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1 | /* | |
2 | * kernel/power/hibernate.c - Hibernation (a.k.a 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@ucw.cz> | |
7 | * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc. | |
8 | * | |
9 | * This file is released under the GPLv2. | |
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/kmod.h> | |
18 | #include <linux/delay.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/pm.h> | |
22 | #include <linux/console.h> | |
23 | #include <linux/cpu.h> | |
24 | #include <linux/freezer.h> | |
25 | #include <linux/gfp.h> | |
26 | #include <scsi/scsi_scan.h> | |
27 | #include <asm/suspend.h> | |
28 | ||
29 | #include "power.h" | |
30 | ||
31 | ||
32 | static int noresume = 0; | |
33 | static char resume_file[256] = CONFIG_PM_STD_PARTITION; | |
34 | dev_t swsusp_resume_device; | |
35 | sector_t swsusp_resume_block; | |
36 | int in_suspend __nosavedata = 0; | |
37 | ||
38 | enum { | |
39 | HIBERNATION_INVALID, | |
40 | HIBERNATION_PLATFORM, | |
41 | HIBERNATION_TEST, | |
42 | HIBERNATION_TESTPROC, | |
43 | HIBERNATION_SHUTDOWN, | |
44 | HIBERNATION_REBOOT, | |
45 | /* keep last */ | |
46 | __HIBERNATION_AFTER_LAST | |
47 | }; | |
48 | #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1) | |
49 | #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1) | |
50 | ||
51 | static int hibernation_mode = HIBERNATION_SHUTDOWN; | |
52 | ||
53 | static struct platform_hibernation_ops *hibernation_ops; | |
54 | ||
55 | /** | |
56 | * hibernation_set_ops - set the global hibernate operations | |
57 | * @ops: the hibernation operations to use in subsequent hibernation transitions | |
58 | */ | |
59 | ||
60 | void hibernation_set_ops(struct platform_hibernation_ops *ops) | |
61 | { | |
62 | if (ops && !(ops->begin && ops->end && ops->pre_snapshot | |
63 | && ops->prepare && ops->finish && ops->enter && ops->pre_restore | |
64 | && ops->restore_cleanup)) { | |
65 | WARN_ON(1); | |
66 | return; | |
67 | } | |
68 | mutex_lock(&pm_mutex); | |
69 | hibernation_ops = ops; | |
70 | if (ops) | |
71 | hibernation_mode = HIBERNATION_PLATFORM; | |
72 | else if (hibernation_mode == HIBERNATION_PLATFORM) | |
73 | hibernation_mode = HIBERNATION_SHUTDOWN; | |
74 | ||
75 | mutex_unlock(&pm_mutex); | |
76 | } | |
77 | ||
78 | static bool entering_platform_hibernation; | |
79 | ||
80 | bool system_entering_hibernation(void) | |
81 | { | |
82 | return entering_platform_hibernation; | |
83 | } | |
84 | EXPORT_SYMBOL(system_entering_hibernation); | |
85 | ||
86 | #ifdef CONFIG_PM_DEBUG | |
87 | static void hibernation_debug_sleep(void) | |
88 | { | |
89 | printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n"); | |
90 | mdelay(5000); | |
91 | } | |
92 | ||
93 | static int hibernation_testmode(int mode) | |
94 | { | |
95 | if (hibernation_mode == mode) { | |
96 | hibernation_debug_sleep(); | |
97 | return 1; | |
98 | } | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static int hibernation_test(int level) | |
103 | { | |
104 | if (pm_test_level == level) { | |
105 | hibernation_debug_sleep(); | |
106 | return 1; | |
107 | } | |
108 | return 0; | |
109 | } | |
110 | #else /* !CONFIG_PM_DEBUG */ | |
111 | static int hibernation_testmode(int mode) { return 0; } | |
112 | static int hibernation_test(int level) { return 0; } | |
113 | #endif /* !CONFIG_PM_DEBUG */ | |
114 | ||
115 | /** | |
116 | * platform_begin - tell the platform driver that we're starting | |
117 | * hibernation | |
118 | */ | |
119 | ||
120 | static int platform_begin(int platform_mode) | |
121 | { | |
122 | return (platform_mode && hibernation_ops) ? | |
123 | hibernation_ops->begin() : 0; | |
124 | } | |
125 | ||
126 | /** | |
127 | * platform_end - tell the platform driver that we've entered the | |
128 | * working state | |
129 | */ | |
130 | ||
131 | static void platform_end(int platform_mode) | |
132 | { | |
133 | if (platform_mode && hibernation_ops) | |
134 | hibernation_ops->end(); | |
