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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(); | |
120 | enable_nonboot_cpus(); | |
121 | thaw_processes(); | |
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 | ||
134 | if (freeze_processes()) { | |
135 | error = -EBUSY; | |
136 | return error; | |
137 | } | |
138 | ||
139 | if (pm_disk_mode == PM_DISK_PLATFORM) { | |
140 | if (pm_ops && pm_ops->prepare) { | |
141 | if ((error = pm_ops->prepare(PM_SUSPEND_DISK))) | |
142 | return error; | |
143 | } | |
144 | } | |
145 | ||
146 | /* Free memory before shutting down devices. */ | |
147 | free_some_memory(); | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static void unprepare_processes(void) | |
153 | { | |
154 | enable_nonboot_cpus(); | |
155 | thaw_processes(); | |
156 | pm_restore_console(); | |
157 | } | |
158 | ||
159 | static int prepare_devices(void) | |
160 | { | |
161 | int error; | |
162 | ||
163 | disable_nonboot_cpus(); | |
164 | if ((error = device_suspend(PMSG_FREEZE))) { | |
165 | printk("Some devices failed to suspend\n"); | |
166 | platform_finish(); | |
167 | enable_nonboot_cpus(); | |
168 | return error; | |
169 | } | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | /** | |
175 | * pm_suspend_disk - The granpappy of power management. | |
176 | * | |
177 | * If we're going through the firmware, then get it over with quickly. | |
178 | * | |
179 | * If not, then call swsusp to do its thing, then figure out how | |
180 | * to power down the system. | |
181 | */ | |
182 | ||
183 | int pm_suspend_disk(void) | |
184 | { | |
185 | int error; | |
186 | ||
187 | error = prepare_processes(); | |
188 | if (!error) { | |
189 | error = prepare_devices(); | |
190 | } | |
191 | ||
192 | if (error) { | |
193 | unprepare_processes(); | |
194 | return error; | |
195 | } | |
196 | ||
197 | pr_debug("PM: Attempting to suspend to disk.\n"); | |
198 | if (pm_disk_mode == PM_DISK_FIRMWARE) | |
199 | return pm_ops->enter(PM_SUSPEND_DISK); | |
200 | ||
201 | pr_debug("PM: snapshotting memory.\n"); | |
202 | in_suspend = 1; | |
203 | if ((error = swsusp_suspend())) | |
204 | goto Done; | |
205 | ||
206 | if (in_suspend) { | |
207 | pr_debug("PM: writing image.\n"); | |
208 | error = swsusp_write(); | |
209 | if (!error) | |
210 | power_down(pm_disk_mode); | |
211 | } else | |
212 | pr_debug("PM: Image restored successfully.\n"); | |
213 | swsusp_free(); | |
214 | Done: | |
215 | finish(); | |
216 | return error; | |
217 | } | |
218 | ||
219 | ||
220 | /** | |
221 | * software_resume - Resume from a saved image. | |
222 | * | |
223 | * Called as a late_initcall (so all devices are discovered and | |
224 | * initialized), we call swsusp to see if we have a saved image or not. | |
225 | * If so, we quiesce devices, the restore the saved image. We will | |
226 | * return above (in pm_suspend_disk() ) if everything goes well. | |
227 | * Otherwise, we fail gracefully and return to the normally | |
228 | * scheduled program. | |
229 | * | |
230 | */ | |
231 | ||
232 | static int software_resume(void) | |
233 | { | |
234 | int error; | |
235 | ||
236 | if (noresume) { | |
237 | /** | |
238 | * FIXME: If noresume is specified, we need to find the partition | |
239 | * and reset it back to normal swap space. | |
240 | */ | |
241 | return 0; | |
242 | } | |
243 | ||
244 | pr_debug("PM: Checking swsusp image.\n"); | |
245 | ||
246 | if ((error = swsusp_check())) | |
247 | goto Done; | |
248 | ||
249 | pr_debug("PM: Preparing processes for restore.\n"); | |
250 | ||
251 | if ((error = prepare_processes())) { | |
252 | swsusp_close(); | |
253 | goto Cleanup; | |
254 | } | |
255 | ||
256 | pr_debug("PM: Reading swsusp image.\n"); | |
257 | ||
258 | if ((error = swsusp_read())) | |
259 | goto Cleanup; | |
260 | ||
261 | pr_debug("PM: Preparing devices for restore.\n"); | |
262 | ||
263 | if ((error = prepare_devices())) | |
264 | goto Free; | |
265 | ||
266 | mb(); | |
267 | ||
268 | pr_debug("PM: Restoring saved image.\n"); | |
269 | swsusp_resume(); | |
270 | pr_debug("PM: Restore failed, recovering.n"); | |
271 | finish(); | |
272 | Free: | |
273 | swsusp_free(); | |
274 | Cleanup: | |
275 | unprepare_processes(); | |
276 | Done: | |
277 | pr_debug("PM: Resume from disk failed.\n"); | |
278 | return 0; | |
279 | } | |
280 | ||
281 | late_initcall(software_resume); | |
282 | ||
283 | ||
284 | static char * pm_disk_modes[] = { | |
