mac80211: implement ieee80211_tx_rate_update to update rate

Current mac80211 has provision to update tx status through
ieee80211_tx_status() and ieee80211_tx_status_ext(). But
drivers like ath10k updates the tx status from the skb except
txrate, txrate will be updated from a different path, peer stats.

Using ieee80211_tx_status_ext() in two different paths
(one for the stats, one for the tx rate) would duplicate
the stats instead.

To avoid this stats duplication, ieee80211_tx_rate_update()
is implemented.

Signed-off-by: Anilkumar Kolli <akolli@codeaurora.org>
[minor commit message editing, use initializers in code]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -4379,6 +4379,21 @@ void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 void ieee80211_sta_set_expected_throughput(struct ieee80211_sta *pubsta,
 					   u32 thr);
 
+/**
+ * ieee80211_tx_rate_update - transmit rate update callback
+ *
+ * Drivers should call this functions with a non-NULL pub sta
+ * This function can be used in drivers that does not have provision
+ * in updating the tx rate in data path.
+ *
+ * @hw: the hardware the frame was transmitted by
+ * @pubsta: the station to update the tx rate for.
+ * @info: tx status information
+ */
+void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
+			      struct ieee80211_sta *pubsta,
+			      struct ieee80211_tx_info *info);
+
 /**
  * ieee80211_tx_status - transmit status callback
  *

net/mac80211/status.c

@@ -987,6 +987,25 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL(ieee80211_tx_status_ext);
 
+void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
+			      struct ieee80211_sta *pubsta,
+			      struct ieee80211_tx_info *info)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_supported_band *sband = hw->wiphy->bands[info->band];
+	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
+	struct ieee80211_tx_status status = {
+		.info = info,
+		.sta = pubsta,
+	};
+
+	rate_control_tx_status(local, sband, &status);
+
+	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL))
+		sta->tx_stats.last_rate = info->status.rates[0];
+}
+EXPORT_SYMBOL(ieee80211_tx_rate_update);
+
 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
 {
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);