Root/kernel/power/hibernate.c

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 *
9 * This file is released under the GPLv2.
10 */
11
12#include <linux/suspend.h>
13#include <linux/syscalls.h>
14#include <linux/reboot.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/kmod.h>
18#include <linux/delay.h>
19#include <linux/fs.h>
20#include <linux/mount.h>
21#include <linux/pm.h>
22#include <linux/console.h>
23#include <linux/cpu.h>
24#include <linux/freezer.h>
25#include <linux/gfp.h>
26#include <linux/syscore_ops.h>
27#include <scsi/scsi_scan.h>
28
29#include "power.h"
30
31
32static int nocompress = 0;
33static int noresume = 0;
34static char resume_file[256] = CONFIG_PM_STD_PARTITION;
35dev_t swsusp_resume_device;
36sector_t swsusp_resume_block;
37int in_suspend __nosavedata = 0;
38
39enum {
40    HIBERNATION_INVALID,
41    HIBERNATION_PLATFORM,
42    HIBERNATION_TEST,
43    HIBERNATION_TESTPROC,
44    HIBERNATION_SHUTDOWN,
45    HIBERNATION_REBOOT,
46    /* keep last */
47    __HIBERNATION_AFTER_LAST
48};
49#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
50#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
51
52static int hibernation_mode = HIBERNATION_SHUTDOWN;
53
54static const struct platform_hibernation_ops *hibernation_ops;
55
56/**
57 * hibernation_set_ops - Set the global hibernate operations.
58 * @ops: Hibernation operations to use in subsequent hibernation transitions.
59 */
60void hibernation_set_ops(const struct platform_hibernation_ops *ops)
61{
62    if (ops && !(ops->begin && ops->end && ops->pre_snapshot
63        && ops->prepare && ops->finish && ops->enter && ops->pre_restore
64        && ops->restore_cleanup && ops->leave)) {
65        WARN_ON(1);
66        return;
67    }
68    mutex_lock(&pm_mutex);
69    hibernation_ops = ops;
70    if (ops)
71        hibernation_mode = HIBERNATION_PLATFORM;
72    else if (hibernation_mode == HIBERNATION_PLATFORM)
73        hibernation_mode = HIBERNATION_SHUTDOWN;
74
75    mutex_unlock(&pm_mutex);
76}
77
78static bool entering_platform_hibernation;
79
80bool system_entering_hibernation(void)
81{
82    return entering_platform_hibernation;
83}
84EXPORT_SYMBOL(system_entering_hibernation);
85
86#ifdef CONFIG_PM_DEBUG
87static void hibernation_debug_sleep(void)
88{
89    printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
90    mdelay(5000);
91}
92
93static int hibernation_testmode(int mode)
94{
95    if (hibernation_mode == mode) {
96        hibernation_debug_sleep();
97        return 1;
98    }
99    return 0;
100}
101
102static int hibernation_test(int level)
103{
104    if (pm_test_level == level) {
105        hibernation_debug_sleep();
106        return 1;
107    }
108    return 0;
109}
110#else /* !CONFIG_PM_DEBUG */
111static int hibernation_testmode(int mode) { return 0; }
112static int hibernation_test(int level) { return 0; }
113#endif /* !CONFIG_PM_DEBUG */
114
115/**
116 * platform_begin - Call platform to start hibernation.
117 * @platform_mode: Whether or not to use the platform driver.
118 */
119static int platform_begin(int platform_mode)
120{
121    return (platform_mode && hibernation_ops) ?
122        hibernation_ops->begin() : 0;
123}
124
125/**
126 * platform_end - Call platform to finish transition to the working state.
127 * @platform_mode: Whether or not to use the platform driver.
128 */
129static void platform_end(int platform_mode)
130{
131    if (platform_mode && hibernation_ops)
132        hibernation_ops->end();
133}
134
135/**
136 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
137 * @platform_mode: Whether or not to use the platform driver.
138 *
139 * Use the platform driver to prepare the system for creating a hibernate image,
140 * if so configured, and return an error code if that fails.
141 */
142
143static int platform_pre_snapshot(int platform_mode)
144{
145    return (platform_mode && hibernation_ops) ?
146        hibernation_ops->pre_snapshot() : 0;
147}
148
149/**
150 * platform_leave - Call platform to prepare a transition to the working state.
