aboutsummaryrefslogtreecommitdiff
path: root/net/dsa/dsa2.c
blob: 076908fdd29b6b056b25aeaba6a67e9de1fb9656 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/dsa/dsa2.c - Hardware switch handling, binding version 2
 * Copyright (c) 2008-2009 Marvell Semiconductor
 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/rtnetlink.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <net/devlink.h>

#include "dsa_priv.h"

static DEFINE_MUTEX(dsa2_mutex);
LIST_HEAD(dsa_tree_list);

static const struct devlink_ops dsa_devlink_ops = {
};

struct dsa_switch *dsa_switch_find(int tree_index, int sw_index)
{
	struct dsa_switch_tree *dst;
	struct dsa_port *dp;

	list_for_each_entry(dst, &dsa_tree_list, list) {
		if (dst->index != tree_index)
			continue;

		list_for_each_entry(dp, &dst->ports, list) {
			if (dp->ds->index != sw_index)
				continue;

			return dp->ds;
		}
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(dsa_switch_find);

static struct dsa_switch_tree *dsa_tree_find(int index)
{
	struct dsa_switch_tree *dst;

	list_for_each_entry(dst, &dsa_tree_list, list)
		if (dst->index == index)
			return dst;

	return NULL;
}

static struct dsa_switch_tree *dsa_tree_alloc(int index)
{
	struct dsa_switch_tree *dst;

	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
	if (!dst)
		return NULL;

	dst->index = index;

	INIT_LIST_HEAD(&dst->rtable);

	INIT_LIST_HEAD(&dst->ports);

	INIT_LIST_HEAD(&dst->list);
	list_add_tail(&dst->list, &dsa_tree_list);

	kref_init(&dst->refcount);

	return dst;
}

static void dsa_tree_free(struct dsa_switch_tree *dst)
{
	list_del(&dst->list);
	kfree(dst);
}

static struct dsa_switch_tree *dsa_tree_get(struct dsa_switch_tree *dst)
{
	if (dst)
		kref_get(&dst->refcount);

	return dst;
}

static struct dsa_switch_tree *dsa_tree_touch(int index)
{
	struct dsa_switch_tree *dst;

	dst = dsa_tree_find(index);
	if (dst)
		return dsa_tree_get(dst);
	else
		return dsa_tree_alloc(index);
}

static void dsa_tree_release(struct kref *ref)
{
	struct dsa_switch_tree *dst;

	dst = container_of(ref, struct dsa_switch_tree, refcount);

	dsa_tree_free(dst);
}

static void dsa_tree_put(struct dsa_switch_tree *dst)
{
	if (dst)
		kref_put(&dst->refcount, dsa_tree_release);
}

static bool dsa_port_is_dsa(struct dsa_port *port)
{
	return port->type == DSA_PORT_TYPE_DSA;
}

static bool dsa_port_is_cpu(struct dsa_port *port)
{
	return port->type == DSA_PORT_TYPE_CPU;
}

static bool dsa_port_is_user(struct dsa_port *dp)
{
	return dp->type == DSA_PORT_TYPE_USER;
}

static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
						   struct device_node *dn)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dp->dn == dn)
			return dp;

	return NULL;
}

static struct dsa_link *dsa_link_touch(struct dsa_port *dp,
				       struct dsa_port *link_dp)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst;
	struct dsa_link *dl;

	dst = ds->dst;

	list_for_each_entry(dl, &dst->rtable, list)
		if (dl->dp == dp && dl->link_dp == link_dp)
			return dl;

	dl = kzalloc(sizeof(*dl), GFP_KERNEL);
	if (!dl)
		return NULL;

	dl->dp = dp;
	dl->link_dp = link_dp;

