summaryrefslogtreecommitdiffstats
path: root/kernel/power/disk.c
blob: 06331374d8624627e4071ca5df6b70cdf16c190b (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
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
/*
 * kernel/power/disk.c - Suspend-to-disk support.
 *
 * Copyright (c) 2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 * Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
 *
 * This file is released under the GPLv2.
 *
 */

#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>

#include "power.h"


static int noresume = 0;
char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
sector_t swsusp_resume_block;

/**
 *	platform_prepare - prepare the machine for hibernation using the
 *	platform driver if so configured and return an error code if it fails
 */

static inline int platform_prepare(void)
{
	int error = 0;

	switch (pm_disk_mode) {
	case PM_DISK_TEST:
	case PM_DISK_TESTPROC:
	case PM_DISK_SHUTDOWN:
	case PM_DISK_REBOOT:
		break;
	default:
		if (pm_ops && pm_ops->prepare)
			error = pm_ops->prepare(PM_SUSPEND_DISK);
	}
	return error;
}

/**
 *	power_down - Shut machine down for hibernate.
 *
 *	Use the platform driver, if configured so; otherwise try
 *	to power off or reboot.
 */

static void power_down(void)
{
	switch (pm_disk_mode) {
	case PM_DISK_TEST:
	case PM_DISK_TESTPROC:
		break;
	case PM_DISK_SHUTDOWN:
		kernel_power_off();
		break;
	case PM_DISK_REBOOT:
		kernel_restart(NULL);
		break;
	default:
		if (pm_ops && pm_ops->enter) {
			kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
			pm_ops->enter(PM_SUSPEND_DISK);
			break;
		}
	}
	kernel_halt();
	/*
	 * Valid image is on the disk, if we continue we risk serious data
	 * corruption after resume.
	 */
	printk(KERN_CRIT "Please power me down manually\n");
	while(1);
}

static inline void platform_finish(void)
{
	switch (pm_disk_mode) {
	case PM_DISK_TEST:
	case PM_DISK_TESTPROC:
	case PM_DISK_SHUTDOWN:
	case PM_DISK_REBOOT:
		break;
	default:
		if (pm_ops && pm_ops->finish)
			pm_ops->finish(PM_SUSPEND_DISK);
	}
}

static void unprepare_processes(void)
{
	thaw_processes();
	pm_restore_console();
}

static int prepare_processes(void)
{
	int error = 0;

	pm_prepare_console();
	if (freeze_processes()) {
		error = -EBUSY;
		unprepare_processes();
	}
	return error;
}

/**
 *	pm_suspend_disk - The granpappy of hibernation power management.
 *
 *	If not, then call swsusp to do its thing, then figure out how
 *	to power down the system.
 */

int pm_suspend_disk(void)
{
	int error;

	/* The snapshot device should not be opened while we're running */
	if (!atomic_add_unless(&snapshot_device_available, -1, 0))
		return -EBUSY;

	/* Allocate memory management structures */
	error = create_basic_memory_bitmaps();
	if (error)
		goto Exit;

	error = prepare_processes();
	if (error)
		goto Finish;

	if (pm_disk_mode == PM_DISK_TESTPROC) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto Thaw;
	}

	/* Free memory before shutting down devices. */
	error = swsusp_shrink_memory();
	if (error)
		goto Thaw;

	error = platform_prepare();
	if (error)
		goto Thaw;

	suspend_console();
	error = device_suspend(PMSG_FREEZE);
	if (error) {
		printk(KERN_ERR "PM: Some devices failed to suspend\n");
		goto Resume_devices;
	}
	error = disable_nonboot_cpus();
	if (error)
		goto Enable_cpus;

	if (pm_disk_mode == PM_DISK_TEST) {
		printk("swsusp debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		goto Enable_cpus;
	}

	pr_debug("PM: snapshotting memory.\n");
	in_suspend = 1;
	error = swsusp_suspend();
	if (error)
		goto Enable_cpus;

	if (in_suspend) {
		enable_nonboot_cpus();
		platform_finish();
		device_resume();
		resume_console();
		pr_debug("PM: writing image.\n");
		error = swsusp_write();
		if (!error)
			power_down();
		else {
			swsusp_free();
			goto Thaw;
		}
	} else {
		pr_debug("PM: Image restored successfully.\n");
	}

	swsusp_free();
 Enable_cpus:
	enable_nonboot_cpus();
 Resume_devices:
	platform_finish();
	device_resume();
	resume_console();
 Thaw:
	unprepare_processes();
 Finish:
	free_basic_memory_bitmaps();
 Exit:
	atomic_inc(&snapshot_device_available);
	return error;
}


