Function vm_map_wire_locked

freebsd/vm/vm_map.c:3463–3695

* vm_map_wire_locked: * * Implements both kernel and user wiring. Returns with the map locked, * the map lock may be dropped. */

 *	the map lock may be dropped.
 */
int
vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
{
	vm_map_entry_t entry, first_entry, next_entry, prev_entry;
	vm_offset_t faddr, saved_end, saved_start;
	u_long incr, npages;
	u_int bidx, last_timestamp;
	int rv;
	bool holes_ok, need_wakeup, user_wire;
	vm_prot_t prot;

	VM_MAP_ASSERT_LOCKED(map);

	if (start == end)
		return (KERN_SUCCESS);
	prot = 0;
	if (flags & VM_MAP_WIRE_WRITE)
		prot |= VM_PROT_WRITE;
	holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
	user_wire = (flags & VM_MAP_WIRE_USER) != 0;
	VM_MAP_RANGE_CHECK(map, start, end);
	if (!vm_map_lookup_entry(map, start, &first_entry)) {
		if (holes_ok)
			first_entry = vm_map_entry_succ(first_entry);
		else
			return (KERN_INVALID_ADDRESS);
	}
	for (entry = first_entry; entry->start < end; entry = next_entry) {
		if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
			/*
			 * We have not yet clipped the entry.
			 */
			next_entry = vm_map_entry_in_transition(map, start,
			    &end, holes_ok, entry);
			if (next_entry == NULL) {
				if (entry == first_entry)
					return (KERN_INVALID_ADDRESS);
				rv = KERN_INVALID_ADDRESS;
				goto done;
			}
			first_entry = (entry == first_entry) ?
			    next_entry : NULL;
			continue;
		}
		rv = vm_map_clip_start(map, entry, start);
		if (rv != KERN_SUCCESS)
			goto done;
		rv = vm_map_clip_end(map, entry, end);
		if (rv != KERN_SUCCESS)
			goto done;

		/*
		 * Mark the entry in case the map lock is released.  (See
		 * above.)
		 */
		KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
		    entry->wiring_thread == NULL,
		    ("owned map entry %p", entry));