Commit | Line | Data |
---|---|---|
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; | |
129 | loff_t offset, avail; | |
130 | ||
131 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
132 | return -ENOTTY; | |
133 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
134 | return -ENOTTY; | |
135 | if (!capable(CAP_SYS_ADMIN)) | |
136 | return -EPERM; | |
137 | ||
138 | data = filp->private_data; | |
139 | ||
140 | switch (cmd) { | |
141 | ||
142 | case SNAPSHOT_FREEZE: | |
143 | if (data->frozen) | |
144 | break; | |
6e1819d6 | 145 | down(&pm_sem); |
e3920fb4 RW |
146 | error = disable_nonboot_cpus(); |
147 | if (!error) { | |
148 | error = freeze_processes(); | |
149 | if (error) { | |
150 | thaw_processes(); | |
5c339d45 | 151 | enable_nonboot_cpus(); |
e3920fb4 RW |
152 | error = -EBUSY; |
153 | } | |
6e1819d6 RW |
154 | } |
155 | up(&pm_sem); | |
156 | if (!error) | |
157 | data->frozen = 1; | |
158 | break; | |
159 | ||
160 | case SNAPSHOT_UNFREEZE: | |
161 | if (!data->frozen) | |
162 | break; | |
163 | down(&pm_sem); | |
164 | thaw_processes(); | |
165 | enable_nonboot_cpus(); | |
6e1819d6 RW |
166 | up(&pm_sem); |
167 | data->frozen = 0; | |
168 | break; | |
169 | ||
170 | case SNAPSHOT_ATOMIC_SNAPSHOT: | |
171 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { | |
172 | error = -EPERM; | |
173 | break; | |
174 | } | |
175 | down(&pm_sem); | |
176 | /* Free memory before shutting down devices. */ | |
177 | error = swsusp_shrink_memory(); | |
178 | if (!error) { | |
97c7801c | 179 | suspend_console(); |
6e1819d6 RW |
180 | error = device_suspend(PMSG_FREEZE); |
181 | if (!error) { | |
182 | in_suspend = 1; | |
183 | error = swsusp_suspend(); | |
184 | device_resume(); | |
185 | } | |
97c7801c | 186 | resume_console(); |
6e1819d6 RW |
187 | } |
188 | up(&pm_sem); | |
189 | if (!error) | |
190 | error = put_user(in_suspend, (unsigned int __user *)arg); | |
191 | if (!error) | |
192 | data->ready = 1; | |
193 | break; | |
194 | ||
195 | case SNAPSHOT_ATOMIC_RESTORE: | |
196 | if (data->mode != O_WRONLY || !data->frozen || | |
197 | !snapshot_image_loaded(&data->handle)) { | |
198 | error = -EPERM; | |
199 | break; | |
200 | } | |
940864dd | 201 | snapshot_free_unused_memory(&data->handle); |
6e1819d6 RW |
202 | down(&pm_sem); |
203 | pm_prepare_console(); | |
97c7801c | 204 | suspend_console(); |
f1cc0a89 | 205 | error = device_suspend(PMSG_PRETHAW); |
6e1819d6 RW |
206 | if (!error) { |
207 | error = swsusp_resume(); | |
208 | device_resume(); | |
209 | } | |
97c7801c | 210 | resume_console(); |
6e1819d6 RW |
211 | pm_restore_console(); |
212 | up(&pm_sem); | |
213 | break; | |
214 | ||
215 | case SNAPSHOT_FREE: | |
216 | swsusp_free(); | |
217 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
218 | data->ready = 0; | |
219 | break; | |
220 | ||
221 | case SNAPSHOT_SET_IMAGE_SIZE: | |
222 | image_size = arg; | |
223 | break; | |
224 | ||
225 | case SNAPSHOT_AVAIL_SWAP: | |
226 | avail = count_swap_pages(data->swap, 1); | |
227 | avail <<= PAGE_SHIFT; | |
228 | error = put_user(avail, (loff_t __user *)arg); | |
229 | break; | |
230 | ||
231 | case SNAPSHOT_GET_SWAP_PAGE: | |
232 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
233 | error = -ENODEV; | |
234 | break; | |
235 | } | |
236 | if (!data->bitmap) { | |
237 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); | |
238 | if (!data->bitmap) { | |
239 | error = -ENOMEM; | |
240 | break; | |
241 | } | |
242 | } | |
243 | offset = alloc_swap_page(data->swap, data->bitmap); | |
