drivers/acpi/parser/psloop.c - kernel/msm-4.9 - Gitiles

 /******************************************************************************
  *
  * Module Name: psloop - Main AML parse loop
  *
  *****************************************************************************/

 /*
  * Copyright (C) 2000 - 2006, R. Byron Moore
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions, and the following disclaimer,
  *    without modification.
  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  *    substantially similar to the "NO WARRANTY" disclaimer below
  *    ("Disclaimer") and any redistribution must be conditioned upon
  *    including a substantially similar Disclaimer requirement for further
  *    binary redistribution.
  * 3. Neither the names of the above-listed copyright holders nor the names
  *    of any contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * Alternatively, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") version 2 as published by the Free
  * Software Foundation.
  *
  * NO WARRANTY
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  */

 /*
  * Parse the AML and build an operation tree as most interpreters,
  * like Perl, do.  Parsing is done by hand rather than with a YACC
  * generated parser to tightly constrain stack and dynamic memory
  * usage.  At the same time, parsing is kept flexible and the code
  * fairly compact by parsing based on a list of AML opcode
  * templates in aml_op_info[]
  */

 #include <acpi/acpi.h>
 #include <acpi/acparser.h>
 #include <acpi/acdispat.h>
 #include <acpi/amlcode.h>

 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psloop")

 static u32 acpi_gbl_depth = 0;

 /*******************************************************************************
  *
  * FUNCTION:    acpi_ps_parse_loop
  *
  * PARAMETERS:  walk_state          - Current state
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
  *              a tree of ops.
  *
  ******************************************************************************/

 acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
 {
 	acpi_status status = AE_OK;
 	acpi_status status2;
 	union acpi_parse_object *op = NULL;	/* current op */
 	union acpi_parse_object *arg = NULL;
 	union acpi_parse_object *pre_op = NULL;
 	struct acpi_parse_state *parser_state;
 	u8 *aml_op_start = NULL;

 	ACPI_FUNCTION_TRACE_PTR("ps_parse_loop", walk_state);

 	if (walk_state->descending_callback == NULL) {
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}

 	parser_state = &walk_state->parser_state;
 	walk_state->arg_types = 0;

 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))

 	if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
 		/* We are restarting a preempted control method */

 		if (acpi_ps_has_completed_scope(parser_state)) {
 			/*
 			 * We must check if a predicate to an IF or WHILE statement
 			 * was just completed
 			 */
 			if ((parser_state->scope->parse_scope.op) &&
 			    ((parser_state->scope->parse_scope.op->common.
 			      aml_opcode == AML_IF_OP)
 			     || (parser_state->scope->parse_scope.op->common.
 				 aml_opcode == AML_WHILE_OP))
 			    && (walk_state->control_state)
 			    && (walk_state->control_state->common.state ==
 				ACPI_CONTROL_PREDICATE_EXECUTING)) {
 				/*
 				 * A predicate was just completed, get the value of the
 				 * predicate and branch based on that value
 				 */
 				walk_state->op = NULL;
 				status =
 				    acpi_ds_get_predicate_value(walk_state,
 								ACPI_TO_POINTER
 								(TRUE));
 				if (ACPI_FAILURE(status)
 				    && ((status & AE_CODE_MASK) !=
 					AE_CODE_CONTROL)) {
 					if (status == AE_AML_NO_RETURN_VALUE) {
 						ACPI_EXCEPTION((AE_INFO, status,
 								"Invoked method did not return a value"));

 					}
 					ACPI_EXCEPTION((AE_INFO, status,
 							"get_predicate Failed"));
 					return_ACPI_STATUS(status);
 				}

 				status =
 				    acpi_ps_next_parse_state(walk_state, op,
 							     status);
 			}

 			acpi_ps_pop_scope(parser_state, &op,
 					  &walk_state->arg_types,
 					  &walk_state->arg_count);
 			ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 					  "Popped scope, Op=%p\n", op));
 		} else if (walk_state->prev_op) {
 			/* We were in the middle of an op */

 			op = walk_state->prev_op;
 			walk_state->arg_types = walk_state->prev_arg_types;
 		}
 	}
 #endif

 	/* Iterative parsing loop, while there is more AML to process: */

 	while ((parser_state->aml < parser_state->aml_end) || (op)) {
 		aml_op_start = parser_state->aml;
 		if (!op) {
 			/* Get the next opcode from the AML stream */

 			walk_state->aml_offset =
 			    (u32) ACPI_PTR_DIFF(parser_state->aml,
 						parser_state->aml_start);
 			walk_state->opcode = acpi_ps_peek_opcode(parser_state);

 			/*
 			 * First cut to determine what we have found:
 			 * 1) A valid AML opcode
 			 * 2) A name string
 			 * 3) An unknown/invalid opcode
 			 */
 			walk_state->op_info =
 			    acpi_ps_get_opcode_info(walk_state->opcode);
 			switch (walk_state->op_info->class) {
 			case AML_CLASS_ASCII:
 			case AML_CLASS_PREFIX:
 				/*
 				 * Starts with a valid prefix or ASCII char, this is a name
 				 * string.  Convert the bare name string to a namepath.
 				 */
 				walk_state->opcode = AML_INT_NAMEPATH_OP;
 				walk_state->arg_types = ARGP_NAMESTRING;
 				break;

 			case AML_CLASS_UNKNOWN:

 				/* The opcode is unrecognized.  Just skip unknown opcodes */

 				ACPI_ERROR((AE_INFO,
 					    "Found unknown opcode %X at AML address %p offset %X, ignoring",
 					    walk_state->opcode,
 					    parser_state->aml,
 					    walk_state->aml_offset));

 				ACPI_DUMP_BUFFER(parser_state->aml, 128);

