xref: /linux/drivers/acpi/sleep.c (revision 273b281fa22c293963ee3e6eec418f5dda2dbc83)
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 
20 #include <asm/io.h>
21 
22 #include <acpi/acpi_bus.h>
23 #include <acpi/acpi_drivers.h>
24 
25 #include "internal.h"
26 #include "sleep.h"
27 
28 u8 sleep_states[ACPI_S_STATE_COUNT];
29 
30 static void acpi_sleep_tts_switch(u32 acpi_state)
31 {
32 	union acpi_object in_arg = { ACPI_TYPE_INTEGER };
33 	struct acpi_object_list arg_list = { 1, &in_arg };
34 	acpi_status status = AE_OK;
35 
36 	in_arg.integer.value = acpi_state;
37 	status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
38 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
39 		/*
40 		 * OS can't evaluate the _TTS object correctly. Some warning
41 		 * message will be printed. But it won't break anything.
42 		 */
43 		printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
44 	}
45 }
46 
47 static int tts_notify_reboot(struct notifier_block *this,
48 			unsigned long code, void *x)
49 {
50 	acpi_sleep_tts_switch(ACPI_STATE_S5);
51 	return NOTIFY_DONE;
52 }
53 
54 static struct notifier_block tts_notifier = {
55 	.notifier_call	= tts_notify_reboot,
56 	.next		= NULL,
57 	.priority	= 0,
58 };
59 
60 static int acpi_sleep_prepare(u32 acpi_state)
61 {
62 #ifdef CONFIG_ACPI_SLEEP
63 	/* do we have a wakeup address for S2 and S3? */
64 	if (acpi_state == ACPI_STATE_S3) {
65 		if (!acpi_wakeup_address) {
66 			return -EFAULT;
67 		}
68 		acpi_set_firmware_waking_vector(
69 				(acpi_physical_address)acpi_wakeup_address);
70 
71 	}
72 	ACPI_FLUSH_CPU_CACHE();
73 	acpi_enable_wakeup_device_prep(acpi_state);
74 #endif
75 	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
76 		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  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
85  * user to request that behavior by using the 'acpi_old_suspend_ordering'
86  * kernel command line option that causes the following variable to be set.
87  */
88 static bool old_suspend_ordering;
89 
90 void __init acpi_old_suspend_ordering(void)
91 {
92 	old_suspend_ordering = true;
93 }
94 
95 /**
96  *	acpi_pm_disable_gpes - Disable the GPEs.
97  */
98 static int acpi_pm_disable_gpes(void)
99 {
100 	acpi_disable_all_gpes();
101 	return 0;
102 }
103 
104 /**
105  *	__acpi_pm_prepare - Prepare the platform to enter the target state.
106  *
107  *	If necessary, set the firmware waking vector and do arch-specific
108  *	nastiness to get the wakeup code to the waking vector.
109  */
110 static int __acpi_pm_prepare(void)
111 {
112 	int error = acpi_sleep_prepare(acpi_target_sleep_state);
113 
114 	if (error)
115 		acpi_target_sleep_state = ACPI_STATE_S0;
116 	return error;
117 }
118 
119 /**
120  *	acpi_pm_prepare - Prepare the platform to enter the target sleep
121  *		state and disable the GPEs.
122  */
123 static int acpi_pm_prepare(void)
124 {
125 	int error = __acpi_pm_prepare();
126 
127 	if (!error)
128 		acpi_disable_all_gpes();
129 	return error;
130 }
131 
132 /**
133  *	acpi_pm_finish - Instruct the platform to leave a sleep state.
134  *
135  *	This is called after we wake back up (or if entering the sleep state
136  *	failed).
137  */
138 static void acpi_pm_finish(void)
139 {
140 	u32 acpi_state = acpi_target_sleep_state;
141 
142 	if (acpi_state == ACPI_STATE_S0)
143 		return;
144 
145 	printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
146 		acpi_state);
147 	acpi_disable_wakeup_device(acpi_state);
148 	acpi_leave_sleep_state(acpi_state);
149 
150 	/* reset firmware waking vector */
151 	acpi_set_firmware_waking_vector((acpi_physical_address) 0);
152 
153 	acpi_target_sleep_state = ACPI_STATE_S0;
154 }
155 
156 /**
157  *	acpi_pm_end - Finish up suspend sequence.
158  */
159 static void acpi_pm_end(void)
160 {
161 	/*
162 	 * This is necessary in case acpi_pm_finish() is not called during a
163 	 * failing transition to a sleep state.
