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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);
v5.14.15
   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/genhd.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();
  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	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  97	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  98	    && ops->restore_cleanup && ops->leave)) {
  99		WARN_ON(1);
 100		return;
 101	}
 102	lock_system_sleep();
 103	hibernation_ops = ops;
 104	if (ops)
 105		hibernation_mode = HIBERNATION_PLATFORM;
 106	else if (hibernation_mode == HIBERNATION_PLATFORM)
 107		hibernation_mode = HIBERNATION_SHUTDOWN;
 108
 109	unlock_system_sleep();
 110}
 111EXPORT_SYMBOL_GPL(hibernation_set_ops);
 112
 113static bool entering_platform_hibernation;
 114
 115bool system_entering_hibernation(void)
 116{
 117	return entering_platform_hibernation;
 118}
 119EXPORT_SYMBOL(system_entering_hibernation);
 120
 121#ifdef CONFIG_PM_DEBUG
 122static void hibernation_debug_sleep(void)
 123{
 124	pr_info("debug: Waiting for 5 seconds.\n");
 125	mdelay(5000);
 126}
 127
 128static int hibernation_test(int level)
 129{
 130	if (pm_test_level == level) {
 131		hibernation_debug_sleep();
 132		return 1;
 133	}
 134	return 0;
 135}
 136#else /* !CONFIG_PM_DEBUG */
 137static int hibernation_test(int level) { return 0; }
 138#endif /* !CONFIG_PM_DEBUG */
 139
 140/**
 141 * platform_begin - Call platform to start hibernation.
 142 * @platform_mode: Whether or not to use the platform driver.
 143 */
 144static int platform_begin(int platform_mode)
 145{
 146	return (platform_mode && hibernation_ops) ?
 147		hibernation_ops->begin(PMSG_FREEZE) : 0;
 148}
 149
 150/**
 151 * platform_end - Call platform to finish transition to the working state.
 152 * @platform_mode: Whether or not to use the platform driver.
 153 */
 154static void platform_end(int platform_mode)
 155{
 156	if (platform_mode && hibernation_ops)
 157		hibernation_ops->end();
 158}
 159
 160/**
 161 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 162 * @platform_mode: Whether or not to use the platform driver.
 163 *
 164 * Use the platform driver to prepare the system for creating a hibernate image,
 165 * if so configured, and return an error code if that fails.
 166 */
 167
 168static int platform_pre_snapshot(int platform_mode)
 169{
 170	return (platform_mode && hibernation_ops) ?
 171		hibernation_ops->pre_snapshot() : 0;
 172}
 173
 174/**
 175 * platform_leave - Call platform to prepare a transition to the working state.
 176 * @platform_mode: Whether or not to use the platform driver.
 177 *
 178 * Use the platform driver prepare to prepare the machine for switching to the
 179 * normal mode of operation.
 180 *
 181 * This routine is called on one CPU with interrupts disabled.
 182 */
 183static void platform_leave(int platform_mode)
 184{
 185	if (platform_mode && hibernation_ops)
 186		hibernation_ops->leave();
 187}
 188
 189/**
 190 * platform_finish - Call platform to switch the system to the working state.
 191 * @platform_mode: Whether or not to use the platform driver.
 192 *
 193 * Use the platform driver to switch the machine to the normal mode of
 194 * operation.
 195 *
 196 * This routine must be called after platform_prepare().
 197 */
 198static void platform_finish(int platform_mode)
 199{
 200	if (platform_mode && hibernation_ops)
 201		hibernation_ops->finish();
 202}
 203
 204/**
 205 * platform_pre_restore - Prepare for hibernate image restoration.
 206 * @platform_mode: Whether or not to use the platform driver.
 207 *
 208 * Use the platform driver to prepare the system for resume from a hibernation
 209 * image.
 210 *
 211 * If the restore fails after this function has been called,
 212 * platform_restore_cleanup() must be called.
 213 */
 214static int platform_pre_restore(int platform_mode)
 215{
 216	return (platform_mode && hibernation_ops) ?
 217		hibernation_ops->pre_restore() : 0;
 218}
 219
 220/**
 221 * platform_restore_cleanup - Switch to the working state after failing restore.
 222 * @platform_mode: Whether or not to use the platform driver.
 223 *
 224 * Use the platform driver to switch the system to the normal mode of operation
 225 * after a failing restore.
 226 *
 227 * If platform_pre_restore() has been called before the failing restore, this
 228 * function must be called too, regardless of the result of
 229 * platform_pre_restore().
