Training courses

Kernel and Embedded Linux

Bootlin training courses

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

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
/*****************************************************************************
 *                                                                           *
 * File: sge.c                                                               *
 * $Revision: 1.26 $                                                         *
 * $Date: 2005/06/21 18:29:48 $                                              *
 * Description:                                                              *
 *  DMA engine.                                                              *
 *  part of the Chelsio 10Gb Ethernet Driver.                                *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the GNU General Public License, version 2, as       *
 * published by the Free Software Foundation.                                *
 *                                                                           *
 * You should have received a copy of the GNU General Public License along   *
 * with this program; if not, see <http://www.gnu.org/licenses/>.            *
 *                                                                           *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED    *
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF      *
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.                     *
 *                                                                           *
 * http://www.chelsio.com                                                    *
 *                                                                           *
 * Copyright (c) 2003 - 2005 Chelsio Communications, Inc.                    *
 * All rights reserved.                                                      *
 *                                                                           *
 * Maintainers: maintainers@chelsio.com                                      *
 *                                                                           *
 * Authors: Dimitrios Michailidis   <dm@chelsio.com>                         *
 *          Tina Yang               <tainay@chelsio.com>                     *
 *          Felix Marti             <felix@chelsio.com>                      *
 *          Scott Bardone           <sbardone@chelsio.com>                   *
 *          Kurt Ottaway            <kottaway@chelsio.com>                   *
 *          Frank DiMambro          <frank@chelsio.com>                      *
 *                                                                           *
 * History:                                                                  *
 *                                                                           *
 ****************************************************************************/

#include "common.h"

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/ktime.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/skbuff.h>
#include <linux/mm.h>
#include <linux/tcp.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <linux/prefetch.h>

#include "cpl5_cmd.h"
#include "sge.h"
#include "regs.h"
#include "espi.h"

/* This belongs in if_ether.h */
#define ETH_P_CPL5 0xf

#define SGE_CMDQ_N		2
#define SGE_FREELQ_N		2
#define SGE_CMDQ0_E_N		1024
#define SGE_CMDQ1_E_N		128
#define SGE_FREEL_SIZE		4096
#define SGE_JUMBO_FREEL_SIZE	512
#define SGE_FREEL_REFILL_THRESH	16
#define SGE_RESPQ_E_N		1024
#define SGE_INTRTIMER_NRES	1000
#define SGE_RX_SM_BUF_SIZE	1536
#define SGE_TX_DESC_MAX_PLEN	16384

#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)

/*
 * Period of the TX buffer reclaim timer.  This timer does not need to run
 * frequently as TX buffers are usually reclaimed by new TX packets.
 */
#define TX_RECLAIM_PERIOD (HZ / 4)

#define M_CMD_LEN       0x7fffffff
#define V_CMD_LEN(v)    (v)
#define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
#define V_CMD_GEN1(v)   ((v) << 31)
#define V_CMD_GEN2(v)   (v)
#define F_CMD_DATAVALID (1 << 1)
#define F_CMD_SOP       (1 << 2)
#define V_CMD_EOP(v)    ((v) << 3)

/*
 * Command queue, receive buffer list, and response queue descriptors.
 */
#if defined(__BIG_ENDIAN_BITFIELD)
struct cmdQ_e {
	u32 addr_lo;
	u32 len_gen;
	u32 flags;
	u32 addr_hi;
};

struct freelQ_e {
	u32 addr_lo;
	u32 len_gen;
	u32 gen2;
	u32 addr_hi;
};

struct respQ_e {
	u32 Qsleeping		: 4;
	u32 Cmdq1CreditReturn	: 5;
	u32 Cmdq1DmaComplete	: 5;
	u32 Cmdq0CreditReturn	: 5;
	u32 Cmdq0DmaComplete	: 5;
	u32 FreelistQid		: 2;
	u32 CreditValid		: 1;
	u32 DataValid		: 1;
	u32 Offload		: 1;
	u32 Eop			: 1;
	u32 Sop			: 1;
	u32 GenerationBit	: 1;
	u32 BufferLength;
};
#elif defined(__LITTLE_ENDIAN_BITFIELD)
struct cmdQ_e {
	u32 len_gen;
	u32 addr_lo;
	u32 addr_hi;
	u32 flags;
};

struct freelQ_e {
	u32 len_gen;
	u32 addr_lo;
	u32 addr_hi;
	u32 gen2;
};

struct respQ_e {
	u32 BufferLength;
	u32 GenerationBit	: 1;
	u32 Sop			: 1;
	u32 Eop			: 1;
	u32 Offload		: 1;
	u32 DataValid		: 1;
	u32 CreditValid		: 1;
	u32 FreelistQid		: 2;
	u32 Cmdq0DmaComplete	: 5;
	u32 Cmdq0CreditReturn	: 5;
	u32 Cmdq1DmaComplete	: 5;
	u32 Cmdq1CreditReturn	: 5;
	u32 Qsleeping		: 4;
} ;
#endif

/*
 * SW Context Command and Freelist Queue Descriptors
 */
struct cmdQ_ce {
	struct sk_buff *skb;
	DEFINE_DMA_UNMAP_ADDR(dma_addr);
	DEFINE_DMA_UNMAP_LEN(dma_len);
};

struct freelQ_ce {
	struct sk_buff *skb;
	DEFINE_DMA_UNMAP_ADDR(dma_addr);
	DEFINE_DMA_UNMAP_LEN(dma_len);
};

/*
 * SW command, freelist and response rings
 */
struct cmdQ {
	unsigned long   status;         /* HW DMA fetch status */
	unsigned int    in_use;         /* # of in-use command descriptors */
	unsigned int	size;	        /* # of descriptors */
	unsigned int    processed;      /* total # of descs HW has processed */
	unsigned int    cleaned;        /* total # of descs SW has reclaimed */
	unsigned int    stop_thres;     /* SW TX queue suspend threshold */
	u16		pidx;           /* producer index (SW) */
	u16		cidx;           /* consumer index (HW) */
	u8		genbit;         /* current generation (=valid) bit */
	u8              sop;            /* is next entry start of packet? */
	struct cmdQ_e  *entries;        /* HW command descriptor Q */
	struct cmdQ_ce *centries;       /* SW command context descriptor Q */
	dma_addr_t	dma_addr;       /* DMA addr HW command descriptor Q */
	spinlock_t	lock;           /* Lock to protect cmdQ enqueuing */
};

struct freelQ {
	unsigned int	credits;        /* # of available RX buffers */
	unsigned int	size;	        /* free list capacity */
	u16		pidx;           /* producer index (SW) */
	u16		cidx;           /* consumer index (HW) */
	u16		rx_buffer_size; /* Buffer size on this free list */
	u16             dma_offset;     /* DMA offset to align IP headers */
	u16             recycleq_idx;   /* skb recycle q to use */
	u8		genbit;	        /* current generation (=valid) bit */
	struct freelQ_e	*entries;       /* HW freelist descriptor Q */
	struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
	dma_addr_t	dma_addr;       /* DMA addr HW freelist descriptor Q */
};

struct respQ {
	unsigned int	credits;        /* credits to be returned to SGE */
	unsigned int	size;	        /* # of response Q descriptors */
	u16		cidx;	        /* consumer index (SW) */
	u8		genbit;	        /* current generation(=valid) bit */
	struct respQ_e *entries;        /* HW response descriptor Q */
	dma_addr_t	dma_addr;       /* DMA addr HW response descriptor Q */
};

/* Bit flags for cmdQ.status */
enum {
	CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
	CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
};

