+static int __pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct poll_wqueues *pwq = wait->private;
+ DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task);
+
+ /*
+ * Although this function is called under waitqueue lock, LOCK
+ * doesn't imply write barrier and the users expect write
+ * barrier semantics on wakeup functions. The following
+ * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
+ * and is paired with set_mb() in poll_schedule_timeout.
+ */
+ smp_wmb();
+ pwq->triggered = 1;
+
+ /*
+ * Perform the default wake up operation using a dummy
+ * waitqueue.
+ *
+ * TODO: This is hacky but there currently is no interface to
+ * pass in @sync. @sync is scheduled to be removed and once
+ * that happens, wake_up_process() can be used directly.
+ */
+ return default_wake_function(&dummy_wait, mode, sync, key);
+}
+
+static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct poll_table_entry *entry;
+
+ entry = container_of(wait, struct poll_table_entry, wait);
+ if (key && !((unsigned long)key & entry->key))
+ return 0;
+ return __pollwake(wait, mode, sync, key);
+}
+