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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * net/dsa/dsa2.c - Hardware switch handling, binding version 2
  4 * Copyright (c) 2008-2009 Marvell Semiconductor
  5 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
  6 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
  7 */
  8
  9#include <linux/device.h>
 10#include <linux/err.h>
 11#include <linux/list.h>
 12#include <linux/netdevice.h>
 13#include <linux/slab.h>
 14#include <linux/rtnetlink.h>
 15#include <linux/of.h>
 16#include <linux/of_net.h>
 17#include <net/devlink.h>
 18
 19#include "dsa_priv.h"
 20
 21static DEFINE_MUTEX(dsa2_mutex);
 22LIST_HEAD(dsa_tree_list);
 23
 24static const struct devlink_ops dsa_devlink_ops = {
 25};
 26
 27struct dsa_switch *dsa_switch_find(int tree_index, int sw_index)
 28{
 29	struct dsa_switch_tree *dst;
 30	struct dsa_port *dp;
 31
 32	list_for_each_entry(dst, &dsa_tree_list, list) {
 33		if (dst->index != tree_index)
 34			continue;
 35
 36		list_for_each_entry(dp, &dst->ports, list) {
 37			if (dp->ds->index != sw_index)
 38				continue;
 39
 40			return dp->ds;
 41		}
 42	}
 43
 44	return NULL;
 45}
 46EXPORT_SYMBOL_GPL(dsa_switch_find);
 47
 48static struct dsa_switch_tree *dsa_tree_find(int index)
 49{
 50	struct dsa_switch_tree *dst;
 51
 52	list_for_each_entry(dst, &dsa_tree_list, list)
 53		if (dst->index == index)
 54			return dst;
 55
 56	return NULL;
 57}
 58
 59static struct dsa_switch_tree *dsa_tree_alloc(int index)
 60{
 61	struct dsa_switch_tree *dst;
 62
 63	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
 64	if (!dst)
 65		return NULL;
 66
 67	dst->index = index;
 68
 69	INIT_LIST_HEAD(&dst->rtable);
 70
 71	INIT_LIST_HEAD(&dst->ports);
 72
 73	INIT_LIST_HEAD(&dst->list);
 74	list_add_tail(&dst->list, &dsa_tree_list);
 75
 76	kref_init(&dst->refcount);
 77
 78	return dst;
 79}
 80
 81static void dsa_tree_free(struct dsa_switch_tree *dst)
 82{
 83	list_del(&dst->list);
 84	kfree(dst);
 85}
 86
 87static struct dsa_switch_tree *dsa_tree_get(struct dsa_switch_tree *dst)
 88{
 89	if (dst)
 90		kref_get(&dst->refcount);
 91
 92	return dst;
 93}
 94
 95static struct dsa_switch_tree *dsa_tree_touch(int index)
 96{
 97	struct dsa_switch_tree *dst;
 98
 99	dst = dsa_tree_find(index);
100	if (dst)
101		return dsa_tree_get(dst);
102	else
103		return dsa_tree_alloc(index);
104}
105
106static void dsa_tree_release(struct kref *ref)
107{
108	struct dsa_switch_tree *dst;
109
110	dst = container_of(ref, struct dsa_switch_tree, refcount);
111
112	dsa_tree_free(dst);
113}
114
115static void dsa_tree_put(struct dsa_switch_tree *dst)
116{
117	if (dst)
118		kref_put(&dst->refcount, dsa_tree_release);
119}
120
121static bool dsa_port_is_dsa(struct dsa_port *port)
122{
123	return port->type == DSA_PORT_TYPE_DSA;
124}
125
126static bool dsa_port_is_cpu(struct dsa_port *port)
127{
128	return port->type == DSA_PORT_TYPE_CPU;
129}
130
131static bool dsa_port_is_user(struct dsa_port *dp)
132{
133	return dp->type == DSA_PORT_TYPE_USER;
134}
135
136static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
