aboutsummaryrefslogtreecommitdiff
path: root/kernel/power/user.c
blob: 6d8f535c2b88e11952b3871ecb88d8fa0378ab40 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
/*
 * linux/kernel/power/user.c
 *
 * This file provides the user space interface for software suspend/resume.
 *
 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
 *
 * This file is released under the GPLv2.
 *
 */

#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/kmod.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
#include <scsi/scsi_scan.h>

#include <asm/uaccess.h>

#include "power.h"

/*
 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
 * will be removed in the future.  They are only preserved here for
 * compatibility with existing userland utilities.
 */
#define SNAPSHOT_SET_SWAP_FILE	_IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
#define SNAPSHOT_PMOPS		_IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)

#define PMOPS_PREPARE	1
#define PMOPS_ENTER	2
#define PMOPS_FINISH	3

/*
 * NOTE: The following ioctl definitions are wrong and have been replaced with
 * correct ones.  They are only preserved here for compatibility with existing
 * userland utilities and will be removed in the future.
 */
#define SNAPSHOT_ATOMIC_SNAPSHOT	_IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
#define SNAPSHOT_SET_IMAGE_SIZE		_IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
#define SNAPSHOT_AVAIL_SWAP		_IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
#define SNAPSHOT_GET_SWAP_PAGE		_IOR(SNAPSHOT_IOC_MAGIC, 8, void *)


#define SNAPSHOT_MINOR	231

static struct snapshot_data {
	struct snapshot_handle handle;
	int swap;
	int mode;
	char frozen;
	char ready;
	char platform_support;
} snapshot_state;

atomic_t snapshot_device_available = ATOMIC_INIT(1);

static int snapshot_open(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;
	int error;

	mutex_lock(&pm_mutex);

	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
		error = -EBUSY;
		goto Unlock;
	}

	if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
		atomic_inc(&snapshot_device_available);
		error = -ENOSYS;
		goto Unlock;
	}
	if(create_basic_memory_bitmaps()) {
		atomic_inc(&snapshot_device_available);
		error = -ENOMEM;
		goto Unlock;
	}
	nonseekable_open(inode, filp);
	data = &snapshot_state;
	filp->private_data = data;
	memset(&data->handle, 0, sizeof(struct snapshot_handle));
	if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
		/* Hibernating.  The image device should be accessible. */
		data->swap = swsusp_resume_device ?
			swap_type_of(swsusp_resume_device, 0, NULL) : -1;
		data->mode = O_RDONLY;
		error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
		if (error)
			pm_notifier_call_chain(PM_POST_HIBERNATION);
	} else {
		/*
		 * Resuming.  We may need to wait for the image device to
		 * appear.
		 */
		wait_for_device_probe();
		scsi_complete_async_scans();

		data->swap = -1;
		data->mode = O_WRONLY;
		error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
		if (error)
			pm_notifier_call_chain(PM_POST_RESTORE);
	}
	if (error) {
		free_basic_memory_bitmaps();
		atomic_inc(&snapshot_device_available);
	}
	data->frozen = 0;
	data->ready = 0;
	data->platform_support = 0;

 Unlock:
	mutex_unlock(&pm_mutex);

	return error;
}

static int snapshot_release(struct inode *inode, struct file *filp)
{
	struct snapshot_data *data;

	mutex_lock(&pm_mutex);

	swsusp_free();
	free_basic_memory_bitmaps();
	data = filp->private_data;
	free_all_swap_pages(data->swap);
	if (data->frozen) {
		pm_restore_gfp_mask();
		thaw_processes();
	}
	pm_notifier_call_chain(data->mode == O_RDONLY ?
			PM_POST_HIBERNATION : PM_POST_RESTORE);
	atomic_inc(&snapshot_device_available);

	mutex_unlock(&pm_mutex);

