blob: 19e50fcbf4d6f52771f573094f4fa635bcfd5ff6 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
* APEI Boot Error Record Table (BERT) support
* Copyright 2011 Intel Corp.
* Author: Huang Ying <>
* Under normal circumstances, when a hardware error occurs, the error
* handler receives control and processes the error. This gives OSPM a
* chance to process the error condition, report it, and optionally attempt
* recovery. In some cases, the system is unable to process an error.
* For example, system firmware or a management controller may choose to
* reset the system or the system might experience an uncontrolled crash
* or reset.The boot error source is used to report unhandled errors that
* occurred in a previous boot. This mechanism is described in the BERT
* table.
* For more information about BERT, please refer to ACPI Specification
* version 4.0, section 17.3.1
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include "apei-internal.h"
#undef pr_fmt
#define pr_fmt(fmt) "BERT: " fmt
static int bert_disable;
static void __init bert_print_all(struct acpi_bert_region *region,
unsigned int region_len)
struct acpi_hest_generic_status *estatus =
(struct acpi_hest_generic_status *)region;
int remain = region_len;
u32 estatus_len;
while (remain >= sizeof(struct acpi_bert_region)) {
estatus_len = cper_estatus_len(estatus);
if (remain < estatus_len) {
pr_err(FW_BUG "Truncated status block (length: %u).\n",
/* No more error records. */
if (!estatus->block_status)
if (cper_estatus_check(estatus)) {
pr_err(FW_BUG "Invalid error record.\n");
pr_info_once("Error records from previous boot:\n");
cper_estatus_print(KERN_INFO HW_ERR, estatus);
* Because the boot error source is "one-time polled" type,
* clear Block Status of current Generic Error Status Block,
* once it's printed.
estatus->block_status = 0;
estatus = (void *)estatus + estatus_len;
remain -= estatus_len;
static int __init setup_bert_disable(char *str)
bert_disable = 1;
return 0;
__setup("bert_disable", setup_bert_disable);
static int __init bert_check_table(struct acpi_table_bert *bert_tab)
if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
bert_tab->region_length < sizeof(struct acpi_bert_region))
return -EINVAL;
return 0;
static int __init bert_init(void)
struct apei_resources bert_resources;
struct acpi_bert_region *boot_error_region;
struct acpi_table_bert *bert_tab;
unsigned int region_len;
acpi_status status;
int rc = 0;
if (acpi_disabled)
return 0;
if (bert_disable) {
pr_info("Boot Error Record Table support is disabled.\n");
return 0;
status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
if (status == AE_NOT_FOUND)
return 0;
if (ACPI_FAILURE(status)) {
pr_err("get table failed, %s.\n", acpi_format_exception(status));
return -EINVAL;
rc = bert_check_table(bert_tab);
if (rc) {
pr_err(FW_BUG "table invalid.\n");
goto out_put_bert_tab;
region_len = bert_tab->region_length;
rc = apei_resources_add(&bert_resources, bert_tab->address,
region_len, true);
if (rc)
goto out_put_bert_tab;
rc = apei_resources_request(&bert_resources, "APEI BERT");
if (rc)
goto out_fini;
boot_error_region = ioremap_cache(bert_tab->address, region_len);
if (boot_error_region) {
bert_print_all(boot_error_region, region_len);
} else {
rc = -ENOMEM;
acpi_put_table((struct acpi_table_header *)bert_tab);
return rc;