Look for best matches first */
			if ((sense_table[i][0] & drv_err) ==
			    sense_table[i][0]) {
				*sk = sense_table[i][1];
				*asc = sense_table[i][2];
				*ascq = sense_table[i][3];
				goto translate_done;
			}
		}
	}

	/*
	 * Fall back to interpreting status bits.  Note that if the drv_err
	 * has only the ABRT bit set, we decode drv_stat.  ABRT by itself
	 * is not descriptive enough.
	 */
	for (i = 0; stat_table[i][0] != 0xFF; i++) {
		if (stat_table[i][0] & drv_stat) {
			*sk = stat_table[i][1];
			*asc = stat_table[i][2];
			*ascq = stat_table[i][3];
			goto translate_done;
		}
	}

	/*
	 * We need a sensible error return here, which is tricky, and one
	 * that won't cause people to do things like return a disk wrongly.
	 */
	*sk = ABORTED_COMMAND;
	*asc = 0x00;
	*ascq = 0x00;

 translate_done:
	if (verbose)
		printk(KERN_ERR "ata%u: translated ATA stat/err 0x%02x/%02x "
		       "to SCSI SK/ASC/ASCQ 0x%x/%02x/%02x\n",
		       id, drv_stat, drv_err, *sk, *asc, *ascq);
	return;
}

/*
 *	ata_gen_passthru_sense - Generate check condition sense block.
 *	@qc: Command that completed.
 *
 *	This function is specific to the ATA descriptor format sense
 *	block specified for the ATA pass through commands.  Regardless
 *	of whether the command errored or not, return a sense
 *	block. Copy all controller registers into the sense
 *	block. If there was no error, we get the request from an ATA
 *	passthrough command, so we use the following sense data:
 *	sk = RECOVERED ERROR
 *	asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE
 *      
 *
 *	LOCKING:
 *	None.
 */
static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *cmd = qc->scsicmd;
	struct ata_taskfile *tf = &qc->result_tf;
	unsigned char *sb = cmd->sense_buffer;
	unsigned char *desc = sb + 8;
	int verbose = qc->ap->ops->error_handler == NULL;

	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);

	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

	/*
	 * Use ata_to_sense_error() to map status register bits
	 * onto sense key, asc & ascq.
	 */
	if (qc->err_mask ||
	    tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
		ata_to_sense_error(qc->ap->print_id, tf->command, tf->feature,
				   &sb[1], &sb[2], &sb[3], verbose);
		sb[1] &= 0x0f;
	} else {
		sb[1] = RECOVERED_ERROR;
		sb[2] = 0;
		sb[3] = 0x1D;
	}

	/*
	 * Sense data is current and format is descriptor.
	 */
	sb[0] = 0x72;

	desc[0] = 0x09;

	/* set length of additional sense data */
	sb[7] = 14;
	desc[1] = 12;

	/*
	 * Copy registers into sense buffer.
	 */
	desc[2] = 0x00;
	desc[3] = tf->feature;	/* == error reg */
	desc[5] = tf->nsect;
	desc[7] = tf->lbal;
	desc[9] = tf->lbam;
	desc[11] = tf->lbah;
	desc[12] = tf->device;
	desc[13] = tf->command; /* == status reg */

	/*
	 * Fill in Extend bit, and the high order bytes
	 * if applicable.
	 */
	if (tf->flags & ATA_TFLAG_LBA48) {
		desc[2] |= 0x01;
		desc[4] = tf->hob_nsect;
		desc[6] = tf->hob_lbal;
		desc[8] = tf->hob_lbam;
		desc[10] = tf->hob_lbah;
	}
}

/**
 *	ata_gen_ata_sense - generate a SCSI fixed sense block
 *	@qc: Command that we are erroring out
 *
 *	Generate sense block for a failed ATA command @qc.  Descriptor
 *	format is used to accommodate LBA48 block address.
 *
 *	LOCKING:
 *	None.
 */
static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
{
	struct ata_device *dev = qc->dev;
	struct scsi_cmnd *cmd = qc->scsicmd;
	struct ata_taskfile *tf = &qc->result_tf;
	unsigned char *sb = cmd->sense_buffer;
	unsigned char *desc = sb + 8;
	int verbose = qc->ap->ops->error_handler == NULL;
	u64 block;

	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);

	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;

	/* sense data is current and format is descriptor */
	sb[0] = 0x72;

	/* Use ata_to_sense_error() to map status register bits
	 * onto sense key, asc & ascq.
	 */
	if (qc->err_mask ||
	    tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
		ata_to_sense_error(qc->ap->print_id, tf->command, tf->feature,
				   &sb[1], &sb[2], &sb[3], verbose);
		sb[1] &= 0x0f;
	}

	block = ata_tf_read_block(&qc->result_tf, dev);

	/* information sense data descriptor */
	sb[7] = 12;
	desc[0] = 0x00;
	desc[1] = 10;

	desc[2] |= 0x80;	/* valid */
	desc[6] = block >> 40;
	desc[7] = block >> 32;
	desc[8] = block >> 24;
	desc[9] = block >> 16;
	desc[10] = block >> 8;
	desc[11] = block;
}

static void ata_scsi_sdev_config(struct scsi_device *sdev)
{
	sdev->use_10_for_rw = 1;
	sdev->use_10_for_ms = 1;
	sdev->no_report_opcodes = 1;
	sdev->no_write_same = 1;

	/* Schedule policy is determined by ->qc_defer() callback and
	 * it needs to see every deferred qc.  Set dev_blocked to 1 to
	 * prevent SCSI midlayer from automatically deferring
	 * requests.
	 */
	sdev->max_device_blocked = 1;
}

/**
 *	atapi_drain_needed - Check whether data transfer may overflow
 *	@rq: request to be checked
 *
 *	ATAPI commands which transfer variable length data to host
 *	might overflow due to application error or hardare bug.  This
 *	function checks whether overflow should be drained and ignored
 *	for @request.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	1 if ; otherwise, 0.
 */
static int atapi_drain_needed(struct request *rq)
{
	if (likely(rq->cmd_type != REQ_TYPE_BLOCK_PC))
		return 0;

	if (!blk_rq_bytes(rq) || (rq->cmd_flags & REQ_WRITE))
		return 0;

	return atapi_cmd_type(rq->cmd[0]) == ATAPI_MISC;
}

static int ata_scsi_dev_config(struct scsi_device *sdev,
			       struct ata_device *dev)
{
	struct request_queue *q = sdev->request_queue;

	if (!ata_id_has_unload(dev->id))
		dev->flags |= ATA_DFLAG_NO_UNLOAD;

	/* configure max sectors */
	blk_queue_max_hw_sectors(q, dev->max_sectors);

	if (dev->class == ATA_DEV_ATAPI) {
		void *buf;

		sdev->sector_size = ATA_SECT_SIZE;

		/* set DMA padding */
		blk_queue_update_dma_pad(q, ATA_DMA_PAD_SZ - 1);

		/* configure draining */
		buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
		if (!buf) {
			ata_dev_err(dev, "drain buffer allocation failed\n");
			return -ENOMEM;
		}

		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
	} else {
		sdev->sector_size = ata_id_logical_sector_size(dev->id);
		sdev->manage_start_stop = 1;
	}

	/*
	 * ata_pio_sectors() expects buffer for each sector to not cross
	 * page boundary.  Enforce it by requiring buffers to be sector
	 * aligned, which works iff sector_size is not larger than
	 * PAGE_SIZE.  ATAPI devices also need the alignment as
	 * IDENTIFY_PACKET is executed as ATA_PROT_PIO.
	 */
	if (sdev->sector_size > PAGE_SIZE)
		ata_dev_warn(dev,
			"sector_size=%u > PAGE_SIZE, PIO may malfunction\n",
			sdev->sector_size);

	blk_queue_update_dma_alignment(q, sdev->sector_size - 1);

	if (dev->flags & ATA_DFLAG_AN)
		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);

	if (dev->flags & ATA_DFLAG_NCQ) {
		int depth;

		depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
		depth = min(ATA_MAX_QUEUE - 1, depth);
		scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
	}

	blk_queue_flush_queueable(q, false);

	dev->sdev = sdev;
	return 0;
}

/**
 *	ata_scsi_slave_config - Set SCSI device attributes
 *	@sdev: SCSI device to examine
 *
 *	This is called before we actually start reading
 *	and writing to the device, to configure certain
 *	SCSI mid-layer behaviors.
 *
 *	LOCKING:
 *	Defined by SCSI layer.  We don't really care.
 */

int ata_scsi_slave_config(struct scsi_device *sdev)
{
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
	int rc = 0;

	ata_scsi_sdev_config(sdev);

	if (dev)
		rc = ata_scsi_dev_config(sdev, dev);

	return rc;
}

/**
 *	ata_scsi_slave_destroy - SCSI device is about to be destroyed
 *	@sdev: SCSI device to be destroyed
 *
 *	@sdev is about to be destroyed for hot/warm unplugging.  If
 *	this unplugging was initiated by libata as indicated by NULL
 *	dev->sdev, this function doesn't have to do anything.
 *	Otherwise, SCSI layer initiated warm-unplug is in progress.
 *	Clear dev->sdev, schedule the device for ATA detach and invoke
 *	EH.
 *
 *	LOCKING:
 *	Defined by SCSI layer.  We don't really care.
 */
void ata_scsi_slave_destroy(struct scsi_device *sdev)
{
	struct ata_port *ap = ata_shost_to_port(sdev->host);
	struct request_queue *q = sdev->request_queue;
	unsigned long flags;
	struct ata_device *dev;

	if (!ap->ops->error_handler)
		return;

	spin_lock_irqsave(ap->lock, flags);
	dev = __ata_scsi_find_dev(ap, sdev);
	if (dev && dev->sdev) {
		/* SCSI device already in CANCEL state, no need to offline it */
		dev->sdev = NULL;
		dev->flags |= ATA_DFLAG_DETACH;
		ata_port_schedule_eh(ap);
	}
	spin_unlock_irqrestore(ap->lock, flags);

	kfree(q->dma_drain_buffer);
	q->dma_drain_buffer = NULL;
	q->dma_drain_size = 0;
}

/**
 *	__ata_change_queue_depth - helper for ata_scsi_change_queue_depth
 *	@ap: ATA port to which the device change the queue depth
 *	@sdev: SCSI device to configure queue depth for
 *	@queue_depth: new queue depth
 *	@reason: calling context
 *
 *	libsas and libata have different approaches for associating a sdev to
 *	its ata_port.
 *
 */
int __ata_change_queue_depth(struct ata_port *ap, struct scsi_device *sdev,
			     int queue_depth, int reason)
{
	struct ata_device *dev;
	unsigned long flags;

	if (reason != SCSI_QDEPTH_DEFAULT)
		return -EOPNOTSUPP;

	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
		return sdev->queue_depth;

	dev = ata_scsi_find_dev(ap, sdev);
	if (!dev || !ata_dev_enabled(dev))
		return sdev->queue_depth;

	/* NCQ enabled? */
	spin_lock_irqsave(ap->lock, flags);
	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
		dev->flags |= ATA_DFLAG_NCQ_OFF;
		queue_depth = 1;
	}
	spin_unlock_irqrestore(ap->lock, flags);

	/* limit and apply queue depth */
	queue_depth = min(queue_depth, sdev->host->can_queue);
	queue_depth = min(queue_depth, ata_id_queue_depth(dev->id));
	queue_depth = min(queue_depth, ATA_MAX_QUEUE - 1);

	if (sdev->queue_depth == queue_depth)
		return -EINVAL;

	scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, queue_depth);
	return queue_depth;
}

/**
 *	ata_scsi_change_queue_depth - SCSI callback for queue depth config
 *	@sdev: SCSI device to configure queue depth for
 *	@queue_depth: new queue depth
 *	@reason: calling context
 *
 *	This is libata standard hostt->change_queue_depth callback.
 *	SCSI will call into this callback when user tries to set queue
 *	depth via sysfs.
 *
 *	LOCKING:
 *	SCSI layer (we don't care)
 *
 *	RETURNS:
 *	Newly configured queue depth.
 */
int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth,
				int reason)
{
	struct ata_port *ap = ata_shost_to_port(sdev->host);

	return __ata_change_queue_depth(ap, sdev, queue_depth, reason);
}

/**
 *	ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
 *	@qc: Storage for translated ATA taskfile
 *
 *	Sets up an ATA taskfile to issue STANDBY (to stop) or READ VERIFY
 *	(to start). Perhaps these commands should be preceded by
 *	CHECK POWER MODE to see what power mode the device is already in.
 *	[See SAT revision 5 at www.t10.org]
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */
static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_taskfile *tf = &qc->tf;
	const u8 *cdb = scmd->cmnd;

	if (scmd->cmd_len < 5)
		goto invalid_fld;

