1. 根目录:
2. arch
3. ia64
4. include
5. asm
6. mmu.h

#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