Pull ia64-clocksource into release branch
[linux-2.6] / 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
27 #include <asm/uaccess.h>
28
29 #include "power.h"
30
31 #define SNAPSHOT_MINOR  231
32
33 static struct snapshot_data {
34         struct snapshot_handle handle;
35         int swap;
36         int mode;
37         char frozen;
38         char ready;
39         char platform_suspend;
40 } snapshot_state;
41
42 atomic_t snapshot_device_available = ATOMIC_INIT(1);
43
44 static int snapshot_open(struct inode *inode, struct file *filp)
45 {
46         struct snapshot_data *data;
47
48         if (!atomic_add_unless(&snapshot_device_available, -1, 0))
49                 return -EBUSY;
50
51         if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
52                 atomic_inc(&snapshot_device_available);
53                 return -ENOSYS;
54         }
55         if(create_basic_memory_bitmaps()) {
56                 atomic_inc(&snapshot_device_available);
57                 return -ENOMEM;
58         }
59         nonseekable_open(inode, filp);
60         data = &snapshot_state;
61         filp->private_data = data;
62         memset(&data->handle, 0, sizeof(struct snapshot_handle));
63         if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
64                 data->swap = swsusp_resume_device ?
65                         swap_type_of(swsusp_resume_device, 0, NULL) : -1;
66                 data->mode = O_RDONLY;
67         } else {
68                 data->swap = -1;
69                 data->mode = O_WRONLY;
70         }
71         data->frozen = 0;
72         data->ready = 0;
73         data->platform_suspend = 0;
74
75         return 0;
76 }
77
78 static int snapshot_release(struct inode *inode, struct file *filp)
79 {
80         struct snapshot_data *data;
81
82         swsusp_free();
83         free_basic_memory_bitmaps();
84         data = filp->private_data;
85         free_all_swap_pages(data->swap);
86         if (data->frozen) {
87                 mutex_lock(&pm_mutex);
88                 thaw_processes();
89                 mutex_unlock(&pm_mutex);
90         }
91         atomic_inc(&snapshot_device_available);
92         return 0;
93 }
94
95 static ssize_t snapshot_read(struct file *filp, char __user *buf,
96                              size_t count, loff_t *offp)
97 {
98         struct snapshot_data *data;
99         ssize_t res;
100
101         data = filp->private_data;
102         if (!data->ready)
103                 return -ENODATA;
104         res = snapshot_read_next(&data->handle, count);
105         if (res > 0) {
106                 if (copy_to_user(buf, data_of(data->handle), res))
107                         res = -EFAULT;
108                 else
109                         *offp = data->handle.offset;
110         }
111         return res;
112 }
113
114 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
115                               size_t count, loff_t *offp)
116 {
117         struct snapshot_data *data;
118         ssize_t res;
119
120         data = filp->private_data;
121         res = snapshot_write_next(&data->handle, count);
122         if (res > 0) {
123                 if (copy_from_user(data_of(data->handle), buf, res))
124                         res = -EFAULT;
125                 else
126                         *offp = data->handle.offset;
127         }
128         return res;
129 }
130
131 static int snapshot_ioctl(struct inode *inode, struct file *filp,
132                           unsigned int cmd, unsigned long arg)
133 {
134         int error = 0;
135         struct snapshot_data *data;
136         loff_t avail;
137         sector_t offset;
138
139         if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
140                 return -ENOTTY;
141         if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
142                 return -ENOTTY;
143         if (!capable(CAP_SYS_ADMIN))
144                 return -EPERM;
145
146         data = filp->private_data;
147
148         switch (cmd) {
149
150         case SNAPSHOT_FREEZE:
151                 if (data->frozen)
152                         break;
153                 mutex_lock(&pm_mutex);
154                 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
155                 if (!error) {
156                         error = freeze_processes();
157                         if (error)
158                                 thaw_processes();
159                 }
160                 if (error)
161                         pm_notifier_call_chain(PM_POST_HIBERNATION);
162                 mutex_unlock(&pm_mutex);
163                 if (!error)
164                         data->frozen = 1;
165                 break;
166
167         case SNAPSHOT_UNFREEZE:
168                 if (!data->frozen || data->ready)
169                         break;
170                 mutex_lock(&pm_mutex);
171                 thaw_processes();
172                 pm_notifier_call_chain(PM_POST_HIBERNATION);
173                 mutex_unlock(&pm_mutex);
174                 data->frozen = 0;
175                 break;
176
177         case SNAPSHOT_ATOMIC_SNAPSHOT:
178                 if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
179                         error = -EPERM;
180                         break;
181                 }
182                 error = hibernation_snapshot(data->platform_suspend);
183                 if (!error)
184                         error = put_user(in_suspend, (unsigned int __user *)arg);
185                 if (!error)
186                         data->ready = 1;
187                 break;
188
189         case SNAPSHOT_ATOMIC_RESTORE:
190                 snapshot_write_finalize(&data->handle);
191                 if (data->mode != O_WRONLY || !data->frozen ||
192                     !snapshot_image_loaded(&data->handle)) {
193                         error = -EPERM;
194                         break;
195                 }
196                 error = hibernation_restore(data->platform_suspend);