	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
	tf->protocol = ATA_PROT_NODATA;
	if (cdb[1] & 0x1) {
		;	/* ignore IMMED bit, violates sat-r05 */
	}
	if (cdb[4] & 0x2)
		goto invalid_fld;       /* LOEJ bit set not supported */
	if (((cdb[4] >> 4) & 0xf) != 0)
		goto invalid_fld;       /* power conditions not supported */

	if (cdb[4] & 0x1) {
		tf->nsect = 1;	/* 1 sector, lba=0 */

		if (qc->dev->flags & ATA_DFLAG_LBA) {
			tf->flags |= ATA_TFLAG_LBA;

			tf->lbah = 0x0;
			tf->lbam = 0x0;
			tf->lbal = 0x0;
			tf->device |= ATA_LBA;
		} else {
			/* CHS */
			tf->lbal = 0x1; /* sect */
			tf->lbam = 0x0; /* cyl low */
			tf->lbah = 0x0; /* cyl high */
		}

		tf->command = ATA_CMD_VERIFY;	/* READ VERIFY */
	} else {
		/* Some odd clown BIOSen issue spindown on power off (ACPI S4
		 * or S5) causing some drives to spin up and down again.
		 */
		if ((qc->ap->flags & ATA_FLAG_NO_POWEROFF_SPINDOWN) &&
		    system_state == SYSTEM_POWER_OFF)
			goto skip;

		if ((qc->ap->flags & ATA_FLAG_NO_HIBERNATE_SPINDOWN) &&
		     system_entering_hibernation())
			goto skip;

		/* Issue ATA STANDBY IMMEDIATE command */
		tf->command = ATA_CMD_STANDBYNOW1;
	}

	/*
	 * Standby and Idle condition timers could be implemented but that
	 * would require libata to implement the Power condition mode page
	 * and allow the user to change it. Changing mode pages requires
	 * MODE SELECT to be implemented.
	 */

	return 0;

 invalid_fld:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	return 1;
 skip:
	scmd->result = SAM_STAT_GOOD;
	return 1;
}


/**
 *	ata_scsi_flush_xlat - Translate SCSI SYNCHRONIZE CACHE command
 *	@qc: Storage for translated ATA taskfile
 *
 *	Sets up an ATA taskfile to issue FLUSH CACHE or
 *	FLUSH CACHE EXT.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */
static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc)
{
	struct ata_taskfile *tf = &qc->tf;

	tf->flags |= ATA_TFLAG_DEVICE;
	tf->protocol = ATA_PROT_NODATA;

	if (qc->dev->flags & ATA_DFLAG_FLUSH_EXT)
		tf->command = ATA_CMD_FLUSH_EXT;
	else
		tf->command = ATA_CMD_FLUSH;

	/* flush is critical for IO integrity, consider it an IO command */
	qc->flags |= ATA_QCFLAG_IO;

	return 0;
}

/**
 *	scsi_6_lba_len - Get LBA and transfer length
 *	@cdb: SCSI command to translate
 *
 *	Calculate LBA and transfer length for 6-byte commands.
 *
 *	RETURNS:
 *	@plba: the LBA
 *	@plen: the transfer length
 */
static void scsi_6_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
{
	u64 lba = 0;
	u32 len;

	VPRINTK("six-byte command\n");

	lba |= ((u64)(cdb[1] & 0x1f)) << 16;
	lba |= ((u64)cdb[2]) << 8;
	lba |= ((u64)cdb[3]);

	len = cdb[4];

	*plba = lba;
	*plen = len;
}

/**
 *	scsi_10_lba_len - Get LBA and transfer length
 *	@cdb: SCSI command to translate
 *
 *	Calculate LBA and transfer length for 10-byte commands.
 *
 *	RETURNS:
 *	@plba: the LBA
 *	@plen: the transfer length
 */
static void scsi_10_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
{
	u64 lba = 0;
	u32 len = 0;

	VPRINTK("ten-byte command\n");

	lba |= ((u64)cdb[2]) << 24;
	lba |= ((u64)cdb[3]) << 16;
	lba |= ((u64)cdb[4]) << 8;
	lba |= ((u64)cdb[5]);

	len |= ((u32)cdb[7]) << 8;
	len |= ((u32)cdb[8]);

	*plba = lba;
	*plen = len;
}

/**
 *	scsi_16_lba_len - Get LBA and transfer length
 *	@cdb: SCSI command to translate
 *
 *	Calculate LBA and transfer length for 16-byte commands.
 *
 *	RETURNS:
 *	@plba: the LBA
 *	@plen: the transfer length
 */
static void scsi_16_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
{
	u64 lba = 0;
	u32 len = 0;

	VPRINTK("sixteen-byte command\n");

	lba |= ((u64)cdb[2]) << 56;
	lba |= ((u64)cdb[3]) << 48;
	lba |= ((u64)cdb[4]) << 40;
	lba |= ((u64)cdb[5]) << 32;
	lba |= ((u64)cdb[6]) << 24;
	lba |= ((u64)cdb[7]) << 16;
	lba |= ((u64)cdb[8]) << 8;
	lba |= ((u64)cdb[9]);

	len |= ((u32)cdb[10]) << 24;
	len |= ((u32)cdb[11]) << 16;
	len |= ((u32)cdb[12]) << 8;
	len |= ((u32)cdb[13]);

	*plba = lba;
	*plen = len;
}

/**
 *	ata_scsi_verify_xlat - Translate SCSI VERIFY command into an ATA one
 *	@qc: Storage for translated ATA taskfile
 *
 *	Converts SCSI VERIFY command to an ATA READ VERIFY command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */
static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_taskfile *tf = &qc->tf;
	struct ata_device *dev = qc->dev;
	u64 dev_sectors = qc->dev->n_sectors;
	const u8 *cdb = scmd->cmnd;
	u64 block;
	u32 n_block;

	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf->protocol = ATA_PROT_NODATA;

	if (cdb[0] == VERIFY) {
		if (scmd->cmd_len < 10)
			goto invalid_fld;
		scsi_10_lba_len(cdb, &block, &n_block);
	} else if (cdb[0] == VERIFY_16) {
		if (scmd->cmd_len < 16)
			goto invalid_fld;
		scsi_16_lba_len(cdb, &block, &n_block);
	} else
		goto invalid_fld;

	if (!n_block)
		goto nothing_to_do;
	if (block >= dev_sectors)
		goto out_of_range;
	if ((block + n_block) > dev_sectors)
		goto out_of_range;

	if (dev->flags & ATA_DFLAG_LBA) {
		tf->flags |= ATA_TFLAG_LBA;

		if (lba_28_ok(block, n_block)) {
			/* use LBA28 */
			tf->command = ATA_CMD_VERIFY;
			tf->device |= (block >> 24) & 0xf;
		} else if (lba_48_ok(block, n_block)) {
			if (!(dev->flags & ATA_DFLAG_LBA48))
				goto out_of_range;

			/* use LBA48 */
			tf->flags |= ATA_TFLAG_LBA48;
			tf->command = ATA_CMD_VERIFY_EXT;

			tf->hob_nsect = (n_block >> 8) & 0xff;

			tf->hob_lbah = (block >> 40) & 0xff;
			tf->hob_lbam = (block >> 32) & 0xff;
			tf->hob_lbal = (block >> 24) & 0xff;
		} else
			/* request too large even for LBA48 */
			goto out_of_range;

		tf->nsect = n_block & 0xff;

		tf->lbah = (block >> 16) & 0xff;
		tf->lbam = (block >> 8) & 0xff;
		tf->lbal = block & 0xff;

		tf->device |= ATA_LBA;
	} else {
		/* CHS */
		u32 sect, head, cyl, track;

		if (!lba_28_ok(block, n_block))
			goto out_of_range;

		/* Convert LBA to CHS */
		track = (u32)block / dev->sectors;
		cyl   = track / dev->heads;
		head  = track % dev->heads;
		sect  = (u32)block % dev->sectors + 1;

		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
			(u32)block, track, cyl, head, sect);

		/* Check whether the converted CHS can fit.
		   Cylinder: 0-65535
		   Head: 0-15
		   Sector: 1-255*/
		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
			goto out_of_range;

		tf->command = ATA_CMD_VERIFY;
		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
		tf->lbal = sect;
		tf->lbam = cyl;
		tf->lbah = cyl >> 8;
		tf->device |= head;
	}

	return 0;

invalid_fld:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	return 1;

out_of_range:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);
	/* "Logical Block Address out of range" */
	return 1;

nothing_to_do:
	scmd->result = SAM_STAT_GOOD;
	return 1;
}

/**
 *	ata_scsi_rw_xlat - Translate SCSI r/w command into an ATA one
 *	@qc: Storage for translated ATA taskfile
 *
 *	Converts any of six SCSI read/write commands into the
 *	ATA counterpart, including starting sector (LBA),
 *	sector count, and taking into account the device's LBA48
 *	support.
 *
 *	Commands %READ_6, %READ_10, %READ_16, %WRITE_6, %WRITE_10, and
 *	%WRITE_16 are currently supported.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */
static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	const u8 *cdb = scmd->cmnd;
	unsigned int tf_flags = 0;
	u64 block;
	u32 n_block;
	int rc;

	if (cdb[0] == WRITE_10 || cdb[0] == WRITE_6 || cdb[0] == WRITE_16)
		tf_flags |= ATA_TFLAG_WRITE;

	/* Calculate the SCSI LBA, transfer length and FUA. */
	switch (cdb[0]) {
	case READ_10:
	case WRITE_10:
		if (unlikely(scmd->cmd_len < 10))
			goto invalid_fld;
		scsi_10_lba_len(cdb, &block, &n_block);
		if (cdb[1] & (1 << 3))
			tf_flags |= ATA_TFLAG_FUA;
		break;
	case READ_6:
	case WRITE_6:
		if (unlikely(scmd->cmd_len < 6))
			goto invalid_fld;
		scsi_6_lba_len(cdb, &block, &n_block);

		/* for 6-byte r/w commands, transfer length 0
		 * means 256 blocks of data, not 0 block.
		 */
		if (!n_block)
			n_block = 256;
		break;
	case READ_16:
	case WRITE_16:
		if (unlikely(scmd->cmd_len < 16))
			goto invalid_fld;
		scsi_16_lba_len(cdb, &block, &n_block);
		if (cdb[1] & (1 << 3))
			tf_flags |= ATA_TFLAG_FUA;
		break;
	default:
		DPRINTK("no-byte command\n");
		goto invalid_fld;
	}

	/* Check and compose ATA command */
	if (!n_block)
		/* For 10-byte and 16-byte SCSI R/W commands, transfer
		 * length 0 means transfer 0 block of data.
		 * However, for ATA R/W commands, sector count 0 means
		 * 256 or 65536 sectors, not 0 sectors as in SCSI.
		 *
		 * WARNING: one or two older ATA drives treat 0 as 0...
		 */
		goto nothing_to_do;

	qc->flags |= ATA_QCFLAG_IO;
	qc->nbytes = n_block * scmd->device->sector_size;

	rc = ata_build_rw_tf(&qc->tf, qc->dev, block, n_block, tf_flags,
			     qc->tag);
	if (likely(rc == 0))
		return 0;

	if (rc == -ERANGE)
		goto out_of_range;
	/* treat all other errors as -EINVAL, fall through */
invalid_fld:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	return 1;

out_of_range:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);
	/* "Logical Block Address out of range" */
	return 1;

nothing_to_do:
	scmd->result = SAM_STAT_GOOD;
	return 1;
}

static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct scsi_cmnd *cmd = qc->scsicmd;
	u8 *cdb = cmd->cmnd;
	int need_sense = (qc->err_mask != 0);