 230 */
 231static void platform_restore_cleanup(int platform_mode)
 232{
 233	if (platform_mode && hibernation_ops)
 234		hibernation_ops->restore_cleanup();
 235}
 236
 237/**
 238 * platform_recover - Recover from a failure to suspend devices.
 239 * @platform_mode: Whether or not to use the platform driver.
 240 */
 241static void platform_recover(int platform_mode)
 242{
 243	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 244		hibernation_ops->recover();
 245}
 246
 247/**
 248 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 249 * @start: Starting event.
 250 * @stop: Final event.
 251 * @nr_pages: Number of memory pages processed between @start and @stop.
 252 * @msg: Additional diagnostic message to print.
 253 */
 254void swsusp_show_speed(ktime_t start, ktime_t stop,
 255		      unsigned nr_pages, char *msg)
 256{
 257	ktime_t diff;
 258	u64 elapsed_centisecs64;
 259	unsigned int centisecs;
 260	unsigned int k;
 261	unsigned int kps;
 262
 263	diff = ktime_sub(stop, start);
 264	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 265	centisecs = elapsed_centisecs64;
 266	if (centisecs == 0)
 267		centisecs = 1;	/* avoid div-by-zero */
 268	k = nr_pages * (PAGE_SIZE / 1024);
 269	kps = (k * 100) / centisecs;
 270	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 271		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 272		(kps % 1000) / 10);
 273}
 274
 275__weak int arch_resume_nosmt(void)
 276{
 277	return 0;
 278}
 279
 280/**
 281 * create_image - Create a hibernation image.
 282 * @platform_mode: Whether or not to use the platform driver.
 283 *
 284 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 285 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 286 *
 287 * Control reappears in this routine after the subsequent restore.
 288 */
 289static int create_image(int platform_mode)
 290{
 291	int error;
 292
 293	error = dpm_suspend_end(PMSG_FREEZE);
 294	if (error) {
 295		pr_err("Some devices failed to power down, aborting\n");
 296		return error;
 297	}
 298
 299	error = platform_pre_snapshot(platform_mode);
 300	if (error || hibernation_test(TEST_PLATFORM))
 301		goto Platform_finish;
 302
 303	error = suspend_disable_secondary_cpus();
 304	if (error || hibernation_test(TEST_CPUS))
 305		goto Enable_cpus;
 306
 307	local_irq_disable();
 308
 309	system_state = SYSTEM_SUSPEND;
 310
 311	error = syscore_suspend();
 312	if (error) {
 313		pr_err("Some system devices failed to power down, aborting\n");
 314		goto Enable_irqs;
 315	}
 316
 317	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 318		goto Power_up;
 319
 320	in_suspend = 1;
 321	save_processor_state();
 322	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 323	error = swsusp_arch_suspend();
 324	/* Restore control flow magically appears here */
 325	restore_processor_state();
 326	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 327	if (error)
 328		pr_err("Error %d creating image\n", error);
 329
 330	if (!in_suspend) {
 331		events_check_enabled = false;
 332		clear_or_poison_free_pages();
 333	}
 334
 335	platform_leave(platform_mode);
 336
 337 Power_up:
 338	syscore_resume();
 339
 340 Enable_irqs:
 341	system_state = SYSTEM_RUNNING;
 342	local_irq_enable();
 343
 344 Enable_cpus:
 345	suspend_enable_secondary_cpus();
 346
 347	/* Allow architectures to do nosmt-specific post-resume dances */
 348	if (!in_suspend)
 349		error = arch_resume_nosmt();
 350
 351 Platform_finish:
 352	platform_finish(platform_mode);
 353
 354	dpm_resume_start(in_suspend ?
 355		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 356
 357	return error;
 358}
 359
 360/**
 361 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 362 * @platform_mode: If set, use platform driver to prepare for the transition.
 363 *
 364 * This routine must be called with system_transition_mutex held.
 365 */
 366int hibernation_snapshot(int platform_mode)
 367{
 368	pm_message_t msg;
 369	int error;
 370
 371	pm_suspend_clear_flags();
 372	error = platform_begin(platform_mode);
 373	if (error)
 374		goto Close;
 375
 376	/* Preallocate image memory before shutting down devices. */
 377	error = hibernate_preallocate_memory();
 378	if (error)
 379		goto Close;
 380
 381	error = freeze_kernel_threads();
 382	if (error)
 383		goto Cleanup;
 384
 385	if (hibernation_test(TEST_FREEZER)) {
 386
 387		/*
 388		 * Indicate to the caller that we are returning due to a
 389		 * successful freezer test.
