bus.c revision 61686124f47d7c4b78610346c5f8f9d8a6d46bb5 
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/list.h>
29#include <linux/sched.h>
30#include <linux/pm.h>
31#include <linux/pm_legacy.h>
32#include <linux/device.h>
33#include <linux/proc_fs.h>
34#ifdef CONFIG_X86
35#include <asm/mpspec.h>
36#endif
37#include <acpi/acpi_bus.h>
38#include <acpi/acpi_drivers.h>
39
40#define _COMPONENT		ACPI_BUS_COMPONENT
41ACPI_MODULE_NAME("acpi_bus")
42#ifdef	CONFIG_X86
43extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
44#endif
45
46FADT_DESCRIPTOR acpi_fadt;
47EXPORT_SYMBOL(acpi_fadt);
48
49struct acpi_device *acpi_root;
50struct proc_dir_entry *acpi_root_dir;
51EXPORT_SYMBOL(acpi_root_dir);
52
53#define STRUCT_TO_INT(s)	(*((int*)&s))
54
55/* --------------------------------------------------------------------------
56                                Device Management
57   -------------------------------------------------------------------------- */
58
59int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
60{
61	acpi_status status = AE_OK;
62
63	ACPI_FUNCTION_TRACE("acpi_bus_get_device");
64
65	if (!device)
66		return_VALUE(-EINVAL);
67
68	/* TBD: Support fixed-feature devices */
69
70	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
71	if (ACPI_FAILURE(status) || !*device) {
72		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "No context for object [%p]\n",
73				  handle));
74		return_VALUE(-ENODEV);
75	}
76
77	return_VALUE(0);
78}
79
80EXPORT_SYMBOL(acpi_bus_get_device);
81
82int acpi_bus_get_status(struct acpi_device *device)
83{
84	acpi_status status = AE_OK;
85	unsigned long sta = 0;
86
87	ACPI_FUNCTION_TRACE("acpi_bus_get_status");
88
89	if (!device)
90		return_VALUE(-EINVAL);
91
92	/*
93	 * Evaluate _STA if present.
94	 */
95	if (device->flags.dynamic_status) {
96		status =
97		    acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
98		if (ACPI_FAILURE(status))
99			return_VALUE(-ENODEV);
100		STRUCT_TO_INT(device->status) = (int)sta;
101	}
102
103	/*
104	 * Otherwise we assume the status of our parent (unless we don't
105	 * have one, in which case status is implied).
106	 */
107	else if (device->parent)
108		device->status = device->parent->status;
109	else
110		STRUCT_TO_INT(device->status) = 0x0F;
111
112	if (device->status.functional && !device->status.present) {
113		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
114		       "functional but not present; setting present\n",
115		       device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
116		device->status.present = 1;
117	}
118
119	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
120			  device->pnp.bus_id,
121			  (u32) STRUCT_TO_INT(device->status)));
122
123	return_VALUE(0);
124}
125
126EXPORT_SYMBOL(acpi_bus_get_status);
127
128/* --------------------------------------------------------------------------
129                                 Power Management
130   -------------------------------------------------------------------------- */
131
132int acpi_bus_get_power(acpi_handle handle, int *state)
133{
134	int result = 0;
135	acpi_status status = 0;
136	struct acpi_device *device = NULL;
137	unsigned long psc = 0;
138
139	ACPI_FUNCTION_TRACE("acpi_bus_get_power");
140
141	result = acpi_bus_get_device(handle, &device);
142	if (result)
143		return_VALUE(result);
144
145	*state = ACPI_STATE_UNKNOWN;
146
147	if (!device->flags.power_manageable) {
148		/* TBD: Non-recursive algorithm for walking up hierarchy */
149		if (device->parent)
150			*state = device->parent->power.state;
151		else
152			*state = ACPI_STATE_D0;
153	} else {
154		/*
155		 * Get the device's power state either directly (via _PSC) or
156		 * indirectly (via power resources).
