Index: uspace/lib/libc/include/atomic.h
===================================================================
--- uspace/lib/libc/include/atomic.h	(revision d9ece1cb4b86e7a2d4c513bf4f6e95007768812f)
+++ uspace/lib/libc/include/atomic.h	(revision d359e227814167b2f1a4abcd50ab5cfb08a40982)
@@ -36,4 +36,6 @@
 #define LIBC_ATOMIC_H_
 
+#include <bool.h>
+
 typedef struct atomic {
 	volatile long count;
@@ -52,4 +54,9 @@
 }
 
+static inline bool cas(atomic_t *val, long ov, long nv)
+{
+	return __sync_bool_compare_and_swap(&val->count, ov, nv);
+}
+
 #endif