ACPI, APEI, GHES: Add PCIe AER recovery support
[linux-2.6.git] / drivers / acpi / sleep.c
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
21 #include <asm/io.h>
22
23 #include <acpi/acpi_bus.h>
24 #include <acpi/acpi_drivers.h>
25
26 #include "internal.h"
27 #include "sleep.h"
28
29 static u8 sleep_states[ACPI_S_STATE_COUNT];
30
31 static void acpi_sleep_tts_switch(u32 acpi_state)
32 {
33         union acpi_object in_arg = { ACPI_TYPE_INTEGER };
34         struct acpi_object_list arg_list = { 1, &in_arg };
35         acpi_status status = AE_OK;
36
37         in_arg.integer.value = acpi_state;
38         status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
39         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
40                 /*
41                  * OS can't evaluate the _TTS object correctly. Some warning
42                  * message will be printed. But it won't break anything.
43                  */
44                 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
45         }
46 }
47
48 static int tts_notify_reboot(struct notifier_block *this,
49                         unsigned long code, void *x)
50 {
51         acpi_sleep_tts_switch(ACPI_STATE_S5);
52         return NOTIFY_DONE;
53 }
54
55 static struct notifier_block tts_notifier = {
56         .notifier_call  = tts_notify_reboot,
57         .next           = NULL,
58         .priority       = 0,
59 };
60
61 static int acpi_sleep_prepare(u32 acpi_state)
62 {
63 #ifdef CONFIG_ACPI_SLEEP
64         /* do we have a wakeup address for S2 and S3? */
65         if (acpi_state == ACPI_STATE_S3) {
66                 if (!acpi_wakeup_address) {
67                         return -EFAULT;
68                 }
69                 acpi_set_firmware_waking_vector(
70                                 (acpi_physical_address)acpi_wakeup_address);
71
72         }
73         ACPI_FLUSH_CPU_CACHE();
74 #endif
75         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
76                 acpi_state);
77         acpi_enable_wakeup_devices(acpi_state);
78         acpi_enter_sleep_state_prep(acpi_state);
79         return 0;
80 }
81
82 #ifdef CONFIG_ACPI_SLEEP
83 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
84
85 /*
86  * The ACPI specification wants us to save NVS memory regions during hibernation
87  * and to restore them during the subsequent resume.  Windows does that also for
88  * suspend to RAM.  However, it is known that this mechanism does not work on
89  * all machines, so we allow the user to disable it with the help of the
90  * 'acpi_sleep=nonvs' kernel command line option.
91  */
92 static bool nvs_nosave;
93
94 void __init acpi_nvs_nosave(void)
95 {
96         nvs_nosave = true;
97 }
98
99 /*
100  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
101  * user to request that behavior by using the 'acpi_old_suspend_ordering'
102  * kernel command line option that causes the following variable to be set.
103  */
104 static bool old_suspend_ordering;
105
106 void __init acpi_old_suspend_ordering(void)
107 {
108         old_suspend_ordering = true;
109 }
110
111 /**
112  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
113  */
114 static int acpi_pm_freeze(void)
115 {
116         acpi_disable_all_gpes();
117         acpi_os_wait_events_complete(NULL);
118         acpi_ec_block_transactions();
119         return 0;
120 }
121
122 /**
123  * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
124  */
125 static int acpi_pm_pre_suspend(void)
126 {
127         acpi_pm_freeze();
128         return suspend_nvs_save();
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                 error = 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         suspend_nvs_free();
171
172         if (acpi_state == ACPI_STATE_S0)
173                 return;
174
175         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
176                 acpi_state);
177         acpi_disable_wakeup_devices(acpi_state);
178         acpi_leave_sleep_state(acpi_state);
179
180         /* reset firmware waking vector */
181         acpi_set_firmware_waking_vector((acpi_physical_address) 0);
182
183         acpi_target_sleep_state = ACPI_STATE_S0;
184 }
185
186 /**
187  *      acpi_pm_end - Finish up suspend sequence.
