Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek...
[sfrench/cifs-2.6.git] / drivers / acpi / acpica / dsutils.c
1 /*******************************************************************************
2  *
3  * Module Name: dsutils - Dispatcher utilities
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2017, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "acnamesp.h"
51 #include "acdebug.h"
52
53 #define _COMPONENT          ACPI_DISPATCHER
54 ACPI_MODULE_NAME("dsutils")
55
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_ds_clear_implicit_return
59  *
60  * PARAMETERS:  walk_state          - Current State
61  *
62  * RETURN:      None.
63  *
64  * DESCRIPTION: Clear and remove a reference on an implicit return value. Used
65  *              to delete "stale" return values (if enabled, the return value
66  *              from every operator is saved at least momentarily, in case the
67  *              parent method exits.)
68  *
69  ******************************************************************************/
70 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
71 {
72         ACPI_FUNCTION_NAME(ds_clear_implicit_return);
73
74         /*
75          * Slack must be enabled for this feature
76          */
77         if (!acpi_gbl_enable_interpreter_slack) {
78                 return;
79         }
80
81         if (walk_state->implicit_return_obj) {
82                 /*
83                  * Delete any "stale" implicit return. However, in
84                  * complex statements, the implicit return value can be
85                  * bubbled up several levels.
86                  */
87                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
88                                   "Removing reference on stale implicit return obj %p\n",
89                                   walk_state->implicit_return_obj));
90
91                 acpi_ut_remove_reference(walk_state->implicit_return_obj);
92                 walk_state->implicit_return_obj = NULL;
93         }
94 }
95
96 #ifndef ACPI_NO_METHOD_EXECUTION
97 /*******************************************************************************
98  *
99  * FUNCTION:    acpi_ds_do_implicit_return
100  *
101  * PARAMETERS:  return_desc         - The return value
102  *              walk_state          - Current State
103  *              add_reference       - True if a reference should be added to the
104  *                                    return object
105  *
106  * RETURN:      TRUE if implicit return enabled, FALSE otherwise
107  *
108  * DESCRIPTION: Implements the optional "implicit return".  We save the result
109  *              of every ASL operator and control method invocation in case the
110  *              parent method exit. Before storing a new return value, we
111  *              delete the previous return value.
112  *
113  ******************************************************************************/
114
115 u8
116 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
117                            struct acpi_walk_state *walk_state, u8 add_reference)
118 {
119         ACPI_FUNCTION_NAME(ds_do_implicit_return);
120
121         /*
122          * Slack must be enabled for this feature, and we must
123          * have a valid return object
124          */
125         if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
126                 return (FALSE);
127         }
128
129         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
130                           "Result %p will be implicitly returned; Prev=%p\n",
131                           return_desc, walk_state->implicit_return_obj));
132
133         /*
134          * Delete any "stale" implicit return value first. However, in
135          * complex statements, the implicit return value can be
136          * bubbled up several levels, so we don't clear the value if it
137          * is the same as the return_desc.
138          */
139         if (walk_state->implicit_return_obj) {
140                 if (walk_state->implicit_return_obj == return_desc) {
141                         return (TRUE);
142                 }
143                 acpi_ds_clear_implicit_return(walk_state);
144         }
145
146         /* Save the implicit return value, add a reference if requested */
147
148         walk_state->implicit_return_obj = return_desc;
149         if (add_reference) {
150                 acpi_ut_add_reference(return_desc);
151         }
152
153         return (TRUE);
154 }
155
156 /*******************************************************************************
157  *
158  * FUNCTION:    acpi_ds_is_result_used
159  *
160  * PARAMETERS:  op                  - Current Op
161  *              walk_state          - Current State
162  *
163  * RETURN:      TRUE if result is used, FALSE otherwise
164  *
165  * DESCRIPTION: Check if a result object will be used by the parent
166  *
167  ******************************************************************************/
168
169 u8
170 acpi_ds_is_result_used(union acpi_parse_object * op,
171                        struct acpi_walk_state * walk_state)
172 {
173         const struct acpi_opcode_info *parent_info;
174
175         ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
176
177         /* Must have both an Op and a Result Object */
178
179         if (!op) {
180                 ACPI_ERROR((AE_INFO, "Null Op"));
181                 return_UINT8(TRUE);
182         }
183
184         /*
185          * We know that this operator is not a
186          * Return() operator (would not come here.) The following code is the
187          * optional support for a so-called "implicit return". Some AML code
188          * assumes that the last value of the method is "implicitly" returned
189          * to the caller. Just save the last result as the return value.
