![Rafael J. Wysocki](/assets/img/avatar_default.png)
The sysfs files /sys/power/disk and /sys/power/state do not work as documented, since they allow the user to write only a few initial characters of the input string to trigger the option (eg. 'echo pl > /sys/power/disk' activates the platform mode of hibernation). Fix it. Special thanks to Peter Moulder <Peter.Moulder@infotech.monash.edu.au> for pointing out the problem. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
554 lines
11 KiB
C
554 lines
11 KiB
C
/*
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* kernel/power/disk.c - Suspend-to-disk support.
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*
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* Copyright (c) 2003 Patrick Mochel
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* Copyright (c) 2003 Open Source Development Lab
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* Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
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*
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* This file is released under the GPLv2.
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*
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*/
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#include <linux/suspend.h>
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#include <linux/syscalls.h>
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#include <linux/reboot.h>
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#include <linux/string.h>
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#include <linux/device.h>
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#include <linux/delay.h>
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#include <linux/fs.h>
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#include <linux/mount.h>
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#include <linux/pm.h>
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#include <linux/console.h>
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#include <linux/cpu.h>
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#include <linux/freezer.h>
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#include "power.h"
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static int noresume = 0;
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char resume_file[256] = CONFIG_PM_STD_PARTITION;
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dev_t swsusp_resume_device;
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sector_t swsusp_resume_block;
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enum {
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HIBERNATION_INVALID,
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HIBERNATION_PLATFORM,
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HIBERNATION_TEST,
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HIBERNATION_TESTPROC,
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HIBERNATION_SHUTDOWN,
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HIBERNATION_REBOOT,
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/* keep last */
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__HIBERNATION_AFTER_LAST
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};
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#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
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#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
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static int hibernation_mode = HIBERNATION_SHUTDOWN;
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struct hibernation_ops *hibernation_ops;
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/**
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* hibernation_set_ops - set the global hibernate operations
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* @ops: the hibernation operations to use in subsequent hibernation transitions
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*/
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void hibernation_set_ops(struct hibernation_ops *ops)
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{
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if (ops && !(ops->prepare && ops->enter && ops->finish)) {
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WARN_ON(1);
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return;
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}
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mutex_lock(&pm_mutex);
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hibernation_ops = ops;
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if (ops)
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hibernation_mode = HIBERNATION_PLATFORM;
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else if (hibernation_mode == HIBERNATION_PLATFORM)
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hibernation_mode = HIBERNATION_SHUTDOWN;
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mutex_unlock(&pm_mutex);
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}
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/**
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* platform_prepare - prepare the machine for hibernation using the
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* platform driver if so configured and return an error code if it fails
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*/
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static int platform_prepare(void)
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{
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return (hibernation_mode == HIBERNATION_PLATFORM && hibernation_ops) ?
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hibernation_ops->prepare() : 0;
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}
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/**
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* platform_finish - switch the machine to the normal mode of operation
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* using the platform driver (must be called after platform_prepare())
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*/
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static void platform_finish(void)
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{
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if (hibernation_mode == HIBERNATION_PLATFORM && hibernation_ops)
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hibernation_ops->finish();
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}
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/**
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* power_down - Shut the machine down for hibernation.
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*
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* Use the platform driver, if configured so; otherwise try
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* to power off or reboot.
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*/
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static void power_down(void)
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{
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switch (hibernation_mode) {
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case HIBERNATION_TEST:
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case HIBERNATION_TESTPROC:
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break;
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case HIBERNATION_SHUTDOWN:
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kernel_power_off();
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break;
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case HIBERNATION_REBOOT:
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kernel_restart(NULL);
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break;
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case HIBERNATION_PLATFORM:
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if (hibernation_ops) {
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kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
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hibernation_ops->enter();
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break;
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}
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}
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kernel_halt();
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/*
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* Valid image is on the disk, if we continue we risk serious data
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* corruption after resume.
