wifi: cfg80211: add flush functions for wiphy work

[ Upstream commit 56cfb8ce1f7f6c4e5ca571a2ec0880e131cd0311 ]

There may be sometimes reasons to actually run the work
if it's pending, add flush functions for both regular and
delayed wiphy work that will do this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Stable-dep-of: eadfb54756ae ("wifi: mac80211: move sched-scan stop work to wiphy work")
Signed-off-by: Sasha Levin <sashal@kernel.org>

include/net/cfg80211.h

@@ -5690,6 +5690,16 @@ void wiphy_work_queue(struct wiphy *wiphy, struct wiphy_work *work);
  */
 void wiphy_work_cancel(struct wiphy *wiphy, struct wiphy_work *work);
 
+/**
+ * wiphy_work_flush - flush previously queued work
+ * @wiphy: the wiphy, for debug purposes
+ * @work: the work to flush, this can be %NULL to flush all work
+ *
+ * Flush the work (i.e. run it if pending). This must be called
+ * under the wiphy mutex acquired by wiphy_lock().
+ */
+void wiphy_work_flush(struct wiphy *wiphy, struct wiphy_work *work);
+
 struct wiphy_delayed_work {
 	struct wiphy_work work;
 	struct wiphy *wiphy;
@@ -5733,6 +5743,17 @@ void wiphy_delayed_work_queue(struct wiphy *wiphy,
 void wiphy_delayed_work_cancel(struct wiphy *wiphy,
 			       struct wiphy_delayed_work *dwork);
 
+/**
+ * wiphy_delayed work_flush - flush previously queued delayed work
+ * @wiphy: the wiphy, for debug purposes
+ * @work: the work to flush
+ *
+ * Flush the work (i.e. run it if pending). This must be called
+ * under the wiphy mutex acquired by wiphy_lock().
+ */
+void wiphy_delayed_work_flush(struct wiphy *wiphy,
+			      struct wiphy_delayed_work *dwork);
+
 /**
  * struct wireless_dev - wireless device state
  *

net/wireless/core.c

@@ -1042,7 +1042,8 @@ void wiphy_rfkill_start_polling(struct wiphy *wiphy)
 }
 EXPORT_SYMBOL(wiphy_rfkill_start_polling);
 
-void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev)
+void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev,
+				  struct wiphy_work *end)
 {
 	unsigned int runaway_limit = 100;
 	unsigned long flags;
@@ -1061,6 +1062,10 @@ void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev)
 		wk->func(&rdev->wiphy, wk);
 
 		spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
+
+		if (wk == end)
+			break;
+
 		if (WARN_ON(--runaway_limit == 0))
 			INIT_LIST_HEAD(&rdev->wiphy_work_list);
 	}
@@ -1111,7 +1116,7 @@ void wiphy_unregister(struct wiphy *wiphy)
 #endif
 
 	/* surely nothing is reachable now, clean up work */
-	cfg80211_process_wiphy_works(rdev);
+	cfg80211_process_wiphy_works(rdev, NULL);
 	wiphy_unlock(&rdev->wiphy);
 	rtnl_unlock();
 
@@ -1636,6 +1641,21 @@ void wiphy_work_cancel(struct wiphy *wiphy, struct wiphy_work *work)
 }
 EXPORT_SYMBOL_GPL(wiphy_work_cancel);
 
+void wiphy_work_flush(struct wiphy *wiphy, struct wiphy_work *work)
+{
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
+	unsigned long flags;
+	bool run;
+
+	spin_lock_irqsave(&rdev->wiphy_work_lock, flags);
+	run = !work || !list_empty(&work->entry);
+	spin_unlock_irqrestore(&rdev->wiphy_work_lock, flags);
+
+	if (run)
+		cfg80211_process_wiphy_works(rdev, work);
+}
+EXPORT_SYMBOL_GPL(wiphy_work_flush);
+
 void wiphy_delayed_work_timer(struct timer_list *t)
 {
 	struct wiphy_delayed_work *dwork = from_timer(dwork, t, timer);
@@ -1668,6 +1688,16 @@ void wiphy_delayed_work_cancel(struct wiphy *wiphy,
 }
 EXPORT_SYMBOL_GPL(wiphy_delayed_work_cancel);
 
+void wiphy_delayed_work_flush(struct wiphy *wiphy,
+			      struct wiphy_delayed_work *dwork)
+{
+	lockdep_assert_held(&wiphy->mtx);
+
+	del_timer_sync(&dwork->timer);
+	wiphy_work_flush(wiphy, &dwork->work);
+}
+EXPORT_SYMBOL_GPL(wiphy_delayed_work_flush);
+
 static int __init cfg80211_init(void)
 {
 	int err;

net/wireless/core.h

@@ -461,7 +461,8 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 			  struct net_device *dev, enum nl80211_iftype ntype,
 			  struct vif_params *params);
 void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev);
-void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev);
+void cfg80211_process_wiphy_works(struct cfg80211_registered_device *rdev,
+				  struct wiphy_work *end);
 void cfg80211_process_wdev_events(struct wireless_dev *wdev);
 
 bool cfg80211_does_bw_fit_range(const struct ieee80211_freq_range *freq_range,

net/wireless/sysfs.c

@@ -105,14 +105,14 @@ static int wiphy_suspend(struct device *dev)
 			cfg80211_leave_all(rdev);
 			cfg80211_process_rdev_events(rdev);
 		}
-		cfg80211_process_wiphy_works(rdev);
+		cfg80211_process_wiphy_works(rdev, NULL);
 		if (rdev->ops->suspend)
 			ret = rdev_suspend(rdev, rdev->wiphy.wowlan_config);
 		if (ret == 1) {
 			/* Driver refuse to configure wowlan */
 			cfg80211_leave_all(rdev);
 			cfg80211_process_rdev_events(rdev);
-			cfg80211_process_wiphy_works(rdev);
+			cfg80211_process_wiphy_works(rdev, NULL);
 			ret = rdev_suspend(rdev, NULL);
 		}
 		if (ret == 0)