/* T204 TX SW scheduler */

/* Per T204 TX port */
struct sched_port {
	unsigned int	avail;		/* available bits - quota */
	unsigned int	drain_bits_per_1024ns; /* drain rate */
	unsigned int	speed;		/* drain rate, mbps */
	unsigned int	mtu;		/* mtu size */
	struct sk_buff_head skbq;	/* pending skbs */
};

/* Per T204 device */
struct sched {
	ktime_t         last_updated;   /* last time quotas were computed */
	unsigned int	max_avail;	/* max bits to be sent to any port */
	unsigned int	port;		/* port index (round robin ports) */
	unsigned int	num;		/* num skbs in per port queues */
	struct sched_port p[MAX_NPORTS];
	struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
};
static void restart_sched(unsigned long);


/*
 * Main SGE data structure
 *
 * Interrupts are handled by a single CPU and it is likely that on a MP system
 * the application is migrated to another CPU. In that scenario, we try to
 * separate the RX(in irq context) and TX state in order to decrease memory
 * contention.
 */
struct sge {
	struct adapter *adapter;	/* adapter backpointer */
	struct net_device *netdev;      /* netdevice backpointer */
	struct freelQ	freelQ[SGE_FREELQ_N]; /* buffer free lists */
	struct respQ	respQ;		/* response Q */
	unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
	unsigned int	rx_pkt_pad;     /* RX padding for L2 packets */
	unsigned int	jumbo_fl;       /* jumbo freelist Q index */
	unsigned int	intrtimer_nres;	/* no-resource interrupt timer */
	unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
	struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
	struct timer_list espibug_timer;
	unsigned long	espibug_timeout;
	struct sk_buff	*espibug_skb[MAX_NPORTS];
	u32		sge_control;	/* shadow value of sge control reg */
	struct sge_intr_counts stats;
	struct sge_port_stats __percpu *port_stats[MAX_NPORTS];
	struct sched	*tx_sched;
	struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
};

static const u8 ch_mac_addr[ETH_ALEN] = {
	0x0, 0x7, 0x43, 0x0, 0x0, 0x0
};

/*
 * stop tasklet and free all pending skb's
 */
static void tx_sched_stop(struct sge *sge)
{
	struct sched *s = sge->tx_sched;
	int i;

	tasklet_kill(&s->sched_tsk);

	for (i = 0; i < MAX_NPORTS; i++)
		__skb_queue_purge(&s->p[s->port].skbq);
}

/*
 * t1_sched_update_parms() is called when the MTU or link speed changes. It
 * re-computes scheduler parameters to scope with the change.
 */
unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
				   unsigned int mtu, unsigned int speed)
{
	struct sched *s = sge->tx_sched;
	struct sched_port *p = &s->p[port];
	unsigned int max_avail_segs;

	pr_debug("%s mtu=%d speed=%d\n", __func__, mtu, speed);
	if (speed)
		p->speed = speed;
	if (mtu)
		p->mtu = mtu;

	if (speed || mtu) {
		unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
		do_div(drain, (p->mtu + 50) * 1000);
		p->drain_bits_per_1024ns = (unsigned int) drain;

		if (p->speed < 1000)
			p->drain_bits_per_1024ns =
				90 * p->drain_bits_per_1024ns / 100;
	}

	if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
		p->drain_bits_per_1024ns -= 16;
		s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
		max_avail_segs = max(1U, 4096 / (p->mtu - 40));
	} else {
		s->max_avail = 16384;
		max_avail_segs = max(1U, 9000 / (p->mtu - 40));
	}

	pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
		 "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
		 p->speed, s->max_avail, max_avail_segs,
		 p->drain_bits_per_1024ns);

	return max_avail_segs * (p->mtu - 40);
}

#if 0

/*
 * t1_sched_max_avail_bytes() tells the scheduler the maximum amount of
 * data that can be pushed per port.
 */
void t1_sched_set_max_avail_bytes(struct sge *sge, unsigned int val)
{
	struct sched *s = sge->tx_sched;
	unsigned int i;

	s->max_avail = val;
	for (i = 0; i < MAX_NPORTS; i++)
		t1_sched_update_parms(sge, i, 0, 0);
}

/*
 * t1_sched_set_drain_bits_per_us() tells the scheduler at which rate a port
 * is draining.
 */
void t1_sched_set_drain_bits_per_us(struct sge *sge, unsigned int port,
					 unsigned int val)
{
	struct sched *s = sge->tx_sched;
	struct sched_port *p = &s->p[port];
	p->drain_bits_per_1024ns = val * 1024 / 1000;
	t1_sched_update_parms(sge, port, 0, 0);
}

#endif  /*  0  */

/*
 * tx_sched_init() allocates resources and does basic initialization.
 */
static int tx_sched_init(struct sge *sge)
{
	struct sched *s;
	int i;

	s = kzalloc(sizeof (struct sched), GFP_KERNEL);
	if (!s)
		return -ENOMEM;

	pr_debug("tx_sched_init\n");
	tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
	sge->tx_sched = s;

	for (i = 0; i < MAX_NPORTS; i++) {
		skb_queue_head_init(&s->p[i].skbq);
		t1_sched_update_parms(sge, i, 1500, 1000);
	}

	return 0;
}

/*
 * sched_update_avail() computes the delta since the last time it was called
 * and updates the per port quota (number of bits that can be sent to the any
 * port).
 */
static inline int sched_update_avail(struct sge *sge)
{
	struct sched *s = sge->tx_sched;
	ktime_t now = ktime_get();
	unsigned int i;
	long long delta_time_ns;

	delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));

	pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
	if (delta_time_ns < 15000)
		return 0;

	for (i = 0; i < MAX_NPORTS; i++) {
		struct sched_port *p = &s->p[i];
		unsigned int delta_avail;

		delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
		p->avail = min(p->avail + delta_avail, s->max_avail);
	}

	s->last_updated = now;

	return 1;
}

/*
 * sched_skb() is called from two different places. In the tx path, any
 * packet generating load on an output port will call sched_skb()
 * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
 * context (skb == NULL).
 * The scheduler only returns a skb (which will then be sent) if the
 * length of the skb is <= the current quota of the output port.
 */
static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
				unsigned int credits)
{
	struct sched *s = sge->tx_sched;
	struct sk_buff_head *skbq;
	unsigned int i, len, update = 1;

	pr_debug("sched_skb %p\n", skb);
	if (!skb) {
		if (!s->num)
			return NULL;
	} else {
		skbq = &s->p[skb->dev->if_port].skbq;
		__skb_queue_tail(skbq, skb);
		s->num++;
		skb = NULL;
	}

	if (credits < MAX_SKB_FRAGS + 1)
		goto out;

again:
	for (i = 0; i < MAX_NPORTS; i++) {
		s->port = (s->port + 1) & (MAX_NPORTS - 1);
		skbq = &s->p[s->port].skbq;

		skb = skb_peek(skbq);

		if (!skb)
			continue;

		len = skb->len;
		if (len <= s->p[s->port].avail) {
			s->p[s->port].avail -= len;
			s->num--;
			__skb_unlink(skb, skbq);
			goto out;
		}
		skb = NULL;
	}

	if (update-- && sched_update_avail(sge))
		goto again;

out:
	/* If there are more pending skbs, we use the hardware to schedule us
	 * again.
	 */
	if (s->num && !skb) {
		struct cmdQ *q = &sge->cmdQ[0];
		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
		}
	}
	pr_debug("sched_skb ret %p\n", skb);

	return skb;
}

/*
 * PIO to indicate that memory mapped Q contains valid descriptor(s).
 */
static inline void doorbell_pio(struct adapter *adapter, u32 val)
{
	wmb();
	writel(val, adapter->regs + A_SG_DOORBELL);
}

