[PATCH] cfq-iosched: fix crash in do_div()
[linux-2.6.git] / drivers / acpi / executer / exoparg1.c
1
2 /******************************************************************************
3  *
4  * Module Name: exoparg1 - AML execution - opcodes with 1 argument
5  *
6  *****************************************************************************/
7
8 /*
9  * Copyright (C) 2000 - 2006, R. Byron Moore
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44
45 #include <acpi/acpi.h>
46 #include <acpi/acparser.h>
47 #include <acpi/acdispat.h>
48 #include <acpi/acinterp.h>
49 #include <acpi/amlcode.h>
50 #include <acpi/acnamesp.h>
51
52 #define _COMPONENT          ACPI_EXECUTER
53 ACPI_MODULE_NAME("exoparg1")
54
55 /*!
56  * Naming convention for AML interpreter execution routines.
57  *
58  * The routines that begin execution of AML opcodes are named with a common
59  * convention based upon the number of arguments, the number of target operands,
60  * and whether or not a value is returned:
61  *
62  *      AcpiExOpcode_xA_yT_zR
63  *
64  * Where:
65  *
66  * xA - ARGUMENTS:    The number of arguments (input operands) that are
67  *                    required for this opcode type (0 through 6 args).
68  * yT - TARGETS:      The number of targets (output operands) that are required
69  *                    for this opcode type (0, 1, or 2 targets).
70  * zR - RETURN VALUE: Indicates whether this opcode type returns a value
71  *                    as the function return (0 or 1).
72  *
73  * The AcpiExOpcode* functions are called via the Dispatcher component with
74  * fully resolved operands.
75 !*/
76 /*******************************************************************************
77  *
78  * FUNCTION:    acpi_ex_opcode_0A_0T_1R
79  *
80  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
81  *
82  * RETURN:      Status
83  *
84  * DESCRIPTION: Execute operator with no operands, one return value
85  *
86  ******************************************************************************/
87 acpi_status acpi_ex_opcode_0A_0T_1R(struct acpi_walk_state *walk_state)
88 {
89         acpi_status status = AE_OK;
90         union acpi_operand_object *return_desc = NULL;
91
92         ACPI_FUNCTION_TRACE_STR("ex_opcode_0A_0T_1R",
93                                 acpi_ps_get_opcode_name(walk_state->opcode));
94
95         /* Examine the AML opcode */
96
97         switch (walk_state->opcode) {
98         case AML_TIMER_OP:      /*  Timer () */
99
100                 /* Create a return object of type Integer */
101
102                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
103                 if (!return_desc) {
104                         status = AE_NO_MEMORY;
105                         goto cleanup;
106                 }
107 #if ACPI_MACHINE_WIDTH != 16
108                 return_desc->integer.value = acpi_os_get_timer();
109 #endif
110                 break;
111
112         default:                /*  Unknown opcode  */
113
114                 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
115                             walk_state->opcode));
116                 status = AE_AML_BAD_OPCODE;
117                 break;
118         }
119
120       cleanup:
121
122         /* Delete return object on error */
123
124         if ((ACPI_FAILURE(status)) || walk_state->result_obj) {
125                 acpi_ut_remove_reference(return_desc);
126         } else {
127                 /* Save the return value */
128
129                 walk_state->result_obj = return_desc;
130         }
131
132         return_ACPI_STATUS(status);
133 }
134
135 /*******************************************************************************
136  *
137  * FUNCTION:    acpi_ex_opcode_1A_0T_0R
138  *
139  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
140  *
141  * RETURN:      Status
142  *
143  * DESCRIPTION: Execute Type 1 monadic operator with numeric operand on
144  *              object stack
145  *
146  ******************************************************************************/
147
148 acpi_status acpi_ex_opcode_1A_0T_0R(struct acpi_walk_state *walk_state)
149 {
150         union acpi_operand_object **operand = &walk_state->operands[0];
151         acpi_status status = AE_OK;
152
153         ACPI_FUNCTION_TRACE_STR("ex_opcode_1A_0T_0R",
154                                 acpi_ps_get_opcode_name(walk_state->opcode));
155
156         /* Examine the AML opcode */
157
158         switch (walk_state->opcode) {
159         case AML_RELEASE_OP:    /*  Release (mutex_object) */
160
161                 status = acpi_ex_release_mutex(operand[0], walk_state);
162                 break;
163
164         case AML_RESET_OP:      /*  Reset (event_object) */
165
166                 status = acpi_ex_system_reset_event(operand[0]);
