Free Electrons

Embedded Linux Experts

  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
/* viohs.c: LDOM Virtual I/O handshake helper layer.
 *
 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
 */

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <asm/ldc.h>
#include <asm/vio.h>

int vio_ldc_send(struct vio_driver_state *vio, void *data, int len)
{
	int err, limit = 1000;

	err = -EINVAL;
	while (limit-- > 0) {
		err = ldc_write(vio->lp, data, len);
		if (!err || (err != -EAGAIN))
			break;
		udelay(1);
	}

	return err;
}
EXPORT_SYMBOL(vio_ldc_send);

static int send_ctrl(struct vio_driver_state *vio,
		     struct vio_msg_tag *tag, int len)
{
	tag->sid = vio_send_sid(vio);
	return vio_ldc_send(vio, tag, len);
}

static void init_tag(struct vio_msg_tag *tag, u8 type, u8 stype, u16 stype_env)
{
	tag->type = type;
	tag->stype = stype;
	tag->stype_env = stype_env;
}

static int send_version(struct vio_driver_state *vio, u16 major, u16 minor)
{
	struct vio_ver_info pkt;

	vio->_local_sid = (u32) sched_clock();

	memset(&pkt, 0, sizeof(pkt));
	init_tag(&pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_VER_INFO);
	pkt.major = major;
	pkt.minor = minor;
	pkt.dev_class = vio->dev_class;

	viodbg(HS, "SEND VERSION INFO maj[%u] min[%u] devclass[%u]\n",
	       major, minor, vio->dev_class);

	return send_ctrl(vio, &pkt.tag, sizeof(pkt));
}

static int start_handshake(struct vio_driver_state *vio)
{
	int err;

	viodbg(HS, "START HANDSHAKE\n");

	vio->hs_state = VIO_HS_INVALID;

	err = send_version(vio,
			   vio->ver_table[0].major,
			   vio->ver_table[0].minor);
	if (err < 0)
		return err;

	return 0;
}

static void flush_rx_dring(struct vio_driver_state *vio)
{
	struct vio_dring_state *dr;
	u64 ident;

	BUG_ON(!(vio->dr_state & VIO_DR_STATE_RXREG));

	dr = &vio->drings[VIO_DRIVER_RX_RING];
	ident = dr->ident;

	BUG_ON(!vio->desc_buf);
	kfree(vio->desc_buf);
	vio->desc_buf = NULL;

	memset(dr, 0, sizeof(*dr));
	dr->ident = ident;
}

void vio_link_state_change(struct vio_driver_state *vio, int event)
{
	if (event == LDC_EVENT_UP) {
		vio->hs_state = VIO_HS_INVALID;

		switch (vio->dev_class) {
		case VDEV_NETWORK:
		case VDEV_NETWORK_SWITCH:
			vio->dr_state = (VIO_DR_STATE_TXREQ |
					 VIO_DR_STATE_RXREQ);
			break;

		case VDEV_DISK:
			vio->dr_state = VIO_DR_STATE_TXREQ;
			break;
		case VDEV_DISK_SERVER:
			vio->dr_state = VIO_DR_STATE_RXREQ;
			break;
		}
		start_handshake(vio);
	} else if (event == LDC_EVENT_RESET) {
		vio->hs_state = VIO_HS_INVALID;

		if (vio->dr_state & VIO_DR_STATE_RXREG)
			flush_rx_dring(vio);

		vio->dr_state = 0x00;
		memset(&vio->ver, 0, sizeof(vio->ver));

		ldc_disconnect(vio->lp);
	}
}
EXPORT_SYMBOL(vio_link_state_change);

static int handshake_failure(struct vio_driver_state *vio)
{
	struct vio_dring_state *dr;

