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v4.10.11
 
   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#include <linux/export.h>
  14#include <linux/suspend.h>
  15#include <linux/syscalls.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/console.h>
  25#include <linux/cpu.h>
  26#include <linux/freezer.h>
  27#include <linux/gfp.h>
  28#include <linux/syscore_ops.h>
  29#include <linux/ctype.h>
  30#include <linux/genhd.h>
  31#include <linux/ktime.h>
 
 
  32#include <trace/events/power.h>
  33
  34#include "power.h"
  35
  36
  37static int nocompress;
  38static int noresume;
  39static int nohibernate;
  40static int resume_wait;
  41static unsigned int resume_delay;
  42static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  43dev_t swsusp_resume_device;
  44sector_t swsusp_resume_block;
  45__visible int in_suspend __nosavedata;
  46
 
 
 
 
 
 
 
 
 
  47enum {
  48	HIBERNATION_INVALID,
  49	HIBERNATION_PLATFORM,
  50	HIBERNATION_SHUTDOWN,
  51	HIBERNATION_REBOOT,
  52#ifdef CONFIG_SUSPEND
  53	HIBERNATION_SUSPEND,
  54#endif
  55	HIBERNATION_TEST_RESUME,
  56	/* keep last */
  57	__HIBERNATION_AFTER_LAST
  58};
  59#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  60#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  61
  62static int hibernation_mode = HIBERNATION_SHUTDOWN;
  63
  64bool freezer_test_done;
  65
  66static const struct platform_hibernation_ops *hibernation_ops;
  67
 
 
 
 
 
 
 
 
 
 
 
 
  68bool hibernation_available(void)
  69{
  70	return (nohibernate == 0);
 
 
  71}
  72
  73/**
  74 * hibernation_set_ops - Set the global hibernate operations.
  75 * @ops: Hibernation operations to use in subsequent hibernation transitions.
  76 */
  77void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  78{
 
 
  79	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  80	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  81	    && ops->restore_cleanup && ops->leave)) {
  82		WARN_ON(1);
  83		return;
  84	}
  85	lock_system_sleep();
 
 
  86	hibernation_ops = ops;
  87	if (ops)
  88		hibernation_mode = HIBERNATION_PLATFORM;
  89	else if (hibernation_mode == HIBERNATION_PLATFORM)
  90		hibernation_mode = HIBERNATION_SHUTDOWN;
  91
  92	unlock_system_sleep();
  93}
  94EXPORT_SYMBOL_GPL(hibernation_set_ops);
  95
  96static bool entering_platform_hibernation;
  97
  98bool system_entering_hibernation(void)
  99{
 100	return entering_platform_hibernation;
 101}
 102EXPORT_SYMBOL(system_entering_hibernation);
 103
 104#ifdef CONFIG_PM_DEBUG
 105static void hibernation_debug_sleep(void)
 106{
 107	printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
 108	mdelay(5000);
 109}
 110
 111static int hibernation_test(int level)
 112{
 113	if (pm_test_level == level) {
 114		hibernation_debug_sleep();
 115		return 1;
 116	}
 117	return 0;
 118}
 119#else /* !CONFIG_PM_DEBUG */
 120static int hibernation_test(int level) { return 0; }
 121#endif /* !CONFIG_PM_DEBUG */
 122
 123/**
 124 * platform_begin - Call platform to start hibernation.
 125 * @platform_mode: Whether or not to use the platform driver.
 126 */
 127static int platform_begin(int platform_mode)
 128{
 129	return (platform_mode && hibernation_ops) ?
 130		hibernation_ops->begin() : 0;
 131}
 132
 133/**
 134 * platform_end - Call platform to finish transition to the working state.
 135 * @platform_mode: Whether or not to use the platform driver.
 136 */
 137static void platform_end(int platform_mode)
 138{
 139	if (platform_mode && hibernation_ops)
 140		hibernation_ops->end();
 141}
 142
 143/**
 144 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 145 * @platform_mode: Whether or not to use the platform driver.
 146 *
 147 * Use the platform driver to prepare the system for creating a hibernate image,
 148 * if so configured, and return an error code if that fails.
 149 */
 150
 151static int platform_pre_snapshot(int platform_mode)
 152{
 153	return (platform_mode && hibernation_ops) ?
 154		hibernation_ops->pre_snapshot() : 0;
 155}
 156
 157/**
 158 * platform_leave - Call platform to prepare a transition to the working state.
 159 * @platform_mode: Whether or not to use the platform driver.
 160 *
 161 * Use the platform driver prepare to prepare the machine for switching to the
 162 * normal mode of operation.
 163 *
 164 * This routine is called on one CPU with interrupts disabled.
 165 */
 166static void platform_leave(int platform_mode)
 167{
 168	if (platform_mode && hibernation_ops)
 169		hibernation_ops->leave();
 170}
 171
 172/**
 173 * platform_finish - Call platform to switch the system to the working state.
 174 * @platform_mode: Whether or not to use the platform driver.
 175 *
 176 * Use the platform driver to switch the machine to the normal mode of
 177 * operation.
 178 *
 179 * This routine must be called after platform_prepare().
 180 */
 181static void platform_finish(int platform_mode)
 182{
 183	if (platform_mode && hibernation_ops)
 184		hibernation_ops->finish();
 185}
 186
 187/**
 188 * platform_pre_restore - Prepare for hibernate image restoration.
 189 * @platform_mode: Whether or not to use the platform driver.
 190 *
 191 * Use the platform driver to prepare the system for resume from a hibernation
 192 * image.
 193 *
 194 * If the restore fails after this function has been called,
 195 * platform_restore_cleanup() must be called.
 196 */
 197static int platform_pre_restore(int platform_mode)
 198{
 199	return (platform_mode && hibernation_ops) ?
 200		hibernation_ops->pre_restore() : 0;
 201}
 202
 203/**
 204 * platform_restore_cleanup - Switch to the working state after failing restore.
 205 * @platform_mode: Whether or not to use the platform driver.
 206 *
 207 * Use the platform driver to switch the system to the normal mode of operation
 208 * after a failing restore.
 209 *
 210 * If platform_pre_restore() has been called before the failing restore, this
 211 * function must be called too, regardless of the result of
 212 * platform_pre_restore().
 213 */
 214static void platform_restore_cleanup(int platform_mode)
 215{
 216	if (platform_mode && hibernation_ops)
 217		hibernation_ops->restore_cleanup();
 218}
 219
 220/**
 221 * platform_recover - Recover from a failure to suspend devices.
 222 * @platform_mode: Whether or not to use the platform driver.
 223 */
 224static void platform_recover(int platform_mode)
 225{
 226	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 227		hibernation_ops->recover();
 228}
 229
 230/**
 231 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 232 * @start: Starting event.
 233 * @stop: Final event.
 234 * @nr_pages: Number of memory pages processed between @start and @stop.
 235 * @msg: Additional diagnostic message to print.
 236 */
 237void swsusp_show_speed(ktime_t start, ktime_t stop,
 238		      unsigned nr_pages, char *msg)
 239{
 240	ktime_t diff;
 241	u64 elapsed_centisecs64;
 242	unsigned int centisecs;
 243	unsigned int k;
 244	unsigned int kps;
 245
 246	diff = ktime_sub(stop, start);
 247	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 248	centisecs = elapsed_centisecs64;
 249	if (centisecs == 0)
 250		centisecs = 1;	/* avoid div-by-zero */
 251	k = nr_pages * (PAGE_SIZE / 1024);
 252	kps = (k * 100) / centisecs;
 253	printk(KERN_INFO "PM: %s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 254			msg, k,
 255			centisecs / 100, centisecs % 100,
 256			kps / 1000, (kps % 1000) / 10);
 
 
 
 
 257}
 258
 259/**
 260 * create_image - Create a hibernation image.
 261 * @platform_mode: Whether or not to use the platform driver.
 262 *
 263 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 264 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 265 *
 266 * Control reappears in this routine after the subsequent restore.
 267 */
 268static int create_image(int platform_mode)
 269{
 270	int error;
 271
 272	error = dpm_suspend_end(PMSG_FREEZE);
 273	if (error) {
 274		printk(KERN_ERR "PM: Some devices failed to power down, "
 275			"aborting hibernation\n");
 276		return error;
 277	}
 278
 279	error = platform_pre_snapshot(platform_mode);
 280	if (error || hibernation_test(TEST_PLATFORM))
 281		goto Platform_finish;
 282
 283	error = disable_nonboot_cpus();
 284	if (error || hibernation_test(TEST_CPUS))
 285		goto Enable_cpus;
 286
 287	local_irq_disable();
 288
 
 
 289	error = syscore_suspend();
 290	if (error) {
 291		printk(KERN_ERR "PM: Some system devices failed to power down, "
 292			"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		printk(KERN_ERR "PM: Error %d creating hibernation image\n",
 308			error);
 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		printk(KERN_ERR "PM: Some devices failed to power down, "
 436			"aborting resume\n");
 437		return error;
 438	}
 439
 440	error = platform_pre_restore(platform_mode);
 441	if (error)
 442		goto Cleanup;
 443
 
 
 444	error = hibernate_resume_nonboot_cpu_disable();
 445	if (error)
 446		goto Enable_cpus;
 447
 448	local_irq_disable();
 