244 | if (offset) { | |
245 | offset <<= PAGE_SHIFT; | |
246 | error = put_user(offset, (loff_t __user *)arg); | |
247 | } else { | |
248 | error = -ENOSPC; | |
249 | } | |
250 | break; | |
251 | ||
252 | case SNAPSHOT_FREE_SWAP_PAGES: | |
253 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
254 | error = -ENODEV; | |
255 | break; | |
256 | } | |
257 | free_all_swap_pages(data->swap, data->bitmap); | |
258 | free_bitmap(data->bitmap); | |
259 | data->bitmap = NULL; | |
260 | break; | |
261 | ||
262 | case SNAPSHOT_SET_SWAP_FILE: | |
263 | if (!data->bitmap) { | |
264 | /* | |
265 | * User space encodes device types as two-byte values, | |
266 | * so we need to recode them | |
267 | */ | |
268 | if (old_decode_dev(arg)) { | |
915bae9e | 269 | data->swap = swap_type_of(old_decode_dev(arg), 0); |
6e1819d6 RW |
270 | if (data->swap < 0) |
271 | error = -ENODEV; | |
272 | } else { | |
273 | data->swap = -1; | |
274 | error = -EINVAL; | |
275 | } | |
276 | } else { | |
277 | error = -EPERM; | |
278 | } | |
279 | break; | |
280 | ||
9b238205 LT |
281 | case SNAPSHOT_S2RAM: |
282 | if (!data->frozen) { | |
283 | error = -EPERM; | |
284 | break; | |
285 | } | |
286 | ||
287 | if (down_trylock(&pm_sem)) { | |
288 | error = -EBUSY; | |
289 | break; | |
290 | } | |
291 | ||
292 | if (pm_ops->prepare) { | |
293 | error = pm_ops->prepare(PM_SUSPEND_MEM); | |
294 | if (error) | |
295 | goto OutS3; | |
296 | } | |
297 | ||
298 | /* Put devices to sleep */ | |
97c7801c | 299 | suspend_console(); |
9b238205 LT |
300 | error = device_suspend(PMSG_SUSPEND); |
301 | if (error) { | |
302 | printk(KERN_ERR "Failed to suspend some devices.\n"); | |
303 | } else { | |
304 | /* Enter S3, system is already frozen */ | |
305 | suspend_enter(PM_SUSPEND_MEM); | |
306 | ||
307 | /* Wake up devices */ | |
308 | device_resume(); | |
309 | } | |
97c7801c | 310 | resume_console(); |
9b238205 LT |
311 | if (pm_ops->finish) |
312 | pm_ops->finish(PM_SUSPEND_MEM); | |
313 | ||
314 | OutS3: | |
315 | up(&pm_sem); | |
316 | break; | |
317 | ||
3592695c SS |
318 | case SNAPSHOT_PMOPS: |
319 | switch (arg) { | |
320 | ||
321 | case PMOPS_PREPARE: | |
322 | if (pm_ops->prepare) { | |
323 | error = pm_ops->prepare(PM_SUSPEND_DISK); | |
324 | } | |
325 | break; | |
326 | ||
327 | case PMOPS_ENTER: | |
328 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); | |
329 | error = pm_ops->enter(PM_SUSPEND_DISK); | |
330 | break; | |
331 | ||
332 | case PMOPS_FINISH: | |
333 | if (pm_ops && pm_ops->finish) { | |
334 | pm_ops->finish(PM_SUSPEND_DISK); | |
335 | } | |
336 | break; | |
337 | ||
338 | default: | |
339 | printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); | |
340 | error = -EINVAL; | |
341 | ||
342 | } | |
343 | break; | |
344 | ||
6e1819d6 RW |
345 | default: |
346 | error = -ENOTTY; | |
347 | ||
348 | } | |
349 | ||
350 | return error; | |
351 | } | |
352 | ||
353 | static struct file_operations snapshot_fops = { | |
354 | .open = snapshot_open, | |
355 | .release = snapshot_release, | |
356 | .read = snapshot_read, | |
357 | .write = snapshot_write, | |
358 | .llseek = no_llseek, | |
359 | .ioctl = snapshot_ioctl, | |
360 | }; | |
361 | ||
362 | static struct miscdevice snapshot_device = { | |
363 | .minor = SNAPSHOT_MINOR, | |
364 | .name = "snapshot", | |
365 | .fops = &snapshot_fops, | |
366 | }; | |
367 | ||
368 | static int __init snapshot_device_init(void) | |
369 | { | |
370 | return misc_register(&snapshot_device); | |
371 | }; | |
372 | ||
373 | device_initcall(snapshot_device_init); |