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v3.1
 
  1/*******************************************************************************
  2 *
  3 * Module Name: dsutils - Dispatcher utilities
  4 *
  5 ******************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2011, 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
 54ACPI_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 ******************************************************************************/
 70void 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
115u8
116acpi_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
169u8
170acpi_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			/*
245			 * If we are executing the predicate AND this is the predicate op,
246			 * we will use the return value
247			 */
248			if ((walk_state->control_state->common.state ==
249			     ACPI_CONTROL_PREDICATE_EXECUTING)
250			    && (walk_state->control_state->control.
251				predicate_op == op)) {
252				goto result_used;
253			}
254			break;
255
256		default:
 
257			/* Ignore other control opcodes */
 
258			break;
259		}
260
261		/* The general control opcode returns no result */
262
263		goto result_not_used;
264
265	case AML_CLASS_CREATE:
266
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 ==
279			AML_VAR_PACKAGE_OP)
280		    || (op->common.parent->common.aml_opcode == AML_BUFFER_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		/*
297		 * In all other cases. the parent will actually use the return
298		 * object, so keep it.
299		 */
300		goto result_used;
301	}
302
303      result_used:
304	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
305			  "Result of [%s] used by Parent [%s] Op=%p\n",
306			  acpi_ps_get_opcode_name(op->common.aml_opcode),
307			  acpi_ps_get_opcode_name(op->common.parent->common.
308						  aml_opcode), op));
309
310	return_UINT8(TRUE);
311
312      result_not_used:
313	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
314			  "Result of [%s] not used by Parent [%s] Op=%p\n",
315			  acpi_ps_get_opcode_name(op->common.aml_opcode),
316			  acpi_ps_get_opcode_name(op->common.parent->common.
317						  aml_opcode), op));
318
319	return_UINT8(FALSE);
320}
321
322/*******************************************************************************
323 *
324 * FUNCTION:    acpi_ds_delete_result_if_not_used
325 *
326 * PARAMETERS:  Op              - Current parse Op
327 *              result_obj      - Result of the operation
328 *              walk_state      - Current state
329 *
330 * RETURN:      Status
331 *
332 * DESCRIPTION: Used after interpretation of an opcode.  If there is an internal
333 *              result descriptor, check if the parent opcode will actually use
334 *              this result.  If not, delete the result now so that it will
335 *              not become orphaned.
336 *
337 ******************************************************************************/
338
339void
340acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
341				  union acpi_operand_object *result_obj,
342				  struct acpi_walk_state *walk_state)
343{
344	union acpi_operand_object *obj_desc;
345	acpi_status status;
346
347	ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
348
349	if (!op) {
350		ACPI_ERROR((AE_INFO, "Null Op"));
351		return_VOID;
352	}
353
354	if (!result_obj) {
355		return_VOID;
356	}
357
358	if (!acpi_ds_is_result_used(op, walk_state)) {
359
360		/* Must pop the result stack (obj_desc should be equal to result_obj) */
361
362		status = acpi_ds_result_pop(&obj_desc, walk_state);
363		if (ACPI_SUCCESS(status)) {
364			acpi_ut_remove_reference(result_obj);
365		}
366	}
367
368	return_VOID;
369}
370
371/*******************************************************************************
372 *
373 * FUNCTION:    acpi_ds_resolve_operands
374 *
375 * PARAMETERS:  walk_state          - Current walk state with operands on stack
376 *
377 * RETURN:      Status
378 *
379 * DESCRIPTION: Resolve all operands to their values.  Used to prepare
380 *              arguments to a control method invocation (a call from one
381 *              method to another.)
382 *
383 ******************************************************************************/
384
385acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
386{
387	u32 i;
388	acpi_status status = AE_OK;
389
390	ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
391
392	/*
393	 * Attempt to resolve each of the valid operands
394	 * Method arguments are passed by reference, not by value.  This means
395	 * that the actual objects are passed, not copies of the objects.
396	 */
397	for (i = 0; i < walk_state->num_operands; i++) {
398		status =
399		    acpi_ex_resolve_to_value(&walk_state->operands[i],
400					     walk_state);
401		if (ACPI_FAILURE(status)) {
402			break;
403		}
404	}
405
406	return_ACPI_STATUS(status);
407}
408
409/*******************************************************************************
410 *
411 * FUNCTION:    acpi_ds_clear_operands
412 *
413 * PARAMETERS:  walk_state          - Current walk state with operands on stack
414 *
415 * RETURN:      None
416 *
417 * DESCRIPTION: Clear all operands on the current walk state operand stack.
418 *
419 ******************************************************************************/
420
421void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
422{
423	u32 i;
424
425	ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
426
427	/* Remove a reference on each operand on the stack */
428
429	for (i = 0; i < walk_state->num_operands; i++) {
430		/*
431		 * Remove a reference to all operands, including both
432		 * "Arguments" and "Targets".
433		 */
434		acpi_ut_remove_reference(walk_state->operands[i]);
435		walk_state->operands[i] = NULL;
436	}
437
438	walk_state->num_operands = 0;
439	return_VOID;
440}
441#endif
442
443/*******************************************************************************
444 *
445 * FUNCTION:    acpi_ds_create_operand
446 *
447 * PARAMETERS:  walk_state      - Current walk state
448 *              Arg             - Parse object for the argument
449 *              arg_index       - Which argument (zero based)
450 *
451 * RETURN:      Status
452 *
453 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
454 *              opcode to the equivalent interpreter object.  This may include
455 *              looking up a name or entering a new name into the internal
456 *              namespace.
457 *
458 ******************************************************************************/
459
460acpi_status
461acpi_ds_create_operand(struct acpi_walk_state *walk_state,
462		       union acpi_parse_object *arg, u32 arg_index)
463{
464	acpi_status status = AE_OK;
465	char *name_string;
466	u32 name_length;
467	union acpi_operand_object *obj_desc;
468	union acpi_parse_object *parent_op;
469	u16 opcode;
470	acpi_interpreter_mode interpreter_mode;
471	const struct acpi_opcode_info *op_info;
472
473	ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
474
475	/* A valid name must be looked up in the namespace */
476
477	if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
478	    (arg->common.value.string) &&
479	    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
480		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
481				  arg));
482
483		/* Get the entire name string from the AML stream */
484
485		status =
486		    acpi_ex_get_name_string(ACPI_TYPE_ANY,
487					    arg->common.value.buffer,
488					    &name_string, &name_length);
489
490		if (ACPI_FAILURE(status)) {
491			return_ACPI_STATUS(status);
492		}
493
494		/* All prefixes have been handled, and the name is in name_string */
495
496		/*
497		 * Special handling for buffer_field declarations. This is a deferred
498		 * opcode that unfortunately defines the field name as the last
499		 * parameter instead of the first.  We get here when we are performing
500		 * the deferred execution, so the actual name of the field is already
501		 * in the namespace.  We don't want to attempt to look it up again
502		 * because we may be executing in a different scope than where the
503		 * actual opcode exists.
504		 */
505		if ((walk_state->deferred_node) &&
506		    (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
507		    && (arg_index ==
508			(u32) ((walk_state->opcode ==
509				AML_CREATE_FIELD_OP) ? 3 : 2))) {
510			obj_desc =
511			    ACPI_CAST_PTR(union acpi_operand_object,
512					  walk_state->deferred_node);
513			status = AE_OK;
514		} else {	/* All other opcodes */
515
516			/*
517			 * Differentiate between a namespace "create" operation
518			 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
519			 * IMODE_EXECUTE) in order to support the creation of
520			 * namespace objects during the execution of control methods.
521			 */
522			parent_op = arg->common.parent;
523			op_info =
524			    acpi_ps_get_opcode_info(parent_op->common.
525						    aml_opcode);
526			if ((op_info->flags & AML_NSNODE)
527			    && (parent_op->common.aml_opcode !=
528				AML_INT_METHODCALL_OP)
 