 449
 450	error = syscore_suspend();
 451	if (error)
 452		goto Enable_irqs;
 453
 454	save_processor_state();
 455	error = restore_highmem();
 456	if (!error) {
 457		error = swsusp_arch_resume();
 458		/*
 459		 * The code below is only ever reached in case of a failure.
 460		 * Otherwise, execution continues at the place where
 461		 * swsusp_arch_suspend() was called.
 462		 */
 463		BUG_ON(!error);
 464		/*
 465		 * This call to restore_highmem() reverts the changes made by
 466		 * the previous one.
 467		 */
 468		restore_highmem();
 469	}
 470	/*
 471	 * The only reason why swsusp_arch_resume() can fail is memory being
 472	 * very tight, so we have to free it as soon as we can to avoid
 473	 * subsequent failures.
 474	 */
 475	swsusp_free();
 476	restore_processor_state();
 477	touch_softlockup_watchdog();
 478
 479	syscore_resume();
 480
 481 Enable_irqs:
 
 482	local_irq_enable();
 483
 484 Enable_cpus:
 485	enable_nonboot_cpus();
 486
 487 Cleanup:
 488	platform_restore_cleanup(platform_mode);
 489
 490	dpm_resume_start(PMSG_RECOVER);
 491
 492	return error;
 493}
 494
 495/**
 496 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 497 * @platform_mode: If set, use platform driver to prepare for the transition.
 498 *
 499 * This routine must be called with pm_mutex held.  If it is successful, control
 500 * reappears in the restored target kernel in hibernation_snapshot().
 
 501 */
 502int hibernation_restore(int platform_mode)
 503{
 504	int error;
 505
 506	pm_prepare_console();
 507	suspend_console();
 508	pm_restrict_gfp_mask();
 509	error = dpm_suspend_start(PMSG_QUIESCE);
 510	if (!error) {
 511		error = resume_target_kernel(platform_mode);
 512		/*
 513		 * The above should either succeed and jump to the new kernel,
 514		 * or return with an error. Otherwise things are just
 515		 * undefined, so let's be paranoid.
 516		 */
 517		BUG_ON(!error);
 518	}
 519	dpm_resume_end(PMSG_RECOVER);
 520	pm_restore_gfp_mask();
 521	resume_console();
 522	pm_restore_console();
 523	return error;
 524}
 525
 526/**
 527 * hibernation_platform_enter - Power off the system using the platform driver.
 528 */
 529int hibernation_platform_enter(void)
 530{
 531	int error;
 532
 533	if (!hibernation_ops)
 534		return -ENOSYS;
 535
 536	/*
 537	 * We have cancelled the power transition by running
 538	 * hibernation_ops->finish() before saving the image, so we should let
 539	 * the firmware know that we're going to enter the sleep state after all
 540	 */
 541	error = hibernation_ops->begin();
 542	if (error)
 543		goto Close;
 544
 545	entering_platform_hibernation = true;
 546	suspend_console();
 547	error = dpm_suspend_start(PMSG_HIBERNATE);
 548	if (error) {
 549		if (hibernation_ops->recover)
 550			hibernation_ops->recover();
 551		goto Resume_devices;
 552	}
 553
 554	error = dpm_suspend_end(PMSG_HIBERNATE);
 555	if (error)
 556		goto Resume_devices;
 557
 558	error = hibernation_ops->prepare();
 559	if (error)
 560		goto Platform_finish;
 561
 562	error = disable_nonboot_cpus();
 563	if (error)
 564		goto Enable_cpus;
 565
 566	local_irq_disable();
 
 567	syscore_suspend();
 568	if (pm_wakeup_pending()) {
 569		error = -EAGAIN;
 570		goto Power_up;
 571	}
 572
 573	hibernation_ops->enter();
 574	/* We should never get here */
 575	while (1);
 576
 577 Power_up:
 578	syscore_resume();
 
 579	local_irq_enable();
 580
 581 Enable_cpus:
 582	enable_nonboot_cpus();
 583
 584 Platform_finish:
 585	hibernation_ops->finish();
 586
 587	dpm_resume_start(PMSG_RESTORE);
 588
 589 Resume_devices:
 590	entering_platform_hibernation = false;
 591	dpm_resume_end(PMSG_RESTORE);
 592	resume_console();
 593
 594 Close:
 595	hibernation_ops->end();
 596
 597	return error;
 598}
 599
 600/**
 601 * power_down - Shut the machine down for hibernation.
 602 *
 603 * Use the platform driver, if configured, to put the system into the sleep
 604 * state corresponding to hibernation, or try to power it off or reboot,
 605 * depending on the value of hibernation_mode.
 606 */
 607static void power_down(void)
 608{
 609#ifdef CONFIG_SUSPEND
 610	int error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 611#endif
 612
 613	switch (hibernation_mode) {
 614	case HIBERNATION_REBOOT:
 615		kernel_restart(NULL);
 616		break;
 617	case HIBERNATION_PLATFORM:
 618		hibernation_platform_enter();
 
 
 
 
 
 
 
 619	case HIBERNATION_SHUTDOWN:
 620		if (pm_power_off)
 621			kernel_power_off();
 622		break;
 623#ifdef CONFIG_SUSPEND
 624	case HIBERNATION_SUSPEND:
 625		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 626		if (error) {
 627			if (hibernation_ops)
 628				hibernation_mode = HIBERNATION_PLATFORM;
 629			else
 630				hibernation_mode = HIBERNATION_SHUTDOWN;
 631			power_down();
 632		}
 633		/*
 634		 * Restore swap signature.
 635		 */
 636		error = swsusp_unmark();
 637		if (error)
 638			printk(KERN_ERR "PM: Swap will be unusable! "
 639			                "Try swapon -a.\n");
 640		return;
 641#endif
 642	}
 643	kernel_halt();
 644	/*
 645	 * Valid image is on the disk, if we continue we risk serious data
 646	 * corruption after resume.
 647	 */
 648	printk(KERN_CRIT "PM: Please power down manually\n");
 649	while (1)
 650		cpu_relax();
 651}
 652
 653static int load_image_and_restore(void)
 654{
 655	int error;
 656	unsigned int flags;
 657
 658	pr_debug("PM: Loading hibernation image.\n");
 659
 660	lock_device_hotplug();
 661	error = create_basic_memory_bitmaps();
 662	if (error)
 
 663		goto Unlock;
 
 664
 665	error = swsusp_read(&flags);
 666	swsusp_close(FMODE_READ);
 667	if (!error)
 668		hibernation_restore(flags & SF_PLATFORM_MODE);
 669
 670	printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
 671	swsusp_free();
 672	free_basic_memory_bitmaps();
 673 Unlock:
 674	unlock_device_hotplug();
 675
 676	return error;
 677}
 678
 
 
 
 679/**
 680 * hibernate - Carry out system hibernation, including saving the image.
 681 */
 682int hibernate(void)
 683{
 684	int error, nr_calls = 0;
 685	bool snapshot_test = false;
 
 
 686
 687	if (!hibernation_available()) {
 688		pr_debug("PM: Hibernation not available.\n");
 689		return -EPERM;
 690	}
 691
 692	lock_system_sleep();
 
 
 
 
 
 
 
 
 
 
 
 693	/* The snapshot device should not be opened while we're running */
 694	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 695		error = -EBUSY;
 696		goto Unlock;
 697	}
 698
 
 699	pm_prepare_console();
 700	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 701	if (error) {
 702		nr_calls--;
 703		goto Exit;
 704	}
 705
 706	printk(KERN_INFO "PM: Syncing filesystems ... ");
 707	sys_sync();
 708	printk("done.\n");
 709
 710	error = freeze_processes();
 711	if (error)
 712		goto Exit;
 713
 714	lock_device_hotplug();
 715	/* Allocate memory management structures */
 716	error = create_basic_memory_bitmaps();
 717	if (error)
 718		goto Thaw;
 719
 720	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 721	if (error || freezer_test_done)
 722		goto Free_bitmaps;
 723
 724	if (in_suspend) {
 725		unsigned int flags = 0;
 726
 727		if (hibernation_mode == HIBERNATION_PLATFORM)
 728			flags |= SF_PLATFORM_MODE;
 729		if (nocompress)
 730			flags |= SF_NOCOMPRESS_MODE;
 731		else
 732		        flags |= SF_CRC32_MODE;
 733
 734		pr_debug("PM: writing image.\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 735		error = swsusp_write(flags);
 736		swsusp_free();
 737		if (!error) {
 738			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 739				snapshot_test = true;
 740			else
 741				power_down();
 742		}
 743		in_suspend = 0;
 744		pm_restore_gfp_mask();
 745	} else {
 746		pr_debug("PM: Image restored successfully.\n");
 747	}
 748
 749 Free_bitmaps:
 750	free_basic_memory_bitmaps();
 751 Thaw:
 752	unlock_device_hotplug();
 753	if (snapshot_test) {
 754		pr_debug("PM: Checking hibernation image\n");
 755		error = swsusp_check();
 756		if (!error)
 757			error = load_image_and_restore();
 758	}
 759	thaw_processes();
 760
 761	/* Don't bother checking whether freezer_test_done is true */
 762	freezer_test_done = false;
 763 Exit:
 764	__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 
 765	pm_restore_console();
 766	atomic_inc(&snapshot_device_available);
 767 Unlock:
 768	unlock_system_sleep();
 
