
     ˆ¾Èƒh¹ÂÅ      
     ˆÀÈƒu¡;_†I|¥�+ÃÆ     /* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Generic barrier definitions.
 *
 * It should be possible to use these on really simple architectures,
 * but it serves more as a starting point for new ports.
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */
#ifndef __ASM_GENERIC_BARRIER_H
#define __ASM_GENERIC_BARRIER_H

#ifndef __ASSEMBLY__

#include <linux/compiler.h>
#include <linux/kcsan-checks.h>
#include <asm/rwonce.h>

#ifndef nop
#define nop()	asm volatile ("nop")
#endif

/*
 * Architectures that want generic instrumentation can define __ prefixed
 * variants of all barriers.
 */

#ifdef __mb
#define mb()	do { kcsan_mb(); __mb(); } while (0)
#endif

#ifdef __rmb
#define rmb()	do { kcsan_rmb(); __rmb(); } while (0)
#endif

#ifdef __wmb
#define wmb()	do { kcsan_wmb(); __wmb(); } while (0)
#endif

#ifdef __dma_mb
#define dma_mb()	do { kcsan_mb(); __dma_mb(); } while (0)
#endif

#ifdef __dma_rmb
#define dma_rmb()	do { kcsan_rmb(); __dma_rmb(); } while (0)
#endif

#ifdef __dma_wmb
#define dma_wmb()	do { kcsan_wmb(); __dma_wmb(); } while (0)
#endif

/*
 * Force strict CPU ordering. And yes, this is required on UP too when we're
 * talking to devices.
 *
 * Fall back to compiler barriers if nothing better is provided.
 */

#ifndef mb
#define mb()	barrier()
#endif

#ifndef rmb
#define rmb()	mb()
#endif

#ifndef wmb
#define wmb()	mb()
#endif

#ifndef dma_mb
#define dma_mb()	mb()
#endif

#ifndef dma_rmb
#define dma_rmb()	rmb()
#endif

#ifndef dma_wmb
#define dma_wmb()	wmb()
#endif

#ifndef __smp_mb
#define __smp_mb()	mb()
#endif

#ifndef __smp_rmb
#define __smp_rmb()	rmb()
#endif

#ifndef __smp_wmb
#define __smp_wmb()	wmb()
#endif

#ifdef CONFIG_SMP

#ifndef smp_mb
#define smp_mb()	do { kcsan_mb(); __smp_mb(); } while (0)
#endif

#ifndef smp_rmb
#define smp_rmb()	do { kcsan_rmb(); __smp_rmb(); } while (0)
#endif

#ifndef smp_wmb
#define smp_wmb()	do { kcsan_wmb(); __smp_wmb(); } while (0)
#endif

#else	/* !CONFIG_SMP */

#ifndef smp_mb
#define smp_mb()	barrier()
#endif

#ifndef smp_rmb
#define smp_rmb()	barrier()
#endif

#ifndef smp_wmb
#define smp_wmb()	barrier()
#endif

#endif	/* CONFIG_SMP */

#ifndef __smp_store_mb
#define __smp_store_mb(var, value)  do { WRITE_ONCE(var, value); __smp_mb(); } while (0)
#endif

#ifndef __smp_mb__before_atomic
#define __smp_mb__before_atomic()	__smp_mb()
#endif

#ifndef __smp_mb__after_atomic
#define __smp_mb__after_atomic()	__smp_mb()
#endif

#ifndef __smp_store_release
#define __smp_store_release(p, v)					\
do {									\
	compiletime_assert_atomic_type(*p);				\
	__smp_mb();							\
	WRITE_ONCE(*p, v);						\
} while (0)
#endif

#ifndef __smp_load_acquire
#define __smp_load_acquire(p)						\
({									\
	__unqual_scalar_typeof(*p) ___p1 = READ_ONCE(*p);		\
	compiletime_assert_atomic_type(*p);				\
	__smp_mb();							\
	(typeof(*p))___p1;						\
})
#endif

#ifdef CONFIG_SMP

#ifndef smp_store_mb
#define smp_store_mb(var, value)  do { kcsan_mb(); __smp_store_mb(var, value); } while (0)
#endif

#ifndef smp_mb__before_atomic
#define smp_mb__before_atomic()	do { kcsan_mb(); __smp_mb__before_atomic(); } while (0)
#endif

#ifndef smp_mb__after_atomic
#define smp_mb__after_atomic()	do { kcsan_mb(); __smp_mb__after_atomic(); } while (0)
#endif

#ifndef smp_store_release
#define smp_store_release(p, v) do { kcsan_release(); __smp_store_release(p, v); } while (0)
#endif

#ifndef smp_load_acquire
#define smp_load_acquire(p) __smp_load_acquire(p)
#endif

#else	/* !CONFIG_SMP */

#ifndef smp_store_mb
#define smp_store_mb(var, value)  do { WRITE_ONCE(var, value); barrier(); } while (0)
#endif

#ifndef smp_mb__before_atomic
#define smp_mb__before_atomic()	barrier()
#endif

#ifndef smp_mb__after_atomic
#define smp_mb__after_atomic()	barrier()
#endif

#ifndef smp_store_release
#define smp_store_release(p, v)						\
do {									\
	compiletime_assert_atomic_type(*p);				\
	barrier();							\
	WRITE_ONCE(*p, v);						\
} while (0)
#endif

#ifndef smp_load_acquire
#def