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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2019 Facebook */
#ifndef __LIBBPF_LIBBPF_UTIL_H
#define __LIBBPF_LIBBPF_UTIL_H
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/* Use these barrier functions instead of smp_[rw]mb() when they are
* used in a libbpf header file. That way they can be built into the
* application that uses libbpf.
*/
#if defined(__i386__) || defined(__x86_64__)
# define libbpf_smp_rmb() asm volatile("" : : : "memory")
# define libbpf_smp_wmb() asm volatile("" : : : "memory")
# define libbpf_smp_mb() \
asm volatile("lock; addl $0,-4(%%rsp)" : : : "memory", "cc")
/* Hinders stores to be observed before older loads. */
# define libbpf_smp_rwmb() asm volatile("" : : : "memory")
#elif defined(__aarch64__)
# define libbpf_smp_rmb() asm volatile("dmb ishld" : : : "memory")
# define libbpf_smp_wmb() asm volatile("dmb ishst" : : : "memory")
# define libbpf_smp_mb() asm volatile("dmb ish" : : : "memory")
# define libbpf_smp_rwmb() libbpf_smp_mb()
#elif defined(__arm__)
/* These are only valid for armv7 and above */
# define libbpf_smp_rmb() asm volatile("dmb ish" : : : "memory")
# define libbpf_smp_wmb() asm volatile("dmb ishst" : : : "memory")
# define libbpf_smp_mb() asm volatile("dmb ish" : : : "memory")
# define libbpf_smp_rwmb() libbpf_smp_mb()
#else
/* Architecture missing native barrier functions. */
# define libbpf_smp_rmb() __sync_synchronize()
# define libbpf_smp_wmb() __sync_synchronize()
# define libbpf_smp_mb() __sync_synchronize()
# define libbpf_smp_rwmb() __sync_synchronize()
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif
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