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