Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-x86
[linux-2.6] / drivers / acpi / bus.c
1 /*
2  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
3  *
4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or (at
11  *  your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/kernel.h>
29 #include <linux/list.h>
30 #include <linux/sched.h>
31 #include <linux/pm.h>
32 #include <linux/pm_legacy.h>
33 #include <linux/device.h>
34 #include <linux/proc_fs.h>
35 #ifdef CONFIG_X86
36 #include <asm/mpspec.h>
37 #endif
38 #include <acpi/acpi_bus.h>
39 #include <acpi/acpi_drivers.h>
40
41 #define _COMPONENT              ACPI_BUS_COMPONENT
42 ACPI_MODULE_NAME("bus");
43 #ifdef  CONFIG_X86
44 extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
45 #endif
46
47 struct acpi_device *acpi_root;
48 struct proc_dir_entry *acpi_root_dir;
49 EXPORT_SYMBOL(acpi_root_dir);
50
51 #define STRUCT_TO_INT(s)        (*((int*)&s))
52
53 /* --------------------------------------------------------------------------
54                                 Device Management
55    -------------------------------------------------------------------------- */
56
57 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
58 {
59         acpi_status status = AE_OK;
60
61
62         if (!device)
63                 return -EINVAL;
64
65         /* TBD: Support fixed-feature devices */
66
67         status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
68         if (ACPI_FAILURE(status) || !*device) {
69                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
70                                   handle));
71                 return -ENODEV;
72         }
73
74         return 0;
75 }
76
77 EXPORT_SYMBOL(acpi_bus_get_device);
78
79 int acpi_bus_get_status(struct acpi_device *device)
80 {
81         acpi_status status = AE_OK;
82         unsigned long sta = 0;
83
84
85         if (!device)
86                 return -EINVAL;
87
88         /*
89          * Evaluate _STA if present.
90          */
91         if (device->flags.dynamic_status) {
92                 status =
93                     acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
94                 if (ACPI_FAILURE(status))
95                         return -ENODEV;
96                 STRUCT_TO_INT(device->status) = (int)sta;
97         }
98
99         /*
100          * Otherwise we assume the status of our parent (unless we don't
101          * have one, in which case status is implied).
102          */
103         else if (device->parent)
104                 device->status = device->parent->status;
105         else
106                 STRUCT_TO_INT(device->status) =
107                     ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
108                     ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
109
110         if (device->status.functional && !device->status.present) {
111                 printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
112                        "functional but not present; setting present\n",
113                        device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
114                 device->status.present = 1;
115         }
116
117         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
118                           device->pnp.bus_id,
119                           (u32) STRUCT_TO_INT(device->status)));
120
121         return 0;
122 }
123
124 EXPORT_SYMBOL(acpi_bus_get_status);
125
126 /* --------------------------------------------------------------------------
127                                  Power Management
128    -------------------------------------------------------------------------- */
129
130 int acpi_bus_get_power(acpi_handle handle, int *state)
131 {
132         int result = 0;
133         acpi_status status = 0;
134         struct acpi_device *device = NULL;
135         unsigned long psc = 0;
136
137
138         result = acpi_bus_get_device(handle, &device);
139         if (result)
140                 return result;
141
142         *state = ACPI_STATE_UNKNOWN;
143
144         if (!device->flags.power_manageable) {
145                 /* TBD: Non-recursive algorithm for walking up hierarchy */
146                 if (device->parent)
147                         *state = device->parent->power.state;
148                 else
149                         *state = ACPI_STATE_D0;
150         } else {
151                 /*
152                  * Get the device's power state either directly (via _PSC) or
153                  * indirectly (via power resources).
