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 /* Function takes a reference on the module owning the tagger,
  88  * so dsa_tag_driver_put must be called afterwards.
  89  */
  90 const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf)
  91 {
  92         const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
  93         struct dsa_tag_driver *dsa_tag_driver;
  94
  95         mutex_lock(&dsa_tag_drivers_lock);
  96         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
  97                 const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
  98
  99                 if (!sysfs_streq(buf, tmp->name))
 100                         continue;
 101
 102                 if (!try_module_get(dsa_tag_driver->owner))
 103                         break;
 104
 105                 ops = tmp;
 106                 break;
 107         }
 108         mutex_unlock(&dsa_tag_drivers_lock);
 109
 110         return ops;
 111 }
 112
 113 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
 114 {
 115         struct dsa_tag_driver *dsa_tag_driver;
 116         const struct dsa_device_ops *ops;
 117         bool found = false;
 118
 119         request_module("%s%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
 120
 121         mutex_lock(&dsa_tag_drivers_lock);
 122         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 123                 ops = dsa_tag_driver->ops;
 124                 if (ops->proto == tag_protocol) {
 125                         found = true;
 126                         break;
 127                 }
 128         }
 129
 130         if (found) {
 131                 if (!try_module_get(dsa_tag_driver->owner))
 132                         ops = ERR_PTR(-ENOPROTOOPT);
 133         } else {
 134                 ops = ERR_PTR(-ENOPROTOOPT);
 135         }
 136
 137         mutex_unlock(&dsa_tag_drivers_lock);
 138
 139         return ops;
 140 }
 141
 142 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
 143 {
 144         struct dsa_tag_driver *dsa_tag_driver;
 145
 146         mutex_lock(&dsa_tag_drivers_lock);
 147         list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 148                 if (dsa_tag_driver->ops == ops) {
 149                         module_put(dsa_tag_driver->owner);
 150                         break;
 151                 }
 152         }
 153         mutex_unlock(&dsa_tag_drivers_lock);
 154 }
 155
 156 static int dev_is_class(struct device *dev, void *class)
 157 {
 158         if (dev->class != NULL && !strcmp(dev->class->name, class))
 159                 return 1;
 160
 161         return 0;
 162 }
 163
 164 static struct device *dev_find_class(struct device *parent, char *class)
 165 {
 166         if (dev_is_class(parent, class)) {
 167                 get_device(parent);
 168                 return parent;
 169         }
 170
 171         return device_find_child(parent, class, dev_is_class);
 172 }
 173
 174 struct net_device *dsa_dev_to_net_device(struct device *dev)
 175 {
 176         struct device *d;
 177
 178         d = dev_find_class(dev, "net");
 179         if (d != NULL) {
 180                 struct net_device *nd;
 181
 182                 nd = to_net_dev(d);
 183                 dev_hold(nd);
 184                 put_device(d);
 185
 186                 return nd;
 187         }
 188
 189         return NULL;
 190 }
 191 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
 192
 193 /* Determine if we should defer delivery of skb until we have a rx timestamp.
 194  *
 195  * Called from dsa_switch_rcv. For now, this will only work if tagging is
 196  * enabled on the switch. Normally the MAC driver would retrieve the hardware
 197  * timestamp when it reads the packet out of the hardware. However in a DSA
 198  * switch, the DSA driver owning the interface to which the packet is
 199  * delivered is never notified unless we do so here.
 200  */
 201 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
 202                                        struct sk_buff *skb)
 203 {
 204         struct dsa_switch *ds = p->dp->ds;
 205         unsigned int type;
 206
 207         if (skb_headroom(skb) < ETH_HLEN)
 208                 return false;
 209
 210         __skb_push(skb, ETH_HLEN);
 211
 212         type = ptp_classify_raw(skb);
 213
 214         __skb_pull(skb, ETH_HLEN);
 215
 216         if (type == PTP_CLASS_NONE)
 217                 return false;
 218
 219         if (likely(ds->ops->port_rxtstamp))
 220                 return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
 221
 222         return false;
 223 }
 224
 225 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 226                           struct packet_type *pt, struct net_device *unused)
 227 {
 228         struct dsa_port *cpu_dp = dev->dsa_ptr;
 229         struct sk_buff *nskb = NULL;
 230         struct dsa_slave_priv *p;
 231
 232         if (unlikely(!cpu_dp)) {
 233                 kfree_skb(skb);
 234                 return 0;
 235         }
 236
 237         skb = skb_unshare(skb, GFP_ATOMIC);
 238         if (!skb)
 239                 return 0;
 240
 241         nskb = cpu_dp->rcv(skb, dev);
 242         if (!nskb) {
 243                 kfree_skb(skb);
 244                 return 0;
 245         }
 246
 247         skb = nskb;
 248         skb_push(skb, ETH_HLEN);
 249         skb->pkt_type = PACKET_HOST;
 250         skb->protocol = eth_type_trans(skb, skb->dev);
 251
 252         if (unlikely(!dsa_slave_dev_check(skb->dev))) {
 253                 /* Packet is to be injected directly on an upper
 254                  * device, e.g. a team/bond, so skip all DSA-port
 255                  * specific actions.
