xref: /openbmc/linux/drivers/acpi/bus.c (revision e8e0929d)
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/device.h>
33 #include <linux/proc_fs.h>
34 #include <linux/acpi.h>
35 #ifdef CONFIG_X86
36 #include <asm/mpspec.h>
37 #endif
38 #include <linux/pci.h>
39 #include <acpi/acpi_bus.h>
40 #include <acpi/acpi_drivers.h>
41 #include <linux/dmi.h>
42 
43 #include "internal.h"
44 
45 #define _COMPONENT		ACPI_BUS_COMPONENT
46 ACPI_MODULE_NAME("bus");
47 
48 struct acpi_device *acpi_root;
49 struct proc_dir_entry *acpi_root_dir;
50 EXPORT_SYMBOL(acpi_root_dir);
51 
52 #define STRUCT_TO_INT(s)	(*((int*)&s))
53 
54 static int set_power_nocheck(const struct dmi_system_id *id)
55 {
56 	printk(KERN_NOTICE PREFIX "%s detected - "
57 		"disable power check in power transistion\n", id->ident);
58 	acpi_power_nocheck = 1;
59 	return 0;
60 }
61 static struct dmi_system_id __cpuinitdata power_nocheck_dmi_table[] = {
62 	{
63 	set_power_nocheck, "HP Pavilion 05", {
64 	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
65 	DMI_MATCH(DMI_SYS_VENDOR, "HP Pavilion 05"),
66 	DMI_MATCH(DMI_PRODUCT_VERSION, "2001211RE101GLEND") }, NULL},
67 	{},
68 };
69 
70 
71 /* --------------------------------------------------------------------------
72                                 Device Management
73    -------------------------------------------------------------------------- */
74 
75 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
76 {
77 	acpi_status status = AE_OK;
78 
79 
80 	if (!device)
81 		return -EINVAL;
82 
83 	/* TBD: Support fixed-feature devices */
84 
85 	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
86 	if (ACPI_FAILURE(status) || !*device) {
87 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
88 				  handle));
89 		return -ENODEV;
90 	}
91 
92 	return 0;
93 }
94 
95 EXPORT_SYMBOL(acpi_bus_get_device);
96 
97 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
98 				       unsigned long long *sta)
99 {
100 	acpi_status status;
101 
102 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
103 	if (ACPI_SUCCESS(status))
104 		return AE_OK;
105 
106 	if (status == AE_NOT_FOUND) {
107 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
108 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
109 		return AE_OK;
110 	}
111 	return status;
112 }
113 
114 int acpi_bus_get_status(struct acpi_device *device)
115 {
116 	acpi_status status;
117 	unsigned long long sta;
118 
119 	status = acpi_bus_get_status_handle(device->handle, &sta);
120 	if (ACPI_FAILURE(status))
121 		return -ENODEV;
122 
123 	STRUCT_TO_INT(device->status) = (int) sta;
124 
125 	if (device->status.functional && !device->status.present) {
126 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
127 		       "functional but not present;\n",
128 			device->pnp.bus_id,
129 			(u32) STRUCT_TO_INT(device->status)));
130 	}
131 
132 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
133 			  device->pnp.bus_id,
134 			  (u32) STRUCT_TO_INT(device->status)));
135 	return 0;
136 }
137 EXPORT_SYMBOL(acpi_bus_get_status);
138 
139 void acpi_bus_private_data_handler(acpi_handle handle,
140 				   void *context)
141 {
142 	return;
143 }
144 EXPORT_SYMBOL(acpi_bus_private_data_handler);
145 
146 int acpi_bus_get_private_data(acpi_handle handle, void **data)
147 {
148 	acpi_status status = AE_OK;
149 
150 	if (!*data)
151 		return -EINVAL;
152 
153 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
154 	if (ACPI_FAILURE(status) || !*data) {
155 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
156 				handle));
157 		return -ENODEV;
158 	}
159 
160 	return 0;
161 }
162 EXPORT_SYMBOL(acpi_bus_get_private_data);
163 
164 /* --------------------------------------------------------------------------
165                                  Power Management
166    -------------------------------------------------------------------------- */
167 
168 int acpi_bus_get_power(acpi_handle handle, int *state)
169 {
170 	int result = 0;
171 	acpi_status status = 0;
172 	struct acpi_device *device = NULL;
173 	unsigned long long psc = 0;
174 
175 
176 	result = acpi_bus_get_device(handle, &device);
177 	if (result)
178 		return result;
179 
180 	*state = ACPI_STATE_UNKNOWN;
181 
182 	if (!device->flags.power_manageable) {
183 		/* TBD: Non-recursive algorithm for walking up hierarchy */
184 		if (device->parent)
185 			*state = device->parent->power.state;
186 		else
187 			*state = ACPI_STATE_D0;
188 	} else {
189 		/*
190 		 * Get the device's power state either directly (via _PSC) or
191 		 * indirectly (via power resources).
