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v5.9
   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 <trace/events/power.h>
  35
  36#include "power.h"
  37
  38
  39static int nocompress;
  40static int noresume;
  41static int nohibernate;
  42static int resume_wait;
  43static unsigned int resume_delay;
  44static char resume_file[256] = CONFIG_PM_STD_PARTITION;
  45dev_t swsusp_resume_device;
  46sector_t swsusp_resume_block;
  47__visible int in_suspend __nosavedata;
  48
  49enum {
  50	HIBERNATION_INVALID,
  51	HIBERNATION_PLATFORM,
  52	HIBERNATION_SHUTDOWN,
  53	HIBERNATION_REBOOT,
  54#ifdef CONFIG_SUSPEND
  55	HIBERNATION_SUSPEND,
  56#endif
  57	HIBERNATION_TEST_RESUME,
  58	/* keep last */
  59	__HIBERNATION_AFTER_LAST
  60};
  61#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
  62#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
  63
  64static int hibernation_mode = HIBERNATION_SHUTDOWN;
  65
  66bool freezer_test_done;
  67
  68static const struct platform_hibernation_ops *hibernation_ops;
  69
  70static atomic_t hibernate_atomic = ATOMIC_INIT(1);
  71
  72bool hibernate_acquire(void)
  73{
  74	return atomic_add_unless(&hibernate_atomic, -1, 0);
  75}
  76
  77void hibernate_release(void)
  78{
  79	atomic_inc(&hibernate_atomic);
  80}
  81
  82bool hibernation_available(void)
  83{
  84	return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
  85}
  86
  87/**
  88 * hibernation_set_ops - Set the global hibernate operations.
  89 * @ops: Hibernation operations to use in subsequent hibernation transitions.
  90 */
  91void hibernation_set_ops(const struct platform_hibernation_ops *ops)
  92{
  93	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
  94	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore
  95	    && ops->restore_cleanup && ops->leave)) {
  96		WARN_ON(1);
  97		return;
  98	}
  99	lock_system_sleep();
 100	hibernation_ops = ops;
 101	if (ops)
 102		hibernation_mode = HIBERNATION_PLATFORM;
 103	else if (hibernation_mode == HIBERNATION_PLATFORM)
 104		hibernation_mode = HIBERNATION_SHUTDOWN;
 105
 106	unlock_system_sleep();
 107}
 108EXPORT_SYMBOL_GPL(hibernation_set_ops);
 109
 110static bool entering_platform_hibernation;
 111
 112bool system_entering_hibernation(void)
 113{
 114	return entering_platform_hibernation;
 115}
 116EXPORT_SYMBOL(system_entering_hibernation);
 117
 118#ifdef CONFIG_PM_DEBUG
 119static void hibernation_debug_sleep(void)
 120{
 121	pr_info("debug: Waiting for 5 seconds.\n");
 122	mdelay(5000);
 123}
 124
 125static int hibernation_test(int level)
 126{
 127	if (pm_test_level == level) {
 128		hibernation_debug_sleep();
 129		return 1;
 130	}
 131	return 0;
 132}
 133#else /* !CONFIG_PM_DEBUG */
 134static int hibernation_test(int level) { return 0; }
 135#endif /* !CONFIG_PM_DEBUG */
 136
 137/**
 138 * platform_begin - Call platform to start hibernation.
 139 * @platform_mode: Whether or not to use the platform driver.
 140 */
 141static int platform_begin(int platform_mode)
 142{
 143	return (platform_mode && hibernation_ops) ?
 144		hibernation_ops->begin(PMSG_FREEZE) : 0;
 145}
 146
 147/**
 148 * platform_end - Call platform to finish transition to the working state.
 149 * @platform_mode: Whether or not to use the platform driver.
 150 */
 151static void platform_end(int platform_mode)
 152{
 153	if (platform_mode && hibernation_ops)
 154		hibernation_ops->end();
 155}
 156
 157/**
 158 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
 159 * @platform_mode: Whether or not to use the platform driver.
 160 *
 161 * Use the platform driver to prepare the system for creating a hibernate image,
 162 * if so configured, and return an error code if that fails.
 163 */
 164
 165static int platform_pre_snapshot(int platform_mode)
 166{
 167	return (platform_mode && hibernation_ops) ?
 168		hibernation_ops->pre_snapshot() : 0;
 169}
 170
 171/**
 172 * platform_leave - Call platform to prepare a transition to the working state.
 173 * @platform_mode: Whether or not to use the platform driver.
 174 *
 175 * Use the platform driver prepare to prepare the machine for switching to the
 176 * normal mode of operation.
 177 *
 178 * This routine is called on one CPU with interrupts disabled.
