xref: /openbmc/linux/drivers/acpi/bus.c (revision fd589a8f)
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 
42 #include "internal.h"
43 
44 #define _COMPONENT		ACPI_BUS_COMPONENT
45 ACPI_MODULE_NAME("bus");
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 static int set_power_nocheck(const struct dmi_system_id *id)
54 {
55 	printk(KERN_NOTICE PREFIX "%s detected - "
56 		"disable power check in power transistion\n", id->ident);
57 	acpi_power_nocheck = 1;
58 	return 0;
59 }
60 static struct dmi_system_id __cpuinitdata power_nocheck_dmi_table[] = {
61 	{
62 	set_power_nocheck, "HP Pavilion 05", {
63 	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
64 	DMI_MATCH(DMI_SYS_VENDOR, "HP Pavilion 05"),
65 	DMI_MATCH(DMI_PRODUCT_VERSION, "2001211RE101GLEND") }, NULL},
66 	{},
67 };
68 
69 
70 /* --------------------------------------------------------------------------
71                                 Device Management
72    -------------------------------------------------------------------------- */
73 
74 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
75 {
76 	acpi_status status = AE_OK;
77 
78 
79 	if (!device)
80 		return -EINVAL;
81 
82 	/* TBD: Support fixed-feature devices */
83 
84 	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
85 	if (ACPI_FAILURE(status) || !*device) {
86 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
87 				  handle));
88 		return -ENODEV;
89 	}
90 
91 	return 0;
92 }
93 
94 EXPORT_SYMBOL(acpi_bus_get_device);
95 
96 int acpi_bus_get_status(struct acpi_device *device)
97 {
98 	acpi_status status = AE_OK;
99 	unsigned long long sta = 0;
100 
101 
102 	if (!device)
103 		return -EINVAL;
104 
105 	/*
106 	 * Evaluate _STA if present.
107 	 */
108 	if (device->flags.dynamic_status) {
109 		status =
110 		    acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
111 		if (ACPI_FAILURE(status))
112 			return -ENODEV;
113 		STRUCT_TO_INT(device->status) = (int)sta;
114 	}
115 
116 	/*
117 	 * According to ACPI spec some device can be present and functional
118 	 * even if the parent is not present but functional.
119 	 * In such conditions the child device should not inherit the status
120 	 * from the parent.
121 	 */
122 	else
123 		STRUCT_TO_INT(device->status) =
124 		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
125 		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
126 
127 	if (device->status.functional && !device->status.present) {
128 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
129 		       "functional but not present;\n",
130 			device->pnp.bus_id,
131 			(u32) STRUCT_TO_INT(device->status)));
132 	}
133 
134 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
135 			  device->pnp.bus_id,
136 			  (u32) STRUCT_TO_INT(device->status)));
137 
138 	return 0;
139 }
140 
141 EXPORT_SYMBOL(acpi_bus_get_status);
142 
143 void acpi_bus_private_data_handler(acpi_handle handle,
144 				   u32 function, void *context)
145 {
146 	return;
147 }
148 EXPORT_SYMBOL(acpi_bus_private_data_handler);
149 
150 int acpi_bus_get_private_data(acpi_handle handle, void **data)
151 {
152 	acpi_status status = AE_OK;
153 
154 	if (!*data)
155 		return -EINVAL;
156 
157 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
158 	if (ACPI_FAILURE(status) || !*data) {
159 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
160 				handle));
161 		return -ENODEV;
162 	}
163 
164 	return 0;
165 }
166 EXPORT_SYMBOL(acpi_bus_get_private_data);
167 
168 /* --------------------------------------------------------------------------
169                                  Power Management
170    -------------------------------------------------------------------------- */
171 
172 int acpi_bus_get_power(acpi_handle handle, int *state)
173 {
174 	int result = 0;
175 	acpi_status status = 0;
176 	struct acpi_device *device = NULL;
177 	unsigned long long psc = 0;
178 
179 
180 	result = acpi_bus_get_device(handle, &device);
181 	if (result)
182 		return result;
183 
184 	*state = ACPI_STATE_UNKNOWN;
185 
186 	if (!device->flags.power_manageable) {
187 		/* TBD: Non-recursive algorithm for walking up hierarchy */
188 		if (device->parent)
189 			*state = device->parent->power.state;
190 		else
191 			*state = ACPI_STATE_D0;
192 	} else {
193 		/*
194 		 * Get the device's power state either directly (via _PSC) or
195 		 * indirectly (via power resources).
