Index: sys/compat/cloudabi/cloudabi_futex.c
===================================================================
--- sys/compat/cloudabi/cloudabi_futex.c
+++ sys/compat/cloudabi/cloudabi_futex.c
@@ -35,7 +35,7 @@
 #include <sys/proc.h>
 #include <sys/sx.h>
 #include <sys/systm.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 
 #include <contrib/cloudabi/cloudabi_types_common.h>
 
Index: sys/compat/linux/linux_futex.c
===================================================================
--- sys/compat/linux/linux_futex.c
+++ sys/compat/linux/linux_futex.c
@@ -57,7 +57,7 @@
 #include <sys/queue.h>
 #include <sys/sched.h>
 #include <sys/sdt.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 
 #include <vm/vm_extern.h>
 
Index: sys/kern/kern_exec.c
===================================================================
--- sys/kern/kern_exec.c
+++ sys/kern/kern_exec.c
@@ -70,7 +70,7 @@
 #include <sys/sysent.h>
 #include <sys/sysproto.h>
 #include <sys/timers.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <sys/vnode.h>
 #include <sys/wait.h>
 #ifdef KTRACE
Index: sys/kern/kern_exit.c
===================================================================
--- sys/kern/kern_exit.c
+++ sys/kern/kern_exit.c
@@ -76,7 +76,7 @@
 #include <sys/sem.h>
 #include <sys/sysent.h>
 #include <sys/timers.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #ifdef KTRACE
 #include <sys/ktrace.h>
 #endif
Index: sys/kern/kern_kthread.c
===================================================================
--- sys/kern/kern_kthread.c
+++ sys/kern/kern_kthread.c
@@ -41,7 +41,7 @@
 #include <sys/signalvar.h>
 #include <sys/sysent.h>
 #include <sys/sx.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <sys/unistd.h>
 #include <sys/wait.h>
 #include <sys/sched.h>
Index: sys/kern/kern_racct.c
===================================================================
--- sys/kern/kern_racct.c
+++ sys/kern/kern_racct.c
@@ -57,7 +57,7 @@
 #include <sys/sysctl.h>
 #include <sys/sysent.h>
 #include <sys/sysproto.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <machine/smp.h>
 
 #ifdef RCTL
Index: sys/kern/kern_resource.c
===================================================================
--- sys/kern/kern_resource.c
+++ sys/kern/kern_resource.c
@@ -59,7 +59,7 @@
 #include <sys/sysctl.h>
 #include <sys/sysent.h>
 #include <sys/time.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 
 #include <vm/vm.h>
 #include <vm/vm_param.h>
Index: sys/kern/kern_thr.c
===================================================================
--- sys/kern/kern_thr.c
+++ sys/kern/kern_thr.c
@@ -54,7 +54,7 @@
 #include <sys/ucontext.h>
 #include <sys/thr.h>
 #include <sys/rtprio.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <sys/limits.h>
 #ifdef	HWPMC_HOOKS
 #include <sys/pmckern.h>
Index: sys/kern/kern_thread.c
===================================================================
--- sys/kern/kern_thread.c
+++ sys/kern/kern_thread.c
@@ -56,7 +56,7 @@
 #include <sys/taskqueue.h>
 #include <sys/ktr.h>
 #include <sys/rwlock.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <sys/vmmeter.h>
 #include <sys/cpuset.h>
 #ifdef	HWPMC_HOOKS
Index: sys/kern/kern_umtx.c
===================================================================
--- sys/kern/kern_umtx.c
+++ sys/kern/kern_umtx.c
@@ -63,6 +63,7 @@
 #include <sys/time.h>
 #include <sys/eventhandler.h>
 #include <sys/umtx.h>
+#include <sys/umtxvar.h>
 
 #include <security/mac/mac_framework.h>
 
Index: sys/kern/sched_4bsd.c
===================================================================
--- sys/kern/sched_4bsd.c
+++ sys/kern/sched_4bsd.c
@@ -56,7 +56,7 @@
 #include <sys/sysctl.h>
 #include <sys/sx.h>
 #include <sys/turnstile.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <machine/pcb.h>
 #include <machine/smp.h>
 
Index: sys/kern/sched_ule.c
===================================================================
--- sys/kern/sched_ule.c
+++ sys/kern/sched_ule.c
@@ -61,7 +61,7 @@
 #include <sys/sysctl.h>
 #include <sys/sysproto.h>
 #include <sys/turnstile.h>
-#include <sys/umtx.h>
+#include <sys/umtxvar.h>
 #include <sys/vmmeter.h>
 #include <sys/cpuset.h>
 #include <sys/sbuf.h>
Index: sys/sys/umtx.h
===================================================================
--- sys/sys/umtx.h
+++ sys/sys/umtx.h
@@ -129,83 +129,10 @@
 	uintptr_t	robust_inact_offset;
 };
 
