Commit | Line | Data |
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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> | |
14 | #include <linux/string.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/miscdevice.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/swap.h> | |
19 | #include <linux/swapops.h> | |
20 | #include <linux/pm.h> | |
21 | #include <linux/fs.h> | |
97c7801c | 22 | #include <linux/console.h> |
e3920fb4 | 23 | #include <linux/cpu.h> |
6e1819d6 RW |
24 | |
25 | #include <asm/uaccess.h> | |
26 | ||
27 | #include "power.h" | |
28 | ||
29 | #define SNAPSHOT_MINOR 231 | |
30 | ||
31 | static struct snapshot_data { | |
32 | struct snapshot_handle handle; | |
33 | int swap; | |
34 | struct bitmap_page *bitmap; | |
35 | int mode; | |
36 | char frozen; | |
37 | char ready; | |
38 | } snapshot_state; | |
39 | ||
40 | static atomic_t device_available = ATOMIC_INIT(1); | |
41 | ||
42 | static int snapshot_open(struct inode *inode, struct file *filp) | |
43 | { | |
44 | struct snapshot_data *data; | |
45 | ||
46 | if (!atomic_add_unless(&device_available, -1, 0)) | |
47 | return -EBUSY; | |
48 | ||
49 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) | |
50 | return -ENOSYS; | |
51 | ||
52 | nonseekable_open(inode, filp); | |
53 | data = &snapshot_state; | |
54 | filp->private_data = data; | |
55 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
56 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
57 | data->swap = swsusp_resume_device ? swap_type_of(swsusp_resume_device) : -1; | |
58 | data->mode = O_RDONLY; | |
59 | } else { | |
60 | data->swap = -1; | |
61 | data->mode = O_WRONLY; | |
62 | } | |
63 | data->bitmap = NULL; | |
64 | data->frozen = 0; | |
65 | data->ready = 0; | |
66 | ||
67 | return 0; | |
68 | } | |
69 | ||
70 | static int snapshot_release(struct inode *inode, struct file *filp) | |
71 | { | |
72 | struct snapshot_data *data; | |
73 | ||
74 | swsusp_free(); | |
75 | data = filp->private_data; | |
76 | free_all_swap_pages(data->swap, data->bitmap); | |
77 | free_bitmap(data->bitmap); | |
78 | if (data->frozen) { | |
79 | down(&pm_sem); | |
80 | thaw_processes(); | |
81 | enable_nonboot_cpus(); | |
82 | up(&pm_sem); | |
83 | } | |
84 | atomic_inc(&device_available); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
89 | size_t count, loff_t *offp) | |
90 | { | |
91 | struct snapshot_data *data; | |
92 | ssize_t res; | |
93 | ||
94 | data = filp->private_data; | |
95 | res = snapshot_read_next(&data->handle, count); | |
96 | if (res > 0) { | |
97 | if (copy_to_user(buf, data_of(data->handle), res)) | |
98 | res = -EFAULT; | |
99 | else | |
100 | *offp = data->handle.offset; | |
101 | } | |
102 | return res; | |
103 | } | |
104 | ||
105 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
106 | size_t count, loff_t *offp) | |
107 | { | |
108 | struct snapshot_data *data; | |
109 | ssize_t res; | |
110 | ||
111 | data = filp->private_data; | |
112 | res = snapshot_write_next(&data->handle, count); | |
113 | if (res > 0) { | |
114 | if (copy_from_user(data_of(data->handle), buf, res)) | |
115 | res = -EFAULT; | |
116 | else | |
117 | *offp = data->handle.offset; | |
118 | } | |
119 | return res; | |
120 | } | |