	INIT_LIST_HEAD(&dl->list);
	list_add_tail(&dl->list, &dst->rtable);

	return dl;
}

static bool dsa_port_setup_routing_table(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst = ds->dst;
	struct device_node *dn = dp->dn;
	struct of_phandle_iterator it;
	struct dsa_port *link_dp;
	struct dsa_link *dl;
	int err;

	of_for_each_phandle(&it, err, dn, "link", NULL, 0) {
		link_dp = dsa_tree_find_port_by_node(dst, it.node);
		if (!link_dp) {
			of_node_put(it.node);
			return false;
		}

		dl = dsa_link_touch(dp, link_dp);
		if (!dl) {
			of_node_put(it.node);
			return false;
		}
	}

	return true;
}

static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
{
	bool complete = true;
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list) {
		if (dsa_port_is_dsa(dp)) {
			complete = dsa_port_setup_routing_table(dp);
			if (!complete)
				break;
		}
	}

	return complete;
}

static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_cpu(dp))
			return dp;

	return NULL;
}

static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
{
	struct dsa_port *cpu_dp, *dp;

	cpu_dp = dsa_tree_find_first_cpu(dst);
	if (!cpu_dp) {
		pr_err("DSA: tree %d has no CPU port\n", dst->index);
		return -EINVAL;
	}

	/* Assign the default CPU port to all ports of the fabric */
	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
			dp->cpu_dp = cpu_dp;

	return 0;
}

static void dsa_tree_teardown_default_cpu(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
			dp->cpu_dp = NULL;
}

static int dsa_port_setup(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst = ds->dst;
	const unsigned char *id = (const unsigned char *)&dst->index;
	const unsigned char len = sizeof(dst->index);
	struct devlink_port *dlp = &dp->devlink_port;
	bool dsa_port_link_registered = false;
	bool devlink_port_registered = false;
	struct devlink *dl = ds->devlink;
	bool dsa_port_enabled = false;
	int err = 0;

	if (dp->setup)
		return 0;

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		dsa_port_disable(dp);
		break;
	case DSA_PORT_TYPE_CPU:
		memset(dlp, 0, sizeof(*dlp));
		devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_CPU,
				       dp->index, false, 0, id, len);
		err = devlink_port_register(dl, dlp, dp->index);
		if (err)
			break;
		devlink_port_registered = true;

		err = dsa_port_link_register_of(dp);
		if (err)
			break;
		dsa_port_link_registered = true;

		err = dsa_port_enable(dp, NULL);
		if (err)
			break;
		dsa_port_enabled = true;

		break;
	case DSA_PORT_TYPE_DSA:
		memset(dlp, 0, sizeof(*dlp));
		devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_DSA,
				       dp->index, false, 0, id, len);
		err = devlink_port_register(dl, dlp, dp->index);
		if (err)
			break;
		devlink_port_registered = true;

		err = dsa_port_link_register_of(dp);
		if (err)
			break;
		dsa_port_link_registered = true;

		err = dsa_port_enable(dp, NULL);
		if (err)
			break;
		dsa_port_enabled = true;

		break;
	case DSA_PORT_TYPE_USER:
		memset(dlp, 0, sizeof(*dlp));
		devlink_port_attrs_set(dlp, DEVLINK_PORT_FLAVOUR_PHYSICAL,
				       dp->index, false, 0, id, len);
		err = devlink_port_register(dl, dlp, dp->index);
		if (err)
			break;
		devlink_port_registered = true;

		dp->mac = of_get_mac_address(dp->dn);
		err = dsa_slave_create(dp);
		if (err)
			break;

		devlink_port_type_eth_set(dlp, dp->slave);
		break;
	}

	if (err && dsa_port_enabled)
		dsa_port_disable(dp);
	if (err && dsa_port_link_registered)
		dsa_port_link_unregister_of(dp);
	if (err && devlink_port_registered)
		devlink_port_unregister(dlp);
	if (err)
		return err;

	dp->setup = true;

	return 0;
}

static void dsa_port_teardown(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;

	if (!dp->setup)
		return;

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		break;
	case DSA_PORT_TYPE_CPU:
		dsa_port_disable(dp);
		dsa_tag_driver_put(dp->tag_ops);
		devlink_port_unregister(dlp);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_DSA:
		dsa_port_disable(dp);
		devlink_port_unregister(dlp);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_USER:
		devlink_port_unregister(dlp);
		if (dp->slave) {
			dsa_slave_destroy(dp->slave);
			dp->slave = NULL;
		}
		break;
	}

	dp->setup = false;
}

static int dsa_switch_setup(struct dsa_switch *ds)
{
	struct dsa_devlink_priv *dl_priv;
	int err;

	if (ds->setup)
		return 0;

	/* Initialize ds->phys_mii_mask before registering the slave MDIO bus
	 * driver and before ops->setup() has run, since the switch drivers and
	 * the slave MDIO bus driver rely on these values for probing PHY
	 * devices or not
	 */
	ds->phys_mii_mask |= dsa_user_ports(ds);

