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/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 <linux/rtc.h>
  30 #include <trace/events/power.h>
  31 #include <linux/compiler.h>
  32 #include <linux/moduleparam.h>
  33 #include <linux/wakeup_reason.h>
  34
  35 #include "power.h"
  36
  37 const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
  38 const char *pm_states[PM_SUSPEND_MAX];
  39
  40 unsigned int pm_suspend_global_flags;
  41 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
  42
  43 static const struct platform_suspend_ops *suspend_ops;
  44 static const struct platform_freeze_ops *freeze_ops;
  45 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
  46
  47 enum freeze_state __read_mostly suspend_freeze_state;
  48 static DEFINE_SPINLOCK(suspend_freeze_lock);
  49
  50 void freeze_set_ops(const struct platform_freeze_ops *ops)
  51 {
  52         lock_system_sleep();
  53         freeze_ops = ops;
  54         unlock_system_sleep();
  55 }
  56
  57 static void freeze_begin(void)
  58 {
  59         suspend_freeze_state = FREEZE_STATE_NONE;
  60 }
  61
  62 static void freeze_enter(void)
  63 {
  64         spin_lock_irq(&suspend_freeze_lock);
  65         if (pm_wakeup_pending())
  66                 goto out;
  67
  68         suspend_freeze_state = FREEZE_STATE_ENTER;
  69         spin_unlock_irq(&suspend_freeze_lock);
  70
  71         get_online_cpus();
  72         cpuidle_resume();
  73
  74         /* Push all the CPUs into the idle loop. */
  75         wake_up_all_idle_cpus();
  76         pr_debug("PM: suspend-to-idle\n");
  77         /* Make the current CPU wait so it can enter the idle loop too. */
  78         wait_event(suspend_freeze_wait_head,
  79                    suspend_freeze_state == FREEZE_STATE_WAKE);
  80         pr_debug("PM: resume from suspend-to-idle\n");
  81
  82         cpuidle_pause();
  83         put_online_cpus();
  84
  85         spin_lock_irq(&suspend_freeze_lock);
  86
  87  out:
  88         suspend_freeze_state = FREEZE_STATE_NONE;
  89         spin_unlock_irq(&suspend_freeze_lock);
  90 }
  91
  92 void freeze_wake(void)
  93 {
  94         unsigned long flags;
  95
  96         spin_lock_irqsave(&suspend_freeze_lock, flags);
  97         if (suspend_freeze_state > FREEZE_STATE_NONE) {
  98                 suspend_freeze_state = FREEZE_STATE_WAKE;
  99                 wake_up(&suspend_freeze_wait_head);
 100         }
 101         spin_unlock_irqrestore(&suspend_freeze_lock, flags);
 102 }
 103 EXPORT_SYMBOL_GPL(freeze_wake);
 104
 105 static bool valid_state(suspend_state_t state)
 106 {
 107         /*
 108          * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
 109          * support and need to be valid to the low level
 110          * implementation, no valid callback implies that none are valid.
 111          */
 112         return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
 113 }
 114
 115 /*
 116  * If this is set, the "mem" label always corresponds to the deepest sleep state
 117  * available, the "standby" label corresponds to the second deepest sleep state
 118  * available (if any), and the "freeze" label corresponds to the remaining
 119  * available sleep state (if there is one).
 120  */
 121 static bool relative_states;
 122
 123 static int __init sleep_states_setup(char *str)
 124 {
 125         relative_states = !strncmp(str, "1", 1);
 126         pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
 127         return 1;
 128 }
 129
 130 __setup("relative_sleep_states=", sleep_states_setup);
 131
 132 /**
 133  * suspend_set_ops - Set the global suspend method table.
 134  * @ops: Suspend operations to use.
 135  */
 136 void suspend_set_ops(const struct platform_suspend_ops *ops)
 137 {
 138         suspend_state_t i;
 139         int j = 0;
 140
 141         lock_system_sleep();
 142
 143         suspend_ops = ops;
 144         for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
 145                 if (valid_state(i)) {
 146                         pm_states[i] = pm_labels[j++];
 147                 } else if (!relative_states) {
 148                         pm_states[i] = NULL;
 149                         j++;
 150                 }
 151
 152         pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
 153
 154         unlock_system_sleep();
 155 }
 156 EXPORT_SYMBOL_GPL(suspend_set_ops);
 157
 158 /**
 159  * suspend_valid_only_mem - Generic memory-only valid callback.
