xref: /linux/drivers/acpi/sleep.c (revision c9895ed5a84dc3cbc86a9d6d5656d8c187f53380)
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 static 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 #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 /*
85  * The ACPI specification wants us to save NVS memory regions during hibernation
86  * and to restore them during the subsequent resume.  Windows does that also for
87  * suspend to RAM.  However, it is known that this mechanism does not work on
88  * all machines, so we allow the user to disable it with the help of the
89  * 'acpi_sleep=nonvs' kernel command line option.
90  */
91 static bool nvs_nosave;
92 
93 void __init acpi_nvs_nosave(void)
94 {
95 	nvs_nosave = true;
96 }
97 
98 /*
99  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
100  * user to request that behavior by using the 'acpi_old_suspend_ordering'
101  * kernel command line option that causes the following variable to be set.
102  */
103 static bool old_suspend_ordering;
104 
105 void __init acpi_old_suspend_ordering(void)
106 {
107 	old_suspend_ordering = true;
108 }
109 
110 /**
111  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
112  */
113 static int acpi_pm_freeze(void)
114 {
115 	acpi_disable_all_gpes();
116 	acpi_os_wait_events_complete(NULL);
117 	acpi_ec_block_transactions();
118 	return 0;
119 }
120 
121 /**
122  * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
123  */
124 static int acpi_pm_pre_suspend(void)
125 {
126 	acpi_pm_freeze();
127 	return suspend_nvs_save();
128 }
129 
130 /**
131  *	__acpi_pm_prepare - Prepare the platform to enter the target state.
132  *
133  *	If necessary, set the firmware waking vector and do arch-specific
134  *	nastiness to get the wakeup code to the waking vector.
135  */
136 static int __acpi_pm_prepare(void)
137 {
138 	int error = acpi_sleep_prepare(acpi_target_sleep_state);
139 	if (error)
140 		acpi_target_sleep_state = ACPI_STATE_S0;
141 
142 	return error;
143 }
144 
145 /**
146  *	acpi_pm_prepare - Prepare the platform to enter the target sleep
147  *		state and disable the GPEs.
148  */
149 static int acpi_pm_prepare(void)
150 {
151 	int error = __acpi_pm_prepare();
152 	if (!error)
153 		error = acpi_pm_pre_suspend();
154 
155 	return error;
156 }
157 
158 /**
159  *	acpi_pm_finish - Instruct the platform to leave a sleep state.
160  *
161  *	This is called after we wake back up (or if entering the sleep state
162  *	failed).
163  */
164 static void acpi_pm_finish(void)
165 {
166 	u32 acpi_state = acpi_target_sleep_state;
167 
168 	acpi_ec_unblock_transactions();
169 	suspend_nvs_free();
170 
171 	if (acpi_state == ACPI_STATE_S0)
172 		return;
173 
174 	printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
175 		acpi_state);
176 	acpi_disable_wakeup_devices(acpi_state);
177 	acpi_leave_sleep_state(acpi_state);
178 
179 	/* reset firmware waking vector */
180 	acpi_set_firmware_waking_vector((acpi_physical_address) 0);
181 
182 	acpi_target_sleep_state = ACPI_STATE_S0;
183 }
184 
185 /**
186  *	acpi_pm_end - Finish up suspend sequence.
187  */
188 static void acpi_pm_end(void)
189 {
190 	/*
191 	 * This is necessary in case acpi_pm_finish() is not called during a
192 	 * failing transition to a sleep state.
193 	 */
194 	acpi_target_sleep_state = ACPI_STATE_S0;
195 	acpi_sleep_tts_switch(acpi_target_sleep_state);
196 }
197 #else /* !CONFIG_ACPI_SLEEP */
198 #define acpi_target_sleep_state	ACPI_STATE_S0
199 #endif /* CONFIG_ACPI_SLEEP */
200 
201 #ifdef CONFIG_SUSPEND
202 extern void do_suspend_lowlevel(void);
203 
204 static u32 acpi_suspend_states[] = {
205 	[PM_SUSPEND_ON] = ACPI_STATE_S0,
206 	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
207 	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
208 	[PM_SUSPEND_MAX] = ACPI_STATE_S5
209 };
210 
211 /**
212  *	acpi_suspend_begin - Set the target system sleep state to the state
213  *		associated with given @pm_state, if supported.