164 	 */
165 	acpi_target_sleep_state = ACPI_STATE_S0;
166 	acpi_sleep_tts_switch(acpi_target_sleep_state);
167 }
168 #else /* !CONFIG_ACPI_SLEEP */
169 #define acpi_target_sleep_state	ACPI_STATE_S0
170 #endif /* CONFIG_ACPI_SLEEP */
171 
172 #ifdef CONFIG_SUSPEND
173 /*
174  * According to the ACPI specification the BIOS should make sure that ACPI is
175  * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
176  * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
177  * on such systems during resume.  Unfortunately that doesn't help in
178  * particularly pathological cases in which SCI_EN has to be set directly on
179  * resume, although the specification states very clearly that this flag is
180  * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
181  * cases.
182  */
183 static bool set_sci_en_on_resume;
184 
185 extern void do_suspend_lowlevel(void);
186 
187 static u32 acpi_suspend_states[] = {
188 	[PM_SUSPEND_ON] = ACPI_STATE_S0,
189 	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
190 	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
191 	[PM_SUSPEND_MAX] = ACPI_STATE_S5
192 };
193 
194 /**
195  *	acpi_suspend_begin - Set the target system sleep state to the state
196  *		associated with given @pm_state, if supported.
197  */
198 static int acpi_suspend_begin(suspend_state_t pm_state)
199 {
200 	u32 acpi_state = acpi_suspend_states[pm_state];
201 	int error = 0;
202 
203 	if (sleep_states[acpi_state]) {
204 		acpi_target_sleep_state = acpi_state;
205 		acpi_sleep_tts_switch(acpi_target_sleep_state);
206 	} else {
207 		printk(KERN_ERR "ACPI does not support this state: %d\n",
208 			pm_state);
209 		error = -ENOSYS;
210 	}
211 	return error;
212 }
213 
214 /**
215  *	acpi_suspend_enter - Actually enter a sleep state.
216  *	@pm_state: ignored
217  *
218  *	Flush caches and go to sleep. For STR we have to call arch-specific
219  *	assembly, which in turn call acpi_enter_sleep_state().
220  *	It's unfortunate, but it works. Please fix if you're feeling frisky.
221  */
222 static int acpi_suspend_enter(suspend_state_t pm_state)
223 {
224 	acpi_status status = AE_OK;
225 	unsigned long flags = 0;
226 	u32 acpi_state = acpi_target_sleep_state;
227 
228 	ACPI_FLUSH_CPU_CACHE();
229 
230 	/* Do arch specific saving of state. */
231 	if (acpi_state == ACPI_STATE_S3) {
232 		int error = acpi_save_state_mem();
233 
234 		if (error)
235 			return error;
236 	}
237 
238 	local_irq_save(flags);
239 	acpi_enable_wakeup_device(acpi_state);
240 	switch (acpi_state) {
241 	case ACPI_STATE_S1:
242 		barrier();
243 		status = acpi_enter_sleep_state(acpi_state);
244 		break;
245 
246 	case ACPI_STATE_S3:
247 		do_suspend_lowlevel();
248 		break;
249 	}
250 
251 	/* If ACPI is not enabled by the BIOS, we need to enable it here. */
252 	if (set_sci_en_on_resume)
253 		acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
254 	else
255 		acpi_enable();
256 
257 	/* Reprogram control registers and execute _BFS */
258 	acpi_leave_sleep_state_prep(acpi_state);
259 
260 	/* ACPI 3.0 specs (P62) says that it's the responsibility
261 	 * of the OSPM to clear the status bit [ implying that the
262 	 * POWER_BUTTON event should not reach userspace ]
263 	 */
264 	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
265 		acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
266 
267 	/*
268 	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
269 	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
270 	 * acpi_leave_sleep_state will reenable specific GPEs later
271 	 */
272 	acpi_disable_all_gpes();
273 
274 	local_irq_restore(flags);
275 	printk(KERN_DEBUG "Back to C!\n");
276 
277 	/* restore processor state */
278 	if (acpi_state == ACPI_STATE_S3)
279 		acpi_restore_state_mem();
280 
281 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
282 }
283 
284 static int acpi_suspend_state_valid(suspend_state_t pm_state)
285 {
286 	u32 acpi_state;
287 
288 	switch (pm_state) {
289 	case PM_SUSPEND_ON:
290 	case PM_SUSPEND_STANDBY:
291 	case PM_SUSPEND_MEM:
292 		acpi_state = acpi_suspend_states[pm_state];
293 
294 		return sleep_states[acpi_state];
295 	default:
296 		return 0;
297 	}
298 }
299 
300 static struct platform_suspend_ops acpi_suspend_ops = {
301 	.valid = acpi_suspend_state_valid,
302 	.begin = acpi_suspend_begin,
303 	.prepare_late = acpi_pm_prepare,
304 	.enter = acpi_suspend_enter,
305 	.wake = acpi_pm_finish,
306 	.end = acpi_pm_end,
307 };
308 
309 /**
310  *	acpi_suspend_begin_old - Set the target system sleep state to the
311  *		state associated with given @pm_state, if supported, and
312  *		execute the _PTS control method.  This function is used if the
313  *		pre-ACPI 2.0 suspend ordering has been requested.
