| // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 |
| /****************************************************************************** |
| * |
| * Module Name: nswalk - Functions for walking the ACPI namespace |
| * |
| * Copyright (C) 2000 - 2022, Intel Corp. |
| * |
| *****************************************************************************/ |
| |
| #include <acpi/acpi.h> |
| #include "accommon.h" |
| #include "acnamesp.h" |
| |
| #define _COMPONENT ACPI_NAMESPACE |
| ACPI_MODULE_NAME("nswalk") |
| |
| /******************************************************************************* |
| * |
| * FUNCTION: acpi_ns_get_next_node |
| * |
| * PARAMETERS: parent_node - Parent node whose children we are |
| * getting |
| * child_node - Previous child that was found. |
| * The NEXT child will be returned |
| * |
| * RETURN: struct 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. |
| * |
| ******************************************************************************/ |
| struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node |
| *parent_node, |
| struct acpi_namespace_node |
| *child_node) |
| { |
| ACPI_FUNCTION_ENTRY(); |
| |
| if (!child_node) { |
| |
| /* It's really the parent's _scope_ that we want */ |
| |
| return (parent_node->child); |
| } |
| |
| /* Otherwise just return the next peer */ |
| |
| return (child_node->peer); |
| } |
| |
| /******************************************************************************* |
| * |
| * FUNCTION: acpi_ns_get_next_node_typed |
| * |
| * 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: struct 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. |
| * |
| ******************************************************************************/ |
| |
| struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type, |
| struct |
| acpi_namespace_node |
| *parent_node, |
| struct |
| acpi_namespace_node |
| *child_node) |
| { |
| struct acpi_namespace_node *next_node = NULL; |
| |
| ACPI_FUNCTION_ENTRY(); |
| |
| next_node = acpi_ns_get_next_node(parent_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 peer node */ |
| |
| next_node = next_node->peer; |
| } |
| |
| /* 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 |
| * flags - Whether to unlock the NS before invoking |
| * the callback routine |
| * descending_callback - Called during tree descent |
| * when an object of "Type" is found |
| * ascending_callback - Called during tree ascent |
| * when an object of "Type" is found |
| * context - Passed to user function(s) above |
| * 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 callback function is called whenever a node that matches |
| * the type parameter is found. If the callback 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 callback function(s) can be |
| * tailored to each task, whether it is a print function, |
| * a compare function, etc. |
| * |
| ******************************************************************************/ |
| |
| acpi_status |
| acpi_ns_walk_namespace(acpi_object_type type, |
| acpi_handle start_node, |
| u32 max_depth, |
| u32 flags, |
| acpi_walk_callback descending_callback, |
| acpi_walk_callback ascending_callback, |
| void *context, void **return_value) |
| { |
| acpi_status status; |
| acpi_status mutex_status; |
| struct acpi_namespace_node *child_node; |
| struct acpi_namespace_node *parent_node; |
| acpi_object_type child_type; |
| u32 level; |
| u8 node_previously_visited = FALSE; |
| |
| ACPI_FUNCTION_TRACE(ns_walk_namespace); |
| |
| /* Special case for the namespace Root Node */ |
| |
| if (start_node == ACPI_ROOT_OBJECT) { |
| start_node = acpi_gbl_root_node; |
| if (!start_node) { |
| return_ACPI_STATUS(AE_NO_NAMESPACE); |
| } |
| } |
| |
| /* Null child means "get first node" */ |
| |
| parent_node = start_node; |
| child_node = acpi_ns_get_next_node(parent_node, NULL); |
| 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 && child_node) { |
| status = AE_OK; |
| |
| /* Found next child, get the type if we are not searching for ANY */ |
| |
| if (type != ACPI_TYPE_ANY) { |
| child_type = child_node->type; |
| } |
| |
| /* |
| * Ignore all temporary namespace nodes (created during control |
| * method execution) unless told otherwise. These temporary nodes |
| * can cause a race condition because they can be deleted during |
| * the execution of the user function (if the namespace is |
| * unlocked before invocation of the user function.) Only the |
| * debugger namespace dump will examine the temporary nodes. |
| */ |
| if ((child_node->flags & ANOBJ_TEMPORARY) && |
| !(flags & ACPI_NS_WALK_TEMP_NODES)) { |
| status = AE_CTRL_DEPTH; |
| } |
| |
| /* Type must match requested type */ |
| |
| else if (child_type == type) { |
| /* |
| * Found a matching node, invoke the user callback function. |
| * Unlock the namespace if flag is set. |
| */ |
| if (flags & ACPI_NS_WALK_UNLOCK) { |
| mutex_status = |
| acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); |
| if (ACPI_FAILURE(mutex_status)) { |
| return_ACPI_STATUS(mutex_status); |
| } |
| } |
| |
| /* |
| * Invoke the user function, either descending, ascending, |
| * or both. |
| */ |
| if (!node_previously_visited) { |
| if (descending_callback) { |
| status = |
| descending_callback(child_node, |
| level, context, |
| return_value); |
| } |
| } else { |
| if (ascending_callback) { |
| status = |
| ascending_callback(child_node, |
| level, context, |
| return_value); |
| } |
| } |
| |
| if (flags & ACPI_NS_WALK_UNLOCK) { |
| mutex_status = |
| acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); |
| if (ACPI_FAILURE(mutex_status)) { |
| return_ACPI_STATUS(mutex_status); |
| } |
| } |
| |
| 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); |
| |
| default: |
| |
| /* All others are valid exceptions */ |
| |
| return_ACPI_STATUS(status); |
| } |
| } |
| |
| /* |
| * 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 (!node_previously_visited && |
| (level < max_depth) && (status != AE_CTRL_DEPTH)) { |
| if (child_node->child) { |
| |
| /* There is at least one child of this node, visit it */ |
| |
| level++; |
| parent_node = child_node; |
| child_node = |
| acpi_ns_get_next_node(parent_node, NULL); |
| continue; |
| } |
| } |
| |
| /* No more children, re-visit this node */ |
| |
| if (!node_previously_visited) { |
| node_previously_visited = TRUE; |
| continue; |
| } |
| |
| /* No more children, visit peers */ |
| |
| child_node = acpi_ns_get_next_node(parent_node, child_node); |
| if (child_node) { |
| node_previously_visited = FALSE; |
| } |
| |
| /* No peers, re-visit parent */ |
| |
| 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 = parent_node->parent; |
| |
| node_previously_visited = TRUE; |
| } |
| } |
| |
| /* Complete walk, not terminated by user function */ |
| |
| return_ACPI_STATUS(AE_OK); |
| } |
