acpi_status
acpi_ns_lookup(union acpi_generic_state *scope_info,
char *pathname,
acpi_object_type type,
acpi_interpreter_mode interpreter_mode,
u32 flags,
struct acpi_walk_state *walk_state,
struct acpi_namespace_node **return_node)
{
acpi_status status;
char *path = pathname;
struct acpi_namespace_node *prefix_node;
struct acpi_namespace_node *current_node = NULL;
struct acpi_namespace_node *this_node = NULL;
u32 num_segments;
u32 num_carats;
acpi_name simple_name;
acpi_object_type type_to_check_for;
acpi_object_type this_search_type;
u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
u32 local_flags;
ACPI_FUNCTION_TRACE(ns_lookup);
if (!return_node) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
*return_node = ACPI_ENTRY_NOT_FOUND;
acpi_gbl_ns_lookup_count++;
if (!acpi_gbl_root_node) {
return_ACPI_STATUS(AE_NO_NAMESPACE);
}
/*
* Get the prefix scope.
* A null scope means use the root scope
*/
if ((!scope_info) || (!scope_info->scope.node)) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Null scope prefix, using root node (%p)\n",
acpi_gbl_root_node));
prefix_node = acpi_gbl_root_node;
} else {
prefix_node = scope_info->scope.node;
if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
ACPI_DESC_TYPE_NAMED) {
ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
prefix_node,
acpi_ut_get_descriptor_name(prefix_node)));
return_ACPI_STATUS(AE_AML_INTERNAL);
}
if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
/*
* This node might not be a actual "scope" node (such as a
* Device/Method, etc.) It could be a Package or other object node.
* Backup up the tree to find the containing scope node.
*/
while (!acpi_ns_opens_scope(prefix_node->type) &&
prefix_node->type != ACPI_TYPE_ANY) {
prefix_node =
acpi_ns_get_parent_node(prefix_node);
}
}
}
/* Save type TBD: may be no longer necessary */
type_to_check_for = type;
/*
* Begin examination of the actual pathname
*/
if (!pathname) {
/* A Null name_path is allowed and refers to the root */
num_segments = 0;
this_node = acpi_gbl_root_node;
path = "";
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Null Pathname (Zero segments), Flags=%X\n",
flags));
} else {
/*
* Name pointer is valid (and must be in internal name format)
*
* Check for scope prefixes:
*
* As represented in the AML stream, a namepath consists of an
* optional scope prefix followed by a name segment part.
*
* If present, the scope prefix is either a Root Prefix (in
* which case the name is fully qualified), or one or more
* Parent Prefixes (in which case the name's scope is relative
* to the current scope).
*/
if (*path == (u8) AML_ROOT_PREFIX) {
/* Pathname is fully qualified, start from the root */
this_node = acpi_gbl_root_node;
search_parent_flag = ACPI_NS_NO_UPSEARCH;
/* Point to name segment part */
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Path is absolute from root [%p]\n",
this_node));
} else {
/* Pathname is relative to current scope, start there */
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Searching relative to prefix scope [%4.4s] (%p)\n",
acpi_ut_get_node_name(prefix_node),
prefix_node));
/*
* Handle multiple Parent Prefixes (carat) by just getting
* the parent node for each prefix instance.
*/
this_node = prefix_node;
num_carats = 0;
while (*path == (u8) AML_PARENT_PREFIX) {
/* Name is fully qualified, no search rules apply */
search_parent_flag = ACPI_NS_NO_UPSEARCH;
/*
* Point past this prefix to the name segment
* part or the next Parent Prefix
*/
path++;
/* Backup to the parent node */
num_carats++;
this_node = acpi_ns_get_parent_node(this_node);
if (!this_node) {
/* Current scope has no parent scope */
ACPI_ERROR((AE_INFO,
"ACPI path has too many parent prefixes (^) - reached beyond root node"));
return_ACPI_STATUS(AE_NOT_FOUND);
}
}
if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Search scope is [%4.4s], path has %d carat(s)\n",
acpi_ut_get_node_name
(this_node), num_carats));
}
}
/*
* Determine the number of ACPI name segments in this pathname.
*
* The segment part consists of either:
* - A Null name segment (0)
* - A dual_name_prefix followed by two 4-byte name segments
* - A multi_name_prefix followed by a byte indicating the
* number of segments and the segments themselves.
* - A single 4-byte name segment
*
* Examine the name prefix opcode, if any, to determine the number of
* segments.
*/
switch (*path) {
case 0:
/*
* Null name after a root or parent prefixes. We already
* have the correct target node and there are no name segments.
