summaryrefslogtreecommitdiff
path: root/drivers/block/skd_main.c
blob: ab893a7571a2babe4c314d94bc3b13efd51e0d33 (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
/*
 * Driver for sTec s1120 PCIe SSDs. sTec was acquired in 2013 by HGST and HGST
 * was acquired by Western Digital in 2012.
 *
 * Copyright 2012 sTec, Inc.
 * Copyright (c) 2017 Western Digital Corporation or its affiliates.
 *
 * This file is part of the Linux kernel, and is made available under
 * the terms of the GNU General Public License version 2.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/compiler.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/hdreg.h>
#include <linux/dma-mapping.h>
#include <linux/completion.h>
#include <linux/scatterlist.h>
#include <linux/version.h>
#include <linux/err.h>
#include <linux/aer.h>
#include <linux/wait.h>
#include <linux/stringify.h>
#include <scsi/scsi.h>
#include <scsi/sg.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/unaligned.h>

#include "skd_s1120.h"

static int skd_dbg_level;
static int skd_isr_comp_limit = 4;

#define SKD_ASSERT(expr) \
	do { \
		if (unlikely(!(expr))) { \
			pr_err("Assertion failed! %s,%s,%s,line=%d\n",	\
			       # expr, __FILE__, __func__, __LINE__); \
		} \
	} while (0)

#define DRV_NAME "skd"
#define PFX DRV_NAME ": "

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("STEC s1120 PCIe SSD block driver");

#define PCI_VENDOR_ID_STEC      0x1B39
#define PCI_DEVICE_ID_S1120     0x0001

#define SKD_FUA_NV		(1 << 1)
#define SKD_MINORS_PER_DEVICE   16

#define SKD_MAX_QUEUE_DEPTH     200u

#define SKD_PAUSE_TIMEOUT       (5 * 1000)

#define SKD_N_FITMSG_BYTES      (512u)
#define SKD_MAX_REQ_PER_MSG	14

#define SKD_N_SPECIAL_FITMSG_BYTES      (128u)

/* SG elements are 32 bytes, so we can make this 4096 and still be under the
 * 128KB limit.  That allows 4096*4K = 16M xfer size
 */
#define SKD_N_SG_PER_REQ_DEFAULT 256u

#define SKD_N_COMPLETION_ENTRY  256u
#define SKD_N_READ_CAP_BYTES    (8u)

#define SKD_N_INTERNAL_BYTES    (512u)

#define SKD_SKCOMP_SIZE							\
	((sizeof(struct fit_completion_entry_v1) +			\
	  sizeof(struct fit_comp_error_info)) * SKD_N_COMPLETION_ENTRY)

/* 5 bits of uniqifier, 0xF800 */
#define SKD_ID_TABLE_MASK       (3u << 8u)
#define  SKD_ID_RW_REQUEST      (0u << 8u)
#define  SKD_ID_INTERNAL        (1u << 8u)
#define  SKD_ID_FIT_MSG         (3u << 8u)
#define SKD_ID_SLOT_MASK        0x00FFu
#define SKD_ID_SLOT_AND_TABLE_MASK 0x03FFu

#define SKD_N_MAX_SECTORS 2048u

#define SKD_MAX_RETRIES 2u

#define SKD_TIMER_SECONDS(seconds) (seconds)
#define SKD_TIMER_MINUTES(minutes) ((minutes) * (60))

#define INQ_STD_NBYTES 36

enum skd_drvr_state {
	SKD_DRVR_STATE_LOAD,
	SKD_DRVR_STATE_IDLE,
	SKD_DRVR_STATE_BUSY,
	SKD_DRVR_STATE_STARTING,
	SKD_DRVR_STATE_ONLINE,
	SKD_DRVR_STATE_PAUSING,
	SKD_DRVR_STATE_PAUSED,
	SKD_DRVR_STATE_RESTARTING,
	SKD_DRVR_STATE_RESUMING,
	SKD_DRVR_STATE_STOPPING,
	SKD_DRVR_STATE_FAULT,
	SKD_DRVR_STATE_DISAPPEARED,
	SKD_DRVR_STATE_PROTOCOL_MISMATCH,
	SKD_DRVR_STATE_BUSY_ERASE,
	SKD_DRVR_STATE_BUSY_SANITIZE,
	SKD_DRVR_STATE_BUSY_IMMINENT,
	SKD_DRVR_STATE_WAIT_BOOT,
	SKD_DRVR_STATE_SYNCING,
};

#define SKD_WAIT_BOOT_TIMO      SKD_TIMER_SECONDS(90u)
#define SKD_STARTING_TIMO       SKD_TIMER_SECONDS(8u)
#define SKD_RESTARTING_TIMO     SKD_TIMER_MINUTES(4u)
#define SKD_BUSY_TIMO           SKD_TIMER_MINUTES(20u)
#define SKD_STARTED_BUSY_TIMO   SKD_TIMER_SECONDS(60u)
#define SKD_START_WAIT_SECONDS  90u

enum skd_req_state {
	SKD_REQ_STATE_IDLE,
	SKD_REQ_STATE_SETUP,
	SKD_REQ_STATE_BUSY,
	SKD_REQ_STATE_COMPLETED,
	SKD_REQ_STATE_TIMEOUT,
};

enum skd_check_status_action {
	SKD_CHECK_STATUS_REPORT_GOOD,
	SKD_CHECK_STATUS_REPORT_SMART_ALERT,
	SKD_CHECK_STATUS_REQUEUE_REQUEST,
	SKD_CHECK_STATUS_REPORT_ERROR,
	SKD_CHECK_STATUS_BUSY_IMMINENT,
};

struct skd_msg_buf {
	struct fit_msg_hdr	fmh;
	struct skd_scsi_request	scsi[SKD_MAX_REQ_PER_MSG];
};

struct skd_fitmsg_context {
	u32 id;

	u32 length;

	struct skd_msg_buf *msg_buf;
	dma_addr_t mb_dma_address;
};

struct skd_request_context {
	enum skd_req_state state;

	u16 id;
	u32 fitmsg_id;

	u8 flush_cmd;

	enum dma_data_direction data_dir;
	struct scatterlist *sg;
	u32 n_sg;
	u32 sg_byte_count;

	struct fit_sg_descriptor *sksg_list;
	dma_addr_t sksg_dma_address;

	struct fit_completion_entry_v1 completion;

	struct fit_comp_error_info err_info;
	int retries;

	blk_status_t status;
};

struct skd_special_context {
	struct skd_request_context req;

	void *data_buf;
	dma_addr_t db_dma_address;

	struct skd_msg_buf *msg_buf;
	dma_addr_t mb_dma_address;
};

typedef enum skd_irq_type {
	SKD_IRQ_LEGACY,
	SKD_IRQ_MSI,
	SKD_IRQ_MSIX
} skd_irq_type_t;

#define SKD_MAX_BARS                    2

struct skd_device {
	void __iomem *mem_map[SKD_MAX_BARS];
	resource_size_t mem_phys[SKD_MAX_BARS];
	u32 mem_size[SKD_MAX_BARS];

	struct skd_msix_entry *msix_entries;

	struct pci_dev *pdev;
	int pcie_error_reporting_is_enabled;

	spinlock_t lock;
	struct gendisk *disk;
	struct blk_mq_tag_set tag_set;
	struct request_queue *queue;
	struct skd_fitmsg_context *skmsg;
	struct device *class_dev;
	int gendisk_on;
	int sync_done;

	u32 devno;
	u32 major;
	char isr_name[30];

	enum skd_drvr_state state;
	u32 drive_state;

	u32 cur_max_queue_depth;
	u32 queue_low_water_mark;
	u32 dev_max_queue_depth;

	u32 num_fitmsg_context;
	u32 num_req_context;

	struct skd_fitmsg_context *skmsg_table;

	struct skd_special_context internal_skspcl;
	u32 read_cap_blocksize;
	u32 read_cap_last_lba;
	int read_cap_is_valid;
	int inquiry_is_valid;
	u8 inq_serial_num[13];  /*12 chars plus null term */

	u8 skcomp_cycle;
	u32 skcomp_ix;
	struct kmem_cache *msgbuf_cache;
	struct kmem_cache *sglist_cache;
	struct kmem_cache *databuf_cache;
	struct fit_completion_entry_v1 *skcomp_table;
	struct fit_comp_error_info *skerr_table;
	dma_addr_t cq_dma_address;

	wait_queue_head_t waitq;

	struct timer_list timer;
	u32 timer_countdown;
	u32 timer_substate;

	int sgs_per_request;
	u32 last_mtd;

	u32 proto_ver;

	int dbg_level;
	u32 connect_time_stamp;
	int connect_retries;
#define SKD_MAX_CONNECT_RETRIES 16
	u32 drive_jiffies;

	u32 timo_slot;

	struct work_struct start_queue;
	struct work_struct completion_worker;
};

#define SKD_WRITEL(DEV, VAL, OFF) skd_reg_write32(DEV, VAL, OFF)
#define SKD_READL(DEV, OFF)      skd_reg_read32(DEV, OFF)
#define SKD_WRITEQ(DEV, VAL, OFF) skd_reg_write64(DEV, VAL, OFF)

static inline u32 skd_reg_read32(struct skd_device *skdev, u32 offset)
{
	u32 val = readl(skdev->mem_map[1] + offset);

	if (unlikely(skdev->dbg_level >= 2))
		dev_dbg(&skdev->pdev->dev, "offset %x = %x\n", offset, val);
	return val;
}

static inline void skd_reg_write32(struct skd_device *skdev, u32 val,
				   u32 offset)
{
	writel(val, skdev->mem_map[1] + offset);
	if (unlikely(skdev->dbg_level >= 2))
		dev_dbg(&skdev->pdev->dev, "offset %x = %x\n", offset, val);
}

static inline void skd_reg_write64(struct skd_device *skdev, u64 val,
				   u32 offset)
{
	writeq(val, skdev->mem_map[1] + offset);
	if (unlikely(skdev->dbg_level >= 2))
		dev_dbg(&skdev->pdev->dev, "offset %x = %016llx\n", offset,
			val);
}


#define SKD_IRQ_DEFAULT SKD_IRQ_MSIX
static int skd_isr_type = SKD_IRQ_DEFAULT;

module_param(skd_isr_type, int, 0444);
MODULE_PARM_DESC(skd_isr_type, "Interrupt type capability."
		 " (0==legacy, 1==MSI, 2==MSI-X, default==1)");

#define SKD_MAX_REQ_PER_MSG_DEFAULT 1
static int skd_max_req_per_msg = SKD_MAX_REQ_PER_MSG_DEFAULT;

module_param(skd_max_req_per_msg, int, 0444);
MODULE_PARM_DESC(skd_max_req_per_msg,
		 "Maximum SCSI requests packed in a single message."
		 " (1-" __stringify(SKD_MAX_REQ_PER_MSG) ", default==1)");

#define SKD_MAX_QUEUE_DEPTH_DEFAULT 64
#define SKD_MAX_QUEUE_DEPTH_DEFAULT_STR "64"
static int skd_max_queue_depth = SKD_MAX_QUEUE_DEPTH_DEFAULT;

module_param(skd_max_queue_depth, int, 0444);
MODULE_PARM_DESC(skd_max_queue_depth,
		 "Maximum SCSI requests issued to s1120."
		 " (1-200, default==" SKD_MAX_QUEUE_DEPTH_DEFAULT_STR ")");

static int skd_sgs_per_request = SKD_N_SG_PER_REQ_DEFAULT;
module_param(skd_sgs_per_request, int, 0444);
MODULE_PARM_DESC(skd_sgs_per_request,
		 "Maximum SG elements per block request."
		 " (1-4096, default==256)");

static int skd_max_pass_thru = 1;
module_param(skd_max_pass_thru, int, 0444);
MODULE_PARM_DESC(skd_max_pass_thru,
		 "Maximum SCSI pass-thru at a time. IGNORED");

module_param(skd_dbg_level, int, 0444);
MODULE_PARM_DESC(skd_dbg_level, "s1120 debug level (0,1,2)");

module_param(skd_isr_comp_limit, int, 0444);
MODULE_PARM_DESC(skd_isr_comp_limit, "s1120 isr comp limit (0=none) default=4");

/* Major device number dynamically assigned. */
static u32 skd_major;

static void skd_destruct(struct skd_device *skdev);
static const struct block_device_operations skd_blockdev_ops;
static void skd_send_fitmsg(struct skd_device *skdev,
			    struct skd_fitmsg_context *skmsg);
static void skd_send_special_fitmsg(struct skd_device *skdev,
				    struct skd_special_context *skspcl);
static bool skd_preop_sg_list(struct skd_device *skdev,
			     struct skd_request_context *skreq);
static void skd_postop_sg_list(struct skd_device *skdev,
			       struct skd_request_context *skreq);

static void skd_restart_device(struct skd_device *skdev);
static int skd_quiesce_dev(struct skd_device *skdev);
static int skd_unquiesce_dev(struct skd_device *skdev);
static void skd_disable_interrupts(struct skd_device *skdev);
static void skd_isr_fwstate(struct skd_device *skdev);
static void skd_recover_requests(struct skd_device *skdev);
static void skd_soft_reset(struct skd_device *skdev);

const char *skd_drive_state_to_str(int state);
const char *skd_skdev_state_to_str(enum skd_drvr_state state);
static void skd_log_skdev(struct skd_device *skdev, const char *event);
static void skd_log_skreq(struct skd_device *skdev,
			  struct skd_request_context *skreq, const char *event);

/*
 *****************************************************************************
 * READ/WRITE REQUESTS
 *****************************************************************************
 */
static bool skd_inc_in_flight(struct request *rq, void *data, bool reserved)
{
	int *count = data;

	count++;
	return true;
}

static int skd_in_flight(struct skd_device *skdev)
{
	int count = 0;

	blk_mq_tagset_busy_iter(&skdev->tag_set, skd_inc_in_flight, &count);

	return count;
}

static void
skd_prep_rw_cdb(struct skd_scsi_request *scsi_req,
		int data_dir, unsigned lba,
		unsigned count)
{
	if (data_dir == READ)
		scsi_req->cdb[0] = READ_10;
	else
		scsi_req->cdb[0] = WRITE_10;

	scsi_req->cdb[1] = 0;
	scsi_req->cdb[2] = (lba & 0xff000000) >> 24;
	scsi_req->cdb[3] = (lba & 0xff0000) >> 16;
	scsi_req->cdb[4] = (lba & 0xff00) >> 8;
	scsi_req->cdb[5] = (lba & 0xff);
	scsi_req->cdb[6] = 0;
	scsi_req->cdb[7] = (count & 0xff00) >> 8;
	scsi_req->cdb[8] = count & 0xff;
	scsi_req->cdb[9] = 0;
}

static void
skd_prep_zerosize_flush_cdb(struct skd_scsi_request *scsi_req,
			    struct skd_request_context *skreq)
{
	skreq->flush_cmd = 1;

	scsi_req->cdb[0] = SYNCHRONIZE_CACHE;
	scsi_req->cdb[1] = 0;
	scsi_req->cdb[2] = 0;
	scsi_req->cdb[3] = 0;
	scsi_req->cdb[4] = 0;
	scsi_req->cdb[5] = 0;
	scsi_req->cdb[6] = 0;
	scsi_req->cdb[7] = 0;
	scsi_req->cdb[8] = 0;
	scsi_req->cdb[9] = 0;
}

/*
 * Return true if and only if all pending requests should be failed.
 */
static bool skd_fail_all(struct request_queue *q)
{
	struct skd_device *skdev = q->queuedata;