529			    && (parent_op->common.aml_opcode != AML_REGION_OP)
530			    && (parent_op->common.aml_opcode !=
531				AML_INT_NAMEPATH_OP)) {
532
533				/* Enter name into namespace if not found */
534
535				interpreter_mode = ACPI_IMODE_LOAD_PASS2;
536			} else {
537				/* Return a failure if name not found */
538
539				interpreter_mode = ACPI_IMODE_EXECUTE;
540			}
541
542			status =
543			    acpi_ns_lookup(walk_state->scope_info, name_string,
544					   ACPI_TYPE_ANY, interpreter_mode,
545					   ACPI_NS_SEARCH_PARENT |
546					   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
547					   ACPI_CAST_INDIRECT_PTR(struct
548								  acpi_namespace_node,
549								  &obj_desc));
550			/*
551			 * The only case where we pass through (ignore) a NOT_FOUND
552			 * error is for the cond_ref_of opcode.
553			 */
554			if (status == AE_NOT_FOUND) {
555				if (parent_op->common.aml_opcode ==
556				    AML_COND_REF_OF_OP) {
557					/*
558					 * For the Conditional Reference op, it's OK if
559					 * the name is not found;  We just need a way to
560					 * indicate this to the interpreter, set the
561					 * object to the root
562					 */
563					obj_desc = ACPI_CAST_PTR(union
 
564								 acpi_operand_object,
565								 acpi_gbl_root_node);
566					status = AE_OK;
 
 
 
 
 
 
 
 
 
 
567				} else {
568					/*
569					 * We just plain didn't find it -- which is a
570					 * very serious error at this point
571					 */
572					status = AE_AML_NAME_NOT_FOUND;
573				}
574			}
575
576			if (ACPI_FAILURE(status)) {
577				ACPI_ERROR_NAMESPACE(name_string, status);
 