167                 break;
168
169         case AML_SIGNAL_OP:     /*  Signal (event_object) */
170
171                 status = acpi_ex_system_signal_event(operand[0]);
172                 break;
173
174         case AML_SLEEP_OP:      /*  Sleep (msec_time) */
175
176                 status = acpi_ex_system_do_suspend(operand[0]->integer.value);
177                 break;
178
179         case AML_STALL_OP:      /*  Stall (usec_time) */
180
181                 status =
182                     acpi_ex_system_do_stall((u32) operand[0]->integer.value);
183                 break;
184
185         case AML_UNLOAD_OP:     /*  Unload (Handle) */
186
187                 status = acpi_ex_unload_table(operand[0]);
188                 break;
189
190         default:                /*  Unknown opcode  */
191
192                 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
193                             walk_state->opcode));
194                 status = AE_AML_BAD_OPCODE;
195                 break;
196         }
197
198         return_ACPI_STATUS(status);
199 }
200
201 /*******************************************************************************
202  *
203  * FUNCTION:    acpi_ex_opcode_1A_1T_0R
204  *
205  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
206  *
207  * RETURN:      Status
208  *
209  * DESCRIPTION: Execute opcode with one argument, one target, and no
210  *              return value.
211  *
212  ******************************************************************************/
213
214 acpi_status acpi_ex_opcode_1A_1T_0R(struct acpi_walk_state *walk_state)
215 {
216         acpi_status status = AE_OK;
217         union acpi_operand_object **operand = &walk_state->operands[0];
218
219         ACPI_FUNCTION_TRACE_STR("ex_opcode_1A_1T_0R",
220                                 acpi_ps_get_opcode_name(walk_state->opcode));
221
222         /* Examine the AML opcode */
223
224         switch (walk_state->opcode) {
225         case AML_LOAD_OP:
226
227                 status = acpi_ex_load_op(operand[0], operand[1], walk_state);
228                 break;
229
230         default:                /* Unknown opcode */
231
232                 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
233                             walk_state->opcode));
234                 status = AE_AML_BAD_OPCODE;
235                 goto cleanup;
236         }
237
238       cleanup:
239
240         return_ACPI_STATUS(status);
241 }
242
243 /*******************************************************************************
244  *
245  * FUNCTION:    acpi_ex_opcode_1A_1T_1R
246  *
247  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
248  *
249  * RETURN:      Status
250  *
251  * DESCRIPTION: Execute opcode with one argument, one target, and a
252  *              return value.
253  *
254  ******************************************************************************/
255
256 acpi_status acpi_ex_opcode_1A_1T_1R(struct acpi_walk_state *walk_state)
257 {
258         acpi_status status = AE_OK;
259         union acpi_operand_object **operand = &walk_state->operands[0];
260         union acpi_operand_object *return_desc = NULL;
261         union acpi_operand_object *return_desc2 = NULL;
262         u32 temp32;
263         u32 i;
264         acpi_integer power_of_ten;
265         acpi_integer digit;
266
267         ACPI_FUNCTION_TRACE_STR("ex_opcode_1A_1T_1R",
268                                 acpi_ps_get_opcode_name(walk_state->opcode));
269
270         /* Examine the AML opcode */
271
272         switch (walk_state->opcode) {
273         case AML_BIT_NOT_OP:
274         case AML_FIND_SET_LEFT_BIT_OP:
275         case AML_FIND_SET_RIGHT_BIT_OP:
276         case AML_FROM_BCD_OP:
277         case AML_TO_BCD_OP:
278         case AML_COND_REF_OF_OP:
279
280                 /* Create a return object of type Integer for these opcodes */
281
282                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
283                 if (!return_desc) {
284                         status = AE_NO_MEMORY;
285                         goto cleanup;
286                 }
287
288                 switch (walk_state->opcode) {
289                 case AML_BIT_NOT_OP:    /* Not (Operand, Result)  */
290
291                         return_desc->integer.value = ~operand[0]->integer.value;
292                         break;
293
294                 case AML_FIND_SET_LEFT_BIT_OP:  /* find_set_left_bit (Operand, Result) */
295
296                         return_desc->integer.value = operand[0]->integer.value;
297
298                         /*
299                          * Acpi specification describes Integer type as a little
300                          * endian unsigned value, so this boundary condition is valid.