 179 */
 180static void platform_leave(int platform_mode)
 181{
 182	if (platform_mode && hibernation_ops)
 183		hibernation_ops->leave();
 184}
 185
 186/**
 187 * platform_finish - Call platform to switch the system to the working state.
 188 * @platform_mode: Whether or not to use the platform driver.
 189 *
 190 * Use the platform driver to switch the machine to the normal mode of
 191 * operation.
 192 *
 193 * This routine must be called after platform_prepare().
 194 */
 195static void platform_finish(int platform_mode)
 196{
 197	if (platform_mode && hibernation_ops)
 198		hibernation_ops->finish();
 199}
 200
 201/**
 202 * platform_pre_restore - Prepare for hibernate image restoration.
 203 * @platform_mode: Whether or not to use the platform driver.
 204 *
 205 * Use the platform driver to prepare the system for resume from a hibernation
 206 * image.
 207 *
 208 * If the restore fails after this function has been called,
 209 * platform_restore_cleanup() must be called.
 210 */
 211static int platform_pre_restore(int platform_mode)
 212{
 213	return (platform_mode && hibernation_ops) ?
 214		hibernation_ops->pre_restore() : 0;
 215}
 216
 217/**
 218 * platform_restore_cleanup - Switch to the working state after failing restore.
 219 * @platform_mode: Whether or not to use the platform driver.
 220 *
 221 * Use the platform driver to switch the system to the normal mode of operation
 222 * after a failing restore.
 223 *
 224 * If platform_pre_restore() has been called before the failing restore, this
 225 * function must be called too, regardless of the result of
 226 * platform_pre_restore().
 227 */
 228static void platform_restore_cleanup(int platform_mode)
 229{
 230	if (platform_mode && hibernation_ops)
 231		hibernation_ops->restore_cleanup();
 232}
 233
 234/**
 235 * platform_recover - Recover from a failure to suspend devices.
 236 * @platform_mode: Whether or not to use the platform driver.
 237 */
 238static void platform_recover(int platform_mode)
 239{
 240	if (platform_mode && hibernation_ops && hibernation_ops->recover)
 241		hibernation_ops->recover();
 242}
 243
 244/**
 245 * swsusp_show_speed - Print time elapsed between two events during hibernation.
 246 * @start: Starting event.
 247 * @stop: Final event.
 248 * @nr_pages: Number of memory pages processed between @start and @stop.
 249 * @msg: Additional diagnostic message to print.
 250 */
 251void swsusp_show_speed(ktime_t start, ktime_t stop,
 252		      unsigned nr_pages, char *msg)
 253{
 254	ktime_t diff;
 255	u64 elapsed_centisecs64;
 256	unsigned int centisecs;
 257	unsigned int k;
 258	unsigned int kps;
 259
 260	diff = ktime_sub(stop, start);
 261	elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
 262	centisecs = elapsed_centisecs64;
 263	if (centisecs == 0)
 264		centisecs = 1;	/* avoid div-by-zero */
 265	k = nr_pages * (PAGE_SIZE / 1024);
 266	kps = (k * 100) / centisecs;
 267	pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
 268		msg, k, centisecs / 100, centisecs % 100, kps / 1000,
 269		(kps % 1000) / 10);
 270}
 271
 272__weak int arch_resume_nosmt(void)
 273{
 274	return 0;
 275}
 276
 277/**
 278 * create_image - Create a hibernation image.
 279 * @platform_mode: Whether or not to use the platform driver.
 280 *
 281 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
 282 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
 283 *
 284 * Control reappears in this routine after the subsequent restore.
 285 */
 286static int create_image(int platform_mode)
 287{
 288	int error;
 289
 290	error = dpm_suspend_end(PMSG_FREEZE);
 291	if (error) {
 292		pr_err("Some devices failed to power down, aborting\n");
 
 293		return error;
 294	}
 295
 296	error = platform_pre_snapshot(platform_mode);
 297	if (error || hibernation_test(TEST_PLATFORM))
 298		goto Platform_finish;
 299
 300	error = suspend_disable_secondary_cpus();
 301	if (error || hibernation_test(TEST_CPUS))
 302		goto Enable_cpus;
 303
 304	local_irq_disable();
 305
 306	system_state = SYSTEM_SUSPEND;
 307
 308	error = syscore_suspend();
 309	if (error) {
 310		pr_err("Some system devices failed to power down, aborting\n");
 
 311		goto Enable_irqs;
 312	}
 313
 314	if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
 315		goto Power_up;
 316
 317	in_suspend = 1;
 318	save_processor_state();
 319	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
 320	error = swsusp_arch_suspend();
 321	/* Restore control flow magically appears here */
 322	restore_processor_state();
 323	trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
 324	if (error)
 325		pr_err("Error %d creating image\n", error);
 326
 327	if (!in_suspend) {
 328		events_check_enabled = false;
 329		clear_free_pages();
 330	}
 331
 332	platform_leave(platform_mode);
 333
 334 Power_up:
 335	syscore_resume();
 336
 337 Enable_irqs:
 338	system_state = SYSTEM_RUNNING;
 339	local_irq_enable();
 340
 341 Enable_cpus:
 342	suspend_enable_secondary_cpus();
 343
 344	/* Allow architectures to do nosmt-specific post-resume dances */
 345	if (!in_suspend)
 346		error = arch_resume_nosmt();
 347
 348 Platform_finish:
 349	platform_finish(platform_mode);
 350
 351	dpm_resume_start(in_suspend ?
