drivers/acpi/hed.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ACPI Hardware Error Device (PNP0C33) Driver
   4  *
   5  * Copyright (C) 2010, Intel Corp.
   6  *      Author: Huang Ying <ying.huang@intel.com>
   7  *
   8  * ACPI Hardware Error Device is used to report some hardware errors
   9  * notified via SCI, mainly the corrected errors.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/acpi.h>
  16 #include <acpi/hed.h>
  17
  18 static const struct acpi_device_id acpi_hed_ids[] = {
  19         {"PNP0C33", 0},
  20         {"", 0},
  21 };
  22 MODULE_DEVICE_TABLE(acpi, acpi_hed_ids);
  23
  24 static acpi_handle hed_handle;
  25
  26 static BLOCKING_NOTIFIER_HEAD(acpi_hed_notify_list);
  27
  28 int register_acpi_hed_notifier(struct notifier_block *nb)
  29 {
  30         return blocking_notifier_chain_register(&acpi_hed_notify_list, nb);
  31 }
  32 EXPORT_SYMBOL_GPL(register_acpi_hed_notifier);
  33
  34 void unregister_acpi_hed_notifier(struct notifier_block *nb)
  35 {
  36         blocking_notifier_chain_unregister(&acpi_hed_notify_list, nb);
  37 }
  38 EXPORT_SYMBOL_GPL(unregister_acpi_hed_notifier);
  39
  40 /*
  41  * SCI to report hardware error is forwarded to the listeners of HED,
  42  * it is used by HEST Generic Hardware Error Source with notify type
  43  * SCI.
  44  */
  45 static void acpi_hed_notify(acpi_handle handle, u32 event, void *data)
  46 {
  47         blocking_notifier_call_chain(&acpi_hed_notify_list, 0, NULL);
  48 }
  49
  50 static int acpi_hed_add(struct acpi_device *device)
  51 {
  52         int err;
  53
  54         /* Only one hardware error device */
  55         if (hed_handle)
  56                 return -EINVAL;
  57         hed_handle = device->handle;
  58
  59         err = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
  60                                               acpi_hed_notify, device);
  61         if (err)
  62                 hed_handle = NULL;
  63
  64         return err;
  65 }
  66
  67 static void acpi_hed_remove(struct acpi_device *device)
  68 {
  69         acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
  70                                        acpi_hed_notify);
  71         hed_handle = NULL;
  72 }
  73
  74 static struct acpi_driver acpi_hed_driver = {
  75         .name = "hardware_error_device",
  76         .class = "hardware_error",
  77         .ids = acpi_hed_ids,
  78         .ops = {
  79                 .add = acpi_hed_add,
  80                 .remove = acpi_hed_remove,
  81         },
  82 };
  83 module_acpi_driver(acpi_hed_driver);
  84
  85 MODULE_AUTHOR("Huang Ying");
  86 MODULE_DESCRIPTION("ACPI Hardware Error Device Driver");
  87 MODULE_LICENSE("GPL");