 256                  */
 257                 netif_rx(skb);
 258                 return 0;
 259         }
 260
 261         p = netdev_priv(skb->dev);
 262
 263         if (unlikely(cpu_dp->ds->untag_bridge_pvid)) {
 264                 nskb = dsa_untag_bridge_pvid(skb);
 265                 if (!nskb) {
 266                         kfree_skb(skb);
 267                         return 0;
 268                 }
 269                 skb = nskb;
 270         }
 271
 272         dev_sw_netstats_rx_add(skb->dev, skb->len);
 273
 274         if (dsa_skb_defer_rx_timestamp(p, skb))
 275                 return 0;
 276
 277         gro_cells_receive(&p->gcells, skb);
 278
 279         return 0;
 280 }
 281
 282 #ifdef CONFIG_PM_SLEEP
 283 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 284 {
 285         const struct dsa_port *dp = dsa_to_port(ds, p);
 286
 287         return dp->type == DSA_PORT_TYPE_USER && dp->slave;
 288 }
 289
 290 int dsa_switch_suspend(struct dsa_switch *ds)
 291 {
 292         int i, ret = 0;
 293
 294         /* Suspend slave network devices */
 295         for (i = 0; i < ds->num_ports; i++) {
 296                 if (!dsa_is_port_initialized(ds, i))
 297                         continue;
 298
 299                 ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
 300                 if (ret)
 301                         return ret;
 302         }
 303
 304         if (ds->ops->suspend)
 305                 ret = ds->ops->suspend(ds);
 306
 307         return ret;
 308 }
 309 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
 310
 311 int dsa_switch_resume(struct dsa_switch *ds)
 312 {
 313         int i, ret = 0;
 314
 315         if (ds->ops->resume)
 316                 ret = ds->ops->resume(ds);
 317
 318         if (ret)
 319                 return ret;
 320
 321         /* Resume slave network devices */
 322         for (i = 0; i < ds->num_ports; i++) {
 323                 if (!dsa_is_port_initialized(ds, i))
 324                         continue;
 325
 326                 ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
 327                 if (ret)
 328                         return ret;
 329         }
 330
 331         return 0;
 332 }
 333 EXPORT_SYMBOL_GPL(dsa_switch_resume);
 334 #endif
 335
 336 static struct packet_type dsa_pack_type __read_mostly = {
 337         .type   = cpu_to_be16(ETH_P_XDSA),
 338         .func   = dsa_switch_rcv,
 339 };
 340
 341 static struct workqueue_struct *dsa_owq;
 342
 343 bool dsa_schedule_work(struct work_struct *work)
 344 {
 345         return queue_work(dsa_owq, work);
 346 }
 347
 348 void dsa_flush_workqueue(void)
 349 {
 350         flush_workqueue(dsa_owq);
 351 }
 352 EXPORT_SYMBOL_GPL(dsa_flush_workqueue);
 353
 354 int dsa_devlink_param_get(struct devlink *dl, u32 id,
 355                           struct devlink_param_gset_ctx *ctx)
 356 {
 357         struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 358
 359         if (!ds->ops->devlink_param_get)
 360                 return -EOPNOTSUPP;
 361
 362         return ds->ops->devlink_param_get(ds, id, ctx);
 363 }
 364 EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
 365
 366 int dsa_devlink_param_set(struct devlink *dl, u32 id,
 367                           struct devlink_param_gset_ctx *ctx)
 368 {
 369         struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 370
 371         if (!ds->ops->devlink_param_set)
 372                 return -EOPNOTSUPP;
 373
 374         return ds->ops->devlink_param_set(ds, id, ctx);
 375 }
 376 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
 377
 378 int dsa_devlink_params_register(struct dsa_switch *ds,
 379                                 const struct devlink_param *params,
 380                                 size_t params_count)
 381 {
 382         return devlink_params_register(ds->devlink, params, params_count);
 383 }
 384 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
 385
 386 void dsa_devlink_params_unregister(struct dsa_switch *ds,
 387                                    const struct devlink_param *params,
 388                                    size_t params_count)
 389 {
 390         devlink_params_unregister(ds->devlink, params, params_count);
 391 }
 392 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
 393
 394 int dsa_devlink_resource_register(struct dsa_switch *ds,
 395                                   const char *resource_name,
