mac80211: Add TXQ scheduling API

This adds an API to mac80211 to handle scheduling of TXQs and changes the
interface between driver and mac80211 for TXQ handling as follows:

- The wake_tx_queue callback interface no longer includes the TXQ. Instead,
  the driver is expected to retrieve that from ieee80211_next_txq()

- Two new mac80211 functions are added: ieee80211_next_txq() and
  ieee80211_schedule_txq(). The former returns the next TXQ that should be
  scheduled, and is how the driver gets a queue to pull packets from. The
  latter is called internally by mac80211 to start scheduling a queue, and
  the driver is supposed to call it to re-schedule the TXQ after it is
  finished pulling packets from it (unless the queue emptied).

The ath9k and ath10k drivers are changed to use the new API.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 48 insertions, 1 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 25904af38839..842881ca8f20 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1439,6 +1439,7 @@ void ieee80211_txq_init(struct ieee80211_sub_if_data *sdata,
 	codel_vars_init(&txqi->def_cvars);
 	codel_stats_init(&txqi->cstats);
 	__skb_queue_head_init(&txqi->frags);
+	INIT_LIST_HEAD(&txqi->schedule_order);
 
 	txqi->txq.vif = &sdata->vif;
 
@@ -1462,6 +1463,7 @@ void ieee80211_txq_purge(struct ieee80211_local *local,
 
 	fq_tin_reset(fq, tin, fq_skb_free_func);
 	ieee80211_purge_tx_queue(&local->hw, &txqi->frags);
+	list_del_init(&txqi->schedule_order);
 }
 
 int ieee80211_txq_setup_flows(struct ieee80211_local *local)
@@ -1558,7 +1560,8 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local,
 	ieee80211_txq_enqueue(local, txqi, skb);
 	spin_unlock_bh(&fq->lock);
 
-	drv_wake_tx_queue(local, txqi);
+	if (ieee80211_schedule_txq(&local->hw, &txqi->txq))
+		drv_wake_tx_queue(local);
 
 	return true;
 }
@@ -3553,6 +3556,50 @@ out:
 }
 EXPORT_SYMBOL(ieee80211_tx_dequeue);
 
+bool ieee80211_schedule_txq(struct ieee80211_hw *hw,
+			    struct ieee80211_txq *txq)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct txq_info *txqi = to_txq_info(txq);
+	bool ret = false;
+
+	spin_lock_bh(&local->active_txq_lock);
+
+	if (list_empty(&txqi->schedule_order)) {
+		list_add_tail(&txqi->schedule_order, &local->active_txqs);
+		ret = true;
+	}
+
+	spin_unlock_bh(&local->active_txq_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(ieee80211_schedule_txq);
+
+struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct txq_info *txqi = NULL;
+
+	spin_lock_bh(&local->active_txq_lock);
+
+	if (list_empty(&local->active_txqs))
+		goto out;
+
+	txqi = list_first_entry(&local->active_txqs,
+				struct txq_info, schedule_order);
+	list_del_init(&txqi->schedule_order);
+
+out:
+	spin_unlock_bh(&local->active_txq_lock);
+
+	if (!txqi)
+		return NULL;
+
+	return &txqi->txq;
+}
+EXPORT_SYMBOL(ieee80211_next_txq);
+
 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  struct net_device *dev,
 				  u32 info_flags)