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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
/* Load-Acquire Store-Release barriers used by the XDP socket
* library. The following macros should *NOT* be considered part of
* the xsk.h API, and is subject to change anytime.
*
* LIBRARY INTERNAL
*/
#define __XSK_READ_ONCE(x) (*(volatile typeof(x) *)&x)
#define __XSK_WRITE_ONCE(x, v) (*(volatile typeof(x) *)&x) = (v)
#if defined(__i386__) || defined(__x86_64__)
# define libbpf_smp_store_release(p, v) \
do { \
asm volatile("" : : : "memory"); \
__XSK_WRITE_ONCE(*p, v); \
} while (0)
# define libbpf_smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \
asm volatile("" : : : "memory"); \
___p1; \
})
#elif defined(__aarch64__)
# define libbpf_smp_store_release(p, v) \
asm volatile ("stlr %w1, %0" : "=Q" (*p) : "r" (v) : "memory")
# define libbpf_smp_load_acquire(p) \
({ \
typeof(*p) ___p1; \
asm volatile ("ldar %w0, %1" \
: "=r" (___p1) : "Q" (*p) : "memory"); \
___p1; \
})
#elif defined(__riscv)
# define libbpf_smp_store_release(p, v) \
do { \
asm volatile ("fence rw,w" : : : "memory"); \
__XSK_WRITE_ONCE(*p, v); \
} while (0)
# define libbpf_smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \
asm volatile ("fence r,rw" : : : "memory"); \
___p1; \
})
#endif
#ifndef libbpf_smp_store_release
#define libbpf_smp_store_release(p, v) \
do { \
__sync_synchronize(); \
__XSK_WRITE_ONCE(*p, v); \
} while (0)
#endif
#ifndef libbpf_smp_load_acquire
#define libbpf_smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = __XSK_READ_ONCE(*p); \
__sync_synchronize(); \
___p1; \
})
#endif
/* LIBRARY INTERNAL -- END */
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif
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