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v6.2
   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/export.h>
  15#include <linux/suspend.h>
 
  16#include <linux/reboot.h>
  17#include <linux/string.h>
  18#include <linux/device.h>
  19#include <linux/async.h>
  20#include <linux/delay.h>
  21#include <linux/fs.h>
  22#include <linux/mount.h>
  23#include <linux/pm.h>
  24#include <linux/nmi.h>
  25#include <linux/console.h>
  26#include <linux/cpu.h>
  27#include <linux/freezer.h>
  28#include <linux/gfp.h>
  29#include <linux/syscore_ops.h>
  30#include <linux/ctype.h>
 
  31#include <linux/ktime.h>
  32#include <linux/security.h>
  33#include <linux/secretmem.h>
  34#include <trace/events/power.h>
  35
  36#include "power.h"
  37
  38
  39static int nocompress;
  40static int noresume;
  41static int nohibernate;
  42static int resume_wait;
  43static unsigned int resume_delay;
  44static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  45dev_t swsusp_resume_device;
  46sector_t swsusp_resume_block;
  47__visible int in_suspend __nosavedata;
  48
  49enum {
  50	HIBERNATION_INVALID,
  51	HIBERNATION_PLATFORM,
  52	HIBERNATION_SHUTDOWN,
  53	HIBERNATION_REBOOT,
  54#ifdef CONFIG_SUSPEND
  55	HIBERNATION_SUSPEND,
  56#endif
  57	HIBERNATION_TEST_RESUME,
  58	/* keep last */
  59	__HIBERNATION_AFTER_LAST
  60};
  61#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  62#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  63
  64static int hibernation_mode = HIBERNATION_SHUTDOWN;
  65
  66bool freezer_test_done;
  67
  68static const struct platform_hibernation_ops *hibernation_ops;
  69
  70static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  71
  72bool hibernate_acquire(void)
  73{
  74	return atomic_add_unless(&hibernate_atomic, -1, 0);
  75}
  76
  77void hibernate_release(void)
  78{
  79	atomic_inc(&hibernate_atomic);
  80}
  81
  82bool hibernation_available(void)
  83{
  84	return nohibernate == 0 &&
  85		!security_locked_down(LOCKDOWN_HIBERNATION) &&
  86		!secretmem_active() && !cxl_mem_active();
  87}
  88
  89/**
  90 * hibernation_set_ops - Set the global hibernate operations.
  91 * @ops: Hibernation operations to use in subsequent hibernation transitions.
  92 */
  93void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  94{
  95	unsigned int sleep_flags;
  96
  97	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  98	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  99	    && ops->restore_cleanup && ops->leave)) {
 100		WARN_ON(1);
 101		return;
 102	}
 103
 104	sleep_flags = lock_system_sleep();
 105
 106	hibernation_ops = ops;
 107	if (ops)
 108		hibernation_mode = HIBERNATION_PLATFORM;
 109	else if (hibernation_mode == HIBERNATION_PLATFORM)
 110		hibernation_mode = HIBERNATION_SHUTDOWN;
 111
 112	unlock_system_sleep(sleep_flags);
 113}
 114EXPORT_SYMBOL_GPL(hibernation_set_ops);
 115
 116static bool entering_platform_hibernation;
 117
 118bool system_entering_hibernation(void)
 119{
 120	return entering_platform_hibernation;
 121}
 122EXPORT_SYMBOL(system_entering_hibernation);
 123
 124#ifdef CONFIG_PM_DEBUG
 125static void hibernation_debug_sleep(void)
 126{
 127	pr_info("debug: Waiting for 5 seconds.\n");
 128	mdelay(5000);
 129}
 130
 131static int hibernation_test(int level)
 132{
 133	if (pm_test_level == level) {
 134		hibernation_debug_sleep();
 135		return 1;
 136	}
 137	return 0;
 138}
 139#else /* !CONFIG_PM_DEBUG */
 140static int hibernation_test(int level) { return 0; }
 141#endif /* !CONFIG_PM_DEBUG */
 142
 143/**
 144 * platform_begin - Call platform to start hibernation.
 145 * @platform_mode: Whether or not to use the platform driver.
 146 */
 147static int platform_begin(int platform_mode)
 148{
 149	return (platform_mode && hibernation_ops) ?
 150		hibernation_ops->begin(PMSG_FREEZE) : 0;
 151}
 152
 153/**
 154 * platform_end - Call platform to finish transition to the working state.
 155 * @platform_mode: Whether or not to use the platform driver.
 156 */
 157static void platform_end(int platform_mode)
 158{
 159	if (platform_mode && hibernation_ops)
 160		hibernation_ops->end();
 161}
 162
 163/**
 164 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 165 * @platform_mode: Whether or not to use the platform driver.
 166 *
 167 * Use the platform driver to prepare the system for creating a hibernate image,
 168 * if so configured, and return an error code if that fails.
 169 */
 170
 171static int platform_pre_snapshot(int platform_mode)
 172{
 173	return (platform_mode && hibernation_ops) ?
 174		hibernation_ops->pre_snapshot() : 0;
 175}
 176
 177/**
 178 * platform_leave - Call platform to prepare a transition to the working state.
 179 * @platform_mode: Whether or not to use the platform driver.
 180 *
 181 * Use the platform driver prepare to prepare the machine for switching to the
 182 * normal mode of operation.
 183 *
 184 * This routine is called on one CPU with interrupts disabled.
 185 */
 186static void platform_leave(int platform_mode)
 187{
 188	if (platform_mode && hibernation_ops)
 189		hibernation_ops->leave();
 190}
 191
 192/**
 193 * platform_finish - Call platform to switch the system to the working state.
 194 * @platform_mode: Whether or not to use the platform driver.
 195 *
 196 * Use the platform driver to switch the machine to the normal mode of
 197 * operation.
 198 *
 199 * This routine must be called after platform_prepare().
 200 */
 201static void platform_finish(int platform_mode)
 202{
 203	if (platform_mode && hibernation_ops)
 204		hibernation_ops->finish();
 205}
 206
 207/**
 208 * platform_pre_restore - Prepare for hibernate image restoration.
 209 * @platform_mode: Whether or not to use the platform driver.
 210 *
 211 * Use the platform driver to prepare the system for resume from a hibernation
 212 * image.
 213 *
 214 * If the restore fails after this function has been called,
 215 * platform_restore_cleanup() must be called.
 216 */
 217static int platform_pre_restore(int platform_mode)
 218{
 219	return (platform_mode && hibernation_ops) ?
 220		hibernation_ops->pre_restore() : 0;
 221}
 222
 223/**
 224 * platform_restore_cleanup - Switch to the working state after failing restore.
 225 * @platform_mode: Whether or not to use the platform driver.
 226 *
 227 * Use the platform driver to switch the system to the normal mode of operation
 228 * after a failing restore.
 229 *
 230 * If platform_pre_restore() has been called before the failing restore, this
 231 * function must be called too, regardless of the result of
 232 * platform_pre_restore().
 233 */
 234static void platform_restore_cleanup(int platform_mode)
 235{
 236	if (platform_mode && hibernation_ops)
 237		hibernation_ops->restore_cleanup();
 238}
 239
 240/**
 241 * platform_recover - Recover from a failure to suspend devices.
 242 * @platform_mode: Whether or not to use the platform driver.
 243 */
 244static void platform_recover(int platform_mode)
 245{
 246	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 247		hibernation_ops->recover();
 248}
 249
 250/**
 251 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 252 * @start: Starting event.
 253 * @stop: Final event.
 254 * @nr_pages: Number of memory pages processed between @start and @stop.
 255 * @msg: Additional diagnostic message to print.
 256 */
 257void swsusp_show_speed(ktime_t start, ktime_t stop,
 258		      unsigned nr_pages, char *msg)
 259{
 260	ktime_t diff;
 261	u64 elapsed_centisecs64;
 262	unsigned int centisecs;
 263	unsigned int k;
 264	unsigned int kps;
 265
 266	diff = ktime_sub(stop, start);
 267	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 268	centisecs = elapsed_centisecs64;
 269	if (centisecs == 0)
 270		centisecs = 1;	/* avoid div-by-zero */
 271	k = nr_pages * (PAGE_SIZE / 1024);
 272	kps = (k * 100) / centisecs;
 273	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 274		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 275		(kps % 1000) / 10);
 276}
 277
 278__weak int arch_resume_nosmt(void)
 279{
 280	return 0;
 281}
 282
 283/**
 284 * create_image - Create a hibernation image.
 285 * @platform_mode: Whether or not to use the platform driver.
 286 *
 287 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 288 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 289 *
 290 * Control reappears in this routine after the subsequent restore.
 291 */
 292static int create_image(int platform_mode)
 293{
 294	int error;
 295
 296	error = dpm_suspend_end(PMSG_FREEZE);
 297	if (error) {
 298		pr_err("Some devices failed to power down, aborting\n");
 299		return error;
 300	}
 301
 302	error = platform_pre_snapshot(platform_mode);
 303	if (error || hibernation_test(TEST_PLATFORM))
 304		goto Platform_finish;
 305
 306	error = pm_sleep_disable_secondary_cpus();
 307	if (error || hibernation_test(TEST_CPUS))
 308		goto Enable_cpus;
 309
 310	local_irq_disable();
 311
 312	system_state = SYSTEM_SUSPEND;
 313
 314	error = syscore_suspend();
 315	if (error) {
 316		pr_err("Some system devices failed to power down, aborting\n");
 317		goto Enable_irqs;
 318	}
 319
 320	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 321		goto Power_up;
 322
 323	in_suspend = 1;
 324	save_processor_state();
 325	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 326	error = swsusp_arch_suspend();
 327	/* Restore control flow magically appears here */
 328	restore_processor_state();
 329	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 330	if (error)
 331		pr_err("Error %d creating image\n", error);
 332
 333	if (!in_suspend) {
 334		events_check_enabled = false;
 335		clear_or_poison_free_pages();
 336	}
 337
