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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> | |
19 | #include "power.h" | |
20 | ||
21 | ||
22 | extern suspend_disk_method_t pm_disk_mode; | |
23 | extern struct pm_ops * pm_ops; | |
24 | ||
25 | extern int swsusp_suspend(void); | |
26 | extern int swsusp_write(void); | |
27 | extern int swsusp_check(void); | |
28 | extern int swsusp_read(void); | |
29 | extern void swsusp_close(void); | |
30 | extern int swsusp_resume(void); | |
31 | extern int swsusp_free(void); | |
32 | ||
33 | ||
34 | static int noresume = 0; | |
35 | char resume_file[256] = CONFIG_PM_STD_PARTITION; | |
36 | dev_t swsusp_resume_device; | |
37 | ||
38 | /** | |
39 | * power_down - Shut machine down for hibernate. | |
40 | * @mode: Suspend-to-disk mode | |
41 | * | |
42 | * Use the platform driver, if configured so, and return gracefully if it | |
43 | * fails. | |
44 | * Otherwise, try to power off and reboot. If they fail, halt the machine, | |
45 | * there ain't no turning back. | |
46 | */ | |
47 | ||
48 | static void power_down(suspend_disk_method_t mode) | |
49 | { | |
50 | unsigned long flags; | |
51 | int error = 0; | |
52 | ||
53 | local_irq_save(flags); | |
54 | switch(mode) { | |
55 | case PM_DISK_PLATFORM: | |
56 | device_shutdown(); | |
57 | error = pm_ops->enter(PM_SUSPEND_DISK); | |
58 | break; | |
59 | case PM_DISK_SHUTDOWN: | |
60 | printk("Powering off system\n"); | |
61 | device_shutdown(); | |
62 | machine_power_off(); | |
63 | break; | |
64 | case PM_DISK_REBOOT: | |
65 | device_shutdown(); | |
66 | machine_restart(NULL); | |
67 | break; | |
68 | } | |
69 | machine_halt(); | |
70 | /* Valid image is on the disk, if we continue we risk serious data corruption | |
71 | after resume. */ | |
72 | printk(KERN_CRIT "Please power me down manually\n"); | |
73 | while(1); | |
74 | } | |
75 | ||
76 | ||
77 | static int in_suspend __nosavedata = 0; | |
78 | ||
79 | ||
80 | /** | |
81 | * free_some_memory - Try to free as much memory as possible | |
82 | * | |
83 | * ... but do not OOM-kill anyone | |
84 | * | |
85 | * Notice: all userland should be stopped at this point, or | |
86 | * livelock is possible. | |
87 | */ | |
88 | ||
89 | static void free_some_memory(void) | |
90 | { | |
91 | unsigned int i = 0; | |
92 | unsigned int tmp; | |
93 | unsigned long pages = 0; | |
94 | char *p = "-\\|/"; | |
95 | ||
96 | printk("Freeing memory... "); | |
97 | while ((tmp = shrink_all_memory(10000))) { | |
98 | pages += tmp; | |
99 | printk("\b%c", p[i]); | |
100 | i++; | |
101 | if (i > 3) | |
102 | i = 0; | |
103 | } | |
104 | printk("\bdone (%li pages freed)\n", pages); | |
105 | } | |
106 | ||
107 | ||
108 | static inline void platform_finish(void) | |
109 | { | |
110 | if (pm_disk_mode == PM_DISK_PLATFORM) { | |
111 | if (pm_ops && pm_ops->finish) | |
112 | pm_ops->finish(PM_SUSPEND_DISK); | |
113 | } | |
114 | } | |
115 | ||
116 | static void finish(void) | |
117 | { | |
118 | device_resume(); | |
119 | platform_finish(); | |
1da177e4 | 120 | thaw_processes(); |
5a72e04d | 121 | enable_nonboot_cpus(); |
1da177e4 LT |
122 | pm_restore_console(); |
123 | } | |
124 | ||
125 | ||
126 | static int prepare_processes(void) | |
127 | { | |
128 | int error; | |
129 | ||
130 | pm_prepare_console(); | |
131 | ||
132 | sys_sync(); | |
133 | ||
5a72e04d LS |
134 | disable_nonboot_cpus(); |
135 | ||
1da177e4 LT |
136 | if (freeze_processes()) { |
137 | error = -EBUSY; | |
5a72e04d | 138 | goto thaw; |
1da177e4 LT |
139 | } |
140 | ||
141 | if (pm_disk_mode == PM_DISK_PLATFORM) { | |
142 | if (pm_ops && pm_ops->prepare) { | |
143 | if ((error = pm_ops->prepare(PM_SUSPEND_DISK))) | |
5a72e04d | 144 | goto thaw; |
1da177e4 LT |
145 | } |
146 | } | |
147 | ||
148 | /* Free memory before shutting down devices. */ | |
149 | free_some_memory(); | |
1da177e4 | 150 | return 0; |
5a72e04d LS |
151 | thaw: |
152 | thaw_processes(); | |
153 | enable_nonboot_cpus(); | |
154 | pm_restore_console(); | |
155 | return error; | |
1da177e4 LT |
156 | } |
157 | ||
158 | static void unprepare_processes(void) | |
159 | { | |
5a72e04d | 160 | platform_finish(); |
1da177e4 | 161 | thaw_processes(); |
5a72e04d | 162 | enable_nonboot_cpus(); |
1da177e4 LT |
163 | pm_restore_console(); |
164 | } | |
165 | ||
166 | static int prepare_devices(void) | |
167 | { | |
168 | int error; | |
169 | ||
5a72e04d | 170 | if ((error = device_suspend(PMSG_FREEZE))) |
