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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> |
7dfb7103 | 25 | #include <linux/freezer.h> |
6e1819d6 RW |
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 | struct bitmap_page *bitmap; | |
37 | int mode; | |
38 | char frozen; | |
39 | char ready; | |
40 | } snapshot_state; | |
41 | ||
42 | static atomic_t 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(&device_available, -1, 0)) | |
49 | return -EBUSY; | |
50 | ||
51 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) | |
52 | return -ENOSYS; | |
53 | ||
54 | nonseekable_open(inode, filp); | |
55 | data = &snapshot_state; | |
56 | filp->private_data = data; | |
57 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
58 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
915bae9e RW |
59 | data->swap = swsusp_resume_device ? |
60 | swap_type_of(swsusp_resume_device, 0) : -1; | |
6e1819d6 RW |
61 | data->mode = O_RDONLY; |
62 | } else { | |
63 | data->swap = -1; | |
64 | data->mode = O_WRONLY; | |
65 | } | |
66 | data->bitmap = NULL; | |
67 | data->frozen = 0; | |
68 | data->ready = 0; | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static int snapshot_release(struct inode *inode, struct file *filp) | |
74 | { | |
75 | struct snapshot_data *data; | |
76 | ||
77 | swsusp_free(); | |
78 | data = filp->private_data; | |
79 | free_all_swap_pages(data->swap, data->bitmap); | |
80 | free_bitmap(data->bitmap); | |
81 | if (data->frozen) { | |
a6d70980 | 82 | mutex_lock(&pm_mutex); |
6e1819d6 RW |
83 | thaw_processes(); |
84 | enable_nonboot_cpus(); | |
a6d70980 | 85 | mutex_unlock(&pm_mutex); |
6e1819d6 RW |
86 | } |
87 | atomic_inc(&device_available); | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
92 | size_t count, loff_t *offp) | |
93 | { | |
94 | struct snapshot_data *data; | |
95 | ssize_t res; | |
96 | ||
97 | data = filp->private_data; | |
98 | res = snapshot_read_next(&data->handle, count); | |
99 | if (res > 0) { | |
100 | if (copy_to_user(buf, data_of(data->handle), res)) | |
101 | res = -EFAULT; | |
102 | else | |
103 | *offp = data->handle.offset; | |
104 | } | |
105 | return res; | |
106 | } | |
107 | ||
108 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
109 | size_t count, loff_t *offp) | |
110 | { | |
111 | struct snapshot_data *data; | |
112 | ssize_t res; | |
113 | ||
114 | data = filp->private_data; | |
115 | res = snapshot_write_next(&data->handle, count); | |
116 | if (res > 0) { | |
117 | if (copy_from_user(data_of(data->handle), buf, res)) | |
118 | res = -EFAULT; | |
119 | else | |
120 | *offp = data->handle.offset; | |
121 | } | |
122 | return res; | |
123 | } | |
124 | ||
125 | static int snapshot_ioctl(struct inode *inode, struct file *filp, | |
126 | unsigned int cmd, unsigned long arg) | |
127 | { | |
128 | int error = 0; | |
129 | struct snapshot_data *data; | |
3aef83e0 RW |
130 | loff_t avail; |
131 | sector_t offset; | |
6e1819d6 RW |
132 | |
133 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
134 | return -ENOTTY; | |
135 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
136 | return -ENOTTY; | |
137 | if (!capable(CAP_SYS_ADMIN)) | |
138 | return -EPERM; | |
139 | ||
140 | data = filp->private_data; | |
141 | ||
142 | switch (cmd) { | |
143 | ||
144 | case SNAPSHOT_FREEZE: | |
145 | if (data->frozen) | |
146 | break; | |
a6d70980 | 147 | mutex_lock(&pm_mutex); |
e3920fb4 RW |
148 | error = disable_nonboot_cpus(); |
149 | if (!error) { | |
150 | error = freeze_processes(); | |
151 | if (error) { | |
152 | thaw_processes(); | |
5c339d45 | 153 | enable_nonboot_cpus(); |
e3920fb4 RW |
154 | error = -EBUSY; |