 338	platform_leave(platform_mode);
 339
 340 Power_up:
 341	syscore_resume();
 342
 343 Enable_irqs:
 344	system_state = SYSTEM_RUNNING;
 345	local_irq_enable();
 346
 347 Enable_cpus:
 348	pm_sleep_enable_secondary_cpus();
 349
 350	/* Allow architectures to do nosmt-specific post-resume dances */
 351	if (!in_suspend)
 352		error = arch_resume_nosmt();
 353
 354 Platform_finish:
 355	platform_finish(platform_mode);
 356
 357	dpm_resume_start(in_suspend ?
 358		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 359
 360	return error;
 361}
 362
 363/**
 364 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 365 * @platform_mode: If set, use platform driver to prepare for the transition.
 366 *
 367 * This routine must be called with system_transition_mutex held.
 368 */
 369int hibernation_snapshot(int platform_mode)
 370{
 371	pm_message_t msg;
 372	int error;
 373
 374	pm_suspend_clear_flags();
 375	error = platform_begin(platform_mode);
 376	if (error)
 377		goto Close;
 378
 379	/* Preallocate image memory before shutting down devices. */
 380	error = hibernate_preallocate_memory();
 381	if (error)
 382		goto Close;
 383
 384	error = freeze_kernel_threads();
 385	if (error)
 386		goto Cleanup;
 387
 388	if (hibernation_test(TEST_FREEZER)) {
 389
 390		/*
 391		 * Indicate to the caller that we are returning due to a
 392		 * successful freezer test.
 393		 */
 394		freezer_test_done = true;
 395		goto Thaw;
 396	}
 397
 398	error = dpm_prepare(PMSG_FREEZE);
 399	if (error) {
 400		dpm_complete(PMSG_RECOVER);
 401		goto Thaw;
 402	}
 403
 404	suspend_console();
 405	pm_restrict_gfp_mask();
 406
 407	error = dpm_suspend(PMSG_FREEZE);
 408
 409	if (error || hibernation_test(TEST_DEVICES))
 410		platform_recover(platform_mode);
 411	else
 412		error = create_image(platform_mode);
 413
 414	/*
 415	 * In the case that we call create_image() above, the control
 416	 * returns here (1) after the image has been created or the
 417	 * image creation has failed and (2) after a successful restore.
 418	 */
 419
 420	/* We may need to release the preallocated image pages here. */
 421	if (error || !in_suspend)
 422		swsusp_free();
 423
 424	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 425	dpm_resume(msg);
 426
 427	if (error || !in_suspend)
 428		pm_restore_gfp_mask();
 429
 430	resume_console();
 431	dpm_complete(msg);
 432
 433 Close:
 434	platform_end(platform_mode);
 435	return error;
 436
 437 Thaw:
 438	thaw_kernel_threads();
 439 Cleanup:
 440	swsusp_free();
 441	goto Close;
 442}
 443
 444int __weak hibernate_resume_nonboot_cpu_disable(void)
 445{
 446	return suspend_disable_secondary_cpus();
 447}
 448
 449/**
 450 * resume_target_kernel - Restore system state from a hibernation image.
 451 * @platform_mode: Whether or not to use the platform driver.
 452 *
 453 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 454 * contents of highmem that have not been restored yet from the image and run
 455 * the low-level code that will restore the remaining contents of memory and
 456 * switch to the just restored target kernel.
 457 */
 458static int resume_target_kernel(bool platform_mode)
 459{
 460	int error;
 461
 462	error = dpm_suspend_end(PMSG_QUIESCE);
 463	if (error) {
 464		pr_err("Some devices failed to power down, aborting resume\n");
 465		return error;
 466	}
 467
 468	error = platform_pre_restore(platform_mode);
 469	if (error)
 470		goto Cleanup;
 471
 472	cpuidle_pause();
 473
 474	error = hibernate_resume_nonboot_cpu_disable();
 475	if (error)
 476		goto Enable_cpus;
 477
 478	local_irq_disable();
 479	system_state = SYSTEM_SUSPEND;
 480
 481	error = syscore_suspend();
 482	if (error)
 483		goto Enable_irqs;
 484
 485	save_processor_state();
 486	error = restore_highmem();
 487	if (!error) {
 488		error = swsusp_arch_resume();
 489		/*
 490		 * The code below is only ever reached in case of a failure.
 491		 * Otherwise, execution continues at the place where
 492		 * swsusp_arch_suspend() was called.
 493		 */
 494		BUG_ON(!error);
 495		/*
 496		 * This call to restore_highmem() reverts the changes made by
 497		 * the previous one.
 498		 */
 499		restore_highmem();
 500	}
 501	/*
 502	 * The only reason why swsusp_arch_resume() can fail is memory being
 503	 * very tight, so we have to free it as soon as we can to avoid
 504	 * subsequent failures.
 505	 */
 506	swsusp_free();
 507	restore_processor_state();
 508	touch_softlockup_watchdog();
 509
 510	syscore_resume();
 511
 512 Enable_irqs:
 513	system_state = SYSTEM_RUNNING;
 514	local_irq_enable();
 515
 516 Enable_cpus:
 517	pm_sleep_enable_secondary_cpus();
 518
 519 Cleanup:
 520	platform_restore_cleanup(platform_mode);
 521
 522	dpm_resume_start(PMSG_RECOVER);
 523
 524	return error;
 525}
 526
 527/**
 528 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 529 * @platform_mode: If set, use platform driver to prepare for the transition.
 530 *
 531 * This routine must be called with system_transition_mutex held.  If it is
 532 * successful, control reappears in the restored target kernel in
 533 * hibernation_snapshot().
 534 */
 535int hibernation_restore(int platform_mode)
 536{
 537	int error;
 538
 539	pm_prepare_console();
 540	suspend_console();
 541	pm_restrict_gfp_mask();
 542	error = dpm_suspend_start(PMSG_QUIESCE);
 543	if (!error) {
 544		error = resume_target_kernel(platform_mode);
 545		/*
 546		 * The above should either succeed and jump to the new kernel,
 547		 * or return with an error. Otherwise things are just
 548		 * undefined, so let's be paranoid.
 549		 */
 550		BUG_ON(!error);
 551	}
 552	dpm_resume_end(PMSG_RECOVER);
 553	pm_restore_gfp_mask();
 554	resume_console();
 555	pm_restore_console();
 556	return error;
 557}
 558
 559/**
 560 * hibernation_platform_enter - Power off the system using the platform driver.
 561 */
 562int hibernation_platform_enter(void)
 563{
 564	int error;
 565
 566	if (!hibernation_ops)
 567		return -ENOSYS;
 568
 569	/*
 570	 * We have cancelled the power transition by running
 571	 * hibernation_ops->finish() before saving the image, so we should let
 572	 * the firmware know that we're going to enter the sleep state after all
 573	 */
 574	error = hibernation_ops->begin(PMSG_HIBERNATE);
 575	if (error)
 576		goto Close;
 577
 578	entering_platform_hibernation = true;
 579	suspend_console();
 580	error = dpm_suspend_start(PMSG_HIBERNATE);
 581	if (error) {
 582		if (hibernation_ops->recover)
 583			hibernation_ops->recover();
 584		goto Resume_devices;
 585	}
 586
 587	error = dpm_suspend_end(PMSG_HIBERNATE);
 588	if (error)
 589		goto Resume_devices;
 590
 591	error = hibernation_ops->prepare();
 592	if (error)
 593		goto Platform_finish;
 594
 595	error = pm_sleep_disable_secondary_cpus();
 596	if (error)
 597		goto Enable_cpus;
 598
 599	local_irq_disable();
 600	system_state = SYSTEM_SUSPEND;
 601	syscore_suspend();
 602	if (pm_wakeup_pending()) {
 603		error = -EAGAIN;
 604		goto Power_up;
 605	}
 606
 607	hibernation_ops->enter();
 608	/* We should never get here */
 609	while (1);
 610
 611 Power_up:
 612	syscore_resume();
 613	system_state = SYSTEM_RUNNING;
 614	local_irq_enable();
 615
 616 Enable_cpus:
 617	pm_sleep_enable_secondary_cpus();
 618
 619 Platform_finish:
 620	hibernation_ops->finish();
 621
 622	dpm_resume_start(PMSG_RESTORE);
 623
 624 Resume_devices:
 625	entering_platform_hibernation = false;
 626	dpm_resume_end(PMSG_RESTORE);
 627	resume_console();
 628
 629 Close:
 630	hibernation_ops->end();
 631
 632	return error;
 633}
 634
 635/**
 636 * power_down - Shut the machine down for hibernation.
 637 *
 638 * Use the platform driver, if configured, to put the system into the sleep
 639 * state corresponding to hibernation, or try to power it off or reboot,
 640 * depending on the value of hibernation_mode.
 641 */
 642static void power_down(void)
 643{
 644#ifdef CONFIG_SUSPEND
 645	int error;
 646
 647	if (hibernation_mode == HIBERNATION_SUSPEND) {
 648		error = suspend_devices_and_enter(mem_sleep_current);
 649		if (error) {
 650			hibernation_mode = hibernation_ops ?
 651						HIBERNATION_PLATFORM :
 652						HIBERNATION_SHUTDOWN;
 653		} else {
 654			/* Restore swap signature. */
 655			error = swsusp_unmark();
 656			if (error)
 657				pr_err("Swap will be unusable! Try swapon -a.\n");
 658
 659			return;
 660		}
 661	}
 662#endif
 663
 664	switch (hibernation_mode) {
 665	case HIBERNATION_REBOOT:
 666		kernel_restart(NULL);
 667		break;
 668	case HIBERNATION_PLATFORM:
 669		hibernation_platform_enter();
 670		fallthrough;
 671	case HIBERNATION_SHUTDOWN:
 672		if (kernel_can_power_off())
 673			kernel_power_off();
 674		break;
 675	}
 676	kernel_halt();
 677	/*
 678	 * Valid image is on the disk, if we continue we risk serious data
 679	 * corruption after resume.
 680	 */
 681	pr_crit("Power down manually\n");
 682	while (1)
 683		cpu_relax();
 684}
 685
 686static int load_image_and_restore(void)
 687{
 688	int error;
 689	unsigned int flags;
 690
 691	pm_pr_dbg("Loading hibernation image.\n");
 692
 693	lock_device_hotplug();
 694	error = create_basic_memory_bitmaps();
 695	if (error) {
 696		swsusp_close(FMODE_READ | FMODE_EXCL);
 697		goto Unlock;
 698	}
 699
 700	error = swsusp_read(&flags);
 701	swsusp_close(FMODE_READ | FMODE_EXCL);
 702	if (!error)
 703		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 704
 705	pr_err("Failed to load image, recovering.\n");
 706	swsusp_free();
 707	free_basic_memory_bitmaps();
 708 Unlock:
 709	unlock_device_hotplug();
 710
 711	return error;
 712}
 713
 714/**
 715 * hibernate - Carry out system hibernation, including saving the image.
 716 */
 717int hibernate(void)
 718{
 
