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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 - Cambridge Greys Limited
 * Copyright (C) 2011 - 2014 Cisco Systems Inc
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
 * James Leu (jleu@mindspring.net).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 */

#include <linux/version.h>
#include <linux/memblock.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/platform_device.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <init.h>
#include <irq_kern.h>
#include <irq_user.h>
#include <net_kern.h>
#include <os.h>
#include "mconsole_kern.h"
#include "vector_user.h"
#include "vector_kern.h"

/*
 * Adapted from network devices with the following major changes:
 * All transports are static - simplifies the code significantly
 * Multiple FDs/IRQs per device
 * Vector IO optionally used for read/write, falling back to legacy
 * based on configuration and/or availability
 * Configuration is no longer positional - L2TPv3 and GRE require up to
 * 10 parameters, passing this as positional is not fit for purpose.
 * Only socket transports are supported
 */


#define DRIVER_NAME "uml-vector"
#define DRIVER_VERSION "01"
struct vector_cmd_line_arg {
	struct list_head list;
	int unit;
	char *arguments;
};

struct vector_device {
	struct list_head list;
	struct net_device *dev;
	struct platform_device pdev;
	int unit;
	int opened;
};

static LIST_HEAD(vec_cmd_line);

static DEFINE_SPINLOCK(vector_devices_lock);
static LIST_HEAD(vector_devices);

static int driver_registered;

static void vector_eth_configure(int n, struct arglist *def);

/* Argument accessors to set variables (and/or set default values)
 * mtu, buffer sizing, default headroom, etc
 */

#define DEFAULT_HEADROOM 2
#define SAFETY_MARGIN 32
#define DEFAULT_VECTOR_SIZE 64
#define TX_SMALL_PACKET 128
#define MAX_IOV_SIZE (MAX_SKB_FRAGS + 1)
#define MAX_ITERATIONS 64

static const struct {
	const char string[ETH_GSTRING_LEN];
} ethtool_stats_keys[] = {
	{ "rx_queue_max" },
	{ "rx_queue_running_average" },
	{ "tx_queue_max" },
	{ "tx_queue_running_average" },
	{ "rx_encaps_errors" },
	{ "tx_timeout_count" },
	{ "tx_restart_queue" },
	{ "tx_kicks" },
	{ "tx_flow_control_xon" },
	{ "tx_flow_control_xoff" },
	{ "rx_csum_offload_good" },
	{ "rx_csum_offload_errors"},
	{ "sg_ok"},
	{ "sg_linearized"},
};

#define VECTOR_NUM_STATS	ARRAY_SIZE(ethtool_stats_keys)

static void vector_reset_stats(struct vector_private *vp)
{
	vp->estats.rx_queue_max = 0;
	vp->estats.rx_queue_running_average = 0;
	vp->estats.tx_queue_max = 0;
	vp->estats.tx_queue_running_average = 0;
	vp->estats.rx_encaps_errors = 0;
	vp->estats.tx_timeout_count = 0;
	vp->estats.tx_restart_queue = 0;
	vp->estats.tx_kicks = 0;
	vp->estats.tx_flow_control_xon = 0;
	vp->estats.tx_flow_control_xoff = 0;
	vp->estats.sg_ok = 0;
	vp->estats.sg_linearized = 0;
}

static int get_mtu(struct arglist *def)
{
	char *mtu = uml_vector_fetch_arg(def, "mtu");
	long result;

	if (mtu != NULL) {
		if (kstrtoul(mtu, 10, &result) == 0)
			if ((result < (1 << 16) - 1) && (result >= 576))
				return result;
	}
	return ETH_MAX_PACKET;
}

static int get_depth(struct arglist *def)
{
	char *mtu = uml_vector_fetch_arg(def, "depth");
	long result;

	if (mtu != NULL) {
		if (kstrtoul(mtu, 10, &result) == 0)
			return result;
	}
	return DEFAULT_VECTOR_SIZE;
}

static int get_headroom(struct arglist *def)
{
	char *mtu = uml_vector_fetch_arg(def, "headroom");
	long result;

	if (mtu != NULL) {
		if (kstrtoul(mtu, 10, &result) == 0)
			return result;
	}
	return DEFAULT_HEADROOM;
}

static int get_req_size(struct arglist *def)
{
	char *gro = uml_vector_fetch_arg(def, "gro");
	long result;

	if (gro != NULL) {
		if (kstrtoul(gro, 10, &result) == 0) {
			if (result > 0)
				return 65536;
		}
	}
	return get_mtu(def) + ETH_HEADER_OTHER +
		get_headroom(def) + SAFETY_MARGIN;
}


static int get_transport_options(struct arglist *def)
{
	char *transport = uml_vector_fetch_arg(def, "transport");
	char *vector = uml_vector_fetch_arg(def, "vec");

	int vec_rx = VECTOR_RX;
	int vec_tx = VECTOR_TX;
	long parsed;

	if (vector != NULL) {
		if (kstrtoul(vector, 10, &parsed) == 0) {
			if (parsed == 0) {
				vec_rx = 0;
				vec_tx = 0;
			}
		}
	}


	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
		return 0;
	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
		return (vec_rx | VECTOR_BPF);
	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
		return (vec_rx | vec_tx | VECTOR_QDISC_BYPASS);
	return (vec_rx | vec_tx);
}


/* A mini-buffer for packet drop read
 * All of our supported transports are datagram oriented and we always
 * read using recvmsg or recvmmsg. If we pass a buffer which is smaller
 * than the packet size it still counts as full packet read and will
 * clean the incoming stream to keep sigio/epoll happy
 */

#define DROP_BUFFER_SIZE 32

static char *drop_buffer;

/* Array backed queues optimized for bulk enqueue/dequeue and
 * 1:N (small values of N) or 1:1 enqueuer/dequeuer ratios.
 * For more details and full design rationale see
 * http://foswiki.cambridgegreys.com/Main/EatYourTailAndEnjoyIt
 */


/*
 * Advance the mmsg queue head by n = advance. Resets the queue to
 * maximum enqueue/dequeue-at-once capacity if possible. Called by
 * dequeuers. Caller must hold the head_lock!
 */

static int vector_advancehead(struct vector_queue *qi, int advance)
{
	int queue_depth;

	qi->head =
		(qi->head + advance)
			% qi->max_depth;


	spin_lock(&qi->tail_lock);
	qi->queue_depth -= advance;

