1/******************************************************************************* 2 * 3 * Module Name: nssearch - Namespace search 4 * 5 ******************************************************************************/ 6 7/* 8 * Copyright (C) 2000 - 2007, R. Byron Moore 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 <acpi/acnamesp.h> 46 47#define _COMPONENT ACPI_NAMESPACE 48ACPI_MODULE_NAME("nssearch") 49 50/* Local prototypes */ 51static acpi_status 52acpi_ns_search_parent_tree(u32 target_name, 53 struct acpi_namespace_node *node, 54 acpi_object_type type, 55 struct acpi_namespace_node **return_node); 56 57/******************************************************************************* 58 * 59 * FUNCTION: acpi_ns_search_one_scope 60 * 61 * PARAMETERS: target_name - Ascii ACPI name to search for 62 * parent_node - Starting node where search will begin 63 * Type - Object type to match 64 * return_node - Where the matched Named obj is returned 65 * 66 * RETURN: Status 67 * 68 * DESCRIPTION: Search a single level of the namespace. Performs a 69 * simple search of the specified level, and does not add 70 * entries or search parents. 71 * 72 * 73 * Named object lists are built (and subsequently dumped) in the 74 * order in which the names are encountered during the namespace load; 75 * 76 * All namespace searching is linear in this implementation, but 77 * could be easily modified to support any improved search 78 * algorithm. However, the linear search was chosen for simplicity 79 * and because the trees are small and the other interpreter 80 * execution overhead is relatively high. 81 * 82 * Note: CPU execution analysis has shown that the AML interpreter spends 83 * a very small percentage of its time searching the namespace. Therefore, 84 * the linear search seems to be sufficient, as there would seem to be 85 * little value in improving the search. 86 * 87 ******************************************************************************/ 88 89acpi_status 90acpi_ns_search_one_scope(u32 target_name, 91 struct acpi_namespace_node *parent_node, 92 acpi_object_type type, 93 struct acpi_namespace_node **return_node) 94{ 95 struct acpi_namespace_node *node; 96 97 ACPI_FUNCTION_TRACE(ns_search_one_scope); 98 99#ifdef ACPI_DEBUG_OUTPUT 100 if (ACPI_LV_NAMES & acpi_dbg_level) { 101 char *scope_name; 102 103 scope_name = acpi_ns_get_external_pathname(parent_node); 104 if (scope_name) { 105 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 106 "Searching %s (%p) For [%4.4s] (%s)\n", 107 scope_name, parent_node, 108 ACPI_CAST_PTR(char, &target_name), 109 acpi_ut_get_type_name(type))); 110 111 ACPI_FREE(scope_name); 112 } 113 } 114#endif 115 116 /* 117 * Search for name at this namespace level, which is to say that we 118 * must search for the name among the children of this object 119 */ 120 node = parent_node->child; 121 while (node) { 122 123 /* Check for match against the name */ 124 125 if (node->name.integer == target_name) { 126 127 /* Resolve a control method alias if any */ 128 129 if (acpi_ns_get_type(node) == 130 ACPI_TYPE_LOCAL_METHOD_ALIAS) { 131 node = 132 ACPI_CAST_PTR(struct acpi_namespace_node, 133 node->object); 134 } 135 136 /* Found matching entry */ 137 138 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 139 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n", 140 ACPI_CAST_PTR(char, &target_name), 141 acpi_ut_get_type_name(node->type), 142 node, 143 acpi_ut_get_node_name(parent_node), 144 parent_node)); 145 146 *return_node = node; 147 return_ACPI_STATUS(AE_OK); 148 } 149 150 /* 151 * The last entry in the list points back to the parent, 152 * so a flag is used to indicate the end-of-list 153 */ 154 if (node->flags & ANOBJ_END_OF_PEER_LIST) { 155 156 /* Searched entire list, we are done */ 157 158 break; 159 } 160 161 /* Didn't match name, move on to the next peer object */ 162 163 node = node->peer; 164 } 165 166 /* Searched entire namespace level, not found */ 167 168 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 169 "Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n", 170 