2 * linux/kernel/power/user.c
4 * This file provides the user space interface for software suspend/resume.
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
8 * This file is released under the GPLv2.
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/miscdevice.h>
19 #include <linux/swap.h>
20 #include <linux/swapops.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
25 #include <linux/freezer.h>
27 #include <asm/uaccess.h>
31 #define SNAPSHOT_MINOR 231
33 static struct snapshot_data {
34 struct snapshot_handle handle;
36 struct bitmap_page *bitmap;
40 char platform_suspend;
43 static atomic_t device_available = ATOMIC_INIT(1);
45 static int snapshot_open(struct inode *inode, struct file *filp)
47 struct snapshot_data *data;
49 if (!atomic_add_unless(&device_available, -1, 0))
52 if ((filp->f_flags & O_ACCMODE) == O_RDWR)
55 if(create_basic_memory_bitmaps())
58 nonseekable_open(inode, filp);
59 data = &snapshot_state;
60 filp->private_data = data;
61 memset(&data->handle, 0, sizeof(struct snapshot_handle));
62 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
63 data->swap = swsusp_resume_device ?
64 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
65 data->mode = O_RDONLY;
68 data->mode = O_WRONLY;
73 data->platform_suspend = 0;
78 static int snapshot_release(struct inode *inode, struct file *filp)
80 struct snapshot_data *data;
83 free_basic_memory_bitmaps();
84 data = filp->private_data;
85 free_all_swap_pages(data->swap, data->bitmap);
86 free_bitmap(data->bitmap);
88 mutex_lock(&pm_mutex);
90 enable_nonboot_cpus();
91 mutex_unlock(&pm_mutex);
93 atomic_inc(&device_available);
97 static ssize_t snapshot_read(struct file *filp, char __user *buf,
98 size_t count, loff_t *offp)
100 struct snapshot_data *data;
103 data = filp->private_data;
104 res = snapshot_read_next(&data->handle, count);
106 if (copy_to_user(buf, data_of(data->handle), res))
109 *offp = data->handle.offset;
114 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
115 size_t count, loff_t *offp)
117 struct snapshot_data *data;
120 data = filp->private_data;
121 res = snapshot_write_next(&data->handle, count);
123 if (copy_from_user(data_of(data->handle), buf, res))
126 *offp = data->handle.offset;
131 static inline int platform_prepare(void)
135 if (pm_ops && pm_ops->prepare)
136 error = pm_ops->prepare(PM_SUSPEND_DISK);
141 static inline void platform_finish(void)
143 if (pm_ops && pm_ops->finish)
144 pm_ops->finish(PM_SUSPEND_DISK);
147 static inline int snapshot_suspend(int platform_suspend)
151 mutex_lock(&pm_mutex);
152 /* Free memory before shutting down devices. */
153 error = swsusp_shrink_memory();
157 if (platform_suspend) {
158 error = platform_prepare();
163 error = device_suspend(PMSG_FREEZE);
167 error = disable_nonboot_cpus();
170 error = swsusp_suspend();
172 enable_nonboot_cpus();
174 if (platform_suspend)
180 mutex_unlock(&pm_mutex);
184 static inline int snapshot_restore(int platform_suspend)
188 mutex_lock(&pm_mutex);
189 pm_prepare_console();
190 if (platform_suspend) {
191 error = platform_prepare();
196 error = device_suspend(PMSG_PRETHAW);
200 error = disable_nonboot_cpus();
202 error = swsusp_resume();
204 enable_nonboot_cpus();
206 if (platform_suspend)
212 pm_restore_console();
213 mutex_unlock(&pm_mutex);
217 static int snapshot_ioctl(struct inode *inode, struct file *filp,
218 unsigned int cmd, unsigned long arg)
221 struct snapshot_data *data;
225 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
227 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
229 if (!capable(CAP_SYS_ADMIN))
232 data = filp->private_data;
236 case SNAPSHOT_FREEZE:
239 mutex_lock(&pm_mutex);
240 if (freeze_processes()) {
244 mutex_unlock(&pm_mutex);
249 case SNAPSHOT_UNFREEZE:
252 mutex_lock(&pm_mutex);
254 mutex_unlock(&pm_mutex);
258 case SNAPSHOT_ATOMIC_SNAPSHOT:
259 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
263 error = snapshot_suspend(data->platform_suspend);
265 error = put_user(in_suspend, (unsigned int __user *)arg);
270 case SNAPSHOT_ATOMIC_RESTORE:
271 snapshot_write_finalize(&data->handle);
272 if (data->mode != O_WRONLY || !data->frozen ||
273 !snapshot_image_loaded(&data->handle)) {
277 error = snapshot_restore(data->platform_suspend);
282 memset(&data->handle, 0, sizeof(struct snapshot_handle));
286 case SNAPSHOT_SET_IMAGE_SIZE:
290 case SNAPSHOT_AVAIL_SWAP:
291 avail = count_swap_pages(data->swap, 1);
292 avail <<= PAGE_SHIFT;
293 error = put_user(avail, (loff_t __user *)arg);
296 case SNAPSHOT_GET_SWAP_PAGE:
297 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
302 data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
308 offset = alloc_swapdev_block(data->swap, data->bitmap);
310 offset <<= PAGE_SHIFT;
311 error = put_user(offset, (sector_t __user *)arg);
317 case SNAPSHOT_FREE_SWAP_PAGES:
318 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
322 free_all_swap_pages(data->swap, data->bitmap);
323 free_bitmap(data->bitmap);
327 case SNAPSHOT_SET_SWAP_FILE:
330 * User space encodes device types as two-byte values,
331 * so we need to recode them
333 if (old_decode_dev(arg)) {
334 data->swap = swap_type_of(old_decode_dev(arg),
358 if (!mutex_trylock(&pm_mutex)) {
363 if (pm_ops->prepare) {
364 error = pm_ops->prepare(PM_SUSPEND_MEM);
369 /* Put devices to sleep */
371 error = device_suspend(PMSG_SUSPEND);
373 printk(KERN_ERR "Failed to suspend some devices.\n");
375 error = disable_nonboot_cpus();
377 /* Enter S3, system is already frozen */
378 suspend_enter(PM_SUSPEND_MEM);
379 enable_nonboot_cpus();
381 /* Wake up devices */
386 pm_ops->finish(PM_SUSPEND_MEM);
389 mutex_unlock(&pm_mutex);
398 if (pm_ops && pm_ops->enter) {
399 data->platform_suspend = 1;
407 if (data->platform_suspend) {
408 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
409 error = pm_ops->enter(PM_SUSPEND_DISK);
415 if (data->platform_suspend)
421 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
426 case SNAPSHOT_SET_SWAP_AREA:
430 struct resume_swap_area swap_area;
433 error = copy_from_user(&swap_area, (void __user *)arg,
434 sizeof(struct resume_swap_area));
441 * User space encodes device types as two-byte values,
442 * so we need to recode them
444 swdev = old_decode_dev(swap_area.dev);
446 offset = swap_area.offset;
447 data->swap = swap_type_of(swdev, offset, NULL);
465 static const struct file_operations snapshot_fops = {
466 .open = snapshot_open,
467 .release = snapshot_release,
468 .read = snapshot_read,
469 .write = snapshot_write,
471 .ioctl = snapshot_ioctl,
474 static struct miscdevice snapshot_device = {
475 .minor = SNAPSHOT_MINOR,
477 .fops = &snapshot_fops,
480 static int __init snapshot_device_init(void)
482 return misc_register(&snapshot_device);
485 device_initcall(snapshot_device_init);