 719	bool snapshot_test = false;
 720	unsigned int sleep_flags;
 721	int error;
 722
 723	if (!hibernation_available()) {
 724		pm_pr_dbg("Hibernation not available.\n");
 725		return -EPERM;
 726	}
 727
 728	sleep_flags = lock_system_sleep();
 729	/* The snapshot device should not be opened while we're running */
 730	if (!hibernate_acquire()) {
 731		error = -EBUSY;
 732		goto Unlock;
 733	}
 734
 735	pr_info("hibernation entry\n");
 736	pm_prepare_console();
 737	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 738	if (error)
 739		goto Restore;
 
 
 740
 741	ksys_sync_helper();
 
 
 742
 743	error = freeze_processes();
 744	if (error)
 745		goto Exit;
 746
 747	lock_device_hotplug();
 748	/* Allocate memory management structures */
 749	error = create_basic_memory_bitmaps();
 750	if (error)
 751		goto Thaw;
 752
 753	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 754	if (error || freezer_test_done)
 755		goto Free_bitmaps;
 756
 757	if (in_suspend) {
 758		unsigned int flags = 0;
 759
 760		if (hibernation_mode == HIBERNATION_PLATFORM)
 761			flags |= SF_PLATFORM_MODE;
 762		if (nocompress)
 763			flags |= SF_NOCOMPRESS_MODE;
 764		else
 765		        flags |= SF_CRC32_MODE;
 766
 767		pm_pr_dbg("Writing hibernation image.\n");
 768		error = swsusp_write(flags);
 769		swsusp_free();
 770		if (!error) {
 771			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 772				snapshot_test = true;
 773			else
 774				power_down();
 775		}
 776		in_suspend = 0;
 777		pm_restore_gfp_mask();
 778	} else {
 779		pm_pr_dbg("Hibernation image restored successfully.\n");
 780	}
 781
 782 Free_bitmaps:
 783	free_basic_memory_bitmaps();
 784 Thaw:
 785	unlock_device_hotplug();
 786	if (snapshot_test) {
 787		pm_pr_dbg("Checking hibernation image\n");
 788		error = swsusp_check();
 789		if (!error)
 790			error = load_image_and_restore();
 791	}
 792	thaw_processes();
 793
 794	/* Don't bother checking whether freezer_test_done is true */
 795	freezer_test_done = false;
 796 Exit:
 797	pm_notifier_call_chain(PM_POST_HIBERNATION);
 798 Restore:
 799	pm_restore_console();
 800	hibernate_release();
 801 Unlock:
 802	unlock_system_sleep(sleep_flags);
 803	pr_info("hibernation exit\n");
 804
 805	return error;
 806}
 807
 808/**
 809 * hibernate_quiet_exec - Execute a function with all devices frozen.
 810 * @func: Function to execute.
 811 * @data: Data pointer to pass to @func.
 812 *
 813 * Return the @func return value or an error code if it cannot be executed.
 814 */
 815int hibernate_quiet_exec(int (*func)(void *data), void *data)
 816{
 817	unsigned int sleep_flags;
 818	int error;
 819
 820	sleep_flags = lock_system_sleep();
 821
 822	if (!hibernate_acquire()) {
 823		error = -EBUSY;
 824		goto unlock;
 825	}
 826
 827	pm_prepare_console();
 828
 829	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 830	if (error)
 831		goto restore;
 832
 833	error = freeze_processes();
 834	if (error)
 835		goto exit;
 836
 837	lock_device_hotplug();
 838
 839	pm_suspend_clear_flags();
 840
 841	error = platform_begin(true);
 842	if (error)
 843		goto thaw;
 844
 845	error = freeze_kernel_threads();
 846	if (error)
 847		goto thaw;
 848
 849	error = dpm_prepare(PMSG_FREEZE);
 850	if (error)
 851		goto dpm_complete;
 852
 853	suspend_console();
 854
 855	error = dpm_suspend(PMSG_FREEZE);
 856	if (error)
 857		goto dpm_resume;
 858
 859	error = dpm_suspend_end(PMSG_FREEZE);
 860	if (error)
 861		goto dpm_resume;
 862
 863	error = platform_pre_snapshot(true);
 864	if (error)
 865		goto skip;
 866
 867	error = func(data);
 868
 869skip:
 870	platform_finish(true);
 871
 872	dpm_resume_start(PMSG_THAW);
 873
 874dpm_resume:
 875	dpm_resume(PMSG_THAW);
 876
 877	resume_console();
 878
 879dpm_complete:
 880	dpm_complete(PMSG_THAW);
 881
 882	thaw_kernel_threads();
 883
 884thaw:
 885	platform_end(true);
 886
 887	unlock_device_hotplug();
 888
 889	thaw_processes();
 890
 891exit:
 892	pm_notifier_call_chain(PM_POST_HIBERNATION);
 893
 894restore:
 895	pm_restore_console();
 896
 897	hibernate_release();
 898
 899unlock:
 900	unlock_system_sleep(sleep_flags);
 901
 902	return error;
 903}
 904EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 905
 906/**
 907 * software_resume - Resume from a saved hibernation image.
 908 *
 909 * This routine is called as a late initcall, when all devices have been
 910 * discovered and initialized already.
 911 *
 912 * The image reading code is called to see if there is a hibernation image
 913 * available for reading.  If that is the case, devices are quiesced and the
 914 * contents of memory is restored from the saved image.
 915 *
 916 * If this is successful, control reappears in the restored target kernel in
 917 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 918 * attempts to recover gracefully and make the kernel return to the normal mode
 919 * of operation.
 920 */
 921static int software_resume(void)
 922{
 923	int error;
 924
 925	/*
 926	 * If the user said "noresume".. bail out early.
 927	 */
 928	if (noresume || !hibernation_available())
 929		return 0;
 930
 931	/*
 932	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 933	 * is configured into the kernel. Since the regular hibernate
 934	 * trigger path is via sysfs which takes a buffer mutex before
 935	 * calling hibernate functions (which take system_transition_mutex)
 936	 * this can cause lockdep to complain about a possible ABBA deadlock
 937	 * which cannot happen since we're in the boot code here and
 938	 * sysfs can't be invoked yet. Therefore, we use a subclass
 939	 * here to avoid lockdep complaining.
 940	 */
 941	mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 942
 943	if (swsusp_resume_device)
 944		goto Check_image;
 945
 946	if (!strlen(resume_file)) {
 947		error = -ENOENT;
 948		goto Unlock;
 949	}
 950
 951	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 952
 953	if (resume_delay) {
 954		pr_info("Waiting %dsec before reading resume device ...\n",
 955			resume_delay);
 956		ssleep(resume_delay);
 957	}
 958
 959	/* Check if the device is there */
 960	swsusp_resume_device = name_to_dev_t(resume_file);
 
