net/dsa/dsa.c

   1 /*
   2  * net/dsa/dsa.c - Hardware switch handling
   3  * Copyright (c) 2008-2009 Marvell Semiconductor
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  */
  10
  11 #include <linux/list.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <net/dsa.h>
  17 #include "dsa_priv.h"
  18
  19 char dsa_driver_version[] = "0.1";
  20
  21
  22 /* switch driver registration ***********************************************/
  23 static DEFINE_MUTEX(dsa_switch_drivers_mutex);
  24 static LIST_HEAD(dsa_switch_drivers);
  25
  26 void register_switch_driver(struct dsa_switch_driver *drv)
  27 {
  28         mutex_lock(&dsa_switch_drivers_mutex);
  29         list_add_tail(&drv->list, &dsa_switch_drivers);
  30         mutex_unlock(&dsa_switch_drivers_mutex);
  31 }
  32 EXPORT_SYMBOL_GPL(register_switch_driver);
  33
  34 void unregister_switch_driver(struct dsa_switch_driver *drv)
  35 {
  36         mutex_lock(&dsa_switch_drivers_mutex);
  37         list_del_init(&drv->list);
  38         mutex_unlock(&dsa_switch_drivers_mutex);
  39 }
  40 EXPORT_SYMBOL_GPL(unregister_switch_driver);
  41
  42 static struct dsa_switch_driver *
  43 dsa_switch_probe(struct mii_bus *bus, int sw_addr, char **_name)
  44 {
  45         struct dsa_switch_driver *ret;
  46         struct list_head *list;
  47         char *name;
  48
  49         ret = NULL;
  50         name = NULL;
  51
  52         mutex_lock(&dsa_switch_drivers_mutex);
  53         list_for_each(list, &dsa_switch_drivers) {
  54                 struct dsa_switch_driver *drv;
  55
  56                 drv = list_entry(list, struct dsa_switch_driver, list);
  57
  58                 name = drv->probe(bus, sw_addr);
  59                 if (name != NULL) {
  60                         ret = drv;
  61                         break;
  62                 }
  63         }
  64         mutex_unlock(&dsa_switch_drivers_mutex);
  65
  66         *_name = name;
  67
  68         return ret;
  69 }
  70
  71
  72 /* basic switch operations **************************************************/
  73 static struct dsa_switch *
  74 dsa_switch_setup(struct dsa_switch_tree *dst, int index,
  75                  struct device *parent, struct mii_bus *bus)
  76 {
  77         struct dsa_chip_data *pd = dst->pd->chip + index;
  78         struct dsa_switch_driver *drv;
  79         struct dsa_switch *ds;
  80         int ret;
  81         char *name;
  82         int i;
  83
  84         /*
  85          * Probe for switch model.
  86          */
  87         drv = dsa_switch_probe(bus, pd->sw_addr, &name);
  88         if (drv == NULL) {
  89                 printk(KERN_ERR "%s[%d]: could not detect attached switch\n",
  90                        dst->master_netdev->name, index);
  91                 return ERR_PTR(-EINVAL);
  92         }
  93         printk(KERN_INFO "%s[%d]: detected a %s switch\n",
  94                 dst->master_netdev->name, index, name);
  95
  96
  97         /*
  98          * Allocate and initialise switch state.
  99          */
 100         ds = kzalloc(sizeof(*ds) + drv->priv_size, GFP_KERNEL);
 101         if (ds == NULL)
 102                 return ERR_PTR(-ENOMEM);
 103
 104         ds->dst = dst;
 105         ds->index = index;
 106         ds->pd = dst->pd->chip + index;
 107         ds->drv = drv;
 108         ds->master_mii_bus = bus;
 109
 110
 111         /*
 112          * Validate supplied switch configuration.
 113          */
 114         for (i = 0; i < DSA_MAX_PORTS; i++) {
 115                 char *name;
 116
 117                 name = pd->port_names[i];
 118                 if (name == NULL)
 119                         continue;
 120
 121                 if (!strcmp(name, "cpu")) {
 122                         if (dst->cpu_switch != -1) {
 123                                 printk(KERN_ERR "multiple cpu ports?!\n");
 124                                 ret = -EINVAL;
 125                                 goto out;
 126                         }
 127                         dst->cpu_switch = index;
 128                         dst->cpu_port = i;
 129                 } else if (!strcmp(name, "dsa")) {
 130                         ds->dsa_port_mask |= 1 << i;
 131                 } else {
 132                         ds->phys_port_mask |= 1 << i;
 133                 }
 134         }
 135
 136
 137         /*
 138          * If the CPU connects to this switch, set the switch tree
 139          * tagging protocol to the preferred tagging format of this
 140          * switch.
 141          */
 142         if (ds->dst->cpu_switch == index)
 143                 ds->dst->tag_protocol = drv->tag_protocol;
 144
 145
 146         /*
 147          * Do basic register setup.
