summaryrefslogtreecommitdiffstats
path: root/arch/um/drivers/vector_kern.c
blob: 555203e3e7b45664bdd08e98fe55fdbb5402cdc7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 - 2019 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 <linux/firmware.h>
#include <linux/fs.h>
#include <uapi/linux/filter.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"
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 char *get_bpf_file(struct arglist *def)
{
	return uml_vector_fetch_arg(def, "bpffile");
}

static bool get_bpf_flash(struct arglist *def)
{
	char *allow = uml_vector_fetch_arg(def, "bpfflash");
	long result;

	if (allow != NULL) {
		if (kstrtoul(allow, 10, &result) == 0)
			return (allow > 0);
	}
	return false;
}

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;
	int result = 0;

	if (transport == NULL)
		return -EINVAL;

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

	if (get_bpf_flash(def))
		result = VECTOR_BPF_FLASH;

	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
		return result;
	if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
		return (result | vec_rx | VECTOR_BPF);
	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
		return (result | vec_rx | vec_tx | VECTOR_QDISC_BYPASS);
	return (result | 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) {
		if (vp->bpf)
			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
		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;
	}
	if (vp->bpf != NULL)
		kfree(vp->bpf->filter);
	kfree(vp->bpf);
	vp->bpf = NULL;
	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->bpf = uml_vector_user_bpf(get_bpf_file(vp->parsed));

	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 == NULL))
		vp->bpf = uml_vector_default_bpf(dev->dev_addr);

	if (vp->bpf != NULL)
		uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);

	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, unsigned int txqueue)
{
	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));
}

static int vector_net_load_bpf_flash(struct net_device *dev,
				struct ethtool_flash *efl)
{
	struct vector_private *vp = netdev_priv(dev);
	struct vector_device *vdevice;
	const struct firmware *fw;
	int result = 0;

	if (!(vp->options & VECTOR_BPF_FLASH)) {
		netdev_err(dev, "loading firmware not permitted: %s\n", efl->data);
		return -1;
	}

	spin_lock(&vp->lock);

	if (vp->bpf != NULL) {
		if (vp->opened)
			uml_vector_detach_bpf(vp->fds->rx_fd, vp->bpf);
		kfree(vp->bpf->filter);
		vp->bpf->filter = NULL;
	} else {
		vp->bpf = kmalloc(sizeof(struct sock_fprog), GFP_ATOMIC);
		if (vp->bpf == NULL) {
			netdev_err(dev, "failed to allocate memory for firmware\n");
			goto flash_fail;
		}
	}

	vdevice = find_device(vp->unit);

	if (request_firmware(&fw, efl->data, &vdevice->pdev.dev))
		goto flash_fail;

	vp->bpf->filter = kmemdup(fw->data, fw->size, GFP_ATOMIC);
	if (!vp->bpf->filter)
		goto free_buffer;

	vp->bpf->len = fw->size / sizeof(struct sock_filter);
	release_firmware(fw);

	if (vp->opened)
		result = uml_vector_attach_bpf(vp->fds->rx_fd, vp->bpf);

	spin_unlock(&vp->lock);

	return result;

free_buffer:
	release_firmware(fw);

flash_fail:
	spin_unlock(&vp->lock);
	if (vp->bpf != NULL)
		kfree(vp->bpf->filter);
	kfree(vp->bpf);
	vp->bpf = NULL;
	return -1;
}

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 = {
	.supported_coalesce_params = ETHTOOL_COALESCE_TX_USECS,
	.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,
	.flash_device	= vector_net_load_bpf_flash,
};


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,
		.bpf			= NULL
	});

	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);