214  */
215 static int acpi_suspend_begin(suspend_state_t pm_state)
216 {
217 	u32 acpi_state = acpi_suspend_states[pm_state];
218 	int error = 0;
219 
220 	error = nvs_nosave ? 0 : suspend_nvs_alloc();
221 	if (error)
222 		return error;
223 
224 	if (sleep_states[acpi_state]) {
225 		acpi_target_sleep_state = acpi_state;
226 		acpi_sleep_tts_switch(acpi_target_sleep_state);
227 	} else {
228 		printk(KERN_ERR "ACPI does not support this state: %d\n",
229 			pm_state);
230 		error = -ENOSYS;
231 	}
232 	return error;
233 }
234 
235 /**
236  *	acpi_suspend_enter - Actually enter a sleep state.
237  *	@pm_state: ignored
238  *
239  *	Flush caches and go to sleep. For STR we have to call arch-specific
240  *	assembly, which in turn call acpi_enter_sleep_state().
241  *	It's unfortunate, but it works. Please fix if you're feeling frisky.
242  */
243 static int acpi_suspend_enter(suspend_state_t pm_state)
244 {
245 	acpi_status status = AE_OK;
246 	unsigned long flags = 0;
247 	u32 acpi_state = acpi_target_sleep_state;
248 
249 	ACPI_FLUSH_CPU_CACHE();
250 
251 	/* Do arch specific saving of state. */
252 	if (acpi_state == ACPI_STATE_S3) {
253 		int error = acpi_save_state_mem();
254 
255 		if (error)
256 			return error;
257 	}
258 
259 	local_irq_save(flags);
260 	switch (acpi_state) {
261 	case ACPI_STATE_S1:
262 		barrier();
263 		status = acpi_enter_sleep_state(acpi_state);
264 		break;
265 
266 	case ACPI_STATE_S3:
267 		do_suspend_lowlevel();
268 		break;
269 	}
270 
271 	/* This violates the spec but is required for bug compatibility. */
272 	acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
273 
274 	/* Reprogram control registers and execute _BFS */
275 	acpi_leave_sleep_state_prep(acpi_state);
276 
277 	/* ACPI 3.0 specs (P62) says that it's the responsibility
278 	 * of the OSPM to clear the status bit [ implying that the
279 	 * POWER_BUTTON event should not reach userspace ]
280 	 */
281 	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
282 		acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
283 
284 	/*
285 	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
286 	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
287 	 * acpi_leave_sleep_state will reenable specific GPEs later
288 	 */
289 	acpi_disable_all_gpes();
290 	/* Allow EC transactions to happen. */
291 	acpi_ec_unblock_transactions_early();
292 
293 	local_irq_restore(flags);
294 	printk(KERN_DEBUG "Back to C!\n");
295 
296 	/* restore processor state */
297 	if (acpi_state == ACPI_STATE_S3)
298 		acpi_restore_state_mem();
299 
300 	suspend_nvs_restore();
301 
302 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
303 }
304 
305 static int acpi_suspend_state_valid(suspend_state_t pm_state)
306 {
307 	u32 acpi_state;
308 
309 	switch (pm_state) {
310 	case PM_SUSPEND_ON:
311 	case PM_SUSPEND_STANDBY:
312 	case PM_SUSPEND_MEM:
313 		acpi_state = acpi_suspend_states[pm_state];
314 
315 		return sleep_states[acpi_state];
316 	default:
317 		return 0;
318 	}
319 }
320 
321 static const struct platform_suspend_ops acpi_suspend_ops = {
322 	.valid = acpi_suspend_state_valid,
323 	.begin = acpi_suspend_begin,
324 	.prepare_late = acpi_pm_prepare,
325 	.enter = acpi_suspend_enter,
326 	.wake = acpi_pm_finish,
327 	.end = acpi_pm_end,
328 };
329 
330 /**
331  *	acpi_suspend_begin_old - Set the target system sleep state to the
332  *		state associated with given @pm_state, if supported, and
333  *		execute the _PTS control method.  This function is used if the
334  *		pre-ACPI 2.0 suspend ordering has been requested.
