mac80211: move TX info into skb->cb

This patch converts mac80211 and all drivers to have transmit
information and status in skb->cb rather than allocating extra
memory for it and copying all the data around. To make it fit,
a union is used where only data that is necessary for all steps
is kept outside of the union.

A number of fixes were done by Ivo, as well as the rt2x00 part
of this patch.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c
index 14cde36..e894541 100644
--- a/net/mac80211/rc80211_pid_algo.c
+++ b/net/mac80211/rc80211_pid_algo.c
@@ -237,8 +237,7 @@
 }
 
 static void rate_control_pid_tx_status(void *priv, struct net_device *dev,
-				       struct sk_buff *skb,
-				       struct ieee80211_tx_status *status)
+				       struct sk_buff *skb)
 {
 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
@@ -248,6 +247,7 @@
 	struct rc_pid_sta_info *spinfo;
 	unsigned long period;
 	struct ieee80211_supported_band *sband;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 
 	rcu_read_lock();
 
@@ -266,28 +266,28 @@
 
 	/* Ignore all frames that were sent with a different rate than the rate
 	 * we currently advise mac80211 to use. */
-	if (status->control.tx_rate_idx != sta->txrate_idx)
+	if (info->tx_rate_idx != sta->txrate_idx)
 		goto unlock;
 
 	spinfo = sta->rate_ctrl_priv;
 	spinfo->tx_num_xmit++;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
-	rate_control_pid_event_tx_status(&spinfo->events, status);
+	rate_control_pid_event_tx_status(&spinfo->events, info);
 #endif
 
 	/* We count frames that totally failed to be transmitted as two bad
 	 * frames, those that made it out but had some retries as one good and
 	 * one bad frame. */
-	if (status->excessive_retries) {
+	if (info->status.excessive_retries) {
 		spinfo->tx_num_failed += 2;
 		spinfo->tx_num_xmit++;
-	} else if (status->retry_count) {
+	} else if (info->status.retry_count) {
 		spinfo->tx_num_failed++;
 		spinfo->tx_num_xmit++;
 	}
 
-	if (status->excessive_retries) {
+	if (info->status.excessive_retries) {
 		sta->tx_retry_failed++;
 		sta->tx_num_consecutive_failures++;
 		sta->tx_num_mpdu_fail++;
@@ -295,8 +295,8 @@
 		sta->tx_num_consecutive_failures = 0;
 		sta->tx_num_mpdu_ok++;
 	}
-	sta->tx_retry_count += status->retry_count;
-	sta->tx_num_mpdu_fail += status->retry_count;
+	sta->tx_retry_count += info->status.retry_count;
+	sta->tx_num_mpdu_fail += info->status.retry_count;
 
 	/* Update PID controller state. */
 	period = (HZ * pinfo->sampling_period + 500) / 1000;