xref: /linux/drivers/acpi/sleep.c (revision cb299ba8b5ef2239429484072fea394cd7581bd7)
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 u32 acpi_target_sleep_state = ACPI_STATE_S0;
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 		}
70 		acpi_set_firmware_waking_vector(
71 				(acpi_physical_address)acpi_wakeup_address);
72 
73 	}
74 	ACPI_FLUSH_CPU_CACHE();
75 #endif
76 	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
77 		acpi_state);
78 	acpi_enable_wakeup_devices(acpi_state);
79 	acpi_enter_sleep_state_prep(acpi_state);
80 	return 0;
81 }
82 
83 #ifdef CONFIG_ACPI_SLEEP
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 	suspend_nvs_save();
128 	return 0;
129 }
130 
131 /**
132  *	__acpi_pm_prepare - Prepare the platform to enter the target state.
133  *
134  *	If necessary, set the firmware waking vector and do arch-specific
135  *	nastiness to get the wakeup code to the waking vector.
136  */
137 static int __acpi_pm_prepare(void)
138 {
139 	int error = acpi_sleep_prepare(acpi_target_sleep_state);
140 	if (error)
141 		acpi_target_sleep_state = ACPI_STATE_S0;
142 
143 	return error;
144 }
145 
146 /**
147  *	acpi_pm_prepare - Prepare the platform to enter the target sleep
148  *		state and disable the GPEs.
149  */
150 static int acpi_pm_prepare(void)
151 {
152 	int error = __acpi_pm_prepare();
153 	if (!error)
154 		acpi_pm_pre_suspend();
155 
156 	return error;
157 }
158 
159 /**
160  *	acpi_pm_finish - Instruct the platform to leave a sleep state.
161  *
162  *	This is called after we wake back up (or if entering the sleep state
163  *	failed).
164  */
165 static void acpi_pm_finish(void)
166 {
167 	u32 acpi_state = acpi_target_sleep_state;
168 
169 	acpi_ec_unblock_transactions();
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 	suspend_nvs_free();
191 	/*
192 	 * This is necessary in case acpi_pm_finish() is not called during a
193 	 * failing transition to a sleep state.
194 	 */
195 	acpi_target_sleep_state = ACPI_STATE_S0;
196 	acpi_sleep_tts_switch(acpi_target_sleep_state);
197 }
198 #else /* !CONFIG_ACPI_SLEEP */
199 #define acpi_target_sleep_state	ACPI_STATE_S0
200 #endif /* CONFIG_ACPI_SLEEP */
201 
202 #ifdef CONFIG_SUSPEND
203 extern void do_suspend_lowlevel(void);
204 
205 static u32 acpi_suspend_states[] = {
206 	[PM_SUSPEND_ON] = ACPI_STATE_S0,
207 	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
208 	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
209 	[PM_SUSPEND_MAX] = ACPI_STATE_S5
210 };
211 
212 /**
213  *	acpi_suspend_begin - Set the target system sleep state to the state
214  *		associated with given @pm_state, if supported.
215  */
216 static int acpi_suspend_begin(suspend_state_t pm_state)
217 {
218 	u32 acpi_state = acpi_suspend_states[pm_state];
219 	int error = 0;
220 
221 	error = nvs_nosave ? 0 : suspend_nvs_alloc();
222 	if (error)
223 		return error;
224 
225 	if (sleep_states[acpi_state]) {
226 		acpi_target_sleep_state = acpi_state;
227 		acpi_sleep_tts_switch(acpi_target_sleep_state);
228 	} else {
229 		printk(KERN_ERR "ACPI does not support this state: %d\n",
230 			pm_state);
231 		error = -ENOSYS;
232 	}
233 	return error;
234 }
235 
236 /**
237  *	acpi_suspend_enter - Actually enter a sleep state.
238  *	@pm_state: ignored
239  *
240  *	Flush caches and go to sleep. For STR we have to call arch-specific
241  *	assembly, which in turn call acpi_enter_sleep_state().
242  *	It's unfortunate, but it works. Please fix if you're feeling frisky.
