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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.02/*******************************************************************************3 *4 * Module Name: nssearch - Namespace search5 *6 ******************************************************************************/7 8#include <acpi/acpi.h>9#include "accommon.h"10#include "acnamesp.h"11 12#ifdef ACPI_ASL_COMPILER13#include "amlcode.h"14#endif15 16#define _COMPONENT ACPI_NAMESPACE17ACPI_MODULE_NAME("nssearch")18 19/* Local prototypes */20static acpi_status21acpi_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_scope29 *30 * PARAMETERS: target_name - Ascii ACPI name to search for31 * parent_node - Starting node where search will begin32 * type - Object type to match33 * return_node - Where the matched Named obj is returned34 *35 * RETURN: Status36 *37 * DESCRIPTION: Search a single level of the namespace. Performs a38 * simple search of the specified level, and does not add39 * entries or search parents.40 *41 *42 * Named object lists are built (and subsequently dumped) in the43 * order in which the names are encountered during the namespace load;44 *45 * All namespace searching is linear in this implementation, but46 * could be easily modified to support any improved search47 * algorithm. However, the linear search was chosen for simplicity48 * and because the trees are small and the other interpreter49 * execution overhead is relatively high.50 *51 * Note: CPU execution analysis has shown that the AML interpreter spends52 * a very small percentage of its time searching the namespace. Therefore,53 * the linear search seems to be sufficient, as there would seem to be54 * little value in improving the search.55 *56 ******************************************************************************/57 58acpi_status59acpi_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_OUTPUT69 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#endif84 85 /*86 * Search for name at this namespace level, which is to say that we87 * must search for the name among the children of this object88 */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_tree140 *141 * PARAMETERS: target_name - Ascii ACPI name to search for142 * node - Starting node where search will begin143 * type - Object type to match144 * return_node - Where the matched Node is returned145 *146 * RETURN: Status147 *148 * DESCRIPTION: Called when a name has not been found in the current namespace149 * level. Before adding it or giving up, ACPI scope rules require150 * searching enclosing scopes in cases identified by acpi_ns_local().151 *152 * "A name is located by finding the matching name in the current153 * name space, and then in the parent name space. If the parent154 * name space does not contain the name, the search continues155 * recursively until either the name is found or the name space156 * does not have a parent (the root of the name space). This157 * indicates that the name is not found" (From ACPI Specification,158 * section 5.3)159 *160 ******************************************************************************/161 162static acpi_status163acpi_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 the205 * object type at this point, we only care about the existence of206 * 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_enter228 *229 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars)230 * walk_state - Current state of the walk231 * node - Starting node where search will begin232 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x.233 * Otherwise,search only.234 * type - Object type to match235 * flags - Flags describing the search restrictions236 * return_node - Where the Node is returned237 *238 * RETURN: Status239 *240 * DESCRIPTION: Search for a name segment in a single namespace level,241 * optionally adding it if it is not found. If the passed242 * Type is not Any and the type previously stored in the243 * 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 250acpi_status251acpi_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 if274 * necessary because we don't want to abort because of this, but we want275 * all namespace names to be printable. A warning message is appropriate.276 *277 * This issue came up because there are in fact machines that exhibit278 * 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 error291 */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 node299 * 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_COMPILER329 if (*return_node && (*return_node)->type == ACPI_TYPE_ANY) {330 (*return_node)->flags |= ANOBJ_IS_EXTERNAL;331 }332#endif333 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 pass341 * (name entry) of loading the namespace, search the parent tree (all the342 * way to the root if necessary.) We don't want to perform the parent343 * search when the namespace is actually being loaded. We want to perform344 * 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 the351 * ACPI specification352 */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_COMPILER378 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#endif386 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