drivers/acpi/acpica/psloop.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
 /******************************************************************************
  *
  * Module Name: psloop - Main AML parse loop
  *
  * Copyright (C) 2000 - 2018, Intel Corp.
  *
  *****************************************************************************/

 /*
  * Parse the AML and build an operation tree as most interpreters, (such as
  * Perl) do. Parsing is done by hand rather than with a YACC generated parser
  * to tightly constrain stack and dynamic memory usage. 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 "accommon.h"
 #include "acinterp.h"
 #include "acparser.h"
 #include "acdispat.h"
 #include "amlcode.h"
 #include "acconvert.h"

 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psloop")

 /* Local prototypes */
 static acpi_status
 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
 		      u8 * aml_op_start, union acpi_parse_object *op);

 static void
 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
 			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);

 /*******************************************************************************
  *
  * FUNCTION:    acpi_ps_get_arguments
  *
  * PARAMETERS:  walk_state          - Current state
  *              aml_op_start        - Op start in AML
  *              op                  - Current Op
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Get arguments for passed Op.
  *
  ******************************************************************************/

 static acpi_status
 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
 		      u8 * aml_op_start, union acpi_parse_object *op)
 {
 	acpi_status status = AE_OK;
 	union acpi_parse_object *arg = NULL;
 	const struct acpi_opcode_info *op_info;

 	ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);

 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 			  "Get arguments for opcode [%s]\n",
 			  op->common.aml_op_name));

 	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(&(walk_state->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,
 						   &(walk_state->parser_state),
 						   op,
 						   ACPI_POSSIBLE_METHOD_CALL);
 		if (ACPI_FAILURE(status)) {
 			return_ACPI_STATUS(status);
 		}

 		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 = walk_state->parser_state.aml;

 			switch (op->common.aml_opcode) {
 			case AML_METHOD_OP:
 			case AML_BUFFER_OP:
 			case AML_PACKAGE_OP:
 			case AML_VARIABLE_PACKAGE_OP:
 			case AML_WHILE_OP:

 				break;

 			default:

 				ASL_CV_CAPTURE_COMMENTS(walk_state);
 				break;
 			}

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

 			if (arg) {
 				acpi_ps_append_arg(op, arg);
 			}

 			INCREMENT_ARG_LIST(walk_state->arg_types);
 		}

 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Final argument count: %8.8X pass %u\n",
 				  walk_state->arg_count,
 				  walk_state->pass_number));

 		/*
 		 * This case handles the legacy option that groups all module-level
 		 * code blocks together and defers execution until all of the tables
 		 * are loaded. Execute all of these blocks at this time.
 		 * Execute any module-level code that was detected during the table
 		 * load phase.
 		 *
 		 * Note: this option is deprecated and will be eliminated in the
 		 * future. Use of this option can cause problems with AML code that
 		 * depends upon in-order immediate execution of module-level code.
 		 */
 		if (acpi_gbl_group_module_level_code &&
 		    (walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
 		    ((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:
 				/*
 				 * Currently supported module-level opcodes are:
 				 * IF/ELSE/WHILE. These appear to be the most common,
 				 * and easiest to support since they open an AML
 				 * package.
 				 */
 				if (walk_state->pass_number ==
 				    ACPI_IMODE_LOAD_PASS1) {
 					acpi_ps_link_module_code(op->common.
 								 parent,
 								 aml_op_start,
 								 (u32)
 								 (walk_state->
 								 parser_state.
 								 pkg_end -
 								 aml_op_start),
 								 walk_state->
 								 owner_id);
 				}

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

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

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

 			default:
 				/*
 				 * Check for an unsupported executable opcode at module
 				 * level. We must be in PASS1, the parent must be a SCOPE,
 				 * The opcode class must be EXECUTE, and the opcode must
 				 * not be an argument to another opcode.
 				 */
 				if ((walk_state->pass_number ==
 				     ACPI_IMODE_LOAD_PASS1)
 				    && (op->common.parent->common.aml_opcode ==
 					AML_SCOPE_OP)) {
 					op_info =
 					    acpi_ps_get_opcode_info(op->common.
 								    aml_opcode);
 					if ((op_info->class ==
 					     AML_CLASS_EXECUTE) && (!arg)) {
 						ACPI_WARNING((AE_INFO,
 							      "Unsupported module-level executable opcode "
 							      "0x%.2X at table offset 0x%.4X",
 							      op->common.
 							      aml_opcode,
 							      (u32)
 							      (ACPI_PTR_DIFF
 							       (aml_op_start,
 								walk_state->
 								parser_state.
 								aml_start) +
 							       sizeof(struct
 								      acpi_table_header))));
 					}
 				}
 				break;
 			}
 		}

