aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/utilities/utmisc.c
blob: a77ffcd5570f5e7549b31bb358ac08020f2b8512 (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
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
/*******************************************************************************
 *
 * Module Name: utmisc - common utility procedures
 *
 ******************************************************************************/

/*
 * 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/acnamesp.h>

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utmisc")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_allocate_owner_id
 *
 * PARAMETERS:  owner_id        - Where the new owner ID is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to
 *              track objects created by the table or method, to be deleted
 *              when the method exits or the table is unloaded.
 *
 ******************************************************************************/
acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
{
	acpi_native_uint i;
	acpi_native_uint j;
	acpi_native_uint k;
	acpi_status status;

	ACPI_FUNCTION_TRACE("ut_allocate_owner_id");

	/* Guard against multiple allocations of ID to the same location */

	if (*owner_id) {
		ACPI_REPORT_ERROR(("Owner ID [%2.2X] already exists\n",
				   *owner_id));
		return_ACPI_STATUS(AE_ALREADY_EXISTS);
	}

	/* Mutex for the global ID mask */

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

	/*
	 * Find a free owner ID, cycle through all possible IDs on repeated
	 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have
	 * to be scanned twice.
	 */
	for (i = 0, j = acpi_gbl_last_owner_id_index;
	     i < (ACPI_NUM_OWNERID_MASKS + 1); i++, j++) {
		if (j >= ACPI_NUM_OWNERID_MASKS) {
			j = 0;	/* Wraparound to start of mask array */
		}

		for (k = acpi_gbl_next_owner_id_offset; k < 32; k++) {
			if (acpi_gbl_owner_id_mask[j] == ACPI_UINT32_MAX) {
				/* There are no free IDs in this mask */

				break;
			}

			if (!(acpi_gbl_owner_id_mask[j] & (1 << k))) {
				/*
				 * Found a free ID. The actual ID is the bit index plus one,
				 * making zero an invalid Owner ID. Save this as the last ID
				 * allocated and update the global ID mask.
				 */
				acpi_gbl_owner_id_mask[j] |= (1 << k);

				acpi_gbl_last_owner_id_index = (u8) j;
				acpi_gbl_next_owner_id_offset = (u8) (k + 1);

				/*
				 * Construct encoded ID from the index and bit position
				 *
				 * Note: Last [j].k (bit 255) is never used and is marked
				 * permanently allocated (prevents +1 overflow)
				 */
				*owner_id =
				    (acpi_owner_id) ((k + 1) + ACPI_MUL_32(j));

				ACPI_DEBUG_PRINT((ACPI_DB_VALUES,
						  "Allocated owner_id: %2.2X\n",
						  (unsigned int)*owner_id));
				goto exit;
			}
		}

		acpi_gbl_next_owner_id_offset = 0;
	}

	/*
	 * All owner_ids have been allocated. This typically should
	 * not happen since the IDs are reused after deallocation. The IDs are
	 * allocated upon table load (one per table) and method execution, and
	 * they are released when a table is unloaded or a method completes
	 * execution.
	 *
	 * If this error happens, there may be very deep nesting of invoked control
	 * methods, or there may be a bug where the IDs are not released.
	 */
	status = AE_OWNER_ID_LIMIT;
	ACPI_REPORT_ERROR(("Could not allocate new owner_id (255 max), AE_OWNER_ID_LIMIT\n"));

      exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_release_owner_id
 *
 * PARAMETERS:  owner_id_ptr        - Pointer to a previously allocated owner_iD
 *
 * RETURN:      None. No error is returned because we are either exiting a
 *              control method or unloading a table. Either way, we would
 *              ignore any error anyway.
 *
 * DESCRIPTION: Release a table or method owner ID.  Valid IDs are 1 - 255
 *
 ******************************************************************************/

void acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr)
{
	acpi_owner_id owner_id = *owner_id_ptr;
	acpi_status status;
	acpi_native_uint index;
	u32 bit;

	ACPI_FUNCTION_TRACE_U32("ut_release_owner_id", owner_id);

	/* Always clear the input owner_id (zero is an invalid ID) */

	*owner_id_ptr = 0;