 
 769	return error;
 770}
 771
 772
 773/**
 774 * software_resume - Resume from a saved hibernation image.
 775 *
 776 * This routine is called as a late initcall, when all devices have been
 777 * discovered and initialized already.
 778 *
 779 * The image reading code is called to see if there is a hibernation image
 780 * available for reading.  If that is the case, devices are quiesced and the
 781 * contents of memory is restored from the saved image.
 782 *
 783 * If this is successful, control reappears in the restored target kernel in
 784 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 785 * attempts to recover gracefully and make the kernel return to the normal mode
 786 * of operation.
 787 */
 788static int software_resume(void)
 789{
 790	int error, nr_calls = 0;
 
 791
 792	/*
 793	 * If the user said "noresume".. bail out early.
 794	 */
 795	if (noresume || !hibernation_available())
 796		return 0;
 797
 798	/*
 799	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 800	 * is configured into the kernel. Since the regular hibernate
 801	 * trigger path is via sysfs which takes a buffer mutex before
 802	 * calling hibernate functions (which take pm_mutex) this can
 803	 * cause lockdep to complain about a possible ABBA deadlock
 804	 * which cannot happen since we're in the boot code here and
 805	 * sysfs can't be invoked yet. Therefore, we use a subclass
 806	 * here to avoid lockdep complaining.
 807	 */
 808	mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
 809
 810	if (swsusp_resume_device)
 811		goto Check_image;
 812
 813	if (!strlen(resume_file)) {
 814		error = -ENOENT;
 815		goto Unlock;
 816	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 817
 818	pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 819
 820	if (resume_delay) {
 821		printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
 822			resume_delay);
 823		ssleep(resume_delay);
 824	}
 825
 826	/* Check if the device is there */
 827	swsusp_resume_device = name_to_dev_t(resume_file);
 
 828
 829	/*
 830	 * name_to_dev_t is ineffective to verify parition if resume_file is in
 831	 * integer format. (e.g. major:minor)
 832	 */
 833	if (isdigit(resume_file[0]) && resume_wait) {
 834		int partno;
 835		while (!get_gendisk(swsusp_resume_device, &partno))
 836			msleep(10);
 
 837	}
 838
 839	if (!swsusp_resume_device) {
 840		/*
 841		 * Some device discovery might still be in progress; we need
 842		 * to wait for this to finish.
 843		 */
 844		wait_for_device_probe();
 845
 846		if (resume_wait) {
 847			while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 848				msleep(10);
 849			async_synchronize_full();
 850		}
 851
 852		swsusp_resume_device = name_to_dev_t(resume_file);
 853		if (!swsusp_resume_device) {
 854			error = -ENODEV;
 855			goto Unlock;
 856		}
 857	}
 858
 859 Check_image:
 860	pr_debug("PM: Hibernation image partition %d:%d present\n",
 861		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 862
 863	pr_debug("PM: Looking for hibernation image.\n");
 864	error = swsusp_check();
 
 
 865	if (error)
 866		goto Unlock;
 867
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 868	/* The snapshot device should not be opened while we're running */
 869	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 870		error = -EBUSY;
 871		swsusp_close(FMODE_READ);
 872		goto Unlock;
 873	}
 874
 
 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	pr_debug("PM: 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	atomic_inc(&snapshot_device_available);
 
 892	/* For success case, the suspend path will release the lock */
 893 Unlock:
 894	mutex_unlock(&pm_mutex);
 895	pr_debug("PM: Hibernation image not present or could not be loaded.\n");
 896	return error;
 897 Close_Finish:
 898	swsusp_close(FMODE_READ);
 899	goto Finish;
 900}
 901
 902late_initcall_sync(software_resume);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 903
 904
 905static const char * const hibernation_modes[] = {
 906	[HIBERNATION_PLATFORM]	= "platform",
 907	[HIBERNATION_SHUTDOWN]	= "shutdown",
 908	[HIBERNATION_REBOOT]	= "reboot",
 909#ifdef CONFIG_SUSPEND
 910	[HIBERNATION_SUSPEND]	= "suspend",
 911#endif
 912	[HIBERNATION_TEST_RESUME]	= "test_resume",
 913};
 914
 915/*
 916 * /sys/power/disk - Control hibernation mode.
 917 *
 918 * Hibernation can be handled in several ways.  There are a few different ways
 919 * to put the system into the sleep state: using the platform driver (e.g. ACPI
 920 * or other hibernation_ops), powering it off or rebooting it (for testing
 921 * mostly).
 922 *
 923 * The sysfs file /sys/power/disk provides an interface for selecting the
 924 * hibernation mode to use.  Reading from this file causes the available modes
 925 * to be printed.  There are 3 modes that can be supported:
 926 *
 927 *	'platform'
 928 *	'shutdown'
 929 *	'reboot'
 930 *
 931 * If a platform hibernation driver is in use, 'platform' will be supported
 932 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
 933 * The selected option (i.e. the one corresponding to the current value of
 934 * hibernation_mode) is enclosed by a square bracket.
 935 *
 936 * To select a given hibernation mode it is necessary to write the mode's
 937 * string representation (as returned by reading from /sys/power/disk) back
 938 * into /sys/power/disk.
 939 */
 940
 941static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 942			 char *buf)
 943{
 944	int i;
 945	char *start = buf;
 946
 947	if (!hibernation_available())
 948		return sprintf(buf, "[disabled]\n");
 949
 950	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 951		if (!hibernation_modes[i])
 952			continue;
 953		switch (i) {
 954		case HIBERNATION_SHUTDOWN:
 955		case HIBERNATION_REBOOT:
 956#ifdef CONFIG_SUSPEND
 957		case HIBERNATION_SUSPEND:
 958#endif
 959		case HIBERNATION_TEST_RESUME:
 960			break;
 961		case HIBERNATION_PLATFORM:
 962			if (hibernation_ops)
 963				break;
 964			/* not a valid mode, continue with loop */
 965			continue;
 966		}
 967		if (i == hibernation_mode)
 968			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
 969		else
 970			buf += sprintf(buf, "%s ", hibernation_modes[i]);
 971	}
 972	buf += sprintf(buf, "\n");
 973	return buf-start;
 974}
 975
 976static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 977			  const char *buf, size_t n)
 978{
 
 
 979	int error = 0;
 980	int i;
 981	int len;
 982	char *p;
 983	int mode = HIBERNATION_INVALID;
 984
 985	if (!hibernation_available())
 986		return -EPERM;
 987
 988	p = memchr(buf, '\n', n);
 989	len = p ? p - buf : n;
 990
 991	lock_system_sleep();
 992	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 993		if (len == strlen(hibernation_modes[i])
 994		    && !strncmp(buf, hibernation_modes[i], len)) {
 995			mode = i;
 996			break;
 997		}
 998	}
 999	if (mode != HIBERNATION_INVALID) {
1000		switch (mode) {
1001		case HIBERNATION_SHUTDOWN:
1002		case HIBERNATION_REBOOT:
1003#ifdef CONFIG_SUSPEND
1004		case HIBERNATION_SUSPEND:
1005#endif
1006		case HIBERNATION_TEST_RESUME:
1007			hibernation_mode = mode;
1008			break;
1009		case HIBERNATION_PLATFORM:
1010			if (hibernation_ops)
1011				hibernation_mode = mode;
1012			else
1013				error = -EINVAL;
1014		}
1015	} else
1016		error = -EINVAL;
1017
1018	if (!error)
1019		pr_debug("PM: Hibernation mode set to '%s'\n",
1020			 hibernation_modes[mode]);
1021	unlock_system_sleep();
1022	return error ? error : n;
1023}
1024
1025power_attr(disk);
1026
1027static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1028			   char *buf)
1029{
1030	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
1031		       MINOR(swsusp_resume_device));
1032}
1033
1034static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1035			    const char *buf, size_t n)
1036{
1037	dev_t res;
1038	int len = n;
1039	char *name;
 
 
 
 
 
1040
1041	if (len && buf[len-1] == '\n')
1042		len--;
1043	name = kstrndup(buf, len, GFP_KERNEL);
1044	if (!name)
1045		return -ENOMEM;
1046
1047	res = name_to_dev_t(name);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1048	kfree(name);
1049	if (!res)
1050		return -EINVAL;
1051
1052	lock_system_sleep();
1053	swsusp_resume_device = res;
1054	unlock_system_sleep();
1055	printk(KERN_INFO "PM: Starting manual resume from disk\n");
 
