cf_tlb_miss
int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word);
need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 0);
need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 1);
need_page_fault = cf_tlb_miss(&fp->ptregs, 1, 1, 0);
need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 1, 0);