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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/console.h>
24#include <linux/cpu.h>
25#include <linux/freezer.h>
26#include <scsi/scsi_scan.h>
27
28#include <asm/uaccess.h>
29
30#include "power.h"
31
32/*
33 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34 * will be removed in the future. They are only preserved here for
35 * compatibility with existing userland utilities.
36 */
37#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
38#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
39
40#define PMOPS_PREPARE 1
41#define PMOPS_ENTER 2
42#define PMOPS_FINISH 3
43
44/*
45 * NOTE: The following ioctl definitions are wrong and have been replaced with
46 * correct ones. They are only preserved here for compatibility with existing
47 * userland utilities and will be removed in the future.
48 */
49#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
53
54
55#define SNAPSHOT_MINOR 231
56
57static struct snapshot_data {
58 struct snapshot_handle handle;
59 int swap;
60 int mode;
61 char frozen;
62 char ready;
63 char platform_support;
64} snapshot_state;
65
66atomic_t snapshot_device_available = ATOMIC_INIT(1);
67
68static int snapshot_open(struct inode *inode, struct file *filp)
69{
70 struct snapshot_data *data;
71 int error;
72
73 mutex_lock(&pm_mutex);
74
75 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
76 error = -EBUSY;
77 goto Unlock;
78 }
79
80 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
81 atomic_inc(&snapshot_device_available);
82 error = -ENOSYS;
83 goto Unlock;
84 }
85 if(create_basic_memory_bitmaps()) {
86 atomic_inc(&snapshot_device_available);
87 error = -ENOMEM;
88 goto Unlock;
89 }
90 nonseekable_open(inode, filp);
91 data = &snapshot_state;
92 filp->private_data = data;
93 memset(&data->handle, 0, sizeof(struct snapshot_handle));
94 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
95 /* Hibernating. The image device should be accessible. */
96 data->swap = swsusp_resume_device ?
97 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
98 data->mode = O_RDONLY;
99 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
100 if (error)
101 pm_notifier_call_chain(PM_POST_HIBERNATION);
102 } else {
103 /*
104 * Resuming. We may need to wait for the image device to
105 * appear.
106 */
107 wait_for_device_probe();
108 scsi_complete_async_scans();
109
110 data->swap = -1;
111 data->mode = O_WRONLY;
112 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
113 if (error)
114 pm_notifier_call_chain(PM_POST_RESTORE);
115 }
116 if (error) {
117 free_basic_memory_bitmaps();
118 atomic_inc(&snapshot_device_available);
119 }
120 data->frozen = 0;
121 data->ready = 0;
122 data->platform_support = 0;
123
124 Unlock:
125 mutex_unlock(&pm_mutex);
126
127 return error;
128}
129
130static int snapshot_release(struct inode *inode, struct file *filp)
131{
132 struct snapshot_data *data;
133
134 mutex_lock(&pm_mutex);
135
136 swsusp_free();
137 free_basic_memory_bitmaps();
138 data = filp->private_data;
139 free_all_swap_pages(data->swap);
140 if (data->frozen) {
141 pm_restore_gfp_mask();
142 thaw_processes();
143 }
144 pm_notifier_call_chain(data->mode == O_RDONLY ?