/*
 * Frees all RX buffers on the freelist Q. The caller must make sure that
 * the SGE is turned off before calling this function.
 */
static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
{
	unsigned int cidx = q->cidx;

	while (q->credits--) {
		struct freelQ_ce *ce = &q->centries[cidx];

		pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
				 dma_unmap_len(ce, dma_len),
				 PCI_DMA_FROMDEVICE);
		dev_kfree_skb(ce->skb);
		ce->skb = NULL;
		if (++cidx == q->size)
			cidx = 0;
	}
}

/*
 * Free RX free list and response queue resources.
 */
static void free_rx_resources(struct sge *sge)
{
	struct pci_dev *pdev = sge->adapter->pdev;
	unsigned int size, i;

	if (sge->respQ.entries) {
		size = sizeof(struct respQ_e) * sge->respQ.size;
		pci_free_consistent(pdev, size, sge->respQ.entries,
				    sge->respQ.dma_addr);
	}

	for (i = 0; i < SGE_FREELQ_N; i++) {
		struct freelQ *q = &sge->freelQ[i];

		if (q->centries) {
			free_freelQ_buffers(pdev, q);
			kfree(q->centries);
		}
		if (q->entries) {
			size = sizeof(struct freelQ_e) * q->size;
			pci_free_consistent(pdev, size, q->entries,
					    q->dma_addr);
		}
	}
}

/*
 * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
 * response queue.
 */
static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
{
	struct pci_dev *pdev = sge->adapter->pdev;
	unsigned int size, i;

	for (i = 0; i < SGE_FREELQ_N; i++) {
		struct freelQ *q = &sge->freelQ[i];

		q->genbit = 1;
		q->size = p->freelQ_size[i];
		q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
		size = sizeof(struct freelQ_e) * q->size;
		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
		if (!q->entries)
			goto err_no_mem;

		size = sizeof(struct freelQ_ce) * q->size;
		q->centries = kzalloc(size, GFP_KERNEL);
		if (!q->centries)
			goto err_no_mem;
	}

	/*
	 * Calculate the buffer sizes for the two free lists.  FL0 accommodates
	 * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
	 * including all the sk_buff overhead.
	 *
	 * Note: For T2 FL0 and FL1 are reversed.
	 */
	sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
		sizeof(struct cpl_rx_data) +
		sge->freelQ[!sge->jumbo_fl].dma_offset;

		size = (16 * 1024) -
		    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

	sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;

	/*
	 * Setup which skb recycle Q should be used when recycling buffers from
	 * each free list.
	 */
	sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
	sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;

	sge->respQ.genbit = 1;
	sge->respQ.size = SGE_RESPQ_E_N;
	sge->respQ.credits = 0;
	size = sizeof(struct respQ_e) * sge->respQ.size;
	sge->respQ.entries =
		pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
	if (!sge->respQ.entries)
		goto err_no_mem;
	return 0;

err_no_mem:
	free_rx_resources(sge);
	return -ENOMEM;
}

/*
 * Reclaims n TX descriptors and frees the buffers associated with them.
 */
static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
{
	struct cmdQ_ce *ce;
	struct pci_dev *pdev = sge->adapter->pdev;
	unsigned int cidx = q->cidx;

	q->in_use -= n;
	ce = &q->centries[cidx];
	while (n--) {
		if (likely(dma_unmap_len(ce, dma_len))) {
			pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
					 dma_unmap_len(ce, dma_len),
					 PCI_DMA_TODEVICE);
			if (q->sop)
				q->sop = 0;
		}
		if (ce->skb) {
			dev_kfree_skb_any(ce->skb);
			q->sop = 1;
		}
		ce++;
		if (++cidx == q->size) {
			cidx = 0;
			ce = q->centries;
		}
	}
	q->cidx = cidx;
}

/*
 * Free TX resources.
 *
 * Assumes that SGE is stopped and all interrupts are disabled.
 */
static void free_tx_resources(struct sge *sge)
{
	struct pci_dev *pdev = sge->adapter->pdev;
	unsigned int size, i;

	for (i = 0; i < SGE_CMDQ_N; i++) {
		struct cmdQ *q = &sge->cmdQ[i];

		if (q->centries) {
			if (q->in_use)
				free_cmdQ_buffers(sge, q, q->in_use);
			kfree(q->centries);
		}
		if (q->entries) {
			size = sizeof(struct cmdQ_e) * q->size;
			pci_free_consistent(pdev, size, q->entries,
					    q->dma_addr);
		}
	}
}

/*
 * Allocates basic TX resources, consisting of memory mapped command Qs.
 */
static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
{
	struct pci_dev *pdev = sge->adapter->pdev;
	unsigned int size, i;

	for (i = 0; i < SGE_CMDQ_N; i++) {
		struct cmdQ *q = &sge->cmdQ[i];

		q->genbit = 1;
		q->sop = 1;
		q->size = p->cmdQ_size[i];
		q->in_use = 0;
		q->status = 0;
		q->processed = q->cleaned = 0;
		q->stop_thres = 0;
		spin_lock_init(&q->lock);
		size = sizeof(struct cmdQ_e) * q->size;
		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
		if (!q->entries)
			goto err_no_mem;

		size = sizeof(struct cmdQ_ce) * q->size;
		q->centries = kzalloc(size, GFP_KERNEL);
		if (!q->centries)
			goto err_no_mem;
	}

	/*
	 * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
	 * only.  For queue 0 set the stop threshold so we can handle one more
	 * packet from each port, plus reserve an additional 24 entries for
	 * Ethernet packets only.  Queue 1 never suspends nor do we reserve
	 * space for Ethernet packets.
	 */
	sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
		(MAX_SKB_FRAGS + 1);
	return 0;

err_no_mem:
	free_tx_resources(sge);
	return -ENOMEM;
}

static inline void setup_ring_params(struct adapter *adapter, u64 addr,
				     u32 size, int base_reg_lo,
				     int base_reg_hi, int size_reg)
{
	writel((u32)addr, adapter->regs + base_reg_lo);
	writel(addr >> 32, adapter->regs + base_reg_hi);
	writel(size, adapter->regs + size_reg);
}

/*
 * Enable/disable VLAN acceleration.
 */
void t1_vlan_mode(struct adapter *adapter, netdev_features_t features)
{
	struct sge *sge = adapter->sge;

	if (features & NETIF_F_HW_VLAN_CTAG_RX)
		sge->sge_control |= F_VLAN_XTRACT;
	else
		sge->sge_control &= ~F_VLAN_XTRACT;
	if (adapter->open_device_map) {
		writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
		readl(adapter->regs + A_SG_CONTROL);   /* flush */
	}
}

/*
 * Programs the various SGE registers. However, the engine is not yet enabled,
 * but sge->sge_control is setup and ready to go.
 */
static void configure_sge(struct sge *sge, struct sge_params *p)
{
	struct adapter *ap = sge->adapter;

	writel(0, ap->regs + A_SG_CONTROL);
	setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
			  A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
	setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
			  A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
	setup_ring_params(ap, sge->freelQ[0].dma_addr,
			  sge->freelQ[0].size, A_SG_FL0BASELWR,
			  A_SG_FL0BASEUPR, A_SG_FL0SIZE);
	setup_ring_params(ap, sge->freelQ[1].dma_addr,
			  sge->freelQ[1].size, A_SG_FL1BASELWR,
			  A_SG_FL1BASEUPR, A_SG_FL1SIZE);

	/* The threshold comparison uses <. */
	writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);

	setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
			  A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
	writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);

	sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
		F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
		V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
		V_RX_PKT_OFFSET(sge->rx_pkt_pad);

