From: Johannes Berg <johannes.berg@intel.com>

Right now, the only way to iterate stations is to declare an
iterator function, possibly data structure to use, and pass all
that to the iteration helper function. This is annoying, and
there's really no inherent need for it.

Add a new for_each_station() macro that does the iteration in
a more ergonomic way. To avoid even more exported functions, do
the old ieee80211_iterate_stations_mtx() as an inline using the
new way, which may also let the compiler optimise it a bit more,
e.g. via inlining the iterator function.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/mac80211.h | 29 +++++++++++++++++++++++++----
 net/mac80211/util.c    | 23 +++++++++++++++++------
 2 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 88ae5d60d9b9..36daccef6554 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -6338,6 +6338,20 @@ void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 						struct ieee80211_sta *sta),
 				       void *data);
 
+struct ieee80211_sta *
+__ieee80211_iterate_stations(struct ieee80211_hw *hw,
+			     struct ieee80211_sta *prev);
+
+/**
+ * for_each_station - iterate stations under wiphy mutex
+ * @sta: the iterator variable
+ * @hw: the HW to iterate for
+ */
+#define for_each_station(sta, hw)					\
+	for (sta = __ieee80211_iterate_stations(hw, NULL);		\
+	     sta;							\
+	     sta = __ieee80211_iterate_stations(hw, sta))
+
 /**
  * ieee80211_iterate_stations_mtx - iterate stations
  *
@@ -6350,10 +6364,17 @@ void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
  * @iterator: the iterator function to call
  * @data: first argument of the iterator function
  */
-void ieee80211_iterate_stations_mtx(struct ieee80211_hw *hw,
-				    void (*iterator)(void *data,
-						     struct ieee80211_sta *sta),
-				    void *data);
+static inline void
+ieee80211_iterate_stations_mtx(struct ieee80211_hw *hw,
+			       void (*iterator)(void *data,
+						struct ieee80211_sta *sta),
+			       void *data)
+{
+	struct ieee80211_sta *sta;
+
+	for_each_station(sta, hw)
+		iterator(data, sta);
+}
 
 /**
  * ieee80211_queue_work - add work onto the mac80211 workqueue
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 13f2e911f330..b95f7d50e77d 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -880,18 +880,29 @@ void ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 }
 EXPORT_SYMBOL_GPL(ieee80211_iterate_stations_atomic);
 
-void ieee80211_iterate_stations_mtx(struct ieee80211_hw *hw,
-				    void (*iterator)(void *data,
-						     struct ieee80211_sta *sta),
-				    void *data)
+struct ieee80211_sta *
+__ieee80211_iterate_stations(struct ieee80211_hw *hw,
+			     struct ieee80211_sta *prev)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
+	struct sta_info *sta = NULL;
 
 	lockdep_assert_wiphy(local->hw.wiphy);
 
-	__iterate_stations(local, iterator, data);
+	if (prev)
+		sta = container_of(prev, struct sta_info, sta);
+
+	sta = list_prepare_entry(sta, &local->sta_list, list);
+	list_for_each_entry_continue(sta, &local->sta_list, list) {
+		if (!sta->uploaded)
+			continue;
+
+		return &sta->sta;
+	}
+
+	return NULL;
 }
-EXPORT_SYMBOL_GPL(ieee80211_iterate_stations_mtx);
+EXPORT_SYMBOL_GPL(__ieee80211_iterate_stations);
 
 struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev)
 {
-- 
2.52.0