1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /******************************************************************************* 3 * 4 * Module Name: nssearch - Namespace search 5 * 6 ******************************************************************************/ 7 8 #include <acpi/acpi.h> 9 #include "accommon.h" 10 #include "acnamesp.h" 11 12 #ifdef ACPI_ASL_COMPILER 13 #include "amlcode.h" 14 #endif 15 16 #define _COMPONENT ACPI_NAMESPACE 17 ACPI_MODULE_NAME("nssearch") 18 19 /* Local prototypes */ 20 static acpi_status 21 acpi_ns_search_parent_tree(u32 target_name, 22 struct acpi_namespace_node *node, 23 acpi_object_type type, 24 struct acpi_namespace_node **return_node); 25 26 /******************************************************************************* 27 * 28 * FUNCTION: acpi_ns_search_one_scope 29 * 30 * PARAMETERS: target_name - Ascii ACPI name to search for 31 * parent_node - Starting node where search will begin 32 * type - Object type to match 33 * return_node - Where the matched Named obj is returned 34 * 35 * RETURN: Status 36 * 37 * DESCRIPTION: Search a single level of the namespace. Performs a 38 * simple search of the specified level, and does not add 39 * entries or search parents. 40 * 41 * 42 * Named object lists are built (and subsequently dumped) in the 43 * order in which the names are encountered during the namespace load; 44 * 45 * All namespace searching is linear in this implementation, but 46 * could be easily modified to support any improved search 47 * algorithm. However, the linear search was chosen for simplicity 48 * and because the trees are small and the other interpreter 49 * execution overhead is relatively high. 50 * 51 * Note: CPU execution analysis has shown that the AML interpreter spends 52 * a very small percentage of its time searching the namespace. Therefore, 53 * the linear search seems to be sufficient, as there would seem to be 54 * little value in improving the search. 55 * 56 ******************************************************************************/ 57 58 acpi_status 59 acpi_ns_search_one_scope(u32 target_name, 60 struct acpi_namespace_node *parent_node, 61 acpi_object_type type, 62 struct acpi_namespace_node **return_node) 63 { 64 struct acpi_namespace_node *node; 65 66 ACPI_FUNCTION_TRACE(ns_search_one_scope); 67 68 #ifdef ACPI_DEBUG_OUTPUT 69 if (ACPI_LV_NAMES & acpi_dbg_level) { 70 char *scope_name; 71 72 scope_name = acpi_ns_get_normalized_pathname(parent_node, TRUE); 73 if (scope_name) { 74 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 75 "Searching %s (%p) For [%4.4s] (%s)\n", 76 scope_name, parent_node, 77 ACPI_CAST_PTR(char, &target_name), 78 acpi_ut_get_type_name(type))); 79 80 ACPI_FREE(scope_name); 81 } 82 } 83 #endif 84 85 /* 86 * Search for name at this namespace level, which is to say that we 87 * must search for the name among the children of this object 88 */ 89 node = parent_node->child; 90 while (node) { 91 92 /* Check for match against the name */ 93 94 if (node->name.integer == target_name) { 95 96 /* Resolve a control method alias if any */ 97 98 if (acpi_ns_get_type(node) == 99 ACPI_TYPE_LOCAL_METHOD_ALIAS) { 100 node = 101 ACPI_CAST_PTR(struct acpi_namespace_node, 102 node->object); 103 } 104 105 /* Found matching entry */ 106 107 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 108 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n", 109 ACPI_CAST_PTR(char, &target_name), 110 acpi_ut_get_type_name(node->type), 111 node, 112 acpi_ut_get_node_name(parent_node), 113 parent_node)); 114 115 *return_node = node; 116 return_ACPI_STATUS(AE_OK); 117 } 118 119 /* Didn't match name, move on to the next peer object */ 120 121 node = node->peer; 122 } 123 124 /* Searched entire namespace level, not found */ 125 126 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 127 "Name [%4.4s] (%s) not found in search in scope [%4.4s] " 128 "%p first child %p\n", 129 ACPI_CAST_PTR(char, &target_name), 130 acpi_ut_get_type_name(type), 131 acpi_ut_get_node_name(parent_node), parent_node, 132 parent_node->child)); 133 134 return_ACPI_STATUS(AE_NOT_FOUND); 135 } 136 137 /******************************************************************************* 138 * 139 * FUNCTION: acpi_ns_search_parent_tree 140 * 141 * PARAMETERS: target_name - Ascii ACPI name to search for 142 * node - Starting node where search will begin 143 * type - Object type to match 144 * return_node - Where the matched Node is returned 145 * 146 * RETURN: Status 147 * 148 * DESCRIPTION: Called when a name has not been found in the current namespace 149 * level. Before adding it or giving up, ACPI scope rules require 150 * searching enclosing scopes in cases identified by acpi_ns_local(). 