192 		 */
193 		if (device->power.flags.explicit_get) {
194 			status = acpi_evaluate_integer(device->handle, "_PSC",
195 						       NULL, &psc);
196 			if (ACPI_FAILURE(status))
197 				return -ENODEV;
198 			device->power.state = (int)psc;
199 		} else if (device->power.flags.power_resources) {
200 			result = acpi_power_get_inferred_state(device);
201 			if (result)
202 				return result;
203 		}
204 
205 		*state = device->power.state;
206 	}
207 
208 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
209 			  device->pnp.bus_id, device->power.state));
210 
211 	return 0;
212 }
213 
214 EXPORT_SYMBOL(acpi_bus_get_power);
215 
216 int acpi_bus_set_power(acpi_handle handle, int state)
217 {
218 	int result = 0;
219 	acpi_status status = AE_OK;
220 	struct acpi_device *device = NULL;
221 	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
222 
223 
224 	result = acpi_bus_get_device(handle, &device);
225 	if (result)
226 		return result;
227 
228 	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
229 		return -EINVAL;
230 
231 	/* Make sure this is a valid target state */
232 
233 	if (!device->flags.power_manageable) {
234 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
235 				kobject_name(&device->dev.kobj)));
236 		return -ENODEV;
237 	}
238 	/*
239 	 * Get device's current power state
240 	 */
241 	if (!acpi_power_nocheck) {
242 		/*
243 		 * Maybe the incorrect power state is returned on the bogus
244 		 * bios, which is different with the real power state.
245 		 * For example: the bios returns D0 state and the real power
246 		 * state is D3. OS expects to set the device to D0 state. In
247 		 * such case if OS uses the power state returned by the BIOS,
248 		 * the device can't be transisted to the correct power state.
249 		 * So if the acpi_power_nocheck is set, it is unnecessary to
250 		 * get the power state by calling acpi_bus_get_power.
251 		 */
252 		acpi_bus_get_power(device->handle, &device->power.state);
253 	}
254 	if ((state == device->power.state) && !device->flags.force_power_state) {
255 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
256 				  state));
257 		return 0;
258 	}
259 
260 	if (!device->power.states[state].flags.valid) {
261 		printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
262 		return -ENODEV;
263 	}
264 	if (device->parent && (state < device->parent->power.state)) {
265 		printk(KERN_WARNING PREFIX
266 			      "Cannot set device to a higher-powered"
267 			      " state than parent\n");
268 		return -ENODEV;
269 	}
270 
271 	/*
272 	 * Transition Power
273 	 * ----------------
274 	 * On transitions to a high-powered state we first apply power (via
275 	 * power resources) then evalute _PSx.  Conversly for transitions to
276 	 * a lower-powered state.
