// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
*
* Module Name: nssearch - Namespace search
*
******************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#ifdef ACPI_ASL_COMPILER
#include "amlcode.h"
#endif
#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_one_scope
*
* PARAMETERS: target_name - Ascii ACPI name to search for
* parent_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.
*
* Note: CPU execution analysis has shown that the AML interpreter spends
* a very small percentage of its time searching the namespace. Therefore,
* the linear search seems to be sufficient, as there would seem to be
* little value in improving the search.
*
******************************************************************************/
acpi_status
acpi_ns_search_one_scope(u32 target_name,
struct acpi_namespace_node *parent_node,
acpi_object_type type,
struct acpi_namespace_node **return_node)
{
struct acpi_namespace_node *node;
ACPI_FUNCTION_TRACE(ns_search_one_scope);
#ifdef ACPI_DEBUG_OUTPUT
if (ACPI_LV_NAMES & acpi_dbg_level) {
char *scope_name;
scope_name = acpi_ns_get_normalized_pathname(parent_node,
TRUE);
if (scope_name) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Searching %s (%p) For [%4.4s] (%s)\n",
scope_name, parent_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
*/
node = parent_node->child;
while (node) {
/* Check for match against the name */
if (node->name.integer == target_name) {
/* Resolve a control method alias if any */
if (acpi_ns_get_type(node) ==
ACPI_TYPE_LOCAL_METHOD_ALIAS) {
node =
ACPI_CAST_PTR(
struct acpi_namespace_node,
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(node->type),
node,
acpi_ut_get_node_name(parent_node),
parent_node));
*return_node = node;
return_ACPI_STATUS(AE_OK);
}
/* Didn't match name, move on to the next peer object */
node = 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(parent_node), parent_node,
parent_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 = node->parent;
/*
* 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_one_scope(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 = parent_node->parent;
}
/* 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 parameter: Node %p Name 0x%X ReturnNode %p",
node, target_name, return_node));
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/*
* Name must consist of valid ACPI characters. We will repair the name if
* necessary because we don't want to abort because of this, but we want
* all namespace names to be printable. A warning message is appropriate.
*
* This issue came up because there are in fact machines that exhibit
* this problem, and we want to be able to enable ACPI support for them,
* even though there are a few bad names.
*/
acpi_ut_repair_name(ACPI_CAST_PTR(
char, &target_name));
/* Try to find the name in the namespace level specified by the caller */
*return_node = ACPI_ENTRY_NOT_FOUND;
status = acpi_ns_search_one_scope(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) {
/* The node was found in the namespace */
/*
* If the namespace override feature is enabled for this node,
* delete any existing attached sub-object and make the node
* look like a new node that is owned by the override table.
*/
if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Namespace override: %4.4s pass %u type %X Owner %X\n",
ACPI_CAST_PTR(
char,
&target_name),
interpreter_mode,
(*return_node)->type,
walk_state->owner_id));
acpi_ns_delete_children(*return_node);
if (acpi_gbl_runtime_namespace_override) {
acpi_ut_remove_reference((*return_node)->object);
(*return_node)->object = NULL;
(*return_node)->owner_id =
walk_state->owner_id;
}
else {
acpi_ns_remove_node(*return_node);
*return_node = ACPI_ENTRY_NOT_FOUND;
}
}
/* Return an error if we don't expect to find the object */
else if (flags & ACPI_NS_ERROR_IF_FOUND) {
status = AE_ALREADY_EXISTS;
}
}
#ifdef ACPI_ASL_COMPILER
if (*return_node && (*return_node)->type == ACPI_TYPE_ANY) {
(*return_node)->flags |= ANOBJ_IS_EXTERNAL;
}
#endif
/* 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);
}
#ifdef ACPI_ASL_COMPILER
/* Node is an object defined by an External() statement */
if (flags & ACPI_NS_EXTERNAL ||
(walk_state && walk_state->opcode == AML_SCOPE_OP)) {
new_node->flags |= ANOBJ_IS_EXTERNAL;
}
#endif
if (flags & ACPI_NS_TEMPORARY) {
new_node->flags |= ANOBJ_TEMPORARY;
}
/* 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);
}
