1 /******************************************************************************* 2 * 3 * Module Name: nssearch - Namespace search 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2014, 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 #ifdef ACPI_ASL_COMPILER 49 #include "amlcode.h" 50 #endif 51 52 #define _COMPONENT ACPI_NAMESPACE 53 ACPI_MODULE_NAME("nssearch") 54 55 /* Local prototypes */ 56 static acpi_status 57 acpi_ns_search_parent_tree(u32 target_name, 58 struct acpi_namespace_node *node, 59 acpi_object_type type, 60 struct acpi_namespace_node **return_node); 61 62 /******************************************************************************* 63 * 64 * FUNCTION: acpi_ns_search_one_scope 65 * 66 * PARAMETERS: target_name - Ascii ACPI name to search for 67 * parent_node - Starting node where search will begin 68 * type - Object type to match 69 * return_node - Where the matched Named obj is returned 70 * 71 * RETURN: Status 72 * 73 * DESCRIPTION: Search a single level of the namespace. Performs a 74 * simple search of the specified level, and does not add 75 * entries or search parents. 76 * 77 * 78 * Named object lists are built (and subsequently dumped) in the 79 * order in which the names are encountered during the namespace load; 80 * 81 * All namespace searching is linear in this implementation, but 82 * could be easily modified to support any improved search 83 * algorithm. However, the linear search was chosen for simplicity 84 * and because the trees are small and the other interpreter 85 * execution overhead is relatively high. 86 * 87 * Note: CPU execution analysis has shown that the AML interpreter spends 88 * a very small percentage of its time searching the namespace. Therefore, 89 * the linear search seems to be sufficient, as there would seem to be 90 * little value in improving the search. 91 * 92 ******************************************************************************/ 93 94 acpi_status 95 acpi_ns_search_one_scope(u32 target_name, 96 struct acpi_namespace_node *parent_node, 97 acpi_object_type type, 98 struct acpi_namespace_node **return_node) 99 { 100 struct acpi_namespace_node *node; 101 102 ACPI_FUNCTION_TRACE(ns_search_one_scope); 103 104 #ifdef ACPI_DEBUG_OUTPUT 105 if (ACPI_LV_NAMES & acpi_dbg_level) { 106 char *scope_name; 107 108 scope_name = acpi_ns_get_external_pathname(parent_node); 109 if (scope_name) { 110 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 111 "Searching %s (%p) For [%4.4s] (%s)\n", 112 scope_name, parent_node, 113 ACPI_CAST_PTR(char, &target_name), 114 acpi_ut_get_type_name(type))); 115 116 ACPI_FREE(scope_name); 117 } 118 } 119 #endif 120 121 /* 122 * Search for name at this namespace level, which is to say that we 123 * must search for the name among the children of this object 124 */ 125 node = parent_node->child; 126 while (node) { 127 128 /* Check for match against the name */ 129 130 if (node->name.integer == target_name) { 131 132 /* Resolve a control method alias if any */ 133 134 if (acpi_ns_get_type(node) == 135 ACPI_TYPE_LOCAL_METHOD_ALIAS) { 136 node = 137 ACPI_CAST_PTR(struct acpi_namespace_node, 138 node->object); 139 } 140 141 /* Found matching entry */ 142 143 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 144 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n", 145 ACPI_CAST_PTR(char, &target_name), 146 acpi_ut_get_type_name(node->type), 147 node, 148 acpi_ut_get_node_name(parent_node), 149 parent_node)); 150 151 *return_node = node; 152 return_ACPI_STATUS(AE_OK); 153 } 154 155 /* Didn't match name, move on to the next peer object */ 156 157 node = node->peer; 158 } 159 160 /* Searched entire namespace level, not found */ 161 162 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 163 "Name [%4.4s] (%s) not found in search in scope [%4.4s] " 164 "%p first child %p\n", 165 ACPI_CAST_PTR(char, &target_name), 166 acpi_ut_get_type_name(type), 167 