1 files changed, 84 insertions, 0 deletions

diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h
new file mode 100644
index 000000000000..1dc129ac2feb
--- /dev/null
+++ b/arch/sparc/include/asm/rwsem.h
@@ -0,0 +1,84 @@
+/*
+ * rwsem.h: R/W semaphores implemented using CAS
+ *
+ * Written by David S. Miller (davem@redhat.com), 2001.
+ * Derived from asm-i386/rwsem.h
+ */
+#ifndef _SPARC64_RWSEM_H
+#define _SPARC64_RWSEM_H
+
+#ifndef _LINUX_RWSEM_H
+#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
+#endif
+
+#ifdef __KERNEL__
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <asm/rwsem-const.h>
+
+struct rwsem_waiter;
+
+struct rw_semaphore {
+        signed int count;
+        spinlock_t              wait_lock;
+        struct list_head        wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        struct lockdep_map      dep_map;
+#endif
+};
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
+#else
+# define __RWSEM_DEP_MAP_INIT(lockname)
+#endif
+
+#define __RWSEM_INITIALIZER(name) \
+{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
+  __RWSEM_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(name) \
+        struct rw_semaphore name = __RWSEM_INITIALIZER(name)
+
+extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
+                         struct lock_class_key *key);
+
+#define init_rwsem(sem)                                         \
+do {                                                            \
+        static struct lock_class_key __key;                     \
+                                                                \
+        __init_rwsem((sem), #sem, &__key);                      \
+} while (0)
+
+extern void __down_read(struct rw_semaphore *sem);
+extern int __down_read_trylock(struct rw_semaphore *sem);
+extern void __down_write(struct rw_semaphore *sem);
+extern int __down_write_trylock(struct rw_semaphore *sem);
+extern void __up_read(struct rw_semaphore *sem);
+extern void __up_write(struct rw_semaphore *sem);
+extern void __downgrade_write(struct rw_semaphore *sem);
+
+static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+{
+        __down_write(sem);
+}
+
+static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
+{
+        return atomic_add_return(delta, (atomic_t *)(&sem->count));
+}
+
+static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
+{
+        atomic_add(delta, (atomic_t *)(&sem->count));
+}
+
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+        return (sem->count != 0);
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _SPARC64_RWSEM_H */