	/* XXX Put policy here...  Perhaps start a timer to fire
	 * XXX in 100 ms, which will bring the link up and retry
	 * XXX the handshake.
	 */

	viodbg(HS, "HANDSHAKE FAILURE\n");

	vio->dr_state &= ~(VIO_DR_STATE_TXREG |
			   VIO_DR_STATE_RXREG);

	dr = &vio->drings[VIO_DRIVER_RX_RING];
	memset(dr, 0, sizeof(*dr));

	kfree(vio->desc_buf);
	vio->desc_buf = NULL;
	vio->desc_buf_len = 0;

	vio->hs_state = VIO_HS_INVALID;

	return -ECONNRESET;
}

static int process_unknown(struct vio_driver_state *vio, void *arg)
{
	struct vio_msg_tag *pkt = arg;

	viodbg(HS, "UNKNOWN CONTROL [%02x:%02x:%04x:%08x]\n",
	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);

	printk(KERN_ERR "vio: ID[%lu] Resetting connection.\n",
	       vio->vdev->channel_id);

	ldc_disconnect(vio->lp);

	return -ECONNRESET;
}

static int send_dreg(struct vio_driver_state *vio)
{
	struct vio_dring_state *dr = &vio->drings[VIO_DRIVER_TX_RING];
	union {
		struct vio_dring_register pkt;
		char all[sizeof(struct vio_dring_register) +
			 (sizeof(struct ldc_trans_cookie) *
			  dr->ncookies)];
	} u;
	int i;

	memset(&u, 0, sizeof(u));
	init_tag(&u.pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_DRING_REG);
	u.pkt.dring_ident = 0;
	u.pkt.num_descr = dr->num_entries;
	u.pkt.descr_size = dr->entry_size;
	u.pkt.options = VIO_TX_DRING;
	u.pkt.num_cookies = dr->ncookies;

	viodbg(HS, "SEND DRING_REG INFO ndesc[%u] dsz[%u] opt[0x%x] "
	       "ncookies[%u]\n",
	       u.pkt.num_descr, u.pkt.descr_size, u.pkt.options,
	       u.pkt.num_cookies);

	for (i = 0; i < dr->ncookies; i++) {
		u.pkt.cookies[i] = dr->cookies[i];

		viodbg(HS, "DRING COOKIE(%d) [%016llx:%016llx]\n",
		       i,
		       (unsigned long long) u.pkt.cookies[i].cookie_addr,
		       (unsigned long long) u.pkt.cookies[i].cookie_size);
	}

	return send_ctrl(vio, &u.pkt.tag, sizeof(u));
}

static int send_rdx(struct vio_driver_state *vio)
{
	struct vio_rdx pkt;

	memset(&pkt, 0, sizeof(pkt));

	init_tag(&pkt.tag, VIO_TYPE_CTRL, VIO_SUBTYPE_INFO, VIO_RDX);

	viodbg(HS, "SEND RDX INFO\n");

	return send_ctrl(vio, &pkt.tag, sizeof(pkt));
}

static int send_attr(struct vio_driver_state *vio)
{
	return vio->ops->send_attr(vio);
}

static struct vio_version *find_by_major(struct vio_driver_state *vio,
					 u16 major)
{
	struct vio_version *ret = NULL;
	int i;

	for (i = 0; i < vio->ver_table_entries; i++) {
		struct vio_version *v = &vio->ver_table[i];
		if (v->major <= major) {
			ret = v;
			break;
		}
	}
	return ret;
}

static int process_ver_info(struct vio_driver_state *vio,
			    struct vio_ver_info *pkt)
{
	struct vio_version *vap;
	int err;

	viodbg(HS, "GOT VERSION INFO maj[%u] min[%u] devclass[%u]\n",
	       pkt->major, pkt->minor, pkt->dev_class);

	if (vio->hs_state != VIO_HS_INVALID) {
		/* XXX Perhaps invoke start_handshake? XXX */
		memset(&vio->ver, 0, sizeof(vio->ver));
		vio->hs_state = VIO_HS_INVALID;
	}

	vap = find_by_major(vio, pkt->major);

	vio->_peer_sid = pkt->tag.sid;