 
1056	noresume = 0;
1057	software_resume();
1058	return n;
1059}
1060
1061power_attr(resume);
1062
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1063static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1064			       char *buf)
1065{
1066	return sprintf(buf, "%lu\n", image_size);
1067}
1068
1069static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1070				const char *buf, size_t n)
1071{
1072	unsigned long size;
1073
1074	if (sscanf(buf, "%lu", &size) == 1) {
1075		image_size = size;
1076		return n;
1077	}
1078
1079	return -EINVAL;
1080}
1081
1082power_attr(image_size);
1083
1084static ssize_t reserved_size_show(struct kobject *kobj,
1085				  struct kobj_attribute *attr, char *buf)
1086{
1087	return sprintf(buf, "%lu\n", reserved_size);
1088}
1089
1090static ssize_t reserved_size_store(struct kobject *kobj,
1091				   struct kobj_attribute *attr,
1092				   const char *buf, size_t n)
1093{
1094	unsigned long size;
1095
1096	if (sscanf(buf, "%lu", &size) == 1) {
1097		reserved_size = size;
1098		return n;
1099	}
1100
1101	return -EINVAL;
1102}
1103
1104power_attr(reserved_size);
1105
1106static struct attribute * g[] = {
1107	&disk_attr.attr,
 
1108	&resume_attr.attr,
1109	&image_size_attr.attr,
1110	&reserved_size_attr.attr,
1111	NULL,
1112};
1113
1114
1115static struct attribute_group attr_group = {
1116	.attrs = g,
1117};
1118
1119
1120static int __init pm_disk_init(void)
1121{
1122	return sysfs_create_group(power_kobj, &attr_group);
1123}
1124
1125core_initcall(pm_disk_init);
1126
1127
1128static int __init resume_setup(char *str)
1129{
1130	if (noresume)
1131		return 1;
1132
1133	strncpy( resume_file, str, 255 );
1134	return 1;
1135}
1136
1137static int __init resume_offset_setup(char *str)
1138{
1139	unsigned long long offset;
1140
1141	if (noresume)
1142		return 1;
1143
1144	if (sscanf(str, "%llu", &offset) == 1)
1145		swsusp_resume_block = offset;
1146
1147	return 1;
1148}
1149
1150static int __init hibernate_setup(char *str)
1151{
1152	if (!strncmp(str, "noresume", 8)) {
1153		noresume = 1;
1154	} else if (!strncmp(str, "nocompress", 10)) {
1155		nocompress = 1;
1156	} else if (!strncmp(str, "no", 2)) {
1157		noresume = 1;
1158		nohibernate = 1;
1159	} else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
1160		   && !strncmp(str, "protect_image", 13)) {
1161		enable_restore_image_protection();
1162	}
1163	return 1;
1164}
1165
1166static int __init noresume_setup(char *str)
1167{
1168	noresume = 1;
1169	return 1;
1170}
1171
1172static int __init resumewait_setup(char *str)
1173{
1174	resume_wait = 1;
1175	return 1;
1176}
1177
1178static int __init resumedelay_setup(char *str)
1179{
1180	int rc = kstrtouint(str, 0, &resume_delay);
1181
1182	if (rc)
1183		return rc;
1184	return 1;
1185}
1186
1187static int __init nohibernate_setup(char *str)
1188{
1189	noresume = 1;
1190	nohibernate = 1;
1191	return 1;
1192}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1193
1194__setup("noresume", noresume_setup);
1195__setup("resume_offset=", resume_offset_setup);
1196__setup("resume=", resume_setup);
1197__setup("hibernate=", hibernate_setup);
1198__setup("resumewait", resumewait_setup);
1199__setup("resumedelay=", resumedelay_setup);
1200__setup("nohibernate", nohibernate_setup);
v6.9.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
   4 *
   5 * Copyright (c) 2003 Patrick Mochel
   6 * Copyright (c) 2003 Open Source Development Lab
   7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
   8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
   9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
 
 
  10 */
  11
  12#define pr_fmt(fmt) "PM: hibernation: " fmt
  13
  14#include <linux/blkdev.h>
  15#include <linux/export.h>
  16#include <linux/suspend.h>
 
  17#include <linux/reboot.h>
  18#include <linux/string.h>
  19#include <linux/device.h>
  20#include <linux/async.h>
  21#include <linux/delay.h>
  22#include <linux/fs.h>
  23#include <linux/mount.h>
  24#include <linux/pm.h>
  25#include <linux/nmi.h>
  26#include <linux/console.h>
  27#include <linux/cpu.h>
  28#include <linux/freezer.h>
  29#include <linux/gfp.h>
  30#include <linux/syscore_ops.h>
  31#include <linux/ctype.h>
 
  32#include <linux/ktime.h>
  33#include <linux/security.h>
  34#include <linux/secretmem.h>
  35#include <trace/events/power.h>
  36
  37#include "power.h"
  38
  39
  40static int nocompress;
  41static int noresume;
  42static int nohibernate;
  43static int resume_wait;
  44static unsigned int resume_delay;
  45static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  46dev_t swsusp_resume_device;
  47sector_t swsusp_resume_block;
  48__visible int in_suspend __nosavedata;
  49
  50static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
  51
  52/*
  53 * Compression/decompression algorithm to be used while saving/loading
  54 * image to/from disk. This would later be used in 'kernel/power/swap.c'
  55 * to allocate comp streams.
  56 */
  57char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
  58
  59enum {
  60	HIBERNATION_INVALID,
  61	HIBERNATION_PLATFORM,
  62	HIBERNATION_SHUTDOWN,
  63	HIBERNATION_REBOOT,
  64#ifdef CONFIG_SUSPEND
  65	HIBERNATION_SUSPEND,
  66#endif
  67	HIBERNATION_TEST_RESUME,
  68	/* keep last */
  69	__HIBERNATION_AFTER_LAST
  70};
  71#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  72#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  73
  74static int hibernation_mode = HIBERNATION_SHUTDOWN;
  75
  76bool freezer_test_done;
  77
  78static const struct platform_hibernation_ops *hibernation_ops;
  79
  80static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  81
  82bool hibernate_acquire(void)
  83{
  84	return atomic_add_unless(&hibernate_atomic, -1, 0);
  85}
  86
  87void hibernate_release(void)
  88{
  89	atomic_inc(&hibernate_atomic);
  90}
  91
  92bool hibernation_available(void)
  93{
  94	return nohibernate == 0 &&
  95		!security_locked_down(LOCKDOWN_HIBERNATION) &&
  96		!secretmem_active() && !cxl_mem_active();
  97}
  98
  99/**
 100 * hibernation_set_ops - Set the global hibernate operations.
 101 * @ops: Hibernation operations to use in subsequent hibernation transitions.
 102 */
 103void hibernation_set_ops(const struct platform_hibernation_ops *ops)
 104{
 105	unsigned int sleep_flags;
 106
 107	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
 108	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
 109	    && ops->restore_cleanup && ops->leave)) {
 110		WARN_ON(1);
 111		return;
 112	}
 113
 114	sleep_flags = lock_system_sleep();
 115
 116	hibernation_ops = ops;
 117	if (ops)
 118		hibernation_mode = HIBERNATION_PLATFORM;
 119	else if (hibernation_mode == HIBERNATION_PLATFORM)
 120		hibernation_mode = HIBERNATION_SHUTDOWN;
 121
 122	unlock_system_sleep(sleep_flags);
 123}
 124EXPORT_SYMBOL_GPL(hibernation_set_ops);
 125
 126static bool entering_platform_hibernation;
 127
 128bool system_entering_hibernation(void)
 129{
 130	return entering_platform_hibernation;
 131}
 132EXPORT_SYMBOL(system_entering_hibernation);
 133
 134#ifdef CONFIG_PM_DEBUG
 135static void hibernation_debug_sleep(void)
 136{
 137	pr_info("debug: Waiting for 5 seconds.\n");
 138	mdelay(5000);
 139}
 140
 141static int hibernation_test(int level)
 142{
 143	if (pm_test_level == level) {
 144		hibernation_debug_sleep();
 145		return 1;
 146	}
 147	return 0;
 148}
 149#else /* !CONFIG_PM_DEBUG */
 150static int hibernation_test(int level) { return 0; }
 151#endif /* !CONFIG_PM_DEBUG */
 152
 153/**
 154 * platform_begin - Call platform to start hibernation.
 155 * @platform_mode: Whether or not to use the platform driver.
 156 */
 157static int platform_begin(int platform_mode)
 158{
 159	return (platform_mode && hibernation_ops) ?
 160		hibernation_ops->begin(PMSG_FREEZE) : 0;
 161}
 162
 163/**
 164 * platform_end - Call platform to finish transition to the working state.
 165 * @platform_mode: Whether or not to use the platform driver.
 166 */
 167static void platform_end(int platform_mode)
 168{
 169	if (platform_mode && hibernation_ops)
 170		hibernation_ops->end();
 171}
 172
 173/**
 174 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 175 * @platform_mode: Whether or not to use the platform driver.
 176 *
 177 * Use the platform driver to prepare the system for creating a hibernate image,
 178 * if so configured, and return an error code if that fails.
 179 */
 180
 181static int platform_pre_snapshot(int platform_mode)
 182{
 183	return (platform_mode && hibernation_ops) ?
 184		hibernation_ops->pre_snapshot() : 0;
 185}
 186
 187/**
 188 * platform_leave - Call platform to prepare a transition to the working state.
 189 * @platform_mode: Whether or not to use the platform driver.
 190 *
 191 * Use the platform driver prepare to prepare the machine for switching to the
 192 * normal mode of operation.
 193 *
 194 * This routine is called on one CPU with interrupts disabled.
 195 */
 196static void platform_leave(int platform_mode)
 197{
 198	if (platform_mode && hibernation_ops)
 199		hibernation_ops->leave();
 200}
 201
 202/**
 203 * platform_finish - Call platform to switch the system to the working state.
 204 * @platform_mode: Whether or not to use the platform driver.
 205 *
 206 * Use the platform driver to switch the machine to the normal mode of
 207 * operation.
 208 *
 209 * This routine must be called after platform_prepare().
 210 */
 211static void platform_finish(int platform_mode)
 212{
 213	if (platform_mode && hibernation_ops)
 214		hibernation_ops->finish();
 215}
 216
 217/**
 218 * platform_pre_restore - Prepare for hibernate image restoration.
 219 * @platform_mode: Whether or not to use the platform driver.
 220 *
 221 * Use the platform driver to prepare the system for resume from a hibernation
 222 * image.
 223 *
 224 * If the restore fails after this function has been called,
 225 * platform_restore_cleanup() must be called.
 226 */
 227static int platform_pre_restore(int platform_mode)
 228{
 229	return (platform_mode && hibernation_ops) ?
 230		hibernation_ops->pre_restore() : 0;
 231}
 232
 233/**
 234 * platform_restore_cleanup - Switch to the working state after failing restore.
 235 * @platform_mode: Whether or not to use the platform driver.
 236 *
 237 * Use the platform driver to switch the system to the normal mode of operation
 238 * after a failing restore.
 239 *
 240 * If platform_pre_restore() has been called before the failing restore, this
 241 * function must be called too, regardless of the result of
 242 * platform_pre_restore().
 243 */
 244static void platform_restore_cleanup(int platform_mode)
 245{
 246	if (platform_mode && hibernation_ops)
 247		hibernation_ops->restore_cleanup();
 248}
 249
 250/**
 251 * platform_recover - Recover from a failure to suspend devices.
 252 * @platform_mode: Whether or not to use the platform driver.
 253 */
 254static void platform_recover(int platform_mode)
 255{
 256	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 257		hibernation_ops->recover();
 258}
 259
 260/**
 261 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 262 * @start: Starting event.
 263 * @stop: Final event.
 264 * @nr_pages: Number of memory pages processed between @start and @stop.
 265 * @msg: Additional diagnostic message to print.
 266 */
 267void swsusp_show_speed(ktime_t start, ktime_t stop,
 268		      unsigned nr_pages, char *msg)
 269{
 270	ktime_t diff;
 271	u64 elapsed_centisecs64;
 272	unsigned int centisecs;
 273	unsigned int k;
 274	unsigned int kps;
 275
 276	diff = ktime_sub(stop, start);
 277	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 278	centisecs = elapsed_centisecs64;
 279	if (centisecs == 0)
 280		centisecs = 1;	/* avoid div-by-zero */
 281	k = nr_pages * (PAGE_SIZE / 1024);
 282	kps = (k * 100) / centisecs;
 283	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 284		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 285		(kps % 1000) / 10);
 286}
 287
 288__weak int arch_resume_nosmt(void)
 289{
 290	return 0;
 291}
 292
 293/**
 294 * create_image - Create a hibernation image.
 295 * @platform_mode: Whether or not to use the platform driver.
 296 *
 297 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 298 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 299 *
 300 * Control reappears in this routine after the subsequent restore.
 301 */
 302static int create_image(int platform_mode)
 303{
 304	int error;
 305
 306	error = dpm_suspend_end(PMSG_FREEZE);
 307	if (error) {
 308		pr_err("Some devices failed to power down, aborting\n");
 