196 		 */
197 		if (device->power.flags.explicit_get) {
198 			status = acpi_evaluate_integer(device->handle, "_PSC",
199 						       NULL, &psc);
200 			if (ACPI_FAILURE(status))
201 				return -ENODEV;
202 			device->power.state = (int)psc;
203 		} else if (device->power.flags.power_resources) {
204 			result = acpi_power_get_inferred_state(device);
205 			if (result)
206 				return result;
207 		}
208 
209 		*state = device->power.state;
210 	}
211 
212 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
213 			  device->pnp.bus_id, device->power.state));
214 
215 	return 0;
216 }
217 
218 EXPORT_SYMBOL(acpi_bus_get_power);
219 
220 int acpi_bus_set_power(acpi_handle handle, int state)
221 {
222 	int result = 0;
223 	acpi_status status = AE_OK;
224 	struct acpi_device *device = NULL;
225 	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
226 
227 
228 	result = acpi_bus_get_device(handle, &device);
229 	if (result)
230 		return result;
231 
232 	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
233 		return -EINVAL;
234 
235 	/* Make sure this is a valid target state */
236 
237 	if (!device->flags.power_manageable) {
238 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
239 				kobject_name(&device->dev.kobj)));
240 		return -ENODEV;
241 	}
242 	/*
243 	 * Get device's current power state
244 	 */
245 	if (!acpi_power_nocheck) {
246 		/*
247 		 * Maybe the incorrect power state is returned on the bogus
248 		 * bios, which is different with the real power state.
249 		 * For example: the bios returns D0 state and the real power
250 		 * state is D3. OS expects to set the device to D0 state. In
251 		 * such case if OS uses the power state returned by the BIOS,
252 		 * the device can't be transisted to the correct power state.
253 		 * So if the acpi_power_nocheck is set, it is unnecessary to
254 		 * get the power state by calling acpi_bus_get_power.
255 		 */
256 		acpi_bus_get_power(device->handle, &device->power.state);
257 	}
258 	if ((state == device->power.state) && !device->flags.force_power_state) {
259 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
260 				  state));
261 		return 0;
262 	}
263 
264 	if (!device->power.states[state].flags.valid) {
265 		printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
266 		return -ENODEV;
267 	}
268 	if (device->parent && (state < device->parent->power.state)) {
269 		printk(KERN_WARNING PREFIX
270 			      "Cannot set device to a higher-powered"
271 			      " state than parent\n");
272 		return -ENODEV;
273 	}
274 
275 	/*
276 	 * Transition Power
277 	 * ----------------
278 	 * On transitions to a high-powered state we first apply power (via
279 	 * power resources) then evalute _PSx.  Conversly for transitions to
280 	 * a lower-powered state.
281 	 */
282 	if (state < device->power.state) {
283 		if (device->power.flags.power_resources) {
284 			result = acpi_power_transition(device, state);
285 			if (result)
286 				goto end;
287 		}
288 		if (device->power.states[state].flags.explicit_set) {
289 			status = acpi_evaluate_object(device->handle,
290 						      object_name, NULL, NULL);
291 			if (ACPI_FAILURE(status)) {
292 				result = -ENODEV;
293 				goto end;
294 			}
295 		}
296 	} else {
297 		if (device->power.states[state].flags.explicit_set) {
298 			status = acpi_evaluate_object(device->handle,
299 						      object_name, NULL, NULL);
300 			if (ACPI_FAILURE(status)) {
301 				result = -ENODEV;
302 				goto end;
303 			}
304 		}
305 		if (device->power.flags.power_resources) {
306 			result = acpi_power_transition(device, state);
307 			if (result)
308 				goto end;
309 		}
310 	}
311 
312       end:
313 	if (result)
314 		printk(KERN_WARNING PREFIX
315 			      "Device [%s] failed to transition to D%d\n",
316 			      device->pnp.bus_id, state);
317 	else {
318 		device->power.state = state;
319 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
320 				  "Device [%s] transitioned to D%d\n",
321 				  device->pnp.bus_id, state));
322 	}
323 
324 	return result;
325 }
326 
327 EXPORT_SYMBOL(acpi_bus_set_power);
328 
329 bool acpi_bus_power_manageable(acpi_handle handle)
330 {
331 	struct acpi_device *device;
332 	int result;
333 
334 	result = acpi_bus_get_device(handle, &device);
335 	return result ? false : device->flags.power_manageable;
336 }
337 
338 EXPORT_SYMBOL(acpi_bus_power_manageable);
339 
340 bool acpi_bus_can_wakeup(acpi_handle handle)
341 {
342 	struct acpi_device *device;