135 | } | |
136 | ||
137 | /** | |
138 | * platform_pre_snapshot - prepare the machine for hibernation using the | |
139 | * platform driver if so configured and return an error code if it fails | |
140 | */ | |
141 | ||
142 | static int platform_pre_snapshot(int platform_mode) | |
143 | { | |
144 | return (platform_mode && hibernation_ops) ? | |
145 | hibernation_ops->pre_snapshot() : 0; | |
146 | } | |
147 | ||
148 | /** | |
149 | * platform_leave - prepare the machine for switching to the normal mode | |
150 | * of operation using the platform driver (called with interrupts disabled) | |
151 | */ | |
152 | ||
153 | static void platform_leave(int platform_mode) | |
154 | { | |
155 | if (platform_mode && hibernation_ops) | |
156 | hibernation_ops->leave(); | |
157 | } | |
158 | ||
159 | /** | |
160 | * platform_finish - switch the machine to the normal mode of operation | |
161 | * using the platform driver (must be called after platform_prepare()) | |
162 | */ | |
163 | ||
164 | static void platform_finish(int platform_mode) | |
165 | { | |
166 | if (platform_mode && hibernation_ops) | |
167 | hibernation_ops->finish(); | |
168 | } | |
169 | ||
170 | /** | |
171 | * platform_pre_restore - prepare the platform for the restoration from a | |
172 | * hibernation image. If the restore fails after this function has been | |
173 | * called, platform_restore_cleanup() must be called. | |
174 | */ | |
175 | ||
176 | static int platform_pre_restore(int platform_mode) | |
177 | { | |
178 | return (platform_mode && hibernation_ops) ? | |
179 | hibernation_ops->pre_restore() : 0; | |
180 | } | |
181 | ||
182 | /** | |
183 | * platform_restore_cleanup - switch the platform to the normal mode of | |
184 | * operation after a failing restore. If platform_pre_restore() has been | |
185 | * called before the failing restore, this function must be called too, | |
186 | * regardless of the result of platform_pre_restore(). | |
187 | */ | |
188 | ||
189 | static void platform_restore_cleanup(int platform_mode) | |
190 | { | |
191 | if (platform_mode && hibernation_ops) | |
192 | hibernation_ops->restore_cleanup(); | |
193 | } | |
194 | ||
195 | /** | |
196 | * platform_recover - recover the platform from a failure to suspend | |
197 | * devices. | |
198 | */ | |
199 | ||
200 | static void platform_recover(int platform_mode) | |
201 | { | |
202 | if (platform_mode && hibernation_ops && hibernation_ops->recover) | |
203 | hibernation_ops->recover(); | |
204 | } | |
205 | ||
206 | /** | |
207 | * swsusp_show_speed - print the time elapsed between two events. | |
208 | * @start: Starting event. | |
209 | * @stop: Final event. | |
210 | * @nr_pages - number of pages processed between @start and @stop | |
211 | * @msg - introductory message to print | |
212 | */ | |
213 | ||
214 | void swsusp_show_speed(struct timeval *start, struct timeval *stop, | |
215 | unsigned nr_pages, char *msg) | |
216 | { | |
217 | s64 elapsed_centisecs64; | |
218 | int centisecs; | |
219 | int k; | |
220 | int kps; | |
221 | ||
222 | elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start); | |
223 | do_div(elapsed_centisecs64, NSEC_PER_SEC / 100); | |
224 | centisecs = elapsed_centisecs64; | |
225 | if (centisecs == 0) | |
226 | centisecs = 1; /* avoid div-by-zero */ | |
227 | k = nr_pages * (PAGE_SIZE / 1024); | |
228 | kps = (k * 100) / centisecs; | |
229 | printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", | |
230 | msg, k, | |
231 | centisecs / 100, centisecs % 100, | |
232 | kps / 1000, (kps % 1000) / 10); | |
233 | } | |
234 | ||
235 | /** | |
236 | * create_image - freeze devices that need to be frozen with interrupts | |
237 | * off, create the hibernation image and thaw those devices. Control | |
238 | * reappears in this routine after a restore. | |
239 | */ | |
240 | ||
241 | static int create_image(int platform_mode) | |
242 | { | |
243 | int error; | |
244 | ||
245 | error = arch_prepare_suspend(); | |
