#ifndef __MMU_H#define __MMU_H/* * Type for a context number. We declare it volatile to ensure proper * ordering when it's accessed outside of spinlock'd critical sections * (e.g., as done in activate_mm() and init_new_context()). */typedefvolatileunsignedlongmm_context_t;typedefunsignedlongnv_mm_context_t;#endif