void arc_mmu_init()

in mm/tlb.c [638:690]

• 27 lines of code
• 12 McCabe index (conditional complexity)

void arc_mmu_init(void)
{
	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
	char str[256];
	int compat = 0;

	pr_info("%s", arc_mmu_mumbojumbo(0, str, sizeof(str)));

	/*
	 * Can't be done in processor.h due to header include dependencies
	 */
	BUILD_BUG_ON(!IS_ALIGNED((CONFIG_ARC_KVADDR_SIZE << 20), PMD_SIZE));

	/*
	 * stack top size sanity check,
	 * Can't be done in processor.h due to header include dependencies
	 */
	BUILD_BUG_ON(!IS_ALIGNED(STACK_TOP, PMD_SIZE));

	/*
	 * Ensure that MMU features assumed by kernel exist in hardware.
	 *  - For older ARC700 cpus, only v3 supported
	 *  - For HS cpus, v4 was baseline and v5 is backwards compatible
	 *    (will run older software).
	 */
	if (is_isa_arcompact() && mmu->ver == 3)
		compat = 1;
	else if (is_isa_arcv2() && mmu->ver >= 4)
		compat = 1;

	if (!compat)
		panic("MMU ver %d doesn't match kernel built for\n", mmu->ver);

	if (mmu->pg_sz_k != TO_KB(PAGE_SIZE))
		panic("MMU pg size != PAGE_SIZE (%luk)\n", TO_KB(PAGE_SIZE));

	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
	    mmu->s_pg_sz_m != TO_MB(HPAGE_PMD_SIZE))
		panic("MMU Super pg size != Linux HPAGE_PMD_SIZE (%luM)\n",
		      (unsigned long)TO_MB(HPAGE_PMD_SIZE));

	if (IS_ENABLED(CONFIG_ARC_HAS_PAE40) && !mmu->pae)
		panic("Hardware doesn't support PAE40\n");

	/* Enable the MMU with ASID 0 */
	mmu_setup_asid(NULL, 0);

	/* cache the pgd pointer in MMU SCRATCH reg (ARCv2 only) */
	mmu_setup_pgd(NULL, swapper_pg_dir);

	if (pae40_exist_but_not_enab())
		write_aux_reg(ARC_REG_TLBPD1HI, 0);
}