mac80211: Add debugfs callbacks for station addition/removal

Provide drivers with hooks to create debugfs files when
a new station is added. This would help drivers to take
advantage of mac80211's station list infrastructure and not maintain
tedious station management code internally.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
[ifdef inline wrapper functions]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -2208,6 +2208,14 @@ enum ieee80211_rate_control_changed {
  * @sta_remove: Notifies low level driver about removal of an associated
  *	station, AP, IBSS/WDS/mesh peer etc. This callback can sleep.
  *
+ * @sta_add_debugfs: Drivers can use this callback to add debugfs files
+ *	when a station is added to mac80211's station list. This callback
+ *	and @sta_remove_debugfs should be within a CONFIG_MAC80211_DEBUGFS
+ *	conditional. This callback can sleep.
+ *
+ * @sta_remove_debugfs: Remove the debugfs files which were added using
+ *	@sta_add_debugfs. This callback can sleep.
+ *
  * @sta_notify: Notifies low level driver about power state transition of an
  *	associated station, AP,  IBSS/WDS/mesh peer etc. For a VIF operating
  *	in AP mode, this callback will not be called when the flag
@@ -2489,6 +2497,16 @@ struct ieee80211_ops {
 		       struct ieee80211_sta *sta);
 	int (*sta_remove)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			  struct ieee80211_sta *sta);
+#ifdef CONFIG_MAC80211_DEBUGFS
+	void (*sta_add_debugfs)(struct ieee80211_hw *hw,
+				struct ieee80211_vif *vif,
+				struct ieee80211_sta *sta,
+				struct dentry *dir);
+	void (*sta_remove_debugfs)(struct ieee80211_hw *hw,
+				   struct ieee80211_vif *vif,
+				   struct ieee80211_sta *sta,
+				   struct dentry *dir);
+#endif
 	void (*sta_notify)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum sta_notify_cmd, struct ieee80211_sta *sta);
 	int (*sta_state)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,

net/mac80211/debugfs_sta.c

@@ -14,6 +14,7 @@
 #include "debugfs.h"
 #include "debugfs_sta.h"
 #include "sta_info.h"
+#include "driver-ops.h"
 
 /* sta attributtes */
 
@@ -334,6 +335,8 @@ STA_OPS(ht_capa);
 
 void ieee80211_sta_debugfs_add(struct sta_info *sta)
 {
+	struct ieee80211_local *local = sta->local;
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct dentry *stations_dir = sta->sdata->debugfs.subdir_stations;
 	u8 mac[3*ETH_ALEN];
 
@@ -379,10 +382,16 @@ void ieee80211_sta_debugfs_add(struct sta_info *sta)
 	DEBUGFS_ADD_COUNTER(tx_retry_failed, tx_retry_failed);
 	DEBUGFS_ADD_COUNTER(tx_retry_count, tx_retry_count);
 	DEBUGFS_ADD_COUNTER(wep_weak_iv_count, wep_weak_iv_count);
+
+	drv_sta_add_debugfs(local, sdata, &sta->sta, sta->debugfs.dir);
 }
 
 void ieee80211_sta_debugfs_remove(struct sta_info *sta)
 {
+	struct ieee80211_local *local = sta->local;
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
+
+	drv_sta_remove_debugfs(local, sdata, &sta->sta, sta->debugfs.dir);
 	debugfs_remove_recursive(sta->debugfs.dir);
 	sta->debugfs.dir = NULL;
 }

net/mac80211/driver-ops.h

@@ -490,6 +490,38 @@ static inline void drv_sta_remove(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+#ifdef CONFIG_MAC80211_DEBUGFS
+static inline void drv_sta_add_debugfs(struct ieee80211_local *local,
+				       struct ieee80211_sub_if_data *sdata,
+				       struct ieee80211_sta *sta,
+				       struct dentry *dir)
+{
+	might_sleep();
+
+	sdata = get_bss_sdata(sdata);
+	check_sdata_in_driver(sdata);
+
+	if (local->ops->sta_add_debugfs)
+		local->ops->sta_add_debugfs(&local->hw, &sdata->vif,
+					    sta, dir);
+}
+
+static inline void drv_sta_remove_debugfs(struct ieee80211_local *local,
+					  struct ieee80211_sub_if_data *sdata,
+					  struct ieee80211_sta *sta,
+					  struct dentry *dir)
+{
+	might_sleep();
+
+	sdata = get_bss_sdata(sdata);
+	check_sdata_in_driver(sdata);
+
+	if (local->ops->sta_remove_debugfs)
+		local->ops->sta_remove_debugfs(&local->hw, &sdata->vif,
+					       sta, dir);
+}
+#endif
+
 static inline __must_check
 int drv_sta_state(struct ieee80211_local *local,
 		  struct ieee80211_sub_if_data *sdata,