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 #include <linux/wakeup_reason.h>
  31
  32 #include "power.h"
  33
  34 struct pm_sleep_state pm_states[PM_SUSPEND_MAX] = {
  35         [PM_SUSPEND_FREEZE] = { .label = "freeze", .state = PM_SUSPEND_FREEZE },
  36         [PM_SUSPEND_STANDBY] = { .label = "standby", },
  37         [PM_SUSPEND_MEM] = { .label = "mem", },
  38 };
  39
  40 static const struct platform_suspend_ops *suspend_ops;
  41
  42 static bool need_suspend_ops(suspend_state_t state)
  43 {
  44         return !!(state > PM_SUSPEND_FREEZE);
  45 }
  46
  47 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
  48 static bool suspend_freeze_wake;
  49
  50 static void freeze_begin(void)
  51 {
  52         suspend_freeze_wake = false;
  53 }
  54
  55 static void freeze_enter(void)
  56 {
  57         wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
  58 }
  59
  60 void freeze_wake(void)
  61 {
  62         suspend_freeze_wake = true;
  63         wake_up(&suspend_freeze_wait_head);
  64 }
  65 EXPORT_SYMBOL_GPL(freeze_wake);
  66
  67 static bool valid_state(suspend_state_t state)
  68 {
  69         /*
  70          * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
  71          * support and need to be valid to the low level
  72          * implementation, no valid callback implies that none are valid.
  73          */
  74         return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
  75 }
  76
  77 /**
  78  * suspend_set_ops - Set the global suspend method table.
  79  * @ops: Suspend operations to use.
  80  */
  81 void suspend_set_ops(const struct platform_suspend_ops *ops)
  82 {
  83         suspend_state_t i;
  84
  85         lock_system_sleep();
  86
  87         suspend_ops = ops;
  88         for (i = PM_SUSPEND_STANDBY; i <= PM_SUSPEND_MEM; i++)
  89                 pm_states[i].state = valid_state(i) ? i : 0;
  90
  91         unlock_system_sleep();
  92 }
  93 EXPORT_SYMBOL_GPL(suspend_set_ops);
  94
  95 /**
  96  * suspend_valid_only_mem - Generic memory-only valid callback.
  97  *
  98  * Platform drivers that implement mem suspend only and only need to check for
  99  * that in their .valid() callback can use this instead of rolling their own
 100  * .valid() callback.
 101  */
 102 int suspend_valid_only_mem(suspend_state_t state)
 103 {
 104         return state == PM_SUSPEND_MEM;
 105 }
 106 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
 107
 108 static int suspend_test(int level)
 109 {
 110 #ifdef CONFIG_PM_DEBUG
 111         if (pm_test_level == level) {
 112                 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
 113                 mdelay(5000);
 114                 return 1;
 115         }
 116 #endif /* !CONFIG_PM_DEBUG */
 117         return 0;
 118 }
 119
 120 /**
 121  * suspend_prepare - Prepare for entering system sleep state.
 122  *
 123  * Common code run for every system sleep state that can be entered (except for
 124  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 125  * freeze processes.
 126  */
 127 static int suspend_prepare(suspend_state_t state)
 128 {
 129         int error;
 130
 131         if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 132                 return -EPERM;
 133
 134         pm_prepare_console();
 135
 136         error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
 137         if (error)
 138                 goto Finish;
 139
 140         error = suspend_freeze_processes();
 141         if (!error)
 142                 return 0;
 143         log_suspend_abort_reason("One or more tasks refusing to freeze");
 144         suspend_stats.failed_freeze++;
 145         dpm_save_failed_step(SUSPEND_FREEZE);
 146  Finish:
 147         pm_notifier_call_chain(PM_POST_SUSPEND);
 148         pm_restore_console();
 149         return error;
 150 }
 151
 152 /* default implementation */
 153 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
 154 {
 155         local_irq_disable();
 156 }
 157
 158 /* default implementation */
 159 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
 160 {
 161         local_irq_enable();
 162 }
 163
 164 /**
 165  * suspend_enter - Make the system enter the given sleep state.
 166  * @state: System sleep state to enter.
 167  * @wakeup: Returns information that the sleep state should not be re-entered.
 168  *
 169  * This function should be called after devices have been suspended.
 170  */
 171 static int suspend_enter(suspend_state_t state, bool *wakeup)
 172 {
 173         char suspend_abort[MAX_SUSPEND_ABORT_LEN];
 174         int error, last_dev;
 175
 176         if (need_suspend_ops(state) && suspend_ops->prepare) {
 177                 error = suspend_ops->prepare();
 178                 if (error)
 179                         goto Platform_finish;
 180         }
 181
 182         error = dpm_suspend_end(PMSG_SUSPEND);
 183         if (error) {
 184                 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 185                 last_dev %= REC_FAILED_NUM;
 186                 printk(KERN_ERR "PM: Some devices failed to power down\n");
 187                 log_suspend_abort_reason("%s device failed to power down",
 188                         suspend_stats.failed_devs[last_dev]);
 189                 goto Platform_finish;
 190         }
 191
 192         if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 193                 error = suspend_ops->prepare_late();
 194                 if (error)
 195                         goto Platform_wake;
 196         }
 197
 198         if (suspend_test(TEST_PLATFORM))
 199                 goto Platform_wake;
 200
 201         /*
 202          * PM_SUSPEND_FREEZE equals
 203          * frozen processes + suspended devices + idle processors.
 204          * Thus we should invoke freeze_enter() soon after
 205          * all the devices are suspended.
