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

   * Copyright (C) 2000 - 2016, Intel Corp.

   * 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, (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"

  
  #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);
  
  	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;

  
  			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);
  		}

  		/*
  		 * Handle executable code at "module-level". This refers to
  		 * executable opcodes that appear outside of any control method.
  		 */
  		if ((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
  "));
  
  				/* 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_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)
  				    (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.
   *
   ******************************************************************************/
  
  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
  ",
  				  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
  ",
  				  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
  ", 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) {
  			status =
  			    acpi_ps_create_op(walk_state, aml_op_start, &op);
  			if (ACPI_FAILURE(status)) {
  				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);

  				}

  				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;
  
  		/* 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);

  				}

  				continue;

  			}
  		}
  
  		/* 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)) {

  				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;

  			}
  		}

  		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);

  }