This is xnu-4903.221.2. See this file in:
/*
 * Copyright (c) 2016 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <sys/sysctl.h>

extern kern_return_t test_pmap_enter_disconnect(unsigned int);
extern kern_return_t test_pmap_iommu_disconnect(void);

static int
sysctl_test_pmap_enter_disconnect(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
{
	unsigned int num_loops;
	int error, changed;
	error = sysctl_io_number(req, 0, sizeof(num_loops), &num_loops, &changed);
	if (error || !changed)
		return error;
	return test_pmap_enter_disconnect(num_loops);
}

SYSCTL_PROC(_kern, OID_AUTO, pmap_enter_disconnect_test,
        CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
        0, 0, sysctl_test_pmap_enter_disconnect, "I", "");

static int
sysctl_test_pmap_iommu_disconnect(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
{
	unsigned int run = 0;
	int error, changed;
	error = sysctl_io_number(req, 0, sizeof(run), &run, &changed);
	if (error || !changed)
		return error;
	return test_pmap_iommu_disconnect();
}

SYSCTL_PROC(_kern, OID_AUTO, pmap_iommu_disconnect_test,
        CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
        0, 0, sysctl_test_pmap_iommu_disconnect, "I", "");