246 | if (error) | |
247 | return error; | |
248 | ||
249 | /* At this point, dpm_suspend_start() has been called, but *not* | |
250 | * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now. | |
251 | * Otherwise, drivers for some devices (e.g. interrupt controllers) | |
252 | * become desynchronized with the actual state of the hardware | |
253 | * at resume time, and evil weirdness ensues. | |
254 | */ | |
255 | error = dpm_suspend_noirq(PMSG_FREEZE); | |
256 | if (error) { | |
257 | printk(KERN_ERR "PM: Some devices failed to power down, " | |
258 | "aborting hibernation\n"); | |
259 | return error; | |
260 | } | |
261 | ||
262 | error = platform_pre_snapshot(platform_mode); | |
263 | if (error || hibernation_test(TEST_PLATFORM)) | |
264 | goto Platform_finish; | |
265 | ||
266 | error = disable_nonboot_cpus(); | |
267 | if (error || hibernation_test(TEST_CPUS) | |
268 | || hibernation_testmode(HIBERNATION_TEST)) | |
269 | goto Enable_cpus; | |
270 | ||
271 | local_irq_disable(); | |
272 | ||
273 | error = sysdev_suspend(PMSG_FREEZE); | |
274 | if (error) { | |
275 | printk(KERN_ERR "PM: Some system devices failed to power down, " | |
276 | "aborting hibernation\n"); | |
277 | goto Enable_irqs; | |
278 | } | |
279 | ||
280 | if (hibernation_test(TEST_CORE) || !pm_check_wakeup_events()) | |
281 | goto Power_up; | |
282 | ||
283 | in_suspend = 1; | |
284 | save_processor_state(); | |
285 | error = swsusp_arch_suspend(); | |
286 | if (error) | |
287 | printk(KERN_ERR "PM: Error %d creating hibernation image\n", | |
288 | error); | |
289 | /* Restore control flow magically appears here */ | |
290 | restore_processor_state(); | |
291 | if (!in_suspend) { | |
292 | events_check_enabled = false; | |
293 | platform_leave(platform_mode); | |
294 | } | |
295 | ||
296 | Power_up: | |
297 | sysdev_resume(); | |
298 | /* NOTE: dpm_resume_noirq() is just a resume() for devices | |
299 | * that suspended with irqs off ... no overall powerup. | |
300 | */ | |
301 | ||
302 | Enable_irqs: | |
303 | local_irq_enable(); | |
304 | ||
305 | Enable_cpus: | |
306 | enable_nonboot_cpus(); | |
307 | ||
308 | Platform_finish: | |
309 | platform_finish(platform_mode); | |
310 | ||
311 | dpm_resume_noirq(in_suspend ? | |
312 | (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); | |
313 | ||
314 | return error; | |
315 | } | |
316 | ||
317 | /** | |
318 | * hibernation_snapshot - quiesce devices and create the hibernation | |
319 | * snapshot image. | |
320 | * @platform_mode - if set, use the platform driver, if available, to | |
321 | * prepare the platform firmware for the power transition. | |
322 | * | |
323 | * Must be called with pm_mutex held | |
324 | */ | |
325 | ||
326 | int hibernation_snapshot(int platform_mode) | |
327 | { | |
328 | int error; | |
329 | gfp_t saved_mask; | |
330 | ||
331 | error = platform_begin(platform_mode); | |
332 | if (error) | |
333 | goto Close; | |
334 | ||
335 | /* Preallocate image memory before shutting down devices. */ | |
336 | error = hibernate_preallocate_memory(); | |
337 | if (error) | |
338 | goto Close; | |
339 | ||
340 | suspend_console(); | |
341 | hibernation_freeze_swap(); | |
342 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); | |
343 | error = dpm_suspend_start(PMSG_FREEZE); | |
344 | if (error) | |
345 | goto Recover_platform; | |
346 | ||
347 | if (hibernation_test(TEST_DEVICES)) | |
348 | goto Recover_platform; | |
349 | ||
350 | error = create_image(platform_mode); | |
351 | /* Control returns here after successful restore */ | |
352 | ||
353 | Resume_devices: | |
354 | /* We may need to release the preallocated image pages here. */ | |
355 | if (error || !in_suspend) | |
356 | swsusp_free(); | |
357 | ||
358 | dpm_resume_end(in_suspend ? | |
359 | (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); | |
360 | set_gfp_allowed_mask(saved_mask); | |
361 | resume_console(); | |
362 | Close: | |
363 | platform_end(platform_mode); | |
364 | return error; | |
