net/dsa/dsa.c

   1 /*
   2  * net/dsa/dsa.c - Hardware switch handling
   3  * Copyright (c) 2008-2009 Marvell Semiconductor
   4  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/list.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/module.h>
  17 #include <net/dsa.h>
  18 #include <linux/of.h>
  19 #include <linux/of_mdio.h>
  20 #include <linux/of_platform.h>
  21 #include "dsa_priv.h"
  22
  23 char dsa_driver_version[] = "0.1";
  24
  25
  26 /* switch driver registration ***********************************************/
  27 static DEFINE_MUTEX(dsa_switch_drivers_mutex);
  28 static LIST_HEAD(dsa_switch_drivers);
  29
  30 void register_switch_driver(struct dsa_switch_driver *drv)
  31 {
  32         mutex_lock(&dsa_switch_drivers_mutex);
  33         list_add_tail(&drv->list, &dsa_switch_drivers);
  34         mutex_unlock(&dsa_switch_drivers_mutex);
  35 }
  36 EXPORT_SYMBOL_GPL(register_switch_driver);
  37
  38 void unregister_switch_driver(struct dsa_switch_driver *drv)
  39 {
  40         mutex_lock(&dsa_switch_drivers_mutex);
  41         list_del_init(&drv->list);
  42         mutex_unlock(&dsa_switch_drivers_mutex);
  43 }
  44 EXPORT_SYMBOL_GPL(unregister_switch_driver);
  45
  46 static struct dsa_switch_driver *
  47 dsa_switch_probe(struct mii_bus *bus, int sw_addr, char **_name)
  48 {
  49         struct dsa_switch_driver *ret;
  50         struct list_head *list;
  51         char *name;
  52
  53         ret = NULL;
  54         name = NULL;
  55
  56         mutex_lock(&dsa_switch_drivers_mutex);
  57         list_for_each(list, &dsa_switch_drivers) {
  58                 struct dsa_switch_driver *drv;
  59
  60                 drv = list_entry(list, struct dsa_switch_driver, list);
  61
  62                 name = drv->probe(bus, sw_addr);
  63                 if (name != NULL) {
  64                         ret = drv;
  65                         break;
  66                 }
  67         }
  68         mutex_unlock(&dsa_switch_drivers_mutex);
  69
  70         *_name = name;
  71
  72         return ret;
  73 }
  74
  75
  76 /* basic switch operations **************************************************/
  77 static struct dsa_switch *
  78 dsa_switch_setup(struct dsa_switch_tree *dst, int index,
  79                  struct device *parent, struct mii_bus *bus)
  80 {
  81         struct dsa_chip_data *pd = dst->pd->chip + index;
  82         struct dsa_switch_driver *drv;
  83         struct dsa_switch *ds;
  84         int ret;
  85         char *name;
  86         int i;
  87         bool valid_name_found = false;
  88
  89         /*
  90          * Probe for switch model.
  91          */
  92         drv = dsa_switch_probe(bus, pd->sw_addr, &name);
  93         if (drv == NULL) {
  94                 printk(KERN_ERR "%s[%d]: could not detect attached switch\n",
  95                        dst->master_netdev->name, index);
  96                 return ERR_PTR(-EINVAL);
  97         }
  98         printk(KERN_INFO "%s[%d]: detected a %s switch\n",
  99                 dst->master_netdev->name, index, name);
 100
 101
 102         /*
 103          * Allocate and initialise switch state.
 104          */
 105         ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL);
 106         if (ds == NULL)
 107                 return ERR_PTR(-ENOMEM);
 108
 109         ds->dst = dst;
 110         ds->index = index;
 111         ds->pd = dst->pd->chip + index;
 112         ds->drv = drv;
 113         ds->master_mii_bus = bus;
 114
 115
 116         /*
 117          * Validate supplied switch configuration.