	/* we are at 0, use this to
	 * reset head and tail so we can use max size vectors
	 */

	if (qi->queue_depth == 0) {
		qi->head = 0;
		qi->tail = 0;
	}
	queue_depth = qi->queue_depth;
	spin_unlock(&qi->tail_lock);
	return queue_depth;
}

/*	Advance the queue tail by n = advance.
 *	This is called by enqueuers which should hold the
 *	head lock already
 */

static int vector_advancetail(struct vector_queue *qi, int advance)
{
	int queue_depth;

	qi->tail =
		(qi->tail + advance)
			% qi->max_depth;
	spin_lock(&qi->head_lock);
	qi->queue_depth += advance;
	queue_depth = qi->queue_depth;
	spin_unlock(&qi->head_lock);
	return queue_depth;
}

static int prep_msg(struct vector_private *vp,
	struct sk_buff *skb,
	struct iovec *iov)
{
	int iov_index = 0;
	int nr_frags, frag;
	skb_frag_t *skb_frag;

	nr_frags = skb_shinfo(skb)->nr_frags;
	if (nr_frags > MAX_IOV_SIZE) {
		if (skb_linearize(skb) != 0)
			goto drop;
	}
	if (vp->header_size > 0) {
		iov[iov_index].iov_len = vp->header_size;
		vp->form_header(iov[iov_index].iov_base, skb, vp);
		iov_index++;
	}
	iov[iov_index].iov_base = skb->data;
	if (nr_frags > 0) {
		iov[iov_index].iov_len = skb->len - skb->data_len;
		vp->estats.sg_ok++;
	} else
		iov[iov_index].iov_len = skb->len;
	iov_index++;
	for (frag = 0; frag < nr_frags; frag++) {
		skb_frag = &skb_shinfo(skb)->frags[frag];
		iov[iov_index].iov_base = skb_frag_address_safe(skb_frag);
		iov[iov_index].iov_len = skb_frag_size(skb_frag);
		iov_index++;
	}
	return iov_index;
drop:
	return -1;
}
/*
 * Generic vector enqueue with support for forming headers using transport
 * specific callback. Allows GRE, L2TPv3, RAW and other transports
 * to use a common enqueue procedure in vector mode
 */

static int vector_enqueue(struct vector_queue *qi, struct sk_buff *skb)
{
	struct vector_private *vp = netdev_priv(qi->dev);
	int queue_depth;
	int packet_len;
	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
	int iov_count;

	spin_lock(&qi->tail_lock);
	spin_lock(&qi->head_lock);
	queue_depth = qi->queue_depth;
	spin_unlock(&qi->head_lock);

	if (skb)
		packet_len = skb->len;

	if (queue_depth < qi->max_depth) {

		*(qi->skbuff_vector + qi->tail) = skb;
		mmsg_vector += qi->tail;
		iov_count = prep_msg(
			vp,
			skb,
			mmsg_vector->msg_hdr.msg_iov
		);
		if (iov_count < 1)
			goto drop;
		mmsg_vector->msg_hdr.msg_iovlen = iov_count;
		mmsg_vector->msg_hdr.msg_name = vp->fds->remote_addr;
		mmsg_vector->msg_hdr.msg_namelen = vp->fds->remote_addr_size;
		queue_depth = vector_advancetail(qi, 1);
	} else
		goto drop;
	spin_unlock(&qi->tail_lock);
	return queue_depth;
drop:
	qi->dev->stats.tx_dropped++;
	if (skb != NULL) {
		packet_len = skb->len;
		dev_consume_skb_any(skb);
		netdev_completed_queue(qi->dev, 1, packet_len);
	}
	spin_unlock(&qi->tail_lock);
	return queue_depth;
}

static int consume_vector_skbs(struct vector_queue *qi, int count)
{
	struct sk_buff *skb;
	int skb_index;
	int bytes_compl = 0;

	for (skb_index = qi->head; skb_index < qi->head + count; skb_index++) {
		skb = *(qi->skbuff_vector + skb_index);
		/* mark as empty to ensure correct destruction if
		 * needed
		 */
		bytes_compl += skb->len;
		*(qi->skbuff_vector + skb_index) = NULL;
		dev_consume_skb_any(skb);
	}
	qi->dev->stats.tx_bytes += bytes_compl;
	qi->dev->stats.tx_packets += count;
	netdev_completed_queue(qi->dev, count, bytes_compl);
	return vector_advancehead(qi, count);
}

/*
 * Generic vector deque via sendmmsg with support for forming headers
 * using transport specific callback. Allows GRE, L2TPv3, RAW and
 * other transports to use a common dequeue procedure in vector mode
 */


static int vector_send(struct vector_queue *qi)
{
	struct vector_private *vp = netdev_priv(qi->dev);
	struct mmsghdr *send_from;
	int result = 0, send_len, queue_depth = qi->max_depth;

	if (spin_trylock(&qi->head_lock)) {
		if (spin_trylock(&qi->tail_lock)) {
			/* update queue_depth to current value */
			queue_depth = qi->queue_depth;
			spin_unlock(&qi->tail_lock);
			while (queue_depth > 0) {
				/* Calculate the start of the vector */
				send_len = queue_depth;
				send_from = qi->mmsg_vector;
				send_from += qi->head;
				/* Adjust vector size if wraparound */
				if (send_len + qi->head > qi->max_depth)
					send_len = qi->max_depth - qi->head;
				/* Try to TX as many packets as possible */
				if (send_len > 0) {
					result = uml_vector_sendmmsg(
						 vp->fds->tx_fd,
						 send_from,
						 send_len,
						 0
					);
					vp->in_write_poll =
						(result != send_len);
				}
				/* For some of the sendmmsg error scenarios
				 * we may end being unsure in the TX success
				 * for all packets. It is safer to declare
				 * them all TX-ed and blame the network.
				 */
				if (result < 0) {
					if (net_ratelimit())
						netdev_err(vp->dev, "sendmmsg err=%i\n",
							result);
					vp->in_error = true;
					result = send_len;
				}
				if (result > 0) {
					queue_depth =
						consume_vector_skbs(qi, result);
					/* This is equivalent to an TX IRQ.
					 * Restart the upper layers to feed us
					 * more packets.
					 */
					if (result > vp->estats.tx_queue_max)
						vp->estats.tx_queue_max = result;
					vp->estats.tx_queue_running_average =
						(vp->estats.tx_queue_running_average + result) >> 1;
				}
				netif_trans_update(qi->dev);
				netif_wake_queue(qi->dev);
				/* if TX is busy, break out of the send loop,
				 *  poll write IRQ will reschedule xmit for us
				 */
				if (result != send_len) {
					vp->estats.tx_restart_queue++;
					break;
				}
			}
		}
		spin_unlock(&qi->head_lock);
	} else {
		tasklet_schedule(&vp->tx_poll);
	}
	return queue_depth;
}

