mac80211: add ieee80211_iterate_active_interfaces_rtnl()
If it is needed to disconnect multiple virtual interfaces after
(WoWLAN-) suspend, the most obvious approach would be to iterate
all interfaces by calling ieee80211_iterate_active_interfaces()
and then call ieee80211_resume_disconnect() for each one. This
is what the iwlmvm driver does.
Unfortunately, this causes a locking dependency from mac80211's
iflist_mtx to the key_mtx. This is problematic as the former is
intentionally never held while calling any driver operation to
allow drivers to iterate with their own locks held. The key_mtx
is held while installing a key into the driver though, so this
new lock dependency means drivers implementing the logic above
can no longer hold their own lock while iterating.
To fix this, add a new ieee80211_iterate_active_interfaces_rtnl()
function that iterates while the RTNL is already held. This is
true during suspend/resume, so that then the locking dependency
isn't introduced.
While at it, also refactor the various interface iterators and
keep only a single implementation called by the various cases.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index cc6035f..3411c59 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3920,6 +3920,25 @@
void *data);
/**
+ * ieee80211_iterate_active_interfaces_rtnl - iterate active interfaces
+ *
+ * This function iterates over the interfaces associated with a given
+ * hardware that are currently active and calls the callback for them.
+ * This version can only be used while holding the RTNL.
+ *
+ * @hw: the hardware struct of which the interfaces should be iterated over
+ * @iter_flags: iteration flags, see &enum ieee80211_interface_iteration_flags
+ * @iterator: the iterator function to call, cannot sleep
+ * @data: first argument of the iterator function
+ */
+void ieee80211_iterate_active_interfaces_rtnl(struct ieee80211_hw *hw,
+ u32 iter_flags,
+ void (*iterator)(void *data,
+ u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data);
+
+/**
* ieee80211_queue_work - add work onto the mac80211 workqueue
*
* Drivers and mac80211 use this to add work onto the mac80211 workqueue.