578			}
579		}
580
581		/* Free the namestring created above */
582
583		ACPI_FREE(name_string);
584
585		/* Check status from the lookup */
586
587		if (ACPI_FAILURE(status)) {
588			return_ACPI_STATUS(status);
589		}
590
591		/* Put the resulting object onto the current object stack */
592
593		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
594		if (ACPI_FAILURE(status)) {
595			return_ACPI_STATUS(status);
596		}
597		ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
598				   (obj_desc, walk_state));
599	} else {
600		/* Check for null name case */
601
602		if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
603		    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
604			/*
605			 * If the name is null, this means that this is an
606			 * optional result parameter that was not specified
607			 * in the original ASL.  Create a Zero Constant for a
608			 * placeholder.  (Store to a constant is a Noop.)
609			 */
610			opcode = AML_ZERO_OP;	/* Has no arguments! */
611
612			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
613					  "Null namepath: Arg=%p\n", arg));
614		} else {
615			opcode = arg->common.aml_opcode;
616		}
617
618		/* Get the object type of the argument */
619
620		op_info = acpi_ps_get_opcode_info(opcode);
621		if (op_info->object_type == ACPI_TYPE_INVALID) {
622			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
623		}
624
625		if ((op_info->flags & AML_HAS_RETVAL)
626		    || (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
627			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
628					  "Argument previously created, already stacked\n"));
629
630			ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
631					   (walk_state->
632					    operands[walk_state->num_operands -
633						     1], walk_state));
634
635			/*
636			 * Use value that was already previously returned
637			 * by the evaluation of this argument
638			 */
639			status = acpi_ds_result_pop(&obj_desc, walk_state);
640			if (ACPI_FAILURE(status)) {
641				/*
642				 * Only error is underflow, and this indicates
643				 * a missing or null operand!
644				 */
645				ACPI_EXCEPTION((AE_INFO, status,
646						"Missing or null operand"));
647				return_ACPI_STATUS(status);
648			}
649		} else {
650			/* Create an ACPI_INTERNAL_OBJECT for the argument */
651
652			obj_desc =
653			    acpi_ut_create_internal_object(op_info->
654							   object_type);
655			if (!obj_desc) {
656				return_ACPI_STATUS(AE_NO_MEMORY);
657			}
658
659			/* Initialize the new object */
660
661			status =
662			    acpi_ds_init_object_from_op(walk_state, arg, opcode,
663							&obj_desc);
664			if (ACPI_FAILURE(status)) {
665				acpi_ut_delete_object_desc(obj_desc);
666				return_ACPI_STATUS(status);
667			}
668		}
669
670		/* Put the operand object on the object stack */
671
672		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
673		if (ACPI_FAILURE(status)) {
674			return_ACPI_STATUS(status);
675		}
676
677		ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object
678				   (obj_desc, walk_state));
679	}
680
681	return_ACPI_STATUS(AE_OK);
682}
683
684/*******************************************************************************
685 *
686 * FUNCTION:    acpi_ds_create_operands
687 *
688 * PARAMETERS:  walk_state          - Current state
689 *              first_arg           - First argument of a parser argument tree
690 *
691 * RETURN:      Status
692 *
693 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
694 *              namespace objects and place those argument object on the object
695 *              stack in preparation for evaluation by the interpreter.
696 *
697 ******************************************************************************/
698
699acpi_status
700acpi_ds_create_operands(struct acpi_walk_state *walk_state,
701			union acpi_parse_object *first_arg)
702{
703	acpi_status status = AE_OK;
704	union acpi_parse_object *arg;
705	union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
706	u32 arg_count = 0;
707	u32 index = walk_state->num_operands;
708	u32 i;
709
710	ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
711
712	/* Get all arguments in the list */
713
714	arg = first_arg;
715	while (arg) {
716		if (index >= ACPI_OBJ_NUM_OPERANDS) {
717			return_ACPI_STATUS(AE_BAD_DATA);
718		}
719
720		arguments[index] = arg;
721		walk_state->operands[index] = NULL;
722
723		/* Move on to next argument, if any */
724
725		arg = arg->common.next;
726		arg_count++;
727		index++;
728	}
729
730	index--;
 
 
731
732	/* It is the appropriate order to get objects from the Result stack */
733
 
734	for (i = 0; i < arg_count; i++) {
735		arg = arguments[index];
736
737		/* Force the filling of the operand stack in inverse order */
738
739		walk_state->operand_index = (u8) index;
740
741		status = acpi_ds_create_operand(walk_state, arg, index);
742		if (ACPI_FAILURE(status)) {
743			goto cleanup;
744		}
745
746		index--;
747
748		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
749				  "Arg #%u (%p) done, Arg1=%p\n", index, arg,
750				  first_arg));
 
