xref: /freebsd/sys/x86/acpica/OsdEnvironment.c (revision d37eb51047221dc3322b34db1038ff3aa533883f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/sysctl.h>
34 
35 #include <contrib/dev/acpica/include/acpi.h>
36 #include <contrib/dev/acpica/include/aclocal.h>
37 #include <contrib/dev/acpica/include/actables.h>
38 
39 static u_long acpi_root_phys;
40 
41 SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &acpi_root_phys, 0,
42     "The physical address of the RSDP");
43 
44 ACPI_STATUS
45 AcpiOsInitialize(void)
46 {
47 
48 	return (AE_OK);
49 }
50 
51 ACPI_STATUS
52 AcpiOsTerminate(void)
53 {
54 
55 	return (AE_OK);
56 }
57 
58 static u_long
59 acpi_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 	return (0);
67 }
68 
69 static u_long
70 acpi_get_root_from_memory(void)
71 {
72 	ACPI_PHYSICAL_ADDRESS acpi_root;
73 
74 	if (ACPI_SUCCESS(AcpiFindRootPointer(&acpi_root)))
75 		return (acpi_root);
76 
77 	return (0);
78 }
79 
80 ACPI_PHYSICAL_ADDRESS
81 AcpiOsGetRootPointer(void)
82 {
83 
84 	if (acpi_root_phys == 0) {
85 		acpi_root_phys = acpi_get_root_from_loader();
86 		if (acpi_root_phys == 0)
87 			acpi_root_phys = acpi_get_root_from_memory();
88 	}
89 
90 	return (acpi_root_phys);
91 }
92