 160  *
 161  * Platform drivers that implement mem suspend only and only need to check for
 162  * that in their .valid() callback can use this instead of rolling their own
 163  * .valid() callback.
 164  */
 165 int suspend_valid_only_mem(suspend_state_t state)
 166 {
 167         return state == PM_SUSPEND_MEM;
 168 }
 169 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
 170
 171 static bool sleep_state_supported(suspend_state_t state)
 172 {
 173         return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
 174 }
 175
 176 static int platform_suspend_prepare(suspend_state_t state)
 177 {
 178         return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
 179                 suspend_ops->prepare() : 0;
 180 }
 181
 182 static int platform_suspend_prepare_late(suspend_state_t state)
 183 {
 184         return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
 185                 freeze_ops->prepare() : 0;
 186 }
 187
 188 static int platform_suspend_prepare_noirq(suspend_state_t state)
 189 {
 190         return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
 191                 suspend_ops->prepare_late() : 0;
 192 }
 193
 194 static void platform_resume_noirq(suspend_state_t state)
 195 {
 196         if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
 197                 suspend_ops->wake();
 198 }
 199
 200 static void platform_resume_early(suspend_state_t state)
 201 {
 202         if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
 203                 freeze_ops->restore();
 204 }
 205
 206 static void platform_resume_finish(suspend_state_t state)
 207 {
 208         if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
 209                 suspend_ops->finish();
 210 }
 211
 212 static int platform_suspend_begin(suspend_state_t state)
 213 {
 214         if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
 215                 return freeze_ops->begin();
 216         else if (suspend_ops->begin)
 217                 return suspend_ops->begin(state);
 218         else
 219                 return 0;
 220 }
 221
 222 static void platform_resume_end(suspend_state_t state)
 223 {
 224         if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
 225                 freeze_ops->end();
 226         else if (suspend_ops->end)
 227                 suspend_ops->end();
 228 }
 229
 230 static void platform_recover(suspend_state_t state)
 231 {
 232         if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
 233                 suspend_ops->recover();
 234 }
 235
 236 static bool platform_suspend_again(suspend_state_t state)
 237 {
 238         return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
 239                 suspend_ops->suspend_again() : false;
 240 }
 241
 242 #ifdef CONFIG_PM_DEBUG
 243 static unsigned int pm_test_delay = 5;
 244 module_param(pm_test_delay, uint, 0644);
 245 MODULE_PARM_DESC(pm_test_delay,
 246                  "Number of seconds to wait before resuming from suspend test");
 247 #endif
 248
 249 static int suspend_test(int level)
 250 {
 251 #ifdef CONFIG_PM_DEBUG
 252         if (pm_test_level == level) {
 253                 printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
 254                                 pm_test_delay);
 255                 mdelay(pm_test_delay * 1000);
 256                 return 1;
 257         }
 258 #endif /* !CONFIG_PM_DEBUG */
 259         return 0;
 260 }
 261
 262 /**
 263  * suspend_prepare - Prepare for entering system sleep state.
 264  *
 265  * Common code run for every system sleep state that can be entered (except for
 266  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 267  * freeze processes.
 268  */
 269 static int suspend_prepare(suspend_state_t state)
 270 {
 271         int error, nr_calls = 0;
 272
 273         if (!sleep_state_supported(state))
 274                 return -EPERM;
 275
 276         pm_prepare_console();
 277
 278         error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
 279         if (error) {
 280                 nr_calls--;
 281                 goto Finish;
 282         }
 283
 284         trace_suspend_resume(TPS("freeze_processes"), 0, true);
 285         error = suspend_freeze_processes();
 286         trace_suspend_resume(TPS("freeze_processes"), 0, false);
 287         if (!error)
 288                 return 0;
 289
 290         suspend_stats.failed_freeze++;
 291         dpm_save_failed_step(SUSPEND_FREEZE);
 292  Finish:
 293         __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
 294         pm_restore_console();
 295         return error;
 296 }
 297
 298 /* default implementation */
 299 void __weak arch_suspend_disable_irqs(void)
 300 {
 301         local_irq_disable();
 302 }
 303
 304 /* default implementation */
 305 void __weak arch_suspend_enable_irqs(void)
 306 {
 307         local_irq_enable();
 308 }
 309
 310 /**
 311  * suspend_enter - Make the system enter the given sleep state.
 312  * @state: System sleep state to enter.
 313  * @wakeup: Returns information that the sleep state should not be re-entered.
 314  *
 315  * This function should be called after devices have been suspended.
