summaryrefslogtreecommitdiffstats
path: root/drivers/net/iseries_veth.c
blob: 53dd39e9130ef7372b01d0c1b0b31b236708a9ff (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
/* File veth.c created by Kyle A. Lucke on Mon Aug  7 2000. */
/*
 * IBM eServer iSeries Virtual Ethernet Device Driver
 * Copyright (C) 2001 Kyle A. Lucke (klucke@us.ibm.com), IBM Corp.
 * Substantially cleaned up by:
 * Copyright (C) 2003 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
 * Copyright (C) 2004-2005 Michael Ellerman, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 *
 * This module implements the virtual ethernet device for iSeries LPAR
 * Linux.  It uses hypervisor message passing to implement an
 * ethernet-like network device communicating between partitions on
 * the iSeries.
 *
 * The iSeries LPAR hypervisor currently allows for up to 16 different
 * virtual ethernets.  These are all dynamically configurable on
 * OS/400 partitions, but dynamic configuration is not supported under
 * Linux yet.  An ethXX network device will be created for each
 * virtual ethernet this partition is connected to.
 *
 * - This driver is responsible for routing packets to and from other
 *   partitions.  The MAC addresses used by the virtual ethernets
 *   contains meaning and must not be modified.
 *
 * - Having 2 virtual ethernets to the same remote partition DOES NOT
 *   double the available bandwidth.  The 2 devices will share the
 *   available hypervisor bandwidth.
 *
 * - If you send a packet to your own mac address, it will just be
 *   dropped, you won't get it on the receive side.
 *
 * - Multicast is implemented by sending the frame frame to every
 *   other partition.  It is the responsibility of the receiving
 *   partition to filter the addresses desired.
 *
 * Tunable parameters:
 *
 * VETH_NUMBUFFERS: This compile time option defaults to 120.  It
 * controls how much memory Linux will allocate per remote partition
 * it is communicating with.  It can be thought of as the maximum
 * number of packets outstanding to a remote partition at a time.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/ethtool.h>
#include <linux/if_ether.h>
#include <linux/slab.h>

#include <asm/abs_addr.h>
#include <asm/iseries/mf.h>
#include <asm/uaccess.h>
#include <asm/firmware.h>
#include <asm/iseries/hv_lp_config.h>
#include <asm/iseries/hv_types.h>
#include <asm/iseries/hv_lp_event.h>
#include <asm/iommu.h>
#include <asm/vio.h>

#undef DEBUG

MODULE_AUTHOR("Kyle Lucke <klucke@us.ibm.com>");
MODULE_DESCRIPTION("iSeries Virtual ethernet driver");
MODULE_LICENSE("GPL");

#define VETH_EVENT_CAP	(0)
#define VETH_EVENT_FRAMES	(1)
#define VETH_EVENT_MONITOR	(2)
#define VETH_EVENT_FRAMES_ACK	(3)

#define VETH_MAX_ACKS_PER_MSG	(20)
#define VETH_MAX_FRAMES_PER_MSG	(6)

struct veth_frames_data {
	u32 addr[VETH_MAX_FRAMES_PER_MSG];
	u16 len[VETH_MAX_FRAMES_PER_MSG];
	u32 eofmask;
};
#define VETH_EOF_SHIFT		(32-VETH_MAX_FRAMES_PER_MSG)

struct veth_frames_ack_data {
	u16 token[VETH_MAX_ACKS_PER_MSG];
};

struct veth_cap_data {
	u8 caps_version;
	u8 rsvd1;
	u16 num_buffers;
	u16 ack_threshold;
	u16 rsvd2;
	u32 ack_timeout;
	u32 rsvd3;
	u64 rsvd4[3];
};

struct veth_lpevent {
	struct HvLpEvent base_event;
	union {
		struct veth_cap_data caps_data;
		struct veth_frames_data frames_data;
		struct veth_frames_ack_data frames_ack_data;
	} u;

};

#define DRV_NAME	"iseries_veth"
#define DRV_VERSION	"2.0"

#define VETH_NUMBUFFERS		(120)
#define VETH_ACKTIMEOUT 	(1000000) /* microseconds */
#define VETH_MAX_MCAST		(12)

#define VETH_MAX_MTU		(9000)

#if VETH_NUMBUFFERS < 10
#define ACK_THRESHOLD 		(1)
#elif VETH_NUMBUFFERS < 20
#define ACK_THRESHOLD 		(4)
#elif VETH_NUMBUFFERS < 40
#define ACK_THRESHOLD 		(10)
#else
#define ACK_THRESHOLD 		(20)
#endif

#define	VETH_STATE_SHUTDOWN	(0x0001)
#define VETH_STATE_OPEN		(0x0002)
#define VETH_STATE_RESET	(0x0004)
#define VETH_STATE_SENTMON	(0x0008)
#define VETH_STATE_SENTCAPS	(0x0010)
#define VETH_STATE_GOTCAPACK	(0x0020)
#define VETH_STATE_GOTCAPS	(0x0040)
#define VETH_STATE_SENTCAPACK	(0x0080)
#define VETH_STATE_READY	(0x0100)

struct veth_msg {
	struct veth_msg *next;
	struct veth_frames_data data;
	int token;
	int in_use;
	struct sk_buff *skb;
	struct device *dev;
};

struct veth_lpar_connection {
	HvLpIndex remote_lp;
	struct delayed_work statemachine_wq;
	struct veth_msg *msgs;
	int num_events;
	struct veth_cap_data local_caps;

	struct kobject kobject;
	struct timer_list ack_timer;

	struct timer_list reset_timer;
	unsigned int reset_timeout;
	unsigned long last_contact;
	int outstanding_tx;

	spinlock_t lock;
	unsigned long state;
	HvLpInstanceId src_inst;
	HvLpInstanceId dst_inst;
	struct veth_lpevent cap_event, cap_ack_event;
	u16 pending_acks[VETH_MAX_ACKS_PER_MSG];
	u32 num_pending_acks;

	int num_ack_events;
	struct veth_cap_data remote_caps;
	u32 ack_timeout;

	struct veth_msg *msg_stack_head;
};

struct veth_port {
	struct device *dev;
	u64 mac_addr;
	HvLpIndexMap lpar_map;

	/* queue_lock protects the stopped_map and dev's queue. */
	spinlock_t queue_lock;
	HvLpIndexMap stopped_map;

	/* mcast_gate protects promiscuous, num_mcast & mcast_addr. */
	rwlock_t mcast_gate;
	int promiscuous;
	int num_mcast;
	u64 mcast_addr[VETH_MAX_MCAST];

	struct kobject kobject;
};

static HvLpIndex this_lp;
static struct veth_lpar_connection *veth_cnx[HVMAXARCHITECTEDLPS]; /* = 0 */
static struct net_device *veth_dev[HVMAXARCHITECTEDVIRTUALLANS]; /* = 0 */

static int veth_start_xmit(struct sk_buff *skb, struct net_device *dev);
static void veth_recycle_msg(struct veth_lpar_connection *, struct veth_msg *);
static void veth_wake_queues(struct veth_lpar_connection *cnx);
static void veth_stop_queues(struct veth_lpar_connection *cnx);
static void veth_receive(struct veth_lpar_connection *, struct veth_lpevent *);
static void veth_release_connection(struct kobject *kobject);
static void veth_timed_ack(unsigned long ptr);
static void veth_timed_reset(unsigned long ptr);