 
 
 
 
 
 
 
 
 
 
 961	if (!swsusp_resume_device) {
 962		/*
 963		 * Some device discovery might still be in progress; we need
 964		 * to wait for this to finish.
 965		 */
 966		wait_for_device_probe();
 967
 968		if (resume_wait) {
 969			while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 970				msleep(10);
 971			async_synchronize_full();
 972		}
 973
 974		swsusp_resume_device = name_to_dev_t(resume_file);
 975		if (!swsusp_resume_device) {
 976			error = -ENODEV;
 977			goto Unlock;
 978		}
 979	}
 980
 981 Check_image:
 982	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 983		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 984
 985	pm_pr_dbg("Looking for hibernation image.\n");
 986	error = swsusp_check();
 987	if (error)
 988		goto Unlock;
 989
 990	/* The snapshot device should not be opened while we're running */
 991	if (!hibernate_acquire()) {
 992		error = -EBUSY;
 993		swsusp_close(FMODE_READ | FMODE_EXCL);
 994		goto Unlock;
 995	}
 996
 997	pr_info("resume from hibernation\n");
 998	pm_prepare_console();
 999	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1000	if (error)
1001		goto Restore;
1002
1003	pm_pr_dbg("Preparing processes for hibernation restore.\n");
1004	error = freeze_processes();
1005	if (error)
1006		goto Close_Finish;
1007
1008	error = freeze_kernel_threads();
1009	if (error) {
1010		thaw_processes();
1011		goto Close_Finish;
1012	}
1013
 
 
 
 
1014	error = load_image_and_restore();
1015	thaw_processes();
1016 Finish:
1017	pm_notifier_call_chain(PM_POST_RESTORE);
1018 Restore:
1019	pm_restore_console();
1020	pr_info("resume failed (%d)\n", error);
1021	hibernate_release();
1022	/* For success case, the suspend path will release the lock */
1023 Unlock:
1024	mutex_unlock(&system_transition_mutex);
1025	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1026	return error;
1027 Close_Finish:
1028	swsusp_close(FMODE_READ | FMODE_EXCL);
1029	goto Finish;
1030}
1031
1032late_initcall_sync(software_resume);
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 res;
1172
1173	if (len && buf[len-1] == '\n')
1174		len--;
1175	name = kstrndup(buf, len, GFP_KERNEL);
1176	if (!name)
1177		return -ENOMEM;
1178
1179	res = name_to_dev_t(name);
1180	kfree(name);
1181	if (!res)
1182		return -EINVAL;
1183
1184	sleep_flags = lock_system_sleep();
1185	swsusp_resume_device = res;
1186	unlock_system_sleep(sleep_flags);
1187
1188	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1189		  swsusp_resume_device);
1190	noresume = 0;
1191	software_resume();
1192	return n;
1193}
1194
1195power_attr(resume);
1196
1197static ssize_t resume_offset_show(struct kobject *kobj,
1198				  struct kobj_attribute *attr, char *buf)
1199{
1200	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1201}
1202
1203static ssize_t resume_offset_store(struct kobject *kobj,
1204				   struct kobj_attribute *attr, const char *buf,
1205				   size_t n)
1206{
1207	unsigned long long offset;
1208	int rc;
1209
1210	rc = kstrtoull(buf, 0, &offset);
1211	if (rc)
1212		return rc;
1213	swsusp_resume_block = offset;
1214
1215	return n;
1216}
1217
1218power_attr(resume_offset);
1219
1220static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1221			       char *buf)
1222{
1223	return sprintf(buf, "%lu\n", image_size);
1224}
1225
1226static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1227				const char *buf, size_t n)
1228{
1229	unsigned long size;
1230
1231	if (sscanf(buf, "%lu", &size) == 1) {
1232		image_size = size;
1233		return n;
1234	}
1235
1236	return -EINVAL;
1237}
1238
1239power_attr(image_size);
1240
1241static ssize_t reserved_size_show(struct kobject *kobj,
1242				  struct kobj_attribute *attr, char *buf)
1243{
1244	return sprintf(buf, "%lu\n", reserved_size);
1245}
1246
1247static ssize_t reserved_size_store(struct kobject *kobj,
1248				   struct kobj_attribute *attr,
1249				   const char *buf, size_t n)
1250{
1251	unsigned long size;
1252
1253	if (sscanf(buf, "%lu", &size) == 1) {
1254		reserved_size = size;
1255		return n;
1256	}
1257
1258	return -EINVAL;
1259}
1260
1261power_attr(reserved_size);
1262
1263static struct attribute *g[] = {
1264	&disk_attr.attr,
1265	&resume_offset_attr.attr,
1266	&resume_attr.attr,
1267	&image_size_attr.attr,
1268	&reserved_size_attr.attr,
1269	NULL,
1270};
1271
1272
1273static const struct attribute_group attr_group = {
1274	.attrs = g,
1275};
1276
1277
1278static int __init pm_disk_init(void)
1279{
1280	return sysfs_create_group(power_kobj, &attr_group);
1281}
1282
1283core_initcall(pm_disk_init);
1284
1285
1286static int __init resume_setup(char *str)
1287{
1288	if (noresume)
1289		return 1;
1290
1291	strncpy(resume_file, str, 255);
1292	return 1;
1293}
1294
1295static int __init resume_offset_setup(char *str)
1296{
1297	unsigned long long offset;
1298
1299	if (noresume)
1300		return 1;
1301
1302	if (sscanf(str, "%llu", &offset) == 1)
1303		swsusp_resume_block = offset;
1304
1305	return 1;
1306}
1307
1308static int __init hibernate_setup(char *str)
1309{
1310	if (!strncmp(str, "noresume", 8)) {
1311		noresume = 1;
1312	} else if (!strncmp(str, "nocompress", 10)) {
1313		nocompress = 1;
1314	} else if (!strncmp(str, "no", 2)) {
1315		noresume = 1;
1316		nohibernate = 1;
1317	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1318		   && !strncmp(str, "protect_image", 13)) {
1319		enable_restore_image_protection();
1320	}
1321	return 1;
1322}
1323
1324static int __init noresume_setup(char *str)
1325{
1326	noresume = 1;
1327	return 1;
1328}
1329
1330static int __init resumewait_setup(char *str)
1331{
1332	resume_wait = 1;
1333	return 1;
1334}
1335
1336static int __init resumedelay_setup(char *str)
1337{
1338	int rc = kstrtouint(str, 0, &resume_delay);
1339
1340	if (rc)
1341		pr_warn("resumedelay: bad option string '%s'\n", str);
1342	return 1;
1343}
1344
1345static int __init nohibernate_setup(char *str)
1346{
1347	noresume = 1;
1348	nohibernate = 1;
1349	return 1;
1350}
1351
1352__setup("noresume", noresume_setup);
1353__setup("resume_offset=", resume_offset_setup);
1354__setup("resume=", resume_setup);
1355__setup("hibernate=", hibernate_setup);
1356__setup("resumewait", resumewait_setup);
1357__setup("resumedelay=", resumedelay_setup);
1358__setup("nohibernate", nohibernate_setup);
v4.17
 