301                          */
302                         for (temp32 = 0; return_desc->integer.value &&
303                              temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
304                                 return_desc->integer.value >>= 1;
305                         }
306
307                         return_desc->integer.value = temp32;
308                         break;
309
310                 case AML_FIND_SET_RIGHT_BIT_OP: /* find_set_right_bit (Operand, Result) */
311
312                         return_desc->integer.value = operand[0]->integer.value;
313
314                         /*
315                          * The Acpi specification describes Integer type as a little
316                          * endian unsigned value, so this boundary condition is valid.
317                          */
318                         for (temp32 = 0; return_desc->integer.value &&
319                              temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {
320                                 return_desc->integer.value <<= 1;
321                         }
322
323                         /* Since the bit position is one-based, subtract from 33 (65) */
324
325                         return_desc->integer.value = temp32 == 0 ? 0 :
326                             (ACPI_INTEGER_BIT_SIZE + 1) - temp32;
327                         break;
328
329                 case AML_FROM_BCD_OP:   /* from_bcd (BCDValue, Result) */
330
331                         /*
332                          * The 64-bit ACPI integer can hold 16 4-bit BCD characters
333                          * (if table is 32-bit, integer can hold 8 BCD characters)
334                          * Convert each 4-bit BCD value
335                          */
336                         power_of_ten = 1;
337                         return_desc->integer.value = 0;
338                         digit = operand[0]->integer.value;
339
340                         /* Convert each BCD digit (each is one nybble wide) */
341
342                         for (i = 0;
343                              (i < acpi_gbl_integer_nybble_width) && (digit > 0);
344                              i++) {
345                                 /* Get the least significant 4-bit BCD digit */
346
347                                 temp32 = ((u32) digit) & 0xF;
348
349                                 /* Check the range of the digit */
350
351                                 if (temp32 > 9) {
352                                         ACPI_ERROR((AE_INFO,
353                                                     "BCD digit too large (not decimal): 0x%X",
354                                                     temp32));
355
356                                         status = AE_AML_NUMERIC_OVERFLOW;
357                                         goto cleanup;
358                                 }
359
360                                 /* Sum the digit into the result with the current power of 10 */
361
362                                 return_desc->integer.value +=
363                                     (((acpi_integer) temp32) * power_of_ten);
364
365                                 /* Shift to next BCD digit */
366
367                                 digit >>= 4;
368
369                                 /* Next power of 10 */
370
371                                 power_of_ten *= 10;
372                         }
373                         break;
374
375                 case AML_TO_BCD_OP:     /* to_bcd (Operand, Result) */
376
377                         return_desc->integer.value = 0;
378                         digit = operand[0]->integer.value;
379
380                         /* Each BCD digit is one nybble wide */
381
382                         for (i = 0;
383                              (i < acpi_gbl_integer_nybble_width) && (digit > 0);
384                              i++) {
385                                 (void)acpi_ut_short_divide(digit, 10, &digit,
386                                                            &temp32);
387
388                                 /*
389                                  * Insert the BCD digit that resides in the
390                                  * remainder from above
391                                  */
392                                 return_desc->integer.value |=
393                                     (((acpi_integer) temp32) << ACPI_MUL_4(i));
394                         }
395
396                         /* Overflow if there is any data left in Digit */
397
398                         if (digit > 0) {
399                                 ACPI_ERROR((AE_INFO,
400                                             "Integer too large to convert to BCD: %8.8X%8.8X",
401                                             ACPI_FORMAT_UINT64(operand[0]->
