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 struct pm_sleep_state pm_states[PM_SUSPEND_MAX] = {
  34 #ifdef CONFIG_EARLYSUSPEND
  35         [PM_SUSPEND_ON]         = { .label = "on", },
  36 #endif
  37         [PM_SUSPEND_FREEZE] = { .label = "freeze", .state = PM_SUSPEND_FREEZE },
  38         [PM_SUSPEND_STANDBY] = { .label = "standby", },
  39         [PM_SUSPEND_MEM] = { .label = "mem", },
  40 };
  41
  42 static const struct platform_suspend_ops *suspend_ops;
  43
  44 static bool need_suspend_ops(suspend_state_t state)
  45 {
  46         return !!(state > PM_SUSPEND_FREEZE);
  47 }
  48
  49 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
  50 static bool suspend_freeze_wake;
  51
  52 static void freeze_begin(void)
  53 {
  54         suspend_freeze_wake = false;
  55 }
  56
  57 static void freeze_enter(void)
  58 {
  59         wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
  60 }
  61
  62 void freeze_wake(void)
  63 {
  64         suspend_freeze_wake = true;
  65         wake_up(&suspend_freeze_wait_head);
  66 }
  67 EXPORT_SYMBOL_GPL(freeze_wake);
  68
  69 bool valid_state(suspend_state_t state)
  70 {
  71         /*
  72          * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
  73          * support and need to be valid to the low level
  74          * implementation, no valid callback implies that none are valid.
  75          */
  76         return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
  77 }
  78
  79 /**
  80  * suspend_set_ops - Set the global suspend method table.
  81  * @ops: Suspend operations to use.
  82  */
  83 void suspend_set_ops(const struct platform_suspend_ops *ops)
  84 {
  85         suspend_state_t i;
  86
  87         lock_system_sleep();
  88
  89         suspend_ops = ops;
  90         for (i = PM_SUSPEND_STANDBY; i <= PM_SUSPEND_MEM; i++)
  91                 pm_states[i].state = valid_state(i) ? i : 0;
  92
  93         unlock_system_sleep();
  94 }
  95 EXPORT_SYMBOL_GPL(suspend_set_ops);
  96
  97 /**
  98  * suspend_valid_only_mem - Generic memory-only valid callback.
  99  *
 100  * Platform drivers that implement mem suspend only and only need to check for
 101  * that in their .valid() callback can use this instead of rolling their own
 102  * .valid() callback.
 103  */
 104 int suspend_valid_only_mem(suspend_state_t state)
 105 {
 106         return state == PM_SUSPEND_MEM;
 107 }
 108 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
 109
 110 static int suspend_test(int level)
 111 {
 112 #ifdef CONFIG_PM_DEBUG
 113         if (pm_test_level == level) {
 114                 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
 115                 mdelay(5000);
 116                 return 1;
 117         }
 118 #endif /* !CONFIG_PM_DEBUG */
 119         return 0;
 120 }
 121
 122 /**
 123  * suspend_prepare - Prepare for entering system sleep state.
 124  *
 125  * Common code run for every system sleep state that can be entered (except for
 126  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 127  * freeze processes.
 128  */
 129 static int suspend_prepare(suspend_state_t state)
 130 {
 131         int error;
 132
 133         if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 134                 return -EPERM;
 135
 136         pm_prepare_console();
 137
 138         error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
 139         if (error)
 140                 goto Finish;
 141
 142         error = suspend_freeze_processes();
 143         if (!error)
 144                 return 0;
 145
 146         suspend_stats.failed_freeze++;
 147         dpm_save_failed_step(SUSPEND_FREEZE);
 148  Finish:
 149         pm_notifier_call_chain(PM_POST_SUSPEND);
 150         pm_restore_console();
 151         return error;
 152 }
 153
 154 /* default implementation */
 155 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
 156 {
 157         local_irq_disable();
 158 }
 159
 160 /* default implementation */
 161 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
 162 {
 163         local_irq_enable();
 164 }
 165
 166 /**
 167  * suspend_enter - Make the system enter the given sleep state.
