mac80211: reduce reliance on netdev

For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.

In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.

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

net/mac80211/ieee80211_i.h

@@ -140,7 +140,6 @@ typedef unsigned __bitwise__ ieee80211_tx_result;
 
 struct ieee80211_tx_data {
 	struct sk_buff *skb;
-	struct net_device *dev;
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
 	struct sta_info *sta;
@@ -433,6 +432,8 @@ struct ieee80211_sub_if_data {
 
 	int drop_unencrypted;
 
+	char name[IFNAMSIZ];
+
 	/*
 	 * keep track of whether the HT opmode (stored in
 	 * vif.bss_info.ht_operation_mode) is valid.
@@ -937,6 +938,8 @@ void ieee80211_rx_bss_put(struct ieee80211_local *local,
 			  struct ieee80211_bss *bss);
 
 /* interface handling */
+int ieee80211_iface_init(void);
+void ieee80211_iface_exit(void);
 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 		     struct net_device **new_dev, enum nl80211_iftype type,
 		     struct vif_params *params);