335  */
336 static int acpi_suspend_begin_old(suspend_state_t pm_state)
337 {
338 	int error = acpi_suspend_begin(pm_state);
339 	if (!error)
340 		error = __acpi_pm_prepare();
341 
342 	return error;
343 }
344 
345 /*
346  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
347  * been requested.
348  */
349 static const struct platform_suspend_ops acpi_suspend_ops_old = {
350 	.valid = acpi_suspend_state_valid,
351 	.begin = acpi_suspend_begin_old,
352 	.prepare_late = acpi_pm_pre_suspend,
353 	.enter = acpi_suspend_enter,
354 	.wake = acpi_pm_finish,
355 	.end = acpi_pm_end,
356 	.recover = acpi_pm_finish,
357 };
358 
359 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
360 {
361 	old_suspend_ordering = true;
362 	return 0;
363 }
364 
365 static int __init init_nvs_nosave(const struct dmi_system_id *d)
366 {
367 	acpi_nvs_nosave();
368 	return 0;
369 }
370 
371 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
372 	{
373 	.callback = init_old_suspend_ordering,
374 	.ident = "Abit KN9 (nForce4 variant)",
375 	.matches = {
376 		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
377 		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
378 		},
379 	},
380 	{
381 	.callback = init_old_suspend_ordering,
382 	.ident = "HP xw4600 Workstation",
383 	.matches = {
384 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
385 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
386 		},
387 	},
388 	{
389 	.callback = init_old_suspend_ordering,
390 	.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
391 	.matches = {
392 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
393 		DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
394 		},
395 	},
396 	{
397 	.callback = init_old_suspend_ordering,
398 	.ident = "Panasonic CF51-2L",
399 	.matches = {
400 		DMI_MATCH(DMI_BOARD_VENDOR,
401 				"Matsushita Electric Industrial Co.,Ltd."),
402 		DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
403 		},
404 	},
405 	{
406 	.callback = init_nvs_nosave,
407 	.ident = "Sony Vaio VGN-SR11M",
408 	.matches = {
409 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
410 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
411 		},
412 	},
413 	{
414 	.callback = init_nvs_nosave,
415 	.ident = "Everex StepNote Series",
416 	.matches = {
417 		DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
418 		DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
419 		},
420 	},
421 	{
422 	.callback = init_nvs_nosave,
423 	.ident = "Sony Vaio VPCEB1Z1E",
424 	.matches = {
425 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
426 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
427 		},
428 	},
429 	{
430 	.callback = init_nvs_nosave,
431 	.ident = "Sony Vaio VGN-NW130D",
432 	.matches = {
433 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
434 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
435 		},
436 	},
437 	{
438 	.callback = init_nvs_nosave,
439 	.ident = "Averatec AV1020-ED2",
440 	.matches = {
441 		DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
442 		DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
443 		},
444 	},
445 	{},
446 };
447 #endif /* CONFIG_SUSPEND */
448 
449 #ifdef CONFIG_HIBERNATION
450 static unsigned long s4_hardware_signature;
451 static struct acpi_table_facs *facs;
452 static bool nosigcheck;
453 
454 void __init acpi_no_s4_hw_signature(void)
455 {
456 	nosigcheck = true;
457 }
458 
459 static int acpi_hibernation_begin(void)
460 {
461 	int error;
462 
463 	error = nvs_nosave ? 0 : suspend_nvs_alloc();
464 	if (!error) {
465 		acpi_target_sleep_state = ACPI_STATE_S4;
466 		acpi_sleep_tts_switch(acpi_target_sleep_state);
467 	}
468 
469 	return error;
470 }
471 
472 static int acpi_hibernation_enter(void)
473 {
474 	acpi_status status = AE_OK;
475 	unsigned long flags = 0;
476 
477 	ACPI_FLUSH_CPU_CACHE();
478 
479 	local_irq_save(flags);
480 	/* This shouldn't return.  If it returns, we have a problem */
481 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
482 	/* Reprogram control registers and execute _BFS */
483 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
484 	local_irq_restore(flags);
485 
486 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
487 }
488 
489 static void acpi_hibernation_leave(void)
490 {
491 	/*
492 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
493 	 * enable it here.