402                                                                integer.value)));
403                                 status = AE_AML_NUMERIC_OVERFLOW;
404                                 goto cleanup;
405                         }
406                         break;
407
408                 case AML_COND_REF_OF_OP:        /* cond_ref_of (source_object, Result) */
409
410                         /*
411                          * This op is a little strange because the internal return value is
412                          * different than the return value stored in the result descriptor
413                          * (There are really two return values)
414                          */
415                         if ((struct acpi_namespace_node *)operand[0] ==
416                             acpi_gbl_root_node) {
417                                 /*
418                                  * This means that the object does not exist in the namespace,
419                                  * return FALSE
420                                  */
421                                 return_desc->integer.value = 0;
422                                 goto cleanup;
423                         }
424
425                         /* Get the object reference, store it, and remove our reference */
426
427                         status = acpi_ex_get_object_reference(operand[0],
428                                                               &return_desc2,
429                                                               walk_state);
430                         if (ACPI_FAILURE(status)) {
431                                 goto cleanup;
432                         }
433
434                         status =
435                             acpi_ex_store(return_desc2, operand[1], walk_state);
436                         acpi_ut_remove_reference(return_desc2);
437
438                         /* The object exists in the namespace, return TRUE */
439
440                         return_desc->integer.value = ACPI_INTEGER_MAX;
441                         goto cleanup;
442
443                 default:
444                         /* No other opcodes get here */
445                         break;
446                 }
447                 break;
448
449         case AML_STORE_OP:      /* Store (Source, Target) */
450
451                 /*
452                  * A store operand is typically a number, string, buffer or lvalue
453                  * Be careful about deleting the source object,
454                  * since the object itself may have been stored.
455                  */
456                 status = acpi_ex_store(operand[0], operand[1], walk_state);
457                 if (ACPI_FAILURE(status)) {
458                         return_ACPI_STATUS(status);
459                 }
460
461                 /* It is possible that the Store already produced a return object */
462
463                 if (!walk_state->result_obj) {
464                         /*
465                          * Normally, we would remove a reference on the Operand[0]
466                          * parameter; But since it is being used as the internal return
467                          * object (meaning we would normally increment it), the two
468                          * cancel out, and we simply don't do anything.
469                          */
470                         walk_state->result_obj = operand[0];
471                         walk_state->operands[0] = NULL; /* Prevent deletion */
472                 }
473                 return_ACPI_STATUS(status);
474
475                 /*
476                  * ACPI 2.0 Opcodes
477                  */
478         case AML_COPY_OP:       /* Copy (Source, Target) */
479
480                 status =
481                     acpi_ut_copy_iobject_to_iobject(operand[0], &return_desc,
482                                                     walk_state);
483                 break;
484
485         case AML_TO_DECSTRING_OP:       /* to_decimal_string (Data, Result) */
486
487                 status = acpi_ex_convert_to_string(operand[0], &return_desc,
488                                                    ACPI_EXPLICIT_CONVERT_DECIMAL);
489                 if (return_desc == operand[0]) {
490                         /* No conversion performed, add ref to handle return value */
491                         acpi_ut_add_reference(return_desc);
492                 }
493                 break;
494
495         case AML_TO_HEXSTRING_OP:       /* to_hex_string (Data, Result) */
496
497                 status = acpi_ex_convert_to_string(operand[0], &return_desc,
498                                                    ACPI_EXPLICIT_CONVERT_HEX);
499                 if (return_desc == operand[0]) {
500                         /* No conversion performed, add ref to handle return value */
