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
   9 static void (*orig_pm_power_off)(void);
  10
  11 int efi_reboot_quirk_mode = -1;
  12
  13 void 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
  49 bool __weak efi_poweroff_required(void)
  50 {
  51         return false;
  52 }
  53
  54 static 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
  65 static 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 }
  77 late_initcall(efi_shutdown_init);