	/* For ATA pass thru (SAT) commands, generate a sense block if
	 * user mandated it or if there's an error.  Note that if we
	 * generate because the user forced us to [CK_COND =1], a check
	 * condition is generated and the ATA register values are returned
	 * whether the command completed successfully or not. If there
	 * was no error, we use the following sense data:
	 * sk = RECOVERED ERROR
	 * asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE
	 */
	if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
	    ((cdb[2] & 0x20) || need_sense)) {
		ata_gen_passthru_sense(qc);
	} else {
		if (!need_sense) {
			cmd->result = SAM_STAT_GOOD;
		} else {
			/* TODO: decide which descriptor format to use
			 * for 48b LBA devices and call that here
			 * instead of the fixed desc, which is only
			 * good for smaller LBA (and maybe CHS?)
			 * devices.
			 */
			ata_gen_ata_sense(qc);
		}
	}

	if (need_sense && !ap->ops->error_handler)
		ata_dump_status(ap->print_id, &qc->result_tf);

	qc->scsidone(cmd);

	ata_qc_free(qc);
}

/**
 *	ata_scsi_translate - Translate then issue SCSI command to ATA device
 *	@dev: ATA device to which the command is addressed
 *	@cmd: SCSI command to execute
 *	@xlat_func: Actor which translates @cmd to an ATA taskfile
 *
 *	Our ->queuecommand() function has decided that the SCSI
 *	command issued can be directly translated into an ATA
 *	command, rather than handled internally.
 *
 *	This function sets up an ata_queued_cmd structure for the
 *	SCSI command, and sends that ata_queued_cmd to the hardware.
 *
 *	The xlat_func argument (actor) returns 0 if ready to execute
 *	ATA command, else 1 to finish translation. If 1 is returned
 *	then cmd->result (and possibly cmd->sense_buffer) are assumed
 *	to be set reflecting an error condition or clean (early)
 *	termination.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	0 on success, SCSI_ML_QUEUE_DEVICE_BUSY if the command
 *	needs to be deferred.
 */
static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
			      ata_xlat_func_t xlat_func)
{
	struct ata_port *ap = dev->link->ap;
	struct ata_queued_cmd *qc;
	int rc;

	VPRINTK("ENTER\n");

	qc = ata_scsi_qc_new(dev, cmd);
	if (!qc)
		goto err_mem;

	/* data is present; dma-map it */
	if (cmd->sc_data_direction == DMA_FROM_DEVICE ||
	    cmd->sc_data_direction == DMA_TO_DEVICE) {
		if (unlikely(scsi_bufflen(cmd) < 1)) {
			ata_dev_warn(dev, "WARNING: zero len r/w req\n");
			goto err_did;
		}

		ata_sg_init(qc, scsi_sglist(cmd), scsi_sg_count(cmd));

		qc->dma_dir = cmd->sc_data_direction;
	}

	qc->complete_fn = ata_scsi_qc_complete;

	if (xlat_func(qc))
		goto early_finish;

	if (ap->ops->qc_defer) {
		if ((rc = ap->ops->qc_defer(qc)))
			goto defer;
	}

	/* select device, send command to hardware */
	ata_qc_issue(qc);

	VPRINTK("EXIT\n");
	return 0;

early_finish:
	ata_qc_free(qc);
	cmd->scsi_done(cmd);
	DPRINTK("EXIT - early finish (good or error)\n");
	return 0;

err_did:
	ata_qc_free(qc);
	cmd->result = (DID_ERROR << 16);
	cmd->scsi_done(cmd);
err_mem:
	DPRINTK("EXIT - internal\n");
	return 0;

defer:
	ata_qc_free(qc);
	DPRINTK("EXIT - defer\n");
	if (rc == ATA_DEFER_LINK)
		return SCSI_MLQUEUE_DEVICE_BUSY;
	else
		return SCSI_MLQUEUE_HOST_BUSY;
}

/**
 *	ata_scsi_rbuf_get - Map response buffer.
 *	@cmd: SCSI command containing buffer to be mapped.
 *	@flags: unsigned long variable to store irq enable status
 *	@copy_in: copy in from user buffer
 *
 *	Prepare buffer for simulated SCSI commands.
 *
 *	LOCKING:
 *	spin_lock_irqsave(ata_scsi_rbuf_lock) on success
 *
 *	RETURNS:
 *	Pointer to response buffer.
 */
static void *ata_scsi_rbuf_get(struct scsi_cmnd *cmd, bool copy_in,
			       unsigned long *flags)
{
	spin_lock_irqsave(&ata_scsi_rbuf_lock, *flags);

	memset(ata_scsi_rbuf, 0, ATA_SCSI_RBUF_SIZE);
	if (copy_in)
		sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				  ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
	return ata_scsi_rbuf;
}

/**
 *	ata_scsi_rbuf_put - Unmap response buffer.
 *	@cmd: SCSI command containing buffer to be unmapped.
 *	@copy_out: copy out result
 *	@flags: @flags passed to ata_scsi_rbuf_get()
 *
 *	Returns rbuf buffer.  The result is copied to @cmd's buffer if
 *	@copy_back is true.
 *
 *	LOCKING:
 *	Unlocks ata_scsi_rbuf_lock.
 */
static inline void ata_scsi_rbuf_put(struct scsi_cmnd *cmd, bool copy_out,
				     unsigned long *flags)
{
	if (copy_out)
		sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				    ata_scsi_rbuf, ATA_SCSI_RBUF_SIZE);
	spin_unlock_irqrestore(&ata_scsi_rbuf_lock, *flags);
}

/**
 *	ata_scsi_rbuf_fill - wrapper for SCSI command simulators
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@actor: Callback hook for desired SCSI command simulator
 *
 *	Takes care of the hard work of simulating a SCSI command...
 *	Mapping the response buffer, calling the command's handler,
 *	and handling the handler's return value.  This return value
 *	indicates whether the handler wishes the SCSI command to be
 *	completed successfully (0), or not (in which case cmd->result
 *	and sense buffer are assumed to be set).
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
		unsigned int (*actor)(struct ata_scsi_args *args, u8 *rbuf))
{
	u8 *rbuf;
	unsigned int rc;
	struct scsi_cmnd *cmd = args->cmd;
	unsigned long flags;

	rbuf = ata_scsi_rbuf_get(cmd, false, &flags);
	rc = actor(args, rbuf);
	ata_scsi_rbuf_put(cmd, rc == 0, &flags);

	if (rc == 0)
		cmd->result = SAM_STAT_GOOD;
	args->done(cmd);
}

/**
 *	ata_scsiop_inq_std - Simulate INQUIRY command
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Returns standard device identification data associated
 *	with non-VPD INQUIRY command output.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
{
	const u8 versions[] = {
		0x60,	/* SAM-3 (no version claimed) */

		0x03,
		0x20,	/* SBC-2 (no version claimed) */

		0x02,
		0x60	/* SPC-3 (no version claimed) */
	};
	u8 hdr[] = {
		TYPE_DISK,
		0,
		0x5,	/* claim SPC-3 version compatibility */
		2,
		95 - 4
	};

	VPRINTK("ENTER\n");

	/* set scsi removeable (RMB) bit per ata bit */
	if (ata_id_removeable(args->id))
		hdr[1] |= (1 << 7);

	memcpy(rbuf, hdr, sizeof(hdr));
	memcpy(&rbuf[8], "ATA     ", 8);
	ata_id_string(args->id, &rbuf[16], ATA_ID_PROD, 16);

	/* From SAT, use last 2 words from fw rev unless they are spaces */
	ata_id_string(args->id, &rbuf[32], ATA_ID_FW_REV + 2, 4);
	if (strncmp(&rbuf[32], "    ", 4) == 0)
		ata_id_string(args->id, &rbuf[32], ATA_ID_FW_REV, 4);

	if (rbuf[32] == 0 || rbuf[32] == ' ')
		memcpy(&rbuf[32], "n/a ", 4);

	memcpy(rbuf + 59, versions, sizeof(versions));

	return 0;
}

/**
 *	ata_scsiop_inq_00 - Simulate INQUIRY VPD page 0, list of pages
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Returns list of inquiry VPD pages available.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_inq_00(struct ata_scsi_args *args, u8 *rbuf)
{
	const u8 pages[] = {
		0x00,	/* page 0x00, this page */
		0x80,	/* page 0x80, unit serial no page */
		0x83,	/* page 0x83, device ident page */
		0x89,	/* page 0x89, ata info page */
		0xb0,	/* page 0xb0, block limits page */
		0xb1,	/* page 0xb1, block device characteristics page */
		0xb2,	/* page 0xb2, thin provisioning page */
	};

	rbuf[3] = sizeof(pages);	/* number of supported VPD pages */
	memcpy(rbuf + 4, pages, sizeof(pages));
	return 0;
}

/**
 *	ata_scsiop_inq_80 - Simulate INQUIRY VPD page 80, device serial number
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Returns ATA device serial number.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_inq_80(struct ata_scsi_args *args, u8 *rbuf)
{
	const u8 hdr[] = {
		0,
		0x80,			/* this page code */
		0,
		ATA_ID_SERNO_LEN,	/* page len */
	};

	memcpy(rbuf, hdr, sizeof(hdr));
	ata_id_string(args->id, (unsigned char *) &rbuf[4],
		      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
	return 0;
}

/**
 *	ata_scsiop_inq_83 - Simulate INQUIRY VPD page 83, device identity
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Yields two logical unit device identification designators:
 *	 - vendor specific ASCII containing the ATA serial number
 *	 - SAT defined "t10 vendor id based" containing ASCII vendor
 *	   name ("ATA     "), model and serial numbers.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf)
{
	const int sat_model_serial_desc_len = 68;
	int num;

	rbuf[1] = 0x83;			/* this page code */
	num = 4;

	/* piv=0, assoc=lu, code_set=ACSII, designator=vendor */
	rbuf[num + 0] = 2;
	rbuf[num + 3] = ATA_ID_SERNO_LEN;
	num += 4;
	ata_id_string(args->id, (unsigned char *) rbuf + num,
		      ATA_ID_SERNO, ATA_ID_SERNO_LEN);
	num += ATA_ID_SERNO_LEN;

	/* SAT defined lu model and serial numbers descriptor */
	/* piv=0, assoc=lu, code_set=ACSII, designator=t10 vendor id */
	rbuf[num + 0] = 2;
	rbuf[num + 1] = 1;
	rbuf[num + 3] = sat_model_serial_desc_len;
	num += 4;
	memcpy(rbuf + num, "ATA     ", 8);
	num += 8;
	ata_id_string(args->id, (unsigned char *) rbuf + num, ATA_ID_PROD,
		      ATA_ID_PROD_LEN);
	num += ATA_ID_PROD_LEN;
	ata_id_string(args->id, (unsigned char *) rbuf + num, ATA_ID_SERNO,
		      ATA_ID_SERNO_LEN);
	num += ATA_ID_SERNO_LEN;

	if (ata_id_has_wwn(args->id)) {
		/* SAT defined lu world wide name */
		/* piv=0, assoc=lu, code_set=binary, designator=NAA */
		rbuf[num + 0] = 1;
		rbuf[num + 1] = 3;
		rbuf[num + 3] = ATA_ID_WWN_LEN;
		num += 4;
		ata_id_string(args->id, (unsigned char *) rbuf + num,
			      ATA_ID_WWN, ATA_ID_WWN_LEN);
		num += ATA_ID_WWN_LEN;
	}
	rbuf[3] = num - 4;    /* page len (assume less than 256 bytes) */
	return 0;
}

/**
 *	ata_scsiop_inq_89 - Simulate INQUIRY VPD page 89, ATA info
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Yields SAT-specified ATA VPD page.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_inq_89(struct ata_scsi_args *args, u8 *rbuf)
{
	struct ata_taskfile tf;

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

	rbuf[1] = 0x89;			/* our page code */
	rbuf[2] = (0x238 >> 8);		/* page size fixed at 238h */
	rbuf[3] = (0x238 & 0xff);

	memcpy(&rbuf[8], "linux   ", 8);
	memcpy(&rbuf[16], "libata          ", 16);
	memcpy(&rbuf[32], DRV_VERSION, 4);