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
783acpi_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_VAR_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}
v6.13.7
  1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/*******************************************************************************
  3 *
  4 * Module Name: dsutils - Dispatcher utilities
  5 *
  6 ******************************************************************************/
  7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  8#include <acpi/acpi.h>
  9#include "accommon.h"
 10#include "acparser.h"
 11#include "amlcode.h"
 12#include "acdispat.h"
 13#include "acinterp.h"
 14#include "acnamesp.h"
 15#include "acdebug.h"
 16
 17#define _COMPONENT          ACPI_DISPATCHER
 18ACPI_MODULE_NAME("dsutils")
 19
 20/*******************************************************************************
 21 *
 22 * FUNCTION:    acpi_ds_clear_implicit_return
 23 *
 24 * PARAMETERS:  walk_state          - Current State
 25 *
 26 * RETURN:      None.
 27 *
 28 * DESCRIPTION: Clear and remove a reference on an implicit return value. Used
 29 *              to delete "stale" return values (if enabled, the return value
 30 *              from every operator is saved at least momentarily, in case the
 31 *              parent method exits.)
 32 *
 33 ******************************************************************************/
 34void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
 35{
 36	ACPI_FUNCTION_NAME(ds_clear_implicit_return);
 37
 38	/*
 39	 * Slack must be enabled for this feature
 40	 */
 41	if (!acpi_gbl_enable_interpreter_slack) {
 42		return;
 43	}
 44
 45	if (walk_state->implicit_return_obj) {
 46		/*
 47		 * Delete any "stale" implicit return. However, in
 48		 * complex statements, the implicit return value can be
 49		 * bubbled up several levels.
 50		 */
 51		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 52				  "Removing reference on stale implicit return obj %p\n",
 53				  walk_state->implicit_return_obj));
 54
 55		acpi_ut_remove_reference(walk_state->implicit_return_obj);
 56		walk_state->implicit_return_obj = NULL;
 57	}
 58}
 59
 
 60/*******************************************************************************
 61 *
 62 * FUNCTION:    acpi_ds_do_implicit_return
 63 *
 64 * PARAMETERS:  return_desc         - The return value
 65 *              walk_state          - Current State
 66 *              add_reference       - True if a reference should be added to the
 67 *                                    return object
 68 *
 69 * RETURN:      TRUE if implicit return enabled, FALSE otherwise
 70 *
 71 * DESCRIPTION: Implements the optional "implicit return".  We save the result
 72 *              of every ASL operator and control method invocation in case the
 73 *              parent method exit. Before storing a new return value, we
 74 *              delete the previous return value.
 75 *
 76 ******************************************************************************/
 77
 78u8
 79acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
 80			   struct acpi_walk_state *walk_state, u8 add_reference)
 81{
 82	ACPI_FUNCTION_NAME(ds_do_implicit_return);
 83
 84	/*
 85	 * Slack must be enabled for this feature, and we must
 86	 * have a valid return object
 87	 */
 88	if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
 89		return (FALSE);
 90	}
 91
 92	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 93			  "Result %p will be implicitly returned; Prev=%p\n",
 94			  return_desc, walk_state->implicit_return_obj));
 95
 96	/*
 97	 * Delete any "stale" implicit return value first. However, in
 98	 * complex statements, the implicit return value can be
 99	 * bubbled up several levels, so we don't clear the value if it
100	 * is the same as the return_desc.
101	 */
102	if (walk_state->implicit_return_obj) {
103		if (walk_state->implicit_return_obj == return_desc) {
104			return (TRUE);
105		}
106		acpi_ds_clear_implicit_return(walk_state);
107	}
108
109	/* Save the implicit return value, add a reference if requested */
110
111	walk_state->implicit_return_obj = return_desc;
112	if (add_reference) {
113		acpi_ut_add_reference(return_desc);
114	}
115
116	return (TRUE);
117}
118
119/*******************************************************************************
120 *
121 * FUNCTION:    acpi_ds_is_result_used
122 *
123 * PARAMETERS:  op                  - Current Op
124 *              walk_state          - Current State
125 *
126 * RETURN:      TRUE if result is used, FALSE otherwise
127 *
128 * DESCRIPTION: Check if a result object will be used by the parent
129 *
130 ******************************************************************************/
131
132u8
133acpi_ds_is_result_used(union acpi_parse_object * op,
134		       struct acpi_walk_state * walk_state)
135{
136	const struct acpi_opcode_info *parent_info;
137
138	ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
139
140	/* Must have both an Op and a Result Object */
141
142	if (!op) {
143		ACPI_ERROR((AE_INFO, "Null Op"));
144		return_UINT8(TRUE);
145	}
146
147	/*
148	 * We know that this operator is not a
149	 * Return() operator (would not come here.) The following code is the
150	 * optional support for a so-called "implicit return". Some AML code
151	 * assumes that the last value of the method is "implicitly" returned
152	 * to the caller. Just save the last result as the return value.
153	 * NOTE: this is optional because the ASL language does not actually
154	 * support this behavior.
155	 */
156	(void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
157					 TRUE);
158
159	/*
160	 * Now determine if the parent will use the result
161	 *
162	 * If there is no parent, or the parent is a scope_op, we are executing
163	 * at the method level. An executing method typically has no parent,
164	 * since each method is parsed separately. A method invoked externally
165	 * via execute_control_method has a scope_op as the parent.
166	 */
167	if ((!op->common.parent) ||
168	    (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
169
170		/* No parent, the return value cannot possibly be used */
171
172		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
173				  "At Method level, result of [%s] not used\n",
174				  acpi_ps_get_opcode_name(op->common.
175							  aml_opcode)));
176		return_UINT8(FALSE);
177	}
178
179	/* Get info on the parent. The root_op is AML_SCOPE */
180
181	parent_info =
182	    acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
183	if (parent_info->class == AML_CLASS_UNKNOWN) {
184		ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
185		return_UINT8(FALSE);
186	}
187
188	/*
189	 * Decide what to do with the result based on the parent. If
190	 * the parent opcode will not use the result, delete the object.
191	 * Otherwise leave it as is, it will be deleted when it is used
192	 * as an operand later.
193	 */
194	switch (parent_info->class) {
195	case AML_CLASS_CONTROL:
196
197		switch (op->common.parent->common.aml_opcode) {
198		case AML_RETURN_OP:
199
200			/* Never delete the return value associated with a return opcode */
201
202			goto result_used;
203
204		case AML_IF_OP:
205		case AML_WHILE_OP:
 
