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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}
v4.17
  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#ifndef ACPI_NO_METHOD_EXECUTION
 61/*******************************************************************************
 62 *
 63 * FUNCTION:    acpi_ds_do_implicit_return
 64 *
 65 * PARAMETERS:  return_desc         - The return value
 66 *              walk_state          - Current State
 67 *              add_reference       - True if a reference should be added to the
 68 *                                    return object
 69 *
 70 * RETURN:      TRUE if implicit return enabled, FALSE otherwise
 71 *
 72 * DESCRIPTION: Implements the optional "implicit return".  We save the result
 73 *              of every ASL operator and control method invocation in case the
 74 *              parent method exit. Before storing a new return value, we
 75 *              delete the previous return value.
 76 *
 77 ******************************************************************************/
 78
 79u8
 80acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
 81			   struct acpi_walk_state *walk_state, u8 add_reference)
 82{
 83	ACPI_FUNCTION_NAME(ds_do_implicit_return);
 84
 85	/*
 86	 * Slack must be enabled for this feature, and we must
 87	 * have a valid return object
 88	 */
 89	if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
 90		return (FALSE);
 91	}
 92
 93	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 94			  "Result %p will be implicitly returned; Prev=%p\n",
 95			  return_desc, walk_state->implicit_return_obj));
 96
 97	/*
 98	 * Delete any "stale" implicit return value first. However, in
 99	 * complex statements, the implicit return value can be
100	 * bubbled up several levels, so we don't clear the value if it
101	 * is the same as the return_desc.
102	 */
103	if (walk_state->implicit_return_obj) {
104		if (walk_state->implicit_return_obj == return_desc) {
105			return (TRUE);
106		}
107		acpi_ds_clear_implicit_return(walk_state);
108	}
109
110	/* Save the implicit return value, add a reference if requested */
111
112	walk_state->implicit_return_obj = return_desc;
113	if (add_reference) {
114		acpi_ut_add_reference(return_desc);
115	}
116
117	return (TRUE);
118}
119
120/*******************************************************************************
121 *
122 * FUNCTION:    acpi_ds_is_result_used
123 *
124 * PARAMETERS:  op                  - Current Op
125 *              walk_state          - Current State
126 *
127 * RETURN:      TRUE if result is used, FALSE otherwise
128 *
129 * DESCRIPTION: Check if a result object will be used by the parent
130 *
131 ******************************************************************************/
132
133u8
134acpi_ds_is_result_used(union acpi_parse_object * op,
135		       struct acpi_walk_state * walk_state)
136{
137	const struct acpi_opcode_info *parent_info;
138
139	ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
140
141	/* Must have both an Op and a Result Object */
142
143	if (!op) {
144		ACPI_ERROR((AE_INFO, "Null Op"));
145		return_UINT8(TRUE);
146	}
147
148	/*
149	 * We know that this operator is not a
150	 * Return() operator (would not come here.) The following code is the
151	 * optional support for a so-called "implicit return". Some AML code
152	 * assumes that the last value of the method is "implicitly" returned
153	 * to the caller. Just save the last result as the return value.
154	 * NOTE: this is optional because the ASL language does not actually
155	 * support this behavior.
156	 */
157	(void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
158					 TRUE);
159
160	/*
161	 * Now determine if the parent will use the result
162	 *
163	 * If there is no parent, or the parent is a scope_op, we are executing
164	 * at the method level. An executing method typically has no parent,
165	 * since each method is parsed separately. A method invoked externally
166	 * via execute_control_method has a scope_op as the parent.
167	 */
168	if ((!op->common.parent) ||
169	    (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
170
171		/* No parent, the return value cannot possibly be used */
172
173		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
174				  "At Method level, result of [%s] not used\n",
175				  acpi_ps_get_opcode_name(op->common.
176							  aml_opcode)));
177		return_UINT8(FALSE);
178	}
179
180	/* Get info on the parent. The root_op is AML_SCOPE */
181
182	parent_info =
183	    acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
184	if (parent_info->class == AML_CLASS_UNKNOWN) {
185		ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
186		return_UINT8(FALSE);
187	}
188
189	/*
190	 * Decide what to do with the result based on the parent. If
191	 * the parent opcode will not use the result, delete the object.
192	 * Otherwise leave it as is, it will be deleted when it is used
193	 * as an operand later.
194	 */
195	switch (parent_info->class) {
196	case AML_CLASS_CONTROL:
197
198		switch (op->common.parent->common.aml_opcode) {
199		case AML_RETURN_OP:
200
201			/* Never delete the return value associated with a return opcode */
202
203			goto result_used;
204
205		case AML_IF_OP:
206		case AML_WHILE_OP:
 
