Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
/*-
 * Copyright (c) 2009 Yahoo! Inc.
 * Copyright (c) 2011-2015 LSI Corp.
 * Copyright (c) 2013-2016 Avago Technologies
 * Copyright 2000-2020 Broadcom Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Broadcom Inc. (LSI) MPT-Fusion Host Adapter FreeBSD
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/* Communications core for Avago Technologies (LSI) MPT3 */

/* TODO Move headers to mprvar */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/selinfo.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <sys/uio.h>
#include <sys/sysctl.h>
#include <sys/smp.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/taskqueue.h>
#include <sys/endian.h>
#include <sys/eventhandler.h>
#include <sys/sbuf.h>
#include <sys/priv.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <sys/proc.h>

#include <dev/pci/pcivar.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/scsi/scsi_all.h>

#include <dev/mpr/mpi/mpi2_type.h>
#include <dev/mpr/mpi/mpi2.h>
#include <dev/mpr/mpi/mpi2_ioc.h>
#include <dev/mpr/mpi/mpi2_sas.h>
#include <dev/mpr/mpi/mpi2_pci.h>
#include <dev/mpr/mpi/mpi2_cnfg.h>
#include <dev/mpr/mpi/mpi2_init.h>
#include <dev/mpr/mpi/mpi2_tool.h>
#include <dev/mpr/mpr_ioctl.h>
#include <dev/mpr/mprvar.h>
#include <dev/mpr/mpr_table.h>
#include <dev/mpr/mpr_sas.h>

static int mpr_diag_reset(struct mpr_softc *sc, int sleep_flag);
static int mpr_init_queues(struct mpr_softc *sc);
static void mpr_resize_queues(struct mpr_softc *sc);
static int mpr_message_unit_reset(struct mpr_softc *sc, int sleep_flag);
static int mpr_transition_operational(struct mpr_softc *sc);
static int mpr_iocfacts_allocate(struct mpr_softc *sc, uint8_t attaching);
static void mpr_iocfacts_free(struct mpr_softc *sc);
static void mpr_startup(void *arg);
static int mpr_send_iocinit(struct mpr_softc *sc);
static int mpr_alloc_queues(struct mpr_softc *sc);
static int mpr_alloc_hw_queues(struct mpr_softc *sc);
static int mpr_alloc_replies(struct mpr_softc *sc);
static int mpr_alloc_requests(struct mpr_softc *sc);
static int mpr_alloc_nvme_prp_pages(struct mpr_softc *sc);
static int mpr_attach_log(struct mpr_softc *sc);
static __inline void mpr_complete_command(struct mpr_softc *sc,
    struct mpr_command *cm);
static void mpr_dispatch_event(struct mpr_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *reply);
static void mpr_config_complete(struct mpr_softc *sc, struct mpr_command *cm);
static void mpr_periodic(void *);
static int mpr_reregister_events(struct mpr_softc *sc);
static void mpr_enqueue_request(struct mpr_softc *sc, struct mpr_command *cm);
static int mpr_get_iocfacts(struct mpr_softc *sc, MPI2_IOC_FACTS_REPLY *facts);
static int mpr_wait_db_ack(struct mpr_softc *sc, int timeout, int sleep_flag);
static int mpr_debug_sysctl(SYSCTL_HANDLER_ARGS);
static int mpr_dump_reqs(SYSCTL_HANDLER_ARGS);
static void mpr_parse_debug(struct mpr_softc *sc, char *list);

SYSCTL_NODE(_hw, OID_AUTO, mpr, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "MPR Driver Parameters");

MALLOC_DEFINE(M_MPR, "mpr", "mpr driver memory");

/*
 * Do a "Diagnostic Reset" aka a hard reset.  This should get the chip out of
 * any state and back to its initialization state machine.
 */
static char mpt2_reset_magic[] = { 0x00, 0x0f, 0x04, 0x0b, 0x02, 0x07, 0x0d };

/* 
 * Added this union to smoothly convert le64toh cm->cm_desc.Words.
 * Compiler only supports uint64_t to be passed as an argument.
 * Otherwise it will throw this error:
 * "aggregate value used where an integer was expected"
 */
typedef union {
        u64 word;
        struct {
                u32 low;
                u32 high;
        } u;
} request_descriptor_t;

/* Rate limit chain-fail messages to 1 per minute */
static struct timeval mpr_chainfail_interval = { 60, 0 };

/* 
 * sleep_flag can be either CAN_SLEEP or NO_SLEEP.
 * If this function is called from process context, it can sleep
 * and there is no harm to sleep, in case if this fuction is called
 * from Interrupt handler, we can not sleep and need NO_SLEEP flag set.
 * based on sleep flags driver will call either msleep, pause or DELAY.
 * msleep and pause are of same variant, but pause is used when mpr_mtx
 * is not hold by driver.
 */
static int
mpr_diag_reset(struct mpr_softc *sc,int sleep_flag)
{
	uint32_t reg;
	int i, error, tries = 0;
	uint8_t first_wait_done = FALSE;

	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	/* Clear any pending interrupts */
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

	/*
	 * Force NO_SLEEP for threads prohibited to sleep
 	 * e.a Thread from interrupt handler are prohibited to sleep.
 	 */
	if (curthread->td_no_sleeping)
		sleep_flag = NO_SLEEP;

	mpr_dprint(sc, MPR_INIT, "sequence start, sleep_flag=%d\n", sleep_flag);
	/* Push the magic sequence */
	error = ETIMEDOUT;
	while (tries++ < 20) {
		for (i = 0; i < sizeof(mpt2_reset_magic); i++)
			mpr_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET,
			    mpt2_reset_magic[i]);

		/* wait 100 msec */
		if (mtx_owned(&sc->mpr_mtx) && sleep_flag == CAN_SLEEP)
			msleep(&sc->msleep_fake_chan, &sc->mpr_mtx, 0,
			    "mprdiag", hz/10);
		else if (sleep_flag == CAN_SLEEP)
			pause("mprdiag", hz/10);
		else
			DELAY(100 * 1000);

		reg = mpr_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
		if (reg & MPI2_DIAG_DIAG_WRITE_ENABLE) {
			error = 0;
			break;
		}
	}
	if (error) {
		mpr_dprint(sc, MPR_INIT, "sequence failed, error=%d, exit\n",
		    error);
		return (error);
	}

	/* Send the actual reset.  XXX need to refresh the reg? */
	reg |= MPI2_DIAG_RESET_ADAPTER;
	mpr_dprint(sc, MPR_INIT, "sequence success, sending reset, reg= 0x%x\n",
	    reg);
	mpr_regwrite(sc, MPI2_HOST_DIAGNOSTIC_OFFSET, reg);

	/* Wait up to 300 seconds in 50ms intervals */
	error = ETIMEDOUT;
	for (i = 0; i < 6000; i++) {
		/*
		 * Wait 50 msec. If this is the first time through, wait 256
		 * msec to satisfy Diag Reset timing requirements.
		 */
		if (first_wait_done) {
			if (mtx_owned(&sc->mpr_mtx) && sleep_flag == CAN_SLEEP)
				msleep(&sc->msleep_fake_chan, &sc->mpr_mtx, 0,
				    "mprdiag", hz/20);
			else if (sleep_flag == CAN_SLEEP)
				pause("mprdiag", hz/20);
			else
				DELAY(50 * 1000);
		} else {
			DELAY(256 * 1000);
			first_wait_done = TRUE;
		}
		/*
		 * Check for the RESET_ADAPTER bit to be cleared first, then
		 * wait for the RESET state to be cleared, which takes a little
		 * longer.
		 */
		reg = mpr_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
		if (reg & MPI2_DIAG_RESET_ADAPTER) {
			continue;
		}
		reg = mpr_regread(sc, MPI2_DOORBELL_OFFSET);
		if ((reg & MPI2_IOC_STATE_MASK) != MPI2_IOC_STATE_RESET) {
			error = 0;
			break;
		}
	}
	if (error) {
		mpr_dprint(sc, MPR_INIT, "reset failed, error= %d, exit\n",
		    error);
		return (error);
	}

	mpr_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET, 0x0);
	mpr_dprint(sc, MPR_INIT, "diag reset success, exit\n");

	return (0);
}

static int
mpr_message_unit_reset(struct mpr_softc *sc, int sleep_flag)
{
	int error;

	MPR_FUNCTRACE(sc);

	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	error = 0;
	mpr_regwrite(sc, MPI2_DOORBELL_OFFSET,
	    MPI2_FUNCTION_IOC_MESSAGE_UNIT_RESET <<
	    MPI2_DOORBELL_FUNCTION_SHIFT);

	if (mpr_wait_db_ack(sc, 5, sleep_flag) != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT,
		    "Doorbell handshake failed\n");
		error = ETIMEDOUT;
	}

	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);
	return (error);
}

static int
mpr_transition_ready(struct mpr_softc *sc)
{
	uint32_t reg, state;
	int error, tries = 0;
	int sleep_flags;

	MPR_FUNCTRACE(sc);
	/* If we are in attach call, do not sleep */
	sleep_flags = (sc->mpr_flags & MPR_FLAGS_ATTACH_DONE)
	    ? CAN_SLEEP : NO_SLEEP;

	error = 0;

	mpr_dprint(sc, MPR_INIT, "%s entered, sleep_flags= %d\n",
	    __func__, sleep_flags);

	while (tries++ < 1200) {
		reg = mpr_regread(sc, MPI2_DOORBELL_OFFSET);
		mpr_dprint(sc, MPR_INIT, "  Doorbell= 0x%x\n", reg);

		/*
		 * Ensure the IOC is ready to talk.  If it's not, try
		 * resetting it.
		 */
		if (reg & MPI2_DOORBELL_USED) {
			mpr_dprint(sc, MPR_INIT, "  Not ready, sending diag "
			    "reset\n");
			mpr_diag_reset(sc, sleep_flags);
			DELAY(50000);
			continue;
		}

		/* Is the adapter owned by another peer? */
		if ((reg & MPI2_DOORBELL_WHO_INIT_MASK) ==
		    (MPI2_WHOINIT_PCI_PEER << MPI2_DOORBELL_WHO_INIT_SHIFT)) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, "IOC is under the "
			    "control of another peer host, aborting "
			    "initialization.\n");
			error = ENXIO;
			break;
		}
		
		state = reg & MPI2_IOC_STATE_MASK;
		if (state == MPI2_IOC_STATE_READY) {
			/* Ready to go! */
			error = 0;
			break;
		} else if (state == MPI2_IOC_STATE_FAULT) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, "IOC in fault "
			    "state 0x%x, resetting\n",
			    state & MPI2_DOORBELL_FAULT_CODE_MASK);
			mpr_diag_reset(sc, sleep_flags);
		} else if (state == MPI2_IOC_STATE_OPERATIONAL) {
			/* Need to take ownership */
			mpr_message_unit_reset(sc, sleep_flags);
		} else if (state == MPI2_IOC_STATE_RESET) {
			/* Wait a bit, IOC might be in transition */
			mpr_dprint(sc, MPR_INIT|MPR_FAULT,
			    "IOC in unexpected reset state\n");
		} else {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT,
			    "IOC in unknown state 0x%x\n", state);
			error = EINVAL;
			break;
		}

		/* Wait 50ms for things to settle down. */
		DELAY(50000);
	}

	if (error)
		mpr_dprint(sc, MPR_INIT|MPR_FAULT,
		    "Cannot transition IOC to ready\n");
	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);
	return (error);
}

static int
mpr_transition_operational(struct mpr_softc *sc)
{
	uint32_t reg, state;
	int error;

	MPR_FUNCTRACE(sc);

	error = 0;
	reg = mpr_regread(sc, MPI2_DOORBELL_OFFSET);
	mpr_dprint(sc, MPR_INIT, "%s entered, Doorbell= 0x%x\n", __func__, reg);

	state = reg & MPI2_IOC_STATE_MASK;
	if (state != MPI2_IOC_STATE_READY) {
		mpr_dprint(sc, MPR_INIT, "IOC not ready\n");
		if ((error = mpr_transition_ready(sc)) != 0) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, 
			    "failed to transition ready, exit\n");
			return (error);
		}
	}

	error = mpr_send_iocinit(sc);
	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);

	return (error);
}

static void
mpr_resize_queues(struct mpr_softc *sc)
{
	u_int reqcr, prireqcr, maxio, sges_per_frame, chain_seg_size;

	/*
	 * Size the queues. Since the reply queues always need one free
	 * entry, we'll deduct one reply message here.  The LSI documents
	 * suggest instead to add a count to the request queue, but I think
	 * that it's better to deduct from reply queue.
	 */
	prireqcr = MAX(1, sc->max_prireqframes);
	prireqcr = MIN(prireqcr, sc->facts->HighPriorityCredit);

	reqcr = MAX(2, sc->max_reqframes);
	reqcr = MIN(reqcr, sc->facts->RequestCredit);

	sc->num_reqs = prireqcr + reqcr;
	sc->num_prireqs = prireqcr;
	sc->num_replies = MIN(sc->max_replyframes + sc->max_evtframes,
	    sc->facts->MaxReplyDescriptorPostQueueDepth) - 1;

	/* Store the request frame size in bytes rather than as 32bit words */
	sc->reqframesz = sc->facts->IOCRequestFrameSize * 4;

	/*
	 * Gen3 and beyond uses the IOCMaxChainSegmentSize from IOC Facts to
	 * get the size of a Chain Frame.  Previous versions use the size as a
	 * Request Frame for the Chain Frame size.  If IOCMaxChainSegmentSize
	 * is 0, use the default value.  The IOCMaxChainSegmentSize is the
	 * number of 16-byte elelements that can fit in a Chain Frame, which is
	 * the size of an IEEE Simple SGE.
	 */
	if (sc->facts->MsgVersion >= MPI2_VERSION_02_05) {
		chain_seg_size = htole16(sc->facts->IOCMaxChainSegmentSize);
		if (chain_seg_size == 0)
			chain_seg_size = MPR_DEFAULT_CHAIN_SEG_SIZE;
		sc->chain_frame_size = chain_seg_size *
		    MPR_MAX_CHAIN_ELEMENT_SIZE;
	} else {
		sc->chain_frame_size = sc->reqframesz;
	}

	/*
	 * Max IO Size is Page Size * the following:
	 * ((SGEs per frame - 1 for chain element) * Max Chain Depth)
	 * + 1 for no chain needed in last frame
	 *
	 * If user suggests a Max IO size to use, use the smaller of the
	 * user's value and the calculated value as long as the user's
	 * value is larger than 0. The user's value is in pages.
	 */
	sges_per_frame = sc->chain_frame_size/sizeof(MPI2_IEEE_SGE_SIMPLE64)-1;
	maxio = (sges_per_frame * sc->facts->MaxChainDepth + 1) * PAGE_SIZE;

	/*
	 * If I/O size limitation requested then use it and pass up to CAM.
	 * If not, use MAXPHYS as an optimization hint, but report HW limit.
	 */
	if (sc->max_io_pages > 0) {
		maxio = min(maxio, sc->max_io_pages * PAGE_SIZE);
		sc->maxio = maxio;
	} else {
		sc->maxio = maxio;
		maxio = min(maxio, MAXPHYS);
	}

	sc->num_chains = (maxio / PAGE_SIZE + sges_per_frame - 2) /
	    sges_per_frame * reqcr;
	if (sc->max_chains > 0 && sc->max_chains < sc->num_chains)
		sc->num_chains = sc->max_chains;

	/*
	 * Figure out the number of MSIx-based queues.  If the firmware or
	 * user has done something crazy and not allowed enough credit for
	 * the queues to be useful then don't enable multi-queue.
	 */
	if (sc->facts->MaxMSIxVectors < 2)
		sc->msi_msgs = 1;

	if (sc->msi_msgs > 1) {
		sc->msi_msgs = MIN(sc->msi_msgs, mp_ncpus);
		sc->msi_msgs = MIN(sc->msi_msgs, sc->facts->MaxMSIxVectors);
		if (sc->num_reqs / sc->msi_msgs < 2)
			sc->msi_msgs = 1;
	}

	mpr_dprint(sc, MPR_INIT, "Sized queues to q=%d reqs=%d replies=%d\n",
	    sc->msi_msgs, sc->num_reqs, sc->num_replies);
}

/*
 * This is called during attach and when re-initializing due to a Diag Reset.
 * IOC Facts is used to allocate many of the structures needed by the driver.
 * If called from attach, de-allocation is not required because the driver has
 * not allocated any structures yet, but if called from a Diag Reset, previously
 * allocated structures based on IOC Facts will need to be freed and re-
 * allocated bases on the latest IOC Facts.
 */
static int
mpr_iocfacts_allocate(struct mpr_softc *sc, uint8_t attaching)
{
	int error;
	Mpi2IOCFactsReply_t saved_facts;
	uint8_t saved_mode, reallocating;

	mpr_dprint(sc, MPR_INIT|MPR_TRACE, "%s entered\n", __func__);

	/* Save old IOC Facts and then only reallocate if Facts have changed */
	if (!attaching) {
		bcopy(sc->facts, &saved_facts, sizeof(MPI2_IOC_FACTS_REPLY));
	}

	/*
	 * Get IOC Facts.  In all cases throughout this function, panic if doing
	 * a re-initialization and only return the error if attaching so the OS
	 * can handle it.
	 */
	if ((error = mpr_get_iocfacts(sc, sc->facts)) != 0) {
		if (attaching) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, "Failed to get "
			    "IOC Facts with error %d, exit\n", error);
			return (error);
		} else {
			panic("%s failed to get IOC Facts with error %d\n",
			    __func__, error);
		}
	}