	/* Zero is not a valid owner_iD */

	if (owner_id == 0) {
		ACPI_REPORT_ERROR(("Invalid owner_id: %2.2X\n", owner_id));
		return_VOID;
	}

	/* Mutex for the global ID mask */

	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
	if (ACPI_FAILURE(status)) {
		return_VOID;
	}

	/* Normalize the ID to zero */

	owner_id--;

	/* Decode ID to index/offset pair */

	index = ACPI_DIV_32(owner_id);
	bit = 1 << ACPI_MOD_32(owner_id);

	/* Free the owner ID only if it is valid */

	if (acpi_gbl_owner_id_mask[index] & bit) {
		acpi_gbl_owner_id_mask[index] ^= bit;
	} else {
		ACPI_REPORT_ERROR(("Release of non-allocated owner_id: %2.2X\n",
				   owner_id + 1));
	}

	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_strupr (strupr)
 *
 * PARAMETERS:  src_string      - The source string to convert
 *
 * RETURN:      None
 *
 * DESCRIPTION: Convert string to uppercase
 *
 * NOTE: This is not a POSIX function, so it appears here, not in utclib.c
 *
 ******************************************************************************/

void acpi_ut_strupr(char *src_string)
{
	char *string;

	ACPI_FUNCTION_ENTRY();

	if (!src_string) {
		return;
	}

	/* Walk entire string, uppercasing the letters */

	for (string = src_string; *string; string++) {
		*string = (char)ACPI_TOUPPER(*string);
	}

	return;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_print_string
 *
 * PARAMETERS:  String          - Null terminated ASCII string
 *              max_length      - Maximum output length
 *
 * RETURN:      None
 *
 * DESCRIPTION: Dump an ASCII string with support for ACPI-defined escape
 *              sequences.
 *
 ******************************************************************************/

void acpi_ut_print_string(char *string, u8 max_length)
{
	u32 i;

	if (!string) {
		acpi_os_printf("<\"NULL STRING PTR\">");
		return;
	}

	acpi_os_printf("\"");
	for (i = 0; string[i] && (i < max_length); i++) {
		/* Escape sequences */

		switch (string[i]) {
		case 0x07:
			acpi_os_printf("\\a");	/* BELL */
			break;

		case 0x08:
			acpi_os_printf("\\b");	/* BACKSPACE */
			break;

		case 0x0C:
			acpi_os_printf("\\f");	/* FORMFEED */
			break;

		case 0x0A:
			acpi_os_printf("\\n");	/* LINEFEED */
			break;

		case 0x0D:
			acpi_os_printf("\\r");	/* CARRIAGE RETURN */
			break;

		case 0x09:
			acpi_os_printf("\\t");	/* HORIZONTAL TAB */
			break;

		case 0x0B:
			acpi_os_printf("\\v");	/* VERTICAL TAB */
			break;

		case '\'':	/* Single Quote */
		case '\"':	/* Double Quote */
		case '\\':	/* Backslash */
			acpi_os_printf("\\%c", (int)string[i]);
			break;

		default:

			/* Check for printable character or hex escape */

			if (ACPI_IS_PRINT(string[i])) {
				/* This is a normal character */

				acpi_os_printf("%c", (int)string[i]);
			} else {
				/* All others will be Hex escapes */

				acpi_os_printf("\\x%2.2X", (s32) string[i]);
			}
			break;
		}
	}
	acpi_os_printf("\"");

	if (i == max_length && string[i]) {
		acpi_os_printf("...");
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_dword_byte_swap
 *
 * PARAMETERS:  Value           - Value to be converted
 *
 * RETURN:      u32 integer with bytes swapped
 *
 * DESCRIPTION: Convert a 32-bit value to big-endian (swap the bytes)
 *
 ******************************************************************************/

u32 acpi_ut_dword_byte_swap(u32 value)
{
	union {
		u32 value;
		u8 bytes[4];
	} out;
	union {
		u32 value;
		u8 bytes[4];
	} in;

