[TCP]: Fix linkage errors on i386.

To avoid raw division, use ktime_to_timeval() to get usec.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/ktime.h

@@ -259,6 +259,12 @@ static inline s64 ktime_to_ns(const ktime_t kt)
 
 #endif
 
+static inline s64 ktime_to_us(const ktime_t kt)
+{
+	struct timeval tv = ktime_to_timeval(kt);
+	return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
+}
+
 /*
  * The resolution of the clocks. The resolution value is returned in
  * the clock_getres() system call to give application programmers an

net/ipv4/tcp_illinois.c

@@ -90,7 +90,7 @@ static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, ktime_t last)
 
 	ca->acked = pkts_acked;
 
-	rtt = ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC;
+	rtt = ktime_to_us(net_timedelta(last));
 
 	/* ignore bogus values, this prevents wraparound in alpha math */
 	if (rtt > RTT_MAX)

net/ipv4/tcp_lp.c

@@ -266,7 +266,7 @@ static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked, ktime_t last)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct lp *lp = inet_csk_ca(sk);
 
-	tcp_lp_rtt_sample(sk,  ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC);
+	tcp_lp_rtt_sample(sk,  ktime_to_us(net_timedelta(last)));
 
 	/* calc inference */
 	if (tcp_time_stamp > tp->rx_opt.rcv_tsecr)

net/ipv4/tcp_vegas.c

@@ -118,7 +118,7 @@ void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, ktime_t last)
 	u32 vrtt;
 
 	/* Never allow zero rtt or baseRTT */
-	vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1;
+	vrtt = ktime_to_us(net_timedelta(last)) + 1;
 
 	/* Filter to find propagation delay: */
 	if (vrtt < vegas->baseRTT)

net/ipv4/tcp_veno.c

@@ -75,7 +75,7 @@ static void tcp_veno_pkts_acked(struct sock *sk, u32 cnt, ktime_t last)
 	u32 vrtt;
 
 	/* Never allow zero rtt or baseRTT */
-	vrtt = (ktime_to_ns(net_timedelta(last)) / NSEC_PER_USEC) + 1;
+	vrtt = ktime_to_us(net_timedelta(last)) + 1;
 
 	/* Filter to find propagation delay: */
 	if (vrtt < veno->basertt)