xref: /openbmc/linux/drivers/acpi/bus.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 #include <linux/slab.h>
36 #ifdef CONFIG_X86
37 #include <asm/mpspec.h>
38 #endif
39 #include <linux/pci.h>
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
42 #include <linux/dmi.h>
43 
44 #include "internal.h"
45 
46 #define _COMPONENT		ACPI_BUS_COMPONENT
47 ACPI_MODULE_NAME("bus");
48 
49 struct acpi_device *acpi_root;
50 struct proc_dir_entry *acpi_root_dir;
51 EXPORT_SYMBOL(acpi_root_dir);
52 
53 #define STRUCT_TO_INT(s)	(*((int*)&s))
54 
55 static int set_power_nocheck(const struct dmi_system_id *id)
56 {
57 	printk(KERN_NOTICE PREFIX "%s detected - "
58 		"disable power check in power transition\n", id->ident);
59 	acpi_power_nocheck = 1;
60 	return 0;
61 }
62 static struct dmi_system_id __cpuinitdata power_nocheck_dmi_table[] = {
63 	{
64 	set_power_nocheck, "HP Pavilion 05", {
65 	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
66 	DMI_MATCH(DMI_SYS_VENDOR, "HP Pavilion 05"),
67 	DMI_MATCH(DMI_PRODUCT_VERSION, "2001211RE101GLEND") }, NULL},
68 	{},
69 };
70 
71 
72 #ifdef CONFIG_X86
73 static int set_copy_dsdt(const struct dmi_system_id *id)
74 {
75 	printk(KERN_NOTICE "%s detected - "
76 		"force copy of DSDT to local memory\n", id->ident);
77 	acpi_gbl_copy_dsdt_locally = 1;
78 	return 0;
79 }
80 
81 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
82 	/*
83 	 * Invoke DSDT corruption work-around on all Toshiba Satellite.
84 	 * https://bugzilla.kernel.org/show_bug.cgi?id=14679
85 	 */
86 	{
87 	 .callback = set_copy_dsdt,
88 	 .ident = "TOSHIBA Satellite",
89 	 .matches = {
90 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
91 		DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
92 		},
93 	},
94 	{}
95 };
96 #else
97 static struct dmi_system_id dsdt_dmi_table[] __initdata = {
98 	{}
99 };
100 #endif
101 
102 /* --------------------------------------------------------------------------
103                                 Device Management
104    -------------------------------------------------------------------------- */
105 
106 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
107 {
108 	acpi_status status = AE_OK;
109 
110 
111 	if (!device)
112 		return -EINVAL;
113 
114 	/* TBD: Support fixed-feature devices */
115 
116 	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
117 	if (ACPI_FAILURE(status) || !*device) {
118 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
119 				  handle));
120 		return -ENODEV;
121 	}
122 
123 	return 0;
124 }
125 
126 EXPORT_SYMBOL(acpi_bus_get_device);
127 
128 acpi_status acpi_bus_get_status_handle(acpi_handle handle,
129 				       unsigned long long *sta)
130 {
131 	acpi_status status;
132 
133 	status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
134 	if (ACPI_SUCCESS(status))
135 		return AE_OK;
136 
137 	if (status == AE_NOT_FOUND) {
138 		*sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
139 		       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
140 		return AE_OK;
141 	}
142 	return status;
143 }
144 
145 int acpi_bus_get_status(struct acpi_device *device)
146 {
147 	acpi_status status;
148 	unsigned long long sta;
149 
150 	status = acpi_bus_get_status_handle(device->handle, &sta);
151 	if (ACPI_FAILURE(status))
152 		return -ENODEV;
153 
154 	STRUCT_TO_INT(device->status) = (int) sta;
155 
156 	if (device->status.functional && !device->status.present) {
157 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
158 		       "functional but not present;\n",
159 			device->pnp.bus_id,
160 			(u32) STRUCT_TO_INT(device->status)));
161 	}
162 
163 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
164 			  device->pnp.bus_id,
165 			  (u32) STRUCT_TO_INT(device->status)));
166 	return 0;
167 }
168 EXPORT_SYMBOL(acpi_bus_get_status);
169 
170 void acpi_bus_private_data_handler(acpi_handle handle,
171 				   void *context)
172 {
173 	return;
174 }
175 EXPORT_SYMBOL(acpi_bus_private_data_handler);
176 
177 int acpi_bus_get_private_data(acpi_handle handle, void **data)
178 {
