Merge branch 'nvs' into release
[linux-3.10.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
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 #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         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 struct dmi_system_id __initdata acpisleep_dmi_table[] = {
367         {
368         .callback = init_old_suspend_ordering,
369         .ident = "Abit KN9 (nForce4 variant)",
370         .matches = {
371                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
372                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
373                 },
374         },
375         {
376         .callback = init_old_suspend_ordering,
377         .ident = "HP xw4600 Workstation",
378         .matches = {
379                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
380                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
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_old_suspend_ordering,
393         .ident = "Panasonic CF51-2L",
394         .matches = {
395                 DMI_MATCH(DMI_BOARD_VENDOR,
396                                 "Matsushita Electric Industrial Co.,Ltd."),
397                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
398                 },
399         },
400         {},
401 };
402 #endif /* CONFIG_SUSPEND */
403
404 #ifdef CONFIG_HIBERNATION
405 static unsigned long s4_hardware_signature;
406 static struct acpi_table_facs *facs;
407 static bool nosigcheck;
408
409 void __init acpi_no_s4_hw_signature(void)
410 {
411         nosigcheck = true;
412 }
413
414 static int acpi_hibernation_begin(void)
415 {
416         int error;
417
418         error = nvs_nosave ? 0 : suspend_nvs_alloc();
419         if (!error) {
420                 acpi_target_sleep_state = ACPI_STATE_S4;
421                 acpi_sleep_tts_switch(acpi_target_sleep_state);
422         }
423
424         return error;
425 }
426
427 static int acpi_hibernation_enter(void)
428 {
429         acpi_status status = AE_OK;
430         unsigned long flags = 0;
431
432         ACPI_FLUSH_CPU_CACHE();
433
434         local_irq_save(flags);
435         /* This shouldn't return.  If it returns, we have a problem */
436         status = acpi_enter_sleep_state(ACPI_STATE_S4);
437         /* Reprogram control registers and execute _BFS */
438         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
439         local_irq_restore(flags);
440
441         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
442 }
443
444 static void acpi_hibernation_leave(void)
445 {
446         /*
447          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
448          * enable it here.
449          */
450         acpi_enable();
451         /* Reprogram control registers and execute _BFS */
452         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
453         /* Check the hardware signature */
454         if (facs && s4_hardware_signature != facs->hardware_signature) {
455                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
456                         "cannot resume!\n");
457                 panic("ACPI S4 hardware signature mismatch");
458         }
459         /* Restore the NVS memory area */
460         suspend_nvs_restore();
461         /* Allow EC transactions to happen. */
462         acpi_ec_unblock_transactions_early();
463 }
464
465 static void acpi_pm_thaw(void)
466 {
467         acpi_ec_unblock_transactions();
468         acpi_enable_all_runtime_gpes();
469 }
470
471 static struct platform_hibernation_ops acpi_hibernation_ops = {
472         .begin = acpi_hibernation_begin,
473         .end = acpi_pm_end,
474         .pre_snapshot = acpi_pm_prepare,
475         .finish = acpi_pm_finish,
476         .prepare = acpi_pm_prepare,
477         .enter = acpi_hibernation_enter,
478         .leave = acpi_hibernation_leave,
479         .pre_restore = acpi_pm_freeze,
480         .restore_cleanup = acpi_pm_thaw,
481 };
482
483 /**
484  *      acpi_hibernation_begin_old - Set the target system sleep state to
485  *              ACPI_STATE_S4 and execute the _PTS control method.  This
486  *              function is used if the pre-ACPI 2.0 suspend ordering has been
487  *              requested.
488  */
489 static int acpi_hibernation_begin_old(void)
490 {
491         int error;
492         /*
493          * The _TTS object should always be evaluated before the _PTS object.
494          * When the old_suspended_ordering is true, the _PTS object is
495          * evaluated in the acpi_sleep_prepare.
496          */
497         acpi_sleep_tts_switch(ACPI_STATE_S4);
498
499         error = acpi_sleep_prepare(ACPI_STATE_S4);
500
501         if (!error) {
502                 if (!nvs_nosave)
503                         error = suspend_nvs_alloc();
504                 if (!error)
505                         acpi_target_sleep_state = ACPI_STATE_S4;
506         }
507         return error;
508 }
509
510 /*
511  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
512  * been requested.
