summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/events/evgpeblk.c
blob: bb0eb50cd28fda50909e46800304895900e45647 (plain)
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
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
/******************************************************************************
 *
 * Module Name: evgpeblk - GPE block creation and initialization.
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2006, R. Byron Moore
 * 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 <acpi/acevents.h>
#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evgpeblk")

/* Local prototypes */
static acpi_status
acpi_ev_save_method_info(acpi_handle obj_handle,
			 u32 level, void *obj_desc, void **return_value);

static acpi_status
acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
			  u32 level, void *info, void **return_value);

static struct acpi_gpe_xrupt_info *acpi_ev_get_gpe_xrupt_block(u32
							       interrupt_number);

static acpi_status
acpi_ev_delete_gpe_xrupt(struct acpi_gpe_xrupt_info *gpe_xrupt);

static acpi_status
acpi_ev_install_gpe_block(struct acpi_gpe_block_info *gpe_block,
			  u32 interrupt_number);

static acpi_status
acpi_ev_create_gpe_info_blocks(struct acpi_gpe_block_info *gpe_block);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_valid_gpe_event
 *
 * PARAMETERS:  gpe_event_info              - Info for this GPE
 *
 * RETURN:      TRUE if the gpe_event is valid
 *
 * DESCRIPTION: Validate a GPE event. DO NOT CALL FROM INTERRUPT LEVEL.
 *              Should be called only when the GPE lists are semaphore locked
 *              and not subject to change.
 *
 ******************************************************************************/

u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
{
	struct acpi_gpe_xrupt_info *gpe_xrupt_block;
	struct acpi_gpe_block_info *gpe_block;

	ACPI_FUNCTION_ENTRY();

	/* No need for spin lock since we are not changing any list elements */

	/* Walk the GPE interrupt levels */

	gpe_xrupt_block = acpi_gbl_gpe_xrupt_list_head;
	while (gpe_xrupt_block) {
		gpe_block = gpe_xrupt_block->gpe_block_list_head;

		/* Walk the GPE blocks on this interrupt level */

		while (gpe_block) {
			if ((&gpe_block->event_info[0] <= gpe_event_info) &&
			    (&gpe_block->
			     event_info[((acpi_size) gpe_block->
					 register_count) * 8] >
			     gpe_event_info)) {
				return (TRUE);
			}

			gpe_block = gpe_block->next;
		}

		gpe_xrupt_block = gpe_xrupt_block->next;
	}

	return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_walk_gpe_list
 *
 * PARAMETERS:  gpe_walk_callback   - Routine called for each GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Walk the GPE lists.
 *
 ******************************************************************************/

acpi_status acpi_ev_walk_gpe_list(acpi_gpe_callback gpe_walk_callback)
{
	struct acpi_gpe_block_info *gpe_block;
	struct acpi_gpe_xrupt_info *gpe_xrupt_info;
	acpi_status status = AE_OK;
	acpi_cpu_flags flags;

	ACPI_FUNCTION_TRACE(ev_walk_gpe_list);

	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);

	/* Walk the interrupt level descriptor list */

	gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
	while (gpe_xrupt_info) {

		/* Walk all Gpe Blocks attached to this interrupt level */

		gpe_block = gpe_xrupt_info->gpe_block_list_head;
		while (gpe_block) {

			/* One callback per GPE block */

			status = gpe_walk_callback(gpe_xrupt_info, gpe_block);
			if (ACPI_FAILURE(status)) {
				goto unlock_and_exit;
			}

			gpe_block = gpe_block->next;
		}

		gpe_xrupt_info = gpe_xrupt_info->next;
	}

      unlock_and_exit:
	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_delete_gpe_handlers
 *
 * PARAMETERS:  gpe_xrupt_info      - GPE Interrupt info
 *              gpe_block           - Gpe Block info
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Delete all Handler objects found in the GPE data structs.
 *              Used only prior to termination.
 *
 ******************************************************************************/

acpi_status
acpi_ev_delete_gpe_handlers(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
			    struct acpi_gpe_block_info *gpe_block)
{
	struct acpi_gpe_event_info *gpe_event_info;
	acpi_native_uint i;
	acpi_native_uint j;

	ACPI_FUNCTION_TRACE(ev_delete_gpe_handlers);

