Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
[linux-2.6.git] / kernel / power / user.c
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         loff_t pg_offp = *offp & ~PAGE_MASK;
155
156         mutex_lock(&pm_mutex);
157
158         data = filp->private_data;
159         if (!data->ready) {
160                 res = -ENODATA;
161                 goto Unlock;
162         }
163         if (!pg_offp) { /* on page boundary? */
164                 res = snapshot_read_next(&data->handle);
165                 if (res <= 0)
166                         goto Unlock;
167         } else {
168                 res = PAGE_SIZE - pg_offp;
169         }
170
171         res = simple_read_from_buffer(buf, count, &pg_offp,
172                         data_of(data->handle), res);
173         if (res > 0)
174                 *offp += res;
175
176  Unlock:
177         mutex_unlock(&pm_mutex);
178
179         return res;
180 }
181
182 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
183                               size_t count, loff_t *offp)
184 {
185         struct snapshot_data *data;
186         ssize_t res;
187         loff_t pg_offp = *offp & ~PAGE_MASK;
188
189         mutex_lock(&pm_mutex);
190
191         data = filp->private_data;
192
193         if (!pg_offp) {
194                 res = snapshot_write_next(&data->handle);
195                 if (res <= 0)
196                         goto unlock;
197         } else {
198                 res = PAGE_SIZE - pg_offp;
199         }
200
201         res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
202                         buf, count);
203         if (res > 0)
204                 *offp += res;
205 unlock:
206         mutex_unlock(&pm_mutex);
207
208         return res;
209 }
210
211 static void snapshot_deprecated_ioctl(unsigned int cmd)
212 {
213         if (printk_ratelimit())
214                 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
215                                 "be removed soon, update your suspend-to-disk "
216                                 "utilities\n",
217                                 __builtin_return_address(0), cmd);
218 }
219
220 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
221                                                         unsigned long arg)
222 {
223         int error = 0;
224         struct snapshot_data *data;
225         loff_t size;
226         sector_t offset;
227
228         if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
229                 return -ENOTTY;
230         if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
231                 return -ENOTTY;
232         if (!capable(CAP_SYS_ADMIN))
233                 return -EPERM;
234
235         if (!mutex_trylock(&pm_mutex))
236                 return -EBUSY;
237
238         data = filp->private_data;
239
240         switch (cmd) {
241
242         case SNAPSHOT_FREEZE:
243                 if (data->frozen)
244                         break;
245
246                 printk("Syncing filesystems ... ");
247                 sys_sync();
248                 printk("done.\n");
249
250                 error = usermodehelper_disable();
251                 if (error)
252                         break;
253
254                 error = freeze_processes();
255                 if (error) {
256                         thaw_processes();
257                         usermodehelper_enable();
258                 }
259                 if (!error)
260                         data->frozen = 1;
261                 break;
262
263         case SNAPSHOT_UNFREEZE:
264                 if (!data->frozen || data->ready)
265                         break;
266                 thaw_processes();
267                 usermodehelper_enable();
268                 data->frozen = 0;
269                 break;
270
271         case SNAPSHOT_ATOMIC_SNAPSHOT:
272                 snapshot_deprecated_ioctl(cmd);
273         case SNAPSHOT_CREATE_IMAGE:
274                 if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
275                         error = -EPERM;
276                         break;
277                 }
278                 error = hibernation_snapshot(data->platform_support);
279                 if (!error)
280                         error = put_user(in_suspend, (int __user *)arg);
281                 if (!error)
282                         data->ready = 1;
283                 break;
284
285         case SNAPSHOT_ATOMIC_RESTORE:
286                 snapshot_write_finalize(&data->handle);
287                 if (data->mode != O_WRONLY || !data->frozen ||
288                     !snapshot_image_loaded(&data->handle)) {
289                         error = -EPERM;
290                         break;
291                 }
292                 error = hibernation_restore(data->platform_support);
293                 break;
294
295         case SNAPSHOT_FREE:
296                 swsusp_free();
297                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
298                 data->ready = 0;
299                 break;
300
301         case SNAPSHOT_SET_IMAGE_SIZE:
302                 snapshot_deprecated_ioctl(cmd);
303         case SNAPSHOT_PREF_IMAGE_SIZE:
304                 image_size = arg;
305                 break;
306
307         case SNAPSHOT_GET_IMAGE_SIZE:
308                 if (!data->ready) {
309                         error = -ENODATA;
310                         break;
311                 }
312                 size = snapshot_get_image_size();
313                 size <<= PAGE_SHIFT;
314                 error = put_user(size, (loff_t __user *)arg);
315                 break;
316
317         case SNAPSHOT_AVAIL_SWAP:
318                 snapshot_deprecated_ioctl(cmd);
319         case SNAPSHOT_AVAIL_SWAP_SIZE:
320                 size = count_swap_pages(data->swap, 1);
321                 size <<= PAGE_SHIFT;