188  */
189 static void acpi_pm_end(void)
190 {
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 static u32 acpi_suspend_states[] = {
204         [PM_SUSPEND_ON] = ACPI_STATE_S0,
205         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
206         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
207         [PM_SUSPEND_MAX] = ACPI_STATE_S5
208 };
209
210 /**
211  *      acpi_suspend_begin - Set the target system sleep state to the state
212  *              associated with given @pm_state, if supported.
213  */
214 static int acpi_suspend_begin(suspend_state_t pm_state)
215 {
216         u32 acpi_state = acpi_suspend_states[pm_state];
217         int error = 0;
218
219         error = nvs_nosave ? 0 : suspend_nvs_alloc();
220         if (error)
221                 return error;
222
223         if (sleep_states[acpi_state]) {
224                 acpi_target_sleep_state = acpi_state;
225                 acpi_sleep_tts_switch(acpi_target_sleep_state);
226         } else {
227                 printk(KERN_ERR "ACPI does not support this state: %d\n",
228                         pm_state);
229                 error = -ENOSYS;
230         }
231         return error;
232 }
233
234 /**
235  *      acpi_suspend_enter - Actually enter a sleep state.
236  *      @pm_state: ignored
237  *
238  *      Flush caches and go to sleep. For STR we have to call arch-specific
239  *      assembly, which in turn call acpi_enter_sleep_state().
240  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
241  */
242 static int acpi_suspend_enter(suspend_state_t pm_state)
243 {
244         acpi_status status = AE_OK;
245         u32 acpi_state = acpi_target_sleep_state;
246         int error;
247
248         ACPI_FLUSH_CPU_CACHE();
249
250         switch (acpi_state) {
251         case ACPI_STATE_S1:
252                 barrier();
253                 status = acpi_enter_sleep_state(acpi_state);
254                 break;
255
256         case ACPI_STATE_S3:
257                 error = acpi_suspend_lowlevel();
258                 if (error)
259                         return error;
260                 pr_info(PREFIX "Low-level resume complete\n");
261                 break;
262         }
263
264         /* This violates the spec but is required for bug compatibility. */
265         acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
266
267         /* Reprogram control registers and execute _BFS */
268         acpi_leave_sleep_state_prep(acpi_state);
269
270         /* ACPI 3.0 specs (P62) says that it's the responsibility
271          * of the OSPM to clear the status bit [ implying that the
272          * POWER_BUTTON event should not reach userspace ]
273          */
274         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
275                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
276
277         /*
278          * Disable and clear GPE status before interrupt is enabled. Some GPEs
279          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
280          * acpi_leave_sleep_state will reenable specific GPEs later
281          */
282         acpi_disable_all_gpes();
283         /* Allow EC transactions to happen. */
284         acpi_ec_unblock_transactions_early();
285
286         suspend_nvs_restore();
287
288         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
289 }
290
291 static int acpi_suspend_state_valid(suspend_state_t pm_state)
292 {
293         u32 acpi_state;
294
295         switch (pm_state) {
296         case PM_SUSPEND_ON:
297         case PM_SUSPEND_STANDBY:
298         case PM_SUSPEND_MEM:
299                 acpi_state = acpi_suspend_states[pm_state];
300
301                 return sleep_states[acpi_state];
302         default:
303                 return 0;
304         }
305 }
306
307 static const struct platform_suspend_ops acpi_suspend_ops = {
308         .valid = acpi_suspend_state_valid,
309         .begin = acpi_suspend_begin,
310         .prepare_late = acpi_pm_prepare,
311         .enter = acpi_suspend_enter,
312         .wake = acpi_pm_finish,
313         .end = acpi_pm_end,
314 };
315
316 /**
317  *      acpi_suspend_begin_old - Set the target system sleep state to the
318  *              state associated with given @pm_state, if supported, and
319  *              execute the _PTS control method.  This function is used if the
320  *              pre-ACPI 2.0 suspend ordering has been requested.