 148          */
 149         ret = drv->setup(ds);
 150         if (ret < 0)
 151                 goto out;
 152
 153         ret = drv->set_addr(ds, dst->master_netdev->dev_addr);
 154         if (ret < 0)
 155                 goto out;
 156
 157         ds->slave_mii_bus = mdiobus_alloc();
 158         if (ds->slave_mii_bus == NULL) {
 159                 ret = -ENOMEM;
 160                 goto out;
 161         }
 162         dsa_slave_mii_bus_init(ds);
 163
 164         ret = mdiobus_register(ds->slave_mii_bus);
 165         if (ret < 0)
 166                 goto out_free;
 167
 168
 169         /*
 170          * Create network devices for physical switch ports.
 171          */
 172         for (i = 0; i < DSA_MAX_PORTS; i++) {
 173                 struct net_device *slave_dev;
 174
 175                 if (!(ds->phys_port_mask & (1 << i)))
 176                         continue;
 177
 178                 slave_dev = dsa_slave_create(ds, parent, i, pd->port_names[i]);
 179                 if (slave_dev == NULL) {
 180                         printk(KERN_ERR "%s[%d]: can't create dsa "
 181                                "slave device for port %d(%s)\n",
 182                                dst->master_netdev->name,
 183                                index, i, pd->port_names[i]);
 184                         continue;
 185                 }
 186
 187                 ds->ports[i] = slave_dev;
 188         }
 189
 190         return ds;
 191
 192 out_free:
 193         mdiobus_free(ds->slave_mii_bus);
 194 out:
 195         kfree(ds);
 196         return ERR_PTR(ret);
 197 }
 198
 199 static void dsa_switch_destroy(struct dsa_switch *ds)
 200 {
 201 }
 202
 203
 204 /* link polling *************************************************************/
 205 static void dsa_link_poll_work(struct work_struct *ugly)
 206 {
 207         struct dsa_switch_tree *dst;
 208         int i;
 209
 210         dst = container_of(ugly, struct dsa_switch_tree, link_poll_work);
 211
 212         for (i = 0; i < dst->pd->nr_chips; i++) {
 213                 struct dsa_switch *ds = dst->ds[i];
 214
 215                 if (ds != NULL && ds->drv->poll_link != NULL)
 216                         ds->drv->poll_link(ds);
 217         }
 218
 219         mod_timer(&dst->link_poll_timer, round_jiffies(jiffies + HZ));
 220 }
 221
 222 static void dsa_link_poll_timer(unsigned long _dst)
 223 {
 224         struct dsa_switch_tree *dst = (void *)_dst;
 225
 226         schedule_work(&dst->link_poll_work);
 227 }
 228
 229
 230 /* platform driver init and cleanup *****************************************/
 231 static int dev_is_class(struct device *dev, void *class)
 232 {
 233         if (dev->class != NULL && !strcmp(dev->class->name, class))
 234                 return 1;
 235
 236         return 0;
 237 }
 238
 239 static struct device *dev_find_class(struct device *parent, char *class)
 240 {
 241         if (dev_is_class(parent, class)) {
 242                 get_device(parent);
 243                 return parent;
 244         }
 245
 246         return device_find_child(parent, class, dev_is_class);
 247 }
 248
 249 static struct mii_bus *dev_to_mii_bus(struct device *dev)
 250 {
 251         struct device *d;
 252
 253         d = dev_find_class(dev, "mdio_bus");
 254         if (d != NULL) {
 255                 struct mii_bus *bus;
 256
 257                 bus = to_mii_bus(d);
 258                 put_device(d);
 259
 260                 return bus;
 261         }
 262
 263         return NULL;
 264 }
 265
 266 static struct net_device *dev_to_net_device(struct device *dev)
 267 {
 268         struct device *d;
 269
 270         d = dev_find_class(dev, "net");
 271         if (d != NULL) {
 272                 struct net_device *nd;
 273
 274                 nd = to_net_dev(d);
 275                 dev_hold(nd);
 276                 put_device(d);
 277
 278                 return nd;
 279         }
 280
 281         return NULL;
 282 }
 283
 284 static int dsa_probe(struct platform_device *pdev)
 285 {
 286         static int dsa_version_printed;
 287         struct dsa_platform_data *pd = pdev->dev.platform_data;
 288         struct net_device *dev;
 289         struct dsa_switch_tree *dst;
 290         int i;
 291
 292         if (!dsa_version_printed++)
 293                 printk(KERN_NOTICE "Distributed Switch Architecture "
 294                         "driver version %s\n", dsa_driver_version);
 295
 296         if (pd == NULL || pd->netdev == NULL)
 297                 return -EINVAL;
 298
