locking/rtmutex: Remove rt_mutex_timed_lock()

rt_mutex_timed_lock() has no callers since:

  c051b21f ("rtmutex: Confine deadlock logic to futex")

Remove it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210326153943.061103415@linutronix.de

include/linux/rtmutex.h

@@ -115,9 +115,6 @@ extern void rt_mutex_lock(struct rt_mutex *lock);
 #endif
 
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
-extern int rt_mutex_timed_lock(struct rt_mutex *lock,
-			       struct hrtimer_sleeper *timeout);
-
 extern int rt_mutex_trylock(struct rt_mutex *lock);
 
 extern void rt_mutex_unlock(struct rt_mutex *lock);

kernel/locking/rtmutex.c

@@ -1394,21 +1394,6 @@ rt_mutex_fastlock(struct rt_mutex *lock, int state,
 	return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
 }
 
-static inline int
-rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
-			struct hrtimer_sleeper *timeout,
-			enum rtmutex_chainwalk chwalk,
-			int (*slowfn)(struct rt_mutex *lock, int state,
-				      struct hrtimer_sleeper *timeout,
-				      enum rtmutex_chainwalk chwalk))
-{
-	if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
-	    likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
-		return 0;
-
-	return slowfn(lock, state, timeout, chwalk);
-}
-
 static inline int
 rt_mutex_fasttrylock(struct rt_mutex *lock,
 		     int (*slowfn)(struct rt_mutex *lock))
@@ -1516,37 +1501,6 @@ int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock)
 	return __rt_mutex_slowtrylock(lock);
 }
 
-/**
- * rt_mutex_timed_lock - lock a rt_mutex interruptible
- *			the timeout structure is provided
- *			by the caller
- *
- * @lock:		the rt_mutex to be locked
- * @timeout:		timeout structure or NULL (no timeout)
- *
- * Returns:
- *  0		on success
- * -EINTR	when interrupted by a signal
- * -ETIMEDOUT	when the timeout expired
- */
-int
-rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout)
-{
-	int ret;
-
-	might_sleep();
-
-	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-	ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
-				       RT_MUTEX_MIN_CHAINWALK,
-				       rt_mutex_slowlock);
-	if (ret)
-		mutex_release(&lock->dep_map, _RET_IP_);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
-
 /**
  * rt_mutex_trylock - try to lock a rt_mutex
  *