321  */
322 static int acpi_suspend_begin_old(suspend_state_t pm_state)
323 {
324         int error = acpi_suspend_begin(pm_state);
325         if (!error)
326                 error = __acpi_pm_prepare();
327
328         return error;
329 }
330
331 /*
332  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
333  * been requested.
334  */
335 static const struct platform_suspend_ops acpi_suspend_ops_old = {
336         .valid = acpi_suspend_state_valid,
337         .begin = acpi_suspend_begin_old,
338         .prepare_late = acpi_pm_pre_suspend,
339         .enter = acpi_suspend_enter,
340         .wake = acpi_pm_finish,
341         .end = acpi_pm_end,
342         .recover = acpi_pm_finish,
343 };
344
345 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
346 {
347         old_suspend_ordering = true;
348         return 0;
349 }
350
351 static int __init init_nvs_nosave(const struct dmi_system_id *d)
352 {
353         acpi_nvs_nosave();
354         return 0;
355 }
356
357 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
358         {
359         .callback = init_old_suspend_ordering,
360         .ident = "Abit KN9 (nForce4 variant)",
361         .matches = {
362                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
363                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
364                 },
365         },
366         {
367         .callback = init_old_suspend_ordering,
368         .ident = "HP xw4600 Workstation",
369         .matches = {
370                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
371                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
372                 },
373         },
374         {
375         .callback = init_old_suspend_ordering,
376         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
377         .matches = {
378                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
379                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
380                 },
381         },
382         {
383         .callback = init_old_suspend_ordering,
384         .ident = "Panasonic CF51-2L",
385         .matches = {
386                 DMI_MATCH(DMI_BOARD_VENDOR,
387                                 "Matsushita Electric Industrial Co.,Ltd."),
388                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
389                 },
390         },
391         {
392         .callback = init_nvs_nosave,
393         .ident = "Sony Vaio VGN-FW21E",
394         .matches = {
395                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
396                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21E"),
397                 },
398         },
399         {
400         .callback = init_nvs_nosave,
401         .ident = "Sony Vaio VPCEB17FX",
402         .matches = {
403                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
404                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB17FX"),
405                 },
406         },
407         {
408         .callback = init_nvs_nosave,
409         .ident = "Sony Vaio VGN-SR11M",
410         .matches = {
411                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
412                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
413                 },
414         },
415         {
416         .callback = init_nvs_nosave,
417         .ident = "Everex StepNote Series",
418         .matches = {
419                 DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
420                 DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
421                 },
422         },
423         {
424         .callback = init_nvs_nosave,
425         .ident = "Sony Vaio VPCEB1Z1E",
426         .matches = {
427                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
428                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
429                 },
430         },
431         {
432         .callback = init_nvs_nosave,
433         .ident = "Sony Vaio VGN-NW130D",
434         .matches = {
435                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
436                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
437                 },
438         },
439         {
440         .callback = init_nvs_nosave,
441         .ident = "Averatec AV1020-ED2",
442         .matches = {
443                 DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
444                 DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
445                 },
446         },
447         {
448         .callback = init_old_suspend_ordering,
449         .ident = "Asus A8N-SLI DELUXE",
450         .matches = {
451                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
