drivers/net/ethernet/mellanox/mlx5/core/en/rep/neigh.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /* Copyright (c) 2020 Mellanox Technologies. */
   3
   4 #include <linux/refcount.h>
   5 #include <linux/list.h>
   6 #include <linux/rculist.h>
   7 #include <linux/rtnetlink.h>
   8 #include <linux/workqueue.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/notifier.h>
  11 #include <net/netevent.h>
  12 #include <net/arp.h>
  13 #include "neigh.h"
  14 #include "tc.h"
  15 #include "en_rep.h"
  16 #include "fs_core.h"
  17 #include "diag/en_rep_tracepoint.h"
  18
  19 static unsigned long mlx5e_rep_ipv6_interval(void)
  20 {
  21         if (IS_ENABLED(CONFIG_IPV6) && ipv6_stub->nd_tbl)
  22                 return NEIGH_VAR(&ipv6_stub->nd_tbl->parms, DELAY_PROBE_TIME);
  23
  24         return ~0UL;
  25 }
  26
  27 static void mlx5e_rep_neigh_update_init_interval(struct mlx5e_rep_priv *rpriv)
  28 {
  29         unsigned long ipv4_interval = NEIGH_VAR(&arp_tbl.parms, DELAY_PROBE_TIME);
  30         unsigned long ipv6_interval = mlx5e_rep_ipv6_interval();
  31         struct net_device *netdev = rpriv->netdev;
  32         struct mlx5e_priv *priv = netdev_priv(netdev);
  33
  34         rpriv->neigh_update.min_interval = min_t(unsigned long, ipv6_interval, ipv4_interval);
  35         mlx5_fc_update_sampling_interval(priv->mdev, rpriv->neigh_update.min_interval);
  36 }
  37
  38 void mlx5e_rep_queue_neigh_stats_work(struct mlx5e_priv *priv)
  39 {
  40         struct mlx5e_rep_priv *rpriv = priv->ppriv;
  41         struct mlx5e_neigh_update_table *neigh_update = &rpriv->neigh_update;
  42
  43         mlx5_fc_queue_stats_work(priv->mdev,
  44                                  &neigh_update->neigh_stats_work,
  45                                  neigh_update->min_interval);
  46 }
  47
  48 static bool mlx5e_rep_neigh_entry_hold(struct mlx5e_neigh_hash_entry *nhe)
  49 {
  50         return refcount_inc_not_zero(&nhe->refcnt);
  51 }
  52
  53 static void mlx5e_rep_neigh_entry_remove(struct mlx5e_neigh_hash_entry *nhe);
  54
  55 void mlx5e_rep_neigh_entry_release(struct mlx5e_neigh_hash_entry *nhe)
  56 {
  57         if (refcount_dec_and_test(&nhe->refcnt)) {
  58                 mlx5e_rep_neigh_entry_remove(nhe);
  59                 kfree_rcu(nhe, rcu);
  60         }
  61 }
  62
  63 static struct mlx5e_neigh_hash_entry *
  64 mlx5e_get_next_nhe(struct mlx5e_rep_priv *rpriv,
  65                    struct mlx5e_neigh_hash_entry *nhe)
  66 {
  67         struct mlx5e_neigh_hash_entry *next = NULL;
  68
  69         rcu_read_lock();
  70
  71         for (next = nhe ?