365 | ||
366 | Recover_platform: | |
367 | platform_recover(platform_mode); | |
368 | goto Resume_devices; | |
369 | } | |
370 | ||
371 | /** | |
372 | * resume_target_kernel - prepare devices that need to be suspended with | |
373 | * interrupts off, restore the contents of highmem that have not been | |
374 | * restored yet from the image and run the low level code that will restore | |
375 | * the remaining contents of memory and switch to the just restored target | |
376 | * kernel. | |
377 | */ | |
378 | ||
379 | static int resume_target_kernel(bool platform_mode) | |
380 | { | |
381 | int error; | |
382 | ||
383 | error = dpm_suspend_noirq(PMSG_QUIESCE); | |
384 | if (error) { | |
385 | printk(KERN_ERR "PM: Some devices failed to power down, " | |
386 | "aborting resume\n"); | |
387 | return error; | |
388 | } | |
389 | ||
390 | error = platform_pre_restore(platform_mode); | |
391 | if (error) | |
392 | goto Cleanup; | |
393 | ||
394 | error = disable_nonboot_cpus(); | |
395 | if (error) | |
396 | goto Enable_cpus; | |
397 | ||
398 | local_irq_disable(); | |
399 | ||
400 | error = sysdev_suspend(PMSG_QUIESCE); | |
401 | if (error) | |
402 | goto Enable_irqs; | |
403 | ||
404 | /* We'll ignore saved state, but this gets preempt count (etc) right */ | |
405 | save_processor_state(); | |
406 | error = restore_highmem(); | |
407 | if (!error) { | |
408 | error = swsusp_arch_resume(); | |
409 | /* | |
410 | * The code below is only ever reached in case of a failure. | |
411 | * Otherwise execution continues at place where | |
412 | * swsusp_arch_suspend() was called | |
413 | */ | |
414 | BUG_ON(!error); | |
415 | /* This call to restore_highmem() undos the previous one */ | |
416 | restore_highmem(); | |
417 | } | |
418 | /* | |
419 | * The only reason why swsusp_arch_resume() can fail is memory being | |
420 | * very tight, so we have to free it as soon as we can to avoid | |
421 | * subsequent failures | |
422 | */ | |
423 | swsusp_free(); | |
424 | restore_processor_state(); | |
425 | touch_softlockup_watchdog(); | |
426 | ||
427 | sysdev_resume(); | |
428 | ||
429 | Enable_irqs: | |
430 | local_irq_enable(); | |
431 | ||
432 | Enable_cpus: | |
433 | enable_nonboot_cpus(); | |
434 | ||
435 | Cleanup: | |
436 | platform_restore_cleanup(platform_mode); | |
437 | ||
438 | dpm_resume_noirq(PMSG_RECOVER); | |
439 | ||
440 | return error; | |
441 | } | |
442 | ||
443 | /** | |
444 | * hibernation_restore - quiesce devices and restore the hibernation | |
445 | * snapshot image. If successful, control returns in hibernation_snaphot() | |
446 | * @platform_mode - if set, use the platform driver, if available, to | |
447 | * prepare the platform firmware for the transition. | |
448 | * | |
449 | * Must be called with pm_mutex held | |
450 | */ | |
451 | ||
452 | int hibernation_restore(int platform_mode) | |
453 | { | |
454 | int error; | |
455 | gfp_t saved_mask; | |
456 | ||
457 | pm_prepare_console(); | |
458 | suspend_console(); | |
459 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); | |
460 | error = dpm_suspend_start(PMSG_QUIESCE); | |
461 | if (!error) { | |
462 | error = resume_target_kernel(platform_mode); | |
463 | dpm_resume_end(PMSG_RECOVER); | |
464 | } | |
465 | set_gfp_allowed_mask(saved_mask); | |
466 | resume_console(); | |
467 | pm_restore_console(); | |
468 | return error; | |
469 | } | |
470 | ||
471 | /** | |
472 | * hibernation_platform_enter - enter the hibernation state using the | |
473 | * platform driver (if available) | |
474 | */ | |
475 | ||
476 | int hibernation_platform_enter(void) | |
477 | { | |
478 | int error; | |
479 | gfp_t saved_mask; | |
480 | ||
481 | if (!hibernation_ops) | |
482 | return -ENOSYS; | |
483 | ||
484 | /* | |
485 | * We have cancelled the power transition by running | |
486 | * hibernation_ops->finish() before saving the image, so we should let | |
487 | * the firmware know that we're going to enter the sleep state after all | |
