Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   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
// SPDX-License-Identifier: GPL-2.0
/*
 * PCI detection and setup code
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/of_pci.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/cpumask.h>
#include <linux/aer.h>
#include <linux/acpi.h>
#include <linux/hypervisor.h>
#include <linux/irqdomain.h>
#include <linux/pm_runtime.h>
#include <linux/bitfield.h>
#include "pci.h"

#define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
#define CARDBUS_RESERVE_BUSNR	3

static struct resource busn_resource = {
	.name	= "PCI busn",
	.start	= 0,
	.end	= 255,
	.flags	= IORESOURCE_BUS,
};

/* Ugh.  Need to stop exporting this to modules. */
LIST_HEAD(pci_root_buses);
EXPORT_SYMBOL(pci_root_buses);

static LIST_HEAD(pci_domain_busn_res_list);

struct pci_domain_busn_res {
	struct list_head list;
	struct resource res;
	int domain_nr;
};

static struct resource *get_pci_domain_busn_res(int domain_nr)
{
	struct pci_domain_busn_res *r;

	list_for_each_entry(r, &pci_domain_busn_res_list, list)
		if (r->domain_nr == domain_nr)
			return &r->res;

	r = kzalloc(sizeof(*r), GFP_KERNEL);
	if (!r)
		return NULL;

	r->domain_nr = domain_nr;
	r->res.start = 0;
	r->res.end = 0xff;
	r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED;

	list_add_tail(&r->list, &pci_domain_busn_res_list);

	return &r->res;
}

/*
 * Some device drivers need know if PCI is initiated.
 * Basically, we think PCI is not initiated when there
 * is no device to be found on the pci_bus_type.
 */
int no_pci_devices(void)
{
	struct device *dev;
	int no_devices;

	dev = bus_find_next_device(&pci_bus_type, NULL);
	no_devices = (dev == NULL);
	put_device(dev);
	return no_devices;
}
EXPORT_SYMBOL(no_pci_devices);

/*
 * PCI Bus Class
 */
static void release_pcibus_dev(struct device *dev)
{
	struct pci_bus *pci_bus = to_pci_bus(dev);

	put_device(pci_bus->bridge);
	pci_bus_remove_resources(pci_bus);
	pci_release_bus_of_node(pci_bus);
	kfree(pci_bus);
}

static const struct class pcibus_class = {
	.name		= "pci_bus",
	.dev_release	= &release_pcibus_dev,
	.dev_groups	= pcibus_groups,
};

static int __init pcibus_class_init(void)
{
	return class_register(&pcibus_class);
}
postcore_initcall(pcibus_class_init);

static u64 pci_size(u64 base, u64 maxbase, u64 mask)
{
	u64 size = mask & maxbase;	/* Find the significant bits */
	if (!size)
		return 0;

	/*
	 * Get the lowest of them to find the decode size, and from that
	 * the extent.
	 */
	size = size & ~(size-1);

	/*
	 * base == maxbase can be valid only if the BAR has already been
	 * programmed with all 1s.
	 */
	if (base == maxbase && ((base | (size - 1)) & mask) != mask)
		return 0;

	return size;
}

static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
{
	u32 mem_type;
	unsigned long flags;

	if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
		flags = bar & ~PCI_BASE_ADDRESS_IO_MASK;
		flags |= IORESOURCE_IO;
		return flags;
	}

	flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK;
	flags |= IORESOURCE_MEM;
	if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
		flags |= IORESOURCE_PREFETCH;

	mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK;
	switch (mem_type) {
	case PCI_BASE_ADDRESS_MEM_TYPE_32:
		break;
	case PCI_BASE_ADDRESS_MEM_TYPE_1M:
		/* 1M mem BAR treated as 32-bit BAR */
		break;
	case PCI_BASE_ADDRESS_MEM_TYPE_64:
		flags |= IORESOURCE_MEM_64;
		break;
	default:
		/* mem unknown type treated as 32-bit BAR */
		break;
	}
	return flags;
}

#define PCI_COMMAND_DECODE_ENABLE	(PCI_COMMAND_MEMORY | PCI_COMMAND_IO)

/**
 * __pci_read_base - Read a PCI BAR
 * @dev: the PCI device
 * @type: type of the BAR
 * @res: resource buffer to be filled in
 * @pos: BAR position in the config space
 *
 * Returns 1 if the BAR is 64-bit, or 0 if 32-bit.
 */
int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
		    struct resource *res, unsigned int pos)
{
	u32 l = 0, sz = 0, mask;
	u64 l64, sz64, mask64;
	u16 orig_cmd;
	struct pci_bus_region region, inverted_region;
	const char *res_name = pci_resource_name(dev, res - dev->resource);

	mask = type ? PCI_ROM_ADDRESS_MASK : ~0;

	/* No printks while decoding is disabled! */
	if (!dev->mmio_always_on) {
		pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
		if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) {
			pci_write_config_word(dev, PCI_COMMAND,
				orig_cmd & ~PCI_COMMAND_DECODE_ENABLE);
		}
	}

	res->name = pci_name(dev);

	pci_read_config_dword(dev, pos, &l);
	pci_write_config_dword(dev, pos, l | mask);
	pci_read_config_dword(dev, pos, &sz);
	pci_write_config_dword(dev, pos, l);

	/*
	 * All bits set in sz means the device isn't working properly.
	 * If the BAR isn't implemented, all bits must be 0.  If it's a
	 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
	 * 1 must be clear.
	 */
	if (PCI_POSSIBLE_ERROR(sz))
		sz = 0;

	/*
	 * I don't know how l can have all bits set.  Copied from old code.
	 * Maybe it fixes a bug on some ancient platform.
	 */
	if (PCI_POSSIBLE_ERROR(l))
		l = 0;

	if (type == pci_bar_unknown) {
		res->flags = decode_bar(dev, l);
		res->flags |= IORESOURCE_SIZEALIGN;
		if (res->flags & IORESOURCE_IO) {
			l64 = l & PCI_BASE_ADDRESS_IO_MASK;
			sz64 = sz & PCI_BASE_ADDRESS_IO_MASK;
			mask64 = PCI_BASE_ADDRESS_IO_MASK & (u32)IO_SPACE_LIMIT;
		} else {
			l64 = l & PCI_BASE_ADDRESS_MEM_MASK;
			sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
			mask64 = (u32)PCI_BASE_ADDRESS_MEM_MASK;
		}
	} else {
		if (l & PCI_ROM_ADDRESS_ENABLE)
			res->flags |= IORESOURCE_ROM_ENABLE;
		l64 = l & PCI_ROM_ADDRESS_MASK;
		sz64 = sz & PCI_ROM_ADDRESS_MASK;
		mask64 = PCI_ROM_ADDRESS_MASK;
	}

	if (res->flags & IORESOURCE_MEM_64) {
		pci_read_config_dword(dev, pos + 4, &l);
		pci_write_config_dword(dev, pos + 4, ~0);
		pci_read_config_dword(dev, pos + 4, &sz);
		pci_write_config_dword(dev, pos + 4, l);

		l64 |= ((u64)l << 32);
		sz64 |= ((u64)sz << 32);
		mask64 |= ((u64)~0 << 32);
	}

	if (!dev->mmio_always_on && (orig_cmd & PCI_COMMAND_DECODE_ENABLE))
		pci_write_config_word(dev, PCI_COMMAND, orig_cmd);

	if (!sz64)
		goto fail;

	sz64 = pci_size(l64, sz64, mask64);
	if (!sz64) {
		pci_info(dev, FW_BUG "%s: invalid; can't size\n", res_name);
		goto fail;
	}

	if (res->flags & IORESOURCE_MEM_64) {
		if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8)
		    && sz64 > 0x100000000ULL) {
			res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
			res->start = 0;
			res->end = 0;
			pci_err(dev, "%s: can't handle BAR larger than 4GB (size %#010llx)\n",
				res_name, (unsigned long long)sz64);
			goto out;
		}

		if ((sizeof(pci_bus_addr_t) < 8) && l) {
			/* Above 32-bit boundary; try to reallocate */
			res->flags |= IORESOURCE_UNSET;
			res->start = 0;
			res->end = sz64 - 1;
			pci_info(dev, "%s: can't handle BAR above 4GB (bus address %#010llx)\n",
				 res_name, (unsigned long long)l64);
			goto out;
		}
	}

	region.start = l64;
	region.end = l64 + sz64 - 1;

	pcibios_bus_to_resource(dev->bus, res, &region);
	pcibios_resource_to_bus(dev->bus, &inverted_region, res);

	/*
	 * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is
	 * the corresponding resource address (the physical address used by
	 * the CPU.  Converting that resource address back to a bus address
	 * should yield the original BAR value:
	 *
	 *     resource_to_bus(bus_to_resource(A)) == A
	 *
	 * If it doesn't, CPU accesses to "bus_to_resource(A)" will not
	 * be claimed by the device.
	 */
	if (inverted_region.start != region.start) {
		res->flags |= IORESOURCE_UNSET;
		res->start = 0;
		res->end = region.end - region.start;
		pci_info(dev, "%s: initial BAR value %#010llx invalid\n",
			 res_name, (unsigned long long)region.start);
	}

	goto out;


fail:
	res->flags = 0;
out:
	if (res->flags)
		pci_info(dev, "%s %pR\n", res_name, res);

	return (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
}

static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
{
	unsigned int pos, reg;

	if (dev->non_compliant_bars)
		return;

	/* Per PCIe r4.0, sec 9.3.4.1.11, the VF BARs are all RO Zero */
	if (dev->is_virtfn)
		return;

	for (pos = 0; pos < howmany; pos++) {
		struct resource *res = &dev->resource[pos];
		reg = PCI_BASE_ADDRESS_0 + (pos << 2);
		pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
	}

	if (rom) {
		struct resource *res = &dev->resource[PCI_ROM_RESOURCE];
		dev->rom_base_reg = rom;
		res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH |
				IORESOURCE_READONLY | IORESOURCE_SIZEALIGN;
		__pci_read_base(dev, pci_bar_mem32, res, rom);
	}
}

static void pci_read_bridge_io(struct pci_dev *dev, struct resource *res,
			       bool log)
{
	u8 io_base_lo, io_limit_lo;
	unsigned long io_mask, io_granularity, base, limit;
	struct pci_bus_region region;

	io_mask = PCI_IO_RANGE_MASK;
	io_granularity = 0x1000;
	if (dev->io_window_1k) {
		/* Support 1K I/O space granularity */
		io_mask = PCI_IO_1K_RANGE_MASK;
		io_granularity = 0x400;
	}

	pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
	pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
	base = (io_base_lo & io_mask) << 8;
	limit = (io_limit_lo & io_mask) << 8;

	if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
		u16 io_base_hi, io_limit_hi;

		pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
		pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
		base |= ((unsigned long) io_base_hi << 16);
		limit |= ((unsigned long) io_limit_hi << 16);
	}

	if (base <= limit) {
		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
		region.start = base;
		region.end = limit + io_granularity - 1;
		pcibios_bus_to_resource(dev->bus, res, &region);
		if (log)
			pci_info(dev, "  bridge window %pR\n", res);
	}
}

static void pci_read_bridge_mmio(struct pci_dev *dev, struct resource *res,
				 bool log)
{
	u16 mem_base_lo, mem_limit_lo;
	unsigned long base, limit;
	struct pci_bus_region region;

	pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
	pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
	base = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
	limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
	if (base <= limit) {
		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
		region.start = base;
		region.end = limit + 0xfffff;
		pcibios_bus_to_resource(dev->bus, res, &region);
		if (log)
			pci_info(dev, "  bridge window %pR\n", res);
	}
}

static void pci_read_bridge_mmio_pref(struct pci_dev *dev, struct resource *res,
				      bool log)
{
	u16 mem_base_lo, mem_limit_lo;
	u64 base64, limit64;
	pci_bus_addr_t base, limit;
	struct pci_bus_region region;

	pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
	pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
	base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
	limit64 = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;

	if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
		u32 mem_base_hi, mem_limit_hi;

		pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
		pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);