 118          */
 119         for (i = 0; i < DSA_MAX_PORTS; i++) {
 120                 char *name;
 121
 122                 name = pd->port_names[i];
 123                 if (name == NULL)
 124                         continue;
 125
 126                 if (!strcmp(name, "cpu")) {
 127                         if (dst->cpu_switch != -1) {
 128                                 printk(KERN_ERR "multiple cpu ports?!\n");
 129                                 ret = -EINVAL;
 130                                 goto out;
 131                         }
 132                         dst->cpu_switch = index;
 133                         dst->cpu_port = i;
 134                 } else if (!strcmp(name, "dsa")) {
 135                         ds->dsa_port_mask |= 1 << i;
 136                 } else {
 137                         ds->phys_port_mask |= 1 << i;
 138                 }
 139                 valid_name_found = true;
 140         }
 141
 142         if (!valid_name_found && i == DSA_MAX_PORTS) {
 143                 ret = -EINVAL;
 144                 goto out;
 145         }
 146
 147         /* Make the built-in MII bus mask match the number of ports,
 148          * switch drivers can override this later
 149          */
 150         ds->phys_mii_mask = ds->phys_port_mask;
 151
 152         /*
 153          * If the CPU connects to this switch, set the switch tree
 154          * tagging protocol to the preferred tagging format of this
 155          * switch.
 156          */
 157         if (ds->dst->cpu_switch == index)
 158                 ds->dst->tag_protocol = drv->tag_protocol;
 159
 160
 161         /*
 162          * Do basic register setup.
 163          */
 164         ret = drv->setup(ds);
 165         if (ret < 0)
 166                 goto out;
 167
 168         ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
 169         if (ret < 0)
 170                 goto out;
 171
 172         ds->slave_mii_bus = mdiobus_alloc();
 173         if (ds->slave_mii_bus == NULL) {
 174                 ret = -ENOMEM;
 175                 goto out;
 176         }
 177         dsa_slave_mii_bus_init(ds);
 178
 179         ret = mdiobus_register(ds->slave_mii_bus);
 180         if (ret < 0)
 181                 goto out_free;
 182
 183
 184         /*
 185          * Create network devices for physical switch ports.
 186          */
 187         for (i = 0; i < DSA_MAX_PORTS; i++) {
 188                 struct net_device *slave_dev;
 189
 190                 if (!(ds->phys_port_mask & (1 << i)))
 191                         continue;
 192
 193                 slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]);
 194                 if (slave_dev == NULL) {
 195                         printk(KERN_ERR "%s[%d]: can't create dsa "
 196                                "slave device for port %d(%s)\n",
 197                                dst->master_netdev->name,
 198                                index, i, pd->port_names[i]);
 199                         continue;
 200                 }
 201
 202                 ds->ports[i] = slave_dev;
 203         }
 204
 205         return ds;
 206
 207 out_free:
 208         mdiobus_free(ds->slave_mii_bus);
 209 out:
 210         kfree(ds);
 211         return ERR_PTR(ret);
 212 }
 213
 214 static void dsa_switch_destroy(struct dsa_switch *ds)
 215 {
 216 }
 217
 218
 219 /* link polling *************************************************************/
 220 static void dsa_link_poll_work(struct work_struct *ugly)
 221 {
 222         struct dsa_switch_tree *dst;
 223         int i;
 224
 225         dst = container_of(ugly, struct dsa_switch_tree, link_poll_work);
 226
 227         for (i = 0; i < dst->pd->nr_chips; i++) {
 228                 struct dsa_switch *ds = dst->ds[i];
 229
 230                 if (ds != NULL && ds->drv->poll_link != NULL)
 231                         ds->drv->poll_link(ds);
 232         }
 233
 234         mod_timer(&dst->link_poll_timer, round_jiffies(jiffies + HZ));
 235 }
 236
 237 static void dsa_link_poll_timer(unsigned long _dst)
 238 {
 239         struct dsa_switch_tree *dst = (void *)_dst;
 240
 241         schedule_work(&dst->link_poll_work);
 242 }
 243
 244
 245 /* platform driver init and cleanup *****************************************/
 246 static int dev_is_class(struct device *dev, void *class)
 247 {
 248         if (dev->class != NULL && !strcmp(dev->class->name, class))
 249                 return 1;
 250
 251         return 0;
 252 }
 253
 254 static struct device *dev_find_class(struct device *parent, char *class)
 255 {
 256         if (dev_is_class(parent, class)) {
 257                 get_device(parent);
 258                 return parent;
 259         }
 260
 261         return device_find_child(parent, class, dev_is_class);
 262 }
 263
 264 static struct mii_bus *dev_to_mii_bus(struct device *dev)
 265 {
 266         struct device *d;
 267
 268         d = dev_find_class(dev, "mdio_bus");
 269         if (d != NULL) {
 270                 struct mii_bus *bus;
 271
