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1 /*******************************************************************************
2  *
3  * Module Name: dsutils - Dispatcher utilities
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "acnamesp.h"
51 #include "acdebug.h"
52 
53 #define _COMPONENT          ACPI_DISPATCHER
54 ACPI_MODULE_NAME("dsutils")
55 
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_ds_clear_implicit_return
59  *
60  * PARAMETERS:  walk_state          - Current State
61  *
62  * RETURN:      None.
63  *
64  * DESCRIPTION: Clear and remove a reference on an implicit return value. Used
65  *              to delete "stale" return values (if enabled, the return value
66  *              from every operator is saved at least momentarily, in case the
67  *              parent method exits.)
68  *
69  ******************************************************************************/
acpi_ds_clear_implicit_return(struct acpi_walk_state * walk_state)70 void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)
71 {
72 	ACPI_FUNCTION_NAME(ds_clear_implicit_return);
73 
74 	/*
75 	 * Slack must be enabled for this feature
76 	 */
77 	if (!acpi_gbl_enable_interpreter_slack) {
78 		return;
79 	}
80 
81 	if (walk_state->implicit_return_obj) {
82 		/*
83 		 * Delete any "stale" implicit return. However, in
84 		 * complex statements, the implicit return value can be
85 		 * bubbled up several levels.
86 		 */
87 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
88 				  "Removing reference on stale implicit return obj %p\n",
89 				  walk_state->implicit_return_obj));
90 
91 		acpi_ut_remove_reference(walk_state->implicit_return_obj);
92 		walk_state->implicit_return_obj = NULL;
93 	}
94 }
95 
96 #ifndef ACPI_NO_METHOD_EXECUTION
97 /*******************************************************************************
98  *
99  * FUNCTION:    acpi_ds_do_implicit_return
100  *
101  * PARAMETERS:  return_desc         - The return value
102  *              walk_state          - Current State
103  *              add_reference       - True if a reference should be added to the
104  *                                    return object
105  *
106  * RETURN:      TRUE if implicit return enabled, FALSE otherwise
107  *
108  * DESCRIPTION: Implements the optional "implicit return".  We save the result
109  *              of every ASL operator and control method invocation in case the
110  *              parent method exit. Before storing a new return value, we
111  *              delete the previous return value.
112  *
113  ******************************************************************************/
114 
115 u8
acpi_ds_do_implicit_return(union acpi_operand_object * return_desc,struct acpi_walk_state * walk_state,u8 add_reference)116 acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,
117 			   struct acpi_walk_state *walk_state, u8 add_reference)
118 {
119 	ACPI_FUNCTION_NAME(ds_do_implicit_return);
120 
121 	/*
122 	 * Slack must be enabled for this feature, and we must
123 	 * have a valid return object
124 	 */
125 	if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
126 		return (FALSE);
127 	}
128 
129 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
130 			  "Result %p will be implicitly returned; Prev=%p\n",
131 			  return_desc, walk_state->implicit_return_obj));
132 
133 	/*
134 	 * Delete any "stale" implicit return value first. However, in
135 	 * complex statements, the implicit return value can be
136 	 * bubbled up several levels, so we don't clear the value if it
137 	 * is the same as the return_desc.
138 	 */
139 	if (walk_state->implicit_return_obj) {
140 		if (walk_state->implicit_return_obj == return_desc) {
141 			return (TRUE);
142 		}
143 		acpi_ds_clear_implicit_return(walk_state);
144 	}
145 
146 	/* Save the implicit return value, add a reference if requested */
147 
148 	walk_state->implicit_return_obj = return_desc;
149 	if (add_reference) {
150 		acpi_ut_add_reference(return_desc);
151 	}
152 
153 	return (TRUE);
154 }
155 
156 /*******************************************************************************
157  *
158  * FUNCTION:    acpi_ds_is_result_used
159  *
160  * PARAMETERS:  op                  - Current Op
161  *              walk_state          - Current State
162  *
163  * RETURN:      TRUE if result is used, FALSE otherwise
164  *
165  * DESCRIPTION: Check if a result object will be used by the parent
166  *
167  ******************************************************************************/
168 
169 u8
acpi_ds_is_result_used(union acpi_parse_object * op,struct acpi_walk_state * walk_state)170 acpi_ds_is_result_used(union acpi_parse_object * op,
171 		       struct acpi_walk_state * walk_state)
172 {
173 	const struct acpi_opcode_info *parent_info;
174 
175 	ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
176 
177 	/* Must have both an Op and a Result Object */
178 
179 	if (!op) {
180 		ACPI_ERROR((AE_INFO, "Null Op"));
181 		return_UINT8(TRUE);
182 	}
183 
184 	/*
185 	 * We know that this operator is not a
186 	 * Return() operator (would not come here.) The following code is the
187 	 * optional support for a so-called "implicit return". Some AML code
188 	 * assumes that the last value of the method is "implicitly" returned
189 	 * to the caller. Just save the last result as the return value.