		/*
		 * Some bridges set the base > limit by default, and some
		 * (broken) BIOSes do not initialize them.  If we find
		 * this, just assume they are not being used.
		 */
		if (mem_base_hi <= mem_limit_hi) {
			base64 |= (u64) mem_base_hi << 32;
			limit64 |= (u64) mem_limit_hi << 32;
		}
	}

	base = (pci_bus_addr_t) base64;
	limit = (pci_bus_addr_t) limit64;

	if (base != base64) {
		pci_err(dev, "can't handle bridge window above 4GB (bus address %#010llx)\n",
			(unsigned long long) base64);
		return;
	}

	if (base <= limit) {
		res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) |
					 IORESOURCE_MEM | IORESOURCE_PREFETCH;
		if (res->flags & PCI_PREF_RANGE_TYPE_64)
			res->flags |= IORESOURCE_MEM_64;
		region.start = base;
		region.end = limit + 0xfffff;
		pcibios_bus_to_resource(dev->bus, res, &region);
		if (log)
			pci_info(dev, "  bridge window %pR\n", res);
	}
}

static void pci_read_bridge_windows(struct pci_dev *bridge)
{
	u32 buses;
	u16 io;
	u32 pmem, tmp;
	struct resource res;

	pci_read_config_dword(bridge, PCI_PRIMARY_BUS, &buses);
	res.flags = IORESOURCE_BUS;
	res.start = (buses >> 8) & 0xff;
	res.end = (buses >> 16) & 0xff;
	pci_info(bridge, "PCI bridge to %pR%s\n", &res,
		 bridge->transparent ? " (subtractive decode)" : "");

	pci_read_config_word(bridge, PCI_IO_BASE, &io);
	if (!io) {
		pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
		pci_read_config_word(bridge, PCI_IO_BASE, &io);
		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
	}
	if (io) {
		bridge->io_window = 1;
		pci_read_bridge_io(bridge, &res, true);
	}

	pci_read_bridge_mmio(bridge, &res, true);

	/*
	 * DECchip 21050 pass 2 errata: the bridge may miss an address
	 * disconnect boundary by one PCI data phase.  Workaround: do not
	 * use prefetching on this device.
	 */
	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
		return;

	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
	if (!pmem) {
		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
					       0xffe0fff0);
		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
	}
	if (!pmem)
		return;

	bridge->pref_window = 1;

	if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {

		/*
		 * Bridge claims to have a 64-bit prefetchable memory
		 * window; verify that the upper bits are actually
		 * writable.
		 */
		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem);
		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
				       0xffffffff);
		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem);
		if (tmp)
			bridge->pref_64_window = 1;
	}

	pci_read_bridge_mmio_pref(bridge, &res, true);
}

void pci_read_bridge_bases(struct pci_bus *child)
{
	struct pci_dev *dev = child->self;
	struct resource *res;
	int i;

	if (pci_is_root_bus(child))	/* It's a host bus, nothing to read */
		return;

	pci_info(dev, "PCI bridge to %pR%s\n",
		 &child->busn_res,
		 dev->transparent ? " (subtractive decode)" : "");

	pci_bus_remove_resources(child);
	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
		child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];

	pci_read_bridge_io(child->self, child->resource[0], false);
	pci_read_bridge_mmio(child->self, child->resource[1], false);
	pci_read_bridge_mmio_pref(child->self, child->resource[2], false);

	if (dev->transparent) {
		pci_bus_for_each_resource(child->parent, res) {
			if (res && res->flags) {
				pci_bus_add_resource(child, res,
						     PCI_SUBTRACTIVE_DECODE);
				pci_info(dev, "  bridge window %pR (subtractive decode)\n",
					   res);
			}
		}
	}
}

static struct pci_bus *pci_alloc_bus(struct pci_bus *parent)
{
	struct pci_bus *b;

	b = kzalloc(sizeof(*b), GFP_KERNEL);
	if (!b)
		return NULL;

	INIT_LIST_HEAD(&b->node);
	INIT_LIST_HEAD(&b->children);
	INIT_LIST_HEAD(&b->devices);
	INIT_LIST_HEAD(&b->slots);
	INIT_LIST_HEAD(&b->resources);
	b->max_bus_speed = PCI_SPEED_UNKNOWN;
	b->cur_bus_speed = PCI_SPEED_UNKNOWN;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
	if (parent)
		b->domain_nr = parent->domain_nr;
#endif
	return b;
}

static void pci_release_host_bridge_dev(struct device *dev)
{
	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);

	if (bridge->release_fn)
		bridge->release_fn(bridge);

	pci_free_resource_list(&bridge->windows);
	pci_free_resource_list(&bridge->dma_ranges);
	kfree(bridge);
}

static void pci_init_host_bridge(struct pci_host_bridge *bridge)
{
	INIT_LIST_HEAD(&bridge->windows);
	INIT_LIST_HEAD(&bridge->dma_ranges);

	/*
	 * We assume we can manage these PCIe features.  Some systems may
	 * reserve these for use by the platform itself, e.g., an ACPI BIOS
	 * may implement its own AER handling and use _OSC to prevent the
	 * OS from interfering.
	 */
	bridge->native_aer = 1;
	bridge->native_pcie_hotplug = 1;
	bridge->native_shpc_hotplug = 1;
	bridge->native_pme = 1;
	bridge->native_ltr = 1;
	bridge->native_dpc = 1;
	bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET;
	bridge->native_cxl_error = 1;

	device_initialize(&bridge->dev);
}

struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
{
	struct pci_host_bridge *bridge;

	bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
	if (!bridge)
		return NULL;

	pci_init_host_bridge(bridge);
	bridge->dev.release = pci_release_host_bridge_dev;

	return bridge;
}
EXPORT_SYMBOL(pci_alloc_host_bridge);

static void devm_pci_alloc_host_bridge_release(void *data)
{
	pci_free_host_bridge(data);
}

struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
						   size_t priv)
{
	int ret;
	struct pci_host_bridge *bridge;

	bridge = pci_alloc_host_bridge(priv);
	if (!bridge)
		return NULL;

	bridge->dev.parent = dev;

	ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release,
				       bridge);
	if (ret)
		return NULL;

	ret = devm_of_pci_bridge_init(dev, bridge);
	if (ret)
		return NULL;

	return bridge;
}
EXPORT_SYMBOL(devm_pci_alloc_host_bridge);

void pci_free_host_bridge(struct pci_host_bridge *bridge)
{
	put_device(&bridge->dev);
}
EXPORT_SYMBOL(pci_free_host_bridge);

/* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */
static const unsigned char pcix_bus_speed[] = {
	PCI_SPEED_UNKNOWN,		/* 0 */
	PCI_SPEED_66MHz_PCIX,		/* 1 */
	PCI_SPEED_100MHz_PCIX,		/* 2 */
	PCI_SPEED_133MHz_PCIX,		/* 3 */
	PCI_SPEED_UNKNOWN,		/* 4 */
	PCI_SPEED_66MHz_PCIX_ECC,	/* 5 */
	PCI_SPEED_100MHz_PCIX_ECC,	/* 6 */
	PCI_SPEED_133MHz_PCIX_ECC,	/* 7 */
	PCI_SPEED_UNKNOWN,		/* 8 */
	PCI_SPEED_66MHz_PCIX_266,	/* 9 */
	PCI_SPEED_100MHz_PCIX_266,	/* A */
	PCI_SPEED_133MHz_PCIX_266,	/* B */
	PCI_SPEED_UNKNOWN,		/* C */
	PCI_SPEED_66MHz_PCIX_533,	/* D */
	PCI_SPEED_100MHz_PCIX_533,	/* E */
	PCI_SPEED_133MHz_PCIX_533	/* F */
};

/* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */
const unsigned char pcie_link_speed[] = {
	PCI_SPEED_UNKNOWN,		/* 0 */
	PCIE_SPEED_2_5GT,		/* 1 */
	PCIE_SPEED_5_0GT,		/* 2 */
	PCIE_SPEED_8_0GT,		/* 3 */
	PCIE_SPEED_16_0GT,		/* 4 */
	PCIE_SPEED_32_0GT,		/* 5 */
	PCIE_SPEED_64_0GT,		/* 6 */
	PCI_SPEED_UNKNOWN,		/* 7 */
	PCI_SPEED_UNKNOWN,		/* 8 */
	PCI_SPEED_UNKNOWN,		/* 9 */
	PCI_SPEED_UNKNOWN,		/* A */
	PCI_SPEED_UNKNOWN,		/* B */
	PCI_SPEED_UNKNOWN,		/* C */
	PCI_SPEED_UNKNOWN,		/* D */
	PCI_SPEED_UNKNOWN,		/* E */
	PCI_SPEED_UNKNOWN		/* F */
};
EXPORT_SYMBOL_GPL(pcie_link_speed);

const char *pci_speed_string(enum pci_bus_speed speed)
{
	/* Indexed by the pci_bus_speed enum */
	static const char *speed_strings[] = {
	    "33 MHz PCI",		/* 0x00 */
	    "66 MHz PCI",		/* 0x01 */
	    "66 MHz PCI-X",		/* 0x02 */
	    "100 MHz PCI-X",		/* 0x03 */
	    "133 MHz PCI-X",		/* 0x04 */
	    NULL,			/* 0x05 */
	    NULL,			/* 0x06 */
	    NULL,			/* 0x07 */
	    NULL,			/* 0x08 */
	    "66 MHz PCI-X 266",		/* 0x09 */
	    "100 MHz PCI-X 266",	/* 0x0a */
	    "133 MHz PCI-X 266",	/* 0x0b */
	    "Unknown AGP",		/* 0x0c */
	    "1x AGP",			/* 0x0d */
	    "2x AGP",			/* 0x0e */
	    "4x AGP",			/* 0x0f */
	    "8x AGP",			/* 0x10 */
	    "66 MHz PCI-X 533",		/* 0x11 */
	    "100 MHz PCI-X 533",	/* 0x12 */
	    "133 MHz PCI-X 533",	/* 0x13 */
	    "2.5 GT/s PCIe",		/* 0x14 */
	    "5.0 GT/s PCIe",		/* 0x15 */
	    "8.0 GT/s PCIe",		/* 0x16 */
	    "16.0 GT/s PCIe",		/* 0x17 */
	    "32.0 GT/s PCIe",		/* 0x18 */
	    "64.0 GT/s PCIe",		/* 0x19 */
	};

	if (speed < ARRAY_SIZE(speed_strings))
		return speed_strings[speed];
	return "Unknown";
}
EXPORT_SYMBOL_GPL(pci_speed_string);

void pcie_update_link_speed(struct pci_bus *bus, u16 linksta)
{
	bus->cur_bus_speed = pcie_link_speed[linksta & PCI_EXP_LNKSTA_CLS];
}
EXPORT_SYMBOL_GPL(pcie_update_link_speed);

static unsigned char agp_speeds[] = {
	AGP_UNKNOWN,
	AGP_1X,
	AGP_2X,
	AGP_4X,
	AGP_8X
};

static enum pci_bus_speed agp_speed(int agp3, int agpstat)
{
	int index = 0;

	if (agpstat & 4)
		index = 3;
	else if (agpstat & 2)
		index = 2;
	else if (agpstat & 1)
		index = 1;
	else
		goto out;

	if (agp3) {
		index += 2;
		if (index == 5)
			index = 0;
	}

 out:
	return agp_speeds[index];
}

static void pci_set_bus_speed(struct pci_bus *bus)
{
	struct pci_dev *bridge = bus->self;
	int pos;

	pos = pci_find_capability(bridge, PCI_CAP_ID_AGP);
	if (!pos)
		pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3);
	if (pos) {
		u32 agpstat, agpcmd;

		pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat);
		bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7);

		pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd);
		bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7);
	}

	pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
	if (pos) {
		u16 status;
		enum pci_bus_speed max;

		pci_read_config_word(bridge, pos + PCI_X_BRIDGE_SSTATUS,
				     &status);

		if (status & PCI_X_SSTATUS_533MHZ) {
			max = PCI_SPEED_133MHz_PCIX_533;
		} else if (status & PCI_X_SSTATUS_266MHZ) {
			max = PCI_SPEED_133MHz_PCIX_266;
		} else if (status & PCI_X_SSTATUS_133MHZ) {
			if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2)
				max = PCI_SPEED_133MHz_PCIX_ECC;
			else
				max = PCI_SPEED_133MHz_PCIX;
		} else {
			max = PCI_SPEED_66MHz_PCIX;
		}

		bus->max_bus_speed = max;
		bus->cur_bus_speed =
			pcix_bus_speed[FIELD_GET(PCI_X_SSTATUS_FREQ, status)];

		return;
	}

	if (pci_is_pcie(bridge)) {
		u32 linkcap;
		u16 linksta;

		pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap);
		bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS];

		pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta);
		pcie_update_link_speed(bus, linksta);
	}
}

static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
{
	struct irq_domain *d;