151 * @platform_mode: Whether or not to use the platform driver.
152 *
153 * Use the platform driver prepare to prepare the machine for switching to the
154 * normal mode of operation.
155 *
156 * This routine is called on one CPU with interrupts disabled.
157 */
158static void platform_leave(int platform_mode)
159{
160    if (platform_mode && hibernation_ops)
161        hibernation_ops->leave();
162}
163
164/**
165 * platform_finish - Call platform to switch the system to the working state.
166 * @platform_mode: Whether or not to use the platform driver.
167 *
168 * Use the platform driver to switch the machine to the normal mode of
169 * operation.
170 *
171 * This routine must be called after platform_prepare().
172 */
173static void platform_finish(int platform_mode)
174{
175    if (platform_mode && hibernation_ops)
176        hibernation_ops->finish();
177}
178
179/**
180 * platform_pre_restore - Prepare for hibernate image restoration.
181 * @platform_mode: Whether or not to use the platform driver.
182 *
183 * Use the platform driver to prepare the system for resume from a hibernation
184 * image.
185 *
186 * If the restore fails after this function has been called,
187 * platform_restore_cleanup() must be called.
188 */
189static int platform_pre_restore(int platform_mode)
190{
191    return (platform_mode && hibernation_ops) ?
192        hibernation_ops->pre_restore() : 0;
193}
194
195/**
196 * platform_restore_cleanup - Switch to the working state after failing restore.
197 * @platform_mode: Whether or not to use the platform driver.
198 *
199 * Use the platform driver to switch the system to the normal mode of operation
200 * after a failing restore.
201 *
202 * If platform_pre_restore() has been called before the failing restore, this
203 * function must be called too, regardless of the result of
204 * platform_pre_restore().
205 */
206static void platform_restore_cleanup(int platform_mode)
207{
208    if (platform_mode && hibernation_ops)
209        hibernation_ops->restore_cleanup();
210}
211
212/**
213 * platform_recover - Recover from a failure to suspend devices.
214 * @platform_mode: Whether or not to use the platform driver.
215 */
216static void platform_recover(int platform_mode)
217{
218    if (platform_mode && hibernation_ops && hibernation_ops->recover)
219        hibernation_ops->recover();
220}
221
222/**
223 * swsusp_show_speed - Print time elapsed between two events during hibernation.
224 * @start: Starting event.
225 * @stop: Final event.
226 * @nr_pages: Number of memory pages processed between @start and @stop.
227 * @msg: Additional diagnostic message to print.
228 */
229void swsusp_show_speed(struct timeval *start, struct timeval *stop,
230            unsigned nr_pages, char *msg)
231{
232    s64 elapsed_centisecs64;
233    int centisecs;
234    int k;
235    int kps;
236
237    elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
238    do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
239    centisecs = elapsed_centisecs64;
240    if (centisecs == 0)
241        centisecs = 1; /* avoid div-by-zero */
242    k = nr_pages * (PAGE_SIZE / 1024);
243    kps = (k * 100) / centisecs;
244    printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
245            msg, k,
246            centisecs / 100, centisecs % 100,
247            kps / 1000, (kps % 1000) / 10);
248}
249
250/**
251 * create_image - Create a hibernation image.
252 * @platform_mode: Whether or not to use the platform driver.
253 *
254 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
255 * and execute the drivers' .thaw_noirq() callbacks.
256 *
257 * Control reappears in this routine after the subsequent restore.