488 | */ | |
489 | error = hibernation_ops->begin(); | |
490 | if (error) | |
491 | goto Close; | |
492 | ||
493 | entering_platform_hibernation = true; | |
494 | suspend_console(); | |
495 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); | |
496 | error = dpm_suspend_start(PMSG_HIBERNATE); | |
497 | if (error) { | |
498 | if (hibernation_ops->recover) | |
499 | hibernation_ops->recover(); | |
500 | goto Resume_devices; | |
501 | } | |
502 | ||
503 | error = dpm_suspend_noirq(PMSG_HIBERNATE); | |
504 | if (error) | |
505 | goto Resume_devices; | |
506 | ||
507 | error = hibernation_ops->prepare(); | |
508 | if (error) | |
509 | goto Platform_finish; | |
510 | ||
511 | error = disable_nonboot_cpus(); | |
512 | if (error) | |
513 | goto Platform_finish; | |
514 | ||
515 | local_irq_disable(); | |
516 | sysdev_suspend(PMSG_HIBERNATE); | |
517 | if (!pm_check_wakeup_events()) { | |
518 | error = -EAGAIN; | |
519 | goto Power_up; | |
520 | } | |
521 | ||
522 | hibernation_ops->enter(); | |
523 | /* We should never get here */ | |
524 | while (1); | |
525 | ||
526 | Power_up: | |
527 | sysdev_resume(); | |
528 | local_irq_enable(); | |
529 | enable_nonboot_cpus(); | |
530 | ||
531 | Platform_finish: | |
532 | hibernation_ops->finish(); | |
533 | ||
534 | dpm_resume_noirq(PMSG_RESTORE); | |
535 | ||
536 | Resume_devices: | |
537 | entering_platform_hibernation = false; | |
538 | dpm_resume_end(PMSG_RESTORE); | |
539 | set_gfp_allowed_mask(saved_mask); | |
540 | resume_console(); | |
541 | ||
542 | Close: | |
543 | hibernation_ops->end(); | |
544 | ||
545 | return error; | |
546 | } | |
547 | ||
548 | /** | |
549 | * power_down - Shut the machine down for hibernation. | |
550 | * | |
551 | * Use the platform driver, if configured so; otherwise try | |
552 | * to power off or reboot. | |
553 | */ | |
554 | ||
555 | static void power_down(void) | |
556 | { | |
557 | switch (hibernation_mode) { | |
558 | case HIBERNATION_TEST: | |
559 | case HIBERNATION_TESTPROC: | |
560 | break; | |
561 | case HIBERNATION_REBOOT: | |
562 | kernel_restart(NULL); | |
563 | break; | |
564 | case HIBERNATION_PLATFORM: | |
565 | hibernation_platform_enter(); | |
566 | case HIBERNATION_SHUTDOWN: | |
567 | kernel_power_off(); | |
568 | break; | |
569 | } | |
570 | kernel_halt(); | |
571 | /* | |
572 | * Valid image is on the disk, if we continue we risk serious data | |
573 | * corruption after resume. | |
574 | */ | |
575 | printk(KERN_CRIT "PM: Please power down manually\n"); | |
576 | while(1); | |
577 | } | |
578 | ||
579 | static int prepare_processes(void) | |
580 | { | |
581 | int error = 0; | |
582 | ||
583 | if (freeze_processes()) { | |
584 | error = -EBUSY; | |
585 | thaw_processes(); | |
586 | } | |
587 | return error; | |
588 | } | |
589 | ||
590 | /** | |
591 | * hibernate - The granpappy of the built-in hibernation management | |
592 | */ | |
593 | ||
594 | int hibernate(void) | |
595 | { | |
596 | int error; | |
597 | ||
598 | mutex_lock(&pm_mutex); | |
599 | /* The snapshot device should not be opened while we're running */ | |
600 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { | |
601 | error = -EBUSY; | |
602 | goto Unlock; | |
603 | } | |
604 | ||
605 | pm_prepare_console(); | |
606 | error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); | |
607 | if (error) | |
608 | goto Exit; | |
609 | ||
610 | error = usermodehelper_disable(); | |
611 | if (error) | |
612 | goto Exit; | |
613 | ||
614 | /* Allocate memory management structures */ | |
615 | error = create_basic_memory_bitmaps(); | |
616 | if (error) | |
617 | goto Exit; | |
618 | ||
619 | printk(KERN_INFO "PM: Syncing filesystems ... "); | |
620 | sys_sync(); | |
621 | printk("done.\n"); | |
622 | ||
623 | error = prepare_processes(); | |
624 | if (error) | |
625 | goto Finish; | |
626 | ||
627 | if (hibernation_test(TEST_FREEZER)) | |
628 | goto Thaw; | |
629 | ||
630 | if (hibernation_testmode(HIBERNATION_TESTPROC)) | |
631 | goto Thaw; | |