190 	 * NOTE: this is optional because the ASL language does not actually
191 	 * support this behavior.
192 	 */
193 	(void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
194 					 TRUE);
195 
196 	/*
197 	 * Now determine if the parent will use the result
198 	 *
199 	 * If there is no parent, or the parent is a scope_op, we are executing
200 	 * at the method level. An executing method typically has no parent,
201 	 * since each method is parsed separately. A method invoked externally
202 	 * via execute_control_method has a scope_op as the parent.
203 	 */
204 	if ((!op->common.parent) ||
205 	    (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
206 
207 		/* No parent, the return value cannot possibly be used */
208 
209 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
210 				  "At Method level, result of [%s] not used\n",
211 				  acpi_ps_get_opcode_name(op->common.
212 							  aml_opcode)));
213 		return_UINT8(FALSE);
214 	}
215 
216 	/* Get info on the parent. The root_op is AML_SCOPE */
217 
218 	parent_info =
219 	    acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
220 	if (parent_info->class == AML_CLASS_UNKNOWN) {
221 		ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));
222 		return_UINT8(FALSE);
223 	}
224 
225 	/*
226 	 * Decide what to do with the result based on the parent. If
227 	 * the parent opcode will not use the result, delete the object.
228 	 * Otherwise leave it as is, it will be deleted when it is used
229 	 * as an operand later.
230 	 */
231 	switch (parent_info->class) {
232 	case AML_CLASS_CONTROL:
233 
234 		switch (op->common.parent->common.aml_opcode) {
235 		case AML_RETURN_OP:
236 
237 			/* Never delete the return value associated with a return opcode */
238 
239 			goto result_used;
240 
241 		case AML_IF_OP:
242 		case AML_WHILE_OP:
243 			/*
244 			 * If we are executing the predicate AND this is the predicate op,
245 			 * we will use the return value
246 			 */
247 			if ((walk_state->control_state->common.state ==
248 			     ACPI_CONTROL_PREDICATE_EXECUTING) &&
249 			    (walk_state->control_state->control.predicate_op ==
250 			     op)) {
251 				goto result_used;
252 			}
253 			break;
254 
255 		default:
256 
257 			/* Ignore other control opcodes */
258 
259 			break;
260 		}
261 
262 		/* The general control opcode returns no result */
263 
264 		goto result_not_used;
265 
266 	case AML_CLASS_CREATE:
267 		/*
268 		 * These opcodes allow term_arg(s) as operands and therefore
269 		 * the operands can be method calls. The result is used.
270 		 */
271 		goto result_used;
272 
273 	case AML_CLASS_NAMED_OBJECT:
274 
275 		if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
276 		    (op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
277 		    || (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
278 		    || (op->common.parent->common.aml_opcode ==
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 		 * In all other cases. the parent will actually use the return
297 		 * object, so keep it.
298 		 */
299 		goto result_used;
300 	}
301 
302 result_used:
303 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
304 			  "Result of [%s] used by Parent [%s] Op=%p\n",
305 			  acpi_ps_get_opcode_name(op->common.aml_opcode),
306 			  acpi_ps_get_opcode_name(op->common.parent->common.
307 						  aml_opcode), op));
308 
309 	return_UINT8(TRUE);
310 
311 result_not_used:
312 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
313 			  "Result of [%s] not used by Parent [%s] Op=%p\n",
314 			  acpi_ps_get_opcode_name(op->common.aml_opcode),
315 			  acpi_ps_get_opcode_name(op->common.parent->common.
316 						  aml_opcode), op));
317 
318 	return_UINT8(FALSE);
319 }
320 
321 /*******************************************************************************
322  *
323  * FUNCTION:    acpi_ds_delete_result_if_not_used
324  *
325  * PARAMETERS:  op              - Current parse Op
326  *              result_obj      - Result of the operation
327  *              walk_state      - Current state
328  *
329  * RETURN:      Status
330  *
331  * DESCRIPTION: Used after interpretation of an opcode. If there is an internal
332  *              result descriptor, check if the parent opcode will actually use
333  *              this result. If not, delete the result now so that it will
334  *              not become orphaned.
