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v6.8
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   4 *
   5 * Copyright (c) 2003 Patrick Mochel
   6 * Copyright (c) 2003 Open Source Development Lab
   7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  10 */
  11
  12#define pr_fmt(fmt) "PM: hibernation: " fmt
  13
  14#include <linux/blkdev.h>
  15#include <linux/export.h>
  16#include <linux/suspend.h>
  17#include <linux/reboot.h>
  18#include <linux/string.h>
  19#include <linux/device.h>
  20#include <linux/async.h>
  21#include <linux/delay.h>
  22#include <linux/fs.h>
  23#include <linux/mount.h>
  24#include <linux/pm.h>
  25#include <linux/nmi.h>
  26#include <linux/console.h>
  27#include <linux/cpu.h>
  28#include <linux/freezer.h>
  29#include <linux/gfp.h>
  30#include <linux/syscore_ops.h>
  31#include <linux/ctype.h>
  32#include <linux/ktime.h>
  33#include <linux/security.h>
  34#include <linux/secretmem.h>
  35#include <trace/events/power.h>
  36
  37#include "power.h"
  38
  39
  40static int nocompress;
  41static int noresume;
  42static int nohibernate;
  43static int resume_wait;
  44static unsigned int resume_delay;
  45static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  46dev_t swsusp_resume_device;
  47sector_t swsusp_resume_block;
  48__visible int in_suspend __nosavedata;
  49
 
 
 
 
 
 
 
 
 