	ACPI_FUNCTION_ENTRY();

	in.value = value;

	out.bytes[0] = in.bytes[3];
	out.bytes[1] = in.bytes[2];
	out.bytes[2] = in.bytes[1];
	out.bytes[3] = in.bytes[0];

	return (out.value);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_set_integer_width
 *
 * PARAMETERS:  Revision            From DSDT header
 *
 * RETURN:      None
 *
 * DESCRIPTION: Set the global integer bit width based upon the revision
 *              of the DSDT.  For Revision 1 and 0, Integers are 32 bits.
 *              For Revision 2 and above, Integers are 64 bits.  Yes, this
 *              makes a difference.
 *
 ******************************************************************************/

void acpi_ut_set_integer_width(u8 revision)
{

	if (revision <= 1) {
		acpi_gbl_integer_bit_width = 32;
		acpi_gbl_integer_nybble_width = 8;
		acpi_gbl_integer_byte_width = 4;
	} else {
		acpi_gbl_integer_bit_width = 64;
		acpi_gbl_integer_nybble_width = 16;
		acpi_gbl_integer_byte_width = 8;
	}
}

#ifdef ACPI_DEBUG_OUTPUT
/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_display_init_pathname
 *
 * PARAMETERS:  Type                - Object type of the node
 *              obj_handle          - Handle whose pathname will be displayed
 *              Path                - Additional path string to be appended.
 *                                      (NULL if no extra path)
 *
 * RETURN:      acpi_status
 *
 * DESCRIPTION: Display full pathname of an object, DEBUG ONLY
 *
 ******************************************************************************/

void
acpi_ut_display_init_pathname(u8 type,
			      struct acpi_namespace_node *obj_handle,
			      char *path)
{
	acpi_status status;
	struct acpi_buffer buffer;

	ACPI_FUNCTION_ENTRY();

	/* Only print the path if the appropriate debug level is enabled */

	if (!(acpi_dbg_level & ACPI_LV_INIT_NAMES)) {
		return;
	}

	/* Get the full pathname to the node */

	buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
	status = acpi_ns_handle_to_pathname(obj_handle, &buffer);
	if (ACPI_FAILURE(status)) {
		return;
	}

	/* Print what we're doing */

	switch (type) {
	case ACPI_TYPE_METHOD:
		acpi_os_printf("Executing  ");
		break;

	default:
		acpi_os_printf("Initializing ");
		break;
	}

	/* Print the object type and pathname */

	acpi_os_printf("%-12s %s",
		       acpi_ut_get_type_name(type), (char *)buffer.pointer);

	/* Extra path is used to append names like _STA, _INI, etc. */

	if (path) {
		acpi_os_printf(".%s", path);
	}
	acpi_os_printf("\n");

	ACPI_MEM_FREE(buffer.pointer);
}
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_valid_acpi_name
 *
 * PARAMETERS:  Name            - The name to be examined
 *
 * RETURN:      TRUE if the name is valid, FALSE otherwise
 *
 * DESCRIPTION: Check for a valid ACPI name.  Each character must be one of:
 *              1) Upper case alpha
 *              2) numeric
 *              3) underscore
 *
 ******************************************************************************/

u8 acpi_ut_valid_acpi_name(u32 name)
{
	char *name_ptr = (char *)&name;
	char character;
	acpi_native_uint i;

	ACPI_FUNCTION_ENTRY();

	for (i = 0; i < ACPI_NAME_SIZE; i++) {
		character = *name_ptr;
		name_ptr++;

		if (!((character == '_') ||
		      (character >= 'A' && character <= 'Z') ||
		      (character >= '0' && character <= '9'))) {
			return (FALSE);
		}
	}

	return (TRUE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_valid_acpi_character
 *
 * PARAMETERS:  Character           - The character to be examined
 *
 * RETURN:      1 if Character may appear in a name, else 0
 *
 * DESCRIPTION: Check for a printable character
 *
 ******************************************************************************/

u8 acpi_ut_valid_acpi_character(char character)
{

	ACPI_FUNCTION_ENTRY();

	return ((u8) ((character == '_') ||
		      (character >= 'A' && character <= 'Z') ||
		      (character >= '0' && character <= '9')));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_strtoul64
 *
 * PARAMETERS:  String          - Null terminated string
 *              Base            - Radix of the string: 10, 16, or ACPI_ANY_BASE
 *              ret_integer     - Where the converted integer is returned
 *
 * RETURN:      Status and Converted value
 *
 * DESCRIPTION: Convert a string into an unsigned value.
 *              NOTE: Does not support Octal strings, not needed.
 *
 ******************************************************************************/

acpi_status
acpi_ut_strtoul64(char *string, u32 base, acpi_integer * ret_integer)
{
	u32 this_digit = 0;
	acpi_integer return_value = 0;
	acpi_integer quotient;