513  */
514 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
515         .begin = acpi_hibernation_begin_old,
516         .end = acpi_pm_end,
517         .pre_snapshot = acpi_pm_pre_suspend,
518         .prepare = acpi_pm_freeze,
519         .finish = acpi_pm_finish,
520         .enter = acpi_hibernation_enter,
521         .leave = acpi_hibernation_leave,
522         .pre_restore = acpi_pm_freeze,
523         .restore_cleanup = acpi_pm_thaw,
524         .recover = acpi_pm_finish,
525 };
526 #endif /* CONFIG_HIBERNATION */
527
528 int acpi_suspend(u32 acpi_state)
529 {
530         suspend_state_t states[] = {
531                 [1] = PM_SUSPEND_STANDBY,
532                 [3] = PM_SUSPEND_MEM,
533                 [5] = PM_SUSPEND_MAX
534         };
535
536         if (acpi_state < 6 && states[acpi_state])
537                 return pm_suspend(states[acpi_state]);
538         if (acpi_state == 4)
539                 return hibernate();
540         return -EINVAL;
541 }
542
543 #ifdef CONFIG_PM_SLEEP
544 /**
545  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
546  *              in the system sleep state given by %acpi_target_sleep_state
547  *      @dev: device to examine; its driver model wakeup flags control
548  *              whether it should be able to wake up the system
549  *      @d_min_p: used to store the upper limit of allowed states range
550  *      Return value: preferred power state of the device on success, -ENODEV on
551  *              failure (ie. if there's no 'struct acpi_device' for @dev)
552  *
553  *      Find the lowest power (highest number) ACPI device power state that
554  *      device @dev can be in while the system is in the sleep state represented
555  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
556  *      able to wake up the system from this sleep state.  If @d_min_p is set,
557  *      the highest power (lowest number) device power state of @dev allowed
558  *      in this system sleep state is stored at the location pointed to by it.
559  *
560  *      The caller must ensure that @dev is valid before using this function.
561  *      The caller is also responsible for figuring out if the device is
562  *      supposed to be able to wake up the system and passing this information
563  *      via @wake.
564  */
565
566 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
567 {
568         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
569         struct acpi_device *adev;
570         char acpi_method[] = "_SxD";
571         unsigned long long d_min, d_max;
572
573         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
574                 printk(KERN_DEBUG "ACPI handle has no context!\n");
575                 return -ENODEV;
576         }
577
578         acpi_method[2] = '0' + acpi_target_sleep_state;
579         /*
580          * If the sleep state is S0, we will return D3, but if the device has
581          * _S0W, we will use the value from _S0W
582          */
583         d_min = ACPI_STATE_D0;
584         d_max = ACPI_STATE_D3;
585
586         /*
587          * If present, _SxD methods return the minimum D-state (highest power
588          * state) we can use for the corresponding S-states.  Otherwise, the
589          * minimum D-state is D0 (ACPI 3.x).
590          *
591          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
592          * provided -- that's our fault recovery, we ignore retval.
593          */
594         if (acpi_target_sleep_state > ACPI_STATE_S0)
595                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
596
597         /*
598          * If _PRW says we can wake up the system from the target sleep state,
599          * the D-state returned by _SxD is sufficient for that (we assume a
600          * wakeup-aware driver if wake is set).  Still, if _SxW exists
601          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
602          * can wake the system.  _S0W may be valid, too.