243  */
244 static int acpi_suspend_enter(suspend_state_t pm_state)
245 {
246 	acpi_status status = AE_OK;
247 	unsigned long flags = 0;
248 	u32 acpi_state = acpi_target_sleep_state;
249 
250 	ACPI_FLUSH_CPU_CACHE();
251 
252 	/* Do arch specific saving of state. */
253 	if (acpi_state == ACPI_STATE_S3) {
254 		int error = acpi_save_state_mem();
255 
256 		if (error)
257 			return error;
258 	}
259 
260 	local_irq_save(flags);
261 	switch (acpi_state) {
262 	case ACPI_STATE_S1:
263 		barrier();
264 		status = acpi_enter_sleep_state(acpi_state);
265 		break;
266 
267 	case ACPI_STATE_S3:
268 		do_suspend_lowlevel();
269 		break;
270 	}
271 
272 	/* This violates the spec but is required for bug compatibility. */
273 	acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
274 
275 	/* Reprogram control registers and execute _BFS */
276 	acpi_leave_sleep_state_prep(acpi_state);
277 
278 	/* ACPI 3.0 specs (P62) says that it's the responsibility
279 	 * of the OSPM to clear the status bit [ implying that the
280 	 * POWER_BUTTON event should not reach userspace ]
281 	 */
282 	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
283 		acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
284 
285 	/*
286 	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
287 	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
288 	 * acpi_leave_sleep_state will reenable specific GPEs later
289 	 */
290 	acpi_disable_all_gpes();
291 	/* Allow EC transactions to happen. */
292 	acpi_ec_unblock_transactions_early();
293 
294 	local_irq_restore(flags);
295 	printk(KERN_DEBUG "Back to C!\n");
296 
297 	/* restore processor state */
298 	if (acpi_state == ACPI_STATE_S3)
299 		acpi_restore_state_mem();
300 
301 	suspend_nvs_restore();
302 
303 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
304 }
305 
306 static int acpi_suspend_state_valid(suspend_state_t pm_state)
307 {
308 	u32 acpi_state;
309 
310 	switch (pm_state) {
311 	case PM_SUSPEND_ON:
312 	case PM_SUSPEND_STANDBY:
313 	case PM_SUSPEND_MEM:
314 		acpi_state = acpi_suspend_states[pm_state];
315 
316 		return sleep_states[acpi_state];
317 	default:
318 		return 0;
319 	}
320 }
321 
322 static struct platform_suspend_ops acpi_suspend_ops = {
323 	.valid = acpi_suspend_state_valid,
324 	.begin = acpi_suspend_begin,
325 	.prepare_late = acpi_pm_prepare,
326 	.enter = acpi_suspend_enter,
327 	.wake = acpi_pm_finish,
328 	.end = acpi_pm_end,
329 };
330 
331 /**
332  *	acpi_suspend_begin_old - Set the target system sleep state to the
333  *		state associated with given @pm_state, if supported, and
334  *		execute the _PTS control method.  This function is used if the
335  *		pre-ACPI 2.0 suspend ordering has been requested.
336  */
337 static int acpi_suspend_begin_old(suspend_state_t pm_state)
338 {
339 	int error = acpi_suspend_begin(pm_state);
340 	if (!error)
341 		error = __acpi_pm_prepare();
342 
343 	return error;
344 }
345 
346 /*
347  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
348  * been requested.
349  */
350 static struct platform_suspend_ops acpi_suspend_ops_old = {
351 	.valid = acpi_suspend_state_valid,
352 	.begin = acpi_suspend_begin_old,
353 	.prepare_late = acpi_pm_pre_suspend,
354 	.enter = acpi_suspend_enter,
355 	.wake = acpi_pm_finish,
356 	.end = acpi_pm_end,
357 	.recover = acpi_pm_finish,
358 };
359 
360 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
361 {
362 	old_suspend_ordering = true;
363 	return 0;
364 }
365 
366 static int __init init_nvs_nosave(const struct dmi_system_id *d)
367 {
368 	acpi_nvs_nosave();
369 	return 0;
370 }
371 
372 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
373 	{
374 	.callback = init_old_suspend_ordering,
375 	.ident = "Abit KN9 (nForce4 variant)",
376 	.matches = {
377 		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
378 		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
379 		},
380 	},
381 	{
382 	.callback = init_old_suspend_ordering,
383 	.ident = "HP xw4600 Workstation",
384 	.matches = {
385 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
386 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
387 		},
388 	},
389 	{
390 	.callback = init_old_suspend_ordering,
391 	.ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
392 	.matches = {