	/* Examine each GPE Register within the block */

	for (i = 0; i < gpe_block->register_count; i++) {

		/* Now look at the individual GPEs in this byte register */

		for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
			gpe_event_info =
			    &gpe_block->
			    event_info[(i * ACPI_GPE_REGISTER_WIDTH) + j];

			if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
			    ACPI_GPE_DISPATCH_HANDLER) {
				ACPI_FREE(gpe_event_info->dispatch.handler);
				gpe_event_info->dispatch.handler = NULL;
				gpe_event_info->flags &=
				    ~ACPI_GPE_DISPATCH_MASK;
			}
		}
	}

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_save_method_info
 *
 * PARAMETERS:  Callback from walk_namespace
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
 *              control method under the _GPE portion of the namespace.
 *              Extract the name and GPE type from the object, saving this
 *              information for quick lookup during GPE dispatch
 *
 *              The name of each GPE control method is of the form:
 *              "_Lxx" or "_Exx"
 *              Where:
 *                  L      - means that the GPE is level triggered
 *                  E      - means that the GPE is edge triggered
 *                  xx     - is the GPE number [in HEX]
 *
 ******************************************************************************/

static acpi_status
acpi_ev_save_method_info(acpi_handle obj_handle,
			 u32 level, void *obj_desc, void **return_value)
{
	struct acpi_gpe_block_info *gpe_block = (void *)obj_desc;
	struct acpi_gpe_event_info *gpe_event_info;
	u32 gpe_number;
	char name[ACPI_NAME_SIZE + 1];
	u8 type;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_save_method_info);

	/*
	 * _Lxx and _Exx GPE method support
	 *
	 * 1) Extract the name from the object and convert to a string
	 */
	ACPI_MOVE_32_TO_32(name,
			   &((struct acpi_namespace_node *)obj_handle)->name.
			   integer);
	name[ACPI_NAME_SIZE] = 0;

	/*
	 * 2) Edge/Level determination is based on the 2nd character
	 *    of the method name
	 *
	 * NOTE: Default GPE type is RUNTIME. May be changed later to WAKE
	 * if a _PRW object is found that points to this GPE.
	 */
	switch (name[1]) {
	case 'L':
		type = ACPI_GPE_LEVEL_TRIGGERED;
		break;

	case 'E':
		type = ACPI_GPE_EDGE_TRIGGERED;
		break;

	default:
		/* Unknown method type, just ignore it! */

		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
				  "Ignoring unknown GPE method type: %s (name not of form _Lxx or _Exx)",
				  name));
		return_ACPI_STATUS(AE_OK);
	}

	/* Convert the last two characters of the name to the GPE Number */

	gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
	if (gpe_number == ACPI_UINT32_MAX) {

		/* Conversion failed; invalid method, just ignore it */

		ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
				  "Could not extract GPE number from name: %s (name is not of form _Lxx or _Exx)",
				  name));
		return_ACPI_STATUS(AE_OK);
	}

	/* Ensure that we have a valid GPE number for this GPE block */

	if ((gpe_number < gpe_block->block_base_number) ||
	    (gpe_number >=
	     (gpe_block->block_base_number +
	      (gpe_block->register_count * 8)))) {
		/*
		 * Not valid for this GPE block, just ignore it
		 * However, it may be valid for a different GPE block, since GPE0 and GPE1
		 * methods both appear under \_GPE.
		 */
		return_ACPI_STATUS(AE_OK);
	}

	/*
	 * Now we can add this information to the gpe_event_info block
	 * for use during dispatch of this GPE. Default type is RUNTIME, although
	 * this may change when the _PRW methods are executed later.
	 */
	gpe_event_info =
	    &gpe_block->event_info[gpe_number - gpe_block->block_base_number];

	gpe_event_info->flags = (u8)
	    (type | ACPI_GPE_DISPATCH_METHOD | ACPI_GPE_TYPE_RUNTIME);

	gpe_event_info->dispatch.method_node =
	    (struct acpi_namespace_node *)obj_handle;

	/* Update enable mask, but don't enable the HW GPE as of yet */

	status = acpi_ev_enable_gpe(gpe_event_info, FALSE);

	ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
			  "Registered GPE method %s as GPE number 0x%.2X\n",
			  name, gpe_number));
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_match_prw_and_gpe
 *
 * PARAMETERS:  Callback from walk_namespace
 *
 * RETURN:      Status. NOTE: We ignore errors so that the _PRW walk is
 *              not aborted on a single _PRW failure.
 *
 * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
 *              Device. Run the _PRW method. If present, extract the GPE
 *              number and mark the GPE as a WAKE GPE.
 *
 ******************************************************************************/

static acpi_status
acpi_ev_match_prw_and_gpe(acpi_handle obj_handle,
			  u32 level, void *info, void **return_value)
{
	struct acpi_gpe_walk_info *gpe_info = (void *)info;
	struct acpi_namespace_node *gpe_device;
	struct acpi_gpe_block_info *gpe_block;
	struct acpi_namespace_node *target_gpe_device;
	struct acpi_gpe_event_info *gpe_event_info;
	union acpi_operand_object *pkg_desc;
	union acpi_operand_object *obj_desc;
	u32 gpe_number;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_match_prw_and_gpe);

	/* Check for a _PRW method under this device */

	status = acpi_ut_evaluate_object(obj_handle, METHOD_NAME__PRW,
					 ACPI_BTYPE_PACKAGE, &pkg_desc);
	if (ACPI_FAILURE(status)) {

		/* Ignore all errors from _PRW, we don't want to abort the subsystem */

		return_ACPI_STATUS(AE_OK);
	}

	/* The returned _PRW package must have at least two elements */

	if (pkg_desc->package.count < 2) {
		goto cleanup;
	}

	/* Extract pointers from the input context */

	gpe_device = gpe_info->gpe_device;
	gpe_block = gpe_info->gpe_block;

	/*
	 * The _PRW object must return a package, we are only interested
	 * in the first element
	 */
	obj_desc = pkg_desc->package.elements[0];

	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_INTEGER) {

		/* Use FADT-defined GPE device (from definition of _PRW) */

		target_gpe_device = acpi_gbl_fadt_gpe_device;

		/* Integer is the GPE number in the FADT described GPE blocks */

		gpe_number = (u32) obj_desc->integer.value;
	} else if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_PACKAGE) {

		/* Package contains a GPE reference and GPE number within a GPE block */

		if ((obj_desc->package.count < 2) ||
		    (ACPI_GET_OBJECT_TYPE(obj_desc->package.elements[0]) !=
		     ACPI_TYPE_LOCAL_REFERENCE)
		    || (ACPI_GET_OBJECT_TYPE(obj_desc->package.elements[1]) !=
			ACPI_TYPE_INTEGER)) {
			goto cleanup;
		}

		/* Get GPE block reference and decode */

		target_gpe_device =
		    obj_desc->package.elements[0]->reference.node;
		gpe_number = (u32) obj_desc->package.elements[1]->integer.value;
	} else {
		/* Unknown type, just ignore it */

		goto cleanup;
	}

	/*
	 * Is this GPE within this block?
	 *
	 * TRUE iff these conditions are true:
	 *     1) The GPE devices match.
	 *     2) The GPE index(number) is within the range of the Gpe Block
	 *          associated with the GPE device.
	 */
	if ((gpe_device == target_gpe_device) &&
	    (gpe_number >= gpe_block->block_base_number) &&
	    (gpe_number <
	     gpe_block->block_base_number + (gpe_block->register_count * 8))) {
		gpe_event_info =
		    &gpe_block->event_info[gpe_number -
					   gpe_block->block_base_number];

		/* Mark GPE for WAKE-ONLY but WAKE_DISABLED */

		gpe_event_info->flags &=
		    ~(ACPI_GPE_WAKE_ENABLED | ACPI_GPE_RUN_ENABLED);

		status =
		    acpi_ev_set_gpe_type(gpe_event_info, ACPI_GPE_TYPE_WAKE);
		if (ACPI_FAILURE(status)) {
			goto cleanup;
		}
		status =
		    acpi_ev_update_gpe_enable_masks(gpe_event_info,
						    ACPI_GPE_DISABLE);
	}

