hest.c revision ad6861547b52ad7c31eacc336b79ac91d7fded75 
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 <linux/platform_device.h>
38#include <acpi/apei.h>
39
40#include "apei-internal.h"
41
42#define HEST_PFX "HEST: "
43
44int hest_disable;
45EXPORT_SYMBOL_GPL(hest_disable);
46
47/* HEST table parsing */
48
49static struct acpi_table_hest *__read_mostly hest_tab;
50
51static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
52	[ACPI_HEST_TYPE_IA32_CHECK] = -1,	/* need further calculation */
53	[ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
54	[ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
55	[ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
56	[ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
57	[ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
58	[ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
59};
60
61static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
62{
63	u16 hest_type = hest_hdr->type;
64	int len;
65
66	if (hest_type >= ACPI_HEST_TYPE_RESERVED)
67		return 0;
68
69	len = hest_esrc_len_tab[hest_type];
70
71	if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
72		struct acpi_hest_ia_corrected *cmc;
73		cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
74		len = sizeof(*cmc) + cmc->num_hardware_banks *
75			sizeof(struct acpi_hest_ia_error_bank);
76	} else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
77		struct acpi_hest_ia_machine_check *mc;
78		mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
79		len = sizeof(*mc) + mc->num_hardware_banks *
80			sizeof(struct acpi_hest_ia_error_bank);
81	}
82	BUG_ON(len == -1);
83
84	return len;
85};
86
87int apei_hest_parse(apei_hest_func_t func, void *data)
88{
89	struct acpi_hest_header *hest_hdr;
90	int i, rc, len;
91
92	if (hest_disable)
93		return -EINVAL;
94
95	hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
96	for (i = 0; i < hest_tab->error_source_count; i++) {
97		len = hest_esrc_len(hest_hdr);
98		if (!len) {
99			pr_warning(FW_WARN HEST_PFX
100				   "Unknown or unused hardware error source "
101				   "type: %d for hardware error source: %d.\n",
102				   hest_hdr->type, hest_hdr->source_id);
103			return -EINVAL;
104		}
105		if ((void *)hest_hdr + len >
106		    (void *)hest_tab + hest_tab->header.length) {
107			pr_warning(FW_BUG HEST_PFX
108		"Table contents overflow for hardware error source: %d.\n",
109				hest_hdr->source_id);
110			return -EINVAL;
111		}
112
113		rc = func(hest_hdr, data);
114		if (rc)
115			return rc;
116
117		hest_hdr = (void *)hest_hdr + len;
118	}
119
120	return 0;
121}
122EXPORT_SYMBOL_GPL(apei_hest_parse);
123
124struct ghes_arr {
125	struct platform_device **ghes_devs;
126	unsigned int count;
127};
128
129static int __init hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)
130{
131	int *count = data;
132
133	if (hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR)
134		(*count)++;
135	return 0;
136}
137
138static int __init hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
139{
140	struct platform_device *ghes_dev;
141	struct ghes_arr *ghes_arr = data;
142	int rc, i;
143
144	if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
145		return 0;
146
147	if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
148		return 0;
149	for (i = 0; i < ghes_arr->count; i++) {
150		struct acpi_hest_header *hdr;
151		ghes_dev = ghes_arr->ghes_devs[i];
152		hdr = *(struct acpi_hest_header **)ghes_dev->dev.platform_data;
153		if (hdr->source_id == hest_hdr->source_id) {
154			pr_warning(FW_WARN HEST_PFX "Duplicated hardware error source ID: %d.\n",
155				   hdr->source_id);
156			return -EIO;
157		}
158	}
159	ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
160	if (!ghes_dev)
161		return -ENOMEM;
162
163	rc = platform_device_add_data(ghes_dev, &hest_hdr, sizeof(void *));
164	if (rc)
165		goto err;
166
167	rc = platform_device_add(ghes_dev);
168	if (rc)
169		goto err;
170	ghes_arr->ghes_devs[ghes_arr->count++] = ghes_dev;
171
172	return 0;
173err:
174	platform_device_put(ghes_dev);
175	return rc;
176}
177
178static int __init hest_ghes_dev_register(unsigned int ghes_count)
179{
180	int rc, i;
181	struct ghes_arr ghes_arr;
182
183	ghes_arr.count = 0;
184	ghes_arr.ghes_devs = kmalloc(sizeof(void *) * ghes_count, GFP_KERNEL);
185	if (!ghes_arr.ghes_devs)
186		return -ENOMEM;
187
188	rc = apei_hest_parse(hest_parse_ghes, &ghes_arr);
189	if (rc)
190		goto err;
191out:
192	kfree(ghes_arr.ghes_devs);
193	return rc;
194err:
195	for (i = 0; i < ghes_arr.count; i++)
196		platform_device_unregister(ghes_arr.ghes_devs[i]);
197	goto out;
198}
199
200static int __init setup_hest_disable(char *str)
201{
202	hest_disable = 1;
203	return 0;
204}
205
206__setup("hest_disable", setup_hest_disable);
207
208void __init acpi_hest_init(void)
209{
210	acpi_status status;
211	int rc = -ENODEV;
212	unsigned int ghes_count = 0;
213
214	if (hest_disable) {
215		pr_info(HEST_PFX "Table parsing disabled.\n");
216		return;
217	}
218
219	if (acpi_disabled)
220		goto err;
221
222	status = acpi_get_table(ACPI_SIG_HEST, 0,
223				(struct acpi_table_header **)&hest_tab);
224	if (status == AE_NOT_FOUND)
225		goto err;
226	else if (ACPI_FAILURE(status)) {
227		const char *msg = acpi_format_exception(status);
228		pr_err(HEST_PFX "Failed to get table, %s\n", msg);
229		rc = -EINVAL;
230		goto err;
231	}
232
233	if (!ghes_disable) {
234		rc = apei_hest_parse(hest_parse_ghes_count, &ghes_count);
235		if (rc)
236			goto err;
237		rc = hest_ghes_dev_register(ghes_count);
238		if (rc)
239			goto err;
240	}
241
242	pr_info(HEST_PFX "Table parsing has been initialized.\n");
243	return;
244err:
245	hest_disable = 1;
246}
247