	MPR_DPRINT_PAGE(sc, MPR_XINFO, iocfacts, sc->facts);

	snprintf(sc->fw_version, sizeof(sc->fw_version), 
	    "%02d.%02d.%02d.%02d", 
	    sc->facts->FWVersion.Struct.Major,
	    sc->facts->FWVersion.Struct.Minor,
	    sc->facts->FWVersion.Struct.Unit,
	    sc->facts->FWVersion.Struct.Dev);

	snprintf(sc->msg_version, sizeof(sc->msg_version), "%d.%d",
	    (sc->facts->MsgVersion & MPI2_IOCFACTS_MSGVERSION_MAJOR_MASK) >>
	    MPI2_IOCFACTS_MSGVERSION_MAJOR_SHIFT,
	    (sc->facts->MsgVersion & MPI2_IOCFACTS_MSGVERSION_MINOR_MASK) >>
	    MPI2_IOCFACTS_MSGVERSION_MINOR_SHIFT);

	mpr_dprint(sc, MPR_INFO, "Firmware: %s, Driver: %s\n", sc->fw_version,
	    MPR_DRIVER_VERSION);
	mpr_dprint(sc, MPR_INFO,
	    "IOCCapabilities: %b\n", sc->facts->IOCCapabilities,
	    "\20" "\3ScsiTaskFull" "\4DiagTrace" "\5SnapBuf" "\6ExtBuf"
	    "\7EEDP" "\10BiDirTarg" "\11Multicast" "\14TransRetry" "\15IR"
	    "\16EventReplay" "\17RaidAccel" "\20MSIXIndex" "\21HostDisc"
	    "\22FastPath" "\23RDPQArray" "\24AtomicReqDesc" "\25PCIeSRIOV");

	/*
	 * If the chip doesn't support event replay then a hard reset will be
	 * required to trigger a full discovery.  Do the reset here then
	 * retransition to Ready.  A hard reset might have already been done,
	 * but it doesn't hurt to do it again.  Only do this if attaching, not
	 * for a Diag Reset.
	 */
	if (attaching && ((sc->facts->IOCCapabilities &
	    MPI2_IOCFACTS_CAPABILITY_EVENT_REPLAY) == 0)) {
		mpr_dprint(sc, MPR_INIT, "No event replay, resetting\n");
		mpr_diag_reset(sc, NO_SLEEP);
		if ((error = mpr_transition_ready(sc)) != 0) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, "Failed to "
			    "transition to ready with error %d, exit\n",
			    error);
			return (error);
		}
	}

	/*
	 * Set flag if IR Firmware is loaded.  If the RAID Capability has
	 * changed from the previous IOC Facts, log a warning, but only if
	 * checking this after a Diag Reset and not during attach.
	 */
	saved_mode = sc->ir_firmware;
	if (sc->facts->IOCCapabilities &
	    MPI2_IOCFACTS_CAPABILITY_INTEGRATED_RAID)
		sc->ir_firmware = 1;
	if (!attaching) {
		if (sc->ir_firmware != saved_mode) {
			mpr_dprint(sc, MPR_INIT|MPR_FAULT, "new IR/IT mode "
			    "in IOC Facts does not match previous mode\n");
		}
	}

	/* Only deallocate and reallocate if relevant IOC Facts have changed */
	reallocating = FALSE;
	sc->mpr_flags &= ~MPR_FLAGS_REALLOCATED;

	if ((!attaching) &&
	    ((saved_facts.MsgVersion != sc->facts->MsgVersion) ||
	    (saved_facts.HeaderVersion != sc->facts->HeaderVersion) ||
	    (saved_facts.MaxChainDepth != sc->facts->MaxChainDepth) ||
	    (saved_facts.RequestCredit != sc->facts->RequestCredit) ||
	    (saved_facts.ProductID != sc->facts->ProductID) ||
	    (saved_facts.IOCCapabilities != sc->facts->IOCCapabilities) ||
	    (saved_facts.IOCRequestFrameSize !=
	    sc->facts->IOCRequestFrameSize) ||
	    (saved_facts.IOCMaxChainSegmentSize !=
	    sc->facts->IOCMaxChainSegmentSize) ||
	    (saved_facts.MaxTargets != sc->facts->MaxTargets) ||
	    (saved_facts.MaxSasExpanders != sc->facts->MaxSasExpanders) ||
	    (saved_facts.MaxEnclosures != sc->facts->MaxEnclosures) ||
	    (saved_facts.HighPriorityCredit != sc->facts->HighPriorityCredit) ||
	    (saved_facts.MaxReplyDescriptorPostQueueDepth !=
	    sc->facts->MaxReplyDescriptorPostQueueDepth) ||
	    (saved_facts.ReplyFrameSize != sc->facts->ReplyFrameSize) ||
	    (saved_facts.MaxVolumes != sc->facts->MaxVolumes) ||
	    (saved_facts.MaxPersistentEntries !=
	    sc->facts->MaxPersistentEntries))) {
		reallocating = TRUE;

		/* Record that we reallocated everything */
		sc->mpr_flags |= MPR_FLAGS_REALLOCATED;
	}

	/*
	 * Some things should be done if attaching or re-allocating after a Diag
	 * Reset, but are not needed after a Diag Reset if the FW has not
	 * changed.
	 */
	if (attaching || reallocating) {
		/*
		 * Check if controller supports FW diag buffers and set flag to
		 * enable each type.
		 */
		if (sc->facts->IOCCapabilities &
		    MPI2_IOCFACTS_CAPABILITY_DIAG_TRACE_BUFFER)
			sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_TRACE].
			    enabled = TRUE;
		if (sc->facts->IOCCapabilities &
		    MPI2_IOCFACTS_CAPABILITY_SNAPSHOT_BUFFER)
			sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_SNAPSHOT].
			    enabled = TRUE;
		if (sc->facts->IOCCapabilities &
		    MPI2_IOCFACTS_CAPABILITY_EXTENDED_BUFFER)
			sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_EXTENDED].
			    enabled = TRUE;

		/*
		 * Set flags for some supported items.
		 */
		if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_EEDP)
			sc->eedp_enabled = TRUE;
		if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_TLR)
			sc->control_TLR = TRUE;
		if ((sc->facts->IOCCapabilities &
		    MPI26_IOCFACTS_CAPABILITY_ATOMIC_REQ) &&
		    (sc->mpr_flags & MPR_FLAGS_SEA_IOC))
			sc->atomic_desc_capable = TRUE;

		mpr_resize_queues(sc);

		/*
		 * Initialize all Tail Queues
		 */
		TAILQ_INIT(&sc->req_list);
		TAILQ_INIT(&sc->high_priority_req_list);
		TAILQ_INIT(&sc->chain_list);
		TAILQ_INIT(&sc->prp_page_list);
		TAILQ_INIT(&sc->tm_list);
	}

	/*
	 * If doing a Diag Reset and the FW is significantly different
	 * (reallocating will be set above in IOC Facts comparison), then all
	 * buffers based on the IOC Facts will need to be freed before they are
	 * reallocated.
	 */
	if (reallocating) {
		mpr_iocfacts_free(sc);
		mprsas_realloc_targets(sc, saved_facts.MaxTargets +
		    saved_facts.MaxVolumes);
	}

	/*
	 * Any deallocation has been completed.  Now start reallocating
	 * if needed.  Will only need to reallocate if attaching or if the new
	 * IOC Facts are different from the previous IOC Facts after a Diag
	 * Reset. Targets have already been allocated above if needed.
	 */
	error = 0;
	while (attaching || reallocating) {
		if ((error = mpr_alloc_hw_queues(sc)) != 0)
			break;
		if ((error = mpr_alloc_replies(sc)) != 0)
			break;
		if ((error = mpr_alloc_requests(sc)) != 0)
			break;
		if ((error = mpr_alloc_queues(sc)) != 0)
			break;
		break;
	}
	if (error) {
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "Failed to alloc queues with error %d\n", error);
		mpr_free(sc);
		return (error);
	}

	/* Always initialize the queues */
	bzero(sc->free_queue, sc->fqdepth * 4);
	mpr_init_queues(sc);

	/*
	 * Always get the chip out of the reset state, but only panic if not
	 * attaching.  If attaching and there is an error, that is handled by
	 * the OS.
	 */
	error = mpr_transition_operational(sc);
	if (error != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT, "Failed to "
		    "transition to operational with error %d\n", error);
		mpr_free(sc);
		return (error);
	}

	/*
	 * Finish the queue initialization.
	 * These are set here instead of in mpr_init_queues() because the
	 * IOC resets these values during the state transition in
	 * mpr_transition_operational().  The free index is set to 1
	 * because the corresponding index in the IOC is set to 0, and the
	 * IOC treats the queues as full if both are set to the same value.
	 * Hence the reason that the queue can't hold all of the possible
	 * replies.
	 */
	sc->replypostindex = 0;
	mpr_regwrite(sc, MPI2_REPLY_FREE_HOST_INDEX_OFFSET, sc->replyfreeindex);
	mpr_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET, 0);

	/*
	 * Attach the subsystems so they can prepare their event masks.
	 * XXX Should be dynamic so that IM/IR and user modules can attach
	 */
	error = 0;
	while (attaching) {
		mpr_dprint(sc, MPR_INIT, "Attaching subsystems\n");
		if ((error = mpr_attach_log(sc)) != 0)
			break;
		if ((error = mpr_attach_sas(sc)) != 0)
			break;
		if ((error = mpr_attach_user(sc)) != 0)
			break;
		break;
	}
	if (error) {
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "Failed to attach all subsystems: error %d\n", error);
		mpr_free(sc);
		return (error);
	}

	/*
	 * XXX If the number of MSI-X vectors changes during re-init, this
	 * won't see it and adjust.
	 */
	if (attaching && (error = mpr_pci_setup_interrupts(sc)) != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "Failed to setup interrupts\n");
		mpr_free(sc);
		return (error);
	}

	return (error);
}

/*
 * This is called if memory is being free (during detach for example) and when
 * buffers need to be reallocated due to a Diag Reset.
 */
static void
mpr_iocfacts_free(struct mpr_softc *sc)
{
	struct mpr_command *cm;
	int i;

	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	if (sc->free_busaddr != 0)
		bus_dmamap_unload(sc->queues_dmat, sc->queues_map);
	if (sc->free_queue != NULL)
		bus_dmamem_free(sc->queues_dmat, sc->free_queue,
		    sc->queues_map);
	if (sc->queues_dmat != NULL)
		bus_dma_tag_destroy(sc->queues_dmat);

	if (sc->chain_frames != NULL) {
		bus_dmamap_unload(sc->chain_dmat, sc->chain_map);
		bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
		    sc->chain_map);
	}
	if (sc->chain_dmat != NULL)
		bus_dma_tag_destroy(sc->chain_dmat);

	if (sc->sense_busaddr != 0)
		bus_dmamap_unload(sc->sense_dmat, sc->sense_map);
	if (sc->sense_frames != NULL)
		bus_dmamem_free(sc->sense_dmat, sc->sense_frames,
		    sc->sense_map);
	if (sc->sense_dmat != NULL)
		bus_dma_tag_destroy(sc->sense_dmat);

	if (sc->prp_page_busaddr != 0)
		bus_dmamap_unload(sc->prp_page_dmat, sc->prp_page_map);
	if (sc->prp_pages != NULL)
		bus_dmamem_free(sc->prp_page_dmat, sc->prp_pages,
		    sc->prp_page_map);
	if (sc->prp_page_dmat != NULL)
		bus_dma_tag_destroy(sc->prp_page_dmat);

	if (sc->reply_busaddr != 0)
		bus_dmamap_unload(sc->reply_dmat, sc->reply_map);
	if (sc->reply_frames != NULL)
		bus_dmamem_free(sc->reply_dmat, sc->reply_frames,
		    sc->reply_map);
	if (sc->reply_dmat != NULL)
		bus_dma_tag_destroy(sc->reply_dmat);

	if (sc->req_busaddr != 0)
		bus_dmamap_unload(sc->req_dmat, sc->req_map);
	if (sc->req_frames != NULL)
		bus_dmamem_free(sc->req_dmat, sc->req_frames, sc->req_map);
	if (sc->req_dmat != NULL)
		bus_dma_tag_destroy(sc->req_dmat);

	if (sc->chains != NULL)
		free(sc->chains, M_MPR);
	if (sc->prps != NULL)
		free(sc->prps, M_MPR);
	if (sc->commands != NULL) {
		for (i = 1; i < sc->num_reqs; i++) {
			cm = &sc->commands[i];
			bus_dmamap_destroy(sc->buffer_dmat, cm->cm_dmamap);
		}
		free(sc->commands, M_MPR);
	}
	if (sc->buffer_dmat != NULL)
		bus_dma_tag_destroy(sc->buffer_dmat);

	mpr_pci_free_interrupts(sc);
	free(sc->queues, M_MPR);
	sc->queues = NULL;
}

/* 
 * The terms diag reset and hard reset are used interchangeably in the MPI
 * docs to mean resetting the controller chip.  In this code diag reset
 * cleans everything up, and the hard reset function just sends the reset
 * sequence to the chip.  This should probably be refactored so that every
 * subsystem gets a reset notification of some sort, and can clean up
 * appropriately.
 */
int
mpr_reinit(struct mpr_softc *sc)
{
	int error;
	struct mprsas_softc *sassc;

	sassc = sc->sassc;

	MPR_FUNCTRACE(sc);

	mtx_assert(&sc->mpr_mtx, MA_OWNED);

	mpr_dprint(sc, MPR_INIT|MPR_INFO, "Reinitializing controller\n");
	if (sc->mpr_flags & MPR_FLAGS_DIAGRESET) {
		mpr_dprint(sc, MPR_INIT, "Reset already in progress\n");
		return 0;
	}

	/*
	 * Make sure the completion callbacks can recognize they're getting
	 * a NULL cm_reply due to a reset.
	 */
	sc->mpr_flags |= MPR_FLAGS_DIAGRESET;

	/*
	 * Mask interrupts here.
	 */
	mpr_dprint(sc, MPR_INIT, "Masking interrupts and resetting\n");
	mpr_mask_intr(sc);

	error = mpr_diag_reset(sc, CAN_SLEEP);
	if (error != 0) {
		panic("%s hard reset failed with error %d\n", __func__, error);
	}

	/* Restore the PCI state, including the MSI-X registers */
	mpr_pci_restore(sc);

	/* Give the I/O subsystem special priority to get itself prepared */
	mprsas_handle_reinit(sc);

	/*
	 * Get IOC Facts and allocate all structures based on this information.
	 * The attach function will also call mpr_iocfacts_allocate at startup.
	 * If relevant values have changed in IOC Facts, this function will free
	 * all of the memory based on IOC Facts and reallocate that memory.
	 */
	if ((error = mpr_iocfacts_allocate(sc, FALSE)) != 0) {
		panic("%s IOC Facts based allocation failed with error %d\n",
		    __func__, error);
	}

	/*
	 * Mapping structures will be re-allocated after getting IOC Page8, so
	 * free these structures here.
	 */
	mpr_mapping_exit(sc);

	/*
	 * The static page function currently read is IOC Page8.  Others can be
	 * added in future.  It's possible that the values in IOC Page8 have
	 * changed after a Diag Reset due to user modification, so always read
	 * these.  Interrupts are masked, so unmask them before getting config
	 * pages.
	 */
	mpr_unmask_intr(sc);
	sc->mpr_flags &= ~MPR_FLAGS_DIAGRESET;
	mpr_base_static_config_pages(sc);

	/*
	 * Some mapping info is based in IOC Page8 data, so re-initialize the
	 * mapping tables.
	 */
	mpr_mapping_initialize(sc);

	/*
	 * Restart will reload the event masks clobbered by the reset, and
	 * then enable the port.
	 */
	mpr_reregister_events(sc);

	/* the end of discovery will release the simq, so we're done. */
	mpr_dprint(sc, MPR_INIT|MPR_XINFO, "Finished sc %p post %u free %u\n", 
	    sc, sc->replypostindex, sc->replyfreeindex);
	mprsas_release_simq_reinit(sassc);
	mpr_dprint(sc, MPR_INIT, "%s exit error= %d\n", __func__, error);

	return 0;
}

/* Wait for the chip to ACK a word that we've put into its FIFO 
 * Wait for <timeout> seconds. In single loop wait for busy loop
 * for 500 microseconds.
 * Total is [ 0.5 * (2000 * <timeout>) ] in miliseconds.
 * */
static int
mpr_wait_db_ack(struct mpr_softc *sc, int timeout, int sleep_flag)
{
	u32 cntdn, count;
	u32 int_status;
	u32 doorbell;

	count = 0;
	cntdn = (sleep_flag == CAN_SLEEP) ? 1000*timeout : 2000*timeout;
	do {
		int_status = mpr_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
		if (!(int_status & MPI2_HIS_SYS2IOC_DB_STATUS)) {
			mpr_dprint(sc, MPR_TRACE, "%s: successful count(%d), "
			    "timeout(%d)\n", __func__, count, timeout);
			return 0;
		} else if (int_status & MPI2_HIS_IOC2SYS_DB_STATUS) {
			doorbell = mpr_regread(sc, MPI2_DOORBELL_OFFSET);
			if ((doorbell & MPI2_IOC_STATE_MASK) ==
			    MPI2_IOC_STATE_FAULT) {
				mpr_dprint(sc, MPR_FAULT,
				    "fault_state(0x%04x)!\n", doorbell);
				return (EFAULT);
			}
		} else if (int_status == 0xFFFFFFFF)
			goto out;
			
		/*
		 * If it can sleep, sleep for 1 milisecond, else busy loop for
 		 * 0.5 milisecond
		 */
		if (mtx_owned(&sc->mpr_mtx) && sleep_flag == CAN_SLEEP)
			msleep(&sc->msleep_fake_chan, &sc->mpr_mtx, 0, "mprdba",
			    hz/1000);
		else if (sleep_flag == CAN_SLEEP)
			pause("mprdba", hz/1000);
		else
			DELAY(500);
		count++;
	} while (--cntdn);

out:
	mpr_dprint(sc, MPR_FAULT, "%s: failed due to timeout count(%d), "
		"int_status(%x)!\n", __func__, count, int_status);
	return (ETIMEDOUT);
}