 				/* Assume one-byte bad opcode */

 				parser_state->aml++;
 				continue;

 			default:

 				/* Found opcode info, this is a normal opcode */

 				parser_state->aml +=
 				    acpi_ps_get_opcode_size(walk_state->opcode);
 				walk_state->arg_types =
 				    walk_state->op_info->parse_args;
 				break;
 			}

 			/* Create Op structure and append to parent's argument list */

 			if (walk_state->op_info->flags & AML_NAMED) {
 				/* Allocate a new pre_op if necessary */

 				if (!pre_op) {
 					pre_op =
 					    acpi_ps_alloc_op(walk_state->
 							     opcode);
 					if (!pre_op) {
 						status = AE_NO_MEMORY;
 						goto close_this_op;
 					}
 				}

 				pre_op->common.value.arg = NULL;
 				pre_op->common.aml_opcode = walk_state->opcode;

 				/*
 				 * Get and append arguments until we find the node that contains
 				 * the name (the type ARGP_NAME).
 				 */
 				while (GET_CURRENT_ARG_TYPE
 				       (walk_state->arg_types)
 				       &&
 				       (GET_CURRENT_ARG_TYPE
 					(walk_state->arg_types) != ARGP_NAME)) {
 					status =
 					    acpi_ps_get_next_arg(walk_state,
 								 parser_state,
 								 GET_CURRENT_ARG_TYPE
 								 (walk_state->
 								  arg_types),
 								 &arg);
 					if (ACPI_FAILURE(status)) {
 						goto close_this_op;
 					}

 					acpi_ps_append_arg(pre_op, arg);
 					INCREMENT_ARG_LIST(walk_state->
 							   arg_types);
 				}

 				/*
 				 * Make sure that we found a NAME and didn't run out of
 				 * arguments
 				 */
 				if (!GET_CURRENT_ARG_TYPE
 				    (walk_state->arg_types)) {
 					status = AE_AML_NO_OPERAND;
 					goto close_this_op;
 				}

 				/* We know that this arg is a name, move to next arg */

 				INCREMENT_ARG_LIST(walk_state->arg_types);

 				/*
 				 * Find the object.  This will either insert the object into
 				 * the namespace or simply look it up
 				 */
 				walk_state->op = NULL;

 				status =
 				    walk_state->descending_callback(walk_state,
 								    &op);
 				if (ACPI_FAILURE(status)) {
 					ACPI_EXCEPTION((AE_INFO, status,
 							"During name lookup/catalog"));
 					goto close_this_op;
 				}

 				if (!op) {
 					continue;
 				}

 				status =
 				    acpi_ps_next_parse_state(walk_state, op,
 							     status);
 				if (status == AE_CTRL_PENDING) {
 					status = AE_OK;
 					goto close_this_op;
 				}

 				if (ACPI_FAILURE(status)) {
 					goto close_this_op;
 				}

 				acpi_ps_append_arg(op,
 						   pre_op->common.value.arg);
 				acpi_gbl_depth++;

 				if (op->common.aml_opcode == AML_REGION_OP) {
 					/*
 					 * Defer final parsing of an operation_region body,
 					 * because we don't have enough info in the first pass
 					 * to parse it correctly (i.e., there may be method
 					 * calls within the term_arg elements of the body.)
 					 *
 					 * However, we must continue parsing because
 					 * the opregion is not a standalone package --
 					 * we don't know where the end is at this point.
 					 *
 					 * (Length is unknown until parse of the body complete)
 					 */
 					op->named.data = aml_op_start;
 					op->named.length = 0;
 				}
 			} else {
 				/* Not a named opcode, just allocate Op and append to parent */

 				walk_state->op_info =
 				    acpi_ps_get_opcode_info(walk_state->opcode);
 				op = acpi_ps_alloc_op(walk_state->opcode);
 				if (!op) {
 					status = AE_NO_MEMORY;
 					goto close_this_op;
 				}

 				if (walk_state->op_info->flags & AML_CREATE) {
 					/*
 					 * Backup to beginning of create_xXXfield declaration
 					 * body_length is unknown until we parse the body
 					 */
 					op->named.data = aml_op_start;
 					op->named.length = 0;
 				}

 				acpi_ps_append_arg(acpi_ps_get_parent_scope
 						   (parser_state), op);

 				if ((walk_state->descending_callback != NULL)) {
 					/*
 					 * Find the object. This will either insert the object into
 					 * the namespace or simply look it up
 					 */
 					walk_state->op = op;

 					status =
 					    walk_state->
 					    descending_callback(walk_state,
 								&op);
 					status =
 					    acpi_ps_next_parse_state(walk_state,
 								     op,
 								     status);
 					if (status == AE_CTRL_PENDING) {
 						status = AE_OK;
 						goto close_this_op;
 					}

 					if (ACPI_FAILURE(status)) {
 						goto close_this_op;
 					}
 				}
 			}

 			op->common.aml_offset = walk_state->aml_offset;

 			if (walk_state->op_info) {
 				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 						  "Opcode %4.4X [%s] Op %p Aml %p aml_offset %5.5X\n",
 						  (u32) op->common.aml_opcode,
 						  walk_state->op_info->name, op,
 						  parser_state->aml,
 						  op->common.aml_offset));
 			}
 		}

 		/*
 		 * Start arg_count at zero because we don't know if there are
 		 * any args yet
 		 */
 		walk_state->arg_count = 0;

 		/* Are there any arguments that must be processed? */

 		if (walk_state->arg_types) {
 			/* Get arguments */

 			switch (op->common.aml_opcode) {
 			case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
 			case AML_WORD_OP:	/* AML_WORDDATA_ARG */
 			case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
 			case AML_QWORD_OP:	/* AML_QWORDATA_ARG */
 			case AML_STRING_OP:	/* AML_ASCIICHARLIST_ARG */