	/* we don't store the ATA device signature, so we fake it */

	tf.command = ATA_DRDY;		/* really, this is Status reg */
	tf.lbal = 0x1;
	tf.nsect = 0x1;

	ata_tf_to_fis(&tf, 0, 1, &rbuf[36]);	/* TODO: PMP? */
	rbuf[36] = 0x34;		/* force D2H Reg FIS (34h) */

	rbuf[56] = ATA_CMD_ID_ATA;

	memcpy(&rbuf[60], &args->id[0], 512);
	return 0;
}

static unsigned int ata_scsiop_inq_b0(struct ata_scsi_args *args, u8 *rbuf)
{
	u16 min_io_sectors;

	rbuf[1] = 0xb0;
	rbuf[3] = 0x3c;		/* required VPD size with unmap support */

	/*
	 * Optimal transfer length granularity.
	 *
	 * This is always one physical block, but for disks with a smaller
	 * logical than physical sector size we need to figure out what the
	 * latter is.
	 */
	min_io_sectors = 1 << ata_id_log2_per_physical_sector(args->id);
	put_unaligned_be16(min_io_sectors, &rbuf[6]);

	/*
	 * Optimal unmap granularity.
	 *
	 * The ATA spec doesn't even know about a granularity or alignment
	 * for the TRIM command.  We can leave away most of the unmap related
	 * VPD page entries, but we have specifify a granularity to signal
	 * that we support some form of unmap - in thise case via WRITE SAME
	 * with the unmap bit set.
	 */
	if (ata_id_has_trim(args->id)) {
		put_unaligned_be64(65535 * 512 / 8, &rbuf[36]);
		put_unaligned_be32(1, &rbuf[28]);
	}

	return 0;
}

static unsigned int ata_scsiop_inq_b1(struct ata_scsi_args *args, u8 *rbuf)
{
	int form_factor = ata_id_form_factor(args->id);
	int media_rotation_rate = ata_id_rotation_rate(args->id);

	rbuf[1] = 0xb1;
	rbuf[3] = 0x3c;
	rbuf[4] = media_rotation_rate >> 8;
	rbuf[5] = media_rotation_rate;
	rbuf[7] = form_factor;

	return 0;
}

static unsigned int ata_scsiop_inq_b2(struct ata_scsi_args *args, u8 *rbuf)
{
	/* SCSI Thin Provisioning VPD page: SBC-3 rev 22 or later */
	rbuf[1] = 0xb2;
	rbuf[3] = 0x4;
	rbuf[5] = 1 << 6;	/* TPWS */

	return 0;
}

/**
 *	ata_scsiop_noop - Command handler that simply returns success.
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	No operation.  Simply returns success to caller, to indicate
 *	that the caller should successfully complete this SCSI command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_noop(struct ata_scsi_args *args, u8 *rbuf)
{
	VPRINTK("ENTER\n");
	return 0;
}

/**
 *	modecpy - Prepare response for MODE SENSE
 *	@dest: output buffer
 *	@src: data being copied
 *	@n: length of mode page
 *	@changeable: whether changeable parameters are requested
 *
 *	Generate a generic MODE SENSE page for either current or changeable
 *	parameters.
 *
 *	LOCKING:
 *	None.
 */
static void modecpy(u8 *dest, const u8 *src, int n, bool changeable)
{
	if (changeable) {
		memcpy(dest, src, 2);
		memset(dest + 2, 0, n - 2);
	} else {
		memcpy(dest, src, n);
	}
}

/**
 *	ata_msense_caching - Simulate MODE SENSE caching info page
 *	@id: device IDENTIFY data
 *	@buf: output buffer
 *	@changeable: whether changeable parameters are requested
 *
 *	Generate a caching info page, which conditionally indicates
 *	write caching to the SCSI layer, depending on device
 *	capabilities.
 *
 *	LOCKING:
 *	None.
 */
static unsigned int ata_msense_caching(u16 *id, u8 *buf, bool changeable)
{
	modecpy(buf, def_cache_mpage, sizeof(def_cache_mpage), changeable);
	if (changeable || ata_id_wcache_enabled(id))
		buf[2] |= (1 << 2);	/* write cache enable */
	if (!changeable && !ata_id_rahead_enabled(id))
		buf[12] |= (1 << 5);	/* disable read ahead */
	return sizeof(def_cache_mpage);
}

/**
 *	ata_msense_ctl_mode - Simulate MODE SENSE control mode page
 *	@buf: output buffer
 *	@changeable: whether changeable parameters are requested
 *
 *	Generate a generic MODE SENSE control mode page.
 *
 *	LOCKING:
 *	None.
 */
static unsigned int ata_msense_ctl_mode(u8 *buf, bool changeable)
{
	modecpy(buf, def_control_mpage, sizeof(def_control_mpage), changeable);
	return sizeof(def_control_mpage);
}

/**
 *	ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
 *	@buf: output buffer
 *	@changeable: whether changeable parameters are requested
 *
 *	Generate a generic MODE SENSE r/w error recovery page.
 *
 *	LOCKING:
 *	None.
 */
static unsigned int ata_msense_rw_recovery(u8 *buf, bool changeable)
{
	modecpy(buf, def_rw_recovery_mpage, sizeof(def_rw_recovery_mpage),
		changeable);
	return sizeof(def_rw_recovery_mpage);
}

/*
 * We can turn this into a real blacklist if it's needed, for now just
 * blacklist any Maxtor BANC1G10 revision firmware
 */
static int ata_dev_supports_fua(u16 *id)
{
	unsigned char model[ATA_ID_PROD_LEN + 1], fw[ATA_ID_FW_REV_LEN + 1];

	if (!libata_fua)
		return 0;
	if (!ata_id_has_fua(id))
		return 0;

	ata_id_c_string(id, model, ATA_ID_PROD, sizeof(model));
	ata_id_c_string(id, fw, ATA_ID_FW_REV, sizeof(fw));

	if (strcmp(model, "Maxtor"))
		return 1;
	if (strcmp(fw, "BANC1G10"))
		return 1;

	return 0; /* blacklisted */
}

/**
 *	ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Simulate MODE SENSE commands. Assume this is invoked for direct
 *	access devices (e.g. disks) only. There should be no block
 *	descriptor for other device types.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
{
	struct ata_device *dev = args->dev;
	u8 *scsicmd = args->cmd->cmnd, *p = rbuf;
	const u8 sat_blk_desc[] = {
		0, 0, 0, 0,	/* number of blocks: sat unspecified */
		0,
		0, 0x2, 0x0	/* block length: 512 bytes */
	};
	u8 pg, spg;
	unsigned int ebd, page_control, six_byte;
	u8 dpofua;

	VPRINTK("ENTER\n");

	six_byte = (scsicmd[0] == MODE_SENSE);
	ebd = !(scsicmd[1] & 0x8);      /* dbd bit inverted == edb */
	/*
	 * LLBA bit in msense(10) ignored (compliant)
	 */

	page_control = scsicmd[2] >> 6;
	switch (page_control) {
	case 0: /* current */
	case 1: /* changeable */
	case 2: /* defaults */
		break;  /* supported */
	case 3: /* saved */
		goto saving_not_supp;
	default:
		goto invalid_fld;
	}

	if (six_byte)
		p += 4 + (ebd ? 8 : 0);
	else
		p += 8 + (ebd ? 8 : 0);

	pg = scsicmd[2] & 0x3f;
	spg = scsicmd[3];
	/*
	 * No mode subpages supported (yet) but asking for _all_
	 * subpages may be valid
	 */
	if (spg && (spg != ALL_SUB_MPAGES))
		goto invalid_fld;

	switch(pg) {
	case RW_RECOVERY_MPAGE:
		p += ata_msense_rw_recovery(p, page_control == 1);
		break;

	case CACHE_MPAGE:
		p += ata_msense_caching(args->id, p, page_control == 1);
		break;

	case CONTROL_MPAGE:
		p += ata_msense_ctl_mode(p, page_control == 1);
		break;

	case ALL_MPAGES:
		p += ata_msense_rw_recovery(p, page_control == 1);
		p += ata_msense_caching(args->id, p, page_control == 1);
		p += ata_msense_ctl_mode(p, page_control == 1);
		break;

	default:		/* invalid page code */
		goto invalid_fld;
	}

	dpofua = 0;
	if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
	    (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
		dpofua = 1 << 4;

	if (six_byte) {
		rbuf[0] = p - rbuf - 1;
		rbuf[2] |= dpofua;
		if (ebd) {
			rbuf[3] = sizeof(sat_blk_desc);
			memcpy(rbuf + 4, sat_blk_desc, sizeof(sat_blk_desc));
		}
	} else {
		unsigned int output_len = p - rbuf - 2;

		rbuf[0] = output_len >> 8;
		rbuf[1] = output_len;
		rbuf[3] |= dpofua;
		if (ebd) {
			rbuf[7] = sizeof(sat_blk_desc);
			memcpy(rbuf + 8, sat_blk_desc, sizeof(sat_blk_desc));
		}
	}
	return 0;

invalid_fld:
	ata_scsi_set_sense(args->cmd, ILLEGAL_REQUEST, 0x24, 0x0);
	/* "Invalid field in cbd" */
	return 1;

saving_not_supp:
	ata_scsi_set_sense(args->cmd, ILLEGAL_REQUEST, 0x39, 0x0);
	 /* "Saving parameters not supported" */
	return 1;
}

/**
 *	ata_scsiop_read_cap - Simulate READ CAPACITY[ 16] commands
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Simulate READ CAPACITY commands.
 *
 *	LOCKING:
 *	None.
 */
static unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf)
{
	struct ata_device *dev = args->dev;
	u64 last_lba = dev->n_sectors - 1; /* LBA of the last block */
	u32 sector_size; /* physical sector size in bytes */
	u8 log2_per_phys;
	u16 lowest_aligned;

	sector_size = ata_id_logical_sector_size(dev->id);
	log2_per_phys = ata_id_log2_per_physical_sector(dev->id);
	lowest_aligned = ata_id_logical_sector_offset(dev->id, log2_per_phys);

	VPRINTK("ENTER\n");

	if (args->cmd->cmnd[0] == READ_CAPACITY) {
		if (last_lba >= 0xffffffffULL)
			last_lba = 0xffffffff;

		/* sector count, 32-bit */
		rbuf[0] = last_lba >> (8 * 3);
		rbuf[1] = last_lba >> (8 * 2);
		rbuf[2] = last_lba >> (8 * 1);
		rbuf[3] = last_lba;

		/* sector size */
		rbuf[4] = sector_size >> (8 * 3);
		rbuf[5] = sector_size >> (8 * 2);
		rbuf[6] = sector_size >> (8 * 1);
		rbuf[7] = sector_size;
	} else {
		/* sector count, 64-bit */
		rbuf[0] = last_lba >> (8 * 7);
		rbuf[1] = last_lba >> (8 * 6);
		rbuf[2] = last_lba >> (8 * 5);
		rbuf[3] = last_lba >> (8 * 4);
		rbuf[4] = last_lba >> (8 * 3);
		rbuf[5] = last_lba >> (8 * 2);
		rbuf[6] = last_lba >> (8 * 1);
		rbuf[7] = last_lba;

		/* sector size */
		rbuf[ 8] = sector_size >> (8 * 3);
		rbuf[ 9] = sector_size >> (8 * 2);
		rbuf[10] = sector_size >> (8 * 1);
		rbuf[11] = sector_size;

		rbuf[12] = 0;
		rbuf[13] = log2_per_phys;
		rbuf[14] = (lowest_aligned >> 8) & 0x3f;
		rbuf[15] = lowest_aligned;

		if (ata_id_has_trim(args->id)) {
			rbuf[14] |= 0x80; /* TPE */

			if (ata_id_has_zero_after_trim(args->id))
				rbuf[14] |= 0x40; /* TPRZ */
		}
	}

	return 0;
}

/**
 *	ata_scsiop_report_luns - Simulate REPORT LUNS command
 *	@args: device IDENTIFY data / SCSI command of interest.
 *	@rbuf: Response buffer, to which simulated SCSI cmd output is sent.
 *
 *	Simulate REPORT LUNS command.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsiop_report_luns(struct ata_scsi_args *args, u8 *rbuf)
{
	VPRINTK("ENTER\n");
	rbuf[3] = 8;	/* just one lun, LUN 0, size 8 bytes */

	return 0;
}

static void atapi_sense_complete(struct ata_queued_cmd *qc)
{
	if (qc->err_mask && ((qc->err_mask & AC_ERR_DEV) == 0)) {
		/* FIXME: not quite right; we don't want the
		 * translation of taskfile registers into
		 * a sense descriptors, since that's only
		 * correct for ATA, not ATAPI
		 */
		ata_gen_passthru_sense(qc);
	}

	qc->scsidone(qc->scsicmd);
	ata_qc_free(qc);
}

/* is it pointless to prefer PIO for "safety reasons"? */
static inline int ata_pio_use_silly(struct ata_port *ap)
{
	return (ap->flags & ATA_FLAG_PIO_DMA);
}

static void atapi_request_sense(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct scsi_cmnd *cmd = qc->scsicmd;

