1 files changed, 169 insertions, 0 deletions

diff --git a/include/asm-mn10300/semaphore.h b/include/asm-mn10300/semaphore.h
new file mode 100644
index 000000000000..5a9e1ad0b253
--- /dev/null
+++ b/include/asm-mn10300/semaphore.h
@@ -0,0 +1,169 @@
+/* MN10300 Semaphores
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_SEMAPHORE_H
+#define _ASM_SEMAPHORE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/linkage.h>
+#include <linux/wait.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+
+#define SEMAPHORE_DEBUG         0
+
+/*
+ * the semaphore definition
+ * - if count is >0 then there are tokens available on the semaphore for down
+ *   to collect
+ * - if count is <=0 then there are no spare tokens, and anyone that wants one
+ *   must wait
+ * - if wait_list is not empty, then there are processes waiting for the
+ *   semaphore
+ */
+struct semaphore {
+        atomic_t                count;          /* it's not really atomic, it's
+                                                 * just that certain modules
+                                                 * expect to be able to access
+                                                 * it directly */
+        spinlock_t              wait_lock;
+        struct list_head        wait_list;
+#if SEMAPHORE_DEBUG
+        unsigned                __magic;
+#endif
+};
+
+#if SEMAPHORE_DEBUG
+# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
+#else
+# define __SEM_DEBUG_INIT(name)
+#endif
+
+
+#define __SEMAPHORE_INITIALIZER(name, init_count)                       \
+{                                                                       \
+        .count          = ATOMIC_INIT(init_count),                      \
+        .wait_lock      = __SPIN_LOCK_UNLOCKED((name).wait_lock),       \
+        .wait_list      = LIST_HEAD_INIT((name).wait_list)              \
+        __SEM_DEBUG_INIT(name)                                          \
+}
+
+#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, unsigned long flags);
+extern int  __down_interruptible(struct semaphore *sem, unsigned long flags);
+extern void __up(struct semaphore *sem);
+
+static inline void down(struct semaphore *sem)
+{
+        unsigned long flags;
+        int count;
+
+#if SEMAPHORE_DEBUG
+        CHECK_MAGIC(sem->__magic);
+#endif
+
+        spin_lock_irqsave(&sem->wait_lock, flags);
+        count = atomic_read(&sem->count);
+        if (likely(count > 0)) {
+                atomic_set(&sem->count, count - 1);
+                spin_unlock_irqrestore(&sem->wait_lock, flags);
+        } else {
+                __down(sem, flags);
+        }
+}
+
+static inline int down_interruptible(struct semaphore *sem)
+{
+        unsigned long flags;
+        int count, ret = 0;
+
+#if SEMAPHORE_DEBUG
+        CHECK_MAGIC(sem->__magic);
+#endif
+
+        spin_lock_irqsave(&sem->wait_lock, flags);
+        count = atomic_read(&sem->count);
+        if (likely(count > 0)) {
+                atomic_set(&sem->count, count - 1);
+                spin_unlock_irqrestore(&sem->wait_lock, flags);
+        } else {
+                ret = __down_interruptible(sem, flags);
+        }
+        return ret;
+}
+
+/*
+ * non-blockingly attempt to down() a semaphore.
+ * - returns zero if we acquired it
+ */
+static inline int down_trylock(struct semaphore *sem)
+{
+        unsigned long flags;
+        int count, success = 0;
+
+#if SEMAPHORE_DEBUG
+        CHECK_MAGIC(sem->__magic);
+#endif
+
+        spin_lock_irqsave(&sem->wait_lock, flags);
+        count = atomic_read(&sem->count);
+        if (likely(count > 0)) {
+                atomic_set(&sem->count, count - 1);
+                success = 1;
+        }
+        spin_unlock_irqrestore(&sem->wait_lock, flags);
+        return !success;
+}
+
+static inline void up(struct semaphore *sem)
+{
+        unsigned long flags;
+
+#if SEMAPHORE_DEBUG
+        CHECK_MAGIC(sem->__magic);
+#endif
+
+        spin_lock_irqsave(&sem->wait_lock, flags);
+        if (!list_empty(&sem->wait_list))
+                __up(sem);
+        else
+                atomic_set(&sem->count, atomic_read(&sem->count) + 1);
+        spin_unlock_irqrestore(&sem->wait_lock, flags);
+}
+
+static inline int sem_getcount(struct semaphore *sem)
+{
+        return atomic_read(&sem->count);
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif