Function pmap_release

freebsd/amd64/amd64/pmap.c:4644–4686

* Release any resources held by the given physical map. * Called when a pmap initialized by pmap_pinit is being released. * Should only be called if the map contains no valid mappings. */

 * Should only be called if the map contains no valid mappings.
 */
void
pmap_release(pmap_t pmap)
{
	vm_page_t m;
	int i;

	KASSERT(pmap->pm_stats.resident_count == 0,
	    ("pmap_release: pmap %p resident count %ld != 0",
	    pmap, pmap->pm_stats.resident_count));
	KASSERT(vm_radix_is_empty(&pmap->pm_root),
	    ("pmap_release: pmap %p has reserved page table page(s)",
	    pmap));
	KASSERT(CPU_EMPTY(&pmap->pm_active),
	    ("releasing active pmap %p", pmap));

	m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pmap->pm_pmltop));

	if (pmap_is_la57(pmap)) {
		pmap->pm_pmltop[pmap_pml5e_index(UPT_MAX_ADDRESS)] = 0;
		pmap->pm_pmltop[PML5PML5I] = 0;
	} else {
		for (i = 0; i < NKPML4E; i++)	/* KVA */
			pmap->pm_pmltop[KPML4BASE + i] = 0;
		for (i = 0; i < ndmpdpphys; i++)/* Direct Map */
			pmap->pm_pmltop[DMPML4I + i] = 0;
		pmap->pm_pmltop[PML4PML4I] = 0;	/* Recursive Mapping */
		for (i = 0; i < lm_ents; i++)	/* Large Map */
			pmap->pm_pmltop[LMSPML4I + i] = 0;
	}

	vm_page_unwire_noq(m);
	vm_page_free_zero(m);

	if (pmap->pm_pmltopu != NULL) {
		m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t)pmap->
		    pm_pmltopu));
		vm_page_unwire_noq(m);
		vm_page_free(m);
	}
	if (pmap->pm_type == PT_X86 &&
	    (cpu_stdext_feature2 & CPUID_STDEXT2_PKU) != 0)
		rangeset_fini(&pmap->pm_pkru);
}

static int
kvm_size(SYSCTL_HANDLER_ARGS)