int cf_tlb_miss()

in mm/mcfmmu.c [86:167]
68 lines of code
18 McCabe index (conditional complexity)

int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word)
{
	unsigned long flags, mmuar, mmutr;
	struct mm_struct *mm;
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	int asid;

	local_irq_save(flags);

	mmuar = (dtlb) ? mmu_read(MMUAR) :
		regs->pc + (extension_word * sizeof(long));

	mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm;
	if (!mm) {
		local_irq_restore(flags);
		return -1;
	}

	pgd = pgd_offset(mm, mmuar);
	if (pgd_none(*pgd))  {
		local_irq_restore(flags);
		return -1;
	}

	p4d = p4d_offset(pgd, mmuar);
	if (p4d_none(*p4d)) {
		local_irq_restore(flags);
		return -1;
	}

	pud = pud_offset(p4d, mmuar);
	if (pud_none(*pud)) {
		local_irq_restore(flags);
		return -1;
	}

	pmd = pmd_offset(pud, mmuar);
	if (pmd_none(*pmd)) {
		local_irq_restore(flags);
		return -1;
	}

	pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar)
				: pte_offset_map(pmd, mmuar);
	if (pte_none(*pte) || !pte_present(*pte)) {
		local_irq_restore(flags);
		return -1;
	}

	if (write) {
		if (!pte_write(*pte)) {
			local_irq_restore(flags);
			return -1;
		}
		set_pte(pte, pte_mkdirty(*pte));
	}

	set_pte(pte, pte_mkyoung(*pte));
	asid = mm->context & 0xff;
	if (!pte_dirty(*pte) && !KMAPAREA(mmuar))
		set_pte(pte, pte_wrprotect(*pte));

	mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V;
	if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE))
		mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT;
	mmu_write(MMUTR, mmutr);

	mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
		((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);

	if (dtlb)
		mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
	else
		mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA);

	local_irq_restore(flags);
	return 0;
}