  50enum {
  51	HIBERNATION_INVALID,
  52	HIBERNATION_PLATFORM,
  53	HIBERNATION_SHUTDOWN,
  54	HIBERNATION_REBOOT,
  55#ifdef CONFIG_SUSPEND
  56	HIBERNATION_SUSPEND,
  57#endif
  58	HIBERNATION_TEST_RESUME,
  59	/* keep last */
  60	__HIBERNATION_AFTER_LAST
  61};
  62#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  63#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  64
  65static int hibernation_mode = HIBERNATION_SHUTDOWN;
  66
  67bool freezer_test_done;
  68
  69static const struct platform_hibernation_ops *hibernation_ops;
  70
  71static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  72
  73bool hibernate_acquire(void)
  74{
  75	return atomic_add_unless(&hibernate_atomic, -1, 0);
  76}
  77
  78void hibernate_release(void)
  79{
  80	atomic_inc(&hibernate_atomic);
  81}
  82
  83bool hibernation_available(void)
  84{
  85	return nohibernate == 0 &&
  86		!security_locked_down(LOCKDOWN_HIBERNATION) &&
  87		!secretmem_active() && !cxl_mem_active();
  88}
  89
  90/**
  91 * hibernation_set_ops - Set the global hibernate operations.
  92 * @ops: Hibernation operations to use in subsequent hibernation transitions.
  93 */
  94void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  95{
  96	unsigned int sleep_flags;
  97
  98	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  99	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
 100	    && ops->restore_cleanup && ops->leave)) {
 101		WARN_ON(1);
 102		return;
 103	}
 104
 105	sleep_flags = lock_system_sleep();
 106
 107	hibernation_ops = ops;
 108	if (ops)
 109		hibernation_mode = HIBERNATION_PLATFORM;
 110	else if (hibernation_mode == HIBERNATION_PLATFORM)
 111		hibernation_mode = HIBERNATION_SHUTDOWN;
 112
 113	unlock_system_sleep(sleep_flags);
 114}
 115EXPORT_SYMBOL_GPL(hibernation_set_ops);
 116
 117static bool entering_platform_hibernation;
 118
 119bool system_entering_hibernation(void)
 120{
 121	return entering_platform_hibernation;
 122}
 123EXPORT_SYMBOL(system_entering_hibernation);
 124
 125#ifdef CONFIG_PM_DEBUG
 126static void hibernation_debug_sleep(void)
 127{
 128	pr_info("debug: Waiting for 5 seconds.\n");
 129	mdelay(5000);
 130}
 131
 132static int hibernation_test(int level)
 133{
 134	if (pm_test_level == level) {
 135		hibernation_debug_sleep();
 136		return 1;
 137	}
 138	return 0;
 139}
 140#else /* !CONFIG_PM_DEBUG */
 141static int hibernation_test(int level) { return 0; }
 142#endif /* !CONFIG_PM_DEBUG */
 143
 144/**
 145 * platform_begin - Call platform to start hibernation.
 146 * @platform_mode: Whether or not to use the platform driver.
 147 */
 148static int platform_begin(int platform_mode)
 149{
 150	return (platform_mode && hibernation_ops) ?
 151		hibernation_ops->begin(PMSG_FREEZE) : 0;
 152}
 153
 154/**
 155 * platform_end - Call platform to finish transition to the working state.
 156 * @platform_mode: Whether or not to use the platform driver.
 157 */
 158static void platform_end(int platform_mode)
 159{
 160	if (platform_mode && hibernation_ops)
 161		hibernation_ops->end();
 162}
 163
 164/**
 165 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 166 * @platform_mode: Whether or not to use the platform driver.
 167 *
 168 * Use the platform driver to prepare the system for creating a hibernate image,
 169 * if so configured, and return an error code if that fails.
 170 */
 171
 172static int platform_pre_snapshot(int platform_mode)
 173{
 174	return (platform_mode && hibernation_ops) ?
 175		hibernation_ops->pre_snapshot() : 0;
 176}
 177
 178/**
 179 * platform_leave - Call platform to prepare a transition to the working state.
 180 * @platform_mode: Whether or not to use the platform driver.
 181 *
 182 * Use the platform driver prepare to prepare the machine for switching to the
 183 * normal mode of operation.
 184 *
 185 * This routine is called on one CPU with interrupts disabled.
 186 */
 187static void platform_leave(int platform_mode)
 188{
 189	if (platform_mode && hibernation_ops)
 190		hibernation_ops->leave();
 191}
 192
 193/**
 194 * platform_finish - Call platform to switch the system to the working state.
 195 * @platform_mode: Whether or not to use the platform driver.
 196 *
 197 * Use the platform driver to switch the machine to the normal mode of
 198 * operation.
 199 *
 200 * This routine must be called after platform_prepare().
 201 */
 202static void platform_finish(int platform_mode)
 203{
 204	if (platform_mode && hibernation_ops)
 205		hibernation_ops->finish();
 206}
 207
 208/**
 209 * platform_pre_restore - Prepare for hibernate image restoration.
 210 * @platform_mode: Whether or not to use the platform driver.
 211 *
 212 * Use the platform driver to prepare the system for resume from a hibernation
 213 * image.
 214 *
 215 * If the restore fails after this function has been called,
 216 * platform_restore_cleanup() must be called.
 217 */
 218static int platform_pre_restore(int platform_mode)
 219{
 220	return (platform_mode && hibernation_ops) ?
 221		hibernation_ops->pre_restore() : 0;
 222}
 223
 224/**
 225 * platform_restore_cleanup - Switch to the working state after failing restore.
 226 * @platform_mode: Whether or not to use the platform driver.
 227 *
 228 * Use the platform driver to switch the system to the normal mode of operation
 229 * after a failing restore.
 230 *
 231 * If platform_pre_restore() has been called before the failing restore, this
 232 * function must be called too, regardless of the result of
 233 * platform_pre_restore().
 234 */
 235static void platform_restore_cleanup(int platform_mode)
 236{
 237	if (platform_mode && hibernation_ops)
 238		hibernation_ops->restore_cleanup();
 239}
 240
 241/**
 242 * platform_recover - Recover from a failure to suspend devices.
 243 * @platform_mode: Whether or not to use the platform driver.
 244 */
 245static void platform_recover(int platform_mode)
 246{
 247	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 248		hibernation_ops->recover();
 249}
 250
 251/**
 252 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 253 * @start: Starting event.
 254 * @stop: Final event.
 255 * @nr_pages: Number of memory pages processed between @start and @stop.
 256 * @msg: Additional diagnostic message to print.
 257 */
 258void swsusp_show_speed(ktime_t start, ktime_t stop,
 259		      unsigned nr_pages, char *msg)
 260{
 261	ktime_t diff;
 262	u64 elapsed_centisecs64;
 263	unsigned int centisecs;
 264	unsigned int k;
 265	unsigned int kps;
 266
 267	diff = ktime_sub(stop, start);
 268	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 269	centisecs = elapsed_centisecs64;
 270	if (centisecs == 0)
 271		centisecs = 1;	/* avoid div-by-zero */
 272	k = nr_pages * (PAGE_SIZE / 1024);
 273	kps = (k * 100) / centisecs;
 274	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 275		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 276		(kps % 1000) / 10);
 277}
 278
 279__weak int arch_resume_nosmt(void)
 280{
 281	return 0;
 282}
 283
 284/**
 285 * create_image - Create a hibernation image.
 286 * @platform_mode: Whether or not to use the platform driver.
 287 *
 288 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 289 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 290 *
 291 * Control reappears in this routine after the subsequent restore.
 292 */
 293static int create_image(int platform_mode)
 294{
 295	int error;
 296
 297	error = dpm_suspend_end(PMSG_FREEZE);
 298	if (error) {
 299		pr_err("Some devices failed to power down, aborting\n");
 300		return error;
 301	}
 302
 303	error = platform_pre_snapshot(platform_mode);
 304	if (error || hibernation_test(TEST_PLATFORM))
 305		goto Platform_finish;
 306
 307	error = pm_sleep_disable_secondary_cpus();
 308	if (error || hibernation_test(TEST_CPUS))
 309		goto Enable_cpus;
 310
 311	local_irq_disable();
 312
 313	system_state = SYSTEM_SUSPEND;
 314
 315	error = syscore_suspend();
 316	if (error) {
 317		pr_err("Some system devices failed to power down, aborting\n");
 318		goto Enable_irqs;
 319	}
 320
 321	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 322		goto Power_up;
 323
 324	in_suspend = 1;
 325	save_processor_state();
 326	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 327	error = swsusp_arch_suspend();
 328	/* Restore control flow magically appears here */
 329	restore_processor_state();
 330	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 331	if (error)
 332		pr_err("Error %d creating image\n", error);
 333
 334	if (!in_suspend) {
 335		events_check_enabled = false;
 336		clear_or_poison_free_pages();
 337	}
 338
 339	platform_leave(platform_mode);
 340
 341 Power_up:
 342	syscore_resume();
 343
 344 Enable_irqs:
 345	system_state = SYSTEM_RUNNING;
 346	local_irq_enable();
 347
 348 Enable_cpus:
 349	pm_sleep_enable_secondary_cpus();
 350
 351	/* Allow architectures to do nosmt-specific post-resume dances */
 352	if (!in_suspend)
 353		error = arch_resume_nosmt();
 354
 355 Platform_finish:
 356	platform_finish(platform_mode);
 357
 358	dpm_resume_start(in_suspend ?
 359		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 360
 361	return error;
 362}
 363
 364/**
 365 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 366 * @platform_mode: If set, use platform driver to prepare for the transition.
 367 *
 368 * This routine must be called with system_transition_mutex held.
 369 */
 370int hibernation_snapshot(int platform_mode)
 371{
 372	pm_message_t msg;
 373	int error;
 374
 375	pm_suspend_clear_flags();
 376	error = platform_begin(platform_mode);
 377	if (error)
 378		goto Close;
 379
 380	/* Preallocate image memory before shutting down devices. */
 381	error = hibernate_preallocate_memory();
 382	if (error)
 383		goto Close;
 384
 385	error = freeze_kernel_threads();
 386	if (error)
 387		goto Cleanup;
 388
 389	if (hibernation_test(TEST_FREEZER)) {
 390
 391		/*
 392		 * Indicate to the caller that we are returning due to a
 393		 * successful freezer test.
 394		 */
 395		freezer_test_done = true;
 396		goto Thaw;
 397	}
 398
 399	error = dpm_prepare(PMSG_FREEZE);
 400	if (error) {
 401		dpm_complete(PMSG_RECOVER);
 402		goto Thaw;
 403	}
 404
 405	suspend_console();
 406	pm_restrict_gfp_mask();
 407
 408	error = dpm_suspend(PMSG_FREEZE);
 409
 410	if (error || hibernation_test(TEST_DEVICES))
 411		platform_recover(platform_mode);
 412	else
 413		error = create_image(platform_mode);
 414
 415	/*
 416	 * In the case that we call create_image() above, the control
 417	 * returns here (1) after the image has been created or the
 418	 * image creation has failed and (2) after a successful restore.
 419	 */
 420
 421	/* We may need to release the preallocated image pages here. */
 422	if (error || !in_suspend)
 423		swsusp_free();
 424
 425	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 426	dpm_resume(msg);
 427
 428	if (error || !in_suspend)
 429		pm_restore_gfp_mask();
 430
 431	resume_console();
 432	dpm_complete(msg);
 433
 434 Close:
 435	platform_end(platform_mode);
 436	return error;
 437
 438 Thaw:
 439	thaw_kernel_threads();
 440 Cleanup:
 441	swsusp_free();
 442	goto Close;
 443}
 444
 445int __weak hibernate_resume_nonboot_cpu_disable(void)
 446{
 447	return suspend_disable_secondary_cpus();
 448}
 449
 450/**
 451 * resume_target_kernel - Restore system state from a hibernation image.
 452 * @platform_mode: Whether or not to use the platform driver.
 453 *
 454 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 455 * contents of highmem that have not been restored yet from the image and run
 456 * the low-level code that will restore the remaining contents of memory and
 457 * switch to the just restored target kernel.
 458 */
 459static int resume_target_kernel(bool platform_mode)
 460{
 461	int error;
 462
 463	error = dpm_suspend_end(PMSG_QUIESCE);
 464	if (error) {
 465		pr_err("Some devices failed to power down, aborting resume\n");
 466		return error;
 467	}
 468
 469	error = platform_pre_restore(platform_mode);
 470	if (error)
 471		goto Cleanup;
 472
 473	cpuidle_pause();
 474
 475	error = hibernate_resume_nonboot_cpu_disable();
 476	if (error)
 477		goto Enable_cpus;
 478
 479	local_irq_disable();
 480	system_state = SYSTEM_SUSPEND;
 481
 482	error = syscore_suspend();
 483	if (error)
 484		goto Enable_irqs;
 485
 486	save_processor_state();
 487	error = restore_highmem();
 488	if (!error) {
 489		error = swsusp_arch_resume();
 490		/*
 491		 * The code below is only ever reached in case of a failure.
 492		 * Otherwise, execution continues at the place where
 493		 * swsusp_arch_suspend() was called.
 494		 */
 495		BUG_ON(!error);
 496		/*
 497		 * This call to restore_highmem() reverts the changes made by
 498		 * the previous one.
 499		 */
 500		restore_highmem();
 501	}
 502	/*
 503	 * The only reason why swsusp_arch_resume() can fail is memory being
 504	 * very tight, so we have to free it as soon as we can to avoid
 505	 * subsequent failures.
 506	 */
 507	swsusp_free();
 508	restore_processor_state();
 509	touch_softlockup_watchdog();
 510
 511	syscore_resume();
 512
 513 Enable_irqs:
 514	system_state = SYSTEM_RUNNING;
 515	local_irq_enable();
 516
 517 Enable_cpus:
 518	pm_sleep_enable_secondary_cpus();
 519
 520 Cleanup:
 521	platform_restore_cleanup(platform_mode);
 522
 523	dpm_resume_start(PMSG_RECOVER);
 524
 525	return error;
 526}
 527
 528/**
 529 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 530 * @platform_mode: If set, use platform driver to prepare for the transition.
 531 *
 532 * This routine must be called with system_transition_mutex held.  If it is
 533 * successful, control reappears in the restored target kernel in
 534 * hibernation_snapshot().
 535 */
 536int hibernation_restore(int platform_mode)
 537{
 538	int error;
 539
 540	pm_prepare_console();
 541	suspend_console();
 542	pm_restrict_gfp_mask();
 543	error = dpm_suspend_start(PMSG_QUIESCE);
 544	if (!error) {
 545		error = resume_target_kernel(platform_mode);
 546		/*
 547		 * The above should either succeed and jump to the new kernel,
 548		 * or return with an error. Otherwise things are just
 549		 * undefined, so let's be paranoid.
 550		 */
 551		BUG_ON(!error);
 552	}
 553	dpm_resume_end(PMSG_RECOVER);
 554	pm_restore_gfp_mask();
 555	resume_console();
 556	pm_restore_console();
 557	return error;
 558}
 559
 560/**
 561 * hibernation_platform_enter - Power off the system using the platform driver.
 562 */
 563int hibernation_platform_enter(void)
 564{
 565	int error;
 566
 567	if (!hibernation_ops)
 568		return -ENOSYS;
 569
 570	/*
 571	 * We have cancelled the power transition by running
 572	 * hibernation_ops->finish() before saving the image, so we should let
 573	 * the firmware know that we're going to enter the sleep state after all
 574	 */
 575	error = hibernation_ops->begin(PMSG_HIBERNATE);
 576	if (error)
 577		goto Close;
 578
 579	entering_platform_hibernation = true;
 580	suspend_console();
 581	error = dpm_suspend_start(PMSG_HIBERNATE);
 582	if (error) {
 583		if (hibernation_ops->recover)
 584			hibernation_ops->recover();
 585		goto Resume_devices;
 586	}
 587
 588	error = dpm_suspend_end(PMSG_HIBERNATE);
 589	if (error)
 590		goto Resume_devices;
 591
 592	error = hibernation_ops->prepare();
 593	if (error)
 594		goto Platform_finish;
 595
 596	error = pm_sleep_disable_secondary_cpus();
 597	if (error)
 598		goto Enable_cpus;
 599
 600	local_irq_disable();
 601	system_state = SYSTEM_SUSPEND;
 602	syscore_suspend();
 603	if (pm_wakeup_pending()) {
 604		error = -EAGAIN;
 605		goto Power_up;
 606	}
 607
 608	hibernation_ops->enter();
 609	/* We should never get here */
 610	while (1);
 611
 612 Power_up:
 613	syscore_resume();
 614	system_state = SYSTEM_RUNNING;
 615	local_irq_enable();
 616
 617 Enable_cpus:
 618	pm_sleep_enable_secondary_cpus();
 619
 620 Platform_finish:
 621	hibernation_ops->finish();
 622
 623	dpm_resume_start(PMSG_RESTORE);
 624
 625 Resume_devices:
 626	entering_platform_hibernation = false;
 627	dpm_resume_end(PMSG_RESTORE);
 628	resume_console();
 629
 630 Close:
 631	hibernation_ops->end();
 632
 633	return error;
 634}
 635
 636/**
 637 * power_down - Shut the machine down for hibernation.
 638 *
 639 * Use the platform driver, if configured, to put the system into the sleep
 640 * state corresponding to hibernation, or try to power it off or reboot,
 641 * depending on the value of hibernation_mode.
 642 */
 643static void power_down(void)
 644{
 645	int error;
 646
 647#ifdef CONFIG_SUSPEND
 648	if (hibernation_mode == HIBERNATION_SUSPEND) {
 649		error = suspend_devices_and_enter(mem_sleep_current);
 650		if (error) {
 651			hibernation_mode = hibernation_ops ?
 652						HIBERNATION_PLATFORM :
 653						HIBERNATION_SHUTDOWN;
 654		} else {
 655			/* Restore swap signature. */
 656			error = swsusp_unmark();
 657			if (error)
 658				pr_err("Swap will be unusable! Try swapon -a.\n");
 659
 660			return;
 661		}
 662	}
 663#endif
 664
 665	switch (hibernation_mode) {
 666	case HIBERNATION_REBOOT:
 667		kernel_restart(NULL);
 668		break;
 669	case HIBERNATION_PLATFORM:
 670		error = hibernation_platform_enter();
 671		if (error == -EAGAIN || error == -EBUSY) {
 672			swsusp_unmark();
 673			events_check_enabled = false;
 674			pr_info("Wakeup event detected during hibernation, rolling back.\n");
 675			return;
 676		}
 677		fallthrough;
 678	case HIBERNATION_SHUTDOWN:
 679		if (kernel_can_power_off())
 680			kernel_power_off();
 681		break;
 682	}
 683	kernel_halt();
 684	/*
 685	 * Valid image is on the disk, if we continue we risk serious data
 686	 * corruption after resume.
 687	 */
 688	pr_crit("Power down manually\n");
 689	while (1)
 690		cpu_relax();
 691}
 692
 693static int load_image_and_restore(void)
 694{
 695	int error;
 696	unsigned int flags;
 697
 698	pm_pr_dbg("Loading hibernation image.\n");
 699
 700	lock_device_hotplug();
 701	error = create_basic_memory_bitmaps();
 702	if (error) {
 703		swsusp_close();
 704		goto Unlock;
 705	}
 706
 707	error = swsusp_read(&flags);
 708	swsusp_close();
 709	if (!error)
 710		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 711
 712	pr_err("Failed to load image, recovering.\n");
 713	swsusp_free();
 714	free_basic_memory_bitmaps();
 715 Unlock:
 716	unlock_device_hotplug();
 717
 718	return error;
 719}
 720
 