  72                      list_next_or_null_rcu(&rpriv->neigh_update.neigh_list,
  73                                            &nhe->neigh_list,
  74                                            struct mlx5e_neigh_hash_entry,
  75                                            neigh_list) :
  76                      list_first_or_null_rcu(&rpriv->neigh_update.neigh_list,
  77                                             struct mlx5e_neigh_hash_entry,
  78                                             neigh_list);
  79              next;
  80              next = list_next_or_null_rcu(&rpriv->neigh_update.neigh_list,
  81                                           &next->neigh_list,
  82                                           struct mlx5e_neigh_hash_entry,
  83                                           neigh_list))
  84                 if (mlx5e_rep_neigh_entry_hold(next))
  85                         break;
  86
  87         rcu_read_unlock();
  88
  89         if (nhe)
  90                 mlx5e_rep_neigh_entry_release(nhe);
  91
  92         return next;
  93 }
  94
  95 static void mlx5e_rep_neigh_stats_work(struct work_struct *work)
  96 {
  97         struct mlx5e_rep_priv *rpriv = container_of(work, struct mlx5e_rep_priv,
  98                                                     neigh_update.neigh_stats_work.work);
  99         struct net_device *netdev = rpriv->netdev;
 100         struct mlx5e_priv *priv = netdev_priv(netdev);
 101         struct mlx5e_neigh_hash_entry *nhe = NULL;
 102
 103         rtnl_lock();
 104         if (!list_empty(&rpriv->neigh_update.neigh_list))
 105                 mlx5e_rep_queue_neigh_stats_work(priv);
 106
 107         while ((nhe = mlx5e_get_next_nhe(rpriv, nhe)) != NULL)
 108                 mlx5e_tc_update_neigh_used_value(nhe);
 109
 110         rtnl_unlock();
 111 }
 112
 113 struct neigh_update_work {
 114         struct work_struct work;
 115         struct neighbour *n;
 116         struct mlx5e_neigh_hash_entry *nhe;
 117 };
 118
 119 static void mlx5e_release_neigh_update_work(struct neigh_update_work *update_work)
 120 {
 121         neigh_release(update_work->n);
 122         mlx5e_rep_neigh_entry_release(update_work->nhe);
 123         kfree(update_work);
 124 }
 125
 126 static void mlx5e_rep_neigh_update(struct work_struct *work)
 127 {
 128         struct neigh_update_work *update_work = container_of(work, struct neigh_update_work,
 129                                                              work);
 130         struct mlx5e_neigh_hash_entry *nhe = update_work->nhe;
 131         struct neighbour *n = update_work->n;
 132         struct mlx5e_encap_entry *e = NULL;
 133         bool neigh_connected, same_dev;
 134         unsigned char ha[ETH_ALEN];
 135         u8 nud_state, dead;
 136
 137         rtnl_lock();
 138
 139         /* If these parameters are changed after we release the lock,
 140          * we'll receive another event letting us know about it.
 141          * We use this lock to avoid inconsistency between the neigh validity
 142          * and it's hw address.
 143          */
 144         read_lock_bh(&n->lock);
 145         memcpy(ha, n->ha, ETH_ALEN);
 146         nud_state = n->nud_state;
 147         dead = n->dead;
 148         same_dev = READ_ONCE(nhe->neigh_dev) == n->dev;
 149         read_unlock_bh(&n->lock);
 150
 151         neigh_connected = (nud_state & NUD_VALID) && !dead;
 152
 153         trace_mlx5e_rep_neigh_update(nhe, ha, neigh_connected);
 154
 155         if (!same_dev)
 156                 goto out;
 157
 158         /* mlx5e_get_next_init_encap() releases previous encap before returning
 159          * the next one.
 160          */
 161         while ((e = mlx5e_get_next_init_encap(nhe, e)) != NULL)
 162                 mlx5e_rep_update_flows(netdev_priv(e->out_dev), e, neigh_connected, ha);
 163
 164 out:
 165         rtnl_unlock();
 166         mlx5e_release_neigh_update_work(update_work);
 167 }
 168
 169 static struct neigh_update_work *mlx5e_alloc_neigh_update_work(struct mlx5e_priv *priv,
 170                                                                struct neighbour *n)
 171 {
 172         struct neigh_update_work *update_work;
 173         struct mlx5e_neigh_hash_entry *nhe;
 174         struct mlx5e_neigh m_neigh = {};
 175
 176         update_work = kzalloc(sizeof(*update_work), GFP_ATOMIC);
 177         if (WARN_ON(!update_work))
 178                 return NULL;
 179
 180         m_neigh.family = n->ops->family;
 181         memcpy(&m_neigh.dst_ip, n->primary_key, n->tbl->key_len);
 182
 183         /* Obtain reference to nhe as last step in order not to release it in
 184          * atomic context.
