dsa2.c 19.7 KB
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
// 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);

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 devlink_port *dlp = &dp->devlink_port;
	bool dsa_port_link_registered = false;
	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:
		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:
		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:
		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)
		return err;

	dp->setup = true;

	return 0;
}

static int dsa_port_devlink_setup(struct dsa_port *dp)
{
	struct devlink_port *dlp = &dp->devlink_port;
	struct dsa_switch_tree *dst = dp->ds->dst;
	struct devlink_port_attrs attrs = {};
	struct devlink *dl = dp->ds->devlink;
	const unsigned char *id;
	unsigned char len;
	int err;

	id = (const unsigned char *)&dst->index;
	len = sizeof(dst->index);

	attrs.phys.port_number = dp->index;
	memcpy(attrs.switch_id.id, id, len);
	attrs.switch_id.id_len = len;
	memset(dlp, 0, sizeof(*dlp));

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_UNUSED;
		break;
	case DSA_PORT_TYPE_CPU:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_CPU;
		break;
	case DSA_PORT_TYPE_DSA:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_DSA;
		break;
	case DSA_PORT_TYPE_USER:
		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
		break;
	}

	devlink_port_attrs_set(dlp, &attrs);
	err = devlink_port_register(dl, dlp, dp->index);

	if (!err)
		dp->devlink_port_setup = true;

	return err;
}

static void dsa_port_teardown(struct dsa_port *dp)
{
	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);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_DSA:
		dsa_port_disable(dp);
		dsa_port_link_unregister_of(dp);
		break;
	case DSA_PORT_TYPE_USER:
		if (dp->slave) {
			dsa_slave_destroy(dp->slave);
			dp->slave = NULL;
		}
		break;
	}

	dp->setup = false;
}

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

	if (dp->devlink_port_setup)
		devlink_port_unregister(dlp);
	dp->devlink_port_setup = false;
}

static int dsa_devlink_info_get(struct devlink *dl,
				struct devlink_info_req *req,
				struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dsa_devlink_to_ds(dl);

	if (ds->ops->devlink_info_get)
		return ds->ops->devlink_info_get(ds, req, extack);

	return -EOPNOTSUPP;
}

static const struct devlink_ops dsa_devlink_ops = {
	.info_get = dsa_devlink_info_get,
};

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

	/* Setup devlink port instances now, so that the switch
	 * setup() can register regions etc, against the ports
	 */
	list_for_each_entry(dp, &ds->dst->ports, list) {
		if (dp->ds == ds) {
			err = dsa_port_devlink_setup(dp);
			if (err)
				goto unregister_devlink_ports;
		}
	}

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

	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_ports:
	list_for_each_entry(dp, &ds->dst->ports, list)
		if (dp->ds == ds)
			dsa_port_devlink_teardown(dp);
	devlink_unregister(ds->devlink);
free_devlink:
	devlink_free(ds->devlink);
	ds->devlink = NULL;

	return err;
}

static void dsa_switch_teardown(struct dsa_switch *ds)
{
	struct dsa_port *dp;

	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) {
		list_for_each_entry(dp, &ds->dst->ports, list)
			if (dp->ds == ds)
				dsa_port_devlink_teardown(dp);
		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) {
		/* The second possibility is "ethernet-ports" */
		ports = of_get_child_by_name(dn, "ethernet-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);