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 #include <scsi/scsi_scan.h>
27
28 #include <asm/uaccess.h>
29
30 #include "power.h"
31
32 /*
33 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34 * will be removed in the future. They are only preserved here for
35 * compatibility with existing userland utilities.
36 */
37 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
38 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
39
40 #define PMOPS_PREPARE 1
41 #define PMOPS_ENTER 2
42 #define PMOPS_FINISH 3
43
44 /*
45 * NOTE: The following ioctl definitions are wrong and have been replaced with
46 * correct ones. They are only preserved here for compatibility with existing
47 * userland utilities and will be removed in the future.
48 */
49 #define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50 #define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51 #define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52 #define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
53
54
55 #define SNAPSHOT_MINOR 231
56
57 static struct snapshot_data {
58 struct snapshot_handle handle;
59 int swap;
60 int mode;
61 char frozen;
62 char ready;
63 char platform_support;
64 } snapshot_state;
65
66 atomic_t snapshot_device_available = ATOMIC_INIT(1);
67
snapshot_open(struct inode * inode,struct file * filp)68 static int snapshot_open(struct inode *inode, struct file *filp)
69 {
70 struct snapshot_data *data;
71 int error;
72
73 mutex_lock(&pm_mutex);
74
75 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
76 error = -EBUSY;
77 goto Unlock;
78 }
79
80 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
81 atomic_inc(&snapshot_device_available);
82 error = -ENOSYS;
83 goto Unlock;
84 }
85 if(create_basic_memory_bitmaps()) {
86 atomic_inc(&snapshot_device_available);
87 error = -ENOMEM;
88 goto Unlock;
89 }
90 nonseekable_open(inode, filp);
91 data = &snapshot_state;
92 filp->private_data = data;
93 memset(&data->handle, 0, sizeof(struct snapshot_handle));
94 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
95 /* Hibernating. The image device should be accessible. */
96 data->swap = swsusp_resume_device ?
97 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
98 data->mode = O_RDONLY;
99 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
100 if (error)
101 pm_notifier_call_chain(PM_POST_HIBERNATION);
102 } else {
103 /*
104 * Resuming. We may need to wait for the image device to
105 * appear.
106 */
107 wait_for_device_probe();
108 scsi_complete_async_scans();
109
110 data->swap = -1;
111 data->mode = O_WRONLY;
112 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
113 if (error)
114 pm_notifier_call_chain(PM_POST_RESTORE);
115 }
116 if (error)
117 atomic_inc(&snapshot_device_available);
118 data->frozen = 0;
119 data->ready = 0;
120 data->platform_support = 0;
121
122 Unlock:
123 mutex_unlock(&pm_mutex);
124
125 return error;
126 }
127
snapshot_release(struct inode * inode,struct file * filp)128 static int snapshot_release(struct inode *inode, struct file *filp)
129 {
130 struct snapshot_data *data;
131
132 mutex_lock(&pm_mutex);
133
134 swsusp_free();
135 free_basic_memory_bitmaps();
136 data = filp->private_data;
137 free_all_swap_pages(data->swap);
138 if (data->frozen) {
139 pm_restore_gfp_mask();
140 thaw_processes();
141 }
142 pm_notifier_call_chain(data->mode == O_RDONLY ?