258 */
259static int create_image(int platform_mode)
260{
261    int error;
262
263    error = dpm_suspend_noirq(PMSG_FREEZE);
264    if (error) {
265        printk(KERN_ERR "PM: Some devices failed to power down, "
266            "aborting hibernation\n");
267        return error;
268    }
269
270    error = platform_pre_snapshot(platform_mode);
271    if (error || hibernation_test(TEST_PLATFORM))
272        goto Platform_finish;
273
274    error = disable_nonboot_cpus();
275    if (error || hibernation_test(TEST_CPUS)
276        || hibernation_testmode(HIBERNATION_TEST))
277        goto Enable_cpus;
278
279    local_irq_disable();
280
281    error = syscore_suspend();
282    if (error) {
283        printk(KERN_ERR "PM: Some system devices failed to power down, "
284            "aborting hibernation\n");
285        goto Enable_irqs;
286    }
287
288    if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
289        goto Power_up;
290
291    in_suspend = 1;
292    save_processor_state();
293    error = swsusp_arch_suspend();
294    if (error)
295        printk(KERN_ERR "PM: Error %d creating hibernation image\n",
296            error);
297    /* Restore control flow magically appears here */
298    restore_processor_state();
299    if (!in_suspend) {
300        events_check_enabled = false;
301        platform_leave(platform_mode);
302    }
303
304 Power_up:
305    syscore_resume();
306
307 Enable_irqs:
308    local_irq_enable();
309
310 Enable_cpus:
311    enable_nonboot_cpus();
312
313 Platform_finish:
314    platform_finish(platform_mode);
315
316    dpm_resume_noirq(in_suspend ?
317        (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
318
319    return error;
320}
321
322/**
323 * hibernation_snapshot - Quiesce devices and create a hibernation image.
324 * @platform_mode: If set, use platform driver to prepare for the transition.
325 *
326 * This routine must be called with pm_mutex held.
327 */
328int hibernation_snapshot(int platform_mode)
329{
330    pm_message_t msg = PMSG_RECOVER;
331    int error;
332
333    error = platform_begin(platform_mode);
334    if (error)
335        goto Close;
336
337    error = dpm_prepare(PMSG_FREEZE);
338    if (error)
339        goto Complete_devices;
340
341    /* Preallocate image memory before shutting down devices. */
342    error = hibernate_preallocate_memory();
343    if (error)
344        goto Complete_devices;
345
346    suspend_console();
347    pm_restrict_gfp_mask();
348    error = dpm_suspend(PMSG_FREEZE);
349    if (error)
350        goto Recover_platform;
351
352    if (hibernation_test(TEST_DEVICES))
353        goto Recover_platform;
354
355    error = create_image(platform_mode);
356    /*
357     * Control returns here (1) after the image has been created or the
358     * image creation has failed and (2) after a successful restore.
359     */
360
361 Resume_devices:
362    /* We may need to release the preallocated image pages here. */
363    if (error || !in_suspend)
364        swsusp_free();
365
366    msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
367    dpm_resume(msg);
368
369    if (error || !in_suspend)
370        pm_restore_gfp_mask();
371
372    resume_console();
373
374 Complete_devices:
375    dpm_complete(msg);
376
377 Close:
378    platform_end(platform_mode);
379    return error;
380
381 Recover_platform:
382    platform_recover(platform_mode);
383    goto Resume_devices;
384}
385
386/**
387 * resume_target_kernel - Restore system state from a hibernation image.
388 * @platform_mode: Whether or not to use the platform driver.
389 *
390 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
391 * highmem that have not been restored yet from the image and run the low-level
392 * code that will restore the remaining contents of memory and switch to the
393 * just restored target kernel.
394 */
395static int resume_target_kernel(bool platform_mode)
396{
397    int error;
398
399    error = dpm_suspend_noirq(PMSG_QUIESCE);
400    if (error) {
401        printk(KERN_ERR "PM: Some devices failed to power down, "
402            "aborting resume\n");
403        return error;
404    }
405
406    error = platform_pre_restore(platform_mode);
407    if (error)
408        goto Cleanup;
409
410    error = disable_nonboot_cpus();
411    if (error)
412        goto Enable_cpus;
413
414    local_irq_disable();
415
416    error = syscore_suspend();
417    if (error)
418        goto Enable_irqs;
419
420    save_processor_state();
421    error = restore_highmem();
422    if (!error) {
423        error = swsusp_arch_resume();
424        /*
425         * The code below is only ever reached in case of a failure.
426         * Otherwise, execution continues at the place where
427         * swsusp_arch_suspend() was called.
428         */
429        BUG_ON(!error);
430        /*
431         * This call to restore_highmem() reverts the changes made by
432         * the previous one.
433         */
434        restore_highmem();
435    }
436    /*
437     * The only reason why swsusp_arch_resume() can fail is memory being
438     * very tight, so we have to free it as soon as we can to avoid
439     * subsequent failures.