	/* Add the switch to devlink before calling setup, so that setup can
	 * add dpipe tables
	 */
	ds->devlink = devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv));
	if (!ds->devlink)
		return -ENOMEM;
	dl_priv = devlink_priv(ds->devlink);
	dl_priv->ds = ds;

	err = devlink_register(ds->devlink, ds->dev);
	if (err)
		goto free_devlink;

	err = dsa_switch_register_notifier(ds);
	if (err)
		goto unregister_devlink;

	err = ds->ops->setup(ds);
	if (err < 0)
		goto unregister_notifier;

	devlink_params_publish(ds->devlink);

	if (!ds->slave_mii_bus && ds->ops->phy_read) {
		ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);
		if (!ds->slave_mii_bus) {
			err = -ENOMEM;
			goto unregister_notifier;
		}

		dsa_slave_mii_bus_init(ds);

		err = mdiobus_register(ds->slave_mii_bus);
		if (err < 0)
			goto unregister_notifier;
	}

	ds->setup = true;

	return 0;

unregister_notifier:
	dsa_switch_unregister_notifier(ds);
unregister_devlink:
	devlink_unregister(ds->devlink);
free_devlink:
	devlink_free(ds->devlink);
	ds->devlink = NULL;

	return err;
}

static void dsa_switch_teardown(struct dsa_switch *ds)
{
	if (!ds->setup)
		return;

	if (ds->slave_mii_bus && ds->ops->phy_read)
		mdiobus_unregister(ds->slave_mii_bus);

	dsa_switch_unregister_notifier(ds);

	if (ds->ops->teardown)
		ds->ops->teardown(ds);

	if (ds->devlink) {
		devlink_unregister(ds->devlink);
		devlink_free(ds->devlink);
		ds->devlink = NULL;
	}

	ds->setup = false;
}

static int dsa_tree_setup_switches(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;
	int err;

	list_for_each_entry(dp, &dst->ports, list) {
		err = dsa_switch_setup(dp->ds);
		if (err)
			goto teardown;
	}

	list_for_each_entry(dp, &dst->ports, list) {
		err = dsa_port_setup(dp);
		if (err)
			continue;
	}

	return 0;

teardown:
	list_for_each_entry(dp, &dst->ports, list)
		dsa_port_teardown(dp);

	list_for_each_entry(dp, &dst->ports, list)
		dsa_switch_teardown(dp->ds);

	return err;
}

static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		dsa_port_teardown(dp);

	list_for_each_entry(dp, &dst->ports, list)
		dsa_switch_teardown(dp->ds);
}

static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;
	int err;

	list_for_each_entry(dp, &dst->ports, list) {
		if (dsa_port_is_cpu(dp)) {
			err = dsa_master_setup(dp->master, dp);
			if (err)
				return err;
		}
	}

	return 0;
}

static void dsa_tree_teardown_master(struct dsa_switch_tree *dst)
{
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dsa_port_is_cpu(dp))
			dsa_master_teardown(dp->master);
}

static int dsa_tree_setup(struct dsa_switch_tree *dst)
{
	bool complete;
	int err;

	if (dst->setup) {
		pr_err("DSA: tree %d already setup! Disjoint trees?\n",
		       dst->index);
		return -EEXIST;
	}

	complete = dsa_tree_setup_routing_table(dst);
	if (!complete)
		return 0;

	err = dsa_tree_setup_default_cpu(dst);
	if (err)
		return err;

	err = dsa_tree_setup_switches(dst);
	if (err)
		goto teardown_default_cpu;

	err = dsa_tree_setup_master(dst);
	if (err)
		goto teardown_switches;

	dst->setup = true;

	pr_info("DSA: tree %d setup\n", dst->index);

	return 0;

teardown_switches:
	dsa_tree_teardown_switches(dst);
teardown_default_cpu:
	dsa_tree_teardown_default_cpu(dst);

	return err;
}

static void dsa_tree_teardown(struct dsa_switch_tree *dst)
{
	struct dsa_link *dl, *next;

	if (!dst->setup)
		return;

	dsa_tree_teardown_master(dst);

	dsa_tree_teardown_switches(dst);

	dsa_tree_teardown_default_cpu(dst);

	list_for_each_entry_safe(dl, next, &dst->rtable, list) {
		list_del(&dl->list);
		kfree(dl);
	}

	pr_info("DSA: tree %d torn down\n", dst->index);

	dst->setup = false;
}

static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
{
	struct dsa_switch_tree *dst = ds->dst;
	struct dsa_port *dp;

	list_for_each_entry(dp, &dst->ports, list)
		if (dp->ds == ds && dp->index == index)
			return dp;