 390		 */
 391		freezer_test_done = true;
 392		goto Thaw;
 393	}
 394
 395	error = dpm_prepare(PMSG_FREEZE);
 396	if (error) {
 397		dpm_complete(PMSG_RECOVER);
 398		goto Thaw;
 399	}
 400
 401	suspend_console();
 402	pm_restrict_gfp_mask();
 403
 404	error = dpm_suspend(PMSG_FREEZE);
 405
 406	if (error || hibernation_test(TEST_DEVICES))
 407		platform_recover(platform_mode);
 408	else
 409		error = create_image(platform_mode);
 410
 411	/*
 412	 * In the case that we call create_image() above, the control
 413	 * returns here (1) after the image has been created or the
 414	 * image creation has failed and (2) after a successful restore.
 415	 */
 416
 417	/* We may need to release the preallocated image pages here. */
 418	if (error || !in_suspend)
 419		swsusp_free();
 420
 421	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 422	dpm_resume(msg);
 423
 424	if (error || !in_suspend)
 425		pm_restore_gfp_mask();
 426
 427	resume_console();
 428	dpm_complete(msg);
 429
 430 Close:
 431	platform_end(platform_mode);
 432	return error;
 433
 434 Thaw:
 435	thaw_kernel_threads();
 436 Cleanup:
 437	swsusp_free();
 438	goto Close;
 439}
 440
 441int __weak hibernate_resume_nonboot_cpu_disable(void)
 442{
 443	return suspend_disable_secondary_cpus();
 444}
 445
 446/**
 447 * resume_target_kernel - Restore system state from a hibernation image.
 448 * @platform_mode: Whether or not to use the platform driver.
 449 *
 450 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 451 * contents of highmem that have not been restored yet from the image and run
 452 * the low-level code that will restore the remaining contents of memory and
 453 * switch to the just restored target kernel.
 454 */
 455static int resume_target_kernel(bool platform_mode)
 456{
 457	int error;
 458
 459	error = dpm_suspend_end(PMSG_QUIESCE);
 460	if (error) {
 461		pr_err("Some devices failed to power down, aborting resume\n");
 462		return error;
 463	}
 464
 465	error = platform_pre_restore(platform_mode);
 466	if (error)
 467		goto Cleanup;
 468
 469	error = hibernate_resume_nonboot_cpu_disable();
 470	if (error)
 471		goto Enable_cpus;
 472
 473	local_irq_disable();
 474	system_state = SYSTEM_SUSPEND;
 475
 476	error = syscore_suspend();
 477	if (error)
 478		goto Enable_irqs;
 479
 480	save_processor_state();
 481	error = restore_highmem();
 482	if (!error) {
 483		error = swsusp_arch_resume();
 484		/*
 485		 * The code below is only ever reached in case of a failure.
 486		 * Otherwise, execution continues at the place where
 487		 * swsusp_arch_suspend() was called.
 488		 */
 489		BUG_ON(!error);
 490		/*
 491		 * This call to restore_highmem() reverts the changes made by
 492		 * the previous one.
 493		 */
 494		restore_highmem();
 495	}
 496	/*
 497	 * The only reason why swsusp_arch_resume() can fail is memory being
 498	 * very tight, so we have to free it as soon as we can to avoid
 499	 * subsequent failures.
 500	 */
 501	swsusp_free();
 502	restore_processor_state();
 503	touch_softlockup_watchdog();
 504
 505	syscore_resume();
 506
 507 Enable_irqs:
 508	system_state = SYSTEM_RUNNING;
 509	local_irq_enable();
 510
 511 Enable_cpus:
 512	suspend_enable_secondary_cpus();
 513
 514 Cleanup:
 515	platform_restore_cleanup(platform_mode);
 516
 517	dpm_resume_start(PMSG_RECOVER);
 518
 519	return error;
 520}
 521
 522/**
 523 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 524 * @platform_mode: If set, use platform driver to prepare for the transition.
 525 *
 526 * This routine must be called with system_transition_mutex held.  If it is
 527 * successful, control reappears in the restored target kernel in
 528 * hibernation_snapshot().
 529 */
 530int hibernation_restore(int platform_mode)
 531{
 532	int error;
 533
 534	pm_prepare_console();
 535	suspend_console();
 536	pm_restrict_gfp_mask();
 537	error = dpm_suspend_start(PMSG_QUIESCE);
 538	if (!error) {
 539		error = resume_target_kernel(platform_mode);
 540		/*
 541		 * The above should either succeed and jump to the new kernel,
 542		 * or return with an error. Otherwise things are just
 543		 * undefined, so let's be paranoid.