   1/*
   2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   3 *
   4 * Copyright (c) 2003 Patrick Mochel
   5 * Copyright (c) 2003 Open Source Development Lab
   6 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   8 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
   9 *
  10 * This file is released under the GPLv2.
  11 */
  12
  13#define pr_fmt(fmt) "PM: " fmt
  14
  15#include <linux/export.h>
  16#include <linux/suspend.h>
  17#include <linux/syscalls.h>
  18#include <linux/reboot.h>
  19#include <linux/string.h>
  20#include <linux/device.h>
  21#include <linux/async.h>
  22#include <linux/delay.h>
  23#include <linux/fs.h>
  24#include <linux/mount.h>
  25#include <linux/pm.h>
  26#include <linux/nmi.h>
  27#include <linux/console.h>
  28#include <linux/cpu.h>
  29#include <linux/freezer.h>
  30#include <linux/gfp.h>
  31#include <linux/syscore_ops.h>
  32#include <linux/ctype.h>
  33#include <linux/genhd.h>
  34#include <linux/ktime.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
 
 
 
 
 
 
 
 
 
 
 
 
  71bool hibernation_available(void)
  72{
  73	return (nohibernate == 0);
 
 
  74}
  75
  76/**
  77 * hibernation_set_ops - Set the global hibernate operations.
  78 * @ops: Hibernation operations to use in subsequent hibernation transitions.
  79 */
  80void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  81{
 
 
  82	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  83	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  84	    && ops->restore_cleanup && ops->leave)) {
  85		WARN_ON(1);
  86		return;
  87	}
  88	lock_system_sleep();
 
 
  89	hibernation_ops = ops;
  90	if (ops)
  91		hibernation_mode = HIBERNATION_PLATFORM;
  92	else if (hibernation_mode == HIBERNATION_PLATFORM)
  93		hibernation_mode = HIBERNATION_SHUTDOWN;
  94
  95	unlock_system_sleep();
  96}
  97EXPORT_SYMBOL_GPL(hibernation_set_ops);
  98
  99static bool entering_platform_hibernation;
 100
 101bool system_entering_hibernation(void)
 102{
 103	return entering_platform_hibernation;
 104}
 105EXPORT_SYMBOL(system_entering_hibernation);
 106
 107#ifdef CONFIG_PM_DEBUG
 108static void hibernation_debug_sleep(void)
 109{
 110	pr_info("hibernation debug: Waiting for 5 seconds.\n");
 111	mdelay(5000);
 112}
 113
 114static int hibernation_test(int level)
 115{
 116	if (pm_test_level == level) {
 117		hibernation_debug_sleep();
 118		return 1;
 119	}
 120	return 0;
 121}
 122#else /* !CONFIG_PM_DEBUG */
 123static int hibernation_test(int level) { return 0; }
 124#endif /* !CONFIG_PM_DEBUG */
 125
 126/**
 127 * platform_begin - Call platform to start hibernation.
 128 * @platform_mode: Whether or not to use the platform driver.
 129 */
 130static int platform_begin(int platform_mode)
 131{
 132	return (platform_mode && hibernation_ops) ?
 133		hibernation_ops->begin() : 0;
 134}
 135
 136/**
 137 * platform_end - Call platform to finish transition to the working state.
 138 * @platform_mode: Whether or not to use the platform driver.
 139 */
 140static void platform_end(int platform_mode)
 141{
 142	if (platform_mode && hibernation_ops)
 143		hibernation_ops->end();
 144}
 145
 146/**
 147 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 148 * @platform_mode: Whether or not to use the platform driver.
 149 *
 150 * Use the platform driver to prepare the system for creating a hibernate image,
 151 * if so configured, and return an error code if that fails.
 152 */
 153
 154static int platform_pre_snapshot(int platform_mode)
 155{
 156	return (platform_mode && hibernation_ops) ?
 157		hibernation_ops->pre_snapshot() : 0;
 158}
 159
 160/**
 161 * platform_leave - Call platform to prepare a transition to the working state.
 162 * @platform_mode: Whether or not to use the platform driver.
 163 *
 164 * Use the platform driver prepare to prepare the machine for switching to the
 165 * normal mode of operation.
 166 *
 167 * This routine is called on one CPU with interrupts disabled.
 168 */
 169static void platform_leave(int platform_mode)
 170{
 171	if (platform_mode && hibernation_ops)
 172		hibernation_ops->leave();
 173}
 174
 175/**
 176 * platform_finish - Call platform to switch the system to the working state.
 177 * @platform_mode: Whether or not to use the platform driver.
 178 *
 179 * Use the platform driver to switch the machine to the normal mode of
 180 * operation.
 181 *
 182 * This routine must be called after platform_prepare().
 183 */
 184static void platform_finish(int platform_mode)
 185{
 186	if (platform_mode && hibernation_ops)
 187		hibernation_ops->finish();
 188}
 189
 190/**
 191 * platform_pre_restore - Prepare for hibernate image restoration.
 192 * @platform_mode: Whether or not to use the platform driver.
 193 *
 194 * Use the platform driver to prepare the system for resume from a hibernation
 195 * image.
 196 *
 197 * If the restore fails after this function has been called,
 198 * platform_restore_cleanup() must be called.
 199 */
 200static int platform_pre_restore(int platform_mode)
 201{
 202	return (platform_mode && hibernation_ops) ?
 203		hibernation_ops->pre_restore() : 0;
 204}
 205
 206/**
 207 * platform_restore_cleanup - Switch to the working state after failing restore.
 208 * @platform_mode: Whether or not to use the platform driver.
 209 *
 210 * Use the platform driver to switch the system to the normal mode of operation
 211 * after a failing restore.
 212 *
 213 * If platform_pre_restore() has been called before the failing restore, this
 214 * function must be called too, regardless of the result of
 215 * platform_pre_restore().
 216 */
 217static void platform_restore_cleanup(int platform_mode)
 218{
 219	if (platform_mode && hibernation_ops)
 220		hibernation_ops->restore_cleanup();
 221}
 222
 223/**
 224 * platform_recover - Recover from a failure to suspend devices.
 225 * @platform_mode: Whether or not to use the platform driver.
 226 */
 227static void platform_recover(int platform_mode)
 228{
 229	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 230		hibernation_ops->recover();
 231}
 232
 233/**
 234 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 235 * @start: Starting event.
 236 * @stop: Final event.
 237 * @nr_pages: Number of memory pages processed between @start and @stop.
 238 * @msg: Additional diagnostic message to print.
 239 */
 240void swsusp_show_speed(ktime_t start, ktime_t stop,
 241		      unsigned nr_pages, char *msg)
 242{
 243	ktime_t diff;
 244	u64 elapsed_centisecs64;
 245	unsigned int centisecs;
 246	unsigned int k;
 247	unsigned int kps;
 248
 249	diff = ktime_sub(stop, start);
 250	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 251	centisecs = elapsed_centisecs64;
 252	if (centisecs == 0)
 253		centisecs = 1;	/* avoid div-by-zero */
 254	k = nr_pages * (PAGE_SIZE / 1024);
 255	kps = (k * 100) / centisecs;
 256	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 257		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 258		(kps % 1000) / 10);
 259}
 260
 
 
 
 
 
 261/**
 262 * create_image - Create a hibernation image.
 263 * @platform_mode: Whether or not to use the platform driver.
 264 *
 265 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 266 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 267 *
 268 * Control reappears in this routine after the subsequent restore.
 269 */
 270static int create_image(int platform_mode)
 271{
 272	int error;
 273
 274	error = dpm_suspend_end(PMSG_FREEZE);
 275	if (error) {
 276		pr_err("Some devices failed to power down, aborting hibernation\n");
 277		return error;
 278	}
 279
 280	error = platform_pre_snapshot(platform_mode);
 281	if (error || hibernation_test(TEST_PLATFORM))
 282		goto Platform_finish;
 283
 284	error = disable_nonboot_cpus();
 285	if (error || hibernation_test(TEST_CPUS))
 286		goto Enable_cpus;
 287
 288	local_irq_disable();
 289
 
 
 290	error = syscore_suspend();
 291	if (error) {
 292		pr_err("Some system devices failed to power down, aborting hibernation\n");
 293		goto Enable_irqs;
 294	}
 295
 296	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 297		goto Power_up;
 298
 299	in_suspend = 1;
 300	save_processor_state();
 301	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 302	error = swsusp_arch_suspend();
 303	/* Restore control flow magically appears here */
 304	restore_processor_state();
 305	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 306	if (error)
 307		pr_err("Error %d creating hibernation image\n", error);
 308
 309	if (!in_suspend) {
 310		events_check_enabled = false;
 311		clear_free_pages();
 312	}
 313
 314	platform_leave(platform_mode);
 315
 316 Power_up:
 317	syscore_resume();
 318
 319 Enable_irqs:
 
