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1/*
2 * linux/kernel/power/user.c
3 *
4 * This file provides the user space interface for software suspend/resume.
5 *
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
7 *
8 * This file is released under the GPLv2.
9 *
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/miscdevice.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/swapops.h>
21#include <linux/pm.h>
22#include <linux/fs.h>
23#include <linux/compat.h>
24#include <linux/console.h>
25#include <linux/cpu.h>
26#include <linux/freezer.h>
27
28#include <asm/uaccess.h>
29
30#include "power.h"
31
32
33#define SNAPSHOT_MINOR 231
34
35static struct snapshot_data {
36 struct snapshot_handle handle;
37 int swap;
38 int mode;
39 bool frozen;
40 bool ready;
41 bool platform_support;
42 bool free_bitmaps;
43} snapshot_state;
44
45atomic_t snapshot_device_available = ATOMIC_INIT(1);
46
47static int snapshot_open(struct inode *inode, struct file *filp)
48{
49 struct snapshot_data *data;
50 int error;
51
52 if (!hibernation_available())
53 return -EPERM;
54
55 lock_system_sleep();
56
57 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
58 error = -EBUSY;
59 goto Unlock;
60 }
61
62 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
63 atomic_inc(&snapshot_device_available);
64 error = -ENOSYS;
65 goto Unlock;
66 }
67 nonseekable_open(inode, filp);
68 data = &snapshot_state;
69 filp->private_data = data;
70 memset(&data->handle, 0, sizeof(struct snapshot_handle));
71 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
72 /* Hibernating. The image device should be accessible. */
73 data->swap = swsusp_resume_device ?
74 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
75 data->mode = O_RDONLY;
76 data->free_bitmaps = false;
77 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
78 if (error)
79 pm_notifier_call_chain(PM_POST_HIBERNATION);
80 } else {
81 /*
82 * Resuming. We may need to wait for the image device to
83 * appear.
84 */
85 wait_for_device_probe();
86
87 data->swap = -1;
88 data->mode = O_WRONLY;
89 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
90 if (!error) {
91 error = create_basic_memory_bitmaps();
92 data->free_bitmaps = !error;
93 }
94 if (error)
95 pm_notifier_call_chain(PM_POST_RESTORE);
96 }
97 if (error)
98 atomic_inc(&snapshot_device_available);
99
100 data->frozen = false;
101 data->ready = false;
102 data->platform_support = false;
103
104 Unlock:
105 unlock_system_sleep();
106
107 return error;
108}
109
110static int snapshot_release(struct inode *inode, struct file *filp)
111{
112 struct snapshot_data *data;
113
114 lock_system_sleep();
115
116 swsusp_free();
117 data = filp->private_data;
118 free_all_swap_pages(data->swap);
119 if (data->frozen) {
120 pm_restore_gfp_mask();
121 free_basic_memory_bitmaps();
122 thaw_processes();
123 } else if (data->free_bitmaps) {
124 free_basic_memory_bitmaps();
125 }
126 pm_notifier_call_chain(data->mode == O_RDONLY ?
