linux/net/dsa/dsa.c
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   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
  19char dsa_driver_version[] = "0.1";
  20
  21
  22/* switch driver registration ***********************************************/
  23static DEFINE_MUTEX(dsa_switch_drivers_mutex);
  24static LIST_HEAD(dsa_switch_drivers);
  25
  26void 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}
  32EXPORT_SYMBOL_GPL(register_switch_driver);
  33
  34void 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}
  40EXPORT_SYMBOL_GPL(unregister_switch_driver);
  41
  42static struct dsa_switch_driver *
  43dsa_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 **************************************************/
  73static struct dsa_switch *
  74dsa_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
 192out_free:
 193        mdiobus_free(ds->slave_mii_bus);
 194out:
 195        kfree(ds);
 196        return ERR_PTR(ret);
 197}
 198
 199static void dsa_switch_destroy(struct dsa_switch *ds)
 200{
 201}
 202
 203
 204/* link polling *************************************************************/
 205static 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
 222static 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 *****************************************/
 231static 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
 239static 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
 249static 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
 266static 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
 284static 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
 365static 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(&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
 385static void dsa_shutdown(struct platform_device *pdev)
 386{
 387}
 388
 389static 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
 399static 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}
 418module_init(dsa_init_module);
 419
 420static 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}
 433module_exit(dsa_cleanup_module);
 434
 435MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 436MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 437MODULE_LICENSE("GPL");
 438MODULE_ALIAS("platform:dsa");
 439
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