*/
num_segments = 0;
type = this_node->type;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Prefix-only Pathname (Zero name segments), Flags=%X\n",
flags));
break;
case AML_DUAL_NAME_PREFIX:
/* More than one name_seg, search rules do not apply */
search_parent_flag = ACPI_NS_NO_UPSEARCH;
/* Two segments, point to first name segment */
num_segments = 2;
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Dual Pathname (2 segments, Flags=%X)\n",
flags));
break;
case AML_MULTI_NAME_PREFIX_OP:
/* More than one name_seg, search rules do not apply */
search_parent_flag = ACPI_NS_NO_UPSEARCH;
/* Extract segment count, point to first name segment */
path++;
num_segments = (u32) (u8) * path;
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Multi Pathname (%d Segments, Flags=%X)\n",
num_segments, flags));
break;
default:
/*
* Not a Null name, no Dual or Multi prefix, hence there is
* only one name segment and Pathname is already pointing to it.
*/
num_segments = 1;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Simple Pathname (1 segment, Flags=%X)\n",
flags));
break;
}
ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
}
/*
* Search namespace for each segment of the name. Loop through and
* verify (or add to the namespace) each name segment.
*
* The object type is significant only at the last name
* segment. (We don't care about the types along the path, only
* the type of the final target object.)
*/
this_search_type = ACPI_TYPE_ANY;
current_node = this_node;
while (num_segments && current_node) {
num_segments--;
if (!num_segments) {
/*
* This is the last segment, enable typechecking
*/
this_search_type = type;
/*
* Only allow automatic parent search (search rules) if the caller
* requested it AND we have a single, non-fully-qualified name_seg
*/
if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
(flags & ACPI_NS_SEARCH_PARENT)) {
local_flags |= ACPI_NS_SEARCH_PARENT;
}
/* Set error flag according to caller */
if (flags & ACPI_NS_ERROR_IF_FOUND) {
local_flags |= ACPI_NS_ERROR_IF_FOUND;
}
}
/* Extract one ACPI name from the front of the pathname */
ACPI_MOVE_32_TO_32(&simple_name, path);
/* Try to find the single (4 character) ACPI name */
status =
acpi_ns_search_and_enter(simple_name, walk_state,
current_node, interpreter_mode,
this_search_type, local_flags,
&this_node);
if (ACPI_FAILURE(status)) {
if (status == AE_NOT_FOUND) {
/* Name not found in ACPI namespace */
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Name [%4.4s] not found in scope [%4.4s] %p\n",
(char *)&simple_name,
(char *)¤t_node->name,
current_node));
}
*return_node = this_node;
return_ACPI_STATUS(status);
}
/* More segments to follow? */
if (num_segments > 0) {
/*
* If we have an alias to an object that opens a scope (such as a
* device or processor), we need to dereference the alias here so that
* we can access any children of the original node (via the remaining
* segments).
*/
if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
if (!this_node->object) {
return_ACPI_STATUS(AE_NOT_EXIST);
}
if (acpi_ns_opens_scope
(((struct acpi_namespace_node *)this_node->
object)->type)) {
this_node =
(struct acpi_namespace_node *)
this_node->object;
}
}
}
/* Special handling for the last segment (num_segments == 0) */
else {
/*
* Sanity typecheck of the target object:
*
* If 1) This is the last segment (num_segments == 0)
* 2) And we are looking for a specific type
* (Not checking for TYPE_ANY)
* 3) Which is not an alias
* 4) Which is not a local type (TYPE_SCOPE)
* 5) And the type of target object is known (not TYPE_ANY)
* 6) And target object does not match what we are looking for
*
* Then we have a type mismatch. Just warn and ignore it.
*/
if ((type_to_check_for != ACPI_TYPE_ANY) &&
(type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
(type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
&& (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
&& (this_node->type != ACPI_TYPE_ANY)
&& (this_node->type != type_to_check_for)) {
/* Complain about a type mismatch */
ACPI_WARNING((AE_INFO,
"NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
ACPI_CAST_PTR(char, &simple_name),
acpi_ut_get_type_name(this_node->
type),
acpi_ut_get_type_name
(type_to_check_for)));
}
/*
* If this is the last name segment and we are not looking for a
* specific type, but the type of found object is known, use that type
* to (later) see if it opens a scope.