 272                 bus = to_mii_bus(d);
 273                 put_device(d);
 274
 275                 return bus;
 276         }
 277
 278         return NULL;
 279 }
 280
 281 static struct net_device *dev_to_net_device(struct device *dev)
 282 {
 283         struct device *d;
 284
 285         d = dev_find_class(dev, "net");
 286         if (d != NULL) {
 287                 struct net_device *nd;
 288
 289                 nd = to_net_dev(d);
 290                 dev_hold(nd);
 291                 put_device(d);
 292
 293                 return nd;
 294         }
 295
 296         return NULL;
 297 }
 298
 299 #ifdef CONFIG_OF
 300 static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
 301                                         struct dsa_chip_data *cd,
 302                                         int chip_index,
 303                                         struct device_node *link)
 304 {
 305         int ret;
 306         const __be32 *reg;
 307         int link_port_addr;
 308         int link_sw_addr;
 309         struct device_node *parent_sw;
 310         int len;
 311
 312         parent_sw = of_get_parent(link);
 313         if (!parent_sw)
 314                 return -EINVAL;
 315
 316         reg = of_get_property(parent_sw, "reg", &len);
 317         if (!reg || (len != sizeof(*reg) * 2))
 318                 return -EINVAL;
 319
 320         link_sw_addr = be32_to_cpup(reg + 1);
 321
 322         if (link_sw_addr >= pd->nr_chips)
 323                 return -EINVAL;
 324
 325         /* First time routing table allocation */
 326         if (!cd->rtable) {
 327                 cd->rtable = kmalloc(pd->nr_chips * sizeof(s8), GFP_KERNEL);
 328                 if (!cd->rtable)
 329                         return -ENOMEM;
 330
 331                 /* default to no valid uplink/downlink */
 332                 memset(cd->rtable, -1, pd->nr_chips * sizeof(s8));
 333         }
 334
 335         reg = of_get_property(link, "reg", NULL);
 336         if (!reg) {
 337                 ret = -EINVAL;
 338                 goto out;
 339         }
 340
 341         link_port_addr = be32_to_cpup(reg);
 342
 343         cd->rtable[link_sw_addr] = link_port_addr;
 344
 345         return 0;
 346 out:
 347         kfree(cd->rtable);
 348         return ret;
 349 }
 350
 351 static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
 352 {
 353         int i;
 354         int port_index;
 355
 356         for (i = 0; i < pd->nr_chips; i++) {
 357                 port_index = 0;
 358                 while (port_index < DSA_MAX_PORTS) {
 359                         kfree(pd->chip[i].port_names[port_index]);
 360                         port_index++;
 361                 }
 362                 kfree(pd->chip[i].rtable);
 363         }
 364         kfree(pd->chip);
 365 }
 366
 367 static int dsa_of_probe(struct platform_device *pdev)
 368 {
 369         struct device_node *np = pdev->dev.of_node;
 370         struct device_node *child, *mdio, *ethernet, *port, *link;
 371         struct mii_bus *mdio_bus;
 372         struct platform_device *ethernet_dev;
 373         struct dsa_platform_data *pd;
 374         struct dsa_chip_data *cd;
 375         const char *port_name;
 376         int chip_index, port_index;
 377         const unsigned int *sw_addr, *port_reg;
 378         int ret;
 379
 380         mdio = of_parse_phandle(np, "dsa,mii-bus", 0);
 381         if (!mdio)
 382                 return -EINVAL;
 383
 384         mdio_bus = of_mdio_find_bus(mdio);
 385         if (!mdio_bus)
 386                 return -EINVAL;
 387
 388         ethernet = of_parse_phandle(np, "dsa,ethernet", 0);
 389         if (!ethernet)
 390                 return -EINVAL;
 391
 392         ethernet_dev = of_find_device_by_node(ethernet);
 393         if (!ethernet_dev)
 394                 return -ENODEV;
 395
 396         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 397         if (!pd)
 398                 return -ENOMEM;
 399
 400         pdev->dev.platform_data = pd;
 401         pd->netdev = &ethernet_dev->dev;
 402         pd->nr_chips = of_get_child_count(np);
 403         if (pd->nr_chips > DSA_MAX_SWITCHES)
 404                 pd->nr_chips = DSA_MAX_SWITCHES;
 405
 406         pd->chip = kzalloc(pd->nr_chips * sizeof(struct dsa_chip_data),
 407                         GFP_KERNEL);
 408         if (!pd->chip) {
 409                 ret = -ENOMEM;
 410                 goto out_free;
 411         }
 412
 413         chip_index = -1;
 414         for_each_available_child_of_node(np, child) {
 415                 chip_index++;
 416                 cd = &pd->chip[chip_index];
 417
 418                 cd->of_node = child;
 419                 cd->mii_bus = &mdio_bus->dev;
 420
 421                 sw_addr = of_get_property(child, "reg", NULL);
 422                 if (!sw_addr)
 423                         continue;
 424
 425                 cd->sw_addr = be32_to_cpup(sw_addr);
 426                 if (cd->sw_addr > PHY_MAX_ADDR)
 427                         continue;