343 	int result;
344 
345 	result = acpi_bus_get_device(handle, &device);
346 	return result ? false : device->wakeup.flags.valid;
347 }
348 
349 EXPORT_SYMBOL(acpi_bus_can_wakeup);
350 
351 /* --------------------------------------------------------------------------
352                                 Event Management
353    -------------------------------------------------------------------------- */
354 
355 #ifdef CONFIG_ACPI_PROC_EVENT
356 static DEFINE_SPINLOCK(acpi_bus_event_lock);
357 
358 LIST_HEAD(acpi_bus_event_list);
359 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
360 
361 extern int event_is_open;
362 
363 int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
364 {
365 	struct acpi_bus_event *event;
366 	unsigned long flags = 0;
367 
368 	/* drop event on the floor if no one's listening */
369 	if (!event_is_open)
370 		return 0;
371 
372 	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
373 	if (!event)
374 		return -ENOMEM;
375 
376 	strcpy(event->device_class, device_class);
377 	strcpy(event->bus_id, bus_id);
378 	event->type = type;
379 	event->data = data;
380 
381 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
382 	list_add_tail(&event->node, &acpi_bus_event_list);
383 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
384 
385 	wake_up_interruptible(&acpi_bus_event_queue);
386 
387 	return 0;
388 
389 }
390 
391 EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
392 
393 int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
394 {
395 	if (!device)
396 		return -EINVAL;
397 	return acpi_bus_generate_proc_event4(device->pnp.device_class,
398 					     device->pnp.bus_id, type, data);
399 }
400 
401 EXPORT_SYMBOL(acpi_bus_generate_proc_event);
402 
403 int acpi_bus_receive_event(struct acpi_bus_event *event)
404 {
405 	unsigned long flags = 0;
406 	struct acpi_bus_event *entry = NULL;
407 
408 	DECLARE_WAITQUEUE(wait, current);
409 
410 
411 	if (!event)
412 		return -EINVAL;
413 
414 	if (list_empty(&acpi_bus_event_list)) {
415 
416 		set_current_state(TASK_INTERRUPTIBLE);
417 		add_wait_queue(&acpi_bus_event_queue, &wait);
418 
419 		if (list_empty(&acpi_bus_event_list))
420 			schedule();
421 
422 		remove_wait_queue(&acpi_bus_event_queue, &wait);
423 		set_current_state(TASK_RUNNING);
424 
425 		if (signal_pending(current))
426 			return -ERESTARTSYS;
427 	}
428 
429 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
430 	if (!list_empty(&acpi_bus_event_list)) {
431 		entry = list_entry(acpi_bus_event_list.next,
432 				   struct acpi_bus_event, node);
433 		list_del(&entry->node);
434 	}
435 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
436 
437 	if (!entry)
438 		return -ENODEV;
439 
440 	memcpy(event, entry, sizeof(struct acpi_bus_event));
441 
442 	kfree(entry);
443 
444 	return 0;
445 }
446 
447 #endif	/* CONFIG_ACPI_PROC_EVENT */
448 
449 /* --------------------------------------------------------------------------
450                              Notification Handling
451    -------------------------------------------------------------------------- */
452 
453 static void acpi_bus_check_device(acpi_handle handle)
454 {
455 	struct acpi_device *device;
456 	acpi_status status;
457 	struct acpi_device_status old_status;
458 
459 	if (acpi_bus_get_device(handle, &device))
460 		return;
461 	if (!device)
462 		return;
463 
464 	old_status = device->status;
465 
466 	/*
467 	 * Make sure this device's parent is present before we go about
468 	 * messing with the device.
469 	 */
470 	if (device->parent && !device->parent->status.present) {
471 		device->status = device->parent->status;
472 		return;
473 	}
474 
475 	status = acpi_bus_get_status(device);
476 	if (ACPI_FAILURE(status))
477 		return;
478 
479 	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
480 		return;
481 
482 	/*
483 	 * Device Insertion/Removal
484 	 */
485 	if ((device->status.present) && !(old_status.present)) {
486 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
487 		/* TBD: Handle device insertion */
488 	} else if (!(device->status.present) && (old_status.present)) {
489 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
490 		/* TBD: Handle device removal */
491 	}
492 }
493 
494 static void acpi_bus_check_scope(acpi_handle handle)
495 {
496 	/* Status Change? */
497 	acpi_bus_check_device(handle);
498 
499 	/*
500 	 * TBD: Enumerate child devices within this device's scope and
501 	 *       run acpi_bus_check_device()'s on them.