	/* If the host bridge driver sets a MSI domain of the bridge, use it */
	d = dev_get_msi_domain(bus->bridge);

	/*
	 * Any firmware interface that can resolve the msi_domain
	 * should be called from here.
	 */
	if (!d)
		d = pci_host_bridge_of_msi_domain(bus);
	if (!d)
		d = pci_host_bridge_acpi_msi_domain(bus);

	/*
	 * If no IRQ domain was found via the OF tree, try looking it up
	 * directly through the fwnode_handle.
	 */
	if (!d) {
		struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus);

		if (fwnode)
			d = irq_find_matching_fwnode(fwnode,
						     DOMAIN_BUS_PCI_MSI);
	}

	return d;
}

static void pci_set_bus_msi_domain(struct pci_bus *bus)
{
	struct irq_domain *d;
	struct pci_bus *b;

	/*
	 * The bus can be a root bus, a subordinate bus, or a virtual bus
	 * created by an SR-IOV device.  Walk up to the first bridge device
	 * found or derive the domain from the host bridge.
	 */
	for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) {
		if (b->self)
			d = dev_get_msi_domain(&b->self->dev);
	}

	if (!d)
		d = pci_host_bridge_msi_domain(b);

	dev_set_msi_domain(&bus->dev, d);
}

static bool pci_preserve_config(struct pci_host_bridge *host_bridge)
{
	if (pci_acpi_preserve_config(host_bridge))
		return true;

	if (host_bridge->dev.parent && host_bridge->dev.parent->of_node)
		return of_pci_preserve_config(host_bridge->dev.parent->of_node);

	return false;
}

static int pci_register_host_bridge(struct pci_host_bridge *bridge)
{
	struct device *parent = bridge->dev.parent;
	struct resource_entry *window, *next, *n;
	struct pci_bus *bus, *b;
	resource_size_t offset, next_offset;
	LIST_HEAD(resources);
	struct resource *res, *next_res;
	char addr[64], *fmt;
	const char *name;
	int err;

	bus = pci_alloc_bus(NULL);
	if (!bus)
		return -ENOMEM;

	bridge->bus = bus;

	bus->sysdata = bridge->sysdata;
	bus->ops = bridge->ops;
	bus->number = bus->busn_res.start = bridge->busnr;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
	if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET)
		bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
	else
		bus->domain_nr = bridge->domain_nr;
	if (bus->domain_nr < 0) {
		err = bus->domain_nr;
		goto free;
	}
#endif

	b = pci_find_bus(pci_domain_nr(bus), bridge->busnr);
	if (b) {
		/* Ignore it if we already got here via a different bridge */
		dev_dbg(&b->dev, "bus already known\n");
		err = -EEXIST;
		goto free;
	}

	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus),
		     bridge->busnr);

	err = pcibios_root_bridge_prepare(bridge);
	if (err)
		goto free;

	/* Temporarily move resources off the list */
	list_splice_init(&bridge->windows, &resources);
	err = device_add(&bridge->dev);
	if (err) {
		put_device(&bridge->dev);
		goto free;
	}
	bus->bridge = get_device(&bridge->dev);
	device_enable_async_suspend(bus->bridge);
	pci_set_bus_of_node(bus);
	pci_set_bus_msi_domain(bus);
	if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) &&
	    !pci_host_of_has_msi_map(parent))
		bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;

	if (!parent)
		set_dev_node(bus->bridge, pcibus_to_node(bus));

	bus->dev.class = &pcibus_class;
	bus->dev.parent = bus->bridge;

	dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number);
	name = dev_name(&bus->dev);

	err = device_register(&bus->dev);
	if (err)
		goto unregister;

	pcibios_add_bus(bus);

	if (bus->ops->add_bus) {
		err = bus->ops->add_bus(bus);
		if (WARN_ON(err < 0))
			dev_err(&bus->dev, "failed to add bus: %d\n", err);
	}

	/* Create legacy_io and legacy_mem files for this bus */
	pci_create_legacy_files(bus);

	if (parent)
		dev_info(parent, "PCI host bridge to bus %s\n", name);
	else
		pr_info("PCI host bridge to bus %s\n", name);

	if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE)
		dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n");

	/* Check if the boot configuration by FW needs to be preserved */
	bridge->preserve_config = pci_preserve_config(bridge);

	/* Coalesce contiguous windows */
	resource_list_for_each_entry_safe(window, n, &resources) {
		if (list_is_last(&window->node, &resources))
			break;

		next = list_next_entry(window, node);
		offset = window->offset;
		res = window->res;
		next_offset = next->offset;
		next_res = next->res;

		if (res->flags != next_res->flags || offset != next_offset)
			continue;

		if (res->end + 1 == next_res->start) {
			next_res->start = res->start;
			res->flags = res->start = res->end = 0;
		}
	}

	/* Add initial resources to the bus */
	resource_list_for_each_entry_safe(window, n, &resources) {
		offset = window->offset;
		res = window->res;
		if (!res->flags && !res->start && !res->end) {
			release_resource(res);
			resource_list_destroy_entry(window);
			continue;
		}

		list_move_tail(&window->node, &bridge->windows);

		if (res->flags & IORESOURCE_BUS)
			pci_bus_insert_busn_res(bus, bus->number, res->end);
		else
			pci_bus_add_resource(bus, res, 0);

		if (offset) {
			if (resource_type(res) == IORESOURCE_IO)
				fmt = " (bus address [%#06llx-%#06llx])";
			else
				fmt = " (bus address [%#010llx-%#010llx])";

			snprintf(addr, sizeof(addr), fmt,
				 (unsigned long long)(res->start - offset),
				 (unsigned long long)(res->end - offset));
		} else
			addr[0] = '\0';

		dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr);
	}

	down_write(&pci_bus_sem);
	list_add_tail(&bus->node, &pci_root_buses);
	up_write(&pci_bus_sem);

	return 0;

unregister:
	put_device(&bridge->dev);
	device_del(&bridge->dev);

free:
#ifdef CONFIG_PCI_DOMAINS_GENERIC
	pci_bus_release_domain_nr(parent, bus->domain_nr);
#endif
	kfree(bus);
	return err;
}

static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge)
{
	int pos;
	u32 status;

	/*
	 * If extended config space isn't accessible on a bridge's primary
	 * bus, we certainly can't access it on the secondary bus.
	 */
	if (bridge->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
		return false;

	/*
	 * PCIe Root Ports and switch ports are PCIe on both sides, so if
	 * extended config space is accessible on the primary, it's also
	 * accessible on the secondary.
	 */
	if (pci_is_pcie(bridge) &&
	    (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT ||
	     pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM ||
	     pci_pcie_type(bridge) == PCI_EXP_TYPE_DOWNSTREAM))
		return true;

	/*
	 * For the other bridge types:
	 *   - PCI-to-PCI bridges
	 *   - PCIe-to-PCI/PCI-X forward bridges
	 *   - PCI/PCI-X-to-PCIe reverse bridges
	 * extended config space on the secondary side is only accessible
	 * if the bridge supports PCI-X Mode 2.
	 */
	pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
	if (!pos)
		return false;

	pci_read_config_dword(bridge, pos + PCI_X_STATUS, &status);
	return status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ);
}

static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
					   struct pci_dev *bridge, int busnr)
{
	struct pci_bus *child;
	struct pci_host_bridge *host;
	int i;
	int ret;

	/* Allocate a new bus and inherit stuff from the parent */
	child = pci_alloc_bus(parent);
	if (!child)
		return NULL;

	child->parent = parent;
	child->sysdata = parent->sysdata;
	child->bus_flags = parent->bus_flags;

	host = pci_find_host_bridge(parent);
	if (host->child_ops)
		child->ops = host->child_ops;
	else
		child->ops = parent->ops;

	/*
	 * Initialize some portions of the bus device, but don't register
	 * it now as the parent is not properly set up yet.
	 */
	child->dev.class = &pcibus_class;
	dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr);

	/* Set up the primary, secondary and subordinate bus numbers */
	child->number = child->busn_res.start = busnr;
	child->primary = parent->busn_res.start;
	child->busn_res.end = 0xff;

	if (!bridge) {
		child->dev.parent = parent->bridge;
		goto add_dev;
	}

	child->self = bridge;
	child->bridge = get_device(&bridge->dev);
	child->dev.parent = child->bridge;
	pci_set_bus_of_node(child);
	pci_set_bus_speed(child);

	/*
	 * Check whether extended config space is accessible on the child
	 * bus.  Note that we currently assume it is always accessible on
	 * the root bus.
	 */
	if (!pci_bridge_child_ext_cfg_accessible(bridge)) {
		child->bus_flags |= PCI_BUS_FLAGS_NO_EXTCFG;
		pci_info(child, "extended config space not accessible\n");
	}

	/* Set up default resource pointers and names */
	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
		child->resource[i]->name = child->name;
	}
	bridge->subordinate = child;

add_dev:
	pci_set_bus_msi_domain(child);
	ret = device_register(&child->dev);
	WARN_ON(ret < 0);

	pcibios_add_bus(child);

	if (child->ops->add_bus) {
		ret = child->ops->add_bus(child);
		if (WARN_ON(ret < 0))
			dev_err(&child->dev, "failed to add bus: %d\n", ret);
	}

	/* Create legacy_io and legacy_mem files for this bus */
	pci_create_legacy_files(child);

	return child;
}

struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
				int busnr)
{
	struct pci_bus *child;

	child = pci_alloc_child_bus(parent, dev, busnr);
	if (child) {
		down_write(&pci_bus_sem);
		list_add_tail(&child->node, &parent->children);
		up_write(&pci_bus_sem);
	}
	return child;
}
EXPORT_SYMBOL(pci_add_new_bus);

static void pci_enable_rrs_sv(struct pci_dev *pdev)
{
	u16 root_cap = 0;

	/* Enable Configuration RRS Software Visibility if supported */
	pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap);
	if (root_cap & PCI_EXP_RTCAP_RRS_SV) {
		pcie_capability_set_word(pdev, PCI_EXP_RTCTL,
					 PCI_EXP_RTCTL_RRS_SVE);
		pdev->config_rrs_sv = 1;
	}
}

static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
					      unsigned int available_buses);
/**
 * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus
 * numbers from EA capability.
 * @dev: Bridge
 * @sec: updated with secondary bus number from EA
 * @sub: updated with subordinate bus number from EA
 *
 * If @dev is a bridge with EA capability that specifies valid secondary
 * and subordinate bus numbers, return true with the bus numbers in @sec
 * and @sub.  Otherwise return false.
 */
static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
{
	int ea, offset;
	u32 dw;
	u8 ea_sec, ea_sub;