 				/* Fill in constant or string argument directly */

 				acpi_ps_get_next_simple_arg(parser_state,
 							    GET_CURRENT_ARG_TYPE
 							    (walk_state->
 							     arg_types), op);
 				break;

 			case AML_INT_NAMEPATH_OP:	/* AML_NAMESTRING_ARG */

 				status =
 				    acpi_ps_get_next_namepath(walk_state,
 							      parser_state, op,
 							      1);
 				if (ACPI_FAILURE(status)) {
 					goto close_this_op;
 				}

 				walk_state->arg_types = 0;
 				break;

 			default:
 				/*
 				 * Op is not a constant or string, append each argument
 				 * to the Op
 				 */
 				while (GET_CURRENT_ARG_TYPE
 				       (walk_state->arg_types)
 				       && !walk_state->arg_count) {
 					walk_state->aml_offset = (u32)
 					    ACPI_PTR_DIFF(parser_state->aml,
 							  parser_state->
 							  aml_start);

 					status =
 					    acpi_ps_get_next_arg(walk_state,
 								 parser_state,
 								 GET_CURRENT_ARG_TYPE
 								 (walk_state->
 								  arg_types),
 								 &arg);
 					if (ACPI_FAILURE(status)) {
 						goto close_this_op;
 					}

 					if (arg) {
 						arg->common.aml_offset =
 						    walk_state->aml_offset;
 						acpi_ps_append_arg(op, arg);
 					}
 					INCREMENT_ARG_LIST(walk_state->
 							   arg_types);
 				}

 				/* Special processing for certain opcodes */

 				/* TBD (remove): Temporary mechanism to disable this code if needed */

 #ifdef ACPI_ENABLE_MODULE_LEVEL_CODE

 				if ((walk_state->pass_number <=
 				     ACPI_IMODE_LOAD_PASS1)
 				    &&
 				    ((walk_state->
 				      parse_flags & ACPI_PARSE_DISASSEMBLE) ==
 				     0)) {
 					/*
 					 * We want to skip If/Else/While constructs during Pass1
 					 * because we want to actually conditionally execute the
 					 * code during Pass2.
 					 *
 					 * Except for disassembly, where we always want to
 					 * walk the If/Else/While packages
 					 */
 					switch (op->common.aml_opcode) {
 					case AML_IF_OP:
 					case AML_ELSE_OP:
 					case AML_WHILE_OP:

 						ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 								  "Pass1: Skipping an If/Else/While body\n"));

 						/* Skip body of if/else/while in pass 1 */

 						parser_state->aml =
 						    parser_state->pkg_end;
 						walk_state->arg_count = 0;
 						break;

 					default:
 						break;
 					}
 				}
 #endif
 				switch (op->common.aml_opcode) {
 				case AML_METHOD_OP:

 					/*
 					 * Skip parsing of control method
 					 * because we don't have enough info in the first pass
 					 * to parse it correctly.
 					 *
 					 * Save the length and address of the body
 					 */
 					op->named.data = parser_state->aml;
 					op->named.length =
 					    (u32) (parser_state->pkg_end -
 						   parser_state->aml);

 					/* Skip body of method */

 					parser_state->aml =
 					    parser_state->pkg_end;
 					walk_state->arg_count = 0;
 					break;

 				case AML_BUFFER_OP:
 				case AML_PACKAGE_OP:
 				case AML_VAR_PACKAGE_OP:

 					if ((op->common.parent) &&
 					    (op->common.parent->common.
 					     aml_opcode == AML_NAME_OP)
 					    && (walk_state->pass_number <=
 						ACPI_IMODE_LOAD_PASS2)) {
 						/*
 						 * Skip parsing of Buffers and Packages
 						 * because we don't have enough info in the first pass
 						 * to parse them correctly.
 						 */
 						op->named.data = aml_op_start;
 						op->named.length =
 						    (u32) (parser_state->
 							   pkg_end -
 							   aml_op_start);

 						/* Skip body */

 						parser_state->aml =
 						    parser_state->pkg_end;
 						walk_state->arg_count = 0;
 					}
 					break;

 				case AML_WHILE_OP:

 					if (walk_state->control_state) {
 						walk_state->control_state->
 						    control.package_end =
 						    parser_state->pkg_end;
 					}
 					break;

 				default:

 					/* No action for all other opcodes */
 					break;
 				}
 				break;
 			}
 		}

 		/* Check for arguments that need to be processed */

 		if (walk_state->arg_count) {
 			/*
 			 * There are arguments (complex ones), push Op and
 			 * prepare for argument
 			 */
 			status = acpi_ps_push_scope(parser_state, op,
 						    walk_state->arg_types,
 						    walk_state->arg_count);
 			if (ACPI_FAILURE(status)) {
 				goto close_this_op;
 			}
 			op = NULL;
 			continue;
 		}

 		/*
 		 * All arguments have been processed -- Op is complete,
 		 * prepare for next
 		 */
 		walk_state->op_info =
 		    acpi_ps_get_opcode_info(op->common.aml_opcode);
 		if (walk_state->op_info->flags & AML_NAMED) {
 			if (acpi_gbl_depth) {
 				acpi_gbl_depth--;
 			}

 			if (op->common.aml_opcode == AML_REGION_OP) {
 				/*
 				 * Skip parsing of control method or opregion body,
 				 * because we don't have enough info in the first pass
 				 * to parse them correctly.
 				 *
 				 * Completed parsing an op_region declaration, we now
 				 * know the length.
 				 */
 				op->named.length =
 				    (u32) (parser_state->aml - op->named.data);
 			}
 		}

 		if (walk_state->op_info->flags & AML_CREATE) {
 			/*
 			 * Backup to beginning of create_xXXfield declaration (1 for
 			 * Opcode)
 			 *
 			 * body_length is unknown until we parse the body
 			 */
 			op->named.length =
 			    (u32) (parser_state->aml - op->named.data);
 		}

