linux/net/dsa/dsa.c
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   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
  26static LIST_HEAD(dsa_tag_drivers_list);
  27static DEFINE_MUTEX(dsa_tag_drivers_lock);
  28
  29static 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
  36static 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
  43DSA_TAG_DRIVER(none_ops);
  44
  45static 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
  55void 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
  64static 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}
  70EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
  71
  72void 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}
  80EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
  81
  82const 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 */
  90const 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
 113const 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
 142void 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
 156static 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
 164static 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
 174struct 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}
 191EXPORT_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 */
 201static 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
 225static 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
 283static bool dsa_port_is_initialized(const struct dsa_port *dp)
 284{
 285        return dp->type == DSA_PORT_TYPE_USER && dp->slave;
 286}
 287
 288int dsa_switch_suspend(struct dsa_switch *ds)
 289{
 290        struct dsa_port *dp;
 291        int ret = 0;
 292
 293        /* Suspend slave network devices */
 294        dsa_switch_for_each_port(dp, ds) {
 295                if (!dsa_port_is_initialized(dp))
 296                        continue;
 297
 298                ret = dsa_slave_suspend(dp->slave);
 299                if (ret)
 300                        return ret;
 301        }
 302
 303        if (ds->ops->suspend)
 304                ret = ds->ops->suspend(ds);
 305
 306        return ret;
 307}
 308EXPORT_SYMBOL_GPL(dsa_switch_suspend);
 309
 310int dsa_switch_resume(struct dsa_switch *ds)
 311{
 312        struct dsa_port *dp;
 313        int 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        dsa_switch_for_each_port(dp, ds) {
 323                if (!dsa_port_is_initialized(dp))
 324                        continue;
 325
 326                ret = dsa_slave_resume(dp->slave);
 327                if (ret)
 328                        return ret;
 329        }
 330
 331        return 0;
 332}
 333EXPORT_SYMBOL_GPL(dsa_switch_resume);
 334#endif
 335
 336static struct packet_type dsa_pack_type __read_mostly = {
 337        .type   = cpu_to_be16(ETH_P_XDSA),
 338        .func   = dsa_switch_rcv,
 339};
 340
 341static struct workqueue_struct *dsa_owq;
 342
 343bool dsa_schedule_work(struct work_struct *work)
 344{
 345        return queue_work(dsa_owq, work);
 346}
 347
 348void dsa_flush_workqueue(void)
 349{
 350        flush_workqueue(dsa_owq);
 351}
 352
 353int dsa_devlink_param_get(struct devlink *dl, u32 id,
 354                          struct devlink_param_gset_ctx *ctx)
 355{
 356        struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 357
 358        if (!ds->ops->devlink_param_get)
 359                return -EOPNOTSUPP;
 360
 361        return ds->ops->devlink_param_get(ds, id, ctx);
 362}
 363EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
 364
 365int dsa_devlink_param_set(struct devlink *dl, u32 id,
 366                          struct devlink_param_gset_ctx *ctx)
 367{
 368        struct dsa_switch *ds = dsa_devlink_to_ds(dl);
 369
 370        if (!ds->ops->devlink_param_set)
 371                return -EOPNOTSUPP;
 372
 373        return ds->ops->devlink_param_set(ds, id, ctx);
 374}
 375EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
 376
 377int dsa_devlink_params_register(struct dsa_switch *ds,
 378                                const struct devlink_param *params,
 379                                size_t params_count)
 380{
 381        return devlink_params_register(ds->devlink, params, params_count);
 382}
 383EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
 384
 385void dsa_devlink_params_unregister(struct dsa_switch *ds,
 386                                   const struct devlink_param *params,
 387                                   size_t params_count)
 388{
 389        devlink_params_unregister(ds->devlink, params, params_count);