143 PM_POST_HIBERNATION : PM_POST_RESTORE);
144 atomic_inc(&snapshot_device_available);
145
146 mutex_unlock(&pm_mutex);
147
148 return 0;
149 }
150
snapshot_read(struct file * filp,char __user * buf,size_t count,loff_t * offp)151 static ssize_t snapshot_read(struct file *filp, char __user *buf,
152 size_t count, loff_t *offp)
153 {
154 struct snapshot_data *data;
155 ssize_t res;
156 loff_t pg_offp = *offp & ~PAGE_MASK;
157
158 mutex_lock(&pm_mutex);
159
160 data = filp->private_data;
161 if (!data->ready) {
162 res = -ENODATA;
163 goto Unlock;
164 }
165 if (!pg_offp) { /* on page boundary? */
166 res = snapshot_read_next(&data->handle);
167 if (res <= 0)
168 goto Unlock;
169 } else {
170 res = PAGE_SIZE - pg_offp;
171 }
172
173 res = simple_read_from_buffer(buf, count, &pg_offp,
174 data_of(data->handle), res);
175 if (res > 0)
176 *offp += res;
177
178 Unlock:
179 mutex_unlock(&pm_mutex);
180
181 return res;
182 }
183
snapshot_write(struct file * filp,const char __user * buf,size_t count,loff_t * offp)184 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
185 size_t count, loff_t *offp)
186 {
187 struct snapshot_data *data;
188 ssize_t res;
189 loff_t pg_offp = *offp & ~PAGE_MASK;
190
191 mutex_lock(&pm_mutex);
192
193 data = filp->private_data;
194
195 if (!pg_offp) {
196 res = snapshot_write_next(&data->handle);
197 if (res <= 0)
198 goto unlock;
199 } else {
200 res = PAGE_SIZE - pg_offp;
201 }
202
203 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
204 buf, count);
205 if (res > 0)
206 *offp += res;
207 unlock:
208 mutex_unlock(&pm_mutex);
209
210 return res;
211 }
212
snapshot_deprecated_ioctl(unsigned int cmd)213 static void snapshot_deprecated_ioctl(unsigned int cmd)
214 {
215 if (printk_ratelimit())
216 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
217 "be removed soon, update your suspend-to-disk "
218 "utilities\n",
219 __builtin_return_address(0), cmd);
220 }
221
snapshot_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)222 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
223 unsigned long arg)
224 {
225 int error = 0;
226 struct snapshot_data *data;
227 loff_t size;
228 sector_t offset;
229
230 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
231 return -ENOTTY;
232 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
233 return -ENOTTY;
234 if (!capable(CAP_SYS_ADMIN))
235 return -EPERM;
236
237 if (!mutex_trylock(&pm_mutex))
238 return -EBUSY;
239
240 data = filp->private_data;
241
242 switch (cmd) {
243
244 case SNAPSHOT_FREEZE:
245 if (data->frozen)
246 break;
247
248 printk("Syncing filesystems ... ");
249 sys_sync();
250 printk("done.\n");
251
252 error = usermodehelper_disable();
253 if (error)
254 break;
255
256 error = freeze_processes();
257 if (error) {
258 thaw_processes();
259 usermodehelper_enable();
260 }
261 if (!error)
262 data->frozen = 1;
263 break;
264
265 case SNAPSHOT_UNFREEZE:
266 if (!data->frozen || data->ready)
267 break;
268 pm_restore_gfp_mask();
269 thaw_processes();
270 usermodehelper_enable();
271 data->frozen = 0;
272 break;
273
274 case SNAPSHOT_ATOMIC_SNAPSHOT:
275 snapshot_deprecated_ioctl(cmd);
276 case SNAPSHOT_CREATE_IMAGE:
277 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
278 error = -EPERM;
279 break;
280 }
281 pm_restore_gfp_mask();
282 error = hibernation_snapshot(data->platform_support);
283 if (!error)
284 error = put_user(in_suspend, (int __user *)arg);
285 if (!error)
286 data->ready = 1;
287 break;
288
289 case SNAPSHOT_ATOMIC_RESTORE:
290 snapshot_write_finalize(&data->handle);
291 if (data->mode != O_WRONLY || !data->frozen ||
292 !snapshot_image_loaded(&data->handle)) {
293 error = -EPERM;
294 break;
295 }
296 error = hibernation_restore(data->platform_support);
297 break;
298
299 case SNAPSHOT_FREE:
300 swsusp_free();
301 memset(&data->handle, 0, sizeof(struct snapshot_handle));
302 data->ready = 0;
303 break;
304
305 case SNAPSHOT_SET_IMAGE_SIZE:
306 snapshot_deprecated_ioctl(cmd);
