#ifndef _KREF_H_
#define _KREF_H_
-#include <linux/bug.h>
-#include <linux/atomic.h>
-#include <linux/kernel.h>
-#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/refcount.h>
struct kref {
- atomic_t refcount;
+ refcount_t refcount;
};
-#define KREF_INIT(n) { .refcount = ATOMIC_INIT(n), }
+#define KREF_INIT(n) { .refcount = REFCOUNT_INIT(n), }
/**
* kref_init - initialize object.
*/
static inline void kref_init(struct kref *kref)
{
- atomic_set(&kref->refcount, 1);
+ refcount_set(&kref->refcount, 1);
}
-static inline int kref_read(const struct kref *kref)
+static inline unsigned int kref_read(const struct kref *kref)
{
- return atomic_read(&kref->refcount);
+ return refcount_read(&kref->refcount);
}
/**
*/
static inline void kref_get(struct kref *kref)
{
- /* If refcount was 0 before incrementing then we have a race
- * condition when this kref is freeing by some other thread right now.
- * In this case one should use kref_get_unless_zero()
- */
- WARN_ON_ONCE(atomic_inc_return(&kref->refcount) < 2);
+ refcount_inc(&kref->refcount);
}
/**
{
WARN_ON(release == NULL);
- if (atomic_dec_and_test(&kref->refcount)) {
+ if (refcount_dec_and_test(&kref->refcount)) {
release(kref);
return 1;
}
struct mutex *lock)
{
WARN_ON(release == NULL);
- if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) {
- mutex_lock(lock);
- if (unlikely(!atomic_dec_and_test(&kref->refcount))) {
- mutex_unlock(lock);
- return 0;
- }
+
+ if (refcount_dec_and_mutex_lock(&kref->refcount, lock)) {
+ release(kref);
+ return 1;
+ }
+ return 0;
+}
+
+static inline int kref_put_lock(struct kref *kref,
+ void (*release)(struct kref *kref),
+ spinlock_t *lock)
+{
+ WARN_ON(release == NULL);
+
+ if (refcount_dec_and_lock(&kref->refcount, lock)) {
release(kref);
return 1;
}
*/
static inline int __must_check kref_get_unless_zero(struct kref *kref)
{
- return atomic_add_unless(&kref->refcount, 1, 0);
+ return refcount_inc_not_zero(&kref->refcount);
}
#endif /* _KREF_H_ */