1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * EFI watchdog
4 *
5 * Copyright (c) 2017 Heinrich Schuchardt
6 */
7
8 #include <common.h>
9 #include <efi_loader.h>
10
11 /* Conversion factor from seconds to multiples of 100ns */
12 #define EFI_SECONDS_TO_100NS 10000000ULL
13
14 static struct efi_event *watchdog_timer_event;
15
16 /**
17 * efi_watchdog_timer_notify() - resets system upon watchdog event
18 *
19 * Reset the system when the watchdog event is notified.
20 *
21 * @event: the watchdog event
22 * @context: not used
23 */
efi_watchdog_timer_notify(struct efi_event * event,void * context)24 static void EFIAPI efi_watchdog_timer_notify(struct efi_event *event,
25 void *context)
26 {
27 EFI_ENTRY("%p, %p", event, context);
28
29 printf("\nEFI: Watchdog timeout\n");
30 do_reset(NULL, 0, 0, NULL);
31
32 EFI_EXIT(EFI_UNSUPPORTED);
33 }
34
35 /**
36 * efi_set_watchdog() - resets the watchdog timer
37 *
38 * This function is used by the SetWatchdogTimer service.
39 *
40 * @timeout: seconds before reset by watchdog
41 * Return: status code
42 */
efi_set_watchdog(unsigned long timeout)43 efi_status_t efi_set_watchdog(unsigned long timeout)
44 {
45 efi_status_t r;
46
47 if (timeout)
48 /* Reset watchdog */
49 r = efi_set_timer(watchdog_timer_event, EFI_TIMER_RELATIVE,
50 EFI_SECONDS_TO_100NS * timeout);
51 else
52 /* Deactivate watchdog */
53 r = efi_set_timer(watchdog_timer_event, EFI_TIMER_STOP, 0);
54 return r;
55 }
56
57 /**
58 * efi_watchdog_register() - initializes the EFI watchdog
59 *
60 * This function is called by efi_init_obj_list().
61 *
62 * Return: status code
63 */
efi_watchdog_register(void)64 efi_status_t efi_watchdog_register(void)
65 {
66 efi_status_t r;
67
68 /*
69 * Create a timer event.
70 */
71 r = efi_create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
72 efi_watchdog_timer_notify, NULL, NULL,
73 &watchdog_timer_event);
74 if (r != EFI_SUCCESS) {
75 printf("ERROR: Failed to register watchdog event\n");
76 return r;
77 }
78
79 return EFI_SUCCESS;
80 }
81