154                  */
155                 if (device->power.flags.explicit_get) {
156                         status = acpi_evaluate_integer(device->handle, "_PSC",
157                                                        NULL, &psc);
158                         if (ACPI_FAILURE(status))
159                                 return -ENODEV;
160                         device->power.state = (int)psc;
161                 } else if (device->power.flags.power_resources) {
162                         result = acpi_power_get_inferred_state(device);
163                         if (result)
164                                 return result;
165                 }
166
167                 *state = device->power.state;
168         }
169
170         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
171                           device->pnp.bus_id, device->power.state));
172
173         return 0;
174 }
175
176 EXPORT_SYMBOL(acpi_bus_get_power);
177
178 int acpi_bus_set_power(acpi_handle handle, int state)
179 {
180         int result = 0;
181         acpi_status status = AE_OK;
182         struct acpi_device *device = NULL;
183         char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
184
185
186         result = acpi_bus_get_device(handle, &device);
187         if (result)
188                 return result;
189
190         if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
191                 return -EINVAL;
192
193         /* Make sure this is a valid target state */
194
195         if (!device->flags.power_manageable) {
196                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
197                                 kobject_name(&device->dev.kobj)));
198                 return -ENODEV;
199         }
200         /*
201          * Get device's current power state if it's unknown
202          * This means device power state isn't initialized or previous setting failed
203          */
204         if ((device->power.state == ACPI_STATE_UNKNOWN) || device->flags.force_power_state)
205                 acpi_bus_get_power(device->handle, &device->power.state);
206         if ((state == device->power.state) && !device->flags.force_power_state) {
207                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
208                                   state));
209                 return 0;
210         }
211
212         if (!device->power.states[state].flags.valid) {
213                 printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
214                 return -ENODEV;
215         }
216         if (device->parent && (state < device->parent->power.state)) {
217                 printk(KERN_WARNING PREFIX
218                               "Cannot set device to a higher-powered"
219                               " state than parent\n");
220                 return -ENODEV;
221         }
222
223         /*
224          * Transition Power
225          * ----------------
226          * On transitions to a high-powered state we first apply power (via
227          * power resources) then evalute _PSx.  Conversly for transitions to
228          * a lower-powered state.
229          */
230         if (state < device->power.state) {
231                 if (device->power.flags.power_resources) {
232                         result = acpi_power_transition(device, state);
233                         if (result)
234                                 goto end;
235                 }
236                 if (device->power.states[state].flags.explicit_set) {
237                         status = acpi_evaluate_object(device->handle,
238                                                       object_name, NULL, NULL);
239                         if (ACPI_FAILURE(status)) {
240                                 result = -ENODEV;
241                                 goto end;
242                         }
243                 }
244         } else {
245                 if (device->power.states[state].flags.explicit_set) {
246                         status = acpi_evaluate_object(device->handle,
247                                                       object_name, NULL, NULL);
248                         if (ACPI_FAILURE(status)) {
249                                 result = -ENODEV;
250                                 goto end;
251                         }
252                 }
253                 if (device->power.flags.power_resources) {
254                         result = acpi_power_transition(device, state);
255                         if (result)
256                                 goto end;
257                 }
258         }
259
260       end:
261         if (result)
262                 printk(KERN_WARNING PREFIX
263                               "Transitioning device [%s] to D%d\n",
264                               device->pnp.bus_id, state);
265         else {
266                 device->power.state = state;
267                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
268                                   "Device [%s] transitioned to D%d\n",
269                                   device->pnp.bus_id, state));
270         }
271
272         return result;
273 }
274
275 EXPORT_SYMBOL(acpi_bus_set_power);
276
277 /* --------------------------------------------------------------------------
278                                 Event Management
279    -------------------------------------------------------------------------- */
280
281 #ifdef CONFIG_ACPI_PROC_EVENT
282 static DEFINE_SPINLOCK(acpi_bus_event_lock);
283
284 LIST_HEAD(acpi_bus_event_list);
285 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
286
287 extern int event_is_open;
288
289 int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
290 {
291         struct acpi_bus_event *event;
292         unsigned long flags = 0;
293
294         /* drop event on the floor if no one's listening */
295         if (!event_is_open)