	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
		return false;

	/* find PCI EA capability in list */
	ea = pci_find_capability(dev, PCI_CAP_ID_EA);
	if (!ea)
		return false;

	offset = ea + PCI_EA_FIRST_ENT;
	pci_read_config_dword(dev, offset, &dw);
	ea_sec = FIELD_GET(PCI_EA_SEC_BUS_MASK, dw);
	ea_sub = FIELD_GET(PCI_EA_SUB_BUS_MASK, dw);
	if (ea_sec  == 0 || ea_sub < ea_sec)
		return false;

	*sec = ea_sec;
	*sub = ea_sub;
	return true;
}

/*
 * pci_scan_bridge_extend() - Scan buses behind a bridge
 * @bus: Parent bus the bridge is on
 * @dev: Bridge itself
 * @max: Starting subordinate number of buses behind this bridge
 * @available_buses: Total number of buses available for this bridge and
 *		     the devices below. After the minimal bus space has
 *		     been allocated the remaining buses will be
 *		     distributed equally between hotplug-capable bridges.
 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
 *        that need to be reconfigured.
 *
 * If it's a bridge, configure it and scan the bus behind it.
 * For CardBus bridges, we don't scan behind as the devices will
 * be handled by the bridge driver itself.
 *
 * We need to process bridges in two passes -- first we scan those
 * already configured by the BIOS and after we are done with all of
 * them, we proceed to assigning numbers to the remaining buses in
 * order to avoid overlaps between old and new bus numbers.
 *
 * Return: New subordinate number covering all buses behind this bridge.
 */
static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
				  int max, unsigned int available_buses,
				  int pass)
{
	struct pci_bus *child;
	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
	u32 buses, i, j = 0;
	u16 bctl;
	u8 primary, secondary, subordinate;
	int broken = 0;
	bool fixed_buses;
	u8 fixed_sec, fixed_sub;
	int next_busnr;

	/*
	 * Make sure the bridge is powered on to be able to access config
	 * space of devices below it.
	 */
	pm_runtime_get_sync(&dev->dev);

	pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
	primary = buses & 0xFF;
	secondary = (buses >> 8) & 0xFF;
	subordinate = (buses >> 16) & 0xFF;

	pci_dbg(dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
		secondary, subordinate, pass);

	if (!primary && (primary != bus->number) && secondary && subordinate) {
		pci_warn(dev, "Primary bus is hard wired to 0\n");
		primary = bus->number;
	}

	/* Check if setup is sensible at all */
	if (!pass &&
	    (primary != bus->number || secondary <= bus->number ||
	     secondary > subordinate)) {
		pci_info(dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n",
			 secondary, subordinate);
		broken = 1;
	}

	/*
	 * Disable Master-Abort Mode during probing to avoid reporting of
	 * bus errors in some architectures.
	 */
	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);

	pci_enable_rrs_sv(dev);

	if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
	    !is_cardbus && !broken) {
		unsigned int cmax, buses;

		/*
		 * Bus already configured by firmware, process it in the
		 * first pass and just note the configuration.
		 */
		if (pass)
			goto out;

		/*
		 * The bus might already exist for two reasons: Either we
		 * are rescanning the bus or the bus is reachable through
		 * more than one bridge. The second case can happen with
		 * the i450NX chipset.
		 */
		child = pci_find_bus(pci_domain_nr(bus), secondary);
		if (!child) {
			child = pci_add_new_bus(bus, dev, secondary);
			if (!child)
				goto out;
			child->primary = primary;
			pci_bus_insert_busn_res(child, secondary, subordinate);
			child->bridge_ctl = bctl;
		}

		buses = subordinate - secondary;
		cmax = pci_scan_child_bus_extend(child, buses);
		if (cmax > subordinate)
			pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n",
				 subordinate, cmax);

		/* Subordinate should equal child->busn_res.end */
		if (subordinate > max)
			max = subordinate;
	} else {

		/*
		 * We need to assign a number to this bus which we always
		 * do in the second pass.
		 */
		if (!pass) {
			if (pcibios_assign_all_busses() || broken || is_cardbus)

				/*
				 * Temporarily disable forwarding of the
				 * configuration cycles on all bridges in
				 * this bus segment to avoid possible
				 * conflicts in the second pass between two
				 * bridges programmed with overlapping bus
				 * ranges.
				 */
				pci_write_config_dword(dev, PCI_PRIMARY_BUS,
						       buses & ~0xffffff);
			goto out;
		}

		/* Clear errors */
		pci_write_config_word(dev, PCI_STATUS, 0xffff);

		/* Read bus numbers from EA Capability (if present) */
		fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
		if (fixed_buses)
			next_busnr = fixed_sec;
		else
			next_busnr = max + 1;

		/*
		 * Prevent assigning a bus number that already exists.
		 * This can happen when a bridge is hot-plugged, so in this
		 * case we only re-scan this bus.
		 */
		child = pci_find_bus(pci_domain_nr(bus), next_busnr);
		if (!child) {
			child = pci_add_new_bus(bus, dev, next_busnr);
			if (!child)
				goto out;
			pci_bus_insert_busn_res(child, next_busnr,
						bus->busn_res.end);
		}
		max++;
		if (available_buses)
			available_buses--;

		buses = (buses & 0xff000000)
		      | ((unsigned int)(child->primary)     <<  0)
		      | ((unsigned int)(child->busn_res.start)   <<  8)
		      | ((unsigned int)(child->busn_res.end) << 16);

		/*
		 * yenta.c forces a secondary latency timer of 176.
		 * Copy that behaviour here.
		 */
		if (is_cardbus) {
			buses &= ~0xff000000;
			buses |= CARDBUS_LATENCY_TIMER << 24;
		}

		/* We need to blast all three values with a single write */
		pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);

		if (!is_cardbus) {
			child->bridge_ctl = bctl;
			max = pci_scan_child_bus_extend(child, available_buses);
		} else {

			/*
			 * For CardBus bridges, we leave 4 bus numbers as
			 * cards with a PCI-to-PCI bridge can be inserted
			 * later.
			 */
			for (i = 0; i < CARDBUS_RESERVE_BUSNR; i++) {
				struct pci_bus *parent = bus;
				if (pci_find_bus(pci_domain_nr(bus),
							max+i+1))
					break;
				while (parent->parent) {
					if ((!pcibios_assign_all_busses()) &&
					    (parent->busn_res.end > max) &&
					    (parent->busn_res.end <= max+i)) {
						j = 1;
					}
					parent = parent->parent;
				}
				if (j) {

					/*
					 * Often, there are two CardBus
					 * bridges -- try to leave one
					 * valid bus number for each one.
					 */
					i /= 2;
					break;
				}
			}
			max += i;
		}

		/*
		 * Set subordinate bus number to its real value.
		 * If fixed subordinate bus number exists from EA
		 * capability then use it.
		 */
		if (fixed_buses)
			max = fixed_sub;
		pci_bus_update_busn_res_end(child, max);
		pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
	}

	sprintf(child->name,
		(is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
		pci_domain_nr(bus), child->number);

	/* Check that all devices are accessible */
	while (bus->parent) {
		if ((child->busn_res.end > bus->busn_res.end) ||
		    (child->number > bus->busn_res.end) ||
		    (child->number < bus->number) ||
		    (child->busn_res.end < bus->number)) {
			dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n",
				 &child->busn_res);
			break;
		}
		bus = bus->parent;
	}

out:
	/* Clear errors in the Secondary Status Register */
	pci_write_config_word(dev, PCI_SEC_STATUS, 0xffff);

	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);

	pm_runtime_put(&dev->dev);

	return max;
}

/*
 * pci_scan_bridge() - Scan buses behind a bridge
 * @bus: Parent bus the bridge is on
 * @dev: Bridge itself
 * @max: Starting subordinate number of buses behind this bridge
 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
 *        that need to be reconfigured.
 *
 * If it's a bridge, configure it and scan the bus behind it.
 * For CardBus bridges, we don't scan behind as the devices will
 * be handled by the bridge driver itself.
 *
 * We need to process bridges in two passes -- first we scan those
 * already configured by the BIOS and after we are done with all of
 * them, we proceed to assigning numbers to the remaining buses in
 * order to avoid overlaps between old and new bus numbers.
 *
 * Return: New subordinate number covering all buses behind this bridge.
 */
int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
{
	return pci_scan_bridge_extend(bus, dev, max, 0, pass);
}
EXPORT_SYMBOL(pci_scan_bridge);

/*
 * Read interrupt line and base address registers.
 * The architecture-dependent code can tweak these, of course.
 */
static void pci_read_irq(struct pci_dev *dev)
{
	unsigned char irq;

	/* VFs are not allowed to use INTx, so skip the config reads */
	if (dev->is_virtfn) {
		dev->pin = 0;
		dev->irq = 0;
		return;
	}

	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
	dev->pin = irq;
	if (irq)
		pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
	dev->irq = irq;
}

void set_pcie_port_type(struct pci_dev *pdev)
{
	int pos;
	u16 reg16;
	u32 reg32;
	int type;
	struct pci_dev *parent;

	pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
	if (!pos)
		return;

	pdev->pcie_cap = pos;
	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
	pdev->pcie_flags_reg = reg16;
	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
	pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);

	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &reg32);
	if (reg32 & PCI_EXP_LNKCAP_DLLLARC)
		pdev->link_active_reporting = 1;

	parent = pci_upstream_bridge(pdev);
	if (!parent)
		return;

	/*
	 * Some systems do not identify their upstream/downstream ports
	 * correctly so detect impossible configurations here and correct
	 * the port type accordingly.
	 */
	type = pci_pcie_type(pdev);
	if (type == PCI_EXP_TYPE_DOWNSTREAM) {
		/*
		 * If pdev claims to be downstream port but the parent
		 * device is also downstream port assume pdev is actually
		 * upstream port.
		 */
		if (pcie_downstream_port(parent)) {
			pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n");
			pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
			pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM;
		}
	} else if (type == PCI_EXP_TYPE_UPSTREAM) {
		/*
		 * If pdev claims to be upstream port but the parent
		 * device is also upstream port assume pdev is actually
		 * downstream port.
		 */
		if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) {
			pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n");
			pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
			pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM;
		}
	}
}

void set_pcie_hotplug_bridge(struct pci_dev *pdev)
{
	u32 reg32;

	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32);
	if (reg32 & PCI_EXP_SLTCAP_HPC)
		pdev->is_hotplug_bridge = 1;
}

static void set_pcie_thunderbolt(struct pci_dev *dev)
{
	u16 vsec;

	/* Is the device part of a Thunderbolt controller? */
	vsec = pci_find_vsec_capability(dev, PCI_VENDOR_ID_INTEL, PCI_VSEC_ID_INTEL_TBT);
	if (vsec)
		dev->is_thunderbolt = 1;
}

static void set_pcie_untrusted(struct pci_dev *dev)
{
	struct pci_dev *parent;

	/*
	 * If the upstream bridge is untrusted we treat this device
	 * untrusted as well.
	 */
	parent = pci_upstream_bridge(dev);
	if (parent && (parent->untrusted || parent->external_facing))
		dev->untrusted = true;
}

static void pci_set_removable(struct pci_dev *dev)
{
	struct pci_dev *parent = pci_upstream_bridge(dev);

	/*
	 * We (only) consider everything downstream from an external_facing
	 * device to be removable by the user. We're mainly concerned with
	 * consumer platforms with user accessible thunderbolt ports that are
	 * vulnerable to DMA attacks, and we expect those ports to be marked by
	 * the firmware as external_facing. Devices in traditional hotplug
	 * slots can technically be removed, but the expectation is that unless
	 * the port is marked with external_facing, such devices are less
	 * accessible to user / may not be removed by end user, and thus not
	 * exposed as "removable" to userspace.
	 */
	if (parent &&
	    (parent->external_facing || dev_is_removable(&parent->dev)))
		dev_set_removable(&dev->dev, DEVICE_REMOVABLE);
}