/* Queue destructor. Deliberately stateless so we can use
 * it in queue cleanup if initialization fails.
 */

static void destroy_queue(struct vector_queue *qi)
{
	int i;
	struct iovec *iov;
	struct vector_private *vp = netdev_priv(qi->dev);
	struct mmsghdr *mmsg_vector;

	if (qi == NULL)
		return;
	/* deallocate any skbuffs - we rely on any unused to be
	 * set to NULL.
	 */
	if (qi->skbuff_vector != NULL) {
		for (i = 0; i < qi->max_depth; i++) {
			if (*(qi->skbuff_vector + i) != NULL)
				dev_kfree_skb_any(*(qi->skbuff_vector + i));
		}
		kfree(qi->skbuff_vector);
	}
	/* deallocate matching IOV structures including header buffs */
	if (qi->mmsg_vector != NULL) {
		mmsg_vector = qi->mmsg_vector;
		for (i = 0; i < qi->max_depth; i++) {
			iov = mmsg_vector->msg_hdr.msg_iov;
			if (iov != NULL) {
				if ((vp->header_size > 0) &&
					(iov->iov_base != NULL))
					kfree(iov->iov_base);
				kfree(iov);
			}
			mmsg_vector++;
		}
		kfree(qi->mmsg_vector);
	}
	kfree(qi);
}

/*
 * Queue constructor. Create a queue with a given side.
 */
static struct vector_queue *create_queue(
	struct vector_private *vp,
	int max_size,
	int header_size,
	int num_extra_frags)
{
	struct vector_queue *result;
	int i;
	struct iovec *iov;
	struct mmsghdr *mmsg_vector;

	result = kmalloc(sizeof(struct vector_queue), GFP_KERNEL);
	if (result == NULL)
		return NULL;
	result->max_depth = max_size;
	result->dev = vp->dev;
	result->mmsg_vector = kmalloc(
		(sizeof(struct mmsghdr) * max_size), GFP_KERNEL);
	if (result->mmsg_vector == NULL)
		goto out_mmsg_fail;
	result->skbuff_vector = kmalloc(
		(sizeof(void *) * max_size), GFP_KERNEL);
	if (result->skbuff_vector == NULL)
		goto out_skb_fail;

	/* further failures can be handled safely by destroy_queue*/

	mmsg_vector = result->mmsg_vector;
	for (i = 0; i < max_size; i++) {
		/* Clear all pointers - we use non-NULL as marking on
		 * what to free on destruction
		 */
		*(result->skbuff_vector + i) = NULL;
		mmsg_vector->msg_hdr.msg_iov = NULL;
		mmsg_vector++;
	}
	mmsg_vector = result->mmsg_vector;
	result->max_iov_frags = num_extra_frags;
	for (i = 0; i < max_size; i++) {
		if (vp->header_size > 0)
			iov = kmalloc_array(3 + num_extra_frags,
					    sizeof(struct iovec),
					    GFP_KERNEL
			);
		else
			iov = kmalloc_array(2 + num_extra_frags,
					    sizeof(struct iovec),
					    GFP_KERNEL
			);
		if (iov == NULL)
			goto out_fail;
		mmsg_vector->msg_hdr.msg_iov = iov;
		mmsg_vector->msg_hdr.msg_iovlen = 1;
		mmsg_vector->msg_hdr.msg_control = NULL;
		mmsg_vector->msg_hdr.msg_controllen = 0;
		mmsg_vector->msg_hdr.msg_flags = MSG_DONTWAIT;
		mmsg_vector->msg_hdr.msg_name = NULL;
		mmsg_vector->msg_hdr.msg_namelen = 0;
		if (vp->header_size > 0) {
			iov->iov_base = kmalloc(header_size, GFP_KERNEL);
			if (iov->iov_base == NULL)
				goto out_fail;
			iov->iov_len = header_size;
			mmsg_vector->msg_hdr.msg_iovlen = 2;
			iov++;
		}
		iov->iov_base = NULL;
		iov->iov_len = 0;
		mmsg_vector++;
	}
	spin_lock_init(&result->head_lock);
	spin_lock_init(&result->tail_lock);
	result->queue_depth = 0;
	result->head = 0;
	result->tail = 0;
	return result;
out_skb_fail:
	kfree(result->mmsg_vector);
out_mmsg_fail:
	kfree(result);
	return NULL;
out_fail:
	destroy_queue(result);
	return NULL;
}

