net/dsa/switch.c

   1 /*
   2  * Handling of a single switch chip, part of a switch fabric
   3  *
   4  * Copyright (c) 2017 Savoir-faire Linux Inc.
   5  *      Vivien Didelot <vivien.didelot@savoirfairelinux.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/netdevice.h>
  14 #include <linux/notifier.h>
  15 #include <net/dsa.h>
  16
  17 static int dsa_switch_bridge_join(struct dsa_switch *ds,
  18                                   struct dsa_notifier_bridge_info *info)
  19 {
  20         if (ds->index == info->sw_index && ds->ops->port_bridge_join)
  21                 return ds->ops->port_bridge_join(ds, info->port, info->br);
  22
  23         if (ds->index != info->sw_index && ds->ops->crosschip_bridge_join)
  24                 return ds->ops->crosschip_bridge_join(ds, info->sw_index,
  25                                                       info->port, info->br);
  26
  27         return 0;
  28 }
  29
  30 static int dsa_switch_bridge_leave(struct dsa_switch *ds,
  31                                    struct dsa_notifier_bridge_info *info)
  32 {
  33         if (ds->index == info->sw_index && ds->ops->port_bridge_leave)
  34                 ds->ops->port_bridge_leave(ds, info->port, info->br);
  35
  36         if (ds->index != info->sw_index && ds->ops->crosschip_bridge_leave)
  37                 ds->ops->crosschip_bridge_leave(ds, info->sw_index, info->port,
  38                                                 info->br);
  39
  40         return 0;
  41 }
  42
  43 static int dsa_switch_event(struct notifier_block *nb,
  44                             unsigned long event, void *info)
  45 {
  46         struct dsa_switch *ds = container_of(nb, struct dsa_switch, nb);
  47         int err;
  48
  49         switch (event) {
  50         case DSA_NOTIFIER_BRIDGE_JOIN:
  51                 err = dsa_switch_bridge_join(ds, info);
  52                 break;
  53         case DSA_NOTIFIER_BRIDGE_LEAVE:
  54                 err = dsa_switch_bridge_leave(ds, info);
  55                 break;
  56         default:
  57                 err = -EOPNOTSUPP;
  58                 break;
  59         }
  60
  61         /* Non-switchdev operations cannot be rolled back. If a DSA driver
  62          * returns an error during the chained call, switch chips may be in an
  63          * inconsistent state.
  64          */
  65         if (err)
  66                 dev_dbg(ds->dev, "breaking chain for DSA event %lu (%d)\n",
  67                         event, err);
  68
  69         return notifier_from_errno(err);
  70 }
  71
  72 int dsa_switch_register_notifier(struct dsa_switch *ds)
  73 {
  74         ds->nb.notifier_call = dsa_switch_event;
  75
  76         return raw_notifier_chain_register(&ds->dst->nh, &ds->nb);
  77 }
  78
  79 void dsa_switch_unregister_notifier(struct dsa_switch *ds)
  80 {
  81         int err;
  82
  83         err = raw_notifier_chain_unregister(&ds->dst->nh, &ds->nb);
  84         if (err)
  85                 dev_err(ds->dev, "failed to unregister notifier (%d)\n", err);
  86 }