 
 
 721/**
 722 * hibernate - Carry out system hibernation, including saving the image.
 723 */
 724int hibernate(void)
 725{
 726	bool snapshot_test = false;
 727	unsigned int sleep_flags;
 728	int error;
 729
 730	if (!hibernation_available()) {
 731		pm_pr_dbg("Hibernation not available.\n");
 732		return -EPERM;
 733	}
 734
 
 
 
 
 
 
 
 
 
 
 
 735	sleep_flags = lock_system_sleep();
 736	/* The snapshot device should not be opened while we're running */
 737	if (!hibernate_acquire()) {
 738		error = -EBUSY;
 739		goto Unlock;
 740	}
 741
 742	pr_info("hibernation entry\n");
 743	pm_prepare_console();
 744	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 745	if (error)
 746		goto Restore;
 747
 748	ksys_sync_helper();
 749
 750	error = freeze_processes();
 751	if (error)
 752		goto Exit;
 753
 754	lock_device_hotplug();
 755	/* Allocate memory management structures */
 756	error = create_basic_memory_bitmaps();
 757	if (error)
 758		goto Thaw;
 759
 760	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 761	if (error || freezer_test_done)
 762		goto Free_bitmaps;
 763
 764	if (in_suspend) {
 765		unsigned int flags = 0;
 766
 767		if (hibernation_mode == HIBERNATION_PLATFORM)
 768			flags |= SF_PLATFORM_MODE;
 769		if (nocompress)
 770			flags |= SF_NOCOMPRESS_MODE;
 771		else
 772		        flags |= SF_CRC32_MODE;
 773
 
 
 
 
 
 
 
 
 
 
 
 
 
