1 /******************************************************************************* 2 * 3 * Module Name: nssearch - Namespace search 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2008, 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 "acnamesp.h" 47 48 #define _COMPONENT ACPI_NAMESPACE 49 ACPI_MODULE_NAME("nssearch") 50 51 /* Local prototypes */ 52 static acpi_status 53 acpi_ns_search_parent_tree(u32 target_name, 54 struct acpi_namespace_node *node, 55 acpi_object_type type, 56 struct acpi_namespace_node **return_node); 57 58 /******************************************************************************* 59 * 60 * FUNCTION: acpi_ns_search_one_scope 61 * 62 * PARAMETERS: target_name - Ascii ACPI name to search for 63 * parent_node - Starting node where search will begin 64 * Type - Object type to match 65 * return_node - Where the matched Named obj is returned 66 * 67 * RETURN: Status 68 * 69 * DESCRIPTION: Search a single level of the namespace. Performs a 70 * simple search of the specified level, and does not add 71 * entries or search parents. 72 * 73 * 74 * Named object lists are built (and subsequently dumped) in the 75 * order in which the names are encountered during the namespace load; 76 * 77 * All namespace searching is linear in this implementation, but 78 * could be easily modified to support any improved search 79 * algorithm. However, the linear search was chosen for simplicity 80 * and because the trees are small and the other interpreter 81 * execution overhead is relatively high. 82 * 83 * Note: CPU execution analysis has shown that the AML interpreter spends 84 * a very small percentage of its time searching the namespace. Therefore, 85 * the linear search seems to be sufficient, as there would seem to be 86 * little value in improving the search. 87 * 88 ******************************************************************************/ 89 90 acpi_status 91 acpi_ns_search_one_scope(u32 target_name, 92 struct acpi_namespace_node *parent_node, 93 acpi_object_type type, 94 struct acpi_namespace_node **return_node) 95 { 96 struct acpi_namespace_node *node; 97 98 ACPI_FUNCTION_TRACE(ns_search_one_scope); 99 100 #ifdef ACPI_DEBUG_OUTPUT 101 if (ACPI_LV_NAMES & acpi_dbg_level) { 102 char *scope_name; 103 104 scope_name = acpi_ns_get_external_pathname(parent_node); 105 if (scope_name) { 106 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 107 "Searching %s (%p) For [%4.4s] (%s)\n", 108 scope_name, parent_node, 109 ACPI_CAST_PTR(char, &target_name), 110 acpi_ut_get_type_name(type))); 111 112 ACPI_FREE(scope_name); 113 } 114 } 115 #endif 116 117 /* 118 * Search for name at this namespace level, which is to say that we 119 * must search for the name among the children of this object 120 */ 121 node = parent_node->child; 122 while (node) { 123 124 /* Check for match against the name */ 125 126 if (node->name.integer == target_name) { 127 128 /* Resolve a control method alias if any */ 129 130 if (acpi_ns_get_type(node) == 131 ACPI_TYPE_LOCAL_METHOD_ALIAS) { 132 node = 133 ACPI_CAST_PTR(struct acpi_namespace_node, 134 node->object); 135 } 136 137 /* Found matching entry */ 138 139 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 140 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n", 141 ACPI_CAST_PTR(char, &target_name), 142 acpi_ut_get_type_name(node->type), 143 node, 144 acpi_ut_get_node_name(parent_node), 145 parent_node)); 146 147 *return_node = node; 148 return_ACPI_STATUS(AE_OK); 149 } 150 151 /* 152 * The last entry in the list points back to the parent, 153 * so a flag is used to indicate the end-of-list 154 */ 155 if (node->flags & ANOBJ_END_OF_PEER_LIST) { 156 157 /* Searched entire list, we are done */ 158 159 break; 160 } 161 162 /* Didn't match name, move on to the next peer object */ 163 164 node = node->peer; 165 } 166 167 /* Searched entire namespace level, not found */ 168 169 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 170 "Name [%4.4s] (%s) not found in search in scope [%4.4s] " 171 "%p first child %p\n", 172 ACPI_CAST_PTR(char, &target_name), 173 