ACPI_CAST_PTR(char, &target_name), 171 acpi_ut_get_type_name(type), 172 acpi_ut_get_node_name(parent_node), parent_node, 173 parent_node->child)); 174 175 return_ACPI_STATUS(AE_NOT_FOUND); 176} 177 178/******************************************************************************* 179 * 180 * FUNCTION: acpi_ns_search_parent_tree 181 * 182 * PARAMETERS: target_name - Ascii ACPI name to search for 183 * Node - Starting node where search will begin 184 * Type - Object type to match 185 * return_node - Where the matched Node is returned 186 * 187 * RETURN: Status 188 * 189 * DESCRIPTION: Called when a name has not been found in the current namespace 190 * level. Before adding it or giving up, ACPI scope rules require 191 * searching enclosing scopes in cases identified by acpi_ns_local(). 192 * 193 * "A name is located by finding the matching name in the current 194 * name space, and then in the parent name space. If the parent 195 * name space does not contain the name, the search continues 196 * recursively until either the name is found or the name space 197 * does not have a parent (the root of the name space). This 198 * indicates that the name is not found" (From ACPI Specification, 199 * section 5.3) 200 * 201 ******************************************************************************/ 202 203static acpi_status 204acpi_ns_search_parent_tree(u32 target_name, 205 struct acpi_namespace_node *node, 206 acpi_object_type type, 207 struct acpi_namespace_node **return_node) 208{ 209 acpi_status status; 210 struct acpi_namespace_node *parent_node; 211 212 ACPI_FUNCTION_TRACE(ns_search_parent_tree); 213 214 parent_node = acpi_ns_get_parent_node(node); 215 216 /* 217 * If there is no parent (i.e., we are at the root) or type is "local", 218 * we won't be searching the parent tree. 219 */ 220 if (!parent_node) { 221 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n", 222 ACPI_CAST_PTR(char, &target_name))); 223 return_ACPI_STATUS(AE_NOT_FOUND); 224 } 225 226 if (acpi_ns_local(type)) { 227 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 228 "[%4.4s] type [%s] must be local to this scope (no parent search)\n", 229 ACPI_CAST_PTR(char, &target_name), 230 acpi_ut_get_type_name(type))); 231 return_ACPI_STATUS(AE_NOT_FOUND); 232 } 233 234 /* Search the parent tree */ 235 236 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 237 "Searching parent [%4.4s] for [%4.4s]\n", 238 acpi_ut_get_node_name(parent_node), 239 ACPI_CAST_PTR(char, &target_name))); 240 241 /* 242 * Search parents until target is found or we have backed up to the root 243 */ 244 while (parent_node) { 245 /* 246 * Search parent scope. Use TYPE_ANY because we don't care about the 247 * object type at this point, we only care about the existence of 248 * the actual name we are searching for. Typechecking comes later. 249 */ 250 status = 251 acpi_ns_search_one_scope(target_name, parent_node, 252 ACPI_TYPE_ANY, return_node); 253 if (ACPI_SUCCESS(status)) { 254 return_ACPI_STATUS(status); 255 } 256 257 /* Not found here, go up another level (until we reach the root) */ 258 259 parent_node = acpi_ns_get_parent_node(parent_node); 260 } 261 262 /* Not found in parent tree */ 263 264 return_ACPI_STATUS(AE_NOT_FOUND); 265} 266 267/******************************************************************************* 268 * 269 * FUNCTION: acpi_ns_search_and_enter 270 * 271 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars) 272 * walk_state - Current state of the walk 273 * Node - Starting node where search will begin 274 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x. 275 * Otherwise,search only. 276 * Type - Object type to match 277 * Flags - Flags describing the search restrictions 278 * return_node - Where the Node is returned 279 * 280 * RETURN: Status 281 * 282 * DESCRIPTION: Search for a name segment in a single namespace level, 283 * optionally adding it if it is not found. If the passed 284 * Type is not Any and the type previously stored in the 285 * entry was Any (i.e. unknown), update the stored type. 286 * 287 * In ACPI_IMODE_EXECUTE, search only. 288 * In other modes, search and add if not found. 