OsdEnvironment.c revision 298951 
1/*-
2 * Copyright (c) 2000,2001 Michael Smith
3 * Copyright (c) 2000 BSDi
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/sys/x86/acpica/OsdEnvironment.c 298951 2016-05-03 01:17:40Z jhb $");
30
31#include <sys/types.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/sysctl.h>
35
36#include <contrib/dev/acpica/include/acpi.h>
37#include <contrib/dev/acpica/include/actables.h>
38
39static u_long acpi_root_phys;
40
41SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &acpi_root_phys, 0,
42    "The physical address of the RSDP");
43
44ACPI_STATUS
45AcpiOsInitialize(void)
46{
47
48	return (AE_OK);
49}
50
51ACPI_STATUS
52AcpiOsTerminate(void)
53{
54
55	return (AE_OK);
56}
57
58static u_long
59acpi_get_root_from_loader(void)
60{
61	long acpi_root;
62
63	if (TUNABLE_ULONG_FETCH("acpi.rsdp", &acpi_root))
64		return (acpi_root);
65
66	/*
67	 * The hints mechanism is unreliable (it fails if anybody ever
68	 * compiled in hints to the kernel). It has been replaced
69	 * by the tunable method, but is used here as a fallback to
70	 * retain maximum compatibility between old loaders and new
71	 * kernels. It can be removed after 11.0R.
72	 */
73	if (resource_long_value("acpi", 0, "rsdp", &acpi_root) == 0)
74		return (acpi_root);
75
76	return (0);
77}
78
79static u_long
80acpi_get_root_from_memory(void)
81{
82	ACPI_PHYSICAL_ADDRESS acpi_root;
83
84	if (ACPI_SUCCESS(AcpiFindRootPointer(&acpi_root)))
85		return (acpi_root);
86
87	return (0);
88}
89
90ACPI_PHYSICAL_ADDRESS
91AcpiOsGetRootPointer(void)
92{
93
94	if (acpi_root_phys == 0) {
95		acpi_root_phys = acpi_get_root_from_loader();
96		if (acpi_root_phys == 0)
97			acpi_root_phys = acpi_get_root_from_memory();
98	}
99
100	return (acpi_root_phys);
101}
102