pm: acpi hibernation: utilize hardware signature
[linux-2.6.git] / drivers / acpi / sleep / main.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
19 #include <asm/io.h>
20
21 #include <acpi/acpi_bus.h>
22 #include <acpi/acpi_drivers.h>
23 #include "sleep.h"
24
25 u8 sleep_states[ACPI_S_STATE_COUNT];
26
27 static int acpi_sleep_prepare(u32 acpi_state)
28 {
29 #ifdef CONFIG_ACPI_SLEEP
30         /* do we have a wakeup address for S2 and S3? */
31         if (acpi_state == ACPI_STATE_S3) {
32                 if (!acpi_wakeup_address) {
33                         return -EFAULT;
34                 }
35                 acpi_set_firmware_waking_vector(
36                                 (acpi_physical_address)acpi_wakeup_address);
37
38         }
39         ACPI_FLUSH_CPU_CACHE();
40         acpi_enable_wakeup_device_prep(acpi_state);
41 #endif
42         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
43                 acpi_state);
44         acpi_enter_sleep_state_prep(acpi_state);
45         return 0;
46 }
47
48 #ifdef CONFIG_PM_SLEEP
49 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
50
51 /*
52  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
53  * user to request that behavior by using the 'acpi_old_suspend_ordering'
54  * kernel command line option that causes the following variable to be set.
55  */
56 static bool old_suspend_ordering;
57
58 void __init acpi_old_suspend_ordering(void)
59 {
60         old_suspend_ordering = true;
61 }
62
63 /**
64  *      acpi_pm_disable_gpes - Disable the GPEs.
65  */
66 static int acpi_pm_disable_gpes(void)
67 {
68         acpi_hw_disable_all_gpes();
69         return 0;
70 }
71
72 /**
73  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
74  *
75  *      If necessary, set the firmware waking vector and do arch-specific
76  *      nastiness to get the wakeup code to the waking vector.
77  */
78 static int __acpi_pm_prepare(void)
79 {
80         int error = acpi_sleep_prepare(acpi_target_sleep_state);
81
82         if (error)
83                 acpi_target_sleep_state = ACPI_STATE_S0;
84         return error;
85 }
86
87 /**
88  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
89  *              state and disable the GPEs.
90  */
91 static int acpi_pm_prepare(void)
92 {
93         int error = __acpi_pm_prepare();
94
95         if (!error)
96                 acpi_hw_disable_all_gpes();
97         return error;
98 }
99
100 /**
101  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
102  *
103  *      This is called after we wake back up (or if entering the sleep state
104  *      failed).
105  */
106 static void acpi_pm_finish(void)
107 {
108         u32 acpi_state = acpi_target_sleep_state;
109
110         if (acpi_state == ACPI_STATE_S0)
111                 return;
112
113         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
114                 acpi_state);
115         acpi_disable_wakeup_device(acpi_state);
116         acpi_leave_sleep_state(acpi_state);
117
118         /* reset firmware waking vector */
119         acpi_set_firmware_waking_vector((acpi_physical_address) 0);
120
121         acpi_target_sleep_state = ACPI_STATE_S0;
122 }
123
124 /**
125  *      acpi_pm_end - Finish up suspend sequence.
126  */
127 static void acpi_pm_end(void)
128 {
129         /*
130          * This is necessary in case acpi_pm_finish() is not called during a
131          * failing transition to a sleep state.
132          */
133         acpi_target_sleep_state = ACPI_STATE_S0;
134 }
135 #endif /* CONFIG_PM_SLEEP */
136
137 #ifdef CONFIG_SUSPEND
138 extern void do_suspend_lowlevel(void);
139
140 static u32 acpi_suspend_states[] = {
141         [PM_SUSPEND_ON] = ACPI_STATE_S0,
142         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
143         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
144         [PM_SUSPEND_MAX] = ACPI_STATE_S5
145 };
146
147 /**
148  *      acpi_suspend_begin - Set the target system sleep state to the state
149  *              associated with given @pm_state, if supported.
150  */
151 static int acpi_suspend_begin(suspend_state_t pm_state)
152 {
153         u32 acpi_state = acpi_suspend_states[pm_state];
154         int error = 0;
155
156         if (sleep_states[acpi_state]) {
157                 acpi_target_sleep_state = acpi_state;
158         } else {
159                 printk(KERN_ERR "ACPI does not support this state: %d\n",
160                         pm_state);
161                 error = -ENOSYS;
162         }
163         return error;
164 }
165
166 /**
167  *      acpi_suspend_enter - Actually enter a sleep state.