	DPRINTK("ATAPI request sense\n");

	/* FIXME: is this needed? */
	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);

#ifdef CONFIG_ATA_SFF
	if (ap->ops->sff_tf_read)
		ap->ops->sff_tf_read(ap, &qc->tf);
#endif

	/* fill these in, for the case where they are -not- overwritten */
	cmd->sense_buffer[0] = 0x70;
	cmd->sense_buffer[2] = qc->tf.feature >> 4;

	ata_qc_reinit(qc);

	/* setup sg table and init transfer direction */
	sg_init_one(&qc->sgent, cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
	ata_sg_init(qc, &qc->sgent, 1);
	qc->dma_dir = DMA_FROM_DEVICE;

	memset(&qc->cdb, 0, qc->dev->cdb_len);
	qc->cdb[0] = REQUEST_SENSE;
	qc->cdb[4] = SCSI_SENSE_BUFFERSIZE;

	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	qc->tf.command = ATA_CMD_PACKET;

	if (ata_pio_use_silly(ap)) {
		qc->tf.protocol = ATAPI_PROT_DMA;
		qc->tf.feature |= ATAPI_PKT_DMA;
	} else {
		qc->tf.protocol = ATAPI_PROT_PIO;
		qc->tf.lbam = SCSI_SENSE_BUFFERSIZE;
		qc->tf.lbah = 0;
	}
	qc->nbytes = SCSI_SENSE_BUFFERSIZE;

	qc->complete_fn = atapi_sense_complete;

	ata_qc_issue(qc);

	DPRINTK("EXIT\n");
}

static void atapi_qc_complete(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *cmd = qc->scsicmd;
	unsigned int err_mask = qc->err_mask;

	VPRINTK("ENTER, err_mask 0x%X\n", err_mask);

	/* handle completion from new EH */
	if (unlikely(qc->ap->ops->error_handler &&
		     (err_mask || qc->flags & ATA_QCFLAG_SENSE_VALID))) {

		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) {
			/* FIXME: not quite right; we don't want the
			 * translation of taskfile registers into a
			 * sense descriptors, since that's only
			 * correct for ATA, not ATAPI
			 */
			ata_gen_passthru_sense(qc);
		}

		/* SCSI EH automatically locks door if sdev->locked is
		 * set.  Sometimes door lock request continues to
		 * fail, for example, when no media is present.  This
		 * creates a loop - SCSI EH issues door lock which
		 * fails and gets invoked again to acquire sense data
		 * for the failed command.
		 *
		 * If door lock fails, always clear sdev->locked to
		 * avoid this infinite loop.
		 *
		 * This may happen before SCSI scan is complete.  Make
		 * sure qc->dev->sdev isn't NULL before dereferencing.
		 */
		if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev)
			qc->dev->sdev->locked = 0;

		qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
		qc->scsidone(cmd);
		ata_qc_free(qc);
		return;
	}

	/* successful completion or old EH failure path */
	if (unlikely(err_mask & AC_ERR_DEV)) {
		cmd->result = SAM_STAT_CHECK_CONDITION;
		atapi_request_sense(qc);
		return;
	} else if (unlikely(err_mask)) {
		/* FIXME: not quite right; we don't want the
		 * translation of taskfile registers into
		 * a sense descriptors, since that's only
		 * correct for ATA, not ATAPI
		 */
		ata_gen_passthru_sense(qc);
	} else {
		u8 *scsicmd = cmd->cmnd;

		if ((scsicmd[0] == INQUIRY) && ((scsicmd[1] & 0x03) == 0)) {
			unsigned long flags;
			u8 *buf;

			buf = ata_scsi_rbuf_get(cmd, true, &flags);

	/* ATAPI devices typically report zero for their SCSI version,
	 * and sometimes deviate from the spec WRT response data
	 * format.  If SCSI version is reported as zero like normal,
	 * then we make the following fixups:  1) Fake MMC-5 version,
	 * to indicate to the Linux scsi midlayer this is a modern
	 * device.  2) Ensure response data format / ATAPI information
	 * are always correct.
	 */
			if (buf[2] == 0) {
				buf[2] = 0x5;
				buf[3] = 0x32;
			}

			ata_scsi_rbuf_put(cmd, true, &flags);
		}

		cmd->result = SAM_STAT_GOOD;
	}

	qc->scsidone(cmd);
	ata_qc_free(qc);
}
/**
 *	atapi_xlat - Initialize PACKET taskfile
 *	@qc: command structure to be initialized
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Zero on success, non-zero on failure.
 */
static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_device *dev = qc->dev;
	int nodata = (scmd->sc_data_direction == DMA_NONE);
	int using_pio = !nodata && (dev->flags & ATA_DFLAG_PIO);
	unsigned int nbytes;

	memset(qc->cdb, 0, dev->cdb_len);
	memcpy(qc->cdb, scmd->cmnd, scmd->cmd_len);

	qc->complete_fn = atapi_qc_complete;

	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	if (scmd->sc_data_direction == DMA_TO_DEVICE) {
		qc->tf.flags |= ATA_TFLAG_WRITE;
		DPRINTK("direction: write\n");
	}

	qc->tf.command = ATA_CMD_PACKET;
	ata_qc_set_pc_nbytes(qc);

	/* check whether ATAPI DMA is safe */
	if (!nodata && !using_pio && atapi_check_dma(qc))
		using_pio = 1;

	/* Some controller variants snoop this value for Packet
	 * transfers to do state machine and FIFO management.  Thus we
	 * want to set it properly, and for DMA where it is
	 * effectively meaningless.
	 */
	nbytes = min(ata_qc_raw_nbytes(qc), (unsigned int)63 * 1024);

	/* Most ATAPI devices which honor transfer chunk size don't
	 * behave according to the spec when odd chunk size which
	 * matches the transfer length is specified.  If the number of
	 * bytes to transfer is 2n+1.  According to the spec, what
	 * should happen is to indicate that 2n+1 is going to be
	 * transferred and transfer 2n+2 bytes where the last byte is
	 * padding.
	 *
	 * In practice, this doesn't happen.  ATAPI devices first
	 * indicate and transfer 2n bytes and then indicate and
	 * transfer 2 bytes where the last byte is padding.
	 *
	 * This inconsistency confuses several controllers which
	 * perform PIO using DMA such as Intel AHCIs and sil3124/32.
	 * These controllers use actual number of transferred bytes to
	 * update DMA poitner and transfer of 4n+2 bytes make those
	 * controller push DMA pointer by 4n+4 bytes because SATA data
	 * FISes are aligned to 4 bytes.  This causes data corruption
	 * and buffer overrun.
	 *
	 * Always setting nbytes to even number solves this problem
	 * because then ATAPI devices don't have to split data at 2n
	 * boundaries.
	 */
	if (nbytes & 0x1)
		nbytes++;

	qc->tf.lbam = (nbytes & 0xFF);
	qc->tf.lbah = (nbytes >> 8);

	if (nodata)
		qc->tf.protocol = ATAPI_PROT_NODATA;
	else if (using_pio)
		qc->tf.protocol = ATAPI_PROT_PIO;
	else {
		/* DMA data xfer */
		qc->tf.protocol = ATAPI_PROT_DMA;
		qc->tf.feature |= ATAPI_PKT_DMA;

		if ((dev->flags & ATA_DFLAG_DMADIR) &&
		    (scmd->sc_data_direction != DMA_TO_DEVICE))
			/* some SATA bridges need us to indicate data xfer direction */
			qc->tf.feature |= ATAPI_DMADIR;
	}


	/* FIXME: We need to translate 0x05 READ_BLOCK_LIMITS to a MODE_SENSE
	   as ATAPI tape drives don't get this right otherwise */
	return 0;
}

static struct ata_device *ata_find_dev(struct ata_port *ap, int devno)
{
	if (!sata_pmp_attached(ap)) {
		if (likely(devno < ata_link_max_devices(&ap->link)))
			return &ap->link.device[devno];
	} else {
		if (likely(devno < ap->nr_pmp_links))
			return &ap->pmp_link[devno].device[0];
	}

	return NULL;
}

static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
					      const struct scsi_device *scsidev)
{
	int devno;

	/* skip commands not addressed to targets we simulate */
	if (!sata_pmp_attached(ap)) {
		if (unlikely(scsidev->channel || scsidev->lun))
			return NULL;
		devno = scsidev->id;
	} else {
		if (unlikely(scsidev->id || scsidev->lun))
			return NULL;
		devno = scsidev->channel;
	}

	return ata_find_dev(ap, devno);
}

/**
 *	ata_scsi_find_dev - lookup ata_device from scsi_cmnd
 *	@ap: ATA port to which the device is attached
 *	@scsidev: SCSI device from which we derive the ATA device
 *
 *	Given various information provided in struct scsi_cmnd,
 *	map that onto an ATA bus, and using that mapping
 *	determine which ata_device is associated with the
 *	SCSI command to be sent.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Associated ATA device, or %NULL if not found.
 */
static struct ata_device *
ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
{
	struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);

	if (unlikely(!dev || !ata_dev_enabled(dev)))
		return NULL;

	return dev;
}

/*
 *	ata_scsi_map_proto - Map pass-thru protocol value to taskfile value.
 *	@byte1: Byte 1 from pass-thru CDB.
 *
 *	RETURNS:
 *	ATA_PROT_UNKNOWN if mapping failed/unimplemented, protocol otherwise.
 */
static u8
ata_scsi_map_proto(u8 byte1)
{
	switch((byte1 & 0x1e) >> 1) {
	case 3:		/* Non-data */
		return ATA_PROT_NODATA;

	case 6:		/* DMA */
	case 10:	/* UDMA Data-in */
	case 11:	/* UDMA Data-Out */
		return ATA_PROT_DMA;

	case 4:		/* PIO Data-in */
	case 5:		/* PIO Data-out */
		return ATA_PROT_PIO;

	case 0:		/* Hard Reset */
	case 1:		/* SRST */
	case 8:		/* Device Diagnostic */
	case 9:		/* Device Reset */
	case 7:		/* DMA Queued */
	case 12:	/* FPDMA */
	case 15:	/* Return Response Info */
	default:	/* Reserved */
		break;
	}

	return ATA_PROT_UNKNOWN;
}

/**
 *	ata_scsi_pass_thru - convert ATA pass-thru CDB to taskfile
 *	@qc: command structure to be initialized
 *
 *	Handles either 12 or 16-byte versions of the CDB.
 *
 *	RETURNS:
 *	Zero on success, non-zero on failure.
 */
static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
{
	struct ata_taskfile *tf = &(qc->tf);
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_device *dev = qc->dev;
	const u8 *cdb = scmd->cmnd;

	if ((tf->protocol = ata_scsi_map_proto(cdb[1])) == ATA_PROT_UNKNOWN)
		goto invalid_fld;

	/*
	 * 12 and 16 byte CDBs use different offsets to
	 * provide the various register values.
	 */
	if (cdb[0] == ATA_16) {
		/*
		 * 16-byte CDB - may contain extended commands.
		 *
		 * If that is the case, copy the upper byte register values.
		 */
		if (cdb[1] & 0x01) {
			tf->hob_feature = cdb[3];
			tf->hob_nsect = cdb[5];
			tf->hob_lbal = cdb[7];
			tf->hob_lbam = cdb[9];
			tf->hob_lbah = cdb[11];
			tf->flags |= ATA_TFLAG_LBA48;
		} else
			tf->flags &= ~ATA_TFLAG_LBA48;