 168  * @state: System sleep state to enter.
 169  * @wakeup: Returns information that the sleep state should not be re-entered.
 170  *
 171  * This function should be called after devices have been suspended.
 172  */
 173 static int suspend_enter(suspend_state_t state, bool *wakeup)
 174 {
 175         int error;
 176
 177         if (need_suspend_ops(state) && suspend_ops->prepare) {
 178                 error = suspend_ops->prepare();
 179                 if (error)
 180                         goto Platform_finish;
 181         }
 182
 183         error = dpm_suspend_end(PMSG_SUSPEND);
 184         if (error) {
 185                 printk(KERN_ERR "PM: Some devices failed to power down\n");
 186                 goto Platform_finish;
 187         }
 188
 189         if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 190                 error = suspend_ops->prepare_late();
 191                 if (error)
 192                         goto Platform_wake;
 193         }
 194
 195         if (suspend_test(TEST_PLATFORM))
 196                 goto Platform_wake;
 197
 198         /*
 199          * PM_SUSPEND_FREEZE equals
 200          * frozen processes + suspended devices + idle processors.
 201          * Thus we should invoke freeze_enter() soon after
 202          * all the devices are suspended.
 203          */
 204         if (state == PM_SUSPEND_FREEZE) {
 205                 freeze_enter();
 206                 goto Platform_wake;
 207         }
 208
 209         error = disable_nonboot_cpus();
 210         if (error || suspend_test(TEST_CPUS))
 211                 goto Enable_cpus;
 212
 213         arch_suspend_disable_irqs();
 214         BUG_ON(!irqs_disabled());
 215
 216         error = syscore_suspend();
 217         if (!error) {
 218                 *wakeup = pm_wakeup_pending();
 219                 if (!(suspend_test(TEST_CORE) || *wakeup)) {
 220                         error = suspend_ops->enter(state);
 221                         events_check_enabled = false;
 222                 }
 223                 syscore_resume();
 224         }
 225
 226         arch_suspend_enable_irqs();
 227         BUG_ON(irqs_disabled());
 228
 229  Enable_cpus:
 230         enable_nonboot_cpus();
 231
 232  Platform_wake:
 233         if (need_suspend_ops(state) && suspend_ops->wake)
 234                 suspend_ops->wake();
 235
 236         dpm_resume_start(PMSG_RESUME);
 237
 238  Platform_finish:
 239         if (need_suspend_ops(state) && suspend_ops->finish)
 240                 suspend_ops->finish();
 241
 242         return error;
 243 }
 244
 245 /**
 246  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 247  * @state: System sleep state to enter.
 248  */
 249 int suspend_devices_and_enter(suspend_state_t state)
 250 {
 251         int error;
 252         bool wakeup = false;
 253
 254         if (need_suspend_ops(state) && !suspend_ops)
 255                 return -ENOSYS;
 256
 257 #ifdef CONFIG_TOI
 258         drop_pagecache();
 259 #endif
 260
 261         trace_machine_suspend(state);
 262         if (need_suspend_ops(state) && suspend_ops->begin) {
 263                 error = suspend_ops->begin(state);
 264                 if (error)
 265                         goto Close;
 266         }
 267         suspend_console();
 268         ftrace_stop();
 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
 279         do {
 280                 error = suspend_enter(state, &wakeup);
 281         } while (!error && !wakeup && need_suspend_ops(state)
 282                 && suspend_ops->suspend_again && suspend_ops->suspend_again());
 283
 284  Resume_devices:
 285         suspend_test_start();
 286         dpm_resume_end(PMSG_RESUME);
 287         suspend_test_finish("resume devices");
 288         ftrace_start();
 289         resume_console();
 290  Close:
 291         if (need_suspend_ops(state) && suspend_ops->end)
 292                 suspend_ops->end();
 293         trace_machine_suspend(PWR_EVENT_EXIT);
 294         return error;
 295
 296  Recover_platform:
 297         if (need_suspend_ops(state) && suspend_ops->recover)
 298                 suspend_ops->recover();
 299         goto Resume_devices;
 300 }
 301 EXPORT_SYMBOL_GPL(suspend_devices_and_enter);
 302
 303 /**
 304  * suspend_finish - Clean up before finishing the suspend sequence.
