samples/bpf: xdpsock: order memory on AArch64

Define u_smp_rmb() and u_smp_wmb() to respective barrier instructions.
This ensures the processor will order accesses to queue indices against
accesses to queue ring entries.

Signed-off-by: Brian Brooks <brian.brooks@linaro.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Brian Brooks 2018-07-25 16:08:19 -05:00 committed by Daniel Borkmann
parent 08a852528e
commit 598135e744

View File

@ -145,8 +145,13 @@ static void dump_stats(void);
} while (0)
#define barrier() __asm__ __volatile__("": : :"memory")
#ifdef __aarch64__
#define u_smp_rmb() __asm__ __volatile__("dmb ishld": : :"memory")
#define u_smp_wmb() __asm__ __volatile__("dmb ishst": : :"memory")
#else
#define u_smp_rmb() barrier()
#define u_smp_wmb() barrier()
#endif
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)