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
  35 static int bert_disable;
  36
  37 static 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
  81 static 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
  89 static 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
  98 static 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);
 148 out_fini:
 149         apei_resources_fini(&bert_resources);
 150
 151         return rc;
 152 }
 153
 154 late_initcall(bert_init);