314  */
315 static int acpi_suspend_begin_old(suspend_state_t pm_state)
316 {
317 	int error = acpi_suspend_begin(pm_state);
318 
319 	if (!error)
320 		error = __acpi_pm_prepare();
321 	return error;
322 }
323 
324 /*
325  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
326  * been requested.
327  */
328 static struct platform_suspend_ops acpi_suspend_ops_old = {
329 	.valid = acpi_suspend_state_valid,
330 	.begin = acpi_suspend_begin_old,
331 	.prepare_late = acpi_pm_disable_gpes,
332 	.enter = acpi_suspend_enter,
333 	.wake = acpi_pm_finish,
334 	.end = acpi_pm_end,
335 	.recover = acpi_pm_finish,
336 };
337 
338 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
339 {
340 	old_suspend_ordering = true;
341 	return 0;
342 }
343 
344 static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
345 {
346 	set_sci_en_on_resume = true;
347 	return 0;
348 }
349 
350 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
351 	{
352 	.callback = init_old_suspend_ordering,
353 	.ident = "Abit KN9 (nForce4 variant)",
354 	.matches = {
355 		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
356 		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
357 		},
358 	},
359 	{
360 	.callback = init_old_suspend_ordering,
361 	.ident = "HP xw4600 Workstation",
362 	.matches = {
363 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
364 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
365 		},
366 	},
367 	{
368 	.callback = init_set_sci_en_on_resume,
369 	.ident = "Apple MacBook 1,1",
370 	.matches = {
371 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
372 		DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
373 		},
374 	},
375 	{
376 	.callback = init_set_sci_en_on_resume,
377 	.ident = "Apple MacMini 1,1",
378 	.matches = {
379 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
380 		DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
381 		},
382 	},
383 	{
384 	.callback = init_old_suspend_ordering,
385 	.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
386 	.matches = {
387 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
388 		DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
389 		},
390 	},
391 	{
392 	.callback = init_set_sci_en_on_resume,
393 	.ident = "Toshiba Satellite L300",
394 	.matches = {
395 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
396 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite L300"),
397 		},
398 	},
399 	{
400 	.callback = init_set_sci_en_on_resume,
401 	.ident = "Hewlett-Packard HP G7000 Notebook PC",
402 	.matches = {
403 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
404 		DMI_MATCH(DMI_PRODUCT_NAME, "HP G7000 Notebook PC"),
405 		},
406 	},
407 	{
408 	.callback = init_set_sci_en_on_resume,
409 	.ident = "Hewlett-Packard HP Pavilion dv3 Notebook PC",
410 	.matches = {
411 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
412 		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv3 Notebook PC"),
413 		},
414 	},
415 	{
416 	.callback = init_set_sci_en_on_resume,
417 	.ident = "Hewlett-Packard Pavilion dv4",
418 	.matches = {
419 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
420 		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv4"),
421 		},
422 	},
423 	{
424 	.callback = init_set_sci_en_on_resume,
425 	.ident = "Hewlett-Packard Pavilion dv7",
426 	.matches = {
427 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
428 		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv7"),
429 		},
430 	},
431 	{
432 	.callback = init_set_sci_en_on_resume,
433 	.ident = "Hewlett-Packard Compaq Presario C700 Notebook PC",
434 	.matches = {
435 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
436 		DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario C700 Notebook PC"),
437 		},
438 	},
439 	{
440 	.callback = init_set_sci_en_on_resume,
441 	.ident = "Hewlett-Packard Compaq Presario CQ40 Notebook PC",
442 	.matches = {
443 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
444 		DMI_MATCH(DMI_PRODUCT_NAME, "Compaq Presario CQ40 Notebook PC"),
445 		},
446 	},
447 	{
448 	.callback = init_old_suspend_ordering,
449 	.ident = "Panasonic CF51-2L",
450 	.matches = {
451 		DMI_MATCH(DMI_BOARD_VENDOR,
452 				"Matsushita Electric Industrial Co.,Ltd."),
453 		DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
454 		},
455 	},
456 	{},
457 };
458 #endif /* CONFIG_SUSPEND */
459 
460 #ifdef CONFIG_HIBERNATION
461 /*
462  * The ACPI specification wants us to save NVS memory regions during hibernation
463  * and to restore them during the subsequent resume.  However, it is not certain
464  * if this mechanism is going to work on all machines, so we allow the user to
465  * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
466  * option.