/**
 *	software_resume - Resume from a saved image.
 *
 *	Called as a late_initcall (so all devices are discovered and
 *	initialized), we call swsusp to see if we have a saved image or not.
 *	If so, we quiesce devices, the restore the saved image. We will
 *	return above (in pm_suspend_disk() ) if everything goes well.
 *	Otherwise, we fail gracefully and return to the normally
 *	scheduled program.
 *
 */

static int software_resume(void)
{
	int error;

	mutex_lock(&pm_mutex);
	if (!swsusp_resume_device) {
		if (!strlen(resume_file)) {
			mutex_unlock(&pm_mutex);
			return -ENOENT;
		}
		swsusp_resume_device = name_to_dev_t(resume_file);
		pr_debug("swsusp: Resume From Partition %s\n", resume_file);
	} else {
		pr_debug("swsusp: Resume From Partition %d:%d\n",
			 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
	}

	if (noresume) {
		/**
		 * FIXME: If noresume is specified, we need to find the partition
		 * and reset it back to normal swap space.
		 */
		mutex_unlock(&pm_mutex);
		return 0;
	}

	pr_debug("PM: Checking swsusp image.\n");
	error = swsusp_check();
	if (error)
		goto Unlock;

	/* The snapshot device should not be opened while we're running */
	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
		error = -EBUSY;
		goto Unlock;
	}

	error = create_basic_memory_bitmaps();
	if (error)
		goto Finish;

	pr_debug("PM: Preparing processes for restore.\n");
	error = prepare_processes();
	if (error) {
		swsusp_close();
		goto Done;
	}

	pr_debug("PM: Reading swsusp image.\n");

	error = swsusp_read();
	if (error) {
		swsusp_free();
		goto Thaw;
	}

	pr_debug("PM: Preparing devices for restore.\n");

	suspend_console();
	error = device_suspend(PMSG_PRETHAW);
	if (error)
		goto Free;

	error = disable_nonboot_cpus();
	if (!error)
		swsusp_resume();

	enable_nonboot_cpus();
 Free:
	swsusp_free();
	device_resume();
	resume_console();
 Thaw:
	printk(KERN_ERR "PM: Restore failed, recovering.\n");
	unprepare_processes();
 Done:
	free_basic_memory_bitmaps();
 Finish:
	atomic_inc(&snapshot_device_available);
	/* For success case, the suspend path will release the lock */
 Unlock:
	mutex_unlock(&pm_mutex);
	pr_debug("PM: Resume from disk failed.\n");
	return 0;
}

late_initcall(software_resume);


static const char * const pm_disk_modes[] = {
	[PM_DISK_PLATFORM]	= "platform",
	[PM_DISK_SHUTDOWN]	= "shutdown",
	[PM_DISK_REBOOT]	= "reboot",
	[PM_DISK_TEST]		= "test",
	[PM_DISK_TESTPROC]	= "testproc",
};

/**
 *	disk - Control suspend-to-disk mode
 *
 *	Suspend-to-disk can be handled in several ways. We have a few options
 *	for putting the system to sleep - using the platform driver (e.g. ACPI
 *	or other pm_ops), powering off the system or rebooting the system
 *	(for testing) as well as the two test modes.
 *
 *	The system can support 'platform', and that is known a priori (and
 *	encoded in pm_ops). However, the user may choose 'shutdown' or 'reboot'
 *	as alternatives, as well as the test modes 'test' and 'testproc'.
 *
 *	show() will display what the mode is currently set to.
 *	store() will accept one of
 *
 *	'platform'
 *	'shutdown'
 *	'reboot'
 *	'test'
 *	'testproc'
 *
 *	It will only change to 'platform' if the system
 *	supports it (as determined from pm_ops->pm_disk_mode).
 */