157		 */
158		if (device->power.flags.explicit_get) {
159			status = acpi_evaluate_integer(device->handle, "_PSC",
160						       NULL, &psc);
161			if (ACPI_FAILURE(status))
162				return_VALUE(-ENODEV);
163			device->power.state = (int)psc;
164		} else if (device->power.flags.power_resources) {
165			result = acpi_power_get_inferred_state(device);
166			if (result)
167				return_VALUE(result);
168		}
169
170		*state = device->power.state;
171	}
172
173	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
174			  device->pnp.bus_id, device->power.state));
175
176	return_VALUE(0);
177}
178
179EXPORT_SYMBOL(acpi_bus_get_power);
180
181int acpi_bus_set_power(acpi_handle handle, int state)
182{
183	int result = 0;
184	acpi_status status = AE_OK;
185	struct acpi_device *device = NULL;
186	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
187
188	ACPI_FUNCTION_TRACE("acpi_bus_set_power");
189
190	result = acpi_bus_get_device(handle, &device);
191	if (result)
192		return_VALUE(result);
193
194	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
195		return_VALUE(-EINVAL);
196
197	/* Make sure this is a valid target state */
198
199	if (!device->flags.power_manageable) {
200		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
201				  "Device is not power manageable\n"));
202		return_VALUE(-ENODEV);
203	}
204	/*
205	 * Get device's current power state if it's unknown
206	 * This means device power state isn't initialized or previous setting failed
207	 */
208	if (device->power.state == ACPI_STATE_UNKNOWN)
209		acpi_bus_get_power(device->handle, &device->power.state);
210	if (state == device->power.state) {
211		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
212				  state));
213		return_VALUE(0);
214	}
215	if (!device->power.states[state].flags.valid) {
216		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device does not support D%d\n",
217				  state));
218		return_VALUE(-ENODEV);
219	}
220	if (device->parent && (state < device->parent->power.state)) {
221		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
222				  "Cannot set device to a higher-powered state than parent\n"));
223		return_VALUE(-ENODEV);
224	}
225
226	/*
227	 * Transition Power
228	 * ----------------
229	 * On transitions to a high-powered state we first apply power (via
230	 * power resources) then evalute _PSx.  Conversly for transitions to
231	 * a lower-powered state.
232	 */
233	if (state < device->power.state) {
234		if (device->power.flags.power_resources) {
235			result = acpi_power_transition(device, state);
236			if (result)
237				goto end;
238		}
239		if (device->power.states[state].flags.explicit_set) {
240			status = acpi_evaluate_object(device->handle,
241						      object_name, NULL, NULL);
242			if (ACPI_FAILURE(status)) {
243				result = -ENODEV;
244				goto end;
245			}
246		}
247	} else {
248		if (device->power.states[state].flags.explicit_set) {
249			status = acpi_evaluate_object(device->handle,
250						      object_name, NULL, NULL);
251			if (ACPI_FAILURE(status)) {
252				result = -ENODEV;
253				goto end;
254			}
255		}
256		if (device->power.flags.power_resources) {
257			result = acpi_power_transition(device, state);
258			if (result)
259				goto end;
260		}
261	}
262
263      end:
264	if (result)
265		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
266				  "Error transitioning device [%s] to D%d\n",
267				  device->pnp.bus_id, state));
268	else
269		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
270				  "Device [%s] transitioned to D%d\n",
271				  device->pnp.bus_id, state));
272
273	return_VALUE(result);
274}
275
276EXPORT_SYMBOL(acpi_bus_set_power);
277
278/* --------------------------------------------------------------------------
279                                Event Management
280   -------------------------------------------------------------------------- */
281
282static DEFINE_SPINLOCK(acpi_bus_event_lock);
283
284LIST_HEAD(acpi_bus_event_list);
285DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
286
287extern int event_is_open;
288
289int acpi_bus_generate_event(struct acpi_device *device, u8 type, int data)
290{
291	struct acpi_bus_event *event = NULL;
292	unsigned long flags = 0;
293
294	ACPI_FUNCTION_TRACE("acpi_bus_generate_event");
295
296	if (!device)
297		return_VALUE(-EINVAL);
298
299	/* drop event on the floor if no one's listening */
300	if (!event_is_open)
301		return_VALUE(0);
302
303	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
304	if (!event)
305		return_VALUE(-ENOMEM);
