net/dsa/dsa2.c

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