From ef12f10994281e2e44526fa0abf23fdd7d5bd87f Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sat, 7 Nov 2009 23:04:15 +0100
Subject: locking: Split rwlock from spinlock headers

Move the rwlock defines and inlines into separate header files. This
makes the selection for -rt easier.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
---
 include/linux/rwlock.h | 125 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 include/linux/rwlock.h

(limited to 'include/linux/rwlock.h')

diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
new file mode 100644
index 000000000000..73785b0bd6b9
--- /dev/null
+++ b/include/linux/rwlock.h
@@ -0,0 +1,125 @@
+#ifndef __LINUX_RWLOCK_H
+#define __LINUX_RWLOCK_H
+
+#ifndef __LINUX_SPINLOCK_H
+# error "please don't include this file directly"
+#endif
+
+/*
+ * rwlock related methods
+ *
+ * split out from spinlock.h
+ *
+ * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
+ * Released under the General Public License (GPL).
+ */
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+  extern void __rwlock_init(rwlock_t *lock, const char *name,
+			    struct lock_class_key *key);
+# define rwlock_init(lock)					\
+do {								\
+	static struct lock_class_key __key;			\
+								\
+	__rwlock_init((lock), #lock, &__key);			\
+} while (0)
+#else
+# define rwlock_init(lock)					\
+	do { *(lock) = __RW_LOCK_UNLOCKED(lock); } while (0)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+ extern void _raw_read_lock(rwlock_t *lock);
+#define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
+ extern int _raw_read_trylock(rwlock_t *lock);
+ extern void _raw_read_unlock(rwlock_t *lock);
+ extern void _raw_write_lock(rwlock_t *lock);
+#define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
+ extern int _raw_write_trylock(rwlock_t *lock);
+ extern void _raw_write_unlock(rwlock_t *lock);
+#else
+# define _raw_read_lock(rwlock)		__raw_read_lock(&(rwlock)->raw_lock)
+# define _raw_read_lock_flags(lock, flags) \
+		__raw_read_lock_flags(&(lock)->raw_lock, *(flags))
+# define _raw_read_trylock(rwlock)	__raw_read_trylock(&(rwlock)->raw_lock)
+# define _raw_read_unlock(rwlock)	__raw_read_unlock(&(rwlock)->raw_lock)
+# define _raw_write_lock(rwlock)	__raw_write_lock(&(rwlock)->raw_lock)
+# define _raw_write_lock_flags(lock, flags) \
+		__raw_write_lock_flags(&(lock)->raw_lock, *(flags))
+# define _raw_write_trylock(rwlock)	__raw_write_trylock(&(rwlock)->raw_lock)
+# define _raw_write_unlock(rwlock)	__raw_write_unlock(&(rwlock)->raw_lock)
+#endif
+
+#define read_can_lock(rwlock)		__raw_read_can_lock(&(rwlock)->raw_lock)
+#define write_can_lock(rwlock)		__raw_write_can_lock(&(rwlock)->raw_lock)
+
+/*
+ * Define the various rw_lock methods.  Note we define these
+ * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
+ * methods are defined as nops in the case they are not required.
+ */
+#define read_trylock(lock)		__cond_lock(lock, _read_trylock(lock))
+#define write_trylock(lock)		__cond_lock(lock, _write_trylock(lock))
+
+#define write_lock(lock)		_write_lock(lock)
+#define read_lock(lock)			_read_lock(lock)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = _read_lock_irqsave(lock);	\
+	} while (0)
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = _write_lock_irqsave(lock);	\
+	} while (0)
+
+#else
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_read_lock_irqsave(lock, flags);	\
+	} while (0)
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_write_lock_irqsave(lock, flags);	\
+	} while (0)
+
+#endif
+
+#define read_lock_irq(lock)		_read_lock_irq(lock)
+#define read_lock_bh(lock)		_read_lock_bh(lock)
+#define write_lock_irq(lock)		_write_lock_irq(lock)
+#define write_lock_bh(lock)		_write_lock_bh(lock)
+#define read_unlock(lock)		_read_unlock(lock)
+#define write_unlock(lock)		_write_unlock(lock)
+#define read_unlock_irq(lock)		_read_unlock_irq(lock)
+#define write_unlock_irq(lock)		_write_unlock_irq(lock)
+
+#define read_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_read_unlock_irqrestore(lock, flags);	\
+	} while (0)
+#define read_unlock_bh(lock)		_read_unlock_bh(lock)
+
+#define write_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_write_unlock_irqrestore(lock, flags);	\
+	} while (0)
+#define write_unlock_bh(lock)		_write_unlock_bh(lock)
+
+#define write_trylock_irqsave(lock, flags) \
+({ \
+	local_irq_save(flags); \
+	write_trylock(lock) ? \
+	1 : ({ local_irq_restore(flags); 0; }); \
+})
+
+#endif /* __LINUX_RWLOCK_H */
-- 
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