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;
 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);
 279         if (error)
 280                 goto Finish;
 281
 282         trace_suspend_resume(TPS("freeze_processes"), 0, true);
 283         error = suspend_freeze_processes();
 284         trace_suspend_resume(TPS("freeze_processes"), 0, false);
 285         if (!error)
 286                 return 0;
 287
 288         suspend_stats.failed_freeze++;
 289         dpm_save_failed_step(SUSPEND_FREEZE);
 290  Finish:
 291         pm_notifier_call_chain(PM_POST_SUSPEND);
 292         pm_restore_console();
 293         return error;
 294 }
 295
 296 /* default implementation */
 297 void __weak arch_suspend_disable_irqs(void)
 298 {
 299         local_irq_disable();
 300 }
 301
 302 /* default implementation */
 303 void __weak arch_suspend_enable_irqs(void)
 304 {
 305         local_irq_enable();
 306 }
 307
 308 /**
 309  * suspend_enter - Make the system enter the given sleep state.
 310  * @state: System sleep state to enter.
 311  * @wakeup: Returns information that the sleep state should not be re-entered.
 312  *
 313  * This function should be called after devices have been suspended.
 314  */
 315 static int suspend_enter(suspend_state_t state, bool *wakeup)
 316 {
 317         char suspend_abort[MAX_SUSPEND_ABORT_LEN];
 318         int error, last_dev;
 319
 320         error = platform_suspend_prepare(state);
 321         if (error)
 322                 goto Platform_finish;
 323
 324         error = dpm_suspend_late(PMSG_SUSPEND);
 325         if (error) {
 326                 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 327                 last_dev %= REC_FAILED_NUM;
 328                 printk(KERN_ERR "PM: late suspend of devices failed\n");
 329                 log_suspend_abort_reason("%s device failed to power down",
 330                         suspend_stats.failed_devs[last_dev]);
 331                 goto Platform_finish;
 332         }
 333         error = platform_suspend_prepare_late(state);
 334         if (error)
 335                 goto Devices_early_resume;
 336
 337         error = dpm_suspend_noirq(PMSG_SUSPEND);
 338         if (error) {
 339                 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 340                 last_dev %= REC_FAILED_NUM;
 341                 printk(KERN_ERR "PM: noirq suspend of devices failed\n");
 342                 log_suspend_abort_reason("noirq suspend of %s device failed",
 343                         suspend_stats.failed_devs[last_dev]);
 344                 goto Platform_early_resume;
 345         }
 346         error = platform_suspend_prepare_noirq(state);
 347         if (error)
 348                 goto Platform_wake;
 349
 350         if (suspend_test(TEST_PLATFORM))
 351                 goto Platform_wake;
 352
 353         /*
 354          * PM_SUSPEND_FREEZE equals
 355          * frozen processes + suspended devices + idle processors.
 356          * Thus we should invoke freeze_enter() soon after
 357          * all the devices are suspended.
 358          */
 359         if (state == PM_SUSPEND_FREEZE) {
 360                 trace_suspend_resume(TPS("machine_suspend"), state, true);
 361                 freeze_enter();
 362                 trace_suspend_resume(TPS("machine_suspend"), state, false);
 363                 goto Platform_wake;
 364         }
 365
 366         error = disable_nonboot_cpus();
 367         if (error || suspend_test(TEST_CPUS)) {
 368                 log_suspend_abort_reason("Disabling non-boot cpus failed");
 369                 goto Enable_cpus;
 370         }
 371
 372         arch_suspend_disable_irqs();
 373         BUG_ON(!irqs_disabled());
 374
 375         error = syscore_suspend();
 376         if (!error) {
 377                 *wakeup = pm_wakeup_pending();
 378                 if (!(suspend_test(TEST_CORE) || *wakeup)) {
 379                         trace_suspend_resume(TPS("machine_suspend"),
 380                                 state, true);
 381                         error = suspend_ops->enter(state);
 382                         trace_suspend_resume(TPS("machine_suspend"),
 383                                 state, false);
 384                         events_check_enabled = false;
 385                 } else if (*wakeup) {
 386                         pm_get_active_wakeup_sources(suspend_abort,
 387                                 MAX_SUSPEND_ABORT_LEN);
 388                         log_suspend_abort_reason(suspend_abort);
 389                         error = -EBUSY;
 390                 }
 391                 syscore_resume();
 392         }
 393
 394         arch_suspend_enable_irqs();
 395         BUG_ON(irqs_disabled());
 396
 397  Enable_cpus:
 398         enable_nonboot_cpus();
 399
 400  Platform_wake:
 401         platform_resume_noirq(state);
 402         dpm_resume_noirq(PMSG_RESUME);
 403
 404  Platform_early_resume:
 405         platform_resume_early(state);
 406
 407  Devices_early_resume:
 408         dpm_resume_early(PMSG_RESUME);
 409
 410  Platform_finish:
 411         platform_resume_finish(state);
 412         return error;
 413 }
 414
 415 /**
 416  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 417  * @state: System sleep state to enter.
