Function pmap_remove

freebsd/arm64/arm64/pmap.c:3029–3126

* Remove the given range of addresses from the specified map. * * It is assumed that the start and end are properly * rounded to the page size. */

 *	rounded to the page size.
 */
void
pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
{
	struct rwlock *lock;
	vm_offset_t va_next;
	pd_entry_t *l0, *l1, *l2;
	pt_entry_t l3_paddr;
	struct spglist free;

	/*
	 * Perform an unsynchronized read.  This is, however, safe.
	 */
	if (pmap->pm_stats.resident_count == 0)
		return;

	SLIST_INIT(&free);

	PMAP_LOCK(pmap);

	lock = NULL;
	for (; sva < eva; sva = va_next) {
		if (pmap->pm_stats.resident_count == 0)
			break;

		l0 = pmap_l0(pmap, sva);
		if (pmap_load(l0) == 0) {
			va_next = (sva + L0_SIZE) & ~L0_OFFSET;
			if (va_next < sva)
				va_next = eva;
			continue;
		}

		va_next = (sva + L1_SIZE) & ~L1_OFFSET;
		if (va_next < sva)
			va_next = eva;
		l1 = pmap_l0_to_l1(l0, sva);
		if (pmap_load(l1) == 0)
			continue;
		if ((pmap_load(l1) & ATTR_DESCR_MASK) == L1_BLOCK) {
			KASSERT(va_next <= eva,
			    ("partial update of non-transparent 1G page "
			    "l1 %#lx sva %#lx eva %#lx va_next %#lx",
			    pmap_load(l1), sva, eva, va_next));
			MPASS(pmap != kernel_pmap);
			MPASS((pmap_load(l1) & ATTR_SW_MANAGED) == 0);
			pmap_clear(l1);
			pmap_invalidate_page(pmap, sva);
			pmap_resident_count_dec(pmap, L1_SIZE / PAGE_SIZE);
			pmap_unuse_pt(pmap, sva, pmap_load(l0), &free);
			continue;
		}

		/*
		 * Calculate index for next page table.
		 */
		va_next = (sva + L2_SIZE) & ~L2_OFFSET;
		if (va_next < sva)
			va_next = eva;