 206          */
 207         if (state == PM_SUSPEND_FREEZE) {
 208                 freeze_enter();
 209                 goto Platform_wake;
 210         }
 211
 212         error = disable_nonboot_cpus();
 213         if (error || suspend_test(TEST_CPUS)) {
 214                 log_suspend_abort_reason("Disabling non-boot cpus failed");
 215                 goto Enable_cpus;
 216         }
 217
 218         arch_suspend_disable_irqs();
 219         BUG_ON(!irqs_disabled());
 220
 221         error = syscore_suspend();
 222         if (!error) {
 223                 *wakeup = pm_wakeup_pending();
 224                 if (!(suspend_test(TEST_CORE) || *wakeup)) {
 225                         error = suspend_ops->enter(state);
 226                         events_check_enabled = false;
 227                 } else {
 228                         pm_get_active_wakeup_sources(suspend_abort,
 229                                 MAX_SUSPEND_ABORT_LEN);
 230                         log_suspend_abort_reason(suspend_abort);
 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         trace_machine_suspend(state);
 267         if (need_suspend_ops(state) && suspend_ops->begin) {
 268                 error = suspend_ops->begin(state);
 269                 if (error)
 270                         goto Close;
 271         }
 272         suspend_console();
 273         ftrace_stop();
 274         suspend_test_start();
 275         error = dpm_suspend_start(PMSG_SUSPEND);
 276         if (error) {
 277                 printk(KERN_ERR "PM: Some devices failed to suspend\n");
 278                 log_suspend_abort_reason("Some devices failed to suspend");
 279                 goto Recover_platform;
 280         }
 281         suspend_test_finish("suspend devices");
 282         if (suspend_test(TEST_DEVICES))
 283                 goto Recover_platform;
 284
 285         do {
 286                 error = suspend_enter(state, &wakeup);
 287         } while (!error && !wakeup && need_suspend_ops(state)
 288                 && suspend_ops->suspend_again && suspend_ops->suspend_again());
 289
 290  Resume_devices:
 291         suspend_test_start();
 292         dpm_resume_end(PMSG_RESUME);
 293         suspend_test_finish("resume devices");
 294         ftrace_start();
 295         resume_console();
 296  Close:
 297         if (need_suspend_ops(state) && suspend_ops->end)
 298                 suspend_ops->end();
 299         trace_machine_suspend(PWR_EVENT_EXIT);
 300         return error;
 301
 302  Recover_platform:
 303         if (need_suspend_ops(state) && suspend_ops->recover)
 304                 suspend_ops->recover();
 305         goto Resume_devices;
 306 }
 307
 308 /**
 309  * suspend_finish - Clean up before finishing the suspend sequence.
 310  *
 311  * Call platform code to clean up, restart processes, and free the console that
 312  * we've allocated. This routine is not called for hibernation.
 313  */
 314 static void suspend_finish(void)
 315 {
 316         suspend_thaw_processes();
 317         pm_notifier_call_chain(PM_POST_SUSPEND);
 318         pm_restore_console();
 319 }
 320
 321 /**
 322  * enter_state - Do common work needed to enter system sleep state.
 323  * @state: System sleep state to enter.
 324  *
 325  * Make sure that no one else is trying to put the system into a sleep state.
 326  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 327  * system enter the given sleep state and clean up after wakeup.
 328  */
 329 static int enter_state(suspend_state_t state)
 330 {
 331         int error;
 332
 333         if (state == PM_SUSPEND_FREEZE) {
 334 #ifdef CONFIG_PM_DEBUG
 335                 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
 336                         pr_warning("PM: Unsupported test mode for freeze state,"
 337                                    "please choose none/freezer/devices/platform.\n");
 338                         return -EAGAIN;
 339                 }
 340 #endif
 341         } else if (!valid_state(state)) {
 342                 return -EINVAL;
 343         }
 344         if (!mutex_trylock(&pm_mutex))
 345                 return -EBUSY;
 346
 347         if (state == PM_SUSPEND_FREEZE)
 348                 freeze_begin();
 349
 350         printk(KERN_INFO "PM: Syncing filesystems ... ");
 351         sys_sync();
 352         printk("done.\n");
 353
 354         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label);
 355         error = suspend_prepare(state);
 356         if (error)
 357                 goto Unlock;
 358
 359         if (suspend_test(TEST_FREEZER))
 360                 goto Finish;
 361
 362         pr_debug("PM: Entering %s sleep\n", pm_states[state].label);
 363         pm_restrict_gfp_mask();
 364         error = suspend_devices_and_enter(state);
 365         pm_restore_gfp_mask();
 366
 367  Finish:
 368         pr_debug("PM: Finishing wakeup.\n");
 369         suspend_finish();
 370  Unlock:
 371         mutex_unlock(&pm_mutex);
 372         return error;
 373 }
 374
 375 static void pm_suspend_marker(char *annotation)
 376 {
 377         struct timespec ts;
 378         struct rtc_time tm;
 379
 380         getnstimeofday(&ts);
 381         rtc_time_to_tm(ts.tv_sec, &tm);
 382         pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
 383                 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 384                 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 385 }
 386
 387 /**
 388  * pm_suspend - Externally visible function for suspending the system.
 389  * @state: System sleep state to enter.
 390  *
 391  * Check if the value of @state represents one of the supported states,
 392  * execute enter_state() and update system suspend statistics.
 393  */
 394 int pm_suspend(suspend_state_t state)
 395 {
 396         int error;
 397
 398         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 399                 return -EINVAL;
 400
 401         pm_suspend_marker("entry");
 402         error = enter_state(state);
 403         if (error) {
 404                 suspend_stats.fail++;
 405                 dpm_save_failed_errno(error);
 406         } else {
 407                 suspend_stats.success++;
 408         }
 409         pm_suspend_marker("exit");
 410         return error;
 411 }
 412 EXPORT_SYMBOL(pm_suspend);