tcp_clock_ns
u64 val = tcp_clock_ns();
return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC;
return div_u64(tcp_clock_ns(), NSEC_PER_USEC);
return div_u64(tcp_clock_ns(), NSEC_PER_MSEC);
tsoff = attrs->rcv_tsecr - tcp_ns_to_ts(attrs->usec_ts_ok, tcp_clock_ns());
now = tcp_clock_ns();
return div_u64(tcp_clock_ns(), NSEC_PER_USEC);
return tcp_ns_to_ts(tcp_clock_ns());