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*/
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printk(KERN_CRIT "Please power me down manually\n");
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while(1);
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}
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static void unprepare_processes(void)
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{
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thaw_processes();
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pm_restore_console();
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}
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static int prepare_processes(void)
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{
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int error = 0;
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pm_prepare_console();
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if (freeze_processes()) {
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error = -EBUSY;
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unprepare_processes();
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}
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return error;
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}
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/**
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* hibernate - The granpappy of the built-in hibernation management
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*/
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int hibernate(void)
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{
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int error;
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/* The snapshot device should not be opened while we're running */
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if (!atomic_add_unless(&snapshot_device_available, -1, 0))
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return -EBUSY;
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/* Allocate memory management structures */
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error = create_basic_memory_bitmaps();
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if (error)
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goto Exit;
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error = prepare_processes();
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if (error)
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goto Finish;
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mutex_lock(&pm_mutex);
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if (hibernation_mode == HIBERNATION_TESTPROC) {
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printk("swsusp debug: Waiting for 5 seconds.\n");
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mdelay(5000);
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goto Thaw;
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}
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/* Free memory before shutting down devices. */
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error = swsusp_shrink_memory();
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if (error)
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goto Thaw;
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error = platform_prepare();
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if (error)
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goto Thaw;
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suspend_console();
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error = device_suspend(PMSG_FREEZE);
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if (error) {
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printk(KERN_ERR "PM: Some devices failed to suspend\n");
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goto Resume_devices;
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}
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error = disable_nonboot_cpus();
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if (error)
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goto Enable_cpus;
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if (hibernation_mode == HIBERNATION_TEST) {
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printk("swsusp debug: Waiting for 5 seconds.\n");
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mdelay(5000);
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goto Enable_cpus;
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}
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pr_debug("PM: snapshotting memory.\n");
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in_suspend = 1;
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error = swsusp_suspend();
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if (error)
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goto Enable_cpus;
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if (in_suspend) {
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enable_nonboot_cpus();
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platform_finish();
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device_resume();
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resume_console();
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pr_debug("PM: writing image.\n");
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error = swsusp_write();
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if (!error)
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power_down();
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else {
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swsusp_free();
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goto Thaw;
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}
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} else {
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pr_debug("PM: Image restored successfully.\n");
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}
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swsusp_free();
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Enable_cpus:
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enable_nonboot_cpus();
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Resume_devices:
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platform_finish();
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device_resume();
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resume_console();
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Thaw:
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mutex_unlock(&pm_mutex);
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unprepare_processes();
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Finish:
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free_basic_memory_bitmaps();
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Exit:
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atomic_inc(&snapshot_device_available);
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return error;
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}
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/**
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* software_resume - Resume from a saved image.
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*
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* Called as a late_initcall (so all devices are discovered and
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* initialized), we call swsusp to see if we have a saved image or not.
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* If so, we quiesce devices, the restore the saved image. We will
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* return above (in hibernate() ) if everything goes well.
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* Otherwise, we fail gracefully and return to the normally
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* scheduled program.
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*
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*/
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static int software_resume(void)
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{
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int error;
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mutex_lock(&pm_mutex);
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if (!swsusp_resume_device) {
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if (!strlen(resume_file)) {
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mutex_unlock(&pm_mutex);
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return -ENOENT;
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}
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swsusp_resume_device = name_to_dev_t(resume_file);
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pr_debug("swsusp: Resume From Partition %s\n", resume_file);
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} else {
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pr_debug("swsusp: Resume From Partition %d:%d\n",
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MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
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}
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if (noresume) {
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/**
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* FIXME: If noresume is specified, we need to find the partition
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* and reset it back to normal swap space.
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*/
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mutex_unlock(&pm_mutex);
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return 0;
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}
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pr_debug("PM: Checking swsusp image.\n");
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error = swsusp_check();
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if (error)
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goto Unlock;
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/* The snapshot device should not be opened while we're running */
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if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
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error = -EBUSY;
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goto Unlock;
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}
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error = create_basic_memory_bitmaps();
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if (error)
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goto Finish;
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pr_debug("PM: Preparing processes for restore.\n");
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error = prepare_processes();
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if (error) {
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swsusp_close();
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goto Done;
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}
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pr_debug("PM: Reading swsusp image.\n");
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error = swsusp_read();
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if (error) {
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swsusp_free();
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goto Thaw;
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}
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pr_debug("PM: Preparing devices for restore.\n");
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suspend_console();
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error = device_suspend(PMSG_PRETHAW);
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if (error)
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goto Free;
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error = disable_nonboot_cpus();
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if (!error)
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swsusp_resume();
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enable_nonboot_cpus();
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Free:
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swsusp_free();
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device_resume();
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resume_console();
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Thaw:
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printk(KERN_ERR "PM: Restore failed, recovering.\n");
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unprepare_processes();
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Done:
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free_basic_memory_bitmaps();
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Finish:
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atomic_inc(&snapshot_device_available);
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/* For success case, the suspend path will release the lock */
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Unlock:
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mutex_unlock(&pm_mutex);
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pr_debug("PM: Resume from disk failed.\n");
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return 0;
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}
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late_initcall(software_resume);
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static const char * const hibernation_modes[] = {
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[HIBERNATION_PLATFORM] = "platform",
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[HIBERNATION_SHUTDOWN] = "shutdown",
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[HIBERNATION_REBOOT] = "reboot",
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[HIBERNATION_TEST] = "test",
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[HIBERNATION_TESTPROC] = "testproc",
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};
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/**
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* disk - Control hibernation mode
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*
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* Suspend-to-disk can be handled in several ways. We have a few options
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* for putting the system to sleep - using the platform driver (e.g. ACPI
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* or other hibernation_ops), powering off the system or rebooting the
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* system (for testing) as well as the two test modes.
