Commit dc4564f5 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

locking/ww_mutex: Implement rt_mutex accessors 



Provide the type defines and the helper inlines for rtmutex based ww_mutexes.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.790760545@linutronix.de
parent 653a5b0b

kernel/locking/ww_mutex.h

+80 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */



#ifndef WW_RT



#define MUTEX		mutex

#define MUTEX_WAITER	mutex_waiter
@@ -83,6 +85,82 @@ static inline void lockdep_assert_wait_lock_held(struct mutex *lock) 
	lockdep_assert_held(&lock->wait_lock);

}



#else /* WW_RT */



#define MUTEX		rt_mutex

#define MUTEX_WAITER	rt_mutex_waiter



static inline struct rt_mutex_waiter *

__ww_waiter_first(struct rt_mutex *lock)

{

	struct rb_node *n = rb_first(&lock->rtmutex.waiters.rb_root);

	if (!n)

		return NULL;

	return rb_entry(n, struct rt_mutex_waiter, tree_entry);

}



static inline struct rt_mutex_waiter *

__ww_waiter_next(struct rt_mutex *lock, struct rt_mutex_waiter *w)

{

	struct rb_node *n = rb_next(&w->tree_entry);

	if (!n)

		return NULL;

	return rb_entry(n, struct rt_mutex_waiter, tree_entry);

}



static inline struct rt_mutex_waiter *

__ww_waiter_prev(struct rt_mutex *lock, struct rt_mutex_waiter *w)

{

	struct rb_node *n = rb_prev(&w->tree_entry);

	if (!n)

		return NULL;

	return rb_entry(n, struct rt_mutex_waiter, tree_entry);

}



static inline struct rt_mutex_waiter *

__ww_waiter_last(struct rt_mutex *lock)

{

	struct rb_node *n = rb_last(&lock->rtmutex.waiters.rb_root);

	if (!n)

		return NULL;

	return rb_entry(n, struct rt_mutex_waiter, tree_entry);

}



static inline void

__ww_waiter_add(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, struct rt_mutex_waiter *pos)

{

	/* RT unconditionally adds the waiter first and then removes it on error */

}



static inline struct task_struct *

__ww_mutex_owner(struct rt_mutex *lock)

{

	return rt_mutex_owner(&lock->rtmutex);

}



static inline bool

__ww_mutex_has_waiters(struct rt_mutex *lock)

{

	return rt_mutex_has_waiters(&lock->rtmutex);

}



static inline void lock_wait_lock(struct rt_mutex *lock)

{

	raw_spin_lock(&lock->rtmutex.wait_lock);

}



static inline void unlock_wait_lock(struct rt_mutex *lock)

{

	raw_spin_unlock(&lock->rtmutex.wait_lock);

}



static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock)

{

	lockdep_assert_held(&lock->rtmutex.wait_lock);

}



#endif /* WW_RT */



/*

 * Wait-Die:

 *   The newer transactions are killed when:
@@ -169,7 +247,9 @@ __ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter, 


	if (waiter->ww_ctx->acquired > 0 &&

			__ww_ctx_stamp_after(waiter->ww_ctx, ww_ctx)) {

#ifndef WW_RT

		debug_mutex_wake_waiter(lock, waiter);

#endif

		wake_up_process(waiter->task);

	}