mac80211: allow low level drivers to report packet loss

Add API that allows low level drivers to notify mac80211 about TX
packet loss. This is useful when there are FW triggers to notify the
low level driver about these events.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -2291,6 +2291,17 @@ static inline void ieee80211_tx_status_ni(struct ieee80211_hw *hw,
 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
 				 struct sk_buff *skb);
 
+/**
+ * ieee80211_report_low_ack - report non-responding station
+ *
+ * When operating in AP-mode, call this function to report a non-responding
+ * connected STA.
+ *
+ * @sta: the non-responding connected sta
+ * @num_packets: number of packets sent to @sta without a response
+ */
+void ieee80211_report_low_ack(struct ieee80211_sta *sta, u32 num_packets);
+
 /**
  * ieee80211_beacon_get_tim - beacon generation function
  * @hw: pointer obtained from ieee80211_alloc_hw().

net/mac80211/status.c

@@ -446,3 +446,11 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 	dev_kfree_skb(skb);
 }
 EXPORT_SYMBOL(ieee80211_tx_status);
+
+void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
+{
+	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
+	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
+				    num_packets, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(ieee80211_report_low_ack);