127 PM_POST_HIBERNATION : PM_POST_RESTORE);
128 atomic_inc(&snapshot_device_available);
129
130 unlock_system_sleep();
131
132 return 0;
133}
134
135static ssize_t snapshot_read(struct file *filp, char __user *buf,
136 size_t count, loff_t *offp)
137{
138 struct snapshot_data *data;
139 ssize_t res;
140 loff_t pg_offp = *offp & ~PAGE_MASK;
141
142 lock_system_sleep();
143
144 data = filp->private_data;
145 if (!data->ready) {
146 res = -ENODATA;
147 goto Unlock;
148 }
149 if (!pg_offp) { /* on page boundary? */
150 res = snapshot_read_next(&data->handle);
151 if (res <= 0)
152 goto Unlock;
153 } else {
154 res = PAGE_SIZE - pg_offp;
155 }
156
157 res = simple_read_from_buffer(buf, count, &pg_offp,
158 data_of(data->handle), res);
159 if (res > 0)
160 *offp += res;
161
162 Unlock:
163 unlock_system_sleep();
164
165 return res;
166}
167
168static ssize_t snapshot_write(struct file *filp, const char __user *buf,
169 size_t count, loff_t *offp)
170{
171 struct snapshot_data *data;
172 ssize_t res;
173 loff_t pg_offp = *offp & ~PAGE_MASK;
174
175 lock_system_sleep();
176
177 data = filp->private_data;
178
179 if (!pg_offp) {
180 res = snapshot_write_next(&data->handle);
181 if (res <= 0)
182 goto unlock;
183 } else {
184 res = PAGE_SIZE - pg_offp;
185 }
186
187 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
188 buf, count);
189 if (res > 0)
190 *offp += res;
191unlock:
192 unlock_system_sleep();
193
194 return res;
195}
196
197static long snapshot_ioctl(struct file *filp, unsigned int cmd,
198 unsigned long arg)
199{
200 int error = 0;
201 struct snapshot_data *data;
202 loff_t size;
203 sector_t offset;
204
205 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
206 return -ENOTTY;
207 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
208 return -ENOTTY;
209 if (!capable(CAP_SYS_ADMIN))
210 return -EPERM;
211
212 if (!mutex_trylock(&pm_mutex))
213 return -EBUSY;
214
215 lock_device_hotplug();
216 data = filp->private_data;
217
218 switch (cmd) {
219
220 case SNAPSHOT_FREEZE:
221 if (data->frozen)
222 break;
223
224 printk("Syncing filesystems ... ");
225 sys_sync();
226 printk("done.\n");
227
228 error = freeze_processes();
229 if (error)
230 break;
231
232 error = create_basic_memory_bitmaps();
233 if (error)
234 thaw_processes();
235 else
236 data->frozen = true;
237
238 break;
239
240 case SNAPSHOT_UNFREEZE:
241 if (!data->frozen || data->ready)
242 break;
243 pm_restore_gfp_mask();
244 free_basic_memory_bitmaps();
245 data->free_bitmaps = false;
246 thaw_processes();
247 data->frozen = false;
248 break;
249
250 case SNAPSHOT_CREATE_IMAGE:
251 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
252 error = -EPERM;
253 break;
254 }
255 pm_restore_gfp_mask();
256 error = hibernation_snapshot(data->platform_support);
257 if (!error) {
258 error = put_user(in_suspend, (int __user *)arg);
259 data->ready = !freezer_test_done && !error;
260 freezer_test_done = false;
261 }
262 break;
263
264 case SNAPSHOT_ATOMIC_RESTORE:
265 snapshot_write_finalize(&data->handle);
266 if (data->mode != O_WRONLY || !data->frozen ||
267 !snapshot_image_loaded(&data->handle)) {
268 error = -EPERM;
269 break;
270 }
271 error = hibernation_restore(data->platform_support);
272 break;
273
274 case SNAPSHOT_FREE:
275 swsusp_free();
276 memset(&data->handle, 0, sizeof(struct snapshot_handle));
277 data->ready = false;
278 /*
279 * It is necessary to thaw kernel threads here, because
280 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
281 * SNAPSHOT_FREE. In that case, if kernel threads were not
282 * thawed, the preallocation of memory carried out by
283 * hibernation_snapshot() might run into problems (i.e. it
284 * might fail or even deadlock).