335  *
336  ******************************************************************************/
337 
338 void
acpi_ds_delete_result_if_not_used(union acpi_parse_object * op,union acpi_operand_object * result_obj,struct acpi_walk_state * walk_state)339 acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,
340 				  union acpi_operand_object *result_obj,
341 				  struct acpi_walk_state *walk_state)
342 {
343 	union acpi_operand_object *obj_desc;
344 	acpi_status status;
345 
346 	ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
347 
348 	if (!op) {
349 		ACPI_ERROR((AE_INFO, "Null Op"));
350 		return_VOID;
351 	}
352 
353 	if (!result_obj) {
354 		return_VOID;
355 	}
356 
357 	if (!acpi_ds_is_result_used(op, walk_state)) {
358 
359 		/* Must pop the result stack (obj_desc should be equal to result_obj) */
360 
361 		status = acpi_ds_result_pop(&obj_desc, walk_state);
362 		if (ACPI_SUCCESS(status)) {
363 			acpi_ut_remove_reference(result_obj);
364 		}
365 	}
366 
367 	return_VOID;
368 }
369 
370 /*******************************************************************************
371  *
372  * FUNCTION:    acpi_ds_resolve_operands
373  *
374  * PARAMETERS:  walk_state          - Current walk state with operands on stack
375  *
376  * RETURN:      Status
377  *
378  * DESCRIPTION: Resolve all operands to their values. Used to prepare
379  *              arguments to a control method invocation (a call from one
380  *              method to another.)
381  *
382  ******************************************************************************/
383 
acpi_ds_resolve_operands(struct acpi_walk_state * walk_state)384 acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)
385 {
386 	u32 i;
387 	acpi_status status = AE_OK;
388 
389 	ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
390 
391 	/*
392 	 * Attempt to resolve each of the valid operands
393 	 * Method arguments are passed by reference, not by value. This means
394 	 * that the actual objects are passed, not copies of the objects.
395 	 */
396 	for (i = 0; i < walk_state->num_operands; i++) {
397 		status =
398 		    acpi_ex_resolve_to_value(&walk_state->operands[i],
399 					     walk_state);
400 		if (ACPI_FAILURE(status)) {
401 			break;
402 		}
403 	}
404 
405 	return_ACPI_STATUS(status);
406 }
407 
408 /*******************************************************************************
409  *
410  * FUNCTION:    acpi_ds_clear_operands
411  *
412  * PARAMETERS:  walk_state          - Current walk state with operands on stack
413  *
414  * RETURN:      None
415  *
416  * DESCRIPTION: Clear all operands on the current walk state operand stack.
417  *
418  ******************************************************************************/
419 
acpi_ds_clear_operands(struct acpi_walk_state * walk_state)420 void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)
421 {
422 	u32 i;
423 
424 	ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
425 
426 	/* Remove a reference on each operand on the stack */
427 
428 	for (i = 0; i < walk_state->num_operands; i++) {
429 		/*
430 		 * Remove a reference to all operands, including both
431 		 * "Arguments" and "Targets".
432 		 */
433 		acpi_ut_remove_reference(walk_state->operands[i]);
434 		walk_state->operands[i] = NULL;
435 	}
436 
437 	walk_state->num_operands = 0;
438 	return_VOID;
439 }
440 #endif
441 
442 /*******************************************************************************
443  *
444  * FUNCTION:    acpi_ds_create_operand
445  *
446  * PARAMETERS:  walk_state      - Current walk state
447  *              arg             - Parse object for the argument
448  *              arg_index       - Which argument (zero based)
449  *
450  * RETURN:      Status
451  *
452  * DESCRIPTION: Translate a parse tree object that is an argument to an AML
453  *              opcode to the equivalent interpreter object. This may include
454  *              looking up a name or entering a new name into the internal
455  *              namespace.
