xref: /openbmc/linux/drivers/acpi/sleep.c (revision 97da55fc)
1 /*
2  * sleep.c - ACPI sleep support.
3  *
4  * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
5  * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (c) 2000-2003 Patrick Mochel
7  * Copyright (c) 2003 Open Source Development Lab
8  *
9  * This file is released under the GPLv2.
10  *
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/irq.h>
15 #include <linux/dmi.h>
16 #include <linux/device.h>
17 #include <linux/suspend.h>
18 #include <linux/reboot.h>
19 #include <linux/acpi.h>
20 #include <linux/module.h>
21 
22 #include <asm/io.h>
23 
24 #include <acpi/acpi_bus.h>
25 #include <acpi/acpi_drivers.h>
26 
27 #include "internal.h"
28 #include "sleep.h"
29 
30 static u8 sleep_states[ACPI_S_STATE_COUNT];
31 
32 static void acpi_sleep_tts_switch(u32 acpi_state)
33 {
34 	union acpi_object in_arg = { ACPI_TYPE_INTEGER };
35 	struct acpi_object_list arg_list = { 1, &in_arg };
36 	acpi_status status = AE_OK;
37 
38 	in_arg.integer.value = acpi_state;
39 	status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
40 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
41 		/*
42 		 * OS can't evaluate the _TTS object correctly. Some warning
43 		 * message will be printed. But it won't break anything.
44 		 */
45 		printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
46 	}
47 }
48 
49 static int tts_notify_reboot(struct notifier_block *this,
50 			unsigned long code, void *x)
51 {
52 	acpi_sleep_tts_switch(ACPI_STATE_S5);
53 	return NOTIFY_DONE;
54 }
55 
56 static struct notifier_block tts_notifier = {
57 	.notifier_call	= tts_notify_reboot,
58 	.next		= NULL,
59 	.priority	= 0,
60 };
61 
62 static int acpi_sleep_prepare(u32 acpi_state)
63 {
64 #ifdef CONFIG_ACPI_SLEEP
65 	/* do we have a wakeup address for S2 and S3? */
66 	if (acpi_state == ACPI_STATE_S3) {
67 		if (!acpi_wakeup_address)
68 			return -EFAULT;
69 		acpi_set_firmware_waking_vector(acpi_wakeup_address);
70 
71 	}
72 	ACPI_FLUSH_CPU_CACHE();
73 #endif
74 	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
75 		acpi_state);
76 	acpi_enable_wakeup_devices(acpi_state);
77 	acpi_enter_sleep_state_prep(acpi_state);
78 	return 0;
79 }
80 
81 #ifdef CONFIG_ACPI_SLEEP
82 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
83 
84 u32 acpi_target_system_state(void)
85 {
86 	return acpi_target_sleep_state;
87 }
88 
89 static bool pwr_btn_event_pending;
90 
91 /*
92  * The ACPI specification wants us to save NVS memory regions during hibernation
93  * and to restore them during the subsequent resume.  Windows does that also for
94  * suspend to RAM.  However, it is known that this mechanism does not work on
95  * all machines, so we allow the user to disable it with the help of the
96  * 'acpi_sleep=nonvs' kernel command line option.
97  */
98 static bool nvs_nosave;
99 
100 void __init acpi_nvs_nosave(void)
101 {
102 	nvs_nosave = true;
103 }
104 
105 /*
106  * The ACPI specification wants us to save NVS memory regions during hibernation
107  * but says nothing about saving NVS during S3.  Not all versions of Windows
108  * save NVS on S3 suspend either, and it is clear that not all systems need
109  * NVS to be saved at S3 time.  To improve suspend/resume time, allow the
110  * user to disable saving NVS on S3 if their system does not require it, but
111  * continue to save/restore NVS for S4 as specified.
112  */
113 static bool nvs_nosave_s3;
114 
115 void __init acpi_nvs_nosave_s3(void)
116 {
117 	nvs_nosave_s3 = true;
118 }
119 
120 /*
121  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
122  * user to request that behavior by using the 'acpi_old_suspend_ordering'
123  * kernel command line option that causes the following variable to be set.