	SKD_ASSERT(skdev->state != SKD_DRVR_STATE_ONLINE);

	skd_log_skdev(skdev, "req_not_online");
	switch (skdev->state) {
	case SKD_DRVR_STATE_PAUSING:
	case SKD_DRVR_STATE_PAUSED:
	case SKD_DRVR_STATE_STARTING:
	case SKD_DRVR_STATE_RESTARTING:
	case SKD_DRVR_STATE_WAIT_BOOT:
	/* In case of starting, we haven't started the queue,
	 * so we can't get here... but requests are
	 * possibly hanging out waiting for us because we
	 * reported the dev/skd0 already.  They'll wait
	 * forever if connect doesn't complete.
	 * What to do??? delay dev/skd0 ??
	 */
	case SKD_DRVR_STATE_BUSY:
	case SKD_DRVR_STATE_BUSY_IMMINENT:
	case SKD_DRVR_STATE_BUSY_ERASE:
		return false;

	case SKD_DRVR_STATE_BUSY_SANITIZE:
	case SKD_DRVR_STATE_STOPPING:
	case SKD_DRVR_STATE_SYNCING:
	case SKD_DRVR_STATE_FAULT:
	case SKD_DRVR_STATE_DISAPPEARED:
	default:
		return true;
	}
}

static blk_status_t skd_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
				    const struct blk_mq_queue_data *mqd)
{
	struct request *const req = mqd->rq;
	struct request_queue *const q = req->q;
	struct skd_device *skdev = q->queuedata;
	struct skd_fitmsg_context *skmsg;
	struct fit_msg_hdr *fmh;
	const u32 tag = blk_mq_unique_tag(req);
	struct skd_request_context *const skreq = blk_mq_rq_to_pdu(req);
	struct skd_scsi_request *scsi_req;
	unsigned long flags = 0;
	const u32 lba = blk_rq_pos(req);
	const u32 count = blk_rq_sectors(req);
	const int data_dir = rq_data_dir(req);

	if (unlikely(skdev->state != SKD_DRVR_STATE_ONLINE))
		return skd_fail_all(q) ? BLK_STS_IOERR : BLK_STS_RESOURCE;

	if (!(req->rq_flags & RQF_DONTPREP)) {
		skreq->retries = 0;
		req->rq_flags |= RQF_DONTPREP;
	}

	blk_mq_start_request(req);

	WARN_ONCE(tag >= skd_max_queue_depth, "%#x > %#x (nr_requests = %lu)\n",
		  tag, skd_max_queue_depth, q->nr_requests);

	SKD_ASSERT(skreq->state == SKD_REQ_STATE_IDLE);

	dev_dbg(&skdev->pdev->dev,
		"new req=%p lba=%u(0x%x) count=%u(0x%x) dir=%d\n", req, lba,
		lba, count, count, data_dir);

	skreq->id = tag + SKD_ID_RW_REQUEST;
	skreq->flush_cmd = 0;
	skreq->n_sg = 0;
	skreq->sg_byte_count = 0;

	skreq->fitmsg_id = 0;

	skreq->data_dir = data_dir == READ ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	if (req->bio && !skd_preop_sg_list(skdev, skreq)) {
		dev_dbg(&skdev->pdev->dev, "error Out\n");
		skreq->status = BLK_STS_RESOURCE;
		blk_mq_complete_request(req);
		return BLK_STS_OK;
	}

	dma_sync_single_for_device(&skdev->pdev->dev, skreq->sksg_dma_address,
				   skreq->n_sg *
				   sizeof(struct fit_sg_descriptor),
				   DMA_TO_DEVICE);

	/* Either a FIT msg is in progress or we have to start one. */
	if (skd_max_req_per_msg == 1) {
		skmsg = NULL;
	} else {
		spin_lock_irqsave(&skdev->lock, flags);
		skmsg = skdev->skmsg;
	}
	if (!skmsg) {
		skmsg = &skdev->skmsg_table[tag];
		skdev->skmsg = skmsg;

		/* Initialize the FIT msg header */
		fmh = &skmsg->msg_buf->fmh;
		memset(fmh, 0, sizeof(*fmh));
		fmh->protocol_id = FIT_PROTOCOL_ID_SOFIT;
		skmsg->length = sizeof(*fmh);
	} else {
		fmh = &skmsg->msg_buf->fmh;
	}

	skreq->fitmsg_id = skmsg->id;

	scsi_req = &skmsg->msg_buf->scsi[fmh->num_protocol_cmds_coalesced];
	memset(scsi_req, 0, sizeof(*scsi_req));

	scsi_req->hdr.tag = skreq->id;
	scsi_req->hdr.sg_list_dma_address =
		cpu_to_be64(skreq->sksg_dma_address);

	if (req_op(req) == REQ_OP_FLUSH) {
		skd_prep_zerosize_flush_cdb(scsi_req, skreq);
		SKD_ASSERT(skreq->flush_cmd == 1);
	} else {
		skd_prep_rw_cdb(scsi_req, data_dir, lba, count);
	}

	if (req->cmd_flags & REQ_FUA)
		scsi_req->cdb[1] |= SKD_FUA_NV;

	scsi_req->hdr.sg_list_len_bytes = cpu_to_be32(skreq->sg_byte_count);

	/* Complete resource allocations. */
	skreq->state = SKD_REQ_STATE_BUSY;

	skmsg->length += sizeof(struct skd_scsi_request);
	fmh->num_protocol_cmds_coalesced++;

	dev_dbg(&skdev->pdev->dev, "req=0x%x busy=%d\n", skreq->id,
		skd_in_flight(skdev));

	/*
	 * If the FIT msg buffer is full send it.
	 */
	if (skd_max_req_per_msg == 1) {
		skd_send_fitmsg(skdev, skmsg);
	} else {
		if (mqd->last ||
		    fmh->num_protocol_cmds_coalesced >= skd_max_req_per_msg) {
			skd_send_fitmsg(skdev, skmsg);
			skdev->skmsg = NULL;
		}
		spin_unlock_irqrestore(&skdev->lock, flags);
	}

	return BLK_STS_OK;
}

static enum blk_eh_timer_return skd_timed_out(struct request *req,
					      bool reserved)
{
	struct skd_device *skdev = req->q->queuedata;

	dev_err(&skdev->pdev->dev, "request with tag %#x timed out\n",
		blk_mq_unique_tag(req));

	return BLK_EH_RESET_TIMER;
}

static void skd_complete_rq(struct request *req)
{
	struct skd_request_context *skreq = blk_mq_rq_to_pdu(req);

	blk_mq_end_request(req, skreq->status);
}

static bool skd_preop_sg_list(struct skd_device *skdev,
			     struct skd_request_context *skreq)
{
	struct request *req = blk_mq_rq_from_pdu(skreq);
	struct scatterlist *sgl = &skreq->sg[0], *sg;
	int n_sg;
	int i;

	skreq->sg_byte_count = 0;

	WARN_ON_ONCE(skreq->data_dir != DMA_TO_DEVICE &&
		     skreq->data_dir != DMA_FROM_DEVICE);

	n_sg = blk_rq_map_sg(skdev->queue, req, sgl);
	if (n_sg <= 0)
		return false;

	/*
	 * Map scatterlist to PCI bus addresses.
	 * Note PCI might change the number of entries.
	 */
	n_sg = dma_map_sg(&skdev->pdev->dev, sgl, n_sg, skreq->data_dir);
	if (n_sg <= 0)
		return false;

	SKD_ASSERT(n_sg <= skdev->sgs_per_request);

	skreq->n_sg = n_sg;

	for_each_sg(sgl, sg, n_sg, i) {
		struct fit_sg_descriptor *sgd = &skreq->sksg_list[i];
		u32 cnt = sg_dma_len(sg);
		uint64_t dma_addr = sg_dma_address(sg);

		sgd->control = FIT_SGD_CONTROL_NOT_LAST;
		sgd->byte_count = cnt;
		skreq->sg_byte_count += cnt;
		sgd->host_side_addr = dma_addr;
		sgd->dev_side_addr = 0;
	}

	skreq->sksg_list[n_sg - 1].next_desc_ptr = 0LL;
	skreq->sksg_list[n_sg - 1].control = FIT_SGD_CONTROL_LAST;

	if (unlikely(skdev->dbg_level > 1)) {
		dev_dbg(&skdev->pdev->dev,
			"skreq=%x sksg_list=%p sksg_dma=%pad\n",
			skreq->id, skreq->sksg_list, &skreq->sksg_dma_address);
		for (i = 0; i < n_sg; i++) {
			struct fit_sg_descriptor *sgd = &skreq->sksg_list[i];

			dev_dbg(&skdev->pdev->dev,
				"  sg[%d] count=%u ctrl=0x%x addr=0x%llx next=0x%llx\n",
				i, sgd->byte_count, sgd->control,
				sgd->host_side_addr, sgd->next_desc_ptr);
		}
	}

	return true;
}

static void skd_postop_sg_list(struct skd_device *skdev,
			       struct skd_request_context *skreq)
{
	/*
	 * restore the next ptr for next IO request so we
	 * don't have to set it every time.
	 */
	skreq->sksg_list[skreq->n_sg - 1].next_desc_ptr =
		skreq->sksg_dma_address +
		((skreq->n_sg) * sizeof(struct fit_sg_descriptor));
	dma_unmap_sg(&skdev->pdev->dev, &skreq->sg[0], skreq->n_sg,
		     skreq->data_dir);
}

/*
 *****************************************************************************
 * TIMER
 *****************************************************************************
 */

static void skd_timer_tick_not_online(struct skd_device *skdev);

static void skd_start_queue(struct work_struct *work)
{
	struct skd_device *skdev = container_of(work, typeof(*skdev),
						start_queue);

	/*
	 * Although it is safe to call blk_start_queue() from interrupt
	 * context, blk_mq_start_hw_queues() must not be called from
	 * interrupt context.
	 */
	blk_mq_start_hw_queues(skdev->queue);
}

static void skd_timer_tick(struct timer_list *t)
{
	struct skd_device *skdev = from_timer(skdev, t, timer);
	unsigned long reqflags;
	u32 state;

	if (skdev->state == SKD_DRVR_STATE_FAULT)
		/* The driver has declared fault, and we want it to
		 * stay that way until driver is reloaded.
		 */
		return;

	spin_lock_irqsave(&skdev->lock, reqflags);

	state = SKD_READL(skdev, FIT_STATUS);
	state &= FIT_SR_DRIVE_STATE_MASK;
	if (state != skdev->drive_state)
		skd_isr_fwstate(skdev);

	if (skdev->state != SKD_DRVR_STATE_ONLINE)
		skd_timer_tick_not_online(skdev);

	mod_timer(&skdev->timer, (jiffies + HZ));

	spin_unlock_irqrestore(&skdev->lock, reqflags);
}

static void skd_timer_tick_not_online(struct skd_device *skdev)
{
	switch (skdev->state) {
	case SKD_DRVR_STATE_IDLE:
	case SKD_DRVR_STATE_LOAD:
		break;
	case SKD_DRVR_STATE_BUSY_SANITIZE:
		dev_dbg(&skdev->pdev->dev,
			"drive busy sanitize[%x], driver[%x]\n",
			skdev->drive_state, skdev->state);
		/* If we've been in sanitize for 3 seconds, we figure we're not
		 * going to get anymore completions, so recover requests now
		 */
		if (skdev->timer_countdown > 0) {
			skdev->timer_countdown--;
			return;
		}
		skd_recover_requests(skdev);
		break;

	case SKD_DRVR_STATE_BUSY:
	case SKD_DRVR_STATE_BUSY_IMMINENT:
	case SKD_DRVR_STATE_BUSY_ERASE:
		dev_dbg(&skdev->pdev->dev, "busy[%x], countdown=%d\n",
			skdev->state, skdev->timer_countdown);
		if (skdev->timer_countdown > 0) {
			skdev->timer_countdown--;
			return;
		}
		dev_dbg(&skdev->pdev->dev,
			"busy[%x], timedout=%d, restarting device.",
			skdev->state, skdev->timer_countdown);
		skd_restart_device(skdev);
		break;

	case SKD_DRVR_STATE_WAIT_BOOT:
	case SKD_DRVR_STATE_STARTING:
		if (skdev->timer_countdown > 0) {
			skdev->timer_countdown--;
			return;
		}
		/* For now, we fault the drive.  Could attempt resets to
		 * revcover at some point. */
		skdev->state = SKD_DRVR_STATE_FAULT;

		dev_err(&skdev->pdev->dev, "DriveFault Connect Timeout (%x)\n",
			skdev->drive_state);

		/*start the queue so we can respond with error to requests */
		/* wakeup anyone waiting for startup complete */
		schedule_work(&skdev->start_queue);
		skdev->gendisk_on = -1;
		wake_up_interruptible(&skdev->waitq);
		break;

	case SKD_DRVR_STATE_ONLINE:
		/* shouldn't get here. */
		break;

	case SKD_DRVR_STATE_PAUSING:
	case SKD_DRVR_STATE_PAUSED:
		break;

	case SKD_DRVR_STATE_RESTARTING:
		if (skdev->timer_countdown > 0) {
			skdev->timer_countdown--;
			return;
		}
		/* For now, we fault the drive. Could attempt resets to
		 * revcover at some point. */
		skdev->state = SKD_DRVR_STATE_FAULT;
		dev_err(&skdev->pdev->dev,
			"DriveFault Reconnect Timeout (%x)\n",
			skdev->drive_state);

		/*
		 * Recovering does two things:
		 * 1. completes IO with error
		 * 2. reclaims dma resources
		 * When is it safe to recover requests?
		 * - if the drive state is faulted
		 * - if the state is still soft reset after out timeout
		 * - if the drive registers are dead (state = FF)
		 * If it is "unsafe", we still need to recover, so we will
		 * disable pci bus mastering and disable our interrupts.
		 */

		if ((skdev->drive_state == FIT_SR_DRIVE_SOFT_RESET) ||
		    (skdev->drive_state == FIT_SR_DRIVE_FAULT) ||
		    (skdev->drive_state == FIT_SR_DRIVE_STATE_MASK))
			/* It never came out of soft reset. Try to
			 * recover the requests and then let them
			 * fail. This is to mitigate hung processes. */
			skd_recover_requests(skdev);
		else {
			dev_err(&skdev->pdev->dev, "Disable BusMaster (%x)\n",
				skdev->drive_state);
			pci_disable_device(skdev->pdev);
			skd_disable_interrupts(skdev);
			skd_recover_requests(skdev);
		}

		/*start the queue so we can respond with error to requests */
		/* wakeup anyone waiting for startup complete */
		schedule_work(&skdev->start_queue);
		skdev->gendisk_on = -1;
		wake_up_interruptible(&skdev->waitq);
		break;

	case SKD_DRVR_STATE_RESUMING:
	case SKD_DRVR_STATE_STOPPING:
	case SKD_DRVR_STATE_SYNCING:
	case SKD_DRVR_STATE_FAULT:
	case SKD_DRVR_STATE_DISAPPEARED:
	default:
		break;
	}
}

static int skd_start_timer(struct skd_device *skdev)
{
	int rc;

	timer_setup(&skdev->timer, skd_timer_tick, 0);

	rc = mod_timer(&skdev->timer, (jiffies + HZ));
	if (rc)
		dev_err(&skdev->pdev->dev, "failed to start timer %d\n", rc);
	return rc;
}

static void skd_kill_timer(struct skd_device *skdev)
{
	del_timer_sync(&skdev->timer);
}