467  */
468 static bool s4_no_nvs;
469 
470 void __init acpi_s4_no_nvs(void)
471 {
472 	s4_no_nvs = true;
473 }
474 
475 static unsigned long s4_hardware_signature;
476 static struct acpi_table_facs *facs;
477 static bool nosigcheck;
478 
479 void __init acpi_no_s4_hw_signature(void)
480 {
481 	nosigcheck = true;
482 }
483 
484 static int acpi_hibernation_begin(void)
485 {
486 	int error;
487 
488 	error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
489 	if (!error) {
490 		acpi_target_sleep_state = ACPI_STATE_S4;
491 		acpi_sleep_tts_switch(acpi_target_sleep_state);
492 	}
493 
494 	return error;
495 }
496 
497 static int acpi_hibernation_pre_snapshot(void)
498 {
499 	int error = acpi_pm_prepare();
500 
501 	if (!error)
502 		hibernate_nvs_save();
503 
504 	return error;
505 }
506 
507 static int acpi_hibernation_enter(void)
508 {
509 	acpi_status status = AE_OK;
510 	unsigned long flags = 0;
511 
512 	ACPI_FLUSH_CPU_CACHE();
513 
514 	local_irq_save(flags);
515 	acpi_enable_wakeup_device(ACPI_STATE_S4);
516 	/* This shouldn't return.  If it returns, we have a problem */
517 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
518 	/* Reprogram control registers and execute _BFS */
519 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
520 	local_irq_restore(flags);
521 
522 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
523 }
524 
525 static void acpi_hibernation_finish(void)
526 {
527 	hibernate_nvs_free();
528 	acpi_pm_finish();
529 }
530 
531 static void acpi_hibernation_leave(void)
532 {
533 	/*
534 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
535 	 * enable it here.
536 	 */
537 	acpi_enable();
538 	/* Reprogram control registers and execute _BFS */
539 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
540 	/* Check the hardware signature */
541 	if (facs && s4_hardware_signature != facs->hardware_signature) {
542 		printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
543 			"cannot resume!\n");
544 		panic("ACPI S4 hardware signature mismatch");
545 	}
546 	/* Restore the NVS memory area */
547 	hibernate_nvs_restore();
548 }
549 
550 static void acpi_pm_enable_gpes(void)
551 {
552 	acpi_enable_all_runtime_gpes();
553 }
554 
555 static struct platform_hibernation_ops acpi_hibernation_ops = {
556 	.begin = acpi_hibernation_begin,
557 	.end = acpi_pm_end,
558 	.pre_snapshot = acpi_hibernation_pre_snapshot,
559 	.finish = acpi_hibernation_finish,
560 	.prepare = acpi_pm_prepare,
561 	.enter = acpi_hibernation_enter,
562 	.leave = acpi_hibernation_leave,
563 	.pre_restore = acpi_pm_disable_gpes,
564 	.restore_cleanup = acpi_pm_enable_gpes,
565 };
566 
567 /**
568  *	acpi_hibernation_begin_old - Set the target system sleep state to
569  *		ACPI_STATE_S4 and execute the _PTS control method.  This
570  *		function is used if the pre-ACPI 2.0 suspend ordering has been
571  *		requested.
572  */
573 static int acpi_hibernation_begin_old(void)
574 {
575 	int error;
576 	/*
577 	 * The _TTS object should always be evaluated before the _PTS object.
578 	 * When the old_suspended_ordering is true, the _PTS object is
579 	 * evaluated in the acpi_sleep_prepare.