 316  */
 317 static int suspend_enter(suspend_state_t state, bool *wakeup)
 318 {
 319         char suspend_abort[MAX_SUSPEND_ABORT_LEN];
 320         int error, last_dev;
 321
 322         error = platform_suspend_prepare(state);
 323         if (error)
 324                 goto Platform_finish;
 325
 326         error = dpm_suspend_late(PMSG_SUSPEND);
 327         if (error) {
 328                 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 329                 last_dev %= REC_FAILED_NUM;
 330                 printk(KERN_ERR "PM: late suspend of devices failed\n");
 331                 log_suspend_abort_reason("%s device failed to power down",
 332                         suspend_stats.failed_devs[last_dev]);
 333                 goto Platform_finish;
 334         }
 335         error = platform_suspend_prepare_late(state);
 336         if (error)
 337                 goto Devices_early_resume;
 338
 339         error = dpm_suspend_noirq(PMSG_SUSPEND);
 340         if (error) {
 341                 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 342                 last_dev %= REC_FAILED_NUM;
 343                 printk(KERN_ERR "PM: noirq suspend of devices failed\n");
 344                 log_suspend_abort_reason("noirq suspend of %s device failed",
 345                         suspend_stats.failed_devs[last_dev]);
 346                 goto Platform_early_resume;
 347         }
 348         error = platform_suspend_prepare_noirq(state);
 349         if (error)
 350                 goto Platform_wake;
 351
 352         if (suspend_test(TEST_PLATFORM))
 353                 goto Platform_wake;
 354
 355         /*
 356          * PM_SUSPEND_FREEZE equals
 357          * frozen processes + suspended devices + idle processors.
 358          * Thus we should invoke freeze_enter() soon after
 359          * all the devices are suspended.
 360          */
 361         if (state == PM_SUSPEND_FREEZE) {
 362                 trace_suspend_resume(TPS("machine_suspend"), state, true);
 363                 freeze_enter();
 364                 trace_suspend_resume(TPS("machine_suspend"), state, false);
 365                 goto Platform_wake;
 366         }
 367
 368         error = disable_nonboot_cpus();
 369         if (error || suspend_test(TEST_CPUS)) {
 370                 log_suspend_abort_reason("Disabling non-boot cpus failed");
 371                 goto Enable_cpus;
 372         }
 373
 374         arch_suspend_disable_irqs();
 375         BUG_ON(!irqs_disabled());
 376
 377         error = syscore_suspend();
 378         if (!error) {
 379                 *wakeup = pm_wakeup_pending();
 380                 if (!(suspend_test(TEST_CORE) || *wakeup)) {
 381                         trace_suspend_resume(TPS("machine_suspend"),
 382                                 state, true);
 383                         error = suspend_ops->enter(state);
 384                         trace_suspend_resume(TPS("machine_suspend"),
 385                                 state, false);
 386                         events_check_enabled = false;
 387                 } else if (*wakeup) {
 388                         pm_get_active_wakeup_sources(suspend_abort,
 389                                 MAX_SUSPEND_ABORT_LEN);
 390                         log_suspend_abort_reason(suspend_abort);
 391                         error = -EBUSY;
 392                 }
 393                 syscore_resume();
 394         }
 395
 396         arch_suspend_enable_irqs();
 397         BUG_ON(irqs_disabled());
 398
 399  Enable_cpus:
 400         enable_nonboot_cpus();
 401
 402  Platform_wake:
 403         platform_resume_noirq(state);
 404         dpm_resume_noirq(PMSG_RESUME);
 405
 406  Platform_early_resume:
 407         platform_resume_early(state);
 408
 409  Devices_early_resume:
 410         dpm_resume_early(PMSG_RESUME);
 411
 412  Platform_finish:
 413         platform_resume_finish(state);
 414         return error;
 415 }
 416
 417 /**
 418  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 419  * @state: System sleep state to enter.