 		/* Special processing for certain opcodes */

 		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 = walk_state->parser_state.aml;
 			op->named.length = (u32)
 			    (walk_state->parser_state.pkg_end -
 			     walk_state->parser_state.aml);

 			/* Skip body of method */

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

 		case AML_BUFFER_OP:
 		case AML_PACKAGE_OP:
 		case AML_VARIABLE_PACKAGE_OP:

 			if ((op->common.parent) &&
 			    (op->common.parent->common.aml_opcode ==
 			     AML_NAME_OP)
 			    && (walk_state->pass_number <=
 				ACPI_IMODE_LOAD_PASS2)) {
 				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 						  "Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
 						  walk_state->pass_number,
 						  aml_op_start));

 				/*
 				 * 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)
 				    (walk_state->parser_state.pkg_end -
 				     aml_op_start);

 				/* Skip body */

 				walk_state->parser_state.aml =
 				    walk_state->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 =
 				    walk_state->parser_state.pkg_end;
 			}
 			break;

 		default:

 			/* No action for all other opcodes */

 			break;
 		}

 		break;
 	}

 	return_ACPI_STATUS(AE_OK);
 }

 /*******************************************************************************
  *
  * FUNCTION:    acpi_ps_link_module_code
  *
  * PARAMETERS:  parent_op           - Parent parser op
  *              aml_start           - Pointer to the AML
  *              aml_length          - Length of executable AML
  *              owner_id            - owner_id of module level code
  *
  * RETURN:      None.
  *
  * DESCRIPTION: Wrap the module-level code with a method object and link the
  *              object to the global list. Note, the mutex field of the method
  *              object is used to link multiple module-level code objects.
  *
  * NOTE: In this legacy option, each block of detected executable AML
  * code that is outside of any control method is wrapped with a temporary
  * control method object and placed on a global list below.
  *
  * This function executes the module-level code for all tables only after
  * all of the tables have been loaded. It is a legacy option and is
  * not compatible with other ACPI implementations. See acpi_ns_load_table.
  *
  * This function will be removed when the legacy option is removed.
  *
  ******************************************************************************/

 static void
 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
 			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
 {
 	union acpi_operand_object *prev;
 	union acpi_operand_object *next;
 	union acpi_operand_object *method_obj;
 	struct acpi_namespace_node *parent_node;

 	ACPI_FUNCTION_TRACE(ps_link_module_code);

 	/* Get the tail of the list */

 	prev = next = acpi_gbl_module_code_list;
 	while (next) {
 		prev = next;
 		next = next->method.mutex;
 	}

 	/*
 	 * Insert the module level code into the list. Merge it if it is
 	 * adjacent to the previous element.
 	 */
 	if (!prev ||
 	    ((prev->method.aml_start + prev->method.aml_length) != aml_start)) {

 		/* Create, initialize, and link a new temporary method object */

 		method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
 		if (!method_obj) {
 			return_VOID;
 		}

 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Create/Link new code block: %p\n",
 				  method_obj));

 		if (parent_op->common.node) {
 			parent_node = parent_op->common.node;
 		} else {
 			parent_node = acpi_gbl_root_node;
 		}

 		method_obj->method.aml_start = aml_start;
 		method_obj->method.aml_length = aml_length;
 		method_obj->method.owner_id = owner_id;
 		method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;

 		/*
 		 * Save the parent node in next_object. This is cheating, but we
 		 * don't want to expand the method object.
 		 */
 		method_obj->method.next_object =
 		    ACPI_CAST_PTR(union acpi_operand_object, parent_node);

 		if (!prev) {
 			acpi_gbl_module_code_list = method_obj;
 		} else {
 			prev->method.mutex = method_obj;
 		}
 	} else {
 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Appending to existing code block: %p\n",
 				  prev));

 		prev->method.aml_length += aml_length;
 	}

 	return_VOID;
 }

 /*******************************************************************************
  *
  * 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;
 	union acpi_parse_object *op = NULL;	/* current op */
 	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,
 							"GetPredicate 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)) {
 		ASL_CV_CAPTURE_COMMENTS(walk_state);