206			/*
207			 * If we are executing the predicate AND this is the predicate op,
208			 * we will use the return value
209			 */
210			if ((walk_state->control_state->common.state ==
211			     ACPI_CONTROL_PREDICATE_EXECUTING) &&
212			    (walk_state->control_state->control.predicate_op ==
213			     op)) {
214				goto result_used;
215			}
216			break;
217
218		default:
219
220			/* Ignore other control opcodes */
221
222			break;
223		}
224
225		/* The general control opcode returns no result */
226
227		goto result_not_used;
228
229	case AML_CLASS_CREATE:
 
230		/*
231		 * These opcodes allow term_arg(s) as operands and therefore
232		 * the operands can be method calls. The result is used.
233		 */
234		goto result_used;
235
236	case AML_CLASS_NAMED_OBJECT:
237
238		if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
239		    (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
240		    || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
 
 
241		    || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
242		    || (op->common.parent->common.aml_opcode ==
243			AML_VARIABLE_PACKAGE_OP)
244		    || (op->common.parent->common.aml_opcode ==
245			AML_INT_EVAL_SUBTREE_OP)
246		    || (op->common.parent->common.aml_opcode ==
247			AML_BANK_FIELD_OP)) {
248			/*
249			 * These opcodes allow term_arg(s) as operands and therefore
250			 * the operands can be method calls. The result is used.
251			 */
252			goto result_used;
253		}
254
255		goto result_not_used;
256
257	default:
 
