wifi: mac80211: Drop stations iterator where the iterator function may sleep

This reverts commit acb99b9b ("mac80211: Add stations iterator
where the iterator function may sleep"). A different approach was found
for the rtw88 driver where most of the problematic locks were converted
to a driver-local mutex. Drop ieee80211_iterate_stations() because there
are no users of that function.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20221226191609.2934234-1-martin.blumenstingl@googlemail.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -5888,9 +5888,6 @@ void ieee80211_iterate_active_interfaces_atomic(struct ieee80211_hw *hw,
  * This function iterates over the interfaces associated with a given
  * hardware that are currently active and calls the callback for them.
  * This version can only be used while holding the wiphy mutex.
- * The driver must not call this with a lock held that it can also take in
- * response to callbacks from mac80211, and it must not call this within
- * callbacks made by mac80211 - both would result in deadlocks.
  *
  * @hw: the hardware struct of which the interfaces should be iterated over
  * @iter_flags: iteration flags, see &enum ieee80211_interface_iteration_flags
@@ -5904,24 +5901,6 @@ void ieee80211_iterate_active_interfaces_mtx(struct ieee80211_hw *hw,
 						struct ieee80211_vif *vif),
 					     void *data);
 
-/**
- * ieee80211_iterate_stations - iterate stations
- *
- * This function iterates over all stations associated with a given
- * hardware that are currently uploaded to the driver and calls the callback
- * function for them.
- * This function allows the iterator function to sleep, when the iterator
- * function is atomic @ieee80211_iterate_stations_atomic can be used.
- *
- * @hw: the hardware struct of which the interfaces should be iterated over
- * @iterator: the iterator function to call, cannot sleep
- * @data: first argument of the iterator function
- */
-void ieee80211_iterate_stations(struct ieee80211_hw *hw,
-				void (*iterator)(void *data,
-						 struct ieee80211_sta *sta),
-				void *data);
-
 /**
  * ieee80211_iterate_stations_atomic - iterate stations
  *

net/mac80211/util.c

@@ -868,19 +868,6 @@ static void __iterate_stations(struct ieee80211_local *local,
 	}
 }
 
-void ieee80211_iterate_stations(struct ieee80211_hw *hw,
-				void (*iterator)(void *data,
-						 struct ieee80211_sta *sta),
-				void *data)
-{
-	struct ieee80211_local *local = hw_to_local(hw);
-
-	mutex_lock(&local->sta_mtx);
-	__iterate_stations(local, iterator, data);
-	mutex_unlock(&local->sta_mtx);
-}
-EXPORT_SYMBOL_GPL(ieee80211_iterate_stations);
-
 void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 			void (*iterator)(void *data,
 					 struct ieee80211_sta *sta),