 352		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
 353
 354	return error;
 355}
 356
 357/**
 358 * hibernation_snapshot - Quiesce devices and create a hibernation image.
 359 * @platform_mode: If set, use platform driver to prepare for the transition.
 360 *
 361 * This routine must be called with system_transition_mutex held.
 362 */
 363int hibernation_snapshot(int platform_mode)
 364{
 365	pm_message_t msg;
 366	int error;
 367
 368	pm_suspend_clear_flags();
 369	error = platform_begin(platform_mode);
 370	if (error)
 371		goto Close;
 372
 373	/* Preallocate image memory before shutting down devices. */
 374	error = hibernate_preallocate_memory();
 375	if (error)
 376		goto Close;
 377
 378	error = freeze_kernel_threads();
 379	if (error)
 380		goto Cleanup;
 381
 382	if (hibernation_test(TEST_FREEZER)) {
 383
 384		/*
 385		 * Indicate to the caller that we are returning due to a
 386		 * successful freezer test.
 387		 */
 388		freezer_test_done = true;
 389		goto Thaw;
 390	}
 391
 392	error = dpm_prepare(PMSG_FREEZE);
 393	if (error) {
 394		dpm_complete(PMSG_RECOVER);
 395		goto Thaw;
 396	}
 397
 398	suspend_console();
 399	pm_restrict_gfp_mask();
 400
 401	error = dpm_suspend(PMSG_FREEZE);
 402
 403	if (error || hibernation_test(TEST_DEVICES))
 404		platform_recover(platform_mode);
 405	else
 406		error = create_image(platform_mode);
 407
 408	/*
 409	 * In the case that we call create_image() above, the control
 410	 * returns here (1) after the image has been created or the
 411	 * image creation has failed and (2) after a successful restore.
 412	 */
 413
 414	/* We may need to release the preallocated image pages here. */
 415	if (error || !in_suspend)
 416		swsusp_free();
 417
 418	msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
 419	dpm_resume(msg);
 420
 421	if (error || !in_suspend)
 422		pm_restore_gfp_mask();
 423
 424	resume_console();
 425	dpm_complete(msg);
 426
 427 Close:
 428	platform_end(platform_mode);
 429	return error;
 430
 431 Thaw:
 432	thaw_kernel_threads();
 433 Cleanup:
 434	swsusp_free();
 435	goto Close;
 436}
 437
 438int __weak hibernate_resume_nonboot_cpu_disable(void)
 439{
 440	return suspend_disable_secondary_cpus();
 441}
 442
 443/**
 444 * resume_target_kernel - Restore system state from a hibernation image.
 445 * @platform_mode: Whether or not to use the platform driver.
 446 *
 447 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
 448 * contents of highmem that have not been restored yet from the image and run
 449 * the low-level code that will restore the remaining contents of memory and
 450 * switch to the just restored target kernel.
 451 */
 452static int resume_target_kernel(bool platform_mode)
 453{
 454	int error;
 455
 456	error = dpm_suspend_end(PMSG_QUIESCE);
 457	if (error) {
 458		pr_err("Some devices failed to power down, aborting resume\n");
 
 459		return error;
 460	}
 461
 462	error = platform_pre_restore(platform_mode);
 463	if (error)
 464		goto Cleanup;
 465
 466	error = hibernate_resume_nonboot_cpu_disable();
 467	if (error)
 468		goto Enable_cpus;
 469
 470	local_irq_disable();
 471	system_state = SYSTEM_SUSPEND;
 472
 473	error = syscore_suspend();
 474	if (error)
 475		goto Enable_irqs;
 476
 477	save_processor_state();
 478	error = restore_highmem();
 479	if (!error) {
 480		error = swsusp_arch_resume();
 481		/*
 482		 * The code below is only ever reached in case of a failure.
 483		 * Otherwise, execution continues at the place where
 484		 * swsusp_arch_suspend() was called.
 485		 */
 486		BUG_ON(!error);
 487		/*
 488		 * This call to restore_highmem() reverts the changes made by
 489		 * the previous one.
