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-rw-r--r--include/linux/refcount.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/include/linux/refcount.h b/include/linux/refcount.h
new file mode 100644
index 000000000000..0023fee4bbbc
--- /dev/null
+++ b/include/linux/refcount.h
@@ -0,0 +1,42 @@
+#ifndef _LINUX_REFCOUNT_H
+#define _LINUX_REFCOUNT_H
+
+#include <linux/atomic.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+
+typedef struct refcount_struct {
+ atomic_t refs;
+} refcount_t;
+
+#define REFCOUNT_INIT(n) { .refs = ATOMIC_INIT(n), }
+
+static inline void refcount_set(refcount_t *r, unsigned int n)
+{
+ atomic_set(&r->refs, n);
+}
+
+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 */