1 /*
2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
7 *
8 * This file is released under the GPLv2.
9 */
10
11 #include <linux/string.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/console.h>
16 #include <linux/cpu.h>
17 #include <linux/syscalls.h>
18 #include <linux/gfp.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
22 #include <linux/mm.h>
23 #include <linux/slab.h>
24 #include <linux/export.h>
25 #include <linux/suspend.h>
26 #include <linux/syscore_ops.h>
27 #include <linux/ftrace.h>
28 #include <linux/rtc.h>
29 #include <trace/events/power.h>
30 #include <linux/wakeup_reason.h>
31
32 #include "power.h"
33
34 const char *const pm_states[PM_SUSPEND_MAX] = {
35 [PM_SUSPEND_FREEZE] = "freeze",
36 [PM_SUSPEND_STANDBY] = "standby",
37 [PM_SUSPEND_MEM] = "mem",
38 };
39
40 static const struct platform_suspend_ops *suspend_ops;
41
need_suspend_ops(suspend_state_t state)42 static bool need_suspend_ops(suspend_state_t state)
43 {
44 return !!(state > PM_SUSPEND_FREEZE);
45 }
46
47 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
48 static bool suspend_freeze_wake;
49
freeze_begin(void)50 static void freeze_begin(void)
51 {
52 suspend_freeze_wake = false;
53 }
54
freeze_enter(void)55 static void freeze_enter(void)
56 {
57 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
58 }
59
freeze_wake(void)60 void freeze_wake(void)
61 {
62 suspend_freeze_wake = true;
63 wake_up(&suspend_freeze_wait_head);
64 }
65 EXPORT_SYMBOL_GPL(freeze_wake);
66
67 /**
68 * suspend_set_ops - Set the global suspend method table.
69 * @ops: Suspend operations to use.
70 */
suspend_set_ops(const struct platform_suspend_ops * ops)71 void suspend_set_ops(const struct platform_suspend_ops *ops)
72 {
73 lock_system_sleep();
74 suspend_ops = ops;
75 unlock_system_sleep();
76 }
77 EXPORT_SYMBOL_GPL(suspend_set_ops);
78
valid_state(suspend_state_t state)79 bool valid_state(suspend_state_t state)
80 {
81 if (state == PM_SUSPEND_FREEZE) {
82 #ifdef CONFIG_PM_DEBUG
83 if (pm_test_level != TEST_NONE &&
84 pm_test_level != TEST_FREEZER &&
85 pm_test_level != TEST_DEVICES &&
86 pm_test_level != TEST_PLATFORM) {
87 printk(KERN_WARNING "Unsupported pm_test mode for "
88 "freeze state, please choose "
89 "none/freezer/devices/platform.\n");
90 return false;
91 }
92 #endif
93 return true;
94 }
95 /*
96 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
97 * support and need to be valid to the lowlevel
98 * implementation, no valid callback implies that none are valid.
99 */
100 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
101 }
102
103 /**
104 * suspend_valid_only_mem - Generic memory-only valid callback.
105 *
106 * Platform drivers that implement mem suspend only and only need to check for
107 * that in their .valid() callback can use this instead of rolling their own
108 * .valid() callback.
109 */
suspend_valid_only_mem(suspend_state_t state)110 int suspend_valid_only_mem(suspend_state_t state)
111 {
112 return state == PM_SUSPEND_MEM;
113 }
114 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
115
suspend_test(int level)116 static int suspend_test(int level)
117 {
118 #ifdef CONFIG_PM_DEBUG
119 if (pm_test_level == level) {
120 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
121 mdelay(5000);
122 return 1;
123 }
124 #endif /* !CONFIG_PM_DEBUG */
125 return 0;
126 }
127
128 /**
129 * suspend_prepare - Prepare for entering system sleep state.
130 *
131 * Common code run for every system sleep state that can be entered (except for
132 * hibernation). Run suspend notifiers, allocate the "suspend" console and
133 * freeze processes.