289 * 290 ******************************************************************************/ 291 292acpi_status 293acpi_ns_search_and_enter(u32 target_name, 294 struct acpi_walk_state *walk_state, 295 struct acpi_namespace_node *node, 296 acpi_interpreter_mode interpreter_mode, 297 acpi_object_type type, 298 u32 flags, struct acpi_namespace_node **return_node) 299{ 300 acpi_status status; 301 struct acpi_namespace_node *new_node; 302 303 ACPI_FUNCTION_TRACE(ns_search_and_enter); 304 305 /* Parameter validation */ 306 307 if (!node || !target_name || !return_node) { 308 ACPI_ERROR((AE_INFO, 309 "Null parameter: Node %p Name %X ReturnNode %p", 310 node, target_name, return_node)); 311 return_ACPI_STATUS(AE_BAD_PARAMETER); 312 } 313 314 /* 315 * Name must consist of valid ACPI characters. We will repair the name if 316 * necessary because we don't want to abort because of this, but we want 317 * all namespace names to be printable. A warning message is appropriate. 318 * 319 * This issue came up because there are in fact machines that exhibit 320 * this problem, and we want to be able to enable ACPI support for them, 321 * even though there are a few bad names. 322 */ 323 if (!acpi_ut_valid_acpi_name(target_name)) { 324 target_name = 325 acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name)); 326 327 /* Report warning only if in strict mode or debug mode */ 328 329 if (!acpi_gbl_enable_interpreter_slack) { 330 ACPI_WARNING((AE_INFO, 331 "Found bad character(s) in name, repaired: [%4.4s]\n", 332 ACPI_CAST_PTR(char, &target_name))); 333 } else { 334 ACPI_DEBUG_PRINT((ACPI_DB_WARN, 335 "Found bad character(s) in name, repaired: [%4.4s]\n", 336 ACPI_CAST_PTR(char, &target_name))); 337 } 338 } 339 340 /* Try to find the name in the namespace level specified by the caller */ 341 342 *return_node = ACPI_ENTRY_NOT_FOUND; 343 status = acpi_ns_search_one_scope(target_name, node, type, return_node); 344 if (status != AE_NOT_FOUND) { 345 /* 346 * If we found it AND the request specifies that a find is an error, 347 * return the error 348 */ 349 if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) { 350 status = AE_ALREADY_EXISTS; 351 } 352 353 /* Either found it or there was an error: finished either way */ 354 355 return_ACPI_STATUS(status); 356 } 357 358 /* 359 * The name was not found. If we are NOT performing the first pass 360 * (name entry) of loading the namespace, search the parent tree (all the 361 * way to the root if necessary.) We don't want to perform the parent 362 * search when the namespace is actually being loaded. We want to perform 363 * the search when namespace references are being resolved (load pass 2) 364 * and during the execution phase. 365 */ 366 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) && 367 (flags & ACPI_NS_SEARCH_PARENT)) { 368 /* 369 * Not found at this level - search parent tree according to the 370 * ACPI specification 371 */ 372 status = 373 acpi_ns_search_parent_tree(target_name, node, type, 374 return_node); 375 if (ACPI_SUCCESS(status)) { 376 return_ACPI_STATUS(status); 377 } 378 } 379 380 /* In execute mode, just search, never add names. Exit now */ 381 382 if (interpreter_mode == ACPI_IMODE_EXECUTE) { 383 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 384 "%4.4s Not found in %p [Not adding]\n", 385 ACPI_CAST_PTR(char, &target_name), node)); 386 387 return_ACPI_STATUS(AE_NOT_FOUND); 388 } 389 390 /* Create the new named object */ 391 392 new_node = acpi_ns_create_node(target_name); 393 if (!new_node) { 394 return_ACPI_STATUS(AE_NO_MEMORY); 395 } 396#ifdef ACPI_ASL_COMPILER 397 /* 398 * Node is an object defined by an External() statement 399 */ 400 if (flags & ACPI_NS_EXTERNAL) { 401 new_node->flags |= ANOBJ_IS_EXTERNAL; 402 } 403#endif 404 405 if (flags & ACPI_NS_TEMPORARY) { 406 new_node->flags |= ANOBJ_TEMPORARY; 407 } 408 409 /* Install the new object into the parent's list of children */ 410 411 acpi_ns_install_node(walk_state, node, new_node, type); 412 *return_node = new_node; 413 return_ACPI_STATUS(AE_OK); 414} 415