/*
 * Utility functions
 */

#define veth_info(fmt, args...) \
	printk(KERN_INFO DRV_NAME ": " fmt, ## args)

#define veth_error(fmt, args...) \
	printk(KERN_ERR DRV_NAME ": Error: " fmt, ## args)

#ifdef DEBUG
#define veth_debug(fmt, args...) \
	printk(KERN_DEBUG DRV_NAME ": " fmt, ## args)
#else
#define veth_debug(fmt, args...) do {} while (0)
#endif

/* You must hold the connection's lock when you call this function. */
static inline void veth_stack_push(struct veth_lpar_connection *cnx,
				   struct veth_msg *msg)
{
	msg->next = cnx->msg_stack_head;
	cnx->msg_stack_head = msg;
}

/* You must hold the connection's lock when you call this function. */
static inline struct veth_msg *veth_stack_pop(struct veth_lpar_connection *cnx)
{
	struct veth_msg *msg;

	msg = cnx->msg_stack_head;
	if (msg)
		cnx->msg_stack_head = cnx->msg_stack_head->next;

	return msg;
}

/* You must hold the connection's lock when you call this function. */
static inline int veth_stack_is_empty(struct veth_lpar_connection *cnx)
{
	return cnx->msg_stack_head == NULL;
}

static inline HvLpEvent_Rc
veth_signalevent(struct veth_lpar_connection *cnx, u16 subtype,
		 HvLpEvent_AckInd ackind, HvLpEvent_AckType acktype,
		 u64 token,
		 u64 data1, u64 data2, u64 data3, u64 data4, u64 data5)
{
	return HvCallEvent_signalLpEventFast(cnx->remote_lp,
					     HvLpEvent_Type_VirtualLan,
					     subtype, ackind, acktype,
					     cnx->src_inst,
					     cnx->dst_inst,
					     token, data1, data2, data3,
					     data4, data5);
}

static inline HvLpEvent_Rc veth_signaldata(struct veth_lpar_connection *cnx,
					   u16 subtype, u64 token, void *data)
{
	u64 *p = (u64 *) data;

	return veth_signalevent(cnx, subtype, HvLpEvent_AckInd_NoAck,
				HvLpEvent_AckType_ImmediateAck,
				token, p[0], p[1], p[2], p[3], p[4]);
}

struct veth_allocation {
	struct completion c;
	int num;
};

static void veth_complete_allocation(void *parm, int number)
{
	struct veth_allocation *vc = (struct veth_allocation *)parm;

	vc->num = number;
	complete(&vc->c);
}

static int veth_allocate_events(HvLpIndex rlp, int number)
{
	struct veth_allocation vc =
		{ COMPLETION_INITIALIZER_ONSTACK(vc.c), 0 };

	mf_allocate_lp_events(rlp, HvLpEvent_Type_VirtualLan,
			    sizeof(struct veth_lpevent), number,
			    &veth_complete_allocation, &vc);
	wait_for_completion(&vc.c);

	return vc.num;
}

/*
 * sysfs support
 */

struct veth_cnx_attribute {
	struct attribute attr;
	ssize_t (*show)(struct veth_lpar_connection *, char *buf);
	ssize_t (*store)(struct veth_lpar_connection *, const char *buf);
};

static ssize_t veth_cnx_attribute_show(struct kobject *kobj,
		struct attribute *attr, char *buf)
{
	struct veth_cnx_attribute *cnx_attr;
	struct veth_lpar_connection *cnx;

	cnx_attr = container_of(attr, struct veth_cnx_attribute, attr);
	cnx = container_of(kobj, struct veth_lpar_connection, kobject);

	if (!cnx_attr->show)
		return -EIO;

	return cnx_attr->show(cnx, buf);
}

#define CUSTOM_CNX_ATTR(_name, _format, _expression)			\
static ssize_t _name##_show(struct veth_lpar_connection *cnx, char *buf)\
{									\
	return sprintf(buf, _format, _expression);			\
}									\
struct veth_cnx_attribute veth_cnx_attr_##_name = __ATTR_RO(_name)

#define SIMPLE_CNX_ATTR(_name)	\
	CUSTOM_CNX_ATTR(_name, "%lu\n", (unsigned long)cnx->_name)

SIMPLE_CNX_ATTR(outstanding_tx);
SIMPLE_CNX_ATTR(remote_lp);
SIMPLE_CNX_ATTR(num_events);
SIMPLE_CNX_ATTR(src_inst);
SIMPLE_CNX_ATTR(dst_inst);
SIMPLE_CNX_ATTR(num_pending_acks);
SIMPLE_CNX_ATTR(num_ack_events);
CUSTOM_CNX_ATTR(ack_timeout, "%d\n", jiffies_to_msecs(cnx->ack_timeout));
CUSTOM_CNX_ATTR(reset_timeout, "%d\n", jiffies_to_msecs(cnx->reset_timeout));
CUSTOM_CNX_ATTR(state, "0x%.4lX\n", cnx->state);
CUSTOM_CNX_ATTR(last_contact, "%d\n", cnx->last_contact ?
		jiffies_to_msecs(jiffies - cnx->last_contact) : 0);

#define GET_CNX_ATTR(_name)	(&veth_cnx_attr_##_name.attr)

static struct attribute *veth_cnx_default_attrs[] = {
	GET_CNX_ATTR(outstanding_tx),
	GET_CNX_ATTR(remote_lp),
	GET_CNX_ATTR(num_events),
	GET_CNX_ATTR(reset_timeout),
	GET_CNX_ATTR(last_contact),
	GET_CNX_ATTR(state),
	GET_CNX_ATTR(src_inst),
	GET_CNX_ATTR(dst_inst),
	GET_CNX_ATTR(num_pending_acks),
	GET_CNX_ATTR(num_ack_events),
	GET_CNX_ATTR(ack_timeout),
	NULL
};

static const struct sysfs_ops veth_cnx_sysfs_ops = {
		.show = veth_cnx_attribute_show
};

static struct kobj_type veth_lpar_connection_ktype = {
	.release	= veth_release_connection,
	.sysfs_ops	= &veth_cnx_sysfs_ops,
	.default_attrs	= veth_cnx_default_attrs
};

struct veth_port_attribute {
	struct attribute attr;
	ssize_t (*show)(struct veth_port *, char *buf);
	ssize_t (*store)(struct veth_port *, const char *buf);
};

static ssize_t veth_port_attribute_show(struct kobject *kobj,
		struct attribute *attr, char *buf)
{
	struct veth_port_attribute *port_attr;
	struct veth_port *port;

	port_attr = container_of(attr, struct veth_port_attribute, attr);
	port = container_of(kobj, struct veth_port, kobject);

	if (!port_attr->show)
		return -EIO;

	return port_attr->show(port, buf);
}

#define CUSTOM_PORT_ATTR(_name, _format, _expression)			\
static ssize_t _name##_show(struct veth_port *port, char *buf)		\
{									\
	return sprintf(buf, _format, _expression);			\
}									\
struct veth_port_attribute veth_port_attr_##_name = __ATTR_RO(_name)

