1 files changed, 102 insertions, 0 deletions

diff --git a/include/asm-ia64/semaphore.h b/include/asm-ia64/semaphore.h
new file mode 100644
index 000000000000..3a2f0f3f78f3
--- /dev/null
+++ b/include/asm-ia64/semaphore.h
@@ -0,0 +1,102 @@
+#ifndef _ASM_IA64_SEMAPHORE_H
+#define _ASM_IA64_SEMAPHORE_H
+
+/*
+ * Copyright (C) 1998-2000 Hewlett-Packard Co
+ * Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/wait.h>
+#include <linux/rwsem.h>
+
+#include <asm/atomic.h>
+
+struct semaphore {
+        atomic_t count;
+        int sleepers;
+        wait_queue_head_t wait;
+};
+
+#define __SEMAPHORE_INITIALIZER(name, n)                                \
+{                                                                       \
+        .count          = ATOMIC_INIT(n),                               \
+        .sleepers       = 0,                                            \
+        .wait           = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait)    \
+}
+
+#define __MUTEX_INITIALIZER(name)       __SEMAPHORE_INITIALIZER(name,1)
+
+#define __DECLARE_SEMAPHORE_GENERIC(name,count)                                 \
+        struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
+
+#define DECLARE_MUTEX(name)             __DECLARE_SEMAPHORE_GENERIC(name, 1)
+#define DECLARE_MUTEX_LOCKED(name)      __DECLARE_SEMAPHORE_GENERIC(name, 0)
+
+static inline void
+sema_init (struct semaphore *sem, int val)
+{
+        *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
+}
+
+static inline void
+init_MUTEX (struct semaphore *sem)
+{
+        sema_init(sem, 1);
+}
+
+static inline void
+init_MUTEX_LOCKED (struct semaphore *sem)
+{
+        sema_init(sem, 0);
+}
+
+extern void __down (struct semaphore * sem);
+extern int  __down_interruptible (struct semaphore * sem);
+extern int  __down_trylock (struct semaphore * sem);
+extern void __up (struct semaphore * sem);
+
+/*
+ * Atomically decrement the semaphore's count.  If it goes negative,
+ * block the calling thread in the TASK_UNINTERRUPTIBLE state.
+ */
+static inline void
+down (struct semaphore *sem)
+{
+        might_sleep();
+        if (atomic_dec_return(&sem->count) < 0)
+                __down(sem);
+}
+
+/*
+ * Atomically decrement the semaphore's count.  If it goes negative,
+ * block the calling thread in the TASK_INTERRUPTIBLE state.
+ */
+static inline int
+down_interruptible (struct semaphore * sem)
+{
+        int ret = 0;
+
+        might_sleep();
+        if (atomic_dec_return(&sem->count) < 0)
+                ret = __down_interruptible(sem);
+        return ret;
+}
+
+static inline int
+down_trylock (struct semaphore *sem)
+{
+        int ret = 0;
+
+        if (atomic_dec_return(&sem->count) < 0)
+                ret = __down_trylock(sem);
+        return ret;
+}
+
+static inline void
+up (struct semaphore * sem)
+{
+        if (atomic_inc_return(&sem->count) <= 0)
+                __up(sem);
+}
+
+#endif /* _ASM_IA64_SEMAPHORE_H */