632 | ||
633 | error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); | |
634 | if (error) | |
635 | goto Thaw; | |
636 | ||
637 | if (in_suspend) { | |
638 | unsigned int flags = 0; | |
639 | ||
640 | if (hibernation_mode == HIBERNATION_PLATFORM) | |
641 | flags |= SF_PLATFORM_MODE; | |
642 | pr_debug("PM: writing image.\n"); | |
643 | error = swsusp_write(flags); | |
644 | swsusp_free(); | |
645 | if (!error) | |
646 | power_down(); | |
647 | } else { | |
648 | pr_debug("PM: Image restored successfully.\n"); | |
649 | } | |
650 | ||
651 | Thaw: | |
652 | thaw_processes(); | |
653 | Finish: | |
654 | free_basic_memory_bitmaps(); | |
655 | usermodehelper_enable(); | |
656 | Exit: | |
657 | pm_notifier_call_chain(PM_POST_HIBERNATION); | |
658 | pm_restore_console(); | |
659 | atomic_inc(&snapshot_device_available); | |
660 | Unlock: | |
661 | mutex_unlock(&pm_mutex); | |
662 | return error; | |
663 | } | |
664 | ||
665 | ||
666 | /** | |
667 | * software_resume - Resume from a saved image. | |
668 | * | |
669 | * Called as a late_initcall (so all devices are discovered and | |
670 | * initialized), we call swsusp to see if we have a saved image or not. | |
671 | * If so, we quiesce devices, the restore the saved image. We will | |
672 | * return above (in hibernate() ) if everything goes well. | |
673 | * Otherwise, we fail gracefully and return to the normally | |
674 | * scheduled program. | |
675 | * | |
676 | */ | |
677 | ||
678 | static int software_resume(void) | |
679 | { | |
680 | int error; | |
681 | unsigned int flags; | |
682 | ||
683 | /* | |
684 | * If the user said "noresume".. bail out early. | |
685 | */ | |
686 | if (noresume) | |
687 | return 0; | |
688 | ||
689 | /* | |
690 | * name_to_dev_t() below takes a sysfs buffer mutex when sysfs | |
691 | * is configured into the kernel. Since the regular hibernate | |
692 | * trigger path is via sysfs which takes a buffer mutex before | |
693 | * calling hibernate functions (which take pm_mutex) this can | |
694 | * cause lockdep to complain about a possible ABBA deadlock | |
695 | * which cannot happen since we're in the boot code here and | |
696 | * sysfs can't be invoked yet. Therefore, we use a subclass | |
697 | * here to avoid lockdep complaining. | |
698 | */ | |
699 | mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); | |
700 | ||
701 | if (swsusp_resume_device) | |
702 | goto Check_image; | |
703 | ||
704 | if (!strlen(resume_file)) { | |
705 | error = -ENOENT; | |
706 | goto Unlock; | |
707 | } | |
708 | ||
709 | pr_debug("PM: Checking image partition %s\n", resume_file); | |
710 | ||
711 | /* Check if the device is there */ | |
712 | swsusp_resume_device = name_to_dev_t(resume_file); | |
713 | if (!swsusp_resume_device) { | |
714 | /* | |
715 | * Some device discovery might still be in progress; we need | |
716 | * to wait for this to finish. | |
717 | */ | |
718 | wait_for_device_probe(); | |
719 | /* | |
720 | * We can't depend on SCSI devices being available after loading | |
721 | * one of their modules until scsi_complete_async_scans() is | |
722 | * called and the resume device usually is a SCSI one. | |
723 | */ | |
724 | scsi_complete_async_scans(); | |
725 | ||
726 | swsusp_resume_device = name_to_dev_t(resume_file); | |
727 | if (!swsusp_resume_device) { | |
728 | error = -ENODEV; | |
729 | goto Unlock; | |
730 | } | |
731 | } | |
732 | ||
733 | Check_image: | |
734 | pr_debug("PM: Resume from partition %d:%d\n", | |
735 | MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); | |
736 | ||
737 | pr_debug("PM: Checking hibernation image.\n"); | |
738 | error = swsusp_check(); | |
739 | if (error) | |
740 | goto Unlock; | |
741 | ||
742 | /* The snapshot device should not be opened while we're running */ | |
743 | if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { | |
744 | error = -EBUSY; | |
745 | swsusp_close(FMODE_READ); | |
746 | goto Unlock; | |
747 | } | |
748 | ||
749 | pm_prepare_console(); | |