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*
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* The system can support 'platform', and that is known a priori (and
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* encoded by the presence of hibernation_ops). However, the user may
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* choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
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* test modes, 'test' or 'testproc'.
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*
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* show() will display what the mode is currently set to.
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* store() will accept one of
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*
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* 'platform'
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* 'shutdown'
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* 'reboot'
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* 'test'
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* 'testproc'
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*
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* It will only change to 'platform' if the system
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* supports it (as determined by having hibernation_ops).
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*/
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static ssize_t disk_show(struct kset *kset, char *buf)
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{
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int i;
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char *start = buf;
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for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
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if (!hibernation_modes[i])
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continue;
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switch (i) {
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case HIBERNATION_SHUTDOWN:
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case HIBERNATION_REBOOT:
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case HIBERNATION_TEST:
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case HIBERNATION_TESTPROC:
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break;
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case HIBERNATION_PLATFORM:
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if (hibernation_ops)
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break;
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/* not a valid mode, continue with loop */
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continue;
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}
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if (i == hibernation_mode)
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buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
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else
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buf += sprintf(buf, "%s ", hibernation_modes[i]);
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}
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buf += sprintf(buf, "\n");
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return buf-start;
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}
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static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
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{
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int error = 0;
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int i;
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int len;
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char *p;
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int mode = HIBERNATION_INVALID;
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p = memchr(buf, '\n', n);
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len = p ? p - buf : n;
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mutex_lock(&pm_mutex);
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for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
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if (len == strlen(hibernation_modes[i])
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&& !strncmp(buf, hibernation_modes[i], len)) {
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mode = i;
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break;
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}
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}
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if (mode != HIBERNATION_INVALID) {
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switch (mode) {
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case HIBERNATION_SHUTDOWN:
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case HIBERNATION_REBOOT:
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case HIBERNATION_TEST:
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case HIBERNATION_TESTPROC:
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hibernation_mode = mode;
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break;
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case HIBERNATION_PLATFORM:
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if (hibernation_ops)
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hibernation_mode = mode;
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else
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error = -EINVAL;
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}
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} else
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error = -EINVAL;
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if (!error)
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pr_debug("PM: suspend-to-disk mode set to '%s'\n",
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hibernation_modes[mode]);
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mutex_unlock(&pm_mutex);
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return error ? error : n;
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}
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power_attr(disk);
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static ssize_t resume_show(struct kset *kset, char *buf)
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{
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return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
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MINOR(swsusp_resume_device));
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}
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static ssize_t resume_store(struct kset *kset, const char *buf, size_t n)
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{
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unsigned int maj, min;
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dev_t res;
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int ret = -EINVAL;
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if (sscanf(buf, "%u:%u", &maj, &min) != 2)
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goto out;
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res = MKDEV(maj,min);
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if (maj != MAJOR(res) || min != MINOR(res))
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goto out;
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mutex_lock(&pm_mutex);
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swsusp_resume_device = res;
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mutex_unlock(&pm_mutex);
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printk("Attempting manual resume\n");
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noresume = 0;
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software_resume();
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ret = n;
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out:
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return ret;
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}
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power_attr(resume);
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static ssize_t image_size_show(struct kset *kset, char *buf)
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{
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return sprintf(buf, "%lu\n", image_size);
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}
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static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n)
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{
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unsigned long size;
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if (sscanf(buf, "%lu", &size) == 1) {
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image_size = size;
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return n;
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}
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return -EINVAL;
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}
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power_attr(image_size);
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static struct attribute * g[] = {
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&disk_attr.attr,
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&resume_attr.attr,
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&image_size_attr.attr,
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NULL,
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};
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static struct attribute_group attr_group = {
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.attrs = g,
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};
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static int __init pm_disk_init(void)
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{
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return sysfs_create_group(&power_subsys.kobj, &attr_group);
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}
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core_initcall(pm_disk_init);
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static int __init resume_setup(char *str)
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{
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if (noresume)
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return 1;
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strncpy( resume_file, str, 255 );
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return 1;
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}
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static int __init resume_offset_setup(char *str)
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{
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unsigned long long offset;
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if (noresume)
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return 1;
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if (sscanf(str, "%llu", &offset) == 1)
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swsusp_resume_block = offset;
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return 1;
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}
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static int __init noresume_setup(char *str)
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{
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noresume = 1;
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return 1;
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}
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__setup("noresume", noresume_setup);
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__setup("resume_offset=", resume_offset_setup);
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__setup("resume=", resume_setup);
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