	if (!vap) {
		pkt->tag.stype = VIO_SUBTYPE_NACK;
		pkt->major = 0;
		pkt->minor = 0;
		viodbg(HS, "SEND VERSION NACK maj[0] min[0]\n");
		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
	} else if (vap->major != pkt->major) {
		pkt->tag.stype = VIO_SUBTYPE_NACK;
		pkt->major = vap->major;
		pkt->minor = vap->minor;
		viodbg(HS, "SEND VERSION NACK maj[%u] min[%u]\n",
		       pkt->major, pkt->minor);
		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
	} else {
		struct vio_version ver = {
			.major = pkt->major,
			.minor = pkt->minor,
		};
		if (ver.minor > vap->minor)
			ver.minor = vap->minor;
		pkt->minor = ver.minor;
		pkt->tag.stype = VIO_SUBTYPE_ACK;
		viodbg(HS, "SEND VERSION ACK maj[%u] min[%u]\n",
		       pkt->major, pkt->minor);
		err = send_ctrl(vio, &pkt->tag, sizeof(*pkt));
		if (err > 0) {
			vio->ver = ver;
			vio->hs_state = VIO_HS_GOTVERS;
		}
	}
	if (err < 0)
		return handshake_failure(vio);

	return 0;
}

static int process_ver_ack(struct vio_driver_state *vio,
			   struct vio_ver_info *pkt)
{
	viodbg(HS, "GOT VERSION ACK maj[%u] min[%u] devclass[%u]\n",
	       pkt->major, pkt->minor, pkt->dev_class);

	if (vio->hs_state & VIO_HS_GOTVERS) {
		if (vio->ver.major != pkt->major ||
		    vio->ver.minor != pkt->minor) {
			pkt->tag.stype = VIO_SUBTYPE_NACK;
			(void) send_ctrl(vio, &pkt->tag, sizeof(*pkt));
			return handshake_failure(vio);
		}
	} else {
		vio->ver.major = pkt->major;
		vio->ver.minor = pkt->minor;
		vio->hs_state = VIO_HS_GOTVERS;
	}

	switch (vio->dev_class) {
	case VDEV_NETWORK:
	case VDEV_DISK:
		if (send_attr(vio) < 0)
			return handshake_failure(vio);
		break;

	default:
		break;
	}

	return 0;
}

static int process_ver_nack(struct vio_driver_state *vio,
			    struct vio_ver_info *pkt)
{
	struct vio_version *nver;

	viodbg(HS, "GOT VERSION NACK maj[%u] min[%u] devclass[%u]\n",
	       pkt->major, pkt->minor, pkt->dev_class);

	if (pkt->major == 0 && pkt->minor == 0)
		return handshake_failure(vio);
	nver = find_by_major(vio, pkt->major);
	if (!nver)
		return handshake_failure(vio);

	if (send_version(vio, nver->major, nver->minor) < 0)
		return handshake_failure(vio);

	return 0;
}

static int process_ver(struct vio_driver_state *vio, struct vio_ver_info *pkt)
{
	switch (pkt->tag.stype) {
	case VIO_SUBTYPE_INFO:
		return process_ver_info(vio, pkt);

	case VIO_SUBTYPE_ACK:
		return process_ver_ack(vio, pkt);

	case VIO_SUBTYPE_NACK:
		return process_ver_nack(vio, pkt);

	default:
		return handshake_failure(vio);
	}
}

static int process_attr(struct vio_driver_state *vio, void *pkt)
{
	int err;

	if (!(vio->hs_state & VIO_HS_GOTVERS))
		return handshake_failure(vio);

	err = vio->ops->handle_attr(vio, pkt);
	if (err < 0) {
		return handshake_failure(vio);
	} else {
		vio->hs_state |= VIO_HS_GOT_ATTR;

		if ((vio->dr_state & VIO_DR_STATE_TXREQ) &&
		    !(vio->hs_state & VIO_HS_SENT_DREG)) {
			if (send_dreg(vio) < 0)
				return handshake_failure(vio);

			vio->hs_state |= VIO_HS_SENT_DREG;
		}
	}
	return 0;
}

static int all_drings_registered(struct vio_driver_state *vio)
{
	int need_rx, need_tx;

	need_rx = (vio->dr_state & VIO_DR_STATE_RXREQ);
	need_tx = (vio->dr_state & VIO_DR_STATE_TXREQ);

	if (need_rx &&
	    !(vio->dr_state & VIO_DR_STATE_RXREG))
		return 0;

	if (need_tx &&
	    !(vio->dr_state & VIO_DR_STATE_TXREG))
		return 0;

	return 1;
}

static int process_dreg_info(struct vio_driver_state *vio,
			     struct vio_dring_register *pkt)
{
	struct vio_dring_state *dr;
	int i, len;

	viodbg(HS, "GOT DRING_REG INFO ident[%llx] "
	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
	       (unsigned long long) pkt->dring_ident,
	       pkt->num_descr, pkt->descr_size, pkt->options,
	       pkt->num_cookies);

	if (!(vio->dr_state & VIO_DR_STATE_RXREQ))
		goto send_nack;

	if (vio->dr_state & VIO_DR_STATE_RXREG)
		goto send_nack;