 320	local_irq_enable();
 321
 322 Enable_cpus:
 323	enable_nonboot_cpus();
 
 
 
 
 324
 325 Platform_finish:
 326	platform_finish(platform_mode);
 327
 328	dpm_resume_start(in_suspend ?
 329		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 330
 331	return error;
 332}
 333
 334/**
 335 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 336 * @platform_mode: If set, use platform driver to prepare for the transition.
 337 *
 338 * This routine must be called with pm_mutex held.
 339 */
 340int hibernation_snapshot(int platform_mode)
 341{
 342	pm_message_t msg;
 343	int error;
 344
 345	pm_suspend_clear_flags();
 346	error = platform_begin(platform_mode);
 347	if (error)
 348		goto Close;
 349
 350	/* Preallocate image memory before shutting down devices. */
 351	error = hibernate_preallocate_memory();
 352	if (error)
 353		goto Close;
 354
 355	error = freeze_kernel_threads();
 356	if (error)
 357		goto Cleanup;
 358
 359	if (hibernation_test(TEST_FREEZER)) {
 360
 361		/*
 362		 * Indicate to the caller that we are returning due to a
 363		 * successful freezer test.
 364		 */
 365		freezer_test_done = true;
 366		goto Thaw;
 367	}
 368
 369	error = dpm_prepare(PMSG_FREEZE);
 370	if (error) {
 371		dpm_complete(PMSG_RECOVER);
 372		goto Thaw;
 373	}
 374
 375	suspend_console();
 376	pm_restrict_gfp_mask();
 377
 378	error = dpm_suspend(PMSG_FREEZE);
 379
 380	if (error || hibernation_test(TEST_DEVICES))
 381		platform_recover(platform_mode);
 382	else
 383		error = create_image(platform_mode);
 384
 385	/*
 386	 * In the case that we call create_image() above, the control
 387	 * returns here (1) after the image has been created or the
 388	 * image creation has failed and (2) after a successful restore.
 389	 */
 390
 391	/* We may need to release the preallocated image pages here. */
 392	if (error || !in_suspend)
 393		swsusp_free();
 394
 395	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 396	dpm_resume(msg);
 397
 398	if (error || !in_suspend)
 399		pm_restore_gfp_mask();
 400
 401	resume_console();
 402	dpm_complete(msg);
 403
 404 Close:
 405	platform_end(platform_mode);
 406	return error;
 407
 408 Thaw:
 409	thaw_kernel_threads();
 410 Cleanup:
 411	swsusp_free();
 412	goto Close;
 413}
 414
 415int __weak hibernate_resume_nonboot_cpu_disable(void)
 416{
 417	return disable_nonboot_cpus();
 418}
 419
 420/**
 421 * resume_target_kernel - Restore system state from a hibernation image.
 422 * @platform_mode: Whether or not to use the platform driver.
 423 *
 424 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 425 * contents of highmem that have not been restored yet from the image and run
 426 * the low-level code that will restore the remaining contents of memory and
 427 * switch to the just restored target kernel.
 428 */
 429static int resume_target_kernel(bool platform_mode)
 430{
 431	int error;
 432
 433	error = dpm_suspend_end(PMSG_QUIESCE);
 434	if (error) {
 435		pr_err("Some devices failed to power down, aborting resume\n");
 436		return error;
 437	}
 438
 439	error = platform_pre_restore(platform_mode);
 440	if (error)
 441		goto Cleanup;
 442
 
 
 443	error = hibernate_resume_nonboot_cpu_disable();
 444	if (error)
 445		goto Enable_cpus;
 446
 447	local_irq_disable();
 
 448
 449	error = syscore_suspend();
 450	if (error)
 451		goto Enable_irqs;
 452
 453	save_processor_state();
 454	error = restore_highmem();
 455	if (!error) {
 456		error = swsusp_arch_resume();
 457		/*
 458		 * The code below is only ever reached in case of a failure.
 459		 * Otherwise, execution continues at the place where
 460		 * swsusp_arch_suspend() was called.
 461		 */
 462		BUG_ON(!error);
 463		/*
 464		 * This call to restore_highmem() reverts the changes made by
 465		 * the previous one.
 466		 */
 467		restore_highmem();
 468	}
 469	/*
 470	 * The only reason why swsusp_arch_resume() can fail is memory being
 471	 * very tight, so we have to free it as soon as we can to avoid
 472	 * subsequent failures.
 473	 */
 474	swsusp_free();
 475	restore_processor_state();
 476	touch_softlockup_watchdog();
 477
 478	syscore_resume();
 479
 480 Enable_irqs:
 
 481	local_irq_enable();
 482
 483 Enable_cpus:
 484	enable_nonboot_cpus();
 485
 486 Cleanup:
 487	platform_restore_cleanup(platform_mode);
 488
 489	dpm_resume_start(PMSG_RECOVER);
 490
 491	return error;
 492}
 493
 494/**
 495 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 496 * @platform_mode: If set, use platform driver to prepare for the transition.
 497 *
 498 * This routine must be called with pm_mutex held.  If it is successful, control
 499 * reappears in the restored target kernel in hibernation_snapshot().
 
 500 */
 501int hibernation_restore(int platform_mode)
 502{
 503	int error;
 504
 505	pm_prepare_console();
 506	suspend_console();
 507	pm_restrict_gfp_mask();
 508	error = dpm_suspend_start(PMSG_QUIESCE);
 509	if (!error) {
 510		error = resume_target_kernel(platform_mode);
 511		/*
 512		 * The above should either succeed and jump to the new kernel,
 513		 * or return with an error. Otherwise things are just
 514		 * undefined, so let's be paranoid.
 515		 */
 516		BUG_ON(!error);
 517	}
 518	dpm_resume_end(PMSG_RECOVER);
 519	pm_restore_gfp_mask();
 520	resume_console();
 521	pm_restore_console();
 522	return error;
 523}
 524
 525/**
 526 * hibernation_platform_enter - Power off the system using the platform driver.
 527 */
 528int hibernation_platform_enter(void)
 529{
 530	int error;
 531
 532	if (!hibernation_ops)
 533		return -ENOSYS;
 534
 535	/*
 536	 * We have cancelled the power transition by running
 537	 * hibernation_ops->finish() before saving the image, so we should let
 538	 * the firmware know that we're going to enter the sleep state after all
 539	 */
 540	error = hibernation_ops->begin();
 541	if (error)
 542		goto Close;
 543
 544	entering_platform_hibernation = true;
 545	suspend_console();
 546	error = dpm_suspend_start(PMSG_HIBERNATE);
 547	if (error) {
 548		if (hibernation_ops->recover)
 549			hibernation_ops->recover();
 550		goto Resume_devices;
 551	}
 552
 553	error = dpm_suspend_end(PMSG_HIBERNATE);
 554	if (error)
 555		goto Resume_devices;
 556
 557	error = hibernation_ops->prepare();
 558	if (error)
 559		goto Platform_finish;
 560
 561	error = disable_nonboot_cpus();
 562	if (error)
 563		goto Enable_cpus;
 564
 565	local_irq_disable();
 
 566	syscore_suspend();
 567	if (pm_wakeup_pending()) {
 568		error = -EAGAIN;
 569		goto Power_up;
 570	}
 571
 572	hibernation_ops->enter();
 573	/* We should never get here */
 574	while (1);
 575
 576 Power_up:
 577	syscore_resume();
 
 578	local_irq_enable();
 579
 580 Enable_cpus:
 581	enable_nonboot_cpus();
 582
 583 Platform_finish:
 584	hibernation_ops->finish();
 585
 586	dpm_resume_start(PMSG_RESTORE);
 587
 588 Resume_devices:
 589	entering_platform_hibernation = false;
 590	dpm_resume_end(PMSG_RESTORE);
 591	resume_console();
 592
 593 Close:
 594	hibernation_ops->end();
 595
 596	return error;
 597}
 598
 599/**
 600 * power_down - Shut the machine down for hibernation.
 601 *
 602 * Use the platform driver, if configured, to put the system into the sleep
 603 * state corresponding to hibernation, or try to power it off or reboot,
 604 * depending on the value of hibernation_mode.
 605 */
 606static void power_down(void)
 607{
 608#ifdef CONFIG_SUSPEND
 609	int error;
 610
 611	if (hibernation_mode == HIBERNATION_SUSPEND) {
 612		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 613		if (error) {
 614			hibernation_mode = hibernation_ops ?
 615						HIBERNATION_PLATFORM :
 616						HIBERNATION_SHUTDOWN;
 617		} else {
 618			/* Restore swap signature. */
 619			error = swsusp_unmark();
 620			if (error)
 621				pr_err("Swap will be unusable! Try swapon -a.\n");
 622
 623			return;
 624		}
 625	}
 626#endif
 627
 628	switch (hibernation_mode) {
 629	case HIBERNATION_REBOOT:
 630		kernel_restart(NULL);
 631		break;
 632	case HIBERNATION_PLATFORM:
 633		hibernation_platform_enter();
 
