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a634cc1016
At least on some machines it is necessary to prepare the ACPI firmware for the restoration of the system memory state from the hibernation image if the "platform" mode of hibernation has been used. Namely, in that cases we need to disable the GPEs before replacing the "boot" kernel with the "frozen" kernel (cf. http://bugzilla.kernel.org/show_bug.cgi?id=7887). After the restore they will be re-enabled by hibernation_ops->finish(), but if the restore fails, they have to be re-enabled by the restore code explicitly. For this purpose we can introduce two additional hibernation operations, called pre_restore() and restore_cleanup() and call them from the restore code path. Still, they should be called if the "platform" mode of hibernation has been used, so we need to pass the information about the hibernation mode from the "frozen" kernel to the "boot" kernel in the image header. Apparently, we can't drop the disabling of GPEs before the restore because of Bug #7887 . We also can't do it unconditionally, because the GPEs wouldn't have been enabled after a successful restore if the suspend had been done in the 'shutdown' or 'reboot' mode. In principle we could (and probably should) unconditionally disable the GPEs before each snapshot creation *and* before the restore, but then we'd have to unconditionally enable them after the snapshot creation as well as after the restore (or restore failure) Still, for this purpose we'd need to modify acpi_enter_sleep_state_prep() and acpi_leave_sleep_state() and we'd have to introduce some mechanism synchronizing the disablind/enabling of the GPEs with the device drivers' .suspend()/.resume() routines and with disable_/enable_nonboot_cpus(). However, this would have affected the suspend (ie. s2ram) code as well as the hibernation, which I'd like to avoid in this patch series. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
385 lines
7.7 KiB
C
385 lines
7.7 KiB
C
/*
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* linux/kernel/power/user.c
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*
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* This file provides the user space interface for software suspend/resume.
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*
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* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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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/miscdevice.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/pm.h>
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#include <linux/fs.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 <asm/uaccess.h>
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#include "power.h"
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#define SNAPSHOT_MINOR 231
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static struct snapshot_data {
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struct snapshot_handle handle;
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int swap;
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int mode;
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char frozen;
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char ready;
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char platform_suspend;
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} snapshot_state;
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atomic_t snapshot_device_available = ATOMIC_INIT(1);
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static int snapshot_open(struct inode *inode, struct file *filp)
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{
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struct snapshot_data *data;
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if (!atomic_add_unless(&snapshot_device_available, -1, 0))
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return -EBUSY;
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if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
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atomic_inc(&snapshot_device_available);
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return -ENOSYS;
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}
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if(create_basic_memory_bitmaps()) {
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atomic_inc(&snapshot_device_available);
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return -ENOMEM;
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}
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nonseekable_open(inode, filp);
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data = &snapshot_state;
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filp->private_data = data;
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memset(&data->handle, 0, sizeof(struct snapshot_handle));
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if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
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data->swap = swsusp_resume_device ?
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swap_type_of(swsusp_resume_device, 0, NULL) : -1;
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data->mode = O_RDONLY;
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} else {
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data->swap = -1;
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data->mode = O_WRONLY;
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}
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data->frozen = 0;
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data->ready = 0;
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data->platform_suspend = 0;
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return 0;
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}
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static int snapshot_release(struct inode *inode, struct file *filp)
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{
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struct snapshot_data *data;
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swsusp_free();
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free_basic_memory_bitmaps();
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data = filp->private_data;
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free_all_swap_pages(data->swap);
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if (data->frozen) {
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mutex_lock(&pm_mutex);
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thaw_processes();
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mutex_unlock(&pm_mutex);
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}
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atomic_inc(&snapshot_device_available);
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return 0;
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}
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static ssize_t snapshot_read(struct file *filp, char __user *buf,
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size_t count, loff_t *offp)
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{
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struct snapshot_data *data;
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ssize_t res;
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data = filp->private_data;
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if (!data->ready)
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return -ENODATA;
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res = snapshot_read_next(&data->handle, count);
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if (res > 0) {
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if (copy_to_user(buf, data_of(data->handle), res))
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res = -EFAULT;
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else
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*offp = data->handle.offset;
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}
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return res;
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}
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static ssize_t snapshot_write(struct file *filp, const char __user *buf,
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size_t count, loff_t *offp)
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{
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struct snapshot_data *data;
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ssize_t res;
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data = filp->private_data;
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res = snapshot_write_next(&data->handle, count);
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if (res > 0) {
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if (copy_from_user(data_of(data->handle), buf, res))
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res = -EFAULT;
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else
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*offp = data->handle.offset;
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}
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return res;
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}
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static int snapshot_ioctl(struct inode *inode, struct file *filp,
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unsigned int cmd, unsigned long arg)
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{
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int error = 0;
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struct snapshot_data *data;
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loff_t avail;
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sector_t offset;
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if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
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return -ENOTTY;
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if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
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return -ENOTTY;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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data = filp->private_data;
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switch (cmd) {
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case SNAPSHOT_FREEZE:
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if (data->frozen)
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break;
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mutex_lock(&pm_mutex);
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if (freeze_processes()) {
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thaw_processes();
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error = -EBUSY;
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}
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mutex_unlock(&pm_mutex);
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if (!error)
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data->frozen = 1;
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break;
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case SNAPSHOT_UNFREEZE:
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if (!data->frozen || data->ready)
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break;
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mutex_lock(&pm_mutex);
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thaw_processes();
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mutex_unlock(&pm_mutex);
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data->frozen = 0;
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break;
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case SNAPSHOT_ATOMIC_SNAPSHOT:
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if (data->mode != O_RDONLY || !data->frozen || data->ready) {
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error = -EPERM;
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break;
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}
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error = hibernation_snapshot(data->platform_suspend);
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if (!error)
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error = put_user(in_suspend, (unsigned int __user *)arg);