/*
 * We do not use the RX queue as a proper wraparound queue for now
 * This is not necessary because the consumption via netif_rx()
 * happens in-line. While we can try using the return code of
 * netif_rx() for flow control there are no drivers doing this today.
 * For this RX specific use we ignore the tail/head locks and
 * just read into a prepared queue filled with skbuffs.
 */

static struct sk_buff *prep_skb(
	struct vector_private *vp,
	struct user_msghdr *msg)
{
	int linear = vp->max_packet + vp->headroom + SAFETY_MARGIN;
	struct sk_buff *result;
	int iov_index = 0, len;
	struct iovec *iov = msg->msg_iov;
	int err, nr_frags, frag;
	skb_frag_t *skb_frag;

	if (vp->req_size <= linear)
		len = linear;
	else
		len = vp->req_size;
	result = alloc_skb_with_frags(
		linear,
		len - vp->max_packet,
		3,
		&err,
		GFP_ATOMIC
	);
	if (vp->header_size > 0)
		iov_index++;
	if (result == NULL) {
		iov[iov_index].iov_base = NULL;
		iov[iov_index].iov_len = 0;
		goto done;
	}
	skb_reserve(result, vp->headroom);
	result->dev = vp->dev;
	skb_put(result, vp->max_packet);
	result->data_len = len - vp->max_packet;
	result->len += len - vp->max_packet;
	skb_reset_mac_header(result);
	result->ip_summed = CHECKSUM_NONE;
	iov[iov_index].iov_base = result->data;
	iov[iov_index].iov_len = vp->max_packet;
	iov_index++;

	nr_frags = skb_shinfo(result)->nr_frags;
	for (frag = 0; frag < nr_frags; frag++) {
		skb_frag = &skb_shinfo(result)->frags[frag];
		iov[iov_index].iov_base = skb_frag_address_safe(skb_frag);
		if (iov[iov_index].iov_base != NULL)
			iov[iov_index].iov_len = skb_frag_size(skb_frag);
		else
			iov[iov_index].iov_len = 0;
		iov_index++;
	}
done:
	msg->msg_iovlen = iov_index;
	return result;
}


/* Prepare queue for recvmmsg one-shot rx - fill with fresh sk_buffs*/

static void prep_queue_for_rx(struct vector_queue *qi)
{
	struct vector_private *vp = netdev_priv(qi->dev);
	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
	void **skbuff_vector = qi->skbuff_vector;
	int i;

	if (qi->queue_depth == 0)
		return;
	for (i = 0; i < qi->queue_depth; i++) {
		/* it is OK if allocation fails - recvmmsg with NULL data in
		 * iov argument still performs an RX, just drops the packet
		 * This allows us stop faffing around with a "drop buffer"
		 */

		*skbuff_vector = prep_skb(vp, &mmsg_vector->msg_hdr);
		skbuff_vector++;
		mmsg_vector++;
	}
	qi->queue_depth = 0;
}

static struct vector_device *find_device(int n)
{
	struct vector_device *device;
	struct list_head *ele;

	spin_lock(&vector_devices_lock);
	list_for_each(ele, &vector_devices) {
		device = list_entry(ele, struct vector_device, list);
		if (device->unit == n)
			goto out;
	}
	device = NULL;
 out:
	spin_unlock(&vector_devices_lock);
	return device;
}

static int vector_parse(char *str, int *index_out, char **str_out,
			char **error_out)
{
	int n, len, err;
	char *start = str;

	len = strlen(str);

	while ((*str != ':') && (strlen(str) > 1))
		str++;
	if (*str != ':') {
		*error_out = "Expected ':' after device number";
		return -EINVAL;
	}
	*str = '\0';

	err = kstrtouint(start, 0, &n);
	if (err < 0) {
		*error_out = "Bad device number";
		return err;
	}

	str++;
	if (find_device(n)) {
		*error_out = "Device already configured";
		return -EINVAL;
	}

	*index_out = n;
	*str_out = str;
	return 0;
}

static int vector_config(char *str, char **error_out)
{
	int err, n;
	char *params;
	struct arglist *parsed;

	err = vector_parse(str, &n, &params, error_out);
	if (err != 0)
		return err;

	/* This string is broken up and the pieces used by the underlying
	 * driver. We should copy it to make sure things do not go wrong
	 * later.
	 */

	params = kstrdup(params, GFP_KERNEL);
	if (params == NULL) {
		*error_out = "vector_config failed to strdup string";
		return -ENOMEM;
	}

	parsed = uml_parse_vector_ifspec(params);

	if (parsed == NULL) {
		*error_out = "vector_config failed to parse parameters";
		return -EINVAL;
	}

	vector_eth_configure(n, parsed);
	return 0;
}

static int vector_id(char **str, int *start_out, int *end_out)
{
	char *end;
	int n;

	n = simple_strtoul(*str, &end, 0);
	if ((*end != '\0') || (end == *str))
		return -1;

	*start_out = n;
	*end_out = n;
	*str = end;
	return n;
}

static int vector_remove(int n, char **error_out)
{
	struct vector_device *vec_d;
	struct net_device *dev;
	struct vector_private *vp;

	vec_d = find_device(n);
	if (vec_d == NULL)
		return -ENODEV;
	dev = vec_d->dev;
	vp = netdev_priv(dev);
	if (vp->fds != NULL)
		return -EBUSY;
	unregister_netdev(dev);
	platform_device_unregister(&vec_d->pdev);
	return 0;
}

/*
 * There is no shared per-transport initialization code, so
 * we will just initialize each interface one by one and
 * add them to a list
 */

static struct platform_driver uml_net_driver = {
	.driver = {
		.name = DRIVER_NAME,
	},
};


static void vector_device_release(struct device *dev)
{
	struct vector_device *device = dev_get_drvdata(dev);
	struct net_device *netdev = device->dev;

	list_del(&device->list);
	kfree(device);
	free_netdev(netdev);
}

/* Bog standard recv using recvmsg - not used normally unless the user
 * explicitly specifies not to use recvmmsg vector RX.
 */

static int vector_legacy_rx(struct vector_private *vp)
{
	int pkt_len;
	struct user_msghdr hdr;
	struct iovec iov[2 + MAX_IOV_SIZE]; /* header + data use case only */
	int iovpos = 0;
	struct sk_buff *skb;
	int header_check;

	hdr.msg_name = NULL;
	hdr.msg_namelen = 0;
	hdr.msg_iov = (struct iovec *) &iov;
	hdr.msg_control = NULL;
	hdr.msg_controllen = 0;
	hdr.msg_flags = 0;

	if (vp->header_size > 0) {
		iov[0].iov_base = vp->header_rxbuffer;
		iov[0].iov_len = vp->header_size;
	}

	skb = prep_skb(vp, &hdr);

	if (skb == NULL) {
		/* Read a packet into drop_buffer and don't do
		 * anything with it.
		 */
		iov[iovpos].iov_base = drop_buffer;
		iov[iovpos].iov_len = DROP_BUFFER_SIZE;
		hdr.msg_iovlen = 1;
		vp->dev->stats.rx_dropped++;
	}