/*
 *****************************************************************************
 * INTERNAL REQUESTS -- generated by driver itself
 *****************************************************************************
 */

static int skd_format_internal_skspcl(struct skd_device *skdev)
{
	struct skd_special_context *skspcl = &skdev->internal_skspcl;
	struct fit_sg_descriptor *sgd = &skspcl->req.sksg_list[0];
	struct fit_msg_hdr *fmh;
	uint64_t dma_address;
	struct skd_scsi_request *scsi;

	fmh = &skspcl->msg_buf->fmh;
	fmh->protocol_id = FIT_PROTOCOL_ID_SOFIT;
	fmh->num_protocol_cmds_coalesced = 1;

	scsi = &skspcl->msg_buf->scsi[0];
	memset(scsi, 0, sizeof(*scsi));
	dma_address = skspcl->req.sksg_dma_address;
	scsi->hdr.sg_list_dma_address = cpu_to_be64(dma_address);
	skspcl->req.n_sg = 1;
	sgd->control = FIT_SGD_CONTROL_LAST;
	sgd->byte_count = 0;
	sgd->host_side_addr = skspcl->db_dma_address;
	sgd->dev_side_addr = 0;
	sgd->next_desc_ptr = 0LL;

	return 1;
}

#define WR_BUF_SIZE SKD_N_INTERNAL_BYTES

static void skd_send_internal_skspcl(struct skd_device *skdev,
				     struct skd_special_context *skspcl,
				     u8 opcode)
{
	struct fit_sg_descriptor *sgd = &skspcl->req.sksg_list[0];
	struct skd_scsi_request *scsi;
	unsigned char *buf = skspcl->data_buf;
	int i;

	if (skspcl->req.state != SKD_REQ_STATE_IDLE)
		/*
		 * A refresh is already in progress.
		 * Just wait for it to finish.
		 */
		return;

	skspcl->req.state = SKD_REQ_STATE_BUSY;

	scsi = &skspcl->msg_buf->scsi[0];
	scsi->hdr.tag = skspcl->req.id;

	memset(scsi->cdb, 0, sizeof(scsi->cdb));

	switch (opcode) {
	case TEST_UNIT_READY:
		scsi->cdb[0] = TEST_UNIT_READY;
		sgd->byte_count = 0;
		scsi->hdr.sg_list_len_bytes = 0;
		break;

	case READ_CAPACITY:
		scsi->cdb[0] = READ_CAPACITY;
		sgd->byte_count = SKD_N_READ_CAP_BYTES;
		scsi->hdr.sg_list_len_bytes = cpu_to_be32(sgd->byte_count);
		break;

	case INQUIRY:
		scsi->cdb[0] = INQUIRY;
		scsi->cdb[1] = 0x01;    /* evpd */
		scsi->cdb[2] = 0x80;    /* serial number page */
		scsi->cdb[4] = 0x10;
		sgd->byte_count = 16;
		scsi->hdr.sg_list_len_bytes = cpu_to_be32(sgd->byte_count);
		break;

	case SYNCHRONIZE_CACHE:
		scsi->cdb[0] = SYNCHRONIZE_CACHE;
		sgd->byte_count = 0;
		scsi->hdr.sg_list_len_bytes = 0;
		break;

	case WRITE_BUFFER:
		scsi->cdb[0] = WRITE_BUFFER;
		scsi->cdb[1] = 0x02;
		scsi->cdb[7] = (WR_BUF_SIZE & 0xFF00) >> 8;
		scsi->cdb[8] = WR_BUF_SIZE & 0xFF;
		sgd->byte_count = WR_BUF_SIZE;
		scsi->hdr.sg_list_len_bytes = cpu_to_be32(sgd->byte_count);
		/* fill incrementing byte pattern */
		for (i = 0; i < sgd->byte_count; i++)
			buf[i] = i & 0xFF;
		break;

	case READ_BUFFER:
		scsi->cdb[0] = READ_BUFFER;
		scsi->cdb[1] = 0x02;
		scsi->cdb[7] = (WR_BUF_SIZE & 0xFF00) >> 8;
		scsi->cdb[8] = WR_BUF_SIZE & 0xFF;
		sgd->byte_count = WR_BUF_SIZE;
		scsi->hdr.sg_list_len_bytes = cpu_to_be32(sgd->byte_count);
		memset(skspcl->data_buf, 0, sgd->byte_count);
		break;

	default:
		SKD_ASSERT("Don't know what to send");
		return;

	}
	skd_send_special_fitmsg(skdev, skspcl);
}

static void skd_refresh_device_data(struct skd_device *skdev)
{
	struct skd_special_context *skspcl = &skdev->internal_skspcl;

	skd_send_internal_skspcl(skdev, skspcl, TEST_UNIT_READY);
}

static int skd_chk_read_buf(struct skd_device *skdev,
			    struct skd_special_context *skspcl)
{
	unsigned char *buf = skspcl->data_buf;
	int i;

	/* check for incrementing byte pattern */
	for (i = 0; i < WR_BUF_SIZE; i++)
		if (buf[i] != (i & 0xFF))
			return 1;

	return 0;
}

static void skd_log_check_status(struct skd_device *skdev, u8 status, u8 key,
				 u8 code, u8 qual, u8 fruc)
{
	/* If the check condition is of special interest, log a message */
	if ((status == SAM_STAT_CHECK_CONDITION) && (key == 0x02)
	    && (code == 0x04) && (qual == 0x06)) {
		dev_err(&skdev->pdev->dev,
			"*** LOST_WRITE_DATA ERROR *** key/asc/ascq/fruc %02x/%02x/%02x/%02x\n",
			key, code, qual, fruc);
	}
}

static void skd_complete_internal(struct skd_device *skdev,
				  struct fit_completion_entry_v1 *skcomp,
				  struct fit_comp_error_info *skerr,
				  struct skd_special_context *skspcl)
{
	u8 *buf = skspcl->data_buf;
	u8 status;
	int i;
	struct skd_scsi_request *scsi = &skspcl->msg_buf->scsi[0];

	lockdep_assert_held(&skdev->lock);

	SKD_ASSERT(skspcl == &skdev->internal_skspcl);

	dev_dbg(&skdev->pdev->dev, "complete internal %x\n", scsi->cdb[0]);

	dma_sync_single_for_cpu(&skdev->pdev->dev,
				skspcl->db_dma_address,
				skspcl->req.sksg_list[0].byte_count,
				DMA_BIDIRECTIONAL);

	skspcl->req.completion = *skcomp;
	skspcl->req.state = SKD_REQ_STATE_IDLE;

	status = skspcl->req.completion.status;

	skd_log_check_status(skdev, status, skerr->key, skerr->code,
			     skerr->qual, skerr->fruc);

	switch (scsi->cdb[0]) {
	case TEST_UNIT_READY:
		if (status == SAM_STAT_GOOD)
			skd_send_internal_skspcl(skdev, skspcl, WRITE_BUFFER);
		else if ((status == SAM_STAT_CHECK_CONDITION) &&
			 (skerr->key == MEDIUM_ERROR))
			skd_send_internal_skspcl(skdev, skspcl, WRITE_BUFFER);
		else {
			if (skdev->state == SKD_DRVR_STATE_STOPPING) {
				dev_dbg(&skdev->pdev->dev,
					"TUR failed, don't send anymore state 0x%x\n",
					skdev->state);
				return;
			}
			dev_dbg(&skdev->pdev->dev,
				"**** TUR failed, retry skerr\n");
			skd_send_internal_skspcl(skdev, skspcl,
						 TEST_UNIT_READY);
		}
		break;

	case WRITE_BUFFER:
		if (status == SAM_STAT_GOOD)
			skd_send_internal_skspcl(skdev, skspcl, READ_BUFFER);
		else {
			if (skdev->state == SKD_DRVR_STATE_STOPPING) {
				dev_dbg(&skdev->pdev->dev,
					"write buffer failed, don't send anymore state 0x%x\n",
					skdev->state);
				return;
			}
			dev_dbg(&skdev->pdev->dev,
				"**** write buffer failed, retry skerr\n");
			skd_send_internal_skspcl(skdev, skspcl,
						 TEST_UNIT_READY);
		}
		break;

	case READ_BUFFER:
		if (status == SAM_STAT_GOOD) {
			if (skd_chk_read_buf(skdev, skspcl) == 0)
				skd_send_internal_skspcl(skdev, skspcl,
							 READ_CAPACITY);
			else {
				dev_err(&skdev->pdev->dev,
					"*** W/R Buffer mismatch %d ***\n",
					skdev->connect_retries);
				if (skdev->connect_retries <
				    SKD_MAX_CONNECT_RETRIES) {
					skdev->connect_retries++;
					skd_soft_reset(skdev);
				} else {
					dev_err(&skdev->pdev->dev,
						"W/R Buffer Connect Error\n");
					return;
				}
			}

		} else {
			if (skdev->state == SKD_DRVR_STATE_STOPPING) {
				dev_dbg(&skdev->pdev->dev,
					"read buffer failed, don't send anymore state 0x%x\n",
					skdev->state);
				return;
			}
			dev_dbg(&skdev->pdev->dev,
				"**** read buffer failed, retry skerr\n");
			skd_send_internal_skspcl(skdev, skspcl,
						 TEST_UNIT_READY);
		}
		break;

	case READ_CAPACITY:
		skdev->read_cap_is_valid = 0;
		if (status == SAM_STAT_GOOD) {
			skdev->read_cap_last_lba =
				(buf[0] << 24) | (buf[1] << 16) |
				(buf[2] << 8) | buf[3];
			skdev->read_cap_blocksize =
				(buf[4] << 24) | (buf[5] << 16) |
				(buf[6] << 8) | buf[7];

			dev_dbg(&skdev->pdev->dev, "last lba %d, bs %d\n",
				skdev->read_cap_last_lba,
				skdev->read_cap_blocksize);

			set_capacity(skdev->disk, skdev->read_cap_last_lba + 1);

			skdev->read_cap_is_valid = 1;

			skd_send_internal_skspcl(skdev, skspcl, INQUIRY);
		} else if ((status == SAM_STAT_CHECK_CONDITION) &&
			   (skerr->key == MEDIUM_ERROR)) {
			skdev->read_cap_last_lba = ~0;
			set_capacity(skdev->disk, skdev->read_cap_last_lba + 1);
			dev_dbg(&skdev->pdev->dev, "**** MEDIUM ERROR caused READCAP to fail, ignore failure and continue to inquiry\n");
			skd_send_internal_skspcl(skdev, skspcl, INQUIRY);
		} else {
			dev_dbg(&skdev->pdev->dev, "**** READCAP failed, retry TUR\n");
			skd_send_internal_skspcl(skdev, skspcl,
						 TEST_UNIT_READY);
		}
		break;

	case INQUIRY:
		skdev->inquiry_is_valid = 0;
		if (status == SAM_STAT_GOOD) {
			skdev->inquiry_is_valid = 1;

			for (i = 0; i < 12; i++)
				skdev->inq_serial_num[i] = buf[i + 4];
			skdev->inq_serial_num[12] = 0;
		}

		if (skd_unquiesce_dev(skdev) < 0)
			dev_dbg(&skdev->pdev->dev, "**** failed, to ONLINE device\n");
		 /* connection is complete */
		skdev->connect_retries = 0;
		break;

	case SYNCHRONIZE_CACHE:
		if (status == SAM_STAT_GOOD)
			skdev->sync_done = 1;
		else
			skdev->sync_done = -1;
		wake_up_interruptible(&skdev->waitq);
		break;

	default:
		SKD_ASSERT("we didn't send this");
	}
}

/*
 *****************************************************************************
 * FIT MESSAGES
 *****************************************************************************
 */

static void skd_send_fitmsg(struct skd_device *skdev,
			    struct skd_fitmsg_context *skmsg)
{
	u64 qcmd;

	dev_dbg(&skdev->pdev->dev, "dma address %pad, busy=%d\n",
		&skmsg->mb_dma_address, skd_in_flight(skdev));
	dev_dbg(&skdev->pdev->dev, "msg_buf %p\n", skmsg->msg_buf);

	qcmd = skmsg->mb_dma_address;
	qcmd |= FIT_QCMD_QID_NORMAL;

	if (unlikely(skdev->dbg_level > 1)) {
		u8 *bp = (u8 *)skmsg->msg_buf;
		int i;
		for (i = 0; i < skmsg->length; i += 8) {
			dev_dbg(&skdev->pdev->dev, "msg[%2d] %8ph\n", i,
				&bp[i]);
			if (i == 0)
				i = 64 - 8;
		}
	}

	if (skmsg->length > 256)
		qcmd |= FIT_QCMD_MSGSIZE_512;
	else if (skmsg->length > 128)
		qcmd |= FIT_QCMD_MSGSIZE_256;
	else if (skmsg->length > 64)
		qcmd |= FIT_QCMD_MSGSIZE_128;
	else
		/*
		 * This makes no sense because the FIT msg header is
		 * 64 bytes. If the msg is only 64 bytes long it has
		 * no payload.
		 */
		qcmd |= FIT_QCMD_MSGSIZE_64;

	dma_sync_single_for_device(&skdev->pdev->dev, skmsg->mb_dma_address,
				   skmsg->length, DMA_TO_DEVICE);

	/* Make sure skd_msg_buf is written before the doorbell is triggered. */
	smp_wmb();

	SKD_WRITEQ(skdev, qcmd, FIT_Q_COMMAND);
}

static void skd_send_special_fitmsg(struct skd_device *skdev,
				    struct skd_special_context *skspcl)
{
	u64 qcmd;

	WARN_ON_ONCE(skspcl->req.n_sg != 1);

	if (unlikely(skdev->dbg_level > 1)) {
		u8 *bp = (u8 *)skspcl->msg_buf;
		int i;

		for (i = 0; i < SKD_N_SPECIAL_FITMSG_BYTES; i += 8) {
			dev_dbg(&skdev->pdev->dev, " spcl[%2d] %8ph\n", i,
				&bp[i]);
			if (i == 0)
				i = 64 - 8;
		}

		dev_dbg(&skdev->pdev->dev,
			"skspcl=%p id=%04x sksg_list=%p sksg_dma=%pad\n",
			skspcl, skspcl->req.id, skspcl->req.sksg_list,
			&skspcl->req.sksg_dma_address);
		for (i = 0; i < skspcl->req.n_sg; i++) {
			struct fit_sg_descriptor *sgd =
				&skspcl->req.sksg_list[i];

			dev_dbg(&skdev->pdev->dev,
				"  sg[%d] count=%u ctrl=0x%x addr=0x%llx next=0x%llx\n",
				i, sgd->byte_count, sgd->control,
				sgd->host_side_addr, sgd->next_desc_ptr);
		}
	}

	/*
	 * Special FIT msgs are always 128 bytes: a 64-byte FIT hdr
	 * and one 64-byte SSDI command.
	 */
	qcmd = skspcl->mb_dma_address;
	qcmd |= FIT_QCMD_QID_NORMAL + FIT_QCMD_MSGSIZE_128;

	dma_sync_single_for_device(&skdev->pdev->dev, skspcl->mb_dma_address,
				   SKD_N_SPECIAL_FITMSG_BYTES, DMA_TO_DEVICE);
	dma_sync_single_for_device(&skdev->pdev->dev,
				   skspcl->req.sksg_dma_address,
				   1 * sizeof(struct fit_sg_descriptor),
				   DMA_TO_DEVICE);
	dma_sync_single_for_device(&skdev->pdev->dev,
				   skspcl->db_dma_address,
				   skspcl->req.sksg_list[0].byte_count,
				   DMA_BIDIRECTIONAL);

	/* Make sure skd_msg_buf is written before the doorbell is triggered. */
	smp_wmb();

	SKD_WRITEQ(skdev, qcmd, FIT_Q_COMMAND);
}

/*
 *****************************************************************************
 * COMPLETION QUEUE
 *****************************************************************************
 */

static void skd_complete_other(struct skd_device *skdev,
			       struct fit_completion_entry_v1 *skcomp,
			       struct fit_comp_error_info *skerr);

struct sns_info {
	u8 type;
	u8 stat;
	u8 key;
	u8 asc;
	u8 ascq;
	u8 mask;
	enum skd_check_status_action action;
};

static struct sns_info skd_chkstat_table[] = {
	/* Good */
	{ 0x70, 0x02, RECOVERED_ERROR, 0,    0,	   0x1c,
	  SKD_CHECK_STATUS_REPORT_GOOD },

	/* Smart alerts */
	{ 0x70, 0x02, NO_SENSE,	       0x0B, 0x00, 0x1E,	/* warnings */
	  SKD_CHECK_STATUS_REPORT_SMART_ALERT },
	{ 0x70, 0x02, NO_SENSE,	       0x5D, 0x00, 0x1E,	/* thresholds */
	  SKD_CHECK_STATUS_REPORT_SMART_ALERT },
	{ 0x70, 0x02, RECOVERED_ERROR, 0x0B, 0x01, 0x1F,        /* temperature over trigger */
	  SKD_CHECK_STATUS_REPORT_SMART_ALERT },

