Commit 5f35d5a6 authored by Mukesh Ojha's avatar Mukesh Ojha Committed by Peter Zijlstra
Browse files

locking/mutex: Make __mutex_owner static to mutex.c 



__mutex_owner() should only be used by the mutex api's.
So, to put this restiction let's move the __mutex_owner()
function definition from linux/mutex.h to mutex.c file.

There exist functions that uses __mutex_owner() like
mutex_is_locked() and mutex_trylock_recursive(), So
to keep legacy thing intact move them as well and
export them.

Move mutex_waiter structure also to keep it private to the
file.

Signed-off-by: default avatarMukesh Ojha <mojha@codeaurora.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: mingo@redhat.com
Cc: will@kernel.org
Link: https://lkml.kernel.org/r/1564585504-3543-1-git-send-email-mojha@codeaurora.org
parent 24a376d6

include/linux/mutex.h

+3 −35
Original line number Diff line number Diff line
@@ -65,29 +65,6 @@ struct mutex { 
#endif

};



/*

 * Internal helper function; C doesn't allow us to hide it :/

 *

 * DO NOT USE (outside of mutex code).

 */

static inline struct task_struct *__mutex_owner(struct mutex *lock)

{

	return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);

}



/*

 * This is the control structure for tasks blocked on mutex,

 * which resides on the blocked task's kernel stack:

 */

struct mutex_waiter {

	struct list_head	list;

	struct task_struct	*task;

	struct ww_acquire_ctx	*ww_ctx;

#ifdef CONFIG_DEBUG_MUTEXES

	void			*magic;

#endif

};



#ifdef CONFIG_DEBUG_MUTEXES



#define __DEBUG_MUTEX_INITIALIZER(lockname)				\
@@ -144,10 +121,7 @@ extern void __mutex_init(struct mutex *lock, const char *name, 
 *

 * Returns true if the mutex is locked, false if unlocked.

 */

static inline bool mutex_is_locked(struct mutex *lock)

{

	return __mutex_owner(lock) != NULL;

}

extern bool mutex_is_locked(struct mutex *lock);



/*

 * See kernel/locking/mutex.c for detailed documentation of these APIs.
@@ -220,13 +194,7 @@ enum mutex_trylock_recursive_enum { 
 *  - MUTEX_TRYLOCK_SUCCESS   - lock acquired,

 *  - MUTEX_TRYLOCK_RECURSIVE - we already owned the lock.

 */

static inline /* __deprecated */ __must_check enum mutex_trylock_recursive_enum

mutex_trylock_recursive(struct mutex *lock)

{

	if (unlikely(__mutex_owner(lock) == current))

		return MUTEX_TRYLOCK_RECURSIVE;



	return mutex_trylock(lock);

}

extern /* __deprecated */ __must_check enum mutex_trylock_recursive_enum

mutex_trylock_recursive(struct mutex *lock);



#endif /* __LINUX_MUTEX_H */

kernel/locking/mutex.c

+39 −0
Original line number Diff line number Diff line
@@ -36,6 +36,19 @@ 
# include "mutex.h"

#endif



/*

 * This is the control structure for tasks blocked on mutex,

 * which resides on the blocked task's kernel stack:

 */

struct mutex_waiter {

	struct list_head	list;

	struct task_struct	*task;

	struct ww_acquire_ctx	*ww_ctx;

#ifdef CONFIG_DEBUG_MUTEXES

	void			*magic;

#endif

};



void

__mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)

{
@@ -65,11 +78,37 @@ EXPORT_SYMBOL(__mutex_init); 


#define MUTEX_FLAGS		0x07



/*

 * Internal helper function; C doesn't allow us to hide it :/

 *

 * DO NOT USE (outside of mutex code).

 */

static inline struct task_struct *__mutex_owner(struct mutex *lock)

{

	return (struct task_struct *)(atomic_long_read(&lock->owner) & ~0x07);

}



static inline struct task_struct *__owner_task(unsigned long owner)

{

	return (struct task_struct *)(owner & ~MUTEX_FLAGS);

}



bool mutex_is_locked(struct mutex *lock)

{

	return __mutex_owner(lock) != NULL;

}

EXPORT_SYMBOL(mutex_is_locked);



__must_check enum mutex_trylock_recursive_enum

mutex_trylock_recursive(struct mutex *lock)

{

	if (unlikely(__mutex_owner(lock) == current))

		return MUTEX_TRYLOCK_RECURSIVE;



	return mutex_trylock(lock);

}

EXPORT_SYMBOL(mutex_trylock_recursive);



static inline unsigned long __owner_flags(unsigned long owner)

{

	return owner & MUTEX_FLAGS;

kernel/locking/mutex.h

+2 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#define debug_mutex_unlock(lock)			do { } while (0)

#define debug_mutex_init(lock, name, key)		do { } while (0)



struct mutex_waiter;



static inline void

debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)

{

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