      cleanup:
	acpi_ut_remove_reference(pkg_desc);
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_get_gpe_xrupt_block
 *
 * PARAMETERS:  interrupt_number     - Interrupt for a GPE block
 *
 * RETURN:      A GPE interrupt block
 *
 * DESCRIPTION: Get or Create a GPE interrupt block. There is one interrupt
 *              block per unique interrupt level used for GPEs.
 *              Should be called only when the GPE lists are semaphore locked
 *              and not subject to change.
 *
 ******************************************************************************/

static struct acpi_gpe_xrupt_info *acpi_ev_get_gpe_xrupt_block(u32
							       interrupt_number)
{
	struct acpi_gpe_xrupt_info *next_gpe_xrupt;
	struct acpi_gpe_xrupt_info *gpe_xrupt;
	acpi_status status;
	acpi_cpu_flags flags;

	ACPI_FUNCTION_TRACE(ev_get_gpe_xrupt_block);

	/* No need for lock since we are not changing any list elements here */

	next_gpe_xrupt = acpi_gbl_gpe_xrupt_list_head;
	while (next_gpe_xrupt) {
		if (next_gpe_xrupt->interrupt_number == interrupt_number) {
			return_PTR(next_gpe_xrupt);
		}

		next_gpe_xrupt = next_gpe_xrupt->next;
	}

	/* Not found, must allocate a new xrupt descriptor */

	gpe_xrupt = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_xrupt_info));
	if (!gpe_xrupt) {
		return_PTR(NULL);
	}

	gpe_xrupt->interrupt_number = interrupt_number;

	/* Install new interrupt descriptor with spin lock */

	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
	if (acpi_gbl_gpe_xrupt_list_head) {
		next_gpe_xrupt = acpi_gbl_gpe_xrupt_list_head;
		while (next_gpe_xrupt->next) {
			next_gpe_xrupt = next_gpe_xrupt->next;
		}

		next_gpe_xrupt->next = gpe_xrupt;
		gpe_xrupt->previous = next_gpe_xrupt;
	} else {
		acpi_gbl_gpe_xrupt_list_head = gpe_xrupt;
	}
	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

	/* Install new interrupt handler if not SCI_INT */

	if (interrupt_number != acpi_gbl_FADT.sci_interrupt) {
		status = acpi_os_install_interrupt_handler(interrupt_number,
							   acpi_ev_gpe_xrupt_handler,
							   gpe_xrupt);
		if (ACPI_FAILURE(status)) {
			ACPI_ERROR((AE_INFO,
				    "Could not install GPE interrupt handler at level 0x%X",
				    interrupt_number));
			return_PTR(NULL);
		}
	}

	return_PTR(gpe_xrupt);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_delete_gpe_xrupt
 *
 * PARAMETERS:  gpe_xrupt       - A GPE interrupt info block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove and free a gpe_xrupt block. Remove an associated
 *              interrupt handler if not the SCI interrupt.
 *
 ******************************************************************************/

static acpi_status
acpi_ev_delete_gpe_xrupt(struct acpi_gpe_xrupt_info *gpe_xrupt)
{
	acpi_status status;
	acpi_cpu_flags flags;

	ACPI_FUNCTION_TRACE(ev_delete_gpe_xrupt);

	/* We never want to remove the SCI interrupt handler */

	if (gpe_xrupt->interrupt_number == acpi_gbl_FADT.sci_interrupt) {
		gpe_xrupt->gpe_block_list_head = NULL;
		return_ACPI_STATUS(AE_OK);
	}

	/* Disable this interrupt */

	status =
	    acpi_os_remove_interrupt_handler(gpe_xrupt->interrupt_number,
					     acpi_ev_gpe_xrupt_handler);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Unlink the interrupt block with lock */

	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
	if (gpe_xrupt->previous) {
		gpe_xrupt->previous->next = gpe_xrupt->next;
	}

	if (gpe_xrupt->next) {
		gpe_xrupt->next->previous = gpe_xrupt->previous;
	}
	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

	/* Free the block */

	ACPI_FREE(gpe_xrupt);
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_gpe_block
 *
 * PARAMETERS:  gpe_block       - New GPE block
 *              interrupt_number - Xrupt to be associated with this GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install new GPE block with mutex support
 *
 ******************************************************************************/

static acpi_status
acpi_ev_install_gpe_block(struct acpi_gpe_block_info *gpe_block,
			  u32 interrupt_number)
{
	struct acpi_gpe_block_info *next_gpe_block;
	struct acpi_gpe_xrupt_info *gpe_xrupt_block;
	acpi_status status;
	acpi_cpu_flags flags;