	/* Retry (with limits) */
	{ 0x70, 0x02, 0x0B,	       0,    0,	   0x1C,        /* This one is for DMA ERROR */
	  SKD_CHECK_STATUS_REQUEUE_REQUEST },
	{ 0x70, 0x02, 0x06,	       0x0B, 0x00, 0x1E,        /* warnings */
	  SKD_CHECK_STATUS_REQUEUE_REQUEST },
	{ 0x70, 0x02, 0x06,	       0x5D, 0x00, 0x1E,        /* thresholds */
	  SKD_CHECK_STATUS_REQUEUE_REQUEST },
	{ 0x70, 0x02, 0x06,	       0x80, 0x30, 0x1F,        /* backup power */
	  SKD_CHECK_STATUS_REQUEUE_REQUEST },

	/* Busy (or about to be) */
	{ 0x70, 0x02, 0x06,	       0x3f, 0x01, 0x1F, /* fw changed */
	  SKD_CHECK_STATUS_BUSY_IMMINENT },
};

/*
 * Look up status and sense data to decide how to handle the error
 * from the device.
 * mask says which fields must match e.g., mask=0x18 means check
 * type and stat, ignore key, asc, ascq.
 */

static enum skd_check_status_action
skd_check_status(struct skd_device *skdev,
		 u8 cmp_status, struct fit_comp_error_info *skerr)
{
	int i;

	dev_err(&skdev->pdev->dev, "key/asc/ascq/fruc %02x/%02x/%02x/%02x\n",
		skerr->key, skerr->code, skerr->qual, skerr->fruc);

	dev_dbg(&skdev->pdev->dev,
		"stat: t=%02x stat=%02x k=%02x c=%02x q=%02x fruc=%02x\n",
		skerr->type, cmp_status, skerr->key, skerr->code, skerr->qual,
		skerr->fruc);

	/* Does the info match an entry in the good category? */
	for (i = 0; i < ARRAY_SIZE(skd_chkstat_table); i++) {
		struct sns_info *sns = &skd_chkstat_table[i];

		if (sns->mask & 0x10)
			if (skerr->type != sns->type)
				continue;

		if (sns->mask & 0x08)
			if (cmp_status != sns->stat)
				continue;

		if (sns->mask & 0x04)
			if (skerr->key != sns->key)
				continue;

		if (sns->mask & 0x02)
			if (skerr->code != sns->asc)
				continue;

		if (sns->mask & 0x01)
			if (skerr->qual != sns->ascq)
				continue;

		if (sns->action == SKD_CHECK_STATUS_REPORT_SMART_ALERT) {
			dev_err(&skdev->pdev->dev,
				"SMART Alert: sense key/asc/ascq %02x/%02x/%02x\n",
				skerr->key, skerr->code, skerr->qual);
		}
		return sns->action;
	}

	/* No other match, so nonzero status means error,
	 * zero status means good
	 */
	if (cmp_status) {
		dev_dbg(&skdev->pdev->dev, "status check: error\n");
		return SKD_CHECK_STATUS_REPORT_ERROR;
	}

	dev_dbg(&skdev->pdev->dev, "status check good default\n");
	return SKD_CHECK_STATUS_REPORT_GOOD;
}

static void skd_resolve_req_exception(struct skd_device *skdev,
				      struct skd_request_context *skreq,
				      struct request *req)
{
	u8 cmp_status = skreq->completion.status;

	switch (skd_check_status(skdev, cmp_status, &skreq->err_info)) {
	case SKD_CHECK_STATUS_REPORT_GOOD:
	case SKD_CHECK_STATUS_REPORT_SMART_ALERT:
		skreq->status = BLK_STS_OK;
		blk_mq_complete_request(req);
		break;

	case SKD_CHECK_STATUS_BUSY_IMMINENT:
		skd_log_skreq(skdev, skreq, "retry(busy)");
		blk_mq_requeue_request(req, true);
		dev_info(&skdev->pdev->dev, "drive BUSY imminent\n");
		skdev->state = SKD_DRVR_STATE_BUSY_IMMINENT;
		skdev->timer_countdown = SKD_TIMER_MINUTES(20);
		skd_quiesce_dev(skdev);
		break;

	case SKD_CHECK_STATUS_REQUEUE_REQUEST:
		if (++skreq->retries < SKD_MAX_RETRIES) {
			skd_log_skreq(skdev, skreq, "retry");
			blk_mq_requeue_request(req, true);
			break;
		}
		/* fall through */

	case SKD_CHECK_STATUS_REPORT_ERROR:
	default:
		skreq->status = BLK_STS_IOERR;
		blk_mq_complete_request(req);
		break;
	}
}

static void skd_release_skreq(struct skd_device *skdev,
			      struct skd_request_context *skreq)
{
	/*
	 * Reclaim the skd_request_context
	 */
	skreq->state = SKD_REQ_STATE_IDLE;
}

static int skd_isr_completion_posted(struct skd_device *skdev,
					int limit, int *enqueued)
{
	struct fit_completion_entry_v1 *skcmp;
	struct fit_comp_error_info *skerr;
	u16 req_id;
	u32 tag;
	u16 hwq = 0;
	struct request *rq;
	struct skd_request_context *skreq;
	u16 cmp_cntxt;
	u8 cmp_status;
	u8 cmp_cycle;
	u32 cmp_bytes;
	int rc = 0;
	int processed = 0;

	lockdep_assert_held(&skdev->lock);

	for (;; ) {
		SKD_ASSERT(skdev->skcomp_ix < SKD_N_COMPLETION_ENTRY);

		skcmp = &skdev->skcomp_table[skdev->skcomp_ix];
		cmp_cycle = skcmp->cycle;
		cmp_cntxt = skcmp->tag;
		cmp_status = skcmp->status;
		cmp_bytes = be32_to_cpu(skcmp->num_returned_bytes);

		skerr = &skdev->skerr_table[skdev->skcomp_ix];

		dev_dbg(&skdev->pdev->dev,
			"cycle=%d ix=%d got cycle=%d cmdctxt=0x%x stat=%d busy=%d rbytes=0x%x proto=%d\n",
			skdev->skcomp_cycle, skdev->skcomp_ix, cmp_cycle,
			cmp_cntxt, cmp_status, skd_in_flight(skdev),
			cmp_bytes, skdev->proto_ver);

		if (cmp_cycle != skdev->skcomp_cycle) {
			dev_dbg(&skdev->pdev->dev, "end of completions\n");
			break;
		}
		/*
		 * Update the completion queue head index and possibly
		 * the completion cycle count. 8-bit wrap-around.
		 */
		skdev->skcomp_ix++;
		if (skdev->skcomp_ix >= SKD_N_COMPLETION_ENTRY) {
			skdev->skcomp_ix = 0;
			skdev->skcomp_cycle++;
		}

		/*
		 * The command context is a unique 32-bit ID. The low order
		 * bits help locate the request. The request is usually a
		 * r/w request (see skd_start() above) or a special request.
		 */
		req_id = cmp_cntxt;
		tag = req_id & SKD_ID_SLOT_AND_TABLE_MASK;

		/* Is this other than a r/w request? */
		if (tag >= skdev->num_req_context) {
			/*
			 * This is not a completion for a r/w request.
			 */
			WARN_ON_ONCE(blk_mq_tag_to_rq(skdev->tag_set.tags[hwq],
						      tag));
			skd_complete_other(skdev, skcmp, skerr);
			continue;
		}

		rq = blk_mq_tag_to_rq(skdev->tag_set.tags[hwq], tag);
		if (WARN(!rq, "No request for tag %#x -> %#x\n", cmp_cntxt,
			 tag))
			continue;
		skreq = blk_mq_rq_to_pdu(rq);

		/*
		 * Make sure the request ID for the slot matches.
		 */
		if (skreq->id != req_id) {
			dev_err(&skdev->pdev->dev,
				"Completion mismatch comp_id=0x%04x skreq=0x%04x new=0x%04x\n",
				req_id, skreq->id, cmp_cntxt);

			continue;
		}

		SKD_ASSERT(skreq->state == SKD_REQ_STATE_BUSY);

		skreq->completion = *skcmp;
		if (unlikely(cmp_status == SAM_STAT_CHECK_CONDITION)) {
			skreq->err_info = *skerr;
			skd_log_check_status(skdev, cmp_status, skerr->key,
					     skerr->code, skerr->qual,
					     skerr->fruc);
		}
		/* Release DMA resources for the request. */
		if (skreq->n_sg > 0)
			skd_postop_sg_list(skdev, skreq);

		skd_release_skreq(skdev, skreq);

		/*
		 * Capture the outcome and post it back to the native request.
		 */
		if (likely(cmp_status == SAM_STAT_GOOD)) {
			skreq->status = BLK_STS_OK;
			blk_mq_complete_request(rq);
		} else {
			skd_resolve_req_exception(skdev, skreq, rq);
		}

		/* skd_isr_comp_limit equal zero means no limit */
		if (limit) {
			if (++processed >= limit) {
				rc = 1;
				break;
			}
		}
	}

	if (skdev->state == SKD_DRVR_STATE_PAUSING &&
	    skd_in_flight(skdev) == 0) {
		skdev->state = SKD_DRVR_STATE_PAUSED;
		wake_up_interruptible(&skdev->waitq);
	}

	return rc;
}

static void skd_complete_other(struct skd_device *skdev,
			       struct fit_completion_entry_v1 *skcomp,
			       struct fit_comp_error_info *skerr)
{
	u32 req_id = 0;
	u32 req_table;
	u32 req_slot;
	struct skd_special_context *skspcl;

	lockdep_assert_held(&skdev->lock);

	req_id = skcomp->tag;
	req_table = req_id & SKD_ID_TABLE_MASK;
	req_slot = req_id & SKD_ID_SLOT_MASK;

	dev_dbg(&skdev->pdev->dev, "table=0x%x id=0x%x slot=%d\n", req_table,
		req_id, req_slot);

	/*
	 * Based on the request id, determine how to dispatch this completion.
	 * This swich/case is finding the good cases and forwarding the
	 * completion entry. Errors are reported below the switch.
	 */
	switch (req_table) {
	case SKD_ID_RW_REQUEST:
		/*
		 * The caller, skd_isr_completion_posted() above,
		 * handles r/w requests. The only way we get here
		 * is if the req_slot is out of bounds.
		 */
		break;

	case SKD_ID_INTERNAL:
		if (req_slot == 0) {
			skspcl = &skdev->internal_skspcl;
			if (skspcl->req.id == req_id &&
			    skspcl->req.state == SKD_REQ_STATE_BUSY) {
				skd_complete_internal(skdev,
						      skcomp, skerr, skspcl);
				return;
			}
		}
		break;

	case SKD_ID_FIT_MSG:
		/*
		 * These id's should never appear in a completion record.
		 */
		break;

	default:
		/*
		 * These id's should never appear anywhere;
		 */
		break;
	}

	/*
	 * If we get here it is a bad or stale id.
	 */
}

static void skd_reset_skcomp(struct skd_device *skdev)
{
	memset(skdev->skcomp_table, 0, SKD_SKCOMP_SIZE);

	skdev->skcomp_ix = 0;
	skdev->skcomp_cycle = 1;
}

/*
 *****************************************************************************
 * INTERRUPTS
 *****************************************************************************
 */
static void skd_completion_worker(struct work_struct *work)
{
	struct skd_device *skdev =
		container_of(work, struct skd_device, completion_worker);
	unsigned long flags;
	int flush_enqueued = 0;

	spin_lock_irqsave(&skdev->lock, flags);

	/*
	 * pass in limit=0, which means no limit..
	 * process everything in compq
	 */
	skd_isr_completion_posted(skdev, 0, &flush_enqueued);
	schedule_work(&skdev->start_queue);

	spin_unlock_irqrestore(&skdev->lock, flags);
}

static void skd_isr_msg_from_dev(struct skd_device *skdev);

static irqreturn_t
skd_isr(int irq, void *ptr)
{
	struct skd_device *skdev = ptr;
	u32 intstat;
	u32 ack;
	int rc = 0;
	int deferred = 0;
	int flush_enqueued = 0;

	spin_lock(&skdev->lock);

	for (;; ) {
		intstat = SKD_READL(skdev, FIT_INT_STATUS_HOST);

		ack = FIT_INT_DEF_MASK;
		ack &= intstat;

		dev_dbg(&skdev->pdev->dev, "intstat=0x%x ack=0x%x\n", intstat,
			ack);

		/* As long as there is an int pending on device, keep
		 * running loop.  When none, get out, but if we've never
		 * done any processing, call completion handler?
		 */
		if (ack == 0) {
			/* No interrupts on device, but run the completion
			 * processor anyway?
			 */
			if (rc == 0)
				if (likely (skdev->state
					== SKD_DRVR_STATE_ONLINE))
					deferred = 1;
			break;
		}

		rc = IRQ_HANDLED;

		SKD_WRITEL(skdev, ack, FIT_INT_STATUS_HOST);

		if (likely((skdev->state != SKD_DRVR_STATE_LOAD) &&
			   (skdev->state != SKD_DRVR_STATE_STOPPING))) {
			if (intstat & FIT_ISH_COMPLETION_POSTED) {
				/*
				 * If we have already deferred completion
				 * processing, don't bother running it again
				 */
				if (deferred == 0)
					deferred =
						skd_isr_completion_posted(skdev,
						skd_isr_comp_limit, &flush_enqueued);
			}

			if (intstat & FIT_ISH_FW_STATE_CHANGE) {
				skd_isr_fwstate(skdev);
				if (skdev->state == SKD_DRVR_STATE_FAULT ||
				    skdev->state ==
				    SKD_DRVR_STATE_DISAPPEARED) {
					spin_unlock(&skdev->lock);
					return rc;
				}
			}

			if (intstat & FIT_ISH_MSG_FROM_DEV)
				skd_isr_msg_from_dev(skdev);
		}
	}

	if (unlikely(flush_enqueued))
		schedule_work(&skdev->start_queue);

	if (deferred)
		schedule_work(&skdev->completion_worker);
	else if (!flush_enqueued)
		schedule_work(&skdev->start_queue);

	spin_unlock(&skdev->lock);

	return rc;
}

static void skd_drive_fault(struct skd_device *skdev)
{
	skdev->state = SKD_DRVR_STATE_FAULT;
	dev_err(&skdev->pdev->dev, "Drive FAULT\n");
}

static void skd_drive_disappeared(struct skd_device *skdev)
{
	skdev->state = SKD_DRVR_STATE_DISAPPEARED;
	dev_err(&skdev->pdev->dev, "Drive DISAPPEARED\n");
}

static void skd_isr_fwstate(struct skd_device *skdev)
{
	u32 sense;
	u32 state;
	u32 mtd;
	int prev_driver_state = skdev->state;

	sense = SKD_READL(skdev, FIT_STATUS);
	state = sense & FIT_SR_DRIVE_STATE_MASK;

	dev_err(&skdev->pdev->dev, "s1120 state %s(%d)=>%s(%d)\n",
		skd_drive_state_to_str(skdev->drive_state), skdev->drive_state,
		skd_drive_state_to_str(state), state);

	skdev->drive_state = state;

	switch (skdev->drive_state) {
	case FIT_SR_DRIVE_INIT:
		if (skdev->state == SKD_DRVR_STATE_PROTOCOL_MISMATCH) {
			skd_disable_interrupts(skdev);
			break;
		}
		if (skdev->state == SKD_DRVR_STATE_RESTARTING)
			skd_recover_requests(skdev);
		if (skdev->state == SKD_DRVR_STATE_WAIT_BOOT) {
			skdev->timer_countdown = SKD_STARTING_TIMO;
			skdev->state = SKD_DRVR_STATE_STARTING;
			skd_soft_reset(skdev);
			break;
		}
		mtd = FIT_MXD_CONS(FIT_MTD_FITFW_INIT, 0, 0);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_SR_DRIVE_ONLINE:
		skdev->cur_max_queue_depth = skd_max_queue_depth;
		if (skdev->cur_max_queue_depth > skdev->dev_max_queue_depth)
			skdev->cur_max_queue_depth = skdev->dev_max_queue_depth;

		skdev->queue_low_water_mark =
			skdev->cur_max_queue_depth * 2 / 3 + 1;
		if (skdev->queue_low_water_mark < 1)
			skdev->queue_low_water_mark = 1;
		dev_info(&skdev->pdev->dev,
			 "Queue depth limit=%d dev=%d lowat=%d\n",
			 skdev->cur_max_queue_depth,
			 skdev->dev_max_queue_depth,
			 skdev->queue_low_water_mark);

		skd_refresh_device_data(skdev);
		break;

	case FIT_SR_DRIVE_BUSY:
		skdev->state = SKD_DRVR_STATE_BUSY;
		skdev->timer_countdown = SKD_BUSY_TIMO;
		skd_quiesce_dev(skdev);
		break;
	case FIT_SR_DRIVE_BUSY_SANITIZE:
		/* set timer for 3 seconds, we'll abort any unfinished
		 * commands after that expires
		 */
		skdev->state = SKD_DRVR_STATE_BUSY_SANITIZE;
		skdev->timer_countdown = SKD_TIMER_SECONDS(3);
		schedule_work(&skdev->start_queue);
		break;
	case FIT_SR_DRIVE_BUSY_ERASE:
		skdev->state = SKD_DRVR_STATE_BUSY_ERASE;
		skdev->timer_countdown = SKD_BUSY_TIMO;
		break;
	case FIT_SR_DRIVE_OFFLINE:
		skdev->state = SKD_DRVR_STATE_IDLE;
		break;
	case FIT_SR_DRIVE_SOFT_RESET:
		switch (skdev->state) {
		case SKD_DRVR_STATE_STARTING:
		case SKD_DRVR_STATE_RESTARTING:
			/* Expected by a caller of skd_soft_reset() */
			break;
		default:
			skdev->state = SKD_DRVR_STATE_RESTARTING;
			break;
		}
		break;
	case FIT_SR_DRIVE_FW_BOOTING:
		dev_dbg(&skdev->pdev->dev, "ISR FIT_SR_DRIVE_FW_BOOTING\n");
		skdev->state = SKD_DRVR_STATE_WAIT_BOOT;
		skdev->timer_countdown = SKD_WAIT_BOOT_TIMO;
		break;

	case FIT_SR_DRIVE_DEGRADED:
	case FIT_SR_PCIE_LINK_DOWN:
	case FIT_SR_DRIVE_NEED_FW_DOWNLOAD:
		break;

	case FIT_SR_DRIVE_FAULT:
		skd_drive_fault(skdev);
		skd_recover_requests(skdev);
		schedule_work(&skdev->start_queue);
		break;