 309		return error;
 310	}
 311
 312	error = platform_pre_snapshot(platform_mode);
 313	if (error || hibernation_test(TEST_PLATFORM))
 314		goto Platform_finish;
 315
 316	error = pm_sleep_disable_secondary_cpus();
 317	if (error || hibernation_test(TEST_CPUS))
 318		goto Enable_cpus;
 319
 320	local_irq_disable();
 321
 322	system_state = SYSTEM_SUSPEND;
 323
 324	error = syscore_suspend();
 325	if (error) {
 326		pr_err("Some system devices failed to power down, aborting\n");
 
 327		goto Enable_irqs;
 328	}
 329
 330	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 331		goto Power_up;
 332
 333	in_suspend = 1;
 334	save_processor_state();
 335	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 336	error = swsusp_arch_suspend();
 337	/* Restore control flow magically appears here */
 338	restore_processor_state();
 339	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 340	if (error)
 341		pr_err("Error %d creating image\n", error);
 342
 343	if (!in_suspend) {
 344		events_check_enabled = false;
 345		clear_or_poison_free_pages();
 346	}
 347
 348	platform_leave(platform_mode);
 349
 350 Power_up:
 351	syscore_resume();
 352
 353 Enable_irqs:
 354	system_state = SYSTEM_RUNNING;
 355	local_irq_enable();
 356
 357 Enable_cpus:
 358	pm_sleep_enable_secondary_cpus();
 359
 360	/* Allow architectures to do nosmt-specific post-resume dances */
 361	if (!in_suspend)
 362		error = arch_resume_nosmt();
 363
 364 Platform_finish:
 365	platform_finish(platform_mode);
 366
 367	dpm_resume_start(in_suspend ?
 368		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 369
 370	return error;
 371}
 372
 373/**
 374 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 375 * @platform_mode: If set, use platform driver to prepare for the transition.
 376 *
 377 * This routine must be called with system_transition_mutex held.
 378 */
 379int hibernation_snapshot(int platform_mode)
 380{
 381	pm_message_t msg;
 382	int error;
 383
 384	pm_suspend_clear_flags();
 385	error = platform_begin(platform_mode);
 386	if (error)
 387		goto Close;
 388
 389	/* Preallocate image memory before shutting down devices. */
 390	error = hibernate_preallocate_memory();
 391	if (error)
 392		goto Close;
 393
 394	error = freeze_kernel_threads();
 395	if (error)
 396		goto Cleanup;
 397
 398	if (hibernation_test(TEST_FREEZER)) {
 399
 400		/*
 401		 * Indicate to the caller that we are returning due to a
 402		 * successful freezer test.
 403		 */
 404		freezer_test_done = true;
 405		goto Thaw;
 406	}
 407
 408	error = dpm_prepare(PMSG_FREEZE);
 409	if (error) {
 410		dpm_complete(PMSG_RECOVER);
 411		goto Thaw;
 412	}
 413
 414	suspend_console();
 415	pm_restrict_gfp_mask();
 416
 417	error = dpm_suspend(PMSG_FREEZE);
 418
 419	if (error || hibernation_test(TEST_DEVICES))
 420		platform_recover(platform_mode);
 421	else
 422		error = create_image(platform_mode);
 423
 424	/*
 425	 * In the case that we call create_image() above, the control
 426	 * returns here (1) after the image has been created or the
 427	 * image creation has failed and (2) after a successful restore.
 428	 */
 429
 430	/* We may need to release the preallocated image pages here. */
 431	if (error || !in_suspend)
 432		swsusp_free();
 433
 434	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 435	dpm_resume(msg);
 436
 437	if (error || !in_suspend)
 438		pm_restore_gfp_mask();
 439
 440	resume_console();
 441	dpm_complete(msg);
 442
 443 Close:
 444	platform_end(platform_mode);
 445	return error;
 446
 447 Thaw:
 448	thaw_kernel_threads();
 449 Cleanup:
 450	swsusp_free();
 451	goto Close;
 452}
 453
 454int __weak hibernate_resume_nonboot_cpu_disable(void)
 455{
 456	return suspend_disable_secondary_cpus();
 457}
 458
 459/**
 460 * resume_target_kernel - Restore system state from a hibernation image.
 461 * @platform_mode: Whether or not to use the platform driver.
 462 *
 463 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 464 * contents of highmem that have not been restored yet from the image and run
 465 * the low-level code that will restore the remaining contents of memory and
 466 * switch to the just restored target kernel.
 467 */
 468static int resume_target_kernel(bool platform_mode)
 469{
 470	int error;
 471
 472	error = dpm_suspend_end(PMSG_QUIESCE);
 473	if (error) {
 474		pr_err("Some devices failed to power down, aborting resume\n");
 
