1 files changed, 46 insertions, 0 deletions

diff --git a/include/litmus/locking.h b/include/litmus/locking.h
new file mode 100644
index 00000000000..968ba6fa828
--- /dev/null
+++ b/include/litmus/locking.h
@@ -0,0 +1,46 @@
+#ifndef LITMUS_LOCKING_H
+#define LITMUS_LOCKING_H
+
+#include <litmus/fdso.h>
+
+struct litmus_lock_ops;
+
+extern struct fdso_ops generic_lock_ops;
+
+/* Generic base struct for LITMUS^RT userspace semaphores.
+ * This structure should be embedded in protocol-specific semaphores.
+ */
+struct litmus_lock {
+        struct litmus_lock_ops *ops;
+        int type;
+};
+
+struct litmus_lock_ops {
+        /* Current task tries to obtain / drop a reference to a lock.
+         * Optional methods, allowed by default. */
+        int (*open)(struct litmus_lock*, void* __user);
+        int (*close)(struct litmus_lock*);
+    
+        /* Current tries to lock/unlock this lock (mandatory methods). */
+        int (*lock)(struct litmus_lock*);
+        int (*unlock)(struct litmus_lock*);
+
+    int (*dynamic_group_lock)(struct litmus_lock*, resource_mask_t);
+    int (*dynamic_group_unlock)(struct litmus_lock*, resource_mask_t);
+
+        /* The lock is no longer being referenced (mandatory method). */
+        void (*deallocate)(struct litmus_lock*);
+};
+
+static inline bool is_lock(struct od_table_entry* entry)
+{
+        return entry->class == &generic_lock_ops;
+}
+
+static inline struct litmus_lock* get_lock(struct od_table_entry* entry)
+{
+        BUG_ON(!is_lock(entry));
+        return (struct litmus_lock*) entry->obj->obj;
+}
+
+#endif