net: Define accessors to manipulate QDISC_STATE_RUNNING

Define three helpers to manipulate QDISC_STATE_RUNNIG flag, that a
second patch will move on another location.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/pkt_sched.h

@@ -95,7 +95,7 @@ extern void __qdisc_run(struct Qdisc *q);
 
 static inline void qdisc_run(struct Qdisc *q)
 {
-	if (!test_and_set_bit(__QDISC_STATE_RUNNING, &q->state))
+	if (qdisc_run_begin(q))
 		__qdisc_run(q);
 }
 

include/net/sch_generic.h

@@ -76,6 +76,21 @@ struct Qdisc {
 	struct rcu_head     rcu_head;
 };
 
+static inline bool qdisc_is_running(struct Qdisc *qdisc)
+{
+	return test_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+}
+
+static inline bool qdisc_run_begin(struct Qdisc *qdisc)
+{
+	return !test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+}
+
+static inline void qdisc_run_end(struct Qdisc *qdisc)
+{
+	clear_bit(__QDISC_STATE_RUNNING, &qdisc->state);
+}
+
 struct Qdisc_class_ops {
 	/* Child qdisc manipulation */
 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);

net/core/dev.c

@@ -2047,7 +2047,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 		kfree_skb(skb);
 		rc = NET_XMIT_DROP;
 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
-		   !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) {
+		   qdisc_run_begin(q)) {
 		/*
 		 * This is a work-conserving queue; there are no old skbs
 		 * waiting to be sent out; and the qdisc is not running -
@@ -2059,7 +2059,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 		if (sch_direct_xmit(skb, q, dev, txq, root_lock))
 			__qdisc_run(q);
 		else
-			clear_bit(__QDISC_STATE_RUNNING, &q->state);
+			qdisc_run_end(q);
 
 		rc = NET_XMIT_SUCCESS;
 	} else {

net/sched/sch_generic.c

@@ -205,7 +205,7 @@ void __qdisc_run(struct Qdisc *q)
 		}
 	}
 
-	clear_bit(__QDISC_STATE_RUNNING, &q->state);
+	qdisc_run_end(q);
 }
 
 unsigned long dev_trans_start(struct net_device *dev)
@@ -797,7 +797,7 @@ static bool some_qdisc_is_busy(struct net_device *dev)
 
 		spin_lock_bh(root_lock);
 
-		val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
+		val = (qdisc_is_running(q) ||
 		       test_bit(__QDISC_STATE_SCHED, &q->state));
 
 		spin_unlock_bh(root_lock);