net: act_mirred: allow statistic updates from offloaded actions

Implement .stats_update() callback.  The implementation
is generic and can be reused by other simple actions if
needed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/act_mirred.c

@@ -204,6 +204,13 @@ static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
 	return retval;
 }
 
+static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
+			     u64 lastuse)
+{
+	tcf_lastuse_update(&a->tcfa_tm);
+	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
+}
+
 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 			   int ref)
 {
@@ -281,6 +288,7 @@ static struct tc_action_ops act_mirred_ops = {
 	.type		=	TCA_ACT_MIRRED,
 	.owner		=	THIS_MODULE,
 	.act		=	tcf_mirred,
+	.stats_update	=	tcf_stats_update,
 	.dump		=	tcf_mirred_dump,
 	.cleanup	=	tcf_mirred_release,
 	.init		=	tcf_mirred_init,