	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
	if (!dp)
		return NULL;

	dp->ds = ds;
	dp->index = index;

	INIT_LIST_HEAD(&dp->list);
	list_add_tail(&dp->list, &dst->ports);

	return dp;
}

static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
{
	if (!name)
		name = "eth%d";

	dp->type = DSA_PORT_TYPE_USER;
	dp->name = name;

	return 0;
}

static int dsa_port_parse_dsa(struct dsa_port *dp)
{
	dp->type = DSA_PORT_TYPE_DSA;

	return 0;
}

static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
						  struct net_device *master)
{
	enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
	struct dsa_switch *mds, *ds = dp->ds;
	unsigned int mdp_upstream;
	struct dsa_port *mdp;

	/* It is possible to stack DSA switches onto one another when that
	 * happens the switch driver may want to know if its tagging protocol
	 * is going to work in such a configuration.
	 */
	if (dsa_slave_dev_check(master)) {
		mdp = dsa_slave_to_port(master);
		mds = mdp->ds;
		mdp_upstream = dsa_upstream_port(mds, mdp->index);
		tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
							  DSA_TAG_PROTO_NONE);
	}

	/* If the master device is not itself a DSA slave in a disjoint DSA
	 * tree, then return immediately.
	 */
	return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
}

static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_switch_tree *dst = ds->dst;
	const struct dsa_device_ops *tag_ops;
	enum dsa_tag_protocol tag_protocol;

	tag_protocol = dsa_get_tag_protocol(dp, master);
	tag_ops = dsa_tag_driver_get(tag_protocol);
	if (IS_ERR(tag_ops)) {
		if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
			return -EPROBE_DEFER;
		dev_warn(ds->dev, "No tagger for this switch\n");
		dp->master = NULL;
		return PTR_ERR(tag_ops);
	}

	dp->master = master;
	dp->type = DSA_PORT_TYPE_CPU;
	dp->filter = tag_ops->filter;
	dp->rcv = tag_ops->rcv;
	dp->tag_ops = tag_ops;
	dp->dst = dst;

	return 0;
}

static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
{
	struct device_node *ethernet = of_parse_phandle(dn, "ethernet", 0);
	const char *name = of_get_property(dn, "label", NULL);
	bool link = of_property_read_bool(dn, "link");

	dp->dn = dn;

	if (ethernet) {
		struct net_device *master;

		master = of_find_net_device_by_node(ethernet);
		if (!master)
			return -EPROBE_DEFER;

		return dsa_port_parse_cpu(dp, master);
	}

	if (link)
		return dsa_port_parse_dsa(dp);

	return dsa_port_parse_user(dp, name);
}

static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
				     struct device_node *dn)
{
	struct device_node *ports, *port;
	struct dsa_port *dp;
	int err = 0;
	u32 reg;

	ports = of_get_child_by_name(dn, "ports");
	if (!ports) {
		dev_err(ds->dev, "no ports child node found\n");
		return -EINVAL;
	}

	for_each_available_child_of_node(ports, port) {
		err = of_property_read_u32(port, "reg", &reg);
		if (err)
			goto out_put_node;

		if (reg >= ds->num_ports) {
			err = -EINVAL;
			goto out_put_node;
		}

		dp = dsa_to_port(ds, reg);

		err = dsa_port_parse_of(dp, port);
		if (err)
			goto out_put_node;
	}

out_put_node:
	of_node_put(ports);
	return err;
}

static int dsa_switch_parse_member_of(struct dsa_switch *ds,
				      struct device_node *dn)
{
	u32 m[2] = { 0, 0 };
	int sz;

