/****************************************************************************** * * Module Name: nswalk - Functions for walking the ACPI namespace * $Revision: 26 $ * *****************************************************************************/ /* * Copyright (C) 2000, 2001 R. Byron Moore * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "acpi.h" #include "acinterp.h" #include "acnamesp.h" #define _COMPONENT ACPI_NAMESPACE MODULE_NAME ("nswalk") /******************************************************************************* * * FUNCTION: Acpi_ns_get_next_node * * PARAMETERS: Type - Type of node to be searched for * Parent_node - Parent node whose children we are * getting * Child_node - Previous child that was found. * The NEXT child will be returned * * RETURN: acpi_namespace_node - Pointer to the NEXT child or NULL if * none is found. * * DESCRIPTION: Return the next peer node within the namespace. If Handle * is valid, Scope is ignored. Otherwise, the first node * within Scope is returned. * ******************************************************************************/ acpi_namespace_node * acpi_ns_get_next_node ( acpi_object_type8 type, acpi_namespace_node *parent_node, acpi_namespace_node *child_node) { acpi_namespace_node *next_node = NULL; FUNCTION_ENTRY (); if (!child_node) { /* It's really the parent's _scope_ that we want */ if (parent_node->child) { next_node = parent_node->child; } } else { /* Start search at the NEXT node */ next_node = acpi_ns_get_next_valid_node (child_node); } /* If any type is OK, we are done */ if (type == ACPI_TYPE_ANY) { /* Next_node is NULL if we are at the end-of-list */ return (next_node); } /* Must search for the node -- but within this scope only */ while (next_node) { /* If type matches, we are done */ if (next_node->type == type) { return (next_node); } /* Otherwise, move on to the next node */ next_node = acpi_ns_get_next_valid_node (next_node); } /* Not found */ return (NULL); } /******************************************************************************* * * FUNCTION: Acpi_ns_walk_namespace * * PARAMETERS: Type - acpi_object_type to search for * Start_node - Handle in namespace where search begins * Max_depth - Depth to which search is to reach * Unlock_before_callback- Whether to unlock the NS before invoking * the callback routine * User_function - Called when an object of "Type" is found * Context - Passed to user function * Return_value - from the User_function if terminated early. * Otherwise, returns NULL. * RETURNS: Status * * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, * starting (and ending) at the node specified by Start_handle. * The User_function is called whenever a node that matches * the type parameter is found. If the user function returns * a non-zero value, the search is terminated immediately and this * value is returned to the caller. * * The point of this procedure is to provide a generic namespace * walk routine that can be called from multiple places to * provide multiple services; the User Function can be tailored * to each task, whether it is a print function, a compare * function, etc. * ******************************************************************************/ acpi_status acpi_ns_walk_namespace ( acpi_object_type8 type, acpi_handle start_node, u32 max_depth, u8 unlock_before_callback, acpi_walk_callback user_function, void *context, void **return_value) { acpi_status status; acpi_namespace_node *child_node; acpi_namespace_node *parent_node; acpi_object_type8 child_type; u32 level; FUNCTION_TRACE ("Ns_walk_namespace"); /* Special case for the namespace Root Node */ if (start_node == ACPI_ROOT_OBJECT) { start_node = acpi_gbl_root_node; } /* Null child means "get first node" */ parent_node = start_node; child_node = 0; child_type = ACPI_TYPE_ANY; level = 1; /* * Traverse the tree of nodes until we bubble back up to where we * started. When Level is zero, the loop is done because we have * bubbled up to (and passed) the original parent handle (Start_entry) */ while (level > 0) { /* Get the next node in this scope. Null if not found */ status = AE_OK; child_node = acpi_ns_get_next_node (ACPI_TYPE_ANY, parent_node, child_node); if (child_node) { /* * Found node, Get the type if we are not * searching for ANY */ if (type != ACPI_TYPE_ANY) { child_type = child_node->type; } if (child_type == type) { /* * Found a matching node, invoke the user * callback function */ if (unlock_before_callback) { acpi_ut_release_mutex (ACPI_MTX_NAMESPACE); } status = user_function (child_node, level, context, return_value); if (unlock_before_callback) { acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE); } switch (status) { case AE_OK: case AE_CTRL_DEPTH: /* Just keep going */ break; case AE_CTRL_TERMINATE: /* Exit now, with OK status */ return_ACPI_STATUS (AE_OK); break; default: /* All others are valid exceptions */ return_ACPI_STATUS (status); break; } } /* * Depth first search: * Attempt to go down another level in the namespace * if we are allowed to. Don't go any further if we * have reached the caller specified maximum depth * or if the user function has specified that the * maximum depth has been reached. */ if ((level < max_depth) && (status != AE_CTRL_DEPTH)) { if (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, 0)) { /* * There is at least one child of this * node, visit the onde */ level++; parent_node = child_node; child_node = 0; } } } else { /* * No more children of this node (Acpi_ns_get_next_node * failed), go back upwards in the namespace tree to * the node's parent. */ level--; child_node = parent_node; parent_node = acpi_ns_get_parent_object (parent_node); } } /* Complete walk, not terminated by user function */ return_ACPI_STATUS (AE_OK); }