kernel/power/suspend.c

   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
  31 #include "power.h"
  32
  33 const char *const pm_states[PM_SUSPEND_MAX] = {
  34 //<20130327> <marc.huang> merge from android kernel 3.0 - add [PM_SUSPEND_ON] into pm_states
  35 #ifdef CONFIG_EARLYSUSPEND
  36         [PM_SUSPEND_ON]         = "on",
  37 #endif
  38         [PM_SUSPEND_FREEZE]     = "freeze",
  39         [PM_SUSPEND_STANDBY]    = "standby",
  40         [PM_SUSPEND_MEM]        = "mem",
  41 };
  42
  43 static const struct platform_suspend_ops *suspend_ops;
  44
  45 static bool need_suspend_ops(suspend_state_t state)
  46 {
  47         return !!(state > PM_SUSPEND_FREEZE);
  48 }
  49
  50 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
  51 static bool suspend_freeze_wake;
  52
  53 static void freeze_begin(void)
  54 {
  55         suspend_freeze_wake = false;
  56 }
  57
  58 static void freeze_enter(void)
  59 {
  60         wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
  61 }
  62
  63 void freeze_wake(void)
  64 {
  65         suspend_freeze_wake = true;
  66         wake_up(&suspend_freeze_wait_head);
  67 }
  68 EXPORT_SYMBOL_GPL(freeze_wake);
  69
  70 /**
  71  * suspend_set_ops - Set the global suspend method table.
  72  * @ops: Suspend operations to use.
  73  */
  74 void suspend_set_ops(const struct platform_suspend_ops *ops)
  75 {
  76         lock_system_sleep();
  77         suspend_ops = ops;
  78         unlock_system_sleep();
  79 }
  80 EXPORT_SYMBOL_GPL(suspend_set_ops);
  81
  82 bool valid_state(suspend_state_t state)
  83 {
  84         if (state == PM_SUSPEND_FREEZE) {
  85 #ifdef CONFIG_PM_DEBUG
  86                 if (pm_test_level != TEST_NONE &&
  87                     pm_test_level != TEST_FREEZER &&
  88                     pm_test_level != TEST_DEVICES &&
  89                     pm_test_level != TEST_PLATFORM) {
  90                         printk(KERN_WARNING "Unsupported pm_test mode for "
  91                                         "freeze state, please choose "
  92                                         "none/freezer/devices/platform.\n");
  93                         return false;
  94                 }
  95 #endif
  96                         return true;
  97         }
  98         /*
  99          * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
 100          * support and need to be valid to the lowlevel
 101          * implementation, no valid callback implies that none are valid.
 102          */
 103         return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
 104 }
 105
 106 /**
 107  * suspend_valid_only_mem - Generic memory-only valid callback.
 108  *
 109  * Platform drivers that implement mem suspend only and only need to check for
 110  * that in their .valid() callback can use this instead of rolling their own
 111  * .valid() callback.
 112  */
 113 int suspend_valid_only_mem(suspend_state_t state)
 114 {
 115         return state == PM_SUSPEND_MEM;
 116 }
 117 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
 118
 119 static int suspend_test(int level)
 120 {
 121 #ifdef CONFIG_PM_DEBUG
 122         if (pm_test_level == level) {
 123                 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
 124                 mdelay(5000);
 125                 return 1;
 126         }
 127 #endif /* !CONFIG_PM_DEBUG */
 128         return 0;
 129 }
 130
 131 /**
 132  * suspend_prepare - Prepare for entering system sleep state.
 133  *
 134  * Common code run for every system sleep state that can be entered (except for
 135  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 136  * freeze processes.
 137  */
 138 static int suspend_prepare(suspend_state_t state)
 139 {
 140         int error;
 141
 142         if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 143                 return -EPERM;
 144
 145         pm_prepare_console();
 146
 147         error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
 148         if (error)
 149                 goto Finish;
 150
 151         error = suspend_freeze_processes();
 152         if (!error)
 153                 return 0;
 154
 155         suspend_stats.failed_freeze++;
 156         dpm_save_failed_step(SUSPEND_FREEZE);
 157  Finish:
 158         pm_notifier_call_chain(PM_POST_SUSPEND);
 159         pm_restore_console();
 160         return error;
 161 }
 162
 163 /* default implementation */
 164 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
 165 {
 166         local_irq_disable();
 167 }
 168
 169 /* default implementation */
 170 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
 171 {
 172         local_irq_enable();
 173 }
 174
 175 /**
 176  * suspend_enter - Make the system enter the given sleep state.
 177  * @state: System sleep state to enter.
 178  * @wakeup: Returns information that the sleep state should not be re-entered.
 179  *
 180  * This function should be called after devices have been suspended.
 181  */
 182 static int suspend_enter(suspend_state_t state, bool *wakeup)
 183 {
 184         int error;
 185
 186         if (need_suspend_ops(state) && suspend_ops->prepare) {
 187                 error = suspend_ops->prepare();
 188                 if (error)
 189                         goto Platform_finish;
 190         }
 191
 192         error = dpm_suspend_end(PMSG_SUSPEND);
 193         if (error) {
 194                 printk(KERN_ERR "PM: Some devices failed to power down\n");
 195                 goto Platform_finish;
 196         }
 197
 198         if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 199                 error = suspend_ops->prepare_late();
 200                 if (error)
 201                         goto Platform_wake;
 202         }
 203
 204         if (suspend_test(TEST_PLATFORM))
 205                 goto Platform_wake;
 206
 207         /*
 208          * PM_SUSPEND_FREEZE equals
 209          * frozen processes + suspended devices + idle processors.
 210          * Thus we should invoke freeze_enter() soon after
 211          * all the devices are suspended.
