swsusp: remove code duplication between disk.c and user.c
[linux-3.10.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
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                 if (freeze_processes()) {
155                         thaw_processes();
156                         error = -EBUSY;
157                 }
158                 mutex_unlock(&pm_mutex);
159                 if (!error)
160                         data->frozen = 1;
161                 break;
162
163         case SNAPSHOT_UNFREEZE:
164                 if (!data->frozen || data->ready)
165                         break;
166                 mutex_lock(&pm_mutex);
167                 thaw_processes();
168                 mutex_unlock(&pm_mutex);
169                 data->frozen = 0;
170                 break;
171
172         case SNAPSHOT_ATOMIC_SNAPSHOT:
173                 if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
174                         error = -EPERM;
175                         break;
176                 }
177                 error = hibernation_snapshot(data->platform_suspend);
178                 if (!error)
179                         error = put_user(in_suspend, (unsigned int __user *)arg);
180                 if (!error)
181                         data->ready = 1;
182                 break;
183
184         case SNAPSHOT_ATOMIC_RESTORE:
185                 snapshot_write_finalize(&data->handle);
186                 if (data->mode != O_WRONLY || !data->frozen ||
187                     !snapshot_image_loaded(&data->handle)) {
188                         error = -EPERM;
189                         break;
190                 }
191                 error = hibernation_restore();
192                 break;
193
194         case SNAPSHOT_FREE:
195                 swsusp_free();
196                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
197                 data->ready = 0;
198                 break;
199
200         case SNAPSHOT_SET_IMAGE_SIZE:
201                 image_size = arg;
202                 break;
203
204         case SNAPSHOT_AVAIL_SWAP:
205                 avail = count_swap_pages(data->swap, 1);
206                 avail <<= PAGE_SHIFT;
207                 error = put_user(avail, (loff_t __user *)arg);
208                 break;
209
210         case SNAPSHOT_GET_SWAP_PAGE:
211                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
212                         error = -ENODEV;
213                         break;
214                 }
215                 offset = alloc_swapdev_block(data->swap);
216                 if (offset) {
217                         offset <<= PAGE_SHIFT;
218                         error = put_user(offset, (sector_t __user *)arg);
219                 } else {
220                         error = -ENOSPC;
221                 }
222                 break;
223
224         case SNAPSHOT_FREE_SWAP_PAGES:
225                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
226                         error = -ENODEV;
227                         break;
228                 }
229                 free_all_swap_pages(data->swap);
230                 break;
231
232         case SNAPSHOT_SET_SWAP_FILE:
233                 if (!swsusp_swap_in_use()) {
234                         /*
235                          * User space encodes device types as two-byte values,
236                          * so we need to recode them
237                          */
238                         if (old_decode_dev(arg)) {
239                                 data->swap = swap_type_of(old_decode_dev(arg),
240                                                         0, NULL);
241                                 if (data->swap < 0)
242                                         error = -ENODEV;
243                         } else {
244                                 data->swap = -1;
245                                 error = -EINVAL;
246                         }
247                 } else {
248                         error = -EPERM;
249                 }
250                 break;
251
252         case SNAPSHOT_S2RAM:
253                 if (!pm_ops) {
254                         error = -ENOSYS;
255                         break;
256                 }
257
258                 if (!data->frozen) {
259                         error = -EPERM;
260                         break;
261                 }
262
263                 if (!mutex_trylock(&pm_mutex)) {
264                         error = -EBUSY;
265                         break;
266                 }
267
268                 if (pm_ops->prepare) {
269                         error = pm_ops->prepare(PM_SUSPEND_MEM);
270                         if (error)
271                                 goto OutS3;
272                 }
273
274                 /* Put devices to sleep */
275                 suspend_console();
276                 error = device_suspend(PMSG_SUSPEND);
277                 if (error) {
278                         printk(KERN_ERR "Failed to suspend some devices.\n");
279                 } else {
280                         error = disable_nonboot_cpus();
281                         if (!error) {
282                                 /* Enter S3, system is already frozen */
283                                 suspend_enter(PM_SUSPEND_MEM);
284                                 enable_nonboot_cpus();
285                         }
286                         /* Wake up devices */
287                         device_resume();
288                 }
289                 resume_console();
290                 if (pm_ops->finish)
291                         pm_ops->finish(PM_SUSPEND_MEM);
292
293  OutS3:
294                 mutex_unlock(&pm_mutex);
295                 break;
296
297         case SNAPSHOT_PMOPS:
298                 error = -EINVAL;
299
300                 switch (arg) {
301
302                 case PMOPS_PREPARE:
303                         data->platform_suspend = 1;
304                         error = 0;
305                         break;
306
307                 case PMOPS_ENTER:
308                         if (data->platform_suspend)
309                                 error = hibernation_platform_enter();
310
311                         break;
312
313                 case PMOPS_FINISH:
314                         if (data->platform_suspend)
315                                 error = 0;
316
317                         break;
318
319                 default:
320                         printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
321
322                 }
323                 break;
324
325         case SNAPSHOT_SET_SWAP_AREA:
326                 if (swsusp_swap_in_use()) {
327                         error = -EPERM;
328                 } else {
329                         struct resume_swap_area swap_area;
330                         dev_t swdev;
331
332                         error = copy_from_user(&swap_area, (void __user *)arg,
333                                         sizeof(struct resume_swap_area));
334                         if (error) {
335                                 error = -EFAULT;
336                                 break;
337                         }
338
339                         /*
340                          * User space encodes device types as two-byte values,
341                          * so we need to recode them
342                          */
343                         swdev = old_decode_dev(swap_area.dev);
344                         if (swdev) {
345                                 offset = swap_area.offset;
346                                 data->swap = swap_type_of(swdev, offset, NULL);
347                                 if (data->swap < 0)
348                                         error = -ENODEV;
349                         } else {
350                                 data->swap = -1;
351                                 error = -EINVAL;
352                         }
353                 }
354                 break;
355
356         default:
357                 error = -ENOTTY;
358
359         }
360
361         return error;
362 }
363
364 static const struct file_operations snapshot_fops = {
365         .open = snapshot_open,
366         .release = snapshot_release,
367         .read = snapshot_read,
368         .write = snapshot_write,
369         .llseek = no_llseek,
370         .ioctl = snapshot_ioctl,
371 };
372
373 static struct miscdevice snapshot_device = {
374         .minor = SNAPSHOT_MINOR,
375         .name = "snapshot",
376         .fops = &snapshot_fops,
377 };
378
379 static int __init snapshot_device_init(void)
380 {
381         return misc_register(&snapshot_device);
382 };
383
384 device_initcall(snapshot_device_init);