124  */
125 static bool old_suspend_ordering;
126 
127 void __init acpi_old_suspend_ordering(void)
128 {
129 	old_suspend_ordering = true;
130 }
131 
132 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
133 {
134 	acpi_old_suspend_ordering();
135 	return 0;
136 }
137 
138 static int __init init_nvs_nosave(const struct dmi_system_id *d)
139 {
140 	acpi_nvs_nosave();
141 	return 0;
142 }
143 
144 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
145 	{
146 	.callback = init_old_suspend_ordering,
147 	.ident = "Abit KN9 (nForce4 variant)",
148 	.matches = {
149 		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
150 		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
151 		},
152 	},
153 	{
154 	.callback = init_old_suspend_ordering,
155 	.ident = "HP xw4600 Workstation",
156 	.matches = {
157 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
158 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
159 		},
160 	},
161 	{
162 	.callback = init_old_suspend_ordering,
163 	.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
164 	.matches = {
165 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
166 		DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
167 		},
168 	},
169 	{
170 	.callback = init_old_suspend_ordering,
171 	.ident = "Panasonic CF51-2L",
172 	.matches = {
173 		DMI_MATCH(DMI_BOARD_VENDOR,
174 				"Matsushita Electric Industrial Co.,Ltd."),
175 		DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
176 		},
177 	},
178 	{
179 	.callback = init_nvs_nosave,
180 	.ident = "Sony Vaio VGN-FW41E_H",
181 	.matches = {
182 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
183 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW41E_H"),
184 		},
185 	},
186 	{
187 	.callback = init_nvs_nosave,
188 	.ident = "Sony Vaio VGN-FW21E",
189 	.matches = {
190 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
191 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21E"),
192 		},
193 	},
194 	{
195 	.callback = init_nvs_nosave,
196 	.ident = "Sony Vaio VPCEB17FX",
197 	.matches = {
198 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
199 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB17FX"),
200 		},
201 	},
202 	{
203 	.callback = init_nvs_nosave,
204 	.ident = "Sony Vaio VGN-SR11M",
205 	.matches = {
206 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
207 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
208 		},
209 	},
210 	{
211 	.callback = init_nvs_nosave,
212 	.ident = "Everex StepNote Series",
213 	.matches = {
214 		DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
215 		DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
216 		},
217 	},
218 	{
219 	.callback = init_nvs_nosave,
220 	.ident = "Sony Vaio VPCEB1Z1E",
221 	.matches = {
222 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
223 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
224 		},
225 	},
226 	{
227 	.callback = init_nvs_nosave,
228 	.ident = "Sony Vaio VGN-NW130D",
229 	.matches = {
230 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
231 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
232 		},
233 	},
234 	{
235 	.callback = init_nvs_nosave,
236 	.ident = "Sony Vaio VPCCW29FX",
237 	.matches = {
238 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
239 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCCW29FX"),
240 		},
241 	},
242 	{
243 	.callback = init_nvs_nosave,
244 	.ident = "Averatec AV1020-ED2",
245 	.matches = {
246 		DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
247 		DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
248 		},
249 	},
250 	{
251 	.callback = init_old_suspend_ordering,
252 	.ident = "Asus A8N-SLI DELUXE",
253 	.matches = {
254 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
255 		DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI DELUXE"),
256 		},
257 	},
258 	{
259 	.callback = init_old_suspend_ordering,
260 	.ident = "Asus A8N-SLI Premium",
261 	.matches = {
262 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
263 		DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI Premium"),
264 		},
265 	},
266 	{
267 	.callback = init_nvs_nosave,
268 	.ident = "Sony Vaio VGN-SR26GN_P",
269 	.matches = {
270 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
271 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR26GN_P"),
272 		},
273 	},
274 	{
275 	.callback = init_nvs_nosave,
276 	.ident = "Sony Vaio VPCEB1S1E",
277 	.matches = {
278 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
279 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1S1E"),
280 		},
281 	},
282 	{
283 	.callback = init_nvs_nosave,
284 	.ident = "Sony Vaio VGN-FW520F",
285 	.matches = {
286 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
287 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW520F"),
288 		},
289 	},
290 	{
291 	.callback = init_nvs_nosave,
292 	.ident = "Asus K54C",
293 	.matches = {
294 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
295 		DMI_MATCH(DMI_PRODUCT_NAME, "K54C"),
296 		},
297 	},
298 	{
299 	.callback = init_nvs_nosave,
300 	.ident = "Asus K54HR",
301 	.matches = {
302 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
303 		DMI_MATCH(DMI_PRODUCT_NAME, "K54HR"),
304 		},
305 	},
306 	{},
307 };
308 
309 static void acpi_sleep_dmi_check(void)
310 {
311 	dmi_check_system(acpisleep_dmi_table);
312 }
313 
314 /**
315  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
316  */
317 static int acpi_pm_freeze(void)
318 {
319 	acpi_disable_all_gpes();
320 	acpi_os_wait_events_complete();
321 	acpi_ec_block_transactions();
322 	return 0;
323 }
324 
325 /**
326  * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
327  */
328 static int acpi_pm_pre_suspend(void)
329 {
330 	acpi_pm_freeze();
331 	return suspend_nvs_save();
332 }
333 
334 /**
335  *	__acpi_pm_prepare - Prepare the platform to enter the target state.
