summaryrefslogtreecommitdiff
path: root/include/asm-xtensa/semaphore.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-xtensa/semaphore.h')
-rw-r--r--include/asm-xtensa/semaphore.h129
1 files changed, 129 insertions, 0 deletions
diff --git a/include/asm-xtensa/semaphore.h b/include/asm-xtensa/semaphore.h
new file mode 100644
index 000000000000..c8a7574a9a57
--- /dev/null
+++ b/include/asm-xtensa/semaphore.h
@@ -0,0 +1,129 @@
+/*
+ * linux/include/asm-xtensa/semaphore.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_SEMAPHORE_H
+#define _XTENSA_SEMAPHORE_H
+
+#include <asm/atomic.h>
+#include <asm/system.h>
+#include <linux/wait.h>
+#include <linux/rwsem.h>
+
+struct semaphore {
+ atomic_t count;
+ int sleepers;
+ wait_queue_head_t wait;
+#if WAITQUEUE_DEBUG
+ long __magic;
+#endif
+};
+
+#if WAITQUEUE_DEBUG
+# define __SEM_DEBUG_INIT(name) \
+ , (int)&(name).__magic
+#else
+# define __SEM_DEBUG_INIT(name)
+#endif
+
+#define __SEMAPHORE_INITIALIZER(name,count) \
+ { ATOMIC_INIT(count), \
+ 0, \
+ __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
+ __SEM_DEBUG_INIT(name) }
+
+#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)
+
+extern inline void sema_init (struct semaphore *sem, int val)
+{
+/*
+ * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
+ *
+ * i'd rather use the more flexible initialization above, but sadly
+ * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
+ */
+ atomic_set(&sem->count, val);
+ init_waitqueue_head(&sem->wait);
+#if WAITQUEUE_DEBUG
+ sem->__magic = (int)&sem->__magic;
+#endif
+}
+
+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);
+}
+
+asmlinkage void __down(struct semaphore * sem);
+asmlinkage int __down_interruptible(struct semaphore * sem);
+asmlinkage int __down_trylock(struct semaphore * sem);
+asmlinkage void __up(struct semaphore * sem);
+
+extern spinlock_t semaphore_wake_lock;
+
+extern __inline__ void down(struct semaphore * sem)
+{
+#if WAITQUEUE_DEBUG
+ CHECK_MAGIC(sem->__magic);
+#endif
+
+ if (atomic_sub_return(1, &sem->count) < 0)
+ __down(sem);
+}
+
+extern __inline__ int down_interruptible(struct semaphore * sem)
+{
+ int ret = 0;
+#if WAITQUEUE_DEBUG
+ CHECK_MAGIC(sem->__magic);
+#endif
+
+ if (atomic_sub_return(1, &sem->count) < 0)
+ ret = __down_interruptible(sem);
+ return ret;
+}
+
+extern __inline__ int down_trylock(struct semaphore * sem)
+{
+ int ret = 0;
+#if WAITQUEUE_DEBUG
+ CHECK_MAGIC(sem->__magic);
+#endif
+
+ if (atomic_sub_return(1, &sem->count) < 0)
+ ret = __down_trylock(sem);
+ return ret;
+}
+
+/*
+ * Note! This is subtle. We jump to wake people up only if
+ * the semaphore was negative (== somebody was waiting on it).
+ */
+extern __inline__ void up(struct semaphore * sem)
+{
+#if WAITQUEUE_DEBUG
+ CHECK_MAGIC(sem->__magic);
+#endif
+ if (atomic_add_return(1, &sem->count) <= 0)
+ __up(sem);
+}
+
+#endif /* _XTENSA_SEMAPHORE_H */