1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * APEI Boot Error Record Table (BERT) support
4 *
5 * Copyright 2011 Intel Corp.
6 * Author: Huang Ying <ying.huang@intel.com>
7 *
8 * Under normal circumstances, when a hardware error occurs, the error
9 * handler receives control and processes the error. This gives OSPM a
10 * chance to process the error condition, report it, and optionally attempt
11 * recovery. In some cases, the system is unable to process an error.
12 * For example, system firmware or a management controller may choose to
13 * reset the system or the system might experience an uncontrolled crash
14 * or reset.The boot error source is used to report unhandled errors that
15 * occurred in a previous boot. This mechanism is described in the BERT
16 * table.
17 *
18 * For more information about BERT, please refer to ACPI Specification
19 * version 4.0, section 17.3.1
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/acpi.h>
26 #include <linux/io.h>
27
28 #include "apei-internal.h"
29
30 #undef pr_fmt
31 #define pr_fmt(fmt) "BERT: " fmt
32
33 #define ACPI_BERT_PRINT_MAX_RECORDS 5
34 #define ACPI_BERT_PRINT_MAX_LEN 1024
35
36 static int bert_disable;
37
38 /*
39 * Print "all" the error records in the BERT table, but avoid huge spam to
40 * the console if the BIOS included oversize records, or too many records.
41 * Skipping some records here does not lose anything because the full
42 * data is available to user tools in:
43 * /sys/firmware/acpi/tables/data/BERT
44 */
bert_print_all(struct acpi_bert_region * region,unsigned int region_len)45 static void __init bert_print_all(struct acpi_bert_region *region,
46 unsigned int region_len)
47 {
48 struct acpi_hest_generic_status *estatus =
49 (struct acpi_hest_generic_status *)region;
50 int remain = region_len;
51 int printed = 0, skipped = 0;
52 u32 estatus_len;
53
54 while (remain >= sizeof(struct acpi_bert_region)) {
55 estatus_len = cper_estatus_len(estatus);
56 if (remain < estatus_len) {
57 pr_err(FW_BUG "Truncated status block (length: %u).\n",
58 estatus_len);
59 break;
60 }
61
62 /* No more error records. */
63 if (!estatus->block_status)
64 break;
65
66 if (cper_estatus_check(estatus)) {
67 pr_err(FW_BUG "Invalid error record.\n");
68 break;
69 }
70
71 if (estatus_len < ACPI_BERT_PRINT_MAX_LEN &&
72 printed < ACPI_BERT_PRINT_MAX_RECORDS) {
73 pr_info_once("Error records from previous boot:\n");
74 cper_estatus_print(KERN_INFO HW_ERR, estatus);
75 printed++;
76 } else {
77 skipped++;
78 }
79
80 /*
81 * Because the boot error source is "one-time polled" type,
82 * clear Block Status of current Generic Error Status Block,
83 * once it's printed.
84 */
85 estatus->block_status = 0;
86
87 estatus = (void *)estatus + estatus_len;
88 remain -= estatus_len;
89 }
90
91 if (skipped)
92 pr_info(HW_ERR "Skipped %d error records\n", skipped);
93
94 if (printed + skipped)
95 pr_info("Total records found: %d\n", printed + skipped);
96 }
97
setup_bert_disable(char * str)98 static int __init setup_bert_disable(char *str)
99 {
100 bert_disable = 1;
101
102 return 1;
103 }
104 __setup("bert_disable", setup_bert_disable);
105
bert_check_table(struct acpi_table_bert * bert_tab)106 static int __init bert_check_table(struct acpi_table_bert *bert_tab)
107 {
108 if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
109 bert_tab->region_length < sizeof(struct acpi_bert_region))
110 return -EINVAL;
111
112 return 0;
113 }
114
bert_init(void)115 static int __init bert_init(void)
116 {
117 struct apei_resources bert_resources;
118 struct acpi_bert_region *boot_error_region;
119 struct acpi_table_bert *bert_tab;
120 unsigned int region_len;
121 acpi_status status;
122 int rc = 0;
123
124 if (acpi_disabled)
125 return 0;
126
127 if (bert_disable) {
128 pr_info("Boot Error Record Table support is disabled.\n");
129 return 0;
130 }
131
132 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
133 if (status == AE_NOT_FOUND)
134 return 0;
135
136 if (ACPI_FAILURE(status)) {
137 pr_err("get table failed, %s.\n", acpi_format_exception(status));
138 return -EINVAL;
139 }
140
141 rc = bert_check_table(bert_tab);
142 if (rc) {
143 pr_err(FW_BUG "table invalid.\n");
144 goto out_put_bert_tab;
145 }
146
147 region_len = bert_tab->region_length;
148 apei_resources_init(&bert_resources);
149 rc = apei_resources_add(&bert_resources, bert_tab->address,
150 region_len, true);
151 if (rc)
152 goto out_put_bert_tab;
153 rc = apei_resources_request(&bert_resources, "APEI BERT");
154 if (rc)
155 goto out_fini;
156 boot_error_region = ioremap_cache(bert_tab->address, region_len);
157 if (boot_error_region) {
158 bert_print_all(boot_error_region, region_len);
159 iounmap(boot_error_region);
160 } else {
161 rc = -ENOMEM;
162 }
163
164 apei_resources_release(&bert_resources);
165 out_fini:
166 apei_resources_fini(&bert_resources);
167 out_put_bert_tab:
168 acpi_put_table((struct acpi_table_header *)bert_tab);
169
170 return rc;
171 }
172
173 late_initcall(bert_init);
174