 490		 */
 491		restore_highmem();
 492	}
 493	/*
 494	 * The only reason why swsusp_arch_resume() can fail is memory being
 495	 * very tight, so we have to free it as soon as we can to avoid
 496	 * subsequent failures.
 497	 */
 498	swsusp_free();
 499	restore_processor_state();
 500	touch_softlockup_watchdog();
 501
 502	syscore_resume();
 503
 504 Enable_irqs:
 505	system_state = SYSTEM_RUNNING;
 506	local_irq_enable();
 507
 508 Enable_cpus:
 509	suspend_enable_secondary_cpus();
 510
 511 Cleanup:
 512	platform_restore_cleanup(platform_mode);
 513
 514	dpm_resume_start(PMSG_RECOVER);
 515
 516	return error;
 517}
 518
 519/**
 520 * hibernation_restore - Quiesce devices and restore from a hibernation image.
 521 * @platform_mode: If set, use platform driver to prepare for the transition.
 522 *
 523 * This routine must be called with system_transition_mutex held.  If it is
 524 * successful, control reappears in the restored target kernel in
 525 * hibernation_snapshot().
 526 */
 527int hibernation_restore(int platform_mode)
 528{
 529	int error;
 530
 531	pm_prepare_console();
 532	suspend_console();
 533	pm_restrict_gfp_mask();
 534	error = dpm_suspend_start(PMSG_QUIESCE);
 535	if (!error) {
 536		error = resume_target_kernel(platform_mode);
 537		/*
 538		 * The above should either succeed and jump to the new kernel,
 539		 * or return with an error. Otherwise things are just
 540		 * undefined, so let's be paranoid.
 541		 */
 542		BUG_ON(!error);
 543	}
 544	dpm_resume_end(PMSG_RECOVER);
 545	pm_restore_gfp_mask();
 546	resume_console();
 547	pm_restore_console();
 548	return error;
 549}
 550
 551/**
 552 * hibernation_platform_enter - Power off the system using the platform driver.
 553 */
 554int hibernation_platform_enter(void)
 555{
 556	int error;
 557
 558	if (!hibernation_ops)
 559		return -ENOSYS;
 560
 561	/*
 562	 * We have cancelled the power transition by running
 563	 * hibernation_ops->finish() before saving the image, so we should let
 564	 * the firmware know that we're going to enter the sleep state after all
 565	 */
 566	error = hibernation_ops->begin(PMSG_HIBERNATE);
 567	if (error)
 568		goto Close;
 569
 570	entering_platform_hibernation = true;
 571	suspend_console();
 572	error = dpm_suspend_start(PMSG_HIBERNATE);
 573	if (error) {
 574		if (hibernation_ops->recover)
 575			hibernation_ops->recover();
 576		goto Resume_devices;
 577	}
 578
 579	error = dpm_suspend_end(PMSG_HIBERNATE);
 580	if (error)
 581		goto Resume_devices;
 582
 583	error = hibernation_ops->prepare();
 584	if (error)
 585		goto Platform_finish;
 586
 587	error = suspend_disable_secondary_cpus();
 588	if (error)
 589		goto Enable_cpus;
 590
 591	local_irq_disable();
 592	system_state = SYSTEM_SUSPEND;
 593	syscore_suspend();
 594	if (pm_wakeup_pending()) {
 595		error = -EAGAIN;
 596		goto Power_up;
 597	}
 598
 599	hibernation_ops->enter();
 600	/* We should never get here */
 601	while (1);
 602
 603 Power_up:
 604	syscore_resume();
 605	system_state = SYSTEM_RUNNING;
 606	local_irq_enable();
 607
 608 Enable_cpus:
 609	suspend_enable_secondary_cpus();
 610
 611 Platform_finish:
 612	hibernation_ops->finish();
 613
 614	dpm_resume_start(PMSG_RESTORE);
 615
 616 Resume_devices:
 617	entering_platform_hibernation = false;
 618	dpm_resume_end(PMSG_RESTORE);
 619	resume_console();
 620
 621 Close:
 622	hibernation_ops->end();
 623
 624	return error;
 625}
 626
 627/**
 628 * power_down - Shut the machine down for hibernation.
 629 *
 630 * Use the platform driver, if configured, to put the system into the sleep
 631 * state corresponding to hibernation, or try to power it off or reboot,
 632 * depending on the value of hibernation_mode.
 633 */
 634static void power_down(void)
 635{
 636#ifdef CONFIG_SUSPEND
 637	int error;
 638
 639	if (hibernation_mode == HIBERNATION_SUSPEND) {
 640		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
 641		if (error) {
 642			hibernation_mode = hibernation_ops ?