	ACPI_FUNCTION_TRACE("ut_stroul64");

	if ((!string) || !(*string)) {
		goto error_exit;
	}

	switch (base) {
	case ACPI_ANY_BASE:
	case 10:
	case 16:
		break;

	default:
		/* Invalid Base */
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Skip over any white space in the buffer */

	while (ACPI_IS_SPACE(*string) || *string == '\t') {
		string++;
	}

	/*
	 * If the input parameter Base is zero, then we need to
	 * determine if it is decimal or hexadecimal:
	 */
	if (base == 0) {
		if ((*string == '0') && (ACPI_TOLOWER(*(string + 1)) == 'x')) {
			base = 16;
			string += 2;
		} else {
			base = 10;
		}
	}

	/*
	 * For hexadecimal base, skip over the leading
	 * 0 or 0x, if they are present.
	 */
	if ((base == 16) &&
	    (*string == '0') && (ACPI_TOLOWER(*(string + 1)) == 'x')) {
		string += 2;
	}

	/* Any string left? */

	if (!(*string)) {
		goto error_exit;
	}

	/* Main loop: convert the string to a 64-bit integer */

	while (*string) {
		if (ACPI_IS_DIGIT(*string)) {
			/* Convert ASCII 0-9 to Decimal value */

			this_digit = ((u8) * string) - '0';
		} else {
			if (base == 10) {
				/* Digit is out of range */

				goto error_exit;
			}

			this_digit = (u8) ACPI_TOUPPER(*string);
			if (ACPI_IS_XDIGIT((char)this_digit)) {
				/* Convert ASCII Hex char to value */

				this_digit = this_digit - 'A' + 10;
			} else {
				/*
				 * We allow non-hex chars, just stop now, same as end-of-string.
				 * See ACPI spec, string-to-integer conversion.
				 */
				break;
			}
		}

		/* Divide the digit into the correct position */

		(void)
		    acpi_ut_short_divide((ACPI_INTEGER_MAX -
					  (acpi_integer) this_digit), base,
					 &quotient, NULL);
		if (return_value > quotient) {
			goto error_exit;
		}

		return_value *= base;
		return_value += this_digit;
		string++;
	}

	/* All done, normal exit */

	*ret_integer = return_value;
	return_ACPI_STATUS(AE_OK);

      error_exit:
	/* Base was set/validated above */

	if (base == 10) {
		return_ACPI_STATUS(AE_BAD_DECIMAL_CONSTANT);
	} else {
		return_ACPI_STATUS(AE_BAD_HEX_CONSTANT);
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_update_state_and_push
 *
 * PARAMETERS:  Object          - Object to be added to the new state
 *              Action          - Increment/Decrement
 *              state_list      - List the state will be added to
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a new state and push it
 *
 ******************************************************************************/

acpi_status
acpi_ut_create_update_state_and_push(union acpi_operand_object *object,
				     u16 action,
				     union acpi_generic_state **state_list)
{
	union acpi_generic_state *state;

	ACPI_FUNCTION_ENTRY();

	/* Ignore null objects; these are expected */

	if (!object) {
		return (AE_OK);
	}

	state = acpi_ut_create_update_state(object, action);
	if (!state) {
		return (AE_NO_MEMORY);
	}

	acpi_ut_push_generic_state(state_list, state);
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_walk_package_tree
 *
 * PARAMETERS:  source_object       - The package to walk
 *              target_object       - Target object (if package is being copied)
 *              walk_callback       - Called once for each package element
 *              Context             - Passed to the callback function
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Walk through a package
 *
 ******************************************************************************/

acpi_status
acpi_ut_walk_package_tree(union acpi_operand_object * source_object,
			  void *target_object,
			  acpi_pkg_callback walk_callback, void *context)
{
	acpi_status status = AE_OK;
	union acpi_generic_state *state_list = NULL;
	union acpi_generic_state *state;
	u32 this_index;
	union acpi_operand_object *this_source_obj;