		/*
		 * Always copy low byte, device and command registers.
		 */
		tf->feature = cdb[4];
		tf->nsect = cdb[6];
		tf->lbal = cdb[8];
		tf->lbam = cdb[10];
		tf->lbah = cdb[12];
		tf->device = cdb[13];
		tf->command = cdb[14];
	} else {
		/*
		 * 12-byte CDB - incapable of extended commands.
		 */
		tf->flags &= ~ATA_TFLAG_LBA48;

		tf->feature = cdb[3];
		tf->nsect = cdb[4];
		tf->lbal = cdb[5];
		tf->lbam = cdb[6];
		tf->lbah = cdb[7];
		tf->device = cdb[8];
		tf->command = cdb[9];
	}

	/* enforce correct master/slave bit */
	tf->device = dev->devno ?
		tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;

	switch (tf->command) {
	/* READ/WRITE LONG use a non-standard sect_size */
	case ATA_CMD_READ_LONG:
	case ATA_CMD_READ_LONG_ONCE:
	case ATA_CMD_WRITE_LONG:
	case ATA_CMD_WRITE_LONG_ONCE:
		if (tf->protocol != ATA_PROT_PIO || tf->nsect != 1)
			goto invalid_fld;
		qc->sect_size = scsi_bufflen(scmd);
		break;

	/* commands using reported Logical Block size (e.g. 512 or 4K) */
	case ATA_CMD_CFA_WRITE_NE:
	case ATA_CMD_CFA_TRANS_SECT:
	case ATA_CMD_CFA_WRITE_MULT_NE:
	/* XXX: case ATA_CMD_CFA_WRITE_SECTORS_WITHOUT_ERASE: */
	case ATA_CMD_READ:
	case ATA_CMD_READ_EXT:
	case ATA_CMD_READ_QUEUED:
	/* XXX: case ATA_CMD_READ_QUEUED_EXT: */
	case ATA_CMD_FPDMA_READ:
	case ATA_CMD_READ_MULTI:
	case ATA_CMD_READ_MULTI_EXT:
	case ATA_CMD_PIO_READ:
	case ATA_CMD_PIO_READ_EXT:
	case ATA_CMD_READ_STREAM_DMA_EXT:
	case ATA_CMD_READ_STREAM_EXT:
	case ATA_CMD_VERIFY:
	case ATA_CMD_VERIFY_EXT:
	case ATA_CMD_WRITE:
	case ATA_CMD_WRITE_EXT:
	case ATA_CMD_WRITE_FUA_EXT:
	case ATA_CMD_WRITE_QUEUED:
	case ATA_CMD_WRITE_QUEUED_FUA_EXT:
	case ATA_CMD_FPDMA_WRITE:
	case ATA_CMD_WRITE_MULTI:
	case ATA_CMD_WRITE_MULTI_EXT:
	case ATA_CMD_WRITE_MULTI_FUA_EXT:
	case ATA_CMD_PIO_WRITE:
	case ATA_CMD_PIO_WRITE_EXT:
	case ATA_CMD_WRITE_STREAM_DMA_EXT:
	case ATA_CMD_WRITE_STREAM_EXT:
		qc->sect_size = scmd->device->sector_size;
		break;

	/* Everything else uses 512 byte "sectors" */
	default:
		qc->sect_size = ATA_SECT_SIZE;
	}

	/*
	 * Set flags so that all registers will be written, pass on
	 * write indication (used for PIO/DMA setup), result TF is
	 * copied back and we don't whine too much about its failure.
	 */
	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	if (scmd->sc_data_direction == DMA_TO_DEVICE)
		tf->flags |= ATA_TFLAG_WRITE;

	qc->flags |= ATA_QCFLAG_RESULT_TF | ATA_QCFLAG_QUIET;

	/*
	 * Set transfer length.
	 *
	 * TODO: find out if we need to do more here to
	 *       cover scatter/gather case.
	 */
	ata_qc_set_pc_nbytes(qc);

	/* We may not issue DMA commands if no DMA mode is set */
	if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0)
		goto invalid_fld;

	/* sanity check for pio multi commands */
	if ((cdb[1] & 0xe0) && !is_multi_taskfile(tf))
		goto invalid_fld;

	if (is_multi_taskfile(tf)) {
		unsigned int multi_count = 1 << (cdb[1] >> 5);

		/* compare the passed through multi_count
		 * with the cached multi_count of libata
		 */
		if (multi_count != dev->multi_count)
			ata_dev_warn(dev, "invalid multi_count %u ignored\n",
				     multi_count);
	}

	/*
	 * Filter SET_FEATURES - XFER MODE command -- otherwise,
	 * SET_FEATURES - XFER MODE must be preceded/succeeded
	 * by an update to hardware-specific registers for each
	 * controller (i.e. the reason for ->set_piomode(),
	 * ->set_dmamode(), and ->post_set_mode() hooks).
	 */
	if (tf->command == ATA_CMD_SET_FEATURES &&
	    tf->feature == SETFEATURES_XFER)
		goto invalid_fld;

	/*
	 * Filter TPM commands by default. These provide an
	 * essentially uncontrolled encrypted "back door" between
	 * applications and the disk. Set libata.allow_tpm=1 if you
	 * have a real reason for wanting to use them. This ensures
	 * that installed software cannot easily mess stuff up without
	 * user intent. DVR type users will probably ship with this enabled
	 * for movie content management.
	 *
	 * Note that for ATA8 we can issue a DCS change and DCS freeze lock
	 * for this and should do in future but that it is not sufficient as
	 * DCS is an optional feature set. Thus we also do the software filter
	 * so that we comply with the TC consortium stated goal that the user
	 * can turn off TC features of their system.
	 */
	if (tf->command >= 0x5C && tf->command <= 0x5F && !libata_allow_tpm)
		goto invalid_fld;

	return 0;

 invalid_fld:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x00);
	/* "Invalid field in cdb" */
	return 1;
}

static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
{
	struct ata_taskfile *tf = &qc->tf;
	struct scsi_cmnd *scmd = qc->scsicmd;
	struct ata_device *dev = qc->dev;
	const u8 *cdb = scmd->cmnd;
	u64 block;
	u32 n_block;
	u32 size;
	void *buf;

	/* we may not issue DMA commands if no DMA mode is set */
	if (unlikely(!dev->dma_mode))
		goto invalid_fld;

	if (unlikely(scmd->cmd_len < 16))
		goto invalid_fld;
	scsi_16_lba_len(cdb, &block, &n_block);

	/* for now we only support WRITE SAME with the unmap bit set */
	if (unlikely(!(cdb[1] & 0x8)))
		goto invalid_fld;

	/*
	 * WRITE SAME always has a sector sized buffer as payload, this
	 * should never be a multiple entry S/G list.
	 */
	if (!scsi_sg_count(scmd))
		goto invalid_fld;

	buf = page_address(sg_page(scsi_sglist(scmd)));
	size = ata_set_lba_range_entries(buf, 512, block, n_block);

	if (ata_ncq_enabled(dev) && ata_fpdma_dsm_supported(dev)) {
		/* Newer devices support queued TRIM commands */
		tf->protocol = ATA_PROT_NCQ;
		tf->command = ATA_CMD_FPDMA_SEND;
		tf->hob_nsect = ATA_SUBCMD_FPDMA_SEND_DSM & 0x1f;
		tf->nsect = qc->tag << 3;
		tf->hob_feature = (size / 512) >> 8;
		tf->feature = size / 512;

		tf->auxiliary = 1;
	} else {
		tf->protocol = ATA_PROT_DMA;
		tf->hob_feature = 0;
		tf->feature = ATA_DSM_TRIM;
		tf->hob_nsect = (size / 512) >> 8;
		tf->nsect = size / 512;
		tf->command = ATA_CMD_DSM;
	}

	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48 |
		     ATA_TFLAG_WRITE;

	ata_qc_set_pc_nbytes(qc);

	return 0;

 invalid_fld:
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x00);
	/* "Invalid field in cdb" */
	return 1;
}

/**
 *	ata_mselect_caching - Simulate MODE SELECT for caching info page
 *	@qc: Storage for translated ATA taskfile
 *	@buf: input buffer
 *	@len: number of valid bytes in the input buffer
 *
 *	Prepare a taskfile to modify caching information for the device.
 *
 *	LOCKING:
 *	None.
 */
static int ata_mselect_caching(struct ata_queued_cmd *qc,
			       const u8 *buf, int len)
{
	struct ata_taskfile *tf = &qc->tf;
	struct ata_device *dev = qc->dev;
	char mpage[CACHE_MPAGE_LEN];
	u8 wce;

	/*
	 * The first two bytes of def_cache_mpage are a header, so offsets
	 * in mpage are off by 2 compared to buf.  Same for len.
	 */

	if (len != CACHE_MPAGE_LEN - 2)
		return -EINVAL;

	wce = buf[0] & (1 << 2);

	/*
	 * Check that read-only bits are not modified.
	 */
	ata_msense_caching(dev->id, mpage, false);
	mpage[2] &= ~(1 << 2);
	mpage[2] |= wce;
	if (memcmp(mpage + 2, buf, CACHE_MPAGE_LEN - 2) != 0)
		return -EINVAL;

	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
	tf->protocol = ATA_PROT_NODATA;
	tf->nsect = 0;
	tf->command = ATA_CMD_SET_FEATURES;
	tf->feature = wce ? SETFEATURES_WC_ON : SETFEATURES_WC_OFF;
	return 0;
}

/**
 *	ata_scsiop_mode_select - Simulate MODE SELECT 6, 10 commands
 *	@qc: Storage for translated ATA taskfile
 *
 *	Converts a MODE SELECT command to an ATA SET FEATURES taskfile.
 *	Assume this is invoked for direct access devices (e.g. disks) only.
 *	There should be no block descriptor for other device types.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	const u8 *cdb = scmd->cmnd;
	const u8 *p;
	u8 pg, spg;
	unsigned six_byte, pg_len, hdr_len, bd_len;
	int len;

	VPRINTK("ENTER\n");

	six_byte = (cdb[0] == MODE_SELECT);
	if (six_byte) {
		if (scmd->cmd_len < 5)
			goto invalid_fld;

		len = cdb[4];
		hdr_len = 4;
	} else {
		if (scmd->cmd_len < 9)
			goto invalid_fld;

		len = (cdb[7] << 8) + cdb[8];
		hdr_len = 8;
	}

	/* We only support PF=1, SP=0.  */
	if ((cdb[1] & 0x11) != 0x10)
		goto invalid_fld;

	/* Test early for possible overrun.  */
	if (!scsi_sg_count(scmd) || scsi_sglist(scmd)->length < len)
		goto invalid_param_len;

	p = page_address(sg_page(scsi_sglist(scmd)));

	/* Move past header and block descriptors.  */
	if (len < hdr_len)
		goto invalid_param_len;

	if (six_byte)
		bd_len = p[3];
	else
		bd_len = (p[6] << 8) + p[7];

	len -= hdr_len;
	p += hdr_len;
	if (len < bd_len)
		goto invalid_param_len;
	if (bd_len != 0 && bd_len != 8)
		goto invalid_param;

	len -= bd_len;
	p += bd_len;
	if (len == 0)
		goto skip;

