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6e1819d6 RW |
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> | |
3592695c | 14 | #include <linux/reboot.h> |
6e1819d6 RW |
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> | |
97c7801c | 23 | #include <linux/console.h> |
e3920fb4 | 24 | #include <linux/cpu.h> |
6e1819d6 RW |
25 | |
26 | #include <asm/uaccess.h> | |
27 | ||
28 | #include "power.h" | |
29 | ||
30 | #define SNAPSHOT_MINOR 231 | |
31 | ||
32 | static struct snapshot_data { | |
33 | struct snapshot_handle handle; | |
34 | int swap; | |
35 | struct bitmap_page *bitmap; | |
36 | int mode; | |
37 | char frozen; | |
38 | char ready; | |
39 | } snapshot_state; | |
40 | ||
41 | static atomic_t device_available = ATOMIC_INIT(1); | |
42 | ||
43 | static int snapshot_open(struct inode *inode, struct file *filp) | |
44 | { | |
45 | struct snapshot_data *data; | |
46 | ||
47 | if (!atomic_add_unless(&device_available, -1, 0)) | |
48 | return -EBUSY; | |
49 | ||
50 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) | |
51 | return -ENOSYS; | |
52 | ||
53 | nonseekable_open(inode, filp); | |
54 | data = &snapshot_state; | |
55 | filp->private_data = data; | |
56 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
57 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
915bae9e RW |
58 | data->swap = swsusp_resume_device ? |
59 | swap_type_of(swsusp_resume_device, 0) : -1; | |
6e1819d6 RW |
60 | data->mode = O_RDONLY; |
61 | } else { | |
62 | data->swap = -1; | |
63 | data->mode = O_WRONLY; | |
64 | } | |
65 | data->bitmap = NULL; | |
66 | data->frozen = 0; | |
67 | data->ready = 0; | |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
72 | static int snapshot_release(struct inode *inode, struct file *filp) | |
73 | { | |
74 | struct snapshot_data *data; | |
75 | ||
76 | swsusp_free(); | |
77 | data = filp->private_data; | |
78 | free_all_swap_pages(data->swap, data->bitmap); | |
79 | free_bitmap(data->bitmap); | |
80 | if (data->frozen) { | |
81 | down(&pm_sem); | |
82 | thaw_processes(); | |
83 | enable_nonboot_cpus(); | |
84 | up(&pm_sem); | |
85 | } | |
86 | atomic_inc(&device_available); | |
87 | return 0; | |
88 | } | |
89 | ||
90 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
91 | size_t count, loff_t *offp) | |
92 | { | |
93 | struct snapshot_data *data; | |
94 | ssize_t res; | |
95 | ||
96 | data = filp->private_data; | |
97 | res = snapshot_read_next(&data->handle, count); | |
98 | if (res > 0) { | |
99 | if (copy_to_user(buf, data_of(data->handle), res)) | |
100 | res = -EFAULT; | |
101 | else | |
102 | *offp = data->handle.offset; | |
103 | } | |
104 | return res; | |
105 | } | |
106 | ||
107 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
108 | size_t count, loff_t *offp) | |
109 | { | |
110 | struct snapshot_data *data; | |
111 | ssize_t res; | |
112 | ||
113 | data = filp->private_data; | |
114 | res = snapshot_write_next(&data->handle, count); | |
115 | if (res > 0) { | |
116 | if (copy_from_user(data_of(data->handle), buf, res)) | |
117 | res = -EFAULT; | |
118 | else | |
119 | *offp = data->handle.offset; | |
120 | } | |
121 | return res; | |
122 | } | |
123 | ||
124 | static int snapshot_ioctl(struct inode *inode, struct file *filp, | |
125 | unsigned int cmd, unsigned long arg) | |
126 | { | |
127 | int error = 0; | |
128 | struct snapshot_data *data; | |
3aef83e0 RW |
129 | loff_t avail; |
130 | sector_t offset; | |
6e1819d6 RW |
131 | |
132 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
133 | return -ENOTTY; | |
134 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
135 | return -ENOTTY; | |
136 | if (!capable(CAP_SYS_ADMIN)) | |
137 | return -EPERM; | |
138 | ||
139 | data = filp->private_data; | |
140 | ||
141 | switch (cmd) { | |
