aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/acpica/evregion.c
blob: 2ba28a63fb68527608eb54bb1d37c494ce890c85 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
/******************************************************************************
 *
 * Module Name: evregion - Operation Region support
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2015, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"
#include "acnamesp.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evregion")

extern u8 acpi_gbl_default_address_spaces[];

/* Local prototypes */

static void
acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node);

static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
		u32 level, void *context, void **return_value);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_initialize_op_regions
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG methods for all Operation Regions that have
 *              an installed default region handler.
 *
 ******************************************************************************/

acpi_status acpi_ev_initialize_op_regions(void)
{
	acpi_status status;
	u32 i;

	ACPI_FUNCTION_TRACE(ev_initialize_op_regions);

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Run the _REG methods for op_regions in each default address space */

	for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
		/*
		 * Make sure the installed handler is the DEFAULT handler. If not the
		 * default, the _REG methods will have already been run (when the
		 * handler was installed)
		 */
		if (acpi_ev_has_default_handler(acpi_gbl_root_node,
						acpi_gbl_default_address_spaces
						[i])) {
			status =
			    acpi_ev_execute_reg_methods(acpi_gbl_root_node,
							acpi_gbl_default_address_spaces
							[i]);
		}
	}

	acpi_gbl_reg_methods_executed = TRUE;

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_address_space_dispatch
 *
 * PARAMETERS:  region_obj          - Internal region object
 *              field_obj           - Corresponding field. Can be NULL.
 *              function            - Read or Write operation
 *              region_offset       - Where in the region to read or write
 *              bit_width           - Field width in bits (8, 16, 32, or 64)
 *              value               - Pointer to in or out value, must be
 *                                    a full 64-bit integer
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dispatch an address space or operation region access to
 *              a previously installed handler.
 *
 ******************************************************************************/

acpi_status
acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
			       union acpi_operand_object *field_obj,
			       u32 function,
			       u32 region_offset, u32 bit_width, u64 *value)
{
	acpi_status status;
	acpi_adr_space_handler handler;
	acpi_adr_space_setup region_setup;
	union acpi_operand_object *handler_desc;
	union acpi_operand_object *region_obj2;
	void *region_context = NULL;
	struct acpi_connection_info *context;
	acpi_physical_address address;

	ACPI_FUNCTION_TRACE(ev_address_space_dispatch);

	region_obj2 = acpi_ns_get_secondary_object(region_obj);
	if (!region_obj2) {
		return_ACPI_STATUS(AE_NOT_EXIST);
	}

	/* Ensure that there is a handler associated with this region */

	handler_desc = region_obj->region.handler;
	if (!handler_desc) {
		ACPI_ERROR((AE_INFO,
			    "No handler for Region [%4.4s] (%p) [%s]",
			    acpi_ut_get_node_name(region_obj->region.node),
			    region_obj,
			    acpi_ut_get_region_name(region_obj->region.
						    space_id)));

		return_ACPI_STATUS(AE_NOT_EXIST);
	}

	context = handler_desc->address_space.context;

	/*
	 * It may be the case that the region has never been initialized.
	 * Some types of regions require special init code
	 */
	if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {

		/* This region has not been initialized yet, do it */

		region_setup = handler_desc->address_space.setup;
		if (!region_setup) {

			/* No initialization routine, exit with error */

			ACPI_ERROR((AE_INFO,
				    "No init routine for region(%p) [%s]",
				    region_obj,
				    acpi_ut_get_region_name(region_obj->region.
							    space_id)));
			return_ACPI_STATUS(AE_NOT_EXIST);
		}

		/*
		 * We must exit the interpreter because the region setup will
		 * potentially execute control methods (for example, the _REG method
		 * for this region)
		 */
		acpi_ex_exit_interpreter();

		status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
				      context, &region_context);

		/* Re-enter the interpreter */

		acpi_ex_enter_interpreter();

		/* Check for failure of the Region Setup */

		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"During region initialization: [%s]",
					acpi_ut_get_region_name(region_obj->
								region.
								space_id)));
			return_ACPI_STATUS(status);
		}

		/* Region initialization may have been completed by region_setup */

		if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
			region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;

			/*
			 * Save the returned context for use in all accesses to
			 * the handler for this particular region
			 */
			if (!(region_obj2->extra.region_context)) {
				region_obj2->extra.region_context =
				    region_context;
			}
		}
	}

	/* We have everything we need, we can invoke the address space handler */

	handler = handler_desc->address_space.handler;
	address = (region_obj->region.address + region_offset);

