#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()).
   */
  typedef volatile unsigned long mm_context_t;
  
  typedef unsigned long nv_mm_context_t;
  
  #endif