	ACPI_FUNCTION_TRACE(ev_install_gpe_block);

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

	gpe_xrupt_block = acpi_ev_get_gpe_xrupt_block(interrupt_number);
	if (!gpe_xrupt_block) {
		status = AE_NO_MEMORY;
		goto unlock_and_exit;
	}

	/* Install the new block at the end of the list with lock */

	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
	if (gpe_xrupt_block->gpe_block_list_head) {
		next_gpe_block = gpe_xrupt_block->gpe_block_list_head;
		while (next_gpe_block->next) {
			next_gpe_block = next_gpe_block->next;
		}

		next_gpe_block->next = gpe_block;
		gpe_block->previous = next_gpe_block;
	} else {
		gpe_xrupt_block->gpe_block_list_head = gpe_block;
	}

	gpe_block->xrupt_block = gpe_xrupt_block;
	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

      unlock_and_exit:
	status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_delete_gpe_block
 *
 * PARAMETERS:  gpe_block       - Existing GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove a GPE block
 *
 ******************************************************************************/

acpi_status acpi_ev_delete_gpe_block(struct acpi_gpe_block_info *gpe_block)
{
	acpi_status status;
	acpi_cpu_flags flags;

	ACPI_FUNCTION_TRACE(ev_install_gpe_block);

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

	/* Disable all GPEs in this block */

	status = acpi_hw_disable_gpe_block(gpe_block->xrupt_block, gpe_block);

	if (!gpe_block->previous && !gpe_block->next) {

		/* This is the last gpe_block on this interrupt */

		status = acpi_ev_delete_gpe_xrupt(gpe_block->xrupt_block);
		if (ACPI_FAILURE(status)) {
			goto unlock_and_exit;
		}
	} else {
		/* Remove the block on this interrupt with lock */

		flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
		if (gpe_block->previous) {
			gpe_block->previous->next = gpe_block->next;
		} else {
			gpe_block->xrupt_block->gpe_block_list_head =
			    gpe_block->next;
		}

		if (gpe_block->next) {
			gpe_block->next->previous = gpe_block->previous;
		}
		acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
	}

	/* Free the gpe_block */

	ACPI_FREE(gpe_block->register_info);
	ACPI_FREE(gpe_block->event_info);
	ACPI_FREE(gpe_block);

      unlock_and_exit:
	status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_create_gpe_info_blocks
 *
 * PARAMETERS:  gpe_block   - New GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create the register_info and event_info blocks for this GPE block
 *
 ******************************************************************************/

static acpi_status
acpi_ev_create_gpe_info_blocks(struct acpi_gpe_block_info *gpe_block)
{
	struct acpi_gpe_register_info *gpe_register_info = NULL;
	struct acpi_gpe_event_info *gpe_event_info = NULL;
	struct acpi_gpe_event_info *this_event;
	struct acpi_gpe_register_info *this_register;
	acpi_native_uint i;
	acpi_native_uint j;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_create_gpe_info_blocks);

	/* Allocate the GPE register information block */

	gpe_register_info = ACPI_ALLOCATE_ZEROED((acpi_size) gpe_block->
						 register_count *
						 sizeof(struct
							acpi_gpe_register_info));
	if (!gpe_register_info) {
		ACPI_ERROR((AE_INFO,
			    "Could not allocate the GpeRegisterInfo table"));
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/*
	 * Allocate the GPE event_info block. There are eight distinct GPEs
	 * per register. Initialization to zeros is sufficient.
	 */
	gpe_event_info = ACPI_ALLOCATE_ZEROED(((acpi_size) gpe_block->
					       register_count *
					       ACPI_GPE_REGISTER_WIDTH) *
					      sizeof(struct
						     acpi_gpe_event_info));
	if (!gpe_event_info) {
		ACPI_ERROR((AE_INFO,
			    "Could not allocate the GpeEventInfo table"));
		status = AE_NO_MEMORY;
		goto error_exit;
	}