/* Wait for the chip to signal that the next word in its FIFO can be fetched */
static int
mpr_wait_db_int(struct mpr_softc *sc)
{
	int retry;

	for (retry = 0; retry < MPR_DB_MAX_WAIT; retry++) {
		if ((mpr_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET) &
		    MPI2_HIS_IOC2SYS_DB_STATUS) != 0)
			return (0);
		DELAY(2000);
	}
	return (ETIMEDOUT);
}

/* Step through the synchronous command state machine, i.e. "Doorbell mode" */
static int
mpr_request_sync(struct mpr_softc *sc, void *req, MPI2_DEFAULT_REPLY *reply,
    int req_sz, int reply_sz, int timeout)
{
	uint32_t *data32;
	uint16_t *data16;
	int i, count, ioc_sz, residual;
	int sleep_flags = CAN_SLEEP;

	if (curthread->td_no_sleeping)
		sleep_flags = NO_SLEEP;

	/* Step 1 */
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

	/* Step 2 */
	if (mpr_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
		return (EBUSY);

	/* Step 3
	 * Announce that a message is coming through the doorbell.  Messages
	 * are pushed at 32bit words, so round up if needed.
	 */
	count = (req_sz + 3) / 4;
	mpr_regwrite(sc, MPI2_DOORBELL_OFFSET,
	    (MPI2_FUNCTION_HANDSHAKE << MPI2_DOORBELL_FUNCTION_SHIFT) |
	    (count << MPI2_DOORBELL_ADD_DWORDS_SHIFT));

	/* Step 4 */
	if (mpr_wait_db_int(sc) ||
	    (mpr_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED) == 0) {
		mpr_dprint(sc, MPR_FAULT, "Doorbell failed to activate\n");
		return (ENXIO);
	}
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
	if (mpr_wait_db_ack(sc, 5, sleep_flags) != 0) {
		mpr_dprint(sc, MPR_FAULT, "Doorbell handshake failed\n");
		return (ENXIO);
	}

	/* Step 5 */
	/* Clock out the message data synchronously in 32-bit dwords*/
	data32 = (uint32_t *)req;
	for (i = 0; i < count; i++) {
		mpr_regwrite(sc, MPI2_DOORBELL_OFFSET, htole32(data32[i]));
		if (mpr_wait_db_ack(sc, 5, sleep_flags) != 0) {
			mpr_dprint(sc, MPR_FAULT,
			    "Timeout while writing doorbell\n");
			return (ENXIO);
		}
	}

	/* Step 6 */
	/* Clock in the reply in 16-bit words.  The total length of the
	 * message is always in the 4th byte, so clock out the first 2 words
	 * manually, then loop the rest.
	 */
	data16 = (uint16_t *)reply;
	if (mpr_wait_db_int(sc) != 0) {
		mpr_dprint(sc, MPR_FAULT, "Timeout reading doorbell 0\n");
		return (ENXIO);
	}
	data16[0] =
	    mpr_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
	if (mpr_wait_db_int(sc) != 0) {
		mpr_dprint(sc, MPR_FAULT, "Timeout reading doorbell 1\n");
		return (ENXIO);
	}
	data16[1] =
	    mpr_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

	/* Number of 32bit words in the message */
	ioc_sz = reply->MsgLength;

	/*
	 * Figure out how many 16bit words to clock in without overrunning.
	 * The precision loss with dividing reply_sz can safely be
	 * ignored because the messages can only be multiples of 32bits.
	 */
	residual = 0;
	count = MIN((reply_sz / 4), ioc_sz) * 2;
	if (count < ioc_sz * 2) {
		residual = ioc_sz * 2 - count;
		mpr_dprint(sc, MPR_ERROR, "Driver error, throwing away %d "
		    "residual message words\n", residual);
	}

	for (i = 2; i < count; i++) {
		if (mpr_wait_db_int(sc) != 0) {
			mpr_dprint(sc, MPR_FAULT,
			    "Timeout reading doorbell %d\n", i);
			return (ENXIO);
		}
		data16[i] = mpr_regread(sc, MPI2_DOORBELL_OFFSET) &
		    MPI2_DOORBELL_DATA_MASK;
		mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
	}

	/*
	 * Pull out residual words that won't fit into the provided buffer.
	 * This keeps the chip from hanging due to a driver programming
	 * error.
	 */
	while (residual--) {
		if (mpr_wait_db_int(sc) != 0) {
			mpr_dprint(sc, MPR_FAULT, "Timeout reading doorbell\n");
			return (ENXIO);
		}
		(void)mpr_regread(sc, MPI2_DOORBELL_OFFSET);
		mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
	}

	/* Step 7 */
	if (mpr_wait_db_int(sc) != 0) {
		mpr_dprint(sc, MPR_FAULT, "Timeout waiting to exit doorbell\n");
		return (ENXIO);
	}
	if (mpr_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
		mpr_dprint(sc, MPR_FAULT, "Warning, doorbell still active\n");
	mpr_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

	return (0);
}

static void
mpr_enqueue_request(struct mpr_softc *sc, struct mpr_command *cm)
{
	request_descriptor_t rd;

	MPR_FUNCTRACE(sc);
	mpr_dprint(sc, MPR_TRACE, "SMID %u cm %p ccb %p\n",
	    cm->cm_desc.Default.SMID, cm, cm->cm_ccb);

	if (sc->mpr_flags & MPR_FLAGS_ATTACH_DONE && !(sc->mpr_flags &
	    MPR_FLAGS_SHUTDOWN))
		mtx_assert(&sc->mpr_mtx, MA_OWNED);

	if (++sc->io_cmds_active > sc->io_cmds_highwater)
		sc->io_cmds_highwater++;

	KASSERT(cm->cm_state == MPR_CM_STATE_BUSY, ("command not busy\n"));
	cm->cm_state = MPR_CM_STATE_INQUEUE;

	if (sc->atomic_desc_capable) {
		rd.u.low = cm->cm_desc.Words.Low;
		mpr_regwrite(sc, MPI26_ATOMIC_REQUEST_DESCRIPTOR_POST_OFFSET,
		    rd.u.low);
	} else {
		rd.u.low = cm->cm_desc.Words.Low;
		rd.u.high = cm->cm_desc.Words.High;
		rd.word = htole64(rd.word);
		mpr_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_LOW_OFFSET,
		    rd.u.low);
		mpr_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_HIGH_OFFSET,
		    rd.u.high);
	}
}

/*
 * Just the FACTS, ma'am.
 */
static int
mpr_get_iocfacts(struct mpr_softc *sc, MPI2_IOC_FACTS_REPLY *facts)
{
	MPI2_DEFAULT_REPLY *reply;
	MPI2_IOC_FACTS_REQUEST request;
	int error, req_sz, reply_sz;

	MPR_FUNCTRACE(sc);
	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	req_sz = sizeof(MPI2_IOC_FACTS_REQUEST);
	reply_sz = sizeof(MPI2_IOC_FACTS_REPLY);
	reply = (MPI2_DEFAULT_REPLY *)facts;

	bzero(&request, req_sz);
	request.Function = MPI2_FUNCTION_IOC_FACTS;
	error = mpr_request_sync(sc, &request, reply, req_sz, reply_sz, 5);

	mpr_dprint(sc, MPR_INIT, "%s exit, error= %d\n", __func__, error);
	return (error);
}

static int
mpr_send_iocinit(struct mpr_softc *sc)
{
	MPI2_IOC_INIT_REQUEST	init;
	MPI2_DEFAULT_REPLY	reply;
	int req_sz, reply_sz, error;
	struct timeval now;
	uint64_t time_in_msec;

	MPR_FUNCTRACE(sc);
	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	/* Do a quick sanity check on proper initialization */
	if ((sc->pqdepth == 0) || (sc->fqdepth == 0) || (sc->reqframesz == 0)
	    || (sc->replyframesz == 0)) {
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "Driver not fully initialized for IOCInit\n");
		return (EINVAL);
	}

	req_sz = sizeof(MPI2_IOC_INIT_REQUEST);
	reply_sz = sizeof(MPI2_IOC_INIT_REPLY);
	bzero(&init, req_sz);
	bzero(&reply, reply_sz);

	/*
	 * Fill in the init block.  Note that most addresses are
	 * deliberately in the lower 32bits of memory.  This is a micro-
	 * optimzation for PCI/PCIX, though it's not clear if it helps PCIe.
	 */
	init.Function = MPI2_FUNCTION_IOC_INIT;
	init.WhoInit = MPI2_WHOINIT_HOST_DRIVER;
	init.MsgVersion = htole16(MPI2_VERSION);
	init.HeaderVersion = htole16(MPI2_HEADER_VERSION);
	init.SystemRequestFrameSize = htole16((uint16_t)(sc->reqframesz / 4));
	init.ReplyDescriptorPostQueueDepth = htole16(sc->pqdepth);
	init.ReplyFreeQueueDepth = htole16(sc->fqdepth);
	init.SenseBufferAddressHigh = 0;
	init.SystemReplyAddressHigh = 0;
	init.SystemRequestFrameBaseAddress.High = 0;
	init.SystemRequestFrameBaseAddress.Low =
	    htole32((uint32_t)sc->req_busaddr);
	init.ReplyDescriptorPostQueueAddress.High = 0;
	init.ReplyDescriptorPostQueueAddress.Low =
	    htole32((uint32_t)sc->post_busaddr);
	init.ReplyFreeQueueAddress.High = 0;
	init.ReplyFreeQueueAddress.Low = htole32((uint32_t)sc->free_busaddr);
	getmicrotime(&now);
	time_in_msec = (now.tv_sec * 1000 + now.tv_usec/1000);
	init.TimeStamp.High = htole32((time_in_msec >> 32) & 0xFFFFFFFF);
	init.TimeStamp.Low = htole32(time_in_msec & 0xFFFFFFFF);
	init.HostPageSize = HOST_PAGE_SIZE_4K;

	error = mpr_request_sync(sc, &init, &reply, req_sz, reply_sz, 5);
	if ((reply.IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
		error = ENXIO;

	mpr_dprint(sc, MPR_INIT, "IOCInit status= 0x%x\n", reply.IOCStatus);
	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);
	return (error);
}

void
mpr_memaddr_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
	bus_addr_t *addr;

	addr = arg;
	*addr = segs[0].ds_addr;
}

void
mpr_memaddr_wait_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
	struct mpr_busdma_context *ctx;
	int need_unload, need_free;

	ctx = (struct mpr_busdma_context *)arg;
	need_unload = 0;
	need_free = 0;

	mpr_lock(ctx->softc);
	ctx->error = error;
	ctx->completed = 1;
	if ((error == 0) && (ctx->abandoned == 0)) {
		*ctx->addr = segs[0].ds_addr;
	} else {
		if (nsegs != 0)
			need_unload = 1;
		if (ctx->abandoned != 0)
			need_free = 1;
	}
	if (need_free == 0)
		wakeup(ctx);

	mpr_unlock(ctx->softc);

	if (need_unload != 0) {
		bus_dmamap_unload(ctx->buffer_dmat,
				  ctx->buffer_dmamap);
		*ctx->addr = 0;
	}

	if (need_free != 0)
		free(ctx, M_MPR);
}

static int
mpr_alloc_queues(struct mpr_softc *sc)
{
	struct mpr_queue *q;
	int nq, i;

	nq = sc->msi_msgs;
	mpr_dprint(sc, MPR_INIT|MPR_XINFO, "Allocating %d I/O queues\n", nq);

	sc->queues = malloc(sizeof(struct mpr_queue) * nq, M_MPR,
	     M_NOWAIT|M_ZERO);
	if (sc->queues == NULL)
		return (ENOMEM);

	for (i = 0; i < nq; i++) {
		q = &sc->queues[i];
		mpr_dprint(sc, MPR_INIT, "Configuring queue %d %p\n", i, q);
		q->sc = sc;
		q->qnum = i;
	}
	return (0);
}

static int
mpr_alloc_hw_queues(struct mpr_softc *sc)
{
	bus_dma_template_t t;
	bus_addr_t queues_busaddr;
	uint8_t *queues;
	int qsize, fqsize, pqsize;

	/*
	 * The reply free queue contains 4 byte entries in multiples of 16 and
	 * aligned on a 16 byte boundary. There must always be an unused entry.
	 * This queue supplies fresh reply frames for the firmware to use.
	 *
	 * The reply descriptor post queue contains 8 byte entries in
	 * multiples of 16 and aligned on a 16 byte boundary.  This queue
	 * contains filled-in reply frames sent from the firmware to the host.
	 *
	 * These two queues are allocated together for simplicity.
	 */
	sc->fqdepth = roundup2(sc->num_replies + 1, 16);
	sc->pqdepth = roundup2(sc->num_replies + 1, 16);
	fqsize= sc->fqdepth * 4;
	pqsize = sc->pqdepth * 8;
	qsize = fqsize + pqsize;

	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(16), BD_MAXSIZE(qsize),
	    BD_MAXSEGSIZE(qsize), BD_NSEGMENTS(1),
	    BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
	if (bus_dma_template_tag(&t, &sc->queues_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate queues DMA tag\n");
		return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->queues_dmat, (void **)&queues, BUS_DMA_NOWAIT,
	    &sc->queues_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate queues memory\n");
		return (ENOMEM);
        }
        bzero(queues, qsize);
        bus_dmamap_load(sc->queues_dmat, sc->queues_map, queues, qsize,
	    mpr_memaddr_cb, &queues_busaddr, 0);

	sc->free_queue = (uint32_t *)queues;
	sc->free_busaddr = queues_busaddr;
	sc->post_queue = (MPI2_REPLY_DESCRIPTORS_UNION *)(queues + fqsize);
	sc->post_busaddr = queues_busaddr + fqsize;
	mpr_dprint(sc, MPR_INIT, "free queue busaddr= %#016jx size= %d\n",
	    (uintmax_t)sc->free_busaddr, fqsize);
	mpr_dprint(sc, MPR_INIT, "reply queue busaddr= %#016jx size= %d\n",
	    (uintmax_t)sc->post_busaddr, pqsize);

	return (0);
}

static int
mpr_alloc_replies(struct mpr_softc *sc)
{
	bus_dma_template_t t;
	int rsize, num_replies;

	/* Store the reply frame size in bytes rather than as 32bit words */
	sc->replyframesz = sc->facts->ReplyFrameSize * 4;

	/*
	 * sc->num_replies should be one less than sc->fqdepth.  We need to
	 * allocate space for sc->fqdepth replies, but only sc->num_replies
	 * replies can be used at once.
	 */
	num_replies = max(sc->fqdepth, sc->num_replies);

	rsize = sc->replyframesz * num_replies; 
	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(4), BD_MAXSIZE(rsize),
	    BD_MAXSEGSIZE(rsize), BD_NSEGMENTS(1),
	    BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
	if (bus_dma_template_tag(&t, &sc->reply_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate replies DMA tag\n");
		return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->reply_dmat, (void **)&sc->reply_frames,
	    BUS_DMA_NOWAIT, &sc->reply_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate replies memory\n");
		return (ENOMEM);
        }
        bzero(sc->reply_frames, rsize);
        bus_dmamap_load(sc->reply_dmat, sc->reply_map, sc->reply_frames, rsize,
	    mpr_memaddr_cb, &sc->reply_busaddr, 0);
	mpr_dprint(sc, MPR_INIT, "reply frames busaddr= %#016jx size= %d\n",
	    (uintmax_t)sc->reply_busaddr, rsize);

	return (0);
}

static void
mpr_load_chains_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
	struct mpr_softc *sc = arg;
	struct mpr_chain *chain;
	bus_size_t bo;
	int i, o, s;

	if (error != 0)
		return;

	for (i = 0, o = 0, s = 0; s < nsegs; s++) {
		for (bo = 0; bo + sc->chain_frame_size <= segs[s].ds_len;
		    bo += sc->chain_frame_size) {
			chain = &sc->chains[i++];
			chain->chain =(MPI2_SGE_IO_UNION *)(sc->chain_frames+o);
			chain->chain_busaddr = segs[s].ds_addr + bo;
			o += sc->chain_frame_size;
			mpr_free_chain(sc, chain);
		}
		if (bo != segs[s].ds_len)
			o += segs[s].ds_len - bo;
	}
	sc->chain_free_lowwater = i;
}

static int
mpr_alloc_requests(struct mpr_softc *sc)
{
	bus_dma_template_t t;
	struct mpr_command *cm;
	int i, rsize, nsegs;

	rsize = sc->reqframesz * sc->num_reqs;
	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(16), BD_MAXSIZE(rsize),
	    BD_MAXSEGSIZE(rsize), BD_NSEGMENTS(1),
	    BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
	if (bus_dma_template_tag(&t, &sc->req_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate request DMA tag\n");
		return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->req_dmat, (void **)&sc->req_frames,
	    BUS_DMA_NOWAIT, &sc->req_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate request memory\n");
		return (ENOMEM);
        }
        bzero(sc->req_frames, rsize);
        bus_dmamap_load(sc->req_dmat, sc->req_map, sc->req_frames, rsize,
	    mpr_memaddr_cb, &sc->req_busaddr, 0);
	mpr_dprint(sc, MPR_INIT, "request frames busaddr= %#016jx size= %d\n",
	    (uintmax_t)sc->req_busaddr, rsize);

	sc->chains = malloc(sizeof(struct mpr_chain) * sc->num_chains, M_MPR,
	    M_NOWAIT | M_ZERO);
	if (!sc->chains) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate chain memory\n");
		return (ENOMEM);
	}
	rsize = sc->chain_frame_size * sc->num_chains;
	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(16), BD_MAXSIZE(rsize),
	    BD_MAXSEGSIZE(rsize), BD_NSEGMENTS((howmany(rsize, PAGE_SIZE))));
	if (bus_dma_template_tag(&t, &sc->chain_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate chain DMA tag\n");
		return (ENOMEM);
	}
	if (bus_dmamem_alloc(sc->chain_dmat, (void **)&sc->chain_frames,
	    BUS_DMA_NOWAIT | BUS_DMA_ZERO, &sc->chain_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate chain memory\n");
		return (ENOMEM);
	}
	if (bus_dmamap_load(sc->chain_dmat, sc->chain_map, sc->chain_frames,
	    rsize, mpr_load_chains_cb, sc, BUS_DMA_NOWAIT)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot load chain memory\n");
		bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
		    sc->chain_map);
		return (ENOMEM);
	}

	rsize = MPR_SENSE_LEN * sc->num_reqs;
	bus_dma_template_clone(&t, sc->req_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(1), BD_MAXSIZE(rsize),
	    BD_MAXSEGSIZE(rsize));
	if (bus_dma_template_tag(&t, &sc->sense_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate sense DMA tag\n");
		return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->sense_dmat, (void **)&sc->sense_frames,
	    BUS_DMA_NOWAIT, &sc->sense_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate sense memory\n");
		return (ENOMEM);
        }
        bzero(sc->sense_frames, rsize);
        bus_dmamap_load(sc->sense_dmat, sc->sense_map, sc->sense_frames, rsize,
	    mpr_memaddr_cb, &sc->sense_busaddr, 0);
	mpr_dprint(sc, MPR_INIT, "sense frames busaddr= %#016jx size= %d\n",
	    (uintmax_t)sc->sense_busaddr, rsize);