258		/*
259		 * In all other cases. the parent will actually use the return
260		 * object, so keep it.
261		 */
262		goto result_used;
263	}
264
265result_used:
266	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
267			  "Result of [%s] used by Parent [%s] Op=%p\n",
268			  acpi_ps_get_opcode_name(op->common.aml_opcode),
269			  acpi_ps_get_opcode_name(op->common.parent->common.
270						  aml_opcode), op));
271
272	return_UINT8(TRUE);
273
274result_not_used:
275	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
276			  "Result of [%s] not used by Parent [%s] Op=%p\n",
277			  acpi_ps_get_opcode_name(op->common.aml_opcode),
278			  acpi_ps_get_opcode_name(op->common.parent->common.
279						  aml_opcode), op));
280
281	return_UINT8(FALSE);
282}
283
284/*******************************************************************************
285 *
286 * FUNCTION:    acpi_ds_delete_result_if_not_used
287 *
288 * PARAMETERS:  op              - Current parse Op
289 *              result_obj      - Result of the operation
290 *              walk_state      - Current state
291 *
292 * RETURN:      Status
293 *
294 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
295 *              result descriptor, check if the parent opcode will actually use
296 *              this result. If not, delete the result now so that it will
297 *              not become orphaned.
298 *
299 ******************************************************************************/
300
301void
302acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
303				  union acpi_operand_object *result_obj,
304				  struct acpi_walk_state *walk_state)
305{
306	union acpi_operand_object *obj_desc;
307	acpi_status status;
308
309	ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
310
311	if (!op) {
312		ACPI_ERROR((AE_INFO, "Null Op"));
313		return_VOID;
314	}
315
316	if (!result_obj) {
317		return_VOID;
318	}
319
320	if (!acpi_ds_is_result_used(op, walk_state)) {
321
322		/* Must pop the result stack (obj_desc should be equal to result_obj) */
323
324		status = acpi_ds_result_pop(&obj_desc, walk_state);
325		if (ACPI_SUCCESS(status)) {
326			acpi_ut_remove_reference(result_obj);
327		}
328	}
329
330	return_VOID;
331}
332
333/*******************************************************************************
334 *
335 * FUNCTION:    acpi_ds_resolve_operands
336 *
337 * PARAMETERS:  walk_state          - Current walk state with operands on stack
338 *
339 * RETURN:      Status
340 *
341 * DESCRIPTION: Resolve all operands to their values. Used to prepare
342 *              arguments to a control method invocation (a call from one
343 *              method to another.)
344 *
345 ******************************************************************************/
346
347acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
348{
349	u32 i;
350	acpi_status status = AE_OK;
351
352	ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
353
354	/*
355	 * Attempt to resolve each of the valid operands
356	 * Method arguments are passed by reference, not by value. This means
357	 * that the actual objects are passed, not copies of the objects.
358	 */
359	for (i = 0; i < walk_state->num_operands; i++) {
360		status =
361		    acpi_ex_resolve_to_value(&walk_state->operands[i],
362					     walk_state);
363		if (ACPI_FAILURE(status)) {
364			break;
365		}
366	}
367
368	return_ACPI_STATUS(status);
369}
370
371/*******************************************************************************
372 *
373 * FUNCTION:    acpi_ds_clear_operands
374 *
375 * PARAMETERS:  walk_state          - Current walk state with operands on stack
376 *
377 * RETURN:      None
378 *
379 * DESCRIPTION: Clear all operands on the current walk state operand stack.
380 *
381 ******************************************************************************/
382
383void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
384{
385	u32 i;
386
387	ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
388
389	/* Remove a reference on each operand on the stack */
390
391	for (i = 0; i < walk_state->num_operands; i++) {
392		/*
393		 * Remove a reference to all operands, including both
394		 * "Arguments" and "Targets".
395		 */
396		acpi_ut_remove_reference(walk_state->operands[i]);
397		walk_state->operands[i] = NULL;
398	}
399
400	walk_state->num_operands = 0;
401	return_VOID;
402}
 
403
404/*******************************************************************************
405 *
406 * FUNCTION:    acpi_ds_create_operand
407 *
408 * PARAMETERS:  walk_state      - Current walk state
409 *              arg             - Parse object for the argument
410 *              arg_index       - Which argument (zero based)
411 *
412 * RETURN:      Status
413 *
414 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
415 *              opcode to the equivalent interpreter object. This may include
416 *              looking up a name or entering a new name into the internal
417 *              namespace.
418 *
419 ******************************************************************************/
420
421acpi_status
422acpi_ds_create_operand(struct acpi_walk_state *walk_state,
423		       union acpi_parse_object *arg, u32 arg_index)
424{
425	acpi_status status = AE_OK;
426	char *name_string;
427	u32 name_length;
428	union acpi_operand_object *obj_desc;
429	union acpi_parse_object *parent_op;
430	u16 opcode;
431	acpi_interpreter_mode interpreter_mode;
432	const struct acpi_opcode_info *op_info;
433
434	ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
435
436	/* A valid name must be looked up in the namespace */
437
438	if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
439	    (arg->common.value.string) &&
440	    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
441		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
442				  arg));
443
444		/* Get the entire name string from the AML stream */
445
446		status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
447						 arg->common.value.buffer,
448						 &name_string, &name_length);
 
449
450		if (ACPI_FAILURE(status)) {
451			return_ACPI_STATUS(status);
452		}
453
454		/* All prefixes have been handled, and the name is in name_string */
455
456		/*
457		 * Special handling for buffer_field declarations. This is a deferred
458		 * opcode that unfortunately defines the field name as the last
459		 * parameter instead of the first. We get here when we are performing
460		 * the deferred execution, so the actual name of the field is already
461		 * in the namespace. We don't want to attempt to look it up again
462		 * because we may be executing in a different scope than where the
463		 * actual opcode exists.
464		 */
465		if ((walk_state->deferred_node) &&
466		    (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
467		    && (arg_index == (u32)
468			((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
 