168  *      @pm_state: ignored
169  *
170  *      Flush caches and go to sleep. For STR we have to call arch-specific
171  *      assembly, which in turn call acpi_enter_sleep_state().
172  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
173  */
174 static int acpi_suspend_enter(suspend_state_t pm_state)
175 {
176         acpi_status status = AE_OK;
177         unsigned long flags = 0;
178         u32 acpi_state = acpi_target_sleep_state;
179
180         ACPI_FLUSH_CPU_CACHE();
181
182         /* Do arch specific saving of state. */
183         if (acpi_state == ACPI_STATE_S3) {
184                 int error = acpi_save_state_mem();
185
186                 if (error)
187                         return error;
188         }
189
190         local_irq_save(flags);
191         acpi_enable_wakeup_device(acpi_state);
192         switch (acpi_state) {
193         case ACPI_STATE_S1:
194                 barrier();
195                 status = acpi_enter_sleep_state(acpi_state);
196                 break;
197
198         case ACPI_STATE_S3:
199                 do_suspend_lowlevel();
200                 break;
201         }
202
203         /* Reprogram control registers and execute _BFS */
204         acpi_leave_sleep_state_prep(acpi_state);
205
206         /* ACPI 3.0 specs (P62) says that it's the responsibility
207          * of the OSPM to clear the status bit [ implying that the
208          * POWER_BUTTON event should not reach userspace ]
209          */
210         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
211                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
212
213         /*
214          * Disable and clear GPE status before interrupt is enabled. Some GPEs
215          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
216          * acpi_leave_sleep_state will reenable specific GPEs later
217          */
218         acpi_hw_disable_all_gpes();
219
220         local_irq_restore(flags);
221         printk(KERN_DEBUG "Back to C!\n");
222
223         /* restore processor state */
224         if (acpi_state == ACPI_STATE_S3)
225                 acpi_restore_state_mem();
226
227         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
228 }
229
230 static int acpi_suspend_state_valid(suspend_state_t pm_state)
231 {
232         u32 acpi_state;
233
234         switch (pm_state) {
235         case PM_SUSPEND_ON:
236         case PM_SUSPEND_STANDBY:
237         case PM_SUSPEND_MEM:
238                 acpi_state = acpi_suspend_states[pm_state];
239
240                 return sleep_states[acpi_state];
241         default:
242                 return 0;
243         }
244 }
245
246 static struct platform_suspend_ops acpi_suspend_ops = {
247         .valid = acpi_suspend_state_valid,
248         .begin = acpi_suspend_begin,
249         .prepare = acpi_pm_prepare,
250         .enter = acpi_suspend_enter,
251         .finish = acpi_pm_finish,
252         .end = acpi_pm_end,
253 };
254
255 /**
256  *      acpi_suspend_begin_old - Set the target system sleep state to the
257  *              state associated with given @pm_state, if supported, and
258  *              execute the _PTS control method.  This function is used if the
259  *              pre-ACPI 2.0 suspend ordering has been requested.
260  */
261 static int acpi_suspend_begin_old(suspend_state_t pm_state)
262 {
263         int error = acpi_suspend_begin(pm_state);
264
265         if (!error)
266                 error = __acpi_pm_prepare();
267         return error;
268 }
269
270 /*
271  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
272  * been requested.
273  */
274 static struct platform_suspend_ops acpi_suspend_ops_old = {
275         .valid = acpi_suspend_state_valid,
276         .begin = acpi_suspend_begin_old,
277         .prepare = acpi_pm_disable_gpes,
278         .enter = acpi_suspend_enter,
279         .finish = acpi_pm_finish,
280         .end = acpi_pm_end,
281         .recover = acpi_pm_finish,
282 };
283 #endif /* CONFIG_SUSPEND */
284
285 #ifdef CONFIG_HIBERNATION
286 static unsigned long s4_hardware_signature;
287 static struct acpi_table_facs *facs;
288 static bool nosigcheck;
289
290 void __init acpi_no_s4_hw_signature(void)
291 {
292         nosigcheck = true;
293 }
294
295 static int acpi_hibernation_begin(void)
296 {
297         acpi_target_sleep_state = ACPI_STATE_S4;
298         return 0;
299 }
300
301 static int acpi_hibernation_enter(void)
302 {
303         acpi_status status = AE_OK;
304         unsigned long flags = 0;
305
306         ACPI_FLUSH_CPU_CACHE();
307
308         local_irq_save(flags);
309         acpi_enable_wakeup_device(ACPI_STATE_S4);
310         /* This shouldn't return.  If it returns, we have a problem */
311         status = acpi_enter_sleep_state(ACPI_STATE_S4);
312         /* Reprogram control registers and execute _BFS */
313         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
314         local_irq_restore(flags);
315
316         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
317 }
318
319 static void acpi_hibernation_leave(void)
320 {
321         /*
322          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
323          * enable it here.
