locking/ww_mutex: Abstract out mutex accessors

Move the mutex related access from various ww_mutex functions into helper
functions so they can be substituted for rtmutex based ww_mutex later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211304.622477030@linutronix.de
This commit is contained in:
Peter Zijlstra 2021-08-15 23:28:49 +02:00 committed by Ingo Molnar
parent 843dac28f9
commit 9934ccc75c

View file

@ -53,6 +53,18 @@ __ww_waiter_add(struct mutex *lock, struct mutex_waiter *waiter, struct mutex_wa
__mutex_add_waiter(lock, waiter, p);
}
static inline struct task_struct *
__ww_mutex_owner(struct mutex *lock)
{
return __mutex_owner(lock);
}
static inline bool
__ww_mutex_has_waiters(struct mutex *lock)
{
return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS;
}
/*
* Wait-Die:
* The newer transactions are killed when:
@ -157,7 +169,7 @@ static bool __ww_mutex_wound(struct mutex *lock,
struct ww_acquire_ctx *ww_ctx,
struct ww_acquire_ctx *hold_ctx)
{
struct task_struct *owner = __mutex_owner(lock);
struct task_struct *owner = __ww_mutex_owner(lock);
lockdep_assert_held(&lock->wait_lock);
@ -253,7 +265,7 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
* __ww_mutex_add_waiter() and makes sure we either observe ww->ctx
* and/or !empty list.
*/
if (likely(!(atomic_long_read(&lock->base.owner) & MUTEX_FLAG_WAITERS)))
if (likely(!__ww_mutex_has_waiters(&lock->base)))
return;
/*