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if (!error)
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data->ready = 1;
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break;
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case SNAPSHOT_ATOMIC_RESTORE:
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snapshot_write_finalize(&data->handle);
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if (data->mode != O_WRONLY || !data->frozen ||
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!snapshot_image_loaded(&data->handle)) {
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error = -EPERM;
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break;
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}
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error = hibernation_restore(data->platform_suspend);
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break;
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case SNAPSHOT_FREE:
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swsusp_free();
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memset(&data->handle, 0, sizeof(struct snapshot_handle));
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data->ready = 0;
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break;
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case SNAPSHOT_SET_IMAGE_SIZE:
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image_size = arg;
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break;
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case SNAPSHOT_AVAIL_SWAP:
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avail = count_swap_pages(data->swap, 1);
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avail <<= PAGE_SHIFT;
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error = put_user(avail, (loff_t __user *)arg);
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break;
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case SNAPSHOT_GET_SWAP_PAGE:
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if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
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error = -ENODEV;
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break;
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}
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offset = alloc_swapdev_block(data->swap);
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if (offset) {
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offset <<= PAGE_SHIFT;
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error = put_user(offset, (sector_t __user *)arg);
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} else {
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error = -ENOSPC;
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}
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break;
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case SNAPSHOT_FREE_SWAP_PAGES:
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if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
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error = -ENODEV;
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break;
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}
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free_all_swap_pages(data->swap);
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break;
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case SNAPSHOT_SET_SWAP_FILE:
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if (!swsusp_swap_in_use()) {
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/*
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* User space encodes device types as two-byte values,
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* so we need to recode them
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*/
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if (old_decode_dev(arg)) {
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data->swap = swap_type_of(old_decode_dev(arg),
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0, NULL);
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if (data->swap < 0)
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error = -ENODEV;
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} else {
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data->swap = -1;
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error = -EINVAL;
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}
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} else {
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error = -EPERM;
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}
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break;
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case SNAPSHOT_S2RAM:
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if (!pm_ops) {
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error = -ENOSYS;
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break;
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}
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if (!data->frozen) {
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error = -EPERM;
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break;
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}
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if (!mutex_trylock(&pm_mutex)) {
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error = -EBUSY;
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break;
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}
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if (pm_ops->prepare) {
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error = pm_ops->prepare(PM_SUSPEND_MEM);
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if (error)
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goto OutS3;
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}
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/* Put devices to sleep */
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suspend_console();
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error = device_suspend(PMSG_SUSPEND);
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if (error) {
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printk(KERN_ERR "Failed to suspend some devices.\n");
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} else {
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error = disable_nonboot_cpus();
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if (!error) {
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/* Enter S3, system is already frozen */
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suspend_enter(PM_SUSPEND_MEM);
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enable_nonboot_cpus();
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}
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/* Wake up devices */
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device_resume();
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}
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resume_console();
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if (pm_ops->finish)
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pm_ops->finish(PM_SUSPEND_MEM);
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OutS3:
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mutex_unlock(&pm_mutex);
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break;
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case SNAPSHOT_PMOPS:
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error = -EINVAL;
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switch (arg) {
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case PMOPS_PREPARE:
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data->platform_suspend = 1;
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error = 0;
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break;
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case PMOPS_ENTER:
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if (data->platform_suspend)
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error = hibernation_platform_enter();
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break;
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case PMOPS_FINISH:
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if (data->platform_suspend)
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error = 0;
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break;
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default:
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printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
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}
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break;
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case SNAPSHOT_SET_SWAP_AREA:
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if (swsusp_swap_in_use()) {
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error = -EPERM;
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} else {
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struct resume_swap_area swap_area;
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dev_t swdev;
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error = copy_from_user(&swap_area, (void __user *)arg,
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sizeof(struct resume_swap_area));
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if (error) {
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error = -EFAULT;
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break;
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}
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/*
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* User space encodes device types as two-byte values,
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* so we need to recode them
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*/
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swdev = old_decode_dev(swap_area.dev);
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if (swdev) {
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offset = swap_area.offset;
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data->swap = swap_type_of(swdev, offset, NULL);
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if (data->swap < 0)
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error = -ENODEV;
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} else {
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data->swap = -1;
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error = -EINVAL;
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}
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}
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break;
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default:
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error = -ENOTTY;
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}
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return error;
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}
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static const struct file_operations snapshot_fops = {
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.open = snapshot_open,
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.release = snapshot_release,
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.read = snapshot_read,
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.write = snapshot_write,
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.llseek = no_llseek,
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.ioctl = snapshot_ioctl,
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};
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static struct miscdevice snapshot_device = {
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.minor = SNAPSHOT_MINOR,
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.name = "snapshot",
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.fops = &snapshot_fops,
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};
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static int __init snapshot_device_init(void)
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{
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return misc_register(&snapshot_device);
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};
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device_initcall(snapshot_device_init);
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