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1da177e4 LT |
1 | /* |
2 | * kernel/power/disk.c - Suspend-to-disk support. | |
3 | * | |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Open Source Development Lab | |
6 | * Copyright (c) 2004 Pavel Machek <pavel@suse.cz> | |
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/delay.h> | |
18 | #include <linux/fs.h> | |
d53d9f16 | 19 | #include <linux/mount.h> |
88d10bba | 20 | #include <linux/pm.h> |
d53d9f16 | 21 | |
1da177e4 LT |
22 | #include "power.h" |
23 | ||
24 | ||
25 | extern suspend_disk_method_t pm_disk_mode; | |
1da177e4 LT |
26 | |
27 | extern int swsusp_suspend(void); | |
28 | extern int swsusp_write(void); | |
29 | extern int swsusp_check(void); | |
30 | extern int swsusp_read(void); | |
31 | extern void swsusp_close(void); | |
32 | extern int swsusp_resume(void); | |
1da177e4 LT |
33 | |
34 | ||
35 | static int noresume = 0; | |
36 | char resume_file[256] = CONFIG_PM_STD_PARTITION; | |
37 | dev_t swsusp_resume_device; | |
38 | ||
39 | /** | |
40 | * power_down - Shut machine down for hibernate. | |
41 | * @mode: Suspend-to-disk mode | |
42 | * | |
43 | * Use the platform driver, if configured so, and return gracefully if it | |
44 | * fails. | |
45 | * Otherwise, try to power off and reboot. If they fail, halt the machine, | |
46 | * there ain't no turning back. | |
47 | */ | |
48 | ||
49 | static void power_down(suspend_disk_method_t mode) | |
50 | { | |
1da177e4 LT |
51 | int error = 0; |
52 | ||
1da177e4 LT |
53 | switch(mode) { |
54 | case PM_DISK_PLATFORM: | |
88d10bba | 55 | kernel_power_off_prepare(); |
1da177e4 LT |
56 | error = pm_ops->enter(PM_SUSPEND_DISK); |
57 | break; | |
58 | case PM_DISK_SHUTDOWN: | |
fdde86ac | 59 | kernel_power_off(); |
1da177e4 LT |
60 | break; |
61 | case PM_DISK_REBOOT: | |
fdde86ac | 62 | kernel_restart(NULL); |
1da177e4 LT |
63 | break; |
64 | } | |
fdde86ac | 65 | kernel_halt(); |
1da177e4 LT |
66 | /* Valid image is on the disk, if we continue we risk serious data corruption |
67 | after resume. */ | |
68 | printk(KERN_CRIT "Please power me down manually\n"); | |
69 | while(1); | |
70 | } | |
71 | ||
72 | ||
73 | static int in_suspend __nosavedata = 0; | |
74 | ||
75 | ||
76 | /** | |
77 | * free_some_memory - Try to free as much memory as possible | |
78 | * | |
79 | * ... but do not OOM-kill anyone | |
80 | * | |
81 | * Notice: all userland should be stopped at this point, or | |
82 | * livelock is possible. | |
83 | */ | |
84 | ||
85 | static void free_some_memory(void) | |
86 | { | |
87 | unsigned int i = 0; | |
88 | unsigned int tmp; | |
89 | unsigned long pages = 0; | |
90 | char *p = "-\\|/"; | |
91 | ||
92 | printk("Freeing memory... "); | |
93 | while ((tmp = shrink_all_memory(10000))) { | |
94 | pages += tmp; | |
95 | printk("\b%c", p[i]); | |
96 | i++; | |
97 | if (i > 3) | |
98 | i = 0; | |
99 | } | |
100 | printk("\bdone (%li pages freed)\n", pages); | |
101 | } | |
102 | ||
103 | ||
104 | static inline void platform_finish(void) | |
105 | { | |
106 | if (pm_disk_mode == PM_DISK_PLATFORM) { | |
107 | if (pm_ops && pm_ops->finish) | |
108 | pm_ops->finish(PM_SUSPEND_DISK); | |
109 | } | |
110 | } | |
111 | ||
1da177e4 LT |
112 | static int prepare_processes(void) |
113 | { | |
114 | int error; | |
115 | ||
116 | pm_prepare_console(); | |