acpi_ut_get_type_name(type), 174 acpi_ut_get_node_name(parent_node), parent_node, 175 parent_node->child)); 176 177 return_ACPI_STATUS(AE_NOT_FOUND); 178 } 179 180 /******************************************************************************* 181 * 182 * FUNCTION: acpi_ns_search_parent_tree 183 * 184 * PARAMETERS: target_name - Ascii ACPI name to search for 185 * Node - Starting node where search will begin 186 * Type - Object type to match 187 * return_node - Where the matched Node is returned 188 * 189 * RETURN: Status 190 * 191 * DESCRIPTION: Called when a name has not been found in the current namespace 192 * level. Before adding it or giving up, ACPI scope rules require 193 * searching enclosing scopes in cases identified by acpi_ns_local(). 194 * 195 * "A name is located by finding the matching name in the current 196 * name space, and then in the parent name space. If the parent 197 * name space does not contain the name, the search continues 198 * recursively until either the name is found or the name space 199 * does not have a parent (the root of the name space). This 200 * indicates that the name is not found" (From ACPI Specification, 201 * section 5.3) 202 * 203 ******************************************************************************/ 204 205 static acpi_status 206 acpi_ns_search_parent_tree(u32 target_name, 207 struct acpi_namespace_node *node, 208 acpi_object_type type, 209 struct acpi_namespace_node **return_node) 210 { 211 acpi_status status; 212 struct acpi_namespace_node *parent_node; 213 214 ACPI_FUNCTION_TRACE(ns_search_parent_tree); 215 216 parent_node = acpi_ns_get_parent_node(node); 217 218 /* 219 * If there is no parent (i.e., we are at the root) or type is "local", 220 * we won't be searching the parent tree. 221 */ 222 if (!parent_node) { 223 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n", 224 ACPI_CAST_PTR(char, &target_name))); 225 return_ACPI_STATUS(AE_NOT_FOUND); 226 } 227 228 if (acpi_ns_local(type)) { 229 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 230 "[%4.4s] type [%s] must be local to this scope (no parent search)\n", 231 ACPI_CAST_PTR(char, &target_name), 232 acpi_ut_get_type_name(type))); 233 return_ACPI_STATUS(AE_NOT_FOUND); 234 } 235 236 /* Search the parent tree */ 237 238 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 239 "Searching parent [%4.4s] for [%4.4s]\n", 240 acpi_ut_get_node_name(parent_node), 241 ACPI_CAST_PTR(char, &target_name))); 242 243 /* Search parents until target is found or we have backed up to the root */ 244 245 while (parent_node) { 246 /* 247 * Search parent scope. Use TYPE_ANY because we don't care about the 248 * object type at this point, we only care about the existence of 249 * the actual name we are searching for. Typechecking comes later. 250 */ 251 status = 252 acpi_ns_search_one_scope(target_name, parent_node, 253 ACPI_TYPE_ANY, return_node); 254 if (ACPI_SUCCESS(status)) { 255 return_ACPI_STATUS(status); 256 } 257 258 /* Not found here, go up another level (until we reach the root) */ 259 260 parent_node = acpi_ns_get_parent_node(parent_node); 261 } 262 263 /* Not found in parent tree */ 264 265 return_ACPI_STATUS(AE_NOT_FOUND); 266 } 267 268 /******************************************************************************* 269 * 270 * FUNCTION: acpi_ns_search_and_enter 271 * 272 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars) 273 * walk_state - Current state of the walk 274 * Node - Starting node where search will begin 275 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x. 276 * Otherwise,search only. 277 * Type - Object type to match 278 * Flags - Flags describing the search restrictions 279 * return_node - Where the Node is returned 280 * 281 * RETURN: Status 282 * 283 * DESCRIPTION: Search for a name segment in a single namespace level, 284 * optionally adding it if it is not found. If the passed 285 * Type is not Any and the type previously stored in the 286 * entry was Any (i.e. unknown), update the stored type. 287 * 288 * In ACPI_IMODE_EXECUTE, search only. 289 * In other modes, search and add if not found. 