+/**
+ * down_timeout - acquire the semaphore within a specified time
+ * @sem: the semaphore to be acquired
+ * @jiffies: how long to wait before failing
+ *
+ * Attempts to acquire the semaphore. If no more tasks are allowed to
+ * acquire the semaphore, calling this function will put the task to sleep.
+ * If the semaphore is not released within the specified number of jiffies,
+ * this function returns -ETIME. It returns 0 if the semaphore was acquired.
+ */
+int down_timeout(struct semaphore *sem, long jiffies)
+{
+ unsigned long flags;
+ int result = 0;
+
+ spin_lock_irqsave(&sem->lock, flags);
+ if (likely(sem->count > 0))
+ sem->count--;
+ else
+ result = __down_timeout(sem, jiffies);
+ spin_unlock_irqrestore(&sem->lock, flags);
+
+ return result;
+}
+EXPORT_SYMBOL(down_timeout);
+
+/**
+ * up - release the semaphore
+ * @sem: the semaphore to release
+ *
+ * Release the semaphore. Unlike mutexes, up() may be called from any
+ * context and even by tasks which have never called down().
+ */