603          */
604         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
605             (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
606              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
607                 acpi_status status;
608
609                 acpi_method[3] = 'W';
610                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
611                                                 &d_max);
612                 if (ACPI_FAILURE(status)) {
613                         d_max = d_min;
614                 } else if (d_max < d_min) {
615                         /* Warn the user of the broken DSDT */
616                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
617                                 acpi_method);
618                         /* Sanitize it */
619                         d_min = d_max;
620                 }
621         }
622
623         if (d_min_p)
624                 *d_min_p = d_min;
625         return d_max;
626 }
627
628 /**
629  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
630  *                                  capability of given device
631  *      @dev: device to handle
632  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
633  */
634 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
635 {
636         acpi_handle handle;
637         struct acpi_device *adev;
638         int error;
639
640         if (!device_can_wakeup(dev))
641                 return -EINVAL;
642
643         handle = DEVICE_ACPI_HANDLE(dev);
644         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
645                 dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
646                 return -ENODEV;
647         }
648
649         if (enable) {
650                 error = acpi_enable_wakeup_device_power(adev,
651                                                 acpi_target_sleep_state);
652                 if (!error)
653                         acpi_enable_gpe(adev->wakeup.gpe_device,
654                                         adev->wakeup.gpe_number,
655                                         ACPI_GPE_TYPE_WAKE);
656         } else {
657                 acpi_disable_gpe(adev->wakeup.gpe_device, adev->wakeup.gpe_number,
658                                 ACPI_GPE_TYPE_WAKE);
659                 error = acpi_disable_wakeup_device_power(adev);
660         }
661         if (!error)
662                 dev_info(dev, "wake-up capability %s by ACPI\n",
663                                 enable ? "enabled" : "disabled");
664
665         return error;
666 }
667 #endif
668
669 static void acpi_power_off_prepare(void)
670 {
671         /* Prepare to power off the system */
672         acpi_sleep_prepare(ACPI_STATE_S5);
673         acpi_disable_all_gpes();
674 }
675
676 static void acpi_power_off(void)
677 {
678         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
679         printk(KERN_DEBUG "%s called\n", __func__);
680         local_irq_disable();
681         acpi_enter_sleep_state(ACPI_STATE_S5);
682 }
683
684 /*
685  * ACPI 2.0 created the optional _GTS and _BFS,
686  * but industry adoption has been neither rapid nor broad.
687  *
688  * Linux gets into trouble when it executes poorly validated
689  * paths through the BIOS, so disable _GTS and _BFS by default,
690  * but do speak up and offer the option to enable them.
691  */
692 void __init acpi_gts_bfs_check(void)
693 {
694         acpi_handle dummy;
695
696         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
697         {
698                 printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
699                 printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
700                         "please notify linux-acpi@vger.kernel.org\n");
701         }
702         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
703         {
704                 printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
705                 printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
706                         "please notify linux-acpi@vger.kernel.org\n");
707         }
708 }
709
710 int __init acpi_sleep_init(void)
711 {
712         acpi_status status;
713         u8 type_a, type_b;
714 #ifdef CONFIG_SUSPEND
715         int i = 0;
716
717         dmi_check_system(acpisleep_dmi_table);
718 #endif
719
720         if (acpi_disabled)
721                 return 0;
722
723         sleep_states[ACPI_STATE_S0] = 1;
724         printk(KERN_INFO PREFIX "(supports S0");
725
726 #ifdef CONFIG_SUSPEND
727         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
728                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
729                 if (ACPI_SUCCESS(status)) {
730                         sleep_states[i] = 1;
731                         printk(" S%d", i);
732                 }
733         }
734
735         suspend_set_ops(old_suspend_ordering ?
736                 &acpi_suspend_ops_old : &acpi_suspend_ops);
737 #endif
738
739 #ifdef CONFIG_HIBERNATION
740         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
741         if (ACPI_SUCCESS(status)) {
742                 hibernation_set_ops(old_suspend_ordering ?
743                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
744                 sleep_states[ACPI_STATE_S4] = 1;
745                 printk(" S4");
746                 if (!nosigcheck) {
747                         acpi_get_table(ACPI_SIG_FACS, 1,
748                                 (struct acpi_table_header **)&facs);
749                         if (facs)
750                                 s4_hardware_signature =
751                                         facs->hardware_signature;
752                 }
753         }
754 #endif
755         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
756         if (ACPI_SUCCESS(status)) {
757                 sleep_states[ACPI_STATE_S5] = 1;
758                 printk(" S5");
759                 pm_power_off_prepare = acpi_power_off_prepare;
760                 pm_power_off = acpi_power_off;
761         }
762         printk(")\n");
763         /*
764          * Register the tts_notifier to reboot notifier list so that the _TTS
765          * object can also be evaluated when the system enters S5.
766          */
767         register_reboot_notifier(&tts_notifier);
768         acpi_gts_bfs_check();
769         return 0;
770 }