	pkt_len = uml_vector_recvmsg(vp->fds->rx_fd, &hdr, 0);
	if (pkt_len < 0) {
		vp->in_error = true;
		return pkt_len;
	}

	if (skb != NULL) {
		if (pkt_len > vp->header_size) {
			if (vp->header_size > 0) {
				header_check = vp->verify_header(
					vp->header_rxbuffer, skb, vp);
				if (header_check < 0) {
					dev_kfree_skb_irq(skb);
					vp->dev->stats.rx_dropped++;
					vp->estats.rx_encaps_errors++;
					return 0;
				}
				if (header_check > 0) {
					vp->estats.rx_csum_offload_good++;
					skb->ip_summed = CHECKSUM_UNNECESSARY;
				}
			}
			pskb_trim(skb, pkt_len - vp->rx_header_size);
			skb->protocol = eth_type_trans(skb, skb->dev);
			vp->dev->stats.rx_bytes += skb->len;
			vp->dev->stats.rx_packets++;
			netif_rx(skb);
		} else {
			dev_kfree_skb_irq(skb);
		}
	}
	return pkt_len;
}

/*
 * Packet at a time TX which falls back to vector TX if the
 * underlying transport is busy.
 */



static int writev_tx(struct vector_private *vp, struct sk_buff *skb)
{
	struct iovec iov[3 + MAX_IOV_SIZE];
	int iov_count, pkt_len = 0;

	iov[0].iov_base = vp->header_txbuffer;
	iov_count = prep_msg(vp, skb, (struct iovec *) &iov);

	if (iov_count < 1)
		goto drop;

	pkt_len = uml_vector_writev(
		vp->fds->tx_fd,
		(struct iovec *) &iov,
		iov_count
	);

	if (pkt_len < 0)
		goto drop;

	netif_trans_update(vp->dev);
	netif_wake_queue(vp->dev);

	if (pkt_len > 0) {
		vp->dev->stats.tx_bytes += skb->len;
		vp->dev->stats.tx_packets++;
	} else {
		vp->dev->stats.tx_dropped++;
	}
	consume_skb(skb);
	return pkt_len;
drop:
	vp->dev->stats.tx_dropped++;
	consume_skb(skb);
	if (pkt_len < 0)
		vp->in_error = true;
	return pkt_len;
}

/*
 * Receive as many messages as we can in one call using the special
 * mmsg vector matched to an skb vector which we prepared earlier.
 */

static int vector_mmsg_rx(struct vector_private *vp)
{
	int packet_count, i;
	struct vector_queue *qi = vp->rx_queue;
	struct sk_buff *skb;
	struct mmsghdr *mmsg_vector = qi->mmsg_vector;
	void **skbuff_vector = qi->skbuff_vector;
	int header_check;

	/* Refresh the vector and make sure it is with new skbs and the
	 * iovs are updated to point to them.
	 */

	prep_queue_for_rx(qi);

	/* Fire the Lazy Gun - get as many packets as we can in one go. */

	packet_count = uml_vector_recvmmsg(
		vp->fds->rx_fd, qi->mmsg_vector, qi->max_depth, 0);

	if (packet_count < 0)
		vp->in_error = true;

	if (packet_count <= 0)
		return packet_count;

	/* We treat packet processing as enqueue, buffer refresh as dequeue
	 * The queue_depth tells us how many buffers have been used and how
	 * many do we need to prep the next time prep_queue_for_rx() is called.
	 */

	qi->queue_depth = packet_count;

	for (i = 0; i < packet_count; i++) {
		skb = (*skbuff_vector);
		if (mmsg_vector->msg_len > vp->header_size) {
			if (vp->header_size > 0) {
				header_check = vp->verify_header(
					mmsg_vector->msg_hdr.msg_iov->iov_base,
					skb,
					vp
				);
				if (header_check < 0) {
				/* Overlay header failed to verify - discard.
				 * We can actually keep this skb and reuse it,
				 * but that will make the prep logic too
				 * complex.
				 */
					dev_kfree_skb_irq(skb);
					vp->estats.rx_encaps_errors++;
					continue;
				}
				if (header_check > 0) {
					vp->estats.rx_csum_offload_good++;
					skb->ip_summed = CHECKSUM_UNNECESSARY;
				}
			}
			pskb_trim(skb,
				mmsg_vector->msg_len - vp->rx_header_size);
			skb->protocol = eth_type_trans(skb, skb->dev);
			/*
			 * We do not need to lock on updating stats here
			 * The interrupt loop is non-reentrant.
			 */
			vp->dev->stats.rx_bytes += skb->len;
			vp->dev->stats.rx_packets++;
			netif_rx(skb);
		} else {
			/* Overlay header too short to do anything - discard.
			 * We can actually keep this skb and reuse it,
			 * but that will make the prep logic too complex.
			 */
			if (skb != NULL)
				dev_kfree_skb_irq(skb);
		}
		(*skbuff_vector) = NULL;
		/* Move to the next buffer element */
		mmsg_vector++;
		skbuff_vector++;
	}
	if (packet_count > 0) {
		if (vp->estats.rx_queue_max < packet_count)
			vp->estats.rx_queue_max = packet_count;
		vp->estats.rx_queue_running_average =
			(vp->estats.rx_queue_running_average + packet_count) >> 1;
	}
	return packet_count;
}

static void vector_rx(struct vector_private *vp)
{
	int err;
	int iter = 0;

	if ((vp->options & VECTOR_RX) > 0)
		while (((err = vector_mmsg_rx(vp)) > 0) && (iter < MAX_ITERATIONS))
			iter++;
	else
		while (((err = vector_legacy_rx(vp)) > 0) && (iter < MAX_ITERATIONS))
			iter++;
	if ((err != 0) && net_ratelimit())
		netdev_err(vp->dev, "vector_rx: error(%d)\n", err);
	if (iter == MAX_ITERATIONS)
		netdev_err(vp->dev, "vector_rx: device stuck, remote end may have closed the connection\n");
}

static int vector_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct vector_private *vp = netdev_priv(dev);
	int queue_depth = 0;

	if (vp->in_error) {
		deactivate_fd(vp->fds->rx_fd, vp->rx_irq);
		if ((vp->fds->rx_fd != vp->fds->tx_fd) && (vp->tx_irq != 0))
			deactivate_fd(vp->fds->tx_fd, vp->tx_irq);
		return NETDEV_TX_BUSY;
	}

	if ((vp->options & VECTOR_TX) == 0) {
		writev_tx(vp, skb);
		return NETDEV_TX_OK;
	}