 544		 */
 545		BUG_ON(!error);
 546	}
 547	dpm_resume_end(PMSG_RECOVER);
 548	pm_restore_gfp_mask();
 549	resume_console();
 550	pm_restore_console();
 551	return error;
 552}
 553
 554/**
 555 * hibernation_platform_enter - Power off the system using the platform driver.
 556 */
 557int hibernation_platform_enter(void)
 558{
 559	int error;
 560
 561	if (!hibernation_ops)
 562		return -ENOSYS;
 563
 564	/*
 565	 * We have cancelled the power transition by running
 566	 * hibernation_ops->finish() before saving the image, so we should let
 567	 * the firmware know that we're going to enter the sleep state after all
 568	 */
 569	error = hibernation_ops->begin(PMSG_HIBERNATE);
 570	if (error)
 571		goto Close;
 572
 573	entering_platform_hibernation = true;
 574	suspend_console();
 575	error = dpm_suspend_start(PMSG_HIBERNATE);
 576	if (error) {
 577		if (hibernation_ops->recover)
 578			hibernation_ops->recover();
 579		goto Resume_devices;
 580	}
 581
 582	error = dpm_suspend_end(PMSG_HIBERNATE);
 583	if (error)
 584		goto Resume_devices;
 585
 586	error = hibernation_ops->prepare();
 587	if (error)
 588		goto Platform_finish;
 589
 590	error = suspend_disable_secondary_cpus();
 591	if (error)
 592		goto Enable_cpus;
 593
 594	local_irq_disable();
 595	system_state = SYSTEM_SUSPEND;
 596	syscore_suspend();
 597	if (pm_wakeup_pending()) {
 598		error = -EAGAIN;
 599		goto Power_up;
 600	}
 601
 602	hibernation_ops->enter();
 603	/* We should never get here */
 604	while (1);
 605
 606 Power_up:
 607	syscore_resume();
 608	system_state = SYSTEM_RUNNING;
 609	local_irq_enable();
 610
 611 Enable_cpus:
 612	suspend_enable_secondary_cpus();
 613
 614 Platform_finish:
 615	hibernation_ops->finish();
 616
 617	dpm_resume_start(PMSG_RESTORE);
 618
 619 Resume_devices:
 620	entering_platform_hibernation = false;
 621	dpm_resume_end(PMSG_RESTORE);
 622	resume_console();
 623
 624 Close:
 625	hibernation_ops->end();
 626
 627	return error;
 628}
 629
 630/**
 631 * power_down - Shut the machine down for hibernation.
 632 *
 633 * Use the platform driver, if configured, to put the system into the sleep
 634 * state corresponding to hibernation, or try to power it off or reboot,
 635 * depending on the value of hibernation_mode.
 636 */
 637static void power_down(void)
 638{
 639#ifdef CONFIG_SUSPEND
 640	int error;
 641
 642	if (hibernation_mode == HIBERNATION_SUSPEND) {
 643		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 644		if (error) {
 645			hibernation_mode = hibernation_ops ?
 646						HIBERNATION_PLATFORM :
 647						HIBERNATION_SHUTDOWN;
 648		} else {
 649			/* Restore swap signature. */
 650			error = swsusp_unmark();
 651			if (error)
 652				pr_err("Swap will be unusable! Try swapon -a.\n");
 653
 654			return;
 655		}
 656	}
 657#endif
 658
 659	switch (hibernation_mode) {
 660	case HIBERNATION_REBOOT:
 661		kernel_restart(NULL);
 662		break;
 663	case HIBERNATION_PLATFORM:
 664		hibernation_platform_enter();
 665		fallthrough;
 666	case HIBERNATION_SHUTDOWN:
 667		if (pm_power_off)
 668			kernel_power_off();
 669		break;
 670	}
 671	kernel_halt();
 672	/*
 673	 * Valid image is on the disk, if we continue we risk serious data
 674	 * corruption after resume.
 675	 */
 676	pr_crit("Power down manually\n");
 677	while (1)
 678		cpu_relax();
 679}
 680
 681static int load_image_and_restore(void)
 682{
 683	int error;
 684	unsigned int flags;
 685
 686	pm_pr_dbg("Loading hibernation image.\n");
 687
 688	lock_device_hotplug();
 689	error = create_basic_memory_bitmaps();
 690	if (error)
 691		goto Unlock;
 692
 693	error = swsusp_read(&flags);
 694	swsusp_close(FMODE_READ);
 695	if (!error)
 696		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 697
 698	pr_err("Failed to load image, recovering.\n");
 699	swsusp_free();
 700	free_basic_memory_bitmaps();
 701 Unlock:
 702	unlock_device_hotplug();
 703
 704	return error;
 705}
 706
 707/**
 708 * hibernate - Carry out system hibernation, including saving the image.