 390}
 391EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
 392
 393int dsa_devlink_resource_register(struct dsa_switch *ds,
 394                                  const char *resource_name,
 395                                  u64 resource_size,
 396                                  u64 resource_id,
 397                                  u64 parent_resource_id,
 398                                  const struct devlink_resource_size_params *size_params)
 399{
 400        return devlink_resource_register(ds->devlink, resource_name,
 401                                         resource_size, resource_id,
 402                                         parent_resource_id,
 403                                         size_params);
 404}
 405EXPORT_SYMBOL_GPL(dsa_devlink_resource_register);
 406
 407void dsa_devlink_resources_unregister(struct dsa_switch *ds)
 408{
 409        devlink_resources_unregister(ds->devlink, NULL);
 410}
 411EXPORT_SYMBOL_GPL(dsa_devlink_resources_unregister);
 412
 413void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
 414                                           u64 resource_id,
 415                                           devlink_resource_occ_get_t *occ_get,
 416                                           void *occ_get_priv)
 417{
 418        return devlink_resource_occ_get_register(ds->devlink, resource_id,
 419                                                 occ_get, occ_get_priv);
 420}
 421EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_register);
 422
 423void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
 424                                             u64 resource_id)
 425{
 426        devlink_resource_occ_get_unregister(ds->devlink, resource_id);
 427}
 428EXPORT_SYMBOL_GPL(dsa_devlink_resource_occ_get_unregister);
 429
 430struct devlink_region *
 431dsa_devlink_region_create(struct dsa_switch *ds,
 432                          const struct devlink_region_ops *ops,
 433                          u32 region_max_snapshots, u64 region_size)
 434{
 435        return devlink_region_create(ds->devlink, ops, region_max_snapshots,
 436                                     region_size);
 437}
 438EXPORT_SYMBOL_GPL(dsa_devlink_region_create);
 439
 440struct devlink_region *
 441dsa_devlink_port_region_create(struct dsa_switch *ds,
 442                               int port,
 443                               const struct devlink_port_region_ops *ops,
 444                               u32 region_max_snapshots, u64 region_size)
 445{
 446        struct dsa_port *dp = dsa_to_port(ds, port);
 447
 448        return devlink_port_region_create(&dp->devlink_port, ops,
 449                                          region_max_snapshots,
 450                                          region_size);
 451}
 452EXPORT_SYMBOL_GPL(dsa_devlink_port_region_create);
 453
 454void dsa_devlink_region_destroy(struct devlink_region *region)
 455{
 456        devlink_region_destroy(region);
 457}
 458EXPORT_SYMBOL_GPL(dsa_devlink_region_destroy);
 459
 460struct dsa_port *dsa_port_from_netdev(struct net_device *netdev)
 461{
 462        if (!netdev || !dsa_slave_dev_check(netdev))
 463                return ERR_PTR(-ENODEV);
 464
 465        return dsa_slave_to_port(netdev);
 466}
 467EXPORT_SYMBOL_GPL(dsa_port_from_netdev);
 468
 469static int __init dsa_init_module(void)
 470{
 471        int rc;
 472
 473        dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 474                                          WQ_MEM_RECLAIM);
 475        if (!dsa_owq)
 476                return -ENOMEM;
 477
 478        rc = dsa_slave_register_notifier();
 479        if (rc)
 480                goto register_notifier_fail;
 481
 482        dev_add_pack(&dsa_pack_type);
 483
 484        dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
 485                                THIS_MODULE);
 486
 487        return 0;
 488
 489register_notifier_fail:
 490        destroy_workqueue(dsa_owq);
 491
 492        return rc;
 493}
 494module_init(dsa_init_module);
 495
 496static void __exit dsa_cleanup_module(void)
 497{
 498        dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));
 499
 500        dsa_slave_unregister_notifier();
 501        dev_remove_pack(&dsa_pack_type);
 502        destroy_workqueue(dsa_owq);
 503}
 504module_exit(dsa_cleanup_module);
 505
 506MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 507MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 508MODULE_LICENSE("GPL");
 509MODULE_ALIAS("platform:dsa");
 510