Commit 92f96667 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net/sched: taprio: refactor one skb dequeue from TXQ to separate function 



Future changes will refactor the TXQ selection procedure, and a lot of
stuff will become messy, the indentation of the bulk of the dequeue
procedure would increase, etc.

Break out the bulk of the function into a new one, which knows the TXQ
(child qdisc) we should perform a dequeue from.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarKurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1638bbbe

net/sched/sch_taprio.c

+63 −58
Original line number Diff line number Diff line
@@ -512,88 +512,93 @@ static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry) 
			     atomic64_read(&q->picos_per_byte)));

}



/* Will not be called in the full offload case, since the TX queues are

 * attached to the Qdisc created using qdisc_create_dflt()

 */

static struct sk_buff *taprio_dequeue(struct Qdisc *sch)

static struct sk_buff *taprio_dequeue_from_txq(struct Qdisc *sch, int txq,

					       struct sched_entry *entry,

					       u32 gate_mask)

{

	struct taprio_sched *q = qdisc_priv(sch);

	struct net_device *dev = qdisc_dev(sch);

	struct sk_buff *skb = NULL;

	struct sched_entry *entry;

	u32 gate_mask;

	int i;



	rcu_read_lock();

	entry = rcu_dereference(q->current_entry);

	/* if there's no entry, it means that the schedule didn't

	 * start yet, so force all gates to be open, this is in

	 * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5

	 * "AdminGateStates"

	 */

	gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;



	if (!gate_mask)

		goto done;



	for (i = 0; i < dev->num_tx_queues; i++) {

		struct Qdisc *child = q->qdiscs[i];

	struct Qdisc *child = q->qdiscs[txq];

	struct sk_buff *skb;

	ktime_t guard;

	int prio;

	int len;

	u8 tc;



	if (unlikely(!child))

			continue;

		return NULL;



	if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {

		skb = child->ops->dequeue(child);

		if (!skb)

				continue;

			return NULL;

		goto skb_found;

	}



	skb = child->ops->peek(child);

	if (!skb)

			continue;

		return NULL;



	prio = skb->priority;

	tc = netdev_get_prio_tc_map(dev, prio);



		if (!(gate_mask & BIT(tc))) {

			skb = NULL;

			continue;

		}

	if (!(gate_mask & BIT(tc)))

		return NULL;



	len = qdisc_pkt_len(skb);

		guard = ktime_add_ns(taprio_get_time(q),

				     length_to_duration(q, len));

	guard = ktime_add_ns(taprio_get_time(q), length_to_duration(q, len));



	/* In the case that there's no gate entry, there's no

	 * guard band ...

	 */

	if (gate_mask != TAPRIO_ALL_GATES_OPEN &&

		    ktime_after(guard, entry->close_time)) {

			skb = NULL;

			continue;

		}

	    ktime_after(guard, entry->close_time))

		return NULL;



	/* ... and no budget. */

	if (gate_mask != TAPRIO_ALL_GATES_OPEN &&

		    atomic_sub_return(len, &entry->budget) < 0) {

			skb = NULL;

			continue;

		}

	    atomic_sub_return(len, &entry->budget) < 0)

		return NULL;



	skb = child->ops->dequeue(child);

	if (unlikely(!skb))

			continue;

		return NULL;



skb_found:

	qdisc_bstats_update(sch, skb);

	qdisc_qstats_backlog_dec(sch, skb);

	sch->q.qlen--;



	return skb;

}



/* Will not be called in the full offload case, since the TX queues are

 * attached to the Qdisc created using qdisc_create_dflt()

 */

static struct sk_buff *taprio_dequeue(struct Qdisc *sch)

{

	struct taprio_sched *q = qdisc_priv(sch);

	struct net_device *dev = qdisc_dev(sch);

	struct sk_buff *skb = NULL;

	struct sched_entry *entry;

	u32 gate_mask;

	int i;



	rcu_read_lock();

	entry = rcu_dereference(q->current_entry);

	/* if there's no entry, it means that the schedule didn't

	 * start yet, so force all gates to be open, this is in

	 * accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5

	 * "AdminGateStates"

	 */

	gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;



	if (!gate_mask)

		goto done;



	for (i = 0; i < dev->num_tx_queues; i++) {

		skb = taprio_dequeue_from_txq(sch, i, entry, gate_mask);

		if (skb)

			goto done;

	}