440     */
441    swsusp_free();
442    restore_processor_state();
443    touch_softlockup_watchdog();
444
445    syscore_resume();
446
447 Enable_irqs:
448    local_irq_enable();
449
450 Enable_cpus:
451    enable_nonboot_cpus();
452
453 Cleanup:
454    platform_restore_cleanup(platform_mode);
455
456    dpm_resume_noirq(PMSG_RECOVER);
457
458    return error;
459}
460
461/**
462 * hibernation_restore - Quiesce devices and restore from a hibernation image.
463 * @platform_mode: If set, use platform driver to prepare for the transition.
464 *
465 * This routine must be called with pm_mutex held. If it is successful, control
466 * reappears in the restored target kernel in hibernation_snaphot().
467 */
468int hibernation_restore(int platform_mode)
469{
470    int error;
471
472    pm_prepare_console();
473    suspend_console();
474    pm_restrict_gfp_mask();
475    error = dpm_suspend_start(PMSG_QUIESCE);
476    if (!error) {
477        error = resume_target_kernel(platform_mode);
478        dpm_resume_end(PMSG_RECOVER);
479    }
480    pm_restore_gfp_mask();
481    resume_console();
482    pm_restore_console();
483    return error;
484}
485
486/**
487 * hibernation_platform_enter - Power off the system using the platform driver.
488 */
489int hibernation_platform_enter(void)
490{
491    int error;
492
493    if (!hibernation_ops)
494        return -ENOSYS;
495
496    /*
497     * We have cancelled the power transition by running
498     * hibernation_ops->finish() before saving the image, so we should let
499     * the firmware know that we're going to enter the sleep state after all
500     */
501    error = hibernation_ops->begin();
502    if (error)
503        goto Close;
504
505    entering_platform_hibernation = true;
506    suspend_console();
507    error = dpm_suspend_start(PMSG_HIBERNATE);
508    if (error) {
509        if (hibernation_ops->recover)
510            hibernation_ops->recover();
511        goto Resume_devices;
512    }
513
514    error = dpm_suspend_noirq(PMSG_HIBERNATE);
515    if (error)
516        goto Resume_devices;
517
518    error = hibernation_ops->prepare();
519    if (error)
520        goto Platform_finish;
521
522    error = disable_nonboot_cpus();
523    if (error)
524        goto Platform_finish;
525
526    local_irq_disable();
527    syscore_suspend();
528    if (pm_wakeup_pending()) {
529        error = -EAGAIN;
530        goto Power_up;
531    }
532
533    hibernation_ops->enter();
534    /* We should never get here */
535    while (1);
536
537 Power_up:
538    syscore_resume();
539    local_irq_enable();
540    enable_nonboot_cpus();
541
542 Platform_finish:
543    hibernation_ops->finish();
544
545    dpm_resume_noirq(PMSG_RESTORE);
546
547 Resume_devices:
548    entering_platform_hibernation = false;
549    dpm_resume_end(PMSG_RESTORE);
550    resume_console();
551
552 Close:
553    hibernation_ops->end();
554
555    return error;
556}
557
558/**
559 * power_down - Shut the machine down for hibernation.
560 *
561 * Use the platform driver, if configured, to put the system into the sleep
562 * state corresponding to hibernation, or try to power it off or reboot,
563 * depending on the value of hibernation_mode.
564 */
565static void power_down(void)
566{
567    switch (hibernation_mode) {
568    case HIBERNATION_TEST:
569    case HIBERNATION_TESTPROC:
570        break;
571    case HIBERNATION_REBOOT:
572        kernel_restart(NULL);
573        break;
574    case HIBERNATION_PLATFORM:
575        hibernation_platform_enter();
576    case HIBERNATION_SHUTDOWN:
577        kernel_power_off();
578        break;
579    }
580    kernel_halt();
581    /*
582     * Valid image is on the disk, if we continue we risk serious data
583     * corruption after resume.
584     */
585    printk(KERN_CRIT "PM: Please power down manually\n");
586    while(1);
587}
588
589static int prepare_processes(void)
590{
591    int error = 0;
592
593    if (freeze_processes()) {
594        error = -EBUSY;
595        thaw_processes();
596    }
597    return error;
598}
599
600/**
601 * hibernate - Carry out system hibernation, including saving the image.
