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>

drivers/net/wireless/ath/ath10k/core.c

@@ -2574,9 +2574,7 @@ struct ath10k *ath10k_core_create(size_t priv_size, struct device *dev,
 
 	mutex_init(&ar->conf_mutex);
 	spin_lock_init(&ar->data_lock);
-	spin_lock_init(&ar->txqs_lock);
 
-	INIT_LIST_HEAD(&ar->txqs);
 	INIT_LIST_HEAD(&ar->peers);
 	init_waitqueue_head(&ar->peer_mapping_wq);
 	init_waitqueue_head(&ar->htt.empty_tx_wq);

drivers/net/wireless/ath/ath10k/core.h

@@ -347,7 +347,6 @@ struct ath10k_peer {
 };
 
 struct ath10k_txq {
-	struct list_head list;
 	unsigned long num_fw_queued;
 	unsigned long num_push_allowed;
 };
@@ -895,10 +894,7 @@ struct ath10k {
 
 	/* protects shared structure data */
 	spinlock_t data_lock;
-	/* protects: ar->txqs, artxq->list */
-	spinlock_t txqs_lock;
 
-	struct list_head txqs;
 	struct list_head arvifs;
 	struct list_head peers;
 	struct ath10k_peer *peer_map[ATH10K_MAX_NUM_PEER_IDS];

drivers/net/wireless/ath/ath10k/mac.c

@@ -3830,25 +3830,17 @@ static void ath10k_mac_txq_init(struct ieee80211_txq *txq)
 		return;
 
 	artxq = (void *)txq->drv_priv;
-	INIT_LIST_HEAD(&artxq->list);
 }
 
 static void ath10k_mac_txq_unref(struct ath10k *ar, struct ieee80211_txq *txq)
 {
-	struct ath10k_txq *artxq;
 	struct ath10k_skb_cb *cb;
 	struct sk_buff *msdu;
 	int msdu_id;
 
 	if (!txq)
 		return;
 
-	artxq = (void *)txq->drv_priv;
-	spin_lock_bh(&ar->txqs_lock);
-	if (!list_empty(&artxq->list))
-		list_del_init(&artxq->list);
-	spin_unlock_bh(&ar->txqs_lock);
-
 	spin_lock_bh(&ar->htt.tx_lock);
 	idr_for_each_entry(&ar->htt.pending_tx, msdu, msdu_id) {
 		cb = ATH10K_SKB_CB(msdu);
@@ -3978,23 +3970,17 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
 void ath10k_mac_tx_push_pending(struct ath10k *ar)
 {
 	struct ieee80211_hw *hw = ar->hw;
-	struct ieee80211_txq *txq;
-	struct ath10k_txq *artxq;
-	struct ath10k_txq *last;
+	struct ieee80211_txq *txq, *first = NULL;
 	int ret;
 	int max;
 
 	if (ar->htt.num_pending_tx >= (ar->htt.max_num_pending_tx / 2))
 		return;
 
-	spin_lock_bh(&ar->txqs_lock);
 	rcu_read_lock();
 
-	last = list_last_entry(&ar->txqs, struct ath10k_txq, list);
-	while (!list_empty(&ar->txqs)) {
-		artxq = list_first_entry(&ar->txqs, struct ath10k_txq, list);
-		txq = container_of((void *)artxq, struct ieee80211_txq,
-				   drv_priv);
+	txq = ieee80211_next_txq(hw);
+	while (txq) {
 
 		/* Prevent aggressive sta/tid taking over tx queue */
 		max = 16;
@@ -4005,18 +3991,21 @@ void ath10k_mac_tx_push_pending(struct ath10k *ar)
 				break;
 		}
 
-		list_del_init(&artxq->list);
 		if (ret != -ENOENT)
-			list_add_tail(&artxq->list, &ar->txqs);
+			ieee80211_schedule_txq(hw, txq);
 
 		ath10k_htt_tx_txq_update(hw, txq);
 
-		if (artxq == last || (ret < 0 && ret != -ENOENT))
+		if (first == txq || (ret < 0 && ret != -ENOENT))
 			break;
+
+		if (!first)
+			first = txq;
+
+		txq = ieee80211_next_txq(hw);
 	}
 
 	rcu_read_unlock();
-	spin_unlock_bh(&ar->txqs_lock);
 }
 
 /************/
@@ -4250,34 +4239,22 @@ static void ath10k_mac_op_tx(struct ieee80211_hw *hw,
 	}
 }
 