306
307	strcpy(event->device_class, device->pnp.device_class);
308	strcpy(event->bus_id, device->pnp.bus_id);
309	event->type = type;
310	event->data = data;
311
312	spin_lock_irqsave(&acpi_bus_event_lock, flags);
313	list_add_tail(&event->node, &acpi_bus_event_list);
314	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
315
316	wake_up_interruptible(&acpi_bus_event_queue);
317
318	return_VALUE(0);
319}
320
321EXPORT_SYMBOL(acpi_bus_generate_event);
322
323int acpi_bus_receive_event(struct acpi_bus_event *event)
324{
325	unsigned long flags = 0;
326	struct acpi_bus_event *entry = NULL;
327
328	DECLARE_WAITQUEUE(wait, current);
329
330	ACPI_FUNCTION_TRACE("acpi_bus_receive_event");
331
332	if (!event)
333		return_VALUE(-EINVAL);
334
335	if (list_empty(&acpi_bus_event_list)) {
336
337		set_current_state(TASK_INTERRUPTIBLE);
338		add_wait_queue(&acpi_bus_event_queue, &wait);
339
340		if (list_empty(&acpi_bus_event_list))
341			schedule();
342
343		remove_wait_queue(&acpi_bus_event_queue, &wait);
344		set_current_state(TASK_RUNNING);
345
346		if (signal_pending(current))
347			return_VALUE(-ERESTARTSYS);
348	}
349
350	spin_lock_irqsave(&acpi_bus_event_lock, flags);
351	entry =
352	    list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
353	if (entry)
354		list_del(&entry->node);
355	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
356
357	if (!entry)
358		return_VALUE(-ENODEV);
359
360	memcpy(event, entry, sizeof(struct acpi_bus_event));
361
362	kfree(entry);
363
364	return_VALUE(0);
365}
366
367EXPORT_SYMBOL(acpi_bus_receive_event);
368
369/* --------------------------------------------------------------------------
370                             Notification Handling
371   -------------------------------------------------------------------------- */
372
373static int
374acpi_bus_check_device(struct acpi_device *device, int *status_changed)
375{
376	acpi_status status = 0;
377	struct acpi_device_status old_status;
378
379	ACPI_FUNCTION_TRACE("acpi_bus_check_device");
380
381	if (!device)
382		return_VALUE(-EINVAL);
383
384	if (status_changed)
385		*status_changed = 0;
386
387	old_status = device->status;
388
389	/*
390	 * Make sure this device's parent is present before we go about
391	 * messing with the device.
392	 */
393	if (device->parent && !device->parent->status.present) {
394		device->status = device->parent->status;
395		if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
396			if (status_changed)
397				*status_changed = 1;
398		}
399		return_VALUE(0);
400	}
401
402	status = acpi_bus_get_status(device);
403	if (ACPI_FAILURE(status))
404		return_VALUE(-ENODEV);
405
406	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
407		return_VALUE(0);
408
409	if (status_changed)
410		*status_changed = 1;
411
412	/*
413	 * Device Insertion/Removal
414	 */
415	if ((device->status.present) && !(old_status.present)) {
416		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
417		/* TBD: Handle device insertion */
418	} else if (!(device->status.present) && (old_status.present)) {
419		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
420		/* TBD: Handle device removal */
421	}
422
423	return_VALUE(0);
424}
425
426static int acpi_bus_check_scope(struct acpi_device *device)
427{
428	int result = 0;
429	int status_changed = 0;
430
431	ACPI_FUNCTION_TRACE("acpi_bus_check_scope");
432
433	if (!device)
434		return_VALUE(-EINVAL);
435
436	/* Status Change? */
437	result = acpi_bus_check_device(device, &status_changed);
438	if (result)
439		return_VALUE(result);
440
441	if (!status_changed)
442		return_VALUE(0);
443
444	/*
445	 * TBD: Enumerate child devices within this device's scope and
446	 *       run acpi_bus_check_device()'s on them.
447	 */
448
449	return_VALUE(0);
450}
451
452/**
453 * acpi_bus_notify
454 * ---------------
455 * Callback for all 'system-level' device notifications (values 0x00-0x7F).
456 */
457static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
458{
459	int result = 0;
460	struct acpi_device *device = NULL;
461
462	ACPI_FUNCTION_TRACE("acpi_bus_notify");
463
464	if (acpi_bus_get_device(handle, &device))
465		return_VOID;
466
467	switch (type) {
468
469	case ACPI_NOTIFY_BUS_CHECK:
470		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
471				  "Received BUS CHECK notification for device [%s]\n",
472				  device->pnp.bus_id));
473		result = acpi_bus_check_scope(device);
474		/*
475		 * TBD: We'll need to outsource certain events to non-ACPI
476		 *      drivers via the device manager (device.c).