 428
 429                 for_each_available_child_of_node(child, port) {
 430                         port_reg = of_get_property(port, "reg", NULL);
 431                         if (!port_reg)
 432                                 continue;
 433
 434                         port_index = be32_to_cpup(port_reg);
 435
 436                         port_name = of_get_property(port, "label", NULL);
 437                         if (!port_name)
 438                                 continue;
 439
 440                         cd->port_dn[port_index] = port;
 441
 442                         cd->port_names[port_index] = kstrdup(port_name,
 443                                         GFP_KERNEL);
 444                         if (!cd->port_names[port_index]) {
 445                                 ret = -ENOMEM;
 446                                 goto out_free_chip;
 447                         }
 448
 449                         link = of_parse_phandle(port, "link", 0);
 450
 451                         if (!strcmp(port_name, "dsa") && link &&
 452                                         pd->nr_chips > 1) {
 453                                 ret = dsa_of_setup_routing_table(pd, cd,
 454                                                 chip_index, link);
 455                                 if (ret)
 456                                         goto out_free_chip;
 457                         }
 458
 459                         if (port_index == DSA_MAX_PORTS)
 460                                 break;
 461                 }
 462         }
 463
 464         return 0;
 465
 466 out_free_chip:
 467         dsa_of_free_platform_data(pd);
 468 out_free:
 469         kfree(pd);
 470         pdev->dev.platform_data = NULL;
 471         return ret;
 472 }
 473
 474 static void dsa_of_remove(struct platform_device *pdev)
 475 {
 476         struct dsa_platform_data *pd = pdev->dev.platform_data;
 477
 478         if (!pdev->dev.of_node)
 479                 return;
 480
 481         dsa_of_free_platform_data(pd);
 482         kfree(pd);
 483 }
 484 #else
 485 static inline int dsa_of_probe(struct platform_device *pdev)
 486 {
 487         return 0;
 488 }
 489
 490 static inline void dsa_of_remove(struct platform_device *pdev)
 491 {
 492 }
 493 #endif
 494
 495 static int dsa_probe(struct platform_device *pdev)
 496 {
 497         static int dsa_version_printed;
 498         struct dsa_platform_data *pd = pdev->dev.platform_data;
 499         struct net_device *dev;
 500         struct dsa_switch_tree *dst;
 501         int i, ret;
 502
 503         if (!dsa_version_printed++)
 504                 printk(KERN_NOTICE "Distributed Switch Architecture "
 505                         "driver version %s\n", dsa_driver_version);
 506
 507         if (pdev->dev.of_node) {
 508                 ret = dsa_of_probe(pdev);
 509                 if (ret)
 510                         return ret;
 511
 512                 pd = pdev->dev.platform_data;
 513         }
 514
 515         if (pd == NULL || pd->netdev == NULL)
 516                 return -EINVAL;
 517
 518         dev = dev_to_net_device(pd->netdev);
 519         if (dev == NULL) {
 520                 ret = -EINVAL;
 521                 goto out;
 522         }
 523
 524         if (dev->dsa_ptr != NULL) {
 525                 dev_put(dev);
 526                 ret = -EEXIST;
 527                 goto out;
 528         }
 529
 530         dst = kzalloc(sizeof(*dst), GFP_KERNEL);
 531         if (dst == NULL) {
 532                 dev_put(dev);
 533                 ret = -ENOMEM;
 534                 goto out;
 535         }
 536
 537         platform_set_drvdata(pdev, dst);
 538
 539         dst->pd = pd;
 540         dst->master_netdev = dev;
 541         dst->cpu_switch = -1;
 542         dst->cpu_port = -1;
 543
 544         for (i = 0; i < pd->nr_chips; i++) {
 545                 struct mii_bus *bus;
 546                 struct dsa_switch *ds;
 547
 548                 bus = dev_to_mii_bus(pd->chip[i].mii_bus);
 549                 if (bus == NULL) {
 550                         printk(KERN_ERR "%s[%d]: no mii bus found for "
 551                                 "dsa switch\n", dev->name, i);
 552                         continue;
 553                 }
 554
 555                 ds = dsa_switch_setup(dst, i, &pdev->dev, bus);
 556                 if (IS_ERR(ds)) {
 557                         printk(KERN_ERR "%s[%d]: couldn't create dsa switch "
 558                                 "instance (error %ld)\n", dev->name, i,
 559                                 PTR_ERR(ds));
 560                         continue;
 561                 }
 562
 563                 dst->ds[i] = ds;
 564                 if (ds->drv->poll_link != NULL)
 565                         dst->link_poll_needed = 1;
 566         }
 567
 568         /*
 569          * If we use a tagging format that doesn't have an ethertype
 570          * field, make sure that all packets from this point on get
 571          * sent to the tag format's receive function.