277 	 */
278 	if (state < device->power.state) {
279 		if (device->power.flags.power_resources) {
280 			result = acpi_power_transition(device, state);
281 			if (result)
282 				goto end;
283 		}
284 		if (device->power.states[state].flags.explicit_set) {
285 			status = acpi_evaluate_object(device->handle,
286 						      object_name, NULL, NULL);
287 			if (ACPI_FAILURE(status)) {
288 				result = -ENODEV;
289 				goto end;
290 			}
291 		}
292 	} else {
293 		if (device->power.states[state].flags.explicit_set) {
294 			status = acpi_evaluate_object(device->handle,
295 						      object_name, NULL, NULL);
296 			if (ACPI_FAILURE(status)) {
297 				result = -ENODEV;
298 				goto end;
299 			}
300 		}
301 		if (device->power.flags.power_resources) {
302 			result = acpi_power_transition(device, state);
303 			if (result)
304 				goto end;
305 		}
306 	}
307 
308       end:
309 	if (result)
310 		printk(KERN_WARNING PREFIX
311 			      "Device [%s] failed to transition to D%d\n",
312 			      device->pnp.bus_id, state);
313 	else {
314 		device->power.state = state;
315 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
316 				  "Device [%s] transitioned to D%d\n",
317 				  device->pnp.bus_id, state));
318 	}
319 
320 	return result;
321 }
322 
323 EXPORT_SYMBOL(acpi_bus_set_power);
324 
325 bool acpi_bus_power_manageable(acpi_handle handle)
326 {
327 	struct acpi_device *device;
328 	int result;
329 
330 	result = acpi_bus_get_device(handle, &device);
331 	return result ? false : device->flags.power_manageable;
332 }
333 
334 EXPORT_SYMBOL(acpi_bus_power_manageable);
335 
336 bool acpi_bus_can_wakeup(acpi_handle handle)
337 {
338 	struct acpi_device *device;
339 	int result;
340 
341 	result = acpi_bus_get_device(handle, &device);
342 	return result ? false : device->wakeup.flags.valid;
343 }
344 
345 EXPORT_SYMBOL(acpi_bus_can_wakeup);
346 
347 /* --------------------------------------------------------------------------
348                                 Event Management
349    -------------------------------------------------------------------------- */
350 
351 #ifdef CONFIG_ACPI_PROC_EVENT
352 static DEFINE_SPINLOCK(acpi_bus_event_lock);
353 
354 LIST_HEAD(acpi_bus_event_list);
355 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
356 
357 extern int event_is_open;
358 
359 int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
360 {
361 	struct acpi_bus_event *event;
362 	unsigned long flags = 0;
363 
364 	/* drop event on the floor if no one's listening */
365 	if (!event_is_open)
366 		return 0;
367 
368 	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
369 	if (!event)
370 		return -ENOMEM;
371 
372 	strcpy(event->device_class, device_class);
373 	strcpy(event->bus_id, bus_id);
374 	event->type = type;
375 	event->data = data;
376 
377 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
378 	list_add_tail(&event->node, &acpi_bus_event_list);
379 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
380 
381 	wake_up_interruptible(&acpi_bus_event_queue);
382 
383 	return 0;
384 
385 }
386 
387 EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
388 
389 int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
390 {
391 	if (!device)
392 		return -EINVAL;
393 	return acpi_bus_generate_proc_event4(device->pnp.device_class,
394 					     device->pnp.bus_id, type, data);
395 }
396 
397 EXPORT_SYMBOL(acpi_bus_generate_proc_event);
398 
399 int acpi_bus_receive_event(struct acpi_bus_event *event)
400 {
401 	unsigned long flags = 0;
402 	struct acpi_bus_event *entry = NULL;
403 
404 	DECLARE_WAITQUEUE(wait, current);
405 
406 
407 	if (!event)
408 		return -EINVAL;
409 
410 	if (list_empty(&acpi_bus_event_list)) {
411 
412 		set_current_state(TASK_INTERRUPTIBLE);
