1 files changed, 131 insertions, 0 deletions
diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
new file mode 100644
index 000000000..3dcd617e6
--- /dev/null
+++ b/include/linux/rwlock.h
@@ -0,0 +1,131 @@
+#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 do_raw_read_lock(rwlock_t *lock) __acquires(lock);
+#define do_raw_read_lock_flags(lock, flags) do_raw_read_lock(lock)
+ extern int do_raw_read_trylock(rwlock_t *lock);
+ extern void do_raw_read_unlock(rwlock_t *lock) __releases(lock);
+ extern void do_raw_write_lock(rwlock_t *lock) __acquires(lock);
+#define do_raw_write_lock_flags(lock, flags) do_raw_write_lock(lock)
+ extern int do_raw_write_trylock(rwlock_t *lock);
+ extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
+#else
+
+#ifndef arch_read_lock_flags
+# define arch_read_lock_flags(lock, flags)	arch_read_lock(lock)
+#endif
+
+#ifndef arch_write_lock_flags
+# define arch_write_lock_flags(lock, flags)	arch_write_lock(lock)
+#endif
+
+# define do_raw_read_lock(rwlock)	do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
+# define do_raw_read_lock_flags(lock, flags) \
+		do {__acquire(lock); arch_read_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
+# define do_raw_read_trylock(rwlock)	arch_read_trylock(&(rwlock)->raw_lock)
+# define do_raw_read_unlock(rwlock)	do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
+# define do_raw_write_lock(rwlock)	do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
+# define do_raw_write_lock_flags(lock, flags) \
+		do {__acquire(lock); arch_write_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
+# define do_raw_write_trylock(rwlock)	arch_write_trylock(&(rwlock)->raw_lock)
+# define do_raw_write_unlock(rwlock)	do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
+#endif
+
+/*
+ * 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, _raw_read_trylock(lock))
+#define write_trylock(lock)	__cond_lock(lock, _raw_write_trylock(lock))
+
+#define write_lock(lock)	_raw_write_lock(lock)
+#define read_lock(lock)		_raw_read_lock(lock)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = _raw_read_lock_irqsave(lock);	\
+	} while (0)
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = _raw_write_lock_irqsave(lock);	\
+	} while (0)
+
+#else
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_raw_read_lock_irqsave(lock, flags);	\
+	} while (0)
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_raw_write_lock_irqsave(lock, flags);	\
+	} while (0)
+
+#endif
+
+#define read_lock_irq(lock)		_raw_read_lock_irq(lock)
+#define read_lock_bh(lock)		_raw_read_lock_bh(lock)
+#define write_lock_irq(lock)		_raw_write_lock_irq(lock)
+#define write_lock_bh(lock)		_raw_write_lock_bh(lock)
+#define read_unlock(lock)		_raw_read_unlock(lock)
+#define write_unlock(lock)		_raw_write_unlock(lock)
+#define read_unlock_irq(lock)		_raw_read_unlock_irq(lock)
+#define write_unlock_irq(lock)		_raw_write_unlock_irq(lock)
+
+#define read_unlock_irqrestore(lock, flags)			\
+	do {							\
+		typecheck(unsigned long, flags);		\
+		_raw_read_unlock_irqrestore(lock, flags);	\
+	} while (0)
+#define read_unlock_bh(lock)		_raw_read_unlock_bh(lock)
+
+#define write_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		_raw_write_unlock_irqrestore(lock, flags);	\
+	} while (0)
+#define write_unlock_bh(lock)		_raw_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 */