drivers/acpi/nfit/mce.c

   1 /*
   2  * NFIT - Machine Check Handler
   3  *
   4  * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of version 2 of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  */
  15 #include <linux/notifier.h>
  16 #include <linux/acpi.h>
  17 #include <asm/mce.h>
  18 #include "nfit.h"
  19
  20 static int nfit_handle_mce(struct notifier_block *nb, unsigned long val,
  21                         void *data)
  22 {
  23         struct mce *mce = (struct mce *)data;
  24         struct acpi_nfit_desc *acpi_desc;
  25         struct nfit_spa *nfit_spa;
  26
  27         /* We only care about memory errors */
  28         if (!(mce->status & MCACOD))
  29                 return NOTIFY_DONE;
  30
  31         /*
  32          * mce->addr contains the physical addr accessed that caused the
  33          * machine check. We need to walk through the list of NFITs, and see
  34          * if any of them matches that address, and only then start a scrub.
  35          */
  36         mutex_lock(&acpi_desc_lock);
  37         list_for_each_entry(acpi_desc, &acpi_descs, list) {
  38                 struct device *dev = acpi_desc->dev;
  39                 int found_match = 0;
  40
  41                 mutex_lock(&acpi_desc->init_mutex);
  42                 list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
  43                         struct acpi_nfit_system_address *spa = nfit_spa->spa;
  44
  45                         if (nfit_spa_type(spa) != NFIT_SPA_PM)
  46                                 continue;
  47                         /* find the spa that covers the mce addr */
  48                         if (spa->address > mce->addr)
  49                                 continue;
  50                         if ((spa->address + spa->length - 1) < mce->addr)
  51                                 continue;
  52                         found_match = 1;
  53                         dev_dbg(dev, "%s: addr in SPA %d (0x%llx, 0x%llx)\n",
  54                                 __func__, spa->range_index, spa->address,
  55                                 spa->length);
  56                         /*
  57                          * We can break at the first match because we're going
  58                          * to rescan all the SPA ranges. There shouldn't be any
  59                          * aliasing anyway.
  60                          */
  61                         break;
  62                 }
  63                 mutex_unlock(&acpi_desc->init_mutex);
  64
  65                 /*
  66                  * We can ignore an -EBUSY here because if an ARS is already
  67                  * in progress, just let that be the last authoritative one
  68                  */
  69                 if (found_match)
  70                         acpi_nfit_ars_rescan(acpi_desc);
  71         }
  72
  73         mutex_unlock(&acpi_desc_lock);
  74         return NOTIFY_DONE;
  75 }
  76
  77 static struct notifier_block nfit_mce_dec = {
  78         .notifier_call  = nfit_handle_mce,
  79 };
  80
  81 void nfit_mce_register(void)
  82 {
  83         mce_register_decode_chain(&nfit_mce_dec);
  84 }
  85
  86 void nfit_mce_unregister(void)
  87 {
  88         mce_unregister_decode_chain(&nfit_mce_dec);
  89 }