1. 根目录:
2. arch
3. xtensa
4. include
5. asm
6. nommu_context.h

static inline void init_mmu(void)
{
}

static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}

static inline int init_new_context(struct task_struct *tsk,struct mm_struct *mm)
{
	return 0;
}

static inline void destroy_context(struct mm_struct *mm)
{
}

static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
}

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
				struct task_struct *tsk)
{
}

static inline void deactivate_mm(struct task_struct *tsk, struct mm_struct *mm)
{
}