xref: /freebsd/sys/x86/acpica/OsdEnvironment.c (revision 74d9553e43cfafc29448d0bb836916aa21dea0de)
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("$FreeBSD$");
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/aclocal.h>
38 #include <contrib/dev/acpica/include/actables.h>
39 
40 static u_long acpi_root_phys;
41 
42 SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &acpi_root_phys, 0,
43     "The physical address of the RSDP");
44 
45 ACPI_STATUS
46 AcpiOsInitialize(void)
47 {
48 
49 	return (AE_OK);
50 }
51 
52 ACPI_STATUS
53 AcpiOsTerminate(void)
54 {
55 
56 	return (AE_OK);
57 }
58 
59 static u_long
60 acpi_get_root_from_loader(void)
61 {
62 	long acpi_root;
63 
64 	if (TUNABLE_ULONG_FETCH("acpi.rsdp", &acpi_root))
65 		return (acpi_root);
66 
67 	/*
68 	 * The hints mechanism is unreliable (it fails if anybody ever
69 	 * compiled in hints to the kernel). It has been replaced
70 	 * by the tunable method, but is used here as a fallback to
71 	 * retain maximum compatibility between old loaders and new
72 	 * kernels. It can be removed after 11.0R.
73 	 */
74 	if (resource_long_value("acpi", 0, "rsdp", &acpi_root) == 0)
75 		return (acpi_root);
76 
77 	return (0);
78 }
79 
80 static u_long
81 acpi_get_root_from_memory(void)
82 {
83 	ACPI_PHYSICAL_ADDRESS acpi_root;
84 
85 	if (ACPI_SUCCESS(AcpiFindRootPointer(&acpi_root)))
86 		return (acpi_root);
87 
88 	return (0);
89 }
90 
91 ACPI_PHYSICAL_ADDRESS
92 AcpiOsGetRootPointer(void)
93 {
94 
95 	if (acpi_root_phys == 0) {
96 		acpi_root_phys = acpi_get_root_from_loader();
97 		if (acpi_root_phys == 0)
98 			acpi_root_phys = acpi_get_root_from_memory();
99 	}
100 
101 	return (acpi_root_phys);
102 }
103