mac80211: explicitly notify drivers of frame release

iwlwifi needs to know the number of frames that are
going to be sent to a station while it is asleep so
it can properly handle the uCode blocking of that
station.

Before uAPSD, we got by by telling the device that
a single frame was going to be released whenever we
encountered IEEE80211_TX_CTL_POLL_RESPONSE. With
uAPSD, however, that is no longer possible since
there could be more than a single frame.

To support this model, add a new callback to notify
drivers when frames are going to be released.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 8fa0d2e..68721d37 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -685,4 +685,19 @@
 						    more_data);
 	trace_drv_return_void(local);
 }
+
+static inline void
+drv_allow_buffered_frames(struct ieee80211_local *local,
+			  struct sta_info *sta, u16 tids, int num_frames,
+			  enum ieee80211_frame_release_type reason,
+			  bool more_data)
+{
+	trace_drv_allow_buffered_frames(local, &sta->sta, tids, num_frames,
+					reason, more_data);
+	if (local->ops->allow_buffered_frames)
+		local->ops->allow_buffered_frames(&local->hw, &sta->sta,
+						  tids, num_frames, reason,
+						  more_data);
+	trace_drv_return_void(local);
+}
 #endif /* __MAC80211_DRIVER_OPS */