acpi_table.c revision 1.1 
1/* $NetBSD: acpi_table.c,v 1.1 2018/10/12 22:15:04 jmcneill Exp $ */
2
3/*-
4 * Copyright (c) 2018 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jared McNeill <jmcneill@invisible.ca>.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * ACPI table functions for use in early boot before ACPICA can be safely
34 * initialized.
35 */
36
37#include <sys/cdefs.h>
38__KERNEL_RCSID(0, "$NetBSD: acpi_table.c,v 1.1 2018/10/12 22:15:04 jmcneill Exp $");
39
40#include <sys/param.h>
41#include <sys/bus.h>
42#include <sys/cpu.h>
43#include <sys/device.h>
44
45#include <uvm/uvm_extern.h>
46
47#include <dev/acpi/acpireg.h>
48#include <dev/acpi/acpivar.h>
49
50#include <machine/acpi_machdep.h>
51
52#include <arch/arm/acpi/acpi_table.h>
53
54ACPI_STATUS
55acpi_table_map(ACPI_PHYSICAL_ADDRESS pa, void **hdrp)
56{
57	ACPI_TABLE_HEADER *header;
58	ACPI_STATUS rv;
59	UINT32 length;
60
61	rv = acpi_md_OsMapMemory(pa, sizeof(*header), (void **)&header);
62	if (ACPI_FAILURE(rv))
63		return rv;
64	length = header->Length;
65	acpi_md_OsUnmapMemory(header, sizeof(*header));
66
67	return acpi_md_OsMapMemory(pa, length, hdrp);
68}
69
70void
71acpi_table_unmap(ACPI_TABLE_HEADER *hdrp)
72{
73	acpi_md_OsUnmapMemory(hdrp, hdrp->Length);
74}
75
76ACPI_STATUS
77acpi_table_find(const char *sig, void **hdrp)
78{
79	ACPI_TABLE_RSDP *rsdp;
80	ACPI_TABLE_XSDT *xsdt;
81	ACPI_TABLE_HEADER *header;
82	ACPI_PHYSICAL_ADDRESS pa;
83	ACPI_STATUS rv;
84
85	/* RDSP contains a pointer to the XSDT */
86	pa = 0;
87	rv = acpi_md_OsMapMemory(acpi_md_OsGetRootPointer(), sizeof(*rsdp), (void **)&rsdp);
88	if (ACPI_FAILURE(rv))
89		return rv;
90	if (memcmp(rsdp->Signature, ACPI_SIG_RSDP, sizeof(rsdp->Signature)) == 0)
91		pa = rsdp->XsdtPhysicalAddress;
92	acpi_md_OsUnmapMemory(rsdp, sizeof(*rsdp));
93	if (pa == 0)
94		return AE_NOT_FOUND;
95
96	/* XSDT contains pointers to other tables */
97	rv = acpi_table_map(pa, (void **)&xsdt);
98	if (ACPI_FAILURE(rv))
99		return rv;
100	const u_int entries = (xsdt->Header.Length - sizeof(ACPI_TABLE_HEADER)) / ACPI_XSDT_ENTRY_SIZE;
101	for (u_int n = 0; n < entries; n++) {
102		rv = acpi_table_map(xsdt->TableOffsetEntry[n], (void **)&header);
103		if (ACPI_FAILURE(rv))
104			continue;
105		if (memcmp(header->Signature, sig, sizeof(header->Signature)) == 0) {
106			acpi_table_unmap((ACPI_TABLE_HEADER *)xsdt);
107			*hdrp = header;
108			return AE_OK;
109		}
110	}
111
112	/* Not found */
113	acpi_table_unmap((ACPI_TABLE_HEADER *)xsdt);
114	return AE_NOT_FOUND;
115}
116