413 		add_wait_queue(&acpi_bus_event_queue, &wait);
414 
415 		if (list_empty(&acpi_bus_event_list))
416 			schedule();
417 
418 		remove_wait_queue(&acpi_bus_event_queue, &wait);
419 		set_current_state(TASK_RUNNING);
420 
421 		if (signal_pending(current))
422 			return -ERESTARTSYS;
423 	}
424 
425 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
426 	if (!list_empty(&acpi_bus_event_list)) {
427 		entry = list_entry(acpi_bus_event_list.next,
428 				   struct acpi_bus_event, node);
429 		list_del(&entry->node);
430 	}
431 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
432 
433 	if (!entry)
434 		return -ENODEV;
435 
436 	memcpy(event, entry, sizeof(struct acpi_bus_event));
437 
438 	kfree(entry);
439 
440 	return 0;
441 }
442 
443 #endif	/* CONFIG_ACPI_PROC_EVENT */
444 
445 /* --------------------------------------------------------------------------
446                              Notification Handling
447    -------------------------------------------------------------------------- */
448 
449 static void acpi_bus_check_device(acpi_handle handle)
450 {
451 	struct acpi_device *device;
452 	acpi_status status;
453 	struct acpi_device_status old_status;
454 
455 	if (acpi_bus_get_device(handle, &device))
456 		return;
457 	if (!device)
458 		return;
459 
460 	old_status = device->status;
461 
462 	/*
463 	 * Make sure this device's parent is present before we go about
464 	 * messing with the device.
465 	 */
466 	if (device->parent && !device->parent->status.present) {
467 		device->status = device->parent->status;
468 		return;
469 	}
470 
471 	status = acpi_bus_get_status(device);
472 	if (ACPI_FAILURE(status))
473 		return;
474 
475 	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
476 		return;
477 
478 	/*
479 	 * Device Insertion/Removal
480 	 */
481 	if ((device->status.present) && !(old_status.present)) {
482 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
483 		/* TBD: Handle device insertion */
484 	} else if (!(device->status.present) && (old_status.present)) {
485 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
486 		/* TBD: Handle device removal */
487 	}
488 }
489 
490 static void acpi_bus_check_scope(acpi_handle handle)
491 {
492 	/* Status Change? */
493 	acpi_bus_check_device(handle);
494 
495 	/*
496 	 * TBD: Enumerate child devices within this device's scope and
497 	 *       run acpi_bus_check_device()'s on them.
498 	 */
499 }
500 
501 static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
502 int register_acpi_bus_notifier(struct notifier_block *nb)
503 {
504 	return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
505 }
506 EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
507 
508 void unregister_acpi_bus_notifier(struct notifier_block *nb)
509 {
510 	blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
511 }
512 EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
513 
514 /**
515  * acpi_bus_notify
516  * ---------------
517  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
518  */
519 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
520 {
521 	struct acpi_device *device = NULL;
522 	struct acpi_driver *driver;
523 
524 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
525 			  type, handle));
526 
527 	blocking_notifier_call_chain(&acpi_bus_notify_list,
528 		type, (void *)handle);
529 
530 	switch (type) {
531 
532 	case ACPI_NOTIFY_BUS_CHECK:
533 		acpi_bus_check_scope(handle);
534 		/*
535 		 * TBD: We'll need to outsource certain events to non-ACPI
536 		 *      drivers via the device manager (device.c).
537 		 */
538 		break;
539 
540 	case ACPI_NOTIFY_DEVICE_CHECK:
541 		acpi_bus_check_device(handle);
542 		/*
543 		 * TBD: We'll need to outsource certain events to non-ACPI
544 		 *      drivers via the device manager (device.c).
