linux_dsm_epyc7002/include/linux/refcount.h
David Windsor bd174169c7 locking/refcount: Add refcount_t API kernel-doc comments
Signed-off-by: David Windsor <dwindsor@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: elena.reshetova@intel.com
Cc: kernel-hardening@lists.openwall.com
Link: http://lkml.kernel.org/r/1489160052-20293-1-git-send-email-dwindsor@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-13 07:41:08 +01:00

62 lines
1.7 KiB
C

#ifndef _LINUX_REFCOUNT_H
#define _LINUX_REFCOUNT_H
#include <linux/atomic.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>
/**
* refcount_t - variant of atomic_t specialized for reference counts
* @refs: atomic_t counter field
*
* The counter saturates at UINT_MAX and will not move once
* there. This avoids wrapping the counter and causing 'spurious'
* use-after-free bugs.
*/
typedef struct refcount_struct {
atomic_t refs;
} refcount_t;
#define REFCOUNT_INIT(n) { .refs = ATOMIC_INIT(n), }
/**
* refcount_set - set a refcount's value
* @r: the refcount
* @n: value to which the refcount will be set
*/
static inline void refcount_set(refcount_t *r, unsigned int n)
{
atomic_set(&r->refs, n);
}
/**
* refcount_read - get a refcount's value
* @r: the refcount
*
* Return: the refcount's value
*/
static inline unsigned int refcount_read(const refcount_t *r)
{
return atomic_read(&r->refs);
}
extern __must_check bool refcount_add_not_zero(unsigned int i, refcount_t *r);
extern void refcount_add(unsigned int i, refcount_t *r);
extern __must_check bool refcount_inc_not_zero(refcount_t *r);
extern void refcount_inc(refcount_t *r);
extern __must_check bool refcount_sub_and_test(unsigned int i, refcount_t *r);
extern void refcount_sub(unsigned int i, refcount_t *r);
extern __must_check bool refcount_dec_and_test(refcount_t *r);
extern void refcount_dec(refcount_t *r);
extern __must_check bool refcount_dec_if_one(refcount_t *r);
extern __must_check bool refcount_dec_not_one(refcount_t *r);
extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock);
extern __must_check bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock);
#endif /* _LINUX_REFCOUNT_H */