tcp_bbr: use tcp_jiffies32 instead of tcp_time_stamp

Use tcp_jiffies32 instead of tcp_time_stamp, since
tcp_time_stamp will soon be only used for TCP TS option.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_bbr.c

@@ -730,12 +730,12 @@ static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs)
 	bool filter_expired;
 
 	/* Track min RTT seen in the min_rtt_win_sec filter window: */
-	filter_expired = after(tcp_time_stamp,
+	filter_expired = after(tcp_jiffies32,
 			       bbr->min_rtt_stamp + bbr_min_rtt_win_sec * HZ);
 	if (rs->rtt_us >= 0 &&
 	    (rs->rtt_us <= bbr->min_rtt_us || filter_expired)) {
 		bbr->min_rtt_us = rs->rtt_us;
-		bbr->min_rtt_stamp = tcp_time_stamp;
+		bbr->min_rtt_stamp = tcp_jiffies32;
 	}
 
 	if (bbr_probe_rtt_mode_ms > 0 && filter_expired &&
@@ -754,7 +754,7 @@ static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs)
 		/* Maintain min packets in flight for max(200 ms, 1 round). */
 		if (!bbr->probe_rtt_done_stamp &&
 		    tcp_packets_in_flight(tp) <= bbr_cwnd_min_target) {
-			bbr->probe_rtt_done_stamp = tcp_time_stamp +
+			bbr->probe_rtt_done_stamp = tcp_jiffies32 +
 				msecs_to_jiffies(bbr_probe_rtt_mode_ms);
 			bbr->probe_rtt_round_done = 0;
 			bbr->next_rtt_delivered = tp->delivered;
@@ -762,8 +762,8 @@ static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs)
 			if (bbr->round_start)
 				bbr->probe_rtt_round_done = 1;
 			if (bbr->probe_rtt_round_done &&
-			    after(tcp_time_stamp, bbr->probe_rtt_done_stamp)) {
-				bbr->min_rtt_stamp = tcp_time_stamp;
+			    after(tcp_jiffies32, bbr->probe_rtt_done_stamp)) {
+				bbr->min_rtt_stamp = tcp_jiffies32;
 				bbr->restore_cwnd = 1;  /* snap to prior_cwnd */
 				bbr_reset_mode(sk);
 			}
@@ -810,7 +810,7 @@ static void bbr_init(struct sock *sk)
 	bbr->probe_rtt_done_stamp = 0;
 	bbr->probe_rtt_round_done = 0;
 	bbr->min_rtt_us = tcp_min_rtt(tp);
-	bbr->min_rtt_stamp = tcp_time_stamp;
+	bbr->min_rtt_stamp = tcp_jiffies32;
 
 	minmax_reset(&bbr->bw, bbr->rtt_cnt, 0);  /* init max bw to 0 */