 709 */
 710int hibernate(void)
 711{
 
 712	bool snapshot_test = false;
 713	int error;
 714
 715	if (!hibernation_available()) {
 716		pm_pr_dbg("Hibernation not available.\n");
 717		return -EPERM;
 718	}
 719
 720	lock_system_sleep();
 721	/* The snapshot device should not be opened while we're running */
 722	if (!hibernate_acquire()) {
 723		error = -EBUSY;
 724		goto Unlock;
 725	}
 726
 727	pr_info("hibernation entry\n");
 728	pm_prepare_console();
 729	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 730	if (error)
 731		goto Restore;
 
 
 732
 733	ksys_sync_helper();
 
 
 734
 735	error = freeze_processes();
 736	if (error)
 737		goto Exit;
 738
 739	lock_device_hotplug();
 740	/* Allocate memory management structures */
 741	error = create_basic_memory_bitmaps();
 742	if (error)
 743		goto Thaw;
 744
 745	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 746	if (error || freezer_test_done)
 747		goto Free_bitmaps;
 748
 749	if (in_suspend) {
 750		unsigned int flags = 0;
 751
 752		if (hibernation_mode == HIBERNATION_PLATFORM)
 753			flags |= SF_PLATFORM_MODE;
 754		if (nocompress)
 755			flags |= SF_NOCOMPRESS_MODE;
 756		else
 757		        flags |= SF_CRC32_MODE;
 758
 759		pm_pr_dbg("Writing hibernation image.\n");
 760		error = swsusp_write(flags);
 761		swsusp_free();
 762		if (!error) {
 763			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 764				snapshot_test = true;
 765			else
 766				power_down();
 767		}
 768		in_suspend = 0;
 769		pm_restore_gfp_mask();
 770	} else {
 771		pm_pr_dbg("Hibernation image restored successfully.\n");
 772	}
 773
 774 Free_bitmaps:
 775	free_basic_memory_bitmaps();
 776 Thaw:
 777	unlock_device_hotplug();
 778	if (snapshot_test) {
 779		pm_pr_dbg("Checking hibernation image\n");
 780		error = swsusp_check();
 781		if (!error)
 782			error = load_image_and_restore();
 783	}
 784	thaw_processes();
 785
 786	/* Don't bother checking whether freezer_test_done is true */
 787	freezer_test_done = false;
 788 Exit:
 789	pm_notifier_call_chain(PM_POST_HIBERNATION);
 790 Restore:
 791	pm_restore_console();
 792	hibernate_release();
 793 Unlock:
 794	unlock_system_sleep();
 795	pr_info("hibernation exit\n");
 796
 797	return error;
 798}
 799
 800/**
 801 * hibernate_quiet_exec - Execute a function with all devices frozen.
 802 * @func: Function to execute.
 803 * @data: Data pointer to pass to @func.
 804 *
 805 * Return the @func return value or an error code if it cannot be executed.
 806 */
 807int hibernate_quiet_exec(int (*func)(void *data), void *data)
 808{
 809	int error;
 810
 811	lock_system_sleep();
 812
 813	if (!hibernate_acquire()) {
 814		error = -EBUSY;
 815		goto unlock;
 816	}
 817
 818	pm_prepare_console();
 819
 820	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 821	if (error)
 822		goto restore;
 823
 824	error = freeze_processes();
 825	if (error)
 826		goto exit;
 827
 828	lock_device_hotplug();
 829
 830	pm_suspend_clear_flags();
 831
 832	error = platform_begin(true);
 833	if (error)
 834		goto thaw;
 835
 836	error = freeze_kernel_threads();
 837	if (error)
 838		goto thaw;
 839
 840	error = dpm_prepare(PMSG_FREEZE);
 841	if (error)
 842		goto dpm_complete;
 843
 844	suspend_console();
 845
 846	error = dpm_suspend(PMSG_FREEZE);
 847	if (error)
 848		goto dpm_resume;
 849
 850	error = dpm_suspend_end(PMSG_FREEZE);
 851	if (error)
 852		goto dpm_resume;
 853
 854	error = platform_pre_snapshot(true);
 855	if (error)
 856		goto skip;
 857
 858	error = func(data);
 859
 860skip:
 861	platform_finish(true);
 862
 863	dpm_resume_start(PMSG_THAW);
 864
 865dpm_resume:
 866	dpm_resume(PMSG_THAW);
 867
 868	resume_console();
 869
 870dpm_complete:
 871	dpm_complete(PMSG_THAW);
 872
 873	thaw_kernel_threads();
 874
 875thaw:
 876	platform_end(true);
 877
 878	unlock_device_hotplug();
 879
 880	thaw_processes();
 881
 882exit:
 883	pm_notifier_call_chain(PM_POST_HIBERNATION);
 884
 885restore:
 886	pm_restore_console();
 887
 888	hibernate_release();
 889
 890unlock:
 891	unlock_system_sleep();
 892
 893	return error;
 894}
 895EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 896
 897/**
 898 * software_resume - Resume from a saved hibernation image.