 299         dev = dev_to_net_device(pd->netdev);
 300         if (dev == NULL)
 301                 return -EINVAL;
 302
 303         if (dev->dsa_ptr != NULL) {
 304                 dev_put(dev);
 305                 return -EEXIST;
 306         }
 307
 308         dst = kzalloc(sizeof(*dst), GFP_KERNEL);
 309         if (dst == NULL) {
 310                 dev_put(dev);
 311                 return -ENOMEM;
 312         }
 313
 314         platform_set_drvdata(pdev, dst);
 315
 316         dst->pd = pd;
 317         dst->master_netdev = dev;
 318         dst->cpu_switch = -1;
 319         dst->cpu_port = -1;
 320
 321         for (i = 0; i < pd->nr_chips; i++) {
 322                 struct mii_bus *bus;
 323                 struct dsa_switch *ds;
 324
 325                 bus = dev_to_mii_bus(pd->chip[i].mii_bus);
 326                 if (bus == NULL) {
 327                         printk(KERN_ERR "%s[%d]: no mii bus found for "
 328                                 "dsa switch\n", dev->name, i);
 329                         continue;
 330                 }
 331
 332                 ds = dsa_switch_setup(dst, i, &pdev->dev, bus);
 333                 if (IS_ERR(ds)) {
 334                         printk(KERN_ERR "%s[%d]: couldn't create dsa switch "
 335                                 "instance (error %ld)\n", dev->name, i,
 336                                 PTR_ERR(ds));
 337                         continue;
 338                 }
 339
 340                 dst->ds[i] = ds;
 341                 if (ds->drv->poll_link != NULL)
 342                         dst->link_poll_needed = 1;
 343         }
 344
 345         /*
 346          * If we use a tagging format that doesn't have an ethertype
 347          * field, make sure that all packets from this point on get
 348          * sent to the tag format's receive function.
 349          */
 350         wmb();
 351         dev->dsa_ptr = (void *)dst;
 352
 353         if (dst->link_poll_needed) {
 354                 INIT_WORK(&dst->link_poll_work, dsa_link_poll_work);
 355                 init_timer(&dst->link_poll_timer);
 356                 dst->link_poll_timer.data = (unsigned long)dst;
 357                 dst->link_poll_timer.function = dsa_link_poll_timer;
 358                 dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
 359                 add_timer(&dst->link_poll_timer);
 360         }
 361
 362         return 0;
 363 }
 364
 365 static int dsa_remove(struct platform_device *pdev)
 366 {
 367         struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
 368         int i;
 369
 370         if (dst->link_poll_needed)
 371                 del_timer_sync(&dst->link_poll_timer);
 372
 373         flush_work_sync(&dst->link_poll_work);
 374
 375         for (i = 0; i < dst->pd->nr_chips; i++) {
 376                 struct dsa_switch *ds = dst->ds[i];
 377
 378                 if (ds != NULL)
 379                         dsa_switch_destroy(ds);
 380         }
 381
 382         return 0;
 383 }
 384
 385 static void dsa_shutdown(struct platform_device *pdev)
 386 {
 387 }
 388
 389 static struct platform_driver dsa_driver = {
 390         .probe          = dsa_probe,
 391         .remove         = dsa_remove,
 392         .shutdown       = dsa_shutdown,
 393         .driver = {
 394                 .name   = "dsa",
 395                 .owner  = THIS_MODULE,
 396         },
 397 };
 398
 399 static int __init dsa_init_module(void)
 400 {
 401         int rc;
 402
 403         rc = platform_driver_register(&dsa_driver);
 404         if (rc)
 405                 return rc;
 406
 407 #ifdef CONFIG_NET_DSA_TAG_DSA
 408         dev_add_pack(&dsa_packet_type);
 409 #endif
 410 #ifdef CONFIG_NET_DSA_TAG_EDSA
 411         dev_add_pack(&edsa_packet_type);
 412 #endif
 413 #ifdef CONFIG_NET_DSA_TAG_TRAILER
 414         dev_add_pack(&trailer_packet_type);
 415 #endif
 416         return 0;
 417 }
 418 module_init(dsa_init_module);
 419
 420 static void __exit dsa_cleanup_module(void)
 421 {
 422 #ifdef CONFIG_NET_DSA_TAG_TRAILER
 423         dev_remove_pack(&trailer_packet_type);
 424 #endif
 425 #ifdef CONFIG_NET_DSA_TAG_EDSA
 426         dev_remove_pack(&edsa_packet_type);
 427 #endif
 428 #ifdef CONFIG_NET_DSA_TAG_DSA
 429         dev_remove_pack(&dsa_packet_type);
 430 #endif
 431         platform_driver_unregister(&dsa_driver);
 432 }
 433 module_exit(dsa_cleanup_module);
 434
 435 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 436 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 437 MODULE_LICENSE("GPL");
 438 MODULE_ALIAS("platform:dsa");