134 */
suspend_prepare(suspend_state_t state)135 static int suspend_prepare(suspend_state_t state)
136 {
137 int error;
138
139 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
140 return -EPERM;
141
142 pm_prepare_console();
143
144 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
145 if (error)
146 goto Finish;
147
148 error = suspend_freeze_processes();
149 if (!error)
150 return 0;
151 log_suspend_abort_reason("One or more tasks refusing to freeze");
152 suspend_stats.failed_freeze++;
153 dpm_save_failed_step(SUSPEND_FREEZE);
154 Finish:
155 pm_notifier_call_chain(PM_POST_SUSPEND);
156 pm_restore_console();
157 return error;
158 }
159
160 /* default implementation */
arch_suspend_disable_irqs(void)161 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
162 {
163 local_irq_disable();
164 }
165
166 /* default implementation */
arch_suspend_enable_irqs(void)167 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
168 {
169 local_irq_enable();
170 }
171
172 /**
173 * suspend_enter - Make the system enter the given sleep state.
174 * @state: System sleep state to enter.
175 * @wakeup: Returns information that the sleep state should not be re-entered.
176 *
177 * This function should be called after devices have been suspended.
178 */
suspend_enter(suspend_state_t state,bool * wakeup)179 static int suspend_enter(suspend_state_t state, bool *wakeup)
180 {
181 char suspend_abort[MAX_SUSPEND_ABORT_LEN];
182 int error, last_dev;
183
184 if (need_suspend_ops(state) && suspend_ops->prepare) {
185 error = suspend_ops->prepare();
186 if (error)
187 goto Platform_finish;
188 }
189
190 error = dpm_suspend_end(PMSG_SUSPEND);
191 if (error) {
192 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
193 last_dev %= REC_FAILED_NUM;
194 printk(KERN_ERR "PM: Some devices failed to power down\n");
195 log_suspend_abort_reason("%s device failed to power down",
196 suspend_stats.failed_devs[last_dev]);
197 goto Platform_finish;
198 }
199
200 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
201 error = suspend_ops->prepare_late();
202 if (error)
203 goto Platform_wake;
204 }
205
206 if (suspend_test(TEST_PLATFORM))
207 goto Platform_wake;
208
209 /*
210 * PM_SUSPEND_FREEZE equals
211 * frozen processes + suspended devices + idle processors.
212 * Thus we should invoke freeze_enter() soon after
213 * all the devices are suspended.
214 */
215 if (state == PM_SUSPEND_FREEZE) {
216 freeze_enter();
217 goto Platform_wake;
218 }
219
220 error = disable_nonboot_cpus();
221 if (error || suspend_test(TEST_CPUS)) {
222 log_suspend_abort_reason("Disabling non-boot cpus failed");
223 goto Enable_cpus;
224 }
225
226 arch_suspend_disable_irqs();
227 BUG_ON(!irqs_disabled());
228
229 error = syscore_suspend();
230 if (!error) {
231 *wakeup = pm_wakeup_pending();
232 if (!(suspend_test(TEST_CORE) || *wakeup)) {
233 error = suspend_ops->enter(state);
234 events_check_enabled = false;
235 } else if (*wakeup) {
236 pm_get_active_wakeup_sources(suspend_abort,
237 MAX_SUSPEND_ABORT_LEN);
238 log_suspend_abort_reason(suspend_abort);
239 error = -EBUSY;
240 }
241 syscore_resume();
242 }
243
244 arch_suspend_enable_irqs();
245 BUG_ON(irqs_disabled());
246
247 Enable_cpus:
248 enable_nonboot_cpus();
249
250 Platform_wake:
251 if (need_suspend_ops(state) && suspend_ops->wake)
252 suspend_ops->wake();
253
254 dpm_resume_start(PMSG_RESUME);
255
256 Platform_finish:
257 if (need_suspend_ops(state) && suspend_ops->finish)
258 suspend_ops->finish();
259
260 return error;
261 }
262
263 /**
264 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
265 * @state: System sleep state to enter.
