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 struct sys_off_handler *efi_sys_off_handler;
  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_rt_services_supported(EFI_RT_SUPPORTED_RESET_SYSTEM))
  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 int efi_power_off(struct sys_off_data *data)
  55 {
  56         efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
  57
  58         return NOTIFY_DONE;
  59 }
  60
  61 static int __init efi_shutdown_init(void)
  62 {
  63         if (!efi_rt_services_supported(EFI_RT_SUPPORTED_RESET_SYSTEM))
  64                 return -ENODEV;
  65
  66         if (efi_poweroff_required()) {
  67                 /* SYS_OFF_PRIO_FIRMWARE + 1 so that it runs before acpi_power_off */
  68                 efi_sys_off_handler =
  69                         register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
  70                                                  SYS_OFF_PRIO_FIRMWARE + 1,
  71                                                  efi_power_off, NULL);
  72                 if (IS_ERR(efi_sys_off_handler))
  73                         return PTR_ERR(efi_sys_off_handler);
  74         }
  75
  76         return 0;
  77 }
  78 late_initcall(efi_shutdown_init);