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 <[email protected]>
   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 pcpu_sw_netstats *s;
 205         struct dsa_slave_priv *p;
 206
 207         if (unlikely(!cpu_dp)) {
 208                 kfree_skb(skb);
 209                 return 0;
 210         }
 211
 212         skb = skb_unshare(skb, GFP_ATOMIC);
 213         if (!skb)
 214                 return 0;
 215
 216         nskb = cpu_dp->rcv(skb, dev, pt);
 217         if (!nskb) {
 218                 kfree_skb(skb);
 219                 return 0;
 220         }
 221
 222         skb = nskb;
 223         p = netdev_priv(skb->dev);
 224         skb_push(skb, ETH_HLEN);
 225         skb->pkt_type = PACKET_HOST;
 226         skb->protocol = eth_type_trans(skb, skb->dev);
 227
 228         s = this_cpu_ptr(p->stats64);
 229         u64_stats_update_begin(&s->syncp);
 230         s->rx_packets++;
 231         s->rx_bytes += skb->len;
 232         u64_stats_update_end(&s->syncp);
 233
 234         if (dsa_skb_defer_rx_timestamp(p, skb))
 235                 return 0;
 236
 237         netif_receive_skb(skb);
 238
 239         return 0;
 240 }
 241
 242 #ifdef CONFIG_PM_SLEEP
 243 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 244 {
 245         const struct dsa_port *dp = dsa_to_port(ds, p);
 246
 247         return dp->type == DSA_PORT_TYPE_USER && dp->slave;
 248 }
 249
 250 int dsa_switch_suspend(struct dsa_switch *ds)
 251 {
 252         int i, ret = 0;
 253
 254         /* Suspend slave network devices */
 255         for (i = 0; i < ds->num_ports; i++) {
 256                 if (!dsa_is_port_initialized(ds, i))
 257                         continue;
 258
 259                 ret = dsa_slave_suspend(dsa_to_port(ds, i)->slave);
 260                 if (ret)
 261                         return ret;
 262         }
 263
 264         if (ds->ops->suspend)
 265                 ret = ds->ops->suspend(ds);
 266
 267         return ret;
 268 }
 269 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
 270
 271 int dsa_switch_resume(struct dsa_switch *ds)
 272 {
 273         int i, ret = 0;
 274
 275         if (ds->ops->resume)
 276                 ret = ds->ops->resume(ds);
 277
 278         if (ret)
 279                 return ret;
 280
 281         /* Resume slave network devices */
 282         for (i = 0; i < ds->num_ports; i++) {
 283                 if (!dsa_is_port_initialized(ds, i))
 284                         continue;
 285
 286                 ret = dsa_slave_resume(dsa_to_port(ds, i)->slave);
 287                 if (ret)
 288                         return ret;
 289         }
 290
 291         return 0;
 292 }
 293 EXPORT_SYMBOL_GPL(dsa_switch_resume);
 294 #endif
 295
 296 static struct packet_type dsa_pack_type __read_mostly = {
 297         .type   = cpu_to_be16(ETH_P_XDSA),
 298         .func   = dsa_switch_rcv,
 299 };
 300
 301 static struct workqueue_struct *dsa_owq;
 302
 303 bool dsa_schedule_work(struct work_struct *work)
 304 {
 305         return queue_work(dsa_owq, work);
 306 }
 307
 308 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
 309
 310 int register_dsa_notifier(struct notifier_block *nb)
 311 {
 312         return atomic_notifier_chain_register(&dsa_notif_chain, nb);
 313 }
 314 EXPORT_SYMBOL_GPL(register_dsa_notifier);
 315
 316 int unregister_dsa_notifier(struct notifier_block *nb)
 317 {
 318         return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
 319 }
 320 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
 321
 322 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
 323                        struct dsa_notifier_info *info)
 324 {
 325         info->dev = dev;
 326         return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
 327 }
 328 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
 329
 330 int dsa_devlink_param_get(struct devlink *dl, u32 id,
 331                           struct devlink_param_gset_ctx *ctx)
 332 {
 333         struct dsa_devlink_priv *dl_priv;
 334         struct dsa_switch *ds;
 335
 336         dl_priv = devlink_priv(dl);
 337         ds = dl_priv->ds;
 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_devlink_priv *dl_priv;
 350         struct dsa_switch *ds;
 351
 352         dl_priv = devlink_priv(dl);
 353         ds = dl_priv->ds;
 354
 355         if (!ds->ops->devlink_param_set)
 356                 return -EOPNOTSUPP;
 357
 358         return ds->ops->devlink_param_set(ds, id, ctx);
 359 }
 360 EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
 361
 362 int dsa_devlink_params_register(struct dsa_switch *ds,
 363                                 const struct devlink_param *params,
 364                                 size_t params_count)
 365 {
 366         return devlink_params_register(ds->devlink, params, params_count);
 367 }
 368 EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
 369
 370 void dsa_devlink_params_unregister(struct dsa_switch *ds,
 371                                    const struct devlink_param *params,
 372                                    size_t params_count)
 373 {
 374         devlink_params_unregister(ds->devlink, params, params_count);
 375 }
 376 EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
 377
 378 int dsa_devlink_resource_register(struct dsa_switch *ds,
 379                                   const char *resource_name,
 380                                   u64 resource_size,
 381                                   u64 resource_id,
 382                                   u64 parent_resource_id,
 383                                   const struct devlink_resource_size_params *size_params)
 384 {
 385         return devlink_resource_register(ds->devlink, resource_name,
 386                                          resource_size, resource_id,
 387                                          parent_resource_id,
 388                                          size_params);
 389 }
 390 EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
 391
 392 void dsa_devlink_resources_unregister(struct dsa_switch *ds)
 393 {
 394         devlink_resources_unregister(ds->devlink, NULL);
 395 }
 396 EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
 397
 398 void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
 399                                            u64 resource_id,
 400                                            devlink_resource_occ_get_t *occ_get,
 401                                            void *occ_get_priv)
 402 {
 403         return devlink_resource_occ_get_register(ds->devlink, resource_id,
 404                                                  occ_get, occ_get_priv);
 405 }
 406 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
 407
 408 void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
 409                                              u64 resource_id)
 410 {
 411         devlink_resource_occ_get_unregister(ds->devlink, resource_id);
 412 }
 413 EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
 414
 415 static int __init dsa_init_module(void)
 416 {
 417         int rc;
 418
 419         dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 420                                           WQ_MEM_RECLAIM);
 421         if (!dsa_owq)
 422                 return -ENOMEM;
 423
 424         rc = dsa_slave_register_notifier();
 425         if (rc)
 426                 goto register_notifier_fail;
 427
 428         dev_add_pack(&dsa_pack_type);
 429
 430         dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
 431                                 THIS_MODULE);
 432
 433         return 0;
 434
 435 register_notifier_fail:
 436         destroy_workqueue(dsa_owq);
 437
 438         return rc;
 439 }
 440 module_init(dsa_init_module);
 441
 442 static void __exit dsa_cleanup_module(void)
 443 {
 444         dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
 445
 446         dsa_slave_unregister_notifier();
 447         dev_remove_pack(&dsa_pack_type);
 448         destroy_workqueue(dsa_owq);
 449 }
 450 module_exit(dsa_cleanup_module);
 451
 452 MODULE_AUTHOR("Lennert Buytenhek <[email protected]>");
 453 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 454 MODULE_LICENSE("GPL");
 455 MODULE_ALIAS("platform:dsa");