545 		 */
546 		break;
547 
548 	case ACPI_NOTIFY_DEVICE_WAKE:
549 		/* TBD */
550 		break;
551 
552 	case ACPI_NOTIFY_EJECT_REQUEST:
553 		/* TBD */
554 		break;
555 
556 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
557 		/* TBD: Exactly what does 'light' mean? */
558 		break;
559 
560 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
561 		/* TBD */
562 		break;
563 
564 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
565 		/* TBD */
566 		break;
567 
568 	case ACPI_NOTIFY_POWER_FAULT:
569 		/* TBD */
570 		break;
571 
572 	default:
573 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
574 				  "Received unknown/unsupported notification [%08x]\n",
575 				  type));
576 		break;
577 	}
578 
579 	acpi_bus_get_device(handle, &device);
580 	if (device) {
581 		driver = device->driver;
582 		if (driver && driver->ops.notify &&
583 		    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
584 			driver->ops.notify(device, type);
585 	}
586 }
587 
588 /* --------------------------------------------------------------------------
589                              Initialization/Cleanup
590    -------------------------------------------------------------------------- */
591 
592 static int __init acpi_bus_init_irq(void)
593 {
594 	acpi_status status = AE_OK;
595 	union acpi_object arg = { ACPI_TYPE_INTEGER };
596 	struct acpi_object_list arg_list = { 1, &arg };
597 	char *message = NULL;
598 
599 
600 	/*
601 	 * Let the system know what interrupt model we are using by
602 	 * evaluating the \_PIC object, if exists.
603 	 */
604 
605 	switch (acpi_irq_model) {
606 	case ACPI_IRQ_MODEL_PIC:
607 		message = "PIC";
608 		break;
609 	case ACPI_IRQ_MODEL_IOAPIC:
610 		message = "IOAPIC";
611 		break;
612 	case ACPI_IRQ_MODEL_IOSAPIC:
613 		message = "IOSAPIC";
614 		break;
615 	case ACPI_IRQ_MODEL_PLATFORM:
616 		message = "platform specific model";
617 		break;
618 	default:
619 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
620 		return -ENODEV;
621 	}
622 
623 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
624 
625 	arg.integer.value = acpi_irq_model;
626 
627 	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
628 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
629 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
630 		return -ENODEV;
631 	}
632 
633 	return 0;
634 }
635 
636 u8 acpi_gbl_permanent_mmap;
637 
638 
639 void __init acpi_early_init(void)
640 {
641 	acpi_status status = AE_OK;
642 
643 	if (acpi_disabled)
644 		return;
645 
646 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
647 
648 	/* enable workarounds, unless strict ACPI spec. compliance */
649 	if (!acpi_strict)
650 		acpi_gbl_enable_interpreter_slack = TRUE;
651 
652 	acpi_gbl_permanent_mmap = 1;
653 
654 	status = acpi_reallocate_root_table();
655 	if (ACPI_FAILURE(status)) {
656 		printk(KERN_ERR PREFIX
657 		       "Unable to reallocate ACPI tables\n");
658 		goto error0;
659 	}
660 
661 	status = acpi_initialize_subsystem();
662 	if (ACPI_FAILURE(status)) {
663 		printk(KERN_ERR PREFIX
664 		       "Unable to initialize the ACPI Interpreter\n");
665 		goto error0;
666 	}
667 
668 	status = acpi_load_tables();
669 	if (ACPI_FAILURE(status)) {
670 		printk(KERN_ERR PREFIX
671 		       "Unable to load the System Description Tables\n");
672 		goto error0;
673 	}
674 
675 #ifdef CONFIG_X86
676 	if (!acpi_ioapic) {
677 		/* compatible (0) means level (3) */
678 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
679 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
680 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
681 		}
682 		/* Set PIC-mode SCI trigger type */
683 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
684 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
685 	} else {
686 		/*
687 		 * now that acpi_gbl_FADT is initialized,
688 		 * update it with result from INT_SRC_OVR parsing
689 		 */
690 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
691 	}
692 #endif
693 
694 	status =
695 	    acpi_enable_subsystem(~
696 				  (ACPI_NO_HARDWARE_INIT |
697 				   ACPI_NO_ACPI_ENABLE));
698 	if (ACPI_FAILURE(status)) {
699 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
700 		goto error0;
701 	}
702 
703 	return;
704 
705       error0:
706 	disable_acpi();
707 	return;
708 }
709 
710 static int __init acpi_bus_init(void)
711 {
712 	int result = 0;
713 	acpi_status status = AE_OK;
714 	extern acpi_status acpi_os_initialize1(void);
715 
716 	acpi_os_initialize1();
717 
718 	status =
719 	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
720 	if (ACPI_FAILURE(status)) {
721 		printk(KERN_ERR PREFIX
722 		       "Unable to start the ACPI Interpreter\n");
723 		goto error1;
724 	}
725 
726 	/*
727 	 * ACPI 2.0 requires the EC driver to be loaded and work before
728 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
729 	 * is called).