	/* Don't error out if this optional property isn't found */
	sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
	if (sz < 0 && sz != -EINVAL)
		return sz;

	ds->index = m[1];

	ds->dst = dsa_tree_touch(m[0]);
	if (!ds->dst)
		return -ENOMEM;

	return 0;
}

static int dsa_switch_touch_ports(struct dsa_switch *ds)
{
	struct dsa_port *dp;
	int port;

	for (port = 0; port < ds->num_ports; port++) {
		dp = dsa_port_touch(ds, port);
		if (!dp)
			return -ENOMEM;
	}

	return 0;
}

static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
{
	int err;

	err = dsa_switch_parse_member_of(ds, dn);
	if (err)
		return err;

	err = dsa_switch_touch_ports(ds);
	if (err)
		return err;

	return dsa_switch_parse_ports_of(ds, dn);
}

static int dsa_port_parse(struct dsa_port *dp, const char *name,
			  struct device *dev)
{
	if (!strcmp(name, "cpu")) {
		struct net_device *master;

		master = dsa_dev_to_net_device(dev);
		if (!master)
			return -EPROBE_DEFER;

		dev_put(master);

		return dsa_port_parse_cpu(dp, master);
	}

	if (!strcmp(name, "dsa"))
		return dsa_port_parse_dsa(dp);

	return dsa_port_parse_user(dp, name);
}

static int dsa_switch_parse_ports(struct dsa_switch *ds,
				  struct dsa_chip_data *cd)
{
	bool valid_name_found = false;
	struct dsa_port *dp;
	struct device *dev;
	const char *name;
	unsigned int i;
	int err;

	for (i = 0; i < DSA_MAX_PORTS; i++) {
		name = cd->port_names[i];
		dev = cd->netdev[i];
		dp = dsa_to_port(ds, i);

		if (!name)
			continue;

		err = dsa_port_parse(dp, name, dev);
		if (err)
			return err;

		valid_name_found = true;
	}

	if (!valid_name_found && i == DSA_MAX_PORTS)
		return -EINVAL;

	return 0;
}

static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
{
	int err;

	ds->cd = cd;

	/* We don't support interconnected switches nor multiple trees via
	 * platform data, so this is the unique switch of the tree.
	 */
	ds->index = 0;
	ds->dst = dsa_tree_touch(0);
	if (!ds->dst)
		return -ENOMEM;

	err = dsa_switch_touch_ports(ds);
	if (err)
		return err;

	return dsa_switch_parse_ports(ds, cd);
}

static void dsa_switch_release_ports(struct dsa_switch *ds)
{
	struct dsa_switch_tree *dst = ds->dst;
	struct dsa_port *dp, *next;

	list_for_each_entry_safe(dp, next, &dst->ports, list) {
		if (dp->ds != ds)
			continue;
		list_del(&dp->list);
		kfree(dp);
	}
}

static int dsa_switch_probe(struct dsa_switch *ds)
{
	struct dsa_switch_tree *dst;
	struct dsa_chip_data *pdata;
	struct device_node *np;
	int err;

	if (!ds->dev)
		return -ENODEV;

	pdata = ds->dev->platform_data;
	np = ds->dev->of_node;

	if (!ds->num_ports)
		return -EINVAL;

	if (np) {
		err = dsa_switch_parse_of(ds, np);
		if (err)
			dsa_switch_release_ports(ds);
	} else if (pdata) {
		err = dsa_switch_parse(ds, pdata);
		if (err)
			dsa_switch_release_ports(ds);
	} else {
		err = -ENODEV;
	}

	if (err)
		return err;

	dst = ds->dst;
	dsa_tree_get(dst);
	err = dsa_tree_setup(dst);
	if (err) {
		dsa_switch_release_ports(ds);
		dsa_tree_put(dst);
	}

	return err;
}

int dsa_register_switch(struct dsa_switch *ds)
{
	int err;

	mutex_lock(&dsa2_mutex);
	err = dsa_switch_probe(ds);
	dsa_tree_put(ds->dst);
	mutex_unlock(&dsa2_mutex);

	return err;
}
EXPORT_SYMBOL_GPL(dsa_register_switch);

static void dsa_switch_remove(struct dsa_switch *ds)
{
	struct dsa_switch_tree *dst = ds->dst;

	dsa_tree_teardown(dst);
	dsa_switch_release_ports(ds);
	dsa_tree_put(dst);
}

void dsa_unregister_switch(struct dsa_switch *ds)
{
	mutex_lock(&dsa2_mutex);
	dsa_switch_remove(ds);
	mutex_unlock(&dsa2_mutex);
}
EXPORT_SYMBOL_GPL(dsa_unregister_switch);