acpi_ut_get_node_name(parent_node), parent_node, 168 parent_node->child)); 169 170 return_ACPI_STATUS(AE_NOT_FOUND); 171 } 172 173 /******************************************************************************* 174 * 175 * FUNCTION: acpi_ns_search_parent_tree 176 * 177 * PARAMETERS: target_name - Ascii ACPI name to search for 178 * node - Starting node where search will begin 179 * type - Object type to match 180 * return_node - Where the matched Node is returned 181 * 182 * RETURN: Status 183 * 184 * DESCRIPTION: Called when a name has not been found in the current namespace 185 * level. Before adding it or giving up, ACPI scope rules require 186 * searching enclosing scopes in cases identified by acpi_ns_local(). 187 * 188 * "A name is located by finding the matching name in the current 189 * name space, and then in the parent name space. If the parent 190 * name space does not contain the name, the search continues 191 * recursively until either the name is found or the name space 192 * does not have a parent (the root of the name space). This 193 * indicates that the name is not found" (From ACPI Specification, 194 * section 5.3) 195 * 196 ******************************************************************************/ 197 198 static acpi_status 199 acpi_ns_search_parent_tree(u32 target_name, 200 struct acpi_namespace_node *node, 201 acpi_object_type type, 202 struct acpi_namespace_node **return_node) 203 { 204 acpi_status status; 205 struct acpi_namespace_node *parent_node; 206 207 ACPI_FUNCTION_TRACE(ns_search_parent_tree); 208 209 parent_node = node->parent; 210 211 /* 212 * If there is no parent (i.e., we are at the root) or type is "local", 213 * we won't be searching the parent tree. 214 */ 215 if (!parent_node) { 216 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n", 217 ACPI_CAST_PTR(char, &target_name))); 218 return_ACPI_STATUS(AE_NOT_FOUND); 219 } 220 221 if (acpi_ns_local(type)) { 222 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 223 "[%4.4s] type [%s] must be local to this scope (no parent search)\n", 224 ACPI_CAST_PTR(char, &target_name), 225 acpi_ut_get_type_name(type))); 226 return_ACPI_STATUS(AE_NOT_FOUND); 227 } 228 229 /* Search the parent tree */ 230 231 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 232 "Searching parent [%4.4s] for [%4.4s]\n", 233 acpi_ut_get_node_name(parent_node), 234 ACPI_CAST_PTR(char, &target_name))); 235 236 /* Search parents until target is found or we have backed up to the root */ 237 238 while (parent_node) { 239 /* 240 * Search parent scope. Use TYPE_ANY because we don't care about the 241 * object type at this point, we only care about the existence of 242 * the actual name we are searching for. Typechecking comes later. 243 */ 244 status = 245 acpi_ns_search_one_scope(target_name, parent_node, 246 ACPI_TYPE_ANY, return_node); 247 if (ACPI_SUCCESS(status)) { 248 return_ACPI_STATUS(status); 249 } 250 251 /* Not found here, go up another level (until we reach the root) */ 252 253 parent_node = parent_node->parent; 254 } 255 256 /* Not found in parent tree */ 257 258 return_ACPI_STATUS(AE_NOT_FOUND); 259 } 260 261 /******************************************************************************* 262 * 263 * FUNCTION: acpi_ns_search_and_enter 264 * 265 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars) 266 * walk_state - Current state of the walk 267 * node - Starting node where search will begin 268 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x. 269 * Otherwise,search only. 270 * type - Object type to match 271 * flags - Flags describing the search restrictions 272 * return_node - Where the Node is returned 273 * 274 * RETURN: Status 275 * 276 * DESCRIPTION: Search for a name segment in a single namespace level, 277 * optionally adding it if it is not found. If the passed 278 * Type is not Any and the type previously stored in the 279 * entry was Any (i.e. unknown), update the stored type. 280 * 281 * In ACPI_IMODE_EXECUTE, search only. 282 * In other modes, search and add if not found. 