buf_free
DPAA2_ATOMIC_XCHG(&sc->buf_free, bpconf.free_bufn);
uint32_t buf_free = DPAA2_ATOMIC_READ(&sc->buf_free);
return (sysctl_handle_32(oidp, &buf_free, 0, req));
DPAA2_ATOMIC_XCHG(&sc->buf_free, 0);
struct dpaa2_atomic buf_free;
buf_free(bp);