179 	acpi_status status = AE_OK;
180 
181 	if (!*data)
182 		return -EINVAL;
183 
184 	status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
185 	if (ACPI_FAILURE(status) || !*data) {
186 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
187 				handle));
188 		return -ENODEV;
189 	}
190 
191 	return 0;
192 }
193 EXPORT_SYMBOL(acpi_bus_get_private_data);
194 
195 /* --------------------------------------------------------------------------
196                                  Power Management
197    -------------------------------------------------------------------------- */
198 
199 int acpi_bus_get_power(acpi_handle handle, int *state)
200 {
201 	int result = 0;
202 	acpi_status status = 0;
203 	struct acpi_device *device = NULL;
204 	unsigned long long psc = 0;
205 
206 
207 	result = acpi_bus_get_device(handle, &device);
208 	if (result)
209 		return result;
210 
211 	*state = ACPI_STATE_UNKNOWN;
212 
213 	if (!device->flags.power_manageable) {
214 		/* TBD: Non-recursive algorithm for walking up hierarchy */
215 		if (device->parent)
216 			*state = device->parent->power.state;
217 		else
218 			*state = ACPI_STATE_D0;
219 	} else {
220 		/*
221 		 * Get the device's power state either directly (via _PSC) or
222 		 * indirectly (via power resources).
223 		 */
224 		if (device->power.flags.power_resources) {
225 			result = acpi_power_get_inferred_state(device);
226 			if (result)
227 				return result;
228 		} else if (device->power.flags.explicit_get) {
229 			status = acpi_evaluate_integer(device->handle, "_PSC",
230 						       NULL, &psc);
231 			if (ACPI_FAILURE(status))
232 				return -ENODEV;
233 			device->power.state = (int)psc;
234 		}
235 
236 		*state = device->power.state;
237 	}
238 
239 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
240 			  device->pnp.bus_id, device->power.state));
241 
242 	return 0;
243 }
244 
245 EXPORT_SYMBOL(acpi_bus_get_power);
246 
247 int acpi_bus_set_power(acpi_handle handle, int state)
248 {
249 	int result = 0;
250 	acpi_status status = AE_OK;
251 	struct acpi_device *device = NULL;
252 	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
253 
254 
255 	result = acpi_bus_get_device(handle, &device);
256 	if (result)
257 		return result;
258 
259 	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
260 		return -EINVAL;
261 
262 	/* Make sure this is a valid target state */
263 
264 	if (!device->flags.power_manageable) {
265 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
266 				kobject_name(&device->dev.kobj)));
267 		return -ENODEV;
268 	}
269 	/*
270 	 * Get device's current power state
271 	 */
272 	if (!acpi_power_nocheck) {
273 		/*
274 		 * Maybe the incorrect power state is returned on the bogus
275 		 * bios, which is different with the real power state.
276 		 * For example: the bios returns D0 state and the real power
277 		 * state is D3. OS expects to set the device to D0 state. In
278 		 * such case if OS uses the power state returned by the BIOS,
279 		 * the device can't be transisted to the correct power state.
280 		 * So if the acpi_power_nocheck is set, it is unnecessary to
281 		 * get the power state by calling acpi_bus_get_power.
282 		 */
283 		acpi_bus_get_power(device->handle, &device->power.state);
284 	}
285 	if ((state == device->power.state) && !device->flags.force_power_state) {
286 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
287 				  state));
288 		return 0;
289 	}
290 
291 	if (!device->power.states[state].flags.valid) {
292 		printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
293 		return -ENODEV;
294 	}
295 	if (device->parent && (state < device->parent->power.state)) {
296 		printk(KERN_WARNING PREFIX
297 			      "Cannot set device to a higher-powered"
298 			      " state than parent\n");
299 		return -ENODEV;
300 	}
301 
302 	/*
303 	 * Transition Power
304 	 * ----------------
305 	 * On transitions to a high-powered state we first apply power (via
306 	 * power resources) then evalute _PSx.  Conversly for transitions to
307 	 * a lower-powered state.