283 * 284 ******************************************************************************/ 285 286 acpi_status 287 acpi_ns_search_and_enter(u32 target_name, 288 struct acpi_walk_state *walk_state, 289 struct acpi_namespace_node *node, 290 acpi_interpreter_mode interpreter_mode, 291 acpi_object_type type, 292 u32 flags, struct acpi_namespace_node **return_node) 293 { 294 acpi_status status; 295 struct acpi_namespace_node *new_node; 296 297 ACPI_FUNCTION_TRACE(ns_search_and_enter); 298 299 /* Parameter validation */ 300 301 if (!node || !target_name || !return_node) { 302 ACPI_ERROR((AE_INFO, 303 "Null parameter: Node %p Name 0x%X ReturnNode %p", 304 node, target_name, return_node)); 305 return_ACPI_STATUS(AE_BAD_PARAMETER); 306 } 307 308 /* 309 * Name must consist of valid ACPI characters. We will repair the name if 310 * necessary because we don't want to abort because of this, but we want 311 * all namespace names to be printable. A warning message is appropriate. 312 * 313 * This issue came up because there are in fact machines that exhibit 314 * this problem, and we want to be able to enable ACPI support for them, 315 * even though there are a few bad names. 316 */ 317 acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name)); 318 319 /* Try to find the name in the namespace level specified by the caller */ 320 321 *return_node = ACPI_ENTRY_NOT_FOUND; 322 status = acpi_ns_search_one_scope(target_name, node, type, return_node); 323 if (status != AE_NOT_FOUND) { 324 /* 325 * If we found it AND the request specifies that a find is an error, 326 * return the error 327 */ 328 if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) { 329 status = AE_ALREADY_EXISTS; 330 } 331 #ifdef ACPI_ASL_COMPILER 332 if (*return_node && (*return_node)->type == ACPI_TYPE_ANY) { 333 (*return_node)->flags |= ANOBJ_IS_EXTERNAL; 334 } 335 #endif 336 337 /* Either found it or there was an error: finished either way */ 338 339 return_ACPI_STATUS(status); 340 } 341 342 /* 343 * The name was not found. If we are NOT performing the first pass 344 * (name entry) of loading the namespace, search the parent tree (all the 345 * way to the root if necessary.) We don't want to perform the parent 346 * search when the namespace is actually being loaded. We want to perform 347 * the search when namespace references are being resolved (load pass 2) 348 * and during the execution phase. 349 */ 350 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) && 351 (flags & ACPI_NS_SEARCH_PARENT)) { 352 /* 353 * Not found at this level - search parent tree according to the 354 * ACPI specification 355 */ 356 status = 357 acpi_ns_search_parent_tree(target_name, node, type, 358 return_node); 359 if (ACPI_SUCCESS(status)) { 360 return_ACPI_STATUS(status); 361 } 362 } 363 364 /* In execute mode, just search, never add names. Exit now */ 365 366 if (interpreter_mode == ACPI_IMODE_EXECUTE) { 367 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 368 "%4.4s Not found in %p [Not adding]\n", 369 ACPI_CAST_PTR(char, &target_name), node)); 370 371 return_ACPI_STATUS(AE_NOT_FOUND); 372 } 373 374 /* Create the new named object */ 375 376 new_node = acpi_ns_create_node(target_name); 377 if (!new_node) { 378 return_ACPI_STATUS(AE_NO_MEMORY); 379 } 380 #ifdef ACPI_ASL_COMPILER 381 382 /* Node is an object defined by an External() statement */ 383 384 if (flags & ACPI_NS_EXTERNAL || 385 (walk_state && walk_state->opcode == AML_SCOPE_OP)) { 386 new_node->flags |= ANOBJ_IS_EXTERNAL; 387 } 388 #endif 389 390 if (flags & ACPI_NS_TEMPORARY) { 391 new_node->flags |= ANOBJ_TEMPORARY; 392 } 393 394 /* Install the new object into the parent's list of children */ 395 396 acpi_ns_install_node(walk_state, node, new_node, type); 397 *return_node = new_node; 398 return_ACPI_STATUS(AE_OK); 399 } 400