155 | } | |
6e1819d6 | 156 | } |
a6d70980 | 157 | mutex_unlock(&pm_mutex); |
6e1819d6 RW |
158 | if (!error) |
159 | data->frozen = 1; | |
160 | break; | |
161 | ||
162 | case SNAPSHOT_UNFREEZE: | |
163 | if (!data->frozen) | |
164 | break; | |
a6d70980 | 165 | mutex_lock(&pm_mutex); |
6e1819d6 RW |
166 | thaw_processes(); |
167 | enable_nonboot_cpus(); | |
a6d70980 | 168 | mutex_unlock(&pm_mutex); |
6e1819d6 RW |
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 | } | |
a6d70980 | 177 | mutex_lock(&pm_mutex); |
6e1819d6 RW |
178 | /* Free memory before shutting down devices. */ |
179 | error = swsusp_shrink_memory(); | |
180 | if (!error) { | |
97c7801c | 181 | suspend_console(); |
6e1819d6 RW |
182 | error = device_suspend(PMSG_FREEZE); |
183 | if (!error) { | |
184 | in_suspend = 1; | |
185 | error = swsusp_suspend(); | |
186 | device_resume(); | |
187 | } | |
97c7801c | 188 | resume_console(); |
6e1819d6 | 189 | } |
a6d70980 | 190 | mutex_unlock(&pm_mutex); |
6e1819d6 RW |
191 | if (!error) |
192 | error = put_user(in_suspend, (unsigned int __user *)arg); | |
193 | if (!error) | |
194 | data->ready = 1; | |
195 | break; | |
196 | ||
197 | case SNAPSHOT_ATOMIC_RESTORE: | |
8357376d | 198 | snapshot_write_finalize(&data->handle); |
6e1819d6 RW |
199 | if (data->mode != O_WRONLY || !data->frozen || |
200 | !snapshot_image_loaded(&data->handle)) { | |
201 | error = -EPERM; | |
202 | break; | |
203 | } | |
a6d70980 | 204 | mutex_lock(&pm_mutex); |
6e1819d6 | 205 | pm_prepare_console(); |
97c7801c | 206 | suspend_console(); |
f1cc0a89 | 207 | error = device_suspend(PMSG_PRETHAW); |
6e1819d6 RW |
208 | if (!error) { |
209 | error = swsusp_resume(); | |
210 | device_resume(); | |
211 | } | |
97c7801c | 212 | resume_console(); |
6e1819d6 | 213 | pm_restore_console(); |
a6d70980 | 214 | mutex_unlock(&pm_mutex); |
6e1819d6 RW |
215 | break; |
216 | ||
217 | case SNAPSHOT_FREE: | |
218 | swsusp_free(); | |
219 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
220 | data->ready = 0; | |
221 | break; | |
222 | ||
223 | case SNAPSHOT_SET_IMAGE_SIZE: | |
224 | image_size = arg; | |
225 | break; | |
226 | ||
227 | case SNAPSHOT_AVAIL_SWAP: | |
228 | avail = count_swap_pages(data->swap, 1); | |
229 | avail <<= PAGE_SHIFT; | |
230 | error = put_user(avail, (loff_t __user *)arg); | |
231 | break; | |
232 | ||
233 | case SNAPSHOT_GET_SWAP_PAGE: | |
234 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
235 | error = -ENODEV; | |
236 | break; | |
237 | } | |
238 | if (!data->bitmap) { | |
239 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); | |
240 | if (!data->bitmap) { | |
241 | error = -ENOMEM; | |
242 | break; | |
243 | } | |
244 | } | |
3aef83e0 | 245 | offset = alloc_swapdev_block(data->swap, data->bitmap); |
6e1819d6 RW |
246 | if (offset) { |
247 | offset <<= PAGE_SHIFT; | |
3aef83e0 | 248 | error = put_user(offset, (sector_t __user *)arg); |
6e1819d6 RW |
249 | } else { |
250 | error = -ENOSPC; | |
251 | } | |
252 | break; | |
253 | ||
254 | case SNAPSHOT_FREE_SWAP_PAGES: | |
255 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
256 | error = -ENODEV; | |
257 | break; | |
258 | } | |
259 | free_all_swap_pages(data->swap, data->bitmap); | |
260 | free_bitmap(data->bitmap); | |
261 | data->bitmap = NULL; | |
262 | break; | |
263 | ||
264 | case SNAPSHOT_SET_SWAP_FILE: | |
265 | if (!data->bitmap) { | |
266 | /* | |
267 | * User space encodes device types as two-byte values, | |
268 | * so we need to recode them | |
269 | */ | |
270 | if (old_decode_dev(arg)) { | |
915bae9e | 271 | data->swap = swap_type_of(old_decode_dev(arg), 0); |
6e1819d6 RW |