207			/*
208			 * If we are executing the predicate AND this is the predicate op,
209			 * we will use the return value
210			 */
211			if ((walk_state->control_state->common.state ==
212			     ACPI_CONTROL_PREDICATE_EXECUTING) &&
213			    (walk_state->control_state->control.predicate_op ==
214			     op)) {
215				goto result_used;
216			}
217			break;
218
219		default:
220
221			/* Ignore other control opcodes */
222
223			break;
224		}
225
226		/* The general control opcode returns no result */
227
228		goto result_not_used;
229
230	case AML_CLASS_CREATE:
 
231		/*
232		 * These opcodes allow term_arg(s) as operands and therefore
233		 * the operands can be method calls. The result is used.
234		 */
235		goto result_used;
236
237	case AML_CLASS_NAMED_OBJECT:
238
239		if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
240		    (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
241		    || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
 
 
242		    || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
243		    || (op->common.parent->common.aml_opcode ==
244			AML_VARIABLE_PACKAGE_OP)
245		    || (op->common.parent->common.aml_opcode ==
246			AML_INT_EVAL_SUBTREE_OP)
247		    || (op->common.parent->common.aml_opcode ==
248			AML_BANK_FIELD_OP)) {
249			/*
250			 * These opcodes allow term_arg(s) as operands and therefore
251			 * the operands can be method calls. The result is used.
252			 */
253			goto result_used;
254		}
255
256		goto result_not_used;
257
258	default:
 
259		/*
260		 * In all other cases. the parent will actually use the return
261		 * object, so keep it.
262		 */
263		goto result_used;
264	}
265
266result_used:
267	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
268			  "Result of [%s] used by Parent [%s] Op=%p\n",
269			  acpi_ps_get_opcode_name(op->common.aml_opcode),
270			  acpi_ps_get_opcode_name(op->common.parent->common.
271						  aml_opcode), op));
272
273	return_UINT8(TRUE);
274
275result_not_used:
276	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
277			  "Result of [%s] not used by Parent [%s] Op=%p\n",
278			  acpi_ps_get_opcode_name(op->common.aml_opcode),
279			  acpi_ps_get_opcode_name(op->common.parent->common.
280						  aml_opcode), op));
281
282	return_UINT8(FALSE);
283}
284
285/*******************************************************************************
286 *
287 * FUNCTION:    acpi_ds_delete_result_if_not_used
288 *
289 * PARAMETERS:  op              - Current parse Op
290 *              result_obj      - Result of the operation
291 *              walk_state      - Current state
292 *
293 * RETURN:      Status
294 *
295 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
296 *              result descriptor, check if the parent opcode will actually use
297 *              this result. If not, delete the result now so that it will
298 *              not become orphaned.
299 *
300 ******************************************************************************/
301
302void
303acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
304				  union acpi_operand_object *result_obj,
305				  struct acpi_walk_state *walk_state)
306{
307	union acpi_operand_object *obj_desc;
308	acpi_status status;
309
310	ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
311
312	if (!op) {
313		ACPI_ERROR((AE_INFO, "Null Op"));
314		return_VOID;
315	}
316
317	if (!result_obj) {
318		return_VOID;
319	}
320
321	if (!acpi_ds_is_result_used(op, walk_state)) {
322
323		/* Must pop the result stack (obj_desc should be equal to result_obj) */
324
325		status = acpi_ds_result_pop(&obj_desc, walk_state);
326		if (ACPI_SUCCESS(status)) {
327			acpi_ut_remove_reference(result_obj);
328		}
329	}
330
331	return_VOID;
332}
333
334/*******************************************************************************
