mac802154: Add MLME Tx locked helpers

These have the exact same behavior as before, except they expect the
rtnl to be already taken (and will complain otherwise). This allows
performing MLME transmissions from different contexts.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230103165644.432209-6-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

net/mac802154/ieee802154_i.h

@@ -141,10 +141,16 @@ int ieee802154_mlme_op_pre(struct ieee802154_local *local);
 int ieee802154_mlme_tx(struct ieee802154_local *local,
 		       struct ieee802154_sub_if_data *sdata,
 		       struct sk_buff *skb);
+int ieee802154_mlme_tx_locked(struct ieee802154_local *local,
+			      struct ieee802154_sub_if_data *sdata,
+			      struct sk_buff *skb);
 void ieee802154_mlme_op_post(struct ieee802154_local *local);
 int ieee802154_mlme_tx_one(struct ieee802154_local *local,
 			   struct ieee802154_sub_if_data *sdata,
 			   struct sk_buff *skb);
+int ieee802154_mlme_tx_one_locked(struct ieee802154_local *local,
+				  struct ieee802154_sub_if_data *sdata,
+				  struct sk_buff *skb);
 netdev_tx_t
 ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
 netdev_tx_t

net/mac802154/tx.c

@@ -137,34 +137,37 @@ int ieee802154_mlme_op_pre(struct ieee802154_local *local)
 	return ieee802154_sync_and_hold_queue(local);
 }
 
-int ieee802154_mlme_tx(struct ieee802154_local *local,
-		       struct ieee802154_sub_if_data *sdata,
-		       struct sk_buff *skb)
+int ieee802154_mlme_tx_locked(struct ieee802154_local *local,
+			      struct ieee802154_sub_if_data *sdata,
+			      struct sk_buff *skb)
 {
-	int ret;
-
 	/* Avoid possible calls to ->ndo_stop() when we asynchronously perform
 	 * MLME transmissions.
 	 */
-	rtnl_lock();
+	ASSERT_RTNL();
 
 	/* Ensure the device was not stopped, otherwise error out */
-	if (!local->open_count) {
-		rtnl_unlock();
+	if (!local->open_count)
 		return -ENETDOWN;
-	}
 
 	/* Warn if the ieee802154 core thinks MLME frames can be sent while the
 	 * net interface expects this cannot happen.
 	 */
-	if (WARN_ON_ONCE(!netif_running(sdata->dev))) {
-		rtnl_unlock();
+	if (WARN_ON_ONCE(!netif_running(sdata->dev)))
 		return -ENETDOWN;
-	}
 
 	ieee802154_tx(local, skb);
-	ret = ieee802154_sync_queue(local);
+	return ieee802154_sync_queue(local);
+}
+
+int ieee802154_mlme_tx(struct ieee802154_local *local,
+		       struct ieee802154_sub_if_data *sdata,
+		       struct sk_buff *skb)
+{
+	int ret;
 
+	rtnl_lock();
+	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
 	rtnl_unlock();
 
 	return ret;
@@ -188,6 +191,19 @@ int ieee802154_mlme_tx_one(struct ieee802154_local *local,
 	return ret;
 }
 
+int ieee802154_mlme_tx_one_locked(struct ieee802154_local *local,
+				  struct ieee802154_sub_if_data *sdata,
+				  struct sk_buff *skb)
+{
+	int ret;
+
+	ieee802154_mlme_op_pre(local);
+	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
+	ieee802154_mlme_op_post(local);
+
+	return ret;
+}
+
 static bool ieee802154_queue_is_stopped(struct ieee802154_local *local)
 {
 	return test_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);