393 		DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
394 		DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
395 		},
396 	},
397 	{
398 	.callback = init_old_suspend_ordering,
399 	.ident = "Panasonic CF51-2L",
400 	.matches = {
401 		DMI_MATCH(DMI_BOARD_VENDOR,
402 				"Matsushita Electric Industrial Co.,Ltd."),
403 		DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
404 		},
405 	},
406 	{
407 	.callback = init_nvs_nosave,
408 	.ident = "Sony Vaio VGN-SR11M",
409 	.matches = {
410 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
411 		DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
412 		},
413 	},
414 	{
415 	.callback = init_nvs_nosave,
416 	.ident = "Everex StepNote Series",
417 	.matches = {
418 		DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
419 		DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
420 		},
421 	},
422 	{
423 	.callback = init_nvs_nosave,
424 	.ident = "Sony Vaio VPCEB1Z1E",
425 	.matches = {
426 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
427 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
428 		},
429 	},
430 	{},
431 };
432 #endif /* CONFIG_SUSPEND */
433 
434 #ifdef CONFIG_HIBERNATION
435 static unsigned long s4_hardware_signature;
436 static struct acpi_table_facs *facs;
437 static bool nosigcheck;
438 
439 void __init acpi_no_s4_hw_signature(void)
440 {
441 	nosigcheck = true;
442 }
443 
444 static int acpi_hibernation_begin(void)
445 {
446 	int error;
447 
448 	error = nvs_nosave ? 0 : suspend_nvs_alloc();
449 	if (!error) {
450 		acpi_target_sleep_state = ACPI_STATE_S4;
451 		acpi_sleep_tts_switch(acpi_target_sleep_state);
452 	}
453 
454 	return error;
455 }
456 
457 static int acpi_hibernation_enter(void)
458 {
459 	acpi_status status = AE_OK;
460 	unsigned long flags = 0;
461 
462 	ACPI_FLUSH_CPU_CACHE();
463 
464 	local_irq_save(flags);
465 	/* This shouldn't return.  If it returns, we have a problem */
466 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
467 	/* Reprogram control registers and execute _BFS */
468 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
469 	local_irq_restore(flags);
470 
471 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
472 }
473 
474 static void acpi_hibernation_leave(void)
475 {
476 	/*
477 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
478 	 * enable it here.
479 	 */
480 	acpi_enable();
481 	/* Reprogram control registers and execute _BFS */
482 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
483 	/* Check the hardware signature */
484 	if (facs && s4_hardware_signature != facs->hardware_signature) {
485 		printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
486 			"cannot resume!\n");
487 		panic("ACPI S4 hardware signature mismatch");
488 	}
489 	/* Restore the NVS memory area */
490 	suspend_nvs_restore();
491 	/* Allow EC transactions to happen. */
492 	acpi_ec_unblock_transactions_early();
493 }
494 
495 static void acpi_pm_thaw(void)
496 {
497 	acpi_ec_unblock_transactions();
498 	acpi_enable_all_runtime_gpes();
499 }
500 
501 static struct platform_hibernation_ops acpi_hibernation_ops = {
502 	.begin = acpi_hibernation_begin,
503 	.end = acpi_pm_end,
504 	.pre_snapshot = acpi_pm_prepare,
505 	.finish = acpi_pm_finish,
506 	.prepare = acpi_pm_prepare,
507 	.enter = acpi_hibernation_enter,
508 	.leave = acpi_hibernation_leave,
509 	.pre_restore = acpi_pm_freeze,
510 	.restore_cleanup = acpi_pm_thaw,
511 };
512 
513 /**
514  *	acpi_hibernation_begin_old - Set the target system sleep state to
515  *		ACPI_STATE_S4 and execute the _PTS control method.  This
516  *		function is used if the pre-ACPI 2.0 suspend ordering has been
517  *		requested.
518  */
519 static int acpi_hibernation_begin_old(void)
520 {
521 	int error;
522 	/*
523 	 * The _TTS object should always be evaluated before the _PTS object.
524 	 * When the old_suspended_ordering is true, the _PTS object is
525 	 * evaluated in the acpi_sleep_prepare.
526 	 */
527 	acpi_sleep_tts_switch(ACPI_STATE_S4);
528 
529 	error = acpi_sleep_prepare(ACPI_STATE_S4);
530 
531 	if (!error) {
532 		if (!nvs_nosave)
533 			error = suspend_nvs_alloc();
534 		if (!error)
535 			acpi_target_sleep_state = ACPI_STATE_S4;
536 	}
537 	return error;
538 }
539 
540 /*
541  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
542  * been requested.