285 */
286 thaw_kernel_threads();
287 break;
288
289 case SNAPSHOT_PREF_IMAGE_SIZE:
290 image_size = arg;
291 break;
292
293 case SNAPSHOT_GET_IMAGE_SIZE:
294 if (!data->ready) {
295 error = -ENODATA;
296 break;
297 }
298 size = snapshot_get_image_size();
299 size <<= PAGE_SHIFT;
300 error = put_user(size, (loff_t __user *)arg);
301 break;
302
303 case SNAPSHOT_AVAIL_SWAP_SIZE:
304 size = count_swap_pages(data->swap, 1);
305 size <<= PAGE_SHIFT;
306 error = put_user(size, (loff_t __user *)arg);
307 break;
308
309 case SNAPSHOT_ALLOC_SWAP_PAGE:
310 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
311 error = -ENODEV;
312 break;
313 }
314 offset = alloc_swapdev_block(data->swap);
315 if (offset) {
316 offset <<= PAGE_SHIFT;
317 error = put_user(offset, (loff_t __user *)arg);
318 } else {
319 error = -ENOSPC;
320 }
321 break;
322
323 case SNAPSHOT_FREE_SWAP_PAGES:
324 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
325 error = -ENODEV;
326 break;
327 }
328 free_all_swap_pages(data->swap);
329 break;
330
331 case SNAPSHOT_S2RAM:
332 if (!data->frozen) {
333 error = -EPERM;
334 break;
335 }
336 /*
337 * Tasks are frozen and the notifiers have been called with
338 * PM_HIBERNATION_PREPARE
339 */
340 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
341 data->ready = false;
342 break;
343
344 case SNAPSHOT_PLATFORM_SUPPORT:
345 data->platform_support = !!arg;
346 break;
347
348 case SNAPSHOT_POWER_OFF:
349 if (data->platform_support)
350 error = hibernation_platform_enter();
351 break;
352
353 case SNAPSHOT_SET_SWAP_AREA:
354 if (swsusp_swap_in_use()) {
355 error = -EPERM;
356 } else {
357 struct resume_swap_area swap_area;
358 dev_t swdev;
359
360 error = copy_from_user(&swap_area, (void __user *)arg,
361 sizeof(struct resume_swap_area));
362 if (error) {
363 error = -EFAULT;
364 break;
365 }
366
367 /*
368 * User space encodes device types as two-byte values,
369 * so we need to recode them
370 */
371 swdev = new_decode_dev(swap_area.dev);
372 if (swdev) {
373 offset = swap_area.offset;
374 data->swap = swap_type_of(swdev, offset, NULL);
375 if (data->swap < 0)
376 error = -ENODEV;
377 } else {
378 data->swap = -1;
379 error = -EINVAL;
380 }
381 }
382 break;
383
384 default:
385 error = -ENOTTY;
386
387 }
388
389 unlock_device_hotplug();
390 mutex_unlock(&pm_mutex);
391
392 return error;
393}
394
395#ifdef CONFIG_COMPAT
396
397struct compat_resume_swap_area {
398 compat_loff_t offset;
399 u32 dev;
400} __packed;
401
402static long
403snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
404{
405 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
406
407 switch (cmd) {
408 case SNAPSHOT_GET_IMAGE_SIZE:
409 case SNAPSHOT_AVAIL_SWAP_SIZE:
410 case SNAPSHOT_ALLOC_SWAP_PAGE: {
411 compat_loff_t __user *uoffset = compat_ptr(arg);
412 loff_t offset;
413 mm_segment_t old_fs;
414 int err;
415
416 old_fs = get_fs();
417 set_fs(KERNEL_DS);
418 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
419 set_fs(old_fs);
420 if (!err && put_user(offset, uoffset))
421 err = -EFAULT;
422 return err;
423 }
424
425 case SNAPSHOT_CREATE_IMAGE:
426 return snapshot_ioctl(file, cmd,
427 (unsigned long) compat_ptr(arg));
428
429 case SNAPSHOT_SET_SWAP_AREA: {
430 struct compat_resume_swap_area __user *u_swap_area =
431 compat_ptr(arg);
432 struct resume_swap_area swap_area;
433 mm_segment_t old_fs;
434 int err;
435
436 err = get_user(swap_area.offset, &u_swap_area->offset);
437 err |= get_user(swap_area.dev, &u_swap_area->dev);
438 if (err)
439 return -EFAULT;
440 old_fs = get_fs();
441 set_fs(KERNEL_DS);
442 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
443 (unsigned long) &swap_area);
444 set_fs(old_fs);
445 return err;
446 }
447
448 default:
449 return snapshot_ioctl(file, cmd, arg);
450 }
451}
452
453#endif /* CONFIG_COMPAT */
454
455static const struct file_operations snapshot_fops = {
456 .open = snapshot_open,
457 .release = snapshot_release,
458 .read = snapshot_read,
459 .write = snapshot_write,
460 .llseek = no_llseek,
461 .unlocked_ioctl = snapshot_ioctl,
462#ifdef CONFIG_COMPAT
463 .compat_ioctl = snapshot_compat_ioctl,
464#endif
465};
466
467static struct miscdevice snapshot_device = {
468 .minor = SNAPSHOT_MINOR,
469 .name = "snapshot",
470 .fops = &snapshot_fops,
471};
472
473static int __init snapshot_device_init(void)
474{
475 return misc_register(&snapshot_device);
476};
477
478device_initcall(snapshot_device_init);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/user.c
4 *
5 * This file provides the user space interface for software suspend/resume.