 643						HIBERNATION_PLATFORM :
 644						HIBERNATION_SHUTDOWN;
 645		} else {
 646			/* Restore swap signature. */
 647			error = swsusp_unmark();
 648			if (error)
 649				pr_err("Swap will be unusable! Try swapon -a.\n");
 650
 651			return;
 652		}
 653	}
 654#endif
 655
 656	switch (hibernation_mode) {
 657	case HIBERNATION_REBOOT:
 658		kernel_restart(NULL);
 659		break;
 660	case HIBERNATION_PLATFORM:
 661		hibernation_platform_enter();
 662		fallthrough;
 663	case HIBERNATION_SHUTDOWN:
 664		if (pm_power_off)
 665			kernel_power_off();
 666		break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 667	}
 668	kernel_halt();
 669	/*
 670	 * Valid image is on the disk, if we continue we risk serious data
 671	 * corruption after resume.
 672	 */
 673	pr_crit("Power down manually\n");
 674	while (1)
 675		cpu_relax();
 676}
 677
 678static int load_image_and_restore(void)
 679{
 680	int error;
 681	unsigned int flags;
 682
 683	pm_pr_dbg("Loading hibernation image.\n");
 684
 685	lock_device_hotplug();
 686	error = create_basic_memory_bitmaps();
 687	if (error)
 688		goto Unlock;
 689
 690	error = swsusp_read(&flags);
 691	swsusp_close(FMODE_READ);
 692	if (!error)
 693		error = hibernation_restore(flags & SF_PLATFORM_MODE);
 694
 695	pr_err("Failed to load image, recovering.\n");
 696	swsusp_free();
 697	free_basic_memory_bitmaps();
 698 Unlock:
 699	unlock_device_hotplug();
 700
 701	return error;
 702}
 703
 704/**
 705 * hibernate - Carry out system hibernation, including saving the image.
 706 */
 707int hibernate(void)
 708{
 709	int error, nr_calls = 0;
 710	bool snapshot_test = false;
 711
 712	if (!hibernation_available()) {
 713		pm_pr_dbg("Hibernation not available.\n");
 714		return -EPERM;
 715	}
 716
 717	lock_system_sleep();
 718	/* The snapshot device should not be opened while we're running */
 719	if (!hibernate_acquire()) {
 720		error = -EBUSY;
 721		goto Unlock;
 722	}
 723
 724	pr_info("hibernation entry\n");
 725	pm_prepare_console();
 726	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 727	if (error) {
 728		nr_calls--;
 729		goto Exit;
 730	}
 731
 732	ksys_sync_helper();
 
 
 733
 734	error = freeze_processes();
 735	if (error)
 736		goto Exit;
 737
 738	lock_device_hotplug();
 739	/* Allocate memory management structures */
 740	error = create_basic_memory_bitmaps();
 741	if (error)
 742		goto Thaw;
 743
 744	error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
 745	if (error || freezer_test_done)
 746		goto Free_bitmaps;
 747
 748	if (in_suspend) {
 749		unsigned int flags = 0;
 750
 751		if (hibernation_mode == HIBERNATION_PLATFORM)
 752			flags |= SF_PLATFORM_MODE;
 753		if (nocompress)
 754			flags |= SF_NOCOMPRESS_MODE;
 755		else
 756		        flags |= SF_CRC32_MODE;
 757
 758		pm_pr_dbg("Writing hibernation image.\n");
 759		error = swsusp_write(flags);
 760		swsusp_free();
 761		if (!error) {
 762			if (hibernation_mode == HIBERNATION_TEST_RESUME)
 763				snapshot_test = true;
 764			else
 765				power_down();
 766		}
 767		in_suspend = 0;
 768		pm_restore_gfp_mask();
 769	} else {
 770		pm_pr_dbg("Hibernation image restored successfully.\n");
 771	}
 772
 773 Free_bitmaps:
 774	free_basic_memory_bitmaps();
 775 Thaw:
 776	unlock_device_hotplug();
 777	if (snapshot_test) {
 778		pm_pr_dbg("Checking hibernation image\n");
 779		error = swsusp_check();
 780		if (!error)
 781			error = load_image_and_restore();
 782	}
 783	thaw_processes();
 784
 785	/* Don't bother checking whether freezer_test_done is true */
 786	freezer_test_done = false;
 787 Exit:
 788	__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
 789	pm_restore_console();
 790	hibernate_release();
 791 Unlock:
 792	unlock_system_sleep();
 793	pr_info("hibernation exit\n");
 794
 795	return error;
 796}
 797
 798/**
 799 * hibernate_quiet_exec - Execute a function with all devices frozen.
 800 * @func: Function to execute.
 801 * @data: Data pointer to pass to @func.
 802 *
 803 * Return the @func return value or an error code if it cannot be executed.
