net/dsa/dsa.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/dsa/dsa.c - Hardware switch handling
   4  * Copyright (c) 2008-2009 Marvell Semiconductor
   5  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
   6  */
   7
   8 #include <linux/device.h>
   9 #include <linux/list.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/module.h>
  13 #include <linux/notifier.h>
  14 #include <linux/of.h>
  15 #include <linux/of_mdio.h>
  16 #include <linux/of_platform.h>
  17 #include <linux/of_net.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/sysfs.h>
  20 #include <linux/phy_fixed.h>
  21 #include <linux/ptp_classify.h>
  22 #include <linux/etherdevice.h>
  23
  24 #include "dsa_priv.h"
  25
  26 static LIST_HEAD(dsa_tag_drivers_list);
  27 static DEFINE_MUTEX(dsa_tag_drivers_lock);
  28
  29 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
  30                                             struct net_device *dev)
  31 {
  32         /* Just return the original SKB */
  33         return skb;
  34 }
  35
  36 static const struct dsa_device_ops none_ops = {
  37         .name   = "none",
  38         .proto  = DSA_TAG_PROTO_NONE,
  39         .xmit   = dsa_slave_notag_xmit,
  40         .rcv    = NULL,
  41 };
  42
  43 DSA_TAG_DRIVER(none_ops);
  44
  45 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
  46                                     struct module *owner)
  47 {
  48         dsa_tag_driver->owner = owner;
  49
  50         mutex_lock(&dsa_tag_drivers_lock);
  51         list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
  52         mutex_unlock(&dsa_tag_drivers_lock);
  53 }
  54
  55 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
  56                               unsigned int count, struct module *owner)
  57 {
  58         unsigned int i;
  59
  60         for (i = 0; i < count; i++)
  61                 dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
  62 }
  63
  64 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
  65 {
  66         mutex_lock(&dsa_tag_drivers_lock);
  67         list_del(&dsa_tag_driver->list);
  68         mutex_unlock(&dsa_tag_drivers_lock);
  69 }
  70 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
  71
  72 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
  73                                 unsigned int count)
  74 {
  75         unsigned int i;
  76
  77         for (i = 0; i < count; i++)
  78                 dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
  79 }
  80 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
  81
  82 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
  83 {
  84         return ops->name;
  85 };
  86
  87 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
  88 {
  89         struct dsa_tag_driver *dsa_tag_driver;
  90         const struct dsa_device_ops *ops;
  91         bool found = false;
  92
  93         request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
  94
  95         mutex_lock(&dsa_tag_drivers_lock);
  96         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
  97                 ops = dsa_tag_driver->ops;
  98                 if (ops->proto == tag_protocol) {
  99                         found = true;
 100                         break;
 101                 }
 102         }
 103
 104         if (found) {
 105                 if (!try_module_get(dsa_tag_driver->owner))
 106                         ops = ERR_PTR(-ENOPROTOOPT);
 107         } else {
 108                 ops = ERR_PTR(-ENOPROTOOPT);
 109         }
 110
 111         mutex_unlock(&dsa_tag_drivers_lock);
 112
 113         return ops;
 114 }
 115
 116 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
 117 {
 118         struct dsa_tag_driver *dsa_tag_driver;
 119
 120         mutex_lock(&dsa_tag_drivers_lock);
 121         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 122                 if (dsa_tag_driver->ops == ops) {
 123                         module_put(dsa_tag_driver->owner);
 124                         break;
 125                 }
 126         }
 127         mutex_unlock(&dsa_tag_drivers_lock);
 128 }
 129
 130 static int dev_is_class(struct device *dev, void *class)
 131 {
 132         if (dev->class != NULL && !strcmp(dev->class->name, class))
 133                 return 1;
 134
 135         return 0;
 136 }
 137
 138 static struct device *dev_find_class(struct device *parent, char *class)
 139 {
 140         if (dev_is_class(parent, class)) {
 141                 get_device(parent);
 142                 return parent;
 143         }
 144
 145         return device_find_child(parent, class, dev_is_class);
 146 }
 147
 148 struct net_device *dsa_dev_to_net_device(struct device *dev)
 149 {
 150         struct device *d;
 151
 152         d = dev_find_class(dev, "net");
 153         if (d != NULL) {
 154                 struct net_device *nd;
 155
 156                 nd = to_net_dev(d);
 157                 dev_hold(nd);
 158                 put_device(d);
 159
 160                 return nd;
 161         }
 162
 163         return NULL;
 164 }
 165 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
 166
 167 /* Determine if we should defer delivery of skb until we have a rx timestamp.
 168  *
 169  * Called from dsa_switch_rcv. For now, this will only work if tagging is
 170  * enabled on the switch. Normally the MAC driver would retrieve the hardware
 171  * timestamp when it reads the packet out of the hardware. However in a DSA
 172  * switch, the DSA driver owning the interface to which the packet is
 173  * delivered is never notified unless we do so here.