6 *
7 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
8 */
9
10#include <linux/suspend.h>
11#include <linux/reboot.h>
12#include <linux/string.h>
13#include <linux/device.h>
14#include <linux/miscdevice.h>
15#include <linux/mm.h>
16#include <linux/swap.h>
17#include <linux/swapops.h>
18#include <linux/pm.h>
19#include <linux/fs.h>
20#include <linux/compat.h>
21#include <linux/console.h>
22#include <linux/cpu.h>
23#include <linux/freezer.h>
24
25#include <linux/uaccess.h>
26
27#include "power.h"
28
29
30static struct snapshot_data {
31 struct snapshot_handle handle;
32 int swap;
33 int mode;
34 bool frozen;
35 bool ready;
36 bool platform_support;
37 bool free_bitmaps;
38 dev_t dev;
39} snapshot_state;
40
41int is_hibernate_resume_dev(dev_t dev)
42{
43 return hibernation_available() && snapshot_state.dev == dev;
44}
45
46static int snapshot_open(struct inode *inode, struct file *filp)
47{
48 struct snapshot_data *data;
49 int error;
50
51 if (!hibernation_available())
52 return -EPERM;
53
54 lock_system_sleep();
55
56 if (!hibernate_acquire()) {
57 error = -EBUSY;
58 goto Unlock;
59 }
60
61 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
62 hibernate_release();
63 error = -ENOSYS;
64 goto Unlock;
65 }
66 nonseekable_open(inode, filp);
67 data = &snapshot_state;
68 filp->private_data = data;
69 memset(&data->handle, 0, sizeof(struct snapshot_handle));
70 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
71 /* Hibernating. The image device should be accessible. */
72 data->swap = swap_type_of(swsusp_resume_device, 0);
73 data->mode = O_RDONLY;
74 data->free_bitmaps = false;
75 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
76 } else {
77 /*
78 * Resuming. We may need to wait for the image device to
79 * appear.
80 */
81 wait_for_device_probe();
82
83 data->swap = -1;
84 data->mode = O_WRONLY;
85 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
86 if (!error) {
87 error = create_basic_memory_bitmaps();
88 data->free_bitmaps = !error;
89 }
90 }
91 if (error)
92 hibernate_release();
93
94 data->frozen = false;
95 data->ready = false;
96 data->platform_support = false;
97 data->dev = 0;
98
99 Unlock:
100 unlock_system_sleep();
101
102 return error;
103}
104
105static int snapshot_release(struct inode *inode, struct file *filp)
106{
107 struct snapshot_data *data;
108
109 lock_system_sleep();
110
111 swsusp_free();
112 data = filp->private_data;
113 data->dev = 0;
114 free_all_swap_pages(data->swap);
115 if (data->frozen) {
116 pm_restore_gfp_mask();
117 free_basic_memory_bitmaps();
118 thaw_processes();
119 } else if (data->free_bitmaps) {
120 free_basic_memory_bitmaps();
121 }
122 pm_notifier_call_chain(data->mode == O_RDONLY ?