290 * 291 ******************************************************************************/ 292 293 acpi_status 294 acpi_ns_search_and_enter(u32 target_name, 295 struct acpi_walk_state *walk_state, 296 struct acpi_namespace_node *node, 297 acpi_interpreter_mode interpreter_mode, 298 acpi_object_type type, 299 u32 flags, struct acpi_namespace_node **return_node) 300 { 301 acpi_status status; 302 struct acpi_namespace_node *new_node; 303 304 ACPI_FUNCTION_TRACE(ns_search_and_enter); 305 306 /* Parameter validation */ 307 308 if (!node || !target_name || !return_node) { 309 ACPI_ERROR((AE_INFO, 310 "Null parameter: Node %p Name %X ReturnNode %p", 311 node, target_name, return_node)); 312 return_ACPI_STATUS(AE_BAD_PARAMETER); 313 } 314 315 /* 316 * Name must consist of valid ACPI characters. We will repair the name if 317 * necessary because we don't want to abort because of this, but we want 318 * all namespace names to be printable. A warning message is appropriate. 319 * 320 * This issue came up because there are in fact machines that exhibit 321 * this problem, and we want to be able to enable ACPI support for them, 322 * even though there are a few bad names. 323 */ 324 if (!acpi_ut_valid_acpi_name(target_name)) { 325 target_name = 326 acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name)); 327 328 /* Report warning only if in strict mode or debug mode */ 329 330 if (!acpi_gbl_enable_interpreter_slack) { 331 ACPI_WARNING((AE_INFO, 332 "Found bad character(s) in name, repaired: [%4.4s]\n", 333 ACPI_CAST_PTR(char, &target_name))); 334 } else { 335 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 336 "Found bad character(s) in name, repaired: [%4.4s]\n", 337 ACPI_CAST_PTR(char, &target_name))); 338 } 339 } 340 341 /* Try to find the name in the namespace level specified by the caller */ 342 343 *return_node = ACPI_ENTRY_NOT_FOUND; 344 status = acpi_ns_search_one_scope(target_name, node, type, return_node); 345 if (status != AE_NOT_FOUND) { 346 /* 347 * If we found it AND the request specifies that a find is an error, 348 * return the error 349 */ 350 if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) { 351 status = AE_ALREADY_EXISTS; 352 } 353 354 /* Either found it or there was an error: finished either way */ 355 356 return_ACPI_STATUS(status); 357 } 358 359 /* 360 * The name was not found. If we are NOT performing the first pass 361 * (name entry) of loading the namespace, search the parent tree (all the 362 * way to the root if necessary.) We don't want to perform the parent 363 * search when the namespace is actually being loaded. We want to perform 364 * the search when namespace references are being resolved (load pass 2) 365 * and during the execution phase. 366 */ 367 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) && 368 (flags & ACPI_NS_SEARCH_PARENT)) { 369 /* 370 * Not found at this level - search parent tree according to the 371 * ACPI specification 372 */ 373 status = 374 acpi_ns_search_parent_tree(target_name, node, type, 375 return_node); 376 if (ACPI_SUCCESS(status)) { 377 return_ACPI_STATUS(status); 378 } 379 } 380 381 /* In execute mode, just search, never add names. Exit now */ 382 383 if (interpreter_mode == ACPI_IMODE_EXECUTE) { 384 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 385 "%4.4s Not found in %p [Not adding]\n", 386 ACPI_CAST_PTR(char, &target_name), node)); 387 388 return_ACPI_STATUS(AE_NOT_FOUND); 389 } 390 391 /* Create the new named object */ 392 393 new_node = acpi_ns_create_node(target_name); 394 if (!new_node) { 395 return_ACPI_STATUS(AE_NO_MEMORY); 396 } 397 #ifdef ACPI_ASL_COMPILER 398 399 /* Node is an object defined by an External() statement */ 400 401 if (flags & ACPI_NS_EXTERNAL) { 402 new_node->flags |= ANOBJ_IS_EXTERNAL; 403 } 404 #endif 405 406 if (flags & ACPI_NS_TEMPORARY) { 407 new_node->flags |= ANOBJ_TEMPORARY; 408 } 409 410 /* Install the new object into the parent's list of children */ 411 412 acpi_ns_install_node(walk_state, node, new_node, type); 413 *return_node = new_node; 414 return_ACPI_STATUS(AE_OK); 415 } 416