#define SIMPLE_PORT_ATTR(_name)	\
	CUSTOM_PORT_ATTR(_name, "%lu\n", (unsigned long)port->_name)

SIMPLE_PORT_ATTR(promiscuous);
SIMPLE_PORT_ATTR(num_mcast);
CUSTOM_PORT_ATTR(lpar_map, "0x%X\n", port->lpar_map);
CUSTOM_PORT_ATTR(stopped_map, "0x%X\n", port->stopped_map);
CUSTOM_PORT_ATTR(mac_addr, "0x%llX\n", port->mac_addr);

#define GET_PORT_ATTR(_name)	(&veth_port_attr_##_name.attr)
static struct attribute *veth_port_default_attrs[] = {
	GET_PORT_ATTR(mac_addr),
	GET_PORT_ATTR(lpar_map),
	GET_PORT_ATTR(stopped_map),
	GET_PORT_ATTR(promiscuous),
	GET_PORT_ATTR(num_mcast),
	NULL
};

static const struct sysfs_ops veth_port_sysfs_ops = {
	.show = veth_port_attribute_show
};

static struct kobj_type veth_port_ktype = {
	.sysfs_ops	= &veth_port_sysfs_ops,
	.default_attrs	= veth_port_default_attrs
};

/*
 * LPAR connection code
 */

static inline void veth_kick_statemachine(struct veth_lpar_connection *cnx)
{
	schedule_delayed_work(&cnx->statemachine_wq, 0);
}

static void veth_take_cap(struct veth_lpar_connection *cnx,
			  struct veth_lpevent *event)
{
	unsigned long flags;

	spin_lock_irqsave(&cnx->lock, flags);
	/* Receiving caps may mean the other end has just come up, so
	 * we need to reload the instance ID of the far end */
	cnx->dst_inst =
		HvCallEvent_getTargetLpInstanceId(cnx->remote_lp,
						  HvLpEvent_Type_VirtualLan);

	if (cnx->state & VETH_STATE_GOTCAPS) {
		veth_error("Received a second capabilities from LPAR %d.\n",
			   cnx->remote_lp);
		event->base_event.xRc = HvLpEvent_Rc_BufferNotAvailable;
		HvCallEvent_ackLpEvent((struct HvLpEvent *) event);
	} else {
		memcpy(&cnx->cap_event, event, sizeof(cnx->cap_event));
		cnx->state |= VETH_STATE_GOTCAPS;
		veth_kick_statemachine(cnx);
	}
	spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_take_cap_ack(struct veth_lpar_connection *cnx,
			      struct veth_lpevent *event)
{
	unsigned long flags;

	spin_lock_irqsave(&cnx->lock, flags);
	if (cnx->state & VETH_STATE_GOTCAPACK) {
		veth_error("Received a second capabilities ack from LPAR %d.\n",
			   cnx->remote_lp);
	} else {
		memcpy(&cnx->cap_ack_event, event,
		       sizeof(cnx->cap_ack_event));
		cnx->state |= VETH_STATE_GOTCAPACK;
		veth_kick_statemachine(cnx);
	}
	spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_take_monitor_ack(struct veth_lpar_connection *cnx,
				  struct veth_lpevent *event)
{
	unsigned long flags;

	spin_lock_irqsave(&cnx->lock, flags);
	veth_debug("cnx %d: lost connection.\n", cnx->remote_lp);

	/* Avoid kicking the statemachine once we're shutdown.
	 * It's unnecessary and it could break veth_stop_connection(). */

	if (! (cnx->state & VETH_STATE_SHUTDOWN)) {
		cnx->state |= VETH_STATE_RESET;
		veth_kick_statemachine(cnx);
	}
	spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_handle_ack(struct veth_lpevent *event)
{
	HvLpIndex rlp = event->base_event.xTargetLp;
	struct veth_lpar_connection *cnx = veth_cnx[rlp];

	BUG_ON(! cnx);

	switch (event->base_event.xSubtype) {
	case VETH_EVENT_CAP:
		veth_take_cap_ack(cnx, event);
		break;
	case VETH_EVENT_MONITOR:
		veth_take_monitor_ack(cnx, event);
		break;
	default:
		veth_error("Unknown ack type %d from LPAR %d.\n",
				event->base_event.xSubtype, rlp);
	}
}

static void veth_handle_int(struct veth_lpevent *event)
{
	HvLpIndex rlp = event->base_event.xSourceLp;
	struct veth_lpar_connection *cnx = veth_cnx[rlp];
	unsigned long flags;
	int i, acked = 0;

	BUG_ON(! cnx);

	switch (event->base_event.xSubtype) {
	case VETH_EVENT_CAP:
		veth_take_cap(cnx, event);
		break;
	case VETH_EVENT_MONITOR:
		/* do nothing... this'll hang out here til we're dead,
		 * and the hypervisor will return it for us. */
		break;
	case VETH_EVENT_FRAMES_ACK:
		spin_lock_irqsave(&cnx->lock, flags);

		for (i = 0; i < VETH_MAX_ACKS_PER_MSG; ++i) {
			u16 msgnum = event->u.frames_ack_data.token[i];

			if (msgnum < VETH_NUMBUFFERS) {
				veth_recycle_msg(cnx, cnx->msgs + msgnum);
				cnx->outstanding_tx--;
				acked++;
			}
		}

		if (acked > 0) {
			cnx->last_contact = jiffies;
			veth_wake_queues(cnx);
		}

		spin_unlock_irqrestore(&cnx->lock, flags);
		break;
	case VETH_EVENT_FRAMES:
		veth_receive(cnx, event);
		break;
	default:
		veth_error("Unknown interrupt type %d from LPAR %d.\n",
				event->base_event.xSubtype, rlp);
	}
}

static void veth_handle_event(struct HvLpEvent *event)
{
	struct veth_lpevent *veth_event = (struct veth_lpevent *)event;

	if (hvlpevent_is_ack(event))
		veth_handle_ack(veth_event);
	else
		veth_handle_int(veth_event);
}

static int veth_process_caps(struct veth_lpar_connection *cnx)
{
	struct veth_cap_data *remote_caps = &cnx->remote_caps;
	int num_acks_needed;