123 PM_POST_HIBERNATION : PM_POST_RESTORE);
124 hibernate_release();
125
126 unlock_system_sleep();
127
128 return 0;
129}
130
131static ssize_t snapshot_read(struct file *filp, char __user *buf,
132 size_t count, loff_t *offp)
133{
134 struct snapshot_data *data;
135 ssize_t res;
136 loff_t pg_offp = *offp & ~PAGE_MASK;
137
138 lock_system_sleep();
139
140 data = filp->private_data;
141 if (!data->ready) {
142 res = -ENODATA;
143 goto Unlock;
144 }
145 if (!pg_offp) { /* on page boundary? */
146 res = snapshot_read_next(&data->handle);
147 if (res <= 0)
148 goto Unlock;
149 } else {
150 res = PAGE_SIZE - pg_offp;
151 }
152
153 res = simple_read_from_buffer(buf, count, &pg_offp,
154 data_of(data->handle), res);
155 if (res > 0)
156 *offp += res;
157
158 Unlock:
159 unlock_system_sleep();
160
161 return res;
162}
163
164static ssize_t snapshot_write(struct file *filp, const char __user *buf,
165 size_t count, loff_t *offp)
166{
167 struct snapshot_data *data;
168 ssize_t res;
169 loff_t pg_offp = *offp & ~PAGE_MASK;
170
171 lock_system_sleep();
172
173 data = filp->private_data;
174
175 if (!pg_offp) {
176 res = snapshot_write_next(&data->handle);
177 if (res <= 0)
178 goto unlock;
179 } else {
180 res = PAGE_SIZE - pg_offp;
181 }
182
183 if (!data_of(data->handle)) {
184 res = -EINVAL;
185 goto unlock;
186 }
187
188 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
189 buf, count);
190 if (res > 0)
191 *offp += res;
192unlock:
193 unlock_system_sleep();
194
195 return res;
196}
197
198struct compat_resume_swap_area {
199 compat_loff_t offset;
200 u32 dev;
201} __packed;
202
203static int snapshot_set_swap_area(struct snapshot_data *data,
204 void __user *argp)
205{
206 sector_t offset;
207 dev_t swdev;
208
209 if (swsusp_swap_in_use())
210 return -EPERM;
211
212 if (in_compat_syscall()) {
213 struct compat_resume_swap_area swap_area;
214
215 if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
216 return -EFAULT;
217 swdev = new_decode_dev(swap_area.dev);
218 offset = swap_area.offset;
219 } else {
220 struct resume_swap_area swap_area;
221
222 if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
223 return -EFAULT;
224 swdev = new_decode_dev(swap_area.dev);
225 offset = swap_area.offset;
226 }
227
228 /*
229 * User space encodes device types as two-byte values,
230 * so we need to recode them
231 */
232 data->swap = swap_type_of(swdev, offset);
233 if (data->swap < 0)
234 return swdev ? -ENODEV : -EINVAL;
235 data->dev = swdev;
236 return 0;
237}
238
239static long snapshot_ioctl(struct file *filp, unsigned int cmd,
240 unsigned long arg)
241{
242 int error = 0;
243 struct snapshot_data *data;
244 loff_t size;
245 sector_t offset;
246
247 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
248 return -ENOTTY;
249 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
250 return -ENOTTY;
251 if (!capable(CAP_SYS_ADMIN))
252 return -EPERM;
253
254 if (!mutex_trylock(&system_transition_mutex))
255 return -EBUSY;
256
257 lock_device_hotplug();
258 data = filp->private_data;
259
260 switch (cmd) {
261
262 case SNAPSHOT_FREEZE:
263 if (data->frozen)
264 break;
265
266 ksys_sync_helper();
267
268 error = freeze_processes();
269 if (error)
270 break;
271
272 error = create_basic_memory_bitmaps();
273 if (error)
274 thaw_processes();
275 else
276 data->frozen = true;
277
278 break;
279
280 case SNAPSHOT_UNFREEZE:
281 if (!data->frozen || data->ready)
282 break;
283 pm_restore_gfp_mask();
284 free_basic_memory_bitmaps();
285 data->free_bitmaps = false;
286 thaw_processes();
287 data->frozen = false;
288 break;
289
290 case SNAPSHOT_CREATE_IMAGE:
291 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
292 error = -EPERM;
293 break;
294 }
295 pm_restore_gfp_mask();
296 error = hibernation_snapshot(data->platform_support);
297 if (!error) {
298 error = put_user(in_suspend, (int __user *)arg);
299 data->ready = !freezer_test_done && !error;
300 freezer_test_done = false;
301 }
302 break;
303
304 case SNAPSHOT_ATOMIC_RESTORE:
305 snapshot_write_finalize(&data->handle);
306 if (data->mode != O_WRONLY || !data->frozen ||
307 !snapshot_image_loaded(&data->handle)) {
308 error = -EPERM;
309 break;
310 }
311 error = hibernation_restore(data->platform_support);
312 break;
313
314 case SNAPSHOT_FREE:
315 swsusp_free();
316 memset(&data->handle, 0, sizeof(struct snapshot_handle));
317 data->ready = false;
318 /*
319 * It is necessary to thaw kernel threads here, because
320 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
321 * SNAPSHOT_FREE. In that case, if kernel threads were not
322 * thawed, the preallocation of memory carried out by
323 * hibernation_snapshot() might run into problems (i.e. it
324 * might fail or even deadlock).