324          */
325         acpi_enable();
326         /* Reprogram control registers and execute _BFS */
327         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
328         /* Check the hardware signature */
329         if (facs && s4_hardware_signature != facs->hardware_signature) {
330                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
331                         "cannot resume!\n");
332                 panic("ACPI S4 hardware signature mismatch");
333         }
334 }
335
336 static void acpi_pm_enable_gpes(void)
337 {
338         acpi_hw_enable_all_runtime_gpes();
339 }
340
341 static struct platform_hibernation_ops acpi_hibernation_ops = {
342         .begin = acpi_hibernation_begin,
343         .end = acpi_pm_end,
344         .pre_snapshot = acpi_pm_prepare,
345         .finish = acpi_pm_finish,
346         .prepare = acpi_pm_prepare,
347         .enter = acpi_hibernation_enter,
348         .leave = acpi_hibernation_leave,
349         .pre_restore = acpi_pm_disable_gpes,
350         .restore_cleanup = acpi_pm_enable_gpes,
351 };
352
353 /**
354  *      acpi_hibernation_begin_old - Set the target system sleep state to
355  *              ACPI_STATE_S4 and execute the _PTS control method.  This
356  *              function is used if the pre-ACPI 2.0 suspend ordering has been
357  *              requested.
358  */
359 static int acpi_hibernation_begin_old(void)
360 {
361         int error = acpi_sleep_prepare(ACPI_STATE_S4);
362
363         if (!error)
364                 acpi_target_sleep_state = ACPI_STATE_S4;
365         return error;
366 }
367
368 /*
369  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
370  * been requested.
371  */
372 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
373         .begin = acpi_hibernation_begin_old,
374         .end = acpi_pm_end,
375         .pre_snapshot = acpi_pm_disable_gpes,
376         .finish = acpi_pm_finish,
377         .prepare = acpi_pm_disable_gpes,
378         .enter = acpi_hibernation_enter,
379         .leave = acpi_hibernation_leave,
380         .pre_restore = acpi_pm_disable_gpes,
381         .restore_cleanup = acpi_pm_enable_gpes,
382         .recover = acpi_pm_finish,
383 };
384 #endif /* CONFIG_HIBERNATION */
385
386 int acpi_suspend(u32 acpi_state)
387 {
388         suspend_state_t states[] = {
389                 [1] = PM_SUSPEND_STANDBY,
390                 [3] = PM_SUSPEND_MEM,
391                 [5] = PM_SUSPEND_MAX
392         };
393
394         if (acpi_state < 6 && states[acpi_state])
395                 return pm_suspend(states[acpi_state]);
396         if (acpi_state == 4)
397                 return hibernate();
398         return -EINVAL;
399 }
400
401 #ifdef CONFIG_PM_SLEEP
402 /**
403  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
404  *              in the system sleep state given by %acpi_target_sleep_state
405  *      @dev: device to examine; its driver model wakeup flags control
406  *              whether it should be able to wake up the system
407  *      @d_min_p: used to store the upper limit of allowed states range
408  *      Return value: preferred power state of the device on success, -ENODEV on
409  *              failure (ie. if there's no 'struct acpi_device' for @dev)
410  *
411  *      Find the lowest power (highest number) ACPI device power state that
412  *      device @dev can be in while the system is in the sleep state represented
413  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
414  *      able to wake up the system from this sleep state.  If @d_min_p is set,
415  *      the highest power (lowest number) device power state of @dev allowed
416  *      in this system sleep state is stored at the location pointed to by it.
417  *
418  *      The caller must ensure that @dev is valid before using this function.
419  *      The caller is also responsible for figuring out if the device is
420  *      supposed to be able to wake up the system and passing this information
421  *      via @wake.
