Merge tag 'for-linus-v3.10-rc1-2' of git://oss.sgi.com/xfs/xfs
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / suspend.c
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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>
5a0e3ad6 18#include <linux/gfp.h>
dd4c4f17
MG
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>
6e5fdeed 24#include <linux/export.h>
dd4c4f17 25#include <linux/suspend.h>
40dc166c 26#include <linux/syscore_ops.h>
443772d4 27#include <linux/ftrace.h>
938cfed1 28#include <trace/events/power.h>
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29
30#include "power.h"
31
32const char *const pm_states[PM_SUSPEND_MAX] = {
7e73c5ae 33 [PM_SUSPEND_FREEZE] = "freeze",
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34 [PM_SUSPEND_STANDBY] = "standby",
35 [PM_SUSPEND_MEM] = "mem",
36};
37
2f55ac07 38static const struct platform_suspend_ops *suspend_ops;
a9d70523 39
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40static bool need_suspend_ops(suspend_state_t state)
41{
42 return !!(state > PM_SUSPEND_FREEZE);
43}
44
45static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
46static bool suspend_freeze_wake;
47
48static void freeze_begin(void)
49{
50 suspend_freeze_wake = false;
51}
52
53static void freeze_enter(void)
54{
55 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
56}
57
58void freeze_wake(void)
59{
60 suspend_freeze_wake = true;
61 wake_up(&suspend_freeze_wait_head);
62}
63EXPORT_SYMBOL_GPL(freeze_wake);
64
a9d70523 65/**
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66 * suspend_set_ops - Set the global suspend method table.
67 * @ops: Suspend operations to use.
a9d70523 68 */
2f55ac07 69void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523 70{
bcda53fa 71 lock_system_sleep();
a9d70523 72 suspend_ops = ops;
bcda53fa 73 unlock_system_sleep();
a9d70523 74}
a5e4fd87 75EXPORT_SYMBOL_GPL(suspend_set_ops);
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76
77bool valid_state(suspend_state_t state)
78{
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79 if (state == PM_SUSPEND_FREEZE) {
80#ifdef CONFIG_PM_DEBUG
81 if (pm_test_level != TEST_NONE &&
82 pm_test_level != TEST_FREEZER &&
83 pm_test_level != TEST_DEVICES &&
84 pm_test_level != TEST_PLATFORM) {
85 printk(KERN_WARNING "Unsupported pm_test mode for "
86 "freeze state, please choose "
87 "none/freezer/devices/platform.\n");
88 return false;
89 }
90#endif
91 return true;
92 }
a9d70523 93 /*
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94 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
95 * support and need to be valid to the lowlevel
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96 * implementation, no valid callback implies that none are valid.
97 */
98 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
99}
100
101/**
55ae4519 102 * suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523 103 *
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104 * Platform drivers that implement mem suspend only and only need to check for
105 * that in their .valid() callback can use this instead of rolling their own
106 * .valid() callback.
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107 */
108int suspend_valid_only_mem(suspend_state_t state)
109{
110 return state == PM_SUSPEND_MEM;
111}
a5e4fd87 112EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
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113
114static int suspend_test(int level)
115{
116#ifdef CONFIG_PM_DEBUG
117 if (pm_test_level == level) {
118 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
119 mdelay(5000);
120 return 1;
121 }
122#endif /* !CONFIG_PM_DEBUG */
123 return 0;
124}
125
126/**
55ae4519 127 * suspend_prepare - Prepare for entering system sleep state.
a9d70523 128 *
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129 * Common code run for every system sleep state that can be entered (except for
130 * hibernation). Run suspend notifiers, allocate the "suspend" console and
131 * freeze processes.
a9d70523 132 */
7e73c5ae 133static int suspend_prepare(suspend_state_t state)
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134{
135 int error;
136
7e73c5ae 137 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
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138 return -EPERM;
139
140 pm_prepare_console();
141
142 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
143 if (error)
144 goto Finish;
145
a9d70523 146 error = suspend_freeze_processes();
03afed8b 147 if (!error)
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148 return 0;
149
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150 suspend_stats.failed_freeze++;
151 dpm_save_failed_step(SUSPEND_FREEZE);
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152 Finish:
153 pm_notifier_call_chain(PM_POST_SUSPEND);
154 pm_restore_console();
155 return error;
156}
157
158/* default implementation */
159void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
160{
161 local_irq_disable();
162}
163
164/* default implementation */
165void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
166{
167 local_irq_enable();
168}
169
170/**
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171 * suspend_enter - Make the system enter the given sleep state.
172 * @state: System sleep state to enter.
173 * @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523 174 *
3b5fe852 175 * This function should be called after devices have been suspended.
a9d70523 176 */
3b5fe852 177static int suspend_enter(suspend_state_t state, bool *wakeup)
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178{
179 int error;
180
7e73c5ae 181 if (need_suspend_ops(state) && suspend_ops->prepare) {
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182 error = suspend_ops->prepare();
183 if (error)
ce441011 184 goto Platform_finish;
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185 }
186
cf579dfb 187 error = dpm_suspend_end(PMSG_SUSPEND);
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188 if (error) {
189 printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011 190 goto Platform_finish;
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191 }
192
7e73c5ae 193 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
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194 error = suspend_ops->prepare_late();
195 if (error)
ce441011 196 goto Platform_wake;
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197 }
198
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199 if (suspend_test(TEST_PLATFORM))
200 goto Platform_wake;
201
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202 /*
203 * PM_SUSPEND_FREEZE equals
204 * frozen processes + suspended devices + idle processors.
205 * Thus we should invoke freeze_enter() soon after
206 * all the devices are suspended.