 774		pm_pr_dbg("Writing hibernation image.\n");
 775		error = swsusp_write(flags);
 776		swsusp_free();
 777		if (!error) {
 778			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 779				snapshot_test = true;
 780			else
 781				power_down();
 782		}
 783		in_suspend = 0;
 784		pm_restore_gfp_mask();
 785	} else {
 786		pm_pr_dbg("Hibernation image restored successfully.\n");
 787	}
 788
 789 Free_bitmaps:
 790	free_basic_memory_bitmaps();
 791 Thaw:
 792	unlock_device_hotplug();
 793	if (snapshot_test) {
 794		pm_pr_dbg("Checking hibernation image\n");
 795		error = swsusp_check(false);
 796		if (!error)
 797			error = load_image_and_restore();
 798	}
 799	thaw_processes();
 800
 801	/* Don't bother checking whether freezer_test_done is true */
 802	freezer_test_done = false;
 803 Exit:
 804	pm_notifier_call_chain(PM_POST_HIBERNATION);
 805 Restore:
 806	pm_restore_console();
 807	hibernate_release();
 808 Unlock:
 809	unlock_system_sleep(sleep_flags);
 810	pr_info("hibernation exit\n");
 811
 812	return error;
 813}
 814
 815/**
 816 * hibernate_quiet_exec - Execute a function with all devices frozen.
 817 * @func: Function to execute.
 818 * @data: Data pointer to pass to @func.
 819 *
 820 * Return the @func return value or an error code if it cannot be executed.
 821 */
 822int hibernate_quiet_exec(int (*func)(void *data), void *data)
 823{
 824	unsigned int sleep_flags;
 825	int error;
 826
 827	sleep_flags = lock_system_sleep();
 828
 829	if (!hibernate_acquire()) {
 830		error = -EBUSY;
 831		goto unlock;
 832	}
 833
 834	pm_prepare_console();
 835
 836	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 837	if (error)
 838		goto restore;
 839
 840	error = freeze_processes();
 841	if (error)
 842		goto exit;
 843
 844	lock_device_hotplug();
 845
 846	pm_suspend_clear_flags();
 847
 848	error = platform_begin(true);
 849	if (error)
 850		goto thaw;
 851
 852	error = freeze_kernel_threads();
 853	if (error)
 854		goto thaw;
 855
 856	error = dpm_prepare(PMSG_FREEZE);
 857	if (error)
 858		goto dpm_complete;
 859
 860	suspend_console();
 861
 862	error = dpm_suspend(PMSG_FREEZE);
 863	if (error)
 864		goto dpm_resume;
 865
 866	error = dpm_suspend_end(PMSG_FREEZE);
 867	if (error)
 868		goto dpm_resume;
 869
 870	error = platform_pre_snapshot(true);
 871	if (error)
 872		goto skip;
 873
 874	error = func(data);
 875
 876skip:
 877	platform_finish(true);
 878
 879	dpm_resume_start(PMSG_THAW);
 880
 881dpm_resume:
 882	dpm_resume(PMSG_THAW);
 883
 884	resume_console();
 885
 886dpm_complete:
 887	dpm_complete(PMSG_THAW);
 888
 889	thaw_kernel_threads();
 890
 891thaw:
 892	platform_end(true);
 893
 894	unlock_device_hotplug();
 895
 896	thaw_processes();
 897
 898exit:
 899	pm_notifier_call_chain(PM_POST_HIBERNATION);
 900
 901restore:
 902	pm_restore_console();
 903
 904	hibernate_release();
 905
 906unlock:
 907	unlock_system_sleep(sleep_flags);
 908
 909	return error;
 910}
 911EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 912
 913static int __init find_resume_device(void)
 914{
 915	if (!strlen(resume_file))
 916		return -ENOENT;
 917
 918	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 919
 920	if (resume_delay) {
 921		pr_info("Waiting %dsec before reading resume device ...\n",
 922			resume_delay);
 923		ssleep(resume_delay);
 924	}
 925
 926	/* Check if the device is there */
 927	if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
 928		return 0;
 929
 930	/*
 931	 * Some device discovery might still be in progress; we need to wait for
 932	 * this to finish.
 933	 */
 934	wait_for_device_probe();
 935	if (resume_wait) {
 936		while (early_lookup_bdev(resume_file, &swsusp_resume_device))
 937			msleep(10);
 938		async_synchronize_full();
 939	}
 940
 941	return early_lookup_bdev(resume_file, &swsusp_resume_device);
 942}
 943
 944static int software_resume(void)
 945{
 946	int error;
 947
 948	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 949		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 950
 951	pm_pr_dbg("Looking for hibernation image.\n");
 952
 953	mutex_lock(&system_transition_mutex);
 954	error = swsusp_check(true);
 955	if (error)
 956		goto Unlock;
 957
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 958	/* The snapshot device should not be opened while we're running */
 959	if (!hibernate_acquire()) {
 960		error = -EBUSY;
 961		swsusp_close();
 962		goto Unlock;
 963	}
 964
 965	pr_info("resume from hibernation\n");
 966	pm_prepare_console();
 967	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
 968	if (error)
 969		goto Restore;
 970
 971	pm_pr_dbg("Preparing processes for hibernation restore.\n");
 972	error = freeze_processes();
 973	if (error)
 974		goto Close_Finish;
 975
 976	error = freeze_kernel_threads();
 977	if (error) {
 978		thaw_processes();
 979		goto Close_Finish;
 980	}
 981
 982	error = load_image_and_restore();
 983	thaw_processes();
 984 Finish:
 985	pm_notifier_call_chain(PM_POST_RESTORE);
 986 Restore:
 987	pm_restore_console();
 988	pr_info("resume failed (%d)\n", error);
 989	hibernate_release();
 990	/* For success case, the suspend path will release the lock */
 991 Unlock:
 992	mutex_unlock(&system_transition_mutex);
 993	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
 994	return error;
 995 Close_Finish:
 996	swsusp_close();
 997	goto Finish;
 998}
 999
1000/**
1001 * software_resume_initcall - Resume from a saved hibernation image.
1002 *
1003 * This routine is called as a late initcall, when all devices have been
1004 * discovered and initialized already.
1005 *
1006 * The image reading code is called to see if there is a hibernation image
1007 * available for reading.  If that is the case, devices are quiesced and the
1008 * contents of memory is restored from the saved image.
1009 *
1010 * If this is successful, control reappears in the restored target kernel in
1011 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1012 * attempts to recover gracefully and make the kernel return to the normal mode
1013 * of operation.
1014 */
1015static int __init software_resume_initcall(void)
1016{
1017	/*
1018	 * If the user said "noresume".. bail out early.
1019	 */
1020	if (noresume || !hibernation_available())
1021		return 0;
1022
1023	if (!swsusp_resume_device) {
1024		int error = find_resume_device();
1025
1026		if (error)
1027			return error;
1028	}
1029
1030	return software_resume();
1031}
1032late_initcall_sync(software_resume_initcall);
1033
1034
1035static const char * const hibernation_modes[] = {
1036	[HIBERNATION_PLATFORM]	= "platform",
1037	[HIBERNATION_SHUTDOWN]	= "shutdown",
1038	[HIBERNATION_REBOOT]	= "reboot",
1039#ifdef CONFIG_SUSPEND
1040	[HIBERNATION_SUSPEND]	= "suspend",
1041#endif
1042	[HIBERNATION_TEST_RESUME]	= "test_resume",
1043};
1044
1045/*
1046 * /sys/power/disk - Control hibernation mode.
1047 *
1048 * Hibernation can be handled in several ways.  There are a few different ways
1049 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1050 * or other hibernation_ops), powering it off or rebooting it (for testing
1051 * mostly).
1052 *
1053 * The sysfs file /sys/power/disk provides an interface for selecting the
1054 * hibernation mode to use.  Reading from this file causes the available modes
1055 * to be printed.  There are 3 modes that can be supported:
1056 *
1057 *	'platform'
1058 *	'shutdown'
1059 *	'reboot'
1060 *
1061 * If a platform hibernation driver is in use, 'platform' will be supported
1062 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1063 * The selected option (i.e. the one corresponding to the current value of
1064 * hibernation_mode) is enclosed by a square bracket.
1065 *
1066 * To select a given hibernation mode it is necessary to write the mode's
1067 * string representation (as returned by reading from /sys/power/disk) back
1068 * into /sys/power/disk.
1069 */
1070
1071static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1072			 char *buf)
1073{
1074	int i;
1075	char *start = buf;
1076
1077	if (!hibernation_available())
1078		return sprintf(buf, "[disabled]\n");
1079
1080	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1081		if (!hibernation_modes[i])
1082			continue;
1083		switch (i) {
1084		case HIBERNATION_SHUTDOWN:
1085		case HIBERNATION_REBOOT:
1086#ifdef CONFIG_SUSPEND
1087		case HIBERNATION_SUSPEND:
1088#endif
1089		case HIBERNATION_TEST_RESUME:
1090			break;
1091		case HIBERNATION_PLATFORM:
1092			if (hibernation_ops)
1093				break;
1094			/* not a valid mode, continue with loop */
1095			continue;
1096		}
1097		if (i == hibernation_mode)
1098			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1099		else
1100			buf += sprintf(buf, "%s ", hibernation_modes[i]);
1101	}
1102	buf += sprintf(buf, "\n");
1103	return buf-start;
1104}
1105
1106static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1107			  const char *buf, size_t n)
1108{
1109	int mode = HIBERNATION_INVALID;
1110	unsigned int sleep_flags;
1111	int error = 0;
1112	int len;
1113	char *p;
1114	int i;
1115
1116	if (!hibernation_available())
1117		return -EPERM;
1118
1119	p = memchr(buf, '\n', n);
1120	len = p ? p - buf : n;
1121
1122	sleep_flags = lock_system_sleep();
1123	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1124		if (len == strlen(hibernation_modes[i])
1125		    && !strncmp(buf, hibernation_modes[i], len)) {
1126			mode = i;
1127			break;
1128		}
1129	}
1130	if (mode != HIBERNATION_INVALID) {
1131		switch (mode) {
1132		case HIBERNATION_SHUTDOWN:
1133		case HIBERNATION_REBOOT:
1134#ifdef CONFIG_SUSPEND
1135		case HIBERNATION_SUSPEND:
1136#endif
1137		case HIBERNATION_TEST_RESUME:
1138			hibernation_mode = mode;
1139			break;
1140		case HIBERNATION_PLATFORM:
1141			if (hibernation_ops)
1142				hibernation_mode = mode;
1143			else
1144				error = -EINVAL;
1145		}
1146	} else
1147		error = -EINVAL;
1148
1149	if (!error)
1150		pm_pr_dbg("Hibernation mode set to '%s'\n",
1151			       hibernation_modes[mode]);
1152	unlock_system_sleep(sleep_flags);
1153	return error ? error : n;
1154}
1155
1156power_attr(disk);
1157
1158static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1159			   char *buf)
1160{
1161	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1162		       MINOR(swsusp_resume_device));
1163}
1164
1165static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1166			    const char *buf, size_t n)
1167{
1168	unsigned int sleep_flags;
1169	int len = n;
1170	char *name;
1171	dev_t dev;
1172	int error;
1173
1174	if (!hibernation_available())
1175		return n;
1176
1177	if (len && buf[len-1] == '\n')
1178		len--;
1179	name = kstrndup(buf, len, GFP_KERNEL);
1180	if (!name)
1181		return -ENOMEM;
1182
1183	error = lookup_bdev(name, &dev);
1184	if (error) {
1185		unsigned maj, min, offset;
1186		char *p, dummy;
1187
1188		error = 0;
1189		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1190		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1191				&dummy) == 3) {