502 	 */
503 }
504 
505 static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
506 int register_acpi_bus_notifier(struct notifier_block *nb)
507 {
508 	return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
509 }
510 EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
511 
512 void unregister_acpi_bus_notifier(struct notifier_block *nb)
513 {
514 	blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
515 }
516 EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
517 
518 /**
519  * acpi_bus_notify
520  * ---------------
521  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
522  */
523 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
524 {
525 	struct acpi_device *device = NULL;
526 	struct acpi_driver *driver;
527 
528 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
529 			  type, handle));
530 
531 	blocking_notifier_call_chain(&acpi_bus_notify_list,
532 		type, (void *)handle);
533 
534 	switch (type) {
535 
536 	case ACPI_NOTIFY_BUS_CHECK:
537 		acpi_bus_check_scope(handle);
538 		/*
539 		 * TBD: We'll need to outsource certain events to non-ACPI
540 		 *      drivers via the device manager (device.c).
541 		 */
542 		break;
543 
544 	case ACPI_NOTIFY_DEVICE_CHECK:
545 		acpi_bus_check_device(handle);
546 		/*
547 		 * TBD: We'll need to outsource certain events to non-ACPI
548 		 *      drivers via the device manager (device.c).
549 		 */
550 		break;
551 
552 	case ACPI_NOTIFY_DEVICE_WAKE:
553 		/* TBD */
554 		break;
555 
556 	case ACPI_NOTIFY_EJECT_REQUEST:
557 		/* TBD */
558 		break;
559 
560 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
561 		/* TBD: Exactly what does 'light' mean? */
562 		break;
563 
564 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
565 		/* TBD */
566 		break;
567 
568 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
569 		/* TBD */
570 		break;
571 
572 	case ACPI_NOTIFY_POWER_FAULT:
573 		/* TBD */
574 		break;
575 
576 	default:
577 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
578 				  "Received unknown/unsupported notification [%08x]\n",
579 				  type));
580 		break;
581 	}
582 
583 	acpi_bus_get_device(handle, &device);
584 	if (device) {
585 		driver = device->driver;
586 		if (driver && driver->ops.notify &&
587 		    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
588 			driver->ops.notify(device, type);
589 	}
590 }
591 
592 /* --------------------------------------------------------------------------
593                              Initialization/Cleanup
594    -------------------------------------------------------------------------- */
595 
596 static int __init acpi_bus_init_irq(void)
597 {
598 	acpi_status status = AE_OK;
599 	union acpi_object arg = { ACPI_TYPE_INTEGER };
600 	struct acpi_object_list arg_list = { 1, &arg };
601 	char *message = NULL;
602 
603 
604 	/*
605 	 * Let the system know what interrupt model we are using by
606 	 * evaluating the \_PIC object, if exists.
607 	 */
608 
609 	switch (acpi_irq_model) {
610 	case ACPI_IRQ_MODEL_PIC:
611 		message = "PIC";
612 		break;
613 	case ACPI_IRQ_MODEL_IOAPIC:
614 		message = "IOAPIC";
615 		break;
616 	case ACPI_IRQ_MODEL_IOSAPIC:
617 		message = "IOSAPIC";
618 		break;
619 	case ACPI_IRQ_MODEL_PLATFORM:
620 		message = "platform specific model";
621 		break;
622 	default:
623 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
624 		return -ENODEV;
625 	}
626 
627 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
628 
629 	arg.integer.value = acpi_irq_model;
630 
631 	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
632 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
633 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
634 		return -ENODEV;
635 	}
636 
637 	return 0;
638 }
639 
640 u8 acpi_gbl_permanent_mmap;
641 
642 
643 void __init acpi_early_init(void)
644 {
645 	acpi_status status = AE_OK;
646 
647 	if (acpi_disabled)
648 		return;
649 
650 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
651 
652 	/* enable workarounds, unless strict ACPI spec. compliance */
653 	if (!acpi_strict)
654 		acpi_gbl_enable_interpreter_slack = TRUE;
655 
656 	acpi_gbl_permanent_mmap = 1;
657 
658 	status = acpi_reallocate_root_table();
659 	if (ACPI_FAILURE(status)) {
660 		printk(KERN_ERR PREFIX
661 		       "Unable to reallocate ACPI tables\n");
662 		goto error0;
663 	}
664 
665 	status = acpi_initialize_subsystem();
666 	if (ACPI_FAILURE(status)) {
667 		printk(KERN_ERR PREFIX
668 		       "Unable to initialize the ACPI Interpreter\n");
