/*******************************************************************************
*
* Module Name: nssearch - Namespace search
*
******************************************************************************/
/*
* Copyright (C) 2000 - 2006, R. Byron Moore
* 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.
*/
#include <acpi/acpi.h>
#include <acpi/acnamesp.h>
#define _COMPONENT ACPI_NAMESPACE
ACPI_MODULE_NAME("nssearch")
/* Local prototypes */
static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
struct acpi_namespace_node *node,
acpi_object_type type,
struct acpi_namespace_node **return_node);
/*******************************************************************************
*
* FUNCTION: acpi_ns_search_node
*
* PARAMETERS: target_name - Ascii ACPI name to search for
* Node - Starting node where search will begin
* Type - Object type to match
* return_node - Where the matched Named obj is returned
*
* RETURN: Status
*
* DESCRIPTION: Search a single level of the namespace. Performs a
* simple search of the specified level, and does not add
* entries or search parents.
*
*
* Named object lists are built (and subsequently dumped) in the
* order in which the names are encountered during the namespace load;
*
* All namespace searching is linear in this implementation, but
* could be easily modified to support any improved search
* algorithm. However, the linear search was chosen for simplicity
* and because the trees are small and the other interpreter
* execution overhead is relatively high.
*
******************************************************************************/
acpi_status
acpi_ns_search_node(u32 target_name,
struct acpi_namespace_node *node,
acpi_object_type type,
struct acpi_namespace_node **return_node)
{
struct acpi_namespace_node *next_node;
ACPI_FUNCTION_TRACE("ns_search_node");
#ifdef ACPI_DEBUG_OUTPUT
if (ACPI_LV_NAMES & acpi_dbg_level) {
char *scope_name;
scope_name = acpi_ns_get_external_pathname(node);
if (scope_name) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Searching %s (%p) For [%4.4s] (%s)\n",
scope_name, node, ACPI_CAST_PTR(char,
&target_name),
acpi_ut_get_type_name(type)));
ACPI_FREE(scope_name);
}
}
#endif
/*
* Search for name at this namespace level, which is to say that we
* must search for the name among the children of this object
*/
next_node = node->child;
while (next_node) {
/* Check for match against the name */
if (next_node->name.integer == target_name) {
/* Resolve a control method alias if any */
if (acpi_ns_get_type(next_node) ==
ACPI_TYPE_LOCAL_METHOD_ALIAS) {
next_node =
ACPI_CAST_PTR(struct acpi_namespace_node,
next_node->object);
}
/*
* Found matching entry.
*/
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
ACPI_CAST_PTR(char, &target_name),
acpi_ut_get_type_name(next_node->
type),
next_node,
acpi_ut_get_node_name(node), node));
*return_node = next_node;
return_ACPI_STATUS(AE_OK);
}
/*
* The last entry in the list points back to the parent,
* so a flag is used to indicate the end-of-list
*/
if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
/* Searched entire list, we are done */
break;
}
/* Didn't match name, move on to the next peer object */
next_node = next_node->peer;
}
/* Searched entire namespace level, not found */
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
ACPI_CAST_PTR(char, &target_name),
acpi_ut_get_type_name(type),
acpi_ut_get_node_name(node), node, node->child));
return_ACPI_STATUS(AE_NOT_FOUND);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_search_parent_tree
*
* PARAMETERS: target_name - Ascii ACPI name to search for
* Node - Starting node where search will begin
* Type - Object type to match
* return_node - Where the matched Node is returned
*
* RETURN: Status
*
* DESCRIPTION: Called when a name has not been found in the current namespace
* level. Before adding it or giving up, ACPI scope rules require
* searching enclosing scopes in cases identified by acpi_ns_local().
*
* "A name is located by finding the matching name in the current
* name space, and then in the parent name space. If the parent
* name space does not contain the name, the search continues
* recursively until either the name is found or the name space
* does not have a parent (the root of the name space). This
* indicates that the name is not found" (From ACPI Specification,
* section 5.3)
*
******************************************************************************/
static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
struct acpi_namespace_node *node,
acpi_object_type type,
struct acpi_namespace_node **return_node)
{
acpi_status status;
struct acpi_namespace_node *parent_node;
ACPI_FUNCTION_TRACE("ns_search_parent_tree");
parent_node = acpi_ns_get_parent_node(node);
/*
* If there is no parent (i.e., we are at the root) or type is "local",
* we won't be searching the parent tree.