308 	 */
309 	if (state < device->power.state) {
310 		if (device->power.flags.power_resources) {
311 			result = acpi_power_transition(device, state);
312 			if (result)
313 				goto end;
314 		}
315 		if (device->power.states[state].flags.explicit_set) {
316 			status = acpi_evaluate_object(device->handle,
317 						      object_name, NULL, NULL);
318 			if (ACPI_FAILURE(status)) {
319 				result = -ENODEV;
320 				goto end;
321 			}
322 		}
323 	} else {
324 		if (device->power.states[state].flags.explicit_set) {
325 			status = acpi_evaluate_object(device->handle,
326 						      object_name, NULL, NULL);
327 			if (ACPI_FAILURE(status)) {
328 				result = -ENODEV;
329 				goto end;
330 			}
331 		}
332 		if (device->power.flags.power_resources) {
333 			result = acpi_power_transition(device, state);
334 			if (result)
335 				goto end;
336 		}
337 	}
338 
339       end:
340 	if (result)
341 		printk(KERN_WARNING PREFIX
342 			      "Device [%s] failed to transition to D%d\n",
343 			      device->pnp.bus_id, state);
344 	else {
345 		device->power.state = state;
346 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
347 				  "Device [%s] transitioned to D%d\n",
348 				  device->pnp.bus_id, state));
349 	}
350 
351 	return result;
352 }
353 
354 EXPORT_SYMBOL(acpi_bus_set_power);
355 
356 bool acpi_bus_power_manageable(acpi_handle handle)
357 {
358 	struct acpi_device *device;
359 	int result;
360 
361 	result = acpi_bus_get_device(handle, &device);
362 	return result ? false : device->flags.power_manageable;
363 }
364 
365 EXPORT_SYMBOL(acpi_bus_power_manageable);
366 
367 bool acpi_bus_can_wakeup(acpi_handle handle)
368 {
369 	struct acpi_device *device;
370 	int result;
371 
372 	result = acpi_bus_get_device(handle, &device);
373 	return result ? false : device->wakeup.flags.valid;
374 }
375 
376 EXPORT_SYMBOL(acpi_bus_can_wakeup);
377 
378 static void acpi_print_osc_error(acpi_handle handle,
379 	struct acpi_osc_context *context, char *error)
380 {
381 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
382 	int i;
383 
384 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
385 		printk(KERN_DEBUG "%s\n", error);
386 	else {
387 		printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
388 		kfree(buffer.pointer);
389 	}
390 	printk(KERN_DEBUG"_OSC request data:");
391 	for (i = 0; i < context->cap.length; i += sizeof(u32))
392 		printk("%x ", *((u32 *)(context->cap.pointer + i)));
393 	printk("\n");
394 }
395 
396 static acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
397 {
398 	int i;
399 	static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
400 		24, 26, 28, 30, 32, 34};
401 
402 	if (strlen(str) != 36)
403 		return AE_BAD_PARAMETER;
404 	for (i = 0; i < 36; i++) {
405 		if (i == 8 || i == 13 || i == 18 || i == 23) {
406 			if (str[i] != '-')
407 				return AE_BAD_PARAMETER;
408 		} else if (!isxdigit(str[i]))
409 			return AE_BAD_PARAMETER;
410 	}
411 	for (i = 0; i < 16; i++) {
412 		uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
413 		uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
414 	}
415 	return AE_OK;
416 }
417 
418 acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
419 {
420 	acpi_status status;
421 	struct acpi_object_list input;
422 	union acpi_object in_params[4];
423 	union acpi_object *out_obj;
424 	u8 uuid[16];
425 	u32 errors;
426 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
427 
428 	if (!context)
429 		return AE_ERROR;
430 	if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
431 		return AE_ERROR;
432 	context->ret.length = ACPI_ALLOCATE_BUFFER;
433 	context->ret.pointer = NULL;
434 
435 	/* Setting up input parameters */
436 	input.count = 4;
437 	input.pointer = in_params;
438 	in_params[0].type 		= ACPI_TYPE_BUFFER;
439 	in_params[0].buffer.length 	= 16;
440 	in_params[0].buffer.pointer	= uuid;
441 	in_params[1].type 		= ACPI_TYPE_INTEGER;
442 	in_params[1].integer.value 	= context->rev;
443 	in_params[2].type 		= ACPI_TYPE_INTEGER;
444 	in_params[2].integer.value	= context->cap.length/sizeof(u32);
445 	in_params[3].type		= ACPI_TYPE_BUFFER;
446 	in_params[3].buffer.length 	= context->cap.length;
447 	in_params[3].buffer.pointer 	= context->cap.pointer;
448 