	/*
	 * Special handling for generic_serial_bus and general_purpose_io:
	 * There are three extra parameters that must be passed to the
	 * handler via the context:
	 *   1) Connection buffer, a resource template from Connection() op
	 *   2) Length of the above buffer
	 *   3) Actual access length from the access_as() op
	 *
	 * In addition, for general_purpose_io, the Address and bit_width fields
	 * are defined as follows:
	 *   1) Address is the pin number index of the field (bit offset from
	 *      the previous Connection)
	 *   2) bit_width is the actual bit length of the field (number of pins)
	 */
	if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) &&
	    context && field_obj) {

		/* Get the Connection (resource_template) buffer */

		context->connection = field_obj->field.resource_buffer;
		context->length = field_obj->field.resource_length;
		context->access_length = field_obj->field.access_length;
	}
	if ((region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
	    context && field_obj) {

		/* Get the Connection (resource_template) buffer */

		context->connection = field_obj->field.resource_buffer;
		context->length = field_obj->field.resource_length;
		context->access_length = field_obj->field.access_length;
		address = field_obj->field.pin_number_index;
		bit_width = field_obj->field.bit_length;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
			  "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
			  &region_obj->region.handler->address_space, handler,
			  ACPI_FORMAT_UINT64(address),
			  acpi_ut_get_region_name(region_obj->region.
						  space_id)));

	if (!(handler_desc->address_space.handler_flags &
	      ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
		/*
		 * For handlers other than the default (supplied) handlers, we must
		 * exit the interpreter because the handler *might* block -- we don't
		 * know what it will do, so we can't hold the lock on the intepreter.
		 */
		acpi_ex_exit_interpreter();
	}

	/* Call the handler */

	status = handler(function, address, bit_width, value, context,
			 region_obj2->extra.region_context);

	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
				acpi_ut_get_region_name(region_obj->region.
							space_id)));
	}

	if (!(handler_desc->address_space.handler_flags &
	      ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
		/*
		 * We just returned from a non-default handler, we must re-enter the
		 * interpreter
		 */
		acpi_ex_enter_interpreter();
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_detach_region
 *
 * PARAMETERS:  region_obj          - Region Object
 *              acpi_ns_is_locked   - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Break the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

void
acpi_ev_detach_region(union acpi_operand_object *region_obj,
		      u8 acpi_ns_is_locked)
{
	union acpi_operand_object *handler_obj;
	union acpi_operand_object *obj_desc;
	union acpi_operand_object *start_desc;
	union acpi_operand_object **last_obj_ptr;
	acpi_adr_space_setup region_setup;
	void **region_context;
	union acpi_operand_object *region_obj2;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_detach_region);

	region_obj2 = acpi_ns_get_secondary_object(region_obj);
	if (!region_obj2) {
		return_VOID;
	}
	region_context = &region_obj2->extra.region_context;

	/* Get the address handler from the region object */

	handler_obj = region_obj->region.handler;
	if (!handler_obj) {

		/* This region has no handler, all done */

		return_VOID;
	}

	/* Find this region in the handler's list */

	obj_desc = handler_obj->address_space.region_list;
	start_desc = obj_desc;
	last_obj_ptr = &handler_obj->address_space.region_list;

	while (obj_desc) {

		/* Is this the correct Region? */

		if (obj_desc == region_obj) {
			ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
					  "Removing Region %p from address handler %p\n",
					  region_obj, handler_obj));

			/* This is it, remove it from the handler's list */

			*last_obj_ptr = obj_desc->region.next;
			obj_desc->region.next = NULL;	/* Must clear field */

			if (acpi_ns_is_locked) {
				status =
				    acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
				if (ACPI_FAILURE(status)) {
					return_VOID;
				}
			}

			/* Now stop region accesses by executing the _REG method */

			status =
			    acpi_ev_execute_reg_method(region_obj,
						       ACPI_REG_DISCONNECT);
			if (ACPI_FAILURE(status)) {
				ACPI_EXCEPTION((AE_INFO, status,
						"from region _REG, [%s]",
						acpi_ut_get_region_name
						(region_obj->region.space_id)));
			}

			if (acpi_ns_is_locked) {
				status =
				    acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
				if (ACPI_FAILURE(status)) {
					return_VOID;
				}
			}

			/*
			 * If the region has been activated, call the setup handler with
			 * the deactivate notification
			 */
			if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
				region_setup = handler_obj->address_space.setup;
				status =
				    region_setup(region_obj,
						 ACPI_REGION_DEACTIVATE,
						 handler_obj->address_space.
						 context, region_context);