501                         acpi_ut_add_reference(return_desc);
502                 }
503                 break;
504
505         case AML_TO_BUFFER_OP:  /* to_buffer (Data, Result) */
506
507                 status = acpi_ex_convert_to_buffer(operand[0], &return_desc);
508                 if (return_desc == operand[0]) {
509                         /* No conversion performed, add ref to handle return value */
510                         acpi_ut_add_reference(return_desc);
511                 }
512                 break;
513
514         case AML_TO_INTEGER_OP: /* to_integer (Data, Result) */
515
516                 status = acpi_ex_convert_to_integer(operand[0], &return_desc,
517                                                     ACPI_ANY_BASE);
518                 if (return_desc == operand[0]) {
519                         /* No conversion performed, add ref to handle return value */
520                         acpi_ut_add_reference(return_desc);
521                 }
522                 break;
523
524         case AML_SHIFT_LEFT_BIT_OP:     /* shift_left_bit (Source, bit_num) */
525         case AML_SHIFT_RIGHT_BIT_OP:    /* shift_right_bit (Source, bit_num) */
526
527                 /* These are two obsolete opcodes */
528
529                 ACPI_ERROR((AE_INFO,
530                             "%s is obsolete and not implemented",
531                             acpi_ps_get_opcode_name(walk_state->opcode)));
532                 status = AE_SUPPORT;
533                 goto cleanup;
534
535         default:                /* Unknown opcode */
536
537                 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
538                             walk_state->opcode));
539                 status = AE_AML_BAD_OPCODE;
540                 goto cleanup;
541         }
542
543         if (ACPI_SUCCESS(status)) {
544                 /* Store the return value computed above into the target object */
545
546                 status = acpi_ex_store(return_desc, operand[1], walk_state);
547         }
548
549       cleanup:
550
551         if (!walk_state->result_obj) {
552                 walk_state->result_obj = return_desc;
553         }
554
555         /* Delete return object on error */
556
557         if (ACPI_FAILURE(status)) {
558                 acpi_ut_remove_reference(return_desc);
559         }
560
561         return_ACPI_STATUS(status);
562 }
563
564 /*******************************************************************************
565  *
566  * FUNCTION:    acpi_ex_opcode_1A_0T_1R
567  *
568  * PARAMETERS:  walk_state          - Current state (contains AML opcode)
569  *
570  * RETURN:      Status
571  *
572  * DESCRIPTION: Execute opcode with one argument, no target, and a return value
573  *
574  ******************************************************************************/
575
576 acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)
577 {
578         union acpi_operand_object **operand = &walk_state->operands[0];
579         union acpi_operand_object *temp_desc;
580         union acpi_operand_object *return_desc = NULL;
581         acpi_status status = AE_OK;
582         u32 type;
583         acpi_integer value;
584
585         ACPI_FUNCTION_TRACE_STR("ex_opcode_1A_0T_1R",
586                                 acpi_ps_get_opcode_name(walk_state->opcode));
587
588         /* Examine the AML opcode */
589
590         switch (walk_state->opcode) {
591         case AML_LNOT_OP:       /* LNot (Operand) */
592
593                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
594                 if (!return_desc) {
595                         status = AE_NO_MEMORY;
596                         goto cleanup;
597                 }
598
599                 /*
600                  * Set result to ONES (TRUE) if Value == 0.  Note:
601                  * return_desc->Integer.Value is initially == 0 (FALSE) from above.
602                  */
603                 if (!operand[0]->integer.value) {
604                         return_desc->integer.value = ACPI_INTEGER_MAX;
605                 }
606                 break;
607
608         case AML_DECREMENT_OP:  /* Decrement (Operand)  */
609         case AML_INCREMENT_OP:  /* Increment (Operand)  */
610
611                 /*
612                  * Create a new integer.  Can't just get the base integer and
613                  * increment it because it may be an Arg or Field.
614                  */
615                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
616                 if (!return_desc) {
617                         status = AE_NO_MEMORY;
618                         goto cleanup;
619                 }
620
621                 /*
622                  * Since we are expecting a Reference operand, it can be either a
623                  * NS Node or an internal object.
