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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * APEI Boot Error Record Table (BERT) support4 *5 * Copyright 2011 Intel Corp.6 * Author: Huang Ying <ying.huang@intel.com>7 *8 * Under normal circumstances, when a hardware error occurs, the error9 * handler receives control and processes the error. This gives OSPM a10 * chance to process the error condition, report it, and optionally attempt11 * recovery. In some cases, the system is unable to process an error.12 * For example, system firmware or a management controller may choose to13 * reset the system or the system might experience an uncontrolled crash14 * or reset.The boot error source is used to report unhandled errors that15 * occurred in a previous boot. This mechanism is described in the BERT16 * table.17 *18 * For more information about BERT, please refer to ACPI Specification19 * version 4.0, section 17.3.120 */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_fmt32#define pr_fmt(fmt) "BERT: " fmt33 34#define ACPI_BERT_PRINT_MAX_RECORDS 535#define ACPI_BERT_PRINT_MAX_LEN 102436 37static int bert_disable __initdata;38 39/*40 * Print "all" the error records in the BERT table, but avoid huge spam to41 * the console if the BIOS included oversize records, or too many records.42 * Skipping some records here does not lose anything because the full43 * data is available to user tools in:44 * /sys/firmware/acpi/tables/data/BERT45 */46static 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 99static 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 107static 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 116static 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);166out_fini:167 apei_resources_fini(&bert_resources);168out_put_bert_tab:169 acpi_put_table((struct acpi_table_header *)bert_tab);170 171 return rc;172}173 174late_initcall(bert_init);175