469			obj_desc =
470			    ACPI_CAST_PTR(union acpi_operand_object,
471					  walk_state->deferred_node);
472			status = AE_OK;
473		} else {	/* All other opcodes */
474
475			/*
476			 * Differentiate between a namespace "create" operation
477			 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
478			 * IMODE_EXECUTE) in order to support the creation of
479			 * namespace objects during the execution of control methods.
480			 */
481			parent_op = arg->common.parent;
482			op_info =
483			    acpi_ps_get_opcode_info(parent_op->common.
484						    aml_opcode);
485
486			if ((op_info->flags & AML_NSNODE) &&
487			    (parent_op->common.aml_opcode !=
488			     AML_INT_METHODCALL_OP)
489			    && (parent_op->common.aml_opcode != AML_REGION_OP)
490			    && (parent_op->common.aml_opcode !=
491				AML_INT_NAMEPATH_OP)) {
492
493				/* Enter name into namespace if not found */
494
495				interpreter_mode = ACPI_IMODE_LOAD_PASS2;
496			} else {
497				/* Return a failure if name not found */
498
499				interpreter_mode = ACPI_IMODE_EXECUTE;
500			}
501
502			status =
503			    acpi_ns_lookup(walk_state->scope_info, name_string,
504					   ACPI_TYPE_ANY, interpreter_mode,
505					   ACPI_NS_SEARCH_PARENT |
506					   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
507					   ACPI_CAST_INDIRECT_PTR(struct
508								  acpi_namespace_node,
509								  &obj_desc));
510			/*
511			 * The only case where we pass through (ignore) a NOT_FOUND
512			 * error is for the cond_ref_of opcode.
513			 */
514			if (status == AE_NOT_FOUND) {
515				if (parent_op->common.aml_opcode ==
516				    AML_CONDITIONAL_REF_OF_OP) {
517					/*
518					 * For the Conditional Reference op, it's OK if
519					 * the name is not found;  We just need a way to
520					 * indicate this to the interpreter, set the
521					 * object to the root
522					 */
523					obj_desc =
524					    ACPI_CAST_PTR(union
525								 acpi_operand_object,
526								 acpi_gbl_root_node);
527					status = AE_OK;
528				} else if (parent_op->common.aml_opcode ==
529					   AML_EXTERNAL_OP) {
530					/*
531					 * This opcode should never appear here. It is used only
532					 * by AML disassemblers and is surrounded by an If(0)
533					 * by the ASL compiler.
534					 *
535					 * Therefore, if we see it here, it is a serious error.
536					 */
537					status = AE_AML_BAD_OPCODE;
538				} else {
539					/*
540					 * We just plain didn't find it -- which is a
541					 * very serious error at this point
542					 */
543					status = AE_AML_NAME_NOT_FOUND;
544				}
545			}
546
547			if (ACPI_FAILURE(status)) {
548				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
549						     name_string, status);
550			}
551		}
552
553		/* Free the namestring created above */
554
555		ACPI_FREE(name_string);
556
557		/* Check status from the lookup */
558
559		if (ACPI_FAILURE(status)) {
560			return_ACPI_STATUS(status);
561		}
562
563		/* Put the resulting object onto the current object stack */
564
565		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
566		if (ACPI_FAILURE(status)) {
567			return_ACPI_STATUS(status);
568		}
569
570		acpi_db_display_argument_object(obj_desc, walk_state);
571	} else {
572		/* Check for null name case */
573
574		if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
575		    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
576			/*
577			 * If the name is null, this means that this is an
578			 * optional result parameter that was not specified
579			 * in the original ASL. Create a Zero Constant for a
580			 * placeholder. (Store to a constant is a Noop.)
581			 */
582			opcode = AML_ZERO_OP;	/* Has no arguments! */
583
584			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
585					  "Null namepath: Arg=%p\n", arg));
586		} else {
587			opcode = arg->common.aml_opcode;
588		}
589
590		/* Get the object type of the argument */
591
592		op_info = acpi_ps_get_opcode_info(opcode);
593		if (op_info->object_type == ACPI_TYPE_INVALID) {
594			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
595		}
596
597		if ((op_info->flags & AML_HAS_RETVAL) ||
598		    (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
 
 
 
 
 
 
 
 
599			/*
600			 * Use value that was already previously returned
601			 * by the evaluation of this argument
602			 */
603			status = acpi_ds_result_pop(&obj_desc, walk_state);
604			if (ACPI_FAILURE(status)) {
605				/*
606				 * Only error is underflow, and this indicates
607				 * a missing or null operand!
608				 */
609				ACPI_EXCEPTION((AE_INFO, status,
610						"Missing or null operand"));
611				return_ACPI_STATUS(status);
612			}
613		} else {
614			/* Create an ACPI_INTERNAL_OBJECT for the argument */
615
616			obj_desc =
617			    acpi_ut_create_internal_object(op_info->
618							   object_type);
619			if (!obj_desc) {
620				return_ACPI_STATUS(AE_NO_MEMORY);
621			}
622
623			/* Initialize the new object */
624
625			status =
626			    acpi_ds_init_object_from_op(walk_state, arg, opcode,
627							&obj_desc);
628			if (ACPI_FAILURE(status)) {
629				acpi_ut_delete_object_desc(obj_desc);
630				return_ACPI_STATUS(status);
631			}
632		}
633
634		/* Put the operand object on the object stack */
635
636		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
637		if (ACPI_FAILURE(status)) {
638			return_ACPI_STATUS(status);
639		}
640
641		acpi_db_display_argument_object(obj_desc, walk_state);
 