190          * NOTE: this is optional because the ASL language does not actually
191          * support this behavior.
192          */
193         (void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
194                                          TRUE);
195
196         /*
197          * Now determine if the parent will use the result
198          *
199          * If there is no parent, or the parent is a scope_op, we are executing
200          * at the method level. An executing method typically has no parent,
201          * since each method is parsed separately. A method invoked externally
202          * via execute_control_method has a scope_op as the parent.
203          */
204         if ((!op->common.parent) ||
205             (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
206
207                 /* No parent, the return value cannot possibly be used */
208
209                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
210                                   "At Method level, result of [%s] not used\n",
211                                   acpi_ps_get_opcode_name(op->common.
212                                                           aml_opcode)));
213                 return_UINT8(FALSE);
214         }
215
216         /* Get info on the parent. The root_op is AML_SCOPE */
217
218         parent_info =
219             acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
220         if (parent_info->class == AML_CLASS_UNKNOWN) {
221                 ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
222                 return_UINT8(FALSE);
223         }
224
225         /*
226          * Decide what to do with the result based on the parent. If
227          * the parent opcode will not use the result, delete the object.
228          * Otherwise leave it as is, it will be deleted when it is used
229          * as an operand later.
230          */
231         switch (parent_info->class) {
232         case AML_CLASS_CONTROL:
233
234                 switch (op->common.parent->common.aml_opcode) {
235                 case AML_RETURN_OP:
236
237                         /* Never delete the return value associated with a return opcode */
238
239                         goto result_used;
240
241                 case AML_IF_OP:
242                 case AML_WHILE_OP:
243                         /*
244                          * If we are executing the predicate AND this is the predicate op,
245                          * we will use the return value
246                          */
247                         if ((walk_state->control_state->common.state ==
248                              ACPI_CONTROL_PREDICATE_EXECUTING) &&
249                             (walk_state->control_state->control.predicate_op ==
250                              op)) {
251                                 goto result_used;
252                         }
253                         break;
254
255                 default:
256
257                         /* Ignore other control opcodes */
258
259                         break;
260                 }
261
262                 /* The general control opcode returns no result */
263
264                 goto result_not_used;
265
266         case AML_CLASS_CREATE:
267                 /*
268                  * These opcodes allow term_arg(s) as operands and therefore
269                  * the operands can be method calls. The result is used.
270                  */
271                 goto result_used;
272
273         case AML_CLASS_NAMED_OBJECT:
274
275                 if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
276                     (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
277                     || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
278                     || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
279                     || (op->common.parent->common.aml_opcode ==
280                         AML_VARIABLE_PACKAGE_OP)
281                     || (op->common.parent->common.aml_opcode ==
282                         AML_INT_EVAL_SUBTREE_OP)
283                     || (op->common.parent->common.aml_opcode ==
284                         AML_BANK_FIELD_OP)) {
285                         /*
286                          * These opcodes allow term_arg(s) as operands and therefore
287                          * the operands can be method calls. The result is used.
288                          */
289                         goto result_used;
290                 }
291
292                 goto result_not_used;
293
294         default:
295                 /*
296                  * In all other cases. the parent will actually use the return
297                  * object, so keep it.
298                  */
299                 goto result_used;
300         }
301
302 result_used:
303         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
304                           "Result of [%s] used by Parent [%s] Op=%p\n",
305                           acpi_ps_get_opcode_name(op->common.aml_opcode),
306                           acpi_ps_get_opcode_name(op->common.parent->common.
307                                                   aml_opcode), op));
308
309         return_UINT8(TRUE);
310
311 result_not_used:
312         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
313                           "Result of [%s] not used by Parent [%s] Op=%p\n",
314                           acpi_ps_get_opcode_name(op->common.aml_opcode),
315                           acpi_ps_get_opcode_name(op->common.parent->common.
