iwlegacy: add il_{stop,wake}_queues_by_reason functions

Add functions that will stop/wake all queues. Make them safe
regarding multiple calls and when some ac are stopped/woke
independently.
Tested-by: NJake Edge <jake@lwn.net>
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/common.h

@@ -1299,6 +1299,8 @@ struct il_priv {
 	/* queue refcounts */
 #define IL_MAX_HW_QUEUES	32
 	unsigned long queue_stopped[BITS_TO_LONGS(IL_MAX_HW_QUEUES)];
+#define IL_STOP_REASON_PASSIVE	0
+	unsigned long stop_reason;
 	/* for each AC */
 	atomic_t queue_stop_count[4];
 
@@ -2291,6 +2293,26 @@ il_stop_queue(struct il_priv *il, struct il_tx_queue *txq)
 		_il_stop_queue(il, ac);
 }
 
+static inline void
+il_wake_queues_by_reason(struct il_priv *il, int reason)
+{
+	u8 ac;
+
+	if (test_and_clear_bit(reason, &il->stop_reason))
+		for (ac = 0; ac < 4; ac++)
+			_il_wake_queue(il, ac);
+}
+
+static inline void
+il_stop_queues_by_reason(struct il_priv *il, int reason)
+{
+	u8 ac;
+
+	if (!test_and_set_bit(reason, &il->stop_reason))
+		for (ac = 0; ac < 4; ac++)
+			_il_stop_queue(il, ac);
+}
+
 #ifdef ieee80211_stop_queue
 #undef ieee80211_stop_queue
 #endif