207 */
208 if (state == PM_SUSPEND_FREEZE) {
209 freeze_enter();
210 goto Platform_wake;
211 }
212
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213 error = disable_nonboot_cpus();
214 if (error || suspend_test(TEST_CPUS))
215 goto Enable_cpus;
216
217 arch_suspend_disable_irqs();
218 BUG_ON(!irqs_disabled());
219
2e711c04 220 error = syscore_suspend();
a9d70523 221 if (!error) {
3b5fe852
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222 *wakeup = pm_wakeup_pending();
223 if (!(suspend_test(TEST_CORE) || *wakeup)) {
a9d70523 224 error = suspend_ops->enter(state);
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225 events_check_enabled = false;
226 }
40dc166c 227 syscore_resume();
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228 }
229
230 arch_suspend_enable_irqs();
231 BUG_ON(irqs_disabled());
232
233 Enable_cpus:
234 enable_nonboot_cpus();
235
236 Platform_wake:
7e73c5ae 237 if (need_suspend_ops(state) && suspend_ops->wake)
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238 suspend_ops->wake();
239
cf579dfb 240 dpm_resume_start(PMSG_RESUME);
a9d70523 241
ce441011 242 Platform_finish:
7e73c5ae 243 if (need_suspend_ops(state) && suspend_ops->finish)
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244 suspend_ops->finish();
245
246 return error;
247}
248
249/**
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250 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
251 * @state: System sleep state to enter.
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252 */
253int suspend_devices_and_enter(suspend_state_t state)
254{
255 int error;
3b5fe852 256 bool wakeup = false;
a9d70523 257
7e73c5ae 258 if (need_suspend_ops(state) && !suspend_ops)
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259 return -ENOSYS;
260
938cfed1 261 trace_machine_suspend(state);
7e73c5ae 262 if (need_suspend_ops(state) && suspend_ops->begin) {
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263 error = suspend_ops->begin(state);
264 if (error)
265 goto Close;
266 }
267 suspend_console();
443772d4 268 ftrace_stop();
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269 suspend_test_start();
270 error = dpm_suspend_start(PMSG_SUSPEND);
271 if (error) {
272 printk(KERN_ERR "PM: Some devices failed to suspend\n");
273 goto Recover_platform;
274 }
275 suspend_test_finish("suspend devices");
276 if (suspend_test(TEST_DEVICES))
277 goto Recover_platform;
278
3b5fe852
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279 do {
280 error = suspend_enter(state, &wakeup);
7e73c5ae 281 } while (!error && !wakeup && need_suspend_ops(state)
3b5fe852 282 && suspend_ops->suspend_again && suspend_ops->suspend_again());
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283
284 Resume_devices:
285 suspend_test_start();
286 dpm_resume_end(PMSG_RESUME);
287 suspend_test_finish("resume devices");
443772d4 288 ftrace_start();
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289 resume_console();
290 Close:
7e73c5ae 291 if (need_suspend_ops(state) && suspend_ops->end)
a9d70523 292 suspend_ops->end();
938cfed1 293 trace_machine_suspend(PWR_EVENT_EXIT);
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294 return error;
295
296 Recover_platform:
7e73c5ae 297 if (need_suspend_ops(state) && suspend_ops->recover)
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298 suspend_ops->recover();
299 goto Resume_devices;
300}
301
302/**
55ae4519 303 * suspend_finish - Clean up before finishing the suspend sequence.
a9d70523 304 *
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305 * Call platform code to clean up, restart processes, and free the console that
306 * we've allocated. This routine is not called for hibernation.
a9d70523
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307 */
308static void suspend_finish(void)
309{
310 suspend_thaw_processes();
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311 pm_notifier_call_chain(PM_POST_SUSPEND);
312 pm_restore_console();
313}
314
315/**
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316 * enter_state - Do common work needed to enter system sleep state.
317 * @state: System sleep state to enter.
a9d70523 318 *
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319 * Make sure that no one else is trying to put the system into a sleep state.
320 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
321 * system enter the given sleep state and clean up after wakeup.
a9d70523 322 */
93e1ee43 323static int enter_state(suspend_state_t state)
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324{
325 int error;
326
327 if (!valid_state(state))
328 return -ENODEV;
329
330 if (!mutex_trylock(&pm_mutex))
331 return -EBUSY;
332
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333 if (state == PM_SUSPEND_FREEZE)
334 freeze_begin();
335
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336 printk(KERN_INFO "PM: Syncing filesystems ... ");
337 sys_sync();
338 printk("done.\n");
339
340 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
7e73c5ae 341 error = suspend_prepare(state);
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342 if (error)
343 goto Unlock;
344
345 if (suspend_test(TEST_FREEZER))
346 goto Finish;
347
348 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475 349 pm_restrict_gfp_mask();
a9d70523 350 error = suspend_devices_and_enter(state);
87186475 351 pm_restore_gfp_mask();
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352
353 Finish:
354 pr_debug("PM: Finishing wakeup.\n");
355 suspend_finish();
356 Unlock:
357 mutex_unlock(&pm_mutex);
358 return error;
359}
360
361/**
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362 * pm_suspend - Externally visible function for suspending the system.
363 * @state: System sleep state to enter.
a9d70523 364 *
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365 * Check if the value of @state represents one of the supported states,
366 * execute enter_state() and update system suspend statistics.
a9d70523
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367 */
368int pm_suspend(suspend_state_t state)
369{
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370 int error;
371
372 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
373 return -EINVAL;
374
375 error = enter_state(state);
376 if (error) {
377 suspend_stats.fail++;
378 dpm_save_failed_errno(error);
379 } else {
380 suspend_stats.success++;
2a77c46d 381 }
bc25cf50 382 return error;
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383}
384EXPORT_SYMBOL(pm_suspend);