mac80211: dont use interface indices in drivers

This patch gets rid of the if_id stuff where possible in favour of
a new per-virtual-interface structure "struct ieee80211_vif". This
structure is located at the end of the per-interface structure and
contains a variable length driver-use data area.

This has two advantages:
 * removes the need to look up interfaces by if_id, this is better
   for working with network namespaces and performance
 * allows drivers to store and retrieve per-interface data without
   having to allocate own lists/hash tables

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43legacy/main.c b/drivers/net/wireless/b43legacy/main.c
index 575fd9a..2d5735d 100644
--- a/drivers/net/wireless/b43legacy/main.c
+++ b/drivers/net/wireless/b43legacy/main.c
@@ -976,7 +976,7 @@
 	plcp.data = 0;
 	b43legacy_generate_plcp_hdr(&plcp, size + FCS_LEN, rate);
 	dur = ieee80211_generic_frame_duration(dev->wl->hw,
-					       dev->wl->if_id,
+					       dev->wl->vif,
 					       size,
 					       B43legacy_RATE_TO_100KBPS(rate));
 	/* Write PLCP in two parts and timing for packet transfer */
@@ -1042,7 +1042,7 @@
 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 					 IEEE80211_STYPE_PROBE_RESP);
 	dur = ieee80211_generic_frame_duration(dev->wl->hw,
-					       dev->wl->if_id,
+					       dev->wl->vif,
 					       *dest_size,
 					       B43legacy_RATE_TO_100KBPS(rate));
 	hdr->duration_id = dur;
@@ -2647,7 +2647,7 @@
 }
 
 static int b43legacy_op_config_interface(struct ieee80211_hw *hw,
-					 int if_id,
+					 struct ieee80211_vif *vif,
 					 struct ieee80211_if_conf *conf)
 {
 	struct b43legacy_wl *wl = hw_to_b43legacy_wl(hw);
@@ -2658,7 +2658,7 @@
 		return -ENODEV;
 	mutex_lock(&wl->mutex);
 	spin_lock_irqsave(&wl->irq_lock, flags);
-	B43legacy_WARN_ON(wl->if_id != if_id);
+	B43legacy_WARN_ON(wl->vif != vif);
 	if (conf->bssid)
 		memcpy(wl->bssid, conf->bssid, ETH_ALEN);
 	else
@@ -3177,7 +3177,7 @@
 
 	dev = wl->current_dev;
 	wl->operating = 1;
-	wl->if_id = conf->if_id;
+	wl->vif = conf->vif;
 	wl->if_type = conf->type;
 	memcpy(wl->mac_addr, conf->mac_addr, ETH_ALEN);
 
@@ -3205,7 +3205,8 @@
 	mutex_lock(&wl->mutex);
 
 	B43legacy_WARN_ON(!wl->operating);
-	B43legacy_WARN_ON(wl->if_id != conf->if_id);
+	B43legacy_WARN_ON(wl->vif != conf->vif);
+	wl->vif = NULL;
 
 	wl->operating = 0;