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