1da177e4 | 117 | sys_sync(); |
5a72e04d LS |
118 | disable_nonboot_cpus(); |
119 | ||
1da177e4 LT |
120 | if (freeze_processes()) { |
121 | error = -EBUSY; | |
5a72e04d | 122 | goto thaw; |
1da177e4 LT |
123 | } |
124 | ||
125 | if (pm_disk_mode == PM_DISK_PLATFORM) { | |
126 | if (pm_ops && pm_ops->prepare) { | |
127 | if ((error = pm_ops->prepare(PM_SUSPEND_DISK))) | |
5a72e04d | 128 | goto thaw; |
1da177e4 LT |
129 | } |
130 | } | |
131 | ||
132 | /* Free memory before shutting down devices. */ | |
133 | free_some_memory(); | |
1da177e4 | 134 | return 0; |
5a72e04d LS |
135 | thaw: |
136 | thaw_processes(); | |
137 | enable_nonboot_cpus(); | |
138 | pm_restore_console(); | |
139 | return error; | |
1da177e4 LT |
140 | } |
141 | ||
142 | static void unprepare_processes(void) | |
143 | { | |
5a72e04d | 144 | platform_finish(); |
1da177e4 | 145 | thaw_processes(); |
5a72e04d | 146 | enable_nonboot_cpus(); |
1da177e4 LT |
147 | pm_restore_console(); |
148 | } | |
149 | ||
1da177e4 LT |
150 | /** |
151 | * pm_suspend_disk - The granpappy of power management. | |
152 | * | |
153 | * If we're going through the firmware, then get it over with quickly. | |
154 | * | |
155 | * If not, then call swsusp to do its thing, then figure out how | |
156 | * to power down the system. | |
157 | */ | |
158 | ||
159 | int pm_suspend_disk(void) | |
160 | { | |
161 | int error; | |
162 | ||
163 | error = prepare_processes(); | |
5a72e04d LS |
164 | if (error) |
165 | return error; | |
1da177e4 | 166 | |
99dc7d63 | 167 | error = device_suspend(PMSG_FREEZE); |
1da177e4 | 168 | if (error) { |
99dc7d63 | 169 | printk("Some devices failed to suspend\n"); |
1da177e4 LT |
170 | unprepare_processes(); |
171 | return error; | |
172 | } | |
173 | ||
1da177e4 LT |
174 | pr_debug("PM: snapshotting memory.\n"); |
175 | in_suspend = 1; | |
176 | if ((error = swsusp_suspend())) | |
177 | goto Done; | |
178 | ||
179 | if (in_suspend) { | |
180 | pr_debug("PM: writing image.\n"); | |
181 | error = swsusp_write(); | |
182 | if (!error) | |
183 | power_down(pm_disk_mode); | |
99dc7d63 PM |
184 | else { |
185 | /* swsusp_write can not fail in device_resume, | |
186 | no need to do second device_resume */ | |
187 | swsusp_free(); | |
188 | unprepare_processes(); | |
189 | return error; | |
190 | } | |
1da177e4 LT |
191 | } else |
192 | pr_debug("PM: Image restored successfully.\n"); | |
99dc7d63 | 193 | |
1da177e4 LT |
194 | swsusp_free(); |
195 | Done: | |
99dc7d63 PM |
196 | device_resume(); |
197 | unprepare_processes(); | |
1da177e4 LT |
198 | return error; |
199 | } | |
200 | ||
201 | ||
202 | /** | |
203 | * software_resume - Resume from a saved image. | |
204 | * | |
205 | * Called as a late_initcall (so all devices are discovered and | |
206 | * initialized), we call swsusp to see if we have a saved image or not. | |
207 | * If so, we quiesce devices, the restore the saved image. We will | |
208 | * return above (in pm_suspend_disk() ) if everything goes well. | |
209 | * Otherwise, we fail gracefully and return to the normally | |
210 | * scheduled program. | |
211 | * | |
212 | */ | |
213 | ||
214 | static int software_resume(void) | |
215 | { | |
216 | int error; | |
217 | ||
dd5d666b | 218 | down(&pm_sem); |
3efa147a | 219 | if (!swsusp_resume_device) { |
dd5d666b SL |
220 | if (!strlen(resume_file)) { |