 185          */
 186         rcu_read_lock();
 187         nhe = mlx5e_rep_neigh_entry_lookup(priv, &m_neigh);
 188         rcu_read_unlock();
 189         if (!nhe) {
 190                 kfree(update_work);
 191                 return NULL;
 192         }
 193
 194         INIT_WORK(&update_work->work, mlx5e_rep_neigh_update);
 195         neigh_hold(n);
 196         update_work->n = n;
 197         update_work->nhe = nhe;
 198
 199         return update_work;
 200 }
 201
 202 static int mlx5e_rep_netevent_event(struct notifier_block *nb,
 203                                     unsigned long event, void *ptr)
 204 {
 205         struct mlx5e_rep_priv *rpriv = container_of(nb, struct mlx5e_rep_priv,
 206                                                     neigh_update.netevent_nb);
 207         struct mlx5e_neigh_update_table *neigh_update = &rpriv->neigh_update;
 208         struct net_device *netdev = rpriv->netdev;
 209         struct mlx5e_priv *priv = netdev_priv(netdev);
 210         struct mlx5e_neigh_hash_entry *nhe = NULL;
 211         struct neigh_update_work *update_work;
 212         struct neigh_parms *p;
 213         struct neighbour *n;
 214         bool found = false;
 215
 216         switch (event) {
 217         case NETEVENT_NEIGH_UPDATE:
 218                 n = ptr;
 219 #if IS_ENABLED(CONFIG_IPV6)
 220                 if (n->tbl != ipv6_stub->nd_tbl && n->tbl != &arp_tbl)
 221 #else
 222                 if (n->tbl != &arp_tbl)
 223 #endif
 224                         return NOTIFY_DONE;
 225
 226                 update_work = mlx5e_alloc_neigh_update_work(priv, n);
 227                 if (!update_work)
 228                         return NOTIFY_DONE;
 229
 230                 queue_work(priv->wq, &update_work->work);
 231                 break;
 232
 233         case NETEVENT_DELAY_PROBE_TIME_UPDATE:
 234                 p = ptr;
 235
 236                 /* We check the device is present since we don't care about
 237                  * changes in the default table, we only care about changes
 238                  * done per device delay prob time parameter.
 239                  */
 240 #if IS_ENABLED(CONFIG_IPV6)
 241                 if (!p->dev || (p->tbl != ipv6_stub->nd_tbl && p->tbl != &arp_tbl))
 242 #else
 243                 if (!p->dev || p->tbl != &arp_tbl)
 244 #endif
 245                         return NOTIFY_DONE;
 246
 247                 rcu_read_lock();
 248                 list_for_each_entry_rcu(nhe, &neigh_update->neigh_list,
 249                                         neigh_list) {
 250                         if (p->dev == READ_ONCE(nhe->neigh_dev)) {
 251                                 found = true;
 252                                 break;
 253                         }
 254                 }
 255                 rcu_read_unlock();
 256                 if (!found)
 257                         return NOTIFY_DONE;
 258
 259                 neigh_update->min_interval = min_t(unsigned long,
 260                                                    NEIGH_VAR(p, DELAY_PROBE_TIME),
 261                                                    neigh_update->min_interval);
 262                 mlx5_fc_update_sampling_interval(priv->mdev,
 263                                                  neigh_update->min_interval);
 264                 break;
 265         }
 266         return NOTIFY_DONE;
 267 }
 268
 269 static const struct rhashtable_params mlx5e_neigh_ht_params = {
 270         .head_offset = offsetof(struct mlx5e_neigh_hash_entry, rhash_node),
 271         .key_offset = offsetof(struct mlx5e_neigh_hash_entry, m_neigh),
 272         .key_len = sizeof(struct mlx5e_neigh),
 273         .automatic_shrinking = true,
 274 };
 275
 276 int mlx5e_rep_neigh_init(struct mlx5e_rep_priv *rpriv)
 277 {
 278         struct mlx5e_neigh_update_table *neigh_update = &rpriv->neigh_update;
 279         int err;
 280
 281         err = rhashtable_init(&neigh_update->neigh_ht, &mlx5e_neigh_ht_params);
 282         if (err)
 283                 goto out_err;
 284
 285         INIT_LIST_HEAD(&neigh_update->neigh_list);
 286         mutex_init(&neigh_update->encap_lock);
 287         INIT_DELAYED_WORK(&neigh_update->neigh_stats_work,