335 *
336 * FUNCTION:    acpi_ds_resolve_operands
337 *
338 * PARAMETERS:  walk_state          - Current walk state with operands on stack
339 *
340 * RETURN:      Status
341 *
342 * DESCRIPTION: Resolve all operands to their values. Used to prepare
343 *              arguments to a control method invocation (a call from one
344 *              method to another.)
345 *
346 ******************************************************************************/
347
348acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
349{
350	u32 i;
351	acpi_status status = AE_OK;
352
353	ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
354
355	/*
356	 * Attempt to resolve each of the valid operands
357	 * Method arguments are passed by reference, not by value. This means
358	 * that the actual objects are passed, not copies of the objects.
359	 */
360	for (i = 0; i < walk_state->num_operands; i++) {
361		status =
362		    acpi_ex_resolve_to_value(&walk_state->operands[i],
363					     walk_state);
364		if (ACPI_FAILURE(status)) {
365			break;
366		}
367	}
368
369	return_ACPI_STATUS(status);
370}
371
372/*******************************************************************************
373 *
374 * FUNCTION:    acpi_ds_clear_operands
375 *
376 * PARAMETERS:  walk_state          - Current walk state with operands on stack
377 *
378 * RETURN:      None
379 *
380 * DESCRIPTION: Clear all operands on the current walk state operand stack.
381 *
382 ******************************************************************************/
383
384void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
385{
386	u32 i;
387
388	ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
389
390	/* Remove a reference on each operand on the stack */
391
392	for (i = 0; i < walk_state->num_operands; i++) {
393		/*
394		 * Remove a reference to all operands, including both
395		 * "Arguments" and "Targets".
396		 */
397		acpi_ut_remove_reference(walk_state->operands[i]);
398		walk_state->operands[i] = NULL;
399	}
400
401	walk_state->num_operands = 0;
402	return_VOID;
403}
404#endif
405
406/*******************************************************************************
407 *
408 * FUNCTION:    acpi_ds_create_operand
409 *
410 * PARAMETERS:  walk_state      - Current walk state
411 *              arg             - Parse object for the argument
412 *              arg_index       - Which argument (zero based)
413 *
414 * RETURN:      Status
415 *
416 * DESCRIPTION: Translate a parse tree object that is an argument to an AML
417 *              opcode to the equivalent interpreter object. This may include
418 *              looking up a name or entering a new name into the internal
419 *              namespace.
420 *
421 ******************************************************************************/
422
423acpi_status
424acpi_ds_create_operand(struct acpi_walk_state *walk_state,
425		       union acpi_parse_object *arg, u32 arg_index)
426{
427	acpi_status status = AE_OK;
428	char *name_string;
429	u32 name_length;
430	union acpi_operand_object *obj_desc;
431	union acpi_parse_object *parent_op;
432	u16 opcode;
433	acpi_interpreter_mode interpreter_mode;
434	const struct acpi_opcode_info *op_info;
435
436	ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
437
438	/* A valid name must be looked up in the namespace */
439
440	if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
441	    (arg->common.value.string) &&
442	    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
443		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
444				  arg));
445
446		/* Get the entire name string from the AML stream */
447
448		status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
449						 arg->common.value.buffer,
450						 &name_string, &name_length);
 
