1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * APEI Hardware Error Source Table support
4 *
5 * HEST describes error sources in detail; communicates operational
6 * parameters (i.e. severity levels, masking bits, and threshold
7 * values) to Linux as necessary. It also allows the BIOS to report
8 * non-standard error sources to Linux (for example, chipset-specific
9 * error registers).
10 *
11 * For more information about HEST, please refer to ACPI Specification
12 * version 4.0, section 17.3.2.
13 *
14 * Copyright 2009 Intel Corp.
15 * Author: Huang Ying <ying.huang@intel.com>
16 */
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/acpi.h>
22#include <linux/kdebug.h>
23#include <linux/highmem.h>
24#include <linux/io.h>
25#include <linux/platform_device.h>
26#include <acpi/apei.h>
27#include <acpi/ghes.h>
28
29#include "apei-internal.h"
30
31#define HEST_PFX "HEST: "
32
33int hest_disable;
34EXPORT_SYMBOL_GPL(hest_disable);
35
36/* HEST table parsing */
37
38static struct acpi_table_hest *__read_mostly hest_tab;
39
40static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
41 [ACPI_HEST_TYPE_IA32_CHECK] = -1, /* need further calculation */
42 [ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
43 [ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
44 [ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
45 [ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
46 [ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
47 [ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
48 [ACPI_HEST_TYPE_GENERIC_ERROR_V2] = sizeof(struct acpi_hest_generic_v2),
49 [ACPI_HEST_TYPE_IA32_DEFERRED_CHECK] = -1,
50};
51
52static inline bool is_generic_error(struct acpi_hest_header *hest_hdr)
53{
54 return hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR ||
55 hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
56}
57
58static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
59{
60 u16 hest_type = hest_hdr->type;
61 int len;
62
63 if (hest_type >= ACPI_HEST_TYPE_RESERVED)
64 return 0;
65
66 len = hest_esrc_len_tab[hest_type];
67
68 if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
69 struct acpi_hest_ia_corrected *cmc;
70 cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
71 len = sizeof(*cmc) + cmc->num_hardware_banks *
72 sizeof(struct acpi_hest_ia_error_bank);
73 } else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
74 struct acpi_hest_ia_machine_check *mc;
75 mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
76 len = sizeof(*mc) + mc->num_hardware_banks *
77 sizeof(struct acpi_hest_ia_error_bank);
78 } else if (hest_type == ACPI_HEST_TYPE_IA32_DEFERRED_CHECK) {
79 struct acpi_hest_ia_deferred_check *mc;
80 mc = (struct acpi_hest_ia_deferred_check *)hest_hdr;
81 len = sizeof(*mc) + mc->num_hardware_banks *
82 sizeof(struct acpi_hest_ia_error_bank);
83 }
84 BUG_ON(len == -1);
85
86 return len;
87};
88
89typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
90
91static int 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 || !hest_tab)
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_warn(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_warn(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}
126
127/*
128 * Check if firmware advertises firmware first mode. We need FF bit to be set
129 * along with a set of MC banks which work in FF mode.
130 */
131static int __init hest_parse_cmc(struct acpi_hest_header *hest_hdr, void *data)
132{
133 if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK)
134 return 0;
135
136 if (!acpi_disable_cmcff)
137 return !arch_apei_enable_cmcff(hest_hdr, data);
138
139 return 0;
140}
141
142struct ghes_arr {
143 struct platform_device **ghes_devs;
144 unsigned int count;
145};
146
147static int __init hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)
148{
149 int *count = data;
150
151 if (is_generic_error(hest_hdr))
152 (*count)++;
153 return 0;
154}
155
156static int __init hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
157{
158 struct platform_device *ghes_dev;
159 struct ghes_arr *ghes_arr = data;
160 int rc, i;
161
162 if (!is_generic_error(hest_hdr))
163 return 0;
164
165 if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
166 return 0;
167 for (i = 0; i < ghes_arr->count; i++) {
168 struct acpi_hest_header *hdr;
169 ghes_dev = ghes_arr->ghes_devs[i];
170 hdr = *(struct acpi_hest_header **)ghes_dev->dev.platform_data;
171 if (hdr->source_id == hest_hdr->source_id) {
172 pr_warn(FW_WARN HEST_PFX "Duplicated hardware error source ID: %d.\n",
173 hdr->source_id);
174 return -EIO;
175 }
176 }
177 ghes_dev = platform_device_alloc(name: "GHES", id: hest_hdr->source_id);
178 if (!ghes_dev)
179 return -ENOMEM;
180
181 rc = platform_device_add_data(pdev: ghes_dev, data: &hest_hdr, size: sizeof(void *));
182 if (rc)
183 goto err;
184
185 rc = platform_device_add(pdev: ghes_dev);
186 if (rc)
187 goto err;
188 ghes_arr->ghes_devs[ghes_arr->count++] = ghes_dev;
189
190 return 0;
191err:
192 platform_device_put(pdev: ghes_dev);
193 return rc;
194}
195
196static int __init hest_ghes_dev_register(unsigned int ghes_count)
197{
198 int rc, i;
199 struct ghes_arr ghes_arr;
200
201 ghes_arr.count = 0;
202 ghes_arr.ghes_devs = kmalloc_array(n: ghes_count, size: sizeof(void *),
203 GFP_KERNEL);
204 if (!ghes_arr.ghes_devs)
205 return -ENOMEM;
206
207 rc = apei_hest_parse(func: hest_parse_ghes, data: &ghes_arr);
208 if (rc)
209 goto err;
210
211 rc = ghes_estatus_pool_init(num_ghes: ghes_count);
212 if (rc)
213 goto err;
214
215out:
216 kfree(objp: ghes_arr.ghes_devs);
217 return rc;
218err:
219 for (i = 0; i < ghes_arr.count; i++)
220 platform_device_unregister(ghes_arr.ghes_devs[i]);
221 goto out;
222}
223
224static int __init setup_hest_disable(char *str)
225{
226 hest_disable = HEST_DISABLED;
227 return 1;
228}
229
230__setup("hest_disable", setup_hest_disable);
231
232void __init acpi_hest_init(void)
233{
234 acpi_status status;
235 int rc;
236 unsigned int ghes_count = 0;
237
238 if (hest_disable) {
239 pr_info(HEST_PFX "Table parsing disabled.\n");
240 return;
241 }
242
243 status = acpi_get_table(ACPI_SIG_HEST, instance: 0,
244 out_table: (struct acpi_table_header **)&hest_tab);
245 if (status == AE_NOT_FOUND) {
246 hest_disable = HEST_NOT_FOUND;
247 return;
248 } else if (ACPI_FAILURE(status)) {
249 const char *msg = acpi_format_exception(exception: status);
250 pr_err(HEST_PFX "Failed to get table, %s\n", msg);
251 hest_disable = HEST_DISABLED;
252 return;
253 }
254
255 rc = apei_hest_parse(func: hest_parse_cmc, NULL);
256 if (rc)
257 goto err;
258
259 if (!ghes_disable) {
260 rc = apei_hest_parse(func: hest_parse_ghes_count, data: &ghes_count);
261 if (rc)
262 goto err;
263
264 if (ghes_count)
265 rc = hest_ghes_dev_register(ghes_count);
266 if (rc)
267 goto err;
268 }
269
270 pr_info(HEST_PFX "Table parsing has been initialized.\n");
271 return;
272err:
273 hest_disable = HEST_DISABLED;
274 acpi_put_table(table: (struct acpi_table_header *)hest_tab);
275}
276

source code of linux/drivers/acpi/apei/hest.c