624                  */
625                 temp_desc = operand[0];
626                 if (ACPI_GET_DESCRIPTOR_TYPE(temp_desc) ==
627                     ACPI_DESC_TYPE_OPERAND) {
628                         /* Internal reference object - prevent deletion */
629
630                         acpi_ut_add_reference(temp_desc);
631                 }
632
633                 /*
634                  * Convert the Reference operand to an Integer (This removes a
635                  * reference on the Operand[0] object)
636                  *
637                  * NOTE:  We use LNOT_OP here in order to force resolution of the
638                  * reference operand to an actual integer.
639                  */
640                 status =
641                     acpi_ex_resolve_operands(AML_LNOT_OP, &temp_desc,
642                                              walk_state);
643                 if (ACPI_FAILURE(status)) {
644                         ACPI_EXCEPTION((AE_INFO, status,
645                                         "While resolving operands for [%s]",
646                                         acpi_ps_get_opcode_name(walk_state->
647                                                                 opcode)));
648
649                         goto cleanup;
650                 }
651
652                 /*
653                  * temp_desc is now guaranteed to be an Integer object --
654                  * Perform the actual increment or decrement
655                  */
656                 if (walk_state->opcode == AML_INCREMENT_OP) {
657                         return_desc->integer.value =
658                             temp_desc->integer.value + 1;
659                 } else {
660                         return_desc->integer.value =
661                             temp_desc->integer.value - 1;
662                 }
663
664                 /* Finished with this Integer object */
665
666                 acpi_ut_remove_reference(temp_desc);
667
668                 /*
669                  * Store the result back (indirectly) through the original
670                  * Reference object
671                  */
672                 status = acpi_ex_store(return_desc, operand[0], walk_state);
673                 break;
674
675         case AML_TYPE_OP:       /* object_type (source_object) */
676
677                 /*
678                  * Note: The operand is not resolved at this point because we want to
679                  * get the associated object, not its value.  For example, we don't
680                  * want to resolve a field_unit to its value, we want the actual
681                  * field_unit object.
682                  */
683
684                 /* Get the type of the base object */
685
686                 status =
687                     acpi_ex_resolve_multiple(walk_state, operand[0], &type,
688                                              NULL);
689                 if (ACPI_FAILURE(status)) {
690                         goto cleanup;
691                 }
692                 /* Allocate a descriptor to hold the type. */
693
694                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
695                 if (!return_desc) {
696                         status = AE_NO_MEMORY;
697                         goto cleanup;
698                 }
699
700                 return_desc->integer.value = type;
701                 break;
702
703         case AML_SIZE_OF_OP:    /* size_of (source_object) */
704
705                 /*
706                  * Note: The operand is not resolved at this point because we want to
707                  * get the associated object, not its value.
708                  */
709
710                 /* Get the base object */
711
712                 status = acpi_ex_resolve_multiple(walk_state,
713                                                   operand[0], &type,
714                                                   &temp_desc);
715                 if (ACPI_FAILURE(status)) {
716                         goto cleanup;
717                 }
718
719                 /*
720                  * The type of the base object must be integer, buffer, string, or
721                  * package.  All others are not supported.
722                  *
723                  * NOTE: Integer is not specifically supported by the ACPI spec,
724                  * but is supported implicitly via implicit operand conversion.
725                  * rather than bother with conversion, we just use the byte width
726                  * global (4 or 8 bytes).
