1 files changed, 16 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b95aa72d8823..5a8105e84f7c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -45,6 +45,22 @@
 
 #include <trace/events/tcp.h>
 
+/* Refresh clocks of a TCP socket,
+ * ensuring monotically increasing values.
+ */
+void tcp_mstamp_refresh(struct tcp_sock *tp)
+{
+        u64 val = tcp_clock_ns();
+
+        /* departure time for next data packet */
+        if (val > tp->tcp_wstamp_ns)
+                tp->tcp_wstamp_ns = val;
+
+        val = div_u64(val, NSEC_PER_USEC);
+        if (val > tp->tcp_mstamp)
+                tp->tcp_mstamp = val;
+}
+
 static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
                            int push_one, gfp_t gfp);