1192			dev = MKDEV(maj, min);
1193			if (maj != MAJOR(dev) || min != MINOR(dev))
1194				error = -EINVAL;
1195		} else {
1196			dev = new_decode_dev(simple_strtoul(name, &p, 16));
1197			if (*p)
1198				error = -EINVAL;
1199		}
1200	}
1201	kfree(name);
1202	if (error)
1203		return error;
1204
1205	sleep_flags = lock_system_sleep();
1206	swsusp_resume_device = dev;
1207	unlock_system_sleep(sleep_flags);
1208
1209	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1210		  swsusp_resume_device);
1211	noresume = 0;
1212	software_resume();
1213	return n;
1214}
1215
1216power_attr(resume);
1217
1218static ssize_t resume_offset_show(struct kobject *kobj,
1219				  struct kobj_attribute *attr, char *buf)
1220{
1221	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1222}
1223
1224static ssize_t resume_offset_store(struct kobject *kobj,
1225				   struct kobj_attribute *attr, const char *buf,
1226				   size_t n)
1227{
1228	unsigned long long offset;
1229	int rc;
1230
1231	rc = kstrtoull(buf, 0, &offset);
1232	if (rc)
1233		return rc;
1234	swsusp_resume_block = offset;
1235
1236	return n;
1237}
1238
1239power_attr(resume_offset);
1240
1241static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1242			       char *buf)
1243{
1244	return sprintf(buf, "%lu\n", image_size);
1245}
1246
1247static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1248				const char *buf, size_t n)
1249{
1250	unsigned long size;
1251
1252	if (sscanf(buf, "%lu", &size) == 1) {
1253		image_size = size;
1254		return n;
1255	}
1256
1257	return -EINVAL;
1258}
1259
1260power_attr(image_size);
1261
1262static ssize_t reserved_size_show(struct kobject *kobj,
1263				  struct kobj_attribute *attr, char *buf)
1264{
1265	return sprintf(buf, "%lu\n", reserved_size);
1266}
1267
1268static ssize_t reserved_size_store(struct kobject *kobj,
1269				   struct kobj_attribute *attr,
1270				   const char *buf, size_t n)
1271{
1272	unsigned long size;
1273
1274	if (sscanf(buf, "%lu", &size) == 1) {
1275		reserved_size = size;
1276		return n;
1277	}
1278
1279	return -EINVAL;
1280}
1281
1282power_attr(reserved_size);
1283
1284static struct attribute *g[] = {
1285	&disk_attr.attr,
1286	&resume_offset_attr.attr,
1287	&resume_attr.attr,
1288	&image_size_attr.attr,
1289	&reserved_size_attr.attr,
1290	NULL,
1291};
1292
1293
1294static const struct attribute_group attr_group = {
1295	.attrs = g,
1296};
1297
1298
1299static int __init pm_disk_init(void)
1300{
1301	return sysfs_create_group(power_kobj, &attr_group);
1302}
1303
1304core_initcall(pm_disk_init);
1305
1306
1307static int __init resume_setup(char *str)
1308{
1309	if (noresume)
1310		return 1;
1311
1312	strncpy(resume_file, str, 255);
1313	return 1;
1314}
1315
1316static int __init resume_offset_setup(char *str)
1317{
1318	unsigned long long offset;
1319
1320	if (noresume)
1321		return 1;
1322
1323	if (sscanf(str, "%llu", &offset) == 1)
1324		swsusp_resume_block = offset;
1325
1326	return 1;
1327}
1328
1329static int __init hibernate_setup(char *str)
1330{
1331	if (!strncmp(str, "noresume", 8)) {
1332		noresume = 1;
1333	} else if (!strncmp(str, "nocompress", 10)) {
1334		nocompress = 1;
1335	} else if (!strncmp(str, "no", 2)) {
1336		noresume = 1;
1337		nohibernate = 1;
1338	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1339		   && !strncmp(str, "protect_image", 13)) {
1340		enable_restore_image_protection();
1341	}
1342	return 1;
1343}
1344
1345static int __init noresume_setup(char *str)
1346{
1347	noresume = 1;
1348	return 1;
1349}
1350
1351static int __init resumewait_setup(char *str)
1352{
1353	resume_wait = 1;
1354	return 1;
1355}
1356
1357static int __init resumedelay_setup(char *str)
1358{
1359	int rc = kstrtouint(str, 0, &resume_delay);
1360
1361	if (rc)
1362		pr_warn("resumedelay: bad option string '%s'\n", str);
1363	return 1;
1364}
1365
1366static int __init nohibernate_setup(char *str)
1367{
1368	noresume = 1;
1369	nohibernate = 1;
1370	return 1;
1371}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1372
1373__setup("noresume", noresume_setup);
1374__setup("resume_offset=", resume_offset_setup);
1375__setup("resume=", resume_setup);
1376__setup("hibernate=", hibernate_setup);
1377__setup("resumewait", resumewait_setup);
1378__setup("resumedelay=", resumedelay_setup);
1379__setup("nohibernate", nohibernate_setup);
v6.9.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   4 *
   5 * Copyright (c) 2003 Patrick Mochel
   6 * Copyright (c) 2003 Open Source Development Lab
   7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
  10 */
  11
  12#define pr_fmt(fmt) "PM: hibernation: " fmt
  13
  14#include <linux/blkdev.h>
  15#include <linux/export.h>
  16#include <linux/suspend.h>
  17#include <linux/reboot.h>
  18#include <linux/string.h>
  19#include <linux/device.h>
  20#include <linux/async.h>
  21#include <linux/delay.h>
  22#include <linux/fs.h>
  23#include <linux/mount.h>
  24#include <linux/pm.h>
  25#include <linux/nmi.h>
  26#include <linux/console.h>
  27#include <linux/cpu.h>
  28#include <linux/freezer.h>
  29#include <linux/gfp.h>
  30#include <linux/syscore_ops.h>
  31#include <linux/ctype.h>
  32#include <linux/ktime.h>
  33#include <linux/security.h>
  34#include <linux/secretmem.h>
  35#include <trace/events/power.h>
  36
  37#include "power.h"
  38
  39
  40static int nocompress;
  41static int noresume;
  42static int nohibernate;
  43static int resume_wait;
  44static unsigned int resume_delay;
  45static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  46dev_t swsusp_resume_device;
  47sector_t swsusp_resume_block;
  48__visible int in_suspend __nosavedata;
  49
  50static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
  51
  52/*
  53 * Compression/decompression algorithm to be used while saving/loading
  54 * image to/from disk. This would later be used in 'kernel/power/swap.c'
  55 * to allocate comp streams.
  56 */
  57char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
  58
  59enum {
  60	HIBERNATION_INVALID,
  61	HIBERNATION_PLATFORM,
  62	HIBERNATION_SHUTDOWN,
  63	HIBERNATION_REBOOT,
  64#ifdef CONFIG_SUSPEND
  65	HIBERNATION_SUSPEND,
  66#endif
  67	HIBERNATION_TEST_RESUME,
  68	/* keep last */
  69	__HIBERNATION_AFTER_LAST
  70};
  71#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  72#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  73
  74static int hibernation_mode = HIBERNATION_SHUTDOWN;
  75
  76bool freezer_test_done;
  77
  78static const struct platform_hibernation_ops *hibernation_ops;
  79
  80static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  81
  82bool hibernate_acquire(void)
  83{
  84	return atomic_add_unless(&hibernate_atomic, -1, 0);
  85}
  86
  87void hibernate_release(void)
  88{
  89	atomic_inc(&hibernate_atomic);
  90}
  91
  92bool hibernation_available(void)
  93{
  94	return nohibernate == 0 &&
  95		!security_locked_down(LOCKDOWN_HIBERNATION) &&
  96		!secretmem_active() && !cxl_mem_active();
  97}
  98
  99/**
 100 * hibernation_set_ops - Set the global hibernate operations.
 101 * @ops: Hibernation operations to use in subsequent hibernation transitions.
 102 */
 103void hibernation_set_ops(const struct platform_hibernation_ops *ops)
 104{
 105	unsigned int sleep_flags;
 106
 107	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
 108	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
 109	    && ops->restore_cleanup && ops->leave)) {
 110		WARN_ON(1);
 111		return;
 112	}
 113
 114	sleep_flags = lock_system_sleep();
 115
 116	hibernation_ops = ops;
 117	if (ops)
 118		hibernation_mode = HIBERNATION_PLATFORM;
 119	else if (hibernation_mode == HIBERNATION_PLATFORM)
 120		hibernation_mode = HIBERNATION_SHUTDOWN;
 121
 122	unlock_system_sleep(sleep_flags);
 123}
 124EXPORT_SYMBOL_GPL(hibernation_set_ops);
 125
 126static bool entering_platform_hibernation;
 127
 128bool system_entering_hibernation(void)
 129{
 130	return entering_platform_hibernation;
 131}
 132EXPORT_SYMBOL(system_entering_hibernation);
 133
 134#ifdef CONFIG_PM_DEBUG
 135static void hibernation_debug_sleep(void)
 136{
 137	pr_info("debug: Waiting for 5 seconds.\n");
 138	mdelay(5000);
 139}
 140
 141static int hibernation_test(int level)
 142{
 143	if (pm_test_level == level) {
 144		hibernation_debug_sleep();
 145		return 1;
 146	}
 147	return 0;
 148}
 149#else /* !CONFIG_PM_DEBUG */
 150static int hibernation_test(int level) { return 0; }
 151#endif /* !CONFIG_PM_DEBUG */
 152
 153/**
 154 * platform_begin - Call platform to start hibernation.
 155 * @platform_mode: Whether or not to use the platform driver.
 156 */
 157static int platform_begin(int platform_mode)
 158{
 159	return (platform_mode && hibernation_ops) ?
 160		hibernation_ops->begin(PMSG_FREEZE) : 0;
 161}
 162
 163/**
 164 * platform_end - Call platform to finish transition to the working state.
 165 * @platform_mode: Whether or not to use the platform driver.
 166 */
 167static void platform_end(int platform_mode)
 168{
 169	if (platform_mode && hibernation_ops)
 170		hibernation_ops->end();
 171}
 172
 173/**
 174 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 175 * @platform_mode: Whether or not to use the platform driver.
 176 *
 177 * Use the platform driver to prepare the system for creating a hibernate image,
 178 * if so configured, and return an error code if that fails.
 179 */
 180
 181static int platform_pre_snapshot(int platform_mode)
 182{
 183	return (platform_mode && hibernation_ops) ?
 184		hibernation_ops->pre_snapshot() : 0;
 185}
 186
 187/**
 188 * platform_leave - Call platform to prepare a transition to the working state.
 189 * @platform_mode: Whether or not to use the platform driver.
 190 *
 191 * Use the platform driver prepare to prepare the machine for switching to the
 192 * normal mode of operation.
 193 *
 194 * This routine is called on one CPU with interrupts disabled.
 195 */
 196static void platform_leave(int platform_mode)
 197{
 198	if (platform_mode && hibernation_ops)
 199		hibernation_ops->leave();
 200}
 201
 202/**
 203 * platform_finish - Call platform to switch the system to the working state.
 204 * @platform_mode: Whether or not to use the platform driver.
 205 *
 206 * Use the platform driver to switch the machine to the normal mode of
 207 * operation.
 208 *
 209 * This routine must be called after platform_prepare().
 210 */
 211static void platform_finish(int platform_mode)
 212{
 213	if (platform_mode && hibernation_ops)
 214		hibernation_ops->finish();
 215}
 216
 217/**
 218 * platform_pre_restore - Prepare for hibernate image restoration.
 219 * @platform_mode: Whether or not to use the platform driver.
 220 *
 221 * Use the platform driver to prepare the system for resume from a hibernation
 222 * image.
 223 *
 224 * If the restore fails after this function has been called,
 225 * platform_restore_cleanup() must be called.
 226 */
