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