137						   struct device_node *dn)
138{
139	struct dsa_port *dp;
140
141	list_for_each_entry(dp, &dst->ports, list)
142		if (dp->dn == dn)
143			return dp;
144
145	return NULL;
146}
147
148static struct dsa_link *dsa_link_touch(struct dsa_port *dp,
149				       struct dsa_port *link_dp)
150{
151	struct dsa_switch *ds = dp->ds;
152	struct dsa_switch_tree *dst;
153	struct dsa_link *dl;
154
155	dst = ds->dst;
156
157	list_for_each_entry(dl, &dst->rtable, list)
158		if (dl->dp == dp && dl->link_dp == link_dp)
159			return dl;
160
161	dl = kzalloc(sizeof(*dl), GFP_KERNEL);
162	if (!dl)
163		return NULL;
164
165	dl->dp = dp;
166	dl->link_dp = link_dp;
167
168	INIT_LIST_HEAD(&dl->list);
169	list_add_tail(&dl->list, &dst->rtable);
170
171	return dl;
172}
173
174static bool dsa_port_setup_routing_table(struct dsa_port *dp)
175{
176	struct dsa_switch *ds = dp->ds;
177	struct dsa_switch_tree *dst = ds->dst;
178	struct device_node *dn = dp->dn;
179	struct of_phandle_iterator it;
180	struct dsa_port *link_dp;
181	struct dsa_link *dl;
182	int err;
183
184	of_for_each_phandle(&it, err, dn, "link", NULL, 0) {
185		link_dp = dsa_tree_find_port_by_node(dst, it.node);
186		if (!link_dp) {
187			of_node_put(it.node);
188			return false;
189		}
190
191		dl = dsa_link_touch(dp, link_dp);
192		if (!dl) {
193			of_node_put(it.node);
194			return false;
195		}
196	}
197
198	return true;
199}
200
201static bool dsa_tree_setup_routing_table(struct dsa_switch_tree *dst)
202{
203	bool complete = true;
204	struct dsa_port *dp;
205
206	list_for_each_entry(dp, &dst->ports, list) {
207		if (dsa_port_is_dsa(dp)) {
208			complete = dsa_port_setup_routing_table(dp);
209			if (!complete)
210				break;
211		}
212	}
213
214	return complete;
215}
216
217static struct dsa_port *dsa_tree_find_first_cpu(struct dsa_switch_tree *dst)
218{
219	struct dsa_port *dp;
220
221	list_for_each_entry(dp, &dst->ports, list)
222		if (dsa_port_is_cpu(dp))
223			return dp;
224
225	return NULL;
226}
227
228static int dsa_tree_setup_default_cpu(struct dsa_switch_tree *dst)
229{
230	struct dsa_port *cpu_dp, *dp;
231
232	cpu_dp = dsa_tree_find_first_cpu(dst);
233	if (!cpu_dp) {
234		pr_err("DSA: tree %d has no CPU port\n", dst->index);
235		return -EINVAL;
236	}
237
238	/* Assign the default CPU port to all ports of the fabric */
239	list_for_each_entry(dp, &dst->ports, list)
240		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
241			dp->cpu_dp = cpu_dp;
242
243	return 0;
244}
245
246static void dsa_tree_teardown_default_cpu(struct dsa_switch_tree *dst)
247{
248	struct dsa_port *dp;
249
250	list_for_each_entry(dp, &dst->ports, list)
251		if (dsa_port_is_user(dp) || dsa_port_is_dsa(dp))
252			dp->cpu_dp = NULL;
253}
254
255static int dsa_port_setup(struct dsa_port *dp)
256{
257	struct dsa_switch *ds = dp->ds;
258	struct dsa_switch_tree *dst = ds->dst;
259	const unsigned char *id = (const unsigned char *)&dst->index;
260	const unsigned char len = sizeof(dst->index);
261	struct devlink_port *dlp = &dp->devlink_port;
262	bool dsa_port_link_registered = false;
263	bool devlink_port_registered = false;