#if defined(__BIG_ENDIAN_BITFIELD)
	sge->sge_control |= F_ENABLE_BIG_ENDIAN;
#endif

	/* Initialize no-resource timer */
	sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);

	t1_sge_set_coalesce_params(sge, p);
}

/*
 * Return the payload capacity of the jumbo free-list buffers.
 */
static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
{
	return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
		sge->freelQ[sge->jumbo_fl].dma_offset -
		sizeof(struct cpl_rx_data);
}

/*
 * Frees all SGE related resources and the sge structure itself
 */
void t1_sge_destroy(struct sge *sge)
{
	int i;

	for_each_port(sge->adapter, i)
		free_percpu(sge->port_stats[i]);

	kfree(sge->tx_sched);
	free_tx_resources(sge);
	free_rx_resources(sge);
	kfree(sge);
}

/*
 * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
 * context Q) until the Q is full or alloc_skb fails.
 *
 * It is possible that the generation bits already match, indicating that the
 * buffer is already valid and nothing needs to be done. This happens when we
 * copied a received buffer into a new sk_buff during the interrupt processing.
 *
 * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
 * we specify a RX_OFFSET in order to make sure that the IP header is 4B
 * aligned.
 */
static void refill_free_list(struct sge *sge, struct freelQ *q)
{
	struct pci_dev *pdev = sge->adapter->pdev;
	struct freelQ_ce *ce = &q->centries[q->pidx];
	struct freelQ_e *e = &q->entries[q->pidx];
	unsigned int dma_len = q->rx_buffer_size - q->dma_offset;

	while (q->credits < q->size) {
		struct sk_buff *skb;
		dma_addr_t mapping;

		skb = dev_alloc_skb(q->rx_buffer_size);
		if (!skb)
			break;

		skb_reserve(skb, q->dma_offset);
		mapping = pci_map_single(pdev, skb->data, dma_len,
					 PCI_DMA_FROMDEVICE);
		skb_reserve(skb, sge->rx_pkt_pad);

		ce->skb = skb;
		dma_unmap_addr_set(ce, dma_addr, mapping);
		dma_unmap_len_set(ce, dma_len, dma_len);
		e->addr_lo = (u32)mapping;
		e->addr_hi = (u64)mapping >> 32;
		e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
		wmb();
		e->gen2 = V_CMD_GEN2(q->genbit);

		e++;
		ce++;
		if (++q->pidx == q->size) {
			q->pidx = 0;
			q->genbit ^= 1;
			ce = q->centries;
			e = q->entries;
		}
		q->credits++;
	}
}

/*
 * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
 * of both rings, we go into 'few interrupt mode' in order to give the system
 * time to free up resources.
 */
static void freelQs_empty(struct sge *sge)
{
	struct adapter *adapter = sge->adapter;
	u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
	u32 irqholdoff_reg;

	refill_free_list(sge, &sge->freelQ[0]);
	refill_free_list(sge, &sge->freelQ[1]);

	if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
	    sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
		irq_reg |= F_FL_EXHAUSTED;
		irqholdoff_reg = sge->fixed_intrtimer;
	} else {
		/* Clear the F_FL_EXHAUSTED interrupts for now */
		irq_reg &= ~F_FL_EXHAUSTED;
		irqholdoff_reg = sge->intrtimer_nres;
	}
	writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
	writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);

	/* We reenable the Qs to force a freelist GTS interrupt later */
	doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
}

#define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
#define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
#define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
			F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)

/*
 * Disable SGE Interrupts
 */
void t1_sge_intr_disable(struct sge *sge)
{
	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);

	writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
	writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
}

/*
 * Enable SGE interrupts.
 */
void t1_sge_intr_enable(struct sge *sge)
{
	u32 en = SGE_INT_ENABLE;
	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);

	if (sge->adapter->port[0].dev->hw_features & NETIF_F_TSO)
		en &= ~F_PACKET_TOO_BIG;
	writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
	writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
}

/*
 * Clear SGE interrupts.
 */
void t1_sge_intr_clear(struct sge *sge)
{
	writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
	writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
}

/*
 * SGE 'Error' interrupt handler
 */
int t1_sge_intr_error_handler(struct sge *sge)
{
	struct adapter *adapter = sge->adapter;
	u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);

	if (adapter->port[0].dev->hw_features & NETIF_F_TSO)
		cause &= ~F_PACKET_TOO_BIG;
	if (cause & F_RESPQ_EXHAUSTED)
		sge->stats.respQ_empty++;
	if (cause & F_RESPQ_OVERFLOW) {
		sge->stats.respQ_overflow++;
		pr_alert("%s: SGE response queue overflow\n",
			 adapter->name);
	}
	if (cause & F_FL_EXHAUSTED) {
		sge->stats.freelistQ_empty++;
		freelQs_empty(sge);
	}
	if (cause & F_PACKET_TOO_BIG) {
		sge->stats.pkt_too_big++;
		pr_alert("%s: SGE max packet size exceeded\n",
			 adapter->name);
	}
	if (cause & F_PACKET_MISMATCH) {
		sge->stats.pkt_mismatch++;
		pr_alert("%s: SGE packet mismatch\n", adapter->name);
	}
	if (cause & SGE_INT_FATAL)
		t1_fatal_err(adapter);

	writel(cause, adapter->regs + A_SG_INT_CAUSE);
	return 0;
}

const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
{
	return &sge->stats;
}

void t1_sge_get_port_stats(const struct sge *sge, int port,
			   struct sge_port_stats *ss)
{
	int cpu;

	memset(ss, 0, sizeof(*ss));
	for_each_possible_cpu(cpu) {
		struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);

		ss->rx_cso_good += st->rx_cso_good;
		ss->tx_cso += st->tx_cso;
		ss->tx_tso += st->tx_tso;
		ss->tx_need_hdrroom += st->tx_need_hdrroom;
		ss->vlan_xtract += st->vlan_xtract;
		ss->vlan_insert += st->vlan_insert;
	}
}

/**
 *	recycle_fl_buf - recycle a free list buffer
 *	@fl: the free list
 *	@idx: index of buffer to recycle
 *
 *	Recycles the specified buffer on the given free list by adding it at
 *	the next available slot on the list.
 */
static void recycle_fl_buf(struct freelQ *fl, int idx)
{
	struct freelQ_e *from = &fl->entries[idx];
	struct freelQ_e *to = &fl->entries[fl->pidx];

	fl->centries[fl->pidx] = fl->centries[idx];
	to->addr_lo = from->addr_lo;
	to->addr_hi = from->addr_hi;
	to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
	wmb();
	to->gen2 = V_CMD_GEN2(fl->genbit);
	fl->credits++;

	if (++fl->pidx == fl->size) {
		fl->pidx = 0;
		fl->genbit ^= 1;
	}
}

static int copybreak __read_mostly = 256;
module_param(copybreak, int, 0);
MODULE_PARM_DESC(copybreak, "Receive copy threshold");