	/* Parse both possible formats for the mode page headers.  */
	pg = p[0] & 0x3f;
	if (p[0] & 0x40) {
		if (len < 4)
			goto invalid_param_len;

		spg = p[1];
		pg_len = (p[2] << 8) | p[3];
		p += 4;
		len -= 4;
	} else {
		if (len < 2)
			goto invalid_param_len;

		spg = 0;
		pg_len = p[1];
		p += 2;
		len -= 2;
	}

	/*
	 * No mode subpages supported (yet) but asking for _all_
	 * subpages may be valid
	 */
	if (spg && (spg != ALL_SUB_MPAGES))
		goto invalid_param;
	if (pg_len > len)
		goto invalid_param_len;

	switch (pg) {
	case CACHE_MPAGE:
		if (ata_mselect_caching(qc, p, pg_len) < 0)
			goto invalid_param;
		break;

	default:		/* invalid page code */
		goto invalid_param;
	}

	/*
	 * Only one page has changeable data, so we only support setting one
	 * page at a time.
	 */
	if (len > pg_len)
		goto invalid_param;

	return 0;

 invalid_fld:
	/* "Invalid field in CDB" */
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
	return 1;

 invalid_param:
	/* "Invalid field in parameter list" */
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x26, 0x0);
	return 1;

 invalid_param_len:
	/* "Parameter list length error" */
	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x1a, 0x0);
	return 1;

 skip:
	scmd->result = SAM_STAT_GOOD;
	return 1;
}

/**
 *	ata_get_xlat_func - check if SCSI to ATA translation is possible
 *	@dev: ATA device
 *	@cmd: SCSI command opcode to consider
 *
 *	Look up the SCSI command given, and determine whether the
 *	SCSI command is to be translated or simulated.
 *
 *	RETURNS:
 *	Pointer to translation function if possible, %NULL if not.
 */

static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
{
	switch (cmd) {
	case READ_6:
	case READ_10:
	case READ_16:

	case WRITE_6:
	case WRITE_10:
	case WRITE_16:
		return ata_scsi_rw_xlat;

	case WRITE_SAME_16:
		return ata_scsi_write_same_xlat;

	case SYNCHRONIZE_CACHE:
		if (ata_try_flush_cache(dev))
			return ata_scsi_flush_xlat;
		break;

	case VERIFY:
	case VERIFY_16:
		return ata_scsi_verify_xlat;

	case ATA_12:
	case ATA_16:
		return ata_scsi_pass_thru;

	case MODE_SELECT:
	case MODE_SELECT_10:
		return ata_scsi_mode_select_xlat;
		break;

	case START_STOP:
		return ata_scsi_start_stop_xlat;
	}

	return NULL;
}

/**
 *	ata_scsi_dump_cdb - dump SCSI command contents to dmesg
 *	@ap: ATA port to which the command was being sent
 *	@cmd: SCSI command to dump
 *
 *	Prints the contents of a SCSI command via printk().
 */

static inline void ata_scsi_dump_cdb(struct ata_port *ap,
				     struct scsi_cmnd *cmd)
{
#ifdef ATA_DEBUG
	struct scsi_device *scsidev = cmd->device;
	u8 *scsicmd = cmd->cmnd;

	DPRINTK("CDB (%u:%d,%d,%d) %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
		ap->print_id,
		scsidev->channel, scsidev->id, scsidev->lun,
		scsicmd[0], scsicmd[1], scsicmd[2], scsicmd[3],
		scsicmd[4], scsicmd[5], scsicmd[6], scsicmd[7],
		scsicmd[8]);
#endif
}

static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
				      struct ata_device *dev)
{
	u8 scsi_op = scmd->cmnd[0];
	ata_xlat_func_t xlat_func;
	int rc = 0;

	if (dev->class == ATA_DEV_ATA) {
		if (unlikely(!scmd->cmd_len || scmd->cmd_len > dev->cdb_len))
			goto bad_cdb_len;

		xlat_func = ata_get_xlat_func(dev, scsi_op);
	} else {
		if (unlikely(!scmd->cmd_len))
			goto bad_cdb_len;

		xlat_func = NULL;
		if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
			/* relay SCSI command to ATAPI device */
			int len = COMMAND_SIZE(scsi_op);
			if (unlikely(len > scmd->cmd_len || len > dev->cdb_len))
				goto bad_cdb_len;

			xlat_func = atapi_xlat;
		} else {
			/* ATA_16 passthru, treat as an ATA command */
			if (unlikely(scmd->cmd_len > 16))
				goto bad_cdb_len;

			xlat_func = ata_get_xlat_func(dev, scsi_op);
		}
	}

	if (xlat_func)
		rc = ata_scsi_translate(dev, scmd, xlat_func);
	else
		ata_scsi_simulate(dev, scmd);

	return rc;

 bad_cdb_len:
	DPRINTK("bad CDB len=%u, scsi_op=0x%02x, max=%u\n",
		scmd->cmd_len, scsi_op, dev->cdb_len);
	scmd->result = DID_ERROR << 16;
	scmd->scsi_done(scmd);
	return 0;
}

/**
 *	ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
 *	@shost: SCSI host of command to be sent
 *	@cmd: SCSI command to be sent
 *
 *	In some cases, this function translates SCSI commands into
 *	ATA taskfiles, and queues the taskfiles to be sent to
 *	hardware.  In other cases, this function simulates a
 *	SCSI device by evaluating and responding to certain
 *	SCSI commands.  This creates the overall effect of
 *	ATA and ATAPI devices appearing as SCSI devices.
 *
 *	LOCKING:
 *	ATA host lock
 *
 *	RETURNS:
 *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
 *	0 otherwise.
 */
int ata_scsi_queuecmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
	struct ata_port *ap;
	struct ata_device *dev;
	struct scsi_device *scsidev = cmd->device;
	int rc = 0;
	unsigned long irq_flags;

	ap = ata_shost_to_port(shost);

	spin_lock_irqsave(ap->lock, irq_flags);

	ata_scsi_dump_cdb(ap, cmd);

	dev = ata_scsi_find_dev(ap, scsidev);
	if (likely(dev))
		rc = __ata_scsi_queuecmd(cmd, dev);
	else {
		cmd->result = (DID_BAD_TARGET << 16);
		cmd->scsi_done(cmd);
	}

	spin_unlock_irqrestore(ap->lock, irq_flags);

	return rc;
}

/**
 *	ata_scsi_simulate - simulate SCSI command on ATA device
 *	@dev: the target device
 *	@cmd: SCSI command being sent to device.
 *
 *	Interprets and directly executes a select list of SCSI commands
 *	that can be handled internally.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */

void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
{
	struct ata_scsi_args args;
	const u8 *scsicmd = cmd->cmnd;
	u8 tmp8;

	args.dev = dev;
	args.id = dev->id;
	args.cmd = cmd;
	args.done = cmd->scsi_done;

	switch(scsicmd[0]) {
	/* TODO: worth improving? */
	case FORMAT_UNIT:
		ata_scsi_invalid_field(cmd);
		break;

	case INQUIRY:
		if (scsicmd[1] & 2)	           /* is CmdDt set?  */
			ata_scsi_invalid_field(cmd);
		else if ((scsicmd[1] & 1) == 0)    /* is EVPD clear? */
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_std);
		else switch (scsicmd[2]) {
		case 0x00:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_00);
			break;
		case 0x80:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_80);
			break;
		case 0x83:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_83);
			break;
		case 0x89:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_89);
			break;
		case 0xb0:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b0);
			break;
		case 0xb1:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b1);
			break;
		case 0xb2:
			ata_scsi_rbuf_fill(&args, ata_scsiop_inq_b2);
			break;
		default:
			ata_scsi_invalid_field(cmd);
			break;
		}
		break;

	case MODE_SENSE:
	case MODE_SENSE_10:
		ata_scsi_rbuf_fill(&args, ata_scsiop_mode_sense);
		break;

	case READ_CAPACITY:
		ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
		break;

	case SERVICE_ACTION_IN:
		if ((scsicmd[1] & 0x1f) == SAI_READ_CAPACITY_16)
			ata_scsi_rbuf_fill(&args, ata_scsiop_read_cap);
		else
			ata_scsi_invalid_field(cmd);
		break;

	case REPORT_LUNS:
		ata_scsi_rbuf_fill(&args, ata_scsiop_report_luns);
		break;

	case REQUEST_SENSE:
		ata_scsi_set_sense(cmd, 0, 0, 0);
		cmd->result = (DRIVER_SENSE << 24);
		cmd->scsi_done(cmd);
		break;

	/* if we reach this, then writeback caching is disabled,
	 * turning this into a no-op.
	 */
	case SYNCHRONIZE_CACHE:
		/* fall through */

	/* no-op's, complete with success */
	case REZERO_UNIT:
	case SEEK_6:
	case SEEK_10:
	case TEST_UNIT_READY:
		ata_scsi_rbuf_fill(&args, ata_scsiop_noop);
		break;

	case SEND_DIAGNOSTIC:
		tmp8 = scsicmd[1] & ~(1 << 3);
		if ((tmp8 == 0x4) && (!scsicmd[3]) && (!scsicmd[4]))
			ata_scsi_rbuf_fill(&args, ata_scsiop_noop);
		else
			ata_scsi_invalid_field(cmd);
		break;

	/* all other commands */
	default:
		ata_scsi_set_sense(cmd, ILLEGAL_REQUEST, 0x20, 0x0);
		/* "Invalid command operation code" */
		cmd->scsi_done(cmd);
		break;
	}
}

int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
{
	int i, rc;

	for (i = 0; i < host->n_ports; i++) {
		struct ata_port *ap = host->ports[i];
		struct Scsi_Host *shost;

		rc = -ENOMEM;
		shost = scsi_host_alloc(sht, sizeof(struct ata_port *));
		if (!shost)
			goto err_alloc;

		shost->eh_noresume = 1;
		*(struct ata_port **)&shost->hostdata[0] = ap;
		ap->scsi_host = shost;

		shost->transportt = ata_scsi_transport_template;
		shost->unique_id = ap->print_id;
		shost->max_id = 16;
		shost->max_lun = 1;
		shost->max_channel = 1;
		shost->max_cmd_len = 16;
		shost->no_write_same = 1;

		/* Schedule policy is determined by ->qc_defer()
		 * callback and it needs to see every deferred qc.
		 * Set host_blocked to 1 to prevent SCSI midlayer from
		 * automatically deferring requests.
		 */
		shost->max_host_blocked = 1;

		rc = scsi_add_host_with_dma(ap->scsi_host,
						&ap->tdev, ap->host->dev);
		if (rc)
			goto err_add;
	}

	return 0;

 err_add:
	scsi_host_put(host->ports[i]->scsi_host);
 err_alloc:
	while (--i >= 0) {
		struct Scsi_Host *shost = host->ports[i]->scsi_host;

		scsi_remove_host(shost);
		scsi_host_put(shost);
	}
	return rc;
}

void ata_scsi_scan_host(struct ata_port *ap, int sync)
{
	int tries = 5;
	struct ata_device *last_failed_dev = NULL;
	struct ata_link *link;
	struct ata_device *dev;

 repeat:
	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, link, ENABLED) {
			struct scsi_device *sdev;
			int channel = 0, id = 0;

			if (dev->sdev)
				continue;

			if (ata_is_host_link(link))
				id = dev->devno;
			else
				channel = link->pmp;

			sdev = __scsi_add_device(ap->scsi_host, channel, id, 0,
						 NULL);
			if (!IS_ERR(sdev)) {
				dev->sdev = sdev;
				scsi_device_put(sdev);
			} else {
				dev->sdev = NULL;
			}
		}
	}

	/* If we scanned while EH was in progress or allocation
	 * failure occurred, scan would have failed silently.  Check
	 * whether all devices are attached.
	 */
	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, link, ENABLED) {
			if (!dev->sdev)
				goto exit_loop;
		}
	}
 exit_loop:
	if (!link)
		return;

	/* we're missing some SCSI devices */
	if (sync) {
		/* If caller requested synchrnous scan && we've made
		 * any progress, sleep briefly and repeat.
		 */
		if (dev != last_failed_dev) {
			msleep(100);
			last_failed_dev = dev;
			goto repeat;
		}

		/* We might be failing to detect boot device, give it
		 * a few more chances.
		 */
		if (--tries) {
			msleep(100);
			goto repeat;
		}

		ata_port_err(ap,
			     "WARNING: synchronous SCSI scan failed without making any progress, switching to async\n");
	}

	queue_delayed_work(system_long_wq, &ap->hotplug_task,
			   round_jiffies_relative(HZ));
}

/**
 *	ata_scsi_offline_dev - offline attached SCSI device
 *	@dev: ATA device to offline attached SCSI device for
 *
 *	This function is called from ata_eh_hotplug() and responsible
 *	for taking the SCSI device attached to @dev offline.  This
 *	function is called with host lock which protects dev->sdev
 *	against clearing.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	1 if attached SCSI device exists, 0 otherwise.
 */
int ata_scsi_offline_dev(struct ata_device *dev)
{
	if (dev->sdev) {
		scsi_device_set_state(dev->sdev, SDEV_OFFLINE);
		return 1;
	}
	return 0;
}