602 */
603int hibernate(void)
604{
605    int error;
606
607    mutex_lock(&pm_mutex);
608    /* The snapshot device should not be opened while we're running */
609    if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
610        error = -EBUSY;
611        goto Unlock;
612    }
613
614    pm_prepare_console();
615    error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
616    if (error)
617        goto Exit;
618
619    error = usermodehelper_disable();
620    if (error)
621        goto Exit;
622
623    /* Allocate memory management structures */
624    error = create_basic_memory_bitmaps();
625    if (error)
626        goto Exit;
627
628    printk(KERN_INFO "PM: Syncing filesystems ... ");
629    sys_sync();
630    printk("done.\n");
631
632    error = prepare_processes();
633    if (error)
634        goto Finish;
635
636    if (hibernation_test(TEST_FREEZER))
637        goto Thaw;
638
639    if (hibernation_testmode(HIBERNATION_TESTPROC))
640        goto Thaw;
641
642    error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
643    if (error)
644        goto Thaw;
645
646    if (in_suspend) {
647        unsigned int flags = 0;
648
649        if (hibernation_mode == HIBERNATION_PLATFORM)
650            flags |= SF_PLATFORM_MODE;
651        if (nocompress)
652            flags |= SF_NOCOMPRESS_MODE;
653        pr_debug("PM: writing image.\n");
654        error = swsusp_write(flags);
655        swsusp_free();
656        if (!error)
657            power_down();
658        in_suspend = 0;
659        pm_restore_gfp_mask();
660    } else {
661        pr_debug("PM: Image restored successfully.\n");
662    }
663
664 Thaw:
665    thaw_processes();
666 Finish:
667    free_basic_memory_bitmaps();
668    usermodehelper_enable();
669 Exit:
670    pm_notifier_call_chain(PM_POST_HIBERNATION);
671    pm_restore_console();
672    atomic_inc(&snapshot_device_available);
673 Unlock:
674    mutex_unlock(&pm_mutex);
675    return error;
676}
677
678
679/**
680 * software_resume - Resume from a saved hibernation image.
681 *
682 * This routine is called as a late initcall, when all devices have been
683 * discovered and initialized already.
684 *
685 * The image reading code is called to see if there is a hibernation image
686 * available for reading. If that is the case, devices are quiesced and the
687 * contents of memory is restored from the saved image.
688 *
689 * If this is successful, control reappears in the restored target kernel in
690 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
691 * attempts to recover gracefully and make the kernel return to the normal mode
692 * of operation.
693 */
694static int software_resume(void)
695{
696    int error;
697    unsigned int flags;
698
699    /*
700     * If the user said "noresume".. bail out early.
701     */
702    if (noresume)
703        return 0;
704
705    /*
706     * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
707     * is configured into the kernel. Since the regular hibernate
708     * trigger path is via sysfs which takes a buffer mutex before
709     * calling hibernate functions (which take pm_mutex) this can
710     * cause lockdep to complain about a possible ABBA deadlock
711     * which cannot happen since we're in the boot code here and
712     * sysfs can't be invoked yet. Therefore, we use a subclass
713     * here to avoid lockdep complaining.
714     */
715    mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
716
717    if (swsusp_resume_device)
718        goto Check_image;
719
720    if (!strlen(resume_file)) {
721        error = -ENOENT;
722        goto Unlock;
723    }
724
725    pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
726
727    /* Check if the device is there */
728    swsusp_resume_device = name_to_dev_t(resume_file);
729    if (!swsusp_resume_device) {
730        /*
731         * Some device discovery might still be in progress; we need
732         * to wait for this to finish.
733         */
734        wait_for_device_probe();
735        /*
736         * We can't depend on SCSI devices being available after loading
737         * one of their modules until scsi_complete_async_scans() is
738         * called and the resume device usually is a SCSI one.