 174  */
 175 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
 176                                        struct sk_buff *skb)
 177 {
 178         struct dsa_switch *ds = p->dp->ds;
 179         unsigned int type;
 180
 181         if (skb_headroom(skb) < ETH_HLEN)
 182                 return false;
 183
 184         __skb_push(skb, ETH_HLEN);
 185
 186         type = ptp_classify_raw(skb);
 187
 188         __skb_pull(skb, ETH_HLEN);
 189
 190         if (type == PTP_CLASS_NONE)
 191                 return false;
 192
 193         if (likely(ds->ops->port_rxtstamp))
 194                 return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
 195
 196         return false;
 197 }
 198
 199 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 200                           struct packet_type *pt, struct net_device *unused)
 201 {
 202         struct dsa_port *cpu_dp = dev->dsa_ptr;
 203         struct sk_buff *nskb = NULL;
 204         struct dsa_slave_priv *p;
 205
 206         if (unlikely(!cpu_dp)) {
 207                 kfree_skb(skb);
 208                 return 0;
 209         }
 210
 211         skb = skb_unshare(skb, GFP_ATOMIC);
 212         if (!skb)
 213                 return 0;
 214
 215         nskb = cpu_dp->rcv(skb, dev, pt);
 216         if (!nskb) {
 217                 kfree_skb(skb);
 218                 return 0;
 219         }
 220
 221         skb = nskb;
 222         p = netdev_priv(skb->dev);
 223         skb_push(skb, ETH_HLEN);
 224         skb->pkt_type = PACKET_HOST;
 225         skb->protocol = eth_type_trans(skb, skb->dev);
 226
 227         if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
 228                 nskb = dsa_untag_bridge_pvid(skb);
 229                 if (!nskb) {
 230                         kfree_skb(skb);
 231                         return 0;
 232                 }
 233                 skb = nskb;
 234         }
 235
 236         dev_sw_netstats_rx_add(skb->dev, skb->len);
 237
 238         if (dsa_skb_defer_rx_timestamp(p, skb))
 239                 return 0;
 240
 241         gro_cells_receive(&p->gcells, skb);
 242
 243         return 0;
 244 }
 245
 246 #ifdef CONFIG_PM_SLEEP
 247 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 248 {
 249         const struct dsa_port *dp = dsa_to_port(ds, p);
 250
 251         return dp->type == DSA_PORT_TYPE_USER && dp->slave;
 252 }
 253
 254 int dsa_switch_suspend(struct dsa_switch *ds)
 255 {
 256         int i, ret = 0;
 257
 258         /* Suspend slave network devices */
 259         for (i = 0; i < ds->num_ports; i++) {
 260                 if (!dsa_is_port_initialized(ds, i))
 261                         continue;
 262
 263                 ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
 264                 if (ret)
 265                         return ret;
 266         }
 267
 268         if (ds->ops->suspend)
 269                 ret = ds->ops->suspend(ds);
 270
 271         return ret;
 272 }
 273 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
 274
 275 int dsa_switch_resume(struct dsa_switch *ds)
 276 {
 277         int i, ret = 0;
 278
 279         if (ds->ops->resume)
 280                 ret = ds->ops->resume(ds);
 281
 282         if (ret)
 283                 return ret;
 284
 285         /* Resume slave network devices */
 286         for (i = 0; i < ds->num_ports; i++) {
 287                 if (!dsa_is_port_initialized(ds, i))
 288                         continue;
 289
 290                 ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
 291                 if (ret)
 292                         return ret;
 293         }
 294
 295         return 0;
 296 }
 297 EXPORT_SYMBOL_GPL(dsa_switch_resume);
 298 #endif
 299
 300 static struct packet_type dsa_pack_type __read_mostly = {
 301         .type   = cpu_to_be16(ETH_P_XDSA),
 302         .func   = dsa_switch_rcv,
 303 };
 304
 305 static struct workqueue_struct *dsa_owq;
 306
 307 bool dsa_schedule_work(struct work_struct *work)
 308 {
 309         return queue_work(dsa_owq, work);
 310 }
 311
 312 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
 313
 314 int register_dsa_notifier(struct notifier_block *nb)
 315 {
 316         return atomic_notifier_chain_register(&dsa_notif_chain, nb);
 317 }
 318 EXPORT_SYMBOL_GPL(register_dsa_notifier);
 319
 320 int unregister_dsa_notifier(struct notifier_block *nb)
 321 {
 322         return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
 323 }
 324 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
 325
 326 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
 327                        struct dsa_notifier_info *info)
 328 {
 329         info->dev = dev;
 330         return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
 331 }
 332 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
 333
 334 int dsa_devlink_param_get(struct devlink *dl, u32 id,
 335                           struct devlink_param_gset_ctx *ctx)
 336 {
 337         struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 338
 339         if (!ds->ops->devlink_param_get)
 340                 return -EOPNOTSUPP;
 341
 342         return ds->ops->devlink_param_get(ds, id, ctx);
 343 }
 344 EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
 345
 346 int dsa_devlink_param_set(struct devlink *dl, u32 id,
 347                           struct devlink_param_gset_ctx *ctx)
 348 {
 349         struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 350