452                 DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI DELUXE"),
453                 },
454         },
455         {
456         .callback = init_old_suspend_ordering,
457         .ident = "Asus A8N-SLI Premium",
458         .matches = {
459                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
460                 DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI Premium"),
461                 },
462         },
463         {
464         .callback = init_nvs_nosave,
465         .ident = "Sony Vaio VGN-SR26GN_P",
466         .matches = {
467                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
468                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR26GN_P"),
469                 },
470         },
471         {
472         .callback = init_nvs_nosave,
473         .ident = "Sony Vaio VGN-FW520F",
474         .matches = {
475                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
476                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW520F"),
477                 },
478         },
479         {},
480 };
481 #endif /* CONFIG_SUSPEND */
482
483 #ifdef CONFIG_HIBERNATION
484 static unsigned long s4_hardware_signature;
485 static struct acpi_table_facs *facs;
486 static bool nosigcheck;
487
488 void __init acpi_no_s4_hw_signature(void)
489 {
490         nosigcheck = true;
491 }
492
493 static int acpi_hibernation_begin(void)
494 {
495         int error;
496
497         error = nvs_nosave ? 0 : suspend_nvs_alloc();
498         if (!error) {
499                 acpi_target_sleep_state = ACPI_STATE_S4;
500                 acpi_sleep_tts_switch(acpi_target_sleep_state);
501         }
502
503         return error;
504 }
505
506 static int acpi_hibernation_enter(void)
507 {
508         acpi_status status = AE_OK;
509
510         ACPI_FLUSH_CPU_CACHE();
511
512         /* This shouldn't return.  If it returns, we have a problem */
513         status = acpi_enter_sleep_state(ACPI_STATE_S4);
514         /* Reprogram control registers and execute _BFS */
515         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
516
517         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
518 }
519
520 static void acpi_hibernation_leave(void)
521 {
522         /*
523          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
524          * enable it here.
525          */
526         acpi_enable();
527         /* Reprogram control registers and execute _BFS */
528         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
529         /* Check the hardware signature */
530         if (facs && s4_hardware_signature != facs->hardware_signature) {
531                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
532                         "cannot resume!\n");
533                 panic("ACPI S4 hardware signature mismatch");
534         }
535         /* Restore the NVS memory area */
536         suspend_nvs_restore();
537         /* Allow EC transactions to happen. */
538         acpi_ec_unblock_transactions_early();
539 }
540
541 static void acpi_pm_thaw(void)
542 {
543         acpi_ec_unblock_transactions();
544         acpi_enable_all_runtime_gpes();
545 }
546
547 static const struct platform_hibernation_ops acpi_hibernation_ops = {
548         .begin = acpi_hibernation_begin,
549         .end = acpi_pm_end,
550         .pre_snapshot = acpi_pm_prepare,
551         .finish = acpi_pm_finish,
552         .prepare = acpi_pm_prepare,
553         .enter = acpi_hibernation_enter,
554         .leave = acpi_hibernation_leave,
555         .pre_restore = acpi_pm_freeze,
556         .restore_cleanup = acpi_pm_thaw,
557 };
558
559 /**
560  *      acpi_hibernation_begin_old - Set the target system sleep state to
561  *              ACPI_STATE_S4 and execute the _PTS control method.  This
562  *              function is used if the pre-ACPI 2.0 suspend ordering has been
563  *              requested.
564  */
565 static int acpi_hibernation_begin_old(void)
566 {
567         int error;
568         /*
569          * The _TTS object should always be evaluated before the _PTS object.
570          * When the old_suspended_ordering is true, the _PTS object is
571          * evaluated in the acpi_sleep_prepare.
572          */
573         acpi_sleep_tts_switch(ACPI_STATE_S4);
574
575         error = acpi_sleep_prepare(ACPI_STATE_S4);
576
577         if (!error) {
578                 if (!nvs_nosave)
579                         error = suspend_nvs_alloc();
580                 if (!error)
581                         acpi_target_sleep_state = ACPI_STATE_S4;
582         }
583         return error;
584 }
585
586 /*
587  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
588  * been requested.