 634	case HIBERNATION_SHUTDOWN:
 635		if (pm_power_off)
 636			kernel_power_off();
 637		break;
 638	}
 639	kernel_halt();
 640	/*
 641	 * Valid image is on the disk, if we continue we risk serious data
 642	 * corruption after resume.
 643	 */
 644	pr_crit("Power down manually\n");
 645	while (1)
 646		cpu_relax();
 647}
 648
 649static int load_image_and_restore(void)
 650{
 651	int error;
 652	unsigned int flags;
 653
 654	pm_pr_dbg("Loading hibernation image.\n");
 655
 656	lock_device_hotplug();
 657	error = create_basic_memory_bitmaps();
 658	if (error)
 
 659		goto Unlock;
 
 660
 661	error = swsusp_read(&flags);
 662	swsusp_close(FMODE_READ);
 663	if (!error)
 664		hibernation_restore(flags & SF_PLATFORM_MODE);
 665
 666	pr_err("Failed to load hibernation image, recovering.\n");
 667	swsusp_free();
 668	free_basic_memory_bitmaps();
 669 Unlock:
 670	unlock_device_hotplug();
 671
 672	return error;
 673}
 674
 675/**
 676 * hibernate - Carry out system hibernation, including saving the image.
 677 */
 678int hibernate(void)
 679{
 680	int error, nr_calls = 0;
 681	bool snapshot_test = false;
 
 
 682
 683	if (!hibernation_available()) {
 684		pm_pr_dbg("Hibernation not available.\n");
 685		return -EPERM;
 686	}
 687
 688	lock_system_sleep();
 689	/* The snapshot device should not be opened while we're running */
 690	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 691		error = -EBUSY;
 692		goto Unlock;
 693	}
 694
 695	pr_info("hibernation entry\n");
 696	pm_prepare_console();
 697	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 698	if (error) {
 699		nr_calls--;
 700		goto Exit;
 701	}
 702
 703	pr_info("Syncing filesystems ... \n");
 704	ksys_sync();
 705	pr_info("done.\n");
 706
 707	error = freeze_processes();
 708	if (error)
 709		goto Exit;
 710
 711	lock_device_hotplug();
 712	/* Allocate memory management structures */
 713	error = create_basic_memory_bitmaps();
 714	if (error)
 715		goto Thaw;
 716
 717	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 718	if (error || freezer_test_done)
 719		goto Free_bitmaps;
 720
 721	if (in_suspend) {
 722		unsigned int flags = 0;
 723
 724		if (hibernation_mode == HIBERNATION_PLATFORM)
 725			flags |= SF_PLATFORM_MODE;
 726		if (nocompress)
 727			flags |= SF_NOCOMPRESS_MODE;
 728		else
 729		        flags |= SF_CRC32_MODE;
 730
 731		pm_pr_dbg("Writing image.\n");
 732		error = swsusp_write(flags);
 733		swsusp_free();
 734		if (!error) {
 735			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 736				snapshot_test = true;
 737			else
 738				power_down();
 739		}
 740		in_suspend = 0;
 741		pm_restore_gfp_mask();
 742	} else {
 743		pm_pr_dbg("Image restored successfully.\n");
 744	}
 745
 746 Free_bitmaps:
 747	free_basic_memory_bitmaps();
 748 Thaw:
 749	unlock_device_hotplug();
 750	if (snapshot_test) {
 751		pm_pr_dbg("Checking hibernation image\n");
 752		error = swsusp_check();
 753		if (!error)
 754			error = load_image_and_restore();
 755	}
 756	thaw_processes();
 757
 758	/* Don't bother checking whether freezer_test_done is true */
 759	freezer_test_done = false;
 760 Exit:
 761	__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 
 762	pm_restore_console();
 763	atomic_inc(&snapshot_device_available);
 764 Unlock:
 765	unlock_system_sleep();
 766	pr_info("hibernation exit\n");
 767
 768	return error;
 769}
 770
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 771
 772/**
 773 * software_resume - Resume from a saved hibernation image.
 774 *
 775 * This routine is called as a late initcall, when all devices have been
 776 * discovered and initialized already.
 777 *
 778 * The image reading code is called to see if there is a hibernation image
 779 * available for reading.  If that is the case, devices are quiesced and the
 780 * contents of memory is restored from the saved image.
 781 *
 782 * If this is successful, control reappears in the restored target kernel in
 783 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 784 * attempts to recover gracefully and make the kernel return to the normal mode
 785 * of operation.
 786 */
 787static int software_resume(void)
 788{
 789	int error, nr_calls = 0;
 790
 791	/*
 792	 * If the user said "noresume".. bail out early.
 793	 */
 794	if (noresume || !hibernation_available())
 795		return 0;
 796
 797	/*
 798	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 799	 * is configured into the kernel. Since the regular hibernate
 800	 * trigger path is via sysfs which takes a buffer mutex before
 801	 * calling hibernate functions (which take pm_mutex) this can
 802	 * cause lockdep to complain about a possible ABBA deadlock
 803	 * which cannot happen since we're in the boot code here and
 804	 * sysfs can't be invoked yet. Therefore, we use a subclass
 805	 * here to avoid lockdep complaining.
 806	 */
 807	mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 808
 809	if (swsusp_resume_device)
 810		goto Check_image;
 811
 812	if (!strlen(resume_file)) {
 813		error = -ENOENT;
 814		goto Unlock;
 815	}
 816
 817	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 818
 819	if (resume_delay) {
 820		pr_info("Waiting %dsec before reading resume device ...\n",
 821			resume_delay);
 822		ssleep(resume_delay);
 823	}
 824
 825	/* Check if the device is there */
 826	swsusp_resume_device = name_to_dev_t(resume_file);
 827
 828	/*
 829	 * name_to_dev_t is ineffective to verify parition if resume_file is in
 830	 * integer format. (e.g. major:minor)
 831	 */
 832	if (isdigit(resume_file[0]) && resume_wait) {
 833		int partno;
 834		while (!get_gendisk(swsusp_resume_device, &partno))
 835			msleep(10);
 836	}
 837
 838	if (!swsusp_resume_device) {
 839		/*
 840		 * Some device discovery might still be in progress; we need
 841		 * to wait for this to finish.
 842		 */
 843		wait_for_device_probe();
 844
 845		if (resume_wait) {
 846			while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 847				msleep(10);
 848			async_synchronize_full();
 849		}
 850
 851		swsusp_resume_device = name_to_dev_t(resume_file);
 852		if (!swsusp_resume_device) {
 853			error = -ENODEV;
 854			goto Unlock;
 855		}
 856	}
 857
 858 Check_image:
 859	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 860		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 861
 862	pm_pr_dbg("Looking for hibernation image.\n");
 863	error = swsusp_check();
 864	if (error)
 865		goto Unlock;
 866
 867	/* The snapshot device should not be opened while we're running */
 868	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 869		error = -EBUSY;
 870		swsusp_close(FMODE_READ);
 871		goto Unlock;
 872	}
 873
 874	pr_info("resume from hibernation\n");
 875	pm_prepare_console();
 876	error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
 
 
 
 
 
 
 
 
 
 877	if (error) {
 878		nr_calls--;
 879		goto Close_Finish;
 880	}
 881
 882	pm_pr_dbg("Preparing processes for restore.\n");
 883	error = freeze_processes();
 884	if (error)
 885		goto Close_Finish;
 886	error = load_image_and_restore();
 887	thaw_processes();
 888 Finish:
 889	__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
 