325 */
326 thaw_kernel_threads();
327 break;
328
329 case SNAPSHOT_PREF_IMAGE_SIZE:
330 image_size = arg;
331 break;
332
333 case SNAPSHOT_GET_IMAGE_SIZE:
334 if (!data->ready) {
335 error = -ENODATA;
336 break;
337 }
338 size = snapshot_get_image_size();
339 size <<= PAGE_SHIFT;
340 error = put_user(size, (loff_t __user *)arg);
341 break;
342
343 case SNAPSHOT_AVAIL_SWAP_SIZE:
344 size = count_swap_pages(data->swap, 1);
345 size <<= PAGE_SHIFT;
346 error = put_user(size, (loff_t __user *)arg);
347 break;
348
349 case SNAPSHOT_ALLOC_SWAP_PAGE:
350 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
351 error = -ENODEV;
352 break;
353 }
354 offset = alloc_swapdev_block(data->swap);
355 if (offset) {
356 offset <<= PAGE_SHIFT;
357 error = put_user(offset, (loff_t __user *)arg);
358 } else {
359 error = -ENOSPC;
360 }
361 break;
362
363 case SNAPSHOT_FREE_SWAP_PAGES:
364 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
365 error = -ENODEV;
366 break;
367 }
368 free_all_swap_pages(data->swap);
369 break;
370
371 case SNAPSHOT_S2RAM:
372 if (!data->frozen) {
373 error = -EPERM;
374 break;
375 }
376 /*
377 * Tasks are frozen and the notifiers have been called with
378 * PM_HIBERNATION_PREPARE
379 */
380 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
381 data->ready = false;
382 break;
383
384 case SNAPSHOT_PLATFORM_SUPPORT:
385 data->platform_support = !!arg;
386 break;
387
388 case SNAPSHOT_POWER_OFF:
389 if (data->platform_support)
390 error = hibernation_platform_enter();
391 break;
392
393 case SNAPSHOT_SET_SWAP_AREA:
394 error = snapshot_set_swap_area(data, (void __user *)arg);
395 break;
396
397 default:
398 error = -ENOTTY;
399
400 }
401
402 unlock_device_hotplug();
403 mutex_unlock(&system_transition_mutex);
404
405 return error;
406}
407
408#ifdef CONFIG_COMPAT
409static long
410snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
411{
412 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
413
414 switch (cmd) {
415 case SNAPSHOT_GET_IMAGE_SIZE:
416 case SNAPSHOT_AVAIL_SWAP_SIZE:
417 case SNAPSHOT_ALLOC_SWAP_PAGE:
418 case SNAPSHOT_CREATE_IMAGE:
419 case SNAPSHOT_SET_SWAP_AREA:
420 return snapshot_ioctl(file, cmd,
421 (unsigned long) compat_ptr(arg));
422 default:
423 return snapshot_ioctl(file, cmd, arg);
424 }
425}
426#endif /* CONFIG_COMPAT */
427
428static const struct file_operations snapshot_fops = {
429 .open = snapshot_open,
430 .release = snapshot_release,
431 .read = snapshot_read,
432 .write = snapshot_write,
433 .llseek = no_llseek,
434 .unlocked_ioctl = snapshot_ioctl,
435#ifdef CONFIG_COMPAT
436 .compat_ioctl = snapshot_compat_ioctl,
437#endif
438};
439
440static struct miscdevice snapshot_device = {
441 .minor = SNAPSHOT_MINOR,
442 .name = "snapshot",
443 .fops = &snapshot_fops,
444};
445
446static int __init snapshot_device_init(void)
447{
448 return misc_register(&snapshot_device);
449};
450
451device_initcall(snapshot_device_init);