 804 */
 805int hibernate_quiet_exec(int (*func)(void *data), void *data)
 806{
 807	int error, nr_calls = 0;
 808
 809	lock_system_sleep();
 810
 811	if (!hibernate_acquire()) {
 812		error = -EBUSY;
 813		goto unlock;
 814	}
 815
 816	pm_prepare_console();
 817
 818	error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
 819	if (error) {
 820		nr_calls--;
 821		goto exit;
 822	}
 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, nr_calls, NULL);
 884
 885	pm_restore_console();
 886
 887	hibernate_release();
 888
 889unlock:
 890	unlock_system_sleep();
 891
 892	return error;
 893}
 894EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
 895
 896/**
 897 * software_resume - Resume from a saved hibernation image.
 898 *
 899 * This routine is called as a late initcall, when all devices have been
 900 * discovered and initialized already.
 901 *
 902 * The image reading code is called to see if there is a hibernation image
 903 * available for reading.  If that is the case, devices are quiesced and the
 904 * contents of memory is restored from the saved image.
 905 *
 906 * If this is successful, control reappears in the restored target kernel in
 907 * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
 908 * attempts to recover gracefully and make the kernel return to the normal mode
 909 * of operation.
 910 */
 911static int software_resume(void)
 912{
 913	int error, nr_calls = 0;
 914
 915	/*
 916	 * If the user said "noresume".. bail out early.
 917	 */
 918	if (noresume || !hibernation_available())
 919		return 0;
 920
 921	/*
 922	 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
 923	 * is configured into the kernel. Since the regular hibernate
 924	 * trigger path is via sysfs which takes a buffer mutex before
 925	 * calling hibernate functions (which take system_transition_mutex)
 926	 * this can cause lockdep to complain about a possible ABBA deadlock
 927	 * which cannot happen since we're in the boot code here and
 928	 * sysfs can't be invoked yet. Therefore, we use a subclass
 929	 * here to avoid lockdep complaining.
 930	 */
 931	mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
 932
 933	if (swsusp_resume_device)
 934		goto Check_image;
 935
 936	if (!strlen(resume_file)) {
 937		error = -ENOENT;
 938		goto Unlock;
 939	}
 940
 941	pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
 942
 943	if (resume_delay) {
 944		pr_info("Waiting %dsec before reading resume device ...\n",
 945			resume_delay);
 946		ssleep(resume_delay);
 947	}
 948
 949	/* Check if the device is there */
 950	swsusp_resume_device = name_to_dev_t(resume_file);
 951
 952	/*
 953	 * name_to_dev_t is ineffective to verify parition if resume_file is in
 954	 * integer format. (e.g. major:minor)
 955	 */
 956	if (isdigit(resume_file[0]) && resume_wait) {
 957		int partno;
 958		while (!get_gendisk(swsusp_resume_device, &partno))
 959			msleep(10);
 960	}
 961
 962	if (!swsusp_resume_device) {
 963		/*
 964		 * Some device discovery might still be in progress; we need
 965		 * to wait for this to finish.
 966		 */
 967		wait_for_device_probe();
 968
 969		if (resume_wait) {
 970			while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
 971				msleep(10);
 972			async_synchronize_full();
 973		}
 974
 975		swsusp_resume_device = name_to_dev_t(resume_file);
 976		if (!swsusp_resume_device) {
 977			error = -ENODEV;
 978			goto Unlock;
 979		}
 980	}
 981
 982 Check_image:
 983	pm_pr_dbg("Hibernation image partition %d:%d present\n",
 984		MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
 985
 986	pm_pr_dbg("Looking for hibernation image.\n");
 987	error = swsusp_check();
 988	if (error)
 989		goto Unlock;
 990
 991	/* The snapshot device should not be opened while we're running */
 992	if (!hibernate_acquire()) {
 993		error = -EBUSY;
 994		swsusp_close(FMODE_READ);
 995		goto Unlock;
 996	}
 997
 998	pr_info("resume from hibernation\n");
 999	pm_prepare_console();
1000	error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
1001	if (error) {
1002		nr_calls--;
1003		goto Close_Finish;
1004	}
1005
1006	pm_pr_dbg("Preparing processes for hibernation restore.\n");
1007	error = freeze_processes();
1008	if (error)
1009		goto Close_Finish;
1010
1011	error = freeze_kernel_threads();
1012	if (error) {
1013		thaw_processes();
1014		goto Close_Finish;
1015	}
1016
1017	error = load_image_and_restore();
1018	thaw_processes();
1019 Finish:
1020	__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
1021	pm_restore_console();
1022	pr_info("resume failed (%d)\n", error);
1023	hibernate_release();
1024	/* For success case, the suspend path will release the lock */
1025 Unlock:
1026	mutex_unlock(&system_transition_mutex);
1027	pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1028	return error;
1029 Close_Finish:
1030	swsusp_close(FMODE_READ);
1031	goto Finish;
1032}
1033
1034late_initcall_sync(software_resume);
1035
1036
1037static const char * const hibernation_modes[] = {
1038	[HIBERNATION_PLATFORM]	= "platform",
1039	[HIBERNATION_SHUTDOWN]	= "shutdown",
1040	[HIBERNATION_REBOOT]	= "reboot",
1041#ifdef CONFIG_SUSPEND
1042	[HIBERNATION_SUSPEND]	= "suspend",
1043#endif
1044	[HIBERNATION_TEST_RESUME]	= "test_resume",
1045};
1046
1047/*
1048 * /sys/power/disk - Control hibernation mode.