	/* We do BQL only in the vector path, no point doing it in
	 * packet at a time mode as there is no device queue
	 */

	netdev_sent_queue(vp->dev, skb->len);
	queue_depth = vector_enqueue(vp->tx_queue, skb);

	/* if the device queue is full, stop the upper layers and
	 * flush it.
	 */

	if (queue_depth >= vp->tx_queue->max_depth - 1) {
		vp->estats.tx_kicks++;
		netif_stop_queue(dev);
		vector_send(vp->tx_queue);
		return NETDEV_TX_OK;
	}
	if (netdev_xmit_more()) {
		mod_timer(&vp->tl, vp->coalesce);
		return NETDEV_TX_OK;
	}
	if (skb->len < TX_SMALL_PACKET) {
		vp->estats.tx_kicks++;
		vector_send(vp->tx_queue);
	} else
		tasklet_schedule(&vp->tx_poll);
	return NETDEV_TX_OK;
}

static irqreturn_t vector_rx_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct vector_private *vp = netdev_priv(dev);

	if (!netif_running(dev))
		return IRQ_NONE;
	vector_rx(vp);
	return IRQ_HANDLED;

}

static irqreturn_t vector_tx_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct vector_private *vp = netdev_priv(dev);

	if (!netif_running(dev))
		return IRQ_NONE;
	/* We need to pay attention to it only if we got
	 * -EAGAIN or -ENOBUFFS from sendmmsg. Otherwise
	 * we ignore it. In the future, it may be worth
	 * it to improve the IRQ controller a bit to make
	 * tweaking the IRQ mask less costly
	 */

	if (vp->in_write_poll)
		tasklet_schedule(&vp->tx_poll);
	return IRQ_HANDLED;

}

static int irq_rr;

static int vector_net_close(struct net_device *dev)
{
	struct vector_private *vp = netdev_priv(dev);
	unsigned long flags;

	netif_stop_queue(dev);
	del_timer(&vp->tl);

	if (vp->fds == NULL)
		return 0;

	/* Disable and free all IRQS */
	if (vp->rx_irq > 0) {
		um_free_irq(vp->rx_irq, dev);
		vp->rx_irq = 0;
	}
	if (vp->tx_irq > 0) {
		um_free_irq(vp->tx_irq, dev);
		vp->tx_irq = 0;
	}
	tasklet_kill(&vp->tx_poll);
	if (vp->fds->rx_fd > 0) {
		os_close_file(vp->fds->rx_fd);
		vp->fds->rx_fd = -1;
	}
	if (vp->fds->tx_fd > 0) {
		os_close_file(vp->fds->tx_fd);
		vp->fds->tx_fd = -1;
	}
	kfree(vp->bpf);
	kfree(vp->fds->remote_addr);
	kfree(vp->transport_data);
	kfree(vp->header_rxbuffer);
	kfree(vp->header_txbuffer);
	if (vp->rx_queue != NULL)
		destroy_queue(vp->rx_queue);
	if (vp->tx_queue != NULL)
		destroy_queue(vp->tx_queue);
	kfree(vp->fds);
	vp->fds = NULL;
	spin_lock_irqsave(&vp->lock, flags);
	vp->opened = false;
	vp->in_error = false;
	spin_unlock_irqrestore(&vp->lock, flags);
	return 0;
}

/* TX tasklet */

static void vector_tx_poll(unsigned long data)
{
	struct vector_private *vp = (struct vector_private *)data;

	vp->estats.tx_kicks++;
	vector_send(vp->tx_queue);
}
static void vector_reset_tx(struct work_struct *work)
{
	struct vector_private *vp =
		container_of(work, struct vector_private, reset_tx);
	netdev_reset_queue(vp->dev);
	netif_start_queue(vp->dev);
	netif_wake_queue(vp->dev);
}
static int vector_net_open(struct net_device *dev)
{
	struct vector_private *vp = netdev_priv(dev);
	unsigned long flags;
	int err = -EINVAL;
	struct vector_device *vdevice;

	spin_lock_irqsave(&vp->lock, flags);
	if (vp->opened) {
		spin_unlock_irqrestore(&vp->lock, flags);
		return -ENXIO;
	}
	vp->opened = true;
	spin_unlock_irqrestore(&vp->lock, flags);

	vp->fds = uml_vector_user_open(vp->unit, vp->parsed);

	if (vp->fds == NULL)
		goto out_close;

	if (build_transport_data(vp) < 0)
		goto out_close;

	if ((vp->options & VECTOR_RX) > 0) {
		vp->rx_queue = create_queue(
			vp,
			get_depth(vp->parsed),
			vp->rx_header_size,
			MAX_IOV_SIZE
		);
		vp->rx_queue->queue_depth = get_depth(vp->parsed);
	} else {
		vp->header_rxbuffer = kmalloc(
			vp->rx_header_size,
			GFP_KERNEL
		);
		if (vp->header_rxbuffer == NULL)
			goto out_close;
	}
	if ((vp->options & VECTOR_TX) > 0) {
		vp->tx_queue = create_queue(
			vp,
			get_depth(vp->parsed),
			vp->header_size,
			MAX_IOV_SIZE
		);
	} else {
		vp->header_txbuffer = kmalloc(vp->header_size, GFP_KERNEL);
		if (vp->header_txbuffer == NULL)
			goto out_close;
	}

	/* READ IRQ */
	err = um_request_irq(
		irq_rr + VECTOR_BASE_IRQ, vp->fds->rx_fd,
			IRQ_READ, vector_rx_interrupt,
			IRQF_SHARED, dev->name, dev);
	if (err != 0) {
		netdev_err(dev, "vector_open: failed to get rx irq(%d)\n", err);
		err = -ENETUNREACH;
		goto out_close;
	}
	vp->rx_irq = irq_rr + VECTOR_BASE_IRQ;
	dev->irq = irq_rr + VECTOR_BASE_IRQ;
	irq_rr = (irq_rr + 1) % VECTOR_IRQ_SPACE;