316                                                   aml_opcode), op));
317
318         return_UINT8(FALSE);
319 }
320
321 /*******************************************************************************
322  *
323  * FUNCTION:    acpi_ds_delete_result_if_not_used
324  *
325  * PARAMETERS:  op              - Current parse Op
326  *              result_obj      - Result of the operation
327  *              walk_state      - Current state
328  *
329  * RETURN:      Status
330  *
331  * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
332  *              result descriptor, check if the parent opcode will actually use
333  *              this result. If not, delete the result now so that it will
334  *              not become orphaned.
335  *
336  ******************************************************************************/
337
338 void
339 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
340                                   union acpi_operand_object *result_obj,
341                                   struct acpi_walk_state *walk_state)
342 {
343         union acpi_operand_object *obj_desc;
344         acpi_status status;
345
346         ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
347
348         if (!op) {
349                 ACPI_ERROR((AE_INFO, "Null Op"));
350                 return_VOID;
351         }
352
353         if (!result_obj) {
354                 return_VOID;
355         }
356
357         if (!acpi_ds_is_result_used(op, walk_state)) {
358
359                 /* Must pop the result stack (obj_desc should be equal to result_obj) */
360
361                 status = acpi_ds_result_pop(&obj_desc, walk_state);
362                 if (ACPI_SUCCESS(status)) {
363                         acpi_ut_remove_reference(result_obj);
364                 }
365         }
366
367         return_VOID;
368 }
369
370 /*******************************************************************************
371  *
372  * FUNCTION:    acpi_ds_resolve_operands
373  *
374  * PARAMETERS:  walk_state          - Current walk state with operands on stack
375  *
376  * RETURN:      Status
377  *
378  * DESCRIPTION: Resolve all operands to their values. Used to prepare
379  *              arguments to a control method invocation (a call from one
380  *              method to another.)
381  *
382  ******************************************************************************/
383
384 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
385 {
386         u32 i;
387         acpi_status status = AE_OK;
388
389         ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
390
391         /*
392          * Attempt to resolve each of the valid operands
393          * Method arguments are passed by reference, not by value. This means
394          * that the actual objects are passed, not copies of the objects.
395          */
396         for (i = 0; i < walk_state->num_operands; i++) {
397                 status =
398                     acpi_ex_resolve_to_value(&walk_state->operands[i],
399                                              walk_state);
400                 if (ACPI_FAILURE(status)) {
401                         break;
402                 }
403         }
404
405         return_ACPI_STATUS(status);
406 }
407
408 /*******************************************************************************
409  *
410  * FUNCTION:    acpi_ds_clear_operands
411  *
412  * PARAMETERS:  walk_state          - Current walk state with operands on stack
413  *
414  * RETURN:      None
415  *
416  * DESCRIPTION: Clear all operands on the current walk state operand stack.
417  *
418  ******************************************************************************/
419
420 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
421 {
422         u32 i;
423
424         ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
425
426         /* Remove a reference on each operand on the stack */
427
428         for (i = 0; i < walk_state->num_operands; i++) {
429                 /*
430                  * Remove a reference to all operands, including both
431                  * "Arguments" and "Targets".
432                  */
433                 acpi_ut_remove_reference(walk_state->operands[i]);
434                 walk_state->operands[i] = NULL;
435         }
436
437         walk_state->num_operands = 0;
438         return_VOID;
439 }
440 #endif
441
442 /*******************************************************************************
443  *
444  * FUNCTION:    acpi_ds_create_operand
445  *
446  * PARAMETERS:  walk_state      - Current walk state
447  *              arg             - Parse object for the argument
448  *              arg_index       - Which argument (zero based)
449  *
450  * RETURN:      Status
451  *
452  * DESCRIPTION: Translate a parse tree object that is an argument to an AML
453  *              opcode to the equivalent interpreter object. This may include
454  *              looking up a name or entering a new name into the internal
455  *              namespace.