/**
 * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config?
 * @dev: PCI device
 *
 * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that
 * when forwarding a type1 configuration request the bridge must check that
 * the extended register address field is zero.  The bridge is not permitted
 * to forward the transactions and must handle it as an Unsupported Request.
 * Some bridges do not follow this rule and simply drop the extended register
 * bits, resulting in the standard config space being aliased, every 256
 * bytes across the entire configuration space.  Test for this condition by
 * comparing the first dword of each potential alias to the vendor/device ID.
 * Known offenders:
 *   ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03)
 *   AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40)
 */
static bool pci_ext_cfg_is_aliased(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_QUIRKS
	int pos, ret;
	u32 header, tmp;

	pci_read_config_dword(dev, PCI_VENDOR_ID, &header);

	for (pos = PCI_CFG_SPACE_SIZE;
	     pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) {
		ret = pci_read_config_dword(dev, pos, &tmp);
		if ((ret != PCIBIOS_SUCCESSFUL) || (header != tmp))
			return false;
	}

	return true;
#else
	return false;
#endif
}

/**
 * pci_cfg_space_size_ext - Get the configuration space size of the PCI device
 * @dev: PCI device
 *
 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
 * have 4096 bytes.  Even if the device is capable, that doesn't mean we can
 * access it.  Maybe we don't have a way to generate extended config space
 * accesses, or the device is behind a reverse Express bridge.  So we try
 * reading the dword at 0x100 which must either be 0 or a valid extended
 * capability header.
 */
static int pci_cfg_space_size_ext(struct pci_dev *dev)
{
	u32 status;
	int pos = PCI_CFG_SPACE_SIZE;

	if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL)
		return PCI_CFG_SPACE_SIZE;
	if (PCI_POSSIBLE_ERROR(status) || pci_ext_cfg_is_aliased(dev))
		return PCI_CFG_SPACE_SIZE;

	return PCI_CFG_SPACE_EXP_SIZE;
}

int pci_cfg_space_size(struct pci_dev *dev)
{
	int pos;
	u32 status;
	u16 class;

#ifdef CONFIG_PCI_IOV
	/*
	 * Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to
	 * implement a PCIe capability and therefore must implement extended
	 * config space.  We can skip the NO_EXTCFG test below and the
	 * reachability/aliasing test in pci_cfg_space_size_ext() by virtue of
	 * the fact that the SR-IOV capability on the PF resides in extended
	 * config space and must be accessible and non-aliased to have enabled
	 * support for this VF.  This is a micro performance optimization for
	 * systems supporting many VFs.
	 */
	if (dev->is_virtfn)
		return PCI_CFG_SPACE_EXP_SIZE;
#endif

	if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
		return PCI_CFG_SPACE_SIZE;

	class = dev->class >> 8;
	if (class == PCI_CLASS_BRIDGE_HOST)
		return pci_cfg_space_size_ext(dev);

	if (pci_is_pcie(dev))
		return pci_cfg_space_size_ext(dev);

	pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
	if (!pos)
		return PCI_CFG_SPACE_SIZE;

	pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
	if (status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ))
		return pci_cfg_space_size_ext(dev);

	return PCI_CFG_SPACE_SIZE;
}

static u32 pci_class(struct pci_dev *dev)
{
	u32 class;

#ifdef CONFIG_PCI_IOV
	if (dev->is_virtfn)
		return dev->physfn->sriov->class;
#endif
	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
	return class;
}

static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device)
{
#ifdef CONFIG_PCI_IOV
	if (dev->is_virtfn) {
		*vendor = dev->physfn->sriov->subsystem_vendor;
		*device = dev->physfn->sriov->subsystem_device;
		return;
	}
#endif
	pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor);
	pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device);
}

static u8 pci_hdr_type(struct pci_dev *dev)
{
	u8 hdr_type;

#ifdef CONFIG_PCI_IOV
	if (dev->is_virtfn)
		return dev->physfn->sriov->hdr_type;
#endif
	pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type);
	return hdr_type;
}

#define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)

/**
 * pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability
 * @dev: PCI device
 *
 * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev.  Check this
 * at enumeration-time to avoid modifying PCI_COMMAND at run-time.
 */
static int pci_intx_mask_broken(struct pci_dev *dev)
{
	u16 orig, toggle, new;

	pci_read_config_word(dev, PCI_COMMAND, &orig);
	toggle = orig ^ PCI_COMMAND_INTX_DISABLE;
	pci_write_config_word(dev, PCI_COMMAND, toggle);
	pci_read_config_word(dev, PCI_COMMAND, &new);

	pci_write_config_word(dev, PCI_COMMAND, orig);

	/*
	 * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI
	 * r2.3, so strictly speaking, a device is not *broken* if it's not
	 * writable.  But we'll live with the misnomer for now.
	 */
	if (new != toggle)
		return 1;
	return 0;
}

static void early_dump_pci_device(struct pci_dev *pdev)
{
	u32 value[256 / 4];
	int i;

	pci_info(pdev, "config space:\n");

	for (i = 0; i < 256; i += 4)
		pci_read_config_dword(pdev, i, &value[i / 4]);

	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1,
		       value, 256, false);
}

static const char *pci_type_str(struct pci_dev *dev)
{
	static const char * const str[] = {
		"PCIe Endpoint",
		"PCIe Legacy Endpoint",
		"PCIe unknown",
		"PCIe unknown",
		"PCIe Root Port",
		"PCIe Switch Upstream Port",
		"PCIe Switch Downstream Port",
		"PCIe to PCI/PCI-X bridge",
		"PCI/PCI-X to PCIe bridge",
		"PCIe Root Complex Integrated Endpoint",
		"PCIe Root Complex Event Collector",
	};
	int type;

	if (pci_is_pcie(dev)) {
		type = pci_pcie_type(dev);
		if (type < ARRAY_SIZE(str))
			return str[type];

		return "PCIe unknown";
	}

	switch (dev->hdr_type) {
	case PCI_HEADER_TYPE_NORMAL:
		return "conventional PCI endpoint";
	case PCI_HEADER_TYPE_BRIDGE:
		return "conventional PCI bridge";
	case PCI_HEADER_TYPE_CARDBUS:
		return "CardBus bridge";
	default:
		return "conventional PCI";
	}
}

/**
 * pci_setup_device - Fill in class and map information of a device
 * @dev: the device structure to fill
 *
 * Initialize the device structure with information about the device's
 * vendor,class,memory and IO-space addresses, IRQ lines etc.
 * Called at initialisation of the PCI subsystem and by CardBus services.
 * Returns 0 on success and negative if unknown type of device (not normal,
 * bridge or CardBus).
 */
int pci_setup_device(struct pci_dev *dev)
{
	u32 class;
	u16 cmd;
	u8 hdr_type;
	int err, pos = 0;
	struct pci_bus_region region;
	struct resource *res;

	hdr_type = pci_hdr_type(dev);

	dev->sysdata = dev->bus->sysdata;
	dev->dev.parent = dev->bus->bridge;
	dev->dev.bus = &pci_bus_type;
	dev->hdr_type = hdr_type & 0x7f;
	dev->multifunction = !!(hdr_type & 0x80);
	dev->error_state = pci_channel_io_normal;
	set_pcie_port_type(dev);

	err = pci_set_of_node(dev);
	if (err)
		return err;
	pci_set_acpi_fwnode(dev);

	pci_dev_assign_slot(dev);

	/*
	 * Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
	 * set this higher, assuming the system even supports it.
	 */
	dev->dma_mask = 0xffffffff;

	dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
		     dev->bus->number, PCI_SLOT(dev->devfn),
		     PCI_FUNC(dev->devfn));

	class = pci_class(dev);

	dev->revision = class & 0xff;
	dev->class = class >> 8;		    /* upper 3 bytes */

	if (pci_early_dump)
		early_dump_pci_device(dev);

	/* Need to have dev->class ready */
	dev->cfg_size = pci_cfg_space_size(dev);

	/* Need to have dev->cfg_size ready */
	set_pcie_thunderbolt(dev);

	set_pcie_untrusted(dev);

	/* "Unknown power state" */
	dev->current_state = PCI_UNKNOWN;

	/* Early fixups, before probing the BARs */
	pci_fixup_device(pci_fixup_early, dev);

	pci_set_removable(dev);

	pci_info(dev, "[%04x:%04x] type %02x class %#08x %s\n",
		 dev->vendor, dev->device, dev->hdr_type, dev->class,
		 pci_type_str(dev));

	/* Device class may be changed after fixup */
	class = dev->class >> 8;

	if (dev->non_compliant_bars && !dev->mmio_always_on) {
		pci_read_config_word(dev, PCI_COMMAND, &cmd);
		if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
			pci_info(dev, "device has non-compliant BARs; disabling IO/MEM decoding\n");
			cmd &= ~PCI_COMMAND_IO;
			cmd &= ~PCI_COMMAND_MEMORY;
			pci_write_config_word(dev, PCI_COMMAND, cmd);
		}
	}

	dev->broken_intx_masking = pci_intx_mask_broken(dev);

	switch (dev->hdr_type) {		    /* header type */
	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
		if (class == PCI_CLASS_BRIDGE_PCI)
			goto bad;
		pci_read_irq(dev);
		pci_read_bases(dev, 6, PCI_ROM_ADDRESS);

		pci_subsystem_ids(dev, &dev->subsystem_vendor, &dev->subsystem_device);

		/*
		 * Do the ugly legacy mode stuff here rather than broken chip
		 * quirk code. Legacy mode ATA controllers have fixed
		 * addresses. These are not always echoed in BAR0-3, and
		 * BAR0-3 in a few cases contain junk!
		 */
		if (class == PCI_CLASS_STORAGE_IDE) {
			u8 progif;
			pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
			if ((progif & 1) == 0) {
				region.start = 0x1F0;
				region.end = 0x1F7;
				res = &dev->resource[0];
				res->flags = LEGACY_IO_RESOURCE;
				pcibios_bus_to_resource(dev->bus, res, &region);
				pci_info(dev, "BAR 0 %pR: legacy IDE quirk\n",
					 res);
				region.start = 0x3F6;
				region.end = 0x3F6;
				res = &dev->resource[1];
				res->flags = LEGACY_IO_RESOURCE;
				pcibios_bus_to_resource(dev->bus, res, &region);
				pci_info(dev, "BAR 1 %pR: legacy IDE quirk\n",
					 res);
			}
			if ((progif & 4) == 0) {
				region.start = 0x170;
				region.end = 0x177;
				res = &dev->resource[2];
				res->flags = LEGACY_IO_RESOURCE;
				pcibios_bus_to_resource(dev->bus, res, &region);
				pci_info(dev, "BAR 2 %pR: legacy IDE quirk\n",
					 res);
				region.start = 0x376;
				region.end = 0x376;
				res = &dev->resource[3];
				res->flags = LEGACY_IO_RESOURCE;
				pcibios_bus_to_resource(dev->bus, res, &region);
				pci_info(dev, "BAR 3 %pR: legacy IDE quirk\n",
					 res);
			}
		}
		break;

	case PCI_HEADER_TYPE_BRIDGE:		    /* bridge header */
		/*
		 * The PCI-to-PCI bridge spec requires that subtractive
		 * decoding (i.e. transparent) bridge must have programming
		 * interface code of 0x01.
		 */
		pci_read_irq(dev);
		dev->transparent = ((dev->class & 0xff) == 1);
		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
		pci_read_bridge_windows(dev);
		set_pcie_hotplug_bridge(dev);
		pos = pci_find_capability(dev, PCI_CAP_ID_SSVID);
		if (pos) {
			pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor);
			pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device);
		}
		break;

	case PCI_HEADER_TYPE_CARDBUS:		    /* CardBus bridge header */
		if (class != PCI_CLASS_BRIDGE_CARDBUS)
			goto bad;
		pci_read_irq(dev);
		pci_read_bases(dev, 1, 0);
		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
		break;

	default:				    /* unknown header */
		pci_err(dev, "unknown header type %02x, ignoring device\n",
			dev->hdr_type);
		pci_release_of_node(dev);
		return -EIO;

	bad:
		pci_err(dev, "ignoring class %#08x (doesn't match header type %02x)\n",
			dev->class, dev->hdr_type);
		dev->class = PCI_CLASS_NOT_DEFINED << 8;
	}