422  */
423
424 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
425 {
426         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
427         struct acpi_device *adev;
428         char acpi_method[] = "_SxD";
429         unsigned long d_min, d_max;
430
431         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
432                 printk(KERN_DEBUG "ACPI handle has no context!\n");
433                 return -ENODEV;
434         }
435
436         acpi_method[2] = '0' + acpi_target_sleep_state;
437         /*
438          * If the sleep state is S0, we will return D3, but if the device has
439          * _S0W, we will use the value from _S0W
440          */
441         d_min = ACPI_STATE_D0;
442         d_max = ACPI_STATE_D3;
443
444         /*
445          * If present, _SxD methods return the minimum D-state (highest power
446          * state) we can use for the corresponding S-states.  Otherwise, the
447          * minimum D-state is D0 (ACPI 3.x).
448          *
449          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
450          * provided -- that's our fault recovery, we ignore retval.
451          */
452         if (acpi_target_sleep_state > ACPI_STATE_S0)
453                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
454
455         /*
456          * If _PRW says we can wake up the system from the target sleep state,
457          * the D-state returned by _SxD is sufficient for that (we assume a
458          * wakeup-aware driver if wake is set).  Still, if _SxW exists
459          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
460          * can wake the system.  _S0W may be valid, too.
461          */
462         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
463             (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
464              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
465                 acpi_status status;
466
467                 acpi_method[3] = 'W';
468                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
469                                                 &d_max);
470                 if (ACPI_FAILURE(status)) {
471                         d_max = d_min;
472                 } else if (d_max < d_min) {
473                         /* Warn the user of the broken DSDT */
474                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
475                                 acpi_method);
476                         /* Sanitize it */
477                         d_min = d_max;
478                 }
479         }
480
481         if (d_min_p)
482                 *d_min_p = d_min;
483         return d_max;
484 }
485
486 /**
487  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
488  *                                  capability of given device
489  *      @dev: device to handle
490  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
491  */
492 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
493 {
494         acpi_handle handle;
495         struct acpi_device *adev;
496
497         if (!device_may_wakeup(dev))
498                 return -EINVAL;
499
500         handle = DEVICE_ACPI_HANDLE(dev);
501         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
502                 printk(KERN_DEBUG "ACPI handle has no context!\n");
503                 return -ENODEV;
504         }
505
506         return enable ?
507                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
508                 acpi_disable_wakeup_device_power(adev);
509 }
510 #endif
511
512 static void acpi_power_off_prepare(void)
513 {
514         /* Prepare to power off the system */
515         acpi_sleep_prepare(ACPI_STATE_S5);
516         acpi_hw_disable_all_gpes();
517 }
518
519 static void acpi_power_off(void)
520 {
521         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
522         printk("%s called\n", __func__);
523         local_irq_disable();
524         acpi_enable_wakeup_device(ACPI_STATE_S5);
525         acpi_enter_sleep_state(ACPI_STATE_S5);
526 }
527
528 int __init acpi_sleep_init(void)
529 {
530         acpi_status status;
531         u8 type_a, type_b;
532 #ifdef CONFIG_SUSPEND
533         int i = 0;
534 #endif
535
536         if (acpi_disabled)
537                 return 0;
538
539         sleep_states[ACPI_STATE_S0] = 1;
540         printk(KERN_INFO PREFIX "(supports S0");
541
542 #ifdef CONFIG_SUSPEND
543         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
544                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
545                 if (ACPI_SUCCESS(status)) {
546                         sleep_states[i] = 1;
547                         printk(" S%d", i);
548                 }
549         }
550
551         suspend_set_ops(old_suspend_ordering ?
552                 &acpi_suspend_ops_old : &acpi_suspend_ops);
553 #endif
554
555 #ifdef CONFIG_HIBERNATION
556         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
557         if (ACPI_SUCCESS(status)) {
558                 hibernation_set_ops(old_suspend_ordering ?
559                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
560                 sleep_states[ACPI_STATE_S4] = 1;
561                 printk(" S4");
562                 if (!nosigcheck) {
563                         acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
564                                 (struct acpi_table_header **)&facs);
565                         if (facs)
566                                 s4_hardware_signature =
567                                         facs->hardware_signature;
568                 }
569         }
570 #endif
571         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
572         if (ACPI_SUCCESS(status)) {
573                 sleep_states[ACPI_STATE_S5] = 1;
574                 printk(" S5");
575                 pm_power_off_prepare = acpi_power_off_prepare;
576                 pm_power_off = acpi_power_off;
577         }
578         printk(")\n");
579         return 0;
580 }