	/*
	 * Allocate NVMe PRP Pages for NVMe SGL support only if the FW supports
	 * these devices.
	 */
	if ((sc->facts->MsgVersion >= MPI2_VERSION_02_06) &&
	    (sc->facts->ProtocolFlags & MPI2_IOCFACTS_PROTOCOL_NVME_DEVICES)) {
		if (mpr_alloc_nvme_prp_pages(sc) == ENOMEM)
			return (ENOMEM);
	}

	nsegs = (sc->maxio / PAGE_SIZE) + 1;
	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_MAXSIZE(BUS_SPACE_MAXSIZE_32BIT),
	    BD_NSEGMENTS(nsegs), BD_MAXSEGSIZE(BUS_SPACE_MAXSIZE_32BIT),
	    BD_FLAGS(BUS_DMA_ALLOCNOW), BD_LOCKFUNC(busdma_lock_mutex),
	    BD_LOCKFUNCARG(&sc->mpr_mtx));
	if (bus_dma_template_tag(&t, &sc->buffer_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate buffer DMA tag\n");
		return (ENOMEM);
        }

	/*
	 * SMID 0 cannot be used as a free command per the firmware spec.
	 * Just drop that command instead of risking accounting bugs.
	 */
	sc->commands = malloc(sizeof(struct mpr_command) * sc->num_reqs,
	    M_MPR, M_WAITOK | M_ZERO);
	for (i = 1; i < sc->num_reqs; i++) {
		cm = &sc->commands[i];
		cm->cm_req = sc->req_frames + i * sc->reqframesz;
		cm->cm_req_busaddr = sc->req_busaddr + i * sc->reqframesz;
		cm->cm_sense = &sc->sense_frames[i];
		cm->cm_sense_busaddr = sc->sense_busaddr + i * MPR_SENSE_LEN;
		cm->cm_desc.Default.SMID = i;
		cm->cm_sc = sc;
		cm->cm_state = MPR_CM_STATE_BUSY;
		TAILQ_INIT(&cm->cm_chain_list);
		TAILQ_INIT(&cm->cm_prp_page_list);
		callout_init_mtx(&cm->cm_callout, &sc->mpr_mtx, 0);

		/* XXX Is a failure here a critical problem? */
		if (bus_dmamap_create(sc->buffer_dmat, 0, &cm->cm_dmamap)
		    == 0) {
			if (i <= sc->num_prireqs)
				mpr_free_high_priority_command(sc, cm);
			else
				mpr_free_command(sc, cm);
		} else {
			panic("failed to allocate command %d\n", i);
			sc->num_reqs = i;
			break;
		}
	}

	return (0);
}

/*
 * Allocate contiguous buffers for PCIe NVMe devices for building native PRPs,
 * which are scatter/gather lists for NVMe devices. 
 *
 * This buffer must be contiguous due to the nature of how NVMe PRPs are built
 * and translated by FW.
 *
 * returns ENOMEM if memory could not be allocated, otherwise returns 0.
 */
static int
mpr_alloc_nvme_prp_pages(struct mpr_softc *sc)
{
	bus_dma_template_t t;
	struct mpr_prp_page *prp_page;
	int PRPs_per_page, PRPs_required, pages_required;
	int rsize, i;

	/*
	 * Assuming a MAX_IO_SIZE of 1MB and a PAGE_SIZE of 4k, the max number
	 * of PRPs (NVMe's Scatter/Gather Element) needed per I/O is:
	 * MAX_IO_SIZE / PAGE_SIZE = 256
	 * 
	 * 1 PRP entry in main frame for PRP list pointer still leaves 255 PRPs
	 * required for the remainder of the 1MB I/O. 512 PRPs can fit into one
	 * page (4096 / 8 = 512), so only one page is required for each I/O.
	 *
	 * Each of these buffers will need to be contiguous. For simplicity,
	 * only one buffer is allocated here, which has all of the space
	 * required for the NVMe Queue Depth. If there are problems allocating
	 * this one buffer, this function will need to change to allocate
	 * individual, contiguous NVME_QDEPTH buffers.
	 *
	 * The real calculation will use the real max io size. Above is just an
	 * example.
	 *
	 */
	PRPs_required = sc->maxio / PAGE_SIZE;
	PRPs_per_page = (PAGE_SIZE / PRP_ENTRY_SIZE) - 1;
	pages_required = (PRPs_required / PRPs_per_page) + 1;

	sc->prp_buffer_size = PAGE_SIZE * pages_required; 
	rsize = sc->prp_buffer_size * NVME_QDEPTH; 
	bus_dma_template_init(&t, sc->mpr_parent_dmat);
	BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(4), BD_MAXSIZE(rsize),
	    BD_MAXSEGSIZE(rsize), BD_NSEGMENTS(1),
	    BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
	if (bus_dma_template_tag(&t, &sc->prp_page_dmat)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate NVMe PRP DMA "
		    "tag\n");
		return (ENOMEM);
	}
	if (bus_dmamem_alloc(sc->prp_page_dmat, (void **)&sc->prp_pages,
	    BUS_DMA_NOWAIT, &sc->prp_page_map)) {
		mpr_dprint(sc, MPR_ERROR, "Cannot allocate NVMe PRP memory\n");
		return (ENOMEM);
	}
	bzero(sc->prp_pages, rsize);
	bus_dmamap_load(sc->prp_page_dmat, sc->prp_page_map, sc->prp_pages,
	    rsize, mpr_memaddr_cb, &sc->prp_page_busaddr, 0);

	sc->prps = malloc(sizeof(struct mpr_prp_page) * NVME_QDEPTH, M_MPR,
	    M_WAITOK | M_ZERO);
	for (i = 0; i < NVME_QDEPTH; i++) {
		prp_page = &sc->prps[i];
		prp_page->prp_page = (uint64_t *)(sc->prp_pages +
		    i * sc->prp_buffer_size);
		prp_page->prp_page_busaddr = (uint64_t)(sc->prp_page_busaddr +
		    i * sc->prp_buffer_size);
		mpr_free_prp_page(sc, prp_page);
		sc->prp_pages_free_lowwater++;
	}

	return (0);
}

static int
mpr_init_queues(struct mpr_softc *sc)
{
	int i;

	memset((uint8_t *)sc->post_queue, 0xff, sc->pqdepth * 8);

	/*
	 * According to the spec, we need to use one less reply than we
	 * have space for on the queue.  So sc->num_replies (the number we
	 * use) should be less than sc->fqdepth (allocated size).
	 */
	if (sc->num_replies >= sc->fqdepth)
		return (EINVAL);

	/*
	 * Initialize all of the free queue entries.
	 */
	for (i = 0; i < sc->fqdepth; i++) {
		sc->free_queue[i] = sc->reply_busaddr + (i * sc->replyframesz);
	}
	sc->replyfreeindex = sc->num_replies;

	return (0);
}

/* Get the driver parameter tunables.  Lowest priority are the driver defaults.
 * Next are the global settings, if they exist.  Highest are the per-unit
 * settings, if they exist.
 */
void
mpr_get_tunables(struct mpr_softc *sc)
{
	char tmpstr[80], mpr_debug[80];

	/* XXX default to some debugging for now */
	sc->mpr_debug = MPR_INFO | MPR_FAULT;
	sc->disable_msix = 0;
	sc->disable_msi = 0;
	sc->max_msix = MPR_MSIX_MAX;
	sc->max_chains = MPR_CHAIN_FRAMES;
	sc->max_io_pages = MPR_MAXIO_PAGES;
	sc->enable_ssu = MPR_SSU_ENABLE_SSD_DISABLE_HDD;
	sc->spinup_wait_time = DEFAULT_SPINUP_WAIT;
	sc->use_phynum = 1;
	sc->max_reqframes = MPR_REQ_FRAMES;
	sc->max_prireqframes = MPR_PRI_REQ_FRAMES;
	sc->max_replyframes = MPR_REPLY_FRAMES;
	sc->max_evtframes = MPR_EVT_REPLY_FRAMES;

	/*
	 * Grab the global variables.
	 */
	bzero(mpr_debug, 80);
	if (TUNABLE_STR_FETCH("hw.mpr.debug_level", mpr_debug, 80) != 0)
		mpr_parse_debug(sc, mpr_debug);
	TUNABLE_INT_FETCH("hw.mpr.disable_msix", &sc->disable_msix);
	TUNABLE_INT_FETCH("hw.mpr.disable_msi", &sc->disable_msi);
	TUNABLE_INT_FETCH("hw.mpr.max_msix", &sc->max_msix);
	TUNABLE_INT_FETCH("hw.mpr.max_chains", &sc->max_chains);
	TUNABLE_INT_FETCH("hw.mpr.max_io_pages", &sc->max_io_pages);
	TUNABLE_INT_FETCH("hw.mpr.enable_ssu", &sc->enable_ssu);
	TUNABLE_INT_FETCH("hw.mpr.spinup_wait_time", &sc->spinup_wait_time);
	TUNABLE_INT_FETCH("hw.mpr.use_phy_num", &sc->use_phynum);
	TUNABLE_INT_FETCH("hw.mpr.max_reqframes", &sc->max_reqframes);
	TUNABLE_INT_FETCH("hw.mpr.max_prireqframes", &sc->max_prireqframes);
	TUNABLE_INT_FETCH("hw.mpr.max_replyframes", &sc->max_replyframes);
	TUNABLE_INT_FETCH("hw.mpr.max_evtframes", &sc->max_evtframes);

	/* Grab the unit-instance variables */
	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.debug_level",
	    device_get_unit(sc->mpr_dev));
	bzero(mpr_debug, 80);
	if (TUNABLE_STR_FETCH(tmpstr, mpr_debug, 80) != 0)
		mpr_parse_debug(sc, mpr_debug);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.disable_msix",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->disable_msix);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.disable_msi",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->disable_msi);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_msix",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_msix);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_chains",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_chains);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_io_pages",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_io_pages);

	bzero(sc->exclude_ids, sizeof(sc->exclude_ids));
	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.exclude_ids",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_STR_FETCH(tmpstr, sc->exclude_ids, sizeof(sc->exclude_ids));

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.enable_ssu",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->enable_ssu);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.spinup_wait_time",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->spinup_wait_time);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.use_phy_num",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->use_phynum);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_reqframes",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_reqframes);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_prireqframes",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_prireqframes);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_replyframes",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_replyframes);

	snprintf(tmpstr, sizeof(tmpstr), "dev.mpr.%d.max_evtframes",
	    device_get_unit(sc->mpr_dev));
	TUNABLE_INT_FETCH(tmpstr, &sc->max_evtframes);
}

static void
mpr_setup_sysctl(struct mpr_softc *sc)
{
	struct sysctl_ctx_list	*sysctl_ctx = NULL;
	struct sysctl_oid	*sysctl_tree = NULL;
	char tmpstr[80], tmpstr2[80];

	/*
	 * Setup the sysctl variable so the user can change the debug level
	 * on the fly.
	 */
	snprintf(tmpstr, sizeof(tmpstr), "MPR controller %d",
	    device_get_unit(sc->mpr_dev));
	snprintf(tmpstr2, sizeof(tmpstr2), "%d", device_get_unit(sc->mpr_dev));

	sysctl_ctx = device_get_sysctl_ctx(sc->mpr_dev);
	if (sysctl_ctx != NULL)
		sysctl_tree = device_get_sysctl_tree(sc->mpr_dev);

	if (sysctl_tree == NULL) {
		sysctl_ctx_init(&sc->sysctl_ctx);
		sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
		    SYSCTL_STATIC_CHILDREN(_hw_mpr), OID_AUTO, tmpstr2,
		    CTLFLAG_RD | CTLFLAG_MPSAFE, 0, tmpstr);
		if (sc->sysctl_tree == NULL)
			return;
		sysctl_ctx = &sc->sysctl_ctx;
		sysctl_tree = sc->sysctl_tree;
	}

	SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "debug_level", CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
	    sc, 0, mpr_debug_sysctl, "A", "mpr debug level");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "disable_msix", CTLFLAG_RD, &sc->disable_msix, 0,
	    "Disable the use of MSI-X interrupts");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_msix", CTLFLAG_RD, &sc->max_msix, 0,
	    "User-defined maximum number of MSIX queues");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "msix_msgs", CTLFLAG_RD, &sc->msi_msgs, 0,
	    "Negotiated number of MSIX queues");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_reqframes", CTLFLAG_RD, &sc->max_reqframes, 0,
	    "Total number of allocated request frames");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_prireqframes", CTLFLAG_RD, &sc->max_prireqframes, 0,
	    "Total number of allocated high priority request frames");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_replyframes", CTLFLAG_RD, &sc->max_replyframes, 0,
	    "Total number of allocated reply frames");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_evtframes", CTLFLAG_RD, &sc->max_evtframes, 0,
	    "Total number of event frames allocated");

	SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "firmware_version", CTLFLAG_RD, sc->fw_version,
	    strlen(sc->fw_version), "firmware version");

	SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "driver_version", CTLFLAG_RD, MPR_DRIVER_VERSION,
	    strlen(MPR_DRIVER_VERSION), "driver version");

	SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "msg_version", CTLFLAG_RD, sc->msg_version,
	    strlen(sc->msg_version), "message interface version");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "io_cmds_active", CTLFLAG_RD,
	    &sc->io_cmds_active, 0, "number of currently active commands");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "io_cmds_highwater", CTLFLAG_RD,
	    &sc->io_cmds_highwater, 0, "maximum active commands seen");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "chain_free", CTLFLAG_RD,
	    &sc->chain_free, 0, "number of free chain elements");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "chain_free_lowwater", CTLFLAG_RD,
	    &sc->chain_free_lowwater, 0,"lowest number of free chain elements");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_chains", CTLFLAG_RD,
	    &sc->max_chains, 0,"maximum chain frames that will be allocated");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "max_io_pages", CTLFLAG_RD,
	    &sc->max_io_pages, 0,"maximum pages to allow per I/O (if <1 use "
	    "IOCFacts)");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "enable_ssu", CTLFLAG_RW, &sc->enable_ssu, 0,
	    "enable SSU to SATA SSD/HDD at shutdown");

	SYSCTL_ADD_UQUAD(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "chain_alloc_fail", CTLFLAG_RD,
	    &sc->chain_alloc_fail, "chain allocation failures");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "spinup_wait_time", CTLFLAG_RD,
	    &sc->spinup_wait_time, DEFAULT_SPINUP_WAIT, "seconds to wait for "
	    "spinup after SATA ID error");

	SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "dump_reqs",
	    CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_NEEDGIANT,
	    sc, 0, mpr_dump_reqs, "I", "Dump Active Requests");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "use_phy_num", CTLFLAG_RD, &sc->use_phynum, 0,
	    "Use the phy number for enumeration");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "prp_pages_free", CTLFLAG_RD,
	    &sc->prp_pages_free, 0, "number of free PRP pages");

	SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "prp_pages_free_lowwater", CTLFLAG_RD,
	    &sc->prp_pages_free_lowwater, 0,"lowest number of free PRP pages");

	SYSCTL_ADD_UQUAD(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
	    OID_AUTO, "prp_page_alloc_fail", CTLFLAG_RD,
	    &sc->prp_page_alloc_fail, "PRP page allocation failures");
}

static struct mpr_debug_string {
	char *name;
	int flag;
} mpr_debug_strings[] = {
	{"info", MPR_INFO},
	{"fault", MPR_FAULT},
	{"event", MPR_EVENT},
	{"log", MPR_LOG},
	{"recovery", MPR_RECOVERY},
	{"error", MPR_ERROR},
	{"init", MPR_INIT},
	{"xinfo", MPR_XINFO},
	{"user", MPR_USER},
	{"mapping", MPR_MAPPING},
	{"trace", MPR_TRACE}
};

enum mpr_debug_level_combiner {
	COMB_NONE,
	COMB_ADD,
	COMB_SUB
};

static int
mpr_debug_sysctl(SYSCTL_HANDLER_ARGS)
{
	struct mpr_softc *sc;
	struct mpr_debug_string *string;
	struct sbuf *sbuf;
	char *buffer;
	size_t sz;
	int i, len, debug, error;

	sc = (struct mpr_softc *)arg1;

	error = sysctl_wire_old_buffer(req, 0);
	if (error != 0)
		return (error);

	sbuf = sbuf_new_for_sysctl(NULL, NULL, 128, req);
	debug = sc->mpr_debug;

	sbuf_printf(sbuf, "%#x", debug);

	sz = sizeof(mpr_debug_strings) / sizeof(mpr_debug_strings[0]);
	for (i = 0; i < sz; i++) {
		string = &mpr_debug_strings[i];
		if (debug & string->flag) 
			sbuf_printf(sbuf, ",%s", string->name);
	}

	error = sbuf_finish(sbuf);
	sbuf_delete(sbuf);

	if (error || req->newptr == NULL)
		return (error);

	len = req->newlen - req->newidx;
	if (len == 0)
		return (0);

	buffer = malloc(len, M_MPR, M_ZERO|M_WAITOK);
	error = SYSCTL_IN(req, buffer, len);

	mpr_parse_debug(sc, buffer);

	free(buffer, M_MPR);
	return (error);
}

static void
mpr_parse_debug(struct mpr_softc *sc, char *list)
{
	struct mpr_debug_string *string;
	enum mpr_debug_level_combiner op;
	char *token, *endtoken;
	size_t sz;
	int flags, i;

	if (list == NULL || *list == '\0')
		return;

	if (*list == '+') {
		op = COMB_ADD;
		list++;
	} else if (*list == '-') {
		op = COMB_SUB;
		list++;
	} else
		op = COMB_NONE;
	if (*list == '\0')
		return;

	flags = 0;
	sz = sizeof(mpr_debug_strings) / sizeof(mpr_debug_strings[0]);
	while ((token = strsep(&list, ":,")) != NULL) {
		/* Handle integer flags */
		flags |= strtol(token, &endtoken, 0);
		if (token != endtoken)
			continue;