	/* Convert timer to jiffies */
	cnx->ack_timeout = remote_caps->ack_timeout * HZ / 1000000;

	if ( (remote_caps->num_buffers == 0) ||
	     (remote_caps->ack_threshold > VETH_MAX_ACKS_PER_MSG) ||
	     (remote_caps->ack_threshold == 0) ||
	     (cnx->ack_timeout == 0) ) {
		veth_error("Received incompatible capabilities from LPAR %d.\n",
				cnx->remote_lp);
		return HvLpEvent_Rc_InvalidSubtypeData;
	}

	num_acks_needed = (remote_caps->num_buffers
			   / remote_caps->ack_threshold) + 1;

	/* FIXME: locking on num_ack_events? */
	if (cnx->num_ack_events < num_acks_needed) {
		int num;

		num = veth_allocate_events(cnx->remote_lp,
					   num_acks_needed-cnx->num_ack_events);
		if (num > 0)
			cnx->num_ack_events += num;

		if (cnx->num_ack_events < num_acks_needed) {
			veth_error("Couldn't allocate enough ack events "
					"for LPAR %d.\n", cnx->remote_lp);

			return HvLpEvent_Rc_BufferNotAvailable;
		}
	}


	return HvLpEvent_Rc_Good;
}

/* FIXME: The gotos here are a bit dubious */
static void veth_statemachine(struct work_struct *work)
{
	struct veth_lpar_connection *cnx =
		container_of(work, struct veth_lpar_connection,
			     statemachine_wq.work);
	int rlp = cnx->remote_lp;
	int rc;

	spin_lock_irq(&cnx->lock);

 restart:
	if (cnx->state & VETH_STATE_RESET) {
		if (cnx->state & VETH_STATE_OPEN)
			HvCallEvent_closeLpEventPath(cnx->remote_lp,
						     HvLpEvent_Type_VirtualLan);

		/*
		 * Reset ack data. This prevents the ack_timer actually
		 * doing anything, even if it runs one more time when
		 * we drop the lock below.
		 */
		memset(&cnx->pending_acks, 0xff, sizeof (cnx->pending_acks));
		cnx->num_pending_acks = 0;

		cnx->state &= ~(VETH_STATE_RESET | VETH_STATE_SENTMON
				| VETH_STATE_OPEN | VETH_STATE_SENTCAPS
				| VETH_STATE_GOTCAPACK | VETH_STATE_GOTCAPS
				| VETH_STATE_SENTCAPACK | VETH_STATE_READY);

		/* Clean up any leftover messages */
		if (cnx->msgs) {
			int i;
			for (i = 0; i < VETH_NUMBUFFERS; ++i)
				veth_recycle_msg(cnx, cnx->msgs + i);
		}

		cnx->outstanding_tx = 0;
		veth_wake_queues(cnx);

		/* Drop the lock so we can do stuff that might sleep or
		 * take other locks. */
		spin_unlock_irq(&cnx->lock);

		del_timer_sync(&cnx->ack_timer);
		del_timer_sync(&cnx->reset_timer);

		spin_lock_irq(&cnx->lock);

		if (cnx->state & VETH_STATE_RESET)
			goto restart;

		/* Hack, wait for the other end to reset itself. */
		if (! (cnx->state & VETH_STATE_SHUTDOWN)) {
			schedule_delayed_work(&cnx->statemachine_wq, 5 * HZ);
			goto out;
		}
	}

	if (cnx->state & VETH_STATE_SHUTDOWN)
		/* It's all over, do nothing */
		goto out;

	if ( !(cnx->state & VETH_STATE_OPEN) ) {
		if (! cnx->msgs || (cnx->num_events < (2 + VETH_NUMBUFFERS)) )
			goto cant_cope;

		HvCallEvent_openLpEventPath(rlp, HvLpEvent_Type_VirtualLan);
		cnx->src_inst =
			HvCallEvent_getSourceLpInstanceId(rlp,
							  HvLpEvent_Type_VirtualLan);
		cnx->dst_inst =
			HvCallEvent_getTargetLpInstanceId(rlp,
							  HvLpEvent_Type_VirtualLan);
		cnx->state |= VETH_STATE_OPEN;
	}

	if ( (cnx->state & VETH_STATE_OPEN) &&
	     !(cnx->state & VETH_STATE_SENTMON) ) {
		rc = veth_signalevent(cnx, VETH_EVENT_MONITOR,
				      HvLpEvent_AckInd_DoAck,
				      HvLpEvent_AckType_DeferredAck,
				      0, 0, 0, 0, 0, 0);

		if (rc == HvLpEvent_Rc_Good) {
			cnx->state |= VETH_STATE_SENTMON;
		} else {
			if ( (rc != HvLpEvent_Rc_PartitionDead) &&
			     (rc != HvLpEvent_Rc_PathClosed) )
				veth_error("Error sending monitor to LPAR %d, "
						"rc = %d\n", rlp, rc);

			/* Oh well, hope we get a cap from the other
			 * end and do better when that kicks us */
			goto out;
		}
	}

	if ( (cnx->state & VETH_STATE_OPEN) &&
	     !(cnx->state & VETH_STATE_SENTCAPS)) {
		u64 *rawcap = (u64 *)&cnx->local_caps;

		rc = veth_signalevent(cnx, VETH_EVENT_CAP,
				      HvLpEvent_AckInd_DoAck,
				      HvLpEvent_AckType_ImmediateAck,
				      0, rawcap[0], rawcap[1], rawcap[2],
				      rawcap[3], rawcap[4]);

		if (rc == HvLpEvent_Rc_Good) {
			cnx->state |= VETH_STATE_SENTCAPS;
		} else {
			if ( (rc != HvLpEvent_Rc_PartitionDead) &&
			     (rc != HvLpEvent_Rc_PathClosed) )
				veth_error("Error sending caps to LPAR %d, "
						"rc = %d\n", rlp, rc);

			/* Oh well, hope we get a cap from the other
			 * end and do better when that kicks us */
			goto out;
		}
	}

	if ((cnx->state & VETH_STATE_GOTCAPS) &&
	    !(cnx->state & VETH_STATE_SENTCAPACK)) {
		struct veth_cap_data *remote_caps = &cnx->remote_caps;

		memcpy(remote_caps, &cnx->cap_event.u.caps_data,
		       sizeof(*remote_caps));

		spin_unlock_irq(&cnx->lock);
		rc = veth_process_caps(cnx);
		spin_lock_irq(&cnx->lock);