	BUG_ON(vio->desc_buf);

	vio->desc_buf = kzalloc(pkt->descr_size, GFP_ATOMIC);
	if (!vio->desc_buf)
		goto send_nack;

	vio->desc_buf_len = pkt->descr_size;

	dr = &vio->drings[VIO_DRIVER_RX_RING];

	dr->num_entries = pkt->num_descr;
	dr->entry_size = pkt->descr_size;
	dr->ncookies = pkt->num_cookies;
	for (i = 0; i < dr->ncookies; i++) {
		dr->cookies[i] = pkt->cookies[i];

		viodbg(HS, "DRING COOKIE(%d) [%016llx:%016llx]\n",
		       i,
		       (unsigned long long)
		       pkt->cookies[i].cookie_addr,
		       (unsigned long long)
		       pkt->cookies[i].cookie_size);
	}

	pkt->tag.stype = VIO_SUBTYPE_ACK;
	pkt->dring_ident = ++dr->ident;

	viodbg(HS, "SEND DRING_REG ACK ident[%llx]\n",
	       (unsigned long long) pkt->dring_ident);

	len = (sizeof(*pkt) +
	       (dr->ncookies * sizeof(struct ldc_trans_cookie)));
	if (send_ctrl(vio, &pkt->tag, len) < 0)
		goto send_nack;

	vio->dr_state |= VIO_DR_STATE_RXREG;

	return 0;

send_nack:
	pkt->tag.stype = VIO_SUBTYPE_NACK;
	viodbg(HS, "SEND DRING_REG NACK\n");
	(void) send_ctrl(vio, &pkt->tag, sizeof(*pkt));

	return handshake_failure(vio);
}

static int process_dreg_ack(struct vio_driver_state *vio,
			    struct vio_dring_register *pkt)
{
	struct vio_dring_state *dr;

	viodbg(HS, "GOT DRING_REG ACK ident[%llx] "
	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
	       (unsigned long long) pkt->dring_ident,
	       pkt->num_descr, pkt->descr_size, pkt->options,
	       pkt->num_cookies);

	dr = &vio->drings[VIO_DRIVER_TX_RING];

	if (!(vio->dr_state & VIO_DR_STATE_TXREQ))
		return handshake_failure(vio);

	dr->ident = pkt->dring_ident;
	vio->dr_state |= VIO_DR_STATE_TXREG;

	if (all_drings_registered(vio)) {
		if (send_rdx(vio) < 0)
			return handshake_failure(vio);
		vio->hs_state = VIO_HS_SENT_RDX;
	}
	return 0;
}

static int process_dreg_nack(struct vio_driver_state *vio,
			     struct vio_dring_register *pkt)
{
	viodbg(HS, "GOT DRING_REG NACK ident[%llx] "
	       "ndesc[%u] dsz[%u] opt[0x%x] ncookies[%u]\n",
	       (unsigned long long) pkt->dring_ident,
	       pkt->num_descr, pkt->descr_size, pkt->options,
	       pkt->num_cookies);

	return handshake_failure(vio);
}

static int process_dreg(struct vio_driver_state *vio,
			struct vio_dring_register *pkt)
{
	if (!(vio->hs_state & VIO_HS_GOTVERS))
		return handshake_failure(vio);

	switch (pkt->tag.stype) {
	case VIO_SUBTYPE_INFO:
		return process_dreg_info(vio, pkt);

	case VIO_SUBTYPE_ACK:
		return process_dreg_ack(vio, pkt);

	case VIO_SUBTYPE_NACK:
		return process_dreg_nack(vio, pkt);