449 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
450 	if (ACPI_FAILURE(status))
451 		return status;
452 
453 	if (!output.length)
454 		return AE_NULL_OBJECT;
455 
456 	out_obj = output.pointer;
457 	if (out_obj->type != ACPI_TYPE_BUFFER
458 		|| out_obj->buffer.length != context->cap.length) {
459 		acpi_print_osc_error(handle, context,
460 			"_OSC evaluation returned wrong type");
461 		status = AE_TYPE;
462 		goto out_kfree;
463 	}
464 	/* Need to ignore the bit0 in result code */
465 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
466 	if (errors) {
467 		if (errors & OSC_REQUEST_ERROR)
468 			acpi_print_osc_error(handle, context,
469 				"_OSC request failed");
470 		if (errors & OSC_INVALID_UUID_ERROR)
471 			acpi_print_osc_error(handle, context,
472 				"_OSC invalid UUID");
473 		if (errors & OSC_INVALID_REVISION_ERROR)
474 			acpi_print_osc_error(handle, context,
475 				"_OSC invalid revision");
476 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
477 			if (((u32 *)context->cap.pointer)[OSC_QUERY_TYPE]
478 			    & OSC_QUERY_ENABLE)
479 				goto out_success;
480 			status = AE_SUPPORT;
481 			goto out_kfree;
482 		}
483 		status = AE_ERROR;
484 		goto out_kfree;
485 	}
486 out_success:
487 	context->ret.length = out_obj->buffer.length;
488 	context->ret.pointer = kmalloc(context->ret.length, GFP_KERNEL);
489 	if (!context->ret.pointer) {
490 		status =  AE_NO_MEMORY;
491 		goto out_kfree;
492 	}
493 	memcpy(context->ret.pointer, out_obj->buffer.pointer,
494 		context->ret.length);
495 	status =  AE_OK;
496 
497 out_kfree:
498 	kfree(output.pointer);
499 	if (status != AE_OK)
500 		context->ret.pointer = NULL;
501 	return status;
502 }
503 EXPORT_SYMBOL(acpi_run_osc);
504 
505 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
506 static void acpi_bus_osc_support(void)
507 {
508 	u32 capbuf[2];
509 	struct acpi_osc_context context = {
510 		.uuid_str = sb_uuid_str,
511 		.rev = 1,
512 		.cap.length = 8,
513 		.cap.pointer = capbuf,
514 	};
515 	acpi_handle handle;
516 
517 	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
518 	capbuf[OSC_SUPPORT_TYPE] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
519 #if defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) ||\
520 			defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
521 	capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_PAD_SUPPORT;
522 #endif
523 
524 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
525 	capbuf[OSC_SUPPORT_TYPE] |= OSC_SB_PPC_OST_SUPPORT;
526 #endif
527 	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
528 		return;
529 	if (ACPI_SUCCESS(acpi_run_osc(handle, &context)))
530 		kfree(context.ret.pointer);
531 	/* do we need to check the returned cap? Sounds no */
532 }
533 
534 /* --------------------------------------------------------------------------
535                                 Event Management
536    -------------------------------------------------------------------------- */
537 
538 #ifdef CONFIG_ACPI_PROC_EVENT
539 static DEFINE_SPINLOCK(acpi_bus_event_lock);
540 
541 LIST_HEAD(acpi_bus_event_list);
542 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
543 
544 extern int event_is_open;
545 
546 int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
547 {
548 	struct acpi_bus_event *event;
549 	unsigned long flags = 0;
550 
551 	/* drop event on the floor if no one's listening */
552 	if (!event_is_open)
553 		return 0;
554 
555 	event = kzalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
556 	if (!event)
557 		return -ENOMEM;
558 
559 	strcpy(event->device_class, device_class);
560 	strcpy(event->bus_id, bus_id);
561 	event->type = type;
562 	event->data = data;
563 
564 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
565 	list_add_tail(&event->node, &acpi_bus_event_list);
566 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
567 
568 	wake_up_interruptible(&acpi_bus_event_queue);
569 
570 	return 0;
571 
572 }
573 
574 EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
575 
576 int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
577 {
578 	if (!device)
579 		return -EINVAL;
580 	return acpi_bus_generate_proc_event4(device->pnp.device_class,
581 					     device->pnp.bus_id, type, data);
