LXR linux/drivers/acpi/apei/bert.c

   1/*
   2 * APEI Boot Error Record Table (BERT) support
   3 *
   4 * Copyright 2011 Intel Corp.
   5 *   Author: Huang Ying <ying.huang@intel.com>
   6 *
   7 * Under normal circumstances, when a hardware error occurs, the error
   8 * handler receives control and processes the error. This gives OSPM a
   9 * chance to process the error condition, report it, and optionally attempt
  10 * recovery. In some cases, the system is unable to process an error.
  11 * For example, system firmware or a management controller may choose to
  12 * reset the system or the system might experience an uncontrolled crash
  13 * or reset.The boot error source is used to report unhandled errors that
  14 * occurred in a previous boot. This mechanism is described in the BERT
  15 * table.
  16 *
  17 * For more information about BERT, please refer to ACPI Specification
  18 * version 4.0, section 17.3.1
  19 *
  20 * This file is licensed under GPLv2.
  21 *
  22 */
  23
  24#include <linux/kernel.h>
  25#include <linux/module.h>
  26#include <linux/init.h>
  27#include <linux/acpi.h>
  28#include <linux/io.h>
  29
  30#include "apei-internal.h"
  31
  32#undef pr_fmt
  33#define pr_fmt(fmt) "BERT: " fmt
  34
  35static int bert_disable;
  36
  37static void __init bert_print_all(struct acpi_bert_region *region,
  38                                  unsigned int region_len)
  39{
  40        struct acpi_hest_generic_status *estatus =
  41                (struct acpi_hest_generic_status *)region;
  42        int remain = region_len;
  43        u32 estatus_len;
  44
  45        if (!estatus->block_status)
  46                return;
  47
  48        while (remain > sizeof(struct acpi_bert_region)) {
  49                if (cper_estatus_check(estatus)) {
  50                        pr_err(FW_BUG "Invalid error record.\n");
  51                        return;
  52                }
  53
  54                estatus_len = cper_estatus_len(estatus);
  55                if (remain < estatus_len) {
  56                        pr_err(FW_BUG "Truncated status block (length: %u).\n",
  57                               estatus_len);
  58                        return;
  59                }
  60
  61                pr_info_once("Error records from previous boot:\n");
  62
  63                cper_estatus_print(KERN_INFO HW_ERR, estatus);
  64
  65                /*
  66                 * Because the boot error source is "one-time polled" type,
  67                 * clear Block Status of current Generic Error Status Block,
  68                 * once it's printed.
  69                 */
  70                estatus->block_status = 0;
  71
  72                estatus = (void *)estatus + estatus_len;
  73                /* No more error records. */
  74                if (!estatus->block_status)
  75                        return;
  76
  77                remain -= estatus_len;
  78        }
  79}
  80
  81static int __init setup_bert_disable(char *str)
  82{
  83        bert_disable = 1;
  84
  85        return 0;
  86}
  87__setup("bert_disable", setup_bert_disable);
  88
  89static int __init bert_check_table(struct acpi_table_bert *bert_tab)
  90{
  91        if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
  92            bert_tab->region_length < sizeof(struct acpi_bert_region))
  93                return -EINVAL;
  94
  95        return 0;
  96}
  97
  98static int __init bert_init(void)
  99{
 100        struct apei_resources bert_resources;
 101        struct acpi_bert_region *boot_error_region;
 102        struct acpi_table_bert *bert_tab;
 103        unsigned int region_len;
 104        acpi_status status;
 105        int rc = 0;
 106
 107        if (acpi_disabled)
 108                return 0;
 109
 110        if (bert_disable) {
 111                pr_info("Boot Error Record Table support is disabled.\n");
 112                return 0;
 113        }
 114
 115        status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
 116        if (status == AE_NOT_FOUND)
 117                return 0;
 118
 119        if (ACPI_FAILURE(status)) {
 120                pr_err("get table failed, %s.\n", acpi_format_exception(status));
 121                return -EINVAL;
 122        }
 123
 124        rc = bert_check_table(bert_tab);
 125        if (rc) {
 126                pr_err(FW_BUG "table invalid.\n");
 127                return rc;
 128        }
 129
 130        region_len = bert_tab->region_length;
 131        apei_resources_init(&bert_resources);
 132        rc = apei_resources_add(&bert_resources, bert_tab->address,
 133                                region_len, true);
 134        if (rc)
 135                return rc;
 136        rc = apei_resources_request(&bert_resources, "APEI BERT");
 137        if (rc)
 138                goto out_fini;
 139        boot_error_region = ioremap_cache(bert_tab->address, region_len);
 140        if (boot_error_region) {
 141                bert_print_all(boot_error_region, region_len);
 142                iounmap(boot_error_region);
 143        } else {
 144                rc = -ENOMEM;
 145        }
 146
 147        apei_resources_release(&bert_resources);
 148out_fini:
 149        apei_resources_fini(&bert_resources);
 150
 151        return rc;
 152}
 153
 154late_initcall(bert_init);
 155