 		/* This op complete, notify the dispatcher */

 		if (walk_state->ascending_callback != NULL) {
 			walk_state->op = op;
 			walk_state->opcode = op->common.aml_opcode;

 			status = walk_state->ascending_callback(walk_state);
 			status =
 			    acpi_ps_next_parse_state(walk_state, op, status);
 			if (status == AE_CTRL_PENDING) {
 				status = AE_OK;
 				goto close_this_op;
 			}
 		}

 	      close_this_op:
 		/*
 		 * Finished one argument of the containing scope
 		 */
 		parser_state->scope->parse_scope.arg_count--;

 		/* Finished with pre_op */

 		if (pre_op) {
 			acpi_ps_free_op(pre_op);
 			pre_op = NULL;
 		}

 		/* Close this Op (will result in parse subtree deletion) */

 		status2 = acpi_ps_complete_this_op(walk_state, op);
 		if (ACPI_FAILURE(status2)) {
 			return_ACPI_STATUS(status2);
 		}
 		op = NULL;

 		switch (status) {
 		case AE_OK:
 			break;

 		case AE_CTRL_TRANSFER:

 			/* We are about to transfer to a called method. */

 			walk_state->prev_op = op;
 			walk_state->prev_arg_types = walk_state->arg_types;
 			return_ACPI_STATUS(status);

 		case AE_CTRL_END:

 			acpi_ps_pop_scope(parser_state, &op,
 					  &walk_state->arg_types,
 					  &walk_state->arg_count);

 			if (op) {
 				walk_state->op = op;
 				walk_state->op_info =
 				    acpi_ps_get_opcode_info(op->common.
 							    aml_opcode);
 				walk_state->opcode = op->common.aml_opcode;

 				status =
 				    walk_state->ascending_callback(walk_state);
 				status =
 				    acpi_ps_next_parse_state(walk_state, op,
 							     status);

 				status2 =
 				    acpi_ps_complete_this_op(walk_state, op);
 				if (ACPI_FAILURE(status2)) {
 					return_ACPI_STATUS(status2);
 				}
 				op = NULL;
 			}
 			status = AE_OK;
 			break;

 		case AE_CTRL_BREAK:
 		case AE_CTRL_CONTINUE:

 			/* Pop off scopes until we find the While */

 			while (!op || (op->common.aml_opcode != AML_WHILE_OP)) {
 				acpi_ps_pop_scope(parser_state, &op,
 						  &walk_state->arg_types,
 						  &walk_state->arg_count);

 				if (op->common.aml_opcode != AML_WHILE_OP) {
 					status2 =
 					    acpi_ds_result_stack_pop
 					    (walk_state);
 					if (ACPI_FAILURE(status2)) {
 						return_ACPI_STATUS(status2);
 					}
 				}
 			}

 			/* Close this iteration of the While loop */

 			walk_state->op = op;
 			walk_state->op_info =
 			    acpi_ps_get_opcode_info(op->common.aml_opcode);
 			walk_state->opcode = op->common.aml_opcode;

 			status = walk_state->ascending_callback(walk_state);
 			status =
 			    acpi_ps_next_parse_state(walk_state, op, status);

 			status2 = acpi_ps_complete_this_op(walk_state, op);
 			if (ACPI_FAILURE(status2)) {
 				return_ACPI_STATUS(status2);
 			}
 			op = NULL;

 			status = AE_OK;
 			break;

 		case AE_CTRL_TERMINATE:

 			status = AE_OK;

 			/* Clean up */
 			do {
 				if (op) {
 					status2 =
 					    acpi_ps_complete_this_op(walk_state,
 								     op);
 					if (ACPI_FAILURE(status2)) {
 						return_ACPI_STATUS(status2);
 					}
 				}
 				acpi_ps_pop_scope(parser_state, &op,
 						  &walk_state->arg_types,
 						  &walk_state->arg_count);

 			} while (op);

 			return_ACPI_STATUS(status);

 		default:	/* All other non-AE_OK status */

 			do {
 				if (op) {
 					status2 =
 					    acpi_ps_complete_this_op(walk_state,
 								     op);
 					if (ACPI_FAILURE(status2)) {
 						return_ACPI_STATUS(status2);
 					}
 				}
 				acpi_ps_pop_scope(parser_state, &op,
 						  &walk_state->arg_types,
 						  &walk_state->arg_count);

 			} while (op);

 			/*
 			 * TBD: Cleanup parse ops on error
 			 */
 #if 0
 			if (op == NULL) {
 				acpi_ps_pop_scope(parser_state, &op,
 						  &walk_state->arg_types,
 						  &walk_state->arg_count);
 			}
 #endif
 			walk_state->prev_op = op;
 			walk_state->prev_arg_types = walk_state->arg_types;
 			return_ACPI_STATUS(status);
 		}

 		/* This scope complete? */

 		if (acpi_ps_has_completed_scope(parser_state)) {
 			acpi_ps_pop_scope(parser_state, &op,
 					  &walk_state->arg_types,
 					  &walk_state->arg_count);
 			ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 					  "Popped scope, Op=%p\n", op));
 		} else {
 			op = NULL;
 		}