589  */
590 static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
591         .begin = acpi_hibernation_begin_old,
592         .end = acpi_pm_end,
593         .pre_snapshot = acpi_pm_pre_suspend,
594         .prepare = acpi_pm_freeze,
595         .finish = acpi_pm_finish,
596         .enter = acpi_hibernation_enter,
597         .leave = acpi_hibernation_leave,
598         .pre_restore = acpi_pm_freeze,
599         .restore_cleanup = acpi_pm_thaw,
600         .recover = acpi_pm_finish,
601 };
602 #endif /* CONFIG_HIBERNATION */
603
604 int acpi_suspend(u32 acpi_state)
605 {
606         suspend_state_t states[] = {
607                 [1] = PM_SUSPEND_STANDBY,
608                 [3] = PM_SUSPEND_MEM,
609                 [5] = PM_SUSPEND_MAX
610         };
611
612         if (acpi_state < 6 && states[acpi_state])
613                 return pm_suspend(states[acpi_state]);
614         if (acpi_state == 4)
615                 return hibernate();
616         return -EINVAL;
617 }
618
619 #ifdef CONFIG_PM
620 /**
621  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
622  *              in the system sleep state given by %acpi_target_sleep_state
623  *      @dev: device to examine; its driver model wakeup flags control
624  *              whether it should be able to wake up the system
625  *      @d_min_p: used to store the upper limit of allowed states range
626  *      Return value: preferred power state of the device on success, -ENODEV on
627  *              failure (ie. if there's no 'struct acpi_device' for @dev)
628  *
629  *      Find the lowest power (highest number) ACPI device power state that
630  *      device @dev can be in while the system is in the sleep state represented
631  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
632  *      able to wake up the system from this sleep state.  If @d_min_p is set,
633  *      the highest power (lowest number) device power state of @dev allowed
634  *      in this system sleep state is stored at the location pointed to by it.
635  *
636  *      The caller must ensure that @dev is valid before using this function.
637  *      The caller is also responsible for figuring out if the device is
638  *      supposed to be able to wake up the system and passing this information
639  *      via @wake.
640  */
641
642 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
643 {
644         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
645         struct acpi_device *adev;
646         char acpi_method[] = "_SxD";
647         unsigned long long d_min, d_max;
648
649         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
650                 printk(KERN_DEBUG "ACPI handle has no context!\n");
651                 return -ENODEV;
652         }
653
654         acpi_method[2] = '0' + acpi_target_sleep_state;
655         /*
656          * If the sleep state is S0, we will return D3, but if the device has
657          * _S0W, we will use the value from _S0W
658          */
659         d_min = ACPI_STATE_D0;
660         d_max = ACPI_STATE_D3;
661
662         /*
663          * If present, _SxD methods return the minimum D-state (highest power
664          * state) we can use for the corresponding S-states.  Otherwise, the
665          * minimum D-state is D0 (ACPI 3.x).
666          *
667          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
668          * provided -- that's our fault recovery, we ignore retval.
669          */
670         if (acpi_target_sleep_state > ACPI_STATE_S0)
671                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
672
673         /*
674          * If _PRW says we can wake up the system from the target sleep state,
675          * the D-state returned by _SxD is sufficient for that (we assume a
676          * wakeup-aware driver if wake is set).  Still, if _SxW exists
677          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
678          * can wake the system.  _S0W may be valid, too.
679          */
680         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
681             (device_may_wakeup(dev) &&
682              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
683                 acpi_status status;
684
685                 acpi_method[3] = 'W';
686                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
687                                                 &d_max);
688                 if (ACPI_FAILURE(status)) {
689                         if (acpi_target_sleep_state != ACPI_STATE_S0 ||
690                             status != AE_NOT_FOUND)
691                                 d_max = d_min;
692                 } else if (d_max < d_min) {
693                         /* Warn the user of the broken DSDT */
694                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
695                                 acpi_method);
696                         /* Sanitize it */
697                         d_min = d_max;
698                 }
699         }
700
701         if (d_min_p)
702                 *d_min_p = d_min;
703         return d_max;
704 }
705 #endif /* CONFIG_PM */
706
707 #ifdef CONFIG_PM_SLEEP
708 /**
709  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
710  *                                  capability of given device
711  *      @dev: device to handle
712  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
713  */
714 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
715 {
716         acpi_handle handle;
717         struct acpi_device *adev;
718         int error;
719
720         if (!device_can_wakeup(dev))
721                 return -EINVAL;
722
723         handle = DEVICE_ACPI_HANDLE(dev);
724         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
725                 dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
726                 return -ENODEV;
727         }
728
729         error = enable ?