		/* We dropped the lock, so recheck for anything which
		 * might mess us up */
		if (cnx->state & (VETH_STATE_RESET|VETH_STATE_SHUTDOWN))
			goto restart;

		cnx->cap_event.base_event.xRc = rc;
		HvCallEvent_ackLpEvent((struct HvLpEvent *)&cnx->cap_event);
		if (rc == HvLpEvent_Rc_Good)
			cnx->state |= VETH_STATE_SENTCAPACK;
		else
			goto cant_cope;
	}

	if ((cnx->state & VETH_STATE_GOTCAPACK) &&
	    (cnx->state & VETH_STATE_GOTCAPS) &&
	    !(cnx->state & VETH_STATE_READY)) {
		if (cnx->cap_ack_event.base_event.xRc == HvLpEvent_Rc_Good) {
			/* Start the ACK timer */
			cnx->ack_timer.expires = jiffies + cnx->ack_timeout;
			add_timer(&cnx->ack_timer);
			cnx->state |= VETH_STATE_READY;
		} else {
			veth_error("Caps rejected by LPAR %d, rc = %d\n",
					rlp, cnx->cap_ack_event.base_event.xRc);
			goto cant_cope;
		}
	}

 out:
	spin_unlock_irq(&cnx->lock);
	return;

 cant_cope:
	/* FIXME: we get here if something happens we really can't
	 * cope with.  The link will never work once we get here, and
	 * all we can do is not lock the rest of the system up */
	veth_error("Unrecoverable error on connection to LPAR %d, shutting down"
			" (state = 0x%04lx)\n", rlp, cnx->state);
	cnx->state |= VETH_STATE_SHUTDOWN;
	spin_unlock_irq(&cnx->lock);
}

static int veth_init_connection(u8 rlp)
{
	struct veth_lpar_connection *cnx;
	struct veth_msg *msgs;
	int i;

	if ( (rlp == this_lp) ||
	     ! HvLpConfig_doLpsCommunicateOnVirtualLan(this_lp, rlp) )
		return 0;

	cnx = kzalloc(sizeof(*cnx), GFP_KERNEL);
	if (! cnx)
		return -ENOMEM;

	cnx->remote_lp = rlp;
	spin_lock_init(&cnx->lock);
	INIT_DELAYED_WORK(&cnx->statemachine_wq, veth_statemachine);

	init_timer(&cnx->ack_timer);
	cnx->ack_timer.function = veth_timed_ack;
	cnx->ack_timer.data = (unsigned long) cnx;

	init_timer(&cnx->reset_timer);
	cnx->reset_timer.function = veth_timed_reset;
	cnx->reset_timer.data = (unsigned long) cnx;
	cnx->reset_timeout = 5 * HZ * (VETH_ACKTIMEOUT / 1000000);

	memset(&cnx->pending_acks, 0xff, sizeof (cnx->pending_acks));

	veth_cnx[rlp] = cnx;

	/* This gets us 1 reference, which is held on behalf of the driver
	 * infrastructure. It's released at module unload. */
	kobject_init(&cnx->kobject, &veth_lpar_connection_ktype);

	msgs = kcalloc(VETH_NUMBUFFERS, sizeof(struct veth_msg), GFP_KERNEL);
	if (! msgs) {
		veth_error("Can't allocate buffers for LPAR %d.\n", rlp);
		return -ENOMEM;
	}

	cnx->msgs = msgs;

	for (i = 0; i < VETH_NUMBUFFERS; i++) {
		msgs[i].token = i;
		veth_stack_push(cnx, msgs + i);
	}

	cnx->num_events = veth_allocate_events(rlp, 2 + VETH_NUMBUFFERS);

	if (cnx->num_events < (2 + VETH_NUMBUFFERS)) {
		veth_error("Can't allocate enough events for LPAR %d.\n", rlp);
		return -ENOMEM;
	}

	cnx->local_caps.num_buffers = VETH_NUMBUFFERS;
	cnx->local_caps.ack_threshold = ACK_THRESHOLD;
	cnx->local_caps.ack_timeout = VETH_ACKTIMEOUT;

	return 0;
}

static void veth_stop_connection(struct veth_lpar_connection *cnx)
{
	if (!cnx)
		return;

	spin_lock_irq(&cnx->lock);
	cnx->state |= VETH_STATE_RESET | VETH_STATE_SHUTDOWN;
	veth_kick_statemachine(cnx);
	spin_unlock_irq(&cnx->lock);

	/* ensure the statemachine runs now and waits for its completion */
	flush_delayed_work_sync(&cnx->statemachine_wq);
}

static void veth_destroy_connection(struct veth_lpar_connection *cnx)
{
	if (!cnx)
		return;

	if (cnx->num_events > 0)
		mf_deallocate_lp_events(cnx->remote_lp,
				      HvLpEvent_Type_VirtualLan,
				      cnx->num_events,
				      NULL, NULL);
	if (cnx->num_ack_events > 0)
		mf_deallocate_lp_events(cnx->remote_lp,
				      HvLpEvent_Type_VirtualLan,
				      cnx->num_ack_events,
				      NULL, NULL);

	kfree(cnx->msgs);
	veth_cnx[cnx->remote_lp] = NULL;
	kfree(cnx);
}

static void veth_release_connection(struct kobject *kobj)
{
	struct veth_lpar_connection *cnx;
	cnx = container_of(kobj, struct veth_lpar_connection, kobject);
	veth_stop_connection(cnx);
	veth_destroy_connection(cnx);
}

/*
 * net_device code
 */

static int veth_open(struct net_device *dev)
{
	netif_start_queue(dev);
	return 0;
}

static int veth_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

static int veth_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > VETH_MAX_MTU))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

static void veth_set_multicast_list(struct net_device *dev)
{
	struct veth_port *port = netdev_priv(dev);
	unsigned long flags;

	write_lock_irqsave(&port->mcast_gate, flags);

	if ((dev->flags & IFF_PROMISC) || (dev->flags & IFF_ALLMULTI) ||
			(netdev_mc_count(dev) > VETH_MAX_MCAST)) {
		port->promiscuous = 1;
	} else {
		struct netdev_hw_addr *ha;

		port->promiscuous = 0;

		/* Update table */
		port->num_mcast = 0;

		netdev_for_each_mc_addr(ha, dev) {
			u8 *addr = ha->addr;
			u64 xaddr = 0;

			memcpy(&xaddr, addr, ETH_ALEN);
			port->mcast_addr[port->num_mcast] = xaddr;
			port->num_mcast++;
		}
	}

	write_unlock_irqrestore(&port->mcast_gate, flags);
}

static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
	strncpy(info->driver, DRV_NAME, sizeof(info->driver) - 1);
	info->driver[sizeof(info->driver) - 1] = '\0';
	strncpy(info->version, DRV_VERSION, sizeof(info->version) - 1);
	info->version[sizeof(info->version) - 1] = '\0';
}

static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *ecmd)
{
	ecmd->supported = (SUPPORTED_1000baseT_Full
			  | SUPPORTED_Autoneg | SUPPORTED_FIBRE);
	ecmd->advertising = (SUPPORTED_1000baseT_Full
			    | SUPPORTED_Autoneg | SUPPORTED_FIBRE);
	ecmd->port = PORT_FIBRE;
	ecmd->transceiver = XCVR_INTERNAL;
	ecmd->phy_address = 0;
	ecmd->speed = SPEED_1000;
	ecmd->duplex = DUPLEX_FULL;
	ecmd->autoneg = AUTONEG_ENABLE;
	ecmd->maxtxpkt = 120;
	ecmd->maxrxpkt = 120;
	return 0;
}

static const struct ethtool_ops ops = {
	.get_drvinfo = veth_get_drvinfo,
	.get_settings = veth_get_settings,
	.get_link = ethtool_op_get_link,
};