264	struct devlink_port_attrs attrs = {};
265	struct devlink *dl = ds->devlink;
266	bool dsa_port_enabled = false;
267	int err = 0;
268
269	attrs.phys.port_number = dp->index;
270	memcpy(attrs.switch_id.id, id, len);
271	attrs.switch_id.id_len = len;
272
273	if (dp->setup)
274		return 0;
275
276	switch (dp->type) {
277	case DSA_PORT_TYPE_UNUSED:
278		dsa_port_disable(dp);
279		break;
280	case DSA_PORT_TYPE_CPU:
281		memset(dlp, 0, sizeof(*dlp));
282		attrs.flavour = DEVLINK_PORT_FLAVOUR_CPU;
283		devlink_port_attrs_set(dlp, &attrs);
284		err = devlink_port_register(dl, dlp, dp->index);
285		if (err)
286			break;
287		devlink_port_registered = true;
288
289		err = dsa_port_link_register_of(dp);
290		if (err)
291			break;
292		dsa_port_link_registered = true;
293
294		err = dsa_port_enable(dp, NULL);
295		if (err)
296			break;
297		dsa_port_enabled = true;
298
299		break;
300	case DSA_PORT_TYPE_DSA:
301		memset(dlp, 0, sizeof(*dlp));
302		attrs.flavour = DEVLINK_PORT_FLAVOUR_DSA;
303		devlink_port_attrs_set(dlp, &attrs);
304		err = devlink_port_register(dl, dlp, dp->index);
305		if (err)
306			break;
307		devlink_port_registered = true;
308
309		err = dsa_port_link_register_of(dp);
310		if (err)
311			break;
312		dsa_port_link_registered = true;
313
314		err = dsa_port_enable(dp, NULL);
315		if (err)
316			break;
317		dsa_port_enabled = true;
318
319		break;
320	case DSA_PORT_TYPE_USER:
321		memset(dlp, 0, sizeof(*dlp));
322		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
323		devlink_port_attrs_set(dlp, &attrs);
324		err = devlink_port_register(dl, dlp, dp->index);
325		if (err)
326			break;
327		devlink_port_registered = true;
328
329		dp->mac = of_get_mac_address(dp->dn);
330		err = dsa_slave_create(dp);
331		if (err)
332			break;
333
334		devlink_port_type_eth_set(dlp, dp->slave);
335		break;
336	}
337
338	if (err && dsa_port_enabled)
339		dsa_port_disable(dp);
340	if (err && dsa_port_link_registered)
341		dsa_port_link_unregister_of(dp);
342	if (err && devlink_port_registered)
343		devlink_port_unregister(dlp);
344	if (err)
345		return err;
346
347	dp->setup = true;
348
349	return 0;
350}
351
352static void dsa_port_teardown(struct dsa_port *dp)
353{
354	struct devlink_port *dlp = &dp->devlink_port;
355
356	if (!dp->setup)
357		return;
358
359	switch (dp->type) {
360	case DSA_PORT_TYPE_UNUSED:
361		break;
362	case DSA_PORT_TYPE_CPU:
363		dsa_port_disable(dp);
364		dsa_tag_driver_put(dp->tag_ops);
365		devlink_port_unregister(dlp);
366		dsa_port_link_unregister_of(dp);
367		break;
368	case DSA_PORT_TYPE_DSA:
369		dsa_port_disable(dp);
370		devlink_port_unregister(dlp);
371		dsa_port_link_unregister_of(dp);
372		break;
373	case DSA_PORT_TYPE_USER:
374		devlink_port_unregister(dlp);
375		if (dp->slave) {
376			dsa_slave_destroy(dp->slave);
377			dp->slave = NULL;
378		}
379		break;
380	}
381
382	dp->setup = false;
383}
384
385static int dsa_switch_setup(struct dsa_switch *ds)
386{
387	struct dsa_devlink_priv *dl_priv;
388	int err;
389
390	if (ds->setup)
391		return 0;
392
393	/* Initialize ds->phys_mii_mask before registering the slave MDIO bus
