mac80211: move TX station pointer and restructure TX

Remove the control.sta pointer from ieee80211_tx_info to free up
sufficient space in the TX skb control buffer for the upcoming
Transmit Power Control (TPC).
Instead, the pointer is now on the stack in a new control struct
that is passed as a function parameter to the drivers' tx method.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[reworded commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index b09285c..7373e4b9 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -280,6 +280,7 @@
 	struct ath_txq *txq;
 	struct ath_node *an;
 	u8 paprd;
+	struct ieee80211_sta *sta;
 };
 
 #define ATH_TX_ERROR        0x01
diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h
index 936e920..b30596f 100644
--- a/drivers/net/wireless/ath/ath9k/htc.h
+++ b/drivers/net/wireless/ath/ath9k/htc.h
@@ -542,6 +542,7 @@
 
 int ath9k_tx_init(struct ath9k_htc_priv *priv);
 int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
+		       struct ieee80211_sta *sta,
 		       struct sk_buff *skb, u8 slot, bool is_cab);
 void ath9k_tx_cleanup(struct ath9k_htc_priv *priv);
 bool ath9k_htc_txq_setup(struct ath9k_htc_priv *priv, int subtype);
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
index 77d541f..f42d2eb 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_beacon.c
@@ -326,7 +326,7 @@
 			goto next;
 		}
 
-		ret = ath9k_htc_tx_start(priv, skb, tx_slot, true);
+		ret = ath9k_htc_tx_start(priv, NULL, skb, tx_slot, true);
 		if (ret != 0) {
 			ath9k_htc_tx_clear_slot(priv, tx_slot);
 			dev_kfree_skb_any(skb);
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index c785129..8a0ccf7 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -856,7 +856,9 @@
 /* mac80211 Callbacks */
 /**********************/
 
-static void ath9k_htc_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+static void ath9k_htc_tx(struct ieee80211_hw *hw,
+			 struct ieee80211_tx_control *control,
+			 struct sk_buff *skb)
 {
 	struct ieee80211_hdr *hdr;
 	struct ath9k_htc_priv *priv = hw->priv;
@@ -883,7 +885,7 @@
 		goto fail_tx;
 	}
 
-	ret = ath9k_htc_tx_start(priv, skb, slot, false);
+	ret = ath9k_htc_tx_start(priv, control->sta, skb, slot, false);
 	if (ret != 0) {
 		ath_dbg(common, XMIT, "Tx failed\n");
 		goto clear_slot;
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
index 47e61d0..06cdcb7 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
@@ -333,12 +333,12 @@
 }
 
 int ath9k_htc_tx_start(struct ath9k_htc_priv *priv,
+		       struct ieee80211_sta *sta,
 		       struct sk_buff *skb,
 		       u8 slot, bool is_cab)
 {
 	struct ieee80211_hdr *hdr;
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_sta *sta = tx_info->control.sta;
 	struct ieee80211_vif *vif = tx_info->control.vif;
 	struct ath9k_htc_sta *ista;
 	struct ath9k_htc_vif *avp = NULL;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 6049d8b..4d8dc9f 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -694,7 +694,9 @@
 	return r;
 }
 
-static void ath9k_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+static void ath9k_tx(struct ieee80211_hw *hw,
+		     struct ieee80211_tx_control *control,
+		     struct sk_buff *skb)
 {
 	struct ath_softc *sc = hw->priv;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -754,6 +756,7 @@
 
 	memset(&txctl, 0, sizeof(struct ath_tx_control));
 	txctl.txq = sc->tx.txq_map[skb_get_queue_mapping(skb)];
+	txctl.sta = control->sta;
 
 	ath_dbg(common, XMIT, "transmitting packet, skb: %p\n", skb);
 
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 2c9da6b..ef91f6c 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1773,11 +1773,12 @@
 	TX_STAT_INC(txq->axq_qnum, queued);
 }
 
-static void setup_frame_info(struct ieee80211_hw *hw, struct sk_buff *skb,
+static void setup_frame_info(struct ieee80211_hw *hw,
+			     struct ieee80211_sta *sta,
+			     struct sk_buff *skb,
 			     int framelen)
 {
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_sta *sta = tx_info->control.sta;
 	struct ieee80211_key_conf *hw_key = tx_info->control.hw_key;
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 	const struct ieee80211_rate *rate;
@@ -1935,7 +1936,7 @@
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_sta *sta = info->control.sta;
+	struct ieee80211_sta *sta = txctl->sta;
 	struct ieee80211_vif *vif = info->control.vif;
 	struct ath_softc *sc = hw->priv;
 	struct ath_txq *txq = txctl->txq;
@@ -1979,7 +1980,7 @@
 	    !ieee80211_is_data(hdr->frame_control))
 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
 
-	setup_frame_info(hw, skb, frmlen);
+	setup_frame_info(hw, sta, skb, frmlen);
 
 	/*
 	 * At this point, the vif, hw_key and sta pointers in the tx control