456  *
457  ******************************************************************************/
458
459 acpi_status
460 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
461                        union acpi_parse_object *arg, u32 arg_index)
462 {
463         acpi_status status = AE_OK;
464         char *name_string;
465         u32 name_length;
466         union acpi_operand_object *obj_desc;
467         union acpi_parse_object *parent_op;
468         u16 opcode;
469         acpi_interpreter_mode interpreter_mode;
470         const struct acpi_opcode_info *op_info;
471
472         ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
473
474         /* A valid name must be looked up in the namespace */
475
476         if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
477             (arg->common.value.string) &&
478             !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
479                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
480                                   arg));
481
482                 /* Get the entire name string from the AML stream */
483
484                 status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
485                                                  arg->common.value.buffer,
486                                                  &name_string, &name_length);
487
488                 if (ACPI_FAILURE(status)) {
489                         return_ACPI_STATUS(status);
490                 }
491
492                 /* All prefixes have been handled, and the name is in name_string */
493
494                 /*
495                  * Special handling for buffer_field declarations. This is a deferred
496                  * opcode that unfortunately defines the field name as the last
497                  * parameter instead of the first. We get here when we are performing
498                  * the deferred execution, so the actual name of the field is already
499                  * in the namespace. We don't want to attempt to look it up again
500                  * because we may be executing in a different scope than where the
501                  * actual opcode exists.
502                  */
503                 if ((walk_state->deferred_node) &&
504                     (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
505                     && (arg_index == (u32)
506                         ((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
507                         obj_desc =
508                             ACPI_CAST_PTR(union acpi_operand_object,
509                                           walk_state->deferred_node);
510                         status = AE_OK;
511                 } else {        /* All other opcodes */
512
513                         /*
514                          * Differentiate between a namespace "create" operation
515                          * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
516                          * IMODE_EXECUTE) in order to support the creation of
517                          * namespace objects during the execution of control methods.
518                          */
519                         parent_op = arg->common.parent;
520                         op_info =
521                             acpi_ps_get_opcode_info(parent_op->common.
522                                                     aml_opcode);
523
524                         if ((op_info->flags & AML_NSNODE) &&
525                             (parent_op->common.aml_opcode !=
526                              AML_INT_METHODCALL_OP)
527                             && (parent_op->common.aml_opcode != AML_REGION_OP)
528                             && (parent_op->common.aml_opcode !=
529                                 AML_INT_NAMEPATH_OP)) {
530
531                                 /* Enter name into namespace if not found */
532
533                                 interpreter_mode = ACPI_IMODE_LOAD_PASS2;
534                         } else {
535                                 /* Return a failure if name not found */
536
537                                 interpreter_mode = ACPI_IMODE_EXECUTE;
538                         }
539
540                         status =
541                             acpi_ns_lookup(walk_state->scope_info, name_string,
542                                            ACPI_TYPE_ANY, interpreter_mode,
543                                            ACPI_NS_SEARCH_PARENT |
544                                            ACPI_NS_DONT_OPEN_SCOPE, walk_state,
545                                            ACPI_CAST_INDIRECT_PTR(struct
546                                                                   acpi_namespace_node,
547                                                                   &obj_desc));
548                         /*
549                          * The only case where we pass through (ignore) a NOT_FOUND
550                          * error is for the cond_ref_of opcode.
551                          */
552                         if (status == AE_NOT_FOUND) {
553                                 if (parent_op->common.aml_opcode ==
554                                     AML_CONDITIONAL_REF_OF_OP) {
555                                         /*
556                                          * For the Conditional Reference op, it's OK if
557                                          * the name is not found;  We just need a way to
558                                          * indicate this to the interpreter, set the
559                                          * object to the root
560                                          */
561                                         obj_desc =
562                                             ACPI_CAST_PTR(union
563                                                                  acpi_operand_object,
564                                                                  acpi_gbl_root_node);
565                                         status = AE_OK;
566                                 } else if (parent_op->common.aml_opcode ==
567                                            AML_EXTERNAL_OP) {
568                                         /*
569                                          * This opcode should never appear here. It is used only
570                                          * by AML disassemblers and is surrounded by an If(0)
571                                          * by the ASL compiler.
572                                          *
573                                          * Therefore, if we see it here, it is a serious error.