394	 * driver and before ops->setup() has run, since the switch drivers and
395	 * the slave MDIO bus driver rely on these values for probing PHY
396	 * devices or not
397	 */
398	ds->phys_mii_mask |= dsa_user_ports(ds);
399
400	/* Add the switch to devlink before calling setup, so that setup can
401	 * add dpipe tables
402	 */
403	ds->devlink = devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv));
404	if (!ds->devlink)
405		return -ENOMEM;
406	dl_priv = devlink_priv(ds->devlink);
407	dl_priv->ds = ds;
408
409	err = devlink_register(ds->devlink, ds->dev);
410	if (err)
411		goto free_devlink;
412
413	err = dsa_switch_register_notifier(ds);
414	if (err)
415		goto unregister_devlink;
416
417	err = ds->ops->setup(ds);
418	if (err < 0)
419		goto unregister_notifier;
420
421	devlink_params_publish(ds->devlink);
422
423	if (!ds->slave_mii_bus && ds->ops->phy_read) {
424		ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);
425		if (!ds->slave_mii_bus) {
426			err = -ENOMEM;
427			goto unregister_notifier;
428		}
429
430		dsa_slave_mii_bus_init(ds);
431
432		err = mdiobus_register(ds->slave_mii_bus);
433		if (err < 0)
434			goto unregister_notifier;
435	}
436
437	ds->setup = true;
438
439	return 0;
440
441unregister_notifier:
442	dsa_switch_unregister_notifier(ds);
443unregister_devlink:
444	devlink_unregister(ds->devlink);
445free_devlink:
446	devlink_free(ds->devlink);
447	ds->devlink = NULL;
448
449	return err;
450}
451
452static void dsa_switch_teardown(struct dsa_switch *ds)
453{
454	if (!ds->setup)
455		return;
456
457	if (ds->slave_mii_bus && ds->ops->phy_read)
458		mdiobus_unregister(ds->slave_mii_bus);
459
460	dsa_switch_unregister_notifier(ds);
461
462	if (ds->ops->teardown)
463		ds->ops->teardown(ds);
464
465	if (ds->devlink) {
466		devlink_unregister(ds->devlink);
467		devlink_free(ds->devlink);
468		ds->devlink = NULL;
469	}
470
471	ds->setup = false;
472}
473
474static int dsa_tree_setup_switches(struct dsa_switch_tree *dst)
475{
476	struct dsa_port *dp;
477	int err;
478
479	list_for_each_entry(dp, &dst->ports, list) {
480		err = dsa_switch_setup(dp->ds);
481		if (err)
482			goto teardown;
483	}
484
485	list_for_each_entry(dp, &dst->ports, list) {
486		err = dsa_port_setup(dp);
487		if (err)
488			continue;
489	}
490
491	return 0;
492
493teardown:
494	list_for_each_entry(dp, &dst->ports, list)
495		dsa_port_teardown(dp);
496
497	list_for_each_entry(dp, &dst->ports, list)
498		dsa_switch_teardown(dp->ds);
499
500	return err;
501}
502
503static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
504{
505	struct dsa_port *dp;
506
507	list_for_each_entry(dp, &dst->ports, list)
508		dsa_port_teardown(dp);
509
510	list_for_each_entry(dp, &dst->ports, list)
511		dsa_switch_teardown(dp->ds);
512}
513
514static int dsa_tree_setup_master(struct dsa_switch_tree *dst)
515{
516	struct dsa_port *dp;
517	int err;
518
519	list_for_each_entry(dp, &dst->ports, list) {
520		if (dsa_port_is_cpu(dp)) {
521			err = dsa_master_setup(dp->master, dp);
522			if (err)
523				return err;
524		}
525	}
526
527	return 0;
528}
529
530static void dsa_tree_teardown_master(struct dsa_switch_tree *dst)