	/* WRITE IRQ - we need it only if we have vector TX */
	if ((vp->options & VECTOR_TX) > 0) {
		err = um_request_irq(
			irq_rr + VECTOR_BASE_IRQ, vp->fds->tx_fd,
				IRQ_WRITE, vector_tx_interrupt,
				IRQF_SHARED, dev->name, dev);
		if (err != 0) {
			netdev_err(dev,
				"vector_open: failed to get tx irq(%d)\n", err);
			err = -ENETUNREACH;
			goto out_close;
		}
		vp->tx_irq = irq_rr + VECTOR_BASE_IRQ;
		irq_rr = (irq_rr + 1) % VECTOR_IRQ_SPACE;
	}

	if ((vp->options & VECTOR_QDISC_BYPASS) != 0) {
		if (!uml_raw_enable_qdisc_bypass(vp->fds->rx_fd))
			vp->options |= VECTOR_BPF;
	}
	if ((vp->options & VECTOR_BPF) != 0)
		vp->bpf = uml_vector_default_bpf(vp->fds->rx_fd, dev->dev_addr);

	netif_start_queue(dev);

	/* clear buffer - it can happen that the host side of the interface
	 * is full when we get here. In this case, new data is never queued,
	 * SIGIOs never arrive, and the net never works.
	 */

	vector_rx(vp);

	vector_reset_stats(vp);
	vdevice = find_device(vp->unit);
	vdevice->opened = 1;

	if ((vp->options & VECTOR_TX) != 0)
		add_timer(&vp->tl);
	return 0;
out_close:
	vector_net_close(dev);
	return err;
}


static void vector_net_set_multicast_list(struct net_device *dev)
{
	/* TODO: - we can do some BPF games here */
	return;
}

static void vector_net_tx_timeout(struct net_device *dev)
{
	struct vector_private *vp = netdev_priv(dev);

	vp->estats.tx_timeout_count++;
	netif_trans_update(dev);
	schedule_work(&vp->reset_tx);
}

static netdev_features_t vector_fix_features(struct net_device *dev,
	netdev_features_t features)
{
	features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
	return features;
}

static int vector_set_features(struct net_device *dev,
	netdev_features_t features)
{
	struct vector_private *vp = netdev_priv(dev);
	/* Adjust buffer sizes for GSO/GRO. Unfortunately, there is
	 * no way to negotiate it on raw sockets, so we can change
	 * only our side.
	 */
	if (features & NETIF_F_GRO)
		/* All new frame buffers will be GRO-sized */
		vp->req_size = 65536;
	else
		/* All new frame buffers will be normal sized */
		vp->req_size = vp->max_packet + vp->headroom + SAFETY_MARGIN;
	return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void vector_net_poll_controller(struct net_device *dev)
{
	disable_irq(dev->irq);
	vector_rx_interrupt(dev->irq, dev);
	enable_irq(dev->irq);
}
#endif

static void vector_net_get_drvinfo(struct net_device *dev,
				struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
	strlcpy(info->version, DRIVER_VERSION, sizeof(info->version));
}

static void vector_get_ringparam(struct net_device *netdev,
				struct ethtool_ringparam *ring)
{
	struct vector_private *vp = netdev_priv(netdev);

	ring->rx_max_pending = vp->rx_queue->max_depth;
	ring->tx_max_pending = vp->tx_queue->max_depth;
	ring->rx_pending = vp->rx_queue->max_depth;
	ring->tx_pending = vp->tx_queue->max_depth;
}

static void vector_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
{
	switch (stringset) {
	case ETH_SS_TEST:
		*buf = '\0';
		break;
	case ETH_SS_STATS:
		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
		break;
	default:
		WARN_ON(1);
		break;
	}
}

static int vector_get_sset_count(struct net_device *dev, int sset)
{
	switch (sset) {
	case ETH_SS_TEST:
		return 0;
	case ETH_SS_STATS:
		return VECTOR_NUM_STATS;
	default:
		return -EOPNOTSUPP;
	}
}

static void vector_get_ethtool_stats(struct net_device *dev,
	struct ethtool_stats *estats,
	u64 *tmp_stats)
{
	struct vector_private *vp = netdev_priv(dev);

	memcpy(tmp_stats, &vp->estats, sizeof(struct vector_estats));
}

static int vector_get_coalesce(struct net_device *netdev,
					struct ethtool_coalesce *ec)
{
	struct vector_private *vp = netdev_priv(netdev);

	ec->tx_coalesce_usecs = (vp->coalesce * 1000000) / HZ;
	return 0;
}

static int vector_set_coalesce(struct net_device *netdev,
					struct ethtool_coalesce *ec)
{
	struct vector_private *vp = netdev_priv(netdev);

	vp->coalesce = (ec->tx_coalesce_usecs * HZ) / 1000000;
	if (vp->coalesce == 0)
		vp->coalesce = 1;
	return 0;
}

static const struct ethtool_ops vector_net_ethtool_ops = {
	.get_drvinfo	= vector_net_get_drvinfo,
	.get_link	= ethtool_op_get_link,
	.get_ts_info	= ethtool_op_get_ts_info,
	.get_ringparam	= vector_get_ringparam,
	.get_strings	= vector_get_strings,
	.get_sset_count	= vector_get_sset_count,
	.get_ethtool_stats = vector_get_ethtool_stats,
	.get_coalesce	= vector_get_coalesce,
	.set_coalesce	= vector_set_coalesce,
};


static const struct net_device_ops vector_netdev_ops = {
	.ndo_open		= vector_net_open,
	.ndo_stop		= vector_net_close,
	.ndo_start_xmit		= vector_net_start_xmit,
	.ndo_set_rx_mode	= vector_net_set_multicast_list,
	.ndo_tx_timeout		= vector_net_tx_timeout,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_fix_features	= vector_fix_features,
	.ndo_set_features	= vector_set_features,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller = vector_net_poll_controller,
#endif
};


static void vector_timer_expire(struct timer_list *t)
{
	struct vector_private *vp = from_timer(vp, t, tl);

	vp->estats.tx_kicks++;
	vector_send(vp->tx_queue);
}

static void vector_eth_configure(
		int n,
		struct arglist *def
	)
{
	struct vector_device *device;
	struct net_device *dev;
	struct vector_private *vp;
	int err;

	device = kzalloc(sizeof(*device), GFP_KERNEL);
	if (device == NULL) {
		printk(KERN_ERR "eth_configure failed to allocate struct "
				 "vector_device\n");
		return;
	}
	dev = alloc_etherdev(sizeof(struct vector_private));
	if (dev == NULL) {
		printk(KERN_ERR "eth_configure: failed to allocate struct "
				 "net_device for vec%d\n", n);
		goto out_free_device;
	}

	dev->mtu = get_mtu(def);