 		aml_op_start = parser_state->aml;
 		if (!op) {
 			status =
 			    acpi_ps_create_op(walk_state, aml_op_start, &op);
 			if (ACPI_FAILURE(status)) {
 				/*
 				 * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
 				 * executing it as a control method. However, if we encounter
 				 * an error while loading the table, we need to keep trying to
 				 * load the table rather than aborting the table load. Set the
 				 * status to AE_OK to proceed with the table load.
 				 */
 				if ((walk_state->
 				     parse_flags & ACPI_PARSE_MODULE_LEVEL)
 				    && status == AE_ALREADY_EXISTS) {
 					status = AE_OK;
 				}
 				if (status == AE_CTRL_PARSE_CONTINUE) {
 					continue;
 				}

 				if (status == AE_CTRL_PARSE_PENDING) {
 					status = AE_OK;
 				}

 				if (status == AE_CTRL_TERMINATE) {
 					return_ACPI_STATUS(status);
 				}

 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
 				if (walk_state->opcode == AML_SCOPE_OP) {
 					/*
 					 * If the scope op fails to parse, skip the body of the
 					 * scope op because the parse failure indicates that the
 					 * device may not exist.
 					 */
 					walk_state->parser_state.aml =
 					    walk_state->aml + 1;
 					walk_state->parser_state.aml =
 					    acpi_ps_get_next_package_end
 					    (&walk_state->parser_state);
 					walk_state->aml =
 					    walk_state->parser_state.aml;
 					ACPI_ERROR((AE_INFO,
 						    "Skipping Scope block"));
 				}

 				continue;
 			}

 			acpi_ex_start_trace_opcode(op, walk_state);
 		}

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

 		switch (op->common.aml_opcode) {
 		case AML_BYTE_OP:
 		case AML_WORD_OP:
 		case AML_DWORD_OP:
 		case AML_QWORD_OP:

 			break;

 		default:

 			ASL_CV_CAPTURE_COMMENTS(walk_state);
 			break;
 		}

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

 		if (walk_state->arg_types) {

 			/* Get arguments */

 			status =
 			    acpi_ps_get_arguments(walk_state, aml_op_start, op);
 			if (ACPI_FAILURE(status)) {
 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
 				if ((walk_state->control_state) &&
 				    ((walk_state->control_state->control.
 				      opcode == AML_IF_OP)
 				     || (walk_state->control_state->control.
 					 opcode == AML_WHILE_OP))) {
 					/*
 					 * If the if/while op fails to parse, we will skip parsing
 					 * the body of the op.
 					 */
 					parser_state->aml =
 					    walk_state->control_state->control.
 					    aml_predicate_start + 1;
 					parser_state->aml =
 					    acpi_ps_get_next_package_end
 					    (parser_state);
 					walk_state->aml = parser_state->aml;

 					ACPI_ERROR((AE_INFO,
 						    "Skipping While/If block"));
 					if (*walk_state->aml == AML_ELSE_OP) {
 						ACPI_ERROR((AE_INFO,
 							    "Skipping Else block"));
 						walk_state->parser_state.aml =
 						    walk_state->aml + 1;
 						walk_state->parser_state.aml =
 						    acpi_ps_get_next_package_end
 						    (parser_state);
 						walk_state->aml =
 						    parser_state->aml;
 					}
 					ACPI_FREE(acpi_ut_pop_generic_state
 						  (&walk_state->control_state));
 				}
 				op = NULL;
 				continue;
 			}
 		}

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

 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Parseloop: argument count: %8.8X\n",
 				  walk_state->arg_count));

 		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)) {
 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}

 				continue;
 			}

 			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 (op->common.aml_opcode == AML_REGION_OP ||
 			    op->common.aml_opcode == AML_DATA_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);
 		}

 		if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
 			/*
 			 * Backup to beginning of bank_field declaration
 			 *
 			 * 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;
 			} else
 			    if ((walk_state->
 				 parse_flags & ACPI_PARSE_MODULE_LEVEL)
 				&& status != AE_CTRL_TRANSFER
 				&& ACPI_FAILURE(status)) {
 				/*
 				 * ACPI_PARSE_MODULE_LEVEL flag means that we are currently
 				 * loading a table by executing it as a control method.
 				 * However, if we encounter an error while loading the table,
 				 * we need to keep trying to load the table rather than
 				 * aborting the table load (setting the status to AE_OK
 				 * continues the table load). If we get a failure at this
 				 * point, it means that the dispatcher got an error while
 				 * processing Op (most likely an AML operand error) or a
 				 * control method was called from module level and the
 				 * dispatcher returned AE_CTRL_TRANSFER. In the latter case,
 				 * leave the status alone, there's nothing wrong with it.
 				 */
 				status = AE_OK;
 			}
 		}

 		status = acpi_ps_complete_op(walk_state, &op, status);
 		if (ACPI_FAILURE(status)) {
 			return_ACPI_STATUS(status);
 		}

