Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 | // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 /****************************************************************************** * * Module Name: nswalk - Functions for walking the ACPI namespace * * Copyright (C) 2000 - 2023, Intel Corp. * *****************************************************************************/ #include <acpi/acpi.h> #include "accommon.h" #include "acnamesp.h" #define _COMPONENT ACPI_NAMESPACE ACPI_MODULE_NAME("nswalk") /******************************************************************************* * * FUNCTION: acpi_ns_get_next_node * * PARAMETERS: parent_node - Parent node whose children we are * getting * child_node - Previous child that was found. * The NEXT child will be returned * * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if * none is found. * * DESCRIPTION: Return the next peer node within the namespace. If Handle * is valid, Scope is ignored. Otherwise, the first node * within Scope is returned. * ******************************************************************************/ struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node *parent_node, struct acpi_namespace_node *child_node) { ACPI_FUNCTION_ENTRY(); if (!child_node) { /* It's really the parent's _scope_ that we want */ return (parent_node->child); } /* Otherwise just return the next peer */ return (child_node->peer); } /******************************************************************************* * * FUNCTION: acpi_ns_get_next_node_typed * * PARAMETERS: type - Type of node to be searched for * parent_node - Parent node whose children we are * getting * child_node - Previous child that was found. * The NEXT child will be returned * * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if * none is found. * * DESCRIPTION: Return the next peer node within the namespace. If Handle * is valid, Scope is ignored. Otherwise, the first node * within Scope is returned. * ******************************************************************************/ struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type, struct acpi_namespace_node *parent_node, struct acpi_namespace_node *child_node) { struct acpi_namespace_node *next_node = NULL; ACPI_FUNCTION_ENTRY(); next_node = acpi_ns_get_next_node(parent_node, child_node); /* If any type is OK, we are done */ if (type == ACPI_TYPE_ANY) { /* next_node is NULL if we are at the end-of-list */ return (next_node); } /* Must search for the node -- but within this scope only */ while (next_node) { /* If type matches, we are done */ if (next_node->type == type) { return (next_node); } /* Otherwise, move on to the next peer node */ next_node = next_node->peer; } /* Not found */ return (NULL); } /******************************************************************************* * * FUNCTION: acpi_ns_walk_namespace * * PARAMETERS: type - acpi_object_type to search for * start_node - Handle in namespace where search begins * max_depth - Depth to which search is to reach * flags - Whether to unlock the NS before invoking * the callback routine * descending_callback - Called during tree descent * when an object of "Type" is found * ascending_callback - Called during tree ascent * when an object of "Type" is found * context - Passed to user function(s) above * return_value - from the user_function if terminated * early. Otherwise, returns NULL. * RETURNS: Status * * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, * starting (and ending) at the node specified by start_handle. * The callback function is called whenever a node that matches * the type parameter is found. If the callback function returns * a non-zero value, the search is terminated immediately and * this value is returned to the caller. * * The point of this procedure is to provide a generic namespace * walk routine that can be called from multiple places to * provide multiple services; the callback function(s) can be * tailored to each task, whether it is a print function, * a compare function, etc. * ******************************************************************************/ acpi_status acpi_ns_walk_namespace(acpi_object_type type, acpi_handle start_node, u32 max_depth, u32 flags, acpi_walk_callback descending_callback, acpi_walk_callback ascending_callback, void *context, void **return_value) { acpi_status status; acpi_status mutex_status; struct acpi_namespace_node *child_node; struct acpi_namespace_node *parent_node; acpi_object_type child_type; u32 level; u8 node_previously_visited = FALSE; ACPI_FUNCTION_TRACE(ns_walk_namespace); /* Special case for the namespace Root Node */ if (start_node == ACPI_ROOT_OBJECT) { start_node = acpi_gbl_root_node; if (!start_node) { return_ACPI_STATUS(AE_NO_NAMESPACE); } } /* Null child means "get first node" */ parent_node = start_node; child_node = acpi_ns_get_next_node(parent_node, NULL); child_type = ACPI_TYPE_ANY; level = 1; /* * Traverse the tree of nodes until we bubble back up to where we * started. When Level is zero, the loop is done because we have * bubbled up to (and passed) the original parent handle (start_entry) */ while (level > 0 && child_node) { status = AE_OK; /* Found next child, get the type if we are not searching for ANY */ if (type != ACPI_TYPE_ANY) { child_type = child_node->type; } /* * Ignore all temporary namespace nodes (created during control * method execution) unless told otherwise. These temporary nodes * can cause a race condition because they can be deleted during * the execution of the user function (if the namespace is * unlocked before invocation of the user function.) Only the * debugger namespace dump will examine the temporary nodes. */ if ((child_node->flags & ANOBJ_TEMPORARY) && !(flags & ACPI_NS_WALK_TEMP_NODES)) { status = AE_CTRL_DEPTH; } /* Type must match requested type */ else if (child_type == type) { /* * Found a matching node, invoke the user callback function. * Unlock the namespace if flag is set. */ if (flags & ACPI_NS_WALK_UNLOCK) { mutex_status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); if (ACPI_FAILURE(mutex_status)) { return_ACPI_STATUS(mutex_status); } } /* * Invoke the user function, either descending, ascending, * or both. */ if (!node_previously_visited) { if (descending_callback) { status = descending_callback(child_node, level, context, return_value); } } else { if (ascending_callback) { status = ascending_callback(child_node, level, context, return_value); } } if (flags & ACPI_NS_WALK_UNLOCK) { mutex_status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); if (ACPI_FAILURE(mutex_status)) { return_ACPI_STATUS(mutex_status); } } switch (status) { case AE_OK: case AE_CTRL_DEPTH: /* Just keep going */ break; case AE_CTRL_TERMINATE: /* Exit now, with OK status */ return_ACPI_STATUS(AE_OK); default: /* All others are valid exceptions */ return_ACPI_STATUS(status); } } /* * Depth first search: Attempt to go down another level in the * namespace if we are allowed to. Don't go any further if we have * reached the caller specified maximum depth or if the user * function has specified that the maximum depth has been reached. */ if (!node_previously_visited && (level < max_depth) && (status != AE_CTRL_DEPTH)) { if (child_node->child) { /* There is at least one child of this node, visit it */ level++; parent_node = child_node; child_node = acpi_ns_get_next_node(parent_node, NULL); continue; } } /* No more children, re-visit this node */ if (!node_previously_visited) { node_previously_visited = TRUE; continue; } /* No more children, visit peers */ child_node = acpi_ns_get_next_node(parent_node, child_node); if (child_node) { node_previously_visited = FALSE; } /* No peers, re-visit parent */ else { /* * No more children of this node (acpi_ns_get_next_node failed), go * back upwards in the namespace tree to the node's parent. */ level--; child_node = parent_node; parent_node = parent_node->parent; node_previously_visited = TRUE; } } /* Complete walk, not terminated by user function */ return_ACPI_STATUS(AE_OK); } |