From 4c70f383e0c0273c4092c4efdb414be0966978b7 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 25 Sep 2007 22:40:13 -0700 Subject: [DCCP]: Provide 10s of microsecond timesource This provides a timesource, conveniently used for DCCP timestamps, which returns the elapsed time in 10s of microseconds since initialisation. This makes for a wrap-around time of about 11.9 hours, which should be sufficient for most applications. Signed-off-by: Gerrit Renker Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/timer.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'net/dccp/timer.c') diff --git a/net/dccp/timer.c b/net/dccp/timer.c index 0197a41c256..3af067354bd 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -291,3 +291,24 @@ void dccp_init_xmit_timers(struct sock *sk) inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer, &dccp_keepalive_timer); } + +static ktime_t dccp_timestamp_seed; +/** + * dccp_timestamp - 10s of microseconds time source + * Returns the number of 10s of microseconds since loading DCCP. This is native + * DCCP time difference format (RFC 4340, sec. 13). + * Please note: This will wrap around about circa every 11.9 hours. + */ +u32 dccp_timestamp(void) +{ + s64 delta = ktime_us_delta(ktime_get_real(), dccp_timestamp_seed); + + do_div(delta, 10); + return delta; +} +EXPORT_SYMBOL_GPL(dccp_timestamp); + +void __init dccp_timestamping_init(void) +{ + dccp_timestamp_seed = ktime_get_real(); +} -- cgit v1.2.3-18-g5258