include/net/dsa_stubs.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * include/net/dsa_stubs.h - Stubs for the Distributed Switch Architecture framework
   4  */
   5
   6 #include <linux/mutex.h>
   7 #include <linux/netdevice.h>
   8 #include <linux/net_tstamp.h>
   9 #include <net/dsa.h>
  10
  11 #if IS_ENABLED(CONFIG_NET_DSA)
  12
  13 extern const struct dsa_stubs *dsa_stubs;
  14
  15 struct dsa_stubs {
  16         int (*master_hwtstamp_validate)(struct net_device *dev,
  17                                         const struct kernel_hwtstamp_config *config,
  18                                         struct netlink_ext_ack *extack);
  19 };
  20
  21 static inline int dsa_master_hwtstamp_validate(struct net_device *dev,
  22                                                const struct kernel_hwtstamp_config *config,
  23                                                struct netlink_ext_ack *extack)
  24 {
  25         if (!netdev_uses_dsa(dev))
  26                 return 0;
  27
  28         /* rtnl_lock() is a sufficient guarantee, because as long as
  29          * netdev_uses_dsa() returns true, the dsa_core module is still
  30          * registered, and so, dsa_unregister_stubs() couldn't have run.
  31          * For netdev_uses_dsa() to start returning false, it would imply that
  32          * dsa_master_teardown() has executed, which requires rtnl_lock().
  33          */
  34         ASSERT_RTNL();
  35
  36         return dsa_stubs->master_hwtstamp_validate(dev, config, extack);
  37 }
  38
  39 #else
  40
  41 static inline int dsa_master_hwtstamp_validate(struct net_device *dev,
  42                                                const struct kernel_hwtstamp_config *config,
  43                                                struct netlink_ext_ack *extack)
  44 {
  45         return 0;
  46 }
  47
  48 #endif