456  *
457  ******************************************************************************/
458 
459 acpi_status
acpi_ds_create_operand(struct acpi_walk_state * walk_state,union acpi_parse_object * arg,u32 arg_index)460 acpi_ds_create_operand(struct acpi_walk_state *walk_state,
461 		       union acpi_parse_object *arg, u32 arg_index)
462 {
463 	acpi_status status = AE_OK;
464 	char *name_string;
465 	u32 name_length;
466 	union acpi_operand_object *obj_desc;
467 	union acpi_parse_object *parent_op;
468 	u16 opcode;
469 	acpi_interpreter_mode interpreter_mode;
470 	const struct acpi_opcode_info *op_info;
471 
472 	ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
473 
474 	/* A valid name must be looked up in the namespace */
475 
476 	if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
477 	    (arg->common.value.string) &&
478 	    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
479 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",
480 				  arg));
481 
482 		/* Get the entire name string from the AML stream */
483 
484 		status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
485 						 arg->common.value.buffer,
486 						 &name_string, &name_length);
487 
488 		if (ACPI_FAILURE(status)) {
489 			return_ACPI_STATUS(status);
490 		}
491 
492 		/* All prefixes have been handled, and the name is in name_string */
493 
494 		/*
495 		 * Special handling for buffer_field declarations. This is a deferred
496 		 * opcode that unfortunately defines the field name as the last
497 		 * parameter instead of the first. We get here when we are performing
498 		 * the deferred execution, so the actual name of the field is already
499 		 * in the namespace. We don't want to attempt to look it up again
500 		 * because we may be executing in a different scope than where the
501 		 * actual opcode exists.
502 		 */
503 		if ((walk_state->deferred_node) &&
504 		    (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
505 		    && (arg_index == (u32)
506 			((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
507 			obj_desc =
508 			    ACPI_CAST_PTR(union acpi_operand_object,
509 					  walk_state->deferred_node);
510 			status = AE_OK;
511 		} else {	/* All other opcodes */
512 
513 			/*
514 			 * Differentiate between a namespace "create" operation
515 			 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
516 			 * IMODE_EXECUTE) in order to support the creation of
517 			 * namespace objects during the execution of control methods.
518 			 */
519 			parent_op = arg->common.parent;
520 			op_info =
521 			    acpi_ps_get_opcode_info(parent_op->common.
522 						    aml_opcode);
523 
524 			if ((op_info->flags & AML_NSNODE) &&
525 			    (parent_op->common.aml_opcode !=
526 			     AML_INT_METHODCALL_OP)
527 			    && (parent_op->common.aml_opcode != AML_REGION_OP)
528 			    && (parent_op->common.aml_opcode !=
529 				AML_INT_NAMEPATH_OP)) {
530 
531 				/* Enter name into namespace if not found */
532 
533 				interpreter_mode = ACPI_IMODE_LOAD_PASS2;
534 			} else {
535 				/* Return a failure if name not found */
536 
537 				interpreter_mode = ACPI_IMODE_EXECUTE;
538 			}
539 
540 			status =
541 			    acpi_ns_lookup(walk_state->scope_info, name_string,
542 					   ACPI_TYPE_ANY, interpreter_mode,
543 					   ACPI_NS_SEARCH_PARENT |
544 					   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
545 					   ACPI_CAST_INDIRECT_PTR(struct
546 								  acpi_namespace_node,
547 								  &obj_desc));
548 			/*
549 			 * The only case where we pass through (ignore) a NOT_FOUND
550 			 * error is for the cond_ref_of opcode.
551 			 */
552 			if (status == AE_NOT_FOUND) {
553 				if (parent_op->common.aml_opcode ==
554 				    AML_COND_REF_OF_OP) {
555 					/*
556 					 * For the Conditional Reference op, it's OK if
557 					 * the name is not found;  We just need a way to
558 					 * indicate this to the interpreter, set the
559 					 * object to the root
560 					 */
561 					obj_desc =
562 					    ACPI_CAST_PTR(union
563 								 acpi_operand_object,
564 								 acpi_gbl_root_node);
565 					status = AE_OK;
566 				} else if (parent_op->common.aml_opcode ==
567 					   AML_EXTERNAL_OP) {
568 					/*
569 					 * This opcode should never appear here. It is used only
570 					 * by AML disassemblers and is surrounded by an If(0)
571 					 * by the ASL compiler.
572 					 *
573 					 * Therefore, if we see it here, it is a serious error.
