+/* Start sequence of the highest skb with SACKed bit, valid only if
+ * sacked > 0 or when the caller has ensured validity by itself.
+ */
+static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
+{
+ if (!tp->sacked_out)
+ return tp->snd_una;
+ return TCP_SKB_CB(tp->highest_sack)->seq;
+}
+