xref: /freebsd/sys/x86/acpica/OsdEnvironment.c (revision c6989859ae9388eeb46a24fe88f9b8d07101c710)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2000,2001 Michael Smith
5  * Copyright (c) 2000 BSDi
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
37 
38 #include <contrib/dev/acpica/include/acpi.h>
39 #include <contrib/dev/acpica/include/aclocal.h>
40 #include <contrib/dev/acpica/include/actables.h>
41 
42 static u_long acpi_root_phys;
43 
44 SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &acpi_root_phys, 0,
45     "The physical address of the RSDP");
46 
47 ACPI_STATUS
48 AcpiOsInitialize(void)
49 {
50 
51 	return (AE_OK);
52 }
53 
54 ACPI_STATUS
55 AcpiOsTerminate(void)
56 {
57 
58 	return (AE_OK);
59 }
60 
61 static u_long
62 acpi_get_root_from_loader(void)
63 {
64 	long acpi_root;
65 
66 	if (TUNABLE_ULONG_FETCH("acpi.rsdp", &acpi_root))
67 		return (acpi_root);
68 
69 	/*
70 	 * The hints mechanism is unreliable (it fails if anybody ever
71 	 * compiled in hints to the kernel). It has been replaced
72 	 * by the tunable method, but is used here as a fallback to
73 	 * retain maximum compatibility between old loaders and new
74 	 * kernels. It can be removed after 11.0R.
75 	 */
76 	if (resource_long_value("acpi", 0, "rsdp", &acpi_root) == 0)
77 		return (acpi_root);
78 
79 	return (0);
80 }
81 
82 static u_long
83 acpi_get_root_from_memory(void)
84 {
85 	ACPI_PHYSICAL_ADDRESS acpi_root;
86 
87 	if (ACPI_SUCCESS(AcpiFindRootPointer(&acpi_root)))
88 		return (acpi_root);
89 
90 	return (0);
91 }
92 
93 ACPI_PHYSICAL_ADDRESS
94 AcpiOsGetRootPointer(void)
95 {
96 
97 	if (acpi_root_phys == 0) {
98 		acpi_root_phys = acpi_get_root_from_loader();
99 		if (acpi_root_phys == 0)
100 			acpi_root_phys = acpi_get_root_from_memory();
101 	}
102 
103 	return (acpi_root_phys);
104 }
105