 	}			/* while parser_state->Aml */

 	/*
 	 * Complete the last Op (if not completed), and clear the scope stack.
 	 * It is easily possible to end an AML "package" with an unbounded number
 	 * of open scopes (such as when several ASL blocks are closed with
 	 * sequential closing braces).  We want to terminate each one cleanly.
 	 */
 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "AML package complete at Op %p\n",
 			  op));
 	do {
 		if (op) {
 			if (walk_state->ascending_callback != NULL) {
 				walk_state->op = op;
 				walk_state->op_info =
 				    acpi_ps_get_opcode_info(op->common.
 							    aml_opcode);
 				walk_state->opcode = op->common.aml_opcode;

 				status =
 				    walk_state->ascending_callback(walk_state);
 				status =
 				    acpi_ps_next_parse_state(walk_state, op,
 							     status);
 				if (status == AE_CTRL_PENDING) {
 					status = AE_OK;
 					goto close_this_op;
 				}

 				if (status == AE_CTRL_TERMINATE) {
 					status = AE_OK;

 					/* Clean up */
 					do {
 						if (op) {
 							status2 =
 							    acpi_ps_complete_this_op
 							    (walk_state, op);
 							if (ACPI_FAILURE
 							    (status2)) {
 								return_ACPI_STATUS
 								    (status2);
 							}
 						}

 						acpi_ps_pop_scope(parser_state,
 								  &op,
 								  &walk_state->
 								  arg_types,
 								  &walk_state->
 								  arg_count);

 					} while (op);

 					return_ACPI_STATUS(status);
 				}

 				else if (ACPI_FAILURE(status)) {
 					/* First error is most important */

 					(void)
 					    acpi_ps_complete_this_op(walk_state,
 								     op);
 					return_ACPI_STATUS(status);
 				}
 			}

 			status2 = acpi_ps_complete_this_op(walk_state, op);
 			if (ACPI_FAILURE(status2)) {
 				return_ACPI_STATUS(status2);
 			}
 		}

 		acpi_ps_pop_scope(parser_state, &op, &walk_state->arg_types,
 				  &walk_state->arg_count);

 	} while (op);

 	return_ACPI_STATUS(status);
 }
	/******************************************************************************
	*
	* Module Name: psloop - Main AML parse loop
	*
	*****************************************************************************/

	/*
	* Copyright (C) 2000 - 2006, R. Byron Moore
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions, and the following disclaimer,
	* without modification.
	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	* substantially similar to the "NO WARRANTY" disclaimer below
	* ("Disclaimer") and any redistribution must be conditioned upon
	* including a substantially similar Disclaimer requirement for further
	* binary redistribution.
	* 3. Neither the names of the above-listed copyright holders nor the names
	* of any contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* Alternatively, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") version 2 as published by the Free
	* Software Foundation.
	*
	* NO WARRANTY
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGES.
	*/

	/*
	* Parse the AML and build an operation tree as most interpreters,
	* like Perl, do. Parsing is done by hand rather than with a YACC
	* generated parser to tightly constrain stack and dynamic memory
	* usage. At the same time, parsing is kept flexible and the code
	* fairly compact by parsing based on a list of AML opcode
	* templates in aml_op_info[]
	*/

	#include <acpi/acpi.h>
	#include <acpi/acparser.h>
	#include <acpi/acdispat.h>
	#include <acpi/amlcode.h>

	#define _COMPONENT ACPI_PARSER
	ACPI_MODULE_NAME("psloop")

	static u32 acpi_gbl_depth = 0;

	/*******************************************************************************
	*
	* FUNCTION: acpi_ps_parse_loop
	*
	* PARAMETERS: walk_state - Current state
	*
	* RETURN: Status
	*
	* DESCRIPTION: Parse AML (pointed to by the current parser state) and return
	* a tree of ops.
	*
	******************************************************************************/

	acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
	{
	acpi_status status = AE_OK;
	acpi_status status2;
	union acpi_parse_object op = NULL; / current op */
	union acpi_parse_object *arg = NULL;
	union acpi_parse_object *pre_op = NULL;
	struct acpi_parse_state *parser_state;
	u8 *aml_op_start = NULL;

	ACPI_FUNCTION_TRACE_PTR("ps_parse_loop", walk_state);

	if (walk_state->descending_callback == NULL) {
	return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	parser_state = &walk_state->parser_state;
	walk_state->arg_types = 0;

	#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))

	if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
	/* We are restarting a preempted control method */

	if (acpi_ps_has_completed_scope(parser_state)) {
	/*
	* We must check if a predicate to an IF or WHILE statement
	* was just completed
	*/
	if ((parser_state->scope->parse_scope.op) &&
	((parser_state->scope->parse_scope.op->common.
	aml_opcode == AML_IF_OP)
	\|\| (parser_state->scope->parse_scope.op->common.
	aml_opcode == AML_WHILE_OP))
	&& (walk_state->control_state)
	&& (walk_state->control_state->common.state ==
	ACPI_CONTROL_PREDICATE_EXECUTING)) {
	/*
	* A predicate was just completed, get the value of the
	* predicate and branch based on that value
	*/
	walk_state->op = NULL;
	status =
	acpi_ds_get_predicate_value(walk_state,
	ACPI_TO_POINTER
	(TRUE));
	if (ACPI_FAILURE(status)
	&& ((status & AE_CODE_MASK) !=
	AE_CODE_CONTROL)) {
	if (status == AE_AML_NO_RETURN_VALUE) {
	ACPI_EXCEPTION((AE_INFO, status,
	"Invoked method did not return a value"));

	}
	ACPI_EXCEPTION((AE_INFO, status,
	"get_predicate Failed"));
	return_ACPI_STATUS(status);
	}

	status =
	acpi_ps_next_parse_state(walk_state, op,
	status);
	}

	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Popped scope, Op=%p\n", op));
	} else if (walk_state->prev_op) {
	/* We were in the middle of an op */

	op = walk_state->prev_op;
	walk_state->arg_types = walk_state->prev_arg_types;
	}
	}
	#endif