 899 *
 900 * This routine is called as a late initcall, when all devices have been
 901 * discovered and initialized already.
 902 *
 903 * The image reading code is called to see if there is a hibernation image
 904 * available for reading.  If that is the case, devices are quiesced and the
 905 * contents of memory is restored from the saved image.
 906 *
 907 * If this is successful, control reappears in the restored target kernel in
 908 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 909 * attempts to recover gracefully and make the kernel return to the normal mode
 910 * of operation.
 911 */
 912static int software_resume(void)
 913{
 914	int error;
 915
 916	/*
 917	 * If the user said "noresume".. bail out early.
 918	 */
 919	if (noresume || !hibernation_available())
 920		return 0;
 921
 922	/*
 923	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 924	 * is configured into the kernel. Since the regular hibernate
 925	 * trigger path is via sysfs which takes a buffer mutex before
 926	 * calling hibernate functions (which take system_transition_mutex)
 927	 * this can cause lockdep to complain about a possible ABBA deadlock
 928	 * which cannot happen since we're in the boot code here and
 929	 * sysfs can't be invoked yet. Therefore, we use a subclass
 930	 * here to avoid lockdep complaining.
 931	 */
 932	mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 933
 934	if (swsusp_resume_device)
 935		goto Check_image;
 936
 937	if (!strlen(resume_file)) {
 938		error = -ENOENT;
 939		goto Unlock;
 940	}
 941
 942	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 943
 944	if (resume_delay) {
 945		pr_info("Waiting %dsec before reading resume device ...\n",
 946			resume_delay);
 947		ssleep(resume_delay);
 948	}
 949
 950	/* Check if the device is there */
 951	swsusp_resume_device = name_to_dev_t(resume_file);
 
 
 
 
 
 
 
 
 
 
 
 952	if (!swsusp_resume_device) {
 953		/*
 954		 * Some device discovery might still be in progress; we need
 955		 * to wait for this to finish.
 956		 */
 957		wait_for_device_probe();
 958
 959		if (resume_wait) {
 960			while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 961				msleep(10);
 962			async_synchronize_full();
 963		}
 964
 965		swsusp_resume_device = name_to_dev_t(resume_file);
 966		if (!swsusp_resume_device) {
 967			error = -ENODEV;
 968			goto Unlock;
 969		}
 970	}
 971
 972 Check_image:
 973	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 974		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 975
 976	pm_pr_dbg("Looking for hibernation image.\n");
 977	error = swsusp_check();
 978	if (error)
 979		goto Unlock;
 980
 981	/* The snapshot device should not be opened while we're running */
 982	if (!hibernate_acquire()) {
 983		error = -EBUSY;
 984		swsusp_close(FMODE_READ);
 985		goto Unlock;
 986	}
 987
 988	pr_info("resume from hibernation\n");
 989	pm_prepare_console();
 990	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
 991	if (error)
 992		goto Restore;
 
 
 993
 994	pm_pr_dbg("Preparing processes for hibernation restore.\n");
 995	error = freeze_processes();
 996	if (error)
 997		goto Close_Finish;
 998
 999	error = freeze_kernel_threads();
1000	if (error) {
1001		thaw_processes();
1002		goto Close_Finish;
1003	}
1004
1005	error = load_image_and_restore();
1006	thaw_processes();
1007 Finish:
1008	pm_notifier_call_chain(PM_POST_RESTORE);
1009 Restore:
1010	pm_restore_console();
1011	pr_info("resume failed (%d)\n", error);
1012	hibernate_release();
1013	/* For success case, the suspend path will release the lock */
1014 Unlock:
1015	mutex_unlock(&system_transition_mutex);
1016	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1017	return error;
1018 Close_Finish:
1019	swsusp_close(FMODE_READ);
1020	goto Finish;
1021}
1022
1023late_initcall_sync(software_resume);
1024
1025
1026static const char * const hibernation_modes[] = {
1027	[HIBERNATION_PLATFORM]	= "platform",
1028	[HIBERNATION_SHUTDOWN]	= "shutdown",
1029	[HIBERNATION_REBOOT]	= "reboot",
1030#ifdef CONFIG_SUSPEND
1031	[HIBERNATION_SUSPEND]	= "suspend",
1032#endif
1033	[HIBERNATION_TEST_RESUME]	= "test_resume",
1034};
1035
1036/*
1037 * /sys/power/disk - Control hibernation mode.