531{
532	struct dsa_port *dp;
533
534	list_for_each_entry(dp, &dst->ports, list)
535		if (dsa_port_is_cpu(dp))
536			dsa_master_teardown(dp->master);
537}
538
539static int dsa_tree_setup(struct dsa_switch_tree *dst)
540{
541	bool complete;
542	int err;
543
544	if (dst->setup) {
545		pr_err("DSA: tree %d already setup! Disjoint trees?\n",
546		       dst->index);
547		return -EEXIST;
548	}
549
550	complete = dsa_tree_setup_routing_table(dst);
551	if (!complete)
552		return 0;
553
554	err = dsa_tree_setup_default_cpu(dst);
555	if (err)
556		return err;
557
558	err = dsa_tree_setup_switches(dst);
559	if (err)
560		goto teardown_default_cpu;
561
562	err = dsa_tree_setup_master(dst);
563	if (err)
564		goto teardown_switches;
565
566	dst->setup = true;
567
568	pr_info("DSA: tree %d setup\n", dst->index);
569
570	return 0;
571
572teardown_switches:
573	dsa_tree_teardown_switches(dst);
574teardown_default_cpu:
575	dsa_tree_teardown_default_cpu(dst);
576
577	return err;
578}
579
580static void dsa_tree_teardown(struct dsa_switch_tree *dst)
581{
582	struct dsa_link *dl, *next;
583
584	if (!dst->setup)
585		return;
586
587	dsa_tree_teardown_master(dst);
588
589	dsa_tree_teardown_switches(dst);
590
591	dsa_tree_teardown_default_cpu(dst);
592
593	list_for_each_entry_safe(dl, next, &dst->rtable, list) {
594		list_del(&dl->list);
595		kfree(dl);
596	}
597
598	pr_info("DSA: tree %d torn down\n", dst->index);
599
600	dst->setup = false;
601}
602
603static struct dsa_port *dsa_port_touch(struct dsa_switch *ds, int index)
604{
605	struct dsa_switch_tree *dst = ds->dst;
606	struct dsa_port *dp;
607
608	list_for_each_entry(dp, &dst->ports, list)
609		if (dp->ds == ds && dp->index == index)
610			return dp;
611
612	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
613	if (!dp)
614		return NULL;
615
616	dp->ds = ds;
617	dp->index = index;
618
619	INIT_LIST_HEAD(&dp->list);
620	list_add_tail(&dp->list, &dst->ports);
621
622	return dp;
623}
624
625static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
626{
627	if (!name)
628		name = "eth%d";
629
630	dp->type = DSA_PORT_TYPE_USER;
631	dp->name = name;
632
633	return 0;
634}
635
636static int dsa_port_parse_dsa(struct dsa_port *dp)
637{
638	dp->type = DSA_PORT_TYPE_DSA;
639
640	return 0;
641}
642
643static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp,
644						  struct net_device *master)
645{
646	enum dsa_tag_protocol tag_protocol = DSA_TAG_PROTO_NONE;
647	struct dsa_switch *mds, *ds = dp->ds;
648	unsigned int mdp_upstream;
649	struct dsa_port *mdp;
650
651	/* It is possible to stack DSA switches onto one another when that
652	 * happens the switch driver may want to know if its tagging protocol
653	 * is going to work in such a configuration.
654	 */
655	if (dsa_slave_dev_check(master)) {
656		mdp = dsa_slave_to_port(master);
657		mds = mdp->ds;
658		mdp_upstream = dsa_upstream_port(mds, mdp->index);
659		tag_protocol = mds->ops->get_tag_protocol(mds, mdp_upstream,
660							  DSA_TAG_PROTO_NONE);
661	}
662
663	/* If the master device is not itself a DSA slave in a disjoint DSA
664	 * tree, then return immediately.