 351         if (!ds->ops->devlink_param_set)
 352                 return -EOPNOTSUPP;
 353
 354         return ds->ops->devlink_param_set(ds, id, ctx);
 355 }
 356 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
 357
 358 int dsa_devlink_params_register(struct dsa_switch *ds,
 359                                 const struct devlink_param *params,
 360                                 size_t params_count)
 361 {
 362         return devlink_params_register(ds->devlink, params, params_count);
 363 }
 364 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
 365
 366 void dsa_devlink_params_unregister(struct dsa_switch *ds,
 367                                    const struct devlink_param *params,
 368                                    size_t params_count)
 369 {
 370         devlink_params_unregister(ds->devlink, params, params_count);
 371 }
 372 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
 373
 374 int dsa_devlink_resource_register(struct dsa_switch *ds,
 375                                   const char *resource_name,
 376                                   u64 resource_size,
 377                                   u64 resource_id,
 378                                   u64 parent_resource_id,
 379                                   const struct devlink_resource_size_params *size_params)
 380 {
 381         return devlink_resource_register(ds->devlink, resource_name,
 382                                          resource_size, resource_id,
 383                                          parent_resource_id,
 384                                          size_params);
 385 }
 386 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
 387
 388 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
 389 {
 390         devlink_resources_unregister(ds->devlink, NULL);
 391 }
 392 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
 393
 394 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
 395                                            u64 resource_id,
 396                                            devlink_resource_occ_get_t *occ_get,
 397                                            void *occ_get_priv)
 398 {
 399         return devlink_resource_occ_get_register(ds->devlink, resource_id,
 400                                                  occ_get, occ_get_priv);
 401 }
 402 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
 403
 404 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
 405                                              u64 resource_id)
 406 {
 407         devlink_resource_occ_get_unregister(ds->devlink, resource_id);
 408 }
 409 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
 410
 411 struct devlink_region *
 412 dsa_devlink_region_create(struct dsa_switch *ds,
 413                           const struct devlink_region_ops *ops,
 414                           u32 region_max_snapshots, u64 region_size)
 415 {
 416         return devlink_region_create(ds->devlink, ops, region_max_snapshots,
 417                                      region_size);
 418 }
 419 EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
 420
 421 struct devlink_region *
 422 dsa_devlink_port_region_create(struct dsa_switch *ds,
 423                                int port,
 424                                const struct devlink_port_region_ops *ops,
 425                                u32 region_max_snapshots, u64 region_size)
 426 {
 427         struct dsa_port *dp = dsa_to_port(ds, port);
 428
 429         return devlink_port_region_create(&dp->devlink_port, ops,
 430                                           region_max_snapshots,
 431                                           region_size);
 432 }
 433 EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
 434
 435 void dsa_devlink_region_destroy(struct devlink_region *region)
 436 {
 437         devlink_region_destroy(region);
 438 }
 439 EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
 440
 441 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
 442 {
 443         if (!netdev || !dsa_slave_dev_check(netdev))
 444                 return ERR_PTR(-ENODEV);
 445
 446         return dsa_slave_to_port(netdev);
 447 }
 448 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
 449
 450 static int __init dsa_init_module(void)
 451 {
 452         int rc;
 453
 454         dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 455                                           WQ_MEM_RECLAIM);
 456         if (!dsa_owq)
 457                 return -ENOMEM;
 458
 459         rc = dsa_slave_register_notifier();
 460         if (rc)
 461                 goto register_notifier_fail;
 462
 463         dev_add_pack(&dsa_pack_type);
 464
 465         dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
 466                                 THIS_MODULE);
 467
 468         return 0;
 469
 470 register_notifier_fail:
 471         destroy_workqueue(dsa_owq);
 472
 473         return rc;
 474 }
 475 module_init(dsa_init_module);
 476
 477 static void __exit dsa_cleanup_module(void)
 478 {
 479         dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
 480
 481         dsa_slave_unregister_notifier();
 482         dev_remove_pack(&dsa_pack_type);
 483         destroy_workqueue(dsa_owq);
 484 }
 485 module_exit(dsa_cleanup_module);
 486
 487 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 488 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 489 MODULE_LICENSE("GPL");
 490 MODULE_ALIAS("platform:dsa");