145 PM_POST_HIBERNATION : PM_POST_RESTORE);
146 atomic_inc(&snapshot_device_available);
147
148 mutex_unlock(&pm_mutex);
149
150 return 0;
151}
152
153static ssize_t snapshot_read(struct file *filp, char __user *buf,
154 size_t count, loff_t *offp)
155{
156 struct snapshot_data *data;
157 ssize_t res;
158 loff_t pg_offp = *offp & ~PAGE_MASK;
159
160 mutex_lock(&pm_mutex);
161
162 data = filp->private_data;
163 if (!data->ready) {
164 res = -ENODATA;
165 goto Unlock;
166 }
167 if (!pg_offp) { /* on page boundary? */
168 res = snapshot_read_next(&data->handle);
169 if (res <= 0)
170 goto Unlock;
171 } else {
172 res = PAGE_SIZE - pg_offp;
173 }
174
175 res = simple_read_from_buffer(buf, count, &pg_offp,
176 data_of(data->handle), res);
177 if (res > 0)
178 *offp += res;
179
180 Unlock:
181 mutex_unlock(&pm_mutex);
182
183 return res;
184}
185
186static ssize_t snapshot_write(struct file *filp, const char __user *buf,
187 size_t count, loff_t *offp)
188{
189 struct snapshot_data *data;
190 ssize_t res;
191 loff_t pg_offp = *offp & ~PAGE_MASK;
192
193 mutex_lock(&pm_mutex);
194
195 data = filp->private_data;
196
197 if (!pg_offp) {
198 res = snapshot_write_next(&data->handle);
199 if (res <= 0)
200 goto unlock;
201 } else {
202 res = PAGE_SIZE - pg_offp;
203 }
204
205 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
206 buf, count);
207 if (res > 0)
208 *offp += res;
209unlock:
210 mutex_unlock(&pm_mutex);
211
212 return res;
213}
214
215static void snapshot_deprecated_ioctl(unsigned int cmd)
216{
217 if (printk_ratelimit())
218 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
219 "be removed soon, update your suspend-to-disk "
220 "utilities\n",
221 __builtin_return_address(0), cmd);
222}
223
224static long snapshot_ioctl(struct file *filp, unsigned int cmd,
225 unsigned long arg)
226{
227 int error = 0;
228 struct snapshot_data *data;
229 loff_t size;
230 sector_t offset;
231
232 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
233 return -ENOTTY;
234 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
235 return -ENOTTY;
236 if (!capable(CAP_SYS_ADMIN))
237 return -EPERM;
238
239 if (!mutex_trylock(&pm_mutex))
240 return -EBUSY;
241
242 data = filp->private_data;
243
244 switch (cmd) {
245
246 case SNAPSHOT_FREEZE:
247 if (data->frozen)
248 break;
249
250 printk("Syncing filesystems ... ");
251 sys_sync();
252 printk("done.\n");
253
254 error = usermodehelper_disable();
255 if (error)
256 break;
257
258 error = freeze_processes();
259 if (error) {
260 thaw_processes();
261 usermodehelper_enable();
262 }
263 if (!error)
264 data->frozen = 1;
265 break;
266
267 case SNAPSHOT_UNFREEZE:
268 if (!data->frozen || data->ready)
269 break;
270 pm_restore_gfp_mask();
271 thaw_processes();
272 usermodehelper_enable();
273 data->frozen = 0;
274 break;
275
276 case SNAPSHOT_ATOMIC_SNAPSHOT:
277 snapshot_deprecated_ioctl(cmd);
278 case SNAPSHOT_CREATE_IMAGE:
279 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
280 error = -EPERM;
281 break;
282 }
283 pm_restore_gfp_mask();
284 error = hibernation_snapshot(data->platform_support);
285 if (!error)
286 error = put_user(in_suspend, (int __user *)arg);
287 if (!error)
288 data->ready = 1;
289 break;
290
291 case SNAPSHOT_ATOMIC_RESTORE:
292 snapshot_write_finalize(&data->handle);
293 if (data->mode != O_WRONLY || !data->frozen ||
294 !snapshot_image_loaded(&data->handle)) {
295 error = -EPERM;
296 break;
297 }
298 error = hibernation_restore(data->platform_support);
299 break;
300
301 case SNAPSHOT_FREE:
302 swsusp_free();
303 memset(&data->handle, 0, sizeof(struct snapshot_handle));
304 data->ready = 0;
305 break;
306
307 case SNAPSHOT_SET_IMAGE_SIZE:
308 snapshot_deprecated_ioctl(cmd);
309 case SNAPSHOT_PREF_IMAGE_SIZE:
310 image_size = arg;
311 break;
312
313 case SNAPSHOT_GET_IMAGE_SIZE:
314 if (!data->ready) {
