Merge branch 'dde' into upstream-merged

1 files changed, 78 insertions, 0 deletions

diff --git a/libdde_linux26/contrib/include/linux/rwsem-spinlock.h b/libdde_linux26/contrib/include/linux/rwsem-spinlock.h
new file mode 100644
index 00000000..6c3c0f6c
--- /dev/null
+++ b/libdde_linux26/contrib/include/linux/rwsem-spinlock.h
@@ -0,0 +1,78 @@
+/* rwsem-spinlock.h: fallback C implementation
+ *
+ * Copyright (c) 2001   David Howells (dhowells@redhat.com).
+ * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de>
+ * - Derived also from comments by Linus
+ */
+
+#ifndef _LINUX_RWSEM_SPINLOCK_H
+#define _LINUX_RWSEM_SPINLOCK_H
+
+#ifndef _LINUX_RWSEM_H
+#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
+#endif
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+
+struct rwsem_waiter;
+
+/*
+ * the rw-semaphore definition
+ * - if activity is 0 then there are no active readers or writers
+ * - if activity is +ve then that is the number of active readers
+ * - if activity is -1 then there is one active writer
+ * - if wait_list is not empty, then there are processes waiting for the semaphore
+ */
+struct rw_semaphore {
+	__s32			activity;
+	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) \
+{ 0, __SPIN_LOCK_UNLOCKED(name.wait_lock), 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 void __down_write_nested(struct rw_semaphore *sem, int subclass);
+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 int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->activity != 0);
+}
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_RWSEM_SPINLOCK_H */