/**
 *	get_packet - return the next ingress packet buffer
 *	@adapter: the adapter that received the packet
 *	@fl: the SGE free list holding the packet
 *	@len: the actual packet length, excluding any SGE padding
 *
 *	Get the next packet from a free list and complete setup of the
 *	sk_buff.  If the packet is small we make a copy and recycle the
 *	original buffer, otherwise we use the original buffer itself.  If a
 *	positive drop threshold is supplied packets are dropped and their
 *	buffers recycled if (a) the number of remaining buffers is under the
 *	threshold and the packet is too big to copy, or (b) the packet should
 *	be copied but there is no memory for the copy.
 */
static inline struct sk_buff *get_packet(struct adapter *adapter,
					 struct freelQ *fl, unsigned int len)
{
	const struct freelQ_ce *ce = &fl->centries[fl->cidx];
	struct pci_dev *pdev = adapter->pdev;
	struct sk_buff *skb;

	if (len < copybreak) {
		skb = napi_alloc_skb(&adapter->napi, len);
		if (!skb)
			goto use_orig_buf;

		skb_put(skb, len);
		pci_dma_sync_single_for_cpu(pdev,
					    dma_unmap_addr(ce, dma_addr),
					    dma_unmap_len(ce, dma_len),
					    PCI_DMA_FROMDEVICE);
		skb_copy_from_linear_data(ce->skb, skb->data, len);
		pci_dma_sync_single_for_device(pdev,
					       dma_unmap_addr(ce, dma_addr),
					       dma_unmap_len(ce, dma_len),
					       PCI_DMA_FROMDEVICE);
		recycle_fl_buf(fl, fl->cidx);
		return skb;
	}

use_orig_buf:
	if (fl->credits < 2) {
		recycle_fl_buf(fl, fl->cidx);
		return NULL;
	}

	pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
			 dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
	skb = ce->skb;
	prefetch(skb->data);

	skb_put(skb, len);
	return skb;
}

/**
 *	unexpected_offload - handle an unexpected offload packet
 *	@adapter: the adapter
 *	@fl: the free list that received the packet
 *
 *	Called when we receive an unexpected offload packet (e.g., the TOE
 *	function is disabled or the card is a NIC).  Prints a message and
 *	recycles the buffer.
 */
static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
{
	struct freelQ_ce *ce = &fl->centries[fl->cidx];
	struct sk_buff *skb = ce->skb;

	pci_dma_sync_single_for_cpu(adapter->pdev, dma_unmap_addr(ce, dma_addr),
			    dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
	pr_err("%s: unexpected offload packet, cmd %u\n",
	       adapter->name, *skb->data);
	recycle_fl_buf(fl, fl->cidx);
}

/*
 * T1/T2 SGE limits the maximum DMA size per TX descriptor to
 * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
 * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
 * Note that the *_large_page_tx_descs stuff will be optimized out when
 * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
 *
 * compute_large_page_descs() computes how many additional descriptors are
 * required to break down the stack's request.
 */
static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
{
	unsigned int count = 0;

	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
		unsigned int nfrags = skb_shinfo(skb)->nr_frags;
		unsigned int i, len = skb_headlen(skb);
		while (len > SGE_TX_DESC_MAX_PLEN) {
			count++;
			len -= SGE_TX_DESC_MAX_PLEN;
		}
		for (i = 0; nfrags--; i++) {
			const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
			len = skb_frag_size(frag);
			while (len > SGE_TX_DESC_MAX_PLEN) {
				count++;
				len -= SGE_TX_DESC_MAX_PLEN;
			}
		}
	}
	return count;
}

/*
 * Write a cmdQ entry.
 *
 * Since this function writes the 'flags' field, it must not be used to
 * write the first cmdQ entry.
 */
static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
				 unsigned int len, unsigned int gen,
				 unsigned int eop)
{
	BUG_ON(len > SGE_TX_DESC_MAX_PLEN);

	e->addr_lo = (u32)mapping;
	e->addr_hi = (u64)mapping >> 32;
	e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
	e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
}

/*
 * See comment for previous function.
 *
 * write_tx_descs_large_page() writes additional SGE tx descriptors if
 * *desc_len exceeds HW's capability.
 */
static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
						     struct cmdQ_e **e,
						     struct cmdQ_ce **ce,
						     unsigned int *gen,
						     dma_addr_t *desc_mapping,
						     unsigned int *desc_len,
						     unsigned int nfrags,
						     struct cmdQ *q)
{
	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
		struct cmdQ_e *e1 = *e;
		struct cmdQ_ce *ce1 = *ce;

		while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
			*desc_len -= SGE_TX_DESC_MAX_PLEN;
			write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
				      *gen, nfrags == 0 && *desc_len == 0);
			ce1->skb = NULL;
			dma_unmap_len_set(ce1, dma_len, 0);
			*desc_mapping += SGE_TX_DESC_MAX_PLEN;
			if (*desc_len) {
				ce1++;
				e1++;
				if (++pidx == q->size) {
					pidx = 0;
					*gen ^= 1;
					ce1 = q->centries;
					e1 = q->entries;
				}
			}
		}
		*e = e1;
		*ce = ce1;
	}
	return pidx;
}

/*
 * Write the command descriptors to transmit the given skb starting at
 * descriptor pidx with the given generation.
 */
static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
				  unsigned int pidx, unsigned int gen,
				  struct cmdQ *q)
{
	dma_addr_t mapping, desc_mapping;
	struct cmdQ_e *e, *e1;
	struct cmdQ_ce *ce;
	unsigned int i, flags, first_desc_len, desc_len,
	    nfrags = skb_shinfo(skb)->nr_frags;

	e = e1 = &q->entries[pidx];
	ce = &q->centries[pidx];

	mapping = pci_map_single(adapter->pdev, skb->data,
				 skb_headlen(skb), PCI_DMA_TODEVICE);

	desc_mapping = mapping;
	desc_len = skb_headlen(skb);

	flags = F_CMD_DATAVALID | F_CMD_SOP |
	    V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
	    V_CMD_GEN2(gen);
	first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
	    desc_len : SGE_TX_DESC_MAX_PLEN;
	e->addr_lo = (u32)desc_mapping;
	e->addr_hi = (u64)desc_mapping >> 32;
	e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
	ce->skb = NULL;
	dma_unmap_len_set(ce, dma_len, 0);

	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
	    desc_len > SGE_TX_DESC_MAX_PLEN) {
		desc_mapping += first_desc_len;
		desc_len -= first_desc_len;
		e1++;
		ce++;
		if (++pidx == q->size) {
			pidx = 0;
			gen ^= 1;
			e1 = q->entries;
			ce = q->centries;
		}
		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
						 &desc_mapping, &desc_len,
						 nfrags, q);

		if (likely(desc_len))
			write_tx_desc(e1, desc_mapping, desc_len, gen,
				      nfrags == 0);
	}

	ce->skb = NULL;
	dma_unmap_addr_set(ce, dma_addr, mapping);
	dma_unmap_len_set(ce, dma_len, skb_headlen(skb));

	for (i = 0; nfrags--; i++) {
		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
		e1++;
		ce++;
		if (++pidx == q->size) {
			pidx = 0;
			gen ^= 1;
			e1 = q->entries;
			ce = q->centries;
		}

		mapping = skb_frag_dma_map(&adapter->pdev->dev, frag, 0,
					   skb_frag_size(frag), DMA_TO_DEVICE);
		desc_mapping = mapping;
		desc_len = skb_frag_size(frag);

		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
						 &desc_mapping, &desc_len,
						 nfrags, q);
		if (likely(desc_len))
			write_tx_desc(e1, desc_mapping, desc_len, gen,
				      nfrags == 0);
		ce->skb = NULL;
		dma_unmap_addr_set(ce, dma_addr, mapping);
		dma_unmap_len_set(ce, dma_len, skb_frag_size(frag));
	}
	ce->skb = skb;
	wmb();
	e->flags = flags;
}

/*
 * Clean up completed Tx buffers.
 */
static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
{
	unsigned int reclaim = q->processed - q->cleaned;

	if (reclaim) {
		pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
			 q->processed, q->cleaned);
		free_cmdQ_buffers(sge, q, reclaim);
		q->cleaned += reclaim;
	}
}