1049 *
1050 * Hibernation can be handled in several ways.  There are a few different ways
1051 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1052 * or other hibernation_ops), powering it off or rebooting it (for testing
1053 * mostly).
1054 *
1055 * The sysfs file /sys/power/disk provides an interface for selecting the
1056 * hibernation mode to use.  Reading from this file causes the available modes
1057 * to be printed.  There are 3 modes that can be supported:
1058 *
1059 *	'platform'
1060 *	'shutdown'
1061 *	'reboot'
1062 *
1063 * If a platform hibernation driver is in use, 'platform' will be supported
1064 * and will be used by default.  Otherwise, 'shutdown' will be used by default.
1065 * The selected option (i.e. the one corresponding to the current value of
1066 * hibernation_mode) is enclosed by a square bracket.
1067 *
1068 * To select a given hibernation mode it is necessary to write the mode's
1069 * string representation (as returned by reading from /sys/power/disk) back
1070 * into /sys/power/disk.
1071 */
1072
1073static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1074			 char *buf)
1075{
1076	int i;
1077	char *start = buf;
1078
1079	if (!hibernation_available())
1080		return sprintf(buf, "[disabled]\n");
1081
1082	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1083		if (!hibernation_modes[i])
1084			continue;
1085		switch (i) {
1086		case HIBERNATION_SHUTDOWN:
1087		case HIBERNATION_REBOOT:
1088#ifdef CONFIG_SUSPEND
1089		case HIBERNATION_SUSPEND:
1090#endif
1091		case HIBERNATION_TEST_RESUME:
1092			break;
1093		case HIBERNATION_PLATFORM:
1094			if (hibernation_ops)
1095				break;
1096			/* not a valid mode, continue with loop */
1097			continue;
1098		}
1099		if (i == hibernation_mode)
1100			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1101		else
1102			buf += sprintf(buf, "%s ", hibernation_modes[i]);
1103	}
1104	buf += sprintf(buf, "\n");
1105	return buf-start;
1106}
1107
1108static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1109			  const char *buf, size_t n)
1110{
1111	int error = 0;
1112	int i;
1113	int len;
1114	char *p;
1115	int mode = HIBERNATION_INVALID;
1116
1117	if (!hibernation_available())
1118		return -EPERM;
1119
1120	p = memchr(buf, '\n', n);
1121	len = p ? p - buf : n;
1122
1123	lock_system_sleep();
1124	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1125		if (len == strlen(hibernation_modes[i])
1126		    && !strncmp(buf, hibernation_modes[i], len)) {
1127			mode = i;
1128			break;
1129		}
1130	}
1131	if (mode != HIBERNATION_INVALID) {
1132		switch (mode) {
1133		case HIBERNATION_SHUTDOWN:
1134		case HIBERNATION_REBOOT:
1135#ifdef CONFIG_SUSPEND
1136		case HIBERNATION_SUSPEND:
1137#endif
1138		case HIBERNATION_TEST_RESUME:
1139			hibernation_mode = mode;
1140			break;
1141		case HIBERNATION_PLATFORM:
1142			if (hibernation_ops)
1143				hibernation_mode = mode;
1144			else
1145				error = -EINVAL;
1146		}
1147	} else
1148		error = -EINVAL;
1149
1150	if (!error)
1151		pm_pr_dbg("Hibernation mode set to '%s'\n",
1152			       hibernation_modes[mode]);
1153	unlock_system_sleep();
1154	return error ? error : n;
1155}
1156
1157power_attr(disk);
1158
1159static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1160			   char *buf)
1161{
1162	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1163		       MINOR(swsusp_resume_device));
1164}
1165
1166static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1167			    const char *buf, size_t n)
1168{
1169	dev_t res;
1170	int len = n;
1171	char *name;
1172
1173	if (len && buf[len-1] == '\n')
1174		len--;
1175	name = kstrndup(buf, len, GFP_KERNEL);
1176	if (!name)
1177		return -ENOMEM;
1178
1179	res = name_to_dev_t(name);
1180	kfree(name);
1181	if (!res)
1182		return -EINVAL;
1183
1184	lock_system_sleep();
1185	swsusp_resume_device = res;
1186	unlock_system_sleep();
