https://github.com/torvalds/linux
Tip revision: 1c163f4c7b3f621efff9b28a47abb36f7378d783 authored by Linus Torvalds on 03 March 2019, 23:21:29 UTC
Linux 5.0
Linux 5.0
Tip revision: 1c163f4
nsnames.c
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
*
* Module Name: nsnames - Name manipulation and search
*
******************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "amlcode.h"
#include "acnamesp.h"
#define _COMPONENT ACPI_NAMESPACE
ACPI_MODULE_NAME("nsnames")
/* Local Prototypes */
static void acpi_ns_normalize_pathname(char *original_path);
/*******************************************************************************
*
* FUNCTION: acpi_ns_get_external_pathname
*
* PARAMETERS: node - Namespace node whose pathname is needed
*
* RETURN: Pointer to storage containing the fully qualified name of
* the node, In external format (name segments separated by path
* separators.)
*
* DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
* for error and debug statements.
*
******************************************************************************/
char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
{
char *name_buffer;
ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
name_buffer = acpi_ns_get_normalized_pathname(node, FALSE);
return_PTR(name_buffer);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_get_pathname_length
*
* PARAMETERS: node - Namespace node
*
* RETURN: Length of path, including prefix
*
* DESCRIPTION: Get the length of the pathname string for this node
*
******************************************************************************/
acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
{
acpi_size size;
/* Validate the Node */
if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
ACPI_ERROR((AE_INFO,
"Invalid/cached reference target node: %p, descriptor type %d",
node, ACPI_GET_DESCRIPTOR_TYPE(node)));
return (0);
}
size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
return (size);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_handle_to_name
*
* PARAMETERS: target_handle - Handle of named object whose name is
* to be found
* buffer - Where the name is returned
*
* RETURN: Status, Buffer is filled with name if status is AE_OK
*
* DESCRIPTION: Build and return a full namespace name
*
******************************************************************************/
acpi_status
acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
{
acpi_status status;
struct acpi_namespace_node *node;
const char *node_name;
ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
node = acpi_ns_validate_handle(target_handle);
if (!node) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Validate/Allocate/Clear caller buffer */
status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Just copy the ACPI name from the Node and zero terminate it */
node_name = acpi_ut_get_node_name(node);
ACPI_MOVE_NAME(buffer->pointer, node_name);
((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_handle_to_pathname
*
* PARAMETERS: target_handle - Handle of named object whose name is
* to be found
* buffer - Where the pathname is returned
* no_trailing - Remove trailing '_' for each name
* segment
*
* RETURN: Status, Buffer is filled with pathname if status is AE_OK
*
* DESCRIPTION: Build and return a full namespace pathname
*
******************************************************************************/
acpi_status
acpi_ns_handle_to_pathname(acpi_handle target_handle,
struct acpi_buffer *buffer, u8 no_trailing)
{
acpi_status status;
struct acpi_namespace_node *node;
acpi_size required_size;
ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
node = acpi_ns_validate_handle(target_handle);
if (!node) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Determine size required for the caller buffer */
required_size =
acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
if (!required_size) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Validate/Allocate/Clear caller buffer */
status = acpi_ut_initialize_buffer(buffer, required_size);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Build the path in the caller buffer */
(void)acpi_ns_build_normalized_path(node, buffer->pointer,
required_size, no_trailing);
ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
(char *)buffer->pointer, (u32) required_size));
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_build_normalized_path
*
* PARAMETERS: node - Namespace node
* full_path - Where the path name is returned
* path_size - Size of returned path name buffer
* no_trailing - Remove trailing '_' from each name segment
*
* RETURN: Return 1 if the AML path is empty, otherwise returning (length
* of pathname + 1) which means the 'FullPath' contains a trailing
* null.
*
* DESCRIPTION: Build and return a full namespace pathname.
* Note that if the size of 'FullPath' isn't large enough to
* contain the namespace node's path name, the actual required
* buffer length is returned, and it should be greater than
* 'PathSize'. So callers are able to check the returning value
* to determine the buffer size of 'FullPath'.
*
******************************************************************************/
u32
acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
char *full_path, u32 path_size, u8 no_trailing)
{
u32 length = 0, i;
char name[ACPI_NAME_SIZE];
u8 do_no_trailing;
char c, *left, *right;
struct acpi_namespace_node *next_node;
ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
#define ACPI_PATH_PUT8(path, size, byte, length) \
do { \
if ((length) < (size)) \
{ \
(path)[(length)] = (byte); \
} \
(length)++; \
} while (0)
/*
* Make sure the path_size is correct, so that we don't need to
* validate both full_path and path_size.
