mac80211: simplify key locking

Since I recently made station management able
to sleep, I can now rework key management as
well; since it will no longer need a spinlock
and can also use a mutex instead, a bunch of
code to allow drivers' set_key to sleep while
key management is protected by a spinlock can
now be removed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f8c49c5..952845e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -120,6 +120,9 @@
 	struct ieee80211_key *key;
 	int err;
 
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
 	switch (params->cipher) {
@@ -145,7 +148,7 @@
 	if (!key)
 		return -ENOMEM;
 
-	rcu_read_lock();
+	mutex_lock(&sdata->local->sta_mtx);
 
 	if (mac_addr) {
 		sta = sta_info_get_bss(sdata, mac_addr);
@@ -160,7 +163,7 @@
 
 	err = 0;
  out_unlock:
-	rcu_read_unlock();
+	mutex_unlock(&sdata->local->sta_mtx);
 
 	return err;
 }
@@ -174,7 +177,7 @@
 
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
-	rcu_read_lock();
+	mutex_lock(&sdata->local->sta_mtx);
 
 	if (mac_addr) {
 		ret = -ENOENT;
@@ -202,7 +205,7 @@
 
 	ret = 0;
  out_unlock:
-	rcu_read_unlock();
+	mutex_unlock(&sdata->local->sta_mtx);
 
 	return ret;
 }
@@ -305,15 +308,10 @@
 					struct net_device *dev,
 					u8 key_idx)
 {
-	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
-	rcu_read_lock();
-
-	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	ieee80211_set_default_key(sdata, key_idx);
 
-	rcu_read_unlock();
-
 	return 0;
 }