diff options
Diffstat (limited to 'tools/lib/bpf/xsk.h')
| -rw-r--r-- | tools/lib/bpf/xsk.h | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index a497f00e2962..82ea71a0f3ec 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" { @@ -36,6 +37,10 @@ struct name { \ DEFINE_XSK_RING(xsk_ring_prod); DEFINE_XSK_RING(xsk_ring_cons); +/* For a detailed explanation on the memory barriers associated with the + * ring, please take a look at net/xdp/xsk_queue.h. + */ + struct xsk_umem; struct xsk_socket; @@ -105,7 +110,7 @@ static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb) static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod, size_t nb, __u32 *idx) { - if (unlikely(xsk_prod_nb_free(prod, nb) < nb)) + if (xsk_prod_nb_free(prod, nb) < nb) return 0; *idx = prod->cached_prod; @@ -116,10 +121,10 @@ static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod, 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 signalling - * this to the kernel. + /* 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; } @@ -129,11 +134,11 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, { size_t entries = xsk_cons_nb_avail(cons, nb); - if (likely(entries > 0)) { + if (entries > 0) { /* 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; @@ -144,6 +149,11 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, 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. + */ + libbpf_smp_rwmb(); + *cons->consumer += nb; } |