580 	 */
581 	acpi_sleep_tts_switch(ACPI_STATE_S4);
582 
583 	error = acpi_sleep_prepare(ACPI_STATE_S4);
584 
585 	if (!error) {
586 		if (!s4_no_nvs)
587 			error = hibernate_nvs_alloc();
588 		if (!error)
589 			acpi_target_sleep_state = ACPI_STATE_S4;
590 	}
591 	return error;
592 }
593 
594 static int acpi_hibernation_pre_snapshot_old(void)
595 {
596 	int error = acpi_pm_disable_gpes();
597 
598 	if (!error)
599 		hibernate_nvs_save();
600 
601 	return error;
602 }
603 
604 /*
605  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
606  * been requested.
607  */
608 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
609 	.begin = acpi_hibernation_begin_old,
610 	.end = acpi_pm_end,
611 	.pre_snapshot = acpi_hibernation_pre_snapshot_old,
612 	.finish = acpi_hibernation_finish,
613 	.prepare = acpi_pm_disable_gpes,
614 	.enter = acpi_hibernation_enter,
615 	.leave = acpi_hibernation_leave,
616 	.pre_restore = acpi_pm_disable_gpes,
617 	.restore_cleanup = acpi_pm_enable_gpes,
618 	.recover = acpi_pm_finish,
619 };
620 #endif /* CONFIG_HIBERNATION */
621 
622 int acpi_suspend(u32 acpi_state)
623 {
624 	suspend_state_t states[] = {
625 		[1] = PM_SUSPEND_STANDBY,
626 		[3] = PM_SUSPEND_MEM,
627 		[5] = PM_SUSPEND_MAX
628 	};
629 
630 	if (acpi_state < 6 && states[acpi_state])
631 		return pm_suspend(states[acpi_state]);
632 	if (acpi_state == 4)
633 		return hibernate();
634 	return -EINVAL;
635 }
636 
637 #ifdef CONFIG_PM_SLEEP
638 /**
639  *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
640  *		in the system sleep state given by %acpi_target_sleep_state
641  *	@dev: device to examine; its driver model wakeup flags control
642  *		whether it should be able to wake up the system
643  *	@d_min_p: used to store the upper limit of allowed states range
644  *	Return value: preferred power state of the device on success, -ENODEV on
645  *		failure (ie. if there's no 'struct acpi_device' for @dev)
646  *
647  *	Find the lowest power (highest number) ACPI device power state that
648  *	device @dev can be in while the system is in the sleep state represented
649  *	by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
650  *	able to wake up the system from this sleep state.  If @d_min_p is set,
651  *	the highest power (lowest number) device power state of @dev allowed
652  *	in this system sleep state is stored at the location pointed to by it.
653  *
654  *	The caller must ensure that @dev is valid before using this function.
655  *	The caller is also responsible for figuring out if the device is
656  *	supposed to be able to wake up the system and passing this information
657  *	via @wake.
658  */
659 
660 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
661 {
662 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
663 	struct acpi_device *adev;
664 	char acpi_method[] = "_SxD";
665 	unsigned long long d_min, d_max;
666 
667 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
668 		printk(KERN_DEBUG "ACPI handle has no context!\n");
669 		return -ENODEV;
670 	}
671 
672 	acpi_method[2] = '0' + acpi_target_sleep_state;
673 	/*
674 	 * If the sleep state is S0, we will return D3, but if the device has
675 	 * _S0W, we will use the value from _S0W
676 	 */
677 	d_min = ACPI_STATE_D0;
678 	d_max = ACPI_STATE_D3;
679 
680 	/*
681 	 * If present, _SxD methods return the minimum D-state (highest power
682 	 * state) we can use for the corresponding S-states.  Otherwise, the
683 	 * minimum D-state is D0 (ACPI 3.x).
684 	 *
685 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
686 	 * provided -- that's our fault recovery, we ignore retval.
687 	 */
688 	if (acpi_target_sleep_state > ACPI_STATE_S0)
689 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
690 
691 	/*
692 	 * If _PRW says we can wake up the system from the target sleep state,
693 	 * the D-state returned by _SxD is sufficient for that (we assume a
694 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
695 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
696 	 * can wake the system.  _S0W may be valid, too.
