LXR uboot/lib/efi_loader/efi

   1/*
   2 *  EFI watchdog
   3 *
   4 *  Copyright (c) 2017 Heinrich Schuchardt
   5 *
   6 *  SPDX-License-Identifier:     GPL-2.0+
   7 */
   8
   9#include <common.h>
  10#include <efi_loader.h>
  11
  12/* Conversion factor from seconds to multiples of 100ns */
  13#define EFI_SECONDS_TO_100NS 10000000ULL
  14
  15static struct efi_event *watchdog_timer_event;
  16
  17/*
  18 * Reset the system when the watchdog event is notified.
  19 *
  20 * @event:      the watchdog event
  21 * @context:    not used
  22 */
  23static void EFIAPI efi_watchdog_timer_notify(struct efi_event *event,
  24                                             void *context)
  25{
  26        EFI_ENTRY("%p, %p", event, context);
  27
  28        printf("\nEFI: Watchdog timeout\n");
  29        EFI_CALL_VOID(efi_runtime_services.reset_system(EFI_RESET_COLD,
  30                                                        EFI_SUCCESS, 0, NULL));
  31
  32        EFI_EXIT(EFI_UNSUPPORTED);
  33}
  34
  35/*
  36 * Reset the watchdog timer.
  37 *
  38 * This function is used by the SetWatchdogTimer service.
  39 *
  40 * @timeout:            seconds before reset by watchdog
  41 * @return:             status code
  42 */
  43efi_status_t efi_set_watchdog(unsigned long timeout)
  44{
  45        efi_status_t r;
  46
  47        if (timeout)
  48                /* Reset watchdog */
  49                r = efi_set_timer(watchdog_timer_event, EFI_TIMER_RELATIVE,
  50                                  EFI_SECONDS_TO_100NS * timeout);
  51        else
  52                /* Deactivate watchdog */
  53                r = efi_set_timer(watchdog_timer_event, EFI_TIMER_STOP, 0);
  54        return r;
  55}
  56
  57/*
  58 * Initialize the EFI watchdog.
  59 *
  60 * This function is called by efi_init_obj_list()
  61 */
  62int efi_watchdog_register(void)
  63{
  64        efi_status_t r;
  65
  66        /*
  67         * Create a timer event.
  68         */
  69        r = efi_create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
  70                             efi_watchdog_timer_notify, NULL,
  71                             &watchdog_timer_event);
  72        if (r != EFI_SUCCESS) {
  73                printf("ERROR: Failed to register watchdog event\n");
  74                return r;
  75        }
  76        /*
  77         * The UEFI standard requires that the watchdog timer is set to five
  78         * minutes when invoking an EFI boot option.
  79         *
  80         * Unified Extensible Firmware Interface (UEFI), version 2.7 Errata A
  81         * 7.5. Miscellaneous Boot Services - EFI_BOOT_SERVICES.SetWatchdogTimer
  82         */
  83        r = efi_set_watchdog(300);
  84        if (r != EFI_SUCCESS) {
  85                printf("ERROR: Failed to set watchdog timer\n");
  86                return r;
  87        }
  88        return 0;
  89}
  90