		/* Handle text flags */
		for (i = 0; i < sz; i++) {
			string = &mpr_debug_strings[i];
			if (strcasecmp(token, string->name) == 0) {
				flags |= string->flag;
				break;
			}
		}
	}

	switch (op) {
	case COMB_NONE:
		sc->mpr_debug = flags;
		break;
	case COMB_ADD:
		sc->mpr_debug |= flags;
		break;
	case COMB_SUB:
		sc->mpr_debug &= (~flags);
		break;
	}
	return;
}

struct mpr_dumpreq_hdr {
	uint32_t	smid;
	uint32_t	state;
	uint32_t	numframes;
	uint32_t	deschi;
	uint32_t	desclo;
};

static int
mpr_dump_reqs(SYSCTL_HANDLER_ARGS)
{
	struct mpr_softc *sc;
	struct mpr_chain *chain, *chain1;
	struct mpr_command *cm;
	struct mpr_dumpreq_hdr hdr;
	struct sbuf *sb;
	uint32_t smid, state;
	int i, numreqs, error = 0;

	sc = (struct mpr_softc *)arg1;

	if ((error = priv_check(curthread, PRIV_DRIVER)) != 0) {
		printf("priv check error %d\n", error);
		return (error);
	}

	state = MPR_CM_STATE_INQUEUE;
	smid = 1;
	numreqs = sc->num_reqs;

	if (req->newptr != NULL)
		return (EINVAL);

	if (smid == 0 || smid > sc->num_reqs)
		return (EINVAL);
	if (numreqs <= 0 || (numreqs + smid > sc->num_reqs))
		numreqs = sc->num_reqs;
	sb = sbuf_new_for_sysctl(NULL, NULL, 4096, req);

	/* Best effort, no locking */
	for (i = smid; i < numreqs; i++) {
		cm = &sc->commands[i];
		if (cm->cm_state != state)
			continue;
		hdr.smid = i;
		hdr.state = cm->cm_state;
		hdr.numframes = 1;
		hdr.deschi = cm->cm_desc.Words.High;
		hdr.desclo = cm->cm_desc.Words.Low;
		TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
		   chain1)
			hdr.numframes++;
		sbuf_bcat(sb, &hdr, sizeof(hdr));
		sbuf_bcat(sb, cm->cm_req, 128);
		TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
		    chain1)
			sbuf_bcat(sb, chain->chain, 128);
	}

	error = sbuf_finish(sb);
	sbuf_delete(sb);
	return (error);
}

int
mpr_attach(struct mpr_softc *sc)
{
	int error;

	MPR_FUNCTRACE(sc);
	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	mtx_init(&sc->mpr_mtx, "MPR lock", NULL, MTX_DEF);
	callout_init_mtx(&sc->periodic, &sc->mpr_mtx, 0);
	callout_init_mtx(&sc->device_check_callout, &sc->mpr_mtx, 0);
	TAILQ_INIT(&sc->event_list);
	timevalclear(&sc->lastfail);

	if ((error = mpr_transition_ready(sc)) != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT,
		    "Failed to transition ready\n");
		return (error);
	}

	sc->facts = malloc(sizeof(MPI2_IOC_FACTS_REPLY), M_MPR,
	    M_ZERO|M_NOWAIT);
	if (!sc->facts) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT,
		    "Cannot allocate memory, exit\n");
		return (ENOMEM);
	}

	/*
	 * Get IOC Facts and allocate all structures based on this information.
	 * A Diag Reset will also call mpr_iocfacts_allocate and re-read the IOC
	 * Facts. If relevant values have changed in IOC Facts, this function
	 * will free all of the memory based on IOC Facts and reallocate that
	 * memory.  If this fails, any allocated memory should already be freed.
	 */
	if ((error = mpr_iocfacts_allocate(sc, TRUE)) != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT, "IOC Facts allocation "
		    "failed with error %d\n", error);
		return (error);
	}

	/* Start the periodic watchdog check on the IOC Doorbell */
	mpr_periodic(sc);

	/*
	 * The portenable will kick off discovery events that will drive the
	 * rest of the initialization process.  The CAM/SAS module will
	 * hold up the boot sequence until discovery is complete.
	 */
	sc->mpr_ich.ich_func = mpr_startup;
	sc->mpr_ich.ich_arg = sc;
	if (config_intrhook_establish(&sc->mpr_ich) != 0) {
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "Cannot establish MPR config hook\n");
		error = EINVAL;
	}

	/*
	 * Allow IR to shutdown gracefully when shutdown occurs.
	 */
	sc->shutdown_eh = EVENTHANDLER_REGISTER(shutdown_final,
	    mprsas_ir_shutdown, sc, SHUTDOWN_PRI_DEFAULT);

	if (sc->shutdown_eh == NULL)
		mpr_dprint(sc, MPR_INIT|MPR_ERROR,
		    "shutdown event registration failed\n");

	mpr_setup_sysctl(sc);

	sc->mpr_flags |= MPR_FLAGS_ATTACH_DONE;
	mpr_dprint(sc, MPR_INIT, "%s exit error= %d\n", __func__, error);

	return (error);
}

/* Run through any late-start handlers. */
static void
mpr_startup(void *arg)
{
	struct mpr_softc *sc;

	sc = (struct mpr_softc *)arg;
	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);

	mpr_lock(sc);
	mpr_unmask_intr(sc);

	/* initialize device mapping tables */
	mpr_base_static_config_pages(sc);
	mpr_mapping_initialize(sc);
	mprsas_startup(sc);
	mpr_unlock(sc);

	mpr_dprint(sc, MPR_INIT, "disestablish config intrhook\n");
	config_intrhook_disestablish(&sc->mpr_ich);
	sc->mpr_ich.ich_arg = NULL;

	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);
}

/* Periodic watchdog.  Is called with the driver lock already held. */
static void
mpr_periodic(void *arg)
{
	struct mpr_softc *sc;
	uint32_t db;

	sc = (struct mpr_softc *)arg;
	if (sc->mpr_flags & MPR_FLAGS_SHUTDOWN)
		return;

	db = mpr_regread(sc, MPI2_DOORBELL_OFFSET);
	if ((db & MPI2_IOC_STATE_MASK) == MPI2_IOC_STATE_FAULT) {
		if ((db & MPI2_DOORBELL_FAULT_CODE_MASK) ==
		    IFAULT_IOP_OVER_TEMP_THRESHOLD_EXCEEDED) {
			panic("TEMPERATURE FAULT: STOPPING.");
		}
		mpr_dprint(sc, MPR_FAULT, "IOC Fault 0x%08x, Resetting\n", db);
		mpr_reinit(sc);
	}

	callout_reset(&sc->periodic, MPR_PERIODIC_DELAY * hz, mpr_periodic, sc);
}

static void
mpr_log_evt_handler(struct mpr_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *event)
{
	MPI2_EVENT_DATA_LOG_ENTRY_ADDED *entry;

	MPR_DPRINT_EVENT(sc, generic, event);

	switch (event->Event) {
	case MPI2_EVENT_LOG_DATA:
		mpr_dprint(sc, MPR_EVENT, "MPI2_EVENT_LOG_DATA:\n");
		if (sc->mpr_debug & MPR_EVENT)
			hexdump(event->EventData, event->EventDataLength, NULL,
			    0);
		break;
	case MPI2_EVENT_LOG_ENTRY_ADDED:
		entry = (MPI2_EVENT_DATA_LOG_ENTRY_ADDED *)event->EventData;
		mpr_dprint(sc, MPR_EVENT, "MPI2_EVENT_LOG_ENTRY_ADDED event "
		    "0x%x Sequence %d:\n", entry->LogEntryQualifier,
		     entry->LogSequence);
		break;
	default:
		break;
	}
	return;
}

static int
mpr_attach_log(struct mpr_softc *sc)
{
	uint8_t events[16];

	bzero(events, 16);
	setbit(events, MPI2_EVENT_LOG_DATA);
	setbit(events, MPI2_EVENT_LOG_ENTRY_ADDED);

	mpr_register_events(sc, events, mpr_log_evt_handler, NULL,
	    &sc->mpr_log_eh);

	return (0);
}

static int
mpr_detach_log(struct mpr_softc *sc)
{

	if (sc->mpr_log_eh != NULL)
		mpr_deregister_events(sc, sc->mpr_log_eh);
	return (0);
}

/*
 * Free all of the driver resources and detach submodules.  Should be called
 * without the lock held.
 */
int
mpr_free(struct mpr_softc *sc)
{
	int error;

	mpr_dprint(sc, MPR_INIT, "%s entered\n", __func__);
	/* Turn off the watchdog */
	mpr_lock(sc);
	sc->mpr_flags |= MPR_FLAGS_SHUTDOWN;
	mpr_unlock(sc);
	/* Lock must not be held for this */
	callout_drain(&sc->periodic);
	callout_drain(&sc->device_check_callout);

	if (((error = mpr_detach_log(sc)) != 0) ||
	    ((error = mpr_detach_sas(sc)) != 0)) {
		mpr_dprint(sc, MPR_INIT|MPR_FAULT, "failed to detach "
		    "subsystems, error= %d, exit\n", error);
		return (error);
	}

	mpr_detach_user(sc);

	/* Put the IOC back in the READY state. */
	mpr_lock(sc);
	if ((error = mpr_transition_ready(sc)) != 0) {
		mpr_unlock(sc);
		return (error);
	}
	mpr_unlock(sc);

	if (sc->facts != NULL)
		free(sc->facts, M_MPR);

	/*
	 * Free all buffers that are based on IOC Facts.  A Diag Reset may need
	 * to free these buffers too.
	 */
	mpr_iocfacts_free(sc);

	if (sc->sysctl_tree != NULL)
		sysctl_ctx_free(&sc->sysctl_ctx);

	/* Deregister the shutdown function */
	if (sc->shutdown_eh != NULL)
		EVENTHANDLER_DEREGISTER(shutdown_final, sc->shutdown_eh);

	mtx_destroy(&sc->mpr_mtx);
	mpr_dprint(sc, MPR_INIT, "%s exit\n", __func__);

	return (0);
}

static __inline void
mpr_complete_command(struct mpr_softc *sc, struct mpr_command *cm)
{
	MPR_FUNCTRACE(sc);

	if (cm == NULL) {
		mpr_dprint(sc, MPR_ERROR, "Completing NULL command\n");
		return;
	}

	cm->cm_state = MPR_CM_STATE_BUSY;
	if (cm->cm_flags & MPR_CM_FLAGS_POLLED)
		cm->cm_flags |= MPR_CM_FLAGS_COMPLETE;

	if (cm->cm_complete != NULL) {
		mpr_dprint(sc, MPR_TRACE,
		    "%s cm %p calling cm_complete %p data %p reply %p\n",
		    __func__, cm, cm->cm_complete, cm->cm_complete_data,
		    cm->cm_reply);
		cm->cm_complete(sc, cm);
	}

	if (cm->cm_flags & MPR_CM_FLAGS_WAKEUP) {
		mpr_dprint(sc, MPR_TRACE, "waking up %p\n", cm);
		wakeup(cm);
	}

	if (sc->io_cmds_active != 0) {
		sc->io_cmds_active--;
	} else {
		mpr_dprint(sc, MPR_ERROR, "Warning: io_cmds_active is "
		    "out of sync - resynching to 0\n");
	}
}

static void
mpr_sas_log_info(struct mpr_softc *sc , u32 log_info)
{
	union loginfo_type {
		u32	loginfo;
		struct {
			u32	subcode:16;
			u32	code:8;
			u32	originator:4;
			u32	bus_type:4;
		} dw;
	};
	union loginfo_type sas_loginfo;
	char *originator_str = NULL;

	sas_loginfo.loginfo = log_info;
	if (sas_loginfo.dw.bus_type != 3 /*SAS*/)
		return;

	/* each nexus loss loginfo */
	if (log_info == 0x31170000)
		return;

	/* eat the loginfos associated with task aborts */
	if ((log_info == 30050000) || (log_info == 0x31140000) ||
	    (log_info == 0x31130000))
		return;

	switch (sas_loginfo.dw.originator) {
	case 0:
		originator_str = "IOP";
		break;
	case 1:
		originator_str = "PL";
		break;
	case 2:
		originator_str = "IR";
		break;
	}

	mpr_dprint(sc, MPR_LOG, "log_info(0x%08x): originator(%s), "
	    "code(0x%02x), sub_code(0x%04x)\n", log_info, originator_str,
	    sas_loginfo.dw.code, sas_loginfo.dw.subcode);
}

static void
mpr_display_reply_info(struct mpr_softc *sc, uint8_t *reply)
{
	MPI2DefaultReply_t *mpi_reply;
	u16 sc_status;

	mpi_reply = (MPI2DefaultReply_t*)reply;
	sc_status = le16toh(mpi_reply->IOCStatus);
	if (sc_status & MPI2_IOCSTATUS_FLAG_LOG_INFO_AVAILABLE)
		mpr_sas_log_info(sc, le32toh(mpi_reply->IOCLogInfo));
}

void
mpr_intr(void *data)
{
	struct mpr_softc *sc;
	uint32_t status;

	sc = (struct mpr_softc *)data;
	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	/*
	 * Check interrupt status register to flush the bus.  This is
	 * needed for both INTx interrupts and driver-driven polling
	 */
	status = mpr_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
	if ((status & MPI2_HIS_REPLY_DESCRIPTOR_INTERRUPT) == 0)
		return;

	mpr_lock(sc);
	mpr_intr_locked(data);
	mpr_unlock(sc);
	return;
}

/*
 * In theory, MSI/MSIX interrupts shouldn't need to read any registers on the
 * chip.  Hopefully this theory is correct.
 */
void
mpr_intr_msi(void *data)
{
	struct mpr_softc *sc;

	sc = (struct mpr_softc *)data;
	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);
	mpr_lock(sc);
	mpr_intr_locked(data);
	mpr_unlock(sc);
	return;
}

/*
 * The locking is overly broad and simplistic, but easy to deal with for now.
 */
void
mpr_intr_locked(void *data)
{
	MPI2_REPLY_DESCRIPTORS_UNION *desc;
	MPI2_DIAG_RELEASE_REPLY *rel_rep;
	mpr_fw_diagnostic_buffer_t *pBuffer;
	struct mpr_softc *sc;
	uint64_t tdesc;
	struct mpr_command *cm = NULL;
	uint8_t flags;
	u_int pq;

	sc = (struct mpr_softc *)data;

	pq = sc->replypostindex;
	mpr_dprint(sc, MPR_TRACE,
	    "%s sc %p starting with replypostindex %u\n", 
	    __func__, sc, sc->replypostindex);

	for ( ;; ) {
		cm = NULL;
		desc = &sc->post_queue[sc->replypostindex];

		/*
		 * Copy and clear out the descriptor so that any reentry will
		 * immediately know that this descriptor has already been
		 * looked at.  There is unfortunate casting magic because the
		 * MPI API doesn't have a cardinal 64bit type.
		 */
		tdesc = 0xffffffffffffffff;
		tdesc = atomic_swap_64((uint64_t *)desc, tdesc);
		desc = (MPI2_REPLY_DESCRIPTORS_UNION *)&tdesc;

		flags = desc->Default.ReplyFlags &
		    MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
		if ((flags == MPI2_RPY_DESCRIPT_FLAGS_UNUSED) ||
		    (le32toh(desc->Words.High) == 0xffffffff))
			break;

		/* increment the replypostindex now, so that event handlers
		 * and cm completion handlers which decide to do a diag
		 * reset can zero it without it getting incremented again
		 * afterwards, and we break out of this loop on the next
		 * iteration since the reply post queue has been cleared to
		 * 0xFF and all descriptors look unused (which they are).
		 */
		if (++sc->replypostindex >= sc->pqdepth)
			sc->replypostindex = 0;

		switch (flags) {
		case MPI2_RPY_DESCRIPT_FLAGS_SCSI_IO_SUCCESS:
		case MPI25_RPY_DESCRIPT_FLAGS_FAST_PATH_SCSI_IO_SUCCESS:
		case MPI26_RPY_DESCRIPT_FLAGS_PCIE_ENCAPSULATED_SUCCESS:
			cm = &sc->commands[le16toh(desc->SCSIIOSuccess.SMID)];
			KASSERT(cm->cm_state == MPR_CM_STATE_INQUEUE,
			    ("command not inqueue\n"));
			cm->cm_state = MPR_CM_STATE_BUSY;
			cm->cm_reply = NULL;
			break;
		case MPI2_RPY_DESCRIPT_FLAGS_ADDRESS_REPLY:
		{
			uint32_t baddr;
			uint8_t *reply;