 890	pm_restore_console();
 891	pr_info("resume from hibernation failed (%d)\n", error);
 892	atomic_inc(&snapshot_device_available);
 893	/* For success case, the suspend path will release the lock */
 894 Unlock:
 895	mutex_unlock(&pm_mutex);
 896	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
 897	return error;
 898 Close_Finish:
 899	swsusp_close(FMODE_READ);
 900	goto Finish;
 901}
 902
 903late_initcall_sync(software_resume);
 904
 905
 906static const char * const hibernation_modes[] = {
 907	[HIBERNATION_PLATFORM]	= "platform",
 908	[HIBERNATION_SHUTDOWN]	= "shutdown",
 909	[HIBERNATION_REBOOT]	= "reboot",
 910#ifdef CONFIG_SUSPEND
 911	[HIBERNATION_SUSPEND]	= "suspend",
 912#endif
 913	[HIBERNATION_TEST_RESUME]	= "test_resume",
 914};
 915
 916/*
 917 * /sys/power/disk - Control hibernation mode.
 918 *
 919 * Hibernation can be handled in several ways.  There are a few different ways
 920 * to put the system into the sleep state: using the platform driver (e.g. ACPI
 921 * or other hibernation_ops), powering it off or rebooting it (for testing
 922 * mostly).
 923 *
 924 * The sysfs file /sys/power/disk provides an interface for selecting the
 925 * hibernation mode to use.  Reading from this file causes the available modes
 926 * to be printed.  There are 3 modes that can be supported:
 927 *
 928 *	'platform'
 929 *	'shutdown'
 930 *	'reboot'
 931 *
 932 * If a platform hibernation driver is in use, 'platform' will be supported
 933 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 934 * The selected option (i.e. the one corresponding to the current value of
 935 * hibernation_mode) is enclosed by a square bracket.
 936 *
 937 * To select a given hibernation mode it is necessary to write the mode's
 938 * string representation (as returned by reading from /sys/power/disk) back
 939 * into /sys/power/disk.
 940 */
 941
 942static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 943			 char *buf)
 944{
 945	int i;
 946	char *start = buf;
 947
 948	if (!hibernation_available())
 949		return sprintf(buf, "[disabled]\n");
 950
 951	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 952		if (!hibernation_modes[i])
 953			continue;
 954		switch (i) {
 955		case HIBERNATION_SHUTDOWN:
 956		case HIBERNATION_REBOOT:
 957#ifdef CONFIG_SUSPEND
 958		case HIBERNATION_SUSPEND:
 959#endif
 960		case HIBERNATION_TEST_RESUME:
 961			break;
 962		case HIBERNATION_PLATFORM:
 963			if (hibernation_ops)
 964				break;
 965			/* not a valid mode, continue with loop */
 966			continue;
 967		}
 968		if (i == hibernation_mode)
 969			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 970		else
 971			buf += sprintf(buf, "%s ", hibernation_modes[i]);
 972	}
 973	buf += sprintf(buf, "\n");
 974	return buf-start;
 975}
 976
 977static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 978			  const char *buf, size_t n)
 979{
 
 
 980	int error = 0;
 981	int i;
 982	int len;
 983	char *p;
 984	int mode = HIBERNATION_INVALID;
 985
 986	if (!hibernation_available())
 987		return -EPERM;
 988
 989	p = memchr(buf, '\n', n);
 990	len = p ? p - buf : n;
 991
 992	lock_system_sleep();
 993	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 994		if (len == strlen(hibernation_modes[i])
 995		    && !strncmp(buf, hibernation_modes[i], len)) {
 996			mode = i;
 997			break;
 998		}
 999	}
1000	if (mode != HIBERNATION_INVALID) {
1001		switch (mode) {
1002		case HIBERNATION_SHUTDOWN:
1003		case HIBERNATION_REBOOT:
1004#ifdef CONFIG_SUSPEND
1005		case HIBERNATION_SUSPEND:
1006#endif
1007		case HIBERNATION_TEST_RESUME:
1008			hibernation_mode = mode;
1009			break;
1010		case HIBERNATION_PLATFORM:
1011			if (hibernation_ops)
1012				hibernation_mode = mode;
1013			else
1014				error = -EINVAL;
1015		}
1016	} else
1017		error = -EINVAL;
1018
1019	if (!error)
1020		pm_pr_dbg("Hibernation mode set to '%s'\n",
1021			       hibernation_modes[mode]);
1022	unlock_system_sleep();
1023	return error ? error : n;
1024}
1025
1026power_attr(disk);
1027
1028static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1029			   char *buf)
1030{
1031	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1032		       MINOR(swsusp_resume_device));
1033}
1034
1035static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1036			    const char *buf, size_t n)
1037{
1038	dev_t res;
1039	int len = n;
1040	char *name;
 
1041
1042	if (len && buf[len-1] == '\n')
1043		len--;
1044	name = kstrndup(buf, len, GFP_KERNEL);
1045	if (!name)
1046		return -ENOMEM;
1047
1048	res = name_to_dev_t(name);
1049	kfree(name);
1050	if (!res)
1051		return -EINVAL;
1052
1053	lock_system_sleep();
1054	swsusp_resume_device = res;
1055	unlock_system_sleep();
1056	pm_pr_dbg("Configured resume from disk to %u\n", swsusp_resume_device);
 
 
1057	noresume = 0;
1058	software_resume();
1059	return n;
1060}
1061
1062power_attr(resume);
1063
1064static ssize_t resume_offset_show(struct kobject *kobj,
1065				  struct kobj_attribute *attr, char *buf)
1066{
1067	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1068}
1069
1070static ssize_t resume_offset_store(struct kobject *kobj,
1071				   struct kobj_attribute *attr, const char *buf,
1072				   size_t n)
1073{
1074	unsigned long long offset;
1075	int rc;
1076
1077	rc = kstrtoull(buf, 0, &offset);
1078	if (rc)
1079		return rc;
1080	swsusp_resume_block = offset;
1081
1082	return n;
1083}
1084
1085power_attr(resume_offset);
1086
1087static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1088			       char *buf)
1089{
1090	return sprintf(buf, "%lu\n", image_size);
1091}
1092
1093static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1094				const char *buf, size_t n)
1095{
1096	unsigned long size;
1097
1098	if (sscanf(buf, "%lu", &size) == 1) {
1099		image_size = size;
1100		return n;
1101	}
1102
1103	return -EINVAL;
1104}
1105
1106power_attr(image_size);
1107
1108static ssize_t reserved_size_show(struct kobject *kobj,
1109				  struct kobj_attribute *attr, char *buf)
1110{
1111	return sprintf(buf, "%lu\n", reserved_size);
1112}
1113
1114static ssize_t reserved_size_store(struct kobject *kobj,
1115				   struct kobj_attribute *attr,
1116				   const char *buf, size_t n)
1117{
1118	unsigned long size;
1119
1120	if (sscanf(buf, "%lu", &size) == 1) {
1121		reserved_size = size;
1122		return n;
1123	}
1124
1125	return -EINVAL;
1126}
1127
1128power_attr(reserved_size);
1129
1130static struct attribute * g[] = {
1131	&disk_attr.attr,
1132	&resume_offset_attr.attr,
1133	&resume_attr.attr,
1134	&image_size_attr.attr,
1135	&reserved_size_attr.attr,
1136	NULL,
1137};
1138
1139
1140static const struct attribute_group attr_group = {
1141	.attrs = g,
1142};
1143
1144
1145static int __init pm_disk_init(void)
1146{
1147	return sysfs_create_group(power_kobj, &attr_group);
1148}
1149
1150core_initcall(pm_disk_init);
1151
1152
1153static int __init resume_setup(char *str)
1154{
1155	if (noresume)
1156		return 1;
1157
1158	strncpy( resume_file, str, 255 );
1159	return 1;
1160}
1161
1162static int __init resume_offset_setup(char *str)
1163{
1164	unsigned long long offset;
1165
1166	if (noresume)
1167		return 1;
1168
1169	if (sscanf(str, "%llu", &offset) == 1)
1170		swsusp_resume_block = offset;
1171
1172	return 1;
1173}
1174
1175static int __init hibernate_setup(char *str)
1176{
1177	if (!strncmp(str, "noresume", 8)) {
1178		noresume = 1;
1179	} else if (!strncmp(str, "nocompress", 10)) {
1180		nocompress = 1;
1181	} else if (!strncmp(str, "no", 2)) {
1182		noresume = 1;
1183		nohibernate = 1;
1184	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1185		   && !strncmp(str, "protect_image", 13)) {
1186		enable_restore_image_protection();
1187	}
1188	return 1;
1189}
1190
1191static int __init noresume_setup(char *str)
1192{
1193	noresume = 1;
1194	return 1;
1195}
1196
1197static int __init resumewait_setup(char *str)
1198{
1199	resume_wait = 1;
1200	return 1;
1201}
1202
1203static int __init resumedelay_setup(char *str)
1204{
1205	int rc = kstrtouint(str, 0, &resume_delay);
1206
1207	if (rc)
1208		return rc;
1209	return 1;
1210}
1211
1212static int __init nohibernate_setup(char *str)
1213{
1214	noresume = 1;
1215	nohibernate = 1;
1216	return 1;
1217}
1218
1219__setup("noresume", noresume_setup);
1220__setup("resume_offset=", resume_offset_setup);
1221__setup("resume=", resume_setup);
1222__setup("hibernate=", hibernate_setup);
1223__setup("resumewait", resumewait_setup);
1224__setup("resumedelay=", resumedelay_setup);
1225__setup("nohibernate", nohibernate_setup);