mac80211: reduce station management complexity

Now that IBSS no longer needs to insert stations
from atomic context, we can get rid of all the
special cases for that, and even get rid of the
sta_lock (though it needs to stay as tim_lock.)

This makes the station management code much more
straight-forward.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/ieee80211_i.h

@@ -855,18 +855,15 @@ struct ieee80211_local {
 
 	/* Station data */
 	/*
-	 * The mutex only protects the list and counter,
-	 * reads are done in RCU.
-	 * Additionally, the lock protects the hash table,
-	 * the pending list and each BSS's TIM bitmap.
+	 * The mutex only protects the list, hash table and
+	 * counter, reads are done with RCU.
 	 */
 	struct mutex sta_mtx;
-	spinlock_t sta_lock;
+	spinlock_t tim_lock;
 	unsigned long num_sta;
-	struct list_head sta_list, sta_pending_list;
+	struct list_head sta_list;
 	struct sta_info __rcu *sta_hash[STA_HASH_SIZE];
 	struct timer_list sta_cleanup;
-	struct work_struct sta_finish_work;
 	int sta_generation;
 
 	struct sk_buff_head pending[IEEE80211_MAX_QUEUES];

net/mac80211/tx.c

@@ -2333,9 +2333,9 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 			} else {
 				unsigned long flags;
 
-				spin_lock_irqsave(&local->sta_lock, flags);
+				spin_lock_irqsave(&local->tim_lock, flags);
 				ieee80211_beacon_add_tim(ap, skb, beacon);
-				spin_unlock_irqrestore(&local->sta_lock, flags);
+				spin_unlock_irqrestore(&local->tim_lock, flags);
 			}
 
 			if (tim_offset)