LXR linux/drivers/firmware/efi/reboot.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2014 Intel Corporation; author Matt Fleming
   4 * Copyright (c) 2014 Red Hat, Inc., Mark Salter <msalter@redhat.com>
   5 */
   6#include <linux/efi.h>
   7#include <linux/reboot.h>
   8
   9static void (*orig_pm_power_off)(void);
  10
  11int efi_reboot_quirk_mode = -1;
  12
  13void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
  14{
  15        const char *str[] = { "cold", "warm", "shutdown", "platform" };
  16        int efi_mode, cap_reset_mode;
  17
  18        if (!efi_enabled(EFI_RUNTIME_SERVICES))
  19                return;
  20
  21        switch (reboot_mode) {
  22        case REBOOT_WARM:
  23        case REBOOT_SOFT:
  24                efi_mode = EFI_RESET_WARM;
  25                break;
  26        default:
  27                efi_mode = EFI_RESET_COLD;
  28                break;
  29        }
  30
  31        /*
  32         * If a quirk forced an EFI reset mode, always use that.
  33         */
  34        if (efi_reboot_quirk_mode != -1)
  35                efi_mode = efi_reboot_quirk_mode;
  36
  37        if (efi_capsule_pending(&cap_reset_mode)) {
  38                if (efi_mode != cap_reset_mode)
  39                        printk(KERN_CRIT "efi: %s reset requested but pending "
  40                               "capsule update requires %s reset... Performing "
  41                               "%s reset.\n", str[efi_mode], str[cap_reset_mode],
  42                               str[cap_reset_mode]);
  43                efi_mode = cap_reset_mode;
  44        }
  45
  46        efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL);
  47}
  48
  49bool __weak efi_poweroff_required(void)
  50{
  51        return false;
  52}
  53
  54static void efi_power_off(void)
  55{
  56        efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
  57        /*
  58         * The above call should not return, if it does fall back to
  59         * the original power off method (typically ACPI poweroff).
  60         */
  61        if (orig_pm_power_off)
  62                orig_pm_power_off();
  63}
  64
  65static int __init efi_shutdown_init(void)
  66{
  67        if (!efi_enabled(EFI_RUNTIME_SERVICES))
  68                return -ENODEV;
  69
  70        if (efi_poweroff_required()) {
  71                orig_pm_power_off = pm_power_off;
  72                pm_power_off = efi_power_off;
  73        }
  74
  75        return 0;
  76}
  77late_initcall(efi_shutdown_init);
  78