	/* We found a fine healthy device, go go go... */
	return 0;
}

static void pci_configure_mps(struct pci_dev *dev)
{
	struct pci_dev *bridge = pci_upstream_bridge(dev);
	int mps, mpss, p_mps, rc;

	if (!pci_is_pcie(dev))
		return;

	/* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */
	if (dev->is_virtfn)
		return;

	/*
	 * For Root Complex Integrated Endpoints, program the maximum
	 * supported value unless limited by the PCIE_BUS_PEER2PEER case.
	 */
	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
		if (pcie_bus_config == PCIE_BUS_PEER2PEER)
			mps = 128;
		else
			mps = 128 << dev->pcie_mpss;
		rc = pcie_set_mps(dev, mps);
		if (rc) {
			pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
				 mps);
		}
		return;
	}

	if (!bridge || !pci_is_pcie(bridge))
		return;

	mps = pcie_get_mps(dev);
	p_mps = pcie_get_mps(bridge);

	if (mps == p_mps)
		return;

	if (pcie_bus_config == PCIE_BUS_TUNE_OFF) {
		pci_warn(dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
			 mps, pci_name(bridge), p_mps);
		return;
	}

	/*
	 * Fancier MPS configuration is done later by
	 * pcie_bus_configure_settings()
	 */
	if (pcie_bus_config != PCIE_BUS_DEFAULT)
		return;

	mpss = 128 << dev->pcie_mpss;
	if (mpss < p_mps && pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) {
		pcie_set_mps(bridge, mpss);
		pci_info(dev, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n",
			 mpss, p_mps, 128 << bridge->pcie_mpss);
		p_mps = pcie_get_mps(bridge);
	}

	rc = pcie_set_mps(dev, p_mps);
	if (rc) {
		pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
			 p_mps);
		return;
	}

	pci_info(dev, "Max Payload Size set to %d (was %d, max %d)\n",
		 p_mps, mps, mpss);
}

int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
{
	struct pci_host_bridge *host;
	u32 cap;
	u16 ctl;
	int ret;

	if (!pci_is_pcie(dev))
		return 0;

	ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
	if (ret)
		return 0;

	if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
		return 0;

	ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
	if (ret)
		return 0;

	host = pci_find_host_bridge(dev->bus);
	if (!host)
		return 0;

	/*
	 * If some device in the hierarchy doesn't handle Extended Tags
	 * correctly, make sure they're disabled.
	 */
	if (host->no_ext_tags) {
		if (ctl & PCI_EXP_DEVCTL_EXT_TAG) {
			pci_info(dev, "disabling Extended Tags\n");
			pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
						   PCI_EXP_DEVCTL_EXT_TAG);
		}
		return 0;
	}

	if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) {
		pci_info(dev, "enabling Extended Tags\n");
		pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
					 PCI_EXP_DEVCTL_EXT_TAG);
	}
	return 0;
}

/**
 * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable
 * @dev: PCI device to query
 *
 * Returns true if the device has enabled relaxed ordering attribute.
 */
bool pcie_relaxed_ordering_enabled(struct pci_dev *dev)
{
	u16 v;

	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v);

	return !!(v & PCI_EXP_DEVCTL_RELAX_EN);
}
EXPORT_SYMBOL(pcie_relaxed_ordering_enabled);

static void pci_configure_relaxed_ordering(struct pci_dev *dev)
{
	struct pci_dev *root;

	/* PCI_EXP_DEVCTL_RELAX_EN is RsvdP in VFs */
	if (dev->is_virtfn)
		return;

	if (!pcie_relaxed_ordering_enabled(dev))
		return;

	/*
	 * For now, we only deal with Relaxed Ordering issues with Root
	 * Ports. Peer-to-Peer DMA is another can of worms.
	 */
	root = pcie_find_root_port(dev);
	if (!root)
		return;

	if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) {
		pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
					   PCI_EXP_DEVCTL_RELAX_EN);
		pci_info(dev, "Relaxed Ordering disabled because the Root Port didn't support it\n");
	}
}

static void pci_configure_eetlp_prefix(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_PASID
	struct pci_dev *bridge;
	int pcie_type;
	u32 cap;

	if (!pci_is_pcie(dev))
		return;

	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap);
	if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX))
		return;

	pcie_type = pci_pcie_type(dev);
	if (pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
	    pcie_type == PCI_EXP_TYPE_RC_END)
		dev->eetlp_prefix_path = 1;
	else {
		bridge = pci_upstream_bridge(dev);
		if (bridge && bridge->eetlp_prefix_path)
			dev->eetlp_prefix_path = 1;
	}
#endif
}

static void pci_configure_serr(struct pci_dev *dev)
{
	u16 control;

	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {

		/*
		 * A bridge will not forward ERR_ messages coming from an
		 * endpoint unless SERR# forwarding is enabled.
		 */
		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control);
		if (!(control & PCI_BRIDGE_CTL_SERR)) {
			control |= PCI_BRIDGE_CTL_SERR;
			pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control);
		}
	}
}

static void pci_configure_device(struct pci_dev *dev)
{
	pci_configure_mps(dev);
	pci_configure_extended_tags(dev, NULL);
	pci_configure_relaxed_ordering(dev);
	pci_configure_ltr(dev);
	pci_configure_aspm_l1ss(dev);
	pci_configure_eetlp_prefix(dev);
	pci_configure_serr(dev);

	pci_acpi_program_hp_params(dev);
}

static void pci_release_capabilities(struct pci_dev *dev)
{
	pci_aer_exit(dev);
	pci_rcec_exit(dev);
	pci_iov_release(dev);
	pci_free_cap_save_buffers(dev);
}

/**
 * pci_release_dev - Free a PCI device structure when all users of it are
 *		     finished
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this PCI device are
 * done.
 */
static void pci_release_dev(struct device *dev)
{
	struct pci_dev *pci_dev;

	pci_dev = to_pci_dev(dev);
	pci_release_capabilities(pci_dev);
	pci_release_of_node(pci_dev);
	pcibios_release_device(pci_dev);
	pci_bus_put(pci_dev->bus);
	kfree(pci_dev->driver_override);
	bitmap_free(pci_dev->dma_alias_mask);
	dev_dbg(dev, "device released\n");
	kfree(pci_dev);
}

static const struct device_type pci_dev_type = {
	.groups = pci_dev_attr_groups,
};

struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
{
	struct pci_dev *dev;

	dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	INIT_LIST_HEAD(&dev->bus_list);
	dev->dev.type = &pci_dev_type;
	dev->bus = pci_bus_get(bus);
	dev->driver_exclusive_resource = (struct resource) {
		.name = "PCI Exclusive",
		.start = 0,
		.end = -1,
	};

	spin_lock_init(&dev->pcie_cap_lock);
#ifdef CONFIG_PCI_MSI
	raw_spin_lock_init(&dev->msi_lock);
#endif
	return dev;
}
EXPORT_SYMBOL(pci_alloc_dev);

static bool pci_bus_wait_rrs(struct pci_bus *bus, int devfn, u32 *l,
			     int timeout)
{
	int delay = 1;

	if (!pci_bus_rrs_vendor_id(*l))
		return true;	/* not a Configuration RRS completion */

	if (!timeout)
		return false;	/* RRS, but caller doesn't want to wait */

	/*
	 * We got the reserved Vendor ID that indicates a completion with
	 * Configuration Request Retry Status (RRS).  Retry until we get a
	 * valid Vendor ID or we time out.
	 */
	while (pci_bus_rrs_vendor_id(*l)) {
		if (delay > timeout) {
			pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n",
				pci_domain_nr(bus), bus->number,
				PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);

			return false;
		}
		if (delay >= 1000)
			pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n",
				pci_domain_nr(bus), bus->number,
				PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);

		msleep(delay);
		delay *= 2;

		if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
			return false;
	}

	if (delay >= 1000)
		pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n",
			pci_domain_nr(bus), bus->number,
			PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1);

	return true;
}

bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
					int timeout)
{
	if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
		return false;

	/* Some broken boards return 0 or ~0 (PCI_ERROR_RESPONSE) if a slot is empty: */
	if (PCI_POSSIBLE_ERROR(*l) || *l == 0x00000000 ||
	    *l == 0x0000ffff || *l == 0xffff0000)
		return false;

	if (pci_bus_rrs_vendor_id(*l))
		return pci_bus_wait_rrs(bus, devfn, l, timeout);

	return true;
}

bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
				int timeout)
{
#ifdef CONFIG_PCI_QUIRKS
	struct pci_dev *bridge = bus->self;

	/*
	 * Certain IDT switches have an issue where they improperly trigger
	 * ACS Source Validation errors on completions for config reads.
	 */
	if (bridge && bridge->vendor == PCI_VENDOR_ID_IDT &&
	    bridge->device == 0x80b5)
		return pci_idt_bus_quirk(bus, devfn, l, timeout);
#endif

	return pci_bus_generic_read_dev_vendor_id(bus, devfn, l, timeout);
}
EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);

/*
 * Read the config data for a PCI device, sanity-check it,
 * and fill in the dev structure.
 */
static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
{
	struct pci_dev *dev;
	u32 l;

	if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
		return NULL;

	dev = pci_alloc_dev(bus);
	if (!dev)
		return NULL;

	dev->devfn = devfn;
	dev->vendor = l & 0xffff;
	dev->device = (l >> 16) & 0xffff;

	if (pci_setup_device(dev)) {
		pci_bus_put(dev->bus);
		kfree(dev);
		return NULL;
	}

	return dev;
}

void pcie_report_downtraining(struct pci_dev *dev)
{
	if (!pci_is_pcie(dev))
		return;

	/* Look from the device up to avoid downstream ports with no devices */
	if ((pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) &&
	    (pci_pcie_type(dev) != PCI_EXP_TYPE_LEG_END) &&
	    (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM))
		return;

	/* Multi-function PCIe devices share the same link/status */
	if (PCI_FUNC(dev->devfn) != 0 || dev->is_virtfn)
		return;

	/* Print link status only if the device is constrained by the fabric */
	__pcie_print_link_status(dev, false);
}

static void pci_init_capabilities(struct pci_dev *dev)
{
	pci_ea_init(dev);		/* Enhanced Allocation */
	pci_msi_init(dev);		/* Disable MSI */
	pci_msix_init(dev);		/* Disable MSI-X */

	/* Buffers for saving PCIe and PCI-X capabilities */
	pci_allocate_cap_save_buffers(dev);

	pci_pm_init(dev);		/* Power Management */
	pci_vpd_init(dev);		/* Vital Product Data */
	pci_configure_ari(dev);		/* Alternative Routing-ID Forwarding */
	pci_iov_init(dev);		/* Single Root I/O Virtualization */
	pci_ats_init(dev);		/* Address Translation Services */
	pci_pri_init(dev);		/* Page Request Interface */
	pci_pasid_init(dev);		/* Process Address Space ID */
	pci_acs_init(dev);		/* Access Control Services */
	pci_ptm_init(dev);		/* Precision Time Measurement */
	pci_aer_init(dev);		/* Advanced Error Reporting */
	pci_dpc_init(dev);		/* Downstream Port Containment */
	pci_rcec_init(dev);		/* Root Complex Event Collector */
	pci_doe_init(dev);		/* Data Object Exchange */

	pcie_report_downtraining(dev);
	pci_init_reset_methods(dev);
}

/*
 * This is the equivalent of pci_host_bridge_msi_domain() that acts on
 * devices. Firmware interfaces that can select the MSI domain on a
 * per-device basis should be called from here.
 */
static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
{
	struct irq_domain *d;