582 }
583 
584 EXPORT_SYMBOL(acpi_bus_generate_proc_event);
585 
586 int acpi_bus_receive_event(struct acpi_bus_event *event)
587 {
588 	unsigned long flags = 0;
589 	struct acpi_bus_event *entry = NULL;
590 
591 	DECLARE_WAITQUEUE(wait, current);
592 
593 
594 	if (!event)
595 		return -EINVAL;
596 
597 	if (list_empty(&acpi_bus_event_list)) {
598 
599 		set_current_state(TASK_INTERRUPTIBLE);
600 		add_wait_queue(&acpi_bus_event_queue, &wait);
601 
602 		if (list_empty(&acpi_bus_event_list))
603 			schedule();
604 
605 		remove_wait_queue(&acpi_bus_event_queue, &wait);
606 		set_current_state(TASK_RUNNING);
607 
608 		if (signal_pending(current))
609 			return -ERESTARTSYS;
610 	}
611 
612 	spin_lock_irqsave(&acpi_bus_event_lock, flags);
613 	if (!list_empty(&acpi_bus_event_list)) {
614 		entry = list_entry(acpi_bus_event_list.next,
615 				   struct acpi_bus_event, node);
616 		list_del(&entry->node);
617 	}
618 	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
619 
620 	if (!entry)
621 		return -ENODEV;
622 
623 	memcpy(event, entry, sizeof(struct acpi_bus_event));
624 
625 	kfree(entry);
626 
627 	return 0;
628 }
629 
630 #endif	/* CONFIG_ACPI_PROC_EVENT */
631 
632 /* --------------------------------------------------------------------------
633                              Notification Handling
634    -------------------------------------------------------------------------- */
635 
636 static void acpi_bus_check_device(acpi_handle handle)
637 {
638 	struct acpi_device *device;
639 	acpi_status status;
640 	struct acpi_device_status old_status;
641 
642 	if (acpi_bus_get_device(handle, &device))
643 		return;
644 	if (!device)
645 		return;
646 
647 	old_status = device->status;
648 
649 	/*
650 	 * Make sure this device's parent is present before we go about
651 	 * messing with the device.
652 	 */
653 	if (device->parent && !device->parent->status.present) {
654 		device->status = device->parent->status;
655 		return;
656 	}
657 
658 	status = acpi_bus_get_status(device);
659 	if (ACPI_FAILURE(status))
660 		return;
661 
662 	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
663 		return;
664 
665 	/*
666 	 * Device Insertion/Removal
667 	 */
668 	if ((device->status.present) && !(old_status.present)) {
669 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
670 		/* TBD: Handle device insertion */
671 	} else if (!(device->status.present) && (old_status.present)) {
672 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
673 		/* TBD: Handle device removal */
674 	}
675 }
676 
677 static void acpi_bus_check_scope(acpi_handle handle)
678 {
679 	/* Status Change? */
680 	acpi_bus_check_device(handle);
681 
682 	/*
683 	 * TBD: Enumerate child devices within this device's scope and
684 	 *       run acpi_bus_check_device()'s on them.
685 	 */
686 }
687 
688 static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
689 int register_acpi_bus_notifier(struct notifier_block *nb)
690 {
691 	return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
692 }
693 EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
694 
695 void unregister_acpi_bus_notifier(struct notifier_block *nb)
696 {
697 	blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
698 }
699 EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
700 
701 /**
702  * acpi_bus_notify
703  * ---------------
704  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
705  */
706 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
707 {
708 	struct acpi_device *device = NULL;
709 	struct acpi_driver *driver;
710 
711 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notification %#02x to handle %p\n",
712 			  type, handle));
713 
714 	blocking_notifier_call_chain(&acpi_bus_notify_list,
715 		type, (void *)handle);
716 
717 	switch (type) {
718 
719 	case ACPI_NOTIFY_BUS_CHECK:
720 		acpi_bus_check_scope(handle);
721 		/*
722 		 * TBD: We'll need to outsource certain events to non-ACPI
723 		 *      drivers via the device manager (device.c).
724 		 */
725 		break;
726 
727 	case ACPI_NOTIFY_DEVICE_CHECK:
728 		acpi_bus_check_device(handle);
729 		/*
730 		 * TBD: We'll need to outsource certain events to non-ACPI
731 		 *      drivers via the device manager (device.c).
