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 static int bert_disable;
34
bert_print_all(struct acpi_bert_region * region,unsigned int region_len)35 static void __init bert_print_all(struct acpi_bert_region *region,
36 unsigned int region_len)
37 {
38 struct acpi_hest_generic_status *estatus =
39 (struct acpi_hest_generic_status *)region;
40 int remain = region_len;
41 u32 estatus_len;
42
43 while (remain >= sizeof(struct acpi_bert_region)) {
44 estatus_len = cper_estatus_len(estatus);
45 if (remain < estatus_len) {
46 pr_err(FW_BUG "Truncated status block (length: %u).\n",
47 estatus_len);
48 return;
49 }
50
51 /* No more error records. */
52 if (!estatus->block_status)
53 return;
54
55 if (cper_estatus_check(estatus)) {
56 pr_err(FW_BUG "Invalid error record.\n");
57 return;
58 }
59
60 pr_info_once("Error records from previous boot:\n");
61
62 cper_estatus_print(KERN_INFO HW_ERR, estatus);
63
64 /*
65 * Because the boot error source is "one-time polled" type,
66 * clear Block Status of current Generic Error Status Block,
67 * once it's printed.
68 */
69 estatus->block_status = 0;
70
71 estatus = (void *)estatus + estatus_len;
72 remain -= estatus_len;
73 }
74 }
75
setup_bert_disable(char * str)76 static int __init setup_bert_disable(char *str)
77 {
78 bert_disable = 1;
79
80 return 0;
81 }
82 __setup("bert_disable", setup_bert_disable);
83
bert_check_table(struct acpi_table_bert * bert_tab)84 static int __init bert_check_table(struct acpi_table_bert *bert_tab)
85 {
86 if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
87 bert_tab->region_length < sizeof(struct acpi_bert_region))
88 return -EINVAL;
89
90 return 0;
91 }
92
bert_init(void)93 static int __init bert_init(void)
94 {
95 struct apei_resources bert_resources;
96 struct acpi_bert_region *boot_error_region;
97 struct acpi_table_bert *bert_tab;
98 unsigned int region_len;
99 acpi_status status;
100 int rc = 0;
101
102 if (acpi_disabled)
103 return 0;
104
105 if (bert_disable) {
106 pr_info("Boot Error Record Table support is disabled.\n");
107 return 0;
108 }
109
110 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
111 if (status == AE_NOT_FOUND)
112 return 0;
113
114 if (ACPI_FAILURE(status)) {
115 pr_err("get table failed, %s.\n", acpi_format_exception(status));
116 return -EINVAL;
117 }
118
119 rc = bert_check_table(bert_tab);
120 if (rc) {
121 pr_err(FW_BUG "table invalid.\n");
122 goto out_put_bert_tab;
123 }
124
125 region_len = bert_tab->region_length;
126 apei_resources_init(&bert_resources);
127 rc = apei_resources_add(&bert_resources, bert_tab->address,
128 region_len, true);
129 if (rc)
130 goto out_put_bert_tab;
131 rc = apei_resources_request(&bert_resources, "APEI BERT");
132 if (rc)
133 goto out_fini;
134 boot_error_region = ioremap_cache(bert_tab->address, region_len);
135 if (boot_error_region) {
136 bert_print_all(boot_error_region, region_len);
137 iounmap(boot_error_region);
138 } else {
139 rc = -ENOMEM;
140 }
141
142 apei_resources_release(&bert_resources);
143 out_fini:
144 apei_resources_fini(&bert_resources);
145 out_put_bert_tab:
146 acpi_put_table((struct acpi_table_header *)bert_tab);
147
148 return rc;
149 }
150
151 late_initcall(bert_init);
152