336  *
337  *	If necessary, set the firmware waking vector and do arch-specific
338  *	nastiness to get the wakeup code to the waking vector.
339  */
340 static int __acpi_pm_prepare(void)
341 {
342 	int error = acpi_sleep_prepare(acpi_target_sleep_state);
343 	if (error)
344 		acpi_target_sleep_state = ACPI_STATE_S0;
345 
346 	return error;
347 }
348 
349 /**
350  *	acpi_pm_prepare - Prepare the platform to enter the target sleep
351  *		state and disable the GPEs.
352  */
353 static int acpi_pm_prepare(void)
354 {
355 	int error = __acpi_pm_prepare();
356 	if (!error)
357 		error = acpi_pm_pre_suspend();
358 
359 	return error;
360 }
361 
362 static int find_powerf_dev(struct device *dev, void *data)
363 {
364 	struct acpi_device *device = to_acpi_device(dev);
365 	const char *hid = acpi_device_hid(device);
366 
367 	return !strcmp(hid, ACPI_BUTTON_HID_POWERF);
368 }
369 
370 /**
371  *	acpi_pm_finish - Instruct the platform to leave a sleep state.
372  *
373  *	This is called after we wake back up (or if entering the sleep state
374  *	failed).
375  */
376 static void acpi_pm_finish(void)
377 {
378 	struct device *pwr_btn_dev;
379 	u32 acpi_state = acpi_target_sleep_state;
380 
381 	acpi_ec_unblock_transactions();
382 	suspend_nvs_free();
383 
384 	if (acpi_state == ACPI_STATE_S0)
385 		return;
386 
387 	printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
388 		acpi_state);
389 	acpi_disable_wakeup_devices(acpi_state);
390 	acpi_leave_sleep_state(acpi_state);
391 
392 	/* reset firmware waking vector */
393 	acpi_set_firmware_waking_vector((acpi_physical_address) 0);
394 
395 	acpi_target_sleep_state = ACPI_STATE_S0;
396 
397 	acpi_resume_power_resources();
398 
399 	/* If we were woken with the fixed power button, provide a small
400 	 * hint to userspace in the form of a wakeup event on the fixed power
401 	 * button device (if it can be found).
402 	 *
403 	 * We delay the event generation til now, as the PM layer requires
404 	 * timekeeping to be running before we generate events. */
405 	if (!pwr_btn_event_pending)
406 		return;
407 
408 	pwr_btn_event_pending = false;
409 	pwr_btn_dev = bus_find_device(&acpi_bus_type, NULL, NULL,
410 				      find_powerf_dev);
411 	if (pwr_btn_dev) {
412 		pm_wakeup_event(pwr_btn_dev, 0);
413 		put_device(pwr_btn_dev);
414 	}
415 }
416 
417 /**
418  *	acpi_pm_end - Finish up suspend sequence.
419  */
420 static void acpi_pm_end(void)
421 {
422 	/*
423 	 * This is necessary in case acpi_pm_finish() is not called during a
424 	 * failing transition to a sleep state.
425 	 */
426 	acpi_target_sleep_state = ACPI_STATE_S0;
427 	acpi_sleep_tts_switch(acpi_target_sleep_state);
428 }
429 #else /* !CONFIG_ACPI_SLEEP */
430 #define acpi_target_sleep_state	ACPI_STATE_S0
431 static inline void acpi_sleep_dmi_check(void) {}
432 #endif /* CONFIG_ACPI_SLEEP */
433 
434 #ifdef CONFIG_SUSPEND
435 static u32 acpi_suspend_states[] = {
436 	[PM_SUSPEND_ON] = ACPI_STATE_S0,
437 	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
438 	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
439 	[PM_SUSPEND_MAX] = ACPI_STATE_S5
440 };
441 
442 /**
443  *	acpi_suspend_begin - Set the target system sleep state to the state
444  *		associated with given @pm_state, if supported.