451
452		if (ACPI_FAILURE(status)) {
453			return_ACPI_STATUS(status);
454		}
455
456		/* All prefixes have been handled, and the name is in name_string */
457
458		/*
459		 * Special handling for buffer_field declarations. This is a deferred
460		 * opcode that unfortunately defines the field name as the last
461		 * parameter instead of the first. We get here when we are performing
462		 * the deferred execution, so the actual name of the field is already
463		 * in the namespace. We don't want to attempt to look it up again
464		 * because we may be executing in a different scope than where the
465		 * actual opcode exists.
466		 */
467		if ((walk_state->deferred_node) &&
468		    (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
469		    && (arg_index == (u32)
470			((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
 
471			obj_desc =
472			    ACPI_CAST_PTR(union acpi_operand_object,
473					  walk_state->deferred_node);
474			status = AE_OK;
475		} else {	/* All other opcodes */
476
477			/*
478			 * Differentiate between a namespace "create" operation
479			 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
480			 * IMODE_EXECUTE) in order to support the creation of
481			 * namespace objects during the execution of control methods.
482			 */
483			parent_op = arg->common.parent;
484			op_info =
485			    acpi_ps_get_opcode_info(parent_op->common.
486						    aml_opcode);
487
488			if ((op_info->flags & AML_NSNODE) &&
489			    (parent_op->common.aml_opcode !=
490			     AML_INT_METHODCALL_OP)
491			    && (parent_op->common.aml_opcode != AML_REGION_OP)
492			    && (parent_op->common.aml_opcode !=
493				AML_INT_NAMEPATH_OP)) {
494
495				/* Enter name into namespace if not found */
496
497				interpreter_mode = ACPI_IMODE_LOAD_PASS2;
498			} else {
499				/* Return a failure if name not found */
500
501				interpreter_mode = ACPI_IMODE_EXECUTE;
502			}
503
504			status =
505			    acpi_ns_lookup(walk_state->scope_info, name_string,
506					   ACPI_TYPE_ANY, interpreter_mode,
507					   ACPI_NS_SEARCH_PARENT |
508					   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
509					   ACPI_CAST_INDIRECT_PTR(struct
510								  acpi_namespace_node,
511								  &obj_desc));
512			/*
513			 * The only case where we pass through (ignore) a NOT_FOUND
514			 * error is for the cond_ref_of opcode.
515			 */
516			if (status == AE_NOT_FOUND) {
517				if (parent_op->common.aml_opcode ==
518				    AML_CONDITIONAL_REF_OF_OP) {
519					/*
520					 * For the Conditional Reference op, it's OK if
521					 * the name is not found;  We just need a way to
522					 * indicate this to the interpreter, set the
523					 * object to the root
524					 */
525					obj_desc =
526					    ACPI_CAST_PTR(union
527								 acpi_operand_object,
528								 acpi_gbl_root_node);
529					status = AE_OK;
530				} else if (parent_op->common.aml_opcode ==
531					   AML_EXTERNAL_OP) {
532					/*
533					 * This opcode should never appear here. It is used only
534					 * by AML disassemblers and is surrounded by an If(0)
535					 * by the ASL compiler.
536					 *
537					 * Therefore, if we see it here, it is a serious error.
538					 */
539					status = AE_AML_BAD_OPCODE;
540				} else {
541					/*
542					 * We just plain didn't find it -- which is a
543					 * very serious error at this point
544					 */
545					status = AE_AML_NAME_NOT_FOUND;
546				}
547			}
548
549			if (ACPI_FAILURE(status)) {
550				ACPI_ERROR_NAMESPACE(walk_state->scope_info,
551						     name_string, status);
552			}
553		}
554
555		/* Free the namestring created above */
556
557		ACPI_FREE(name_string);
558
559		/* Check status from the lookup */
560
561		if (ACPI_FAILURE(status)) {
562			return_ACPI_STATUS(status);
563		}
564
565		/* Put the resulting object onto the current object stack */
566
567		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
568		if (ACPI_FAILURE(status)) {
569			return_ACPI_STATUS(status);
570		}
571
572		acpi_db_display_argument_object(obj_desc, walk_state);
573	} else {
574		/* Check for null name case */
575
576		if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
577		    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
578			/*
579			 * If the name is null, this means that this is an
580			 * optional result parameter that was not specified
581			 * in the original ASL. Create a Zero Constant for a
582			 * placeholder. (Store to a constant is a Noop.)
583			 */
584			opcode = AML_ZERO_OP;	/* Has no arguments! */
585
586			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
587					  "Null namepath: Arg=%p\n", arg));
588		} else {
589			opcode = arg->common.aml_opcode;
590		}
591
592		/* Get the object type of the argument */
593
594		op_info = acpi_ps_get_opcode_info(opcode);
595		if (op_info->object_type == ACPI_TYPE_INVALID) {
596			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
597		}
598
599		if ((op_info->flags & AML_HAS_RETVAL) ||
600		    (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
 
 
 
 
 
 
 
 
601			/*
602			 * Use value that was already previously returned
603			 * by the evaluation of this argument
604			 */
605			status = acpi_ds_result_pop(&obj_desc, walk_state);
606			if (ACPI_FAILURE(status)) {
607				/*
608				 * Only error is underflow, and this indicates
609				 * a missing or null operand!
610				 */
611				ACPI_EXCEPTION((AE_INFO, status,
612						"Missing or null operand"));
613				return_ACPI_STATUS(status);
614			}
615		} else {
616			/* Create an ACPI_INTERNAL_OBJECT for the argument */
617
618			obj_desc =
619			    acpi_ut_create_internal_object(op_info->
620							   object_type);
621			if (!obj_desc) {
622				return_ACPI_STATUS(AE_NO_MEMORY);
623			}
624
625			/* Initialize the new object */
626
627			status =
628			    acpi_ds_init_object_from_op(walk_state, arg, opcode,
629							&obj_desc);
630			if (ACPI_FAILURE(status)) {
631				acpi_ut_delete_object_desc(obj_desc);
632				return_ACPI_STATUS(status);
633			}
634		}
635
636		/* Put the operand object on the object stack */
637
638		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
639		if (ACPI_FAILURE(status)) {
640			return_ACPI_STATUS(status);
641		}
642
643		acpi_db_display_argument_object(obj_desc, walk_state);
 