665	 */
666	return ds->ops->get_tag_protocol(ds, dp->index, tag_protocol);
667}
668
669static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
670{
671	struct dsa_switch *ds = dp->ds;
672	struct dsa_switch_tree *dst = ds->dst;
673	const struct dsa_device_ops *tag_ops;
674	enum dsa_tag_protocol tag_protocol;
675
676	tag_protocol = dsa_get_tag_protocol(dp, master);
677	tag_ops = dsa_tag_driver_get(tag_protocol);
678	if (IS_ERR(tag_ops)) {
679		if (PTR_ERR(tag_ops) == -ENOPROTOOPT)
680			return -EPROBE_DEFER;
681		dev_warn(ds->dev, "No tagger for this switch\n");
682		dp->master = NULL;
683		return PTR_ERR(tag_ops);
684	}
685
686	dp->master = master;
687	dp->type = DSA_PORT_TYPE_CPU;
688	dp->filter = tag_ops->filter;
689	dp->rcv = tag_ops->rcv;
690	dp->tag_ops = tag_ops;
691	dp->dst = dst;
692
693	return 0;
694}
695
696static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
697{
698	struct device_node *ethernet = of_parse_phandle(dn, "ethernet", 0);
699	const char *name = of_get_property(dn, "label", NULL);
700	bool link = of_property_read_bool(dn, "link");
701
702	dp->dn = dn;
703
704	if (ethernet) {
705		struct net_device *master;
706
707		master = of_find_net_device_by_node(ethernet);
708		if (!master)
709			return -EPROBE_DEFER;
710
711		return dsa_port_parse_cpu(dp, master);
712	}
713
714	if (link)
715		return dsa_port_parse_dsa(dp);
716
717	return dsa_port_parse_user(dp, name);
718}
719
720static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
721				     struct device_node *dn)
722{
723	struct device_node *ports, *port;
724	struct dsa_port *dp;
725	int err = 0;
726	u32 reg;
727
728	ports = of_get_child_by_name(dn, "ports");
729	if (!ports) {
730		/* The second possibility is "ethernet-ports" */
731		ports = of_get_child_by_name(dn, "ethernet-ports");
732		if (!ports) {
733			dev_err(ds->dev, "no ports child node found\n");
734			return -EINVAL;
735		}
736	}
737
738	for_each_available_child_of_node(ports, port) {
739		err = of_property_read_u32(port, "reg", &reg);
740		if (err)
741			goto out_put_node;
742
743		if (reg >= ds->num_ports) {
744			err = -EINVAL;
745			goto out_put_node;
746		}
747
748		dp = dsa_to_port(ds, reg);
749
750		err = dsa_port_parse_of(dp, port);
751		if (err)
752			goto out_put_node;
753	}
754
755out_put_node:
756	of_node_put(ports);
757	return err;
758}
759
760static int dsa_switch_parse_member_of(struct dsa_switch *ds,
761				      struct device_node *dn)
762{
763	u32 m[2] = { 0, 0 };
764	int sz;
765
766	/* Don't error out if this optional property isn't found */
767	sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
768	if (sz < 0 && sz != -EINVAL)
769		return sz;
770
771	ds->index = m[1];
772
773	ds->dst = dsa_tree_touch(m[0]);
774	if (!ds->dst)
775		return -ENOMEM;
776
777	return 0;
778}
779
780static int dsa_switch_touch_ports(struct dsa_switch *ds)
781{
782	struct dsa_port *dp;
783	int port;
784
785	for (port = 0; port < ds->num_ports; port++) {
786		dp = dsa_port_touch(ds, port);
787		if (!dp)
788			return -ENOMEM;
789	}
790
791	return 0;
792}
793
794static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
795{
796	int err;
797
798	err = dsa_switch_parse_member_of(ds, dn);
799	if (err)
800		return err;
801
802	err = dsa_switch_touch_ports(ds);
803	if (err)
804		return err;
805
806	return dsa_switch_parse_ports_of(ds, dn);