	/* Iterative parsing loop, while there is more AML to process: */

	while ((parser_state->aml < parser_state->aml_end) \|\| (op)) {
	aml_op_start = parser_state->aml;
	if (!op) {
	/* Get the next opcode from the AML stream */

	walk_state->aml_offset =
	(u32) ACPI_PTR_DIFF(parser_state->aml,
	parser_state->aml_start);
	walk_state->opcode = acpi_ps_peek_opcode(parser_state);

	/*
	* First cut to determine what we have found:
	* 1) A valid AML opcode
	* 2) A name string
	* 3) An unknown/invalid opcode
	*/
	walk_state->op_info =
	acpi_ps_get_opcode_info(walk_state->opcode);
	switch (walk_state->op_info->class) {
	case AML_CLASS_ASCII:
	case AML_CLASS_PREFIX:
	/*
	* Starts with a valid prefix or ASCII char, this is a name
	* string. Convert the bare name string to a namepath.
	*/
	walk_state->opcode = AML_INT_NAMEPATH_OP;
	walk_state->arg_types = ARGP_NAMESTRING;
	break;

	case AML_CLASS_UNKNOWN:

	/* The opcode is unrecognized. Just skip unknown opcodes */

	ACPI_ERROR((AE_INFO,
	"Found unknown opcode %X at AML address %p offset %X, ignoring",
	walk_state->opcode,
	parser_state->aml,
	walk_state->aml_offset));

	ACPI_DUMP_BUFFER(parser_state->aml, 128);

	/* Assume one-byte bad opcode */

	parser_state->aml++;
	continue;

	default:

	/* Found opcode info, this is a normal opcode */

	parser_state->aml +=
	acpi_ps_get_opcode_size(walk_state->opcode);
	walk_state->arg_types =
	walk_state->op_info->parse_args;
	break;
	}

	/* Create Op structure and append to parent's argument list */

	if (walk_state->op_info->flags & AML_NAMED) {
	/* Allocate a new pre_op if necessary */

	if (!pre_op) {
	pre_op =
	acpi_ps_alloc_op(walk_state->
	opcode);
	if (!pre_op) {
	status = AE_NO_MEMORY;
	goto close_this_op;
	}
	}

	pre_op->common.value.arg = NULL;
	pre_op->common.aml_opcode = walk_state->opcode;

	/*
	* Get and append arguments until we find the node that contains
	* the name (the type ARGP_NAME).
	*/
	while (GET_CURRENT_ARG_TYPE
	(walk_state->arg_types)
	&&
	(GET_CURRENT_ARG_TYPE
	(walk_state->arg_types) != ARGP_NAME)) {
	status =
	acpi_ps_get_next_arg(walk_state,
	parser_state,
	GET_CURRENT_ARG_TYPE
	(walk_state->
	arg_types),
	&arg);
	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}

	acpi_ps_append_arg(pre_op, arg);
	INCREMENT_ARG_LIST(walk_state->
	arg_types);
	}

	/*
	* Make sure that we found a NAME and didn't run out of
	* arguments
	*/
	if (!GET_CURRENT_ARG_TYPE
	(walk_state->arg_types)) {
	status = AE_AML_NO_OPERAND;
	goto close_this_op;
	}

	/* We know that this arg is a name, move to next arg */

	INCREMENT_ARG_LIST(walk_state->arg_types);

	/*
	* Find the object. This will either insert the object into
	* the namespace or simply look it up
	*/
	walk_state->op = NULL;

	status =
	walk_state->descending_callback(walk_state,
	&op);
	if (ACPI_FAILURE(status)) {
	ACPI_EXCEPTION((AE_INFO, status,
	"During name lookup/catalog"));
	goto close_this_op;
	}

	if (!op) {
	continue;
	}

	status =
	acpi_ps_next_parse_state(walk_state, op,
	status);
	if (status == AE_CTRL_PENDING) {
	status = AE_OK;
	goto close_this_op;
	}

	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}

	acpi_ps_append_arg(op,
	pre_op->common.value.arg);
	acpi_gbl_depth++;

	if (op->common.aml_opcode == AML_REGION_OP) {
	/*
	* Defer final parsing of an operation_region body,
	* because we don't have enough info in the first pass
	* to parse it correctly (i.e., there may be method
	* calls within the term_arg elements of the body.)
	*
	* However, we must continue parsing because
	* the opregion is not a standalone package --
	* we don't know where the end is at this point.
	*
	* (Length is unknown until parse of the body complete)
	*/
	op->named.data = aml_op_start;
	op->named.length = 0;
	}
	} else {
	/* Not a named opcode, just allocate Op and append to parent */

	walk_state->op_info =
	acpi_ps_get_opcode_info(walk_state->opcode);
	op = acpi_ps_alloc_op(walk_state->opcode);
	if (!op) {
	status = AE_NO_MEMORY;
	goto close_this_op;
	}

	if (walk_state->op_info->flags & AML_CREATE) {
	/*
	* Backup to beginning of create_xXXfield declaration
	* body_length is unknown until we parse the body
	*/
	op->named.data = aml_op_start;
	op->named.length = 0;
	}

	acpi_ps_append_arg(acpi_ps_get_parent_scope
	(parser_state), op);

	if ((walk_state->descending_callback != NULL)) {
	/*
	* Find the object. This will either insert the object into
	* the namespace or simply look it up
	*/
	walk_state->op = op;

	status =
	walk_state->
	descending_callback(walk_state,
	&op);
	status =
	acpi_ps_next_parse_state(walk_state,
	op,
	status);
	if (status == AE_CTRL_PENDING) {
	status = AE_OK;
	goto close_this_op;
	}