 418  */
 419 int suspend_devices_and_enter(suspend_state_t state)
 420 {
 421         int error;
 422         bool wakeup = false;
 423
 424         if (!sleep_state_supported(state))
 425                 return -ENOSYS;
 426
 427         error = platform_suspend_begin(state);
 428         if (error)
 429                 goto Close;
 430
 431         suspend_console();
 432         suspend_test_start();
 433         error = dpm_suspend_start(PMSG_SUSPEND);
 434         if (error) {
 435                 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
 436                 log_suspend_abort_reason("Some devices failed to suspend, or early wake event detected");
 437                 goto Recover_platform;
 438         }
 439         suspend_test_finish("suspend devices");
 440         if (suspend_test(TEST_DEVICES))
 441                 goto Recover_platform;
 442
 443         do {
 444                 error = suspend_enter(state, &wakeup);
 445         } while (!error && !wakeup && platform_suspend_again(state));
 446
 447  Resume_devices:
 448         suspend_test_start();
 449         dpm_resume_end(PMSG_RESUME);
 450         suspend_test_finish("resume devices");
 451         trace_suspend_resume(TPS("resume_console"), state, true);
 452         resume_console();
 453         trace_suspend_resume(TPS("resume_console"), state, false);
 454
 455  Close:
 456         platform_resume_end(state);
 457         return error;
 458
 459  Recover_platform:
 460         platform_recover(state);
 461         goto Resume_devices;
 462 }
 463
 464 /**
 465  * suspend_finish - Clean up before finishing the suspend sequence.
 466  *
 467  * Call platform code to clean up, restart processes, and free the console that
 468  * we've allocated. This routine is not called for hibernation.
 469  */
 470 static void suspend_finish(void)
 471 {
 472         suspend_thaw_processes();
 473         pm_notifier_call_chain(PM_POST_SUSPEND);
 474         pm_restore_console();
 475 }
 476
 477 /**
 478  * enter_state - Do common work needed to enter system sleep state.
 479  * @state: System sleep state to enter.
 480  *
 481  * Make sure that no one else is trying to put the system into a sleep state.
 482  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 483  * system enter the given sleep state and clean up after wakeup.
 484  */
 485 static int enter_state(suspend_state_t state)
 486 {
 487         int error;
 488
 489         trace_suspend_resume(TPS("suspend_enter"), state, true);
 490         if (state == PM_SUSPEND_FREEZE) {
 491 #ifdef CONFIG_PM_DEBUG
 492                 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
 493                         pr_warning("PM: Unsupported test mode for suspend to idle,"
 494                                    "please choose none/freezer/devices/platform.\n");
 495                         return -EAGAIN;
 496                 }
 497 #endif
 498         } else if (!valid_state(state)) {
 499                 return -EINVAL;
 500         }
 501         if (!mutex_trylock(&pm_mutex))
 502                 return -EBUSY;
 503
 504         if (state == PM_SUSPEND_FREEZE)
 505                 freeze_begin();
 506
 507 #ifndef CONFIG_SUSPEND_SKIP_SYNC
 508         trace_suspend_resume(TPS("sync_filesystems"), 0, true);
 509         printk(KERN_INFO "PM: Syncing filesystems ... ");
 510         sys_sync();
 511         printk("done.\n");
 512         trace_suspend_resume(TPS("sync_filesystems"), 0, false);
 513 #endif
 514
 515         pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
 516         pm_suspend_clear_flags();
 517         error = suspend_prepare(state);
 518         if (error)
 519                 goto Unlock;
 520
 521         if (suspend_test(TEST_FREEZER))
 522                 goto Finish;
 523
 524         trace_suspend_resume(TPS("suspend_enter"), state, false);
 525         pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
 526         pm_restrict_gfp_mask();
 527         error = suspend_devices_and_enter(state);
 528         pm_restore_gfp_mask();
 529
 530  Finish:
 531         pr_debug("PM: Finishing wakeup.\n");
 532         suspend_finish();
 533  Unlock:
 534         mutex_unlock(&pm_mutex);
 535         return error;
 536 }
 537
 538 static void pm_suspend_marker(char *annotation)
 539 {
 540         struct timespec ts;
 541         struct rtc_time tm;
 542
 543         getnstimeofday(&ts);
 544         rtc_time_to_tm(ts.tv_sec, &tm);
 545         pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
 546                 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 547                 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 548 }
 549
 550 /**
 551  * pm_suspend - Externally visible function for suspending the system.
 552  * @state: System sleep state to enter.
 553  *
 554  * Check if the value of @state represents one of the supported states,
 555  * execute enter_state() and update system suspend statistics.
 556  */
 557 int pm_suspend(suspend_state_t state)
 558 {
 559         int error;
 560
 561         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 562                 return -EINVAL;
 563
 564         pm_suspend_marker("entry");
 565         error = enter_state(state);
 566         if (error) {
 567                 suspend_stats.fail++;
 568                 dpm_save_failed_errno(error);
 569         } else {
 570                 suspend_stats.success++;
 571         }
 572         pm_suspend_marker("exit");
 573         return error;
 574 }
 575 EXPORT_SYMBOL(pm_suspend);