WSL2-Linux-Kernel/drivers/acpi/namespace/nsnames.c

242 строки
7.3 KiB
C

/*******************************************************************************
*
* Module Name: nsnames - Name manipulation and search
*
******************************************************************************/
/*
* Copyright (C) 2000 - 2007, 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/amlcode.h>
#include <acpi/acnamesp.h>
#define _COMPONENT ACPI_NAMESPACE
ACPI_MODULE_NAME("nsnames")
/*******************************************************************************
*
* FUNCTION: acpi_ns_build_external_path
*
* PARAMETERS: Node - NS node whose pathname is needed
* Size - Size of the pathname
* *name_buffer - Where to return the pathname
*
* RETURN: Places the pathname into the name_buffer, in external format
* (name segments separated by path separators)
*
* DESCRIPTION: Generate a full pathaname
*
******************************************************************************/
void
acpi_ns_build_external_path(struct acpi_namespace_node *node,
acpi_size size, char *name_buffer)
{
acpi_size index;
struct acpi_namespace_node *parent_node;
ACPI_FUNCTION_ENTRY();
/* Special case for root */
index = size - 1;
if (index < ACPI_NAME_SIZE) {
name_buffer[0] = AML_ROOT_PREFIX;
name_buffer[1] = 0;
return;
}
/* Store terminator byte, then build name backwards */
parent_node = node;
name_buffer[index] = 0;
while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) {
index -= ACPI_NAME_SIZE;
/* Put the name into the buffer */
ACPI_MOVE_32_TO_32((name_buffer + index), &parent_node->name);
parent_node = acpi_ns_get_parent_node(parent_node);
/* Prefix name with the path separator */
index--;
name_buffer[index] = ACPI_PATH_SEPARATOR;
}
/* Overwrite final separator with the root prefix character */
name_buffer[index] = AML_ROOT_PREFIX;
if (index != 0) {
ACPI_ERROR((AE_INFO,
"Could not construct pathname; index=%X, size=%X, Path=%s",
(u32) index, (u32) size, &name_buffer[size]));
}
return;
}
#ifdef ACPI_DEBUG_OUTPUT
/*******************************************************************************
*
* 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 for debug printing in acpi_ns_search_table().
*
******************************************************************************/
char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
{
char *name_buffer;
acpi_size size;
ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
/* Calculate required buffer size based on depth below root */
size = acpi_ns_get_pathname_length(node);
/* Allocate a buffer to be returned to caller */
name_buffer = ACPI_ALLOCATE_ZEROED(size);
if (!name_buffer) {
ACPI_ERROR((AE_INFO, "Allocation failure"));
return_PTR(NULL);
}
/* Build the path in the allocated buffer */
acpi_ns_build_external_path(node, size, name_buffer);
return_PTR(name_buffer);
}
#endif
/*******************************************************************************
*
* 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;
struct acpi_namespace_node *next_node;
ACPI_FUNCTION_ENTRY();
/*
* Compute length of pathname as 5 * number of name segments.
* Go back up the parent tree to the root
*/
size = 0;
next_node = node;
while (next_node && (next_node != acpi_gbl_root_node)) {
size += ACPI_PATH_SEGMENT_LENGTH;
next_node = acpi_ns_get_parent_node(next_node);
}
if (!size) {
size = 1; /* Root node case */
}
return (size + 1); /* +1 for null string terminator */
}
/*******************************************************************************
*
* 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
*
* 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)
{
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_map_handle_to_node(target_handle);
if (!node) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Determine size required for the caller buffer */
required_size = acpi_ns_get_pathname_length(node);
/* 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 */
acpi_ns_build_external_path(node, required_size, buffer->pointer);
ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
(char *)buffer->pointer, (u32) required_size));
return_ACPI_STATUS(AE_OK);
}