494 	 */
495 	acpi_enable();
496 	/* Reprogram control registers and execute _BFS */
497 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
498 	/* Check the hardware signature */
499 	if (facs && s4_hardware_signature != facs->hardware_signature) {
500 		printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
501 			"cannot resume!\n");
502 		panic("ACPI S4 hardware signature mismatch");
503 	}
504 	/* Restore the NVS memory area */
505 	suspend_nvs_restore();
506 	/* Allow EC transactions to happen. */
507 	acpi_ec_unblock_transactions_early();
508 }
509 
510 static void acpi_pm_thaw(void)
511 {
512 	acpi_ec_unblock_transactions();
513 	acpi_enable_all_runtime_gpes();
514 }
515 
516 static const struct platform_hibernation_ops acpi_hibernation_ops = {
517 	.begin = acpi_hibernation_begin,
518 	.end = acpi_pm_end,
519 	.pre_snapshot = acpi_pm_prepare,
520 	.finish = acpi_pm_finish,
521 	.prepare = acpi_pm_prepare,
522 	.enter = acpi_hibernation_enter,
523 	.leave = acpi_hibernation_leave,
524 	.pre_restore = acpi_pm_freeze,
525 	.restore_cleanup = acpi_pm_thaw,
526 };
527 
528 /**
529  *	acpi_hibernation_begin_old - Set the target system sleep state to
530  *		ACPI_STATE_S4 and execute the _PTS control method.  This
531  *		function is used if the pre-ACPI 2.0 suspend ordering has been
532  *		requested.
533  */
534 static int acpi_hibernation_begin_old(void)
535 {
536 	int error;
537 	/*
538 	 * The _TTS object should always be evaluated before the _PTS object.
539 	 * When the old_suspended_ordering is true, the _PTS object is
540 	 * evaluated in the acpi_sleep_prepare.
541 	 */
542 	acpi_sleep_tts_switch(ACPI_STATE_S4);
543 
544 	error = acpi_sleep_prepare(ACPI_STATE_S4);
545 
546 	if (!error) {
547 		if (!nvs_nosave)
548 			error = suspend_nvs_alloc();
549 		if (!error)
550 			acpi_target_sleep_state = ACPI_STATE_S4;
551 	}
552 	return error;
553 }
554 
555 /*
556  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
557  * been requested.