*/
if (!parent_node) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
ACPI_CAST_PTR(char, &target_name)));
return_ACPI_STATUS(AE_NOT_FOUND);
}
if (acpi_ns_local(type)) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"[%4.4s] type [%s] must be local to this scope (no parent search)\n",
ACPI_CAST_PTR(char, &target_name),
acpi_ut_get_type_name(type)));
return_ACPI_STATUS(AE_NOT_FOUND);
}
/* Search the parent tree */
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Searching parent [%4.4s] for [%4.4s]\n",
acpi_ut_get_node_name(parent_node),
ACPI_CAST_PTR(char, &target_name)));
/*
* Search parents until target is found or we have backed up to the root
*/
while (parent_node) {
/*
* Search parent scope. Use TYPE_ANY because we don't care about the
* object type at this point, we only care about the existence of
* the actual name we are searching for. Typechecking comes later.
*/
status = acpi_ns_search_node(target_name, parent_node,
ACPI_TYPE_ANY, return_node);
if (ACPI_SUCCESS(status)) {
return_ACPI_STATUS(status);
}
/*
* Not found here, go up another level
* (until we reach the root)
*/
parent_node = acpi_ns_get_parent_node(parent_node);
}
/* Not found in parent tree */
return_ACPI_STATUS(AE_NOT_FOUND);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_search_and_enter
*
* PARAMETERS: target_name - Ascii ACPI name to search for (4 chars)
* walk_state - Current state of the walk
* Node - Starting node where search will begin
* interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x.
* Otherwise,search only.
* Type - Object type to match
* Flags - Flags describing the search restrictions
* return_node - Where the Node is returned
*
* RETURN: Status
*
* DESCRIPTION: Search for a name segment in a single namespace level,
* optionally adding it if it is not found. If the passed
* Type is not Any and the type previously stored in the
* entry was Any (i.e. unknown), update the stored type.
*
* In ACPI_IMODE_EXECUTE, search only.
* In other modes, search and add if not found.
*
******************************************************************************/
acpi_status
acpi_ns_search_and_enter(u32 target_name,
struct acpi_walk_state *walk_state,
struct acpi_namespace_node *node,
acpi_interpreter_mode interpreter_mode,
acpi_object_type type,
u32 flags, struct acpi_namespace_node **return_node)
{
acpi_status status;
struct acpi_namespace_node *new_node;
ACPI_FUNCTION_TRACE("ns_search_and_enter");
/* Parameter validation */
if (!node || !target_name || !return_node) {
ACPI_ERROR((AE_INFO,
"Null param: Node %p Name %X return_node %p",
node, target_name, return_node));
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Name must consist of printable characters */
if (!acpi_ut_valid_acpi_name(target_name)) {
ACPI_ERROR((AE_INFO, "Bad character in ACPI Name: %X",
target_name));
return_ACPI_STATUS(AE_BAD_CHARACTER);
}
/* Try to find the name in the namespace level specified by the caller */
*return_node = ACPI_ENTRY_NOT_FOUND;
status = acpi_ns_search_node(target_name, node, type, return_node);
if (status != AE_NOT_FOUND) {
/*
* If we found it AND the request specifies that a find is an error,
* return the error
*/
if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
status = AE_ALREADY_EXISTS;
}
/*
* Either found it or there was an error
* -- finished either way
*/
return_ACPI_STATUS(status);
}
/*
* The name was not found. If we are NOT performing the first pass
* (name entry) of loading the namespace, search the parent tree (all the
* way to the root if necessary.) We don't want to perform the parent
* search when the namespace is actually being loaded. We want to perform
* the search when namespace references are being resolved (load pass 2)
* and during the execution phase.
*/
if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
(flags & ACPI_NS_SEARCH_PARENT)) {
/*
* Not found at this level - search parent tree according to the
* ACPI specification
*/
status =
acpi_ns_search_parent_tree(target_name, node, type,
return_node);
if (ACPI_SUCCESS(status)) {
return_ACPI_STATUS(status);
}
}
/*
* In execute mode, just search, never add names. Exit now.
*/
if (interpreter_mode == ACPI_IMODE_EXECUTE) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"%4.4s Not found in %p [Not adding]\n",
ACPI_CAST_PTR(char, &target_name), node));
return_ACPI_STATUS(AE_NOT_FOUND);
}
/* Create the new named object */
new_node = acpi_ns_create_node(target_name);
if (!new_node) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Install the new object into the parent's list of children */
acpi_ns_install_node(walk_state, node, new_node, type);
*return_node = new_node;
return_ACPI_STATUS(AE_OK);
}