285 | [PM_DISK_FIRMWARE] = "firmware", | |
286 | [PM_DISK_PLATFORM] = "platform", | |
287 | [PM_DISK_SHUTDOWN] = "shutdown", | |
288 | [PM_DISK_REBOOT] = "reboot", | |
289 | }; | |
290 | ||
291 | /** | |
292 | * disk - Control suspend-to-disk mode | |
293 | * | |
294 | * Suspend-to-disk can be handled in several ways. The greatest | |
295 | * distinction is who writes memory to disk - the firmware or the OS. | |
296 | * If the firmware does it, we assume that it also handles suspending | |
297 | * the system. | |
298 | * If the OS does it, then we have three options for putting the system | |
299 | * to sleep - using the platform driver (e.g. ACPI or other PM registers), | |
300 | * powering off the system or rebooting the system (for testing). | |
301 | * | |
302 | * The system will support either 'firmware' or 'platform', and that is | |
303 | * known a priori (and encoded in pm_ops). But, the user may choose | |
304 | * 'shutdown' or 'reboot' as alternatives. | |
305 | * | |
306 | * show() will display what the mode is currently set to. | |
307 | * store() will accept one of | |
308 | * | |
309 | * 'firmware' | |
310 | * 'platform' | |
311 | * 'shutdown' | |
312 | * 'reboot' | |
313 | * | |
314 | * It will only change to 'firmware' or 'platform' if the system | |
315 | * supports it (as determined from pm_ops->pm_disk_mode). | |
316 | */ | |
317 | ||
318 | static ssize_t disk_show(struct subsystem * subsys, char * buf) | |
319 | { | |
320 | return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]); | |
321 | } | |
322 | ||
323 | ||
324 | static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n) | |
325 | { | |
326 | int error = 0; | |
327 | int i; | |
328 | int len; | |
329 | char *p; | |
330 | suspend_disk_method_t mode = 0; | |
331 | ||
332 | p = memchr(buf, '\n', n); | |
333 | len = p ? p - buf : n; | |
334 | ||
335 | down(&pm_sem); | |
336 | for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) { | |
337 | if (!strncmp(buf, pm_disk_modes[i], len)) { | |
338 | mode = i; | |
339 | break; | |
340 | } | |
341 | } | |
342 | if (mode) { | |
343 | if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT) | |
344 | pm_disk_mode = mode; | |
345 | else { | |
346 | if (pm_ops && pm_ops->enter && | |
347 | (mode == pm_ops->pm_disk_mode)) | |
348 | pm_disk_mode = mode; | |
349 | else | |
350 | error = -EINVAL; | |
351 | } | |
352 | } else | |
353 | error = -EINVAL; | |
354 | ||
355 | pr_debug("PM: suspend-to-disk mode set to '%s'\n", | |
356 | pm_disk_modes[mode]); | |
357 | up(&pm_sem); | |
358 | return error ? error : n; | |
359 | } | |
360 | ||
361 | power_attr(disk); | |
362 | ||
363 | static ssize_t resume_show(struct subsystem * subsys, char *buf) | |
364 | { | |
365 | return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device), | |
366 | MINOR(swsusp_resume_device)); | |
367 | } | |
368 | ||
369 | static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n) | |
370 | { | |
371 | int len; | |
372 | char *p; | |
373 | unsigned int maj, min; | |
374 | int error = -EINVAL; | |
375 | dev_t res; | |
376 | ||
377 | p = memchr(buf, '\n', n); | |
378 | len = p ? p - buf : n; | |
379 | ||
380 | if (sscanf(buf, "%u:%u", &maj, &min) == 2) { | |
381 | res = MKDEV(maj,min); | |
382 | if (maj == MAJOR(res) && min == MINOR(res)) { | |
383 | swsusp_resume_device = res; | |
384 | printk("Attempting manual resume\n"); | |
385 | noresume = 0; | |
386 | software_resume(); | |
387 | } | |
388 | } | |
389 | ||
390 | return error >= 0 ? n : error; | |
391 | } | |
392 | ||
393 | power_attr(resume); | |
394 | ||
395 | static struct attribute * g[] = { | |
396 | &disk_attr.attr, | |
397 | &resume_attr.attr, | |
398 | NULL, | |
399 | }; | |
400 | ||
401 | ||
402 | static struct attribute_group attr_group = { | |
403 | .attrs = g, | |
404 | }; | |
405 | ||
406 | ||
407 | static int __init pm_disk_init(void) | |
408 | { | |
409 | return sysfs_create_group(&power_subsys.kset.kobj,&attr_group); | |
410 | } | |
411 | ||
412 | core_initcall(pm_disk_init); | |
413 | ||
414 | ||
415 | static int __init resume_setup(char *str) | |
416 | { | |
417 | if (noresume) | |
418 | return 1; | |
419 | ||
420 | strncpy( resume_file, str, 255 ); | |
421 | return 1; | |
422 | } | |
423 | ||
424 | static int __init noresume_setup(char *str) | |
425 | { | |
426 | noresume = 1; | |
427 | return 1; | |
428 | } | |
429 | ||
430 | __setup("noresume", noresume_setup); | |
431 | __setup("resume=", resume_setup); |