477		 */
478		break;
479
480	case ACPI_NOTIFY_DEVICE_CHECK:
481		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
482				  "Received DEVICE CHECK notification for device [%s]\n",
483				  device->pnp.bus_id));
484		result = acpi_bus_check_device(device, NULL);
485		/*
486		 * TBD: We'll need to outsource certain events to non-ACPI
487		 *      drivers via the device manager (device.c).
488		 */
489		break;
490
491	case ACPI_NOTIFY_DEVICE_WAKE:
492		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
493				  "Received DEVICE WAKE notification for device [%s]\n",
494				  device->pnp.bus_id));
495		/* TBD */
496		break;
497
498	case ACPI_NOTIFY_EJECT_REQUEST:
499		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
500				  "Received EJECT REQUEST notification for device [%s]\n",
501				  device->pnp.bus_id));
502		/* TBD */
503		break;
504
505	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
506		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
507				  "Received DEVICE CHECK LIGHT notification for device [%s]\n",
508				  device->pnp.bus_id));
509		/* TBD: Exactly what does 'light' mean? */
510		break;
511
512	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
513		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
514				  "Received FREQUENCY MISMATCH notification for device [%s]\n",
515				  device->pnp.bus_id));
516		/* TBD */
517		break;
518
519	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
520		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
521				  "Received BUS MODE MISMATCH notification for device [%s]\n",
522				  device->pnp.bus_id));
523		/* TBD */
524		break;
525
526	case ACPI_NOTIFY_POWER_FAULT:
527		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
528				  "Received POWER FAULT notification for device [%s]\n",
529				  device->pnp.bus_id));
530		/* TBD */
531		break;
532
533	default:
534		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
535				  "Received unknown/unsupported notification [%08x]\n",
536				  type));
537		break;
538	}
539
540	return_VOID;
541}
542
543/* --------------------------------------------------------------------------
544                             Initialization/Cleanup
545   -------------------------------------------------------------------------- */
546
547static int __init acpi_bus_init_irq(void)
548{
549	acpi_status status = AE_OK;
550	union acpi_object arg = { ACPI_TYPE_INTEGER };
551	struct acpi_object_list arg_list = { 1, &arg };
552	char *message = NULL;
553
554	ACPI_FUNCTION_TRACE("acpi_bus_init_irq");
555
556	/*
557	 * Let the system know what interrupt model we are using by
558	 * evaluating the \_PIC object, if exists.
559	 */
560
561	switch (acpi_irq_model) {
562	case ACPI_IRQ_MODEL_PIC:
563		message = "PIC";
564		break;
565	case ACPI_IRQ_MODEL_IOAPIC:
566		message = "IOAPIC";
567		break;
568	case ACPI_IRQ_MODEL_IOSAPIC:
569		message = "IOSAPIC";
570		break;
571	default:
572		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
573		return_VALUE(-ENODEV);
574	}
575
576	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
577
578	arg.integer.value = acpi_irq_model;
579
580	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
581	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
582		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PIC\n"));
583		return_VALUE(-ENODEV);
584	}
585
586	return_VALUE(0);
587}
588
589void __init acpi_early_init(void)
590{
591	acpi_status status = AE_OK;
592	struct acpi_buffer buffer = { sizeof(acpi_fadt), &acpi_fadt };
593
594	ACPI_FUNCTION_TRACE("acpi_early_init");
595
596	if (acpi_disabled)
597		return_VOID;
598
599	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
600
601	/* enable workarounds, unless strict ACPI spec. compliance */
602	if (!acpi_strict)
603		acpi_gbl_enable_interpreter_slack = TRUE;
604
605	status = acpi_initialize_subsystem();
606	if (ACPI_FAILURE(status)) {
607		printk(KERN_ERR PREFIX
608		       "Unable to initialize the ACPI Interpreter\n");
609		goto error0;
610	}
611
612	status = acpi_load_tables();
613	if (ACPI_FAILURE(status)) {
614		printk(KERN_ERR PREFIX
615		       "Unable to load the System Description Tables\n");
616		goto error0;
617	}
618
619	/*
620	 * Get a separate copy of the FADT for use by other drivers.