static const struct net_device_ops veth_netdev_ops = {
	.ndo_open		= veth_open,
	.ndo_stop		= veth_close,
	.ndo_start_xmit		= veth_start_xmit,
	.ndo_change_mtu		= veth_change_mtu,
	.ndo_set_multicast_list	= veth_set_multicast_list,
	.ndo_set_mac_address	= NULL,
	.ndo_validate_addr	= eth_validate_addr,
};

static struct net_device *veth_probe_one(int vlan,
		struct vio_dev *vio_dev)
{
	struct net_device *dev;
	struct veth_port *port;
	struct device *vdev = &vio_dev->dev;
	int i, rc;
	const unsigned char *mac_addr;

	mac_addr = vio_get_attribute(vio_dev, "local-mac-address", NULL);
	if (mac_addr == NULL)
		mac_addr = vio_get_attribute(vio_dev, "mac-address", NULL);
	if (mac_addr == NULL) {
		veth_error("Unable to fetch MAC address from device tree.\n");
		return NULL;
	}

	dev = alloc_etherdev(sizeof (struct veth_port));
	if (! dev) {
		veth_error("Unable to allocate net_device structure!\n");
		return NULL;
	}

	port = netdev_priv(dev);

	spin_lock_init(&port->queue_lock);
	rwlock_init(&port->mcast_gate);
	port->stopped_map = 0;

	for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
		HvLpVirtualLanIndexMap map;

		if (i == this_lp)
			continue;
		map = HvLpConfig_getVirtualLanIndexMapForLp(i);
		if (map & (0x8000 >> vlan))
			port->lpar_map |= (1 << i);
	}
	port->dev = vdev;

	memcpy(dev->dev_addr, mac_addr, ETH_ALEN);

	dev->mtu = VETH_MAX_MTU;

	memcpy(&port->mac_addr, mac_addr, ETH_ALEN);

	dev->netdev_ops = &veth_netdev_ops;
	SET_ETHTOOL_OPS(dev, &ops);

	SET_NETDEV_DEV(dev, vdev);

	rc = register_netdev(dev);
	if (rc != 0) {
		veth_error("Failed registering net device for vlan%d.\n", vlan);
		free_netdev(dev);
		return NULL;
	}

	kobject_init(&port->kobject, &veth_port_ktype);
	if (0 != kobject_add(&port->kobject, &dev->dev.kobj, "veth_port"))
		veth_error("Failed adding port for %s to sysfs.\n", dev->name);

	veth_info("%s attached to iSeries vlan %d (LPAR map = 0x%.4X)\n",
			dev->name, vlan, port->lpar_map);

	return dev;
}

/*
 * Tx path
 */

static int veth_transmit_to_one(struct sk_buff *skb, HvLpIndex rlp,
				struct net_device *dev)
{
	struct veth_lpar_connection *cnx = veth_cnx[rlp];
	struct veth_port *port = netdev_priv(dev);
	HvLpEvent_Rc rc;
	struct veth_msg *msg = NULL;
	unsigned long flags;

	if (! cnx)
		return 0;

	spin_lock_irqsave(&cnx->lock, flags);

	if (! (cnx->state & VETH_STATE_READY))
		goto no_error;

	if ((skb->len - ETH_HLEN) > VETH_MAX_MTU)
		goto drop;

	msg = veth_stack_pop(cnx);
	if (! msg)
		goto drop;

	msg->in_use = 1;
	msg->skb = skb_get(skb);

	msg->data.addr[0] = dma_map_single(port->dev, skb->data,
				skb->len, DMA_TO_DEVICE);

	if (dma_mapping_error(port->dev, msg->data.addr[0]))
		goto recycle_and_drop;

	msg->dev = port->dev;
	msg->data.len[0] = skb->len;
	msg->data.eofmask = 1 << VETH_EOF_SHIFT;

	rc = veth_signaldata(cnx, VETH_EVENT_FRAMES, msg->token, &msg->data);

	if (rc != HvLpEvent_Rc_Good)
		goto recycle_and_drop;

	/* If the timer's not already running, start it now. */
	if (0 == cnx->outstanding_tx)
		mod_timer(&cnx->reset_timer, jiffies + cnx->reset_timeout);

	cnx->last_contact = jiffies;
	cnx->outstanding_tx++;

	if (veth_stack_is_empty(cnx))
		veth_stop_queues(cnx);

 no_error:
	spin_unlock_irqrestore(&cnx->lock, flags);
	return 0;

 recycle_and_drop:
	veth_recycle_msg(cnx, msg);
 drop:
	spin_unlock_irqrestore(&cnx->lock, flags);
	return 1;
}

static void veth_transmit_to_many(struct sk_buff *skb,
					  HvLpIndexMap lpmask,
					  struct net_device *dev)
{
	int i, success, error;

	success = error = 0;

	for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
		if ((lpmask & (1 << i)) == 0)
			continue;

		if (veth_transmit_to_one(skb, i, dev))
			error = 1;
		else
			success = 1;
	}

	if (error)
		dev->stats.tx_errors++;

	if (success) {
		dev->stats.tx_packets++;
		dev->stats.tx_bytes += skb->len;
	}
}

static int veth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned char *frame = skb->data;
	struct veth_port *port = netdev_priv(dev);
	HvLpIndexMap lpmask;

	if (is_unicast_ether_addr(frame)) {
		/* unicast packet */
		HvLpIndex rlp = frame[5];

		if ( ! ((1 << rlp) & port->lpar_map) ) {
			dev_kfree_skb(skb);
			return NETDEV_TX_OK;
		}

		lpmask = 1 << rlp;
	} else {
		lpmask = port->lpar_map;
	}

	veth_transmit_to_many(skb, lpmask, dev);

	dev_kfree_skb(skb);

	return NETDEV_TX_OK;
}

/* You must hold the connection's lock when you call this function. */
static void veth_recycle_msg(struct veth_lpar_connection *cnx,
			     struct veth_msg *msg)
{
	u32 dma_address, dma_length;

	if (msg->in_use) {
		msg->in_use = 0;
		dma_address = msg->data.addr[0];
		dma_length = msg->data.len[0];

		if (!dma_mapping_error(msg->dev, dma_address))
			dma_unmap_single(msg->dev, dma_address, dma_length,
					DMA_TO_DEVICE);

		if (msg->skb) {
			dev_kfree_skb_any(msg->skb);
			msg->skb = NULL;
		}

		memset(&msg->data, 0, sizeof(msg->data));
		veth_stack_push(cnx, msg);
	} else if (cnx->state & VETH_STATE_OPEN) {
		veth_error("Non-pending frame (# %d) acked by LPAR %d.\n",
				cnx->remote_lp, msg->token);
	}
}

static void veth_wake_queues(struct veth_lpar_connection *cnx)
{
	int i;

	for (i = 0; i < HVMAXARCHITECTEDVIRTUALLANS; i++) {
		struct net_device *dev = veth_dev[i];
		struct veth_port *port;
		unsigned long flags;

		if (! dev)
			continue;

		port = netdev_priv(dev);

		if (! (port->lpar_map & (1<<cnx->remote_lp)))
			continue;

		spin_lock_irqsave(&port->queue_lock, flags);

		port->stopped_map &= ~(1 << cnx->remote_lp);

		if (0 == port->stopped_map && netif_queue_stopped(dev)) {
			veth_debug("cnx %d: woke queue for %s.\n",
					cnx->remote_lp, dev->name);
			netif_wake_queue(dev);
		}
		spin_unlock_irqrestore(&port->queue_lock, flags);
	}
}

static void veth_stop_queues(struct veth_lpar_connection *cnx)
{
	int i;

	for (i = 0; i < HVMAXARCHITECTEDVIRTUALLANS; i++) {
		struct net_device *dev = veth_dev[i];
		struct veth_port *port;

		if (! dev)
			continue;

		port = netdev_priv(dev);