1038 *
1039 * Hibernation can be handled in several ways.  There are a few different ways
1040 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1041 * or other hibernation_ops), powering it off or rebooting it (for testing
1042 * mostly).
1043 *
1044 * The sysfs file /sys/power/disk provides an interface for selecting the
1045 * hibernation mode to use.  Reading from this file causes the available modes
1046 * to be printed.  There are 3 modes that can be supported:
1047 *
1048 *	'platform'
1049 *	'shutdown'
1050 *	'reboot'
1051 *
1052 * If a platform hibernation driver is in use, 'platform' will be supported
1053 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1054 * The selected option (i.e. the one corresponding to the current value of
1055 * hibernation_mode) is enclosed by a square bracket.
1056 *
1057 * To select a given hibernation mode it is necessary to write the mode's
1058 * string representation (as returned by reading from /sys/power/disk) back
1059 * into /sys/power/disk.
1060 */
1061
1062static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1063			 char *buf)
1064{
1065	int i;
1066	char *start = buf;
1067
1068	if (!hibernation_available())
1069		return sprintf(buf, "[disabled]\n");
1070
1071	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1072		if (!hibernation_modes[i])
1073			continue;
1074		switch (i) {
1075		case HIBERNATION_SHUTDOWN:
1076		case HIBERNATION_REBOOT:
1077#ifdef CONFIG_SUSPEND
1078		case HIBERNATION_SUSPEND:
1079#endif
1080		case HIBERNATION_TEST_RESUME:
1081			break;
1082		case HIBERNATION_PLATFORM:
1083			if (hibernation_ops)
1084				break;
1085			/* not a valid mode, continue with loop */
1086			continue;
1087		}
1088		if (i == hibernation_mode)
1089			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1090		else
1091			buf += sprintf(buf, "%s ", hibernation_modes[i]);
1092	}
1093	buf += sprintf(buf, "\n");
1094	return buf-start;
1095}
1096
1097static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1098			  const char *buf, size_t n)
1099{
1100	int error = 0;
1101	int i;
1102	int len;
1103	char *p;
1104	int mode = HIBERNATION_INVALID;
1105
1106	if (!hibernation_available())
1107		return -EPERM;
1108
1109	p = memchr(buf, '\n', n);
1110	len = p ? p - buf : n;
1111
1112	lock_system_sleep();
1113	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1114		if (len == strlen(hibernation_modes[i])
1115		    && !strncmp(buf, hibernation_modes[i], len)) {
1116			mode = i;
1117			break;
1118		}
1119	}
1120	if (mode != HIBERNATION_INVALID) {
1121		switch (mode) {
1122		case HIBERNATION_SHUTDOWN:
1123		case HIBERNATION_REBOOT:
1124#ifdef CONFIG_SUSPEND
1125		case HIBERNATION_SUSPEND:
1126#endif
1127		case HIBERNATION_TEST_RESUME:
1128			hibernation_mode = mode;
1129			break;
1130		case HIBERNATION_PLATFORM:
1131			if (hibernation_ops)
1132				hibernation_mode = mode;
1133			else
1134				error = -EINVAL;
1135		}
1136	} else
1137		error = -EINVAL;
1138
1139	if (!error)
1140		pm_pr_dbg("Hibernation mode set to '%s'\n",
1141			       hibernation_modes[mode]);
1142	unlock_system_sleep();
1143	return error ? error : n;
1144}
1145
1146power_attr(disk);
1147
1148static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1149			   char *buf)
1150{
1151	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1152		       MINOR(swsusp_resume_device));
1153}
1154
1155static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1156			    const char *buf, size_t n)
1157{
1158	dev_t res;
1159	int len = n;
1160	char *name;
1161
1162	if (len && buf[len-1] == '\n')
1163		len--;
1164	name = kstrndup(buf, len, GFP_KERNEL);
1165	if (!name)
1166		return -ENOMEM;
1167
1168	res = name_to_dev_t(name);
1169	kfree(name);
1170	if (!res)
1171		return -EINVAL;
1172
1173	lock_system_sleep();
1174	swsusp_resume_device = res;
1175	unlock_system_sleep();
