codel: generalize the implementation

This strips out qdisc specific bits from the code
and makes it slightly more reusable. Codel will be
used by wireless/mac80211 in the future.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 3 deletions

diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
index 9b7e2980ee5c..512a94abe351 100644
--- a/net/sched/sch_codel.c
+++ b/net/sched/sch_codel.c
@@ -64,20 +64,33 @@ struct codel_sched_data {
  * to dequeue a packet from queue. Note: backlog is handled in
  * codel, we dont need to reduce it here.
  */
-static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
+static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx)
 {
+	struct Qdisc *sch = ctx;
 	struct sk_buff *skb = __skb_dequeue(&sch->q);
 
+	if (skb)
+		sch->qstats.backlog -= qdisc_pkt_len(skb);
+
 	prefetch(&skb->end); /* we'll need skb_shinfo() */
 	return skb;
 }
 
+static void drop_func(struct sk_buff *skb, void *ctx)
+{
+	struct Qdisc *sch = ctx;
+
+	qdisc_drop(skb, sch);
+}
+
 static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch)
 {
 	struct codel_sched_data *q = qdisc_priv(sch);
 	struct sk_buff *skb;
 
-	skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats, dequeue);
+	skb = codel_dequeue(sch, &sch->qstats.backlog, &q->params, &q->vars,
+			    &q->stats, qdisc_pkt_len, codel_get_enqueue_time,
+			    drop_func, dequeue_func);
 
 	/* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
 	 * or HTB crashes. Defer it for next round.
@@ -173,9 +186,10 @@ static int codel_init(struct Qdisc *sch, struct nlattr *opt)
 
 	sch->limit = DEFAULT_CODEL_LIMIT;
 
-	codel_params_init(&q->params, sch);
+	codel_params_init(&q->params);
 	codel_vars_init(&q->vars);
 	codel_stats_init(&q->stats);
+	q->params.mtu = psched_mtu(qdisc_dev(sch));
 
 	if (opt) {
 		int err = codel_change(sch, opt);