	/*
	 * If a domain has been set through the pcibios_device_add()
	 * callback, then this is the one (platform code knows best).
	 */
	d = dev_get_msi_domain(&dev->dev);
	if (d)
		return d;

	/*
	 * Let's see if we have a firmware interface able to provide
	 * the domain.
	 */
	d = pci_msi_get_device_domain(dev);
	if (d)
		return d;

	return NULL;
}

static void pci_set_msi_domain(struct pci_dev *dev)
{
	struct irq_domain *d;

	/*
	 * If the platform or firmware interfaces cannot supply a
	 * device-specific MSI domain, then inherit the default domain
	 * from the host bridge itself.
	 */
	d = pci_dev_msi_domain(dev);
	if (!d)
		d = dev_get_msi_domain(&dev->bus->dev);

	dev_set_msi_domain(&dev->dev, d);
}

void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
	int ret;

	pci_configure_device(dev);

	device_initialize(&dev->dev);
	dev->dev.release = pci_release_dev;

	set_dev_node(&dev->dev, pcibus_to_node(bus));
	dev->dev.dma_mask = &dev->dma_mask;
	dev->dev.dma_parms = &dev->dma_parms;
	dev->dev.coherent_dma_mask = 0xffffffffull;

	dma_set_max_seg_size(&dev->dev, 65536);
	dma_set_seg_boundary(&dev->dev, 0xffffffff);

	pcie_failed_link_retrain(dev);

	/* Fix up broken headers */
	pci_fixup_device(pci_fixup_header, dev);

	pci_reassigndev_resource_alignment(dev);

	dev->state_saved = false;

	pci_init_capabilities(dev);

	/*
	 * Add the device to our list of discovered devices
	 * and the bus list for fixup functions, etc.
	 */
	down_write(&pci_bus_sem);
	list_add_tail(&dev->bus_list, &bus->devices);
	up_write(&pci_bus_sem);

	ret = pcibios_device_add(dev);
	WARN_ON(ret < 0);

	/* Set up MSI IRQ domain */
	pci_set_msi_domain(dev);

	/* Notifier could use PCI capabilities */
	dev->match_driver = false;
	ret = device_add(&dev->dev);
	WARN_ON(ret < 0);

	pci_npem_create(dev);
}

struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn)
{
	struct pci_dev *dev;

	dev = pci_get_slot(bus, devfn);
	if (dev) {
		pci_dev_put(dev);
		return dev;
	}

	dev = pci_scan_device(bus, devfn);
	if (!dev)
		return NULL;

	pci_device_add(dev, bus);

	return dev;
}
EXPORT_SYMBOL(pci_scan_single_device);

static int next_ari_fn(struct pci_bus *bus, struct pci_dev *dev, int fn)
{
	int pos;
	u16 cap = 0;
	unsigned int next_fn;

	if (!dev)
		return -ENODEV;

	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
	if (!pos)
		return -ENODEV;

	pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap);
	next_fn = PCI_ARI_CAP_NFN(cap);
	if (next_fn <= fn)
		return -ENODEV;	/* protect against malformed list */

	return next_fn;
}

static int next_fn(struct pci_bus *bus, struct pci_dev *dev, int fn)
{
	if (pci_ari_enabled(bus))
		return next_ari_fn(bus, dev, fn);

	if (fn >= 7)
		return -ENODEV;
	/* only multifunction devices may have more functions */
	if (dev && !dev->multifunction)
		return -ENODEV;

	return fn + 1;
}

static int only_one_child(struct pci_bus *bus)
{
	struct pci_dev *bridge = bus->self;

	/*
	 * Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so
	 * we scan for all possible devices, not just Device 0.
	 */
	if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS))
		return 0;

	/*
	 * A PCIe Downstream Port normally leads to a Link with only Device
	 * 0 on it (PCIe spec r3.1, sec 7.3.1).  As an optimization, scan
	 * only for Device 0 in that situation.
	 */
	if (bridge && pci_is_pcie(bridge) && pcie_downstream_port(bridge))
		return 1;

	return 0;
}

/**
 * pci_scan_slot - Scan a PCI slot on a bus for devices
 * @bus: PCI bus to scan
 * @devfn: slot number to scan (must have zero function)
 *
 * Scan a PCI slot on the specified PCI bus for devices, adding
 * discovered devices to the @bus->devices list.  New devices
 * will not have is_added set.
 *
 * Returns the number of new devices found.
 */
int pci_scan_slot(struct pci_bus *bus, int devfn)
{
	struct pci_dev *dev;
	int fn = 0, nr = 0;

	if (only_one_child(bus) && (devfn > 0))
		return 0; /* Already scanned the entire slot */

	do {
		dev = pci_scan_single_device(bus, devfn + fn);
		if (dev) {
			if (!pci_dev_is_added(dev))
				nr++;
			if (fn > 0)
				dev->multifunction = 1;
		} else if (fn == 0) {
			/*
			 * Function 0 is required unless we are running on
			 * a hypervisor that passes through individual PCI
			 * functions.
			 */
			if (!hypervisor_isolated_pci_functions())
				break;
		}
		fn = next_fn(bus, dev, fn);
	} while (fn >= 0);

	/* Only one slot has PCIe device */
	if (bus->self && nr)
		pcie_aspm_init_link_state(bus->self);

	return nr;
}
EXPORT_SYMBOL(pci_scan_slot);

static int pcie_find_smpss(struct pci_dev *dev, void *data)
{
	u8 *smpss = data;

	if (!pci_is_pcie(dev))
		return 0;

	/*
	 * We don't have a way to change MPS settings on devices that have
	 * drivers attached.  A hot-added device might support only the minimum
	 * MPS setting (MPS=128).  Therefore, if the fabric contains a bridge
	 * where devices may be hot-added, we limit the fabric MPS to 128 so
	 * hot-added devices will work correctly.
	 *
	 * However, if we hot-add a device to a slot directly below a Root
	 * Port, it's impossible for there to be other existing devices below
	 * the port.  We don't limit the MPS in this case because we can
	 * reconfigure MPS on both the Root Port and the hot-added device,
	 * and there are no other devices involved.
	 *
	 * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA.
	 */
	if (dev->is_hotplug_bridge &&
	    pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
		*smpss = 0;

	if (*smpss > dev->pcie_mpss)
		*smpss = dev->pcie_mpss;

	return 0;
}

static void pcie_write_mps(struct pci_dev *dev, int mps)
{
	int rc;

	if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
		mps = 128 << dev->pcie_mpss;

		if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT &&
		    dev->bus->self)

			/*
			 * For "Performance", the assumption is made that
			 * downstream communication will never be larger than
			 * the MRRS.  So, the MPS only needs to be configured
			 * for the upstream communication.  This being the case,
			 * walk from the top down and set the MPS of the child
			 * to that of the parent bus.
			 *
			 * Configure the device MPS with the smaller of the
			 * device MPSS or the bridge MPS (which is assumed to be
			 * properly configured at this point to the largest
			 * allowable MPS based on its parent bus).
			 */
			mps = min(mps, pcie_get_mps(dev->bus->self));
	}

	rc = pcie_set_mps(dev, mps);
	if (rc)
		pci_err(dev, "Failed attempting to set the MPS\n");
}

static void pcie_write_mrrs(struct pci_dev *dev)
{
	int rc, mrrs;

	/*
	 * In the "safe" case, do not configure the MRRS.  There appear to be
	 * issues with setting MRRS to 0 on a number of devices.
	 */
	if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
		return;

	/*
	 * For max performance, the MRRS must be set to the largest supported
	 * value.  However, it cannot be configured larger than the MPS the
	 * device or the bus can support.  This should already be properly
	 * configured by a prior call to pcie_write_mps().
	 */
	mrrs = pcie_get_mps(dev);

	/*
	 * MRRS is a R/W register.  Invalid values can be written, but a
	 * subsequent read will verify if the value is acceptable or not.
	 * If the MRRS value provided is not acceptable (e.g., too large),
	 * shrink the value until it is acceptable to the HW.
	 */
	while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
		rc = pcie_set_readrq(dev, mrrs);
		if (!rc)
			break;

		pci_warn(dev, "Failed attempting to set the MRRS\n");
		mrrs /= 2;
	}

	if (mrrs < 128)
		pci_err(dev, "MRRS was unable to be configured with a safe value.  If problems are experienced, try running with pci=pcie_bus_safe\n");
}

static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
{
	int mps, orig_mps;

	if (!pci_is_pcie(dev))
		return 0;

	if (pcie_bus_config == PCIE_BUS_TUNE_OFF ||
	    pcie_bus_config == PCIE_BUS_DEFAULT)
		return 0;

	mps = 128 << *(u8 *)data;
	orig_mps = pcie_get_mps(dev);

	pcie_write_mps(dev, mps);
	pcie_write_mrrs(dev);

	pci_info(dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n",
		 pcie_get_mps(dev), 128 << dev->pcie_mpss,
		 orig_mps, pcie_get_readrq(dev));

	return 0;
}

/*
 * pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down,
 * parents then children fashion.  If this changes, then this code will not
 * work as designed.
 */
void pcie_bus_configure_settings(struct pci_bus *bus)
{
	u8 smpss = 0;

	if (!bus->self)
		return;

	if (!pci_is_pcie(bus->self))
		return;

	/*
	 * FIXME - Peer to peer DMA is possible, though the endpoint would need
	 * to be aware of the MPS of the destination.  To work around this,
	 * simply force the MPS of the entire system to the smallest possible.
	 */
	if (pcie_bus_config == PCIE_BUS_PEER2PEER)
		smpss = 0;

	if (pcie_bus_config == PCIE_BUS_SAFE) {
		smpss = bus->self->pcie_mpss;

		pcie_find_smpss(bus->self, &smpss);
		pci_walk_bus(bus, pcie_find_smpss, &smpss);
	}

	pcie_bus_configure_set(bus->self, &smpss);
	pci_walk_bus(bus, pcie_bus_configure_set, &smpss);
}
EXPORT_SYMBOL_GPL(pcie_bus_configure_settings);

/*
 * Called after each bus is probed, but before its children are examined.  This
 * is marked as __weak because multiple architectures define it.
 */
void __weak pcibios_fixup_bus(struct pci_bus *bus)
{
       /* nothing to do, expected to be removed in the future */
}

/**
 * pci_scan_child_bus_extend() - Scan devices below a bus
 * @bus: Bus to scan for devices
 * @available_buses: Total number of buses available (%0 does not try to
 *		     extend beyond the minimal)
 *
 * Scans devices below @bus including subordinate buses. Returns new
 * subordinate number including all the found devices. Passing
 * @available_buses causes the remaining bus space to be distributed
 * equally between hotplug-capable bridges to allow future extension of the
 * hierarchy.
 */
static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
					      unsigned int available_buses)
{
	unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0;
	unsigned int start = bus->busn_res.start;
	unsigned int devfn, cmax, max = start;
	struct pci_dev *dev;

	dev_dbg(&bus->dev, "scanning bus\n");

	/* Go find them, Rover! */
	for (devfn = 0; devfn < 256; devfn += 8)
		pci_scan_slot(bus, devfn);

	/* Reserve buses for SR-IOV capability */
	used_buses = pci_iov_bus_range(bus);
	max += used_buses;

