mac80211: add improved HW queue control

mac80211 currently only supports one hardware queue
per AC. This is already problematic for off-channel
uses since if we go off channel while the BE queue
is full and then try to send an off-channel frame
the frame will never go out. This will become worse
when we support multi-channel since then a queue on
one channel might be full, but we have to stop the
software queue for all channels. That is obviously
not desirable.

To address this problem allow drivers to register
more hardware queues, and allow them to map them to
virtual interfaces. When they stop a hardware queue
the corresponding AC software queues on the correct
interfaces will be stopped as well. Additionally,
there's an off-channel queue to solve that problem
and a per-interface after-DTIM beacon queue. This
allows drivers to manage software queues closer to
how the hardware works.

Currently, there's a limit of 16 hardware queues.
This may or may not be sufficient, we can adjust it
as needed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 20 insertions, 19 deletions

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 9628a18..5b7053c 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -286,25 +286,25 @@ static inline int ieee80211_ac_from_tid(int tid)
  * a global "agg_queue_stop" refcount.
  */
 static void __acquires(agg_queue)
-ieee80211_stop_queue_agg(struct ieee80211_local *local, int tid)
+ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
 {
-	int queue = ieee80211_ac_from_tid(tid);
+	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 
-	if (atomic_inc_return(&local->agg_queue_stop[queue]) == 1)
+	if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1)
 		ieee80211_stop_queue_by_reason(
-			&local->hw, queue,
+			&sdata->local->hw, queue,
 			IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 	__acquire(agg_queue);
 }
 
 static void __releases(agg_queue)
-ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
+ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid)
 {
-	int queue = ieee80211_ac_from_tid(tid);
+	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 
-	if (atomic_dec_return(&local->agg_queue_stop[queue]) == 0)
+	if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0)
 		ieee80211_wake_queue_by_reason(
-			&local->hw, queue,
+			&sdata->local->hw, queue,
 			IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
 	__release(agg_queue);
 }
@@ -314,13 +314,14 @@ ieee80211_wake_queue_agg(struct ieee80211_local *local, int tid)
  * requires a call to ieee80211_agg_splice_finish later
  */
 static void __acquires(agg_queue)
-ieee80211_agg_splice_packets(struct ieee80211_local *local,
+ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata,
 			     struct tid_ampdu_tx *tid_tx, u16 tid)
 {
-	int queue = ieee80211_ac_from_tid(tid);
+	struct ieee80211_local *local = sdata->local;
+	int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)];
 	unsigned long flags;
 
-	ieee80211_stop_queue_agg(local, tid);
+	ieee80211_stop_queue_agg(sdata, tid);
 
 	if (WARN(!tid_tx, "TID %d gone but expected when splicing aggregates"
 			  " from the pending queue\n", tid))
@@ -336,9 +337,9 @@ ieee80211_agg_splice_packets(struct ieee80211_local *local,
 }
 
 static void __releases(agg_queue)
-ieee80211_agg_splice_finish(struct ieee80211_local *local, u16 tid)
+ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid)
 {
-	ieee80211_wake_queue_agg(local, tid);
+	ieee80211_wake_queue_agg(sdata, tid);
 }
 
 void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
@@ -376,9 +377,9 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 					" tid %d\n", tid);
 #endif
 		spin_lock_bh(&sta->lock);
-		ieee80211_agg_splice_packets(local, tid_tx, tid);
+		ieee80211_agg_splice_packets(sdata, tid_tx, tid);
 		ieee80211_assign_tid_tx(sta, tid, NULL);
-		ieee80211_agg_splice_finish(local, tid);
+		ieee80211_agg_splice_finish(sdata, tid);
 		spin_unlock_bh(&sta->lock);
 
 		kfree_rcu(tid_tx, rcu_head);
@@ -598,14 +599,14 @@ static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
 	 */
 	spin_lock_bh(&sta->lock);
 
-	ieee80211_agg_splice_packets(local, tid_tx, tid);
+	ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
 	/*
 	 * Now mark as operational. This will be visible
 	 * in the TX path, and lets it go lock-free in
 	 * the common case.
 	 */
 	set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state);
-	ieee80211_agg_splice_finish(local, tid);
+	ieee80211_agg_splice_finish(sta->sdata, tid);
 
 	spin_unlock_bh(&sta->lock);
 }
@@ -790,12 +791,12 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid)
 	 * more.
 	 */
 
-	ieee80211_agg_splice_packets(local, tid_tx, tid);
+	ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid);
 
 	/* future packets must not find the tid_tx struct any more */
 	ieee80211_assign_tid_tx(sta, tid, NULL);
 
-	ieee80211_agg_splice_finish(local, tid);
+	ieee80211_agg_splice_finish(sta->sdata, tid);
 
 	kfree_rcu(tid_tx, rcu_head);