543  */
544 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
545 	.begin = acpi_hibernation_begin_old,
546 	.end = acpi_pm_end,
547 	.pre_snapshot = acpi_pm_pre_suspend,
548 	.prepare = acpi_pm_freeze,
549 	.finish = acpi_pm_finish,
550 	.enter = acpi_hibernation_enter,
551 	.leave = acpi_hibernation_leave,
552 	.pre_restore = acpi_pm_freeze,
553 	.restore_cleanup = acpi_pm_thaw,
554 	.recover = acpi_pm_finish,
555 };
556 #endif /* CONFIG_HIBERNATION */
557 
558 int acpi_suspend(u32 acpi_state)
559 {
560 	suspend_state_t states[] = {
561 		[1] = PM_SUSPEND_STANDBY,
562 		[3] = PM_SUSPEND_MEM,
563 		[5] = PM_SUSPEND_MAX
564 	};
565 
566 	if (acpi_state < 6 && states[acpi_state])
567 		return pm_suspend(states[acpi_state]);
568 	if (acpi_state == 4)
569 		return hibernate();
570 	return -EINVAL;
571 }
572 
573 #ifdef CONFIG_PM_OPS
574 /**
575  *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
576  *		in the system sleep state given by %acpi_target_sleep_state
577  *	@dev: device to examine; its driver model wakeup flags control
578  *		whether it should be able to wake up the system
579  *	@d_min_p: used to store the upper limit of allowed states range
580  *	Return value: preferred power state of the device on success, -ENODEV on
581  *		failure (ie. if there's no 'struct acpi_device' for @dev)
582  *
583  *	Find the lowest power (highest number) ACPI device power state that
584  *	device @dev can be in while the system is in the sleep state represented
585  *	by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
586  *	able to wake up the system from this sleep state.  If @d_min_p is set,
587  *	the highest power (lowest number) device power state of @dev allowed
588  *	in this system sleep state is stored at the location pointed to by it.
589  *
590  *	The caller must ensure that @dev is valid before using this function.
591  *	The caller is also responsible for figuring out if the device is
592  *	supposed to be able to wake up the system and passing this information
593  *	via @wake.
594  */
595 
596 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
597 {
598 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
599 	struct acpi_device *adev;
600 	char acpi_method[] = "_SxD";
601 	unsigned long long d_min, d_max;
602 
603 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
604 		printk(KERN_DEBUG "ACPI handle has no context!\n");
605 		return -ENODEV;
606 	}
607 
608 	acpi_method[2] = '0' + acpi_target_sleep_state;
609 	/*
610 	 * If the sleep state is S0, we will return D3, but if the device has
611 	 * _S0W, we will use the value from _S0W
612 	 */
613 	d_min = ACPI_STATE_D0;
614 	d_max = ACPI_STATE_D3;
615 
616 	/*
617 	 * If present, _SxD methods return the minimum D-state (highest power
618 	 * state) we can use for the corresponding S-states.  Otherwise, the
619 	 * minimum D-state is D0 (ACPI 3.x).
620 	 *
621 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
622 	 * provided -- that's our fault recovery, we ignore retval.
623 	 */
624 	if (acpi_target_sleep_state > ACPI_STATE_S0)
625 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
626 
627 	/*
628 	 * If _PRW says we can wake up the system from the target sleep state,
629 	 * the D-state returned by _SxD is sufficient for that (we assume a
630 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
631 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
632 	 * can wake the system.  _S0W may be valid, too.
633 	 */
634 	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
635 	    (device_may_wakeup(dev) &&
636 	     adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
637 		acpi_status status;
638 
639 		acpi_method[3] = 'W';
640 		status = acpi_evaluate_integer(handle, acpi_method, NULL,
641 						&d_max);
642 		if (ACPI_FAILURE(status)) {
643 			if (acpi_target_sleep_state != ACPI_STATE_S0 ||
644 			    status != AE_NOT_FOUND)
645 				d_max = d_min;
646 		} else if (d_max < d_min) {
647 			/* Warn the user of the broken DSDT */
648 			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
649 				acpi_method);
650 			/* Sanitize it */
651 			d_min = d_max;
652 		}
653 	}
654 
655 	if (d_min_p)
656 		*d_min_p = d_min;
657 	return d_max;
658 }
659 #endif /* CONFIG_PM_OPS */
660 
661 #ifdef CONFIG_PM_SLEEP
662 /**
663  *	acpi_pm_device_sleep_wake - enable or disable the system wake-up
664  *                                  capability of given device
665  *	@dev: device to handle
666  *	@enable: 'true' - enable, 'false' - disable the wake-up capability
667  */
668 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
669 {
670 	acpi_handle handle;
671 	struct acpi_device *adev;
672 	int error;
673 
674 	if (!device_can_wakeup(dev))
675 		return -EINVAL;
676 
677 	handle = DEVICE_ACPI_HANDLE(dev);
678 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
679 		dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
680 		return -ENODEV;
681 	}
682 
683 	error = enable ?
