mac80211: introduce refcount for queue_stop_reasons

Sometimes different vifs may be stopping the queues for the same
reason (e.g. when several interfaces are performing a channel switch).
Instead of using a bitmask for the reasons, use an integer that holds
a refcount instead.  In order to keep it backwards compatible,
introduce a boolean in some functions that tell us whether the queue
stopping should be refcounted or not.  For now, use not refcounted for
all calls to keep it functionally the same as before.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 51 insertions, 25 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 6d29e40538ad..4e8513cfdae5 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -317,7 +317,8 @@ void ieee80211_propagate_queue_wake(struct ieee80211_local *local, int queue)
 }
 
 static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
-				   enum queue_stop_reason reason)
+				   enum queue_stop_reason reason,
+				   bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 
@@ -329,7 +330,13 @@ static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
 	if (!test_bit(reason, &local->queue_stop_reasons[queue]))
 		return;
 
-	__clear_bit(reason, &local->queue_stop_reasons[queue]);
+	if (!refcounted)
+		local->q_stop_reasons[queue][reason] = 0;
+	else
+		local->q_stop_reasons[queue][reason]--;
+
+	if (local->q_stop_reasons[queue][reason] == 0)
+		__clear_bit(reason, &local->queue_stop_reasons[queue]);
 
 	if (local->queue_stop_reasons[queue] != 0)
 		/* someone still has this queue stopped */
@@ -344,25 +351,28 @@ static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
 }
 
 void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
-				    enum queue_stop_reason reason)
+				    enum queue_stop_reason reason,
+				    bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	unsigned long flags;
 
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-	__ieee80211_wake_queue(hw, queue, reason);
+	__ieee80211_wake_queue(hw, queue, reason, refcounted);
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
 
 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
 {
 	ieee80211_wake_queue_by_reason(hw, queue,
-				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
+				       IEEE80211_QUEUE_STOP_REASON_DRIVER,
+				       false);
 }
 EXPORT_SYMBOL(ieee80211_wake_queue);
 
 static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
-				   enum queue_stop_reason reason)
+				   enum queue_stop_reason reason,
+				   bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_sub_if_data *sdata;
@@ -373,10 +383,13 @@ static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
 	if (WARN_ON(queue >= hw->queues))
 		return;
 
-	if (test_bit(reason, &local->queue_stop_reasons[queue]))
-		return;
+	if (!refcounted)
+		local->q_stop_reasons[queue][reason] = 1;
+	else
+		local->q_stop_reasons[queue][reason]++;
 
-	__set_bit(reason, &local->queue_stop_reasons[queue]);
+	if (__test_and_set_bit(reason, &local->queue_stop_reasons[queue]))
+		return;
 
 	if (local->hw.queues < IEEE80211_NUM_ACS)
 		n_acs = 1;
@@ -398,20 +411,22 @@ static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
 }
 
 void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,
-				    enum queue_stop_reason reason)
+				    enum queue_stop_reason reason,
+				    bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	unsigned long flags;
 
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-	__ieee80211_stop_queue(hw, queue, reason);
+	__ieee80211_stop_queue(hw, queue, reason, refcounted);
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
 
 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
 {
 	ieee80211_stop_queue_by_reason(hw, queue,
-				       IEEE80211_QUEUE_STOP_REASON_DRIVER);
+				       IEEE80211_QUEUE_STOP_REASON_DRIVER,
+				       false);
 }
 EXPORT_SYMBOL(ieee80211_stop_queue);
 
@@ -429,9 +444,11 @@ void ieee80211_add_pending_skb(struct ieee80211_local *local,
 	}
 
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
-	__ieee80211_stop_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
+	__ieee80211_stop_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD,
+			       false);
 	__skb_queue_tail(&local->pending[queue], skb);
-	__ieee80211_wake_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
+	__ieee80211_wake_queue(hw, queue, IEEE80211_QUEUE_STOP_REASON_SKB_ADD,
+			       false);
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
 
@@ -455,20 +472,23 @@ void ieee80211_add_pending_skbs(struct ieee80211_local *local,
 		queue = info->hw_queue;
 
 		__ieee80211_stop_queue(hw, queue,
-				IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
+				IEEE80211_QUEUE_STOP_REASON_SKB_ADD,
+				false);
 
 		__skb_queue_tail(&local->pending[queue], skb);
 	}
 
 	for (i = 0; i < hw->queues; i++)
 		__ieee80211_wake_queue(hw, i,
-			IEEE80211_QUEUE_STOP_REASON_SKB_ADD);
+			IEEE80211_QUEUE_STOP_REASON_SKB_ADD,
+			false);
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
 
 void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
 				     unsigned long queues,
-				     enum queue_stop_reason reason)
+				     enum queue_stop_reason reason,
+				     bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	unsigned long flags;
@@ -477,7 +497,7 @@ void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 
 	for_each_set_bit(i, &queues, hw->queues)
-		__ieee80211_stop_queue(hw, i, reason);
+		__ieee80211_stop_queue(hw, i, reason, refcounted);
 
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
@@ -485,7 +505,8 @@ void ieee80211_stop_queues_by_reason(struct ieee80211_hw *hw,
 void ieee80211_stop_queues(struct ieee80211_hw *hw)
 {
 	ieee80211_stop_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP,
-					IEEE80211_QUEUE_STOP_REASON_DRIVER);
+					IEEE80211_QUEUE_STOP_REASON_DRIVER,
+					false);
 }
 EXPORT_SYMBOL(ieee80211_stop_queues);
 
@@ -508,7 +529,8 @@ EXPORT_SYMBOL(ieee80211_queue_stopped);
 
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 				     unsigned long queues,
-				     enum queue_stop_reason reason)
+				     enum queue_stop_reason reason,
+				     bool refcounted)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
 	unsigned long flags;
@@ -517,7 +539,7 @@ void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 
 	for_each_set_bit(i, &queues, hw->queues)
-		__ieee80211_wake_queue(hw, i, reason);
+		__ieee80211_wake_queue(hw, i, reason, refcounted);
 
 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 }
@@ -525,7 +547,8 @@ void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
 void ieee80211_wake_queues(struct ieee80211_hw *hw)
 {
 	ieee80211_wake_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP,
-					IEEE80211_QUEUE_STOP_REASON_DRIVER);
+					IEEE80211_QUEUE_STOP_REASON_DRIVER,
+					false);
 }
 EXPORT_SYMBOL(ieee80211_wake_queues);
 
@@ -552,12 +575,14 @@ void ieee80211_flush_queues(struct ieee80211_local *local,
 	}
 
 	ieee80211_stop_queues_by_reason(&local->hw, queues,
-					IEEE80211_QUEUE_STOP_REASON_FLUSH);
+					IEEE80211_QUEUE_STOP_REASON_FLUSH,
+					false);
 
 	drv_flush(local, sdata, queues, false);
 
 	ieee80211_wake_queues_by_reason(&local->hw, queues,
-					IEEE80211_QUEUE_STOP_REASON_FLUSH);
+					IEEE80211_QUEUE_STOP_REASON_FLUSH,
+					false);
 }
 
 static void __iterate_active_interfaces(struct ieee80211_local *local,
@@ -1797,7 +1822,8 @@ int ieee80211_reconfig(struct ieee80211_local *local)
 	}
 
 	ieee80211_wake_queues_by_reason(hw, IEEE80211_MAX_QUEUE_MAP,
-					IEEE80211_QUEUE_STOP_REASON_SUSPEND);
+					IEEE80211_QUEUE_STOP_REASON_SUSPEND,
+					false);
 
 	/*
 	 * Reconfigure sched scan if it was interrupted by FW restart or