558  */
559 static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
560 	.begin = acpi_hibernation_begin_old,
561 	.end = acpi_pm_end,
562 	.pre_snapshot = acpi_pm_pre_suspend,
563 	.prepare = acpi_pm_freeze,
564 	.finish = acpi_pm_finish,
565 	.enter = acpi_hibernation_enter,
566 	.leave = acpi_hibernation_leave,
567 	.pre_restore = acpi_pm_freeze,
568 	.restore_cleanup = acpi_pm_thaw,
569 	.recover = acpi_pm_finish,
570 };
571 #endif /* CONFIG_HIBERNATION */
572 
573 int acpi_suspend(u32 acpi_state)
574 {
575 	suspend_state_t states[] = {
576 		[1] = PM_SUSPEND_STANDBY,
577 		[3] = PM_SUSPEND_MEM,
578 		[5] = PM_SUSPEND_MAX
579 	};
580 
581 	if (acpi_state < 6 && states[acpi_state])
582 		return pm_suspend(states[acpi_state]);
583 	if (acpi_state == 4)
584 		return hibernate();
585 	return -EINVAL;
586 }
587 
588 #ifdef CONFIG_PM_OPS
589 /**
590  *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
591  *		in the system sleep state given by %acpi_target_sleep_state
592  *	@dev: device to examine; its driver model wakeup flags control
593  *		whether it should be able to wake up the system
594  *	@d_min_p: used to store the upper limit of allowed states range
595  *	Return value: preferred power state of the device on success, -ENODEV on
596  *		failure (ie. if there's no 'struct acpi_device' for @dev)
597  *
598  *	Find the lowest power (highest number) ACPI device power state that
599  *	device @dev can be in while the system is in the sleep state represented
600  *	by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
601  *	able to wake up the system from this sleep state.  If @d_min_p is set,
602  *	the highest power (lowest number) device power state of @dev allowed
603  *	in this system sleep state is stored at the location pointed to by it.
604  *
605  *	The caller must ensure that @dev is valid before using this function.
606  *	The caller is also responsible for figuring out if the device is
607  *	supposed to be able to wake up the system and passing this information
608  *	via @wake.
609  */
610 
611 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
612 {
613 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
614 	struct acpi_device *adev;
615 	char acpi_method[] = "_SxD";
616 	unsigned long long d_min, d_max;
617 
618 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
619 		printk(KERN_DEBUG "ACPI handle has no context!\n");
620 		return -ENODEV;
621 	}
622 
623 	acpi_method[2] = '0' + acpi_target_sleep_state;
624 	/*
625 	 * If the sleep state is S0, we will return D3, but if the device has
626 	 * _S0W, we will use the value from _S0W
627 	 */
628 	d_min = ACPI_STATE_D0;
629 	d_max = ACPI_STATE_D3;
630 
631 	/*
632 	 * If present, _SxD methods return the minimum D-state (highest power
633 	 * state) we can use for the corresponding S-states.  Otherwise, the
634 	 * minimum D-state is D0 (ACPI 3.x).
635 	 *
636 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
637 	 * provided -- that's our fault recovery, we ignore retval.
638 	 */
639 	if (acpi_target_sleep_state > ACPI_STATE_S0)
640 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
641 
642 	/*
643 	 * If _PRW says we can wake up the system from the target sleep state,
644 	 * the D-state returned by _SxD is sufficient for that (we assume a
645 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
646 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
647 	 * can wake the system.  _S0W may be valid, too.
648 	 */
649 	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
650 	    (device_may_wakeup(dev) &&
651 	     adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
652 		acpi_status status;
653 
654 		acpi_method[3] = 'W';
655 		status = acpi_evaluate_integer(handle, acpi_method, NULL,
656 						&d_max);
657 		if (ACPI_FAILURE(status)) {
658 			if (acpi_target_sleep_state != ACPI_STATE_S0 ||
659 			    status != AE_NOT_FOUND)
660 				d_max = d_min;
661 		} else if (d_max < d_min) {
662 			/* Warn the user of the broken DSDT */
663 			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
664 				acpi_method);
665 			/* Sanitize it */
666 			d_min = d_max;
667 		}
668 	}
669 
670 	if (d_min_p)
671 		*d_min_p = d_min;
672 	return d_max;
673 }
674 #endif /* CONFIG_PM_OPS */
675 
676 #ifdef CONFIG_PM_SLEEP
677 /**
678  *	acpi_pm_device_sleep_wake - enable or disable the system wake-up
679  *                                  capability of given device
680  *	@dev: device to handle
681  *	@enable: 'true' - enable, 'false' - disable the wake-up capability
682  */
683 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
684 {
685 	acpi_handle handle;
686 	struct acpi_device *adev;
687 	int error;
688 
689 	if (!device_can_wakeup(dev))
690 		return -EINVAL;
691 
692 	handle = DEVICE_ACPI_HANDLE(dev);
693 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
694 		dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
695 		return -ENODEV;
696 	}
697 
698 	error = enable ?
