linux_kernel/drivers/acpi/acpica/pstree.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: pstree - Parser op tree manipulation/traversal/search
 *
 * Copyright (C) 2000 - 2018, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"
#include "amlcode.h"
#include "acconvert.h"

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("pstree")

/* Local prototypes */
#ifdef ACPI_OBSOLETE_FUNCTIONS
union acpi_parse_object *acpi_ps_get_child(union acpi_parse_object *op);
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_arg
 *
 * PARAMETERS:  op              - Get an argument for this op
 *              argn            - Nth argument to get
 *
 * RETURN:      The argument (as an Op object). NULL if argument does not exist
 *
 * DESCRIPTION: Get the specified op's argument.
 *
 ******************************************************************************/

union acpi_parse_object *acpi_ps_get_arg(union acpi_parse_object *op, u32 argn)
{
	union acpi_parse_object *arg = NULL;
	const struct acpi_opcode_info *op_info;

	ACPI_FUNCTION_ENTRY();

/*
	if (Op->Common.aml_opcode == AML_INT_CONNECTION_OP)
	{
		return (Op->Common.Value.Arg);
	}
*/
	/* Get the info structure for this opcode */

	op_info = acpi_ps_get_opcode_info(op->common.aml_opcode);
	if (op_info->class == AML_CLASS_UNKNOWN) {

		/* Invalid opcode or ASCII character */

		return (NULL);
	}

	/* Check if this opcode requires argument sub-objects */

	if (!(op_info->flags & AML_HAS_ARGS)) {

		/* Has no linked argument objects */

		return (NULL);
	}

	/* Get the requested argument object */

	arg = op->common.value.arg;
	while (arg && argn) {
		argn--;
		arg = arg->common.next;
	}

	return (arg);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_append_arg
 *
 * PARAMETERS:  op              - Append an argument to this Op.
 *              arg             - Argument Op to append
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Append an argument to an op's argument list (a NULL arg is OK)
 *
 ******************************************************************************/

void
acpi_ps_append_arg(union acpi_parse_object *op, union acpi_parse_object *arg)
{
	union acpi_parse_object *prev_arg;
	const struct acpi_opcode_info *op_info;

	ACPI_FUNCTION_TRACE(ps_append_arg);

	if (!op) {
		return_VOID;
	}

	/* Get the info structure for this opcode */

	op_info = acpi_ps_get_opcode_info(op->common.aml_opcode);
	if (op_info->class == AML_CLASS_UNKNOWN) {

		/* Invalid opcode */

		ACPI_ERROR((AE_INFO, "Invalid AML Opcode: 0x%2.2X",
			    op->common.aml_opcode));
		return_VOID;
	}

	/* Check if this opcode requires argument sub-objects */

	if (!(op_info->flags & AML_HAS_ARGS)) {

		/* Has no linked argument objects */

		return_VOID;
	}

	/* Append the argument to the linked argument list */

	if (op->common.value.arg) {

		/* Append to existing argument list */

		prev_arg = op->common.value.arg;
		while (prev_arg->common.next) {
			prev_arg = prev_arg->common.next;
		}
		prev_arg->common.next = arg;
	} else {
		/* No argument list, this will be the first argument */

		op->common.value.arg = arg;
	}

	/* Set the parent in this arg and any args linked after it */

	while (arg) {
		arg->common.parent = op;
		arg = arg->common.next;

		op->common.arg_list_length++;
	}

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_depth_next
 *
 * PARAMETERS:  origin          - Root of subtree to search
 *              op              - Last (previous) Op that was found
 *
 * RETURN:      Next Op found in the search.
 *
 * DESCRIPTION: Get next op in tree (walking the tree in depth-first order)
 *              Return NULL when reaching "origin" or when walking up from root
 *
 ******************************************************************************/

union acpi_parse_object *acpi_ps_get_depth_next(union acpi_parse_object *origin,
						union acpi_parse_object *op)
{
	union acpi_parse_object *next = NULL;
	union acpi_parse_object *parent;
	union acpi_parse_object *arg;

	ACPI_FUNCTION_ENTRY();

	if (!op) {
		return (NULL);
	}

	/* Look for an argument or child */

	next = acpi_ps_get_arg(op, 0);
	if (next) {
		ASL_CV_LABEL_FILENODE(next);
		return (next);
	}

	/* Look for a sibling */

	next = op->common.next;
	if (next) {
		ASL_CV_LABEL_FILENODE(next);
		return (next);
	}

	/* Look for a sibling of parent */

	parent = op->common.parent;

	while (parent) {
		arg = acpi_ps_get_arg(parent, 0);
		while (arg && (arg != origin) && (arg != op)) {

			ASL_CV_LABEL_FILENODE(arg);
			arg = arg->common.next;
		}

		if (arg == origin) {

			/* Reached parent of origin, end search */

			return (NULL);
		}

		if (parent->common.next) {

			/* Found sibling of parent */

			ASL_CV_LABEL_FILENODE(parent->common.next);
			return (parent->common.next);
		}

		op = parent;
		parent = parent->common.parent;
	}

	ASL_CV_LABEL_FILENODE(next);
	return (next);
}

#ifdef ACPI_OBSOLETE_FUNCTIONS
/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_child
 *
 * PARAMETERS:  op              - Get the child of this Op
 *
 * RETURN:      Child Op, Null if none is found.
 *
 * DESCRIPTION: Get op's children or NULL if none
 *
 ******************************************************************************/

union acpi_parse_object *acpi_ps_get_child(union acpi_parse_object *op)
{
	union acpi_parse_object *child = NULL;

	ACPI_FUNCTION_ENTRY();

	switch (op->common.aml_opcode) {
	case AML_SCOPE_OP:
	case AML_ELSE_OP:
	case AML_DEVICE_OP:
	case AML_THERMAL_ZONE_OP:
	case AML_INT_METHODCALL_OP:

		child = acpi_ps_get_arg(op, 0);
		break;

	case AML_BUFFER_OP:
	case AML_PACKAGE_OP:
	case AML_VARIABLE_PACKAGE_OP:
	case AML_METHOD_OP:
	case AML_IF_OP:
	case AML_WHILE_OP:
	case AML_FIELD_OP:

		child = acpi_ps_get_arg(op, 1);
		break;

	case AML_POWER_RESOURCE_OP:
	case AML_INDEX_FIELD_OP:

		child = acpi_ps_get_arg(op, 2);
		break;

	case AML_PROCESSOR_OP:
	case AML_BANK_FIELD_OP:

		child = acpi_ps_get_arg(op, 3);
		break;

	default:

		/* All others have no children */

		break;
	}

	return (child);
}
#endif