	/* Save the new Info arrays in the GPE block */

	gpe_block->register_info = gpe_register_info;
	gpe_block->event_info = gpe_event_info;

	/*
	 * Initialize the GPE Register and Event structures. A goal of these
	 * tables is to hide the fact that there are two separate GPE register sets
	 * in a given GPE hardware block, the status registers occupy the first half,
	 * and the enable registers occupy the second half.
	 */
	this_register = gpe_register_info;
	this_event = gpe_event_info;

	for (i = 0; i < gpe_block->register_count; i++) {

		/* Init the register_info for this GPE register (8 GPEs) */

		this_register->base_gpe_number =
		    (u8) (gpe_block->block_base_number +
			  (i * ACPI_GPE_REGISTER_WIDTH));

		ACPI_STORE_ADDRESS(this_register->status_address.address,
				   (gpe_block->block_address.address + i));

		ACPI_STORE_ADDRESS(this_register->enable_address.address,
				   (gpe_block->block_address.address
				    + i + gpe_block->register_count));

		this_register->status_address.space_id =
		    gpe_block->block_address.space_id;
		this_register->enable_address.space_id =
		    gpe_block->block_address.space_id;
		this_register->status_address.bit_width =
		    ACPI_GPE_REGISTER_WIDTH;
		this_register->enable_address.bit_width =
		    ACPI_GPE_REGISTER_WIDTH;
		this_register->status_address.bit_offset =
		    ACPI_GPE_REGISTER_WIDTH;
		this_register->enable_address.bit_offset =
		    ACPI_GPE_REGISTER_WIDTH;

		/* Init the event_info for each GPE within this register */

		for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
			this_event->register_bit = acpi_gbl_decode_to8bit[j];
			this_event->register_info = this_register;
			this_event++;
		}

		/* Disable all GPEs within this register */

		status = acpi_hw_low_level_write(ACPI_GPE_REGISTER_WIDTH, 0x00,
						 &this_register->
						 enable_address);
		if (ACPI_FAILURE(status)) {
			goto error_exit;
		}

		/* Clear any pending GPE events within this register */

		status = acpi_hw_low_level_write(ACPI_GPE_REGISTER_WIDTH, 0xFF,
						 &this_register->
						 status_address);
		if (ACPI_FAILURE(status)) {
			goto error_exit;
		}

		this_register++;
	}

	return_ACPI_STATUS(AE_OK);

      error_exit:
	if (gpe_register_info) {
		ACPI_FREE(gpe_register_info);
	}
	if (gpe_event_info) {
		ACPI_FREE(gpe_event_info);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_create_gpe_block
 *
 * PARAMETERS:  gpe_device          - Handle to the parent GPE block
 *              gpe_block_address   - Address and space_iD
 *              register_count      - Number of GPE register pairs in the block
 *              gpe_block_base_number - Starting GPE number for the block
 *              interrupt_number    - H/W interrupt for the block
 *              return_gpe_block    - Where the new block descriptor is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create and Install a block of GPE registers. All GPEs within
 *              the block are disabled at exit.
 *              Note: Assumes namespace is locked.
 *
 ******************************************************************************/

acpi_status
acpi_ev_create_gpe_block(struct acpi_namespace_node *gpe_device,
			 struct acpi_generic_address *gpe_block_address,
			 u32 register_count,
			 u8 gpe_block_base_number,
			 u32 interrupt_number,
			 struct acpi_gpe_block_info **return_gpe_block)
{
	acpi_status status;
	struct acpi_gpe_block_info *gpe_block;

	ACPI_FUNCTION_TRACE(ev_create_gpe_block);

	if (!register_count) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Allocate a new GPE block */

	gpe_block = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_block_info));
	if (!gpe_block) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Initialize the new GPE block */

	gpe_block->node = gpe_device;
	gpe_block->register_count = register_count;
	gpe_block->block_base_number = gpe_block_base_number;

	ACPI_MEMCPY(&gpe_block->block_address, gpe_block_address,
		    sizeof(struct acpi_generic_address));

	/*
	 * Create the register_info and event_info sub-structures
	 * Note: disables and clears all GPEs in the block
	 */
	status = acpi_ev_create_gpe_info_blocks(gpe_block);
	if (ACPI_FAILURE(status)) {
		ACPI_FREE(gpe_block);
		return_ACPI_STATUS(status);
	}