 475		return error;
 476	}
 477
 478	error = platform_pre_restore(platform_mode);
 479	if (error)
 480		goto Cleanup;
 481
 482	cpuidle_pause();
 483
 484	error = hibernate_resume_nonboot_cpu_disable();
 485	if (error)
 486		goto Enable_cpus;
 487
 488	local_irq_disable();
 489	system_state = SYSTEM_SUSPEND;
 490
 491	error = syscore_suspend();
 492	if (error)
 493		goto Enable_irqs;
 494
 495	save_processor_state();
 496	error = restore_highmem();
 497	if (!error) {
 498		error = swsusp_arch_resume();
 499		/*
 500		 * The code below is only ever reached in case of a failure.
 501		 * Otherwise, execution continues at the place where
 502		 * swsusp_arch_suspend() was called.
 503		 */
 504		BUG_ON(!error);
 505		/*
 506		 * This call to restore_highmem() reverts the changes made by
 507		 * the previous one.
 508		 */
 509		restore_highmem();
 510	}
 511	/*
 512	 * The only reason why swsusp_arch_resume() can fail is memory being
 513	 * very tight, so we have to free it as soon as we can to avoid
 514	 * subsequent failures.
 515	 */
 516	swsusp_free();
 517	restore_processor_state();
 518	touch_softlockup_watchdog();
 519
 520	syscore_resume();
 521
 522 Enable_irqs:
 523	system_state = SYSTEM_RUNNING;
 524	local_irq_enable();
 525
 526 Enable_cpus:
 527	pm_sleep_enable_secondary_cpus();
 528
 529 Cleanup:
 530	platform_restore_cleanup(platform_mode);
 531
 532	dpm_resume_start(PMSG_RECOVER);
 533
 534	return error;
 535}
 536
 537/**
 538 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 539 * @platform_mode: If set, use platform driver to prepare for the transition.
 540 *
 541 * This routine must be called with system_transition_mutex held.  If it is
 542 * successful, control reappears in the restored target kernel in
 543 * hibernation_snapshot().
 544 */
 545int hibernation_restore(int platform_mode)
 546{
 547	int error;
 548
 549	pm_prepare_console();
 550	suspend_console();
 551	pm_restrict_gfp_mask();
 552	error = dpm_suspend_start(PMSG_QUIESCE);
 553	if (!error) {
 554		error = resume_target_kernel(platform_mode);
 555		/*
 556		 * The above should either succeed and jump to the new kernel,
 557		 * or return with an error. Otherwise things are just
 558		 * undefined, so let's be paranoid.
 559		 */
 560		BUG_ON(!error);
 561	}
 562	dpm_resume_end(PMSG_RECOVER);
 563	pm_restore_gfp_mask();
 564	resume_console();
 565	pm_restore_console();
 566	return error;
 567}
 568
 569/**
 570 * hibernation_platform_enter - Power off the system using the platform driver.
 571 */
 572int hibernation_platform_enter(void)
 573{
 574	int error;
 575
 576	if (!hibernation_ops)
 577		return -ENOSYS;
 578
 579	/*
 580	 * We have cancelled the power transition by running
 581	 * hibernation_ops->finish() before saving the image, so we should let
 582	 * the firmware know that we're going to enter the sleep state after all
 583	 */
 584	error = hibernation_ops->begin(PMSG_HIBERNATE);
 585	if (error)
 586		goto Close;
 587
 588	entering_platform_hibernation = true;
 589	suspend_console();
 590	error = dpm_suspend_start(PMSG_HIBERNATE);
 591	if (error) {
 592		if (hibernation_ops->recover)
 593			hibernation_ops->recover();
 594		goto Resume_devices;
 595	}
 596
 597	error = dpm_suspend_end(PMSG_HIBERNATE);
 598	if (error)
 599		goto Resume_devices;
 600
 601	error = hibernation_ops->prepare();
 602	if (error)
 603		goto Platform_finish;
 604
 605	error = pm_sleep_disable_secondary_cpus();
 606	if (error)
 607		goto Enable_cpus;
 608
 609	local_irq_disable();
 610	system_state = SYSTEM_SUSPEND;
 611	syscore_suspend();
 612	if (pm_wakeup_pending()) {
 613		error = -EAGAIN;
 614		goto Power_up;
 615	}
 616
 617	hibernation_ops->enter();
 618	/* We should never get here */
 619	while (1);
 620
 621 Power_up:
 622	syscore_resume();
 623	system_state = SYSTEM_RUNNING;
 624	local_irq_enable();
 625
 626 Enable_cpus:
 627	pm_sleep_enable_secondary_cpus();
 628
 629 Platform_finish:
 630	hibernation_ops->finish();
 631
 632	dpm_resume_start(PMSG_RESTORE);
 633
 634 Resume_devices:
 635	entering_platform_hibernation = false;
 636	dpm_resume_end(PMSG_RESTORE);
 637	resume_console();
 638
 639 Close:
 640	hibernation_ops->end();
 641
 642	return error;
 643}
 644
 645/**
 646 * power_down - Shut the machine down for hibernation.
 647 *
 648 * Use the platform driver, if configured, to put the system into the sleep
 649 * state corresponding to hibernation, or try to power it off or reboot,
 650 * depending on the value of hibernation_mode.
 651 */
 652static void power_down(void)
 653{
 
 654	int error;
 655
 656#ifdef CONFIG_SUSPEND
 657	if (hibernation_mode == HIBERNATION_SUSPEND) {
 658		error = suspend_devices_and_enter(mem_sleep_current);
 659		if (error) {
 660			hibernation_mode = hibernation_ops ?
 661						HIBERNATION_PLATFORM :
 662						HIBERNATION_SHUTDOWN;
 663		} else {
 664			/* Restore swap signature. */
 665			error = swsusp_unmark();
 666			if (error)
 667				pr_err("Swap will be unusable! Try swapon -a.\n");
 668
 669			return;
 670		}
 671	}
 672#endif
 673
 674	switch (hibernation_mode) {
 675	case HIBERNATION_REBOOT:
 676		kernel_restart(NULL);
 677		break;
 678	case HIBERNATION_PLATFORM:
 679		error = hibernation_platform_enter();
 680		if (error == -EAGAIN || error == -EBUSY) {
 681			swsusp_unmark();
 682			events_check_enabled = false;
 683			pr_info("Wakeup event detected during hibernation, rolling back.\n");
 684			return;
 685		}
 686		fallthrough;
 687	case HIBERNATION_SHUTDOWN:
 688		if (kernel_can_power_off())
 689			kernel_power_off();
 690		break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 691	}
 692	kernel_halt();
 693	/*
 694	 * Valid image is on the disk, if we continue we risk serious data
 695	 * corruption after resume.
 696	 */
 697	pr_crit("Power down manually\n");
 698	while (1)
 699		cpu_relax();
 700}
 701
 702static int load_image_and_restore(void)
 703{
 704	int error;
 705	unsigned int flags;
 706
 707	pm_pr_dbg("Loading hibernation image.\n");
 708
 709	lock_device_hotplug();
 710	error = create_basic_memory_bitmaps();
 711	if (error) {
 712		swsusp_close();
 713		goto Unlock;
 714	}
 715
 716	error = swsusp_read(&flags);
 717	swsusp_close();
 718	if (!error)
 719		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 720
 721	pr_err("Failed to load image, recovering.\n");
 722	swsusp_free();
 723	free_basic_memory_bitmaps();
 724 Unlock:
 725	unlock_device_hotplug();
 726
 727	return error;
 728}
 729
 730#define COMPRESSION_ALGO_LZO "lzo"
 731#define COMPRESSION_ALGO_LZ4 "lz4"
 732
 733/**
 734 * hibernate - Carry out system hibernation, including saving the image.
 735 */
 736int hibernate(void)
 737{
 
 738	bool snapshot_test = false;
 739	unsigned int sleep_flags;
 740	int error;
 741
 742	if (!hibernation_available()) {
 743		pm_pr_dbg("Hibernation not available.\n");
 744		return -EPERM;
 745	}
 746
 747	/*
 748	 * Query for the compression algorithm support if compression is enabled.
 749	 */
 750	if (!nocompress) {
 751		strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
 752		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
 753			pr_err("%s compression is not available\n", hib_comp_algo);
 754			return -EOPNOTSUPP;
 755		}
 756	}
 757
 758	sleep_flags = lock_system_sleep();
 759	/* The snapshot device should not be opened while we're running */
 760	if (!hibernate_acquire()) {
 761		error = -EBUSY;
 762		goto Unlock;
 763	}
 764
 765	pr_info("hibernation entry\n");
 766	pm_prepare_console();
 767	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 768	if (error)
 769		goto Restore;
 
 
 770
 771	ksys_sync_helper();
 
 
 772
 773	error = freeze_processes();
 774	if (error)
 775		goto Exit;
 776
 777	lock_device_hotplug();
 778	/* Allocate memory management structures */
 779	error = create_basic_memory_bitmaps();
 780	if (error)
 781		goto Thaw;
 782
 783	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 784	if (error || freezer_test_done)
 785		goto Free_bitmaps;
 786
 787	if (in_suspend) {
 788		unsigned int flags = 0;
 789
 790		if (hibernation_mode == HIBERNATION_PLATFORM)
 791			flags |= SF_PLATFORM_MODE;
 792		if (nocompress) {
 793			flags |= SF_NOCOMPRESS_MODE;
 794		} else {
 795		        flags |= SF_CRC32_MODE;
 796
 797			/*
 798			 * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
 799			 * to override this behaviour and use LZ4.
 800			 *
 801			 * Refer kernel/power/power.h for more details
 802			 */
 803
 804			if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
 805				flags |= SF_COMPRESSION_ALG_LZ4;
 806			else
 807				flags |= SF_COMPRESSION_ALG_LZO;
 808		}
 809
 810		pm_pr_dbg("Writing hibernation image.\n");
 811		error = swsusp_write(flags);
 812		swsusp_free();
 813		if (!error) {
 814			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 815				snapshot_test = true;
 816			else
 817				power_down();
 818		}
 819		in_suspend = 0;
 820		pm_restore_gfp_mask();
 821	} else {
 822		pm_pr_dbg("Hibernation image restored successfully.\n");
 823	}
 824
 825 Free_bitmaps:
 826	free_basic_memory_bitmaps();
 827 Thaw:
 828	unlock_device_hotplug();
 829	if (snapshot_test) {
 830		pm_pr_dbg("Checking hibernation image\n");
 831		error = swsusp_check(false);
 832		if (!error)
 833			error = load_image_and_restore();
 834	}
 835	thaw_processes();
 836
 837	/* Don't bother checking whether freezer_test_done is true */
 838	freezer_test_done = false;
 839 Exit:
 840	pm_notifier_call_chain(PM_POST_HIBERNATION);
 841 Restore:
 842	pm_restore_console();
 843	hibernate_release();
 844 Unlock:
 845	unlock_system_sleep(sleep_flags);
 846	pr_info("hibernation exit\n");
 847
 848	return error;
 849}
 850
 
 851/**
 852 * hibernate_quiet_exec - Execute a function with all devices frozen.
 853 * @func: Function to execute.
 854 * @data: Data pointer to pass to @func.
 