699 		acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
700 		acpi_disable_wakeup_device_power(adev);
701 	if (!error)
702 		dev_info(dev, "wake-up capability %s by ACPI\n",
703 				enable ? "enabled" : "disabled");
704 
705 	return error;
706 }
707 #endif  /* CONFIG_PM_SLEEP */
708 
709 static void acpi_power_off_prepare(void)
710 {
711 	/* Prepare to power off the system */
712 	acpi_sleep_prepare(ACPI_STATE_S5);
713 	acpi_disable_all_gpes();
714 }
715 
716 static void acpi_power_off(void)
717 {
718 	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
719 	printk(KERN_DEBUG "%s called\n", __func__);
720 	local_irq_disable();
721 	acpi_enter_sleep_state(ACPI_STATE_S5);
722 }
723 
724 /*
725  * ACPI 2.0 created the optional _GTS and _BFS,
726  * but industry adoption has been neither rapid nor broad.
727  *
728  * Linux gets into trouble when it executes poorly validated
729  * paths through the BIOS, so disable _GTS and _BFS by default,
730  * but do speak up and offer the option to enable them.
731  */
732 static void __init acpi_gts_bfs_check(void)
733 {
734 	acpi_handle dummy;
735 
736 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
737 	{
738 		printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
739 		printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
740 			"please notify linux-acpi@vger.kernel.org\n");
741 	}
742 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
743 	{
744 		printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
745 		printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
746 			"please notify linux-acpi@vger.kernel.org\n");
747 	}
748 }
749 
750 int __init acpi_sleep_init(void)
751 {
752 	acpi_status status;
753 	u8 type_a, type_b;
754 #ifdef CONFIG_SUSPEND
755 	int i = 0;
756 
757 	dmi_check_system(acpisleep_dmi_table);
758 #endif
759 
760 	if (acpi_disabled)
761 		return 0;
762 
763 	sleep_states[ACPI_STATE_S0] = 1;
764 	printk(KERN_INFO PREFIX "(supports S0");
765 
766 #ifdef CONFIG_SUSPEND
767 	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
768 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
769 		if (ACPI_SUCCESS(status)) {
770 			sleep_states[i] = 1;
771 			printk(" S%d", i);
772 		}
773 	}
774 
775 	suspend_set_ops(old_suspend_ordering ?
776 		&acpi_suspend_ops_old : &acpi_suspend_ops);
777 #endif
778 
779 #ifdef CONFIG_HIBERNATION
780 	status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
781 	if (ACPI_SUCCESS(status)) {
782 		hibernation_set_ops(old_suspend_ordering ?
783 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
784 		sleep_states[ACPI_STATE_S4] = 1;
785 		printk(" S4");
786 		if (!nosigcheck) {
787 			acpi_get_table(ACPI_SIG_FACS, 1,
788 				(struct acpi_table_header **)&facs);
789 			if (facs)
790 				s4_hardware_signature =
791 					facs->hardware_signature;
792 		}
793 	}
794 #endif
795 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
796 	if (ACPI_SUCCESS(status)) {
797 		sleep_states[ACPI_STATE_S5] = 1;
798 		printk(" S5");
799 		pm_power_off_prepare = acpi_power_off_prepare;
800 		pm_power_off = acpi_power_off;
801 	}
802 	printk(")\n");
803 	/*
804 	 * Register the tts_notifier to reboot notifier list so that the _TTS
805 	 * object can also be evaluated when the system enters S5.
806 	 */
807 	register_reboot_notifier(&tts_notifier);
808 	acpi_gts_bfs_check();
809 	return 0;
810 }
811