221 | up(&pm_sem); | |
3efa147a | 222 | return -ENOENT; |
dd5d666b | 223 | } |
3efa147a PM |
224 | swsusp_resume_device = name_to_dev_t(resume_file); |
225 | pr_debug("swsusp: Resume From Partition %s\n", resume_file); | |
226 | } else { | |
227 | pr_debug("swsusp: Resume From Partition %d:%d\n", | |
228 | MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); | |
229 | } | |
230 | ||
1da177e4 LT |
231 | if (noresume) { |
232 | /** | |
233 | * FIXME: If noresume is specified, we need to find the partition | |
234 | * and reset it back to normal swap space. | |
235 | */ | |
dd5d666b | 236 | up(&pm_sem); |
1da177e4 LT |
237 | return 0; |
238 | } | |
239 | ||
240 | pr_debug("PM: Checking swsusp image.\n"); | |
241 | ||
242 | if ((error = swsusp_check())) | |
243 | goto Done; | |
244 | ||
245 | pr_debug("PM: Preparing processes for restore.\n"); | |
246 | ||
247 | if ((error = prepare_processes())) { | |
248 | swsusp_close(); | |
5a72e04d | 249 | goto Done; |
1da177e4 LT |
250 | } |
251 | ||
252 | pr_debug("PM: Reading swsusp image.\n"); | |
253 | ||
2c1b4a5c RW |
254 | if ((error = swsusp_read())) { |
255 | swsusp_free(); | |
256 | goto Thaw; | |
257 | } | |
1da177e4 LT |
258 | |
259 | pr_debug("PM: Preparing devices for restore.\n"); | |
260 | ||
99dc7d63 PM |
261 | if ((error = device_suspend(PMSG_FREEZE))) { |
262 | printk("Some devices failed to suspend\n"); | |
2c1b4a5c RW |
263 | swsusp_free(); |
264 | goto Thaw; | |
99dc7d63 | 265 | } |
1da177e4 LT |
266 | |
267 | mb(); | |
268 | ||
269 | pr_debug("PM: Restoring saved image.\n"); | |
270 | swsusp_resume(); | |
271 | pr_debug("PM: Restore failed, recovering.n"); | |
99dc7d63 | 272 | device_resume(); |
2c1b4a5c | 273 | Thaw: |
1da177e4 LT |
274 | unprepare_processes(); |
275 | Done: | |
dd5d666b SL |
276 | /* For success case, the suspend path will release the lock */ |
277 | up(&pm_sem); | |
1da177e4 LT |
278 | pr_debug("PM: Resume from disk failed.\n"); |
279 | return 0; | |
280 | } | |
281 | ||
282 | late_initcall(software_resume); | |
283 | ||
284 | ||
285 | static char * pm_disk_modes[] = { | |
286 | [PM_DISK_FIRMWARE] = "firmware", | |
287 | [PM_DISK_PLATFORM] = "platform", | |
288 | [PM_DISK_SHUTDOWN] = "shutdown", | |
289 | [PM_DISK_REBOOT] = "reboot", | |
290 | }; | |
291 | ||
292 | /** | |
293 | * disk - Control suspend-to-disk mode | |
294 | * | |
295 | * Suspend-to-disk can be handled in several ways. The greatest | |
296 | * distinction is who writes memory to disk - the firmware or the OS. | |
297 | * If the firmware does it, we assume that it also handles suspending | |
298 | * the system. | |
299 | * If the OS does it, then we have three options for putting the system | |
300 | * to sleep - using the platform driver (e.g. ACPI or other PM registers), | |
301 | * powering off the system or rebooting the system (for testing). | |
302 | * | |
303 | * The system will support either 'firmware' or 'platform', and that is | |
304 | * known a priori (and encoded in pm_ops). But, the user may choose | |
305 | * 'shutdown' or 'reboot' as alternatives. | |
306 | * | |
307 | * show() will display what the mode is currently set to. | |
308 | * store() will accept one of | |
309 | * | |
310 | * 'firmware' | |
311 | * 'platform' | |
312 | * 'shutdown' | |
313 | * 'reboot' | |
314 | * | |