	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}
	}
	}

	op->common.aml_offset = walk_state->aml_offset;

	if (walk_state->op_info) {
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Opcode %4.4X [%s] Op %p Aml %p aml_offset %5.5X\n",
	(u32) op->common.aml_opcode,
	walk_state->op_info->name, op,
	parser_state->aml,
	op->common.aml_offset));
	}
	}

	/*
	* Start arg_count at zero because we don't know if there are
	* any args yet
	*/
	walk_state->arg_count = 0;

	/* Are there any arguments that must be processed? */

	if (walk_state->arg_types) {
	/* Get arguments */

	switch (op->common.aml_opcode) {
	case AML_BYTE_OP: /* AML_BYTEDATA_ARG */
	case AML_WORD_OP: /* AML_WORDDATA_ARG */
	case AML_DWORD_OP: /* AML_DWORDATA_ARG */
	case AML_QWORD_OP: /* AML_QWORDATA_ARG */
	case AML_STRING_OP: /* AML_ASCIICHARLIST_ARG */

	/* Fill in constant or string argument directly */

	acpi_ps_get_next_simple_arg(parser_state,
	GET_CURRENT_ARG_TYPE
	(walk_state->
	arg_types), op);
	break;

	case AML_INT_NAMEPATH_OP: /* AML_NAMESTRING_ARG */

	status =
	acpi_ps_get_next_namepath(walk_state,
	parser_state, op,
	1);
	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}

	walk_state->arg_types = 0;
	break;

	default:
	/*
	* Op is not a constant or string, append each argument
	* to the Op
	*/
	while (GET_CURRENT_ARG_TYPE
	(walk_state->arg_types)
	&& !walk_state->arg_count) {
	walk_state->aml_offset = (u32)
	ACPI_PTR_DIFF(parser_state->aml,
	parser_state->
	aml_start);

	status =
	acpi_ps_get_next_arg(walk_state,
	parser_state,
	GET_CURRENT_ARG_TYPE
	(walk_state->
	arg_types),
	&arg);
	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}

	if (arg) {
	arg->common.aml_offset =
	walk_state->aml_offset;
	acpi_ps_append_arg(op, arg);
	}
	INCREMENT_ARG_LIST(walk_state->
	arg_types);
	}

	/* Special processing for certain opcodes */

	/* TBD (remove): Temporary mechanism to disable this code if needed */

	#ifdef ACPI_ENABLE_MODULE_LEVEL_CODE

	if ((walk_state->pass_number <=
	ACPI_IMODE_LOAD_PASS1)
	&&
	((walk_state->
	parse_flags & ACPI_PARSE_DISASSEMBLE) ==
	0)) {
	/*
	* We want to skip If/Else/While constructs during Pass1
	* because we want to actually conditionally execute the
	* code during Pass2.
	*
	* Except for disassembly, where we always want to
	* walk the If/Else/While packages
	*/
	switch (op->common.aml_opcode) {
	case AML_IF_OP:
	case AML_ELSE_OP:
	case AML_WHILE_OP:

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Pass1: Skipping an If/Else/While body\n"));

	/* Skip body of if/else/while in pass 1 */

	parser_state->aml =
	parser_state->pkg_end;
	walk_state->arg_count = 0;
	break;

	default:
	break;
	}
	}
	#endif
	switch (op->common.aml_opcode) {
	case AML_METHOD_OP:

	/*
	* Skip parsing of control method
	* because we don't have enough info in the first pass
	* to parse it correctly.
	*
	* Save the length and address of the body
	*/
	op->named.data = parser_state->aml;
	op->named.length =
	(u32) (parser_state->pkg_end -
	parser_state->aml);

	/* Skip body of method */

	parser_state->aml =
	parser_state->pkg_end;
	walk_state->arg_count = 0;
	break;

	case AML_BUFFER_OP:
	case AML_PACKAGE_OP:
	case AML_VAR_PACKAGE_OP:

	if ((op->common.parent) &&
	(op->common.parent->common.
	aml_opcode == AML_NAME_OP)
	&& (walk_state->pass_number <=
	ACPI_IMODE_LOAD_PASS2)) {
	/*
	* Skip parsing of Buffers and Packages
	* because we don't have enough info in the first pass
	* to parse them correctly.
	*/
	op->named.data = aml_op_start;
	op->named.length =
	(u32) (parser_state->
	pkg_end -
	aml_op_start);

	/* Skip body */

	parser_state->aml =
	parser_state->pkg_end;
	walk_state->arg_count = 0;
	}
	break;

	case AML_WHILE_OP:

	if (walk_state->control_state) {
	walk_state->control_state->
	control.package_end =
	parser_state->pkg_end;
	}
	break;

	default:

	/* No action for all other opcodes */
	break;
	}
	break;
	}
	}

	/* Check for arguments that need to be processed */

	if (walk_state->arg_count) {
	/*
	* There are arguments (complex ones), push Op and
	* prepare for argument
	*/
	status = acpi_ps_push_scope(parser_state, op,
	walk_state->arg_types,
	walk_state->arg_count);
	if (ACPI_FAILURE(status)) {
	goto close_this_op;
	}
	op = NULL;
	continue;
	}

	/*
	* All arguments have been processed -- Op is complete,
	* prepare for next
	*/
	walk_state->op_info =
	acpi_ps_get_opcode_info(op->common.aml_opcode);
	if (walk_state->op_info->flags & AML_NAMED) {
	if (acpi_gbl_depth) {
	acpi_gbl_depth--;
	}

	if (op->common.aml_opcode == AML_REGION_OP) {
	/*
	* Skip parsing of control method or opregion body,
	* because we don't have enough info in the first pass
	* to parse them correctly.
	*
	* Completed parsing an op_region declaration, we now
	* know the length.
	*/
	op->named.length =
	(u32) (parser_state->aml - op->named.data);
	}
	}

	if (walk_state->op_info->flags & AML_CREATE) {
	/*
	* Backup to beginning of create_xXXfield declaration (1 for
	* Opcode)
	*
	* body_length is unknown until we parse the body
	*/
	op->named.length =
	(u32) (parser_state->aml - op->named.data);
	}