644	}
645
646	return_ACPI_STATUS(AE_OK);
647}
648
649/*******************************************************************************
650 *
651 * FUNCTION:    acpi_ds_create_operands
652 *
653 * PARAMETERS:  walk_state          - Current state
654 *              first_arg           - First argument of a parser argument tree
655 *
656 * RETURN:      Status
657 *
658 * DESCRIPTION: Convert an operator's arguments from a parse tree format to
659 *              namespace objects and place those argument object on the object
660 *              stack in preparation for evaluation by the interpreter.
661 *
662 ******************************************************************************/
663
664acpi_status
665acpi_ds_create_operands(struct acpi_walk_state *walk_state,
666			union acpi_parse_object *first_arg)
667{
668	acpi_status status = AE_OK;
669	union acpi_parse_object *arg;
670	union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
671	u32 arg_count = 0;
672	u32 index = walk_state->num_operands;
673	u32 i;
674
675	ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
676
677	/* Get all arguments in the list */
678
679	arg = first_arg;
680	while (arg) {
681		if (index >= ACPI_OBJ_NUM_OPERANDS) {
682			return_ACPI_STATUS(AE_BAD_DATA);
683		}
684
685		arguments[index] = arg;
686		walk_state->operands[index] = NULL;
687
688		/* Move on to next argument, if any */
689
690		arg = arg->common.next;
691		arg_count++;
692		index++;
693	}
694
695	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
696			  "NumOperands %d, ArgCount %d, Index %d\n",
697			  walk_state->num_operands, arg_count, index));
698
699	/* Create the interpreter arguments, in reverse order */
700
701	index--;
702	for (i = 0; i < arg_count; i++) {
703		arg = arguments[index];
704		walk_state->operand_index = (u8)index;
 
 
 
705
706		status = acpi_ds_create_operand(walk_state, arg, index);
707		if (ACPI_FAILURE(status)) {
708			goto cleanup;
709		}
710
 
 
711		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
712				  "Created Arg #%u (%p) %u args total\n",
713				  index, arg, arg_count));
714		index--;
715	}
716
717	return_ACPI_STATUS(status);
718
719cleanup:
720	/*
721	 * We must undo everything done above; meaning that we must
722	 * pop everything off of the operand stack and delete those
723	 * objects
724	 */
725	acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
726
727	ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
728	return_ACPI_STATUS(status);
729}
730
731/*****************************************************************************
732 *
733 * FUNCTION:    acpi_ds_evaluate_name_path
734 *
735 * PARAMETERS:  walk_state      - Current state of the parse tree walk,
736 *                                the opcode of current operation should be
737 *                                AML_INT_NAMEPATH_OP
738 *
739 * RETURN:      Status
740 *
741 * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
742 *              interpreter object, convert it to value, if needed, duplicate
743 *              it, if needed, and push it onto the current result stack.
744 *
745 ****************************************************************************/
746
747acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
748{
749	acpi_status status = AE_OK;
750	union acpi_parse_object *op = walk_state->op;
751	union acpi_operand_object **operand = &walk_state->operands[0];
752	union acpi_operand_object *new_obj_desc;
753	u8 type;
754
755	ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
756
757	if (!op->common.parent) {
758
759		/* This happens after certain exception processing */
760
761		goto exit;
762	}
763
764	if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
765	    (op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
766	    (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
767
768		/* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
769
770		goto exit;
771	}
772
773	status = acpi_ds_create_operand(walk_state, op, 0);
774	if (ACPI_FAILURE(status)) {
775		goto exit;
776	}
777
778	if (op->common.flags & ACPI_PARSEOP_TARGET) {
779		new_obj_desc = *operand;
780		goto push_result;
781	}
782
783	type = (*operand)->common.type;
784
785	status = acpi_ex_resolve_to_value(operand, walk_state);
786	if (ACPI_FAILURE(status)) {
787		goto exit;
788	}
789
790	if (type == ACPI_TYPE_INTEGER) {
791
792		/* It was incremented by acpi_ex_resolve_to_value */
793
794		acpi_ut_remove_reference(*operand);
795
796		status =
797		    acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
798						    walk_state);
799		if (ACPI_FAILURE(status)) {
800			goto exit;
801		}
802	} else {
803		/*
804		 * The object either was anew created or is
805		 * a Namespace node - don't decrement it.
806		 */
807		new_obj_desc = *operand;
808	}
809
810	/* Cleanup for name-path operand */
811
812	status = acpi_ds_obj_stack_pop(1, walk_state);
813	if (ACPI_FAILURE(status)) {
814		walk_state->result_obj = new_obj_desc;
815		goto exit;
816	}
817
818push_result:
819
820	walk_state->result_obj = new_obj_desc;
821
822	status = acpi_ds_result_push(walk_state->result_obj, walk_state);
823	if (ACPI_SUCCESS(status)) {
824
825		/* Force to take it from stack */
826
827		op->common.flags |= ACPI_PARSEOP_IN_STACK;
828	}
829
830exit:
831
832	return_ACPI_STATUS(status);
833}