				/*
				 * region_context should have been released by the deactivate
				 * operation. We don't need access to it anymore here.
				 */
				if (region_context) {
					*region_context = NULL;
				}

				/* Init routine may fail, Just ignore errors */

				if (ACPI_FAILURE(status)) {
					ACPI_EXCEPTION((AE_INFO, status,
							"from region handler - deactivate, [%s]",
							acpi_ut_get_region_name
							(region_obj->region.
							 space_id)));
				}

				region_obj->region.flags &=
				    ~(AOPOBJ_SETUP_COMPLETE);
			}

			/*
			 * Remove handler reference in the region
			 *
			 * NOTE: this doesn't mean that the region goes away, the region
			 * is just inaccessible as indicated to the _REG method
			 *
			 * If the region is on the handler's list, this must be the
			 * region's handler
			 */
			region_obj->region.handler = NULL;
			acpi_ut_remove_reference(handler_obj);

			return_VOID;
		}

		/* Walk the linked list of handlers */

		last_obj_ptr = &obj_desc->region.next;
		obj_desc = obj_desc->region.next;

		/* Prevent infinite loop if list is corrupted */

		if (obj_desc == start_desc) {
			ACPI_ERROR((AE_INFO,
				    "Circular handler list in region object %p",
				    region_obj));
			return_VOID;
		}
	}

	/* If we get here, the region was not in the handler's region list */

	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
			  "Cannot remove region %p from address handler %p\n",
			  region_obj, handler_obj));

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_attach_region
 *
 * PARAMETERS:  handler_obj         - Handler Object
 *              region_obj          - Region Object
 *              acpi_ns_is_locked   - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Create the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

acpi_status
acpi_ev_attach_region(union acpi_operand_object *handler_obj,
		      union acpi_operand_object *region_obj,
		      u8 acpi_ns_is_locked)
{

	ACPI_FUNCTION_TRACE(ev_attach_region);

	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
			  "Adding Region [%4.4s] %p to address handler %p [%s]\n",
			  acpi_ut_get_node_name(region_obj->region.node),
			  region_obj, handler_obj,
			  acpi_ut_get_region_name(region_obj->region.
						  space_id)));

	/* Link this region to the front of the handler's list */

	region_obj->region.next = handler_obj->address_space.region_list;
	handler_obj->address_space.region_list = region_obj;

	/* Install the region's handler */

	if (region_obj->region.handler) {
		return_ACPI_STATUS(AE_ALREADY_EXISTS);
	}

	region_obj->region.handler = handler_obj;
	acpi_ut_add_reference(handler_obj);

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_execute_reg_method
 *
 * PARAMETERS:  region_obj          - Region object
 *              function            - Passed to _REG: On (1) or Off (0)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG method for a region
 *
 ******************************************************************************/

acpi_status
acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
{
	struct acpi_evaluate_info *info;
	union acpi_operand_object *args[3];
	union acpi_operand_object *region_obj2;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_execute_reg_method);

	region_obj2 = acpi_ns_get_secondary_object(region_obj);
	if (!region_obj2) {
		return_ACPI_STATUS(AE_NOT_EXIST);
	}

	if (region_obj2->extra.method_REG == NULL) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Allocate and initialize the evaluation information block */

	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
	if (!info) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	info->prefix_node = region_obj2->extra.method_REG;
	info->relative_pathname = NULL;
	info->parameters = args;
	info->flags = ACPI_IGNORE_RETURN_VALUE;

	/*
	 * The _REG method has two arguments:
	 *
	 * arg0 - Integer:
	 *  Operation region space ID Same value as region_obj->Region.space_id
	 *
	 * arg1 - Integer:
	 *  connection status 1 for connecting the handler, 0 for disconnecting
	 *  the handler (Passed as a parameter)
	 */
	args[0] =
	    acpi_ut_create_integer_object((u64)region_obj->region.space_id);
	if (!args[0]) {
		status = AE_NO_MEMORY;
		goto cleanup1;
	}

	args[1] = acpi_ut_create_integer_object((u64)function);
	if (!args[1]) {
		status = AE_NO_MEMORY;
		goto cleanup2;
	}

	args[2] = NULL;		/* Terminate list */

	/* Execute the method, no return value */

	ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
			(ACPI_TYPE_METHOD, info->prefix_node, NULL));

	status = acpi_ns_evaluate(info);
	acpi_ut_remove_reference(args[1]);

cleanup2:
	acpi_ut_remove_reference(args[0]);

cleanup1:
	ACPI_FREE(info);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_execute_reg_methods
 *
 * PARAMETERS:  node            - Namespace node for the device
 *              space_id        - The address space ID
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Run all _REG methods for the input Space ID;
 *              Note: assumes namespace is locked, or system init time.
 *
 ******************************************************************************/

acpi_status
acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
			    acpi_adr_space_type space_id)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_execute_reg_methods);