684 		acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
685 		acpi_disable_wakeup_device_power(adev);
686 	if (!error)
687 		dev_info(dev, "wake-up capability %s by ACPI\n",
688 				enable ? "enabled" : "disabled");
689 
690 	return error;
691 }
692 #endif  /* CONFIG_PM_SLEEP */
693 
694 static void acpi_power_off_prepare(void)
695 {
696 	/* Prepare to power off the system */
697 	acpi_sleep_prepare(ACPI_STATE_S5);
698 	acpi_disable_all_gpes();
699 }
700 
701 static void acpi_power_off(void)
702 {
703 	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
704 	printk(KERN_DEBUG "%s called\n", __func__);
705 	local_irq_disable();
706 	acpi_enter_sleep_state(ACPI_STATE_S5);
707 }
708 
709 /*
710  * ACPI 2.0 created the optional _GTS and _BFS,
711  * but industry adoption has been neither rapid nor broad.
712  *
713  * Linux gets into trouble when it executes poorly validated
714  * paths through the BIOS, so disable _GTS and _BFS by default,
715  * but do speak up and offer the option to enable them.
716  */
717 static void __init acpi_gts_bfs_check(void)
718 {
719 	acpi_handle dummy;
720 
721 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
722 	{
723 		printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
724 		printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
725 			"please notify linux-acpi@vger.kernel.org\n");
726 	}
727 	if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
728 	{
729 		printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
730 		printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
731 			"please notify linux-acpi@vger.kernel.org\n");
732 	}
733 }
734 
735 int __init acpi_sleep_init(void)
736 {
737 	acpi_status status;
738 	u8 type_a, type_b;
739 #ifdef CONFIG_SUSPEND
740 	int i = 0;
741 
742 	dmi_check_system(acpisleep_dmi_table);
743 #endif
744 
745 	if (acpi_disabled)
746 		return 0;
747 
748 	sleep_states[ACPI_STATE_S0] = 1;
749 	printk(KERN_INFO PREFIX "(supports S0");
750 
751 #ifdef CONFIG_SUSPEND
752 	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
753 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
754 		if (ACPI_SUCCESS(status)) {
755 			sleep_states[i] = 1;
756 			printk(" S%d", i);
757 		}
758 	}
759 
760 	suspend_set_ops(old_suspend_ordering ?
761 		&acpi_suspend_ops_old : &acpi_suspend_ops);
762 #endif
763 
764 #ifdef CONFIG_HIBERNATION
765 	status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
766 	if (ACPI_SUCCESS(status)) {
767 		hibernation_set_ops(old_suspend_ordering ?
768 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
769 		sleep_states[ACPI_STATE_S4] = 1;
770 		printk(" S4");
771 		if (!nosigcheck) {
772 			acpi_get_table(ACPI_SIG_FACS, 1,
773 				(struct acpi_table_header **)&facs);
774 			if (facs)
775 				s4_hardware_signature =
776 					facs->hardware_signature;
777 		}
778 	}
779 #endif
780 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
781 	if (ACPI_SUCCESS(status)) {
782 		sleep_states[ACPI_STATE_S5] = 1;
783 		printk(" S5");
784 		pm_power_off_prepare = acpi_power_off_prepare;
785 		pm_power_off = acpi_power_off;
786 	}
787 	printk(")\n");
788 	/*
789 	 * Register the tts_notifier to reboot notifier list so that the _TTS
790 	 * object can also be evaluated when the system enters S5.
791 	 */
792 	register_reboot_notifier(&tts_notifier);
793 	acpi_gts_bfs_check();
794 	return 0;
795 }
796