Merge branch 'for-linus' 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                 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
130 static 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
153 static 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
186 static 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;
209 unlock:
210         mutex_unlock(&pm_mutex);
211
212         return res;
213 }
214
215 static 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
224 static 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
466 static 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
475 static struct miscdevice snapshot_device = {
476         .minor = SNAPSHOT_MINOR,
477         .name = "snapshot",
478         .fops = &snapshot_fops,
479 };
480
481 static int __init snapshot_device_init(void)
482 {
483         return misc_register(&snapshot_device);
484 };
485
486 device_initcall(snapshot_device_init);