	default:
		return handshake_failure(vio);
	}
}

static int process_dunreg(struct vio_driver_state *vio,
			  struct vio_dring_unregister *pkt)
{
	struct vio_dring_state *dr = &vio->drings[VIO_DRIVER_RX_RING];

	viodbg(HS, "GOT DRING_UNREG\n");

	if (pkt->dring_ident != dr->ident)
		return 0;

	vio->dr_state &= ~VIO_DR_STATE_RXREG;

	memset(dr, 0, sizeof(*dr));

	kfree(vio->desc_buf);
	vio->desc_buf = NULL;
	vio->desc_buf_len = 0;

	return 0;
}

static int process_rdx_info(struct vio_driver_state *vio, struct vio_rdx *pkt)
{
	viodbg(HS, "GOT RDX INFO\n");

	pkt->tag.stype = VIO_SUBTYPE_ACK;
	viodbg(HS, "SEND RDX ACK\n");
	if (send_ctrl(vio, &pkt->tag, sizeof(*pkt)) < 0)
		return handshake_failure(vio);

	vio->hs_state |= VIO_HS_SENT_RDX_ACK;
	return 0;
}

static int process_rdx_ack(struct vio_driver_state *vio, struct vio_rdx *pkt)
{
	viodbg(HS, "GOT RDX ACK\n");

	if (!(vio->hs_state & VIO_HS_SENT_RDX))
		return handshake_failure(vio);

	vio->hs_state |= VIO_HS_GOT_RDX_ACK;
	return 0;
}

static int process_rdx_nack(struct vio_driver_state *vio, struct vio_rdx *pkt)
{
	viodbg(HS, "GOT RDX NACK\n");

	return handshake_failure(vio);
}

static int process_rdx(struct vio_driver_state *vio, struct vio_rdx *pkt)
{
	if (!all_drings_registered(vio))
		handshake_failure(vio);

	switch (pkt->tag.stype) {
	case VIO_SUBTYPE_INFO:
		return process_rdx_info(vio, pkt);

	case VIO_SUBTYPE_ACK:
		return process_rdx_ack(vio, pkt);

	case VIO_SUBTYPE_NACK:
		return process_rdx_nack(vio, pkt);

	default:
		return handshake_failure(vio);
	}
}

int vio_control_pkt_engine(struct vio_driver_state *vio, void *pkt)
{
	struct vio_msg_tag *tag = pkt;
	u8 prev_state = vio->hs_state;
	int err;

	switch (tag->stype_env) {
	case VIO_VER_INFO:
		err = process_ver(vio, pkt);
		break;

	case VIO_ATTR_INFO:
		err = process_attr(vio, pkt);
		break;

	case VIO_DRING_REG:
		err = process_dreg(vio, pkt);
		break;

	case VIO_DRING_UNREG:
		err = process_dunreg(vio, pkt);
		break;

	case VIO_RDX:
		err = process_rdx(vio, pkt);
		break;

	default:
		err = process_unknown(vio, pkt);
		break;
	}
	if (!err &&
	    vio->hs_state != prev_state &&
	    (vio->hs_state & VIO_HS_COMPLETE))
		vio->ops->handshake_complete(vio);

	return err;
}
EXPORT_SYMBOL(vio_control_pkt_engine);

void vio_conn_reset(struct vio_driver_state *vio)
{
}
EXPORT_SYMBOL(vio_conn_reset);

/* The issue is that the Solaris virtual disk server just mirrors the
 * SID values it gets from the client peer.  So we work around that
 * here in vio_{validate,send}_sid() so that the drivers don't need
 * to be aware of this crap.
 */
int vio_validate_sid(struct vio_driver_state *vio, struct vio_msg_tag *tp)
{
	u32 sid;

	/* Always let VERSION+INFO packets through unchecked, they
	 * define the new SID.
	 */
	if (tp->type == VIO_TYPE_CTRL &&
	    tp->stype == VIO_SUBTYPE_INFO &&
	    tp->stype_env == VIO_VER_INFO)
		return 0;

