1 files changed, 24 insertions, 0 deletions

diff --git a/include/asm-generic/mutex-null.h b/include/asm-generic/mutex-null.h
new file mode 100644
index 000000000000..5cf8b7ce0c45
--- /dev/null
+++ b/include/asm-generic/mutex-null.h
@@ -0,0 +1,24 @@
+/*
+ * asm-generic/mutex-null.h
+ *
+ * Generic implementation of the mutex fastpath, based on NOP :-)
+ *
+ * This is used by the mutex-debugging infrastructure, but it can also
+ * be used by architectures that (for whatever reason) want to use the
+ * spinlock based slowpath.
+ */
+#ifndef _ASM_GENERIC_MUTEX_NULL_H
+#define _ASM_GENERIC_MUTEX_NULL_H
+
+/* extra parameter only needed for mutex debugging: */
+#ifndef __IP__
+# define __IP__
+#endif
+
+#define __mutex_fastpath_lock(count, fail_fn)         fail_fn(count __RET_IP__)
+#define __mutex_fastpath_lock_retval(count, fail_fn)  fail_fn(count __RET_IP__)
+#define __mutex_fastpath_unlock(count, fail_fn)       fail_fn(count __RET_IP__)
+#define __mutex_fastpath_trylock(count, fail_fn)      fail_fn(count)
+#define __mutex_slowpath_needs_to_unlock()            1
+
+#endif