mac80211: add vif debugfs driver callbacks

Add debugfs driver callbacks so drivers can add
debugfs entries for interfaces. Note that they
_must_ remove the entries again as add/remove in
the driver doesn't correspond to add/remove in
debugfs; the former is up/down while the latter
is netdev create/destroy.

Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 434b3c4..2b08b99 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -528,6 +528,43 @@
 		local->ops->sta_remove_debugfs(&local->hw, &sdata->vif,
 					       sta, dir);
 }
+
+static inline
+void drv_add_interface_debugfs(struct ieee80211_local *local,
+			       struct ieee80211_sub_if_data *sdata)
+{
+	might_sleep();
+
+	check_sdata_in_driver(sdata);
+
+	if (!local->ops->add_interface_debugfs)
+		return;
+
+	local->ops->add_interface_debugfs(&local->hw, &sdata->vif,
+					  sdata->debugfs.dir);
+}
+
+static inline
+void drv_remove_interface_debugfs(struct ieee80211_local *local,
+				  struct ieee80211_sub_if_data *sdata)
+{
+	might_sleep();
+
+	check_sdata_in_driver(sdata);
+
+	if (!local->ops->remove_interface_debugfs)
+		return;
+
+	local->ops->remove_interface_debugfs(&local->hw, &sdata->vif,
+					     sdata->debugfs.dir);
+}
+#else
+static inline
+void drv_add_interface_debugfs(struct ieee80211_local *local,
+			       struct ieee80211_sub_if_data *sdata) {}
+static inline
+void drv_remove_interface_debugfs(struct ieee80211_local *local,
+				  struct ieee80211_sub_if_data *sdata) {}
 #endif
 
 static inline __must_check
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 0a36dc6..deb78e8 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -621,6 +621,8 @@
 				goto err_del_interface;
 		}
 
+		drv_add_interface_debugfs(local, sdata);
+
 		if (sdata->vif.type == NL80211_IFTYPE_AP) {
 			local->fif_pspoll++;
 			local->fif_probe_req++;
@@ -882,6 +884,8 @@
 		 */
 		ieee80211_free_keys(sdata);
 
+		drv_remove_interface_debugfs(local, sdata);
+
 		if (going_down)
 			drv_remove_interface(local, sdata);
 	}