807}
808
809static int dsa_port_parse(struct dsa_port *dp, const char *name,
810			  struct device *dev)
811{
812	if (!strcmp(name, "cpu")) {
813		struct net_device *master;
814
815		master = dsa_dev_to_net_device(dev);
816		if (!master)
817			return -EPROBE_DEFER;
818
819		dev_put(master);
820
821		return dsa_port_parse_cpu(dp, master);
822	}
823
824	if (!strcmp(name, "dsa"))
825		return dsa_port_parse_dsa(dp);
826
827	return dsa_port_parse_user(dp, name);
828}
829
830static int dsa_switch_parse_ports(struct dsa_switch *ds,
831				  struct dsa_chip_data *cd)
832{
833	bool valid_name_found = false;
834	struct dsa_port *dp;
835	struct device *dev;
836	const char *name;
837	unsigned int i;
838	int err;
839
840	for (i = 0; i < DSA_MAX_PORTS; i++) {
841		name = cd->port_names[i];
842		dev = cd->netdev[i];
843		dp = dsa_to_port(ds, i);
844
845		if (!name)
846			continue;
847
848		err = dsa_port_parse(dp, name, dev);
849		if (err)
850			return err;
851
852		valid_name_found = true;
853	}
854
855	if (!valid_name_found && i == DSA_MAX_PORTS)
856		return -EINVAL;
857
858	return 0;
859}
860
861static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
862{
863	int err;
864
865	ds->cd = cd;
866
867	/* We don't support interconnected switches nor multiple trees via
868	 * platform data, so this is the unique switch of the tree.
869	 */
870	ds->index = 0;
871	ds->dst = dsa_tree_touch(0);
872	if (!ds->dst)
873		return -ENOMEM;
874
875	err = dsa_switch_touch_ports(ds);
876	if (err)
877		return err;
878
879	return dsa_switch_parse_ports(ds, cd);
880}
881
882static void dsa_switch_release_ports(struct dsa_switch *ds)
883{
884	struct dsa_switch_tree *dst = ds->dst;
885	struct dsa_port *dp, *next;
886
887	list_for_each_entry_safe(dp, next, &dst->ports, list) {
888		if (dp->ds != ds)
889			continue;
890		list_del(&dp->list);
891		kfree(dp);
892	}
893}
894
895static int dsa_switch_probe(struct dsa_switch *ds)
896{
897	struct dsa_switch_tree *dst;
898	struct dsa_chip_data *pdata;
899	struct device_node *np;
900	int err;
901
902	if (!ds->dev)
903		return -ENODEV;
904
905	pdata = ds->dev->platform_data;
906	np = ds->dev->of_node;
907
908	if (!ds->num_ports)
909		return -EINVAL;
910
911	if (np) {
912		err = dsa_switch_parse_of(ds, np);
913		if (err)
914			dsa_switch_release_ports(ds);
915	} else if (pdata) {
916		err = dsa_switch_parse(ds, pdata);
917		if (err)
918			dsa_switch_release_ports(ds);
919	} else {
920		err = -ENODEV;
921	}
922
923	if (err)
924		return err;
925
926	dst = ds->dst;
927	dsa_tree_get(dst);
928	err = dsa_tree_setup(dst);
929	if (err) {
930		dsa_switch_release_ports(ds);
931		dsa_tree_put(dst);
932	}
933
934	return err;
935}
936
937int dsa_register_switch(struct dsa_switch *ds)
938{
939	int err;
940
941	mutex_lock(&dsa2_mutex);
942	err = dsa_switch_probe(ds);
943	dsa_tree_put(ds->dst);
944	mutex_unlock(&dsa2_mutex);
945
946	return err;
947}
948EXPORT_SYMBOL_GPL(dsa_register_switch);
949
950static void dsa_switch_remove(struct dsa_switch *ds)
951{
952	struct dsa_switch_tree *dst = ds->dst;
953
954	dsa_tree_teardown(dst);
955	dsa_switch_release_ports(ds);
956	dsa_tree_put(dst);
957}
958
959void dsa_unregister_switch(struct dsa_switch *ds)
960{
961	mutex_lock(&dsa2_mutex);
962	dsa_switch_remove(ds);
963	mutex_unlock(&dsa2_mutex);
964}
965EXPORT_SYMBOL_GPL(dsa_unregister_switch);