732 		 */
733 		break;
734 
735 	case ACPI_NOTIFY_DEVICE_WAKE:
736 		/* TBD */
737 		break;
738 
739 	case ACPI_NOTIFY_EJECT_REQUEST:
740 		/* TBD */
741 		break;
742 
743 	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
744 		/* TBD: Exactly what does 'light' mean? */
745 		break;
746 
747 	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
748 		/* TBD */
749 		break;
750 
751 	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
752 		/* TBD */
753 		break;
754 
755 	case ACPI_NOTIFY_POWER_FAULT:
756 		/* TBD */
757 		break;
758 
759 	default:
760 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
761 				  "Received unknown/unsupported notification [%08x]\n",
762 				  type));
763 		break;
764 	}
765 
766 	acpi_bus_get_device(handle, &device);
767 	if (device) {
768 		driver = device->driver;
769 		if (driver && driver->ops.notify &&
770 		    (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
771 			driver->ops.notify(device, type);
772 	}
773 }
774 
775 /* --------------------------------------------------------------------------
776                              Initialization/Cleanup
777    -------------------------------------------------------------------------- */
778 
779 static int __init acpi_bus_init_irq(void)
780 {
781 	acpi_status status = AE_OK;
782 	union acpi_object arg = { ACPI_TYPE_INTEGER };
783 	struct acpi_object_list arg_list = { 1, &arg };
784 	char *message = NULL;
785 
786 
787 	/*
788 	 * Let the system know what interrupt model we are using by
789 	 * evaluating the \_PIC object, if exists.
790 	 */
791 
792 	switch (acpi_irq_model) {
793 	case ACPI_IRQ_MODEL_PIC:
794 		message = "PIC";
795 		break;
796 	case ACPI_IRQ_MODEL_IOAPIC:
797 		message = "IOAPIC";
798 		break;
799 	case ACPI_IRQ_MODEL_IOSAPIC:
800 		message = "IOSAPIC";
801 		break;
802 	case ACPI_IRQ_MODEL_PLATFORM:
803 		message = "platform specific model";
804 		break;
805 	default:
806 		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
807 		return -ENODEV;
808 	}
809 
810 	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
811 
812 	arg.integer.value = acpi_irq_model;
813 
814 	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
815 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
816 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
817 		return -ENODEV;
818 	}
819 
820 	return 0;
821 }
822 
823 u8 acpi_gbl_permanent_mmap;
824 
825 
826 void __init acpi_early_init(void)
827 {
828 	acpi_status status = AE_OK;
829 
830 	if (acpi_disabled)
831 		return;
832 
833 	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
834 
835 	/* enable workarounds, unless strict ACPI spec. compliance */
836 	if (!acpi_strict)
837 		acpi_gbl_enable_interpreter_slack = TRUE;
838 
839 	acpi_gbl_permanent_mmap = 1;
840 
841 	/*
842 	 * If the machine falls into the DMI check table,
843 	 * DSDT will be copied to memory
844 	 */
845 	dmi_check_system(dsdt_dmi_table);
846 
847 	status = acpi_reallocate_root_table();
848 	if (ACPI_FAILURE(status)) {
849 		printk(KERN_ERR PREFIX
850 		       "Unable to reallocate ACPI tables\n");
851 		goto error0;
852 	}
853 
854 	status = acpi_initialize_subsystem();
855 	if (ACPI_FAILURE(status)) {
856 		printk(KERN_ERR PREFIX
857 		       "Unable to initialize the ACPI Interpreter\n");
858 		goto error0;
859 	}
860 
861 	status = acpi_load_tables();
862 	if (ACPI_FAILURE(status)) {
863 		printk(KERN_ERR PREFIX
864 		       "Unable to load the System Description Tables\n");
865 		goto error0;
866 	}
867 
868 #ifdef CONFIG_X86
869 	if (!acpi_ioapic) {
870 		/* compatible (0) means level (3) */
871 		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
872 			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
873 			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
874 		}
875 		/* Set PIC-mode SCI trigger type */
876 		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
877 					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
878 	} else {
879 		/*
880 		 * now that acpi_gbl_FADT is initialized,
881 		 * update it with result from INT_SRC_OVR parsing
882 		 */
883 		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
884 	}
885 #endif
886 
887 	status =
888 	    acpi_enable_subsystem(~
889 				  (ACPI_NO_HARDWARE_INIT |
890 				   ACPI_NO_ACPI_ENABLE));
891 	if (ACPI_FAILURE(status)) {
892 		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
893 		goto error0;
894 	}
895 
896 	return;
897 
898       error0:
899 	disable_acpi();
900 	return;
901 }
902 
903 static int __init acpi_bus_init(void)
904 {
905 	int result = 0;
906 	acpi_status status = AE_OK;
907 	extern acpi_status acpi_os_initialize1(void);
908 
909 	acpi_os_initialize1();
910 
911 	status =
912 	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
913 	if (ACPI_FAILURE(status)) {
914 		printk(KERN_ERR PREFIX
915 		       "Unable to start the ACPI Interpreter\n");
916 		goto error1;
917 	}
918 
919 	/*
920 	 * ACPI 2.0 requires the EC driver to be loaded and work before
921 	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
922 	 * is called).