	INIT_LIST_HEAD(&device->list);
	device->unit = n;

	/* If this name ends up conflicting with an existing registered
	 * netdevice, that is OK, register_netdev{,ice}() will notice this
	 * and fail.
	 */
	snprintf(dev->name, sizeof(dev->name), "vec%d", n);
	uml_net_setup_etheraddr(dev, uml_vector_fetch_arg(def, "mac"));
	vp = netdev_priv(dev);

	/* sysfs register */
	if (!driver_registered) {
		platform_driver_register(&uml_net_driver);
		driver_registered = 1;
	}
	device->pdev.id = n;
	device->pdev.name = DRIVER_NAME;
	device->pdev.dev.release = vector_device_release;
	dev_set_drvdata(&device->pdev.dev, device);
	if (platform_device_register(&device->pdev))
		goto out_free_netdev;
	SET_NETDEV_DEV(dev, &device->pdev.dev);

	device->dev = dev;

	*vp = ((struct vector_private)
		{
		.list			= LIST_HEAD_INIT(vp->list),
		.dev			= dev,
		.unit			= n,
		.options		= get_transport_options(def),
		.rx_irq			= 0,
		.tx_irq			= 0,
		.parsed			= def,
		.max_packet		= get_mtu(def) + ETH_HEADER_OTHER,
		/* TODO - we need to calculate headroom so that ip header
		 * is 16 byte aligned all the time
		 */
		.headroom		= get_headroom(def),
		.form_header		= NULL,
		.verify_header		= NULL,
		.header_rxbuffer	= NULL,
		.header_txbuffer	= NULL,
		.header_size		= 0,
		.rx_header_size		= 0,
		.rexmit_scheduled	= false,
		.opened			= false,
		.transport_data		= NULL,
		.in_write_poll		= false,
		.coalesce		= 2,
		.req_size		= get_req_size(def),
		.in_error		= false
		});

	dev->features = dev->hw_features = (NETIF_F_SG | NETIF_F_FRAGLIST);
	tasklet_init(&vp->tx_poll, vector_tx_poll, (unsigned long)vp);
	INIT_WORK(&vp->reset_tx, vector_reset_tx);

	timer_setup(&vp->tl, vector_timer_expire, 0);
	spin_lock_init(&vp->lock);

	/* FIXME */
	dev->netdev_ops = &vector_netdev_ops;
	dev->ethtool_ops = &vector_net_ethtool_ops;
	dev->watchdog_timeo = (HZ >> 1);
	/* primary IRQ - fixme */
	dev->irq = 0; /* we will adjust this once opened */

	rtnl_lock();
	err = register_netdevice(dev);
	rtnl_unlock();
	if (err)
		goto out_undo_user_init;

	spin_lock(&vector_devices_lock);
	list_add(&device->list, &vector_devices);
	spin_unlock(&vector_devices_lock);

	return;

out_undo_user_init:
	return;
out_free_netdev:
	free_netdev(dev);
out_free_device:
	kfree(device);
}




/*
 * Invoked late in the init
 */

static int __init vector_init(void)
{
	struct list_head *ele;
	struct vector_cmd_line_arg *def;
	struct arglist *parsed;

	list_for_each(ele, &vec_cmd_line) {
		def = list_entry(ele, struct vector_cmd_line_arg, list);
		parsed = uml_parse_vector_ifspec(def->arguments);
		if (parsed != NULL)
			vector_eth_configure(def->unit, parsed);
	}
	return 0;
}


/* Invoked at initial argument parsing, only stores
 * arguments until a proper vector_init is called
 * later
 */

static int __init vector_setup(char *str)
{
	char *error;
	int n, err;
	struct vector_cmd_line_arg *new;

	err = vector_parse(str, &n, &str, &error);
	if (err) {
		printk(KERN_ERR "vector_setup - Couldn't parse '%s' : %s\n",
				 str, error);
		return 1;
	}
	new = memblock_alloc(sizeof(*new), SMP_CACHE_BYTES);
	if (!new)
		panic("%s: Failed to allocate %zu bytes\n", __func__,
		      sizeof(*new));
	INIT_LIST_HEAD(&new->list);
	new->unit = n;
	new->arguments = str;
	list_add_tail(&new->list, &vec_cmd_line);
	return 1;
}

__setup("vec", vector_setup);
__uml_help(vector_setup,
"vec[0-9]+:<option>=<value>,<option>=<value>\n"
"	 Configure a vector io network device.\n\n"
);

late_initcall(vector_init);

static struct mc_device vector_mc = {
	.list		= LIST_HEAD_INIT(vector_mc.list),
	.name		= "vec",
	.config		= vector_config,
	.get_config	= NULL,
	.id		= vector_id,
	.remove		= vector_remove,
};

#ifdef CONFIG_INET
static int vector_inetaddr_event(
	struct notifier_block *this,
	unsigned long event,
	void *ptr)
{
	return NOTIFY_DONE;
}

static struct notifier_block vector_inetaddr_notifier = {
	.notifier_call		= vector_inetaddr_event,
};

static void inet_register(void)
{
	register_inetaddr_notifier(&vector_inetaddr_notifier);
}
#else
static inline void inet_register(void)
{
}
#endif

static int vector_net_init(void)
{
	mconsole_register_dev(&vector_mc);
	inet_register();
	return 0;
}

__initcall(vector_net_init);