121 | ||
122 | static int snapshot_ioctl(struct inode *inode, struct file *filp, | |
123 | unsigned int cmd, unsigned long arg) | |
124 | { | |
125 | int error = 0; | |
126 | struct snapshot_data *data; | |
127 | loff_t offset, avail; | |
128 | ||
129 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
130 | return -ENOTTY; | |
131 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
132 | return -ENOTTY; | |
133 | if (!capable(CAP_SYS_ADMIN)) | |
134 | return -EPERM; | |
135 | ||
136 | data = filp->private_data; | |
137 | ||
138 | switch (cmd) { | |
139 | ||
140 | case SNAPSHOT_FREEZE: | |
141 | if (data->frozen) | |
142 | break; | |
6e1819d6 | 143 | down(&pm_sem); |
e3920fb4 RW |
144 | error = disable_nonboot_cpus(); |
145 | if (!error) { | |
146 | error = freeze_processes(); | |
147 | if (error) { | |
148 | thaw_processes(); | |
5c339d45 | 149 | enable_nonboot_cpus(); |
e3920fb4 RW |
150 | error = -EBUSY; |
151 | } | |
6e1819d6 RW |
152 | } |
153 | up(&pm_sem); | |
154 | if (!error) | |
155 | data->frozen = 1; | |
156 | break; | |
157 | ||
158 | case SNAPSHOT_UNFREEZE: | |
159 | if (!data->frozen) | |
160 | break; | |
161 | down(&pm_sem); | |
162 | thaw_processes(); | |
163 | enable_nonboot_cpus(); | |
6e1819d6 RW |
164 | up(&pm_sem); |
165 | data->frozen = 0; | |
166 | break; | |
167 | ||
168 | case SNAPSHOT_ATOMIC_SNAPSHOT: | |
169 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { | |
170 | error = -EPERM; | |
171 | break; | |
172 | } | |
173 | down(&pm_sem); | |
174 | /* Free memory before shutting down devices. */ | |
175 | error = swsusp_shrink_memory(); | |
176 | if (!error) { | |
97c7801c | 177 | suspend_console(); |
6e1819d6 RW |
178 | error = device_suspend(PMSG_FREEZE); |
179 | if (!error) { | |
180 | in_suspend = 1; | |
181 | error = swsusp_suspend(); | |
182 | device_resume(); | |
183 | } | |
97c7801c | 184 | resume_console(); |
6e1819d6 RW |
185 | } |
186 | up(&pm_sem); | |
187 | if (!error) | |
188 | error = put_user(in_suspend, (unsigned int __user *)arg); | |
189 | if (!error) | |
190 | data->ready = 1; | |
191 | break; | |
192 | ||
193 | case SNAPSHOT_ATOMIC_RESTORE: | |
194 | if (data->mode != O_WRONLY || !data->frozen || | |
195 | !snapshot_image_loaded(&data->handle)) { | |
196 | error = -EPERM; | |
197 | break; | |
198 | } | |
940864dd | 199 | snapshot_free_unused_memory(&data->handle); |
6e1819d6 RW |
200 | down(&pm_sem); |
201 | pm_prepare_console(); | |
97c7801c | 202 | suspend_console(); |
f1cc0a89 | 203 | error = device_suspend(PMSG_PRETHAW); |
6e1819d6 RW |
204 | if (!error) { |
205 | error = swsusp_resume(); | |
206 | device_resume(); | |
207 | } | |
97c7801c | 208 | resume_console(); |
6e1819d6 RW |
209 | pm_restore_console(); |
210 | up(&pm_sem); | |
211 | break; | |
212 | ||
213 | case SNAPSHOT_FREE: | |
214 | swsusp_free(); | |
215 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
216 | data->ready = 0; | |
217 | break; | |
218 | ||
219 | case SNAPSHOT_SET_IMAGE_SIZE: | |
220 | image_size = arg; | |
221 | break; | |
222 | ||
223 | case SNAPSHOT_AVAIL_SWAP: | |
224 | avail = count_swap_pages(data->swap, 1); | |
225 | avail <<= PAGE_SHIFT; | |
226 | error = put_user(avail, (loff_t __user *)arg); | |
227 | break; | |