445  */
446 static int acpi_suspend_begin(suspend_state_t pm_state)
447 {
448 	u32 acpi_state = acpi_suspend_states[pm_state];
449 	int error = 0;
450 
451 	error = (nvs_nosave || nvs_nosave_s3) ? 0 : suspend_nvs_alloc();
452 	if (error)
453 		return error;
454 
455 	if (sleep_states[acpi_state]) {
456 		acpi_target_sleep_state = acpi_state;
457 		acpi_sleep_tts_switch(acpi_target_sleep_state);
458 	} else {
459 		printk(KERN_ERR "ACPI does not support this state: %d\n",
460 			pm_state);
461 		error = -ENOSYS;
462 	}
463 	return error;
464 }
465 
466 /**
467  *	acpi_suspend_enter - Actually enter a sleep state.
468  *	@pm_state: ignored
469  *
470  *	Flush caches and go to sleep. For STR we have to call arch-specific
471  *	assembly, which in turn call acpi_enter_sleep_state().
472  *	It's unfortunate, but it works. Please fix if you're feeling frisky.
473  */
474 static int acpi_suspend_enter(suspend_state_t pm_state)
475 {
476 	acpi_status status = AE_OK;
477 	u32 acpi_state = acpi_target_sleep_state;
478 	int error;
479 
480 	ACPI_FLUSH_CPU_CACHE();
481 
482 	switch (acpi_state) {
483 	case ACPI_STATE_S1:
484 		barrier();
485 		status = acpi_enter_sleep_state(acpi_state);
486 		break;
487 
488 	case ACPI_STATE_S3:
489 		error = acpi_suspend_lowlevel();
490 		if (error)
491 			return error;
492 		pr_info(PREFIX "Low-level resume complete\n");
493 		break;
494 	}
495 
496 	/* This violates the spec but is required for bug compatibility. */
497 	acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
498 
499 	/* Reprogram control registers */
500 	acpi_leave_sleep_state_prep(acpi_state);
501 
502 	/* ACPI 3.0 specs (P62) says that it's the responsibility
503 	 * of the OSPM to clear the status bit [ implying that the
504 	 * POWER_BUTTON event should not reach userspace ]
505 	 *
506 	 * However, we do generate a small hint for userspace in the form of
507 	 * a wakeup event. We flag this condition for now and generate the
508 	 * event later, as we're currently too early in resume to be able to
509 	 * generate wakeup events.
510 	 */
511 	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3)) {
512 		acpi_event_status pwr_btn_status;
513 
514 		acpi_get_event_status(ACPI_EVENT_POWER_BUTTON, &pwr_btn_status);
515 
516 		if (pwr_btn_status & ACPI_EVENT_FLAG_SET) {
517 			acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
518 			/* Flag for later */
519 			pwr_btn_event_pending = true;
520 		}
521 	}
522 
523 	/*
524 	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
525 	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
526 	 * acpi_leave_sleep_state will reenable specific GPEs later
527 	 */
528 	acpi_disable_all_gpes();
529 	/* Allow EC transactions to happen. */
530 	acpi_ec_unblock_transactions_early();
531 
532 	suspend_nvs_restore();
533 
534 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
535 }
536 
537 static int acpi_suspend_state_valid(suspend_state_t pm_state)
538 {
539 	u32 acpi_state;
540 
541 	switch (pm_state) {
542 	case PM_SUSPEND_ON:
543 	case PM_SUSPEND_STANDBY:
544 	case PM_SUSPEND_MEM:
545 		acpi_state = acpi_suspend_states[pm_state];
546 
547 		return sleep_states[acpi_state];
548 	default:
549 		return 0;
550 	}
551 }
552 
553 static const struct platform_suspend_ops acpi_suspend_ops = {
554 	.valid = acpi_suspend_state_valid,
555 	.begin = acpi_suspend_begin,
556 	.prepare_late = acpi_pm_prepare,
557 	.enter = acpi_suspend_enter,
558 	.wake = acpi_pm_finish,
559 	.end = acpi_pm_end,
560 };
561 
562 /**
563  *	acpi_suspend_begin_old - Set the target system sleep state to the
564  *		state associated with given @pm_state, if supported, and
565  *		execute the _PTS control method.  This function is used if the
566  *		pre-ACPI 2.0 suspend ordering has been requested.