739         */
740        scsi_complete_async_scans();
741
742        swsusp_resume_device = name_to_dev_t(resume_file);
743        if (!swsusp_resume_device) {
744            error = -ENODEV;
745            goto Unlock;
746        }
747    }
748
749 Check_image:
750    pr_debug("PM: Hibernation image partition %d:%d present\n",
751        MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
752
753    pr_debug("PM: Looking for hibernation image.\n");
754    error = swsusp_check();
755    if (error)
756        goto Unlock;
757
758    /* The snapshot device should not be opened while we're running */
759    if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
760        error = -EBUSY;
761        swsusp_close(FMODE_READ);
762        goto Unlock;
763    }
764
765    pm_prepare_console();
766    error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
767    if (error)
768        goto close_finish;
769
770    error = usermodehelper_disable();
771    if (error)
772        goto close_finish;
773
774    error = create_basic_memory_bitmaps();
775    if (error)
776        goto close_finish;
777
778    pr_debug("PM: Preparing processes for restore.\n");
779    error = prepare_processes();
780    if (error) {
781        swsusp_close(FMODE_READ);
782        goto Done;
783    }
784
785    pr_debug("PM: Loading hibernation image.\n");
786
787    error = swsusp_read(&flags);
788    swsusp_close(FMODE_READ);
789    if (!error)
790        hibernation_restore(flags & SF_PLATFORM_MODE);
791
792    printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
793    swsusp_free();
794    thaw_processes();
795 Done:
796    free_basic_memory_bitmaps();
797    usermodehelper_enable();
798 Finish:
799    pm_notifier_call_chain(PM_POST_RESTORE);
800    pm_restore_console();
801    atomic_inc(&snapshot_device_available);
802    /* For success case, the suspend path will release the lock */
803 Unlock:
804    mutex_unlock(&pm_mutex);
805    pr_debug("PM: Hibernation image not present or could not be loaded.\n");
806    return error;
807close_finish:
808    swsusp_close(FMODE_READ);
809    goto Finish;
810}
811
812late_initcall(software_resume);
813
814
815static const char * const hibernation_modes[] = {
816    [HIBERNATION_PLATFORM] = "platform",
817    [HIBERNATION_SHUTDOWN] = "shutdown",
818    [HIBERNATION_REBOOT] = "reboot",
819    [HIBERNATION_TEST] = "test",
820    [HIBERNATION_TESTPROC] = "testproc",
821};
822
823/*
824 * /sys/power/disk - Control hibernation mode.
825 *
826 * Hibernation can be handled in several ways. There are a few different ways
827 * to put the system into the sleep state: using the platform driver (e.g. ACPI
828 * or other hibernation_ops), powering it off or rebooting it (for testing
829 * mostly), or using one of the two available test modes.
830 *
831 * The sysfs file /sys/power/disk provides an interface for selecting the
832 * hibernation mode to use. Reading from this file causes the available modes
833 * to be printed. There are 5 modes that can be supported:
834 *
835 * 'platform'
836 * 'shutdown'
837 * 'reboot'
838 * 'test'
839 * 'testproc'
840 *
841 * If a platform hibernation driver is in use, 'platform' will be supported
842 * and will be used by default. Otherwise, 'shutdown' will be used by default.
843 * The selected option (i.e. the one corresponding to the current value of
844 * hibernation_mode) is enclosed by a square bracket.
845 *
846 * To select a given hibernation mode it is necessary to write the mode's
847 * string representation (as returned by reading from /sys/power/disk) back
848 * into /sys/power/disk.