	/* Install the new block in the global lists */

	status = acpi_ev_install_gpe_block(gpe_block, interrupt_number);
	if (ACPI_FAILURE(status)) {
		ACPI_FREE(gpe_block);
		return_ACPI_STATUS(status);
	}

	/* Find all GPE methods (_Lxx, _Exx) for this block */

	status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD, gpe_device,
					ACPI_UINT32_MAX, ACPI_NS_WALK_NO_UNLOCK,
					acpi_ev_save_method_info, gpe_block,
					NULL);

	/* Return the new block */

	if (return_gpe_block) {
		(*return_gpe_block) = gpe_block;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
			  "GPE %02X to %02X [%4.4s] %u regs on int 0x%X\n",
			  (u32) gpe_block->block_base_number,
			  (u32) (gpe_block->block_base_number +
				 ((gpe_block->register_count *
				   ACPI_GPE_REGISTER_WIDTH) - 1)),
			  gpe_device->name.ascii, gpe_block->register_count,
			  interrupt_number));

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_initialize_gpe_block
 *
 * PARAMETERS:  gpe_device          - Handle to the parent GPE block
 *              gpe_block           - Gpe Block info
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize and enable a GPE block. First find and run any
 *              _PRT methods associated with the block, then enable the
 *              appropriate GPEs.
 *              Note: Assumes namespace is locked.
 *
 ******************************************************************************/

acpi_status
acpi_ev_initialize_gpe_block(struct acpi_namespace_node *gpe_device,
			     struct acpi_gpe_block_info *gpe_block)
{
	acpi_status status;
	struct acpi_gpe_event_info *gpe_event_info;
	struct acpi_gpe_walk_info gpe_info;
	u32 wake_gpe_count;
	u32 gpe_enabled_count;
	acpi_native_uint i;
	acpi_native_uint j;

	ACPI_FUNCTION_TRACE(ev_initialize_gpe_block);

	/* Ignore a null GPE block (e.g., if no GPE block 1 exists) */

	if (!gpe_block) {
		return_ACPI_STATUS(AE_OK);
	}

	/*
	 * Runtime option: Should wake GPEs be enabled at runtime?  The default
	 * is no, they should only be enabled just as the machine goes to sleep.
	 */
	if (acpi_gbl_leave_wake_gpes_disabled) {
		/*
		 * Differentiate runtime vs wake GPEs, via the _PRW control methods.
		 * Each GPE that has one or more _PRWs that reference it is by
		 * definition a wake GPE and will not be enabled while the machine
		 * is running.
		 */
		gpe_info.gpe_block = gpe_block;
		gpe_info.gpe_device = gpe_device;

		status =
		    acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
					   ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
					   acpi_ev_match_prw_and_gpe, &gpe_info,
					   NULL);
	}

	/*
	 * Enable all GPEs in this block that have these attributes:
	 * 1) are "runtime" or "run/wake" GPEs, and
	 * 2) have a corresponding _Lxx or _Exx method
	 *
	 * Any other GPEs within this block must be enabled via the acpi_enable_gpe()
	 * external interface.
	 */
	wake_gpe_count = 0;
	gpe_enabled_count = 0;

	for (i = 0; i < gpe_block->register_count; i++) {
		for (j = 0; j < 8; j++) {

			/* Get the info block for this particular GPE */

			gpe_event_info =
			    &gpe_block->
			    event_info[(i * ACPI_GPE_REGISTER_WIDTH) + j];

			if (((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
			     ACPI_GPE_DISPATCH_METHOD)
			    && (gpe_event_info->
				flags & ACPI_GPE_TYPE_RUNTIME)) {
				gpe_enabled_count++;
			}

			if (gpe_event_info->flags & ACPI_GPE_TYPE_WAKE) {
				wake_gpe_count++;
			}
		}
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
			  "Found %u Wake, Enabled %u Runtime GPEs in this block\n",
			  wake_gpe_count, gpe_enabled_count));