 227static int platform_pre_restore(int platform_mode)
 228{
 229	return (platform_mode && hibernation_ops) ?
 230		hibernation_ops->pre_restore() : 0;
 231}
 232
 233/**
 234 * platform_restore_cleanup - Switch to the working state after failing restore.
 235 * @platform_mode: Whether or not to use the platform driver.
 236 *
 237 * Use the platform driver to switch the system to the normal mode of operation
 238 * after a failing restore.
 239 *
 240 * If platform_pre_restore() has been called before the failing restore, this
 241 * function must be called too, regardless of the result of
 242 * platform_pre_restore().
 243 */
 244static void platform_restore_cleanup(int platform_mode)
 245{
 246	if (platform_mode && hibernation_ops)
 247		hibernation_ops->restore_cleanup();
 248}
 249
 250/**
 251 * platform_recover - Recover from a failure to suspend devices.
 252 * @platform_mode: Whether or not to use the platform driver.
 253 */
 254static void platform_recover(int platform_mode)
 255{
 256	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 257		hibernation_ops->recover();
 258}
 259
 260/**
 261 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 262 * @start: Starting event.
 263 * @stop: Final event.
 264 * @nr_pages: Number of memory pages processed between @start and @stop.
 265 * @msg: Additional diagnostic message to print.
 266 */
 267void swsusp_show_speed(ktime_t start, ktime_t stop,
 268		      unsigned nr_pages, char *msg)
 269{
 270	ktime_t diff;
 271	u64 elapsed_centisecs64;
 272	unsigned int centisecs;
 273	unsigned int k;
 274	unsigned int kps;
 275
 276	diff = ktime_sub(stop, start);
 277	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 278	centisecs = elapsed_centisecs64;
 279	if (centisecs == 0)
 280		centisecs = 1;	/* avoid div-by-zero */
 281	k = nr_pages * (PAGE_SIZE / 1024);
 282	kps = (k * 100) / centisecs;
 283	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 284		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 285		(kps % 1000) / 10);
 286}
 287
 288__weak int arch_resume_nosmt(void)
 289{
 290	return 0;
 291}
 292
 293/**
 294 * create_image - Create a hibernation image.
 295 * @platform_mode: Whether or not to use the platform driver.
 296 *
 297 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 298 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 299 *
 300 * Control reappears in this routine after the subsequent restore.
 301 */
 302static int create_image(int platform_mode)
 303{
 304	int error;
 305
 306	error = dpm_suspend_end(PMSG_FREEZE);
 307	if (error) {
 308		pr_err("Some devices failed to power down, aborting\n");
 309		return error;
 310	}
 311
 312	error = platform_pre_snapshot(platform_mode);
 313	if (error || hibernation_test(TEST_PLATFORM))
 314		goto Platform_finish;
 315
 316	error = pm_sleep_disable_secondary_cpus();
 317	if (error || hibernation_test(TEST_CPUS))
 318		goto Enable_cpus;
 319
 320	local_irq_disable();
 321
 322	system_state = SYSTEM_SUSPEND;
 323
 324	error = syscore_suspend();
 325	if (error) {
 326		pr_err("Some system devices failed to power down, aborting\n");
 327		goto Enable_irqs;
 328	}
 329
 330	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 331		goto Power_up;
 332
 333	in_suspend = 1;
 334	save_processor_state();
 335	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 336	error = swsusp_arch_suspend();
 337	/* Restore control flow magically appears here */
 338	restore_processor_state();
 339	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 340	if (error)
 341		pr_err("Error %d creating image\n", error);
 342
 343	if (!in_suspend) {
 344		events_check_enabled = false;
 345		clear_or_poison_free_pages();
 346	}
 347
 348	platform_leave(platform_mode);
 349
 350 Power_up:
 351	syscore_resume();
 352
 353 Enable_irqs:
 354	system_state = SYSTEM_RUNNING;
 355	local_irq_enable();
 356
 357 Enable_cpus:
 358	pm_sleep_enable_secondary_cpus();
 359
 360	/* Allow architectures to do nosmt-specific post-resume dances */
 361	if (!in_suspend)
 362		error = arch_resume_nosmt();
 363
 364 Platform_finish:
 365	platform_finish(platform_mode);
 366
 367	dpm_resume_start(in_suspend ?
 368		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 369
 370	return error;
 371}
 372
 373/**
 374 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 375 * @platform_mode: If set, use platform driver to prepare for the transition.
 376 *
 377 * This routine must be called with system_transition_mutex held.
 378 */
 379int hibernation_snapshot(int platform_mode)
 380{
 381	pm_message_t msg;
 382	int error;
 383
 384	pm_suspend_clear_flags();
 385	error = platform_begin(platform_mode);
 386	if (error)
 387		goto Close;
 388
 389	/* Preallocate image memory before shutting down devices. */
 390	error = hibernate_preallocate_memory();
 391	if (error)
 392		goto Close;
 393
 394	error = freeze_kernel_threads();
 395	if (error)
 396		goto Cleanup;
 397
 398	if (hibernation_test(TEST_FREEZER)) {
 399
 400		/*
 401		 * Indicate to the caller that we are returning due to a
 402		 * successful freezer test.
 403		 */
 404		freezer_test_done = true;
 405		goto Thaw;
 406	}
 407
 408	error = dpm_prepare(PMSG_FREEZE);
 409	if (error) {
 410		dpm_complete(PMSG_RECOVER);
 411		goto Thaw;
 412	}
 413
 414	suspend_console();
 415	pm_restrict_gfp_mask();
 416
 417	error = dpm_suspend(PMSG_FREEZE);
 418
 419	if (error || hibernation_test(TEST_DEVICES))
 420		platform_recover(platform_mode);
 421	else
 422		error = create_image(platform_mode);
 423
 424	/*
 425	 * In the case that we call create_image() above, the control
 426	 * returns here (1) after the image has been created or the
 427	 * image creation has failed and (2) after a successful restore.
 428	 */
 429
 430	/* We may need to release the preallocated image pages here. */
 431	if (error || !in_suspend)
 432		swsusp_free();
 433
 434	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 435	dpm_resume(msg);
 436
 437	if (error || !in_suspend)
 438		pm_restore_gfp_mask();
 439
 440	resume_console();
 441	dpm_complete(msg);
 442
 443 Close:
 444	platform_end(platform_mode);
 445	return error;
 446
 447 Thaw:
 448	thaw_kernel_threads();
 449 Cleanup:
 450	swsusp_free();
 451	goto Close;
 452}
 453
 454int __weak hibernate_resume_nonboot_cpu_disable(void)
 455{
 456	return suspend_disable_secondary_cpus();
 457}
 458
 459/**
 460 * resume_target_kernel - Restore system state from a hibernation image.
 461 * @platform_mode: Whether or not to use the platform driver.
 462 *
 463 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 464 * contents of highmem that have not been restored yet from the image and run
 465 * the low-level code that will restore the remaining contents of memory and
 466 * switch to the just restored target kernel.
 467 */
 468static int resume_target_kernel(bool platform_mode)
 469{
 470	int error;
 471
 472	error = dpm_suspend_end(PMSG_QUIESCE);
 473	if (error) {
 474		pr_err("Some devices failed to power down, aborting resume\n");
 475		return error;
 476	}
 477
 478	error = platform_pre_restore(platform_mode);
 479	if (error)
 480		goto Cleanup;
 481
 482	cpuidle_pause();
 483
 484	error = hibernate_resume_nonboot_cpu_disable();
 485	if (error)
 486		goto Enable_cpus;
 487
 488	local_irq_disable();
 489	system_state = SYSTEM_SUSPEND;
 490
 491	error = syscore_suspend();
 492	if (error)
 493		goto Enable_irqs;
 494
 495	save_processor_state();
 496	error = restore_highmem();
 497	if (!error) {
 498		error = swsusp_arch_resume();
 499		/*
 500		 * The code below is only ever reached in case of a failure.
 501		 * Otherwise, execution continues at the place where
 502		 * swsusp_arch_suspend() was called.
 503		 */
 504		BUG_ON(!error);
 505		/*
 506		 * This call to restore_highmem() reverts the changes made by
 507		 * the previous one.
 508		 */
 509		restore_highmem();
 510	}
 511	/*
 512	 * The only reason why swsusp_arch_resume() can fail is memory being
 513	 * very tight, so we have to free it as soon as we can to avoid
 514	 * subsequent failures.
 515	 */
 516	swsusp_free();
 517	restore_processor_state();
 518	touch_softlockup_watchdog();
 519
 520	syscore_resume();
 521
 522 Enable_irqs:
 523	system_state = SYSTEM_RUNNING;
 524	local_irq_enable();
 525
 526 Enable_cpus:
 527	pm_sleep_enable_secondary_cpus();
 528
 529 Cleanup:
 530	platform_restore_cleanup(platform_mode);
 531
 532	dpm_resume_start(PMSG_RECOVER);
 533
 534	return error;
 535}
 536
 537/**
 538 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 539 * @platform_mode: If set, use platform driver to prepare for the transition.
 540 *
 541 * This routine must be called with system_transition_mutex held.  If it is
 542 * successful, control reappears in the restored target kernel in
 543 * hibernation_snapshot().
 544 */
 545int hibernation_restore(int platform_mode)
 546{
 547	int error;
 548
 549	pm_prepare_console();
 550	suspend_console();
 551	pm_restrict_gfp_mask();
 552	error = dpm_suspend_start(PMSG_QUIESCE);
 553	if (!error) {
 554		error = resume_target_kernel(platform_mode);
 555		/*
 556		 * The above should either succeed and jump to the new kernel,
 557		 * or return with an error. Otherwise things are just
 558		 * undefined, so let's be paranoid.
 559		 */
 560		BUG_ON(!error);
 561	}
 562	dpm_resume_end(PMSG_RECOVER);
 563	pm_restore_gfp_mask();
 564	resume_console();
 565	pm_restore_console();
 566	return error;
 567}
 568
 569/**
 570 * hibernation_platform_enter - Power off the system using the platform driver.
 571 */
 572int hibernation_platform_enter(void)
 573{
 574	int error;
 575
 576	if (!hibernation_ops)
 577		return -ENOSYS;
 578
 579	/*
 580	 * We have cancelled the power transition by running
 581	 * hibernation_ops->finish() before saving the image, so we should let
 582	 * the firmware know that we're going to enter the sleep state after all
 583	 */
 584	error = hibernation_ops->begin(PMSG_HIBERNATE);
 585	if (error)
 586		goto Close;
 587
 588	entering_platform_hibernation = true;
 589	suspend_console();
 590	error = dpm_suspend_start(PMSG_HIBERNATE);
 591	if (error) {
 592		if (hibernation_ops->recover)
 593			hibernation_ops->recover();
 594		goto Resume_devices;
 595	}
 596
 597	error = dpm_suspend_end(PMSG_HIBERNATE);
 598	if (error)
 599		goto Resume_devices;
 600
 601	error = hibernation_ops->prepare();
 602	if (error)
 603		goto Platform_finish;
 604
 605	error = pm_sleep_disable_secondary_cpus();
 606	if (error)
 607		goto Enable_cpus;
 608
 609	local_irq_disable();
 610	system_state = SYSTEM_SUSPEND;
 611	syscore_suspend();
 612	if (pm_wakeup_pending()) {
 613		error = -EAGAIN;
 614		goto Power_up;
 615	}
 616
 617	hibernation_ops->enter();
 618	/* We should never get here */
 619	while (1);
 620
 621 Power_up:
 622	syscore_resume();
 623	system_state = SYSTEM_RUNNING;
 624	local_irq_enable();
 625
 626 Enable_cpus:
 627	pm_sleep_enable_secondary_cpus();