			/*
			 * Re-compose the reply address from the address
			 * sent back from the chip.  The ReplyFrameAddress
			 * is the lower 32 bits of the physical address of
			 * particular reply frame.  Convert that address to
			 * host format, and then use that to provide the
			 * offset against the virtual address base
			 * (sc->reply_frames).
			 */
			baddr = le32toh(desc->AddressReply.ReplyFrameAddress);
			reply = sc->reply_frames +
				(baddr - ((uint32_t)sc->reply_busaddr));
			/*
			 * Make sure the reply we got back is in a valid
			 * range.  If not, go ahead and panic here, since
			 * we'll probably panic as soon as we deference the
			 * reply pointer anyway.
			 */
			if ((reply < sc->reply_frames)
			 || (reply > (sc->reply_frames +
			     (sc->fqdepth * sc->replyframesz)))) {
				printf("%s: WARNING: reply %p out of range!\n",
				       __func__, reply);
				printf("%s: reply_frames %p, fqdepth %d, "
				       "frame size %d\n", __func__,
				       sc->reply_frames, sc->fqdepth,
				       sc->replyframesz);
				printf("%s: baddr %#x,\n", __func__, baddr);
				/* LSI-TODO. See Linux Code for Graceful exit */
				panic("Reply address out of range");
			}
			if (le16toh(desc->AddressReply.SMID) == 0) {
				if (((MPI2_DEFAULT_REPLY *)reply)->Function ==
				    MPI2_FUNCTION_DIAG_BUFFER_POST) {
					/*
					 * If SMID is 0 for Diag Buffer Post,
					 * this implies that the reply is due to
					 * a release function with a status that
					 * the buffer has been released.  Set
					 * the buffer flags accordingly.
					 */
					rel_rep =
					    (MPI2_DIAG_RELEASE_REPLY *)reply;
					if ((le16toh(rel_rep->IOCStatus) &
					    MPI2_IOCSTATUS_MASK) ==
					    MPI2_IOCSTATUS_DIAGNOSTIC_RELEASED)
					{
						pBuffer =
						    &sc->fw_diag_buffer_list[
						    rel_rep->BufferType];
						pBuffer->valid_data = TRUE;
						pBuffer->owned_by_firmware =
						    FALSE;
						pBuffer->immediate = FALSE;
					}
				} else
					mpr_dispatch_event(sc, baddr,
					    (MPI2_EVENT_NOTIFICATION_REPLY *)
					    reply);
			} else {
				cm = &sc->commands[
				    le16toh(desc->AddressReply.SMID)];
				if (cm->cm_state == MPR_CM_STATE_INQUEUE) {
					cm->cm_reply = reply;
					cm->cm_reply_data =
					    le32toh(desc->AddressReply.
						ReplyFrameAddress);
				} else {
					mpr_dprint(sc, MPR_RECOVERY,
					    "Bad state for ADDRESS_REPLY status,"
					    " ignoring state %d cm %p\n",
					    cm->cm_state, cm);
				}
			}
			break;
		}
		case MPI2_RPY_DESCRIPT_FLAGS_TARGETASSIST_SUCCESS:
		case MPI2_RPY_DESCRIPT_FLAGS_TARGET_COMMAND_BUFFER:
		case MPI2_RPY_DESCRIPT_FLAGS_RAID_ACCELERATOR_SUCCESS:
		default:
			/* Unhandled */
			mpr_dprint(sc, MPR_ERROR, "Unhandled reply 0x%x\n",
			    desc->Default.ReplyFlags);
			cm = NULL;
			break;
		}

		if (cm != NULL) {
			// Print Error reply frame
			if (cm->cm_reply)
				mpr_display_reply_info(sc,cm->cm_reply);
			mpr_complete_command(sc, cm);
		}
	}

	if (pq != sc->replypostindex) {
		mpr_dprint(sc, MPR_TRACE, "%s sc %p writing postindex %d\n",
		    __func__, sc, sc->replypostindex);
		mpr_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET,
		    sc->replypostindex);
	}

	return;
}

static void
mpr_dispatch_event(struct mpr_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *reply)
{
	struct mpr_event_handle *eh;
	int event, handled = 0;

	event = le16toh(reply->Event);
	TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
		if (isset(eh->mask, event)) {
			eh->callback(sc, data, reply);
			handled++;
		}
	}

	if (handled == 0)
		mpr_dprint(sc, MPR_EVENT, "Unhandled event 0x%x\n",
		    le16toh(event));

	/*
	 * This is the only place that the event/reply should be freed.
	 * Anything wanting to hold onto the event data should have
	 * already copied it into their own storage.
	 */
	mpr_free_reply(sc, data);
}

static void
mpr_reregister_events_complete(struct mpr_softc *sc, struct mpr_command *cm)
{
	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	if (cm->cm_reply)
		MPR_DPRINT_EVENT(sc, generic,
			(MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply);

	mpr_free_command(sc, cm);

	/* next, send a port enable */
	mprsas_startup(sc);
}

/*
 * For both register_events and update_events, the caller supplies a bitmap
 * of events that it _wants_.  These functions then turn that into a bitmask
 * suitable for the controller.
 */
int
mpr_register_events(struct mpr_softc *sc, uint8_t *mask,
    mpr_evt_callback_t *cb, void *data, struct mpr_event_handle **handle)
{
	struct mpr_event_handle *eh;
	int error = 0;

	eh = malloc(sizeof(struct mpr_event_handle), M_MPR, M_WAITOK|M_ZERO);
	eh->callback = cb;
	eh->data = data;
	TAILQ_INSERT_TAIL(&sc->event_list, eh, eh_list);
	if (mask != NULL)
		error = mpr_update_events(sc, eh, mask);
	*handle = eh;

	return (error);
}

int
mpr_update_events(struct mpr_softc *sc, struct mpr_event_handle *handle,
    uint8_t *mask)
{
	MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
	MPI2_EVENT_NOTIFICATION_REPLY *reply = NULL;
	struct mpr_command *cm = NULL;
	struct mpr_event_handle *eh;
	int error, i;

	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	if ((mask != NULL) && (handle != NULL))
		bcopy(mask, &handle->mask[0], 16);
	memset(sc->event_mask, 0xff, 16);

	TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
		for (i = 0; i < 16; i++)
			sc->event_mask[i] &= ~eh->mask[i];
	}

	if ((cm = mpr_alloc_command(sc)) == NULL)
		return (EBUSY);
	evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
	evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
	evtreq->MsgFlags = 0;
	evtreq->SASBroadcastPrimitiveMasks = 0;
#ifdef MPR_DEBUG_ALL_EVENTS
	{
		u_char fullmask[16];
		memset(fullmask, 0x00, 16);
		bcopy(fullmask, (uint8_t *)&evtreq->EventMasks, 16);
	}
#else
		bcopy(sc->event_mask, (uint8_t *)&evtreq->EventMasks, 16);
#endif
	cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
	cm->cm_data = NULL;

	error = mpr_request_polled(sc, &cm);
	if (cm != NULL)
		reply = (MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply;
	if ((reply == NULL) ||
	    (reply->IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
		error = ENXIO;

	if (reply)
		MPR_DPRINT_EVENT(sc, generic, reply);

	mpr_dprint(sc, MPR_TRACE, "%s finished error %d\n", __func__, error);

	if (cm != NULL)
		mpr_free_command(sc, cm);
	return (error);
}

static int
mpr_reregister_events(struct mpr_softc *sc)
{
	MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
	struct mpr_command *cm;
	struct mpr_event_handle *eh;
	int error, i;

	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	/* first, reregister events */

	memset(sc->event_mask, 0xff, 16);

	TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
		for (i = 0; i < 16; i++)
			sc->event_mask[i] &= ~eh->mask[i];
	}

	if ((cm = mpr_alloc_command(sc)) == NULL)
		return (EBUSY);
	evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
	evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
	evtreq->MsgFlags = 0;
	evtreq->SASBroadcastPrimitiveMasks = 0;
#ifdef MPR_DEBUG_ALL_EVENTS
	{
		u_char fullmask[16];
		memset(fullmask, 0x00, 16);
		bcopy(fullmask, (uint8_t *)&evtreq->EventMasks, 16);
	}
#else
		bcopy(sc->event_mask, (uint8_t *)&evtreq->EventMasks, 16);
#endif
	cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
	cm->cm_data = NULL;
	cm->cm_complete = mpr_reregister_events_complete;

	error = mpr_map_command(sc, cm);

	mpr_dprint(sc, MPR_TRACE, "%s finished with error %d\n", __func__,
	    error);
	return (error);
}

int
mpr_deregister_events(struct mpr_softc *sc, struct mpr_event_handle *handle)
{

	TAILQ_REMOVE(&sc->event_list, handle, eh_list);
	free(handle, M_MPR);
	return (mpr_update_events(sc, NULL, NULL));
}

/**
* mpr_build_nvme_prp - This function is called for NVMe end devices to build a
* native SGL (NVMe PRP). The native SGL is built starting in the first PRP entry
* of the NVMe message (PRP1). If the data buffer is small enough to be described
* entirely using PRP1, then PRP2 is not used. If needed, PRP2 is used to
* describe a larger data buffer. If the data buffer is too large to describe
* using the two PRP entriess inside the NVMe message, then PRP1 describes the
* first data memory segment, and PRP2 contains a pointer to a PRP list located
* elsewhere in memory to describe the remaining data memory segments. The PRP
* list will be contiguous.

* The native SGL for NVMe devices is a Physical Region Page (PRP). A PRP
* consists of a list of PRP entries to describe a number of noncontigous
* physical memory segments as a single memory buffer, just as a SGL does. Note
* however, that this function is only used by the IOCTL call, so the memory
* given will be guaranteed to be contiguous. There is no need to translate
* non-contiguous SGL into a PRP in this case. All PRPs will describe contiguous
* space that is one page size each.
*
* Each NVMe message contains two PRP entries. The first (PRP1) either contains
* a PRP list pointer or a PRP element, depending upon the command. PRP2 contains
* the second PRP element if the memory being described fits within 2 PRP
* entries, or a PRP list pointer if the PRP spans more than two entries.
*
* A PRP list pointer contains the address of a PRP list, structured as a linear
* array of PRP entries. Each PRP entry in this list describes a segment of
* physical memory.
*
* Each 64-bit PRP entry comprises an address and an offset field. The address
* always points to the beginning of a PAGE_SIZE physical memory page, and the
* offset describes where within that page the memory segment begins. Only the
* first element in a PRP list may contain a non-zero offest, implying that all
* memory segments following the first begin at the start of a PAGE_SIZE page.
*
* Each PRP element normally describes a chunck of PAGE_SIZE physical memory,
* with exceptions for the first and last elements in the list. If the memory
* being described by the list begins at a non-zero offset within the first page,
* then the first PRP element will contain a non-zero offset indicating where the
* region begins within the page. The last memory segment may end before the end
* of the PAGE_SIZE segment, depending upon the overall size of the memory being
* described by the PRP list. 
*
* Since PRP entries lack any indication of size, the overall data buffer length
* is used to determine where the end of the data memory buffer is located, and
* how many PRP entries are required to describe it.
*
* Returns nothing.
*/
void 
mpr_build_nvme_prp(struct mpr_softc *sc, struct mpr_command *cm,
    Mpi26NVMeEncapsulatedRequest_t *nvme_encap_request, void *data,
    uint32_t data_in_sz, uint32_t data_out_sz)
{
	int			prp_size = PRP_ENTRY_SIZE;
	uint64_t		*prp_entry, *prp1_entry, *prp2_entry;
	uint64_t		*prp_entry_phys, *prp_page, *prp_page_phys;
	uint32_t		offset, entry_len, page_mask_result, page_mask;
	bus_addr_t		paddr;
	size_t			length;
	struct mpr_prp_page	*prp_page_info = NULL;

	/*
	 * Not all commands require a data transfer. If no data, just return
	 * without constructing any PRP.
	 */
	if (!data_in_sz && !data_out_sz)
		return;

	/*
	 * Set pointers to PRP1 and PRP2, which are in the NVMe command. PRP1 is
	 * located at a 24 byte offset from the start of the NVMe command. Then
	 * set the current PRP entry pointer to PRP1.
	 */
	prp1_entry = (uint64_t *)(nvme_encap_request->NVMe_Command +
	    NVME_CMD_PRP1_OFFSET);
	prp2_entry = (uint64_t *)(nvme_encap_request->NVMe_Command +
	    NVME_CMD_PRP2_OFFSET);
	prp_entry = prp1_entry;

	/*
	 * For the PRP entries, use the specially allocated buffer of
	 * contiguous memory. PRP Page allocation failures should not happen
	 * because there should be enough PRP page buffers to account for the
	 * possible NVMe QDepth.
	 */
	prp_page_info = mpr_alloc_prp_page(sc);
	KASSERT(prp_page_info != NULL, ("%s: There are no PRP Pages left to be "
	    "used for building a native NVMe SGL.\n", __func__));
	prp_page = (uint64_t *)prp_page_info->prp_page;
	prp_page_phys = (uint64_t *)(uintptr_t)prp_page_info->prp_page_busaddr;

	/*
	 * Insert the allocated PRP page into the command's PRP page list. This
	 * will be freed when the command is freed.
	 */
	TAILQ_INSERT_TAIL(&cm->cm_prp_page_list, prp_page_info, prp_page_link);

	/*
	 * Check if we are within 1 entry of a page boundary we don't want our
	 * first entry to be a PRP List entry.
	 */
	page_mask = PAGE_SIZE - 1;
	page_mask_result = (uintptr_t)((uint8_t *)prp_page + prp_size) &
	    page_mask;
	if (!page_mask_result)
	{
		/* Bump up to next page boundary. */
		prp_page = (uint64_t *)((uint8_t *)prp_page + prp_size);
		prp_page_phys = (uint64_t *)((uint8_t *)prp_page_phys +
		    prp_size);
	}

	/*
	 * Set PRP physical pointer, which initially points to the current PRP
	 * DMA memory page.
	 */
	prp_entry_phys = prp_page_phys;

	/* Get physical address and length of the data buffer. */
	paddr = (bus_addr_t)(uintptr_t)data;
	if (data_in_sz)
		length = data_in_sz;
	else
		length = data_out_sz;

	/* Loop while the length is not zero. */
	while (length)
	{
		/*
		 * Check if we need to put a list pointer here if we are at page
		 * boundary - prp_size (8 bytes).
		 */
		page_mask_result = (uintptr_t)((uint8_t *)prp_entry_phys +
		    prp_size) & page_mask;
		if (!page_mask_result)
		{
			/*
			 * This is the last entry in a PRP List, so we need to
			 * put a PRP list pointer here. What this does is:
			 *   - bump the current memory pointer to the next
			 *     address, which will be the next full page.
			 *   - set the PRP Entry to point to that page. This is
			 *     now the PRP List pointer.
			 *   - bump the PRP Entry pointer the start of the next
			 *     page. Since all of this PRP memory is contiguous,
			 *     no need to get a new page - it's just the next
			 *     address.
			 */
			prp_entry_phys++;
			*prp_entry =
			    htole64((uint64_t)(uintptr_t)prp_entry_phys);
			prp_entry++;
		}

		/* Need to handle if entry will be part of a page. */
		offset = (uint32_t)paddr & page_mask;
		entry_len = PAGE_SIZE - offset;

		if (prp_entry == prp1_entry)
		{
			/*
			 * Must fill in the first PRP pointer (PRP1) before
			 * moving on.
			 */
			*prp1_entry = htole64((uint64_t)paddr);

			/*
			 * Now point to the second PRP entry within the
			 * command (PRP2).
			 */
			prp_entry = prp2_entry;
		}
		else if (prp_entry == prp2_entry)
		{
			/*
			 * Should the PRP2 entry be a PRP List pointer or just a
			 * regular PRP pointer? If there is more than one more
			 * page of data, must use a PRP List pointer.
			 */
			if (length > PAGE_SIZE)
			{
				/*
				 * PRP2 will contain a PRP List pointer because
				 * more PRP's are needed with this command. The
				 * list will start at the beginning of the
				 * contiguous buffer.
				 */
				*prp2_entry =
				    htole64(
				    (uint64_t)(uintptr_t)prp_entry_phys);

				/*
				 * The next PRP Entry will be the start of the
				 * first PRP List.
				 */
				prp_entry = prp_page;
			}
			else
			{
				/*
				 * After this, the PRP Entries are complete.
				 * This command uses 2 PRP's and no PRP list.
				 */
				*prp2_entry = htole64((uint64_t)paddr);
			}
		}
		else
		{
			/*
			 * Put entry in list and bump the addresses.
			 *
			 * After PRP1 and PRP2 are filled in, this will fill in
			 * all remaining PRP entries in a PRP List, one per each
			 * time through the loop.
			 */
			*prp_entry = htole64((uint64_t)paddr);
			prp_entry++;
			prp_entry_phys++;
		}

		/*
		 * Bump the phys address of the command's data buffer by the
		 * entry_len.
		 */
		paddr += entry_len;

		/* Decrement length accounting for last partial page. */
		if (entry_len > length)
			length = 0;
		else
			length -= entry_len;
	}
}

/*
 * mpr_check_pcie_native_sgl - This function is called for PCIe end devices to
 * determine if the driver needs to build a native SGL. If so, that native SGL
 * is built in the contiguous buffers allocated especially for PCIe SGL
 * creation. If the driver will not build a native SGL, return TRUE and a
 * normal IEEE SGL will be built. Currently this routine supports NVMe devices
 * only.
 *
 * Returns FALSE (0) if native SGL was built, TRUE (1) if no SGL was built.
 */
static int
mpr_check_pcie_native_sgl(struct mpr_softc *sc, struct mpr_command *cm,
    bus_dma_segment_t *segs, int segs_left)
{
	uint32_t		i, sge_dwords, length, offset, entry_len;
	uint32_t		num_entries, buff_len = 0, sges_in_segment;
	uint32_t		page_mask, page_mask_result, *curr_buff;
	uint32_t		*ptr_sgl, *ptr_first_sgl, first_page_offset;
	uint32_t		first_page_data_size, end_residual;
	uint64_t		*msg_phys;
	bus_addr_t		paddr;
	int			build_native_sgl = 0, first_prp_entry;
	int			prp_size = PRP_ENTRY_SIZE;
	Mpi25IeeeSgeChain64_t	*main_chain_element = NULL;
	struct mpr_prp_page	*prp_page_info = NULL;

	mpr_dprint(sc, MPR_TRACE, "%s\n", __func__);