322                 error = put_user(size, (loff_t __user *)arg);
323                 break;
324
325         case SNAPSHOT_GET_SWAP_PAGE:
326                 snapshot_deprecated_ioctl(cmd);
327         case SNAPSHOT_ALLOC_SWAP_PAGE:
328                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
329                         error = -ENODEV;
330                         break;
331                 }
332                 offset = alloc_swapdev_block(data->swap);
333                 if (offset) {
334                         offset <<= PAGE_SHIFT;
335                         error = put_user(offset, (loff_t __user *)arg);
336                 } else {
337                         error = -ENOSPC;
338                 }
339                 break;
340
341         case SNAPSHOT_FREE_SWAP_PAGES:
342                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
343                         error = -ENODEV;
344                         break;
345                 }
346                 free_all_swap_pages(data->swap);
347                 break;
348
349         case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
350                 snapshot_deprecated_ioctl(cmd);
351                 if (!swsusp_swap_in_use()) {
352                         /*
353                          * User space encodes device types as two-byte values,
354                          * so we need to recode them
355                          */
356                         if (old_decode_dev(arg)) {
357                                 data->swap = swap_type_of(old_decode_dev(arg),
358                                                         0, NULL);
359                                 if (data->swap < 0)
360                                         error = -ENODEV;
361                         } else {
362                                 data->swap = -1;
363                                 error = -EINVAL;
364                         }
365                 } else {
366                         error = -EPERM;
367                 }
368                 break;
369
370         case SNAPSHOT_S2RAM:
371                 if (!data->frozen) {
372                         error = -EPERM;
373                         break;
374                 }
375                 /*
376                  * Tasks are frozen and the notifiers have been called with
377                  * PM_HIBERNATION_PREPARE
378                  */
379                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
380                 break;
381
382         case SNAPSHOT_PLATFORM_SUPPORT:
383                 data->platform_support = !!arg;
384                 break;
385
386         case SNAPSHOT_POWER_OFF:
387                 if (data->platform_support)
388                         error = hibernation_platform_enter();
389                 break;
390
391         case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
392                 snapshot_deprecated_ioctl(cmd);
393                 error = -EINVAL;
394
395                 switch (arg) {
396
397                 case PMOPS_PREPARE:
398                         data->platform_support = 1;
399                         error = 0;
400                         break;
401
402                 case PMOPS_ENTER:
403                         if (data->platform_support)
404                                 error = hibernation_platform_enter();
405                         break;
406
407                 case PMOPS_FINISH:
408                         if (data->platform_support)
409                                 error = 0;
410                         break;
411
412                 default:
413                         printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
414
415                 }
416                 break;
417
418         case SNAPSHOT_SET_SWAP_AREA:
419                 if (swsusp_swap_in_use()) {
420                         error = -EPERM;
421                 } else {
422                         struct resume_swap_area swap_area;
423                         dev_t swdev;
424
425                         error = copy_from_user(&swap_area, (void __user *)arg,
426                                         sizeof(struct resume_swap_area));
427                         if (error) {
428                                 error = -EFAULT;
429                                 break;
430                         }
431
432                         /*
433                          * User space encodes device types as two-byte values,
434                          * so we need to recode them
435                          */
436                         swdev = new_decode_dev(swap_area.dev);
437                         if (swdev) {
438                                 offset = swap_area.offset;
439                                 data->swap = swap_type_of(swdev, offset, NULL);
440                                 if (data->swap < 0)
441                                         error = -ENODEV;
442                         } else {
443                                 data->swap = -1;
444                                 error = -EINVAL;
445                         }
446                 }
447                 break;
448
449         default:
450                 error = -ENOTTY;
451
452         }
453
454         mutex_unlock(&pm_mutex);
455
456         return error;
457 }
458
459 static const struct file_operations snapshot_fops = {
460         .open = snapshot_open,
461         .release = snapshot_release,
462         .read = snapshot_read,
463         .write = snapshot_write,
464         .llseek = no_llseek,
465         .unlocked_ioctl = snapshot_ioctl,
466 };
467
468 static struct miscdevice snapshot_device = {
469         .minor = SNAPSHOT_MINOR,
470         .name = "snapshot",
471         .fops = &snapshot_fops,
472 };
473
474 static int __init snapshot_device_init(void)
475 {
476         return misc_register(&snapshot_device);
477 };
478
479 device_initcall(snapshot_device_init);