/*
 * Called from tasklet. Checks the scheduler for any
 * pending skbs that can be sent.
 */
static void restart_sched(unsigned long arg)
{
	struct sge *sge = (struct sge *) arg;
	struct adapter *adapter = sge->adapter;
	struct cmdQ *q = &sge->cmdQ[0];
	struct sk_buff *skb;
	unsigned int credits, queued_skb = 0;

	spin_lock(&q->lock);
	reclaim_completed_tx(sge, q);

	credits = q->size - q->in_use;
	pr_debug("restart_sched credits=%d\n", credits);
	while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
		unsigned int genbit, pidx, count;
	        count = 1 + skb_shinfo(skb)->nr_frags;
		count += compute_large_page_tx_descs(skb);
		q->in_use += count;
		genbit = q->genbit;
		pidx = q->pidx;
		q->pidx += count;
		if (q->pidx >= q->size) {
			q->pidx -= q->size;
			q->genbit ^= 1;
		}
		write_tx_descs(adapter, skb, pidx, genbit, q);
	        credits = q->size - q->in_use;
		queued_skb = 1;
	}

	if (queued_skb) {
		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
		}
	}
	spin_unlock(&q->lock);
}

/**
 *	sge_rx - process an ingress ethernet packet
 *	@sge: the sge structure
 *	@fl: the free list that contains the packet buffer
 *	@len: the packet length
 *
 *	Process an ingress ethernet pakcet and deliver it to the stack.
 */
static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
{
	struct sk_buff *skb;
	const struct cpl_rx_pkt *p;
	struct adapter *adapter = sge->adapter;
	struct sge_port_stats *st;
	struct net_device *dev;

	skb = get_packet(adapter, fl, len - sge->rx_pkt_pad);
	if (unlikely(!skb)) {
		sge->stats.rx_drops++;
		return;
	}

	p = (const struct cpl_rx_pkt *) skb->data;
	if (p->iff >= adapter->params.nports) {
		kfree_skb(skb);
		return;
	}
	__skb_pull(skb, sizeof(*p));

	st = this_cpu_ptr(sge->port_stats[p->iff]);
	dev = adapter->port[p->iff].dev;

	skb->protocol = eth_type_trans(skb, dev);
	if ((dev->features & NETIF_F_RXCSUM) && p->csum == 0xffff &&
	    skb->protocol == htons(ETH_P_IP) &&
	    (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
		++st->rx_cso_good;
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	} else
		skb_checksum_none_assert(skb);

	if (p->vlan_valid) {
		st->vlan_xtract++;
		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(p->vlan));
	}
	netif_receive_skb(skb);
}

/*
 * Returns true if a command queue has enough available descriptors that
 * we can resume Tx operation after temporarily disabling its packet queue.
 */
static inline int enough_free_Tx_descs(const struct cmdQ *q)
{
	unsigned int r = q->processed - q->cleaned;

	return q->in_use - r < (q->size >> 1);
}

/*
 * Called when sufficient space has become available in the SGE command queues
 * after the Tx packet schedulers have been suspended to restart the Tx path.
 */
static void restart_tx_queues(struct sge *sge)
{
	struct adapter *adap = sge->adapter;
	int i;

	if (!enough_free_Tx_descs(&sge->cmdQ[0]))
		return;

	for_each_port(adap, i) {
		struct net_device *nd = adap->port[i].dev;

		if (test_and_clear_bit(nd->if_port, &sge->stopped_tx_queues) &&
		    netif_running(nd)) {
			sge->stats.cmdQ_restarted[2]++;
			netif_wake_queue(nd);
		}
	}
}

/*
 * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
 * information.
 */
static unsigned int update_tx_info(struct adapter *adapter,
					  unsigned int flags,
					  unsigned int pr0)
{
	struct sge *sge = adapter->sge;
	struct cmdQ *cmdq = &sge->cmdQ[0];

	cmdq->processed += pr0;
	if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
		freelQs_empty(sge);
		flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
	}
	if (flags & F_CMDQ0_ENABLE) {
		clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);

		if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
		    !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
			set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
		}
		if (sge->tx_sched)
			tasklet_hi_schedule(&sge->tx_sched->sched_tsk);

		flags &= ~F_CMDQ0_ENABLE;
	}

	if (unlikely(sge->stopped_tx_queues != 0))
		restart_tx_queues(sge);

	return flags;
}

/*
 * Process SGE responses, up to the supplied budget.  Returns the number of
 * responses processed.  A negative budget is effectively unlimited.
 */
static int process_responses(struct adapter *adapter, int budget)
{
	struct sge *sge = adapter->sge;
	struct respQ *q = &sge->respQ;
	struct respQ_e *e = &q->entries[q->cidx];
	int done = 0;
	unsigned int flags = 0;
	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};

	while (done < budget && e->GenerationBit == q->genbit) {
		flags |= e->Qsleeping;

		cmdq_processed[0] += e->Cmdq0CreditReturn;
		cmdq_processed[1] += e->Cmdq1CreditReturn;

		/* We batch updates to the TX side to avoid cacheline
		 * ping-pong of TX state information on MP where the sender
		 * might run on a different CPU than this function...
		 */
		if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {
			flags = update_tx_info(adapter, flags, cmdq_processed[0]);
			cmdq_processed[0] = 0;
		}

		if (unlikely(cmdq_processed[1] > 16)) {
			sge->cmdQ[1].processed += cmdq_processed[1];
			cmdq_processed[1] = 0;
		}

		if (likely(e->DataValid)) {
			struct freelQ *fl = &sge->freelQ[e->FreelistQid];

			BUG_ON(!e->Sop || !e->Eop);
			if (unlikely(e->Offload))
				unexpected_offload(adapter, fl);
			else
				sge_rx(sge, fl, e->BufferLength);

			++done;

			/*
			 * Note: this depends on each packet consuming a
			 * single free-list buffer; cf. the BUG above.
			 */
			if (++fl->cidx == fl->size)
				fl->cidx = 0;
			prefetch(fl->centries[fl->cidx].skb);

			if (unlikely(--fl->credits <
				     fl->size - SGE_FREEL_REFILL_THRESH))
				refill_free_list(sge, fl);
		} else
			sge->stats.pure_rsps++;

		e++;
		if (unlikely(++q->cidx == q->size)) {
			q->cidx = 0;
			q->genbit ^= 1;
			e = q->entries;
		}
		prefetch(e);

		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
			q->credits = 0;
		}
	}

	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
	sge->cmdQ[1].processed += cmdq_processed[1];

	return done;
}

static inline int responses_pending(const struct adapter *adapter)
{
	const struct respQ *Q = &adapter->sge->respQ;
	const struct respQ_e *e = &Q->entries[Q->cidx];

	return e->GenerationBit == Q->genbit;
}

/*
 * A simpler version of process_responses() that handles only pure (i.e.,
 * non data-carrying) responses.  Such respones are too light-weight to justify
 * calling a softirq when using NAPI, so we handle them specially in hard
 * interrupt context.  The function is called with a pointer to a response,
 * which the caller must ensure is a valid pure response.  Returns 1 if it
 * encounters a valid data-carrying response, 0 otherwise.
 */
static int process_pure_responses(struct adapter *adapter)
{
	struct sge *sge = adapter->sge;
	struct respQ *q = &sge->respQ;
	struct respQ_e *e = &q->entries[q->cidx];
	const struct freelQ *fl = &sge->freelQ[e->FreelistQid];
	unsigned int flags = 0;
	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};

	prefetch(fl->centries[fl->cidx].skb);
	if (e->DataValid)
		return 1;

	do {
		flags |= e->Qsleeping;

		cmdq_processed[0] += e->Cmdq0CreditReturn;
		cmdq_processed[1] += e->Cmdq1CreditReturn;

		e++;
		if (unlikely(++q->cidx == q->size)) {
			q->cidx = 0;
			q->genbit ^= 1;
			e = q->entries;
		}
		prefetch(e);