		/* If this cnx is not on the vlan for this port, continue */
		if (! (port->lpar_map & (1 << cnx->remote_lp)))
			continue;

		spin_lock(&port->queue_lock);

		netif_stop_queue(dev);
		port->stopped_map |= (1 << cnx->remote_lp);

		veth_debug("cnx %d: stopped queue for %s, map = 0x%x.\n",
				cnx->remote_lp, dev->name, port->stopped_map);

		spin_unlock(&port->queue_lock);
	}
}

static void veth_timed_reset(unsigned long ptr)
{
	struct veth_lpar_connection *cnx = (struct veth_lpar_connection *)ptr;
	unsigned long trigger_time, flags;

	/* FIXME is it possible this fires after veth_stop_connection()?
	 * That would reschedule the statemachine for 5 seconds and probably
	 * execute it after the module's been unloaded. Hmm. */

	spin_lock_irqsave(&cnx->lock, flags);

	if (cnx->outstanding_tx > 0) {
		trigger_time = cnx->last_contact + cnx->reset_timeout;

		if (trigger_time < jiffies) {
			cnx->state |= VETH_STATE_RESET;
			veth_kick_statemachine(cnx);
			veth_error("%d packets not acked by LPAR %d within %d "
					"seconds, resetting.\n",
					cnx->outstanding_tx, cnx->remote_lp,
					cnx->reset_timeout / HZ);
		} else {
			/* Reschedule the timer */
			trigger_time = jiffies + cnx->reset_timeout;
			mod_timer(&cnx->reset_timer, trigger_time);
		}
	}

	spin_unlock_irqrestore(&cnx->lock, flags);
}

/*
 * Rx path
 */

static inline int veth_frame_wanted(struct veth_port *port, u64 mac_addr)
{
	int wanted = 0;
	int i;
	unsigned long flags;

	if ( (mac_addr == port->mac_addr) || (mac_addr == 0xffffffffffff0000) )
		return 1;

	read_lock_irqsave(&port->mcast_gate, flags);

	if (port->promiscuous) {
		wanted = 1;
		goto out;
	}

	for (i = 0; i < port->num_mcast; ++i) {
		if (port->mcast_addr[i] == mac_addr) {
			wanted = 1;
			break;
		}
	}

 out:
	read_unlock_irqrestore(&port->mcast_gate, flags);

	return wanted;
}

struct dma_chunk {
	u64 addr;
	u64 size;
};

#define VETH_MAX_PAGES_PER_FRAME ( (VETH_MAX_MTU+PAGE_SIZE-2)/PAGE_SIZE + 1 )

static inline void veth_build_dma_list(struct dma_chunk *list,
				       unsigned char *p, unsigned long length)
{
	unsigned long done;
	int i = 1;

	/* FIXME: skbs are contiguous in real addresses.  Do we
	 * really need to break it into PAGE_SIZE chunks, or can we do
	 * it just at the granularity of iSeries real->absolute
	 * mapping?  Indeed, given the way the allocator works, can we
	 * count on them being absolutely contiguous? */
	list[0].addr = iseries_hv_addr(p);
	list[0].size = min(length,
			   PAGE_SIZE - ((unsigned long)p & ~PAGE_MASK));

	done = list[0].size;
	while (done < length) {
		list[i].addr = iseries_hv_addr(p + done);
		list[i].size = min(length-done, PAGE_SIZE);
		done += list[i].size;
		i++;
	}
}

static void veth_flush_acks(struct veth_lpar_connection *cnx)
{
	HvLpEvent_Rc rc;

	rc = veth_signaldata(cnx, VETH_EVENT_FRAMES_ACK,
			     0, &cnx->pending_acks);

	if (rc != HvLpEvent_Rc_Good)
		veth_error("Failed acking frames from LPAR %d, rc = %d\n",
				cnx->remote_lp, (int)rc);

	cnx->num_pending_acks = 0;
	memset(&cnx->pending_acks, 0xff, sizeof(cnx->pending_acks));
}

static void veth_receive(struct veth_lpar_connection *cnx,
			 struct veth_lpevent *event)
{
	struct veth_frames_data *senddata = &event->u.frames_data;
	int startchunk = 0;
	int nchunks;
	unsigned long flags;
	HvLpDma_Rc rc;

	do {
		u16 length = 0;
		struct sk_buff *skb;
		struct dma_chunk local_list[VETH_MAX_PAGES_PER_FRAME];
		struct dma_chunk remote_list[VETH_MAX_FRAMES_PER_MSG];
		u64 dest;
		HvLpVirtualLanIndex vlan;
		struct net_device *dev;
		struct veth_port *port;

		/* FIXME: do we need this? */
		memset(local_list, 0, sizeof(local_list));
		memset(remote_list, 0, sizeof(VETH_MAX_FRAMES_PER_MSG));

		/* a 0 address marks the end of the valid entries */
		if (senddata->addr[startchunk] == 0)
			break;

		/* make sure that we have at least 1 EOF entry in the
		 * remaining entries */
		if (! (senddata->eofmask >> (startchunk + VETH_EOF_SHIFT))) {
			veth_error("Missing EOF fragment in event "
					"eofmask = 0x%x startchunk = %d\n",
					(unsigned)senddata->eofmask,
					startchunk);
			break;
		}

		/* build list of chunks in this frame */
		nchunks = 0;
		do {
			remote_list[nchunks].addr =
				(u64) senddata->addr[startchunk+nchunks] << 32;
			remote_list[nchunks].size =
				senddata->len[startchunk+nchunks];
			length += remote_list[nchunks].size;
		} while (! (senddata->eofmask &
			    (1 << (VETH_EOF_SHIFT + startchunk + nchunks++))));