	/* This op complete, notify the dispatcher */

	if (walk_state->ascending_callback != NULL) {
	walk_state->op = op;
	walk_state->opcode = op->common.aml_opcode;

	status = walk_state->ascending_callback(walk_state);
	status =
	acpi_ps_next_parse_state(walk_state, op, status);
	if (status == AE_CTRL_PENDING) {
	status = AE_OK;
	goto close_this_op;
	}
	}

	close_this_op:
	/*
	* Finished one argument of the containing scope
	*/
	parser_state->scope->parse_scope.arg_count--;

	/* Finished with pre_op */

	if (pre_op) {
	acpi_ps_free_op(pre_op);
	pre_op = NULL;
	}

	/* Close this Op (will result in parse subtree deletion) */

	status2 = acpi_ps_complete_this_op(walk_state, op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	op = NULL;

	switch (status) {
	case AE_OK:
	break;

	case AE_CTRL_TRANSFER:

	/* We are about to transfer to a called method. */

	walk_state->prev_op = op;
	walk_state->prev_arg_types = walk_state->arg_types;
	return_ACPI_STATUS(status);

	case AE_CTRL_END:

	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);

	if (op) {
	walk_state->op = op;
	walk_state->op_info =
	acpi_ps_get_opcode_info(op->common.
	aml_opcode);
	walk_state->opcode = op->common.aml_opcode;

	status =
	walk_state->ascending_callback(walk_state);
	status =
	acpi_ps_next_parse_state(walk_state, op,
	status);

	status2 =
	acpi_ps_complete_this_op(walk_state, op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	op = NULL;
	}
	status = AE_OK;
	break;

	case AE_CTRL_BREAK:
	case AE_CTRL_CONTINUE:

	/* Pop off scopes until we find the While */

	while (!op \|\| (op->common.aml_opcode != AML_WHILE_OP)) {
	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);

	if (op->common.aml_opcode != AML_WHILE_OP) {
	status2 =
	acpi_ds_result_stack_pop
	(walk_state);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	}
	}

	/* Close this iteration of the While loop */

	walk_state->op = op;
	walk_state->op_info =
	acpi_ps_get_opcode_info(op->common.aml_opcode);
	walk_state->opcode = op->common.aml_opcode;

	status = walk_state->ascending_callback(walk_state);
	status =
	acpi_ps_next_parse_state(walk_state, op, status);

	status2 = acpi_ps_complete_this_op(walk_state, op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	op = NULL;

	status = AE_OK;
	break;

	case AE_CTRL_TERMINATE:

	status = AE_OK;

	/* Clean up */
	do {
	if (op) {
	status2 =
	acpi_ps_complete_this_op(walk_state,
	op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	}
	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);

	} while (op);

	return_ACPI_STATUS(status);

	default: /* All other non-AE_OK status */

	do {
	if (op) {
	status2 =
	acpi_ps_complete_this_op(walk_state,
	op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	}
	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);

	} while (op);

	/*
	* TBD: Cleanup parse ops on error
	*/
	#if 0
	if (op == NULL) {
	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);
	}
	#endif
	walk_state->prev_op = op;
	walk_state->prev_arg_types = walk_state->arg_types;
	return_ACPI_STATUS(status);
	}

	/* This scope complete? */

	if (acpi_ps_has_completed_scope(parser_state)) {
	acpi_ps_pop_scope(parser_state, &op,
	&walk_state->arg_types,
	&walk_state->arg_count);
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Popped scope, Op=%p\n", op));
	} else {
	op = NULL;
	}

	} /* while parser_state->Aml */

	/*
	* Complete the last Op (if not completed), and clear the scope stack.
	* It is easily possible to end an AML "package" with an unbounded number
	* of open scopes (such as when several ASL blocks are closed with
	* sequential closing braces). We want to terminate each one cleanly.
	*/
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "AML package complete at Op %p\n",
	op));
	do {
	if (op) {
	if (walk_state->ascending_callback != NULL) {
	walk_state->op = op;
	walk_state->op_info =
	acpi_ps_get_opcode_info(op->common.
	aml_opcode);
	walk_state->opcode = op->common.aml_opcode;

	status =
	walk_state->ascending_callback(walk_state);
	status =
	acpi_ps_next_parse_state(walk_state, op,
	status);
	if (status == AE_CTRL_PENDING) {
	status = AE_OK;
	goto close_this_op;
	}

	if (status == AE_CTRL_TERMINATE) {
	status = AE_OK;

	/* Clean up */
	do {
	if (op) {
	status2 =
	acpi_ps_complete_this_op
	(walk_state, op);
	if (ACPI_FAILURE
	(status2)) {
	return_ACPI_STATUS
	(status2);
	}
	}

	acpi_ps_pop_scope(parser_state,
	&op,
	&walk_state->
	arg_types,
	&walk_state->
	arg_count);

	} while (op);

	return_ACPI_STATUS(status);
	}

	else if (ACPI_FAILURE(status)) {
	/* First error is most important */

	(void)
	acpi_ps_complete_this_op(walk_state,
	op);
	return_ACPI_STATUS(status);
	}
	}

	status2 = acpi_ps_complete_this_op(walk_state, op);
	if (ACPI_FAILURE(status2)) {
	return_ACPI_STATUS(status2);
	}
	}

	acpi_ps_pop_scope(parser_state, &op, &walk_state->arg_types,
	&walk_state->arg_count);

	} while (op);

	return_ACPI_STATUS(status);
	}