750 | error = pm_notifier_call_chain(PM_RESTORE_PREPARE); | |
751 | if (error) | |
752 | goto close_finish; | |
753 | ||
754 | error = usermodehelper_disable(); | |
755 | if (error) | |
756 | goto close_finish; | |
757 | ||
758 | error = create_basic_memory_bitmaps(); | |
759 | if (error) | |
760 | goto close_finish; | |
761 | ||
762 | pr_debug("PM: Preparing processes for restore.\n"); | |
763 | error = prepare_processes(); | |
764 | if (error) { | |
765 | swsusp_close(FMODE_READ); | |
766 | goto Done; | |
767 | } | |
768 | ||
769 | pr_debug("PM: Reading hibernation image.\n"); | |
770 | ||
771 | error = swsusp_read(&flags); | |
772 | swsusp_close(FMODE_READ); | |
773 | if (!error) | |
774 | hibernation_restore(flags & SF_PLATFORM_MODE); | |
775 | ||
776 | printk(KERN_ERR "PM: Restore failed, recovering.\n"); | |
777 | swsusp_free(); | |
778 | thaw_processes(); | |
779 | Done: | |
780 | free_basic_memory_bitmaps(); | |
781 | usermodehelper_enable(); | |
782 | Finish: | |
783 | pm_notifier_call_chain(PM_POST_RESTORE); | |
784 | pm_restore_console(); | |
785 | atomic_inc(&snapshot_device_available); | |
786 | /* For success case, the suspend path will release the lock */ | |
787 | Unlock: | |
788 | mutex_unlock(&pm_mutex); | |
789 | pr_debug("PM: Resume from disk failed.\n"); | |
790 | return error; | |
791 | close_finish: | |
792 | swsusp_close(FMODE_READ); | |
793 | goto Finish; | |
794 | } | |
795 | ||
796 | late_initcall(software_resume); | |
797 | ||
798 | ||
799 | static const char * const hibernation_modes[] = { | |
800 | [HIBERNATION_PLATFORM] = "platform", | |
801 | [HIBERNATION_SHUTDOWN] = "shutdown", | |
802 | [HIBERNATION_REBOOT] = "reboot", | |
803 | [HIBERNATION_TEST] = "test", | |
804 | [HIBERNATION_TESTPROC] = "testproc", | |
805 | }; | |
806 | ||
807 | /** | |
808 | * disk - Control hibernation mode | |
809 | * | |
810 | * Suspend-to-disk can be handled in several ways. We have a few options | |
811 | * for putting the system to sleep - using the platform driver (e.g. ACPI | |
812 | * or other hibernation_ops), powering off the system or rebooting the | |
813 | * system (for testing) as well as the two test modes. | |
814 | * | |
815 | * The system can support 'platform', and that is known a priori (and | |
816 | * encoded by the presence of hibernation_ops). However, the user may | |
817 | * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the | |
818 | * test modes, 'test' or 'testproc'. | |
819 | * | |
820 | * show() will display what the mode is currently set to. | |
821 | * store() will accept one of | |
822 | * | |
823 | * 'platform' | |
824 | * 'shutdown' | |
825 | * 'reboot' | |
826 | * 'test' | |
827 | * 'testproc' | |
828 | * | |
829 | * It will only change to 'platform' if the system | |
830 | * supports it (as determined by having hibernation_ops). | |
831 | */ | |
832 | ||
833 | static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, | |
834 | char *buf) | |
835 | { | |
836 | int i; | |
837 | char *start = buf; | |
838 | ||
839 | for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { | |
840 | if (!hibernation_modes[i]) | |
841 | continue; | |
842 | switch (i) { | |
843 | case HIBERNATION_SHUTDOWN: | |
844 | case HIBERNATION_REBOOT: | |
845 | case HIBERNATION_TEST: | |
846 | case HIBERNATION_TESTPROC: | |
847 | break; | |
848 | case HIBERNATION_PLATFORM: | |
849 | if (hibernation_ops) | |
850 | break; | |
851 | /* not a valid mode, continue with loop */ | |
852 | continue; | |
853 | } | |
854 | if (i == hibernation_mode) | |
855 | buf += sprintf(buf, "[%s] ", hibernation_modes[i]); | |
856 | else | |
857 | buf += sprintf(buf, "%s ", hibernation_modes[i]); | |
858 | } | |
859 | buf += sprintf(buf, "\n"); | |
860 | return buf-start; | |
861 | } | |
862 | ||
863 | ||
864 | static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, | |
865 | const char *buf, size_t n) | |
866 | { | |
867 | int error = 0; | |
868 | int i; | |
869 | int len; | |