296                 return 0;
297
298         event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
299         if (!event)
300                 return -ENOMEM;
301
302         strcpy(event->device_class, device_class);
303         strcpy(event->bus_id, bus_id);
304         event->type = type;
305         event->data = data;
306
307         spin_lock_irqsave(&acpi_bus_event_lock, flags);
308         list_add_tail(&event->node, &acpi_bus_event_list);
309         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
310
311         wake_up_interruptible(&acpi_bus_event_queue);
312
313         return 0;
314
315 }
316
317 EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
318
319 int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
320 {
321         if (!device)
322                 return -EINVAL;
323         return acpi_bus_generate_proc_event4(device->pnp.device_class,
324                                              device->pnp.bus_id, type, data);
325 }
326
327 EXPORT_SYMBOL(acpi_bus_generate_proc_event);
328
329 int acpi_bus_receive_event(struct acpi_bus_event *event)
330 {
331         unsigned long flags = 0;
332         struct acpi_bus_event *entry = NULL;
333
334         DECLARE_WAITQUEUE(wait, current);
335
336
337         if (!event)
338                 return -EINVAL;
339
340         if (list_empty(&acpi_bus_event_list)) {
341
342                 set_current_state(TASK_INTERRUPTIBLE);
343                 add_wait_queue(&acpi_bus_event_queue, &wait);
344
345                 if (list_empty(&acpi_bus_event_list))
346                         schedule();
347
348                 remove_wait_queue(&acpi_bus_event_queue, &wait);
349                 set_current_state(TASK_RUNNING);
350
351                 if (signal_pending(current))
352                         return -ERESTARTSYS;
353         }
354
355         spin_lock_irqsave(&acpi_bus_event_lock, flags);
356         entry =
357             list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
358         if (entry)
359                 list_del(&entry->node);
360         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
361
362         if (!entry)
363                 return -ENODEV;
364
365         memcpy(event, entry, sizeof(struct acpi_bus_event));
366
367         kfree(entry);
368
369         return 0;
370 }
371
372 EXPORT_SYMBOL(acpi_bus_receive_event);
373 #endif  /* CONFIG_ACPI_PROC_EVENT */
374
375 /* --------------------------------------------------------------------------
376                              Notification Handling
377    -------------------------------------------------------------------------- */
378
379 static int
380 acpi_bus_check_device(struct acpi_device *device, int *status_changed)
381 {
382         acpi_status status = 0;
383         struct acpi_device_status old_status;
384
385
386         if (!device)
387                 return -EINVAL;
388
389         if (status_changed)
390                 *status_changed = 0;
391
392         old_status = device->status;
393
394         /*
395          * Make sure this device's parent is present before we go about
396          * messing with the device.
397          */
398         if (device->parent && !device->parent->status.present) {
399                 device->status = device->parent->status;
400                 if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
401                         if (status_changed)
402                                 *status_changed = 1;
403                 }
404                 return 0;
405         }
406
407         status = acpi_bus_get_status(device);
408         if (ACPI_FAILURE(status))
409                 return -ENODEV;
410
411         if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
412                 return 0;
413
414         if (status_changed)
415                 *status_changed = 1;
416
417         /*
418          * Device Insertion/Removal
419          */
420         if ((device->status.present) && !(old_status.present)) {
421                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
422                 /* TBD: Handle device insertion */
423         } else if (!(device->status.present) && (old_status.present)) {
424                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
425                 /* TBD: Handle device removal */
426         }
427
428         return 0;
429 }
430
431 static int acpi_bus_check_scope(struct acpi_device *device)
432 {
433         int result = 0;
434         int status_changed = 0;
435
436
437         if (!device)
438                 return -EINVAL;
439
440         /* Status Change? */
441         result = acpi_bus_check_device(device, &status_changed);
442         if (result)
443                 return result;
444
445         if (!status_changed)
446                 return 0;
447
448         /*
449          * TBD: Enumerate child devices within this device's scope and
450          *       run acpi_bus_check_device()'s on them.
451          */
452
453         return 0;
454 }
455
456 /**
457  * acpi_bus_notify
458  * ---------------
459  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
460  */
461 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
462 {
463         int result = 0;
464         struct acpi_device *device = NULL;
465
466
467         if (acpi_bus_get_device(handle, &device))
468                 return;
469
470         switch (type) {
471
472         case ACPI_NOTIFY_BUS_CHECK:
473                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
474                                   "Received BUS CHECK notification for device [%s]\n",
475                                   device->pnp.bus_id));
476                 result = acpi_bus_check_scope(device);
477                 /*
478                  * TBD: We'll need to outsource certain events to non-ACPI
479                  *      drivers via the device manager (device.c).