 	}			/* while parser_state->Aml */

 	status = acpi_ps_complete_final_op(walk_state, op, status);
 	return_ACPI_STATUS(status);
 }
	// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
	/******************************************************************************
	*
	* Module Name: psloop - Main AML parse loop
	*
	* Copyright (C) 2000 - 2018, Intel Corp.
	*
	*****************************************************************************/

	/*
	* Parse the AML and build an operation tree as most interpreters, (such as
	* Perl) do. Parsing is done by hand rather than with a YACC generated parser
	* to tightly constrain stack and dynamic memory usage. 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 "accommon.h"
	#include "acinterp.h"
	#include "acparser.h"
	#include "acdispat.h"
	#include "amlcode.h"
	#include "acconvert.h"

	#define _COMPONENT ACPI_PARSER
	ACPI_MODULE_NAME("psloop")

	/* Local prototypes */
	static acpi_status
	acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
	u8 * aml_op_start, union acpi_parse_object *op);

	static void
	acpi_ps_link_module_code(union acpi_parse_object *parent_op,
	u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);

	/*******************************************************************************
	*
	* FUNCTION: acpi_ps_get_arguments
	*
	* PARAMETERS: walk_state - Current state
	* aml_op_start - Op start in AML
	* op - Current Op
	*
	* RETURN: Status
	*
	* DESCRIPTION: Get arguments for passed Op.
	*
	******************************************************************************/

	static acpi_status
	acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
	u8 * aml_op_start, union acpi_parse_object *op)
	{
	acpi_status status = AE_OK;
	union acpi_parse_object *arg = NULL;
	const struct acpi_opcode_info *op_info;

	ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Get arguments for opcode [%s]\n",
	op->common.aml_op_name));

	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(&(walk_state->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,
	&(walk_state->parser_state),
	op,
	ACPI_POSSIBLE_METHOD_CALL);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	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 = walk_state->parser_state.aml;

	switch (op->common.aml_opcode) {
	case AML_METHOD_OP:
	case AML_BUFFER_OP:
	case AML_PACKAGE_OP:
	case AML_VARIABLE_PACKAGE_OP:
	case AML_WHILE_OP:

	break;

	default:

	ASL_CV_CAPTURE_COMMENTS(walk_state);
	break;
	}

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

	if (arg) {
	acpi_ps_append_arg(op, arg);
	}

	INCREMENT_ARG_LIST(walk_state->arg_types);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Final argument count: %8.8X pass %u\n",
	walk_state->arg_count,
	walk_state->pass_number));

	/*
	* This case handles the legacy option that groups all module-level
	* code blocks together and defers execution until all of the tables
	* are loaded. Execute all of these blocks at this time.
	* Execute any module-level code that was detected during the table
	* load phase.
	*
	* Note: this option is deprecated and will be eliminated in the
	* future. Use of this option can cause problems with AML code that
	* depends upon in-order immediate execution of module-level code.
	*/
	if (acpi_gbl_group_module_level_code &&
	(walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
	((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:
	/*
	* Currently supported module-level opcodes are:
	* IF/ELSE/WHILE. These appear to be the most common,
	* and easiest to support since they open an AML
	* package.
	*/
	if (walk_state->pass_number ==
	ACPI_IMODE_LOAD_PASS1) {
	acpi_ps_link_module_code(op->common.
	parent,
	aml_op_start,
	(u32)
	(walk_state->
	parser_state.
	pkg_end -
	aml_op_start),
	walk_state->
	owner_id);
	}

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

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

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

	default:
	/*
	* Check for an unsupported executable opcode at module
	* level. We must be in PASS1, the parent must be a SCOPE,
	* The opcode class must be EXECUTE, and the opcode must
	* not be an argument to another opcode.
	*/
	if ((walk_state->pass_number ==
	ACPI_IMODE_LOAD_PASS1)
	&& (op->common.parent->common.aml_opcode ==
	AML_SCOPE_OP)) {
	op_info =
	acpi_ps_get_opcode_info(op->common.
	aml_opcode);
	if ((op_info->class ==
	AML_CLASS_EXECUTE) && (!arg)) {
	ACPI_WARNING((AE_INFO,
	"Unsupported module-level executable opcode "
	"0x%.2X at table offset 0x%.4X",
	op->common.
	aml_opcode,
	(u32)
	(ACPI_PTR_DIFF
	(aml_op_start,
	walk_state->
	parser_state.
	aml_start) +
	sizeof(struct
	acpi_table_header))));
	}
	}
	break;
	}
	}

