drivers/firmware/efi/reboot.c

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