 212          */
 213         if (state == PM_SUSPEND_FREEZE) {
 214                 freeze_enter();
 215                 goto Platform_wake;
 216         }
 217
 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
 241  Platform_wake:
 242         if (need_suspend_ops(state) && suspend_ops->wake)
 243                 suspend_ops->wake();
 244
 245         dpm_resume_start(PMSG_RESUME);
 246
 247  Platform_finish:
 248         if (need_suspend_ops(state) && suspend_ops->finish)
 249                 suspend_ops->finish();
 250
 251         return error;
 252 }
 253
 254 /**
 255  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 256  * @state: System sleep state to enter.
 257  */
 258 int suspend_devices_and_enter(suspend_state_t state)
 259 {
 260         int error;
 261         bool wakeup = false;
 262
 263         if (need_suspend_ops(state) && !suspend_ops)
 264                 return -ENOSYS;
 265
 266 #ifdef CONFIG_TOI
 267         drop_pagecache();
 268 #endif
 269
 270         trace_machine_suspend(state);
 271         if (need_suspend_ops(state) && suspend_ops->begin) {
 272                 error = suspend_ops->begin(state);
 273                 if (error)
 274                         goto Close;
 275         }
 276         suspend_console();
 277         ftrace_stop();
 278         suspend_test_start();
 279         error = dpm_suspend_start(PMSG_SUSPEND);
 280         if (error) {
 281                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
 282                 goto Recover_platform;
 283         }
 284         suspend_test_finish("suspend devices");
 285         if (suspend_test(TEST_DEVICES))
 286                 goto Recover_platform;
 287
 288         do {
 289                 error = suspend_enter(state, &wakeup);
 290         } while (!error && !wakeup && need_suspend_ops(state)
 291                 && suspend_ops->suspend_again && suspend_ops->suspend_again());
 292
 293  Resume_devices:
 294         suspend_test_start();
 295         dpm_resume_end(PMSG_RESUME);
 296         suspend_test_finish("resume devices");
 297         ftrace_start();
 298         resume_console();
 299  Close:
 300         if (need_suspend_ops(state) && suspend_ops->end)
 301                 suspend_ops->end();
 302         trace_machine_suspend(PWR_EVENT_EXIT);
 303         return error;
 304
 305  Recover_platform:
 306         if (need_suspend_ops(state) && suspend_ops->recover)
 307                 suspend_ops->recover();
 308         goto Resume_devices;
 309 }
 310 EXPORT_SYMBOL_GPL(suspend_devices_and_enter);
 311
 312 /**
 313  * suspend_finish - Clean up before finishing the suspend sequence.
 314  *
 315  * Call platform code to clean up, restart processes, and free the console that
 316  * we've allocated. This routine is not called for hibernation.
 317  */
 318 static void suspend_finish(void)
 319 {
 320         suspend_thaw_processes();
 321         pm_notifier_call_chain(PM_POST_SUSPEND);
 322         pm_restore_console();
 323 }
 324
 325 /**
 326  * enter_state - Do common work needed to enter system sleep state.
 327  * @state: System sleep state to enter.
 328  *
 329  * Make sure that no one else is trying to put the system into a sleep state.
 330  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 331  * system enter the given sleep state and clean up after wakeup.
 332  */
 333 //<20130327> <marc.huang> merge from android kernel 3.0 - modify enter_state function to non-static
 334 int enter_state(suspend_state_t state)
 335 {
 336         int error;
 337
 338         if (!valid_state(state))
 339                 return -ENODEV;
 340
 341         if (!mutex_trylock(&pm_mutex))
 342                 return -EBUSY;
 343
 344         if (state == PM_SUSPEND_FREEZE)
 345                 freeze_begin();
 346
 347         printk(KERN_INFO "PM: Syncing filesystems ... ");
 348         #if 1
 349         sys_sync();
 350         #else /* sys_sync WQ ver2.0 use */
 351     //[MTK]
 352     suspend_syssync_enqueue();
 353     suspend_check_sys_sync_done();
 354   #endif
 355         printk("done.\n");
 356
 357         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
 358         error = suspend_prepare(state);
 359         if (error)
 360                 goto Unlock;
 361
 362         if (suspend_test(TEST_FREEZER))
 363                 goto Finish;
 364
 365         pr_debug("PM: Entering %s sleep\n", pm_states[state]);
 366         pm_restrict_gfp_mask();
 367         error = suspend_devices_and_enter(state);
 368         pm_restore_gfp_mask();
 369
 370  Finish:
 371         pr_debug("PM: Finishing wakeup.\n");
 372         suspend_finish();
 373  Unlock:
 374         mutex_unlock(&pm_mutex);
 375         return error;
 376 }
 377
 378 static void pm_suspend_marker(char *annotation)
 379 {
 380         struct timespec ts;
 381         struct rtc_time tm;
 382
 383         getnstimeofday(&ts);
 384         rtc_time_to_tm(ts.tv_sec, &tm);
 385         pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
 386                 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 387                 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 388 }
 389
 390 /**
 391  * pm_suspend - Externally visible function for suspending the system.
 392  * @state: System sleep state to enter.
 393  *
 394  * Check if the value of @state represents one of the supported states,
 395  * execute enter_state() and update system suspend statistics.
 396  */
 397 int pm_suspend(suspend_state_t state)
 398 {
 399         int error;
 400
 401         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 402                 return -EINVAL;
 403
 404         pm_suspend_marker("entry");
 405         error = enter_state(state);
 406         if (error) {
 407                 suspend_stats.fail++;
 408                 dpm_save_failed_errno(error);
 409         } else {
 410                 suspend_stats.success++;
 411         }
 412         pm_suspend_marker("exit");
 413         return error;
 414 }
 415 EXPORT_SYMBOL(pm_suspend);