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
13extern const struct dsa_stubs *dsa_stubs;
14
15struct dsa_stubs {
16	int (*conduit_hwtstamp_validate)(struct net_device *dev,
17					 const struct kernel_hwtstamp_config *config,
18					 struct netlink_ext_ack *extack);
19};
20
21static inline int dsa_conduit_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_conduit_teardown() has executed, which requires rtnl_lock().
33	 */
34	ASSERT_RTNL();
35
36	return dsa_stubs->conduit_hwtstamp_validate(dev, config, extack);
37}
38
39#else
40
41static inline int dsa_conduit_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
49