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/cper.h> 27 #include <linux/io.h> 28 29 #include "apei-internal.h" 30 31 #undef pr_fmt 32 #define pr_fmt(fmt) "BERT: " fmt 33 34 #define ACPI_BERT_PRINT_MAX_RECORDS 5 35 #define ACPI_BERT_PRINT_MAX_LEN 1024 36 37 static int bert_disable; 38 39 /* 40 * Print "all" the error records in the BERT table, but avoid huge spam to 41 * the console if the BIOS included oversize records, or too many records. 42 * Skipping some records here does not lose anything because the full 43 * data is available to user tools in: 44 * /sys/firmware/acpi/tables/data/BERT 45 */ 46 static void __init bert_print_all(struct acpi_bert_region *region, 47 unsigned int region_len) 48 { 49 struct acpi_hest_generic_status *estatus = 50 (struct acpi_hest_generic_status *)region; 51 int remain = region_len; 52 int printed = 0, skipped = 0; 53 u32 estatus_len; 54 55 while (remain >= sizeof(struct acpi_bert_region)) { 56 estatus_len = cper_estatus_len(estatus); 57 if (remain < estatus_len) { 58 pr_err(FW_BUG "Truncated status block (length: %u).\n", 59 estatus_len); 60 break; 61 } 62 63 /* No more error records. */ 64 if (!estatus->block_status) 65 break; 66 67 if (cper_estatus_check(estatus)) { 68 pr_err(FW_BUG "Invalid error record.\n"); 69 break; 70 } 71 72 if (estatus_len < ACPI_BERT_PRINT_MAX_LEN && 73 printed < ACPI_BERT_PRINT_MAX_RECORDS) { 74 pr_info_once("Error records from previous boot:\n"); 75 cper_estatus_print(KERN_INFO HW_ERR, estatus); 76 printed++; 77 } else { 78 skipped++; 79 } 80 81 /* 82 * Because the boot error source is "one-time polled" type, 83 * clear Block Status of current Generic Error Status Block, 84 * once it's printed. 85 */ 86 estatus->block_status = 0; 87 88 estatus = (void *)estatus + estatus_len; 89 remain -= estatus_len; 90 } 91 92 if (skipped) 93 pr_info(HW_ERR "Skipped %d error records\n", skipped); 94 95 if (printed + skipped) 96 pr_info("Total records found: %d\n", printed + skipped); 97 } 98 99 static int __init setup_bert_disable(char *str) 100 { 101 bert_disable = 1; 102 103 return 1; 104 } 105 __setup("bert_disable", setup_bert_disable); 106 107 static int __init bert_check_table(struct acpi_table_bert *bert_tab) 108 { 109 if (bert_tab->header.length < sizeof(struct acpi_table_bert) || 110 bert_tab->region_length < sizeof(struct acpi_bert_region)) 111 return -EINVAL; 112 113 return 0; 114 } 115 116 static int __init bert_init(void) 117 { 118 struct apei_resources bert_resources; 119 struct acpi_bert_region *boot_error_region; 120 struct acpi_table_bert *bert_tab; 121 unsigned int region_len; 122 acpi_status status; 123 int rc = 0; 124 125 if (acpi_disabled) 126 return 0; 127 128 if (bert_disable) { 129 pr_info("Boot Error Record Table support is disabled.\n"); 130 return 0; 131 } 132 133 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab); 134 if (status == AE_NOT_FOUND) 135 return 0; 136 137 if (ACPI_FAILURE(status)) { 138 pr_err("get table failed, %s.\n", acpi_format_exception(status)); 139 return -EINVAL; 140 } 141 142 rc = bert_check_table(bert_tab); 143 if (rc) { 144 pr_err(FW_BUG "table invalid.\n"); 145 goto out_put_bert_tab; 146 } 147 148 region_len = bert_tab->region_length; 149 apei_resources_init(&bert_resources); 150 rc = apei_resources_add(&bert_resources, bert_tab->address, 151 region_len, true); 152 if (rc) 153 goto out_put_bert_tab; 154 rc = apei_resources_request(&bert_resources, "APEI BERT"); 155 if (rc) 156 goto out_fini; 157 boot_error_region = ioremap_cache(bert_tab->address, region_len); 158 if (boot_error_region) { 159 bert_print_all(boot_error_region, region_len); 160 iounmap(boot_error_region); 161 } else { 162 rc = -ENOMEM; 163 } 164 165 apei_resources_release(&bert_resources); 166 out_fini: 167 apei_resources_fini(&bert_resources); 168 out_put_bert_tab: 169 acpi_put_table((struct acpi_table_header *)bert_tab); 170 171 return rc; 172 } 173 174 late_initcall(bert_init); 175