849 */
850
851static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
852             char *buf)
853{
854    int i;
855    char *start = buf;
856
857    for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
858        if (!hibernation_modes[i])
859            continue;
860        switch (i) {
861        case HIBERNATION_SHUTDOWN:
862        case HIBERNATION_REBOOT:
863        case HIBERNATION_TEST:
864        case HIBERNATION_TESTPROC:
865            break;
866        case HIBERNATION_PLATFORM:
867            if (hibernation_ops)
868                break;
869            /* not a valid mode, continue with loop */
870            continue;
871        }
872        if (i == hibernation_mode)
873            buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
874        else
875            buf += sprintf(buf, "%s ", hibernation_modes[i]);
876    }
877    buf += sprintf(buf, "\n");
878    return buf-start;
879}
880
881static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
882              const char *buf, size_t n)
883{
884    int error = 0;
885    int i;
886    int len;
887    char *p;
888    int mode = HIBERNATION_INVALID;
889
890    p = memchr(buf, '\n', n);
891    len = p ? p - buf : n;
892
893    mutex_lock(&pm_mutex);
894    for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
895        if (len == strlen(hibernation_modes[i])
896            && !strncmp(buf, hibernation_modes[i], len)) {
897            mode = i;
898            break;
899        }
900    }
901    if (mode != HIBERNATION_INVALID) {
902        switch (mode) {
903        case HIBERNATION_SHUTDOWN:
904        case HIBERNATION_REBOOT:
905        case HIBERNATION_TEST:
906        case HIBERNATION_TESTPROC:
907            hibernation_mode = mode;
908            break;
909        case HIBERNATION_PLATFORM:
910            if (hibernation_ops)
911                hibernation_mode = mode;
912            else
913                error = -EINVAL;
914        }
915    } else
916        error = -EINVAL;
917
918    if (!error)
919        pr_debug("PM: Hibernation mode set to '%s'\n",
920             hibernation_modes[mode]);
921    mutex_unlock(&pm_mutex);
922    return error ? error : n;
923}
924
925power_attr(disk);
926
927static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
928               char *buf)
929{
930    return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
931               MINOR(swsusp_resume_device));
932}
933
934static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
935                const char *buf, size_t n)
936{
937    unsigned int maj, min;
938    dev_t res;
939    int ret = -EINVAL;
940
941    if (sscanf(buf, "%u:%u", &maj, &min) != 2)
942        goto out;
943
944    res = MKDEV(maj,min);
945    if (maj != MAJOR(res) || min != MINOR(res))
946        goto out;
947
948    mutex_lock(&pm_mutex);
949    swsusp_resume_device = res;
950    mutex_unlock(&pm_mutex);
951    printk(KERN_INFO "PM: Starting manual resume from disk\n");
952    noresume = 0;
953    software_resume();
954    ret = n;
955 out:
956    return ret;
957}
958
959power_attr(resume);
960
961static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
962                   char *buf)
963{
964    return sprintf(buf, "%lu\n", image_size);
965}
966
967static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
968                const char *buf, size_t n)
969{
970    unsigned long size;
971
972    if (sscanf(buf, "%lu", &size) == 1) {
973        image_size = size;
974        return n;
975    }
976
977    return -EINVAL;
978}
979
980power_attr(image_size);
981
982static ssize_t reserved_size_show(struct kobject *kobj,
983                  struct kobj_attribute *attr, char *buf)
984{
985    return sprintf(buf, "%lu\n", reserved_size);
986}
987
988static ssize_t reserved_size_store(struct kobject *kobj,
989                   struct kobj_attribute *attr,
990                   const char *buf, size_t n)
991{
992    unsigned long size;
993
994    if (sscanf(buf, "%lu", &size) == 1) {
995        reserved_size = size;
996        return n;
997    }
998
999    return -EINVAL;
1000}
1001
1002power_attr(reserved_size);
1003
1004static struct attribute * g[] = {
1005    &disk_attr.attr,
1006    &resume_attr.attr,
1007    &image_size_attr.attr,
1008    &reserved_size_attr.attr,
1009    NULL,
1010};
1011
1012
1013static struct attribute_group attr_group = {
1014    .attrs = g,
1015};
1016
1017
1018static int __init pm_disk_init(void)
1019{
1020    return sysfs_create_group(power_kobj, &attr_group);
1021}
1022
1023core_initcall(pm_disk_init);
1024
1025
1026static int __init resume_setup(char *str)
1027{
1028    if (noresume)
1029        return 1;
1030
1031    strncpy( resume_file, str, 255 );
1032    return 1;
1033}
1034
1035static int __init resume_offset_setup(char *str)
1036{
1037    unsigned long long offset;
1038
1039    if (noresume)
1040        return 1;
1041
1042    if (sscanf(str, "%llu", &offset) == 1)
1043        swsusp_resume_block = offset;
1044
1045    return 1;
1046}
1047
1048static int __init hibernate_setup(char *str)
1049{
1050    if (!strncmp(str, "noresume", 8))
1051        noresume = 1;
1052    else if (!strncmp(str, "nocompress", 10))
1053        nocompress = 1;
1054    return 1;
1055}
1056
1057static int __init noresume_setup(char *str)
1058{
1059    noresume = 1;
1060    return 1;
1061}
1062
1063__setup("noresume", noresume_setup);
1064__setup("resume_offset=", resume_offset_setup);
1065__setup("resume=", resume_setup);
1066__setup("hibernate=", hibernate_setup);
1067

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