 420  */
 421 int suspend_devices_and_enter(suspend_state_t state)
 422 {
 423         int error;
 424         bool wakeup = false;
 425
 426         if (!sleep_state_supported(state))
 427                 return -ENOSYS;
 428
 429         error = platform_suspend_begin(state);
 430         if (error)
 431                 goto Close;
 432
 433         suspend_console();
 434         suspend_test_start();
 435         error = dpm_suspend_start(PMSG_SUSPEND);
 436         if (error) {
 437                 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
 438                 log_suspend_abort_reason("Some devices failed to suspend, or early wake event detected");
 439                 goto Recover_platform;
 440         }
 441         suspend_test_finish("suspend devices");
 442         if (suspend_test(TEST_DEVICES))
 443                 goto Recover_platform;
 444
 445         do {
 446                 error = suspend_enter(state, &wakeup);
 447         } while (!error && !wakeup && platform_suspend_again(state));
 448
 449  Resume_devices:
 450         suspend_test_start();
 451         dpm_resume_end(PMSG_RESUME);
 452         suspend_test_finish("resume devices");
 453         trace_suspend_resume(TPS("resume_console"), state, true);
 454         resume_console();
 455         trace_suspend_resume(TPS("resume_console"), state, false);
 456
 457  Close:
 458         platform_resume_end(state);
 459         return error;
 460
 461  Recover_platform:
 462         platform_recover(state);
 463         goto Resume_devices;
 464 }
 465
 466 /**
 467  * suspend_finish - Clean up before finishing the suspend sequence.
 468  *
 469  * Call platform code to clean up, restart processes, and free the console that
 470  * we've allocated. This routine is not called for hibernation.
 471  */
 472 static void suspend_finish(void)
 473 {
 474         suspend_thaw_processes();
 475         pm_notifier_call_chain(PM_POST_SUSPEND);
 476         pm_restore_console();
 477 }
 478
 479 /**
 480  * enter_state - Do common work needed to enter system sleep state.
 481  * @state: System sleep state to enter.
 482  *
 483  * Make sure that no one else is trying to put the system into a sleep state.
 484  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 485  * system enter the given sleep state and clean up after wakeup.
 486  */
 487 static int enter_state(suspend_state_t state)
 488 {
 489         int error;
 490
 491         trace_suspend_resume(TPS("suspend_enter"), state, true);
 492         if (state == PM_SUSPEND_FREEZE) {
 493 #ifdef CONFIG_PM_DEBUG
 494                 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
 495                         pr_warning("PM: Unsupported test mode for suspend to idle,"
 496                                    "please choose none/freezer/devices/platform.\n");
 497                         return -EAGAIN;
 498                 }
 499 #endif
 500         } else if (!valid_state(state)) {
 501                 return -EINVAL;
 502         }
 503         if (!mutex_trylock(&pm_mutex))
 504                 return -EBUSY;
 505
 506         if (state == PM_SUSPEND_FREEZE)
 507                 freeze_begin();
 508
 509 #ifndef CONFIG_SUSPEND_SKIP_SYNC
 510         trace_suspend_resume(TPS("sync_filesystems"), 0, true);
 511         printk(KERN_INFO "PM: Syncing filesystems ... ");
 512         sys_sync();
 513         printk("done.\n");
 514         trace_suspend_resume(TPS("sync_filesystems"), 0, false);
 515 #endif
 516
 517         pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
 518         pm_suspend_clear_flags();
 519         error = suspend_prepare(state);
 520         if (error)
 521                 goto Unlock;
 522
 523         if (suspend_test(TEST_FREEZER))
 524                 goto Finish;
 525
 526         trace_suspend_resume(TPS("suspend_enter"), state, false);
 527         pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
 528         pm_restrict_gfp_mask();
 529         error = suspend_devices_and_enter(state);
 530         pm_restore_gfp_mask();
 531
 532  Finish:
 533         pr_debug("PM: Finishing wakeup.\n");
 534         suspend_finish();
 535  Unlock:
 536         mutex_unlock(&pm_mutex);
 537         return error;
 538 }
 539
 540 static void pm_suspend_marker(char *annotation)
 541 {
 542         struct timespec ts;
 543         struct rtc_time tm;
 544
 545         getnstimeofday(&ts);
 546         rtc_time_to_tm(ts.tv_sec, &tm);
 547         pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
 548                 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 549                 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 550 }
 551
 552 /**
 553  * pm_suspend - Externally visible function for suspending the system.
 554  * @state: System sleep state to enter.
 555  *
 556  * Check if the value of @state represents one of the supported states,
 557  * execute enter_state() and update system suspend statistics.
 558  */
 559 int pm_suspend(suspend_state_t state)
 560 {
 561         int error;
 562
 563         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 564                 return -EINVAL;
 565
 566         pm_suspend_marker("entry");
 567         error = enter_state(state);
 568         if (error) {
 569                 suspend_stats.fail++;
 570                 dpm_save_failed_errno(error);
 571         } else {
 572                 suspend_stats.success++;
 573         }
 574         pm_suspend_marker("exit");
 575         return error;
 576 }
 577 EXPORT_SYMBOL(pm_suspend);