	/* PCIe bus returned all Fs? */
	case 0xFF:
		dev_info(&skdev->pdev->dev, "state=0x%x sense=0x%x\n", state,
			 sense);
		skd_drive_disappeared(skdev);
		skd_recover_requests(skdev);
		schedule_work(&skdev->start_queue);
		break;
	default:
		/*
		 * Uknown FW State. Wait for a state we recognize.
		 */
		break;
	}
	dev_err(&skdev->pdev->dev, "Driver state %s(%d)=>%s(%d)\n",
		skd_skdev_state_to_str(prev_driver_state), prev_driver_state,
		skd_skdev_state_to_str(skdev->state), skdev->state);
}

static bool skd_recover_request(struct request *req, void *data, bool reserved)
{
	struct skd_device *const skdev = data;
	struct skd_request_context *skreq = blk_mq_rq_to_pdu(req);

	if (skreq->state != SKD_REQ_STATE_BUSY)
		return true;

	skd_log_skreq(skdev, skreq, "recover");

	/* Release DMA resources for the request. */
	if (skreq->n_sg > 0)
		skd_postop_sg_list(skdev, skreq);

	skreq->state = SKD_REQ_STATE_IDLE;
	skreq->status = BLK_STS_IOERR;
	blk_mq_complete_request(req);
	return true;
}

static void skd_recover_requests(struct skd_device *skdev)
{
	blk_mq_tagset_busy_iter(&skdev->tag_set, skd_recover_request, skdev);
}

static void skd_isr_msg_from_dev(struct skd_device *skdev)
{
	u32 mfd;
	u32 mtd;
	u32 data;

	mfd = SKD_READL(skdev, FIT_MSG_FROM_DEVICE);

	dev_dbg(&skdev->pdev->dev, "mfd=0x%x last_mtd=0x%x\n", mfd,
		skdev->last_mtd);

	/* ignore any mtd that is an ack for something we didn't send */
	if (FIT_MXD_TYPE(mfd) != FIT_MXD_TYPE(skdev->last_mtd))
		return;

	switch (FIT_MXD_TYPE(mfd)) {
	case FIT_MTD_FITFW_INIT:
		skdev->proto_ver = FIT_PROTOCOL_MAJOR_VER(mfd);

		if (skdev->proto_ver != FIT_PROTOCOL_VERSION_1) {
			dev_err(&skdev->pdev->dev, "protocol mismatch\n");
			dev_err(&skdev->pdev->dev, "  got=%d support=%d\n",
				skdev->proto_ver, FIT_PROTOCOL_VERSION_1);
			dev_err(&skdev->pdev->dev, "  please upgrade driver\n");
			skdev->state = SKD_DRVR_STATE_PROTOCOL_MISMATCH;
			skd_soft_reset(skdev);
			break;
		}
		mtd = FIT_MXD_CONS(FIT_MTD_GET_CMDQ_DEPTH, 0, 0);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_GET_CMDQ_DEPTH:
		skdev->dev_max_queue_depth = FIT_MXD_DATA(mfd);
		mtd = FIT_MXD_CONS(FIT_MTD_SET_COMPQ_DEPTH, 0,
				   SKD_N_COMPLETION_ENTRY);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_SET_COMPQ_DEPTH:
		SKD_WRITEQ(skdev, skdev->cq_dma_address, FIT_MSG_TO_DEVICE_ARG);
		mtd = FIT_MXD_CONS(FIT_MTD_SET_COMPQ_ADDR, 0, 0);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_SET_COMPQ_ADDR:
		skd_reset_skcomp(skdev);
		mtd = FIT_MXD_CONS(FIT_MTD_CMD_LOG_HOST_ID, 0, skdev->devno);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_CMD_LOG_HOST_ID:
		/* hardware interface overflows in y2106 */
		skdev->connect_time_stamp = (u32)ktime_get_real_seconds();
		data = skdev->connect_time_stamp & 0xFFFF;
		mtd = FIT_MXD_CONS(FIT_MTD_CMD_LOG_TIME_STAMP_LO, 0, data);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_CMD_LOG_TIME_STAMP_LO:
		skdev->drive_jiffies = FIT_MXD_DATA(mfd);
		data = (skdev->connect_time_stamp >> 16) & 0xFFFF;
		mtd = FIT_MXD_CONS(FIT_MTD_CMD_LOG_TIME_STAMP_HI, 0, data);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;
		break;

	case FIT_MTD_CMD_LOG_TIME_STAMP_HI:
		skdev->drive_jiffies |= (FIT_MXD_DATA(mfd) << 16);
		mtd = FIT_MXD_CONS(FIT_MTD_ARM_QUEUE, 0, 0);
		SKD_WRITEL(skdev, mtd, FIT_MSG_TO_DEVICE);
		skdev->last_mtd = mtd;

		dev_err(&skdev->pdev->dev, "Time sync driver=0x%x device=0x%x\n",
			skdev->connect_time_stamp, skdev->drive_jiffies);
		break;

	case FIT_MTD_ARM_QUEUE:
		skdev->last_mtd = 0;
		/*
		 * State should be, or soon will be, FIT_SR_DRIVE_ONLINE.
		 */
		break;

	default:
		break;
	}
}

static void skd_disable_interrupts(struct skd_device *skdev)
{
	u32 sense;

	sense = SKD_READL(skdev, FIT_CONTROL);
	sense &= ~FIT_CR_ENABLE_INTERRUPTS;
	SKD_WRITEL(skdev, sense, FIT_CONTROL);
	dev_dbg(&skdev->pdev->dev, "sense 0x%x\n", sense);

	/* Note that the 1s is written. A 1-bit means
	 * disable, a 0 means enable.
	 */
	SKD_WRITEL(skdev, ~0, FIT_INT_MASK_HOST);
}

static void skd_enable_interrupts(struct skd_device *skdev)
{
	u32 val;

	/* unmask interrupts first */
	val = FIT_ISH_FW_STATE_CHANGE +
	      FIT_ISH_COMPLETION_POSTED + FIT_ISH_MSG_FROM_DEV;

	/* Note that the compliment of mask is written. A 1-bit means
	 * disable, a 0 means enable. */
	SKD_WRITEL(skdev, ~val, FIT_INT_MASK_HOST);
	dev_dbg(&skdev->pdev->dev, "interrupt mask=0x%x\n", ~val);

	val = SKD_READL(skdev, FIT_CONTROL);
	val |= FIT_CR_ENABLE_INTERRUPTS;
	dev_dbg(&skdev->pdev->dev, "control=0x%x\n", val);
	SKD_WRITEL(skdev, val, FIT_CONTROL);
}

/*
 *****************************************************************************
 * START, STOP, RESTART, QUIESCE, UNQUIESCE
 *****************************************************************************
 */

static void skd_soft_reset(struct skd_device *skdev)
{
	u32 val;

	val = SKD_READL(skdev, FIT_CONTROL);
	val |= (FIT_CR_SOFT_RESET);
	dev_dbg(&skdev->pdev->dev, "control=0x%x\n", val);
	SKD_WRITEL(skdev, val, FIT_CONTROL);
}

static void skd_start_device(struct skd_device *skdev)
{
	unsigned long flags;
	u32 sense;
	u32 state;

	spin_lock_irqsave(&skdev->lock, flags);

	/* ack all ghost interrupts */
	SKD_WRITEL(skdev, FIT_INT_DEF_MASK, FIT_INT_STATUS_HOST);

	sense = SKD_READL(skdev, FIT_STATUS);

	dev_dbg(&skdev->pdev->dev, "initial status=0x%x\n", sense);

	state = sense & FIT_SR_DRIVE_STATE_MASK;
	skdev->drive_state = state;
	skdev->last_mtd = 0;

	skdev->state = SKD_DRVR_STATE_STARTING;
	skdev->timer_countdown = SKD_STARTING_TIMO;

	skd_enable_interrupts(skdev);

	switch (skdev->drive_state) {
	case FIT_SR_DRIVE_OFFLINE:
		dev_err(&skdev->pdev->dev, "Drive offline...\n");
		break;

	case FIT_SR_DRIVE_FW_BOOTING:
		dev_dbg(&skdev->pdev->dev, "FIT_SR_DRIVE_FW_BOOTING\n");
		skdev->state = SKD_DRVR_STATE_WAIT_BOOT;
		skdev->timer_countdown = SKD_WAIT_BOOT_TIMO;
		break;

	case FIT_SR_DRIVE_BUSY_SANITIZE:
		dev_info(&skdev->pdev->dev, "Start: BUSY_SANITIZE\n");
		skdev->state = SKD_DRVR_STATE_BUSY_SANITIZE;
		skdev->timer_countdown = SKD_STARTED_BUSY_TIMO;
		break;

	case FIT_SR_DRIVE_BUSY_ERASE:
		dev_info(&skdev->pdev->dev, "Start: BUSY_ERASE\n");
		skdev->state = SKD_DRVR_STATE_BUSY_ERASE;
		skdev->timer_countdown = SKD_STARTED_BUSY_TIMO;
		break;

	case FIT_SR_DRIVE_INIT:
	case FIT_SR_DRIVE_ONLINE:
		skd_soft_reset(skdev);
		break;

	case FIT_SR_DRIVE_BUSY:
		dev_err(&skdev->pdev->dev, "Drive Busy...\n");
		skdev->state = SKD_DRVR_STATE_BUSY;
		skdev->timer_countdown = SKD_STARTED_BUSY_TIMO;
		break;

	case FIT_SR_DRIVE_SOFT_RESET:
		dev_err(&skdev->pdev->dev, "drive soft reset in prog\n");
		break;

	case FIT_SR_DRIVE_FAULT:
		/* Fault state is bad...soft reset won't do it...
		 * Hard reset, maybe, but does it work on device?
		 * For now, just fault so the system doesn't hang.
		 */
		skd_drive_fault(skdev);
		/*start the queue so we can respond with error to requests */
		dev_dbg(&skdev->pdev->dev, "starting queue\n");
		schedule_work(&skdev->start_queue);
		skdev->gendisk_on = -1;
		wake_up_interruptible(&skdev->waitq);
		break;

	case 0xFF:
		/* Most likely the device isn't there or isn't responding
		 * to the BAR1 addresses. */
		skd_drive_disappeared(skdev);
		/*start the queue so we can respond with error to requests */
		dev_dbg(&skdev->pdev->dev,
			"starting queue to error-out reqs\n");
		schedule_work(&skdev->start_queue);
		skdev->gendisk_on = -1;
		wake_up_interruptible(&skdev->waitq);
		break;

	default:
		dev_err(&skdev->pdev->dev, "Start: unknown state %x\n",
			skdev->drive_state);
		break;
	}

	state = SKD_READL(skdev, FIT_CONTROL);
	dev_dbg(&skdev->pdev->dev, "FIT Control Status=0x%x\n", state);

	state = SKD_READL(skdev, FIT_INT_STATUS_HOST);
	dev_dbg(&skdev->pdev->dev, "Intr Status=0x%x\n", state);

	state = SKD_READL(skdev, FIT_INT_MASK_HOST);
	dev_dbg(&skdev->pdev->dev, "Intr Mask=0x%x\n", state);

	state = SKD_READL(skdev, FIT_MSG_FROM_DEVICE);
	dev_dbg(&skdev->pdev->dev, "Msg from Dev=0x%x\n", state);

	state = SKD_READL(skdev, FIT_HW_VERSION);
	dev_dbg(&skdev->pdev->dev, "HW version=0x%x\n", state);

	spin_unlock_irqrestore(&skdev->lock, flags);
}

static void skd_stop_device(struct skd_device *skdev)
{
	unsigned long flags;
	struct skd_special_context *skspcl = &skdev->internal_skspcl;
	u32 dev_state;
	int i;

	spin_lock_irqsave(&skdev->lock, flags);

	if (skdev->state != SKD_DRVR_STATE_ONLINE) {
		dev_err(&skdev->pdev->dev, "%s not online no sync\n", __func__);
		goto stop_out;
	}

	if (skspcl->req.state != SKD_REQ_STATE_IDLE) {
		dev_err(&skdev->pdev->dev, "%s no special\n", __func__);
		goto stop_out;
	}

	skdev->state = SKD_DRVR_STATE_SYNCING;
	skdev->sync_done = 0;

	skd_send_internal_skspcl(skdev, skspcl, SYNCHRONIZE_CACHE);

	spin_unlock_irqrestore(&skdev->lock, flags);

	wait_event_interruptible_timeout(skdev->waitq,
					 (skdev->sync_done), (10 * HZ));

	spin_lock_irqsave(&skdev->lock, flags);

	switch (skdev->sync_done) {
	case 0:
		dev_err(&skdev->pdev->dev, "%s no sync\n", __func__);
		break;
	case 1:
		dev_err(&skdev->pdev->dev, "%s sync done\n", __func__);
		break;
	default:
		dev_err(&skdev->pdev->dev, "%s sync error\n", __func__);
	}

stop_out:
	skdev->state = SKD_DRVR_STATE_STOPPING;
	spin_unlock_irqrestore(&skdev->lock, flags);

	skd_kill_timer(skdev);

	spin_lock_irqsave(&skdev->lock, flags);
	skd_disable_interrupts(skdev);

	/* ensure all ints on device are cleared */
	/* soft reset the device to unload with a clean slate */
	SKD_WRITEL(skdev, FIT_INT_DEF_MASK, FIT_INT_STATUS_HOST);
	SKD_WRITEL(skdev, FIT_CR_SOFT_RESET, FIT_CONTROL);

	spin_unlock_irqrestore(&skdev->lock, flags);

	/* poll every 100ms, 1 second timeout */
	for (i = 0; i < 10; i++) {
		dev_state =
			SKD_READL(skdev, FIT_STATUS) & FIT_SR_DRIVE_STATE_MASK;
		if (dev_state == FIT_SR_DRIVE_INIT)
			break;
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(msecs_to_jiffies(100));
	}

	if (dev_state != FIT_SR_DRIVE_INIT)
		dev_err(&skdev->pdev->dev, "%s state error 0x%02x\n", __func__,
			dev_state);
}