272 | if (data->swap < 0) |
273 | error = -ENODEV; | |
274 | } else { | |
275 | data->swap = -1; | |
276 | error = -EINVAL; | |
277 | } | |
278 | } else { | |
279 | error = -EPERM; | |
280 | } | |
281 | break; | |
282 | ||
9b238205 LT |
283 | case SNAPSHOT_S2RAM: |
284 | if (!data->frozen) { | |
285 | error = -EPERM; | |
286 | break; | |
287 | } | |
288 | ||
a6d70980 | 289 | if (!mutex_trylock(&pm_mutex)) { |
9b238205 LT |
290 | error = -EBUSY; |
291 | break; | |
292 | } | |
293 | ||
294 | if (pm_ops->prepare) { | |
295 | error = pm_ops->prepare(PM_SUSPEND_MEM); | |
296 | if (error) | |
297 | goto OutS3; | |
298 | } | |
299 | ||
300 | /* Put devices to sleep */ | |
97c7801c | 301 | suspend_console(); |
9b238205 LT |
302 | error = device_suspend(PMSG_SUSPEND); |
303 | if (error) { | |
304 | printk(KERN_ERR "Failed to suspend some devices.\n"); | |
305 | } else { | |
306 | /* Enter S3, system is already frozen */ | |
307 | suspend_enter(PM_SUSPEND_MEM); | |
308 | ||
309 | /* Wake up devices */ | |
310 | device_resume(); | |
311 | } | |
97c7801c | 312 | resume_console(); |
9b238205 LT |
313 | if (pm_ops->finish) |
314 | pm_ops->finish(PM_SUSPEND_MEM); | |
315 | ||
59a49335 | 316 | OutS3: |
a6d70980 | 317 | mutex_unlock(&pm_mutex); |
9b238205 LT |
318 | break; |
319 | ||
3592695c SS |
320 | case SNAPSHOT_PMOPS: |
321 | switch (arg) { | |
322 | ||
323 | case PMOPS_PREPARE: | |
324 | if (pm_ops->prepare) { | |
325 | error = pm_ops->prepare(PM_SUSPEND_DISK); | |
326 | } | |
327 | break; | |
328 | ||
329 | case PMOPS_ENTER: | |
330 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); | |
331 | error = pm_ops->enter(PM_SUSPEND_DISK); | |
332 | break; | |
333 | ||
334 | case PMOPS_FINISH: | |
335 | if (pm_ops && pm_ops->finish) { | |
336 | pm_ops->finish(PM_SUSPEND_DISK); | |
337 | } | |
338 | break; | |
339 | ||
340 | default: | |
341 | printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); | |
342 | error = -EINVAL; | |
343 | ||
344 | } | |
345 | break; | |
346 | ||
37b2ba12 RW |
347 | case SNAPSHOT_SET_SWAP_AREA: |
348 | if (data->bitmap) { | |
349 | error = -EPERM; | |
350 | } else { | |
351 | struct resume_swap_area swap_area; | |
352 | dev_t swdev; | |
353 | ||
354 | error = copy_from_user(&swap_area, (void __user *)arg, | |
355 | sizeof(struct resume_swap_area)); | |
356 | if (error) { | |
357 | error = -EFAULT; | |
358 | break; | |
359 | } | |
360 | ||
361 | /* | |
362 | * User space encodes device types as two-byte values, | |
363 | * so we need to recode them | |
364 | */ | |
365 | swdev = old_decode_dev(swap_area.dev); | |
366 | if (swdev) { | |
367 | offset = swap_area.offset; | |
368 | data->swap = swap_type_of(swdev, offset); | |
369 | if (data->swap < 0) | |
370 | error = -ENODEV; | |
371 | } else { | |
372 | data->swap = -1; | |
373 | error = -EINVAL; | |
374 | } | |
375 | } | |
376 | break; | |
377 | ||
6e1819d6 RW |
378 | default: |
379 | error = -ENOTTY; | |
380 | ||
381 | } | |
382 | ||
383 | return error; | |
384 | } | |
385 | ||
386 | static struct file_operations snapshot_fops = { | |
387 | .open = snapshot_open, | |
388 | .release = snapshot_release, | |
389 | .read = snapshot_read, | |
390 | .write = snapshot_write, | |
391 | .llseek = no_llseek, | |
392 | .ioctl = snapshot_ioctl, | |
393 | }; | |
394 | ||
395 | static struct miscdevice snapshot_device = { | |
396 | .minor = SNAPSHOT_MINOR, | |
397 | .name = "snapshot", | |
398 | .fops = &snapshot_fops, | |
399 | }; | |
400 | ||
401 | static int __init snapshot_device_init(void) | |
402 | { | |
403 | return misc_register(&snapshot_device); | |
404 | }; | |
405 | ||
406 | device_initcall(snapshot_device_init); |