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 */ 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 95 static int __init setup_bert_disable(char *str) 96 { 97 bert_disable = 1; 98 99 return 1; 100 } 101 __setup("bert_disable", setup_bert_disable); 102 103 static int __init bert_check_table(struct acpi_table_bert *bert_tab) 104 { 105 if (bert_tab->header.length < sizeof(struct acpi_table_bert) || 106 bert_tab->region_length < sizeof(struct acpi_bert_region)) 107 return -EINVAL; 108 109 return 0; 110 } 111 112 static int __init bert_init(void) 113 { 114 struct apei_resources bert_resources; 115 struct acpi_bert_region *boot_error_region; 116 struct acpi_table_bert *bert_tab; 117 unsigned int region_len; 118 acpi_status status; 119 int rc = 0; 120 121 if (acpi_disabled) 122 return 0; 123 124 if (bert_disable) { 125 pr_info("Boot Error Record Table support is disabled.\n"); 126 return 0; 127 } 128 129 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab); 130 if (status == AE_NOT_FOUND) 131 return 0; 132 133 if (ACPI_FAILURE(status)) { 134 pr_err("get table failed, %s.\n", acpi_format_exception(status)); 135 return -EINVAL; 136 } 137 138 rc = bert_check_table(bert_tab); 139 if (rc) { 140 pr_err(FW_BUG "table invalid.\n"); 141 goto out_put_bert_tab; 142 } 143 144 region_len = bert_tab->region_length; 145 apei_resources_init(&bert_resources); 146 rc = apei_resources_add(&bert_resources, bert_tab->address, 147 region_len, true); 148 if (rc) 149 goto out_put_bert_tab; 150 rc = apei_resources_request(&bert_resources, "APEI BERT"); 151 if (rc) 152 goto out_fini; 153 boot_error_region = ioremap_cache(bert_tab->address, region_len); 154 if (boot_error_region) { 155 bert_print_all(boot_error_region, region_len); 156 iounmap(boot_error_region); 157 } else { 158 rc = -ENOMEM; 159 } 160 161 apei_resources_release(&bert_resources); 162 out_fini: 163 apei_resources_fini(&bert_resources); 164 out_put_bert_tab: 165 acpi_put_table((struct acpi_table_header *)bert_tab); 166 167 return rc; 168 } 169 170 late_initcall(bert_init); 171