Add msleep function to the kernel core to prevent duplication.

include/linux/delay.h

@@ -38,4 +38,6 @@ extern unsigned long loops_per_jiffy;
 #define ndelay(x)	udelay(((x)+999)/1000)
 #endif
 
+void msleep(unsigned int msecs);
+
 #endif /* defined(_LINUX_DELAY_H) */

kernel/timer.c

@@ -1485,3 +1485,20 @@ unregister_time_interpolator(struct time_interpolator *ti)
 	spin_unlock(&time_interpolator_lock);
 }
 #endif /* CONFIG_TIME_INTERPOLATION */
+
+/**
+ * msleep - sleep safely even with waitqueue interruptions
+ * @msecs: Time in milliseconds to sleep for
+ */
+void msleep(unsigned int msecs)
+{
+	unsigned long timeout = msecs_to_jiffies(msecs);
+
+	while (timeout) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		timeout = schedule_timeout(timeout);
+	}
+}
+
+EXPORT_SYMBOL(msleep);
+