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
57 static 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
66 atomic_t snapshot_device_available = ATOMIC_INIT(1);
67
68 static 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 atomic_inc(&snapshot_device_available);
118 data->frozen = 0;
119 data->ready = 0;
120 data->platform_support = 0;
121
122 Unlock:
123 mutex_unlock(&pm_mutex);
124
125 return error;
126 }
127
128 static int snapshot_release(struct inode *inode, struct file *filp)
129 {
130 struct snapshot_data *data;
131
132 mutex_lock(&pm_mutex);
133
134 swsusp_free();
135 free_basic_memory_bitmaps();
136 data = filp->private_data;
137 free_all_swap_pages(data->swap);
138 if (data->frozen)
139 thaw_processes();
140 pm_notifier_call_chain(data->mode == O_WRONLY ?
141 PM_POST_HIBERNATION : PM_POST_RESTORE);
142 atomic_inc(&snapshot_device_available);
143
144 mutex_unlock(&pm_mutex);
145
146 return 0;
147 }
148
149 static ssize_t snapshot_read(struct file *filp, char __user *buf,
150 size_t count, loff_t *offp)
151 {
152 struct snapshot_data *data;
153 ssize_t res;
154
155 mutex_lock(&pm_mutex);
156
157 data = filp->private_data;
158 if (!data->ready) {
159 res = -ENODATA;
160 goto Unlock;
161 }
162 res = snapshot_read_next(&data->handle, count);
163 if (res > 0) {
164 if (copy_to_user(buf, data_of(data->handle), res))
165 res = -EFAULT;
166 else
167 *offp = data->handle.offset;
168 }
169
170 Unlock:
171 mutex_unlock(&pm_mutex);
172
173 return res;
174 }
175
176 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
177 size_t count, loff_t *offp)
178 {
179 struct snapshot_data *data;
180 ssize_t res;
181
182 mutex_lock(&pm_mutex);
183
184 data = filp->private_data;
185 res = snapshot_write_next(&data->handle, count);
186 if (res > 0) {
187 if (copy_from_user(data_of(data->handle), buf, res))
188 res = -EFAULT;
189 else
190 *offp = data->handle.offset;
191 }
192
193 mutex_unlock(&pm_mutex);
194
195 return res;
196 }
197
198 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
199 unsigned long arg)
200 {
201 int error = 0;
202 struct snapshot_data *data;
203 loff_t size;
204 sector_t offset;
205
206 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
207 return -ENOTTY;
208 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
209 return -ENOTTY;
210 if (!capable(CAP_SYS_ADMIN))
211 return -EPERM;
212
213 if (!mutex_trylock(&pm_mutex))
214 return -EBUSY;
215
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 = usermodehelper_disable();
229 if (error)
230 break;
231
232 error = freeze_processes();
233 if (error) {
234 thaw_processes();
235 usermodehelper_enable();
236 }
237 if (!error)
238 data->frozen = 1;
239 break;
240
241 case SNAPSHOT_UNFREEZE:
242 if (!data->frozen || data->ready)
243 break;
244 thaw_processes();
245 usermodehelper_enable();
246 data->frozen = 0;
247 break;
248
249 case SNAPSHOT_CREATE_IMAGE:
250 case SNAPSHOT_ATOMIC_SNAPSHOT:
251 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
252 error = -EPERM;
253 break;
254 }
255 error = hibernation_snapshot(data->platform_support);
256 if (!error)
257 error = put_user(in_suspend, (int __user *)arg);
258 if (!error)
259 data->ready = 1;
260 break;
261
262 case SNAPSHOT_ATOMIC_RESTORE:
263 snapshot_write_finalize(&data->handle);
264 if (data->mode != O_WRONLY || !data->frozen ||
265 !snapshot_image_loaded(&data->handle)) {
266 error = -EPERM;
267 break;
268 }
269 error = hibernation_restore(data->platform_support);
270 break;
271
272 case SNAPSHOT_FREE:
273 swsusp_free();
274 memset(&data->handle, 0, sizeof(struct snapshot_handle));
275 data->ready = 0;
276 break;
277
278 case SNAPSHOT_PREF_IMAGE_SIZE:
279 case SNAPSHOT_SET_IMAGE_SIZE:
280 image_size = arg;
281 break;
282
283 case SNAPSHOT_GET_IMAGE_SIZE:
284 if (!data->ready) {
285 error = -ENODATA;
286 break;
287 }
288 size = snapshot_get_image_size();
289 size <<= PAGE_SHIFT;
290 error = put_user(size, (loff_t __user *)arg);
291 break;
292
293 case SNAPSHOT_AVAIL_SWAP_SIZE:
294 case SNAPSHOT_AVAIL_SWAP:
295 size = count_swap_pages(data->swap, 1);
296 size <<= PAGE_SHIFT;
297 error = put_user(size, (loff_t __user *)arg);
298 break;
299
300 case SNAPSHOT_ALLOC_SWAP_PAGE:
301 case SNAPSHOT_GET_SWAP_PAGE:
302 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
303 error = -ENODEV;
304 break;
305 }
306 offset = alloc_swapdev_block(data->swap);
307 if (offset) {
308 offset <<= PAGE_SHIFT;
309 error = put_user(offset, (loff_t __user *)arg);
310 } else {
311 error = -ENOSPC;
312 }
313 break;
314
315 case SNAPSHOT_FREE_SWAP_PAGES:
316 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
317 error = -ENODEV;
318 break;
319 }
320 free_all_swap_pages(data->swap);
321 break;
322
323 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
324 if (!swsusp_swap_in_use()) {
325 /*
326 * User space encodes device types as two-byte values,
327 * so we need to recode them
328 */
329 if (old_decode_dev(arg)) {
330 data->swap = swap_type_of(old_decode_dev(arg),
331 0, NULL);
332 if (data->swap < 0)
333 error = -ENODEV;
334 } else {
335 data->swap = -1;
336 error = -EINVAL;
337 }
338 } else {
339 error = -EPERM;
340 }
341 break;
342
343 case SNAPSHOT_S2RAM:
344 if (!data->frozen) {
345 error = -EPERM;
346 break;
347 }
348 /*
349 * Tasks are frozen and the notifiers have been called with
350 * PM_HIBERNATION_PREPARE
351 */
352 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
353 break;
354
355 case SNAPSHOT_PLATFORM_SUPPORT:
356 data->platform_support = !!arg;
357 break;
358
359 case SNAPSHOT_POWER_OFF:
360 if (data->platform_support)
361 error = hibernation_platform_enter();
362 break;
363
364 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
365 error = -EINVAL;
366
367 switch (arg) {
368
369 case PMOPS_PREPARE:
370 data->platform_support = 1;
371 error = 0;
372 break;
373
374 case PMOPS_ENTER:
375 if (data->platform_support)
376 error = hibernation_platform_enter();
377 break;
378
379 case PMOPS_FINISH:
380 if (data->platform_support)
381 error = 0;
382 break;
383
384 default:
385 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
386
387 }
388 break;
389
390 case SNAPSHOT_SET_SWAP_AREA:
391 if (swsusp_swap_in_use()) {
392 error = -EPERM;
393 } else {
394 struct resume_swap_area swap_area;
395 dev_t swdev;
396
397 error = copy_from_user(&swap_area, (void __user *)arg,
398 sizeof(struct resume_swap_area));
399 if (error) {
400 error = -EFAULT;
401 break;
402 }
403
404 /*
405 * User space encodes device types as two-byte values,
406 * so we need to recode them
407 */
408 swdev = old_decode_dev(swap_area.dev);
409 if (swdev) {
410 offset = swap_area.offset;
411 data->swap = swap_type_of(swdev, offset, NULL);
412 if (data->swap < 0)
413 error = -ENODEV;
414 } else {
415 data->swap = -1;
416 error = -EINVAL;
417 }
418 }
419 break;
420
421 default:
422 error = -ENOTTY;
423
424 }
425
426 mutex_unlock(&pm_mutex);
427
428 return error;
429 }
430
431 static const struct file_operations snapshot_fops = {
432 .open = snapshot_open,
433 .release = snapshot_release,
434 .read = snapshot_read,
435 .write = snapshot_write,
436 .llseek = no_llseek,
437 .unlocked_ioctl = snapshot_ioctl,
438 };
439
440 static struct miscdevice snapshot_device = {
441 .minor = SNAPSHOT_MINOR,
442 .name = "snapshot",
443 .fops = &snapshot_fops,
444 };
445
446 static int __init snapshot_device_init(void)
447 {
448 return misc_register(&snapshot_device);
449 };
450
451 device_initcall(snapshot_device_init);
452
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