480                  */
481                 break;
482
483         case ACPI_NOTIFY_DEVICE_CHECK:
484                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
485                                   "Received DEVICE CHECK notification for device [%s]\n",
486                                   device->pnp.bus_id));
487                 result = acpi_bus_check_device(device, NULL);
488                 /*
489                  * TBD: We'll need to outsource certain events to non-ACPI
490                  *      drivers via the device manager (device.c).
491                  */
492                 break;
493
494         case ACPI_NOTIFY_DEVICE_WAKE:
495                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
496                                   "Received DEVICE WAKE notification for device [%s]\n",
497                                   device->pnp.bus_id));
498                 /* TBD */
499                 break;
500
501         case ACPI_NOTIFY_EJECT_REQUEST:
502                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
503                                   "Received EJECT REQUEST notification for device [%s]\n",
504                                   device->pnp.bus_id));
505                 /* TBD */
506                 break;
507
508         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
509                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
510                                   "Received DEVICE CHECK LIGHT notification for device [%s]\n",
511                                   device->pnp.bus_id));
512                 /* TBD: Exactly what does 'light' mean? */
513                 break;
514
515         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
516                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
517                                   "Received FREQUENCY MISMATCH notification for device [%s]\n",
518                                   device->pnp.bus_id));
519                 /* TBD */
520                 break;
521
522         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
523                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
524                                   "Received BUS MODE MISMATCH notification for device [%s]\n",
525                                   device->pnp.bus_id));
526                 /* TBD */
527                 break;
528
529         case ACPI_NOTIFY_POWER_FAULT:
530                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
531                                   "Received POWER FAULT notification for device [%s]\n",
532                                   device->pnp.bus_id));
533                 /* TBD */
534                 break;
535
536         default:
537                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
538                                   "Received unknown/unsupported notification [%08x]\n",
539                                   type));
540                 break;
541         }
542
543         return;
544 }
545
546 /* --------------------------------------------------------------------------
547                              Initialization/Cleanup
548    -------------------------------------------------------------------------- */
549
550 static int __init acpi_bus_init_irq(void)
551 {
552         acpi_status status = AE_OK;
553         union acpi_object arg = { ACPI_TYPE_INTEGER };
554         struct acpi_object_list arg_list = { 1, &arg };
555         char *message = NULL;
556
557
558         /*
559          * Let the system know what interrupt model we are using by
560          * evaluating the \_PIC object, if exists.
561          */
562
563         switch (acpi_irq_model) {
564         case ACPI_IRQ_MODEL_PIC:
565                 message = "PIC";
566                 break;
567         case ACPI_IRQ_MODEL_IOAPIC:
568                 message = "IOAPIC";
569                 break;
570         case ACPI_IRQ_MODEL_IOSAPIC:
571                 message = "IOSAPIC";
572                 break;
573         case ACPI_IRQ_MODEL_PLATFORM:
574                 message = "platform specific model";
575                 break;
576         default:
577                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
578                 return -ENODEV;
579         }
580
581         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
582
583         arg.integer.value = acpi_irq_model;
584
585         status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
586         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
587                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
588                 return -ENODEV;
589         }
590
591         return 0;
592 }
593
594 acpi_native_uint acpi_gbl_permanent_mmap;
595
596
597 void __init acpi_early_init(void)
598 {
599         acpi_status status = AE_OK;
600
601         if (acpi_disabled)
602                 return;
603
604         printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
605
606         /* enable workarounds, unless strict ACPI spec. compliance */
607         if (!acpi_strict)
608                 acpi_gbl_enable_interpreter_slack = TRUE;
609
610         acpi_gbl_permanent_mmap = 1;
611
612         status = acpi_reallocate_root_table();
613         if (ACPI_FAILURE(status)) {
614                 printk(KERN_ERR PREFIX
615                        "Unable to reallocate ACPI tables\n");
616                 goto error0;
617         }
618
619         status = acpi_initialize_subsystem();
620         if (ACPI_FAILURE(status)) {