*/
if (type == ACPI_TYPE_ANY) {
type = this_node->type;
}
}
/* Point to next name segment and make this node current */
path += ACPI_NAME_SIZE;
current_node = this_node;
}
acpi_status
acpi_ns_lookup(union acpi_generic_state *scope_info,
char *pathname,
acpi_object_type type,
acpi_interpreter_mode interpreter_mode,
u32 flags,
struct acpi_walk_state *walk_state,
struct acpi_namespace_node **return_node)
{
acpi_status status;
char *path = pathname;
struct acpi_namespace_node *prefix_node;
struct acpi_namespace_node *current_node = NULL;
struct acpi_namespace_node *this_node = NULL;
u32 num_segments;
u32 num_carats;
acpi_name simple_name;
acpi_object_type type_to_check_for;
acpi_object_type this_search_type;
u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
u32 local_flags;
ACPI_FUNCTION_TRACE(ns_lookup);
if (!return_node) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
*return_node = ACPI_ENTRY_NOT_FOUND;
acpi_gbl_ns_lookup_count++;
if (!acpi_gbl_root_node) {
return_ACPI_STATUS(AE_NO_NAMESPACE);
}
if ((!scope_info) || (!scope_info->scope.node)) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Null scope prefix, using root node (%p)\n",
acpi_gbl_root_node));
prefix_node = acpi_gbl_root_node;
} else {
prefix_node = scope_info->scope.node;
if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
ACPI_DESC_TYPE_NAMED) {
ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
prefix_node,
acpi_ut_get_descriptor_name(prefix_node)));
return_ACPI_STATUS(AE_AML_INTERNAL);
}
if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
while (!acpi_ns_opens_scope(prefix_node->type) &&
prefix_node->type != ACPI_TYPE_ANY) {
prefix_node = prefix_node->parent;
}
}
}
type_to_check_for = type;
if (!pathname) {
num_segments = 0;
this_node = acpi_gbl_root_node;
path = "";
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Null Pathname (Zero segments), Flags=%X\n",
flags));
} else {
if (*path == (u8) AML_ROOT_PREFIX) {
this_node = acpi_gbl_root_node;
search_parent_flag = ACPI_NS_NO_UPSEARCH;
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Path is absolute from root [%p]\n",
this_node));
} else {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Searching relative to prefix scope [%4.4s] (%p)\n",
acpi_ut_get_node_name(prefix_node),
prefix_node));
this_node = prefix_node;
num_carats = 0;
while (*path == (u8) AML_PARENT_PREFIX) {
search_parent_flag = ACPI_NS_NO_UPSEARCH;
path++;
num_carats++;
this_node = this_node->parent;
if (!this_node) {
ACPI_ERROR((AE_INFO,
"ACPI path has too many parent prefixes (^) "
"- reached beyond root node"));
return_ACPI_STATUS(AE_NOT_FOUND);
}
}
if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Search scope is [%4.4s], path has %u carat(s)\n",
acpi_ut_get_node_name
(this_node), num_carats));
}
}
switch (*path) {
case 0:
num_segments = 0;
type = this_node->type;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Prefix-only Pathname (Zero name segments), Flags=%X\n",
flags));
break;
case AML_DUAL_NAME_PREFIX:
search_parent_flag = ACPI_NS_NO_UPSEARCH;
num_segments = 2;
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Dual Pathname (2 segments, Flags=%X)\n",
flags));
break;
case AML_MULTI_NAME_PREFIX_OP:
search_parent_flag = ACPI_NS_NO_UPSEARCH;
path++;
num_segments = (u32) (u8) * path;
path++;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Multi Pathname (%u Segments, Flags=%X)\n",
num_segments, flags));
break;
default:
num_segments = 1;
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Simple Pathname (1 segment, Flags=%X)\n",
flags));
break;
}
ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
}
this_search_type = ACPI_TYPE_ANY;
current_node = this_node;
while (num_segments && current_node) {
num_segments--;
if (!num_segments) {
this_search_type = type;
if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
(flags & ACPI_NS_SEARCH_PARENT)) {
local_flags |= ACPI_NS_SEARCH_PARENT;
}
if (flags & ACPI_NS_ERROR_IF_FOUND) {
local_flags |= ACPI_NS_ERROR_IF_FOUND;
}
}
ACPI_MOVE_32_TO_32(&simple_name, path);
status =
acpi_ns_search_and_enter(simple_name, walk_state,
current_node, interpreter_mode,
this_search_type, local_flags,
&this_node);
if (ACPI_FAILURE(status)) {
if (status == AE_NOT_FOUND) {
ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
"Name [%4.4s] not found in scope [%4.4s] %p\n",
(char *)&simple_name,
(char *)¤t_node->name,
current_node));
}
*return_node = this_node;
return_ACPI_STATUS(status);
}
if (num_segments > 0) {
if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
if (!this_node->object) {
return_ACPI_STATUS(AE_NOT_EXIST);
}
if (acpi_ns_opens_scope
(((struct acpi_namespace_node *)
this_node->object)->type)) {
this_node =
(struct acpi_namespace_node *)
this_node->object;
}
}
}
else {
if ((type_to_check_for != ACPI_TYPE_ANY) &&
(type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
(type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
&& (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
&& (this_node->type != ACPI_TYPE_ANY)
&& (this_node->type != type_to_check_for)) {
ACPI_WARNING((AE_INFO,
"NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
ACPI_CAST_PTR(char, &simple_name),
acpi_ut_get_type_name(this_node->
type),
acpi_ut_get_type_name
(type_to_check_for)));
}
if (type == ACPI_TYPE_ANY) {
type = this_node->type;
}
}
path += ACPI_NAME_SIZE;
current_node = this_node;
}