	/*
	 * Run all _REG methods for all Operation Regions for this space ID. This
	 * is a separate walk in order to handle any interdependencies between
	 * regions and _REG methods. (i.e. handlers must be installed for all
	 * regions of this Space ID before we can run any _REG methods)
	 */
	status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
					ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run,
					NULL, &space_id, NULL);

	/* Special case for EC: handle "orphan" _REG methods with no region */

	if (space_id == ACPI_ADR_SPACE_EC) {
		acpi_ev_orphan_ec_reg_method(node);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_reg_run
 *
 * PARAMETERS:  walk_namespace callback
 *
 * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 *
 ******************************************************************************/

static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
		u32 level, void *context, void **return_value)
{
	union acpi_operand_object *obj_desc;
	struct acpi_namespace_node *node;
	acpi_adr_space_type space_id;
	acpi_status status;

	space_id = *ACPI_CAST_PTR(acpi_adr_space_type, context);

	/* Convert and validate the device handle */

	node = acpi_ns_validate_handle(obj_handle);
	if (!node) {
		return (AE_BAD_PARAMETER);
	}

	/*
	 * We only care about regions.and objects that are allowed to have address
	 * space handlers
	 */
	if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
		return (AE_OK);
	}

	/* Check for an existing internal object */

	obj_desc = acpi_ns_get_attached_object(node);
	if (!obj_desc) {

		/* No object, just exit */

		return (AE_OK);
	}

	/* Object is a Region */

	if (obj_desc->region.space_id != space_id) {

		/* This region is for a different address space, just ignore it */

		return (AE_OK);
	}

	status = acpi_ev_execute_reg_method(obj_desc, ACPI_REG_CONNECT);
	return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_orphan_ec_reg_method
 *
 * PARAMETERS:  ec_device_node      - Namespace node for an EC device
 *
 * RETURN:      None
 *
 * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
 *              device. This is a _REG method that has no corresponding region
 *              within the EC device scope. The orphan _REG method appears to
 *              have been enabled by the description of the ECDT in the ACPI
 *              specification: "The availability of the region space can be
 *              detected by providing a _REG method object underneath the
 *              Embedded Controller device."
 *
 *              To quickly access the EC device, we use the ec_device_node used
 *              during EC handler installation. Otherwise, we would need to
 *              perform a time consuming namespace walk, executing _HID
 *              methods to find the EC device.
 *
 *  MUTEX:      Assumes the namespace is locked
 *
 ******************************************************************************/

static void
acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node)
{
	acpi_handle reg_method;
	struct acpi_namespace_node *next_node;
	acpi_status status;
	struct acpi_object_list args;
	union acpi_object objects[2];

	ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);

	if (!ec_device_node) {
		return_VOID;
	}

	/* Namespace is currently locked, must release */

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

	/* Get a handle to a _REG method immediately under the EC device */

	status = acpi_get_handle(ec_device_node, METHOD_NAME__REG, &reg_method);
	if (ACPI_FAILURE(status)) {
		goto exit;	/* There is no _REG method present */
	}

	/*
	 * Execute the _REG method only if there is no Operation Region in
	 * this scope with the Embedded Controller space ID. Otherwise, it
	 * will already have been executed. Note, this allows for Regions
	 * with other space IDs to be present; but the code below will then
	 * execute the _REG method with the embedded_control space_ID argument.
	 */
	next_node = acpi_ns_get_next_node(ec_device_node, NULL);
	while (next_node) {
		if ((next_node->type == ACPI_TYPE_REGION) &&
		    (next_node->object) &&
		    (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
			goto exit;	/* Do not execute the _REG */
		}

		next_node = acpi_ns_get_next_node(ec_device_node, next_node);
	}

	/* Evaluate the _REG(embedded_control,Connect) method */

	args.count = 2;
	args.pointer = objects;
	objects[0].type = ACPI_TYPE_INTEGER;
	objects[0].integer.value = ACPI_ADR_SPACE_EC;
	objects[1].type = ACPI_TYPE_INTEGER;
	objects[1].integer.value = ACPI_REG_CONNECT;

	status = acpi_evaluate_object(reg_method, NULL, &args, NULL);

exit:
	/* We ignore all errors from above, don't care */

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	return_VOID;
}