	ACPI_FUNCTION_TRACE("ut_walk_package_tree");

	state = acpi_ut_create_pkg_state(source_object, target_object, 0);
	if (!state) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	while (state) {
		/* Get one element of the package */

		this_index = state->pkg.index;
		this_source_obj = (union acpi_operand_object *)
		    state->pkg.source_object->package.elements[this_index];

		/*
		 * Check for:
		 * 1) An uninitialized package element.  It is completely
		 *    legal to declare a package and leave it uninitialized
		 * 2) Not an internal object - can be a namespace node instead
		 * 3) Any type other than a package.  Packages are handled in else
		 *    case below.
		 */
		if ((!this_source_obj) ||
		    (ACPI_GET_DESCRIPTOR_TYPE(this_source_obj) !=
		     ACPI_DESC_TYPE_OPERAND)
		    || (ACPI_GET_OBJECT_TYPE(this_source_obj) !=
			ACPI_TYPE_PACKAGE)) {
			status =
			    walk_callback(ACPI_COPY_TYPE_SIMPLE,
					  this_source_obj, state, context);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}

			state->pkg.index++;
			while (state->pkg.index >=
			       state->pkg.source_object->package.count) {
				/*
				 * We've handled all of the objects at this level,  This means
				 * that we have just completed a package.  That package may
				 * have contained one or more packages itself.
				 *
				 * Delete this state and pop the previous state (package).
				 */
				acpi_ut_delete_generic_state(state);
				state = acpi_ut_pop_generic_state(&state_list);

				/* Finished when there are no more states */

				if (!state) {
					/*
					 * We have handled all of the objects in the top level
					 * package just add the length of the package objects
					 * and exit
					 */
					return_ACPI_STATUS(AE_OK);
				}

				/*
				 * Go back up a level and move the index past the just
				 * completed package object.
				 */
				state->pkg.index++;
			}
		} else {
			/* This is a subobject of type package */

			status =
			    walk_callback(ACPI_COPY_TYPE_PACKAGE,
					  this_source_obj, state, context);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}

			/*
			 * Push the current state and create a new one
			 * The callback above returned a new target package object.
			 */
			acpi_ut_push_generic_state(&state_list, state);
			state = acpi_ut_create_pkg_state(this_source_obj,
							 state->pkg.
							 this_target_obj, 0);
			if (!state) {
				return_ACPI_STATUS(AE_NO_MEMORY);
			}
		}
	}

	/* We should never get here */

	return_ACPI_STATUS(AE_AML_INTERNAL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_generate_checksum
 *
 * PARAMETERS:  Buffer          - Buffer to be scanned
 *              Length          - number of bytes to examine
 *
 * RETURN:      The generated checksum
 *
 * DESCRIPTION: Generate a checksum on a raw buffer
 *
 ******************************************************************************/

u8 acpi_ut_generate_checksum(u8 * buffer, u32 length)
{
	u32 i;
	signed char sum = 0;

	for (i = 0; i < length; i++) {
		sum = (signed char)(sum + buffer[i]);
	}

	return ((u8) (0 - sum));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_report_error
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print error message
 *
 ******************************************************************************/

void acpi_ut_report_error(char *module_name, u32 line_number)
{

	acpi_os_printf("ACPI Error (%s-%04d): ", module_name, line_number);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_report_warning
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print warning message
 *
 ******************************************************************************/

void acpi_ut_report_warning(char *module_name, u32 line_number)
{

	acpi_os_printf("ACPI Warning (%s-%04d): ", module_name, line_number);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_report_info
 *
 * PARAMETERS:  module_name         - Caller's module name (for error output)
 *              line_number         - Caller's line number (for error output)
 *
 * RETURN:      None
 *
 * DESCRIPTION: Print information message
 *
 ******************************************************************************/

void acpi_ut_report_info(char *module_name, u32 line_number)
{

	acpi_os_printf("ACPI (%s-%04d): ", module_name, line_number);
}