/* assume spinlock is held */
static void skd_restart_device(struct skd_device *skdev)
{
	u32 state;

	/* ack all ghost interrupts */
	SKD_WRITEL(skdev, FIT_INT_DEF_MASK, FIT_INT_STATUS_HOST);

	state = SKD_READL(skdev, FIT_STATUS);

	dev_dbg(&skdev->pdev->dev, "drive status=0x%x\n", state);

	state &= FIT_SR_DRIVE_STATE_MASK;
	skdev->drive_state = state;
	skdev->last_mtd = 0;

	skdev->state = SKD_DRVR_STATE_RESTARTING;
	skdev->timer_countdown = SKD_RESTARTING_TIMO;

	skd_soft_reset(skdev);
}

/* assume spinlock is held */
static int skd_quiesce_dev(struct skd_device *skdev)
{
	int rc = 0;

	switch (skdev->state) {
	case SKD_DRVR_STATE_BUSY:
	case SKD_DRVR_STATE_BUSY_IMMINENT:
		dev_dbg(&skdev->pdev->dev, "stopping queue\n");
		blk_mq_stop_hw_queues(skdev->queue);
		break;
	case SKD_DRVR_STATE_ONLINE:
	case SKD_DRVR_STATE_STOPPING:
	case SKD_DRVR_STATE_SYNCING:
	case SKD_DRVR_STATE_PAUSING:
	case SKD_DRVR_STATE_PAUSED:
	case SKD_DRVR_STATE_STARTING:
	case SKD_DRVR_STATE_RESTARTING:
	case SKD_DRVR_STATE_RESUMING:
	default:
		rc = -EINVAL;
		dev_dbg(&skdev->pdev->dev, "state [%d] not implemented\n",
			skdev->state);
	}
	return rc;
}

/* assume spinlock is held */
static int skd_unquiesce_dev(struct skd_device *skdev)
{
	int prev_driver_state = skdev->state;

	skd_log_skdev(skdev, "unquiesce");
	if (skdev->state == SKD_DRVR_STATE_ONLINE) {
		dev_dbg(&skdev->pdev->dev, "**** device already ONLINE\n");
		return 0;
	}
	if (skdev->drive_state != FIT_SR_DRIVE_ONLINE) {
		/*
		 * If there has been an state change to other than
		 * ONLINE, we will rely on controller state change
		 * to come back online and restart the queue.
		 * The BUSY state means that driver is ready to
		 * continue normal processing but waiting for controller
		 * to become available.
		 */
		skdev->state = SKD_DRVR_STATE_BUSY;
		dev_dbg(&skdev->pdev->dev, "drive BUSY state\n");
		return 0;
	}

	/*
	 * Drive has just come online, driver is either in startup,
	 * paused performing a task, or bust waiting for hardware.
	 */
	switch (skdev->state) {
	case SKD_DRVR_STATE_PAUSED:
	case SKD_DRVR_STATE_BUSY:
	case SKD_DRVR_STATE_BUSY_IMMINENT:
	case SKD_DRVR_STATE_BUSY_ERASE:
	case SKD_DRVR_STATE_STARTING:
	case SKD_DRVR_STATE_RESTARTING:
	case SKD_DRVR_STATE_FAULT:
	case SKD_DRVR_STATE_IDLE:
	case SKD_DRVR_STATE_LOAD:
		skdev->state = SKD_DRVR_STATE_ONLINE;
		dev_err(&skdev->pdev->dev, "Driver state %s(%d)=>%s(%d)\n",
			skd_skdev_state_to_str(prev_driver_state),
			prev_driver_state, skd_skdev_state_to_str(skdev->state),
			skdev->state);
		dev_dbg(&skdev->pdev->dev,
			"**** device ONLINE...starting block queue\n");
		dev_dbg(&skdev->pdev->dev, "starting queue\n");
		dev_info(&skdev->pdev->dev, "STEC s1120 ONLINE\n");
		schedule_work(&skdev->start_queue);
		skdev->gendisk_on = 1;
		wake_up_interruptible(&skdev->waitq);
		break;

	case SKD_DRVR_STATE_DISAPPEARED:
	default:
		dev_dbg(&skdev->pdev->dev,
			"**** driver state %d, not implemented\n",
			skdev->state);
		return -EBUSY;
	}
	return 0;
}

/*
 *****************************************************************************
 * PCIe MSI/MSI-X INTERRUPT HANDLERS
 *****************************************************************************
 */

static irqreturn_t skd_reserved_isr(int irq, void *skd_host_data)
{
	struct skd_device *skdev = skd_host_data;
	unsigned long flags;

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "MSIX = 0x%x\n",
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	dev_err(&skdev->pdev->dev, "MSIX reserved irq %d = 0x%x\n", irq,
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	SKD_WRITEL(skdev, FIT_INT_RESERVED_MASK, FIT_INT_STATUS_HOST);
	spin_unlock_irqrestore(&skdev->lock, flags);
	return IRQ_HANDLED;
}

static irqreturn_t skd_statec_isr(int irq, void *skd_host_data)
{
	struct skd_device *skdev = skd_host_data;
	unsigned long flags;

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "MSIX = 0x%x\n",
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	SKD_WRITEL(skdev, FIT_ISH_FW_STATE_CHANGE, FIT_INT_STATUS_HOST);
	skd_isr_fwstate(skdev);
	spin_unlock_irqrestore(&skdev->lock, flags);
	return IRQ_HANDLED;
}

static irqreturn_t skd_comp_q(int irq, void *skd_host_data)
{
	struct skd_device *skdev = skd_host_data;
	unsigned long flags;
	int flush_enqueued = 0;
	int deferred;

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "MSIX = 0x%x\n",
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	SKD_WRITEL(skdev, FIT_ISH_COMPLETION_POSTED, FIT_INT_STATUS_HOST);
	deferred = skd_isr_completion_posted(skdev, skd_isr_comp_limit,
						&flush_enqueued);
	if (flush_enqueued)
		schedule_work(&skdev->start_queue);

	if (deferred)
		schedule_work(&skdev->completion_worker);
	else if (!flush_enqueued)
		schedule_work(&skdev->start_queue);

	spin_unlock_irqrestore(&skdev->lock, flags);

	return IRQ_HANDLED;
}

static irqreturn_t skd_msg_isr(int irq, void *skd_host_data)
{
	struct skd_device *skdev = skd_host_data;
	unsigned long flags;

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "MSIX = 0x%x\n",
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	SKD_WRITEL(skdev, FIT_ISH_MSG_FROM_DEV, FIT_INT_STATUS_HOST);
	skd_isr_msg_from_dev(skdev);
	spin_unlock_irqrestore(&skdev->lock, flags);
	return IRQ_HANDLED;
}

static irqreturn_t skd_qfull_isr(int irq, void *skd_host_data)
{
	struct skd_device *skdev = skd_host_data;
	unsigned long flags;

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "MSIX = 0x%x\n",
		SKD_READL(skdev, FIT_INT_STATUS_HOST));
	SKD_WRITEL(skdev, FIT_INT_QUEUE_FULL, FIT_INT_STATUS_HOST);
	spin_unlock_irqrestore(&skdev->lock, flags);
	return IRQ_HANDLED;
}

/*
 *****************************************************************************
 * PCIe MSI/MSI-X SETUP
 *****************************************************************************
 */

struct skd_msix_entry {
	char isr_name[30];
};

struct skd_init_msix_entry {
	const char *name;
	irq_handler_t handler;
};

#define SKD_MAX_MSIX_COUNT              13
#define SKD_MIN_MSIX_COUNT              7
#define SKD_BASE_MSIX_IRQ               4

static struct skd_init_msix_entry msix_entries[SKD_MAX_MSIX_COUNT] = {
	{ "(DMA 0)",	    skd_reserved_isr },
	{ "(DMA 1)",	    skd_reserved_isr },
	{ "(DMA 2)",	    skd_reserved_isr },
	{ "(DMA 3)",	    skd_reserved_isr },
	{ "(State Change)", skd_statec_isr   },
	{ "(COMPL_Q)",	    skd_comp_q	     },
	{ "(MSG)",	    skd_msg_isr	     },
	{ "(Reserved)",	    skd_reserved_isr },
	{ "(Reserved)",	    skd_reserved_isr },
	{ "(Queue Full 0)", skd_qfull_isr    },
	{ "(Queue Full 1)", skd_qfull_isr    },
	{ "(Queue Full 2)", skd_qfull_isr    },
	{ "(Queue Full 3)", skd_qfull_isr    },
};

static int skd_acquire_msix(struct skd_device *skdev)
{
	int i, rc;
	struct pci_dev *pdev = skdev->pdev;

	rc = pci_alloc_irq_vectors(pdev, SKD_MAX_MSIX_COUNT, SKD_MAX_MSIX_COUNT,
			PCI_IRQ_MSIX);
	if (rc < 0) {
		dev_err(&skdev->pdev->dev, "failed to enable MSI-X %d\n", rc);
		goto out;
	}

	skdev->msix_entries = kcalloc(SKD_MAX_MSIX_COUNT,
			sizeof(struct skd_msix_entry), GFP_KERNEL);
	if (!skdev->msix_entries) {
		rc = -ENOMEM;
		dev_err(&skdev->pdev->dev, "msix table allocation error\n");
		goto out;
	}

	/* Enable MSI-X vectors for the base queue */
	for (i = 0; i < SKD_MAX_MSIX_COUNT; i++) {
		struct skd_msix_entry *qentry = &skdev->msix_entries[i];

		snprintf(qentry->isr_name, sizeof(qentry->isr_name),
			 "%s%d-msix %s", DRV_NAME, skdev->devno,
			 msix_entries[i].name);

		rc = devm_request_irq(&skdev->pdev->dev,
				pci_irq_vector(skdev->pdev, i),
				msix_entries[i].handler, 0,
				qentry->isr_name, skdev);
		if (rc) {
			dev_err(&skdev->pdev->dev,
				"Unable to register(%d) MSI-X handler %d: %s\n",
				rc, i, qentry->isr_name);
			goto msix_out;
		}
	}

	dev_dbg(&skdev->pdev->dev, "%d msix irq(s) enabled\n",
		SKD_MAX_MSIX_COUNT);
	return 0;

msix_out:
	while (--i >= 0)
		devm_free_irq(&pdev->dev, pci_irq_vector(pdev, i), skdev);
out:
	kfree(skdev->msix_entries);
	skdev->msix_entries = NULL;
	return rc;
}

static int skd_acquire_irq(struct skd_device *skdev)
{
	struct pci_dev *pdev = skdev->pdev;
	unsigned int irq_flag = PCI_IRQ_LEGACY;
	int rc;

	if (skd_isr_type == SKD_IRQ_MSIX) {
		rc = skd_acquire_msix(skdev);
		if (!rc)
			return 0;

		dev_err(&skdev->pdev->dev,
			"failed to enable MSI-X, re-trying with MSI %d\n", rc);
	}

	snprintf(skdev->isr_name, sizeof(skdev->isr_name), "%s%d", DRV_NAME,
			skdev->devno);

	if (skd_isr_type != SKD_IRQ_LEGACY)
		irq_flag |= PCI_IRQ_MSI;
	rc = pci_alloc_irq_vectors(pdev, 1, 1, irq_flag);
	if (rc < 0) {
		dev_err(&skdev->pdev->dev,
			"failed to allocate the MSI interrupt %d\n", rc);
		return rc;
	}

	rc = devm_request_irq(&pdev->dev, pdev->irq, skd_isr,
			pdev->msi_enabled ? 0 : IRQF_SHARED,
			skdev->isr_name, skdev);
	if (rc) {
		pci_free_irq_vectors(pdev);
		dev_err(&skdev->pdev->dev, "failed to allocate interrupt %d\n",
			rc);
		return rc;
	}

	return 0;
}

static void skd_release_irq(struct skd_device *skdev)
{
	struct pci_dev *pdev = skdev->pdev;

	if (skdev->msix_entries) {
		int i;

		for (i = 0; i < SKD_MAX_MSIX_COUNT; i++) {
			devm_free_irq(&pdev->dev, pci_irq_vector(pdev, i),
					skdev);
		}

		kfree(skdev->msix_entries);
		skdev->msix_entries = NULL;
	} else {
		devm_free_irq(&pdev->dev, pdev->irq, skdev);
	}

	pci_free_irq_vectors(pdev);
}

/*
 *****************************************************************************
 * CONSTRUCT
 *****************************************************************************
 */

static void *skd_alloc_dma(struct skd_device *skdev, struct kmem_cache *s,
			   dma_addr_t *dma_handle, gfp_t gfp,
			   enum dma_data_direction dir)
{
	struct device *dev = &skdev->pdev->dev;
	void *buf;

	buf = kmem_cache_alloc(s, gfp);
	if (!buf)
		return NULL;
	*dma_handle = dma_map_single(dev, buf,
				     kmem_cache_size(s), dir);
	if (dma_mapping_error(dev, *dma_handle)) {
		kmem_cache_free(s, buf);
		buf = NULL;
	}
	return buf;
}

static void skd_free_dma(struct skd_device *skdev, struct kmem_cache *s,
			 void *vaddr, dma_addr_t dma_handle,
			 enum dma_data_direction dir)
{
	if (!vaddr)
		return;

	dma_unmap_single(&skdev->pdev->dev, dma_handle,
			 kmem_cache_size(s), dir);
	kmem_cache_free(s, vaddr);
}

static int skd_cons_skcomp(struct skd_device *skdev)
{
	int rc = 0;
	struct fit_completion_entry_v1 *skcomp;

	dev_dbg(&skdev->pdev->dev,
		"comp pci_alloc, total bytes %zd entries %d\n",
		SKD_SKCOMP_SIZE, SKD_N_COMPLETION_ENTRY);

	skcomp = dma_alloc_coherent(&skdev->pdev->dev, SKD_SKCOMP_SIZE,
				    &skdev->cq_dma_address, GFP_KERNEL);

	if (skcomp == NULL) {
		rc = -ENOMEM;
		goto err_out;
	}

	skdev->skcomp_table = skcomp;
	skdev->skerr_table = (struct fit_comp_error_info *)((char *)skcomp +
							   sizeof(*skcomp) *
							   SKD_N_COMPLETION_ENTRY);

err_out:
	return rc;
}

static int skd_cons_skmsg(struct skd_device *skdev)
{
	int rc = 0;
	u32 i;

	dev_dbg(&skdev->pdev->dev,
		"skmsg_table kcalloc, struct %lu, count %u total %lu\n",
		sizeof(struct skd_fitmsg_context), skdev->num_fitmsg_context,
		sizeof(struct skd_fitmsg_context) * skdev->num_fitmsg_context);

	skdev->skmsg_table = kcalloc(skdev->num_fitmsg_context,
				     sizeof(struct skd_fitmsg_context),
				     GFP_KERNEL);
	if (skdev->skmsg_table == NULL) {
		rc = -ENOMEM;
		goto err_out;
	}

	for (i = 0; i < skdev->num_fitmsg_context; i++) {
		struct skd_fitmsg_context *skmsg;

		skmsg = &skdev->skmsg_table[i];

		skmsg->id = i + SKD_ID_FIT_MSG;

		skmsg->msg_buf = dma_alloc_coherent(&skdev->pdev->dev,
						    SKD_N_FITMSG_BYTES,
						    &skmsg->mb_dma_address,
						    GFP_KERNEL);
		if (skmsg->msg_buf == NULL) {
			rc = -ENOMEM;
			goto err_out;
		}