	/* Special processing for certain opcodes */

	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 = walk_state->parser_state.aml;
	op->named.length = (u32)
	(walk_state->parser_state.pkg_end -
	walk_state->parser_state.aml);

	/* Skip body of method */

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

	case AML_BUFFER_OP:
	case AML_PACKAGE_OP:
	case AML_VARIABLE_PACKAGE_OP:

	if ((op->common.parent) &&
	(op->common.parent->common.aml_opcode ==
	AML_NAME_OP)
	&& (walk_state->pass_number <=
	ACPI_IMODE_LOAD_PASS2)) {
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
	walk_state->pass_number,
	aml_op_start));

	/*
	* 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)
	(walk_state->parser_state.pkg_end -
	aml_op_start);

	/* Skip body */

	walk_state->parser_state.aml =
	walk_state->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 =
	walk_state->parser_state.pkg_end;
	}
	break;

	default:

	/* No action for all other opcodes */

	break;
	}

	break;
	}

	return_ACPI_STATUS(AE_OK);
	}

	/*******************************************************************************
	*
	* FUNCTION: acpi_ps_link_module_code
	*
	* PARAMETERS: parent_op - Parent parser op
	* aml_start - Pointer to the AML
	* aml_length - Length of executable AML
	* owner_id - owner_id of module level code
	*
	* RETURN: None.
	*
	* DESCRIPTION: Wrap the module-level code with a method object and link the
	* object to the global list. Note, the mutex field of the method
	* object is used to link multiple module-level code objects.
	*
	* NOTE: In this legacy option, each block of detected executable AML
	* code that is outside of any control method is wrapped with a temporary
	* control method object and placed on a global list below.
	*
	* This function executes the module-level code for all tables only after
	* all of the tables have been loaded. It is a legacy option and is
	* not compatible with other ACPI implementations. See acpi_ns_load_table.
	*
	* This function will be removed when the legacy option is removed.
	*
	******************************************************************************/

	static void
	acpi_ps_link_module_code(union acpi_parse_object *parent_op,
	u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
	{
	union acpi_operand_object *prev;
	union acpi_operand_object *next;
	union acpi_operand_object *method_obj;
	struct acpi_namespace_node *parent_node;

	ACPI_FUNCTION_TRACE(ps_link_module_code);

	/* Get the tail of the list */

	prev = next = acpi_gbl_module_code_list;
	while (next) {
	prev = next;
	next = next->method.mutex;
	}

	/*
	* Insert the module level code into the list. Merge it if it is
	* adjacent to the previous element.
	*/
	if (!prev \|\|
	((prev->method.aml_start + prev->method.aml_length) != aml_start)) {

	/* Create, initialize, and link a new temporary method object */

	method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
	if (!method_obj) {
	return_VOID;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Create/Link new code block: %p\n",
	method_obj));

	if (parent_op->common.node) {
	parent_node = parent_op->common.node;
	} else {
	parent_node = acpi_gbl_root_node;
	}

	method_obj->method.aml_start = aml_start;
	method_obj->method.aml_length = aml_length;
	method_obj->method.owner_id = owner_id;
	method_obj->method.info_flags \|= ACPI_METHOD_MODULE_LEVEL;

	/*
	* Save the parent node in next_object. This is cheating, but we
	* don't want to expand the method object.
	*/
	method_obj->method.next_object =
	ACPI_CAST_PTR(union acpi_operand_object, parent_node);

	if (!prev) {
	acpi_gbl_module_code_list = method_obj;
	} else {
	prev->method.mutex = method_obj;
	}
	} else {
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Appending to existing code block: %p\n",
	prev));

	prev->method.aml_length += aml_length;
	}

	return_VOID;
	}

	/*******************************************************************************
	*
	* 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;
	union acpi_parse_object op = NULL; / current op */
	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,
	"GetPredicate 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)) {
	ASL_CV_CAPTURE_COMMENTS(walk_state);

