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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);
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);