-static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw,
-					struct ieee80211_txq *txq)
+static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw)
 {
-	struct ath10k *ar = hw->priv;
-	struct ath10k_txq *artxq = (void *)txq->drv_priv;
-	struct ieee80211_txq *f_txq;
-	struct ath10k_txq *f_artxq;
+	struct ieee80211_txq *txq;
 	int ret = 0;
 	int max = 16;
 
-	spin_lock_bh(&ar->txqs_lock);
-	if (list_empty(&artxq->list))
-		list_add_tail(&artxq->list, &ar->txqs);
-
-	f_artxq = list_first_entry(&ar->txqs, struct ath10k_txq, list);
-	f_txq = container_of((void *)f_artxq, struct ieee80211_txq, drv_priv);
-	list_del_init(&f_artxq->list);
+	txq = ieee80211_next_txq(hw);
 
-	while (ath10k_mac_tx_can_push(hw, f_txq) && max--) {
-		ret = ath10k_mac_tx_push_txq(hw, f_txq);
+	while (ath10k_mac_tx_can_push(hw, txq) && max--) {
+		ret = ath10k_mac_tx_push_txq(hw, txq);
 		if (ret)
 			break;
 	}
 	if (ret != -ENOENT)
-		list_add_tail(&f_artxq->list, &ar->txqs);
-	spin_unlock_bh(&ar->txqs_lock);
+		ieee80211_schedule_txq(hw, txq);
 
-	ath10k_htt_tx_txq_update(hw, f_txq);
 	ath10k_htt_tx_txq_update(hw, txq);
 }
 

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -246,12 +246,8 @@ struct ath_atx_tid {
 	s8 bar_index;
 	bool active;
 	bool clear_ps_filter;
-	bool has_queued;
 };
 
-void __ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid);
-void ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid);
-
 struct ath_node {
 	struct ath_softc *sc;
 	struct ieee80211_sta *sta; /* station struct we're part of */
@@ -591,8 +587,7 @@ bool ath_drain_all_txq(struct ath_softc *sc);
 void ath_draintxq(struct ath_softc *sc, struct ath_txq *txq);
 void ath_tx_node_init(struct ath_softc *sc, struct ath_node *an);
 void ath_tx_node_cleanup(struct ath_softc *sc, struct ath_node *an);
-void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq);
-void ath_txq_schedule_all(struct ath_softc *sc);
+void ath_txq_schedule(struct ath_softc *sc);
 int ath_tx_init(struct ath_softc *sc, int nbufs);
 int ath_txq_update(struct ath_softc *sc, int qnum,
 		   struct ath9k_tx_queue_info *q);
@@ -618,7 +613,7 @@ void ath9k_release_buffered_frames(struct ieee80211_hw *hw,
 				   u16 tids, int nframes,
 				   enum ieee80211_frame_release_type reason,
 				   bool more_data);
-void ath9k_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *queue);
+void ath9k_wake_tx_queue(struct ieee80211_hw *hw);
 
 /********/
 /* VIFs */

drivers/net/wireless/ath/ath9k/main.c

@@ -266,7 +266,7 @@ static bool ath_complete_reset(struct ath_softc *sc, bool start)
 		}
 	work:
 		ath_restart_work(sc);
-		ath_txq_schedule_all(sc);
+		ath_txq_schedule(sc);
 	}
 
 	sc->gtt_cnt = 0;

drivers/net/wireless/ath/ath9k/recv.c

@@ -1057,8 +1057,6 @@ static void ath_rx_count_airtime(struct ath_softc *sc,
  	if (!!(sc->airtime_flags & AIRTIME_USE_RX)) {
 		spin_lock_bh(&acq->lock);
 		an->airtime_deficit[acno] -= airtime;
-		if (an->airtime_deficit[acno] <= 0)
-			__ath_tx_queue_tid(sc, ATH_AN_2_TID(an, tidno));
 		spin_unlock_bh(&acq->lock);
 	}
 	ath_debug_airtime(sc, an, airtime, 0);