1da177e4 | 171 | printk("Some devices failed to suspend\n"); |
5a72e04d | 172 | return error; |
1da177e4 LT |
173 | } |
174 | ||
175 | /** | |
176 | * pm_suspend_disk - The granpappy of power management. | |
177 | * | |
178 | * If we're going through the firmware, then get it over with quickly. | |
179 | * | |
180 | * If not, then call swsusp to do its thing, then figure out how | |
181 | * to power down the system. | |
182 | */ | |
183 | ||
184 | int pm_suspend_disk(void) | |
185 | { | |
186 | int error; | |
187 | ||
188 | error = prepare_processes(); | |
5a72e04d LS |
189 | if (error) |
190 | return error; | |
191 | error = prepare_devices(); | |
1da177e4 LT |
192 | |
193 | if (error) { | |
194 | unprepare_processes(); | |
195 | return error; | |
196 | } | |
197 | ||
198 | pr_debug("PM: Attempting to suspend to disk.\n"); | |
199 | if (pm_disk_mode == PM_DISK_FIRMWARE) | |
200 | return pm_ops->enter(PM_SUSPEND_DISK); | |
201 | ||
202 | pr_debug("PM: snapshotting memory.\n"); | |
203 | in_suspend = 1; | |
204 | if ((error = swsusp_suspend())) | |
205 | goto Done; | |
206 | ||
207 | if (in_suspend) { | |
208 | pr_debug("PM: writing image.\n"); | |
209 | error = swsusp_write(); | |
210 | if (!error) | |
211 | power_down(pm_disk_mode); | |
212 | } else | |
213 | pr_debug("PM: Image restored successfully.\n"); | |
214 | swsusp_free(); | |
215 | Done: | |
216 | finish(); | |
217 | return error; | |
218 | } | |
219 | ||
220 | ||
221 | /** | |
222 | * software_resume - Resume from a saved image. | |
223 | * | |
224 | * Called as a late_initcall (so all devices are discovered and | |
225 | * initialized), we call swsusp to see if we have a saved image or not. | |
226 | * If so, we quiesce devices, the restore the saved image. We will | |
227 | * return above (in pm_suspend_disk() ) if everything goes well. | |
228 | * Otherwise, we fail gracefully and return to the normally | |
229 | * scheduled program. | |
230 | * | |
231 | */ | |
232 | ||
233 | static int software_resume(void) | |
234 | { | |
235 | int error; | |
236 | ||
237 | if (noresume) { | |
238 | /** | |
239 | * FIXME: If noresume is specified, we need to find the partition | |
240 | * and reset it back to normal swap space. | |
241 | */ | |
242 | return 0; | |
243 | } | |
244 | ||
245 | pr_debug("PM: Checking swsusp image.\n"); | |
246 | ||
247 | if ((error = swsusp_check())) | |
248 | goto Done; | |
249 | ||
250 | pr_debug("PM: Preparing processes for restore.\n"); | |
251 | ||
252 | if ((error = prepare_processes())) { | |
253 | swsusp_close(); | |
5a72e04d | 254 | goto Done; |
1da177e4 LT |
255 | } |
256 | ||
257 | pr_debug("PM: Reading swsusp image.\n"); | |
258 | ||
259 | if ((error = swsusp_read())) | |
260 | goto Cleanup; | |
261 | ||
262 | pr_debug("PM: Preparing devices for restore.\n"); | |
263 | ||
264 | if ((error = prepare_devices())) | |
265 | goto Free; | |
266 | ||
267 | mb(); | |
268 | ||
269 | pr_debug("PM: Restoring saved image.\n"); | |
270 | swsusp_resume(); | |
271 | pr_debug("PM: Restore failed, recovering.n"); | |
272 | finish(); | |
273 | Free: | |
274 | swsusp_free(); | |
275 | Cleanup: | |
276 | unprepare_processes(); | |
277 | Done: | |
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)) { | |
384 | swsusp_resume_device = res; | |
385 | printk("Attempting manual resume\n"); | |
386 | noresume = 0; | |
387 | software_resume(); | |
388 | } | |
389 | } | |
390 | ||
391 | return error >= 0 ? n : error; | |
392 | } | |
393 | ||
394 | power_attr(resume); | |
395 | ||
396 | static struct attribute * g[] = { | |
397 | &disk_attr.attr, | |
398 | &resume_attr.attr, | |
399 | NULL, | |
400 | }; | |
401 | ||
402 | ||
403 | static struct attribute_group attr_group = { | |
404 | .attrs = g, | |
405 | }; | |
406 | ||
407 | ||
408 | static int __init pm_disk_init(void) | |
409 | { | |
410 | return sysfs_create_group(&power_subsys.kset.kobj,&attr_group); | |
411 | } | |
412 | ||
413 | core_initcall(pm_disk_init); | |
414 | ||
415 | ||
416 | static int __init resume_setup(char *str) | |
417 | { | |
418 | if (noresume) | |
419 | return 1; | |
420 | ||
421 | strncpy( resume_file, str, 255 ); | |
422 | return 1; | |
423 | } | |
424 | ||
425 | static int __init noresume_setup(char *str) | |
426 | { | |
427 | noresume = 1; | |
428 | return 1; | |
429 | } | |
430 | ||
431 | __setup("noresume", noresume_setup); | |
432 | __setup("resume=", resume_setup); |