diff options
| -rw-r--r-- | tools/lib/bpf/libbpf_util.h | 25 | ||||
| -rw-r--r-- | tools/lib/bpf/xsk.h | 7 |
2 files changed, 29 insertions, 3 deletions
diff --git a/tools/lib/bpf/libbpf_util.h b/tools/lib/bpf/libbpf_util.h index 81ecda0cb9c9..71fbb2898b87 100644 --- a/tools/lib/bpf/libbpf_util.h +++ b/tools/lib/bpf/libbpf_util.h @@ -23,6 +23,31 @@ do { \ #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) +/* 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") +#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") +#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") +#else +# warning Architecture missing native barrier functions in libbpf_util.h. +# define libbpf_smp_rmb() __sync_synchronize() +# define libbpf_smp_wmb() __sync_synchronize() +# define libbpf_smp_mb() __sync_synchronize() +#endif + #ifdef __cplusplus } /* extern "C" */ #endif diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index f264f24f06ac..2377c7a7f1b1 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -16,6 +16,7 @@ #include <linux/if_xdp.h> #include "libbpf.h" +#include "libbpf_util.h" #ifdef __cplusplus extern "C" { @@ -123,7 +124,7 @@ static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, size_t nb) /* Make sure everything has been written to the ring before indicating * this to the kernel by writing the producer pointer. */ - smp_wmb(); + libbpf_smp_wmb(); *prod->producer += nb; } @@ -137,7 +138,7 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, /* Make sure we do not speculatively read the data before * we have received the packet buffers from the ring. */ - smp_rmb(); + libbpf_smp_rmb(); *idx = cons->cached_cons; cons->cached_cons += entries; @@ -151,7 +152,7 @@ static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb) /* Make sure data has been read before indicating we are done * with the entries by updating the consumer pointer. */ - smp_mb(); + libbpf_smp_mb(); *cons->consumer += nb; } |