	/*
	 * After performing arch-dependent fixup of the bus, look behind
	 * all PCI-to-PCI bridges on this bus.
	 */
	if (!bus->is_added) {
		dev_dbg(&bus->dev, "fixups for bus\n");
		pcibios_fixup_bus(bus);
		bus->is_added = 1;
	}

	/*
	 * Calculate how many hotplug bridges and normal bridges there
	 * are on this bus. We will distribute the additional available
	 * buses between hotplug bridges.
	 */
	for_each_pci_bridge(dev, bus) {
		if (dev->is_hotplug_bridge)
			hotplug_bridges++;
		else
			normal_bridges++;
	}

	/*
	 * Scan bridges that are already configured. We don't touch them
	 * unless they are misconfigured (which will be done in the second
	 * scan below).
	 */
	for_each_pci_bridge(dev, bus) {
		cmax = max;
		max = pci_scan_bridge_extend(bus, dev, max, 0, 0);

		/*
		 * Reserve one bus for each bridge now to avoid extending
		 * hotplug bridges too much during the second scan below.
		 */
		used_buses++;
		if (max - cmax > 1)
			used_buses += max - cmax - 1;
	}

	/* Scan bridges that need to be reconfigured */
	for_each_pci_bridge(dev, bus) {
		unsigned int buses = 0;

		if (!hotplug_bridges && normal_bridges == 1) {
			/*
			 * There is only one bridge on the bus (upstream
			 * port) so it gets all available buses which it
			 * can then distribute to the possible hotplug
			 * bridges below.
			 */
			buses = available_buses;
		} else if (dev->is_hotplug_bridge) {
			/*
			 * Distribute the extra buses between hotplug
			 * bridges if any.
			 */
			buses = available_buses / hotplug_bridges;
			buses = min(buses, available_buses - used_buses + 1);
		}

		cmax = max;
		max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1);
		/* One bus is already accounted so don't add it again */
		if (max - cmax > 1)
			used_buses += max - cmax - 1;
	}

	/*
	 * Make sure a hotplug bridge has at least the minimum requested
	 * number of buses but allow it to grow up to the maximum available
	 * bus number if there is room.
	 */
	if (bus->self && bus->self->is_hotplug_bridge) {
		used_buses = max_t(unsigned int, available_buses,
				   pci_hotplug_bus_size - 1);
		if (max - start < used_buses) {
			max = start + used_buses;

			/* Do not allocate more buses than we have room left */
			if (max > bus->busn_res.end)
				max = bus->busn_res.end;

			dev_dbg(&bus->dev, "%pR extended by %#02x\n",
				&bus->busn_res, max - start);
		}
	}

	/*
	 * We've scanned the bus and so we know all about what's on
	 * the other side of any bridges that may be on this bus plus
	 * any devices.
	 *
	 * Return how far we've got finding sub-buses.
	 */
	dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max);
	return max;
}

/**
 * pci_scan_child_bus() - Scan devices below a bus
 * @bus: Bus to scan for devices
 *
 * Scans devices below @bus including subordinate buses. Returns new
 * subordinate number including all the found devices.
 */
unsigned int pci_scan_child_bus(struct pci_bus *bus)
{
	return pci_scan_child_bus_extend(bus, 0);
}
EXPORT_SYMBOL_GPL(pci_scan_child_bus);

/**
 * pcibios_root_bridge_prepare - Platform-specific host bridge setup
 * @bridge: Host bridge to set up
 *
 * Default empty implementation.  Replace with an architecture-specific setup
 * routine, if necessary.
 */
int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
	return 0;
}

void __weak pcibios_add_bus(struct pci_bus *bus)
{
}

void __weak pcibios_remove_bus(struct pci_bus *bus)
{
}

struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
		struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
	int error;
	struct pci_host_bridge *bridge;

	bridge = pci_alloc_host_bridge(0);
	if (!bridge)
		return NULL;

	bridge->dev.parent = parent;

	list_splice_init(resources, &bridge->windows);
	bridge->sysdata = sysdata;
	bridge->busnr = bus;
	bridge->ops = ops;

	error = pci_register_host_bridge(bridge);
	if (error < 0)
		goto err_out;

	return bridge->bus;

err_out:
	put_device(&bridge->dev);
	return NULL;
}
EXPORT_SYMBOL_GPL(pci_create_root_bus);

int pci_host_probe(struct pci_host_bridge *bridge)
{
	struct pci_bus *bus, *child;
	int ret;

	pci_lock_rescan_remove();
	ret = pci_scan_root_bus_bridge(bridge);
	pci_unlock_rescan_remove();
	if (ret < 0) {
		dev_err(bridge->dev.parent, "Scanning root bridge failed");
		return ret;
	}

	bus = bridge->bus;

	/* If we must preserve the resource configuration, claim now */
	if (bridge->preserve_config)
		pci_bus_claim_resources(bus);

	/*
	 * Assign whatever was left unassigned. If we didn't claim above,
	 * this will reassign everything.
	 */
	pci_assign_unassigned_root_bus_resources(bus);

	list_for_each_entry(child, &bus->children, node)
		pcie_bus_configure_settings(child);

	pci_bus_add_devices(bus);
	return 0;
}
EXPORT_SYMBOL_GPL(pci_host_probe);

int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
{
	struct resource *res = &b->busn_res;
	struct resource *parent_res, *conflict;

	res->start = bus;
	res->end = bus_max;
	res->flags = IORESOURCE_BUS;

	if (!pci_is_root_bus(b))
		parent_res = &b->parent->busn_res;
	else {
		parent_res = get_pci_domain_busn_res(pci_domain_nr(b));
		res->flags |= IORESOURCE_PCI_FIXED;
	}

	conflict = request_resource_conflict(parent_res, res);

	if (conflict)
		dev_info(&b->dev,
			   "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n",
			    res, pci_is_root_bus(b) ? "domain " : "",
			    parent_res, conflict->name, conflict);

	return conflict == NULL;
}

int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max)
{
	struct resource *res = &b->busn_res;
	struct resource old_res = *res;
	resource_size_t size;
	int ret;

	if (res->start > bus_max)
		return -EINVAL;

	size = bus_max - res->start + 1;
	ret = adjust_resource(res, res->start, size);
	dev_info(&b->dev, "busn_res: %pR end %s updated to %02x\n",
			&old_res, ret ? "can not be" : "is", bus_max);

	if (!ret && !res->parent)
		pci_bus_insert_busn_res(b, res->start, res->end);

	return ret;
}

void pci_bus_release_busn_res(struct pci_bus *b)
{
	struct resource *res = &b->busn_res;
	int ret;

	if (!res->flags || !res->parent)
		return;

	ret = release_resource(res);
	dev_info(&b->dev, "busn_res: %pR %s released\n",
			res, ret ? "can not be" : "is");
}

int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge)
{
	struct resource_entry *window;
	bool found = false;
	struct pci_bus *b;
	int max, bus, ret;

	if (!bridge)
		return -EINVAL;

	resource_list_for_each_entry(window, &bridge->windows)
		if (window->res->flags & IORESOURCE_BUS) {
			bridge->busnr = window->res->start;
			found = true;
			break;
		}

	ret = pci_register_host_bridge(bridge);
	if (ret < 0)
		return ret;

	b = bridge->bus;
	bus = bridge->busnr;

	if (!found) {
		dev_info(&b->dev,
		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
			bus);
		pci_bus_insert_busn_res(b, bus, 255);
	}

	max = pci_scan_child_bus(b);

	if (!found)
		pci_bus_update_busn_res_end(b, max);

	return 0;
}
EXPORT_SYMBOL(pci_scan_root_bus_bridge);

struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
		struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
	struct resource_entry *window;
	bool found = false;
	struct pci_bus *b;
	int max;

	resource_list_for_each_entry(window, resources)
		if (window->res->flags & IORESOURCE_BUS) {
			found = true;
			break;
		}

	b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
	if (!b)
		return NULL;

	if (!found) {
		dev_info(&b->dev,
		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
			bus);
		pci_bus_insert_busn_res(b, bus, 255);
	}

	max = pci_scan_child_bus(b);

	if (!found)
		pci_bus_update_busn_res_end(b, max);

	return b;
}
EXPORT_SYMBOL(pci_scan_root_bus);

struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
					void *sysdata)
{
	LIST_HEAD(resources);
	struct pci_bus *b;

	pci_add_resource(&resources, &ioport_resource);
	pci_add_resource(&resources, &iomem_resource);
	pci_add_resource(&resources, &busn_resource);
	b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
	if (b) {
		pci_scan_child_bus(b);
	} else {
		pci_free_resource_list(&resources);
	}
	return b;
}
EXPORT_SYMBOL(pci_scan_bus);

/**
 * pci_rescan_bus_bridge_resize - Scan a PCI bus for devices
 * @bridge: PCI bridge for the bus to scan
 *
 * Scan a PCI bus and child buses for new devices, add them,
 * and enable them, resizing bridge mmio/io resource if necessary
 * and possible.  The caller must ensure the child devices are already
 * removed for resizing to occur.
 *
 * Returns the max number of subordinate bus discovered.
 */
unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge)
{
	unsigned int max;
	struct pci_bus *bus = bridge->subordinate;

	max = pci_scan_child_bus(bus);

	pci_assign_unassigned_bridge_resources(bridge);

	pci_bus_add_devices(bus);

	return max;
}

/**
 * pci_rescan_bus - Scan a PCI bus for devices
 * @bus: PCI bus to scan
 *
 * Scan a PCI bus and child buses for new devices, add them,
 * and enable them.
 *
 * Returns the max number of subordinate bus discovered.
 */
unsigned int pci_rescan_bus(struct pci_bus *bus)
{
	unsigned int max;

	max = pci_scan_child_bus(bus);
	pci_assign_unassigned_bus_resources(bus);
	pci_bus_add_devices(bus);

	return max;
}
EXPORT_SYMBOL_GPL(pci_rescan_bus);

/*
 * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal
 * routines should always be executed under this mutex.
 */
static DEFINE_MUTEX(pci_rescan_remove_lock);

void pci_lock_rescan_remove(void)
{
	mutex_lock(&pci_rescan_remove_lock);
}
EXPORT_SYMBOL_GPL(pci_lock_rescan_remove);

void pci_unlock_rescan_remove(void)
{
	mutex_unlock(&pci_rescan_remove_lock);
}
EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove);

static int __init pci_sort_bf_cmp(const struct device *d_a,
				  const struct device *d_b)
{
	const struct pci_dev *a = to_pci_dev(d_a);
	const struct pci_dev *b = to_pci_dev(d_b);

	if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
	else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;

	if      (a->bus->number < b->bus->number) return -1;
	else if (a->bus->number > b->bus->number) return  1;

	if      (a->devfn < b->devfn) return -1;
	else if (a->devfn > b->devfn) return  1;

	return 0;
}

void __init pci_sort_breadthfirst(void)
{
	bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp);
}

int pci_hp_add_bridge(struct pci_dev *dev)
{
	struct pci_bus *parent = dev->bus;
	int busnr, start = parent->busn_res.start;
	unsigned int available_buses = 0;
	int end = parent->busn_res.end;

	for (busnr = start; busnr <= end; busnr++) {
		if (!pci_find_bus(pci_domain_nr(parent), busnr))
			break;
	}
	if (busnr-- > end) {
		pci_err(dev, "No bus number available for hot-added bridge\n");
		return -1;
	}

	/* Scan bridges that are already configured */
	busnr = pci_scan_bridge(parent, dev, busnr, 0);

	/*
	 * Distribute the available bus numbers between hotplug-capable
	 * bridges to make extending the chain later possible.
	 */
	available_buses = end - busnr;

	/* Scan bridges that need to be reconfigured */
	pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1);

	if (!dev->subordinate)
		return -1;

	return 0;
}
EXPORT_SYMBOL_GPL(pci_hp_add_bridge);