 628
 629 Platform_finish:
 630	hibernation_ops->finish();
 631
 632	dpm_resume_start(PMSG_RESTORE);
 633
 634 Resume_devices:
 635	entering_platform_hibernation = false;
 636	dpm_resume_end(PMSG_RESTORE);
 637	resume_console();
 638
 639 Close:
 640	hibernation_ops->end();
 641
 642	return error;
 643}
 644
 645/**
 646 * power_down - Shut the machine down for hibernation.
 647 *
 648 * Use the platform driver, if configured, to put the system into the sleep
 649 * state corresponding to hibernation, or try to power it off or reboot,
 650 * depending on the value of hibernation_mode.
 651 */
 652static void power_down(void)
 653{
 654	int error;
 655
 656#ifdef CONFIG_SUSPEND
 657	if (hibernation_mode == HIBERNATION_SUSPEND) {
 658		error = suspend_devices_and_enter(mem_sleep_current);
 659		if (error) {
 660			hibernation_mode = hibernation_ops ?
 661						HIBERNATION_PLATFORM :
 662						HIBERNATION_SHUTDOWN;
 663		} else {
 664			/* Restore swap signature. */
 665			error = swsusp_unmark();
 666			if (error)
 667				pr_err("Swap will be unusable! Try swapon -a.\n");
 668
 669			return;
 670		}
 671	}
 672#endif
 673
 674	switch (hibernation_mode) {
 675	case HIBERNATION_REBOOT:
 676		kernel_restart(NULL);
 677		break;
 678	case HIBERNATION_PLATFORM:
 679		error = hibernation_platform_enter();
 680		if (error == -EAGAIN || error == -EBUSY) {
 681			swsusp_unmark();
 682			events_check_enabled = false;
 683			pr_info("Wakeup event detected during hibernation, rolling back.\n");
 684			return;
 685		}
 686		fallthrough;
 687	case HIBERNATION_SHUTDOWN:
 688		if (kernel_can_power_off())
 689			kernel_power_off();
 690		break;
 691	}
 692	kernel_halt();
 693	/*
 694	 * Valid image is on the disk, if we continue we risk serious data
 695	 * corruption after resume.
 696	 */
 697	pr_crit("Power down manually\n");
 698	while (1)
 699		cpu_relax();
 700}
 701
 702static int load_image_and_restore(void)
 703{
 704	int error;
 705	unsigned int flags;
 706
 707	pm_pr_dbg("Loading hibernation image.\n");
 708
 709	lock_device_hotplug();
 710	error = create_basic_memory_bitmaps();
 711	if (error) {
 712		swsusp_close();
 713		goto Unlock;
 714	}
 715
 716	error = swsusp_read(&flags);
 717	swsusp_close();
 718	if (!error)
 719		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 720
 721	pr_err("Failed to load image, recovering.\n");
 722	swsusp_free();
 723	free_basic_memory_bitmaps();
 724 Unlock:
 725	unlock_device_hotplug();
 726
 727	return error;
 728}
 729
 730#define COMPRESSION_ALGO_LZO "lzo"
 731#define COMPRESSION_ALGO_LZ4 "lz4"
 732
 733/**
 734 * hibernate - Carry out system hibernation, including saving the image.
 735 */
 736int hibernate(void)
 737{
 738	bool snapshot_test = false;
 739	unsigned int sleep_flags;
 740	int error;
 741
 742	if (!hibernation_available()) {
 743		pm_pr_dbg("Hibernation not available.\n");
 744		return -EPERM;
 745	}
 746
 747	/*
 748	 * Query for the compression algorithm support if compression is enabled.
 749	 */
 750	if (!nocompress) {
 751		strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
 752		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
 753			pr_err("%s compression is not available\n", hib_comp_algo);
 754			return -EOPNOTSUPP;
 755		}
 756	}
 757
 758	sleep_flags = lock_system_sleep();
 759	/* The snapshot device should not be opened while we're running */
 760	if (!hibernate_acquire()) {
 761		error = -EBUSY;
 762		goto Unlock;
 763	}
 764
 765	pr_info("hibernation entry\n");
 766	pm_prepare_console();
 767	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 768	if (error)
 769		goto Restore;
 770
 771	ksys_sync_helper();
 772
 773	error = freeze_processes();
 774	if (error)
 775		goto Exit;
 776
 777	lock_device_hotplug();
 778	/* Allocate memory management structures */
 779	error = create_basic_memory_bitmaps();
 780	if (error)
 781		goto Thaw;
 782
 783	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 784	if (error || freezer_test_done)
 785		goto Free_bitmaps;
 786
 787	if (in_suspend) {
 788		unsigned int flags = 0;
 789
 790		if (hibernation_mode == HIBERNATION_PLATFORM)
 791			flags |= SF_PLATFORM_MODE;
 792		if (nocompress) {
 793			flags |= SF_NOCOMPRESS_MODE;
 794		} else {
 795		        flags |= SF_CRC32_MODE;
 796
 797			/*
 798			 * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
 799			 * to override this behaviour and use LZ4.
 800			 *
 801			 * Refer kernel/power/power.h for more details
 802			 */
 803
 804			if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
 805				flags |= SF_COMPRESSION_ALG_LZ4;
 806			else
 807				flags |= SF_COMPRESSION_ALG_LZO;
 808		}
 809
 810		pm_pr_dbg("Writing hibernation image.\n");
 811		error = swsusp_write(flags);
 812		swsusp_free();
 813		if (!error) {
 814			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 815				snapshot_test = true;
 816			else
 817				power_down();
 818		}
 819		in_suspend = 0;
 820		pm_restore_gfp_mask();
 821	} else {
 822		pm_pr_dbg("Hibernation image restored successfully.\n");
 823	}
 824
 825 Free_bitmaps:
 826	free_basic_memory_bitmaps();
 827 Thaw:
 828	unlock_device_hotplug();
 829	if (snapshot_test) {
 830		pm_pr_dbg("Checking hibernation image\n");
 831		error = swsusp_check(false);
 832		if (!error)
 833			error = load_image_and_restore();
 834	}
 835	thaw_processes();
 836
 837	/* Don't bother checking whether freezer_test_done is true */
 838	freezer_test_done = false;
 839 Exit:
 840	pm_notifier_call_chain(PM_POST_HIBERNATION);
 841 Restore:
 842	pm_restore_console();
 843	hibernate_release();
 844 Unlock:
 845	unlock_system_sleep(sleep_flags);
 846	pr_info("hibernation exit\n");
 847
 848	return error;
 849}
 850
 851/**
 852 * hibernate_quiet_exec - Execute a function with all devices frozen.
 853 * @func: Function to execute.
 854 * @data: Data pointer to pass to @func.
 855 *
 856 * Return the @func return value or an error code if it cannot be executed.
 857 */
 858int hibernate_quiet_exec(int (*func)(void *data), void *data)
 859{
 860	unsigned int sleep_flags;
 861	int error;
 862
 863	sleep_flags = lock_system_sleep();
 864
 865	if (!hibernate_acquire()) {
 866		error = -EBUSY;
 867		goto unlock;
 868	}
 869
 870	pm_prepare_console();
 871
 872	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 873	if (error)
 874		goto restore;
 875
 876	error = freeze_processes();
 877	if (error)
 878		goto exit;
 879
 880	lock_device_hotplug();
 881
 882	pm_suspend_clear_flags();
 883
 884	error = platform_begin(true);
 885	if (error)
 886		goto thaw;
 887
 888	error = freeze_kernel_threads();
 889	if (error)
 890		goto thaw;
 891
 892	error = dpm_prepare(PMSG_FREEZE);
 893	if (error)
 894		goto dpm_complete;
 895
 896	suspend_console();
 897
 898	error = dpm_suspend(PMSG_FREEZE);
 899	if (error)
 900		goto dpm_resume;
 901
 902	error = dpm_suspend_end(PMSG_FREEZE);
 903	if (error)
 904		goto dpm_resume;
 905
 906	error = platform_pre_snapshot(true);
 907	if (error)
 908		goto skip;
 909
 910	error = func(data);
 911
 912skip:
 913	platform_finish(true);
 914
 915	dpm_resume_start(PMSG_THAW);
 916
 917dpm_resume:
 918	dpm_resume(PMSG_THAW);
 919
 920	resume_console();
 921
 922dpm_complete:
 923	dpm_complete(PMSG_THAW);
 924
 925	thaw_kernel_threads();
 926
 927thaw:
 928	platform_end(true);
 929
 930	unlock_device_hotplug();
 931
 932	thaw_processes();
 933
 934exit:
 935	pm_notifier_call_chain(PM_POST_HIBERNATION);
 936
 937restore:
 938	pm_restore_console();
 939
 940	hibernate_release();
 941
 942unlock:
 943	unlock_system_sleep(sleep_flags);
 944
 945	return error;
 946}
 947EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 948
 949static int __init find_resume_device(void)
 950{
 951	if (!strlen(resume_file))
 952		return -ENOENT;
 953
 954	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 955
 956	if (resume_delay) {
 957		pr_info("Waiting %dsec before reading resume device ...\n",
 958			resume_delay);
 959		ssleep(resume_delay);
 960	}
 961
 962	/* Check if the device is there */
 963	if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
 964		return 0;
 965
 966	/*
 967	 * Some device discovery might still be in progress; we need to wait for
 968	 * this to finish.
 969	 */
 970	wait_for_device_probe();
 971	if (resume_wait) {
 972		while (early_lookup_bdev(resume_file, &swsusp_resume_device))
 973			msleep(10);
 974		async_synchronize_full();
 975	}
 976
 977	return early_lookup_bdev(resume_file, &swsusp_resume_device);
 978}
 979
 980static int software_resume(void)
 981{
 982	int error;
 983
 984	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 985		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 986
 987	pm_pr_dbg("Looking for hibernation image.\n");
 988
 989	mutex_lock(&system_transition_mutex);
 990	error = swsusp_check(true);
 991	if (error)
 992		goto Unlock;
 993
 994	/*
 995	 * Check if the hibernation image is compressed. If so, query for
 996	 * the algorithm support.
 997	 */
 998	if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
 999		if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1000			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
1001		else
1002			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
1003		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
1004			pr_err("%s compression is not available\n", hib_comp_algo);
1005			error = -EOPNOTSUPP;
1006			goto Unlock;
1007		}
1008	}
1009
1010	/* The snapshot device should not be opened while we're running */
1011	if (!hibernate_acquire()) {
1012		error = -EBUSY;
1013		swsusp_close();
1014		goto Unlock;
1015	}
1016
1017	pr_info("resume from hibernation\n");
1018	pm_prepare_console();
1019	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1020	if (error)
1021		goto Restore;
1022
1023	pm_pr_dbg("Preparing processes for hibernation restore.\n");
1024	error = freeze_processes();
1025	if (error)
1026		goto Close_Finish;
1027
1028	error = freeze_kernel_threads();
1029	if (error) {
1030		thaw_processes();
1031		goto Close_Finish;
1032	}
1033
1034	error = load_image_and_restore();
1035	thaw_processes();
1036 Finish:
1037	pm_notifier_call_chain(PM_POST_RESTORE);
1038 Restore:
1039	pm_restore_console();
1040	pr_info("resume failed (%d)\n", error);
1041	hibernate_release();
1042	/* For success case, the suspend path will release the lock */
1043 Unlock:
1044	mutex_unlock(&system_transition_mutex);
1045	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1046	return error;
1047 Close_Finish:
1048	swsusp_close();
1049	goto Finish;
1050}
1051
1052/**
1053 * software_resume_initcall - Resume from a saved hibernation image.
1054 *
1055 * This routine is called as a late initcall, when all devices have been
1056 * discovered and initialized already.
1057 *
1058 * The image reading code is called to see if there is a hibernation image
1059 * available for reading.  If that is the case, devices are quiesced and the