/**
 *	ata_scsi_remove_dev - remove attached SCSI device
 *	@dev: ATA device to remove attached SCSI device for
 *
 *	This function is called from ata_eh_scsi_hotplug() and
 *	responsible for removing the SCSI device attached to @dev.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_scsi_remove_dev(struct ata_device *dev)
{
	struct ata_port *ap = dev->link->ap;
	struct scsi_device *sdev;
	unsigned long flags;

	/* Alas, we need to grab scan_mutex to ensure SCSI device
	 * state doesn't change underneath us and thus
	 * scsi_device_get() always succeeds.  The mutex locking can
	 * be removed if there is __scsi_device_get() interface which
	 * increments reference counts regardless of device state.
	 */
	mutex_lock(&ap->scsi_host->scan_mutex);
	spin_lock_irqsave(ap->lock, flags);

	/* clearing dev->sdev is protected by host lock */
	sdev = dev->sdev;
	dev->sdev = NULL;

	if (sdev) {
		/* If user initiated unplug races with us, sdev can go
		 * away underneath us after the host lock and
		 * scan_mutex are released.  Hold onto it.
		 */
		if (scsi_device_get(sdev) == 0) {
			/* The following ensures the attached sdev is
			 * offline on return from ata_scsi_offline_dev()
			 * regardless it wins or loses the race
			 * against this function.
			 */
			scsi_device_set_state(sdev, SDEV_OFFLINE);
		} else {
			WARN_ON(1);
			sdev = NULL;
		}
	}

	spin_unlock_irqrestore(ap->lock, flags);
	mutex_unlock(&ap->scsi_host->scan_mutex);

	if (sdev) {
		ata_dev_info(dev, "detaching (SCSI %s)\n",
			     dev_name(&sdev->sdev_gendev));

		scsi_remove_device(sdev);
		scsi_device_put(sdev);
	}
}

static void ata_scsi_handle_link_detach(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_device *dev;

	ata_for_each_dev(dev, link, ALL) {
		unsigned long flags;

		if (!(dev->flags & ATA_DFLAG_DETACHED))
			continue;

		spin_lock_irqsave(ap->lock, flags);
		dev->flags &= ~ATA_DFLAG_DETACHED;
		spin_unlock_irqrestore(ap->lock, flags);

		if (zpodd_dev_enabled(dev))
			zpodd_exit(dev);

		ata_scsi_remove_dev(dev);
	}
}

/**
 *	ata_scsi_media_change_notify - send media change event
 *	@dev: Pointer to the disk device with media change event
 *
 *	Tell the block layer to send a media change notification
 *	event.
 *
 * 	LOCKING:
 * 	spin_lock_irqsave(host lock)
 */
void ata_scsi_media_change_notify(struct ata_device *dev)
{
	if (dev->sdev)
		sdev_evt_send_simple(dev->sdev, SDEV_EVT_MEDIA_CHANGE,
				     GFP_ATOMIC);
}

/**
 *	ata_scsi_hotplug - SCSI part of hotplug
 *	@work: Pointer to ATA port to perform SCSI hotplug on
 *
 *	Perform SCSI part of hotplug.  It's executed from a separate
 *	workqueue after EH completes.  This is necessary because SCSI
 *	hot plugging requires working EH and hot unplugging is
 *	synchronized with hot plugging with a mutex.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_scsi_hotplug(struct work_struct *work)
{
	struct ata_port *ap =
		container_of(work, struct ata_port, hotplug_task.work);
	int i;

	if (ap->pflags & ATA_PFLAG_UNLOADING) {
		DPRINTK("ENTER/EXIT - unloading\n");
		return;
	}

	/*
	 * XXX - UGLY HACK
	 *
	 * The block layer suspend/resume path is fundamentally broken due
	 * to freezable kthreads and workqueue and may deadlock if a block
	 * device gets removed while resume is in progress.  I don't know
	 * what the solution is short of removing freezable kthreads and
	 * workqueues altogether.
	 *
	 * The following is an ugly hack to avoid kicking off device
	 * removal while freezer is active.  This is a joke but does avoid
	 * this particular deadlock scenario.
	 *
	 * https://bugzilla.kernel.org/show_bug.cgi?id=62801
	 * http://marc.info/?l=linux-kernel&m=138695698516487
	 */
#ifdef CONFIG_FREEZER
	while (pm_freezing)
		msleep(10);
#endif

	DPRINTK("ENTER\n");
	mutex_lock(&ap->scsi_scan_mutex);

	/* Unplug detached devices.  We cannot use link iterator here
	 * because PMP links have to be scanned even if PMP is
	 * currently not attached.  Iterate manually.
	 */
	ata_scsi_handle_link_detach(&ap->link);
	if (ap->pmp_link)
		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
			ata_scsi_handle_link_detach(&ap->pmp_link[i]);

	/* scan for new ones */
	ata_scsi_scan_host(ap, 0);

	mutex_unlock(&ap->scsi_scan_mutex);
	DPRINTK("EXIT\n");
}

/**
 *	ata_scsi_user_scan - indication for user-initiated bus scan
 *	@shost: SCSI host to scan
 *	@channel: Channel to scan
 *	@id: ID to scan
 *	@lun: LUN to scan
 *
 *	This function is called when user explicitly requests bus
 *	scan.  Set probe pending flag and invoke EH.
 *
 *	LOCKING:
 *	SCSI layer (we don't care)
 *
 *	RETURNS:
 *	Zero.
 */
int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
		       unsigned int id, unsigned int lun)
{
	struct ata_port *ap = ata_shost_to_port(shost);
	unsigned long flags;
	int devno, rc = 0;

	if (!ap->ops->error_handler)
		return -EOPNOTSUPP;

	if (lun != SCAN_WILD_CARD && lun)
		return -EINVAL;

	if (!sata_pmp_attached(ap)) {
		if (channel != SCAN_WILD_CARD && channel)
			return -EINVAL;
		devno = id;
	} else {
		if (id != SCAN_WILD_CARD && id)
			return -EINVAL;
		devno = channel;
	}

	spin_lock_irqsave(ap->lock, flags);

	if (devno == SCAN_WILD_CARD) {
		struct ata_link *link;

		ata_for_each_link(link, ap, EDGE) {
			struct ata_eh_info *ehi = &link->eh_info;
			ehi->probe_mask |= ATA_ALL_DEVICES;
			ehi->action |= ATA_EH_RESET;
		}
	} else {
		struct ata_device *dev = ata_find_dev(ap, devno);

		if (dev) {
			struct ata_eh_info *ehi = &dev->link->eh_info;
			ehi->probe_mask |= 1 << dev->devno;
			ehi->action |= ATA_EH_RESET;
		} else
			rc = -EINVAL;
	}

	if (rc == 0) {
		ata_port_schedule_eh(ap);
		spin_unlock_irqrestore(ap->lock, flags);
		ata_port_wait_eh(ap);
	} else
		spin_unlock_irqrestore(ap->lock, flags);

	return rc;
}

/**
 *	ata_scsi_dev_rescan - initiate scsi_rescan_device()
 *	@work: Pointer to ATA port to perform scsi_rescan_device()
 *
 *	After ATA pass thru (SAT) commands are executed successfully,
 *	libata need to propagate the changes to SCSI layer.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_scsi_dev_rescan(struct work_struct *work)
{
	struct ata_port *ap =
		container_of(work, struct ata_port, scsi_rescan_task);
	struct ata_link *link;
	struct ata_device *dev;
	unsigned long flags;

	mutex_lock(&ap->scsi_scan_mutex);
	spin_lock_irqsave(ap->lock, flags);

	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, link, ENABLED) {
			struct scsi_device *sdev = dev->sdev;

			if (!sdev)
				continue;
			if (scsi_device_get(sdev))
				continue;

			spin_unlock_irqrestore(ap->lock, flags);
			scsi_rescan_device(&(sdev->sdev_gendev));
			scsi_device_put(sdev);
			spin_lock_irqsave(ap->lock, flags);
		}
	}

	spin_unlock_irqrestore(ap->lock, flags);
	mutex_unlock(&ap->scsi_scan_mutex);
}

/**
 *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
 *	@host: ATA host container for all SAS ports
 *	@port_info: Information from low-level host driver
 *	@shost: SCSI host that the scsi device is attached to
 *
 *	LOCKING:
 *	PCI/etc. bus probe sem.
 *
 *	RETURNS:
 *	ata_port pointer on success / NULL on failure.
 */

struct ata_port *ata_sas_port_alloc(struct ata_host *host,
				    struct ata_port_info *port_info,
				    struct Scsi_Host *shost)
{
	struct ata_port *ap;

	ap = ata_port_alloc(host);
	if (!ap)
		return NULL;

	ap->port_no = 0;
	ap->lock = &host->lock;
	ap->pio_mask = port_info->pio_mask;
	ap->mwdma_mask = port_info->mwdma_mask;
	ap->udma_mask = port_info->udma_mask;
	ap->flags |= port_info->flags;
	ap->ops = port_info->port_ops;
	ap->cbl = ATA_CBL_SATA;

	return ap;
}
EXPORT_SYMBOL_GPL(ata_sas_port_alloc);

/**
 *	ata_sas_port_start - Set port up for dma.
 *	@ap: Port to initialize
 *
 *	Called just after data structures for each port are
 *	initialized.
 *
 *	May be used as the port_start() entry in ata_port_operations.
 *
 *	LOCKING:
 *	Inherited from caller.
 */
int ata_sas_port_start(struct ata_port *ap)
{
	/*
	 * the port is marked as frozen at allocation time, but if we don't
	 * have new eh, we won't thaw it
	 */
	if (!ap->ops->error_handler)
		ap->pflags &= ~ATA_PFLAG_FROZEN;
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_port_start);

/**
 *	ata_port_stop - Undo ata_sas_port_start()
 *	@ap: Port to shut down
 *
 *	May be used as the port_stop() entry in ata_port_operations.
 *
 *	LOCKING:
 *	Inherited from caller.
 */

void ata_sas_port_stop(struct ata_port *ap)
{
}
EXPORT_SYMBOL_GPL(ata_sas_port_stop);

/**
 * ata_sas_async_probe - simply schedule probing and return
 * @ap: Port to probe
 *
 * For batch scheduling of probe for sas attached ata devices, assumes
 * the port has already been through ata_sas_port_init()
 */
void ata_sas_async_probe(struct ata_port *ap)
{
	__ata_port_probe(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_async_probe);

int ata_sas_sync_probe(struct ata_port *ap)
{
	return ata_port_probe(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_sync_probe);


/**
 *	ata_sas_port_init - Initialize a SATA device
 *	@ap: SATA port to initialize
 *
 *	LOCKING:
 *	PCI/etc. bus probe sem.
 *
 *	RETURNS:
 *	Zero on success, non-zero on error.
 */

int ata_sas_port_init(struct ata_port *ap)
{
	int rc = ap->ops->port_start(ap);

	if (rc)
		return rc;
	ap->print_id = atomic_inc_return(&ata_print_id);
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_port_init);

/**
 *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
 *	@ap: SATA port to destroy
 *
 */

void ata_sas_port_destroy(struct ata_port *ap)
{
	if (ap->ops->port_stop)
		ap->ops->port_stop(ap);
	kfree(ap);
}
EXPORT_SYMBOL_GPL(ata_sas_port_destroy);

/**
 *	ata_sas_slave_configure - Default slave_config routine for libata devices
 *	@sdev: SCSI device to configure
 *	@ap: ATA port to which SCSI device is attached
 *
 *	RETURNS:
 *	Zero.
 */

int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
{
	ata_scsi_sdev_config(sdev);
	ata_scsi_dev_config(sdev, ap->link.device);
	return 0;
}
EXPORT_SYMBOL_GPL(ata_sas_slave_configure);

/**
 *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
 *	@cmd: SCSI command to be sent
 *	@ap:	ATA port to which the command is being sent
 *
 *	RETURNS:
 *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
 *	0 otherwise.
 */

int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
{
	int rc = 0;

	ata_scsi_dump_cdb(ap, cmd);

	if (likely(ata_dev_enabled(ap->link.device)))
		rc = __ata_scsi_queuecmd(cmd, ap->link.device);
	else {
		cmd->result = (DID_BAD_TARGET << 16);
		cmd->scsi_done(cmd);
	}
	return rc;
}
EXPORT_SYMBOL_GPL(ata_sas_queuecmd);