727                  */
728                 switch (type) {
729                 case ACPI_TYPE_INTEGER:
730                         value = acpi_gbl_integer_byte_width;
731                         break;
732
733                 case ACPI_TYPE_BUFFER:
734                         value = temp_desc->buffer.length;
735                         break;
736
737                 case ACPI_TYPE_STRING:
738                         value = temp_desc->string.length;
739                         break;
740
741                 case ACPI_TYPE_PACKAGE:
742                         value = temp_desc->package.count;
743                         break;
744
745                 default:
746                         ACPI_ERROR((AE_INFO,
747                                     "Operand is not Buf/Int/Str/Pkg - found type %s",
748                                     acpi_ut_get_type_name(type)));
749                         status = AE_AML_OPERAND_TYPE;
750                         goto cleanup;
751                 }
752
753                 /*
754                  * Now that we have the size of the object, create a result
755                  * object to hold the value
756                  */
757                 return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
758                 if (!return_desc) {
759                         status = AE_NO_MEMORY;
760                         goto cleanup;
761                 }
762
763                 return_desc->integer.value = value;
764                 break;
765
766         case AML_REF_OF_OP:     /* ref_of (source_object) */
767
768                 status =
769                     acpi_ex_get_object_reference(operand[0], &return_desc,
770                                                  walk_state);
771                 if (ACPI_FAILURE(status)) {
772                         goto cleanup;
773                 }
774                 break;
775
776         case AML_DEREF_OF_OP:   /* deref_of (obj_reference | String) */
777
778                 /* Check for a method local or argument, or standalone String */
779
780                 if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) !=
781                     ACPI_DESC_TYPE_NAMED) {
782                         switch (ACPI_GET_OBJECT_TYPE(operand[0])) {
783                         case ACPI_TYPE_LOCAL_REFERENCE:
784                                 /*
785                                  * This is a deref_of (local_x | arg_x)
786                                  *
787                                  * Must resolve/dereference the local/arg reference first
788                                  */
789                                 switch (operand[0]->reference.opcode) {
790                                 case AML_LOCAL_OP:
791                                 case AML_ARG_OP:
792
793                                         /* Set Operand[0] to the value of the local/arg */
794
795                                         status =
796                                             acpi_ds_method_data_get_value
797                                             (operand[0]->reference.opcode,
798                                              operand[0]->reference.offset,
799                                              walk_state, &temp_desc);
800                                         if (ACPI_FAILURE(status)) {
801                                                 goto cleanup;
802                                         }
803
804                                         /*
805                                          * Delete our reference to the input object and
806                                          * point to the object just retrieved
807                                          */
808                                         acpi_ut_remove_reference(operand[0]);
809                                         operand[0] = temp_desc;
810                                         break;
811
812                                 case AML_REF_OF_OP:
813
814                                         /* Get the object to which the reference refers */
815
816                                         temp_desc =
817                                             operand[0]->reference.object;
818                                         acpi_ut_remove_reference(operand[0]);
819                                         operand[0] = temp_desc;
820                                         break;
821
822                                 default:
823
824                                         /* Must be an Index op - handled below */
825                                         break;
826                                 }
827                                 break;
828
829                         case ACPI_TYPE_STRING:
830
831                                 /*
832                                  * This is a deref_of (String). The string is a reference
833                                  * to a named ACPI object.
834                                  *
835                                  * 1) Find the owning Node
836                                  * 2) Dereference the node to an actual object.  Could be a
837                                  *    Field, so we need to resolve the node to a value.
838                                  */
839                                 status =
840                                     acpi_ns_get_node_by_path(operand[0]->string.
841                                                              pointer,
842                                                              walk_state->
843                                                              scope_info->scope.
844                                                              node,
845                                                              ACPI_NS_SEARCH_PARENT,
846                                                              ACPI_CAST_INDIRECT_PTR
847                                                              (struct
848                                                               acpi_namespace_node,
849                                                               &return_desc));
850                                 if (ACPI_FAILURE(status)) {
851                                         goto cleanup;
852                                 }
853
854                                 status =
855                                     acpi_ex_resolve_node_to_value
856                                     (ACPI_CAST_INDIRECT_PTR
857                                      (struct acpi_namespace_node, &return_desc),
858                                      walk_state);
859                                 goto cleanup;
860
861                         default:
862
863                                 status = AE_AML_OPERAND_TYPE;
864                                 goto cleanup;
865                         }
866                 }
867
868                 /* Operand[0] may have changed from the code above */
869
870                 if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) ==
871                     ACPI_DESC_TYPE_NAMED) {
872                         /*
873                          * This is a deref_of (object_reference)
874                          * Get the actual object from the Node (This is the dereference).
