hest.c revision 9dc966641677795f4d6b0a9ba630d6a3a3e24a57 
1/*
2 * APEI Hardware Error Souce Table support
3 *
4 * HEST describes error sources in detail; communicates operational
5 * parameters (i.e. severity levels, masking bits, and threshold
6 * values) to Linux as necessary. It also allows the BIOS to report
7 * non-standard error sources to Linux (for example, chipset-specific
8 * error registers).
9 *
10 * For more information about HEST, please refer to ACPI Specification
11 * version 4.0, section 17.3.2.
12 *
13 * Copyright 2009 Intel Corp.
14 *   Author: Huang Ying <ying.huang@intel.com>
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License version
18 * 2 as published by the Free Software Foundation;
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
28 */
29
30#include <linux/kernel.h>
31#include <linux/module.h>
32#include <linux/init.h>
33#include <linux/acpi.h>
34#include <linux/kdebug.h>
35#include <linux/highmem.h>
36#include <linux/io.h>
37#include <acpi/apei.h>
38
39#include "apei-internal.h"
40
41#define HEST_PFX "HEST: "
42
43int hest_disable;
44EXPORT_SYMBOL_GPL(hest_disable);
45
46/* HEST table parsing */
47
48static struct acpi_table_hest *hest_tab;
49
50static int hest_void_parse(struct acpi_hest_header *hest_hdr, void *data)
51{
52	return 0;
53}
54
55static int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
56	[ACPI_HEST_TYPE_IA32_CHECK] = -1,	/* need further calculation */
57	[ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
58	[ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
59	[ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
60	[ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
61	[ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
62	[ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
63};
64
65static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
66{
67	u16 hest_type = hest_hdr->type;
68	int len;
69
70	if (hest_type >= ACPI_HEST_TYPE_RESERVED)
71		return 0;
72
73	len = hest_esrc_len_tab[hest_type];
74
75	if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
76		struct acpi_hest_ia_corrected *cmc;
77		cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
78		len = sizeof(*cmc) + cmc->num_hardware_banks *
79			sizeof(struct acpi_hest_ia_error_bank);
80	} else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
81		struct acpi_hest_ia_machine_check *mc;
82		mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
83		len = sizeof(*mc) + mc->num_hardware_banks *
84			sizeof(struct acpi_hest_ia_error_bank);
85	}
86	BUG_ON(len == -1);
87
88	return len;
89};
90
91int apei_hest_parse(apei_hest_func_t func, void *data)
92{
93	struct acpi_hest_header *hest_hdr;
94	int i, rc, len;
95
96	if (hest_disable)
97		return -EINVAL;
98
99	hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
100	for (i = 0; i < hest_tab->error_source_count; i++) {
101		len = hest_esrc_len(hest_hdr);
102		if (!len) {
103			pr_warning(FW_WARN HEST_PFX
104				   "Unknown or unused hardware error source "
105				   "type: %d for hardware error source: %d.\n",
106				   hest_hdr->type, hest_hdr->source_id);
107			return -EINVAL;
108		}
109		if ((void *)hest_hdr + len >
110		    (void *)hest_tab + hest_tab->header.length) {
111			pr_warning(FW_BUG HEST_PFX
112		"Table contents overflow for hardware error source: %d.\n",
113				hest_hdr->source_id);
114			return -EINVAL;
115		}
116
117		rc = func(hest_hdr, data);
118		if (rc)
119			return rc;
120
121		hest_hdr = (void *)hest_hdr + len;
122	}
123
124	return 0;
125}
126EXPORT_SYMBOL_GPL(apei_hest_parse);
127
128static int __init setup_hest_disable(char *str)
129{
130	hest_disable = 1;
131	return 0;
132}
133
134__setup("hest_disable", setup_hest_disable);
135
136static int __init hest_init(void)
137{
138	acpi_status status;
139	int rc = -ENODEV;
140
141	if (acpi_disabled)
142		goto err;
143
144	if (hest_disable) {
145		pr_info(HEST_PFX "HEST tabling parsing is disabled.\n");
146		goto err;
147	}
148
149	status = acpi_get_table(ACPI_SIG_HEST, 0,
150				(struct acpi_table_header **)&hest_tab);
151	if (status == AE_NOT_FOUND) {
152		pr_info(HEST_PFX "Table is not found!\n");
153		goto err;
154	} else if (ACPI_FAILURE(status)) {
155		const char *msg = acpi_format_exception(status);
156		pr_err(HEST_PFX "Failed to get table, %s\n", msg);
157		rc = -EINVAL;
158		goto err;
159	}
160
161	rc = apei_hest_parse(hest_void_parse, NULL);
162	if (rc)
163		goto err;
164
165	pr_info(HEST_PFX "HEST table parsing is initialized.\n");
166
167	return 0;
168err:
169	hest_disable = 1;
170	return rc;
171}
172
173subsys_initcall(hest_init);
174