	/* Ok, now figure out which SID to use.  */
	switch (vio->dev_class) {
	case VDEV_NETWORK:
	case VDEV_NETWORK_SWITCH:
	case VDEV_DISK_SERVER:
	default:
		sid = vio->_peer_sid;
		break;

	case VDEV_DISK:
		sid = vio->_local_sid;
		break;
	}

	if (sid == tp->sid)
		return 0;
	viodbg(DATA, "BAD SID tag->sid[%08x] peer_sid[%08x] local_sid[%08x]\n",
	       tp->sid, vio->_peer_sid, vio->_local_sid);
	return -EINVAL;
}
EXPORT_SYMBOL(vio_validate_sid);

u32 vio_send_sid(struct vio_driver_state *vio)
{
	switch (vio->dev_class) {
	case VDEV_NETWORK:
	case VDEV_NETWORK_SWITCH:
	case VDEV_DISK:
	default:
		return vio->_local_sid;

	case VDEV_DISK_SERVER:
		return vio->_peer_sid;
	}
}
EXPORT_SYMBOL(vio_send_sid);

int vio_ldc_alloc(struct vio_driver_state *vio,
			 struct ldc_channel_config *base_cfg,
			 void *event_arg)
{
	struct ldc_channel_config cfg = *base_cfg;
	struct ldc_channel *lp;

	cfg.tx_irq = vio->vdev->tx_irq;
	cfg.rx_irq = vio->vdev->rx_irq;

	lp = ldc_alloc(vio->vdev->channel_id, &cfg, event_arg);
	if (IS_ERR(lp))
		return PTR_ERR(lp);

	vio->lp = lp;

	return 0;
}
EXPORT_SYMBOL(vio_ldc_alloc);

void vio_ldc_free(struct vio_driver_state *vio)
{
	ldc_free(vio->lp);
	vio->lp = NULL;

	kfree(vio->desc_buf);
	vio->desc_buf = NULL;
	vio->desc_buf_len = 0;
}
EXPORT_SYMBOL(vio_ldc_free);

void vio_port_up(struct vio_driver_state *vio)
{
	unsigned long flags;
	int err, state;

	spin_lock_irqsave(&vio->lock, flags);

	state = ldc_state(vio->lp);

	err = 0;
	if (state == LDC_STATE_INIT) {
		err = ldc_bind(vio->lp, vio->name);
		if (err)
			printk(KERN_WARNING "%s: Port %lu bind failed, "
			       "err=%d\n",
			       vio->name, vio->vdev->channel_id, err);
	}

	if (!err) {
		err = ldc_connect(vio->lp);
		if (err)
			printk(KERN_WARNING "%s: Port %lu connect failed, "
			       "err=%d\n",
			       vio->name, vio->vdev->channel_id, err);
	}
	if (err) {
		unsigned long expires = jiffies + HZ;

		expires = round_jiffies(expires);
		mod_timer(&vio->timer, expires);
	}

	spin_unlock_irqrestore(&vio->lock, flags);
}
EXPORT_SYMBOL(vio_port_up);

static void vio_port_timer(unsigned long _arg)
{
	struct vio_driver_state *vio = (struct vio_driver_state *) _arg;

	vio_port_up(vio);
}

int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
		    u8 dev_class, struct vio_version *ver_table,
		    int ver_table_size, struct vio_driver_ops *ops,
		    char *name)
{
	switch (dev_class) {
	case VDEV_NETWORK:
	case VDEV_NETWORK_SWITCH:
	case VDEV_DISK:
	case VDEV_DISK_SERVER:
		break;

	default:
		return -EINVAL;
	}

	if (!ops->send_attr ||
	    !ops->handle_attr ||
	    !ops->handshake_complete)
		return -EINVAL;

	if (!ver_table || ver_table_size < 0)
		return -EINVAL;

	if (!name)
		return -EINVAL;

	spin_lock_init(&vio->lock);

	vio->name = name;

	vio->dev_class = dev_class;
	vio->vdev = vdev;

	vio->ver_table = ver_table;
	vio->ver_table_entries = ver_table_size;

	vio->ops = ops;

	setup_timer(&vio->timer, vio_port_timer, (unsigned long) vio);

	return 0;
}
EXPORT_SYMBOL(vio_driver_init);