	/* Enable all valid runtime GPEs found above */

	status = acpi_hw_enable_runtime_gpe_block(NULL, gpe_block);
	if (ACPI_FAILURE(status)) {
		ACPI_ERROR((AE_INFO, "Could not enable GPEs in GpeBlock %p",
			    gpe_block));
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_gpe_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize the GPE data structures
 *
 ******************************************************************************/

acpi_status acpi_ev_gpe_initialize(void)
{
	u32 register_count0 = 0;
	u32 register_count1 = 0;
	u32 gpe_number_max = 0;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_gpe_initialize);

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

	/*
	 * Initialize the GPE Block(s) defined in the FADT
	 *
	 * Why the GPE register block lengths are divided by 2:  From the ACPI Spec,
	 * section "General-Purpose Event Registers", we have:
	 *
	 * "Each register block contains two registers of equal length
	 *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
	 *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
	 *  The length of the GPE1_STS and GPE1_EN registers is equal to
	 *  half the GPE1_LEN. If a generic register block is not supported
	 *  then its respective block pointer and block length values in the
	 *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
	 *  to be the same size."
	 */

	/*
	 * Determine the maximum GPE number for this machine.
	 *
	 * Note: both GPE0 and GPE1 are optional, and either can exist without
	 * the other.
	 *
	 * If EITHER the register length OR the block address are zero, then that
	 * particular block is not supported.
	 */
	if (acpi_gbl_FADT.gpe0_block_length &&
	    acpi_gbl_FADT.xgpe0_block.address) {

		/* GPE block 0 exists (has both length and address > 0) */

		register_count0 = (u16) (acpi_gbl_FADT.gpe0_block_length / 2);

		gpe_number_max =
		    (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;

		/* Install GPE Block 0 */

		status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
						  &acpi_gbl_FADT.xgpe0_block,
						  register_count0, 0,
						  acpi_gbl_FADT.sci_interrupt,
						  &acpi_gbl_gpe_fadt_blocks[0]);

		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Could not create GPE Block 0"));
		}
	}

	if (acpi_gbl_FADT.gpe1_block_length &&
	    acpi_gbl_FADT.xgpe1_block.address) {

		/* GPE block 1 exists (has both length and address > 0) */

		register_count1 = (u16) (acpi_gbl_FADT.gpe1_block_length / 2);

		/* Check for GPE0/GPE1 overlap (if both banks exist) */

		if ((register_count0) &&
		    (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
			ACPI_ERROR((AE_INFO,
				    "GPE0 block (GPE 0 to %d) overlaps the GPE1 block (GPE %d to %d) - Ignoring GPE1",
				    gpe_number_max, acpi_gbl_FADT.gpe1_base,
				    acpi_gbl_FADT.gpe1_base +
				    ((register_count1 *
				      ACPI_GPE_REGISTER_WIDTH) - 1)));

			/* Ignore GPE1 block by setting the register count to zero */

			register_count1 = 0;
		} else {
			/* Install GPE Block 1 */

			status =
			    acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
						     &acpi_gbl_FADT.xgpe1_block,
						     register_count1,
						     acpi_gbl_FADT.gpe1_base,
						     acpi_gbl_FADT.
						     sci_interrupt,
						     &acpi_gbl_gpe_fadt_blocks
						     [1]);

			if (ACPI_FAILURE(status)) {
				ACPI_EXCEPTION((AE_INFO, status,
						"Could not create GPE Block 1"));
			}

			/*
			 * GPE0 and GPE1 do not have to be contiguous in the GPE number
			 * space. However, GPE0 always starts at GPE number zero.
			 */
			gpe_number_max = acpi_gbl_FADT.gpe1_base +
			    ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
		}
	}

	/* Exit if there are no GPE registers */

	if ((register_count0 + register_count1) == 0) {

		/* GPEs are not required by ACPI, this is OK */

		ACPI_DEBUG_PRINT((ACPI_DB_INIT,
				  "There are no GPE blocks defined in the FADT\n"));
		status = AE_OK;
		goto cleanup;
	}

	/* Check for Max GPE number out-of-range */

	if (gpe_number_max > ACPI_GPE_MAX) {
		ACPI_ERROR((AE_INFO,
			    "Maximum GPE number from FADT is too large: 0x%X",
			    gpe_number_max));
		status = AE_BAD_VALUE;
		goto cleanup;
	}

      cleanup:
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return_ACPI_STATUS(AE_OK);
}