151 * 152 * "A name is located by finding the matching name in the current 153 * name space, and then in the parent name space. If the parent 154 * name space does not contain the name, the search continues 155 * recursively until either the name is found or the name space 156 * does not have a parent (the root of the name space). This 157 * indicates that the name is not found" (From ACPI Specification, 158 * section 5.3) 159 * 160 ******************************************************************************/ 161 162 static acpi_status 163 acpi_ns_search_parent_tree(u32 target_name, 164 struct acpi_namespace_node *node, 165 acpi_object_type type, 166 struct acpi_namespace_node **return_node) 167 { 168 acpi_status status; 169 struct acpi_namespace_node *parent_node; 170 171 ACPI_FUNCTION_TRACE(ns_search_parent_tree); 172 173 parent_node = node->parent; 174 175 /* 176 * If there is no parent (i.e., we are at the root) or type is "local", 177 * we won't be searching the parent tree. 178 */ 179 if (!parent_node) { 180 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n", 181 ACPI_CAST_PTR(char, &target_name))); 182 return_ACPI_STATUS(AE_NOT_FOUND); 183 } 184 185 if (acpi_ns_local(type)) { 186 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 187 "[%4.4s] type [%s] must be local to this scope (no parent search)\n", 188 ACPI_CAST_PTR(char, &target_name), 189 acpi_ut_get_type_name(type))); 190 return_ACPI_STATUS(AE_NOT_FOUND); 191 } 192 193 /* Search the parent tree */ 194 195 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 196 "Searching parent [%4.4s] for [%4.4s]\n", 197 acpi_ut_get_node_name(parent_node), 198 ACPI_CAST_PTR(char, &target_name))); 199 200 /* Search parents until target is found or we have backed up to the root */ 201 202 while (parent_node) { 203 /* 204 * Search parent scope. Use TYPE_ANY because we don't care about the 205 * object type at this point, we only care about the existence of 206 * the actual name we are searching for. Typechecking comes later. 207 */ 208 status = 209 acpi_ns_search_one_scope(target_name, parent_node, 210 ACPI_TYPE_ANY, return_node); 211 if (ACPI_SUCCESS(status)) { 212 return_ACPI_STATUS(status); 213 } 214 215 /* Not found here, go up another level (until we reach the root) */ 216 217 parent_node = parent_node->parent; 218 } 219 220 /* Not found in parent tree */ 221 222 return_ACPI_STATUS(AE_NOT_FOUND); 223 } 224 225 /******************************************************************************* 226 * 227 * FUNCTION: acpi_ns_search_and_enter 228 * 229 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars) 230 * walk_state - Current state of the walk 231 * node - Starting node where search will begin 232 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x. 233 * Otherwise,search only. 234 * type - Object type to match 235 * flags - Flags describing the search restrictions 236 * return_node - Where the Node is returned 237 * 238 * RETURN: Status 239 * 240 * DESCRIPTION: Search for a name segment in a single namespace level, 241 * optionally adding it if it is not found. If the passed 242 * Type is not Any and the type previously stored in the 243 * entry was Any (i.e. unknown), update the stored type. 244 * 245 * In ACPI_IMODE_EXECUTE, search only. 246 * In other modes, search and add if not found. 247 * 248 ******************************************************************************/ 249 250 acpi_status 251 acpi_ns_search_and_enter(u32 target_name, 252 struct acpi_walk_state *walk_state, 253 struct acpi_namespace_node *node, 254 acpi_interpreter_mode interpreter_mode, 255 acpi_object_type type, 256 u32 flags, struct acpi_namespace_node **return_node) 257 { 258 acpi_status status; 259 struct acpi_namespace_node *new_node; 260 261 ACPI_FUNCTION_TRACE(ns_search_and_enter); 262 263 /* Parameter validation */ 264 265 if (!node || !target_name || !return_node) { 266 ACPI_ERROR((AE_INFO, 267 "Null parameter: Node %p Name 0x%X ReturnNode %p", 268 node, target_name, return_node)); 269 return_ACPI_STATUS(AE_BAD_PARAMETER); 270 } 271 272 /* 273 * Name must consist of valid ACPI characters. We will repair the name if 274 * necessary because we don't want to abort because of this, but we want 275 * all namespace names to be printable. A warning message is appropriate. 