xref: /openbmc/linux/drivers/firmware/efi/reboot.c (revision 711aab1d)
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);
77