1176	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1177		  swsusp_resume_device);
1178	noresume = 0;
1179	software_resume();
1180	return n;
1181}
1182
1183power_attr(resume);
1184
1185static ssize_t resume_offset_show(struct kobject *kobj,
1186				  struct kobj_attribute *attr, char *buf)
1187{
1188	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1189}
1190
1191static ssize_t resume_offset_store(struct kobject *kobj,
1192				   struct kobj_attribute *attr, const char *buf,
1193				   size_t n)
1194{
1195	unsigned long long offset;
1196	int rc;
1197
1198	rc = kstrtoull(buf, 0, &offset);
1199	if (rc)
1200		return rc;
1201	swsusp_resume_block = offset;
1202
1203	return n;
1204}
1205
1206power_attr(resume_offset);
1207
1208static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1209			       char *buf)
1210{
1211	return sprintf(buf, "%lu\n", image_size);
1212}
1213
1214static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1215				const char *buf, size_t n)
1216{
1217	unsigned long size;
1218
1219	if (sscanf(buf, "%lu", &size) == 1) {
1220		image_size = size;
1221		return n;
1222	}
1223
1224	return -EINVAL;
1225}
1226
1227power_attr(image_size);
1228
1229static ssize_t reserved_size_show(struct kobject *kobj,
1230				  struct kobj_attribute *attr, char *buf)
1231{
1232	return sprintf(buf, "%lu\n", reserved_size);
1233}
1234
1235static ssize_t reserved_size_store(struct kobject *kobj,
1236				   struct kobj_attribute *attr,
1237				   const char *buf, size_t n)
1238{
1239	unsigned long size;
1240
1241	if (sscanf(buf, "%lu", &size) == 1) {
1242		reserved_size = size;
1243		return n;
1244	}
1245
1246	return -EINVAL;
1247}
1248
1249power_attr(reserved_size);
1250
1251static struct attribute *g[] = {
1252	&disk_attr.attr,
1253	&resume_offset_attr.attr,
1254	&resume_attr.attr,
1255	&image_size_attr.attr,
1256	&reserved_size_attr.attr,
1257	NULL,
1258};
1259
1260
1261static const struct attribute_group attr_group = {
1262	.attrs = g,
1263};
1264
1265
1266static int __init pm_disk_init(void)
1267{
1268	return sysfs_create_group(power_kobj, &attr_group);
1269}
1270
1271core_initcall(pm_disk_init);
1272
1273
1274static int __init resume_setup(char *str)
1275{
1276	if (noresume)
1277		return 1;
1278
1279	strncpy(resume_file, str, 255);
1280	return 1;
1281}
1282
1283static int __init resume_offset_setup(char *str)
1284{
1285	unsigned long long offset;
1286
1287	if (noresume)
1288		return 1;
1289
1290	if (sscanf(str, "%llu", &offset) == 1)
1291		swsusp_resume_block = offset;
1292
1293	return 1;
1294}
1295
1296static int __init hibernate_setup(char *str)
1297{
1298	if (!strncmp(str, "noresume", 8)) {
1299		noresume = 1;
1300	} else if (!strncmp(str, "nocompress", 10)) {
1301		nocompress = 1;
1302	} else if (!strncmp(str, "no", 2)) {
1303		noresume = 1;
1304		nohibernate = 1;
1305	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1306		   && !strncmp(str, "protect_image", 13)) {
1307		enable_restore_image_protection();
1308	}
1309	return 1;
1310}
1311
1312static int __init noresume_setup(char *str)
1313{
1314	noresume = 1;
1315	return 1;
1316}
1317
1318static int __init resumewait_setup(char *str)
1319{
1320	resume_wait = 1;
1321	return 1;
1322}
1323
1324static int __init resumedelay_setup(char *str)
1325{
1326	int rc = kstrtouint(str, 0, &resume_delay);
1327
1328	if (rc)
1329		return rc;
1330	return 1;
1331}
1332
1333static int __init nohibernate_setup(char *str)
1334{
1335	noresume = 1;
1336	nohibernate = 1;
1337	return 1;
1338}
1339
1340__setup("noresume", noresume_setup);
1341__setup("resume_offset=", resume_offset_setup);
1342__setup("resume=", resume_setup);
1343__setup("hibernate=", hibernate_setup);
1344__setup("resumewait", resumewait_setup);
1345__setup("resumedelay=", resumedelay_setup);
1346__setup("nohibernate", nohibernate_setup);