*/
if (!full_path) {
path_size = 0;
}
if (!node) {
goto build_trailing_null;
}
next_node = node;
while (next_node && next_node != acpi_gbl_root_node) {
if (next_node != node) {
ACPI_PATH_PUT8(full_path, path_size,
AML_DUAL_NAME_PREFIX, length);
}
ACPI_MOVE_32_TO_32(name, &next_node->name);
do_no_trailing = no_trailing;
for (i = 0; i < 4; i++) {
c = name[4 - i - 1];
if (do_no_trailing && c != '_') {
do_no_trailing = FALSE;
}
if (!do_no_trailing) {
ACPI_PATH_PUT8(full_path, path_size, c, length);
}
}
next_node = next_node->parent;
}
ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
/* Reverse the path string */
if (length <= path_size) {
left = full_path;
right = full_path + length - 1;
while (left < right) {
c = *left;
*left++ = *right;
*right-- = c;
}
}
/* Append the trailing null */
build_trailing_null:
ACPI_PATH_PUT8(full_path, path_size, '\0', length);
#undef ACPI_PATH_PUT8
return_UINT32(length);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_get_normalized_pathname
*
* PARAMETERS: node - Namespace node whose pathname is needed
* no_trailing - Remove trailing '_' from each name segment
*
* RETURN: Pointer to storage containing the fully qualified name of
* the node, In external format (name segments separated by path
* separators.)
*
* DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
* for error and debug statements. All trailing '_' will be
* removed from the full pathname if 'NoTrailing' is specified..
*
******************************************************************************/
char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
u8 no_trailing)
{
char *name_buffer;
acpi_size size;
ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
/* Calculate required buffer size based on depth below root */
size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
if (!size) {
return_PTR(NULL);
}
/* Allocate a buffer to be returned to caller */
name_buffer = ACPI_ALLOCATE_ZEROED(size);
if (!name_buffer) {
ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
return_PTR(NULL);
}
/* Build the path in the allocated buffer */
(void)acpi_ns_build_normalized_path(node, name_buffer, size,
no_trailing);
ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES, "%s: Path \"%s\"\n",
ACPI_GET_FUNCTION_NAME, name_buffer));
return_PTR(name_buffer);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_build_prefixed_pathname
*
* PARAMETERS: prefix_scope - Scope/Path that prefixes the internal path
* internal_path - Name or path of the namespace node
*
* RETURN: None
*
* DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
* 1) Path associated with the prefix_scope namespace node
* 2) External path representation of the Internal path
*
******************************************************************************/
char *acpi_ns_build_prefixed_pathname(union acpi_generic_state *prefix_scope,
const char *internal_path)
{
acpi_status status;
char *full_path = NULL;
char *external_path = NULL;
char *prefix_path = NULL;
u32 prefix_path_length = 0;
/* If there is a prefix, get the pathname to it */
if (prefix_scope && prefix_scope->scope.node) {
prefix_path =
acpi_ns_get_normalized_pathname(prefix_scope->scope.node,
TRUE);
if (prefix_path) {
prefix_path_length = strlen(prefix_path);
}
}
status = acpi_ns_externalize_name(ACPI_UINT32_MAX, internal_path,
NULL, &external_path);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
/* Merge the prefix path and the path. 2 is for one dot and trailing null */
full_path =
ACPI_ALLOCATE_ZEROED(prefix_path_length + strlen(external_path) +
2);
if (!full_path) {
goto cleanup;
}
/* Don't merge if the External path is already fully qualified */
if (prefix_path && (*external_path != '\\') && (*external_path != '^')) {
strcat(full_path, prefix_path);
if (prefix_path[1]) {
strcat(full_path, ".");
}
}
acpi_ns_normalize_pathname(external_path);
strcat(full_path, external_path);
cleanup:
if (prefix_path) {
ACPI_FREE(prefix_path);
}
if (external_path) {
ACPI_FREE(external_path);
}
return (full_path);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_normalize_pathname
*
* PARAMETERS: original_path - Path to be normalized, in External format
*
* RETURN: The original path is processed in-place
*
* DESCRIPTION: Remove trailing underscores from each element of a path.
*
* For example: \A___.B___.C___ becomes \A.B.C
*
******************************************************************************/
static void acpi_ns_normalize_pathname(char *original_path)
{
char *input_path = original_path;
char *new_path_buffer;
char *new_path;
u32 i;
/* Allocate a temp buffer in which to construct the new path */
new_path_buffer = ACPI_ALLOCATE_ZEROED(strlen(input_path) + 1);
new_path = new_path_buffer;
if (!new_path_buffer) {
return;
}
/* Special characters may appear at the beginning of the path */
if (*input_path == '\\') {
*new_path = *input_path;
new_path++;
input_path++;
}
while (*input_path == '^') {
*new_path = *input_path;
new_path++;
input_path++;
}
/* Remainder of the path */
while (*input_path) {
/* Do one nameseg at a time */
for (i = 0; (i < ACPI_NAME_SIZE) && *input_path; i++) {
if ((i == 0) || (*input_path != '_')) { /* First char is allowed to be underscore */
*new_path = *input_path;
new_path++;
}
input_path++;
}
/* Dot means that there are more namesegs to come */
if (*input_path == '.') {
*new_path = *input_path;
new_path++;
input_path++;
}
}
*new_path = 0;
strcpy(original_path, new_path_buffer);
ACPI_FREE(new_path_buffer);
}