		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
			q->credits = 0;
		}
		sge->stats.pure_rsps++;
	} while (e->GenerationBit == q->genbit && !e->DataValid);

	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
	sge->cmdQ[1].processed += cmdq_processed[1];

	return e->GenerationBit == q->genbit;
}

/*
 * Handler for new data events when using NAPI.  This does not need any locking
 * or protection from interrupts as data interrupts are off at this point and
 * other adapter interrupts do not interfere.
 */
int t1_poll(struct napi_struct *napi, int budget)
{
	struct adapter *adapter = container_of(napi, struct adapter, napi);
	int work_done = process_responses(adapter, budget);

	if (likely(work_done < budget)) {
		napi_complete(napi);
		writel(adapter->sge->respQ.cidx,
		       adapter->regs + A_SG_SLEEPING);
	}
	return work_done;
}

irqreturn_t t1_interrupt(int irq, void *data)
{
	struct adapter *adapter = data;
	struct sge *sge = adapter->sge;
	int handled;

	if (likely(responses_pending(adapter))) {
		writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);

		if (napi_schedule_prep(&adapter->napi)) {
			if (process_pure_responses(adapter))
				__napi_schedule(&adapter->napi);
			else {
				/* no data, no NAPI needed */
				writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
				/* undo schedule_prep */
				napi_enable(&adapter->napi);
			}
		}
		return IRQ_HANDLED;
	}

	spin_lock(&adapter->async_lock);
	handled = t1_slow_intr_handler(adapter);
	spin_unlock(&adapter->async_lock);

	if (!handled)
		sge->stats.unhandled_irqs++;

	return IRQ_RETVAL(handled != 0);
}

/*
 * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
 *
 * The code figures out how many entries the sk_buff will require in the
 * cmdQ and updates the cmdQ data structure with the state once the enqueue
 * has complete. Then, it doesn't access the global structure anymore, but
 * uses the corresponding fields on the stack. In conjunction with a spinlock
 * around that code, we can make the function reentrant without holding the
 * lock when we actually enqueue (which might be expensive, especially on
 * architectures with IO MMUs).
 *
 * This runs with softirqs disabled.
 */
static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
		     unsigned int qid, struct net_device *dev)
{
	struct sge *sge = adapter->sge;
	struct cmdQ *q = &sge->cmdQ[qid];
	unsigned int credits, pidx, genbit, count, use_sched_skb = 0;

	spin_lock(&q->lock);

	reclaim_completed_tx(sge, q);

	pidx = q->pidx;
	credits = q->size - q->in_use;
	count = 1 + skb_shinfo(skb)->nr_frags;
	count += compute_large_page_tx_descs(skb);

	/* Ethernet packet */
	if (unlikely(credits < count)) {
		if (!netif_queue_stopped(dev)) {
			netif_stop_queue(dev);
			set_bit(dev->if_port, &sge->stopped_tx_queues);
			sge->stats.cmdQ_full[2]++;
			pr_err("%s: Tx ring full while queue awake!\n",
			       adapter->name);
		}
		spin_unlock(&q->lock);
		return NETDEV_TX_BUSY;
	}

	if (unlikely(credits - count < q->stop_thres)) {
		netif_stop_queue(dev);
		set_bit(dev->if_port, &sge->stopped_tx_queues);
		sge->stats.cmdQ_full[2]++;
	}

	/* T204 cmdQ0 skbs that are destined for a certain port have to go
	 * through the scheduler.
	 */
	if (sge->tx_sched && !qid && skb->dev) {
use_sched:
		use_sched_skb = 1;
		/* Note that the scheduler might return a different skb than
		 * the one passed in.
		 */
		skb = sched_skb(sge, skb, credits);
		if (!skb) {
			spin_unlock(&q->lock);
			return NETDEV_TX_OK;
		}
		pidx = q->pidx;
		count = 1 + skb_shinfo(skb)->nr_frags;
		count += compute_large_page_tx_descs(skb);
	}

	q->in_use += count;
	genbit = q->genbit;
	pidx = q->pidx;
	q->pidx += count;
	if (q->pidx >= q->size) {
		q->pidx -= q->size;
		q->genbit ^= 1;
	}
	spin_unlock(&q->lock);

	write_tx_descs(adapter, skb, pidx, genbit, q);

	/*
	 * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
	 * the doorbell if the Q is asleep. There is a natural race, where
	 * the hardware is going to sleep just after we checked, however,
	 * then the interrupt handler will detect the outstanding TX packet
	 * and ring the doorbell for us.
	 */
	if (qid)
		doorbell_pio(adapter, F_CMDQ1_ENABLE);
	else {
		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
		}
	}

	if (use_sched_skb) {
		if (spin_trylock(&q->lock)) {
			credits = q->size - q->in_use;
			skb = NULL;
			goto use_sched;
		}
	}
	return NETDEV_TX_OK;
}

#define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))

/*
 *	eth_hdr_len - return the length of an Ethernet header
 *	@data: pointer to the start of the Ethernet header
 *
 *	Returns the length of an Ethernet header, including optional VLAN tag.
 */
static inline int eth_hdr_len(const void *data)
{
	const struct ethhdr *e = data;

	return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
}

/*
 * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
 */
netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct adapter *adapter = dev->ml_priv;
	struct sge *sge = adapter->sge;
	struct sge_port_stats *st = this_cpu_ptr(sge->port_stats[dev->if_port]);
	struct cpl_tx_pkt *cpl;
	struct sk_buff *orig_skb = skb;
	int ret;

	if (skb->protocol == htons(ETH_P_CPL5))
		goto send;

	/*
	 * We are using a non-standard hard_header_len.
	 * Allocate more header room in the rare cases it is not big enough.
	 */
	if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
		skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
		++st->tx_need_hdrroom;
		dev_kfree_skb_any(orig_skb);
		if (!skb)
			return NETDEV_TX_OK;
	}

	if (skb_shinfo(skb)->gso_size) {
		int eth_type;
		struct cpl_tx_pkt_lso *hdr;

		++st->tx_tso;

		eth_type = skb_network_offset(skb) == ETH_HLEN ?
			CPL_ETH_II : CPL_ETH_II_VLAN;

		hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
		hdr->opcode = CPL_TX_PKT_LSO;
		hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
		hdr->ip_hdr_words = ip_hdr(skb)->ihl;
		hdr->tcp_hdr_words = tcp_hdr(skb)->doff;
		hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
							  skb_shinfo(skb)->gso_size));
		hdr->len = htonl(skb->len - sizeof(*hdr));
		cpl = (struct cpl_tx_pkt *)hdr;
	} else {
		/*
		 * Packets shorter than ETH_HLEN can break the MAC, drop them
		 * early.  Also, we may get oversized packets because some
		 * parts of the kernel don't handle our unusual hard_header_len
		 * right, drop those too.
		 */
		if (unlikely(skb->len < ETH_HLEN ||
			     skb->len > dev->mtu + eth_hdr_len(skb->data))) {
			netdev_dbg(dev, "packet size %d hdr %d mtu%d\n",
				   skb->len, eth_hdr_len(skb->data), dev->mtu);
			dev_kfree_skb_any(skb);
			return NETDEV_TX_OK;
		}

		if (skb->ip_summed == CHECKSUM_PARTIAL &&
		    ip_hdr(skb)->protocol == IPPROTO_UDP) {
			if (unlikely(skb_checksum_help(skb))) {
				netdev_dbg(dev, "unable to do udp checksum\n");
				dev_kfree_skb_any(skb);
				return NETDEV_TX_OK;
			}
		}