	/*
	 * Add up the sizes of each segment length to get the total transfer
	 * size, which will be checked against the Maximum Data Transfer Size.
	 * If the data transfer length exceeds the MDTS for this device, just
	 * return 1 so a normal IEEE SGL will be built. F/W will break the I/O
	 * up into multiple I/O's. [nvme_mdts = 0 means unlimited]
	 */
	for (i = 0; i < segs_left; i++)
		buff_len += htole32(segs[i].ds_len);
	if ((cm->cm_targ->MDTS > 0) && (buff_len > cm->cm_targ->MDTS))
		return 1;

	/* Create page_mask (to get offset within page) */
	page_mask = PAGE_SIZE - 1;

	/*
	 * Check if the number of elements exceeds the max number that can be
	 * put in the main message frame (H/W can only translate an SGL that
	 * is contained entirely in the main message frame).
	 */
	sges_in_segment = (sc->reqframesz -
	    offsetof(Mpi25SCSIIORequest_t, SGL)) / sizeof(MPI25_SGE_IO_UNION);
	if (segs_left > sges_in_segment)
		build_native_sgl = 1;
	else
	{
		/*
		 * NVMe uses one PRP for each physical page (or part of physical
		 * page).
		 *    if 4 pages or less then IEEE is OK
		 *    if > 5 pages then we need to build a native SGL
		 *    if > 4 and <= 5 pages, then check the physical address of
		 *      the first SG entry, then if this first size in the page
		 *      is >= the residual beyond 4 pages then use IEEE,
		 *      otherwise use native SGL
		 */
		if (buff_len > (PAGE_SIZE * 5))
			build_native_sgl = 1;
		else if ((buff_len > (PAGE_SIZE * 4)) &&
		    (buff_len <= (PAGE_SIZE * 5)) )
		{
			msg_phys = (uint64_t *)(uintptr_t)segs[0].ds_addr;
			first_page_offset =
			    ((uint32_t)(uint64_t)(uintptr_t)msg_phys &
			    page_mask);
			first_page_data_size = PAGE_SIZE - first_page_offset;
			end_residual = buff_len % PAGE_SIZE;

			/*
			 * If offset into first page pushes the end of the data
			 * beyond end of the 5th page, we need the extra PRP
			 * list.
			 */
			if (first_page_data_size < end_residual)
				build_native_sgl = 1;

			/*
			 * Check if first SG entry size is < residual beyond 4
			 * pages.
			 */
			if (htole32(segs[0].ds_len) <
			    (buff_len - (PAGE_SIZE * 4)))
				build_native_sgl = 1;
		}
	}

	/* check if native SGL is needed */
	if (!build_native_sgl)
		return 1;

	/*
	 * Native SGL is needed.
	 * Put a chain element in main message frame that points to the first
	 * chain buffer.
	 *
	 * NOTE:  The ChainOffset field must be 0 when using a chain pointer to
	 *        a native SGL.
	 */

	/* Set main message chain element pointer */
	main_chain_element = (pMpi25IeeeSgeChain64_t)cm->cm_sge;

	/*
	 * For NVMe the chain element needs to be the 2nd SGL entry in the main
	 * message.
	 */
	main_chain_element = (Mpi25IeeeSgeChain64_t *)
	    ((uint8_t *)main_chain_element + sizeof(MPI25_IEEE_SGE_CHAIN64));

	/*
	 * For the PRP entries, use the specially allocated buffer of
	 * contiguous memory. PRP Page allocation failures should not happen
	 * because there should be enough PRP page buffers to account for the
	 * possible NVMe QDepth.
	 */
	prp_page_info = mpr_alloc_prp_page(sc);
	KASSERT(prp_page_info != NULL, ("%s: There are no PRP Pages left to be "
	    "used for building a native NVMe SGL.\n", __func__));
	curr_buff = (uint32_t *)prp_page_info->prp_page;
	msg_phys = (uint64_t *)(uintptr_t)prp_page_info->prp_page_busaddr;

	/*
	 * Insert the allocated PRP page into the command's PRP page list. This
	 * will be freed when the command is freed.
	 */
	TAILQ_INSERT_TAIL(&cm->cm_prp_page_list, prp_page_info, prp_page_link);

	/*
	 * Check if we are within 1 entry of a page boundary we don't want our
	 * first entry to be a PRP List entry.
	 */
	page_mask_result = (uintptr_t)((uint8_t *)curr_buff + prp_size) &
	    page_mask;
	if (!page_mask_result) {
		/* Bump up to next page boundary. */
		curr_buff = (uint32_t *)((uint8_t *)curr_buff + prp_size);
		msg_phys = (uint64_t *)((uint8_t *)msg_phys + prp_size);
	}

	/* Fill in the chain element and make it an NVMe segment type. */
	main_chain_element->Address.High =
	    htole32((uint32_t)((uint64_t)(uintptr_t)msg_phys >> 32));
	main_chain_element->Address.Low =
	    htole32((uint32_t)(uintptr_t)msg_phys);
	main_chain_element->NextChainOffset = 0;
	main_chain_element->Flags = MPI2_IEEE_SGE_FLAGS_CHAIN_ELEMENT |
	    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR |
	    MPI26_IEEE_SGE_FLAGS_NSF_NVME_PRP;

	/* Set SGL pointer to start of contiguous PCIe buffer. */
	ptr_sgl = curr_buff;
	sge_dwords = 2;
	num_entries = 0;

	/*
	 * NVMe has a very convoluted PRP format. One PRP is required for each
	 * page or partial page. We need to split up OS SG entries if they are
	 * longer than one page or cross a page boundary. We also have to insert
	 * a PRP list pointer entry as the last entry in each physical page of
	 * the PRP list.
	 *
	 * NOTE: The first PRP "entry" is actually placed in the first SGL entry
	 * in the main message in IEEE 64 format. The 2nd entry in the main
	 * message is the chain element, and the rest of the PRP entries are
	 * built in the contiguous PCIe buffer.
	 */
	first_prp_entry = 1;
	ptr_first_sgl = (uint32_t *)cm->cm_sge;

	for (i = 0; i < segs_left; i++) {
		/* Get physical address and length of this SG entry. */
		paddr = segs[i].ds_addr;
		length = segs[i].ds_len;

		/*
		 * Check whether a given SGE buffer lies on a non-PAGED
		 * boundary if this is not the first page. If so, this is not
		 * expected so have FW build the SGL.
		 */
		if ((i != 0) && (((uint32_t)paddr & page_mask) != 0)) {
			mpr_dprint(sc, MPR_ERROR, "Unaligned SGE while "
			    "building NVMe PRPs, low address is 0x%x\n",
			    (uint32_t)paddr);
			return 1;
		}

		/* Apart from last SGE, if any other SGE boundary is not page
		 * aligned then it means that hole exists. Existence of hole
		 * leads to data corruption. So fallback to IEEE SGEs.
		 */
		if (i != (segs_left - 1)) {
			if (((uint32_t)paddr + length) & page_mask) {
				mpr_dprint(sc, MPR_ERROR, "Unaligned SGE "
				    "boundary while building NVMe PRPs, low "
				    "address: 0x%x and length: %u\n",
				    (uint32_t)paddr, length);
				return 1;
			}
		}

		/* Loop while the length is not zero. */
		while (length) {
			/*
			 * Check if we need to put a list pointer here if we are
			 * at page boundary - prp_size.
			 */
			page_mask_result = (uintptr_t)((uint8_t *)ptr_sgl +
			    prp_size) & page_mask;
			if (!page_mask_result) {
				/*
				 * Need to put a PRP list pointer here.
				 */
				msg_phys = (uint64_t *)((uint8_t *)msg_phys +
				    prp_size);
				*ptr_sgl = htole32((uintptr_t)msg_phys);
				*(ptr_sgl+1) = htole32((uint64_t)(uintptr_t)
				    msg_phys >> 32);
				ptr_sgl += sge_dwords;
				num_entries++;
			}

			/* Need to handle if entry will be part of a page. */
			offset = (uint32_t)paddr & page_mask;
			entry_len = PAGE_SIZE - offset;
			if (first_prp_entry) {
				/*
				 * Put IEEE entry in first SGE in main message.
				 * (Simple element, System addr, not end of
				 * list.)
				 */
				*ptr_first_sgl = htole32((uint32_t)paddr);
				*(ptr_first_sgl + 1) =
				    htole32((uint32_t)((uint64_t)paddr >> 32));
				*(ptr_first_sgl + 2) = htole32(entry_len);
				*(ptr_first_sgl + 3) = 0;

				/* No longer the first PRP entry. */
				first_prp_entry = 0;
			} else {
				/* Put entry in list. */
				*ptr_sgl = htole32((uint32_t)paddr);
				*(ptr_sgl + 1) =
				    htole32((uint32_t)((uint64_t)paddr >> 32));

				/* Bump ptr_sgl, msg_phys, and num_entries. */
				ptr_sgl += sge_dwords;
				msg_phys = (uint64_t *)((uint8_t *)msg_phys +
				    prp_size);
				num_entries++;
			}

			/* Bump the phys address by the entry_len. */
			paddr += entry_len;

			/* Decrement length accounting for last partial page. */
			if (entry_len > length)
				length = 0;
			else
				length -= entry_len;
		}
	}

	/* Set chain element Length. */
	main_chain_element->Length = htole32(num_entries * prp_size);

	/* Return 0, indicating we built a native SGL. */
	return 0;
}

/*
 * Add a chain element as the next SGE for the specified command.
 * Reset cm_sge and cm_sgesize to indicate all the available space. Chains are
 * only required for IEEE commands.  Therefore there is no code for commands
 * that have the MPR_CM_FLAGS_SGE_SIMPLE flag set (and those commands
 * shouldn't be requesting chains).
 */
static int
mpr_add_chain(struct mpr_command *cm, int segsleft)
{
	struct mpr_softc *sc = cm->cm_sc;
	MPI2_REQUEST_HEADER *req;
	MPI25_IEEE_SGE_CHAIN64 *ieee_sgc;
	struct mpr_chain *chain;
	int sgc_size, current_segs, rem_segs, segs_per_frame;
	uint8_t next_chain_offset = 0;

	/*
	 * Fail if a command is requesting a chain for SIMPLE SGE's.  For SAS3
	 * only IEEE commands should be requesting chains.  Return some error
	 * code other than 0.
	 */
	if (cm->cm_flags & MPR_CM_FLAGS_SGE_SIMPLE) {
		mpr_dprint(sc, MPR_ERROR, "A chain element cannot be added to "
		    "an MPI SGL.\n");
		return(ENOBUFS);
	}

	sgc_size = sizeof(MPI25_IEEE_SGE_CHAIN64);
	if (cm->cm_sglsize < sgc_size)
		panic("MPR: Need SGE Error Code\n");

	chain = mpr_alloc_chain(cm->cm_sc);
	if (chain == NULL)
		return (ENOBUFS);

	/*
	 * Note: a double-linked list is used to make it easier to walk for
	 * debugging.
	 */
	TAILQ_INSERT_TAIL(&cm->cm_chain_list, chain, chain_link);

	/*
	 * Need to know if the number of frames left is more than 1 or not.  If
	 * more than 1 frame is required, NextChainOffset will need to be set,
	 * which will just be the last segment of the frame.
	 */
	rem_segs = 0;
	if (cm->cm_sglsize < (sgc_size * segsleft)) {
		/*
		 * rem_segs is the number of segements remaining after the
		 * segments that will go into the current frame.  Since it is
		 * known that at least one more frame is required, account for
		 * the chain element.  To know if more than one more frame is
		 * required, just check if there will be a remainder after using
		 * the current frame (with this chain) and the next frame.  If
		 * so the NextChainOffset must be the last element of the next
		 * frame.
		 */
		current_segs = (cm->cm_sglsize / sgc_size) - 1;
		rem_segs = segsleft - current_segs;
		segs_per_frame = sc->chain_frame_size / sgc_size;
		if (rem_segs > segs_per_frame) {
			next_chain_offset = segs_per_frame - 1;
		}
	}
	ieee_sgc = &((MPI25_SGE_IO_UNION *)cm->cm_sge)->IeeeChain;
	ieee_sgc->Length = next_chain_offset ?
	    htole32((uint32_t)sc->chain_frame_size) :
	    htole32((uint32_t)rem_segs * (uint32_t)sgc_size);
	ieee_sgc->NextChainOffset = next_chain_offset;
	ieee_sgc->Flags = (MPI2_IEEE_SGE_FLAGS_CHAIN_ELEMENT |
	    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR);
	ieee_sgc->Address.Low = htole32(chain->chain_busaddr);
	ieee_sgc->Address.High = htole32(chain->chain_busaddr >> 32);
	cm->cm_sge = &((MPI25_SGE_IO_UNION *)chain->chain)->IeeeSimple;
	req = (MPI2_REQUEST_HEADER *)cm->cm_req;
	req->ChainOffset = (sc->chain_frame_size - sgc_size) >> 4;

	cm->cm_sglsize = sc->chain_frame_size;
	return (0);
}

/*
 * Add one scatter-gather element to the scatter-gather list for a command.
 * Maintain cm_sglsize and cm_sge as the remaining size and pointer to the
 * next SGE to fill in, respectively.  In Gen3, the MPI SGL does not have a
 * chain, so don't consider any chain additions.
 */
int
mpr_push_sge(struct mpr_command *cm, MPI2_SGE_SIMPLE64 *sge, size_t len,
    int segsleft)
{
	uint32_t saved_buf_len, saved_address_low, saved_address_high;
	u32 sge_flags;

	/*
	 * case 1: >=1 more segment, no room for anything (error)
	 * case 2: 1 more segment and enough room for it
         */

	if (cm->cm_sglsize < (segsleft * sizeof(MPI2_SGE_SIMPLE64))) {
		mpr_dprint(cm->cm_sc, MPR_ERROR,
		    "%s: warning: Not enough room for MPI SGL in frame.\n",
		    __func__);
		return(ENOBUFS);
	}

	KASSERT(segsleft == 1,
	    ("segsleft cannot be more than 1 for an MPI SGL; segsleft = %d\n",
	    segsleft));

	/*
	 * There is one more segment left to add for the MPI SGL and there is
	 * enough room in the frame to add it.  This is the normal case because
	 * MPI SGL's don't have chains, otherwise something is wrong.
	 *
	 * If this is a bi-directional request, need to account for that
	 * here.  Save the pre-filled sge values.  These will be used
	 * either for the 2nd SGL or for a single direction SGL.  If
	 * cm_out_len is non-zero, this is a bi-directional request, so
	 * fill in the OUT SGL first, then the IN SGL, otherwise just
	 * fill in the IN SGL.  Note that at this time, when filling in
	 * 2 SGL's for a bi-directional request, they both use the same
	 * DMA buffer (same cm command).
	 */
	saved_buf_len = sge->FlagsLength & 0x00FFFFFF;
	saved_address_low = sge->Address.Low;
	saved_address_high = sge->Address.High;
	if (cm->cm_out_len) {
		sge->FlagsLength = cm->cm_out_len |
		    ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
		    MPI2_SGE_FLAGS_END_OF_BUFFER |
		    MPI2_SGE_FLAGS_HOST_TO_IOC |
		    MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
		    MPI2_SGE_FLAGS_SHIFT);
		cm->cm_sglsize -= len;
		/* Endian Safe code */
		sge_flags = sge->FlagsLength;
		sge->FlagsLength = htole32(sge_flags);
		sge->Address.High = htole32(sge->Address.High);	
		sge->Address.Low = htole32(sge->Address.Low);
		bcopy(sge, cm->cm_sge, len);
		cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
	}
	sge->FlagsLength = saved_buf_len |
	    ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
	    MPI2_SGE_FLAGS_END_OF_BUFFER |
	    MPI2_SGE_FLAGS_LAST_ELEMENT |
	    MPI2_SGE_FLAGS_END_OF_LIST |
	    MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
	    MPI2_SGE_FLAGS_SHIFT);
	if (cm->cm_flags & MPR_CM_FLAGS_DATAIN) {
		sge->FlagsLength |=
		    ((uint32_t)(MPI2_SGE_FLAGS_IOC_TO_HOST) <<
		    MPI2_SGE_FLAGS_SHIFT);
	} else {
		sge->FlagsLength |=
		    ((uint32_t)(MPI2_SGE_FLAGS_HOST_TO_IOC) <<
		    MPI2_SGE_FLAGS_SHIFT);
	}
	sge->Address.Low = saved_address_low;
	sge->Address.High = saved_address_high;

	cm->cm_sglsize -= len;
	/* Endian Safe code */
	sge_flags = sge->FlagsLength;
	sge->FlagsLength = htole32(sge_flags);
	sge->Address.High = htole32(sge->Address.High);	
	sge->Address.Low = htole32(sge->Address.Low);
	bcopy(sge, cm->cm_sge, len);
	cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
	return (0);
}

/*
 * Add one IEEE scatter-gather element (chain or simple) to the IEEE scatter-
 * gather list for a command.  Maintain cm_sglsize and cm_sge as the
 * remaining size and pointer to the next SGE to fill in, respectively.
 */
int
mpr_push_ieee_sge(struct mpr_command *cm, void *sgep, int segsleft)
{
	MPI2_IEEE_SGE_SIMPLE64 *sge = sgep;
	int error, ieee_sge_size = sizeof(MPI25_SGE_IO_UNION);
	uint32_t saved_buf_len, saved_address_low, saved_address_high;
	uint32_t sge_length;

