-#ifndef swap
-#define swap(a, b) ({typeof(a) _a = a; (a) = (b); (b) = _a;})
-#endif
-
-/**
- * container_of - cast a member of a structure out to the containing structure
- * @ptr: the pointer to the member.
- * @type: the type of the container struct this is embedded in.
- * @member: the name of the member within the struct.
- *
- */
-#ifndef container_of
-#define container_of(ptr, type, member) ({ \
- const typeof( ((type *)0)->member ) *__mptr = (ptr); \
- (type *)( (char *)__mptr - offsetof(type,member) );})
-#endif
+/* Cast a pointer to a struct member to a pointer to the containing struct. */
+#define container_of(ptr, type, member) \
+ ((type *)((char *)(ptr) - offsetof(type, member)))