574 					 */
575 					status = AE_AML_BAD_OPCODE;
576 				} else {
577 					/*
578 					 * We just plain didn't find it -- which is a
579 					 * very serious error at this point
580 					 */
581 					status = AE_AML_NAME_NOT_FOUND;
582 				}
583 			}
584 
585 			if (ACPI_FAILURE(status)) {
586 				ACPI_ERROR_NAMESPACE(name_string, status);
587 			}
588 		}
589 
590 		/* Free the namestring created above */
591 
592 		ACPI_FREE(name_string);
593 
594 		/* Check status from the lookup */
595 
596 		if (ACPI_FAILURE(status)) {
597 			return_ACPI_STATUS(status);
598 		}
599 
600 		/* Put the resulting object onto the current object stack */
601 
602 		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
603 		if (ACPI_FAILURE(status)) {
604 			return_ACPI_STATUS(status);
605 		}
606 
607 		acpi_db_display_argument_object(obj_desc, walk_state);
608 	} else {
609 		/* Check for null name case */
610 
611 		if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
612 		    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
613 			/*
614 			 * If the name is null, this means that this is an
615 			 * optional result parameter that was not specified
616 			 * in the original ASL. Create a Zero Constant for a
617 			 * placeholder. (Store to a constant is a Noop.)
618 			 */
619 			opcode = AML_ZERO_OP;	/* Has no arguments! */
620 
621 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
622 					  "Null namepath: Arg=%p\n", arg));
623 		} else {
624 			opcode = arg->common.aml_opcode;
625 		}
626 
627 		/* Get the object type of the argument */
628 
629 		op_info = acpi_ps_get_opcode_info(opcode);
630 		if (op_info->object_type == ACPI_TYPE_INVALID) {
631 			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
632 		}
633 
634 		if ((op_info->flags & AML_HAS_RETVAL) ||
635 		    (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
636 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
637 					  "Argument previously created, already stacked\n"));
638 
639 			acpi_db_display_argument_object(walk_state->
640 							operands[walk_state->
641 								 num_operands -
642 								 1],
643 							walk_state);
644 
645 			/*
646 			 * Use value that was already previously returned
647 			 * by the evaluation of this argument
648 			 */
649 			status = acpi_ds_result_pop(&obj_desc, walk_state);
650 			if (ACPI_FAILURE(status)) {
651 				/*
652 				 * Only error is underflow, and this indicates
653 				 * a missing or null operand!
654 				 */
655 				ACPI_EXCEPTION((AE_INFO, status,
656 						"Missing or null operand"));
657 				return_ACPI_STATUS(status);
658 			}
659 		} else {
660 			/* Create an ACPI_INTERNAL_OBJECT for the argument */
661 
662 			obj_desc =
663 			    acpi_ut_create_internal_object(op_info->
664 							   object_type);
665 			if (!obj_desc) {
666 				return_ACPI_STATUS(AE_NO_MEMORY);
667 			}
668 
669 			/* Initialize the new object */
670 
671 			status =
672 			    acpi_ds_init_object_from_op(walk_state, arg, opcode,
673 							&obj_desc);
674 			if (ACPI_FAILURE(status)) {
675 				acpi_ut_delete_object_desc(obj_desc);
676 				return_ACPI_STATUS(status);
677 			}
678 		}
679 
680 		/* Put the operand object on the object stack */
681 
682 		status = acpi_ds_obj_stack_push(obj_desc, walk_state);
683 		if (ACPI_FAILURE(status)) {
684 			return_ACPI_STATUS(status);
685 		}
686 
687 		acpi_db_display_argument_object(obj_desc, walk_state);
688 	}
689 
690 	return_ACPI_STATUS(AE_OK);
691 }
692 
693 /*******************************************************************************
694  *
695  * FUNCTION:    acpi_ds_create_operands
696  *
697  * PARAMETERS:  walk_state          - Current state
698  *              first_arg           - First argument of a parser argument tree
699  *
700  * RETURN:      Status
701  *
702  * DESCRIPTION: Convert an operator's arguments from a parse tree format to
703  *              namespace objects and place those argument object on the object
704  *              stack in preparation for evaluation by the interpreter.