 
 
 
 
 855 *
 856 * Return the @func return value or an error code if it cannot be executed.
 
 
 
 857 */
 858int hibernate_quiet_exec(int (*func)(void *data), void *data)
 859{
 860	unsigned int sleep_flags;
 861	int error;
 862
 863	sleep_flags = lock_system_sleep();
 
 
 
 
 864
 865	if (!hibernate_acquire()) {
 866		error = -EBUSY;
 867		goto unlock;
 868	}
 
 
 
 
 
 
 
 869
 870	pm_prepare_console();
 
 871
 872	error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
 873	if (error)
 874		goto restore;
 875
 876	error = freeze_processes();
 877	if (error)
 878		goto exit;
 879
 880	lock_device_hotplug();
 881
 882	pm_suspend_clear_flags();
 883
 884	error = platform_begin(true);
 885	if (error)
 886		goto thaw;
 887
 888	error = freeze_kernel_threads();
 889	if (error)
 890		goto thaw;
 891
 892	error = dpm_prepare(PMSG_FREEZE);
 893	if (error)
 894		goto dpm_complete;
 895
 896	suspend_console();
 897
 898	error = dpm_suspend(PMSG_FREEZE);
 899	if (error)
 900		goto dpm_resume;
 901
 902	error = dpm_suspend_end(PMSG_FREEZE);
 903	if (error)
 904		goto dpm_resume;
 905
 906	error = platform_pre_snapshot(true);
 907	if (error)
 908		goto skip;
 909
 910	error = func(data);
 911
 912skip:
 913	platform_finish(true);
 914
 915	dpm_resume_start(PMSG_THAW);
 916
 917dpm_resume:
 918	dpm_resume(PMSG_THAW);
 919
 920	resume_console();
 921
 922dpm_complete:
 923	dpm_complete(PMSG_THAW);
 924
 925	thaw_kernel_threads();
 926
 927thaw:
 928	platform_end(true);
 929
 930	unlock_device_hotplug();
 931
 932	thaw_processes();
 933
 934exit:
 935	pm_notifier_call_chain(PM_POST_HIBERNATION);
 936
 937restore:
 938	pm_restore_console();
 939
 940	hibernate_release();
 941
 942unlock:
 943	unlock_system_sleep(sleep_flags);
 944
 945	return error;
 946}
 947EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 948
 949static int __init find_resume_device(void)
 950{
 951	if (!strlen(resume_file))
 952		return -ENOENT;
 953
 954	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 955
 956	if (resume_delay) {
 957		pr_info("Waiting %dsec before reading resume device ...\n",
 958			resume_delay);
 959		ssleep(resume_delay);
 960	}
 961
 962	/* Check if the device is there */
 963	if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
 964		return 0;
 965
 966	/*
 967	 * Some device discovery might still be in progress; we need to wait for
 968	 * this to finish.
 969	 */
 970	wait_for_device_probe();
 971	if (resume_wait) {
 972		while (early_lookup_bdev(resume_file, &swsusp_resume_device))
 973			msleep(10);
 974		async_synchronize_full();
 975	}
 976
 977	return early_lookup_bdev(resume_file, &swsusp_resume_device);
 978}
 
 
 
 
 
 
 
 
 
 
 979
 980static int software_resume(void)
 981{
 982	int error;
 
 
 
 983
 984	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 
 985		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 986
 987	pm_pr_dbg("Looking for hibernation image.\n");
 988
 989	mutex_lock(&system_transition_mutex);
 990	error = swsusp_check(true);
 991	if (error)
 992		goto Unlock;
 993
 994	/*
 995	 * Check if the hibernation image is compressed. If so, query for
 996	 * the algorithm support.
 997	 */
 998	if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
 999		if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
1000			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
1001		else
1002			strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
1003		if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
1004			pr_err("%s compression is not available\n", hib_comp_algo);
1005			error = -EOPNOTSUPP;
1006			goto Unlock;
1007		}
1008	}
1009
1010	/* The snapshot device should not be opened while we're running */
1011	if (!hibernate_acquire()) {
1012		error = -EBUSY;
1013		swsusp_close();
1014		goto Unlock;
1015	}
1016
1017	pr_info("resume from hibernation\n");
1018	pm_prepare_console();
1019	error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1020	if (error)
1021		goto Restore;
 
 
1022
1023	pm_pr_dbg("Preparing processes for hibernation restore.\n");
1024	error = freeze_processes();
1025	if (error)
1026		goto Close_Finish;
1027
1028	error = freeze_kernel_threads();
1029	if (error) {
1030		thaw_processes();
1031		goto Close_Finish;
1032	}
1033
1034	error = load_image_and_restore();
1035	thaw_processes();
1036 Finish:
1037	pm_notifier_call_chain(PM_POST_RESTORE);
1038 Restore:
1039	pm_restore_console();
1040	pr_info("resume failed (%d)\n", error);
1041	hibernate_release();
1042	/* For success case, the suspend path will release the lock */
1043 Unlock:
1044	mutex_unlock(&system_transition_mutex);
1045	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1046	return error;
1047 Close_Finish:
1048	swsusp_close();
1049	goto Finish;
1050}
1051
1052/**
1053 * software_resume_initcall - Resume from a saved hibernation image.
1054 *
1055 * This routine is called as a late initcall, when all devices have been
1056 * discovered and initialized already.
1057 *
1058 * The image reading code is called to see if there is a hibernation image
1059 * available for reading.  If that is the case, devices are quiesced and the
1060 * contents of memory is restored from the saved image.
1061 *
1062 * If this is successful, control reappears in the restored target kernel in
1063 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
1064 * attempts to recover gracefully and make the kernel return to the normal mode
1065 * of operation.
1066 */
1067static int __init software_resume_initcall(void)
1068{
1069	/*
1070	 * If the user said "noresume".. bail out early.
1071	 */
1072	if (noresume || !hibernation_available())
1073		return 0;
1074
1075	if (!swsusp_resume_device) {
1076		int error = find_resume_device();
1077
1078		if (error)
1079			return error;
1080	}
1081
1082	return software_resume();
1083}
1084late_initcall_sync(software_resume_initcall);
1085
1086
1087static const char * const hibernation_modes[] = {
1088	[HIBERNATION_PLATFORM]	= "platform",
1089	[HIBERNATION_SHUTDOWN]	= "shutdown",
1090	[HIBERNATION_REBOOT]	= "reboot",
1091#ifdef CONFIG_SUSPEND
1092	[HIBERNATION_SUSPEND]	= "suspend",
1093#endif
1094	[HIBERNATION_TEST_RESUME]	= "test_resume",
1095};
1096
1097/*
1098 * /sys/power/disk - Control hibernation mode.
1099 *
1100 * Hibernation can be handled in several ways.  There are a few different ways
1101 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1102 * or other hibernation_ops), powering it off or rebooting it (for testing
1103 * mostly).
1104 *
1105 * The sysfs file /sys/power/disk provides an interface for selecting the
1106 * hibernation mode to use.  Reading from this file causes the available modes
1107 * to be printed.  There are 3 modes that can be supported:
1108 *
1109 *	'platform'
1110 *	'shutdown'
1111 *	'reboot'
1112 *
1113 * If a platform hibernation driver is in use, 'platform' will be supported
1114 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1115 * The selected option (i.e. the one corresponding to the current value of
1116 * hibernation_mode) is enclosed by a square bracket.
1117 *
1118 * To select a given hibernation mode it is necessary to write the mode's
1119 * string representation (as returned by reading from /sys/power/disk) back
1120 * into /sys/power/disk.
1121 */
1122
1123static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1124			 char *buf)
1125{
1126	int i;
1127	char *start = buf;
1128
1129	if (!hibernation_available())
1130		return sprintf(buf, "[disabled]\n");
1131
1132	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1133		if (!hibernation_modes[i])
1134			continue;
1135		switch (i) {
1136		case HIBERNATION_SHUTDOWN:
1137		case HIBERNATION_REBOOT:
1138#ifdef CONFIG_SUSPEND
1139		case HIBERNATION_SUSPEND:
1140#endif
1141		case HIBERNATION_TEST_RESUME:
1142			break;
1143		case HIBERNATION_PLATFORM:
1144			if (hibernation_ops)
1145				break;
1146			/* not a valid mode, continue with loop */
1147			continue;
1148		}
1149		if (i == hibernation_mode)
1150			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1151		else
1152			buf += sprintf(buf, "%s ", hibernation_modes[i]);
1153	}
1154	buf += sprintf(buf, "\n");
1155	return buf-start;
1156}
1157
1158static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1159			  const char *buf, size_t n)
1160{
1161	int mode = HIBERNATION_INVALID;
1162	unsigned int sleep_flags;
1163	int error = 0;
 