 572          */
 573         wmb();
 574         dev->dsa_ptr = (void *)dst;
 575
 576         if (dst->link_poll_needed) {
 577                 INIT_WORK(&dst->link_poll_work, dsa_link_poll_work);
 578                 init_timer(&dst->link_poll_timer);
 579                 dst->link_poll_timer.data = (unsigned long)dst;
 580                 dst->link_poll_timer.function = dsa_link_poll_timer;
 581                 dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
 582                 add_timer(&dst->link_poll_timer);
 583         }
 584
 585         return 0;
 586
 587 out:
 588         dsa_of_remove(pdev);
 589
 590         return ret;
 591 }
 592
 593 static int dsa_remove(struct platform_device *pdev)
 594 {
 595         struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
 596         int i;
 597
 598         if (dst->link_poll_needed)
 599                 del_timer_sync(&dst->link_poll_timer);
 600
 601         flush_work(&dst->link_poll_work);
 602
 603         for (i = 0; i < dst->pd->nr_chips; i++) {
 604                 struct dsa_switch *ds = dst->ds[i];
 605
 606                 if (ds != NULL)
 607                         dsa_switch_destroy(ds);
 608         }
 609
 610         dsa_of_remove(pdev);
 611
 612         return 0;
 613 }
 614
 615 static void dsa_shutdown(struct platform_device *pdev)
 616 {
 617 }
 618
 619 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 620                           struct packet_type *pt, struct net_device *orig_dev)
 621 {
 622         struct dsa_switch_tree *dst = dev->dsa_ptr;
 623
 624         if (unlikely(dst == NULL)) {
 625                 kfree_skb(skb);
 626                 return 0;
 627         }
 628
 629         return dst->ops->rcv(skb, dev, pt, orig_dev);
 630 }
 631
 632 struct packet_type dsa_pack_type __read_mostly = {
 633         .type   = cpu_to_be16(ETH_P_XDSA),
 634         .func   = dsa_switch_rcv,
 635 };
 636
 637 static const struct of_device_id dsa_of_match_table[] = {
 638         { .compatible = "brcm,bcm7445-switch-v4.0" },
 639         { .compatible = "marvell,dsa", },
 640         {}
 641 };
 642 MODULE_DEVICE_TABLE(of, dsa_of_match_table);
 643
 644 static struct platform_driver dsa_driver = {
 645         .probe          = dsa_probe,
 646         .remove         = dsa_remove,
 647         .shutdown       = dsa_shutdown,
 648         .driver = {
 649                 .name   = "dsa",
 650                 .owner  = THIS_MODULE,
 651                 .of_match_table = dsa_of_match_table,
 652         },
 653 };
 654
 655 static int __init dsa_init_module(void)
 656 {
 657         int rc;
 658
 659         rc = platform_driver_register(&dsa_driver);
 660         if (rc)
 661                 return rc;
 662
 663         dev_add_pack(&dsa_pack_type);
 664
 665         return 0;
 666 }
 667 module_init(dsa_init_module);
 668
 669 static void __exit dsa_cleanup_module(void)
 670 {
 671         dev_remove_pack(&dsa_pack_type);
 672         platform_driver_unregister(&dsa_driver);
 673 }
 674 module_exit(dsa_cleanup_module);
 675
 676 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 677 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 678 MODULE_LICENSE("GPL");
 679 MODULE_ALIAS("platform:dsa");