266 */
suspend_devices_and_enter(suspend_state_t state)267 int suspend_devices_and_enter(suspend_state_t state)
268 {
269 int error;
270 bool wakeup = false;
271
272 if (need_suspend_ops(state) && !suspend_ops)
273 return -ENOSYS;
274
275 trace_machine_suspend(state);
276 if (need_suspend_ops(state) && suspend_ops->begin) {
277 error = suspend_ops->begin(state);
278 if (error)
279 goto Close;
280 }
281 suspend_console();
282 ftrace_stop();
283 suspend_test_start();
284 error = dpm_suspend_start(PMSG_SUSPEND);
285 if (error) {
286 printk(KERN_ERR "PM: Some devices failed to suspend\n");
287 log_suspend_abort_reason("Some devices failed to suspend");
288 goto Recover_platform;
289 }
290 suspend_test_finish("suspend devices");
291 if (suspend_test(TEST_DEVICES))
292 goto Recover_platform;
293
294 do {
295 error = suspend_enter(state, &wakeup);
296 } while (!error && !wakeup && need_suspend_ops(state)
297 && suspend_ops->suspend_again && suspend_ops->suspend_again());
298
299 Resume_devices:
300 suspend_test_start();
301 dpm_resume_end(PMSG_RESUME);
302 suspend_test_finish("resume devices");
303 ftrace_start();
304 resume_console();
305 Close:
306 if (need_suspend_ops(state) && suspend_ops->end)
307 suspend_ops->end();
308 trace_machine_suspend(PWR_EVENT_EXIT);
309 return error;
310
311 Recover_platform:
312 if (need_suspend_ops(state) && suspend_ops->recover)
313 suspend_ops->recover();
314 goto Resume_devices;
315 }
316
317 /**
318 * suspend_finish - Clean up before finishing the suspend sequence.
319 *
320 * Call platform code to clean up, restart processes, and free the console that
321 * we've allocated. This routine is not called for hibernation.
322 */
suspend_finish(void)323 static void suspend_finish(void)
324 {
325 suspend_thaw_processes();
326 pm_notifier_call_chain(PM_POST_SUSPEND);
327 pm_restore_console();
328 }
329
330 /**
331 * enter_state - Do common work needed to enter system sleep state.
332 * @state: System sleep state to enter.
333 *
334 * Make sure that no one else is trying to put the system into a sleep state.
335 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
336 * system enter the given sleep state and clean up after wakeup.
337 */
enter_state(suspend_state_t state)338 static int enter_state(suspend_state_t state)
339 {
340 int error;
341
342 if (!valid_state(state))
343 return -ENODEV;
344
345 if (!mutex_trylock(&pm_mutex))
346 return -EBUSY;
347
348 if (state == PM_SUSPEND_FREEZE)
349 freeze_begin();
350
351 printk(KERN_INFO "PM: Syncing filesystems ... ");
352 sys_sync();
353 printk("done.\n");
354
355 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
356 error = suspend_prepare(state);
357 if (error)
358 goto Unlock;
359
360 if (suspend_test(TEST_FREEZER))
361 goto Finish;
362
363 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
364 pm_restrict_gfp_mask();
365 error = suspend_devices_and_enter(state);
366 pm_restore_gfp_mask();
367
368 Finish:
369 pr_debug("PM: Finishing wakeup.\n");
370 suspend_finish();
371 Unlock:
372 mutex_unlock(&pm_mutex);
373 return error;
374 }
375
pm_suspend_marker(char * annotation)376 static void pm_suspend_marker(char *annotation)
377 {
378 struct timespec ts;
379 struct rtc_time tm;
380
381 getnstimeofday(&ts);
382 rtc_time_to_tm(ts.tv_sec, &tm);
383 pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
384 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
385 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
386 }
387
388 /**
389 * pm_suspend - Externally visible function for suspending the system.
390 * @state: System sleep state to enter.
391 *
392 * Check if the value of @state represents one of the supported states,
393 * execute enter_state() and update system suspend statistics.
394 */
pm_suspend(suspend_state_t state)395 int pm_suspend(suspend_state_t state)
396 {
397 int error;
398
399 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
400 return -EINVAL;
401
402 pm_suspend_marker("entry");
403 error = enter_state(state);
404 if (error) {
405 suspend_stats.fail++;
406 dpm_save_failed_errno(error);
407 } else {
408 suspend_stats.success++;
409 }
410 pm_suspend_marker("exit");
411 return error;
412 }
413 EXPORT_SYMBOL(pm_suspend);
414