315 error = -ENODATA;
316 break;
317 }
318 size = snapshot_get_image_size();
319 size <<= PAGE_SHIFT;
320 error = put_user(size, (loff_t __user *)arg);
321 break;
322
323 case SNAPSHOT_AVAIL_SWAP:
324 snapshot_deprecated_ioctl(cmd);
325 case SNAPSHOT_AVAIL_SWAP_SIZE:
326 size = count_swap_pages(data->swap, 1);
327 size <<= PAGE_SHIFT;
328 error = put_user(size, (loff_t __user *)arg);
329 break;
330
331 case SNAPSHOT_GET_SWAP_PAGE:
332 snapshot_deprecated_ioctl(cmd);
333 case SNAPSHOT_ALLOC_SWAP_PAGE:
334 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
335 error = -ENODEV;
336 break;
337 }
338 offset = alloc_swapdev_block(data->swap);
339 if (offset) {
340 offset <<= PAGE_SHIFT;
341 error = put_user(offset, (loff_t __user *)arg);
342 } else {
343 error = -ENOSPC;
344 }
345 break;
346
347 case SNAPSHOT_FREE_SWAP_PAGES:
348 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
349 error = -ENODEV;
350 break;
351 }
352 free_all_swap_pages(data->swap);
353 break;
354
355 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
356 snapshot_deprecated_ioctl(cmd);
357 if (!swsusp_swap_in_use()) {
358 /*
359 * User space encodes device types as two-byte values,
360 * so we need to recode them
361 */
362 if (old_decode_dev(arg)) {
363 data->swap = swap_type_of(old_decode_dev(arg),
364 0, NULL);
365 if (data->swap < 0)
366 error = -ENODEV;
367 } else {
368 data->swap = -1;
369 error = -EINVAL;
370 }
371 } else {
372 error = -EPERM;
373 }
374 break;
375
376 case SNAPSHOT_S2RAM:
377 if (!data->frozen) {
378 error = -EPERM;
379 break;
380 }
381 /*
382 * Tasks are frozen and the notifiers have been called with
383 * PM_HIBERNATION_PREPARE
384 */
385 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
386 data->ready = 0;
387 break;
388
389 case SNAPSHOT_PLATFORM_SUPPORT:
390 data->platform_support = !!arg;
391 break;
392
393 case SNAPSHOT_POWER_OFF:
394 if (data->platform_support)
395 error = hibernation_platform_enter();
396 break;
397
398 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
399 snapshot_deprecated_ioctl(cmd);
400 error = -EINVAL;
401
402 switch (arg) {
403
404 case PMOPS_PREPARE:
405 data->platform_support = 1;
406 error = 0;
407 break;
408
409 case PMOPS_ENTER:
410 if (data->platform_support)
411 error = hibernation_platform_enter();
412 break;
413
414 case PMOPS_FINISH:
415 if (data->platform_support)
416 error = 0;
417 break;
418
419 default:
420 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
421
422 }
423 break;
424
425 case SNAPSHOT_SET_SWAP_AREA:
426 if (swsusp_swap_in_use()) {
427 error = -EPERM;
428 } else {
429 struct resume_swap_area swap_area;
430 dev_t swdev;
431
432 error = copy_from_user(&swap_area, (void __user *)arg,
433 sizeof(struct resume_swap_area));
434 if (error) {
435 error = -EFAULT;
436 break;
437 }
438
439 /*
440 * User space encodes device types as two-byte values,
441 * so we need to recode them
442 */
443 swdev = new_decode_dev(swap_area.dev);
444 if (swdev) {
445 offset = swap_area.offset;
446 data->swap = swap_type_of(swdev, offset, NULL);
447 if (data->swap < 0)
448 error = -ENODEV;
449 } else {
450 data->swap = -1;
451 error = -EINVAL;
452 }
453 }
454 break;
455
456 default:
457 error = -ENOTTY;
458
459 }
460
461 mutex_unlock(&pm_mutex);
462
463 return error;
464}
465
466static const struct file_operations snapshot_fops = {
467 .open = snapshot_open,
468 .release = snapshot_release,
469 .read = snapshot_read,
470 .write = snapshot_write,
471 .llseek = no_llseek,
472 .unlocked_ioctl = snapshot_ioctl,
473};
474
475static struct miscdevice snapshot_device = {
476 .minor = SNAPSHOT_MINOR,
477 .name = "snapshot",
478 .fops = &snapshot_fops,
479};
480
481static int __init snapshot_device_init(void)
482{
483 return misc_register(&snapshot_device);
484};
485
486device_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);