228 | ||
229 | case SNAPSHOT_GET_SWAP_PAGE: | |
230 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
231 | error = -ENODEV; | |
232 | break; | |
233 | } | |
234 | if (!data->bitmap) { | |
235 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); | |
236 | if (!data->bitmap) { | |
237 | error = -ENOMEM; | |
238 | break; | |
239 | } | |
240 | } | |
241 | offset = alloc_swap_page(data->swap, data->bitmap); | |
242 | if (offset) { | |
243 | offset <<= PAGE_SHIFT; | |
244 | error = put_user(offset, (loff_t __user *)arg); | |
245 | } else { | |
246 | error = -ENOSPC; | |
247 | } | |
248 | break; | |
249 | ||
250 | case SNAPSHOT_FREE_SWAP_PAGES: | |
251 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
252 | error = -ENODEV; | |
253 | break; | |
254 | } | |
255 | free_all_swap_pages(data->swap, data->bitmap); | |
256 | free_bitmap(data->bitmap); | |
257 | data->bitmap = NULL; | |
258 | break; | |
259 | ||
260 | case SNAPSHOT_SET_SWAP_FILE: | |
261 | if (!data->bitmap) { | |
262 | /* | |
263 | * User space encodes device types as two-byte values, | |
264 | * so we need to recode them | |
265 | */ | |
266 | if (old_decode_dev(arg)) { | |
267 | data->swap = swap_type_of(old_decode_dev(arg)); | |
268 | if (data->swap < 0) | |
269 | error = -ENODEV; | |
270 | } else { | |
271 | data->swap = -1; | |
272 | error = -EINVAL; | |
273 | } | |
274 | } else { | |
275 | error = -EPERM; | |
276 | } | |
277 | break; | |
278 | ||
9b238205 LT |
279 | case SNAPSHOT_S2RAM: |
280 | if (!data->frozen) { | |
281 | error = -EPERM; | |
282 | break; | |
283 | } | |
284 | ||
285 | if (down_trylock(&pm_sem)) { | |
286 | error = -EBUSY; | |
287 | break; | |
288 | } | |
289 | ||
290 | if (pm_ops->prepare) { | |
291 | error = pm_ops->prepare(PM_SUSPEND_MEM); | |
292 | if (error) | |
293 | goto OutS3; | |
294 | } | |
295 | ||
296 | /* Put devices to sleep */ | |
97c7801c | 297 | suspend_console(); |
9b238205 LT |
298 | error = device_suspend(PMSG_SUSPEND); |
299 | if (error) { | |
300 | printk(KERN_ERR "Failed to suspend some devices.\n"); | |
301 | } else { | |
302 | /* Enter S3, system is already frozen */ | |
303 | suspend_enter(PM_SUSPEND_MEM); | |
304 | ||
305 | /* Wake up devices */ | |
306 | device_resume(); | |
307 | } | |
97c7801c | 308 | resume_console(); |
9b238205 LT |
309 | if (pm_ops->finish) |
310 | pm_ops->finish(PM_SUSPEND_MEM); | |
311 | ||
312 | OutS3: | |
313 | up(&pm_sem); | |
314 | break; | |
315 | ||
6e1819d6 RW |
316 | default: |
317 | error = -ENOTTY; | |
318 | ||
319 | } | |
320 | ||
321 | return error; | |
322 | } | |
323 | ||
324 | static struct file_operations snapshot_fops = { | |
325 | .open = snapshot_open, | |
326 | .release = snapshot_release, | |
327 | .read = snapshot_read, | |
328 | .write = snapshot_write, | |
329 | .llseek = no_llseek, | |
330 | .ioctl = snapshot_ioctl, | |
331 | }; | |
332 | ||
333 | static struct miscdevice snapshot_device = { | |
334 | .minor = SNAPSHOT_MINOR, | |
335 | .name = "snapshot", | |
336 | .fops = &snapshot_fops, | |
337 | }; | |
338 | ||
339 | static int __init snapshot_device_init(void) | |
340 | { | |
341 | return misc_register(&snapshot_device); | |
342 | }; | |
343 | ||
344 | device_initcall(snapshot_device_init); |