307 case SNAPSHOT_PREF_IMAGE_SIZE:
308 image_size = arg;
309 break;
310
311 case SNAPSHOT_GET_IMAGE_SIZE:
312 if (!data->ready) {
313 error = -ENODATA;
314 break;
315 }
316 size = snapshot_get_image_size();
317 size <<= PAGE_SHIFT;
318 error = put_user(size, (loff_t __user *)arg);
319 break;
320
321 case SNAPSHOT_AVAIL_SWAP:
322 snapshot_deprecated_ioctl(cmd);
323 case SNAPSHOT_AVAIL_SWAP_SIZE:
324 size = count_swap_pages(data->swap, 1);
325 size <<= PAGE_SHIFT;
326 error = put_user(size, (loff_t __user *)arg);
327 break;
328
329 case SNAPSHOT_GET_SWAP_PAGE:
330 snapshot_deprecated_ioctl(cmd);
331 case SNAPSHOT_ALLOC_SWAP_PAGE:
332 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
333 error = -ENODEV;
334 break;
335 }
336 offset = alloc_swapdev_block(data->swap);
337 if (offset) {
338 offset <<= PAGE_SHIFT;
339 error = put_user(offset, (loff_t __user *)arg);
340 } else {
341 error = -ENOSPC;
342 }
343 break;
344
345 case SNAPSHOT_FREE_SWAP_PAGES:
346 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
347 error = -ENODEV;
348 break;
349 }
350 free_all_swap_pages(data->swap);
351 break;
352
353 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
354 snapshot_deprecated_ioctl(cmd);
355 if (!swsusp_swap_in_use()) {
356 /*
357 * User space encodes device types as two-byte values,
358 * so we need to recode them
359 */
360 if (old_decode_dev(arg)) {
361 data->swap = swap_type_of(old_decode_dev(arg),
362 0, NULL);
363 if (data->swap < 0)
364 error = -ENODEV;
365 } else {
366 data->swap = -1;
367 error = -EINVAL;
368 }
369 } else {
370 error = -EPERM;
371 }
372 break;
373
374 case SNAPSHOT_S2RAM:
375 if (!data->frozen) {
376 error = -EPERM;
377 break;
378 }
379 /*
380 * Tasks are frozen and the notifiers have been called with
381 * PM_HIBERNATION_PREPARE
382 */
383 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
384 data->ready = 0;
385 break;
386
387 case SNAPSHOT_PLATFORM_SUPPORT:
388 data->platform_support = !!arg;
389 break;
390
391 case SNAPSHOT_POWER_OFF:
392 if (data->platform_support)
393 error = hibernation_platform_enter();
394 break;
395
396 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
397 snapshot_deprecated_ioctl(cmd);
398 error = -EINVAL;
399
400 switch (arg) {
401
402 case PMOPS_PREPARE:
403 data->platform_support = 1;
404 error = 0;
405 break;
406
407 case PMOPS_ENTER:
408 if (data->platform_support)
409 error = hibernation_platform_enter();
410 break;
411
412 case PMOPS_FINISH:
413 if (data->platform_support)
414 error = 0;
415 break;
416
417 default:
418 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
419
420 }
421 break;
422
423 case SNAPSHOT_SET_SWAP_AREA:
424 if (swsusp_swap_in_use()) {
425 error = -EPERM;
426 } else {
427 struct resume_swap_area swap_area;
428 dev_t swdev;
429
430 error = copy_from_user(&swap_area, (void __user *)arg,
431 sizeof(struct resume_swap_area));
432 if (error) {
433 error = -EFAULT;
434 break;
435 }
436
437 /*
438 * User space encodes device types as two-byte values,
439 * so we need to recode them
440 */
441 swdev = new_decode_dev(swap_area.dev);
442 if (swdev) {
443 offset = swap_area.offset;
444 data->swap = swap_type_of(swdev, offset, NULL);
445 if (data->swap < 0)
446 error = -ENODEV;
447 } else {
448 data->swap = -1;
449 error = -EINVAL;
450 }
451 }
452 break;
453
454 default:
455 error = -ENOTTY;
456
457 }
458
459 mutex_unlock(&pm_mutex);
460
461 return error;
462 }
463
464 static const struct file_operations snapshot_fops = {
465 .open = snapshot_open,
466 .release = snapshot_release,
467 .read = snapshot_read,
468 .write = snapshot_write,
469 .llseek = no_llseek,
470 .unlocked_ioctl = snapshot_ioctl,
471 };
472
473 static struct miscdevice snapshot_device = {
474 .minor = SNAPSHOT_MINOR,
475 .name = "snapshot",
476 .fops = &snapshot_fops,
477 };
478
snapshot_device_init(void)479 static int __init snapshot_device_init(void)
480 {
481 return misc_register(&snapshot_device);
482 };
483
484 device_initcall(snapshot_device_init);
485