923 	 *
924 	 * This is accomplished by looking for the ECDT table, and getting
925 	 * the EC parameters out of that.
926 	 */
927 	status = acpi_ec_ecdt_probe();
928 	/* Ignore result. Not having an ECDT is not fatal. */
929 
930 	acpi_bus_osc_support();
931 
932 	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
933 	if (ACPI_FAILURE(status)) {
934 		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
935 		goto error1;
936 	}
937 
938 	/*
939 	 * _PDC control method may load dynamic SSDT tables,
940 	 * and we need to install the table handler before that.
941 	 */
942 	acpi_sysfs_init();
943 
944 	acpi_early_processor_set_pdc();
945 
946 	/*
947 	 * Maybe EC region is required at bus_scan/acpi_get_devices. So it
948 	 * is necessary to enable it as early as possible.
949 	 */
950 	acpi_boot_ec_enable();
951 
952 	printk(KERN_INFO PREFIX "Interpreter enabled\n");
953 
954 	/* Initialize sleep structures */
955 	acpi_sleep_init();
956 
957 	/*
958 	 * Get the system interrupt model and evaluate \_PIC.
959 	 */
960 	result = acpi_bus_init_irq();
961 	if (result)
962 		goto error1;
963 
964 	/*
965 	 * Register the for all standard device notifications.
966 	 */
967 	status =
968 	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
969 					&acpi_bus_notify, NULL);
970 	if (ACPI_FAILURE(status)) {
971 		printk(KERN_ERR PREFIX
972 		       "Unable to register for device notifications\n");
973 		goto error1;
974 	}
975 
976 	/*
977 	 * Create the top ACPI proc directory
978 	 */
979 	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
980 
981 	return 0;
982 
983 	/* Mimic structured exception handling */
984       error1:
985 	acpi_terminate();
986 	return -ENODEV;
987 }
988 
989 struct kobject *acpi_kobj;
990 
991 static int __init acpi_init(void)
992 {
993 	int result = 0;
994 
995 
996 	if (acpi_disabled) {
997 		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
998 		return -ENODEV;
999 	}
1000 
1001 	acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
1002 	if (!acpi_kobj) {
1003 		printk(KERN_WARNING "%s: kset create error\n", __func__);
1004 		acpi_kobj = NULL;
1005 	}
1006 
1007 	init_acpi_device_notify();
1008 	result = acpi_bus_init();
1009 
1010 	if (!result) {
1011 		pci_mmcfg_late_init();
1012 		if (!(pm_flags & PM_APM))
1013 			pm_flags |= PM_ACPI;
1014 		else {
1015 			printk(KERN_INFO PREFIX
1016 			       "APM is already active, exiting\n");
1017 			disable_acpi();
1018 			result = -ENODEV;
1019 		}
1020 	} else
1021 		disable_acpi();
1022 
1023 	if (acpi_disabled)
1024 		return result;
1025 
1026 	/*
1027 	 * If the laptop falls into the DMI check table, the power state check
1028 	 * will be disabled in the course of device power transition.
1029 	 */
1030 	dmi_check_system(power_nocheck_dmi_table);
1031 
1032 	acpi_scan_init();
1033 	acpi_ec_init();
1034 	acpi_power_init();
1035 	acpi_debugfs_init();
1036 	acpi_sleep_proc_init();
1037 	acpi_wakeup_device_init();
1038 	return result;
1039 }
1040 
1041 subsys_initcall(acpi_init);
1042