1 /******************************************************************************* 2 * 3 * Module Name: nsnames - Name manipulation and search 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2015, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <acpi/acpi.h> 45 #include "accommon.h" 46 #include "amlcode.h" 47 #include "acnamesp.h" 48 49 #define _COMPONENT ACPI_NAMESPACE 50 ACPI_MODULE_NAME("nsnames") 51 52 /******************************************************************************* 53 * 54 * FUNCTION: acpi_ns_build_external_path 55 * 56 * PARAMETERS: node - NS node whose pathname is needed 57 * size - Size of the pathname 58 * *name_buffer - Where to return the pathname 59 * 60 * RETURN: Status 61 * Places the pathname into the name_buffer, in external format 62 * (name segments separated by path separators) 63 * 64 * DESCRIPTION: Generate a full pathaname 65 * 66 ******************************************************************************/ 67 acpi_status 68 acpi_ns_build_external_path(struct acpi_namespace_node *node, 69 acpi_size size, char *name_buffer) 70 { 71 acpi_size index; 72 struct acpi_namespace_node *parent_node; 73 74 ACPI_FUNCTION_ENTRY(); 75 76 /* Special case for root */ 77 78 index = size - 1; 79 if (index < ACPI_NAME_SIZE) { 80 name_buffer[0] = AML_ROOT_PREFIX; 81 name_buffer[1] = 0; 82 return (AE_OK); 83 } 84 85 /* Store terminator byte, then build name backwards */ 86 87 parent_node = node; 88 name_buffer[index] = 0; 89 90 while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) { 91 index -= ACPI_NAME_SIZE; 92 93 /* Put the name into the buffer */ 94 95 ACPI_MOVE_32_TO_32((name_buffer + index), &parent_node->name); 96 parent_node = parent_node->parent; 97 98 /* Prefix name with the path separator */ 99 100 index--; 101 name_buffer[index] = ACPI_PATH_SEPARATOR; 102 } 103 104 /* Overwrite final separator with the root prefix character */ 105 106 name_buffer[index] = AML_ROOT_PREFIX; 107 108 if (index != 0) { 109 ACPI_ERROR((AE_INFO, 110 "Could not construct external pathname; index=%u, size=%u, Path=%s", 111 (u32) index, (u32) size, &name_buffer[size])); 112 113 return (AE_BAD_PARAMETER); 114 } 115 116 return (AE_OK); 117 } 118 119 /******************************************************************************* 120 * 121 * FUNCTION: acpi_ns_get_external_pathname 122 * 123 * PARAMETERS: node - Namespace node whose pathname is needed 124 * 125 * RETURN: Pointer to storage containing the fully qualified name of 126 * the node, In external format (name segments separated by path 127 * separators.) 128 * 129 * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually 130 * for error and debug statements. 131 * 132 ******************************************************************************/ 133 134 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node) 135 { 136 acpi_status status; 137 char *name_buffer; 138 acpi_size size; 139 140 ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node); 141 142 /* Calculate required buffer size based on depth below root */ 143 144 size = acpi_ns_get_pathname_length(node); 145 if (!size) { 146 return_PTR(NULL); 147 } 148 149 /* Allocate a buffer to be returned to caller */ 150 151 name_buffer = ACPI_ALLOCATE_ZEROED(size); 152 if (!name_buffer) { 153 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size)); 154 return_PTR(NULL); 155 } 156 157 /* Build the path in the allocated buffer */ 158 159 status = acpi_ns_build_external_path(node, size, name_buffer); 160 if (ACPI_FAILURE(status)) { 161 ACPI_FREE(name_buffer); 162 return_PTR(NULL); 163 } 164 165 return_PTR(name_buffer); 166 } 167 168 /******************************************************************************* 169 * 170 * FUNCTION: acpi_ns_get_pathname_length 171 * 172 * PARAMETERS: node - Namespace node 173 * 174 * RETURN: Length of path, including prefix 175 * 176 * DESCRIPTION: Get the length of the pathname string for this node 177 * 178 ******************************************************************************/ 179 180 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node) 181 { 182 acpi_size size; 183 struct acpi_namespace_node *next_node; 184 185 ACPI_FUNCTION_ENTRY(); 186 187 /* 188 * Compute length of pathname as 5 * number of name segments. 189 * Go back up the parent tree to the root 190 */ 191 size = 0; 192 next_node = node; 193 194 while (next_node && (next_node != acpi_gbl_root_node)) { 195 if (ACPI_GET_DESCRIPTOR_TYPE(next_node) != ACPI_DESC_TYPE_NAMED) { 196 ACPI_ERROR((AE_INFO, 197 "Invalid Namespace Node (%p) while traversing namespace", 198 next_node)); 199 return (0); 200 } 201 size += ACPI_PATH_SEGMENT_LENGTH; 202 next_node = next_node->parent; 203 } 204 205 if (!size) { 206 size = 1; /* Root node case */ 207 } 208 209 return (size + 1); /* +1 for null string terminator */ 210 } 211 212 /******************************************************************************* 213 * 214 * FUNCTION: acpi_ns_handle_to_pathname 215 * 216 * PARAMETERS: target_handle - Handle of named object whose name is 217 * to be found 218 * buffer - Where the pathname is returned 219 * 220 * RETURN: Status, Buffer is filled with pathname if status is AE_OK 221 * 222 * DESCRIPTION: Build and return a full namespace pathname 223 * 224 ******************************************************************************/ 225 226 acpi_status 227 acpi_ns_handle_to_pathname(acpi_handle target_handle, 228 struct acpi_buffer * buffer) 229 { 230 acpi_status status; 231 struct acpi_namespace_node *node; 232 acpi_size required_size; 233 234 ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle); 235 236 node = acpi_ns_validate_handle(target_handle); 237 if (!node) { 238 return_ACPI_STATUS(AE_BAD_PARAMETER); 239 } 240 241 /* Determine size required for the caller buffer */ 242 243 required_size = acpi_ns_get_pathname_length(node); 244 if (!required_size) { 245 return_ACPI_STATUS(AE_BAD_PARAMETER); 246 } 247 248 /* Validate/Allocate/Clear caller buffer */ 249 250 status = acpi_ut_initialize_buffer(buffer, required_size); 251 if (ACPI_FAILURE(status)) { 252 return_ACPI_STATUS(status); 253 } 254 255 /* Build the path in the caller buffer */ 256 257 status = 258 acpi_ns_build_external_path(node, required_size, buffer->pointer); 259 if (ACPI_FAILURE(status)) { 260 return_ACPI_STATUS(status); 261 } 262 263 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n", 264 (char *)buffer->pointer, (u32) required_size)); 265 return_ACPI_STATUS(AE_OK); 266 } 267