diff options
Diffstat (limited to 'src/bpfswitch/include/bpf/libbpf_util.h')
-rw-r--r-- | src/bpfswitch/include/bpf/libbpf_util.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/bpfswitch/include/bpf/libbpf_util.h b/src/bpfswitch/include/bpf/libbpf_util.h new file mode 100644 index 00000000..59c779c5 --- /dev/null +++ b/src/bpfswitch/include/bpf/libbpf_util.h @@ -0,0 +1,47 @@ +/* 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 |