1060 * contents of memory is restored from the saved image.
1061 *
1062 * If this is successful, control reappears in the restored target kernel in
1063 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1064 * attempts to recover gracefully and make the kernel return to the normal mode
1065 * of operation.
1066 */
1067static int __init software_resume_initcall(void)
1068{
1069	/*
1070	 * If the user said "noresume".. bail out early.
1071	 */
1072	if (noresume || !hibernation_available())
1073		return 0;
1074
1075	if (!swsusp_resume_device) {
1076		int error = find_resume_device();
1077
1078		if (error)
1079			return error;
1080	}
1081
1082	return software_resume();
1083}
1084late_initcall_sync(software_resume_initcall);
1085
1086
1087static const char * const hibernation_modes[] = {
1088	[HIBERNATION_PLATFORM]	= "platform",
1089	[HIBERNATION_SHUTDOWN]	= "shutdown",
1090	[HIBERNATION_REBOOT]	= "reboot",
1091#ifdef CONFIG_SUSPEND
1092	[HIBERNATION_SUSPEND]	= "suspend",
1093#endif
1094	[HIBERNATION_TEST_RESUME]	= "test_resume",
1095};
1096
1097/*
1098 * /sys/power/disk - Control hibernation mode.
1099 *
1100 * Hibernation can be handled in several ways.  There are a few different ways
1101 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1102 * or other hibernation_ops), powering it off or rebooting it (for testing
1103 * mostly).
1104 *
1105 * The sysfs file /sys/power/disk provides an interface for selecting the
1106 * hibernation mode to use.  Reading from this file causes the available modes
1107 * to be printed.  There are 3 modes that can be supported:
1108 *
1109 *	'platform'
1110 *	'shutdown'
1111 *	'reboot'
1112 *
1113 * If a platform hibernation driver is in use, 'platform' will be supported
1114 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1115 * The selected option (i.e. the one corresponding to the current value of
1116 * hibernation_mode) is enclosed by a square bracket.
1117 *
1118 * To select a given hibernation mode it is necessary to write the mode's
1119 * string representation (as returned by reading from /sys/power/disk) back
1120 * into /sys/power/disk.
1121 */
1122
1123static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1124			 char *buf)
1125{
1126	int i;
1127	char *start = buf;
1128
1129	if (!hibernation_available())
1130		return sprintf(buf, "[disabled]\n");
1131
1132	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1133		if (!hibernation_modes[i])
1134			continue;
1135		switch (i) {
1136		case HIBERNATION_SHUTDOWN:
1137		case HIBERNATION_REBOOT:
1138#ifdef CONFIG_SUSPEND
1139		case HIBERNATION_SUSPEND:
1140#endif
1141		case HIBERNATION_TEST_RESUME:
1142			break;
1143		case HIBERNATION_PLATFORM:
1144			if (hibernation_ops)
1145				break;
1146			/* not a valid mode, continue with loop */
1147			continue;
1148		}
1149		if (i == hibernation_mode)
1150			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1151		else
1152			buf += sprintf(buf, "%s ", hibernation_modes[i]);
1153	}
1154	buf += sprintf(buf, "\n");
1155	return buf-start;
1156}
1157
1158static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1159			  const char *buf, size_t n)
1160{
1161	int mode = HIBERNATION_INVALID;
1162	unsigned int sleep_flags;
1163	int error = 0;
1164	int len;
1165	char *p;
1166	int i;
1167
1168	if (!hibernation_available())
1169		return -EPERM;
1170
1171	p = memchr(buf, '\n', n);
1172	len = p ? p - buf : n;
1173
1174	sleep_flags = lock_system_sleep();
1175	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1176		if (len == strlen(hibernation_modes[i])
1177		    && !strncmp(buf, hibernation_modes[i], len)) {
1178			mode = i;
1179			break;
1180		}
1181	}
1182	if (mode != HIBERNATION_INVALID) {
1183		switch (mode) {
1184		case HIBERNATION_SHUTDOWN:
1185		case HIBERNATION_REBOOT:
1186#ifdef CONFIG_SUSPEND
1187		case HIBERNATION_SUSPEND:
1188#endif
1189		case HIBERNATION_TEST_RESUME:
1190			hibernation_mode = mode;
1191			break;
1192		case HIBERNATION_PLATFORM:
1193			if (hibernation_ops)
1194				hibernation_mode = mode;
1195			else
1196				error = -EINVAL;
1197		}
1198	} else
1199		error = -EINVAL;
1200
1201	if (!error)
1202		pm_pr_dbg("Hibernation mode set to '%s'\n",
1203			       hibernation_modes[mode]);
1204	unlock_system_sleep(sleep_flags);
1205	return error ? error : n;
1206}
1207
1208power_attr(disk);
1209
1210static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1211			   char *buf)
1212{
1213	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1214		       MINOR(swsusp_resume_device));
1215}
1216
1217static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1218			    const char *buf, size_t n)
1219{
1220	unsigned int sleep_flags;
1221	int len = n;
1222	char *name;
1223	dev_t dev;
1224	int error;
1225
1226	if (!hibernation_available())
1227		return n;
1228
1229	if (len && buf[len-1] == '\n')
1230		len--;
1231	name = kstrndup(buf, len, GFP_KERNEL);
1232	if (!name)
1233		return -ENOMEM;
1234
1235	error = lookup_bdev(name, &dev);
1236	if (error) {
1237		unsigned maj, min, offset;
1238		char *p, dummy;
1239
1240		error = 0;
1241		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1242		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1243				&dummy) == 3) {
1244			dev = MKDEV(maj, min);
1245			if (maj != MAJOR(dev) || min != MINOR(dev))
1246				error = -EINVAL;
1247		} else {
1248			dev = new_decode_dev(simple_strtoul(name, &p, 16));
1249			if (*p)
1250				error = -EINVAL;
1251		}
1252	}
1253	kfree(name);
1254	if (error)
1255		return error;
1256
1257	sleep_flags = lock_system_sleep();
1258	swsusp_resume_device = dev;
1259	unlock_system_sleep(sleep_flags);
1260
1261	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1262		  swsusp_resume_device);
1263	noresume = 0;
1264	software_resume();
1265	return n;
1266}
1267
1268power_attr(resume);
1269
1270static ssize_t resume_offset_show(struct kobject *kobj,
1271				  struct kobj_attribute *attr, char *buf)
1272{
1273	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1274}
1275
1276static ssize_t resume_offset_store(struct kobject *kobj,
1277				   struct kobj_attribute *attr, const char *buf,
1278				   size_t n)
1279{
1280	unsigned long long offset;
1281	int rc;
1282
1283	rc = kstrtoull(buf, 0, &offset);
1284	if (rc)
1285		return rc;
1286	swsusp_resume_block = offset;
1287
1288	return n;
1289}
1290
1291power_attr(resume_offset);
1292
1293static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1294			       char *buf)
1295{
1296	return sprintf(buf, "%lu\n", image_size);
1297}
1298
1299static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1300				const char *buf, size_t n)
1301{
1302	unsigned long size;
1303
1304	if (sscanf(buf, "%lu", &size) == 1) {
1305		image_size = size;
1306		return n;
1307	}
1308
1309	return -EINVAL;
1310}
1311
1312power_attr(image_size);
1313
1314static ssize_t reserved_size_show(struct kobject *kobj,
1315				  struct kobj_attribute *attr, char *buf)
1316{
1317	return sprintf(buf, "%lu\n", reserved_size);
1318}
1319
1320static ssize_t reserved_size_store(struct kobject *kobj,
1321				   struct kobj_attribute *attr,
1322				   const char *buf, size_t n)
1323{
1324	unsigned long size;
1325
1326	if (sscanf(buf, "%lu", &size) == 1) {
1327		reserved_size = size;
1328		return n;
1329	}
1330
1331	return -EINVAL;
1332}
1333
1334power_attr(reserved_size);
1335
1336static struct attribute *g[] = {
1337	&disk_attr.attr,
1338	&resume_offset_attr.attr,
1339	&resume_attr.attr,
1340	&image_size_attr.attr,
1341	&reserved_size_attr.attr,
1342	NULL,
1343};
1344
1345
1346static const struct attribute_group attr_group = {
1347	.attrs = g,
1348};
1349
1350
1351static int __init pm_disk_init(void)
1352{
1353	return sysfs_create_group(power_kobj, &attr_group);
1354}
1355
1356core_initcall(pm_disk_init);
1357
1358
1359static int __init resume_setup(char *str)
1360{
1361	if (noresume)
1362		return 1;
1363
1364	strncpy(resume_file, str, 255);
1365	return 1;
1366}
1367
1368static int __init resume_offset_setup(char *str)
1369{
1370	unsigned long long offset;
1371
1372	if (noresume)
1373		return 1;
1374
1375	if (sscanf(str, "%llu", &offset) == 1)
1376		swsusp_resume_block = offset;
1377
1378	return 1;
1379}
1380
1381static int __init hibernate_setup(char *str)
1382{
1383	if (!strncmp(str, "noresume", 8)) {
1384		noresume = 1;
1385	} else if (!strncmp(str, "nocompress", 10)) {
1386		nocompress = 1;
1387	} else if (!strncmp(str, "no", 2)) {
1388		noresume = 1;
1389		nohibernate = 1;
1390	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1391		   && !strncmp(str, "protect_image", 13)) {
1392		enable_restore_image_protection();
1393	}
1394	return 1;
1395}
1396
1397static int __init noresume_setup(char *str)
1398{
1399	noresume = 1;
1400	return 1;
1401}
1402
1403static int __init resumewait_setup(char *str)
1404{
1405	resume_wait = 1;
1406	return 1;
1407}
1408
1409static int __init resumedelay_setup(char *str)
1410{
1411	int rc = kstrtouint(str, 0, &resume_delay);
1412
1413	if (rc)
1414		pr_warn("resumedelay: bad option string '%s'\n", str);
1415	return 1;
1416}
1417
1418static int __init nohibernate_setup(char *str)
1419{
1420	noresume = 1;
1421	nohibernate = 1;
1422	return 1;
1423}
1424
1425static const char * const comp_alg_enabled[] = {
1426#if IS_ENABLED(CONFIG_CRYPTO_LZO)
1427	COMPRESSION_ALGO_LZO,
1428#endif
1429#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1430	COMPRESSION_ALGO_LZ4,
1431#endif
1432};
1433
1434static int hibernate_compressor_param_set(const char *compressor,
1435		const struct kernel_param *kp)
1436{
1437	unsigned int sleep_flags;
1438	int index, ret;
1439
1440	sleep_flags = lock_system_sleep();
1441
1442	index = sysfs_match_string(comp_alg_enabled, compressor);
1443	if (index >= 0) {
1444		ret = param_set_copystring(comp_alg_enabled[index], kp);
1445		if (!ret)
1446			strscpy(hib_comp_algo, comp_alg_enabled[index],
1447				sizeof(hib_comp_algo));
1448	} else {
1449		ret = index;
1450	}
1451
1452	unlock_system_sleep(sleep_flags);
1453
1454	if (ret)
1455		pr_debug("Cannot set specified compressor %s\n",
1456			 compressor);
1457
1458	return ret;
1459}
1460
1461static const struct kernel_param_ops hibernate_compressor_param_ops = {
1462	.set    = hibernate_compressor_param_set,
1463	.get    = param_get_string,
1464};
1465
1466static struct kparam_string hibernate_compressor_param_string = {
1467	.maxlen = sizeof(hibernate_compressor),
1468	.string = hibernate_compressor,
1469};
1470
1471module_param_cb(compressor, &hibernate_compressor_param_ops,
1472		&hibernate_compressor_param_string, 0644);
1473MODULE_PARM_DESC(compressor,
1474		 "Compression algorithm to be used with hibernation");
1475
1476__setup("noresume", noresume_setup);
1477__setup("resume_offset=", resume_offset_setup);
1478__setup("resume=", resume_setup);
1479__setup("hibernate=", hibernate_setup);
1480__setup("resumewait", resumewait_setup);
1481__setup("resumedelay=", resumedelay_setup);
1482__setup("nohibernate", nohibernate_setup);