		WARN(((uintptr_t)skmsg->msg_buf | skmsg->mb_dma_address) &
		     (FIT_QCMD_ALIGN - 1),
		     "not aligned: msg_buf %p mb_dma_address %pad\n",
		     skmsg->msg_buf, &skmsg->mb_dma_address);
		memset(skmsg->msg_buf, 0, SKD_N_FITMSG_BYTES);
	}

err_out:
	return rc;
}

static struct fit_sg_descriptor *skd_cons_sg_list(struct skd_device *skdev,
						  u32 n_sg,
						  dma_addr_t *ret_dma_addr)
{
	struct fit_sg_descriptor *sg_list;

	sg_list = skd_alloc_dma(skdev, skdev->sglist_cache, ret_dma_addr,
				GFP_DMA | __GFP_ZERO, DMA_TO_DEVICE);

	if (sg_list != NULL) {
		uint64_t dma_address = *ret_dma_addr;
		u32 i;

		for (i = 0; i < n_sg - 1; i++) {
			uint64_t ndp_off;
			ndp_off = (i + 1) * sizeof(struct fit_sg_descriptor);

			sg_list[i].next_desc_ptr = dma_address + ndp_off;
		}
		sg_list[i].next_desc_ptr = 0LL;
	}

	return sg_list;
}

static void skd_free_sg_list(struct skd_device *skdev,
			     struct fit_sg_descriptor *sg_list,
			     dma_addr_t dma_addr)
{
	if (WARN_ON_ONCE(!sg_list))
		return;

	skd_free_dma(skdev, skdev->sglist_cache, sg_list, dma_addr,
		     DMA_TO_DEVICE);
}

static int skd_init_request(struct blk_mq_tag_set *set, struct request *rq,
			    unsigned int hctx_idx, unsigned int numa_node)
{
	struct skd_device *skdev = set->driver_data;
	struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq);

	skreq->state = SKD_REQ_STATE_IDLE;
	skreq->sg = (void *)(skreq + 1);
	sg_init_table(skreq->sg, skd_sgs_per_request);
	skreq->sksg_list = skd_cons_sg_list(skdev, skd_sgs_per_request,
					    &skreq->sksg_dma_address);

	return skreq->sksg_list ? 0 : -ENOMEM;
}

static void skd_exit_request(struct blk_mq_tag_set *set, struct request *rq,
			     unsigned int hctx_idx)
{
	struct skd_device *skdev = set->driver_data;
	struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq);

	skd_free_sg_list(skdev, skreq->sksg_list, skreq->sksg_dma_address);
}

static int skd_cons_sksb(struct skd_device *skdev)
{
	int rc = 0;
	struct skd_special_context *skspcl;

	skspcl = &skdev->internal_skspcl;

	skspcl->req.id = 0 + SKD_ID_INTERNAL;
	skspcl->req.state = SKD_REQ_STATE_IDLE;

	skspcl->data_buf = skd_alloc_dma(skdev, skdev->databuf_cache,
					 &skspcl->db_dma_address,
					 GFP_DMA | __GFP_ZERO,
					 DMA_BIDIRECTIONAL);
	if (skspcl->data_buf == NULL) {
		rc = -ENOMEM;
		goto err_out;
	}

	skspcl->msg_buf = skd_alloc_dma(skdev, skdev->msgbuf_cache,
					&skspcl->mb_dma_address,
					GFP_DMA | __GFP_ZERO, DMA_TO_DEVICE);
	if (skspcl->msg_buf == NULL) {
		rc = -ENOMEM;
		goto err_out;
	}

	skspcl->req.sksg_list = skd_cons_sg_list(skdev, 1,
						 &skspcl->req.sksg_dma_address);
	if (skspcl->req.sksg_list == NULL) {
		rc = -ENOMEM;
		goto err_out;
	}

	if (!skd_format_internal_skspcl(skdev)) {
		rc = -EINVAL;
		goto err_out;
	}

err_out:
	return rc;
}

static const struct blk_mq_ops skd_mq_ops = {
	.queue_rq	= skd_mq_queue_rq,
	.complete	= skd_complete_rq,
	.timeout	= skd_timed_out,
	.init_request	= skd_init_request,
	.exit_request	= skd_exit_request,
};

static int skd_cons_disk(struct skd_device *skdev)
{
	int rc = 0;
	struct gendisk *disk;
	struct request_queue *q;
	unsigned long flags;

	disk = alloc_disk(SKD_MINORS_PER_DEVICE);
	if (!disk) {
		rc = -ENOMEM;
		goto err_out;
	}

	skdev->disk = disk;
	sprintf(disk->disk_name, DRV_NAME "%u", skdev->devno);

	disk->major = skdev->major;
	disk->first_minor = skdev->devno * SKD_MINORS_PER_DEVICE;
	disk->fops = &skd_blockdev_ops;
	disk->private_data = skdev;

	memset(&skdev->tag_set, 0, sizeof(skdev->tag_set));
	skdev->tag_set.ops = &skd_mq_ops;
	skdev->tag_set.nr_hw_queues = 1;
	skdev->tag_set.queue_depth = skd_max_queue_depth;
	skdev->tag_set.cmd_size = sizeof(struct skd_request_context) +
		skdev->sgs_per_request * sizeof(struct scatterlist);
	skdev->tag_set.numa_node = NUMA_NO_NODE;
	skdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
		BLK_MQ_F_SG_MERGE |
		BLK_ALLOC_POLICY_TO_MQ_FLAG(BLK_TAG_ALLOC_FIFO);
	skdev->tag_set.driver_data = skdev;
	rc = blk_mq_alloc_tag_set(&skdev->tag_set);
	if (rc)
		goto err_out;
	q = blk_mq_init_queue(&skdev->tag_set);
	if (IS_ERR(q)) {
		blk_mq_free_tag_set(&skdev->tag_set);
		rc = PTR_ERR(q);
		goto err_out;
	}
	q->queuedata = skdev;

	skdev->queue = q;
	disk->queue = q;

	blk_queue_write_cache(q, true, true);
	blk_queue_max_segments(q, skdev->sgs_per_request);
	blk_queue_max_hw_sectors(q, SKD_N_MAX_SECTORS);

	/* set optimal I/O size to 8KB */
	blk_queue_io_opt(q, 8192);

	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);

	blk_queue_rq_timeout(q, 8 * HZ);

	spin_lock_irqsave(&skdev->lock, flags);
	dev_dbg(&skdev->pdev->dev, "stopping queue\n");
	blk_mq_stop_hw_queues(skdev->queue);
	spin_unlock_irqrestore(&skdev->lock, flags);

err_out:
	return rc;
}

#define SKD_N_DEV_TABLE         16u
static u32 skd_next_devno;

static struct skd_device *skd_construct(struct pci_dev *pdev)
{
	struct skd_device *skdev;
	int blk_major = skd_major;
	size_t size;
	int rc;

	skdev = kzalloc(sizeof(*skdev), GFP_KERNEL);

	if (!skdev) {
		dev_err(&pdev->dev, "memory alloc failure\n");
		return NULL;
	}

	skdev->state = SKD_DRVR_STATE_LOAD;
	skdev->pdev = pdev;
	skdev->devno = skd_next_devno++;
	skdev->major = blk_major;
	skdev->dev_max_queue_depth = 0;

	skdev->num_req_context = skd_max_queue_depth;
	skdev->num_fitmsg_context = skd_max_queue_depth;
	skdev->cur_max_queue_depth = 1;
	skdev->queue_low_water_mark = 1;
	skdev->proto_ver = 99;
	skdev->sgs_per_request = skd_sgs_per_request;
	skdev->dbg_level = skd_dbg_level;

	spin_lock_init(&skdev->lock);

	INIT_WORK(&skdev->start_queue, skd_start_queue);
	INIT_WORK(&skdev->completion_worker, skd_completion_worker);

	size = max(SKD_N_FITMSG_BYTES, SKD_N_SPECIAL_FITMSG_BYTES);
	skdev->msgbuf_cache = kmem_cache_create("skd-msgbuf", size, 0,
						SLAB_HWCACHE_ALIGN, NULL);
	if (!skdev->msgbuf_cache)
		goto err_out;
	WARN_ONCE(kmem_cache_size(skdev->msgbuf_cache) < size,
		  "skd-msgbuf: %d < %zd\n",
		  kmem_cache_size(skdev->msgbuf_cache), size);
	size = skd_sgs_per_request * sizeof(struct fit_sg_descriptor);
	skdev->sglist_cache = kmem_cache_create("skd-sglist", size, 0,
						SLAB_HWCACHE_ALIGN, NULL);
	if (!skdev->sglist_cache)
		goto err_out;
	WARN_ONCE(kmem_cache_size(skdev->sglist_cache) < size,
		  "skd-sglist: %d < %zd\n",
		  kmem_cache_size(skdev->sglist_cache), size);
	size = SKD_N_INTERNAL_BYTES;
	skdev->databuf_cache = kmem_cache_create("skd-databuf", size, 0,
						 SLAB_HWCACHE_ALIGN, NULL);
	if (!skdev->databuf_cache)
		goto err_out;
	WARN_ONCE(kmem_cache_size(skdev->databuf_cache) < size,
		  "skd-databuf: %d < %zd\n",
		  kmem_cache_size(skdev->databuf_cache), size);

	dev_dbg(&skdev->pdev->dev, "skcomp\n");
	rc = skd_cons_skcomp(skdev);
	if (rc < 0)
		goto err_out;

	dev_dbg(&skdev->pdev->dev, "skmsg\n");
	rc = skd_cons_skmsg(skdev);
	if (rc < 0)
		goto err_out;

	dev_dbg(&skdev->pdev->dev, "sksb\n");
	rc = skd_cons_sksb(skdev);
	if (rc < 0)
		goto err_out;

	dev_dbg(&skdev->pdev->dev, "disk\n");
	rc = skd_cons_disk(skdev);
	if (rc < 0)
		goto err_out;

	dev_dbg(&skdev->pdev->dev, "VICTORY\n");
	return skdev;

err_out:
	dev_dbg(&skdev->pdev->dev, "construct failed\n");
	skd_destruct(skdev);
	return NULL;
}

/*
 *****************************************************************************
 * DESTRUCT (FREE)
 *****************************************************************************
 */

static void skd_free_skcomp(struct skd_device *skdev)
{
	if (skdev->skcomp_table)
		dma_free_coherent(&skdev->pdev->dev, SKD_SKCOMP_SIZE,
				  skdev->skcomp_table, skdev->cq_dma_address);

	skdev->skcomp_table = NULL;
	skdev->cq_dma_address = 0;
}

static void skd_free_skmsg(struct skd_device *skdev)
{
	u32 i;

	if (skdev->skmsg_table == NULL)
		return;

	for (i = 0; i < skdev->num_fitmsg_context; i++) {
		struct skd_fitmsg_context *skmsg;

		skmsg = &skdev->skmsg_table[i];

		if (skmsg->msg_buf != NULL) {
			dma_free_coherent(&skdev->pdev->dev, SKD_N_FITMSG_BYTES,
					  skmsg->msg_buf,
					    skmsg->mb_dma_address);
		}
		skmsg->msg_buf = NULL;
		skmsg->mb_dma_address = 0;
	}

	kfree(skdev->skmsg_table);
	skdev->skmsg_table = NULL;
}

static void skd_free_sksb(struct skd_device *skdev)
{
	struct skd_special_context *skspcl = &skdev->internal_skspcl;

	skd_free_dma(skdev, skdev->databuf_cache, skspcl->data_buf,
		     skspcl->db_dma_address, DMA_BIDIRECTIONAL);

	skspcl->data_buf = NULL;
	skspcl->db_dma_address = 0;

	skd_free_dma(skdev, skdev->msgbuf_cache, skspcl->msg_buf,
		     skspcl->mb_dma_address, DMA_TO_DEVICE);

	skspcl->msg_buf = NULL;
	skspcl->mb_dma_address = 0;

	skd_free_sg_list(skdev, skspcl->req.sksg_list,
			 skspcl->req.sksg_dma_address);

	skspcl->req.sksg_list = NULL;
	skspcl->req.sksg_dma_address = 0;
}

static void skd_free_disk(struct skd_device *skdev)
{
	struct gendisk *disk = skdev->disk;

	if (disk && (disk->flags & GENHD_FL_UP))
		del_gendisk(disk);

	if (skdev->queue) {
		blk_cleanup_queue(skdev->queue);
		skdev->queue = NULL;
		if (disk)
			disk->queue = NULL;
	}

	if (skdev->tag_set.tags)
		blk_mq_free_tag_set(&skdev->tag_set);

	put_disk(disk);
	skdev->disk = NULL;
}

static void skd_destruct(struct skd_device *skdev)
{
	if (skdev == NULL)
		return;

	cancel_work_sync(&skdev->start_queue);

	dev_dbg(&skdev->pdev->dev, "disk\n");
	skd_free_disk(skdev);

	dev_dbg(&skdev->pdev->dev, "sksb\n");
	skd_free_sksb(skdev);

	dev_dbg(&skdev->pdev->dev, "skmsg\n");
	skd_free_skmsg(skdev);

	dev_dbg(&skdev->pdev->dev, "skcomp\n");
	skd_free_skcomp(skdev);

	kmem_cache_destroy(skdev->databuf_cache);
	kmem_cache_destroy(skdev->sglist_cache);
	kmem_cache_destroy(skdev->msgbuf_cache);

	dev_dbg(&skdev->pdev->dev, "skdev\n");
	kfree(skdev);
}

/*
 *****************************************************************************
 * BLOCK DEVICE (BDEV) GLUE
 *****************************************************************************
 */

static int skd_bdev_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct skd_device *skdev;
	u64 capacity;

	skdev = bdev->bd_disk->private_data;

	dev_dbg(&skdev->pdev->dev, "%s: CMD[%s] getgeo device\n",
		bdev->bd_disk->disk_name, current->comm);

	if (skdev->read_cap_is_valid) {
		capacity = get_capacity(skdev->disk);
		geo->heads = 64;
		geo->sectors = 255;
		geo->cylinders = (capacity) / (255 * 64);

		return 0;
	}
	return -EIO;
}

static int skd_bdev_attach(struct device *parent, struct skd_device *skdev)
{
	dev_dbg(&skdev->pdev->dev, "add_disk\n");
	device_add_disk(parent, skdev->disk, NULL);
	return 0;
}

static const struct block_device_operations skd_blockdev_ops = {
	.owner		= THIS_MODULE,
	.getgeo		= skd_bdev_getgeo,
};

/*
 *****************************************************************************
 * PCIe DRIVER GLUE
 *****************************************************************************
 */

static const struct pci_device_id skd_pci_tbl[] = {
	{ PCI_VENDOR_ID_STEC, PCI_DEVICE_ID_S1120,
	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, },
	{ 0 }                     /* terminate list */
};