	/*
	 * case 1: No room for chain or segment (error).
	 * case 2: Two or more segments left but only room for chain.
	 * case 3: Last segment and room for it, so set flags.
	 */

	/*
	 * There should be room for at least one element, or there is a big
	 * problem.
	 */
	if (cm->cm_sglsize < ieee_sge_size)
		panic("MPR: Need SGE Error Code\n");

	if ((segsleft >= 2) && (cm->cm_sglsize < (ieee_sge_size * 2))) {
		if ((error = mpr_add_chain(cm, segsleft)) != 0)
			return (error);
	}

	if (segsleft == 1) {
		/*
		 * If this is a bi-directional request, need to account for that
		 * here.  Save the pre-filled sge values.  These will be used
		 * either for the 2nd SGL or for a single direction SGL.  If
		 * cm_out_len is non-zero, this is a bi-directional request, so
		 * fill in the OUT SGL first, then the IN SGL, otherwise just
		 * fill in the IN SGL.  Note that at this time, when filling in
		 * 2 SGL's for a bi-directional request, they both use the same
		 * DMA buffer (same cm command).
		 */
		saved_buf_len = sge->Length;
		saved_address_low = sge->Address.Low;
		saved_address_high = sge->Address.High;
		if (cm->cm_out_len) {
			sge->Length = cm->cm_out_len;
			sge->Flags = (MPI2_IEEE_SGE_FLAGS_SIMPLE_ELEMENT |
			    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR);
			cm->cm_sglsize -= ieee_sge_size;
			/* Endian Safe code */
			sge_length = sge->Length;
			sge->Length = htole32(sge_length);
			sge->Address.High = htole32(sge->Address.High);	
			sge->Address.Low = htole32(sge->Address.Low);
			bcopy(sgep, cm->cm_sge, ieee_sge_size);
			cm->cm_sge =
			    (MPI25_SGE_IO_UNION *)((uintptr_t)cm->cm_sge +
			    ieee_sge_size);
		}
		sge->Length = saved_buf_len;
		sge->Flags = (MPI2_IEEE_SGE_FLAGS_SIMPLE_ELEMENT |
		    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR |
		    MPI25_IEEE_SGE_FLAGS_END_OF_LIST);
		sge->Address.Low = saved_address_low;
		sge->Address.High = saved_address_high;
	}

	cm->cm_sglsize -= ieee_sge_size;
	/* Endian Safe code */
	sge_length = sge->Length;
	sge->Length = htole32(sge_length);
	sge->Address.High = htole32(sge->Address.High);	
	sge->Address.Low = htole32(sge->Address.Low);
	bcopy(sgep, cm->cm_sge, ieee_sge_size);
	cm->cm_sge = (MPI25_SGE_IO_UNION *)((uintptr_t)cm->cm_sge +
	    ieee_sge_size);
	return (0);
}

/*
 * Add one dma segment to the scatter-gather list for a command.
 */
int
mpr_add_dmaseg(struct mpr_command *cm, vm_paddr_t pa, size_t len, u_int flags,
    int segsleft)
{
	MPI2_SGE_SIMPLE64 sge;
	MPI2_IEEE_SGE_SIMPLE64 ieee_sge;

	if (!(cm->cm_flags & MPR_CM_FLAGS_SGE_SIMPLE)) {
		ieee_sge.Flags = (MPI2_IEEE_SGE_FLAGS_SIMPLE_ELEMENT |
		    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR);
		ieee_sge.Length = len;
		mpr_from_u64(pa, &ieee_sge.Address);

		return (mpr_push_ieee_sge(cm, &ieee_sge, segsleft));
	} else {
		/*
		 * This driver always uses 64-bit address elements for
		 * simplicity.
		 */
		flags |= MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
		    MPI2_SGE_FLAGS_64_BIT_ADDRESSING;
		/* Set Endian safe macro in mpr_push_sge */
		sge.FlagsLength = len | (flags << MPI2_SGE_FLAGS_SHIFT);
		mpr_from_u64(pa, &sge.Address);

		return (mpr_push_sge(cm, &sge, sizeof sge, segsleft));
	}
}

static void
mpr_data_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
	struct mpr_softc *sc;
	struct mpr_command *cm;
	u_int i, dir, sflags;

	cm = (struct mpr_command *)arg;
	sc = cm->cm_sc;

	/*
	 * In this case, just print out a warning and let the chip tell the
	 * user they did the wrong thing.
	 */
	if ((cm->cm_max_segs != 0) && (nsegs > cm->cm_max_segs)) {
		mpr_dprint(sc, MPR_ERROR, "%s: warning: busdma returned %d "
		    "segments, more than the %d allowed\n", __func__, nsegs,
		    cm->cm_max_segs);
	}

	/*
	 * Set up DMA direction flags.  Bi-directional requests are also handled
	 * here.  In that case, both direction flags will be set.
	 */
	sflags = 0;
	if (cm->cm_flags & MPR_CM_FLAGS_SMP_PASS) {
		/*
		 * We have to add a special case for SMP passthrough, there
		 * is no easy way to generically handle it.  The first
		 * S/G element is used for the command (therefore the
		 * direction bit needs to be set).  The second one is used
		 * for the reply.  We'll leave it to the caller to make
		 * sure we only have two buffers.
		 */
		/*
		 * Even though the busdma man page says it doesn't make
		 * sense to have both direction flags, it does in this case.
		 * We have one s/g element being accessed in each direction.
		 */
		dir = BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD;

		/*
		 * Set the direction flag on the first buffer in the SMP
		 * passthrough request.  We'll clear it for the second one.
		 */
		sflags |= MPI2_SGE_FLAGS_DIRECTION |
			  MPI2_SGE_FLAGS_END_OF_BUFFER;
	} else if (cm->cm_flags & MPR_CM_FLAGS_DATAOUT) {
		sflags |= MPI2_SGE_FLAGS_HOST_TO_IOC;
		dir = BUS_DMASYNC_PREWRITE;
	} else
		dir = BUS_DMASYNC_PREREAD;

	/* Check if a native SG list is needed for an NVMe PCIe device. */
	if (cm->cm_targ && cm->cm_targ->is_nvme &&
	    mpr_check_pcie_native_sgl(sc, cm, segs, nsegs) == 0) {
		/* A native SG list was built, skip to end. */
		goto out;
	}

	for (i = 0; i < nsegs; i++) {
		if ((cm->cm_flags & MPR_CM_FLAGS_SMP_PASS) && (i != 0)) {
			sflags &= ~MPI2_SGE_FLAGS_DIRECTION;
		}
		error = mpr_add_dmaseg(cm, segs[i].ds_addr, segs[i].ds_len,
		    sflags, nsegs - i);
		if (error != 0) {
			/* Resource shortage, roll back! */
			if (ratecheck(&sc->lastfail, &mpr_chainfail_interval))
				mpr_dprint(sc, MPR_INFO, "Out of chain frames, "
				    "consider increasing hw.mpr.max_chains.\n");
			cm->cm_flags |= MPR_CM_FLAGS_CHAIN_FAILED;
			mpr_complete_command(sc, cm);
			return;
		}
	}

out:
	bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap, dir);
	mpr_enqueue_request(sc, cm);

	return;
}

static void
mpr_data_cb2(void *arg, bus_dma_segment_t *segs, int nsegs, bus_size_t mapsize,
	     int error)
{
	mpr_data_cb(arg, segs, nsegs, error);
}

/*
 * This is the routine to enqueue commands ansynchronously.
 * Note that the only error path here is from bus_dmamap_load(), which can
 * return EINPROGRESS if it is waiting for resources.  Other than this, it's
 * assumed that if you have a command in-hand, then you have enough credits
 * to use it.
 */
int
mpr_map_command(struct mpr_softc *sc, struct mpr_command *cm)
{
	int error = 0;

	if (cm->cm_flags & MPR_CM_FLAGS_USE_UIO) {
		error = bus_dmamap_load_uio(sc->buffer_dmat, cm->cm_dmamap,
		    &cm->cm_uio, mpr_data_cb2, cm, 0);
	} else if (cm->cm_flags & MPR_CM_FLAGS_USE_CCB) {
		error = bus_dmamap_load_ccb(sc->buffer_dmat, cm->cm_dmamap,
		    cm->cm_data, mpr_data_cb, cm, 0);
	} else if ((cm->cm_data != NULL) && (cm->cm_length != 0)) {
		error = bus_dmamap_load(sc->buffer_dmat, cm->cm_dmamap,
		    cm->cm_data, cm->cm_length, mpr_data_cb, cm, 0);
	} else {
		/* Add a zero-length element as needed */
		if (cm->cm_sge != NULL)
			mpr_add_dmaseg(cm, 0, 0, 0, 1);
		mpr_enqueue_request(sc, cm);
	}

	return (error);
}

/*
 * This is the routine to enqueue commands synchronously.  An error of
 * EINPROGRESS from mpr_map_command() is ignored since the command will
 * be executed and enqueued automatically.  Other errors come from msleep().
 */
int
mpr_wait_command(struct mpr_softc *sc, struct mpr_command **cmp, int timeout,
    int sleep_flag)
{
	int error, rc;
	struct timeval cur_time, start_time;
	struct mpr_command *cm = *cmp;

	if (sc->mpr_flags & MPR_FLAGS_DIAGRESET) 
		return  EBUSY;

	cm->cm_complete = NULL;
	cm->cm_flags |= (MPR_CM_FLAGS_WAKEUP + MPR_CM_FLAGS_POLLED);
	error = mpr_map_command(sc, cm);
	if ((error != 0) && (error != EINPROGRESS))
		return (error);

	// Check for context and wait for 50 mSec at a time until time has
	// expired or the command has finished.  If msleep can't be used, need
	// to poll.
	if (curthread->td_no_sleeping)
		sleep_flag = NO_SLEEP;
	getmicrouptime(&start_time);
	if (mtx_owned(&sc->mpr_mtx) && sleep_flag == CAN_SLEEP) {
		error = msleep(cm, &sc->mpr_mtx, 0, "mprwait", timeout*hz);
		if (error == EWOULDBLOCK) {
			/*
			 * Record the actual elapsed time in the case of a
			 * timeout for the message below.
			 */
			getmicrouptime(&cur_time);
			timevalsub(&cur_time, &start_time);
		}
	} else {
		while ((cm->cm_flags & MPR_CM_FLAGS_COMPLETE) == 0) {
			mpr_intr_locked(sc);
			if (sleep_flag == CAN_SLEEP)
				pause("mprwait", hz/20);
			else
				DELAY(50000);
		
			getmicrouptime(&cur_time);
			timevalsub(&cur_time, &start_time);
			if (cur_time.tv_sec > timeout) {
				error = EWOULDBLOCK;
				break;
			}
		}
	}

	if (error == EWOULDBLOCK) {
		if (cm->cm_timeout_handler == NULL) {
			mpr_dprint(sc, MPR_FAULT, "Calling Reinit from %s, timeout=%d,"
			    " elapsed=%jd\n", __func__, timeout,
			    (intmax_t)cur_time.tv_sec);
			rc = mpr_reinit(sc);
			mpr_dprint(sc, MPR_FAULT, "Reinit %s\n", (rc == 0) ? "success" :
			    "failed");
		} else
			cm->cm_timeout_handler(sc, cm);
		if (sc->mpr_flags & MPR_FLAGS_REALLOCATED) {
			/*
			 * Tell the caller that we freed the command in a
			 * reinit.
			 */
			*cmp = NULL;
		}
		error = ETIMEDOUT;
	}
	return (error);
}

/*
 * This is the routine to enqueue a command synchonously and poll for
 * completion.  Its use should be rare.
 */
int
mpr_request_polled(struct mpr_softc *sc, struct mpr_command **cmp)
{
	int error, rc;
	struct timeval cur_time, start_time;
	struct mpr_command *cm = *cmp;

	error = 0;

	cm->cm_flags |= MPR_CM_FLAGS_POLLED;
	cm->cm_complete = NULL;
	mpr_map_command(sc, cm);

	getmicrouptime(&start_time);
	while ((cm->cm_flags & MPR_CM_FLAGS_COMPLETE) == 0) {
		mpr_intr_locked(sc);

		if (mtx_owned(&sc->mpr_mtx))
			msleep(&sc->msleep_fake_chan, &sc->mpr_mtx, 0,
			    "mprpoll", hz/20);
		else
			pause("mprpoll", hz/20);

		/*
		 * Check for real-time timeout and fail if more than 60 seconds.
		 */
		getmicrouptime(&cur_time);
		timevalsub(&cur_time, &start_time);
		if (cur_time.tv_sec > 60) {
			mpr_dprint(sc, MPR_FAULT, "polling failed\n");
			error = ETIMEDOUT;
			break;
		}
	}
	cm->cm_state = MPR_CM_STATE_BUSY;
	if (error) {
		mpr_dprint(sc, MPR_FAULT, "Calling Reinit from %s\n", __func__);
		rc = mpr_reinit(sc);
		mpr_dprint(sc, MPR_FAULT, "Reinit %s\n", (rc == 0) ? "success" :
		    "failed");

		if (sc->mpr_flags & MPR_FLAGS_REALLOCATED) {
			/*
			 * Tell the caller that we freed the command in a
			 * reinit.
			 */
			*cmp = NULL;
		}
	}
	return (error);
}

/*
 * The MPT driver had a verbose interface for config pages.  In this driver,
 * reduce it to much simpler terms, similar to the Linux driver.
 */
int
mpr_read_config_page(struct mpr_softc *sc, struct mpr_config_params *params)
{
	MPI2_CONFIG_REQUEST *req;
	struct mpr_command *cm;
	int error;

	if (sc->mpr_flags & MPR_FLAGS_BUSY) {
		return (EBUSY);
	}

	cm = mpr_alloc_command(sc);
	if (cm == NULL) {
		return (EBUSY);
	}

	req = (MPI2_CONFIG_REQUEST *)cm->cm_req;
	req->Function = MPI2_FUNCTION_CONFIG;
	req->Action = params->action;
	req->SGLFlags = 0;
	req->ChainOffset = 0;
	req->PageAddress = params->page_address;
	if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
		MPI2_CONFIG_EXTENDED_PAGE_HEADER *hdr;

		hdr = &params->hdr.Ext;
		req->ExtPageType = hdr->ExtPageType;
		req->ExtPageLength = hdr->ExtPageLength;
		req->Header.PageType = MPI2_CONFIG_PAGETYPE_EXTENDED;
		req->Header.PageLength = 0; /* Must be set to zero */
		req->Header.PageNumber = hdr->PageNumber;
		req->Header.PageVersion = hdr->PageVersion;
	} else {
		MPI2_CONFIG_PAGE_HEADER *hdr;

		hdr = &params->hdr.Struct;
		req->Header.PageType = hdr->PageType;
		req->Header.PageNumber = hdr->PageNumber;
		req->Header.PageLength = hdr->PageLength;
		req->Header.PageVersion = hdr->PageVersion;
	}

	cm->cm_data = params->buffer;
	cm->cm_length = params->length;
	if (cm->cm_data != NULL) {
		cm->cm_sge = &req->PageBufferSGE;
		cm->cm_sglsize = sizeof(MPI2_SGE_IO_UNION);
		cm->cm_flags = MPR_CM_FLAGS_SGE_SIMPLE | MPR_CM_FLAGS_DATAIN;
	} else
		cm->cm_sge = NULL;
	cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;

	cm->cm_complete_data = params;
	if (params->callback != NULL) {
		cm->cm_complete = mpr_config_complete;
		return (mpr_map_command(sc, cm));
	} else {
		error = mpr_wait_command(sc, &cm, 0, CAN_SLEEP);
		if (error) {
			mpr_dprint(sc, MPR_FAULT,
			    "Error %d reading config page\n", error);
			if (cm != NULL)
				mpr_free_command(sc, cm);
			return (error);
		}
		mpr_config_complete(sc, cm);
	}

	return (0);
}

int
mpr_write_config_page(struct mpr_softc *sc, struct mpr_config_params *params)
{
	return (EINVAL);
}

static void
mpr_config_complete(struct mpr_softc *sc, struct mpr_command *cm)
{
	MPI2_CONFIG_REPLY *reply;
	struct mpr_config_params *params;

	MPR_FUNCTRACE(sc);
	params = cm->cm_complete_data;

	if (cm->cm_data != NULL) {
		bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap,
		    BUS_DMASYNC_POSTREAD);
		bus_dmamap_unload(sc->buffer_dmat, cm->cm_dmamap);
	}

	/*
	 * XXX KDM need to do more error recovery?  This results in the
	 * device in question not getting probed.
	 */
	if ((cm->cm_flags & MPR_CM_FLAGS_ERROR_MASK) != 0) {
		params->status = MPI2_IOCSTATUS_BUSY;
		goto done;
	}

	reply = (MPI2_CONFIG_REPLY *)cm->cm_reply;
	if (reply == NULL) {
		params->status = MPI2_IOCSTATUS_BUSY;
		goto done;
	}
	params->status = reply->IOCStatus;
	if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
		params->hdr.Ext.ExtPageType = reply->ExtPageType;
		params->hdr.Ext.ExtPageLength = reply->ExtPageLength;
		params->hdr.Ext.PageType = reply->Header.PageType;
		params->hdr.Ext.PageNumber = reply->Header.PageNumber;
		params->hdr.Ext.PageVersion = reply->Header.PageVersion;
	} else {
		params->hdr.Struct.PageType = reply->Header.PageType;
		params->hdr.Struct.PageNumber = reply->Header.PageNumber;
		params->hdr.Struct.PageLength = reply->Header.PageLength;
		params->hdr.Struct.PageVersion = reply->Header.PageVersion;
	}

done:
	mpr_free_command(sc, cm);
	if (params->callback != NULL)
		params->callback(sc, params);

	return;
}