567  */
568 static int acpi_suspend_begin_old(suspend_state_t pm_state)
569 {
570 	int error = acpi_suspend_begin(pm_state);
571 	if (!error)
572 		error = __acpi_pm_prepare();
573 
574 	return error;
575 }
576 
577 /*
578  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
579  * been requested.
580  */
581 static const struct platform_suspend_ops acpi_suspend_ops_old = {
582 	.valid = acpi_suspend_state_valid,
583 	.begin = acpi_suspend_begin_old,
584 	.prepare_late = acpi_pm_pre_suspend,
585 	.enter = acpi_suspend_enter,
586 	.wake = acpi_pm_finish,
587 	.end = acpi_pm_end,
588 	.recover = acpi_pm_finish,
589 };
590 
591 static void acpi_sleep_suspend_setup(void)
592 {
593 	int i;
594 
595 	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
596 		acpi_status status;
597 		u8 type_a, type_b;
598 
599 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
600 		if (ACPI_SUCCESS(status)) {
601 			sleep_states[i] = 1;
602 		}
603 	}
604 
605 	suspend_set_ops(old_suspend_ordering ?
606 		&acpi_suspend_ops_old : &acpi_suspend_ops);
607 }
608 #else /* !CONFIG_SUSPEND */
609 static inline void acpi_sleep_suspend_setup(void) {}
610 #endif /* !CONFIG_SUSPEND */
611 
612 #ifdef CONFIG_HIBERNATION
613 static unsigned long s4_hardware_signature;
614 static struct acpi_table_facs *facs;
615 static bool nosigcheck;
616 
617 void __init acpi_no_s4_hw_signature(void)
618 {
619 	nosigcheck = true;
620 }
621 
622 static int acpi_hibernation_begin(void)
623 {
624 	int error;
625 
626 	error = nvs_nosave ? 0 : suspend_nvs_alloc();
627 	if (!error) {
628 		acpi_target_sleep_state = ACPI_STATE_S4;
629 		acpi_sleep_tts_switch(acpi_target_sleep_state);
630 	}
631 
632 	return error;
633 }
634 
635 static int acpi_hibernation_enter(void)
636 {
637 	acpi_status status = AE_OK;
638 
639 	ACPI_FLUSH_CPU_CACHE();
640 
641 	/* This shouldn't return.  If it returns, we have a problem */
642 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
643 	/* Reprogram control registers */
644 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
645 
646 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
647 }
648 
649 static void acpi_hibernation_leave(void)
650 {
651 	/*
652 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
653 	 * enable it here.
654 	 */
655 	acpi_enable();
656 	/* Reprogram control registers */
657 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
658 	/* Check the hardware signature */
659 	if (facs && s4_hardware_signature != facs->hardware_signature) {
660 		printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
661 			"cannot resume!\n");
662 		panic("ACPI S4 hardware signature mismatch");
663 	}
664 	/* Restore the NVS memory area */
665 	suspend_nvs_restore();
666 	/* Allow EC transactions to happen. */
667 	acpi_ec_unblock_transactions_early();
668 }
669 
670 static void acpi_pm_thaw(void)
671 {
672 	acpi_ec_unblock_transactions();
673 	acpi_enable_all_runtime_gpes();
674 }
675 
676 static const struct platform_hibernation_ops acpi_hibernation_ops = {
677 	.begin = acpi_hibernation_begin,
678 	.end = acpi_pm_end,
679 	.pre_snapshot = acpi_pm_prepare,
680 	.finish = acpi_pm_finish,
681 	.prepare = acpi_pm_prepare,
682 	.enter = acpi_hibernation_enter,
683 	.leave = acpi_hibernation_leave,
684 	.pre_restore = acpi_pm_freeze,
685 	.restore_cleanup = acpi_pm_thaw,
686 };
687 
688 /**
689  *	acpi_hibernation_begin_old - Set the target system sleep state to
690  *		ACPI_STATE_S4 and execute the _PTS control method.  This
691  *		function is used if the pre-ACPI 2.0 suspend ordering has been
692  *		requested.
693  */
694 static int acpi_hibernation_begin_old(void)
695 {
696 	int error;
697 	/*
698 	 * The _TTS object should always be evaluated before the _PTS object.
