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 #define ACPI_BERT_PRINT_MAX_LEN 1024 33 34 static int bert_disable; 35 36 static void __init bert_print_all(struct acpi_bert_region *region, 37 unsigned int region_len) 38 { 39 struct acpi_hest_generic_status *estatus = 40 (struct acpi_hest_generic_status *)region; 41 int remain = region_len; 42 u32 estatus_len; 43 44 while (remain >= sizeof(struct acpi_bert_region)) { 45 estatus_len = cper_estatus_len(estatus); 46 if (remain < estatus_len) { 47 pr_err(FW_BUG "Truncated status block (length: %u).\n", 48 estatus_len); 49 return; 50 } 51 52 /* No more error records. */ 53 if (!estatus->block_status) 54 return; 55 56 if (cper_estatus_check(estatus)) { 57 pr_err(FW_BUG "Invalid error record.\n"); 58 return; 59 } 60 61 pr_info_once("Error records from previous boot:\n"); 62 if (region_len < ACPI_BERT_PRINT_MAX_LEN) 63 cper_estatus_print(KERN_INFO HW_ERR, estatus); 64 else 65 pr_info_once("Max print length exceeded, table data is available at:\n" 66 "/sys/firmware/acpi/tables/data/BERT"); 67 68 /* 69 * Because the boot error source is "one-time polled" type, 70 * clear Block Status of current Generic Error Status Block, 71 * once it's printed. 72 */ 73 estatus->block_status = 0; 74 75 estatus = (void *)estatus + estatus_len; 76 remain -= estatus_len; 77 } 78 } 79 80 static int __init setup_bert_disable(char *str) 81 { 82 bert_disable = 1; 83 84 return 1; 85 } 86 __setup("bert_disable", setup_bert_disable); 87 88 static int __init bert_check_table(struct acpi_table_bert *bert_tab) 89 { 90 if (bert_tab->header.length < sizeof(struct acpi_table_bert) || 91 bert_tab->region_length < sizeof(struct acpi_bert_region)) 92 return -EINVAL; 93 94 return 0; 95 } 96 97 static int __init bert_init(void) 98 { 99 struct apei_resources bert_resources; 100 struct acpi_bert_region *boot_error_region; 101 struct acpi_table_bert *bert_tab; 102 unsigned int region_len; 103 acpi_status status; 104 int rc = 0; 105 106 if (acpi_disabled) 107 return 0; 108 109 if (bert_disable) { 110 pr_info("Boot Error Record Table support is disabled.\n"); 111 return 0; 112 } 113 114 status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab); 115 if (status == AE_NOT_FOUND) 116 return 0; 117 118 if (ACPI_FAILURE(status)) { 119 pr_err("get table failed, %s.\n", acpi_format_exception(status)); 120 return -EINVAL; 121 } 122 123 rc = bert_check_table(bert_tab); 124 if (rc) { 125 pr_err(FW_BUG "table invalid.\n"); 126 goto out_put_bert_tab; 127 } 128 129 region_len = bert_tab->region_length; 130 apei_resources_init(&bert_resources); 131 rc = apei_resources_add(&bert_resources, bert_tab->address, 132 region_len, true); 133 if (rc) 134 goto out_put_bert_tab; 135 rc = apei_resources_request(&bert_resources, "APEI BERT"); 136 if (rc) 137 goto out_fini; 138 boot_error_region = ioremap_cache(bert_tab->address, region_len); 139 if (boot_error_region) { 140 bert_print_all(boot_error_region, region_len); 141 iounmap(boot_error_region); 142 } else { 143 rc = -ENOMEM; 144 } 145 146 apei_resources_release(&bert_resources); 147 out_fini: 148 apei_resources_fini(&bert_resources); 149 out_put_bert_tab: 150 acpi_put_table((struct acpi_table_header *)bert_tab); 151 152 return rc; 153 } 154 155 late_initcall(bert_init); 156