 288                           mlx5e_rep_neigh_stats_work);
 289         mlx5e_rep_neigh_update_init_interval(rpriv);
 290
 291         neigh_update->netevent_nb.notifier_call = mlx5e_rep_netevent_event;
 292         err = register_netevent_notifier(&neigh_update->netevent_nb);
 293         if (err)
 294                 goto out_notifier;
 295         return 0;
 296
 297 out_notifier:
 298         neigh_update->netevent_nb.notifier_call = NULL;
 299         rhashtable_destroy(&neigh_update->neigh_ht);
 300 out_err:
 301         netdev_warn(rpriv->netdev,
 302                     "Failed to initialize neighbours handling for vport %d\n",
 303                     rpriv->rep->vport);
 304         return err;
 305 }
 306
 307 void mlx5e_rep_neigh_cleanup(struct mlx5e_rep_priv *rpriv)
 308 {
 309         struct mlx5e_neigh_update_table *neigh_update = &rpriv->neigh_update;
 310         struct mlx5e_priv *priv = netdev_priv(rpriv->netdev);
 311
 312         if (!rpriv->neigh_update.netevent_nb.notifier_call)
 313                 return;
 314
 315         unregister_netevent_notifier(&neigh_update->netevent_nb);
 316
 317         flush_workqueue(priv->wq); /* flush neigh update works */
 318
 319         cancel_delayed_work_sync(&rpriv->neigh_update.neigh_stats_work);
 320
 321         mutex_destroy(&neigh_update->encap_lock);
 322         rhashtable_destroy(&neigh_update->neigh_ht);
 323 }
 324
 325 static int mlx5e_rep_neigh_entry_insert(struct mlx5e_priv *priv,
 326                                         struct mlx5e_neigh_hash_entry *nhe)
 327 {
 328         struct mlx5e_rep_priv *rpriv = priv->ppriv;
 329         int err;
 330
 331         err = rhashtable_insert_fast(&rpriv->neigh_update.neigh_ht,
 332                                      &nhe->rhash_node,
 333                                      mlx5e_neigh_ht_params);
 334         if (err)
 335                 return err;
 336
 337         list_add_rcu(&nhe->neigh_list, &rpriv->neigh_update.neigh_list);
 338
 339         return err;
 340 }
 341
 342 static void mlx5e_rep_neigh_entry_remove(struct mlx5e_neigh_hash_entry *nhe)
 343 {
 344         struct mlx5e_rep_priv *rpriv = nhe->priv->ppriv;
 345
 346         mutex_lock(&rpriv->neigh_update.encap_lock);
 347
 348         list_del_rcu(&nhe->neigh_list);
 349
 350         rhashtable_remove_fast(&rpriv->neigh_update.neigh_ht,
 351                                &nhe->rhash_node,
 352                                mlx5e_neigh_ht_params);
 353         mutex_unlock(&rpriv->neigh_update.encap_lock);
 354 }
 355
 356 /* This function must only be called under the representor's encap_lock or
 357  * inside rcu read lock section.
 358  */
 359 struct mlx5e_neigh_hash_entry *
 360 mlx5e_rep_neigh_entry_lookup(struct mlx5e_priv *priv,
 361                              struct mlx5e_neigh *m_neigh)
 362 {
 363         struct mlx5e_rep_priv *rpriv = priv->ppriv;
 364         struct mlx5e_neigh_update_table *neigh_update = &rpriv->neigh_update;
 365         struct mlx5e_neigh_hash_entry *nhe;
 366
 367         nhe = rhashtable_lookup_fast(&neigh_update->neigh_ht, m_neigh,
 368                                      mlx5e_neigh_ht_params);
 369         return nhe && mlx5e_rep_neigh_entry_hold(nhe) ? nhe : NULL;
 370 }
 371
 372 int mlx5e_rep_neigh_entry_create(struct mlx5e_priv *priv,
 373                                  struct mlx5e_neigh *m_neigh,
 374                                  struct net_device *neigh_dev,
 375                                  struct mlx5e_neigh_hash_entry **nhe)
 376 {
 377         int err;
 378
 379         *nhe = kzalloc(sizeof(**nhe), GFP_KERNEL);
 380         if (!*nhe)
 381                 return -ENOMEM;
 382
 383         (*nhe)->priv = priv;
 384         memcpy(&(*nhe)->m_neigh, m_neigh, sizeof(*m_neigh));
 385         spin_lock_init(&(*nhe)->encap_list_lock);
 386         INIT_LIST_HEAD(&(*nhe)->encap_list);
 387         refcount_set(&(*nhe)->refcnt, 1);
 388         WRITE_ONCE((*nhe)->neigh_dev, neigh_dev);
 389
 390         err = mlx5e_rep_neigh_entry_insert(priv, *nhe);
 391         if (err)
 392                 goto out_free;
 393         return 0;
 394
 395 out_free:
 396         kfree(*nhe);
 397         return err;
 398 }