730                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
731                 acpi_disable_wakeup_device_power(adev);
732         if (!error)
733                 dev_info(dev, "wake-up capability %s by ACPI\n",
734                                 enable ? "enabled" : "disabled");
735
736         return error;
737 }
738 #endif  /* CONFIG_PM_SLEEP */
739
740 static void acpi_power_off_prepare(void)
741 {
742         /* Prepare to power off the system */
743         acpi_sleep_prepare(ACPI_STATE_S5);
744         acpi_disable_all_gpes();
745 }
746
747 static void acpi_power_off(void)
748 {
749         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
750         printk(KERN_DEBUG "%s called\n", __func__);
751         local_irq_disable();
752         acpi_enter_sleep_state(ACPI_STATE_S5);
753 }
754
755 /*
756  * ACPI 2.0 created the optional _GTS and _BFS,
757  * but industry adoption has been neither rapid nor broad.
758  *
759  * Linux gets into trouble when it executes poorly validated
760  * paths through the BIOS, so disable _GTS and _BFS by default,
761  * but do speak up and offer the option to enable them.
762  */
763 static void __init acpi_gts_bfs_check(void)
764 {
765         acpi_handle dummy;
766
767         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
768         {
769                 printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
770                 printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
771                         "please notify linux-acpi@vger.kernel.org\n");
772         }
773         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
774         {
775                 printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
776                 printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
777                         "please notify linux-acpi@vger.kernel.org\n");
778         }
779 }
780
781 int __init acpi_sleep_init(void)
782 {
783         acpi_status status;
784         u8 type_a, type_b;
785 #ifdef CONFIG_SUSPEND
786         int i = 0;
787
788         dmi_check_system(acpisleep_dmi_table);
789 #endif
790
791         if (acpi_disabled)
792                 return 0;
793
794         sleep_states[ACPI_STATE_S0] = 1;
795         printk(KERN_INFO PREFIX "(supports S0");
796
797 #ifdef CONFIG_SUSPEND
798         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
799                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
800                 if (ACPI_SUCCESS(status)) {
801                         sleep_states[i] = 1;
802                         printk(" S%d", i);
803                 }
804         }
805
806         suspend_set_ops(old_suspend_ordering ?
807                 &acpi_suspend_ops_old : &acpi_suspend_ops);
808 #endif
809
810 #ifdef CONFIG_HIBERNATION
811         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
812         if (ACPI_SUCCESS(status)) {
813                 hibernation_set_ops(old_suspend_ordering ?
814                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
815                 sleep_states[ACPI_STATE_S4] = 1;
816                 printk(" S4");
817                 if (!nosigcheck) {
818                         acpi_get_table(ACPI_SIG_FACS, 1,
819                                 (struct acpi_table_header **)&facs);
820                         if (facs)
821                                 s4_hardware_signature =
822                                         facs->hardware_signature;
823                 }
824         }
825 #endif
826         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
827         if (ACPI_SUCCESS(status)) {
828                 sleep_states[ACPI_STATE_S5] = 1;
829                 printk(" S5");
830                 pm_power_off_prepare = acpi_power_off_prepare;
831                 pm_power_off = acpi_power_off;
832         }
833         printk(")\n");
834         /*
835          * Register the tts_notifier to reboot notifier list so that the _TTS
836          * object can also be evaluated when the system enters S5.
837          */
838         register_reboot_notifier(&tts_notifier);
839         acpi_gts_bfs_check();
840         return 0;
841 }