574                                          */
575                                         status = AE_AML_BAD_OPCODE;
576                                 } else {
577                                         /*
578                                          * We just plain didn't find it -- which is a
579                                          * very serious error at this point
580                                          */
581                                         status = AE_AML_NAME_NOT_FOUND;
582                                 }
583                         }
584
585                         if (ACPI_FAILURE(status)) {
586                                 ACPI_ERROR_NAMESPACE(walk_state->scope_info,
587                                                      name_string, status);
588                         }
589                 }
590
591                 /* Free the namestring created above */
592
593                 ACPI_FREE(name_string);
594
595                 /* Check status from the lookup */
596
597                 if (ACPI_FAILURE(status)) {
598                         return_ACPI_STATUS(status);
599                 }
600
601                 /* Put the resulting object onto the current object stack */
602
603                 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
604                 if (ACPI_FAILURE(status)) {
605                         return_ACPI_STATUS(status);
606                 }
607
608                 acpi_db_display_argument_object(obj_desc, walk_state);
609         } else {
610                 /* Check for null name case */
611
612                 if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
613                     !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
614                         /*
615                          * If the name is null, this means that this is an
616                          * optional result parameter that was not specified
617                          * in the original ASL. Create a Zero Constant for a
618                          * placeholder. (Store to a constant is a Noop.)
619                          */
620                         opcode = AML_ZERO_OP;   /* Has no arguments! */
621
622                         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
623                                           "Null namepath: Arg=%p\n", arg));
624                 } else {
625                         opcode = arg->common.aml_opcode;
626                 }
627
628                 /* Get the object type of the argument */
629
630                 op_info = acpi_ps_get_opcode_info(opcode);
631                 if (op_info->object_type == ACPI_TYPE_INVALID) {
632                         return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
633                 }
634
635                 if ((op_info->flags & AML_HAS_RETVAL) ||
636                     (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
637                         /*
638                          * Use value that was already previously returned
639                          * by the evaluation of this argument
640                          */
641                         status = acpi_ds_result_pop(&obj_desc, walk_state);
642                         if (ACPI_FAILURE(status)) {
643                                 /*
644                                  * Only error is underflow, and this indicates
645                                  * a missing or null operand!
646                                  */
647                                 ACPI_EXCEPTION((AE_INFO, status,
648                                                 "Missing or null operand"));
649                                 return_ACPI_STATUS(status);
650                         }
651                 } else {
652                         /* Create an ACPI_INTERNAL_OBJECT for the argument */
653
654                         obj_desc =
655                             acpi_ut_create_internal_object(op_info->
656                                                            object_type);
657                         if (!obj_desc) {
658                                 return_ACPI_STATUS(AE_NO_MEMORY);
659                         }
660
661                         /* Initialize the new object */
662
663                         status =
664                             acpi_ds_init_object_from_op(walk_state, arg, opcode,
665                                                         &obj_desc);
666                         if (ACPI_FAILURE(status)) {
667                                 acpi_ut_delete_object_desc(obj_desc);
668                                 return_ACPI_STATUS(status);
669                         }
670                 }
671
672                 /* Put the operand object on the object stack */
673
674                 status = acpi_ds_obj_stack_push(obj_desc, walk_state);
675                 if (ACPI_FAILURE(status)) {
676                         return_ACPI_STATUS(status);
677                 }
678
679                 acpi_db_display_argument_object(obj_desc, walk_state);
680         }
681
682         return_ACPI_STATUS(AE_OK);
683 }
684
685 /*******************************************************************************
686  *
687  * FUNCTION:    acpi_ds_create_operands
688  *
689  * PARAMETERS:  walk_state          - Current state
690  *              first_arg           - First argument of a parser argument tree
691  *
692  * RETURN:      Status
693  *
694  * DESCRIPTION: Convert an operator's arguments from a parse tree format to
695  *              namespace objects and place those argument object on the object
696  *              stack in preparation for evaluation by the interpreter.