699 	 * When the old_suspended_ordering is true, the _PTS object is
700 	 * evaluated in the acpi_sleep_prepare.
701 	 */
702 	acpi_sleep_tts_switch(ACPI_STATE_S4);
703 
704 	error = acpi_sleep_prepare(ACPI_STATE_S4);
705 
706 	if (!error) {
707 		if (!nvs_nosave)
708 			error = suspend_nvs_alloc();
709 		if (!error)
710 			acpi_target_sleep_state = ACPI_STATE_S4;
711 	}
712 	return error;
713 }
714 
715 /*
716  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
717  * been requested.
718  */
719 static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
720 	.begin = acpi_hibernation_begin_old,
721 	.end = acpi_pm_end,
722 	.pre_snapshot = acpi_pm_pre_suspend,
723 	.prepare = acpi_pm_freeze,
724 	.finish = acpi_pm_finish,
725 	.enter = acpi_hibernation_enter,
726 	.leave = acpi_hibernation_leave,
727 	.pre_restore = acpi_pm_freeze,
728 	.restore_cleanup = acpi_pm_thaw,
729 	.recover = acpi_pm_finish,
730 };
731 
732 static void acpi_sleep_hibernate_setup(void)
733 {
734 	acpi_status status;
735 	u8 type_a, type_b;
736 
737 	status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
738 	if (ACPI_FAILURE(status))
739 		return;
740 
741 	hibernation_set_ops(old_suspend_ordering ?
742 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
743 	sleep_states[ACPI_STATE_S4] = 1;
744 	if (nosigcheck)
745 		return;
746 
747 	acpi_get_table(ACPI_SIG_FACS, 1, (struct acpi_table_header **)&facs);
748 	if (facs)
749 		s4_hardware_signature = facs->hardware_signature;
750 }
751 #else /* !CONFIG_HIBERNATION */
752 static inline void acpi_sleep_hibernate_setup(void) {}
753 #endif /* !CONFIG_HIBERNATION */
754 
755 int acpi_suspend(u32 acpi_state)
756 {
757 	suspend_state_t states[] = {
758 		[1] = PM_SUSPEND_STANDBY,
759 		[3] = PM_SUSPEND_MEM,
760 		[5] = PM_SUSPEND_MAX
761 	};
762 
763 	if (acpi_state < 6 && states[acpi_state])
764 		return pm_suspend(states[acpi_state]);
765 	if (acpi_state == 4)
766 		return hibernate();
767 	return -EINVAL;
768 }
769 
770 static void acpi_power_off_prepare(void)
771 {
772 	/* Prepare to power off the system */
773 	acpi_sleep_prepare(ACPI_STATE_S5);
774 	acpi_disable_all_gpes();
775 }
776 
777 static void acpi_power_off(void)
778 {
779 	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
780 	printk(KERN_DEBUG "%s called\n", __func__);
781 	local_irq_disable();
782 	acpi_enter_sleep_state(ACPI_STATE_S5);
783 }
784 
785 int __init acpi_sleep_init(void)
786 {
787 	acpi_status status;
788 	u8 type_a, type_b;
789 	char supported[ACPI_S_STATE_COUNT * 3 + 1];
790 	char *pos = supported;
791 	int i;
792 
793 	if (acpi_disabled)
794 		return 0;
795 
796 	acpi_sleep_dmi_check();
797 
798 	sleep_states[ACPI_STATE_S0] = 1;
799 
800 	acpi_sleep_suspend_setup();
801 	acpi_sleep_hibernate_setup();
802 
803 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
804 	if (ACPI_SUCCESS(status)) {
805 		sleep_states[ACPI_STATE_S5] = 1;
806 		pm_power_off_prepare = acpi_power_off_prepare;
807 		pm_power_off = acpi_power_off;
808 	}
809 
810 	supported[0] = 0;
811 	for (i = 0; i < ACPI_S_STATE_COUNT; i++) {
812 		if (sleep_states[i])
813 			pos += sprintf(pos, " S%d", i);
814 	}
815 	pr_info(PREFIX "(supports%s)\n", supported);
816 
817 	/*
818 	 * Register the tts_notifier to reboot notifier list so that the _TTS
819 	 * object can also be evaluated when the system enters S5.
820 	 */
821 	register_reboot_notifier(&tts_notifier);
822 	return 0;
823 }
824