1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * efi_selftest_watchdog
4  *
5  * Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
6  *
7  * The 'watchdog timer' unit test checks that the watchdog timer
8  * will not cause a system restart during the timeout period after
9  * a timer reset.
10  *
11  * The 'watchdog reboot' unit test checks that the watchdog timer
12  * actually reboots the system after a timeout. The test is only
13  * executed on explicit request. Use the following commands:
14  *
15  *	setenv efi_selftest watchdog reboot
16  *	bootefi selftest
17  */
18 
19 #include <efi_selftest.h>
20 
21 /*
22  * This is the communication structure for the notification function.
23  */
24 struct notify_context {
25 	/* Status code returned when resetting watchdog */
26 	efi_status_t status;
27 	/* Number of invocations of the notification function */
28 	unsigned int timer_ticks;
29 };
30 
31 static struct efi_event *event_notify;
32 static struct efi_event *event_wait;
33 static struct efi_boot_services *boottime;
34 static struct notify_context notification_context;
35 static bool watchdog_reset;
36 
37 /*
38  * Notification function, increments the notification count if parameter
39  * context is provided.
40  *
41  * @event	notified event
42  * @context	pointer to the timeout
43  */
44 static void EFIAPI notify(struct efi_event *event, void *context)
45 {
46 	struct notify_context *notify_context = context;
47 	efi_status_t ret = EFI_SUCCESS;
48 
49 	if (!notify_context)
50 		return;
51 
52 	/* Reset watchdog timer to one second */
53 	ret = boottime->set_watchdog_timer(1, 0, 0, NULL);
54 	if (ret != EFI_SUCCESS)
55 		notify_context->status = ret;
56 	/* Count number of calls */
57 	notify_context->timer_ticks++;
58 }
59 
60 /*
61  * Setup unit test.
62  *
63  * Create two timer events.
64  * One with EVT_NOTIFY_SIGNAL, the other with EVT_NOTIFY_WAIT.
65  *
66  * @handle:	handle of the loaded image
67  * @systable:	system table
68  * @return:	EFI_ST_SUCCESS for success
69  */
70 static int setup(const efi_handle_t handle,
71 		 const struct efi_system_table *systable)
72 {
73 	efi_status_t ret;
74 
75 	boottime = systable->boottime;
76 
77 	notification_context.status = EFI_SUCCESS;
78 	notification_context.timer_ticks = 0;
79 	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL,
80 				     TPL_CALLBACK, notify,
81 				     (void *)&notification_context,
82 				     &event_notify);
83 	if (ret != EFI_SUCCESS) {
84 		efi_st_error("could not create event\n");
85 		return EFI_ST_FAILURE;
86 	}
87 	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_WAIT,
88 				     TPL_CALLBACK, notify, NULL, &event_wait);
89 	if (ret != EFI_SUCCESS) {
90 		efi_st_error("could not create event\n");
91 		return EFI_ST_FAILURE;
92 	}
93 	return EFI_ST_SUCCESS;
94 }
95 
96 /*
97  * Execute the test resetting the watchdog in a timely manner. No reboot occurs.
98  *
99  * @handle:	handle of the loaded image
100  * @systable:	system table
101  * @return:	EFI_ST_SUCCESS for success
102  */
103 static int setup_timer(const efi_handle_t handle,
104 		       const struct efi_system_table *systable)
105 {
106 	watchdog_reset = true;
107 	return setup(handle, systable);
108 }
109 
110 /*
111  * Execute the test without resetting the watchdog. A system reboot occurs.
112  *
113  * @handle:	handle of the loaded image
114  * @systable:	system table
115  * @return:	EFI_ST_SUCCESS for success
116  */
117 static int setup_reboot(const efi_handle_t handle,
118 			const struct efi_system_table *systable)
119 {
120 	watchdog_reset = false;
121 	return setup(handle, systable);
122 }
123 
124 /*
125  * Tear down unit test.
126  *
127  * Close the events created in setup.
128  *
129  * @return:	EFI_ST_SUCCESS for success
130  */
131 static int teardown(void)
132 {
133 	efi_status_t ret;
134 
135 	/* Set the watchdog timer to the five minute default value */
136 	ret = boottime->set_watchdog_timer(300, 0, 0, NULL);
137 	if (ret != EFI_SUCCESS) {
138 		efi_st_error("Setting watchdog timer failed\n");
139 		return EFI_ST_FAILURE;
140 	}
141 	if (event_notify) {
142 		ret = boottime->close_event(event_notify);
143 		event_notify = NULL;
144 		if (ret != EFI_SUCCESS) {
145 			efi_st_error("Could not close event\n");
146 			return EFI_ST_FAILURE;
147 		}
148 	}
149 	if (event_wait) {
150 		ret = boottime->close_event(event_wait);
151 		event_wait = NULL;
152 		if (ret != EFI_SUCCESS) {
153 			efi_st_error("Could not close event\n");
154 			return EFI_ST_FAILURE;
155 		}
156 	}
157 	return EFI_ST_SUCCESS;
158 }
159 
160 /*
161  * Execute unit test.
162  *
163  * Run a 600 ms periodic timer that resets the watchdog to one second
164  * on every timer tick.
165  *
166  * Run a 1350 ms single shot timer and check that the 600ms timer has
167  * been called 2 times.
168  *
169  * @return:	EFI_ST_SUCCESS for success
170  */
171 static int execute(void)
172 {
173 	size_t index;
174 	efi_status_t ret;
175 
176 	/* Set the watchdog timeout to one second */
177 	ret = boottime->set_watchdog_timer(1, 0, 0, NULL);
178 	if (ret != EFI_SUCCESS) {
179 		efi_st_error("Setting watchdog timer failed\n");
180 		return EFI_ST_FAILURE;
181 	}
182 	if (watchdog_reset) {
183 		/* Set 600 ms timer */
184 		ret = boottime->set_timer(event_notify, EFI_TIMER_PERIODIC,
185 					  6000000);
186 		if (ret != EFI_SUCCESS) {
187 			efi_st_error("Could not set timer\n");
188 			return EFI_ST_FAILURE;
189 		}
190 	}
191 	/* Set 1350 ms timer */
192 	ret = boottime->set_timer(event_wait, EFI_TIMER_RELATIVE, 13500000);
193 	if (ret != EFI_SUCCESS) {
194 		efi_st_error("Could not set timer\n");
195 		return EFI_ST_FAILURE;
196 	}
197 
198 	ret = boottime->wait_for_event(1, &event_wait, &index);
199 	if (ret != EFI_SUCCESS) {
200 		efi_st_error("Could not wait for event\n");
201 		return EFI_ST_FAILURE;
202 	}
203 	if (notification_context.status != EFI_SUCCESS) {
204 		efi_st_error("Setting watchdog timer failed\n");
205 		return EFI_ST_FAILURE;
206 	}
207 	if (notification_context.timer_ticks != 2) {
208 		efi_st_error("The timer was called %u times, expected 2.\n",
209 			     notification_context.timer_ticks);
210 		return EFI_ST_FAILURE;
211 	}
212 	return EFI_ST_SUCCESS;
213 }
214 
215 EFI_UNIT_TEST(watchdog1) = {
216 	.name = "watchdog timer",
217 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
218 	.setup = setup_timer,
219 	.execute = execute,
220 	.teardown = teardown,
221 };
222 
223 EFI_UNIT_TEST(watchdog2) = {
224 	.name = "watchdog reboot",
225 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
226 	.setup = setup_reboot,
227 	.execute = execute,
228 	.teardown = teardown,
229 	.on_request = true,
230 };
231