276 * 277 * This issue came up because there are in fact machines that exhibit 278 * this problem, and we want to be able to enable ACPI support for them, 279 * even though there are a few bad names. 280 */ 281 acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name)); 282 283 /* Try to find the name in the namespace level specified by the caller */ 284 285 *return_node = ACPI_ENTRY_NOT_FOUND; 286 status = acpi_ns_search_one_scope(target_name, node, type, return_node); 287 if (status != AE_NOT_FOUND) { 288 /* 289 * If we found it AND the request specifies that a find is an error, 290 * return the error 291 */ 292 if (status == AE_OK) { 293 294 /* The node was found in the namespace */ 295 296 /* 297 * If the namespace override feature is enabled for this node, 298 * delete any existing attached sub-object and make the node 299 * look like a new node that is owned by the override table. 300 */ 301 if (flags & ACPI_NS_OVERRIDE_IF_FOUND) { 302 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 303 "Namespace override: %4.4s pass %u type %X Owner %X\n", 304 ACPI_CAST_PTR(char, 305 &target_name), 306 interpreter_mode, 307 (*return_node)->type, 308 walk_state->owner_id)); 309 310 acpi_ns_delete_children(*return_node); 311 if (acpi_gbl_runtime_namespace_override) { 312 acpi_ut_remove_reference((*return_node)->object); 313 (*return_node)->object = NULL; 314 (*return_node)->owner_id = 315 walk_state->owner_id; 316 } else { 317 acpi_ns_remove_node(*return_node); 318 *return_node = ACPI_ENTRY_NOT_FOUND; 319 } 320 } 321 322 /* Return an error if we don't expect to find the object */ 323 324 else if (flags & ACPI_NS_ERROR_IF_FOUND) { 325 status = AE_ALREADY_EXISTS; 326 } 327 } 328 #ifdef ACPI_ASL_COMPILER 329 if (*return_node && (*return_node)->type == ACPI_TYPE_ANY) { 330 (*return_node)->flags |= ANOBJ_IS_EXTERNAL; 331 } 332 #endif 333 334 /* Either found it or there was an error: finished either way */ 335 336 return_ACPI_STATUS(status); 337 } 338 339 /* 340 * The name was not found. If we are NOT performing the first pass 341 * (name entry) of loading the namespace, search the parent tree (all the 342 * way to the root if necessary.) We don't want to perform the parent 343 * search when the namespace is actually being loaded. We want to perform 344 * the search when namespace references are being resolved (load pass 2) 345 * and during the execution phase. 346 */ 347 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) && 348 (flags & ACPI_NS_SEARCH_PARENT)) { 349 /* 350 * Not found at this level - search parent tree according to the 351 * ACPI specification 352 */ 353 status = 354 acpi_ns_search_parent_tree(target_name, node, type, 355 return_node); 356 if (ACPI_SUCCESS(status)) { 357 return_ACPI_STATUS(status); 358 } 359 } 360 361 /* In execute mode, just search, never add names. Exit now */ 362 363 if (interpreter_mode == ACPI_IMODE_EXECUTE) { 364 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 365 "%4.4s Not found in %p [Not adding]\n", 366 ACPI_CAST_PTR(char, &target_name), node)); 367 368 return_ACPI_STATUS(AE_NOT_FOUND); 369 } 370 371 /* Create the new named object */ 372 373 new_node = acpi_ns_create_node(target_name); 374 if (!new_node) { 375 return_ACPI_STATUS(AE_NO_MEMORY); 376 } 377 #ifdef ACPI_ASL_COMPILER 378 379 /* Node is an object defined by an External() statement */ 380 381 if (flags & ACPI_NS_EXTERNAL || 382 (walk_state && walk_state->opcode == AML_SCOPE_OP)) { 383 new_node->flags |= ANOBJ_IS_EXTERNAL; 384 } 385 #endif 386 387 if (flags & ACPI_NS_TEMPORARY) { 388 new_node->flags |= ANOBJ_TEMPORARY; 389 } 390 391 /* Install the new object into the parent's list of children */ 392 393 acpi_ns_install_node(walk_state, node, new_node, type); 394 *return_node = new_node; 395 return_ACPI_STATUS(AE_OK); 396 } 397