diff options
Diffstat (limited to 'tools/lib/bpf/xsk.h')
| -rw-r--r-- | tools/lib/bpf/xsk.h | 70 |
1 files changed, 68 insertions, 2 deletions
diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index a9fdea87b5cd..01c12dca9c10 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -3,7 +3,8 @@ /* * AF_XDP user-space access library. * - * Copyright(c) 2018 - 2019 Intel Corporation. + * Copyright (c) 2018 - 2019 Intel Corporation. + * Copyright (c) 2019 Facebook * * Author(s): Magnus Karlsson <magnus.karlsson@intel.com> */ @@ -13,15 +14,80 @@ #include <stdio.h> #include <stdint.h> +#include <stdbool.h> #include <linux/if_xdp.h> #include "libbpf.h" -#include "libbpf_util.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 */ + /* Do not access these members directly. Use the functions below. */ #define DEFINE_XSK_RING(name) \ struct name { \ |