2 files changed, 48 insertions, 6 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a740be3bb911..1c25b39681b3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2878,7 +2878,6 @@ enum netdev_cmd {
 	NETDEV_OFFLOAD_XSTATS_REPORT_USED,
 	NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
 	NETDEV_XDP_FEAT_CHANGE,
-	NETDEV_PRE_CHANGE_HWTSTAMP,
 };
 const char *netdev_cmd_to_name(enum netdev_cmd cmd);
 
@@ -2929,11 +2928,6 @@ struct netdev_notifier_pre_changeaddr_info {
 	const unsigned char *dev_addr;
 };
 
-struct netdev_notifier_hwtstamp_info {
-	struct netdev_notifier_info info; /* must be first */
-	struct kernel_hwtstamp_config *config;
-};
-
 enum netdev_offload_xstats_type {
 	NETDEV_OFFLOAD_XSTATS_TYPE_L3 = 1,
 };
diff --git a/include/net/dsa_stubs.h b/include/net/dsa_stubs.h
new file mode 100644
index 000000000000..361811750a54
--- /dev/null
+++ b/include/net/dsa_stubs.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * include/net/dsa_stubs.h - Stubs for the Distributed Switch Architecture framework
+ */
+
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/net_tstamp.h>
+#include <net/dsa.h>
+
+#if IS_ENABLED(CONFIG_NET_DSA)
+
+extern const struct dsa_stubs *dsa_stubs;
+
+struct dsa_stubs {
+	int (*master_hwtstamp_validate)(struct net_device *dev,
+					const struct kernel_hwtstamp_config *config,
+					struct netlink_ext_ack *extack);
+};
+
+static inline int dsa_master_hwtstamp_validate(struct net_device *dev,
+					       const struct kernel_hwtstamp_config *config,
+					       struct netlink_ext_ack *extack)
+{
+	if (!netdev_uses_dsa(dev))
+		return 0;
+
+	/* rtnl_lock() is a sufficient guarantee, because as long as
+	 * netdev_uses_dsa() returns true, the dsa_core module is still
+	 * registered, and so, dsa_unregister_stubs() couldn't have run.
+	 * For netdev_uses_dsa() to start returning false, it would imply that
+	 * dsa_master_teardown() has executed, which requires rtnl_lock().
+	 */
+	ASSERT_RTNL();
+
+	return dsa_stubs->master_hwtstamp_validate(dev, config, extack);
+}
+
+#else
+
+static inline int dsa_master_hwtstamp_validate(struct net_device *dev,
+					       const struct kernel_hwtstamp_config *config,
+					       struct netlink_ext_ack *extack)
+{
+	return 0;
+}
+
+#endif