697 	 */
698 	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
699 	    (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
700 	     adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
701 		acpi_status status;
702 
703 		acpi_method[3] = 'W';
704 		status = acpi_evaluate_integer(handle, acpi_method, NULL,
705 						&d_max);
706 		if (ACPI_FAILURE(status)) {
707 			d_max = d_min;
708 		} else if (d_max < d_min) {
709 			/* Warn the user of the broken DSDT */
710 			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
711 				acpi_method);
712 			/* Sanitize it */
713 			d_min = d_max;
714 		}
715 	}
716 
717 	if (d_min_p)
718 		*d_min_p = d_min;
719 	return d_max;
720 }
721 
722 /**
723  *	acpi_pm_device_sleep_wake - enable or disable the system wake-up
724  *                                  capability of given device
725  *	@dev: device to handle
726  *	@enable: 'true' - enable, 'false' - disable the wake-up capability
727  */
728 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
729 {
730 	acpi_handle handle;
731 	struct acpi_device *adev;
732 	int error;
733 
734 	if (!device_can_wakeup(dev))
735 		return -EINVAL;
736 
737 	handle = DEVICE_ACPI_HANDLE(dev);
738 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
739 		dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
740 		return -ENODEV;
741 	}
742 
743 	error = enable ?
744 		acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
745 		acpi_disable_wakeup_device_power(adev);
746 	if (!error)
747 		dev_info(dev, "wake-up capability %s by ACPI\n",
748 				enable ? "enabled" : "disabled");
749 
750 	return error;
751 }
752 #endif
753 
754 static void acpi_power_off_prepare(void)
755 {
756 	/* Prepare to power off the system */
757 	acpi_sleep_prepare(ACPI_STATE_S5);
758 	acpi_disable_all_gpes();
759 }
760 
761 static void acpi_power_off(void)
762 {
763 	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
764 	printk(KERN_DEBUG "%s called\n", __func__);
765 	local_irq_disable();
766 	acpi_enable_wakeup_device(ACPI_STATE_S5);
767 	acpi_enter_sleep_state(ACPI_STATE_S5);
768 }
769 
770 /*
771  * ACPI 2.0 created the optional _GTS and _BFS,
772  * but industry adoption has been neither rapid nor broad.
773  *
774  * Linux gets into trouble when it executes poorly validated
775  * paths through the BIOS, so disable _GTS and _BFS by default,
776  * but do speak up and offer the option to enable them.
777  */
778 void __init acpi_gts_bfs_check(void)
779 {
780 	acpi_handle dummy;
781 
782 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
783 	{
784 		printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
785 		printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
786 			"please notify linux-acpi@vger.kernel.org\n");
787 	}
788 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
789 	{
790 		printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
791 		printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
792 			"please notify linux-acpi@vger.kernel.org\n");
793 	}
794 }
795 
796 int __init acpi_sleep_init(void)
797 {
798 	acpi_status status;
799 	u8 type_a, type_b;
800 #ifdef CONFIG_SUSPEND
801 	int i = 0;
802 
803 	dmi_check_system(acpisleep_dmi_table);
804 #endif
805 
806 	if (acpi_disabled)
807 		return 0;
808 
809 	sleep_states[ACPI_STATE_S0] = 1;
810 	printk(KERN_INFO PREFIX "(supports S0");
811 
812 #ifdef CONFIG_SUSPEND
813 	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
814 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
815 		if (ACPI_SUCCESS(status)) {
816 			sleep_states[i] = 1;
817 			printk(" S%d", i);
818 		}
819 	}
820 
821 	suspend_set_ops(old_suspend_ordering ?
822 		&acpi_suspend_ops_old : &acpi_suspend_ops);
823 #endif
824 
825 #ifdef CONFIG_HIBERNATION
826 	status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
827 	if (ACPI_SUCCESS(status)) {
828 		hibernation_set_ops(old_suspend_ordering ?
829 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
830 		sleep_states[ACPI_STATE_S4] = 1;
831 		printk(" S4");
832 		if (!nosigcheck) {
833 			acpi_get_table(ACPI_SIG_FACS, 1,
834 				(struct acpi_table_header **)&facs);
835 			if (facs)
836 				s4_hardware_signature =
837 					facs->hardware_signature;
838 		}
839 	}
840 #endif
841 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
842 	if (ACPI_SUCCESS(status)) {
843 		sleep_states[ACPI_STATE_S5] = 1;
844 		printk(" S5");
845 		pm_power_off_prepare = acpi_power_off_prepare;
846 		pm_power_off = acpi_power_off;
847 	}
848 	printk(")\n");
849 	/*
850 	 * Register the tts_notifier to reboot notifier list so that the _TTS
851 	 * object can also be evaluated when the system enters S5.
852 	 */
853 	register_reboot_notifier(&tts_notifier);
854 	acpi_gts_bfs_check();
855 	return 0;
856 }
857