705  *
706  ******************************************************************************/
707 
708 acpi_status
acpi_ds_create_operands(struct acpi_walk_state * walk_state,union acpi_parse_object * first_arg)709 acpi_ds_create_operands(struct acpi_walk_state *walk_state,
710 			union acpi_parse_object *first_arg)
711 {
712 	acpi_status status = AE_OK;
713 	union acpi_parse_object *arg;
714 	union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
715 	u32 arg_count = 0;
716 	u32 index = walk_state->num_operands;
717 	u32 i;
718 
719 	ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
720 
721 	/* Get all arguments in the list */
722 
723 	arg = first_arg;
724 	while (arg) {
725 		if (index >= ACPI_OBJ_NUM_OPERANDS) {
726 			return_ACPI_STATUS(AE_BAD_DATA);
727 		}
728 
729 		arguments[index] = arg;
730 		walk_state->operands[index] = NULL;
731 
732 		/* Move on to next argument, if any */
733 
734 		arg = arg->common.next;
735 		arg_count++;
736 		index++;
737 	}
738 
739 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
740 			  "NumOperands %d, ArgCount %d, Index %d\n",
741 			  walk_state->num_operands, arg_count, index));
742 
743 	/* Create the interpreter arguments, in reverse order */
744 
745 	index--;
746 	for (i = 0; i < arg_count; i++) {
747 		arg = arguments[index];
748 		walk_state->operand_index = (u8)index;
749 
750 		status = acpi_ds_create_operand(walk_state, arg, index);
751 		if (ACPI_FAILURE(status)) {
752 			goto cleanup;
753 		}
754 
755 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
756 				  "Created Arg #%u (%p) %u args total\n",
757 				  index, arg, arg_count));
758 		index--;
759 	}
760 
761 	return_ACPI_STATUS(status);
762 
763 cleanup:
764 	/*
765 	 * We must undo everything done above; meaning that we must
766 	 * pop everything off of the operand stack and delete those
767 	 * objects
768 	 */
769 	acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);
770 
771 	ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));
772 	return_ACPI_STATUS(status);
773 }
774 
775 /*****************************************************************************
776  *
777  * FUNCTION:    acpi_ds_evaluate_name_path
778  *
779  * PARAMETERS:  walk_state      - Current state of the parse tree walk,
780  *                                the opcode of current operation should be
781  *                                AML_INT_NAMEPATH_OP
782  *
783  * RETURN:      Status
784  *
785  * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
786  *              interpreter object, convert it to value, if needed, duplicate
787  *              it, if needed, and push it onto the current result stack.
788  *
789  ****************************************************************************/
790 
acpi_ds_evaluate_name_path(struct acpi_walk_state * walk_state)791 acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)
792 {
793 	acpi_status status = AE_OK;
794 	union acpi_parse_object *op = walk_state->op;
795 	union acpi_operand_object **operand = &walk_state->operands[0];
796 	union acpi_operand_object *new_obj_desc;
797 	u8 type;
798 
799 	ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
800 
801 	if (!op->common.parent) {
802 
803 		/* This happens after certain exception processing */
804 
805 		goto exit;
806 	}
807 
808 	if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
809 	    (op->common.parent->common.aml_opcode == AML_VAR_PACKAGE_OP) ||
810 	    (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
811 
812 		/* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
813 
814 		goto exit;
815 	}
816 
817 	status = acpi_ds_create_operand(walk_state, op, 0);
818 	if (ACPI_FAILURE(status)) {
819 		goto exit;
820 	}
821 
822 	if (op->common.flags & ACPI_PARSEOP_TARGET) {
823 		new_obj_desc = *operand;
824 		goto push_result;
825 	}
826 
827 	type = (*operand)->common.type;
828 
829 	status = acpi_ex_resolve_to_value(operand, walk_state);
830 	if (ACPI_FAILURE(status)) {
831 		goto exit;
832 	}
833 
834 	if (type == ACPI_TYPE_INTEGER) {
835 
836 		/* It was incremented by acpi_ex_resolve_to_value */
837 
838 		acpi_ut_remove_reference(*operand);
839 
840 		status =
841 		    acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
842 						    walk_state);
843 		if (ACPI_FAILURE(status)) {
844 			goto exit;
845 		}
846 	} else {
847 		/*
848 		 * The object either was anew created or is
849 		 * a Namespace node - don't decrement it.
850 		 */
851 		new_obj_desc = *operand;
852 	}
853 
854 	/* Cleanup for name-path operand */
855 
856 	status = acpi_ds_obj_stack_pop(1, walk_state);
857 	if (ACPI_FAILURE(status)) {
858 		walk_state->result_obj = new_obj_desc;
859 		goto exit;
860 	}
861 
862 push_result:
863 
864 	walk_state->result_obj = new_obj_desc;
865 
866 	status = acpi_ds_result_push(walk_state->result_obj, walk_state);
867 	if (ACPI_SUCCESS(status)) {
868 
869 		/* Force to take it from stack */
870 
871 		op->common.flags |= ACPI_PARSEOP_IN_STACK;
872 	}
873 
874 exit:
875 
876 	return_ACPI_STATUS(status);
877 }
878