1187	pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1188		  swsusp_resume_device);
1189	noresume = 0;
1190	software_resume();
1191	return n;
1192}
1193
1194power_attr(resume);
1195
1196static ssize_t resume_offset_show(struct kobject *kobj,
1197				  struct kobj_attribute *attr, char *buf)
1198{
1199	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1200}
1201
1202static ssize_t resume_offset_store(struct kobject *kobj,
1203				   struct kobj_attribute *attr, const char *buf,
1204				   size_t n)
1205{
1206	unsigned long long offset;
1207	int rc;
1208
1209	rc = kstrtoull(buf, 0, &offset);
1210	if (rc)
1211		return rc;
1212	swsusp_resume_block = offset;
1213
1214	return n;
1215}
1216
1217power_attr(resume_offset);
1218
1219static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1220			       char *buf)
1221{
1222	return sprintf(buf, "%lu\n", image_size);
1223}
1224
1225static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1226				const char *buf, size_t n)
1227{
1228	unsigned long size;
1229
1230	if (sscanf(buf, "%lu", &size) == 1) {
1231		image_size = size;
1232		return n;
1233	}
1234
1235	return -EINVAL;
1236}
1237
1238power_attr(image_size);
1239
1240static ssize_t reserved_size_show(struct kobject *kobj,
1241				  struct kobj_attribute *attr, char *buf)
1242{
1243	return sprintf(buf, "%lu\n", reserved_size);
1244}
1245
1246static ssize_t reserved_size_store(struct kobject *kobj,
1247				   struct kobj_attribute *attr,
1248				   const char *buf, size_t n)
1249{
1250	unsigned long size;
1251
1252	if (sscanf(buf, "%lu", &size) == 1) {
1253		reserved_size = size;
1254		return n;
1255	}
1256
1257	return -EINVAL;
1258}
1259
1260power_attr(reserved_size);
1261
1262static struct attribute *g[] = {
1263	&disk_attr.attr,
1264	&resume_offset_attr.attr,
1265	&resume_attr.attr,
1266	&image_size_attr.attr,
1267	&reserved_size_attr.attr,
1268	NULL,
1269};
1270
1271
1272static const struct attribute_group attr_group = {
1273	.attrs = g,
1274};
1275
1276
1277static int __init pm_disk_init(void)
1278{
1279	return sysfs_create_group(power_kobj, &attr_group);
1280}
1281
1282core_initcall(pm_disk_init);
1283
1284
1285static int __init resume_setup(char *str)
1286{
1287	if (noresume)
1288		return 1;
1289
1290	strncpy(resume_file, str, 255);
1291	return 1;
1292}
1293
1294static int __init resume_offset_setup(char *str)
1295{
1296	unsigned long long offset;
1297
1298	if (noresume)
1299		return 1;
1300
1301	if (sscanf(str, "%llu", &offset) == 1)
1302		swsusp_resume_block = offset;
1303
1304	return 1;
1305}
1306
1307static int __init hibernate_setup(char *str)
1308{
1309	if (!strncmp(str, "noresume", 8)) {
1310		noresume = 1;
1311	} else if (!strncmp(str, "nocompress", 10)) {
1312		nocompress = 1;
1313	} else if (!strncmp(str, "no", 2)) {
1314		noresume = 1;
1315		nohibernate = 1;
1316	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1317		   && !strncmp(str, "protect_image", 13)) {
1318		enable_restore_image_protection();
1319	}
1320	return 1;
1321}
1322
1323static int __init noresume_setup(char *str)
1324{
1325	noresume = 1;
1326	return 1;
1327}
1328
1329static int __init resumewait_setup(char *str)
1330{
1331	resume_wait = 1;
1332	return 1;
1333}
1334
1335static int __init resumedelay_setup(char *str)
1336{
1337	int rc = kstrtouint(str, 0, &resume_delay);
1338
1339	if (rc)
1340		return rc;
1341	return 1;
1342}
1343
1344static int __init nohibernate_setup(char *str)
1345{
1346	noresume = 1;
1347	nohibernate = 1;
1348	return 1;
1349}
1350
1351__setup("noresume", noresume_setup);
1352__setup("resume_offset=", resume_offset_setup);
1353__setup("resume=", resume_setup);
1354__setup("hibernate=", hibernate_setup);
1355__setup("resumewait", resumewait_setup);
1356__setup("resumedelay=", resumedelay_setup);
1357__setup("nohibernate", nohibernate_setup);
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);