875                          * This case may only happen when a local_x or arg_x is
876                          * dereferenced above.
877                          */
878                         return_desc = acpi_ns_get_attached_object((struct
879                                                                    acpi_namespace_node
880                                                                    *)
881                                                                   operand[0]);
882                         acpi_ut_add_reference(return_desc);
883                 } else {
884                         /*
885                          * This must be a reference object produced by either the
886                          * Index() or ref_of() operator
887                          */
888                         switch (operand[0]->reference.opcode) {
889                         case AML_INDEX_OP:
890
891                                 /*
892                                  * The target type for the Index operator must be
893                                  * either a Buffer or a Package
894                                  */
895                                 switch (operand[0]->reference.target_type) {
896                                 case ACPI_TYPE_BUFFER_FIELD:
897
898                                         temp_desc =
899                                             operand[0]->reference.object;
900
901                                         /*
902                                          * Create a new object that contains one element of the
903                                          * buffer -- the element pointed to by the index.
904                                          *
905                                          * NOTE: index into a buffer is NOT a pointer to a
906                                          * sub-buffer of the main buffer, it is only a pointer to a
907                                          * single element (byte) of the buffer!
908                                          */
909                                         return_desc =
910                                             acpi_ut_create_internal_object
911                                             (ACPI_TYPE_INTEGER);
912                                         if (!return_desc) {
913                                                 status = AE_NO_MEMORY;
914                                                 goto cleanup;
915                                         }
916
917                                         /*
918                                          * Since we are returning the value of the buffer at the
919                                          * indexed location, we don't need to add an additional
920                                          * reference to the buffer itself.
921                                          */
922                                         return_desc->integer.value =
923                                             temp_desc->buffer.
924                                             pointer[operand[0]->reference.
925                                                     offset];
926                                         break;
927
928                                 case ACPI_TYPE_PACKAGE:
929
930                                         /*
931                                          * Return the referenced element of the package.  We must
932                                          * add another reference to the referenced object, however.
933                                          */
934                                         return_desc =
935                                             *(operand[0]->reference.where);
936                                         if (return_desc) {
937                                                 acpi_ut_add_reference
938                                                     (return_desc);
939                                         }
940
941                                         break;
942
943                                 default:
944
945                                         ACPI_ERROR((AE_INFO,
946                                                     "Unknown Index target_type %X in obj %p",
947                                                     operand[0]->reference.
948                                                     target_type, operand[0]));
949                                         status = AE_AML_OPERAND_TYPE;
950                                         goto cleanup;
951                                 }
952                                 break;
953
954                         case AML_REF_OF_OP:
955
956                                 return_desc = operand[0]->reference.object;
957
958                                 if (ACPI_GET_DESCRIPTOR_TYPE(return_desc) ==
959                                     ACPI_DESC_TYPE_NAMED) {
960
961                                         return_desc =
962                                             acpi_ns_get_attached_object((struct
963                                                                          acpi_namespace_node
964                                                                          *)
965                                                                         return_desc);
966                                 }
967
968                                 /* Add another reference to the object! */
969
970                                 acpi_ut_add_reference(return_desc);
971                                 break;
972
973                         default:
974                                 ACPI_ERROR((AE_INFO,
975                                             "Unknown opcode in ref(%p) - %X",
976                                             operand[0],
977                                             operand[0]->reference.opcode));
978
979                                 status = AE_TYPE;
980                                 goto cleanup;
981                         }
982                 }
983                 break;
984
985         default:
986
987                 ACPI_ERROR((AE_INFO, "Unknown AML opcode %X",
988                             walk_state->opcode));
989                 status = AE_AML_BAD_OPCODE;
990                 goto cleanup;
991         }
992
993       cleanup:
994
995         /* Delete return object on error */
996
997         if (ACPI_FAILURE(status)) {
998                 acpi_ut_remove_reference(return_desc);
999         }
1000
1001         walk_state->result_obj = return_desc;
1002         return_ACPI_STATUS(status);
1003 }