142 | ||
143 | case SNAPSHOT_FREEZE: | |
144 | if (data->frozen) | |
145 | break; | |
6e1819d6 | 146 | down(&pm_sem); |
e3920fb4 RW |
147 | error = disable_nonboot_cpus(); |
148 | if (!error) { | |
149 | error = freeze_processes(); | |
150 | if (error) { | |
151 | thaw_processes(); | |
5c339d45 | 152 | enable_nonboot_cpus(); |
e3920fb4 RW |
153 | error = -EBUSY; |
154 | } | |
6e1819d6 RW |
155 | } |
156 | up(&pm_sem); | |
157 | if (!error) | |
158 | data->frozen = 1; | |
159 | break; | |
160 | ||
161 | case SNAPSHOT_UNFREEZE: | |
162 | if (!data->frozen) | |
163 | break; | |
164 | down(&pm_sem); | |
165 | thaw_processes(); | |
166 | enable_nonboot_cpus(); | |
6e1819d6 RW |
167 | up(&pm_sem); |
168 | data->frozen = 0; | |
169 | break; | |
170 | ||
171 | case SNAPSHOT_ATOMIC_SNAPSHOT: | |
172 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { | |
173 | error = -EPERM; | |
174 | break; | |
175 | } | |
176 | down(&pm_sem); | |
177 | /* Free memory before shutting down devices. */ | |
178 | error = swsusp_shrink_memory(); | |
179 | if (!error) { | |
97c7801c | 180 | suspend_console(); |
6e1819d6 RW |
181 | error = device_suspend(PMSG_FREEZE); |
182 | if (!error) { | |
183 | in_suspend = 1; | |
184 | error = swsusp_suspend(); | |
185 | device_resume(); | |
186 | } | |
97c7801c | 187 | resume_console(); |
6e1819d6 RW |
188 | } |
189 | up(&pm_sem); | |
190 | if (!error) | |
191 | error = put_user(in_suspend, (unsigned int __user *)arg); | |
192 | if (!error) | |
193 | data->ready = 1; | |
194 | break; | |
195 | ||
196 | case SNAPSHOT_ATOMIC_RESTORE: | |
197 | if (data->mode != O_WRONLY || !data->frozen || | |
198 | !snapshot_image_loaded(&data->handle)) { | |
199 | error = -EPERM; | |
200 | break; | |
201 | } | |
940864dd | 202 | snapshot_free_unused_memory(&data->handle); |
6e1819d6 RW |
203 | down(&pm_sem); |
204 | pm_prepare_console(); | |
97c7801c | 205 | suspend_console(); |
f1cc0a89 | 206 | error = device_suspend(PMSG_PRETHAW); |
6e1819d6 RW |
207 | if (!error) { |
208 | error = swsusp_resume(); | |
209 | device_resume(); | |
210 | } | |
97c7801c | 211 | resume_console(); |
6e1819d6 RW |
212 | pm_restore_console(); |
213 | up(&pm_sem); | |
214 | break; | |
215 | ||
216 | case SNAPSHOT_FREE: | |
217 | swsusp_free(); | |
218 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
219 | data->ready = 0; | |
220 | break; | |
221 | ||
222 | case SNAPSHOT_SET_IMAGE_SIZE: | |
223 | image_size = arg; | |
224 | break; | |
225 | ||
226 | case SNAPSHOT_AVAIL_SWAP: | |
227 | avail = count_swap_pages(data->swap, 1); | |
228 | avail <<= PAGE_SHIFT; | |
229 | error = put_user(avail, (loff_t __user *)arg); | |
230 | break; | |
231 | ||
232 | case SNAPSHOT_GET_SWAP_PAGE: | |
233 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
234 | error = -ENODEV; | |
235 | break; | |
236 | } | |
237 | if (!data->bitmap) { | |
238 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); | |
239 | if (!data->bitmap) { | |
240 | error = -ENOMEM; | |
241 | break; | |
242 | } | |
243 | } | |
3aef83e0 | 244 | offset = alloc_swapdev_block(data->swap, data->bitmap); |
6e1819d6 RW |
245 | if (offset) { |
246 | offset <<= PAGE_SHIFT; | |
3aef83e0 | 247 | error = put_user(offset, (sector_t __user *)arg); |
6e1819d6 RW |
248 | } else { |
249 | error = -ENOSPC; | |
250 | } | |
251 | break; | |
252 | ||
253 | case SNAPSHOT_FREE_SWAP_PAGES: | |
254 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
255 | error = -ENODEV; | |
256 | break; | |
257 | } | |
258 | free_all_swap_pages(data->swap, data->bitmap); | |
259 | free_bitmap(data->bitmap); | |
260 | data->bitmap = NULL; | |
261 | break; | |
262 | ||
263 | case SNAPSHOT_SET_SWAP_FILE: | |
264 | if (!data->bitmap) { | |
265 | /* | |
266 | * User space encodes device types as two-byte values, | |