		/* length == total length of all chunks */
		/* nchunks == # of chunks in this frame */

		if ((length - ETH_HLEN) > VETH_MAX_MTU) {
			veth_error("Received oversize frame from LPAR %d "
					"(length = %d)\n",
					cnx->remote_lp, length);
			continue;
		}

		skb = alloc_skb(length, GFP_ATOMIC);
		if (!skb)
			continue;

		veth_build_dma_list(local_list, skb->data, length);

		rc = HvCallEvent_dmaBufList(HvLpEvent_Type_VirtualLan,
					    event->base_event.xSourceLp,
					    HvLpDma_Direction_RemoteToLocal,
					    cnx->src_inst,
					    cnx->dst_inst,
					    HvLpDma_AddressType_RealAddress,
					    HvLpDma_AddressType_TceIndex,
					    iseries_hv_addr(&local_list),
					    iseries_hv_addr(&remote_list),
					    length);
		if (rc != HvLpDma_Rc_Good) {
			dev_kfree_skb_irq(skb);
			continue;
		}

		vlan = skb->data[9];
		dev = veth_dev[vlan];
		if (! dev) {
			/*
			 * Some earlier versions of the driver sent
			 * broadcasts down all connections, even to lpars
			 * that weren't on the relevant vlan. So ignore
			 * packets belonging to a vlan we're not on.
			 * We can also be here if we receive packets while
			 * the driver is going down, because then dev is NULL.
			 */
			dev_kfree_skb_irq(skb);
			continue;
		}

		port = netdev_priv(dev);
		dest = *((u64 *) skb->data) & 0xFFFFFFFFFFFF0000;

		if ((vlan > HVMAXARCHITECTEDVIRTUALLANS) || !port) {
			dev_kfree_skb_irq(skb);
			continue;
		}
		if (! veth_frame_wanted(port, dest)) {
			dev_kfree_skb_irq(skb);
			continue;
		}

		skb_put(skb, length);
		skb->protocol = eth_type_trans(skb, dev);
		skb_checksum_none_assert(skb);
		netif_rx(skb);	/* send it up */
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += length;
	} while (startchunk += nchunks, startchunk < VETH_MAX_FRAMES_PER_MSG);

	/* Ack it */
	spin_lock_irqsave(&cnx->lock, flags);
	BUG_ON(cnx->num_pending_acks > VETH_MAX_ACKS_PER_MSG);

	cnx->pending_acks[cnx->num_pending_acks++] =
		event->base_event.xCorrelationToken;

	if ( (cnx->num_pending_acks >= cnx->remote_caps.ack_threshold) ||
	     (cnx->num_pending_acks >= VETH_MAX_ACKS_PER_MSG) )
		veth_flush_acks(cnx);

	spin_unlock_irqrestore(&cnx->lock, flags);
}

static void veth_timed_ack(unsigned long ptr)
{
	struct veth_lpar_connection *cnx = (struct veth_lpar_connection *) ptr;
	unsigned long flags;

	/* Ack all the events */
	spin_lock_irqsave(&cnx->lock, flags);
	if (cnx->num_pending_acks > 0)
		veth_flush_acks(cnx);

	/* Reschedule the timer */
	cnx->ack_timer.expires = jiffies + cnx->ack_timeout;
	add_timer(&cnx->ack_timer);
	spin_unlock_irqrestore(&cnx->lock, flags);
}

static int veth_remove(struct vio_dev *vdev)
{
	struct veth_lpar_connection *cnx;
	struct net_device *dev;
	struct veth_port *port;
	int i;

	dev = veth_dev[vdev->unit_address];

	if (! dev)
		return 0;

	port = netdev_priv(dev);

	for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
		cnx = veth_cnx[i];

		if (cnx && (port->lpar_map & (1 << i))) {
			/* Drop our reference to connections on our VLAN */
			kobject_put(&cnx->kobject);
		}
	}

	veth_dev[vdev->unit_address] = NULL;
	kobject_del(&port->kobject);
	kobject_put(&port->kobject);
	unregister_netdev(dev);
	free_netdev(dev);

	return 0;
}

static int veth_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
	int i = vdev->unit_address;
	struct net_device *dev;
	struct veth_port *port;

	dev = veth_probe_one(i, vdev);
	if (dev == NULL) {
		veth_remove(vdev);
		return 1;
	}
	veth_dev[i] = dev;

	port = netdev_priv(dev);

	/* Start the state machine on each connection on this vlan. If we're
	 * the first dev to do so this will commence link negotiation */
	for (i = 0; i < HVMAXARCHITECTEDLPS; i++) {
		struct veth_lpar_connection *cnx;

		if (! (port->lpar_map & (1 << i)))
			continue;

		cnx = veth_cnx[i];
		if (!cnx)
			continue;

		kobject_get(&cnx->kobject);
		veth_kick_statemachine(cnx);
	}

	return 0;
}

/**
 * veth_device_table: Used by vio.c to match devices that we
 * support.
 */
static struct vio_device_id veth_device_table[] __devinitdata = {
	{ "network", "IBM,iSeries-l-lan" },
	{ "", "" }
};
MODULE_DEVICE_TABLE(vio, veth_device_table);

static struct vio_driver veth_driver = {
	.id_table = veth_device_table,
	.probe = veth_probe,
	.remove = veth_remove,
	.driver = {
		.name = DRV_NAME,
		.owner = THIS_MODULE,
	}
};

/*
 * Module initialization/cleanup
 */

static void __exit veth_module_cleanup(void)
{
	int i;
	struct veth_lpar_connection *cnx;

	/* Disconnect our "irq" to stop events coming from the Hypervisor. */
	HvLpEvent_unregisterHandler(HvLpEvent_Type_VirtualLan);

	for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
		cnx = veth_cnx[i];

		if (!cnx)
			continue;

		/* Cancel work queued from Hypervisor callbacks */
		cancel_delayed_work_sync(&cnx->statemachine_wq);
		/* Remove the connection from sysfs */
		kobject_del(&cnx->kobject);
		/* Drop the driver's reference to the connection */
		kobject_put(&cnx->kobject);
	}

	/* Unregister the driver, which will close all the netdevs and stop
	 * the connections when they're no longer referenced. */
	vio_unregister_driver(&veth_driver);
}
module_exit(veth_module_cleanup);

static int __init veth_module_init(void)
{
	int i;
	int rc;

	if (!firmware_has_feature(FW_FEATURE_ISERIES))
		return -ENODEV;

	this_lp = HvLpConfig_getLpIndex_outline();

	for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
		rc = veth_init_connection(i);
		if (rc != 0)
			goto error;
	}

	HvLpEvent_registerHandler(HvLpEvent_Type_VirtualLan,
				  &veth_handle_event);

	rc = vio_register_driver(&veth_driver);
	if (rc != 0)
		goto error;

	for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
		struct kobject *kobj;

		if (!veth_cnx[i])
			continue;

		kobj = &veth_cnx[i]->kobject;
		/* If the add failes, complain but otherwise continue */
		if (0 != driver_add_kobj(&veth_driver.driver, kobj,
					"cnx%.2d", veth_cnx[i]->remote_lp))
			veth_error("cnx %d: Failed adding to sysfs.\n", i);
	}

	return 0;

error:
	for (i = 0; i < HVMAXARCHITECTEDLPS; ++i) {
		veth_destroy_connection(veth_cnx[i]);
	}

	return rc;
}
module_init(veth_module_init);