 396                                   u64 resource_size,
 397                                   u64 resource_id,
 398                                   u64 parent_resource_id,
 399                                   const struct devlink_resource_size_params *size_params)
 400 {
 401         return devlink_resource_register(ds->devlink, resource_name,
 402                                          resource_size, resource_id,
 403                                          parent_resource_id,
 404                                          size_params);
 405 }
 406 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
 407
 408 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
 409 {
 410         devlink_resources_unregister(ds->devlink, NULL);
 411 }
 412 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
 413
 414 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
 415                                            u64 resource_id,
 416                                            devlink_resource_occ_get_t *occ_get,
 417                                            void *occ_get_priv)
 418 {
 419         return devlink_resource_occ_get_register(ds->devlink, resource_id,
 420                                                  occ_get, occ_get_priv);
 421 }
 422 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
 423
 424 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
 425                                              u64 resource_id)
 426 {
 427         devlink_resource_occ_get_unregister(ds->devlink, resource_id);
 428 }
 429 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
 430
 431 struct devlink_region *
 432 dsa_devlink_region_create(struct dsa_switch *ds,
 433                           const struct devlink_region_ops *ops,
 434                           u32 region_max_snapshots, u64 region_size)
 435 {
 436         return devlink_region_create(ds->devlink, ops, region_max_snapshots,
 437                                      region_size);
 438 }
 439 EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
 440
 441 struct devlink_region *
 442 dsa_devlink_port_region_create(struct dsa_switch *ds,
 443                                int port,
 444                                const struct devlink_port_region_ops *ops,
 445                                u32 region_max_snapshots, u64 region_size)
 446 {
 447         struct dsa_port *dp = dsa_to_port(ds, port);
 448
 449         return devlink_port_region_create(&dp->devlink_port, ops,
 450                                           region_max_snapshots,
 451                                           region_size);
 452 }
 453 EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
 454
 455 void dsa_devlink_region_destroy(struct devlink_region *region)
 456 {
 457         devlink_region_destroy(region);
 458 }
 459 EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
 460
 461 struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
 462 {
 463         if (!netdev || !dsa_slave_dev_check(netdev))
 464                 return ERR_PTR(-ENODEV);
 465
 466         return dsa_slave_to_port(netdev);
 467 }
 468 EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
 469
 470 static int __init dsa_init_module(void)
 471 {
 472         int rc;
 473
 474         dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 475                                           WQ_MEM_RECLAIM);
 476         if (!dsa_owq)
 477                 return -ENOMEM;
 478
 479         rc = dsa_slave_register_notifier();
 480         if (rc)
 481                 goto register_notifier_fail;
 482
 483         dev_add_pack(&dsa_pack_type);
 484
 485         dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
 486                                 THIS_MODULE);
 487
 488         return 0;
 489
 490 register_notifier_fail:
 491         destroy_workqueue(dsa_owq);
 492
 493         return rc;
 494 }
 495 module_init(dsa_init_module);
 496
 497 static void __exit dsa_cleanup_module(void)
 498 {
 499         dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
 500
 501         dsa_slave_unregister_notifier();
 502         dev_remove_pack(&dsa_pack_type);
 503         destroy_workqueue(dsa_owq);
 504 }
 505 module_exit(dsa_cleanup_module);
 506
 507 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 508 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 509 MODULE_LICENSE("GPL");
 510 MODULE_ALIAS("platform:dsa");