	aml_op_start = parser_state->aml;
	if (!op) {
	status =
	acpi_ps_create_op(walk_state, aml_op_start, &op);
	if (ACPI_FAILURE(status)) {
	/*
	* ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
	* executing it as a control method. However, if we encounter
	* an error while loading the table, we need to keep trying to
	* load the table rather than aborting the table load. Set the
	* status to AE_OK to proceed with the table load.
	*/
	if ((walk_state->
	parse_flags & ACPI_PARSE_MODULE_LEVEL)
	&& status == AE_ALREADY_EXISTS) {
	status = AE_OK;
	}
	if (status == AE_CTRL_PARSE_CONTINUE) {
	continue;
	}

	if (status == AE_CTRL_PARSE_PENDING) {
	status = AE_OK;
	}

	if (status == AE_CTRL_TERMINATE) {
	return_ACPI_STATUS(status);
	}

	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	if (walk_state->opcode == AML_SCOPE_OP) {
	/*
	* If the scope op fails to parse, skip the body of the
	* scope op because the parse failure indicates that the
	* device may not exist.
	*/
	walk_state->parser_state.aml =
	walk_state->aml + 1;
	walk_state->parser_state.aml =
	acpi_ps_get_next_package_end
	(&walk_state->parser_state);
	walk_state->aml =
	walk_state->parser_state.aml;
	ACPI_ERROR((AE_INFO,
	"Skipping Scope block"));
	}

	continue;
	}

	acpi_ex_start_trace_opcode(op, walk_state);
	}

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

	switch (op->common.aml_opcode) {
	case AML_BYTE_OP:
	case AML_WORD_OP:
	case AML_DWORD_OP:
	case AML_QWORD_OP:

	break;

	default:

	ASL_CV_CAPTURE_COMMENTS(walk_state);
	break;
	}

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

	if (walk_state->arg_types) {

	/* Get arguments */

	status =
	acpi_ps_get_arguments(walk_state, aml_op_start, op);
	if (ACPI_FAILURE(status)) {
	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	if ((walk_state->control_state) &&
	((walk_state->control_state->control.
	opcode == AML_IF_OP)
	\|\| (walk_state->control_state->control.
	opcode == AML_WHILE_OP))) {
	/*
	* If the if/while op fails to parse, we will skip parsing
	* the body of the op.
	*/
	parser_state->aml =
	walk_state->control_state->control.
	aml_predicate_start + 1;
	parser_state->aml =
	acpi_ps_get_next_package_end
	(parser_state);
	walk_state->aml = parser_state->aml;

	ACPI_ERROR((AE_INFO,
	"Skipping While/If block"));
	if (*walk_state->aml == AML_ELSE_OP) {
	ACPI_ERROR((AE_INFO,
	"Skipping Else block"));
	walk_state->parser_state.aml =
	walk_state->aml + 1;
	walk_state->parser_state.aml =
	acpi_ps_get_next_package_end
	(parser_state);
	walk_state->aml =
	parser_state->aml;
	}
	ACPI_FREE(acpi_ut_pop_generic_state
	(&walk_state->control_state));
	}
	op = NULL;
	continue;
	}
	}

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

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Parseloop: argument count: %8.8X\n",
	walk_state->arg_count));

	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)) {
	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	continue;
	}

	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 (op->common.aml_opcode == AML_REGION_OP \|\|
	op->common.aml_opcode == AML_DATA_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);
	}

	if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
	/*
	* Backup to beginning of bank_field declaration
	*
	* 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;
	} else
	if ((walk_state->
	parse_flags & ACPI_PARSE_MODULE_LEVEL)
	&& status != AE_CTRL_TRANSFER
	&& ACPI_FAILURE(status)) {
	/*
	* ACPI_PARSE_MODULE_LEVEL flag means that we are currently
	* loading a table by executing it as a control method.
	* However, if we encounter an error while loading the table,
	* we need to keep trying to load the table rather than
	* aborting the table load (setting the status to AE_OK
	* continues the table load). If we get a failure at this
	* point, it means that the dispatcher got an error while
	* processing Op (most likely an AML operand error) or a
	* control method was called from module level and the
	* dispatcher returned AE_CTRL_TRANSFER. In the latter case,
	* leave the status alone, there's nothing wrong with it.
	*/
	status = AE_OK;
	}
	}

	status = acpi_ps_complete_op(walk_state, &op, status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	} /* while parser_state->Aml */

	status = acpi_ps_complete_final_op(walk_state, op, status);
	return_ACPI_STATUS(status);
	}