870 | char *p; | |
871 | int mode = HIBERNATION_INVALID; | |
872 | ||
873 | p = memchr(buf, '\n', n); | |
874 | len = p ? p - buf : n; | |
875 | ||
876 | mutex_lock(&pm_mutex); | |
877 | for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { | |
878 | if (len == strlen(hibernation_modes[i]) | |
879 | && !strncmp(buf, hibernation_modes[i], len)) { | |
880 | mode = i; | |
881 | break; | |
882 | } | |
883 | } | |
884 | if (mode != HIBERNATION_INVALID) { | |
885 | switch (mode) { | |
886 | case HIBERNATION_SHUTDOWN: | |
887 | case HIBERNATION_REBOOT: | |
888 | case HIBERNATION_TEST: | |
889 | case HIBERNATION_TESTPROC: | |
890 | hibernation_mode = mode; | |
891 | break; | |
892 | case HIBERNATION_PLATFORM: | |
893 | if (hibernation_ops) | |
894 | hibernation_mode = mode; | |
895 | else | |
896 | error = -EINVAL; | |
897 | } | |
898 | } else | |
899 | error = -EINVAL; | |
900 | ||
901 | if (!error) | |
902 | pr_debug("PM: Hibernation mode set to '%s'\n", | |
903 | hibernation_modes[mode]); | |
904 | mutex_unlock(&pm_mutex); | |
905 | return error ? error : n; | |
906 | } | |
907 | ||
908 | power_attr(disk); | |
909 | ||
910 | static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr, | |
911 | char *buf) | |
912 | { | |
913 | return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device), | |
914 | MINOR(swsusp_resume_device)); | |
915 | } | |
916 | ||
917 | static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr, | |
918 | const char *buf, size_t n) | |
919 | { | |
920 | unsigned int maj, min; | |
921 | dev_t res; | |
922 | int ret = -EINVAL; | |
923 | ||
924 | if (sscanf(buf, "%u:%u", &maj, &min) != 2) | |
925 | goto out; | |
926 | ||
927 | res = MKDEV(maj,min); | |
928 | if (maj != MAJOR(res) || min != MINOR(res)) | |
929 | goto out; | |
930 | ||
931 | mutex_lock(&pm_mutex); | |
932 | swsusp_resume_device = res; | |
933 | mutex_unlock(&pm_mutex); | |
934 | printk(KERN_INFO "PM: Starting manual resume from disk\n"); | |
935 | noresume = 0; | |
936 | software_resume(); | |
937 | ret = n; | |
938 | out: | |
939 | return ret; | |
940 | } | |
941 | ||
942 | power_attr(resume); | |
943 | ||
944 | static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr, | |
945 | char *buf) | |
946 | { | |
947 | return sprintf(buf, "%lu\n", image_size); | |
948 | } | |
949 | ||
950 | static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr, | |
951 | const char *buf, size_t n) | |
952 | { | |
953 | unsigned long size; | |
954 | ||
955 | if (sscanf(buf, "%lu", &size) == 1) { | |
956 | image_size = size; | |
957 | return n; | |
958 | } | |
959 | ||
960 | return -EINVAL; | |
961 | } | |
962 | ||
963 | power_attr(image_size); | |
964 | ||
965 | static struct attribute * g[] = { | |
966 | &disk_attr.attr, | |
967 | &resume_attr.attr, | |
968 | &image_size_attr.attr, | |
969 | NULL, | |
970 | }; | |
971 | ||
972 | ||
973 | static struct attribute_group attr_group = { | |
974 | .attrs = g, | |
975 | }; | |
976 | ||
977 | ||
978 | static int __init pm_disk_init(void) | |
979 | { | |
980 | return sysfs_create_group(power_kobj, &attr_group); | |
981 | } | |
982 | ||
983 | core_initcall(pm_disk_init); | |
984 | ||
985 | ||
986 | static int __init resume_setup(char *str) | |
987 | { | |
988 | if (noresume) | |
989 | return 1; | |
990 | ||
991 | strncpy( resume_file, str, 255 ); | |
992 | return 1; | |
993 | } | |
994 | ||
995 | static int __init resume_offset_setup(char *str) | |
996 | { | |
997 | unsigned long long offset; | |
998 | ||
999 | if (noresume) | |
1000 | return 1; | |
1001 | ||
1002 | if (sscanf(str, "%llu", &offset) == 1) | |
1003 | swsusp_resume_block = offset; | |
1004 | ||
1005 | return 1; | |
1006 | } | |
1007 | ||
1008 | static int __init noresume_setup(char *str) | |
1009 | { | |
1010 | noresume = 1; | |
1011 | return 1; | |
1012 | } | |
1013 | ||
1014 | __setup("noresume", noresume_setup); | |
1015 | __setup("resume_offset=", resume_offset_setup); | |
1016 | __setup("resume=", resume_setup); |