621	 */
622	status = acpi_get_table(ACPI_TABLE_FADT, 1, &buffer);
623	if (ACPI_FAILURE(status)) {
624		printk(KERN_ERR PREFIX "Unable to get the FADT\n");
625		goto error0;
626	}
627#ifdef CONFIG_X86
628	if (!acpi_ioapic) {
629		extern acpi_interrupt_flags acpi_sci_flags;
630
631		/* compatible (0) means level (3) */
632		if (acpi_sci_flags.trigger == 0)
633			acpi_sci_flags.trigger = 3;
634
635		/* Set PIC-mode SCI trigger type */
636		acpi_pic_sci_set_trigger(acpi_fadt.sci_int,
637					 acpi_sci_flags.trigger);
638	} else {
639		extern int acpi_sci_override_gsi;
640		/*
641		 * now that acpi_fadt is initialized,
642		 * update it with result from INT_SRC_OVR parsing
643		 */
644		acpi_fadt.sci_int = acpi_sci_override_gsi;
645	}
646#endif
647
648	status =
649	    acpi_enable_subsystem(~
650				  (ACPI_NO_HARDWARE_INIT |
651				   ACPI_NO_ACPI_ENABLE));
652	if (ACPI_FAILURE(status)) {
653		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
654		goto error0;
655	}
656
657	return_VOID;
658
659      error0:
660	disable_acpi();
661	return_VOID;
662}
663
664static int __init acpi_bus_init(void)
665{
666	int result = 0;
667	acpi_status status = AE_OK;
668	extern acpi_status acpi_os_initialize1(void);
669
670	ACPI_FUNCTION_TRACE("acpi_bus_init");
671
672	status = acpi_os_initialize1();
673
674	status =
675	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
676	if (ACPI_FAILURE(status)) {
677		printk(KERN_ERR PREFIX
678		       "Unable to start the ACPI Interpreter\n");
679		goto error1;
680	}
681
682	if (ACPI_FAILURE(status)) {
683		printk(KERN_ERR PREFIX
684		       "Unable to initialize ACPI OS objects\n");
685		goto error1;
686	}
687#ifdef CONFIG_ACPI_EC
688	/*
689	 * ACPI 2.0 requires the EC driver to be loaded and work before
690	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
691	 * is called).
692	 *
693	 * This is accomplished by looking for the ECDT table, and getting
694	 * the EC parameters out of that.
695	 */
696	status = acpi_ec_ecdt_probe();
697	/* Ignore result. Not having an ECDT is not fatal. */
698#endif
699
700	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
701	if (ACPI_FAILURE(status)) {
702		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
703		goto error1;
704	}
705
706	printk(KERN_INFO PREFIX "Interpreter enabled\n");
707
708	/*
709	 * Get the system interrupt model and evaluate \_PIC.
710	 */
711	result = acpi_bus_init_irq();
712	if (result)
713		goto error1;
714
715	/*
716	 * Register the for all standard device notifications.
717	 */
718	status =
719	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
720					&acpi_bus_notify, NULL);
721	if (ACPI_FAILURE(status)) {
722		printk(KERN_ERR PREFIX
723		       "Unable to register for device notifications\n");
724		goto error1;
725	}
726
727	/*
728	 * Create the top ACPI proc directory
729	 */
730	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
731
732	return_VALUE(0);
733
734	/* Mimic structured exception handling */
735      error1:
736	acpi_terminate();
737	return_VALUE(-ENODEV);
738}
739
740decl_subsys(acpi, NULL, NULL);
741
742static int __init acpi_init(void)
743{
744	int result = 0;
745
746	ACPI_FUNCTION_TRACE("acpi_init");
747
748	if (acpi_disabled) {
749		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
750		return_VALUE(-ENODEV);
751	}
752
753	firmware_register(&acpi_subsys);
754
755	result = acpi_bus_init();
756
757	if (!result) {
758#ifdef CONFIG_PM_LEGACY
759		if (!PM_IS_ACTIVE())
760			pm_active = 1;
761		else {
762			printk(KERN_INFO PREFIX
763			       "APM is already active, exiting\n");
764			disable_acpi();
765			result = -ENODEV;
766		}
767#endif
768	} else
769		disable_acpi();
770
771	return_VALUE(result);
772}
773
774subsys_initcall(acpi_init);
775