642	}
643
644	return_ACPI_STATUS(AE_OK);
645}
646
647/*******************************************************************************
648 *
649 * FUNCTION:    acpi_ds_create_operands
650 *
651 * PARAMETERS:  walk_state          - Current state
652 *              first_arg           - First argument of a parser argument tree
653 *
654 * RETURN:      Status
655 *
656 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
657 *              namespace objects and place those argument object on the object
658 *              stack in preparation for evaluation by the interpreter.
659 *
660 ******************************************************************************/
661
662acpi_status
663acpi_ds_create_operands(struct acpi_walk_state *walk_state,
664			union acpi_parse_object *first_arg)
665{
666	acpi_status status = AE_OK;
667	union acpi_parse_object *arg;
668	union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
669	u32 arg_count = 0;
670	u32 index = walk_state->num_operands;
671	u32 i;
672
673	ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
674
675	/* Get all arguments in the list */
676
677	arg = first_arg;
678	while (arg) {
679		if (index >= ACPI_OBJ_NUM_OPERANDS) {
680			return_ACPI_STATUS(AE_BAD_DATA);
681		}
682
683		arguments[index] = arg;
684		walk_state->operands[index] = NULL;
685
686		/* Move on to next argument, if any */
687
688		arg = arg->common.next;
689		arg_count++;
690		index++;
691	}
692
693	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
694			  "NumOperands %d, ArgCount %d, Index %d\n",
695			  walk_state->num_operands, arg_count, index));
696
697	/* Create the interpreter arguments, in reverse order */
698
699	index--;
700	for (i = 0; i < arg_count; i++) {
701		arg = arguments[index];
702		walk_state->operand_index = (u8)index;
 
 
 
703
704		status = acpi_ds_create_operand(walk_state, arg, index);
705		if (ACPI_FAILURE(status)) {
706			goto cleanup;
707		}
708
 
 
709		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
710				  "Created Arg #%u (%p) %u args total\n",
711				  index, arg, arg_count));
712		index--;
713	}
714
715	return_ACPI_STATUS(status);
716
717cleanup:
718	/*
719	 * We must undo everything done above; meaning that we must
720	 * pop everything off of the operand stack and delete those
721	 * objects
722	 */
723	acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
724
725	ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
726	return_ACPI_STATUS(status);
727}
728
729/*****************************************************************************
730 *
731 * FUNCTION:    acpi_ds_evaluate_name_path
732 *
733 * PARAMETERS:  walk_state      - Current state of the parse tree walk,
734 *                                the opcode of current operation should be
735 *                                AML_INT_NAMEPATH_OP
736 *
737 * RETURN:      Status
738 *
739 * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
740 *              interpreter object, convert it to value, if needed, duplicate
741 *              it, if needed, and push it onto the current result stack.
742 *
743 ****************************************************************************/
744
745acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
746{
747	acpi_status status = AE_OK;
748	union acpi_parse_object *op = walk_state->op;
749	union acpi_operand_object **operand = &walk_state->operands[0];
750	union acpi_operand_object *new_obj_desc;
751	u8 type;
752
753	ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
754
755	if (!op->common.parent) {
756
757		/* This happens after certain exception processing */
758
759		goto exit;
760	}
761
762	if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
763	    (op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
764	    (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
765
766		/* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
767
768		goto exit;
769	}
770
771	status = acpi_ds_create_operand(walk_state, op, 0);
772	if (ACPI_FAILURE(status)) {
773		goto exit;
774	}
775
776	if (op->common.flags & ACPI_PARSEOP_TARGET) {
777		new_obj_desc = *operand;
778		goto push_result;
779	}
780
781	type = (*operand)->common.type;
782
783	status = acpi_ex_resolve_to_value(operand, walk_state);
784	if (ACPI_FAILURE(status)) {
785		goto exit;
786	}
787
788	if (type == ACPI_TYPE_INTEGER) {
789
790		/* It was incremented by acpi_ex_resolve_to_value */
791
792		acpi_ut_remove_reference(*operand);
793
794		status =
795		    acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
796						    walk_state);
797		if (ACPI_FAILURE(status)) {
798			goto exit;
799		}
800	} else {
801		/*
802		 * The object either was anew created or is
803		 * a Namespace node - don't decrement it.
804		 */
805		new_obj_desc = *operand;
806	}
807
808	/* Cleanup for name-path operand */
809
810	status = acpi_ds_obj_stack_pop(1, walk_state);
811	if (ACPI_FAILURE(status)) {
812		walk_state->result_obj = new_obj_desc;
813		goto exit;
814	}
815
816push_result:
817
818	walk_state->result_obj = new_obj_desc;
819
820	status = acpi_ds_result_push(walk_state->result_obj, walk_state);
821	if (ACPI_SUCCESS(status)) {
822
823		/* Force to take it from stack */
824
825		op->common.flags |= ACPI_PARSEOP_IN_STACK;
826	}
827
828exit:
829
830	return_ACPI_STATUS(status);
831}