621                 printk(KERN_ERR PREFIX
622                        "Unable to initialize the ACPI Interpreter\n");
623                 goto error0;
624         }
625
626         status = acpi_load_tables();
627         if (ACPI_FAILURE(status)) {
628                 printk(KERN_ERR PREFIX
629                        "Unable to load the System Description Tables\n");
630                 goto error0;
631         }
632
633 #ifdef CONFIG_X86
634         if (!acpi_ioapic) {
635                 extern u8 acpi_sci_flags;
636
637                 /* compatible (0) means level (3) */
638                 if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
639                         acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
640                         acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
641                 }
642                 /* Set PIC-mode SCI trigger type */
643                 acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
644                                          (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
645         } else {
646                 extern int acpi_sci_override_gsi;
647                 /*
648                  * now that acpi_gbl_FADT is initialized,
649                  * update it with result from INT_SRC_OVR parsing
650                  */
651                 acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
652         }
653 #endif
654
655         status =
656             acpi_enable_subsystem(~
657                                   (ACPI_NO_HARDWARE_INIT |
658                                    ACPI_NO_ACPI_ENABLE));
659         if (ACPI_FAILURE(status)) {
660                 printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
661                 goto error0;
662         }
663
664         return;
665
666       error0:
667         disable_acpi();
668         return;
669 }
670
671 static int __init acpi_bus_init(void)
672 {
673         int result = 0;
674         acpi_status status = AE_OK;
675         extern acpi_status acpi_os_initialize1(void);
676
677
678         status = acpi_os_initialize1();
679
680         status =
681             acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
682         if (ACPI_FAILURE(status)) {
683                 printk(KERN_ERR PREFIX
684                        "Unable to start the ACPI Interpreter\n");
685                 goto error1;
686         }
687
688         if (ACPI_FAILURE(status)) {
689                 printk(KERN_ERR PREFIX
690                        "Unable to initialize ACPI OS objects\n");
691                 goto error1;
692         }
693 #ifdef CONFIG_ACPI_EC
694         /*
695          * ACPI 2.0 requires the EC driver to be loaded and work before
696          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
697          * is called).
698          *
699          * This is accomplished by looking for the ECDT table, and getting
700          * the EC parameters out of that.
701          */
702         status = acpi_ec_ecdt_probe();
703         /* Ignore result. Not having an ECDT is not fatal. */
704 #endif
705
706         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
707         if (ACPI_FAILURE(status)) {
708                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
709                 goto error1;
710         }
711
712         printk(KERN_INFO PREFIX "Interpreter enabled\n");
713
714         /* Initialize sleep structures */
715         acpi_sleep_init();
716
717         /*
718          * Get the system interrupt model and evaluate \_PIC.
719          */
720         result = acpi_bus_init_irq();
721         if (result)
722                 goto error1;
723
724         /*
725          * Register the for all standard device notifications.
726          */
727         status =
728             acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
729                                         &acpi_bus_notify, NULL);
730         if (ACPI_FAILURE(status)) {
731                 printk(KERN_ERR PREFIX
732                        "Unable to register for device notifications\n");
733                 goto error1;
734         }
735
736         /*
737          * Create the top ACPI proc directory
738          */
739         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
740
741         return 0;
742
743         /* Mimic structured exception handling */
744       error1:
745         acpi_terminate();
746         return -ENODEV;
747 }
748
749 decl_subsys(acpi, NULL, NULL);
750
751 static int __init acpi_init(void)
752 {
753         int result = 0;
754
755
756         if (acpi_disabled) {
757                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
758                 return -ENODEV;
759         }
760
761         result = firmware_register(&acpi_subsys);
762         if (result < 0)
763                 printk(KERN_WARNING "%s: firmware_register error: %d\n",
764                         __FUNCTION__, result);
765
766         result = acpi_bus_init();
767
768         if (!result) {
769 #ifdef CONFIG_PM_LEGACY
770                 if (!PM_IS_ACTIVE())
771                         pm_active = 1;
772                 else {
773                         printk(KERN_INFO PREFIX
774                                "APM is already active, exiting\n");
775                         disable_acpi();
776                         result = -ENODEV;
777                 }
778 #endif
779         } else
780                 disable_acpi();
781
782         return result;
783 }
784
785 subsys_initcall(acpi_init);