267 | * so we need to recode them | |
268 | */ | |
269 | if (old_decode_dev(arg)) { | |
915bae9e | 270 | data->swap = swap_type_of(old_decode_dev(arg), 0); |
6e1819d6 RW |
271 | if (data->swap < 0) |
272 | error = -ENODEV; | |
273 | } else { | |
274 | data->swap = -1; | |
275 | error = -EINVAL; | |
276 | } | |
277 | } else { | |
278 | error = -EPERM; | |
279 | } | |
280 | break; | |
281 | ||
9b238205 LT |
282 | case SNAPSHOT_S2RAM: |
283 | if (!data->frozen) { | |
284 | error = -EPERM; | |
285 | break; | |
286 | } | |
287 | ||
288 | if (down_trylock(&pm_sem)) { | |
289 | error = -EBUSY; | |
290 | break; | |
291 | } | |
292 | ||
293 | if (pm_ops->prepare) { | |
294 | error = pm_ops->prepare(PM_SUSPEND_MEM); | |
295 | if (error) | |
296 | goto OutS3; | |
297 | } | |
298 | ||
299 | /* Put devices to sleep */ | |
97c7801c | 300 | suspend_console(); |
9b238205 LT |
301 | error = device_suspend(PMSG_SUSPEND); |
302 | if (error) { | |
303 | printk(KERN_ERR "Failed to suspend some devices.\n"); | |
304 | } else { | |
305 | /* Enter S3, system is already frozen */ | |
306 | suspend_enter(PM_SUSPEND_MEM); | |
307 | ||
308 | /* Wake up devices */ | |
309 | device_resume(); | |
310 | } | |
97c7801c | 311 | resume_console(); |
9b238205 LT |
312 | if (pm_ops->finish) |
313 | pm_ops->finish(PM_SUSPEND_MEM); | |
314 | ||
315 | OutS3: | |
316 | up(&pm_sem); | |
317 | break; | |
318 | ||
3592695c SS |
319 | case SNAPSHOT_PMOPS: |
320 | switch (arg) { | |
321 | ||
322 | case PMOPS_PREPARE: | |
323 | if (pm_ops->prepare) { | |
324 | error = pm_ops->prepare(PM_SUSPEND_DISK); | |
325 | } | |
326 | break; | |
327 | ||
328 | case PMOPS_ENTER: | |
329 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); | |
330 | error = pm_ops->enter(PM_SUSPEND_DISK); | |
331 | break; | |
332 | ||
333 | case PMOPS_FINISH: | |
334 | if (pm_ops && pm_ops->finish) { | |
335 | pm_ops->finish(PM_SUSPEND_DISK); | |
336 | } | |
337 | break; | |
338 | ||
339 | default: | |
340 | printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); | |
341 | error = -EINVAL; | |
342 | ||
343 | } | |
344 | break; | |
345 | ||
37b2ba12 RW |
346 | case SNAPSHOT_SET_SWAP_AREA: |
347 | if (data->bitmap) { | |
348 | error = -EPERM; | |
349 | } else { | |
350 | struct resume_swap_area swap_area; | |
351 | dev_t swdev; | |
352 | ||
353 | error = copy_from_user(&swap_area, (void __user *)arg, | |
354 | sizeof(struct resume_swap_area)); | |
355 | if (error) { | |
356 | error = -EFAULT; | |
357 | break; | |
358 | } | |
359 | ||
360 | /* | |
361 | * User space encodes device types as two-byte values, | |
362 | * so we need to recode them | |
363 | */ | |
364 | swdev = old_decode_dev(swap_area.dev); | |
365 | if (swdev) { | |
366 | offset = swap_area.offset; | |
367 | data->swap = swap_type_of(swdev, offset); | |
368 | if (data->swap < 0) | |
369 | error = -ENODEV; | |
370 | } else { | |
371 | data->swap = -1; | |
372 | error = -EINVAL; | |
373 | } | |
374 | } | |
375 | break; | |
376 | ||
6e1819d6 RW |
377 | default: |
378 | error = -ENOTTY; | |
379 | ||
380 | } | |
381 | ||
382 | return error; | |
383 | } | |
384 | ||
385 | static struct file_operations snapshot_fops = { | |
386 | .open = snapshot_open, | |
387 | .release = snapshot_release, | |
388 | .read = snapshot_read, | |
389 | .write = snapshot_write, | |
390 | .llseek = no_llseek, | |
391 | .ioctl = snapshot_ioctl, | |
392 | }; | |
393 | ||
394 | static struct miscdevice snapshot_device = { | |
395 | .minor = SNAPSHOT_MINOR, | |
396 | .name = "snapshot", | |
397 | .fops = &snapshot_fops, | |
398 | }; | |
399 | ||
400 | static int __init snapshot_device_init(void) | |
401 | { | |
402 | return misc_register(&snapshot_device); | |
403 | }; | |
404 | ||
405 | device_initcall(snapshot_device_init); |