extern int ia64_reg_MCA_extension(int (*fn)(void *, struct ia64_sal_os_state *));
extern void ia64_unreg_MCA_extension(void);
extern u64 ia64_get_rnat(u64 *);
extern int ia64_reg_MCA_extension(int (*fn)(void *, struct ia64_sal_os_state *));
extern void ia64_unreg_MCA_extension(void);
extern u64 ia64_get_rnat(u64 *);