	return 0;
}

static ssize_t snapshot_read(struct file *filp, char __user *buf,
                             size_t count, loff_t *offp)
{
	struct snapshot_data *data;
	ssize_t res;
	loff_t pg_offp = *offp & ~PAGE_MASK;

	mutex_lock(&pm_mutex);

	data = filp->private_data;
	if (!data->ready) {
		res = -ENODATA;
		goto Unlock;
	}
	if (!pg_offp) { /* on page boundary? */
		res = snapshot_read_next(&data->handle);
		if (res <= 0)
			goto Unlock;
	} else {
		res = PAGE_SIZE - pg_offp;
	}

	res = simple_read_from_buffer(buf, count, &pg_offp,
			data_of(data->handle), res);
	if (res > 0)
		*offp += res;

 Unlock:
	mutex_unlock(&pm_mutex);

	return res;
}

static ssize_t snapshot_write(struct file *filp, const char __user *buf,
                              size_t count, loff_t *offp)
{
	struct snapshot_data *data;
	ssize_t res;
	loff_t pg_offp = *offp & ~PAGE_MASK;

	mutex_lock(&pm_mutex);

	data = filp->private_data;

	if (!pg_offp) {
		res = snapshot_write_next(&data->handle);
		if (res <= 0)
			goto unlock;
	} else {
		res = PAGE_SIZE - pg_offp;
	}

	res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
			buf, count);
	if (res > 0)
		*offp += res;
unlock:
	mutex_unlock(&pm_mutex);

	return res;
}

static void snapshot_deprecated_ioctl(unsigned int cmd)
{
	if (printk_ratelimit())
		printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
				"be removed soon, update your suspend-to-disk "
				"utilities\n",
				__builtin_return_address(0), cmd);
}

static long snapshot_ioctl(struct file *filp, unsigned int cmd,
							unsigned long arg)
{
	int error = 0;
	struct snapshot_data *data;
	loff_t size;
	sector_t offset;

	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
		return -ENOTTY;
	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
		return -ENOTTY;
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	data = filp->private_data;

	switch (cmd) {

	case SNAPSHOT_FREEZE:
		if (data->frozen)
			break;

		printk("Syncing filesystems ... ");
		sys_sync();
		printk("done.\n");

		error = usermodehelper_disable();
		if (error)
			break;

		error = freeze_processes();
		if (error) {
			thaw_processes();
			usermodehelper_enable();
		}
		if (!error)
			data->frozen = 1;
		break;

	case SNAPSHOT_UNFREEZE:
		if (!data->frozen || data->ready)
			break;
		pm_restore_gfp_mask();
		thaw_processes();
		usermodehelper_enable();
		data->frozen = 0;
		break;

	case SNAPSHOT_ATOMIC_SNAPSHOT:
		snapshot_deprecated_ioctl(cmd);
	case SNAPSHOT_CREATE_IMAGE:
		if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
			error = -EPERM;
			break;
		}
		pm_restore_gfp_mask();
		error = hibernation_snapshot(data->platform_support);
		if (!error)
			error = put_user(in_suspend, (int __user *)arg);
		if (!error)
			data->ready = 1;
		break;

	case SNAPSHOT_ATOMIC_RESTORE:
		snapshot_write_finalize(&data->handle);
		if (data->mode != O_WRONLY || !data->frozen ||
		    !snapshot_image_loaded(&data->handle)) {
			error = -EPERM;
			break;
		}
		error = hibernation_restore(data->platform_support);
		break;

	case SNAPSHOT_FREE:
		swsusp_free();
		memset(&data->handle, 0, sizeof(struct snapshot_handle));
		data->ready = 0;
		break;

	case SNAPSHOT_SET_IMAGE_SIZE:
		snapshot_deprecated_ioctl(cmd);
	case SNAPSHOT_PREF_IMAGE_SIZE:
		image_size = arg;
		break;

	case SNAPSHOT_GET_IMAGE_SIZE:
		if (!data->ready) {
			error = -ENODATA;
			break;
		}
		size = snapshot_get_image_size();
		size <<= PAGE_SHIFT;
		error = put_user(size, (loff_t __user *)arg);
		break;

