Index: head/sys/sys/refcount.h
===================================================================
--- head/sys/sys/refcount.h	(revision 352249)
+++ head/sys/sys/refcount.h	(revision 352250)
@@ -1,178 +1,178 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org>
  *
  * 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, 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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_REFCOUNT_H__
 #define __SYS_REFCOUNT_H__
 
 #include <machine/atomic.h>
 
 #ifdef _KERNEL
 #include <sys/systm.h>
 #else
 #include <stdbool.h>
 #define	KASSERT(exp, msg)	/* */
 #endif
 
-#define	REFCOUNT_WAITER			(1 << 31) /* Refcount has waiter. */
+#define	REFCOUNT_WAITER			(1U << 31) /* Refcount has waiter. */
 #define	REFCOUNT_SATURATION_VALUE	(3U << 29)
 
 #define	REFCOUNT_SATURATED(val)		(((val) & (1U << 30)) != 0)
 #define	REFCOUNT_COUNT(x)		((x) & ~REFCOUNT_WAITER)
 
 bool refcount_release_last(volatile u_int *count, u_int n, u_int old);
 void refcount_sleep(volatile u_int *count, const char *wmesg, int prio);
 
 /*
  * Attempt to handle reference count overflow and underflow.  Force the counter
  * to stay at the saturation value so that a counter overflow cannot trigger
  * destruction of the containing object and instead leads to a less harmful
  * memory leak.
  */
 static __inline void
 _refcount_update_saturated(volatile u_int *count)
 {
 #ifdef INVARIANTS
 	panic("refcount %p wraparound", count);
 #else
 	atomic_store_int(count, REFCOUNT_SATURATION_VALUE);
 #endif
 }
 
 static __inline void
 refcount_init(volatile u_int *count, u_int value)
 {
 	KASSERT(!REFCOUNT_SATURATED(value),
 	    ("invalid initial refcount value %u", value));
 	*count = value;
 }
 
 static __inline void
 refcount_acquire(volatile u_int *count)
 {
 	u_int old;
 
 	old = atomic_fetchadd_int(count, 1);
 	if (__predict_false(REFCOUNT_SATURATED(old)))
 		_refcount_update_saturated(count);
 }
 
 static __inline void
 refcount_acquiren(volatile u_int *count, u_int n)
 {
 
 	u_int old;
 
 	KASSERT(n < REFCOUNT_SATURATION_VALUE / 2,
 	    ("refcount_acquiren: n %d too large", n));
 	old = atomic_fetchadd_int(count, n);
 	if (__predict_false(REFCOUNT_SATURATED(old)))
 		_refcount_update_saturated(count);
 }
 
 static __inline __result_use_check bool
 refcount_acquire_checked(volatile u_int *count)
 {
 	u_int lcount;
 
 	for (lcount = *count;;) {
 		if (__predict_false(REFCOUNT_SATURATED(lcount + 1)))
 			return (false);
 		if (__predict_true(atomic_fcmpset_int(count, &lcount,
 		    lcount + 1) == 1))
 			return (true);
 	}
 }
 
 static __inline bool
 refcount_releasen(volatile u_int *count, u_int n)
 {
 	u_int old;
 
 	KASSERT(n < REFCOUNT_SATURATION_VALUE / 2,
 	    ("refcount_releasen: n %d too large", n));
 	atomic_thread_fence_rel();
 	old = atomic_fetchadd_int(count, -n);
 	if (__predict_false(n >= REFCOUNT_COUNT(old) ||
 	    REFCOUNT_SATURATED(old)))
 		return (refcount_release_last(count, n, old));
 	return (false);
 }
 
 static __inline bool
 refcount_release(volatile u_int *count)
 {
 
 	return (refcount_releasen(count, 1));
 }
 
 static __inline void
 refcount_wait(volatile u_int *count, const char *wmesg, int prio)
 {
 
 	while (*count != 0)
 		refcount_sleep(count, wmesg, prio);
 }
 
 /*
  * This functions returns non-zero if the refcount was
  * incremented. Else zero is returned.
  */
 static __inline __result_use_check bool
 refcount_acquire_if_not_zero(volatile u_int *count)
 {
 	u_int old;
 
 	old = *count;
 	for (;;) {
 		if (REFCOUNT_COUNT(old) == 0)
 			return (false);
 		if (__predict_false(REFCOUNT_SATURATED(old)))
 			return (true);
 		if (atomic_fcmpset_int(count, &old, old + 1))
 			return (true);
 	}
 }
 
 static __inline __result_use_check bool
 refcount_release_if_not_last(volatile u_int *count)
 {
 	u_int old;
 
 	old = *count;
 	for (;;) {
 		if (REFCOUNT_COUNT(old) == 1)
 			return (false);
 		if (__predict_false(REFCOUNT_SATURATED(old)))
 			return (true);
 		if (atomic_fcmpset_int(count, &old, old - 1))
 			return (true);
 	}
 }
 
 #endif	/* ! __SYS_REFCOUNT_H__ */