730 	 *
731 	 * This is accomplished by looking for the ECDT table, and getting
732 	 * the EC parameters out of that.
733 	 */
734 	status = acpi_ec_ecdt_probe();
735 	/* Ignore result. Not having an ECDT is not fatal. */
736 
737 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
738 	if (ACPI_FAILURE(status)) {
739 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
740 		goto error1;
741 	}
742 
743 	/*
744 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
745 	 * is necessary to enable it as early as possible.
746 	 */
747 	acpi_boot_ec_enable();
748 
749 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
750 
751 	/* Initialize sleep structures */
752 	acpi_sleep_init();
753 
754 	/*
755 	 * Get the system interrupt model and evaluate \_PIC.
756 	 */
757 	result = acpi_bus_init_irq();
758 	if (result)
759 		goto error1;
760 
761 	/*
762 	 * Register the for all standard device notifications.
763 	 */
764 	status =
765 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
766 					&acpi_bus_notify, NULL);
767 	if (ACPI_FAILURE(status)) {
768 		printk(KERN_ERR PREFIX
769 		       "Unable to register for device notifications\n");
770 		goto error1;
771 	}
772 
773 	/*
774 	 * Create the top ACPI proc directory
775 	 */
776 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
777 
778 	return 0;
779 
780 	/* Mimic structured exception handling */
781       error1:
782 	acpi_terminate();
783 	return -ENODEV;
784 }
785 
786 struct kobject *acpi_kobj;
787 
788 static int __init acpi_init(void)
789 {
790 	int result = 0;
791 
792 
793 	if (acpi_disabled) {
794 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
795 		return -ENODEV;
796 	}
797 
798 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
799 	if (!acpi_kobj) {
800 		printk(KERN_WARNING "%s: kset create error\n", __func__);
801 		acpi_kobj = NULL;
802 	}
803 
804 	init_acpi_device_notify();
805 	result = acpi_bus_init();
806 
807 	if (!result) {
808 		pci_mmcfg_late_init();
809 		if (!(pm_flags & PM_APM))
810 			pm_flags |= PM_ACPI;
811 		else {
812 			printk(KERN_INFO PREFIX
813 			       "APM is already active, exiting\n");
814 			disable_acpi();
815 			result = -ENODEV;
816 		}
817 	} else
818 		disable_acpi();
819 
820 	if (acpi_disabled)
821 		return result;
822 
823 	/*
824 	 * If the laptop falls into the DMI check table, the power state check
825 	 * will be disabled in the course of device power transistion.
826 	 */
827 	dmi_check_system(power_nocheck_dmi_table);
828 
829 	acpi_scan_init();
830 	acpi_ec_init();
831 	acpi_power_init();
832 	acpi_system_init();
833 	acpi_debug_init();
834 	acpi_sleep_proc_init();
835 	acpi_wakeup_device_init();
836 	return result;
837 }
838 
839 subsys_initcall(acpi_init);
840