697  *
698  ******************************************************************************/
699
700 acpi_status
701 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
702                         union acpi_parse_object *first_arg)
703 {
704         acpi_status status = AE_OK;
705         union acpi_parse_object *arg;
706         union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
707         u32 arg_count = 0;
708         u32 index = walk_state->num_operands;
709         u32 i;
710
711         ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
712
713         /* Get all arguments in the list */
714
715         arg = first_arg;
716         while (arg) {
717                 if (index >= ACPI_OBJ_NUM_OPERANDS) {
718                         return_ACPI_STATUS(AE_BAD_DATA);
719                 }
720
721                 arguments[index] = arg;
722                 walk_state->operands[index] = NULL;
723
724                 /* Move on to next argument, if any */
725
726                 arg = arg->common.next;
727                 arg_count++;
728                 index++;
729         }
730
731         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
732                           "NumOperands %d, ArgCount %d, Index %d\n",
733                           walk_state->num_operands, arg_count, index));
734
735         /* Create the interpreter arguments, in reverse order */
736
737         index--;
738         for (i = 0; i < arg_count; i++) {
739                 arg = arguments[index];
740                 walk_state->operand_index = (u8)index;
741
742                 status = acpi_ds_create_operand(walk_state, arg, index);
743                 if (ACPI_FAILURE(status)) {
744                         goto cleanup;
745                 }
746
747                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
748                                   "Created Arg #%u (%p) %u args total\n",
749                                   index, arg, arg_count));
750                 index--;
751         }
752
753         return_ACPI_STATUS(status);
754
755 cleanup:
756         /*
757          * We must undo everything done above; meaning that we must
758          * pop everything off of the operand stack and delete those
759          * objects
760          */
761         acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
762
763         ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
764         return_ACPI_STATUS(status);
765 }
766
767 /*****************************************************************************
768  *
769  * FUNCTION:    acpi_ds_evaluate_name_path
770  *
771  * PARAMETERS:  walk_state      - Current state of the parse tree walk,
772  *                                the opcode of current operation should be
773  *                                AML_INT_NAMEPATH_OP
774  *
775  * RETURN:      Status
776  *
777  * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
778  *              interpreter object, convert it to value, if needed, duplicate
779  *              it, if needed, and push it onto the current result stack.
780  *
781  ****************************************************************************/
782
783 acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
784 {
785         acpi_status status = AE_OK;
786         union acpi_parse_object *op = walk_state->op;
787         union acpi_operand_object **operand = &walk_state->operands[0];
788         union acpi_operand_object *new_obj_desc;
789         u8 type;
790
791         ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
792
793         if (!op->common.parent) {
794
795                 /* This happens after certain exception processing */
796
797                 goto exit;
798         }
799
800         if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
801             (op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
802             (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
803
804                 /* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
805
806                 goto exit;
807         }
808
809         status = acpi_ds_create_operand(walk_state, op, 0);
810         if (ACPI_FAILURE(status)) {
811                 goto exit;
812         }
813
814         if (op->common.flags & ACPI_PARSEOP_TARGET) {
815                 new_obj_desc = *operand;
816                 goto push_result;
817         }
818
819         type = (*operand)->common.type;
820
821         status = acpi_ex_resolve_to_value(operand, walk_state);
822         if (ACPI_FAILURE(status)) {
823                 goto exit;
824         }
825
826         if (type == ACPI_TYPE_INTEGER) {
827
828                 /* It was incremented by acpi_ex_resolve_to_value */
829
830                 acpi_ut_remove_reference(*operand);
831
832                 status =
833                     acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
834                                                     walk_state);
835                 if (ACPI_FAILURE(status)) {
836                         goto exit;
837                 }
838         } else {
839                 /*
840                  * The object either was anew created or is
841                  * a Namespace node - don't decrement it.
842                  */
843                 new_obj_desc = *operand;
844         }
845
846         /* Cleanup for name-path operand */
847
848         status = acpi_ds_obj_stack_pop(1, walk_state);
849         if (ACPI_FAILURE(status)) {
850                 walk_state->result_obj = new_obj_desc;
851                 goto exit;
852         }
853
854 push_result:
855
856         walk_state->result_obj = new_obj_desc;
857
858         status = acpi_ds_result_push(walk_state->result_obj, walk_state);
859         if (ACPI_SUCCESS(status)) {
860
861                 /* Force to take it from stack */
862
863                 op->common.flags |= ACPI_PARSEOP_IN_STACK;
864         }
865
866 exit:
867
868         return_ACPI_STATUS(status);
869 }