-#ifndef _KERNEL
-
 __BEGIN_DECLS
 
 int _umtx_op(void *obj, int op, u_long val, void *uaddr, void *uaddr2);
 
 __END_DECLS
 
-#else
-
-/*
- * The umtx_key structure is used by both the Linux futex code and the
- * umtx implementation to map userland addresses to unique keys.
- */
-
-enum {
-	TYPE_SIMPLE_WAIT,
-	TYPE_CV,
-	TYPE_SEM,
-	TYPE_SIMPLE_LOCK,
-	TYPE_NORMAL_UMUTEX,
-	TYPE_PI_UMUTEX,
-	TYPE_PP_UMUTEX,
-	TYPE_RWLOCK,
-	TYPE_FUTEX,
-	TYPE_SHM,
-	TYPE_PI_ROBUST_UMUTEX,
-	TYPE_PP_ROBUST_UMUTEX,
-};
-
-/* Key to represent a unique userland synchronous object */
-struct umtx_key {
-	int	hash;
-	int	type;
-	int	shared;
-	union {
-		struct {
-			struct vm_object *object;
-			uintptr_t	offset;
-		} shared;
-		struct {
-			struct vmspace	*vs;
-			uintptr_t	addr;
-		} private;
-		struct {
-			void		*a;
-			uintptr_t	b;
-		} both;
-	} info;
-};
-
-#define THREAD_SHARE		0
-#define PROCESS_SHARE		1
-#define AUTO_SHARE		2
-
-struct thread;
-
-static inline int
-umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2)
-{
-	return (k1->type == k2->type &&
-		k1->info.both.a == k2->info.both.a &&
-	        k1->info.both.b == k2->info.both.b);
-}
-
-int umtx_copyin_timeout(const void *, struct timespec *);
-void umtx_exec(struct proc *p);
-int umtx_key_get(const void *, int, int, struct umtx_key *);
-void umtx_key_release(struct umtx_key *);
-struct umtx_q *umtxq_alloc(void);
-void umtxq_free(struct umtx_q *);
-int kern_umtx_wake(struct thread *, void *, int, int);
-void umtx_pi_adjust(struct thread *, u_char);
-void umtx_thread_init(struct thread *);
-void umtx_thread_fini(struct thread *);
-void umtx_thread_alloc(struct thread *);
-void umtx_thread_exit(struct thread *);
-
-#endif /* !_KERNEL */
 #endif /* !_SYS_UMTX_H_ */
Index: sys/sys/umtxvar.h
===================================================================
--- /dev/null
+++ sys/sys/umtxvar.h
@@ -0,0 +1,106 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ *
+ */
+
+#ifndef _SYS_UMTXVAR_H_
+#define	_SYS_UMTXVAR_H_
+
+#ifdef _KERNEL
+
+/*
+ * The umtx_key structure is used by both the Linux futex code and the
+ * umtx implementation to map userland addresses to unique keys.
+ */
+enum {
+	TYPE_SIMPLE_WAIT,
+	TYPE_CV,
+	TYPE_SEM,
+	TYPE_SIMPLE_LOCK,
+	TYPE_NORMAL_UMUTEX,
+	TYPE_PI_UMUTEX,
+	TYPE_PP_UMUTEX,
+	TYPE_RWLOCK,
+	TYPE_FUTEX,
+	TYPE_SHM,
+	TYPE_PI_ROBUST_UMUTEX,
+	TYPE_PP_ROBUST_UMUTEX,
+};
+
+/* Key to represent a unique userland synchronous object */
+struct umtx_key {
+	int	hash;
+	int	type;
+	int	shared;
+	union {
+		struct {
+			struct vm_object *object;
+			uintptr_t	offset;
+		} shared;
+		struct {
+			struct vmspace	*vs;
+			uintptr_t	addr;
+		} private;
+		struct {
+			void		*a;
+			uintptr_t	b;
+		} both;
+	} info;
+};
+
+#define THREAD_SHARE		0
+#define PROCESS_SHARE		1
+#define AUTO_SHARE		2
+
+struct thread;
+
+static inline int
+umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2)
+{
+
+	return (k1->type == k2->type &&
+	    k1->info.both.a == k2->info.both.a &&
+	    k1->info.both.b == k2->info.both.b);
+}
+
+int umtx_copyin_timeout(const void *, struct timespec *);
+void umtx_exec(struct proc *p);
+int umtx_key_get(const void *, int, int, struct umtx_key *);
+void umtx_key_release(struct umtx_key *);
+struct umtx_q *umtxq_alloc(void);
+void umtxq_free(struct umtx_q *);
+int kern_umtx_wake(struct thread *, void *, int, int);
+void umtx_pi_adjust(struct thread *, u_char);
+void umtx_thread_init(struct thread *);
+void umtx_thread_fini(struct thread *);
+void umtx_thread_alloc(struct thread *);
+void umtx_thread_exit(struct thread *);
+
+#endif /* _KERNEL */
+#endif /* !_SYS_UMTXVAR_H_ */