 305  *
 306  * Call platform code to clean up, restart processes, and free the console that
 307  * we've allocated. This routine is not called for hibernation.
 308  */
 309 static void suspend_finish(void)
 310 {
 311         suspend_thaw_processes();
 312         pm_notifier_call_chain(PM_POST_SUSPEND);
 313         pm_restore_console();
 314 }
 315
 316 /**
 317  * enter_state - Do common work needed to enter system sleep state.
 318  * @state: System sleep state to enter.
 319  *
 320  * Make sure that no one else is trying to put the system into a sleep state.
 321  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 322  * system enter the given sleep state and clean up after wakeup.
 323  */
 324 //<20130327> <marc.huang> merge from android kernel 3.0 - modify enter_state function to non-static
 325 int enter_state(suspend_state_t state)
 326 {
 327         int error;
 328
 329         if (state == PM_SUSPEND_FREEZE) {
 330 #ifdef CONFIG_PM_DEBUG
 331                 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
 332                         pr_warning("PM: Unsupported test mode for freeze state,"
 333                                    "please choose none/freezer/devices/platform.\n");
 334                         return -EAGAIN;
 335                 }
 336 #endif
 337         } else if (!valid_state(state)) {
 338                 return -EINVAL;
 339         }
 340         if (!mutex_trylock(&pm_mutex))
 341                 return -EBUSY;
 342
 343         if (state == PM_SUSPEND_FREEZE)
 344                 freeze_begin();
 345
 346         printk(KERN_INFO "PM: Syncing filesystems ... ");
 347         #if 1
 348         sys_sync();
 349         #else /* sys_sync WQ ver2.0 use */
 350     //[MTK]
 351     suspend_syssync_enqueue();
 352     suspend_check_sys_sync_done();
 353   #endif
 354         printk("done.\n");
 355
 356         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label);
 357         error = suspend_prepare(state);
 358         if (error)
 359                 goto Unlock;
 360
 361         if (suspend_test(TEST_FREEZER))
 362                 goto Finish;
 363
 364         pr_debug("PM: Entering %s sleep\n", pm_states[state].label);
 365         pm_restrict_gfp_mask();
 366         error = suspend_devices_and_enter(state);
 367         pm_restore_gfp_mask();
 368
 369  Finish:
 370         pr_debug("PM: Finishing wakeup.\n");
 371         suspend_finish();
 372  Unlock:
 373         mutex_unlock(&pm_mutex);
 374         return error;
 375 }
 376
 377 static void pm_suspend_marker(char *annotation)
 378 {
 379         struct timespec ts;
 380         struct rtc_time tm;
 381
 382         getnstimeofday(&ts);
 383         rtc_time_to_tm(ts.tv_sec, &tm);
 384         pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
 385                 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 386                 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 387 }
 388
 389 /**
 390  * pm_suspend - Externally visible function for suspending the system.
 391  * @state: System sleep state to enter.
 392  *
 393  * Check if the value of @state represents one of the supported states,
 394  * execute enter_state() and update system suspend statistics.
 395  */
 396 int pm_suspend(suspend_state_t state)
 397 {
 398         int error;
 399
 400         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 401                 return -EINVAL;
 402
 403         pm_suspend_marker("entry");
 404         error = enter_state(state);
 405         if (error) {
 406                 suspend_stats.fail++;
 407                 dpm_save_failed_errno(error);
 408         } else {
 409                 suspend_stats.success++;
 410         }
 411         pm_suspend_marker("exit");
 412         return error;
 413 }
 414 EXPORT_SYMBOL(pm_suspend);