MODULE_DEVICE_TABLE(pci, skd_pci_tbl);

static char *skd_pci_info(struct skd_device *skdev, char *str)
{
	int pcie_reg;

	strcpy(str, "PCIe (");
	pcie_reg = pci_find_capability(skdev->pdev, PCI_CAP_ID_EXP);

	if (pcie_reg) {

		char lwstr[6];
		uint16_t pcie_lstat, lspeed, lwidth;

		pcie_reg += 0x12;
		pci_read_config_word(skdev->pdev, pcie_reg, &pcie_lstat);
		lspeed = pcie_lstat & (0xF);
		lwidth = (pcie_lstat & 0x3F0) >> 4;

		if (lspeed == 1)
			strcat(str, "2.5GT/s ");
		else if (lspeed == 2)
			strcat(str, "5.0GT/s ");
		else
			strcat(str, "<unknown> ");
		snprintf(lwstr, sizeof(lwstr), "%dX)", lwidth);
		strcat(str, lwstr);
	}
	return str;
}

static int skd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	int i;
	int rc = 0;
	char pci_str[32];
	struct skd_device *skdev;

	dev_dbg(&pdev->dev, "vendor=%04X device=%04x\n", pdev->vendor,
		pdev->device);

	rc = pci_enable_device(pdev);
	if (rc)
		return rc;
	rc = pci_request_regions(pdev, DRV_NAME);
	if (rc)
		goto err_out;
	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (rc)
		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
	if (rc) {
		dev_err(&pdev->dev, "DMA mask error %d\n", rc);
		goto err_out_regions;
	}

	if (!skd_major) {
		rc = register_blkdev(0, DRV_NAME);
		if (rc < 0)
			goto err_out_regions;
		BUG_ON(!rc);
		skd_major = rc;
	}

	skdev = skd_construct(pdev);
	if (skdev == NULL) {
		rc = -ENOMEM;
		goto err_out_regions;
	}

	skd_pci_info(skdev, pci_str);
	dev_info(&pdev->dev, "%s 64bit\n", pci_str);

	pci_set_master(pdev);
	rc = pci_enable_pcie_error_reporting(pdev);
	if (rc) {
		dev_err(&pdev->dev,
			"bad enable of PCIe error reporting rc=%d\n", rc);
		skdev->pcie_error_reporting_is_enabled = 0;
	} else
		skdev->pcie_error_reporting_is_enabled = 1;

	pci_set_drvdata(pdev, skdev);

	for (i = 0; i < SKD_MAX_BARS; i++) {
		skdev->mem_phys[i] = pci_resource_start(pdev, i);
		skdev->mem_size[i] = (u32)pci_resource_len(pdev, i);
		skdev->mem_map[i] = ioremap(skdev->mem_phys[i],
					    skdev->mem_size[i]);
		if (!skdev->mem_map[i]) {
			dev_err(&pdev->dev,
				"Unable to map adapter memory!\n");
			rc = -ENODEV;
			goto err_out_iounmap;
		}
		dev_dbg(&pdev->dev, "mem_map=%p, phyd=%016llx, size=%d\n",
			skdev->mem_map[i], (uint64_t)skdev->mem_phys[i],
			skdev->mem_size[i]);
	}

	rc = skd_acquire_irq(skdev);
	if (rc) {
		dev_err(&pdev->dev, "interrupt resource error %d\n", rc);
		goto err_out_iounmap;
	}

	rc = skd_start_timer(skdev);
	if (rc)
		goto err_out_timer;

	init_waitqueue_head(&skdev->waitq);

	skd_start_device(skdev);

	rc = wait_event_interruptible_timeout(skdev->waitq,
					      (skdev->gendisk_on),
					      (SKD_START_WAIT_SECONDS * HZ));
	if (skdev->gendisk_on > 0) {
		/* device came on-line after reset */
		skd_bdev_attach(&pdev->dev, skdev);
		rc = 0;
	} else {
		/* we timed out, something is wrong with the device,
		   don't add the disk structure */
		dev_err(&pdev->dev, "error: waiting for s1120 timed out %d!\n",
			rc);
		/* in case of no error; we timeout with ENXIO */
		if (!rc)
			rc = -ENXIO;
		goto err_out_timer;
	}

	return rc;

err_out_timer:
	skd_stop_device(skdev);
	skd_release_irq(skdev);

err_out_iounmap:
	for (i = 0; i < SKD_MAX_BARS; i++)
		if (skdev->mem_map[i])
			iounmap(skdev->mem_map[i]);

	if (skdev->pcie_error_reporting_is_enabled)
		pci_disable_pcie_error_reporting(pdev);

	skd_destruct(skdev);

err_out_regions:
	pci_release_regions(pdev);

err_out:
	pci_disable_device(pdev);
	pci_set_drvdata(pdev, NULL);
	return rc;
}

static void skd_pci_remove(struct pci_dev *pdev)
{
	int i;
	struct skd_device *skdev;

	skdev = pci_get_drvdata(pdev);
	if (!skdev) {
		dev_err(&pdev->dev, "no device data for PCI\n");
		return;
	}
	skd_stop_device(skdev);
	skd_release_irq(skdev);

	for (i = 0; i < SKD_MAX_BARS; i++)
		if (skdev->mem_map[i])
			iounmap(skdev->mem_map[i]);

	if (skdev->pcie_error_reporting_is_enabled)
		pci_disable_pcie_error_reporting(pdev);

	skd_destruct(skdev);

	pci_release_regions(pdev);
	pci_disable_device(pdev);
	pci_set_drvdata(pdev, NULL);

	return;
}

static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)
{
	int i;
	struct skd_device *skdev;

	skdev = pci_get_drvdata(pdev);
	if (!skdev) {
		dev_err(&pdev->dev, "no device data for PCI\n");
		return -EIO;
	}

	skd_stop_device(skdev);

	skd_release_irq(skdev);

	for (i = 0; i < SKD_MAX_BARS; i++)
		if (skdev->mem_map[i])
			iounmap(skdev->mem_map[i]);

	if (skdev->pcie_error_reporting_is_enabled)
		pci_disable_pcie_error_reporting(pdev);

	pci_release_regions(pdev);
	pci_save_state(pdev);
	pci_disable_device(pdev);
	pci_set_power_state(pdev, pci_choose_state(pdev, state));
	return 0;
}

static int skd_pci_resume(struct pci_dev *pdev)
{
	int i;
	int rc = 0;
	struct skd_device *skdev;

	skdev = pci_get_drvdata(pdev);
	if (!skdev) {
		dev_err(&pdev->dev, "no device data for PCI\n");
		return -1;
	}

	pci_set_power_state(pdev, PCI_D0);
	pci_enable_wake(pdev, PCI_D0, 0);
	pci_restore_state(pdev);

	rc = pci_enable_device(pdev);
	if (rc)
		return rc;
	rc = pci_request_regions(pdev, DRV_NAME);
	if (rc)
		goto err_out;
	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (rc)
		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
	if (rc) {
		dev_err(&pdev->dev, "DMA mask error %d\n", rc);
		goto err_out_regions;
	}

	pci_set_master(pdev);
	rc = pci_enable_pcie_error_reporting(pdev);
	if (rc) {
		dev_err(&pdev->dev,
			"bad enable of PCIe error reporting rc=%d\n", rc);
		skdev->pcie_error_reporting_is_enabled = 0;
	} else
		skdev->pcie_error_reporting_is_enabled = 1;

	for (i = 0; i < SKD_MAX_BARS; i++) {

		skdev->mem_phys[i] = pci_resource_start(pdev, i);
		skdev->mem_size[i] = (u32)pci_resource_len(pdev, i);
		skdev->mem_map[i] = ioremap(skdev->mem_phys[i],
					    skdev->mem_size[i]);
		if (!skdev->mem_map[i]) {
			dev_err(&pdev->dev, "Unable to map adapter memory!\n");
			rc = -ENODEV;
			goto err_out_iounmap;
		}
		dev_dbg(&pdev->dev, "mem_map=%p, phyd=%016llx, size=%d\n",
			skdev->mem_map[i], (uint64_t)skdev->mem_phys[i],
			skdev->mem_size[i]);
	}
	rc = skd_acquire_irq(skdev);
	if (rc) {
		dev_err(&pdev->dev, "interrupt resource error %d\n", rc);
		goto err_out_iounmap;
	}

	rc = skd_start_timer(skdev);
	if (rc)
		goto err_out_timer;

	init_waitqueue_head(&skdev->waitq);

	skd_start_device(skdev);

	return rc;

err_out_timer:
	skd_stop_device(skdev);
	skd_release_irq(skdev);

err_out_iounmap:
	for (i = 0; i < SKD_MAX_BARS; i++)
		if (skdev->mem_map[i])
			iounmap(skdev->mem_map[i]);

	if (skdev->pcie_error_reporting_is_enabled)
		pci_disable_pcie_error_reporting(pdev);

err_out_regions:
	pci_release_regions(pdev);

err_out:
	pci_disable_device(pdev);
	return rc;
}

static void skd_pci_shutdown(struct pci_dev *pdev)
{
	struct skd_device *skdev;

	dev_err(&pdev->dev, "%s called\n", __func__);

	skdev = pci_get_drvdata(pdev);
	if (!skdev) {
		dev_err(&pdev->dev, "no device data for PCI\n");
		return;
	}

	dev_err(&pdev->dev, "calling stop\n");
	skd_stop_device(skdev);
}

static struct pci_driver skd_driver = {
	.name		= DRV_NAME,
	.id_table	= skd_pci_tbl,
	.probe		= skd_pci_probe,
	.remove		= skd_pci_remove,
	.suspend	= skd_pci_suspend,
	.resume		= skd_pci_resume,
	.shutdown	= skd_pci_shutdown,
};

/*
 *****************************************************************************
 * LOGGING SUPPORT
 *****************************************************************************
 */

const char *skd_drive_state_to_str(int state)
{
	switch (state) {
	case FIT_SR_DRIVE_OFFLINE:
		return "OFFLINE";
	case FIT_SR_DRIVE_INIT:
		return "INIT";
	case FIT_SR_DRIVE_ONLINE:
		return "ONLINE";
	case FIT_SR_DRIVE_BUSY:
		return "BUSY";
	case FIT_SR_DRIVE_FAULT:
		return "FAULT";
	case FIT_SR_DRIVE_DEGRADED:
		return "DEGRADED";
	case FIT_SR_PCIE_LINK_DOWN:
		return "INK_DOWN";
	case FIT_SR_DRIVE_SOFT_RESET:
		return "SOFT_RESET";
	case FIT_SR_DRIVE_NEED_FW_DOWNLOAD:
		return "NEED_FW";
	case FIT_SR_DRIVE_INIT_FAULT:
		return "INIT_FAULT";
	case FIT_SR_DRIVE_BUSY_SANITIZE:
		return "BUSY_SANITIZE";
	case FIT_SR_DRIVE_BUSY_ERASE:
		return "BUSY_ERASE";
	case FIT_SR_DRIVE_FW_BOOTING:
		return "FW_BOOTING";
	default:
		return "???";
	}
}

const char *skd_skdev_state_to_str(enum skd_drvr_state state)
{
	switch (state) {
	case SKD_DRVR_STATE_LOAD:
		return "LOAD";
	case SKD_DRVR_STATE_IDLE:
		return "IDLE";
	case SKD_DRVR_STATE_BUSY:
		return "BUSY";
	case SKD_DRVR_STATE_STARTING:
		return "STARTING";
	case SKD_DRVR_STATE_ONLINE:
		return "ONLINE";
	case SKD_DRVR_STATE_PAUSING:
		return "PAUSING";
	case SKD_DRVR_STATE_PAUSED:
		return "PAUSED";
	case SKD_DRVR_STATE_RESTARTING:
		return "RESTARTING";
	case SKD_DRVR_STATE_RESUMING:
		return "RESUMING";
	case SKD_DRVR_STATE_STOPPING:
		return "STOPPING";
	case SKD_DRVR_STATE_SYNCING:
		return "SYNCING";
	case SKD_DRVR_STATE_FAULT:
		return "FAULT";
	case SKD_DRVR_STATE_DISAPPEARED:
		return "DISAPPEARED";
	case SKD_DRVR_STATE_BUSY_ERASE:
		return "BUSY_ERASE";
	case SKD_DRVR_STATE_BUSY_SANITIZE:
		return "BUSY_SANITIZE";
	case SKD_DRVR_STATE_BUSY_IMMINENT:
		return "BUSY_IMMINENT";
	case SKD_DRVR_STATE_WAIT_BOOT:
		return "WAIT_BOOT";

	default:
		return "???";
	}
}

static const char *skd_skreq_state_to_str(enum skd_req_state state)
{
	switch (state) {
	case SKD_REQ_STATE_IDLE:
		return "IDLE";
	case SKD_REQ_STATE_SETUP:
		return "SETUP";
	case SKD_REQ_STATE_BUSY:
		return "BUSY";
	case SKD_REQ_STATE_COMPLETED:
		return "COMPLETED";
	case SKD_REQ_STATE_TIMEOUT:
		return "TIMEOUT";
	default:
		return "???";
	}
}

static void skd_log_skdev(struct skd_device *skdev, const char *event)
{
	dev_dbg(&skdev->pdev->dev, "skdev=%p event='%s'\n", skdev, event);
	dev_dbg(&skdev->pdev->dev, "  drive_state=%s(%d) driver_state=%s(%d)\n",
		skd_drive_state_to_str(skdev->drive_state), skdev->drive_state,
		skd_skdev_state_to_str(skdev->state), skdev->state);
	dev_dbg(&skdev->pdev->dev, "  busy=%d limit=%d dev=%d lowat=%d\n",
		skd_in_flight(skdev), skdev->cur_max_queue_depth,
		skdev->dev_max_queue_depth, skdev->queue_low_water_mark);
	dev_dbg(&skdev->pdev->dev, "  cycle=%d cycle_ix=%d\n",
		skdev->skcomp_cycle, skdev->skcomp_ix);
}

static void skd_log_skreq(struct skd_device *skdev,
			  struct skd_request_context *skreq, const char *event)
{
	struct request *req = blk_mq_rq_from_pdu(skreq);
	u32 lba = blk_rq_pos(req);
	u32 count = blk_rq_sectors(req);

	dev_dbg(&skdev->pdev->dev, "skreq=%p event='%s'\n", skreq, event);
	dev_dbg(&skdev->pdev->dev, "  state=%s(%d) id=0x%04x fitmsg=0x%04x\n",
		skd_skreq_state_to_str(skreq->state), skreq->state, skreq->id,
		skreq->fitmsg_id);
	dev_dbg(&skdev->pdev->dev, "  sg_dir=%d n_sg=%d\n",
		skreq->data_dir, skreq->n_sg);

	dev_dbg(&skdev->pdev->dev,
		"req=%p lba=%u(0x%x) count=%u(0x%x) dir=%d\n", req, lba, lba,
		count, count, (int)rq_data_dir(req));
}

/*
 *****************************************************************************
 * MODULE GLUE
 *****************************************************************************
 */

static int __init skd_init(void)
{
	BUILD_BUG_ON(sizeof(struct fit_completion_entry_v1) != 8);
	BUILD_BUG_ON(sizeof(struct fit_comp_error_info) != 32);
	BUILD_BUG_ON(sizeof(struct skd_command_header) != 16);
	BUILD_BUG_ON(sizeof(struct skd_scsi_request) != 32);
	BUILD_BUG_ON(sizeof(struct driver_inquiry_data) != 44);
	BUILD_BUG_ON(offsetof(struct skd_msg_buf, fmh) != 0);
	BUILD_BUG_ON(offsetof(struct skd_msg_buf, scsi) != 64);
	BUILD_BUG_ON(sizeof(struct skd_msg_buf) != SKD_N_FITMSG_BYTES);

	switch (skd_isr_type) {
	case SKD_IRQ_LEGACY:
	case SKD_IRQ_MSI:
	case SKD_IRQ_MSIX:
		break;
	default:
		pr_err(PFX "skd_isr_type %d invalid, re-set to %d\n",
		       skd_isr_type, SKD_IRQ_DEFAULT);
		skd_isr_type = SKD_IRQ_DEFAULT;
	}

	if (skd_max_queue_depth < 1 ||
	    skd_max_queue_depth > SKD_MAX_QUEUE_DEPTH) {
		pr_err(PFX "skd_max_queue_depth %d invalid, re-set to %d\n",
		       skd_max_queue_depth, SKD_MAX_QUEUE_DEPTH_DEFAULT);
		skd_max_queue_depth = SKD_MAX_QUEUE_DEPTH_DEFAULT;
	}

	if (skd_max_req_per_msg < 1 ||
	    skd_max_req_per_msg > SKD_MAX_REQ_PER_MSG) {
		pr_err(PFX "skd_max_req_per_msg %d invalid, re-set to %d\n",
		       skd_max_req_per_msg, SKD_MAX_REQ_PER_MSG_DEFAULT);
		skd_max_req_per_msg = SKD_MAX_REQ_PER_MSG_DEFAULT;
	}

	if (skd_sgs_per_request < 1 || skd_sgs_per_request > 4096) {
		pr_err(PFX "skd_sg_per_request %d invalid, re-set to %d\n",
		       skd_sgs_per_request, SKD_N_SG_PER_REQ_DEFAULT);
		skd_sgs_per_request = SKD_N_SG_PER_REQ_DEFAULT;
	}

	if (skd_dbg_level < 0 || skd_dbg_level > 2) {
		pr_err(PFX "skd_dbg_level %d invalid, re-set to %d\n",
		       skd_dbg_level, 0);
		skd_dbg_level = 0;
	}

	if (skd_isr_comp_limit < 0) {
		pr_err(PFX "skd_isr_comp_limit %d invalid, set to %d\n",
		       skd_isr_comp_limit, 0);
		skd_isr_comp_limit = 0;
	}

	return pci_register_driver(&skd_driver);
}

static void __exit skd_exit(void)
{
	pci_unregister_driver(&skd_driver);

	if (skd_major)
		unregister_blkdev(skd_major, DRV_NAME);
}

module_init(skd_init);
module_exit(skd_exit);