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
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/acpi.h>
30#include <linux/kdebug.h>
31#include <linux/highmem.h>
32#include <linux/io.h>
33#include <linux/platform_device.h>
34#include <acpi/apei.h>
35
36#include "apei-internal.h"
37
38#define HEST_PFX "HEST: "
39
40bool hest_disable;
41EXPORT_SYMBOL_GPL(hest_disable);
42
43/* HEST table parsing */
44
45static struct acpi_table_hest *__read_mostly hest_tab;
46
47static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
48	[ACPI_HEST_TYPE_IA32_CHECK] = -1,	/* need further calculation */
49	[ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
50	[ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
51	[ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
52	[ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
53	[ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
54	[ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
55};
56
57static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
58{
59	u16 hest_type = hest_hdr->type;
60	int len;
61
62	if (hest_type >= ACPI_HEST_TYPE_RESERVED)
63		return 0;
64
65	len = hest_esrc_len_tab[hest_type];
66
67	if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
68		struct acpi_hest_ia_corrected *cmc;
69		cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
70		len = sizeof(*cmc) + cmc->num_hardware_banks *
71			sizeof(struct acpi_hest_ia_error_bank);
72	} else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
73		struct acpi_hest_ia_machine_check *mc;
74		mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
75		len = sizeof(*mc) + mc->num_hardware_banks *
76			sizeof(struct acpi_hest_ia_error_bank);
77	}
78	BUG_ON(len == -1);
79
80	return len;
81};
82
83int apei_hest_parse(apei_hest_func_t func, void *data)
84{
85	struct acpi_hest_header *hest_hdr;
86	int i, rc, len;
87
88	if (hest_disable || !hest_tab)
89		return -EINVAL;
90
91	hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
92	for (i = 0; i < hest_tab->error_source_count; i++) {
93		len = hest_esrc_len(hest_hdr);
94		if (!len) {
95			pr_warning(FW_WARN HEST_PFX
96				   "Unknown or unused hardware error source "
97				   "type: %d for hardware error source: %d.\n",
98				   hest_hdr->type, hest_hdr->source_id);
99			return -EINVAL;
100		}
101		if ((void *)hest_hdr + len >
102		    (void *)hest_tab + hest_tab->header.length) {
103			pr_warning(FW_BUG HEST_PFX
104		"Table contents overflow for hardware error source: %d.\n",
105				hest_hdr->source_id);
106			return -EINVAL;
107		}
108
109		rc = func(hest_hdr, data);
110		if (rc)
111			return rc;
112
113		hest_hdr = (void *)hest_hdr + len;
114	}
115
116	return 0;
117}
118EXPORT_SYMBOL_GPL(apei_hest_parse);
119
120/*
121 * Check if firmware advertises firmware first mode. We need FF bit to be set
122 * along with a set of MC banks which work in FF mode.
123 */
124static int __init hest_parse_cmc(struct acpi_hest_header *hest_hdr, void *data)
125{
126	return arch_apei_enable_cmcff(hest_hdr, data);
127}
128
129struct ghes_arr {
130	struct platform_device **ghes_devs;
131	unsigned int count;
132};
133
134static int __init hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)
135{
136	int *count = data;
137
138	if (hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR)
139		(*count)++;
140	return 0;
141}
142
143static int __init hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
144{
145	struct platform_device *ghes_dev;
146	struct ghes_arr *ghes_arr = data;
147	int rc, i;
148
149	if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
150		return 0;
151
152	if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
153		return 0;
154	for (i = 0; i < ghes_arr->count; i++) {
155		struct acpi_hest_header *hdr;
156		ghes_dev = ghes_arr->ghes_devs[i];
157		hdr = *(struct acpi_hest_header **)ghes_dev->dev.platform_data;
158		if (hdr->source_id == hest_hdr->source_id) {
159			pr_warning(FW_WARN HEST_PFX "Duplicated hardware error source ID: %d.\n",
160				   hdr->source_id);
161			return -EIO;
162		}
163	}
164	ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
165	if (!ghes_dev)
166		return -ENOMEM;
167
168	rc = platform_device_add_data(ghes_dev, &hest_hdr, sizeof(void *));
169	if (rc)
170		goto err;
171
172	rc = platform_device_add(ghes_dev);
173	if (rc)
174		goto err;
175	ghes_arr->ghes_devs[ghes_arr->count++] = ghes_dev;
176
177	return 0;
178err:
179	platform_device_put(ghes_dev);
180	return rc;
181}
182
183static int __init hest_ghes_dev_register(unsigned int ghes_count)
184{
185	int rc, i;
186	struct ghes_arr ghes_arr;
187
188	ghes_arr.count = 0;
189	ghes_arr.ghes_devs = kmalloc(sizeof(void *) * ghes_count, GFP_KERNEL);
190	if (!ghes_arr.ghes_devs)
191		return -ENOMEM;
192
193	rc = apei_hest_parse(hest_parse_ghes, &ghes_arr);
194	if (rc)
195		goto err;
196out:
197	kfree(ghes_arr.ghes_devs);
198	return rc;
199err:
200	for (i = 0; i < ghes_arr.count; i++)
201		platform_device_unregister(ghes_arr.ghes_devs[i]);
202	goto out;
203}
204
205static int __init setup_hest_disable(char *str)
206{
207	hest_disable = 1;
208	return 0;
209}
210
211__setup("hest_disable", setup_hest_disable);
212
213void __init acpi_hest_init(void)
214{
215	acpi_status status;
216	int rc = -ENODEV;
217	unsigned int ghes_count = 0;
218
219	if (hest_disable) {
220		pr_info(HEST_PFX "Table parsing disabled.\n");
221		return;
222	}
223
224	status = acpi_get_table(ACPI_SIG_HEST, 0,
225				(struct acpi_table_header **)&hest_tab);
226	if (status == AE_NOT_FOUND)
227		goto err;
228	else if (ACPI_FAILURE(status)) {
229		const char *msg = acpi_format_exception(status);
230		pr_err(HEST_PFX "Failed to get table, %s\n", msg);
231		rc = -EINVAL;
232		goto err;
233	}
234
235	if (!acpi_disable_cmcff)
236		apei_hest_parse(hest_parse_cmc, NULL);
237
238	if (!ghes_disable) {
239		rc = apei_hest_parse(hest_parse_ghes_count, &ghes_count);
240		if (rc)
241			goto err;
242		rc = hest_ghes_dev_register(ghes_count);
243		if (rc)
244			goto err;
245	}
246
247	pr_info(HEST_PFX "Table parsing has been initialized.\n");
248	return;
249err:
250	hest_disable = 1;
251}
252