static ssize_t disk_show(struct kset *kset, char *buf)
{
	int i;
	char *start = buf;

	for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
		if (!pm_disk_modes[i])
			continue;
		switch (i) {
		case PM_DISK_SHUTDOWN:
		case PM_DISK_REBOOT:
		case PM_DISK_TEST:
		case PM_DISK_TESTPROC:
			break;
		default:
			if (pm_ops && pm_ops->enter &&
			    (i == pm_ops->pm_disk_mode))
				break;
			/* not a valid mode, continue with loop */
			continue;
		}
		if (i == pm_disk_mode)
			buf += sprintf(buf, "[%s]", pm_disk_modes[i]);
		else
			buf += sprintf(buf, "%s", pm_disk_modes[i]);
		if (i+1 != PM_DISK_MAX)
			buf += sprintf(buf, " ");
	}
	buf += sprintf(buf, "\n");
	return buf-start;
}


static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
{
	int error = 0;
	int i;
	int len;
	char *p;
	suspend_disk_method_t mode = 0;

	p = memchr(buf, '\n', n);
	len = p ? p - buf : n;

	mutex_lock(&pm_mutex);
	for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
		if (!strncmp(buf, pm_disk_modes[i], len)) {
			mode = i;
			break;
		}
	}
	if (mode) {
		switch (mode) {
		case PM_DISK_SHUTDOWN:
		case PM_DISK_REBOOT:
		case PM_DISK_TEST:
		case PM_DISK_TESTPROC:
			pm_disk_mode = mode;
			break;
		default:
			if (pm_ops && pm_ops->enter &&
			    (mode == pm_ops->pm_disk_mode))
				pm_disk_mode = mode;
			else
				error = -EINVAL;
		}
	} else {
		error = -EINVAL;
	}

	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
		 pm_disk_modes[mode]);
	mutex_unlock(&pm_mutex);
	return error ? error : n;
}

power_attr(disk);

static ssize_t resume_show(struct kset *kset, char *buf)
{
	return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
		       MINOR(swsusp_resume_device));
}

static ssize_t resume_store(struct kset *kset, const char *buf, size_t n)
{
	unsigned int maj, min;
	dev_t res;
	int ret = -EINVAL;

	if (sscanf(buf, "%u:%u", &maj, &min) != 2)
		goto out;

	res = MKDEV(maj,min);
	if (maj != MAJOR(res) || min != MINOR(res))
		goto out;

	mutex_lock(&pm_mutex);
	swsusp_resume_device = res;
	mutex_unlock(&pm_mutex);
	printk("Attempting manual resume\n");
	noresume = 0;
	software_resume();
	ret = n;
 out:
	return ret;
}

power_attr(resume);

static ssize_t image_size_show(struct kset *kset, char *buf)
{
	return sprintf(buf, "%lu\n", image_size);
}

static ssize_t image_size_store(struct kset *kset, const char *buf, size_t n)
{
	unsigned long size;

	if (sscanf(buf, "%lu", &size) == 1) {
		image_size = size;
		return n;
	}

	return -EINVAL;
}

power_attr(image_size);

static struct attribute * g[] = {
	&disk_attr.attr,
	&resume_attr.attr,
	&image_size_attr.attr,
	NULL,
};


static struct attribute_group attr_group = {
	.attrs = g,
};


static int __init pm_disk_init(void)
{
	return sysfs_create_group(&power_subsys.kobj, &attr_group);
}

core_initcall(pm_disk_init);


static int __init resume_setup(char *str)
{
	if (noresume)
		return 1;

	strncpy( resume_file, str, 255 );
	return 1;
}

static int __init resume_offset_setup(char *str)
{
	unsigned long long offset;

	if (noresume)
		return 1;

	if (sscanf(str, "%llu", &offset) == 1)
		swsusp_resume_block = offset;

	return 1;
}

static int __init noresume_setup(char *str)
{
	noresume = 1;
	return 1;
}

__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);