	case SNAPSHOT_AVAIL_SWAP:
		snapshot_deprecated_ioctl(cmd);
	case SNAPSHOT_AVAIL_SWAP_SIZE:
		size = count_swap_pages(data->swap, 1);
		size <<= PAGE_SHIFT;
		error = put_user(size, (loff_t __user *)arg);
		break;

	case SNAPSHOT_GET_SWAP_PAGE:
		snapshot_deprecated_ioctl(cmd);
	case SNAPSHOT_ALLOC_SWAP_PAGE:
		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
			error = -ENODEV;
			break;
		}
		offset = alloc_swapdev_block(data->swap);
		if (offset) {
			offset <<= PAGE_SHIFT;
			error = put_user(offset, (loff_t __user *)arg);
		} else {
			error = -ENOSPC;
		}
		break;

	case SNAPSHOT_FREE_SWAP_PAGES:
		if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
			error = -ENODEV;
			break;
		}
		free_all_swap_pages(data->swap);
		break;

	case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
		snapshot_deprecated_ioctl(cmd);
		if (!swsusp_swap_in_use()) {
			/*
			 * User space encodes device types as two-byte values,
			 * so we need to recode them
			 */
			if (old_decode_dev(arg)) {
				data->swap = swap_type_of(old_decode_dev(arg),
							0, NULL);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		} else {
			error = -EPERM;
		}
		break;

	case SNAPSHOT_S2RAM:
		if (!data->frozen) {
			error = -EPERM;
			break;
		}
		/*
		 * Tasks are frozen and the notifiers have been called with
		 * PM_HIBERNATION_PREPARE
		 */
		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
		data->ready = 0;
		break;

	case SNAPSHOT_PLATFORM_SUPPORT:
		data->platform_support = !!arg;
		break;

	case SNAPSHOT_POWER_OFF:
		if (data->platform_support)
			error = hibernation_platform_enter();
		break;

	case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
		snapshot_deprecated_ioctl(cmd);
		error = -EINVAL;

		switch (arg) {

		case PMOPS_PREPARE:
			data->platform_support = 1;
			error = 0;
			break;

		case PMOPS_ENTER:
			if (data->platform_support)
				error = hibernation_platform_enter();
			break;

		case PMOPS_FINISH:
			if (data->platform_support)
				error = 0;
			break;

		default:
			printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);

		}
		break;

	case SNAPSHOT_SET_SWAP_AREA:
		if (swsusp_swap_in_use()) {
			error = -EPERM;
		} else {
			struct resume_swap_area swap_area;
			dev_t swdev;

			error = copy_from_user(&swap_area, (void __user *)arg,
					sizeof(struct resume_swap_area));
			if (error) {
				error = -EFAULT;
				break;
			}

			/*
			 * User space encodes device types as two-byte values,
			 * so we need to recode them
			 */
			swdev = new_decode_dev(swap_area.dev);
			if (swdev) {
				offset = swap_area.offset;
				data->swap = swap_type_of(swdev, offset, NULL);
				if (data->swap < 0)
					error = -ENODEV;
			} else {
				data->swap = -1;
				error = -EINVAL;
			}
		}
		break;

	default:
		error = -ENOTTY;

	}

	mutex_unlock(&pm_mutex);

	return error;
}

static const struct file_operations snapshot_fops = {
	.open = snapshot_open,
	.release = snapshot_release,
	.read = snapshot_read,
	.write = snapshot_write,
	.llseek = no_llseek,
	.unlocked_ioctl = snapshot_ioctl,
};

static struct miscdevice snapshot_device = {
	.minor = SNAPSHOT_MINOR,
	.name = "snapshot",
	.fops = &snapshot_fops,
};

static int __init snapshot_device_init(void)
{
	return misc_register(&snapshot_device);
};

device_initcall(snapshot_device_init);