315 | * It will only change to 'firmware' or 'platform' if the system | |
316 | * supports it (as determined from pm_ops->pm_disk_mode). | |
317 | */ | |
318 | ||
319 | static ssize_t disk_show(struct subsystem * subsys, char * buf) | |
320 | { | |
321 | return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]); | |
322 | } | |
323 | ||
324 | ||
325 | static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n) | |
326 | { | |
327 | int error = 0; | |
328 | int i; | |
329 | int len; | |
330 | char *p; | |
331 | suspend_disk_method_t mode = 0; | |
332 | ||
333 | p = memchr(buf, '\n', n); | |
334 | len = p ? p - buf : n; | |
335 | ||
336 | down(&pm_sem); | |
337 | for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) { | |
338 | if (!strncmp(buf, pm_disk_modes[i], len)) { | |
339 | mode = i; | |
340 | break; | |
341 | } | |
342 | } | |
343 | if (mode) { | |
344 | if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT) | |
345 | pm_disk_mode = mode; | |
346 | else { | |
347 | if (pm_ops && pm_ops->enter && | |
348 | (mode == pm_ops->pm_disk_mode)) | |
349 | pm_disk_mode = mode; | |
350 | else | |
351 | error = -EINVAL; | |
352 | } | |
353 | } else | |
354 | error = -EINVAL; | |
355 | ||
356 | pr_debug("PM: suspend-to-disk mode set to '%s'\n", | |
357 | pm_disk_modes[mode]); | |
358 | up(&pm_sem); | |
359 | return error ? error : n; | |
360 | } | |
361 | ||
362 | power_attr(disk); | |
363 | ||
364 | static ssize_t resume_show(struct subsystem * subsys, char *buf) | |
365 | { | |
366 | return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device), | |
367 | MINOR(swsusp_resume_device)); | |
368 | } | |
369 | ||
370 | static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n) | |
371 | { | |
372 | int len; | |
373 | char *p; | |
374 | unsigned int maj, min; | |
375 | int error = -EINVAL; | |
376 | dev_t res; | |
377 | ||
378 | p = memchr(buf, '\n', n); | |
379 | len = p ? p - buf : n; | |
380 | ||
381 | if (sscanf(buf, "%u:%u", &maj, &min) == 2) { | |
382 | res = MKDEV(maj,min); | |
383 | if (maj == MAJOR(res) && min == MINOR(res)) { | |
dd5d666b | 384 | down(&pm_sem); |
1da177e4 | 385 | swsusp_resume_device = res; |
dd5d666b | 386 | up(&pm_sem); |
1da177e4 LT |
387 | printk("Attempting manual resume\n"); |
388 | noresume = 0; | |
389 | software_resume(); | |
390 | } | |
391 | } | |
392 | ||
393 | return error >= 0 ? n : error; | |
394 | } | |
395 | ||
396 | power_attr(resume); | |
397 | ||
398 | static struct attribute * g[] = { | |
399 | &disk_attr.attr, | |
400 | &resume_attr.attr, | |
401 | NULL, | |
402 | }; | |
403 | ||
404 | ||
405 | static struct attribute_group attr_group = { | |
406 | .attrs = g, | |
407 | }; | |
408 | ||
409 | ||
410 | static int __init pm_disk_init(void) | |
411 | { | |
412 | return sysfs_create_group(&power_subsys.kset.kobj,&attr_group); | |
413 | } | |
414 | ||
415 | core_initcall(pm_disk_init); | |
416 | ||
417 | ||
418 | static int __init resume_setup(char *str) | |
419 | { | |
420 | if (noresume) | |
421 | return 1; | |
422 | ||
423 | strncpy( resume_file, str, 255 ); | |
424 | return 1; | |
425 | } | |
426 | ||
427 | static int __init noresume_setup(char *str) | |
428 | { | |
429 | noresume = 1; | |
430 | return 1; | |
431 | } | |
432 | ||
433 | __setup("noresume", noresume_setup); | |
434 | __setup("resume=", resume_setup); |