		/* Hmmm, assuming to catch the gratious arp... and we'll use
		 * it to flush out stuck espi packets...
		 */
		if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
			if (skb->protocol == htons(ETH_P_ARP) &&
			    arp_hdr(skb)->ar_op == htons(ARPOP_REQUEST)) {
				adapter->sge->espibug_skb[dev->if_port] = skb;
				/* We want to re-use this skb later. We
				 * simply bump the reference count and it
				 * will not be freed...
				 */
				skb = skb_get(skb);
			}
		}

		cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
		cpl->opcode = CPL_TX_PKT;
		cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
		cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
		/* the length field isn't used so don't bother setting it */

		st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
	}
	cpl->iff = dev->if_port;

	if (skb_vlan_tag_present(skb)) {
		cpl->vlan_valid = 1;
		cpl->vlan = htons(skb_vlan_tag_get(skb));
		st->vlan_insert++;
	} else
		cpl->vlan_valid = 0;

send:
	ret = t1_sge_tx(skb, adapter, 0, dev);

	/* If transmit busy, and we reallocated skb's due to headroom limit,
	 * then silently discard to avoid leak.
	 */
	if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
		dev_kfree_skb_any(skb);
		ret = NETDEV_TX_OK;
	}
	return ret;
}

/*
 * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
 */
static void sge_tx_reclaim_cb(unsigned long data)
{
	int i;
	struct sge *sge = (struct sge *)data;

	for (i = 0; i < SGE_CMDQ_N; ++i) {
		struct cmdQ *q = &sge->cmdQ[i];

		if (!spin_trylock(&q->lock))
			continue;

		reclaim_completed_tx(sge, q);
		if (i == 0 && q->in_use) {    /* flush pending credits */
			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
		}
		spin_unlock(&q->lock);
	}
	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
}

/*
 * Propagate changes of the SGE coalescing parameters to the HW.
 */
int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
{
	sge->fixed_intrtimer = p->rx_coalesce_usecs *
		core_ticks_per_usec(sge->adapter);
	writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
	return 0;
}

/*
 * Allocates both RX and TX resources and configures the SGE. However,
 * the hardware is not enabled yet.
 */
int t1_sge_configure(struct sge *sge, struct sge_params *p)
{
	if (alloc_rx_resources(sge, p))
		return -ENOMEM;
	if (alloc_tx_resources(sge, p)) {
		free_rx_resources(sge);
		return -ENOMEM;
	}
	configure_sge(sge, p);

	/*
	 * Now that we have sized the free lists calculate the payload
	 * capacity of the large buffers.  Other parts of the driver use
	 * this to set the max offload coalescing size so that RX packets
	 * do not overflow our large buffers.
	 */
	p->large_buf_capacity = jumbo_payload_capacity(sge);
	return 0;
}

/*
 * Disables the DMA engine.
 */
void t1_sge_stop(struct sge *sge)
{
	int i;
	writel(0, sge->adapter->regs + A_SG_CONTROL);
	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */

	if (is_T2(sge->adapter))
		del_timer_sync(&sge->espibug_timer);

	del_timer_sync(&sge->tx_reclaim_timer);
	if (sge->tx_sched)
		tx_sched_stop(sge);

	for (i = 0; i < MAX_NPORTS; i++)
		kfree_skb(sge->espibug_skb[i]);
}

/*
 * Enables the DMA engine.
 */
void t1_sge_start(struct sge *sge)
{
	refill_free_list(sge, &sge->freelQ[0]);
	refill_free_list(sge, &sge->freelQ[1]);

	writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
	doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */

	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);

	if (is_T2(sge->adapter))
		mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
}

/*
 * Callback for the T2 ESPI 'stuck packet feature' workaorund
 */
static void espibug_workaround_t204(unsigned long data)
{
	struct adapter *adapter = (struct adapter *)data;
	struct sge *sge = adapter->sge;
	unsigned int nports = adapter->params.nports;
	u32 seop[MAX_NPORTS];

	if (adapter->open_device_map & PORT_MASK) {
		int i;

		if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
			return;

		for (i = 0; i < nports; i++) {
			struct sk_buff *skb = sge->espibug_skb[i];

			if (!netif_running(adapter->port[i].dev) ||
			    netif_queue_stopped(adapter->port[i].dev) ||
			    !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
				continue;

			if (!skb->cb[0]) {
				skb_copy_to_linear_data_offset(skb,
						    sizeof(struct cpl_tx_pkt),
							       ch_mac_addr,
							       ETH_ALEN);
				skb_copy_to_linear_data_offset(skb,
							       skb->len - 10,
							       ch_mac_addr,
							       ETH_ALEN);
				skb->cb[0] = 0xff;
			}

			/* bump the reference count to avoid freeing of
			 * the skb once the DMA has completed.
			 */
			skb = skb_get(skb);
			t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
		}
	}
	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
}

static void espibug_workaround(unsigned long data)
{
	struct adapter *adapter = (struct adapter *)data;
	struct sge *sge = adapter->sge;

	if (netif_running(adapter->port[0].dev)) {
	        struct sk_buff *skb = sge->espibug_skb[0];
	        u32 seop = t1_espi_get_mon(adapter, 0x930, 0);

	        if ((seop & 0xfff0fff) == 0xfff && skb) {
	                if (!skb->cb[0]) {
	                        skb_copy_to_linear_data_offset(skb,
						     sizeof(struct cpl_tx_pkt),
							       ch_mac_addr,
							       ETH_ALEN);
	                        skb_copy_to_linear_data_offset(skb,
							       skb->len - 10,
							       ch_mac_addr,
							       ETH_ALEN);
	                        skb->cb[0] = 0xff;
	                }

	                /* bump the reference count to avoid freeing of the
	                 * skb once the DMA has completed.
	                 */
	                skb = skb_get(skb);
	                t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
	        }
	}
	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
}

/*
 * Creates a t1_sge structure and returns suggested resource parameters.
 */
struct sge *t1_sge_create(struct adapter *adapter, struct sge_params *p)
{
	struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
	int i;

	if (!sge)
		return NULL;

	sge->adapter = adapter;
	sge->netdev = adapter->port[0].dev;
	sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
	sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;

	for_each_port(adapter, i) {
		sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
		if (!sge->port_stats[i])
			goto nomem_port;
	}

	init_timer(&sge->tx_reclaim_timer);
	sge->tx_reclaim_timer.data = (unsigned long)sge;
	sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;

	if (is_T2(sge->adapter)) {
		init_timer(&sge->espibug_timer);

		if (adapter->params.nports > 1) {
			tx_sched_init(sge);
			sge->espibug_timer.function = espibug_workaround_t204;
		} else
			sge->espibug_timer.function = espibug_workaround;
		sge->espibug_timer.data = (unsigned long)sge->adapter;

		sge->espibug_timeout = 1;
		/* for T204, every 10ms */
		if (adapter->params.nports > 1)
			sge->espibug_timeout = HZ/100;
	}


	p->cmdQ_size[0] = SGE_CMDQ0_E_N;
	p->cmdQ_size[1] = SGE_CMDQ1_E_N;
	p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
	p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
	if (sge->tx_sched) {
		if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
			p->rx_coalesce_usecs = 15;
		else
			p->rx_coalesce_usecs = 50;
	} else
		p->rx_coalesce_usecs = 50;

	p->coalesce_enable = 0;
	p->sample_interval_usecs = 0;

	return sge;
nomem_port:
	while (i >= 0) {
		free_percpu(sge->port_stats[i]);
		--i;
	}
	kfree(sge);
	return NULL;

}