1164	int len;
1165	char *p;
1166	int i;
1167
1168	if (!hibernation_available())
1169		return -EPERM;
1170
1171	p = memchr(buf, '\n', n);
1172	len = p ? p - buf : n;
1173
1174	sleep_flags = lock_system_sleep();
1175	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1176		if (len == strlen(hibernation_modes[i])
1177		    && !strncmp(buf, hibernation_modes[i], len)) {
1178			mode = i;
1179			break;
1180		}
1181	}
1182	if (mode != HIBERNATION_INVALID) {
1183		switch (mode) {
1184		case HIBERNATION_SHUTDOWN:
1185		case HIBERNATION_REBOOT:
1186#ifdef CONFIG_SUSPEND
1187		case HIBERNATION_SUSPEND:
1188#endif
1189		case HIBERNATION_TEST_RESUME:
1190			hibernation_mode = mode;
1191			break;
1192		case HIBERNATION_PLATFORM:
1193			if (hibernation_ops)
1194				hibernation_mode = mode;
1195			else
1196				error = -EINVAL;
1197		}
1198	} else
1199		error = -EINVAL;
1200
1201	if (!error)
1202		pm_pr_dbg("Hibernation mode set to '%s'\n",
1203			       hibernation_modes[mode]);
1204	unlock_system_sleep(sleep_flags);
1205	return error ? error : n;
1206}
1207
1208power_attr(disk);
1209
1210static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1211			   char *buf)
1212{
1213	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1214		       MINOR(swsusp_resume_device));
1215}
1216
1217static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1218			    const char *buf, size_t n)
1219{
1220	unsigned int sleep_flags;
1221	int len = n;
1222	char *name;
1223	dev_t dev;
1224	int error;
1225
1226	if (!hibernation_available())
1227		return n;
1228
1229	if (len && buf[len-1] == '\n')
1230		len--;
1231	name = kstrndup(buf, len, GFP_KERNEL);
1232	if (!name)
1233		return -ENOMEM;
1234
1235	error = lookup_bdev(name, &dev);
1236	if (error) {
1237		unsigned maj, min, offset;
1238		char *p, dummy;
1239
1240		error = 0;
1241		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
1242		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
1243				&dummy) == 3) {
1244			dev = MKDEV(maj, min);
1245			if (maj != MAJOR(dev) || min != MINOR(dev))
1246				error = -EINVAL;
1247		} else {
1248			dev = new_decode_dev(simple_strtoul(name, &p, 16));
1249			if (*p)
1250				error = -EINVAL;
1251		}
1252	}
1253	kfree(name);
1254	if (error)
1255		return error;
1256
1257	sleep_flags = lock_system_sleep();
1258	swsusp_resume_device = dev;
1259	unlock_system_sleep(sleep_flags);
1260
1261	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1262		  swsusp_resume_device);
1263	noresume = 0;
1264	software_resume();
1265	return n;
1266}
1267
1268power_attr(resume);
1269
1270static ssize_t resume_offset_show(struct kobject *kobj,
1271				  struct kobj_attribute *attr, char *buf)
1272{
1273	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1274}
1275
1276static ssize_t resume_offset_store(struct kobject *kobj,
1277				   struct kobj_attribute *attr, const char *buf,
1278				   size_t n)
1279{
1280	unsigned long long offset;
1281	int rc;
1282
1283	rc = kstrtoull(buf, 0, &offset);
1284	if (rc)
1285		return rc;
1286	swsusp_resume_block = offset;
1287
1288	return n;
1289}
1290
1291power_attr(resume_offset);
1292
1293static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1294			       char *buf)
1295{
1296	return sprintf(buf, "%lu\n", image_size);
1297}
1298
1299static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1300				const char *buf, size_t n)
1301{
1302	unsigned long size;
1303
1304	if (sscanf(buf, "%lu", &size) == 1) {
1305		image_size = size;
1306		return n;
1307	}
1308
1309	return -EINVAL;
1310}
1311
1312power_attr(image_size);
1313
1314static ssize_t reserved_size_show(struct kobject *kobj,
1315				  struct kobj_attribute *attr, char *buf)
1316{
1317	return sprintf(buf, "%lu\n", reserved_size);
1318}
1319
1320static ssize_t reserved_size_store(struct kobject *kobj,
1321				   struct kobj_attribute *attr,
1322				   const char *buf, size_t n)
1323{
1324	unsigned long size;
1325
1326	if (sscanf(buf, "%lu", &size) == 1) {
1327		reserved_size = size;
1328		return n;
1329	}
1330
1331	return -EINVAL;
1332}
1333
1334power_attr(reserved_size);
1335
1336static struct attribute *g[] = {
1337	&disk_attr.attr,
1338	&resume_offset_attr.attr,
1339	&resume_attr.attr,
1340	&image_size_attr.attr,
1341	&reserved_size_attr.attr,
1342	NULL,
1343};
1344
1345
1346static const struct attribute_group attr_group = {
1347	.attrs = g,
1348};
1349
1350
1351static int __init pm_disk_init(void)
1352{
1353	return sysfs_create_group(power_kobj, &attr_group);
1354}
1355
1356core_initcall(pm_disk_init);
1357
1358
1359static int __init resume_setup(char *str)
1360{
1361	if (noresume)
1362		return 1;
1363
1364	strncpy(resume_file, str, 255);
1365	return 1;
1366}
1367
1368static int __init resume_offset_setup(char *str)
1369{
1370	unsigned long long offset;
1371
1372	if (noresume)
1373		return 1;
1374
1375	if (sscanf(str, "%llu", &offset) == 1)
1376		swsusp_resume_block = offset;
1377
1378	return 1;
1379}
1380
1381static int __init hibernate_setup(char *str)
1382{
1383	if (!strncmp(str, "noresume", 8)) {
1384		noresume = 1;
1385	} else if (!strncmp(str, "nocompress", 10)) {
1386		nocompress = 1;
1387	} else if (!strncmp(str, "no", 2)) {
1388		noresume = 1;
1389		nohibernate = 1;
1390	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1391		   && !strncmp(str, "protect_image", 13)) {
1392		enable_restore_image_protection();
1393	}
1394	return 1;
1395}
1396
1397static int __init noresume_setup(char *str)
1398{
1399	noresume = 1;
1400	return 1;
1401}
1402
1403static int __init resumewait_setup(char *str)
1404{
1405	resume_wait = 1;
1406	return 1;
1407}
1408
1409static int __init resumedelay_setup(char *str)
1410{
1411	int rc = kstrtouint(str, 0, &resume_delay);
1412
1413	if (rc)
1414		pr_warn("resumedelay: bad option string '%s'\n", str);
1415	return 1;
1416}
1417
1418static int __init nohibernate_setup(char *str)
1419{
1420	noresume = 1;
1421	nohibernate = 1;
1422	return 1;
1423}
1424
1425static const char * const comp_alg_enabled[] = {
1426#if IS_ENABLED(CONFIG_CRYPTO_LZO)
1427	COMPRESSION_ALGO_LZO,
1428#endif
1429#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
1430	COMPRESSION_ALGO_LZ4,
1431#endif
1432};
1433
1434static int hibernate_compressor_param_set(const char *compressor,
1435		const struct kernel_param *kp)
1436{
1437	unsigned int sleep_flags;
1438	int index, ret;
1439
1440	sleep_flags = lock_system_sleep();
1441
1442	index = sysfs_match_string(comp_alg_enabled, compressor);
1443	if (index >= 0) {
1444		ret = param_set_copystring(comp_alg_enabled[index], kp);
1445		if (!ret)
1446			strscpy(hib_comp_algo, comp_alg_enabled[index],
1447				sizeof(hib_comp_algo));
1448	} else {
1449		ret = index;
1450	}
1451
1452	unlock_system_sleep(sleep_flags);
1453
1454	if (ret)
1455		pr_debug("Cannot set specified compressor %s\n",
1456			 compressor);
1457
1458	return ret;
1459}
1460
1461static const struct kernel_param_ops hibernate_compressor_param_ops = {
1462	.set    = hibernate_compressor_param_set,
1463	.get    = param_get_string,
1464};
1465
1466static struct kparam_string hibernate_compressor_param_string = {
1467	.maxlen = sizeof(hibernate_compressor),
1468	.string = hibernate_compressor,
1469};
1470
1471module_param_cb(compressor, &hibernate_compressor_param_ops,
1472		&hibernate_compressor_param_string, 0644);
1473MODULE_PARM_DESC(compressor,
1474		 "Compression algorithm to be used with hibernation");
1475
1476__setup("noresume", noresume_setup);
1477__setup("resume_offset=", resume_offset_setup);
1478__setup("resume=", resume_setup);
1479__setup("hibernate=", hibernate_setup);
1480__setup("resumewait", resumewait_setup);
1481__setup("resumedelay=", resumedelay_setup);
1482__setup("nohibernate", nohibernate_setup);