197                 break;
198
199         case SNAPSHOT_FREE:
200                 swsusp_free();
201                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
202                 data->ready = 0;
203                 break;
204
205         case SNAPSHOT_SET_IMAGE_SIZE:
206                 image_size = arg;
207                 break;
208
209         case SNAPSHOT_AVAIL_SWAP:
210                 avail = count_swap_pages(data->swap, 1);
211                 avail <<= PAGE_SHIFT;
212                 error = put_user(avail, (loff_t __user *)arg);
213                 break;
214
215         case SNAPSHOT_GET_SWAP_PAGE:
216                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
217                         error = -ENODEV;
218                         break;
219                 }
220                 offset = alloc_swapdev_block(data->swap);
221                 if (offset) {
222                         offset <<= PAGE_SHIFT;
223                         error = put_user(offset, (sector_t __user *)arg);
224                 } else {
225                         error = -ENOSPC;
226                 }
227                 break;
228
229         case SNAPSHOT_FREE_SWAP_PAGES:
230                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
231                         error = -ENODEV;
232                         break;
233                 }
234                 free_all_swap_pages(data->swap);
235                 break;
236
237         case SNAPSHOT_SET_SWAP_FILE:
238                 if (!swsusp_swap_in_use()) {
239                         /*
240                          * User space encodes device types as two-byte values,
241                          * so we need to recode them
242                          */
243                         if (old_decode_dev(arg)) {
244                                 data->swap = swap_type_of(old_decode_dev(arg),
245                                                         0, NULL);
246                                 if (data->swap < 0)
247                                         error = -ENODEV;
248                         } else {
249                                 data->swap = -1;
250                                 error = -EINVAL;
251                         }
252                 } else {
253                         error = -EPERM;
254                 }
255                 break;
256
257         case SNAPSHOT_S2RAM:
258                 if (!data->frozen) {
259                         error = -EPERM;
260                         break;
261                 }
262                 if (!mutex_trylock(&pm_mutex)) {
263                         error = -EBUSY;
264                         break;
265                 }
266                 /*
267                  * Tasks are frozen and the notifiers have been called with
268                  * PM_HIBERNATION_PREPARE
269                  */
270                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
271                 mutex_unlock(&pm_mutex);
272                 break;
273
274         case SNAPSHOT_PMOPS:
275                 error = -EINVAL;
276
277                 switch (arg) {
278
279                 case PMOPS_PREPARE:
280                         data->platform_suspend = 1;
281                         error = 0;
282                         break;
283
284                 case PMOPS_ENTER:
285                         if (data->platform_suspend)
286                                 error = hibernation_platform_enter();
287
288                         break;
289
290                 case PMOPS_FINISH:
291                         if (data->platform_suspend)
292                                 error = 0;
293
294                         break;
295
296                 default:
297                         printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
298
299                 }
300                 break;
301
302         case SNAPSHOT_SET_SWAP_AREA:
303                 if (swsusp_swap_in_use()) {
304                         error = -EPERM;
305                 } else {
306                         struct resume_swap_area swap_area;
307                         dev_t swdev;
308
309                         error = copy_from_user(&swap_area, (void __user *)arg,
310                                         sizeof(struct resume_swap_area));
311                         if (error) {
312                                 error = -EFAULT;
313                                 break;
314                         }
315
316                         /*
317                          * User space encodes device types as two-byte values,
318                          * so we need to recode them
319                          */
320                         swdev = old_decode_dev(swap_area.dev);
321                         if (swdev) {
322                                 offset = swap_area.offset;
323                                 data->swap = swap_type_of(swdev, offset, NULL);
324                                 if (data->swap < 0)
325                                         error = -ENODEV;
326                         } else {
327                                 data->swap = -1;
328                                 error = -EINVAL;
329                         }
330                 }
331                 break;
332
333         default:
334                 error = -ENOTTY;
335
336         }
337
338         return error;
339 }
340
341 static const struct file_operations snapshot_fops = {
342         .open = snapshot_open,
343         .release = snapshot_release,
344         .read = snapshot_read,
345         .write = snapshot_write,
346         .llseek = no_llseek,
347         .ioctl = snapshot_ioctl,
348 };
349
350 static struct miscdevice snapshot_device = {
351         .minor = SNAPSHOT_MINOR,
352         .name = "snapshot",
353         .fops = &snapshot_fops,
354 };
355
356 static int __init snapshot_device_init(void)
357 {
358         return misc_register(&snapshot_device);
359 };
360
361 device_initcall(snapshot_device_init);