669 		goto error0;
670 	}
671 
672 	status = acpi_load_tables();
673 	if (ACPI_FAILURE(status)) {
674 		printk(KERN_ERR PREFIX
675 		       "Unable to load the System Description Tables\n");
676 		goto error0;
677 	}
678 
679 #ifdef CONFIG_X86
680 	if (!acpi_ioapic) {
681 		/* compatible (0) means level (3) */
682 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
683 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
684 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
685 		}
686 		/* Set PIC-mode SCI trigger type */
687 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
688 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
689 	} else {
690 		/*
691 		 * now that acpi_gbl_FADT is initialized,
692 		 * update it with result from INT_SRC_OVR parsing
693 		 */
694 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
695 	}
696 #endif
697 
698 	status =
699 	    acpi_enable_subsystem(~
700 				  (ACPI_NO_HARDWARE_INIT |
701 				   ACPI_NO_ACPI_ENABLE));
702 	if (ACPI_FAILURE(status)) {
703 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
704 		goto error0;
705 	}
706 
707 	return;
708 
709       error0:
710 	disable_acpi();
711 	return;
712 }
713 
714 static int __init acpi_bus_init(void)
715 {
716 	int result = 0;
717 	acpi_status status = AE_OK;
718 	extern acpi_status acpi_os_initialize1(void);
719 
720 	acpi_os_initialize1();
721 
722 	status =
723 	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
724 	if (ACPI_FAILURE(status)) {
725 		printk(KERN_ERR PREFIX
726 		       "Unable to start the ACPI Interpreter\n");
727 		goto error1;
728 	}
729 
730 	/*
731 	 * ACPI 2.0 requires the EC driver to be loaded and work before
732 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
733 	 * is called).
734 	 *
735 	 * This is accomplished by looking for the ECDT table, and getting
736 	 * the EC parameters out of that.
737 	 */
738 	status = acpi_ec_ecdt_probe();
739 	/* Ignore result. Not having an ECDT is not fatal. */
740 
741 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
742 	if (ACPI_FAILURE(status)) {
743 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
744 		goto error1;
745 	}
746 
747 	/*
748 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
749 	 * is necessary to enable it as early as possible.
750 	 */
751 	acpi_boot_ec_enable();
752 
753 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
754 
755 	/* Initialize sleep structures */
756 	acpi_sleep_init();
757 
758 	/*
759 	 * Get the system interrupt model and evaluate \_PIC.
760 	 */
761 	result = acpi_bus_init_irq();
762 	if (result)
763 		goto error1;
764 
765 	/*
766 	 * Register the for all standard device notifications.
767 	 */
768 	status =
769 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
770 					&acpi_bus_notify, NULL);
771 	if (ACPI_FAILURE(status)) {
772 		printk(KERN_ERR PREFIX
773 		       "Unable to register for device notifications\n");
774 		goto error1;
775 	}
776 
777 	/*
778 	 * Create the top ACPI proc directory
779 	 */
780 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
781 
782 	return 0;
783 
784 	/* Mimic structured exception handling */
785       error1:
786 	acpi_terminate();
787 	return -ENODEV;
788 }
789 
790 struct kobject *acpi_kobj;
791 
792 static int __init acpi_init(void)
793 {
794 	int result = 0;
795 
796 
797 	if (acpi_disabled) {
798 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
799 		return -ENODEV;
800 	}
801 
802 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
803 	if (!acpi_kobj) {
804 		printk(KERN_WARNING "%s: kset create error\n", __func__);
805 		acpi_kobj = NULL;
806 	}
807 
808 	init_acpi_device_notify();
809 	result = acpi_bus_init();
810 
811 	if (!result) {
812 		pci_mmcfg_late_init();
813 		if (!(pm_flags & PM_APM))
814 			pm_flags |= PM_ACPI;
815 		else {
816 			printk(KERN_INFO PREFIX
817 			       "APM is already active, exiting\n");
818 			disable_acpi();
819 			result = -ENODEV;
820 		}
821 	} else
822 		disable_acpi();
823 
824 	if (acpi_disabled)
825 		return result;
826 
827 	/*
828 	 * If the laptop falls into the DMI check table, the power state check
829 	 * will be disabled in the course of device power transistion.
830 	 */
831 	dmi_check_system(power_nocheck_dmi_table);
832 
833 	acpi_scan_init();
834 	acpi_ec_init();
835 	acpi_power_init();
836 	acpi_system_init();
837 	acpi_debug_init();
838 	acpi_sleep_proc_init();
839 	acpi_wakeup_device_init();
840 	return result;
841 }
842 
843 subsys_initcall(acpi_init);
844