diff --git a/sys/compat/linuxkpi/common/include/linux/seqlock.h b/sys/compat/linuxkpi/common/include/linux/seqlock.h
--- a/sys/compat/linuxkpi/common/include/linux/seqlock.h
+++ b/sys/compat/linuxkpi/common/include/linux/seqlock.h
@@ -36,6 +36,8 @@
 #include <sys/rwlock.h>
 #include <sys/seqc.h>
 
+#include <linux/compiler.h>
+
 struct lock_class_key;
 
 struct seqcount {
@@ -84,9 +86,22 @@
 	struct seqcount_mutex:	seqc_write_end				\
     )(&(s)->seqc)
 
+static inline void
+write_seqcount_invalidate(struct seqcount_mutex *seqcount)
+{
+	atomic_thread_fence_rel();
+	seqcount->seqc += SEQC_MOD * 2;
+}
+
 #define	read_seqcount_begin(s)	seqc_read(&(s)->seqc)
 #define	raw_read_seqcount(s)	seqc_read_any(&(s)->seqc)
 
+static inline unsigned int
+seqprop_sequence(const seqcount_mutex_t *seqcount)
+{
+	return (atomic_load_int(&seqcount->seqc));
+}
+
 /*
  * XXX: Are predicts from inline functions still not honored by clang?
  */