Function pmap_copy

freebsd/arm/arm/pmap-v6.c:6037–6160

* Copy the range specified by src_addr/len * from the source map to the range dst_addr/len * in the destination map. * * This routine is only advisory and need not do anything. */

 *	This routine is only advisory and need not do anything.
 */
void
pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len,
    vm_offset_t src_addr)
{
	struct spglist free;
	vm_offset_t addr;
	vm_offset_t end_addr = src_addr + len;
	vm_offset_t nextva;

	if (dst_addr != src_addr)
		return;

	if (!pmap_is_current(src_pmap))
		return;

	rw_wlock(&pvh_global_lock);
	if (dst_pmap < src_pmap) {
		PMAP_LOCK(dst_pmap);
		PMAP_LOCK(src_pmap);
	} else {
		PMAP_LOCK(src_pmap);
		PMAP_LOCK(dst_pmap);
	}
	sched_pin();
	for (addr = src_addr; addr < end_addr; addr = nextva) {
		pt2_entry_t *src_pte2p, *dst_pte2p;
		vm_page_t dst_mpt2pg, src_mpt2pg;
		pt1_entry_t src_pte1;
		u_int pte1_idx;

		KASSERT(addr < VM_MAXUSER_ADDRESS,
		    ("%s: invalid to pmap_copy page tables", __func__));

		nextva = pte1_trunc(addr + PTE1_SIZE);
		if (nextva < addr)
			nextva = end_addr;

		pte1_idx = pte1_index(addr);
		src_pte1 = src_pmap->pm_pt1[pte1_idx];
		if (pte1_is_section(src_pte1)) {
			if ((addr & PTE1_OFFSET) != 0 ||
			    (addr + PTE1_SIZE) > end_addr)
				continue;
			if (dst_pmap->pm_pt1[pte1_idx] == 0 &&
			    (!pte1_is_managed(src_pte1) ||
			    pmap_pv_insert_pte1(dst_pmap, addr, src_pte1,
			    PMAP_ENTER_NORECLAIM))) {
				dst_pmap->pm_pt1[pte1_idx] = src_pte1 &
				    ~PTE1_W;
				dst_pmap->pm_stats.resident_count +=
				    PTE1_SIZE / PAGE_SIZE;
				pmap_pte1_mappings++;
			}
			continue;
		} else if (!pte1_is_link(src_pte1))
			continue;

		src_mpt2pg = PHYS_TO_VM_PAGE(pte1_link_pa(src_pte1));