| 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Module Name: nswalk - Functions for walking the ACPI namespace |
| 4 | * |
| 5 | *****************************************************************************/ |
| 6 | |
| 7 | /* |
| 8 | * Copyright (C) 2000 - 2016, 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.h" |
| 45 | #include "accommon.h" |
| 46 | #include "acnamesp.h" |
| 47 | |
| 48 | |
| 49 | #define _COMPONENT ACPI_NAMESPACE |
| 50 | ACPI_MODULE_NAME ("nswalk" ) |
| 51 | |
| 52 | |
| 53 | /******************************************************************************* |
| 54 | * |
| 55 | * FUNCTION: AcpiNsGetNextNode |
| 56 | * |
| 57 | * PARAMETERS: ParentNode - Parent node whose children we are |
| 58 | * getting |
| 59 | * ChildNode - Previous child that was found. |
| 60 | * The NEXT child will be returned |
| 61 | * |
| 62 | * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if |
| 63 | * none is found. |
| 64 | * |
| 65 | * DESCRIPTION: Return the next peer node within the namespace. If Handle |
| 66 | * is valid, Scope is ignored. Otherwise, the first node |
| 67 | * within Scope is returned. |
| 68 | * |
| 69 | ******************************************************************************/ |
| 70 | |
| 71 | ACPI_NAMESPACE_NODE * |
| 72 | AcpiNsGetNextNode ( |
| 73 | ACPI_NAMESPACE_NODE *ParentNode, |
| 74 | ACPI_NAMESPACE_NODE *ChildNode) |
| 75 | { |
| 76 | ACPI_FUNCTION_ENTRY (); |
| 77 | |
| 78 | |
| 79 | if (!ChildNode) |
| 80 | { |
| 81 | /* It's really the parent's _scope_ that we want */ |
| 82 | |
| 83 | return (ParentNode->Child); |
| 84 | } |
| 85 | |
| 86 | /* Otherwise just return the next peer */ |
| 87 | |
| 88 | return (ChildNode->Peer); |
| 89 | } |
| 90 | |
| 91 | |
| 92 | /******************************************************************************* |
| 93 | * |
| 94 | * FUNCTION: AcpiNsGetNextNodeTyped |
| 95 | * |
| 96 | * PARAMETERS: Type - Type of node to be searched for |
| 97 | * ParentNode - Parent node whose children we are |
| 98 | * getting |
| 99 | * ChildNode - Previous child that was found. |
| 100 | * The NEXT child will be returned |
| 101 | * |
| 102 | * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if |
| 103 | * none is found. |
| 104 | * |
| 105 | * DESCRIPTION: Return the next peer node within the namespace. If Handle |
| 106 | * is valid, Scope is ignored. Otherwise, the first node |
| 107 | * within Scope is returned. |
| 108 | * |
| 109 | ******************************************************************************/ |
| 110 | |
| 111 | ACPI_NAMESPACE_NODE * |
| 112 | AcpiNsGetNextNodeTyped ( |
| 113 | ACPI_OBJECT_TYPE Type, |
| 114 | ACPI_NAMESPACE_NODE *ParentNode, |
| 115 | ACPI_NAMESPACE_NODE *ChildNode) |
| 116 | { |
| 117 | ACPI_NAMESPACE_NODE *NextNode = NULL; |
| 118 | |
| 119 | |
| 120 | ACPI_FUNCTION_ENTRY (); |
| 121 | |
| 122 | |
| 123 | NextNode = AcpiNsGetNextNode (ParentNode, ChildNode); |
| 124 | |
| 125 | /* If any type is OK, we are done */ |
| 126 | |
| 127 | if (Type == ACPI_TYPE_ANY) |
| 128 | { |
| 129 | /* NextNode is NULL if we are at the end-of-list */ |
| 130 | |
| 131 | return (NextNode); |
| 132 | } |
| 133 | |
| 134 | /* Must search for the node -- but within this scope only */ |
| 135 | |
| 136 | while (NextNode) |
| 137 | { |
| 138 | /* If type matches, we are done */ |
| 139 | |
| 140 | if (NextNode->Type == Type) |
| 141 | { |
| 142 | return (NextNode); |
| 143 | } |
| 144 | |
| 145 | /* Otherwise, move on to the next peer node */ |
| 146 | |
| 147 | NextNode = NextNode->Peer; |
| 148 | } |
| 149 | |
| 150 | /* Not found */ |
| 151 | |
| 152 | return (NULL); |
| 153 | } |
| 154 | |
| 155 | |
| 156 | /******************************************************************************* |
| 157 | * |
| 158 | * FUNCTION: AcpiNsWalkNamespace |
| 159 | * |
| 160 | * PARAMETERS: Type - ACPI_OBJECT_TYPE to search for |
| 161 | * StartNode - Handle in namespace where search begins |
| 162 | * MaxDepth - Depth to which search is to reach |
| 163 | * Flags - Whether to unlock the NS before invoking |
| 164 | * the callback routine |
| 165 | * DescendingCallback - Called during tree descent |
| 166 | * when an object of "Type" is found |
| 167 | * AscendingCallback - Called during tree ascent |
| 168 | * when an object of "Type" is found |
| 169 | * Context - Passed to user function(s) above |
| 170 | * ReturnValue - from the UserFunction if terminated |
| 171 | * early. Otherwise, returns NULL. |
| 172 | * RETURNS: Status |
| 173 | * |
| 174 | * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, |
| 175 | * starting (and ending) at the node specified by StartHandle. |
| 176 | * The callback function is called whenever a node that matches |
| 177 | * the type parameter is found. If the callback function returns |
| 178 | * a non-zero value, the search is terminated immediately and |
| 179 | * this value is returned to the caller. |
| 180 | * |
| 181 | * The point of this procedure is to provide a generic namespace |
| 182 | * walk routine that can be called from multiple places to |
| 183 | * provide multiple services; the callback function(s) can be |
| 184 | * tailored to each task, whether it is a print function, |
| 185 | * a compare function, etc. |
| 186 | * |
| 187 | ******************************************************************************/ |
| 188 | |
| 189 | ACPI_STATUS |
| 190 | AcpiNsWalkNamespace ( |
| 191 | ACPI_OBJECT_TYPE Type, |
| 192 | ACPI_HANDLE StartNode, |
| 193 | UINT32 MaxDepth, |
| 194 | UINT32 Flags, |
| 195 | ACPI_WALK_CALLBACK DescendingCallback, |
| 196 | ACPI_WALK_CALLBACK AscendingCallback, |
| 197 | void *Context, |
| 198 | void **ReturnValue) |
| 199 | { |
| 200 | ACPI_STATUS Status; |
| 201 | ACPI_STATUS MutexStatus; |
| 202 | ACPI_NAMESPACE_NODE *ChildNode; |
| 203 | ACPI_NAMESPACE_NODE *ParentNode; |
| 204 | ACPI_OBJECT_TYPE ChildType; |
| 205 | UINT32 Level; |
| 206 | BOOLEAN NodePreviouslyVisited = FALSE; |
| 207 | |
| 208 | |
| 209 | ACPI_FUNCTION_TRACE (NsWalkNamespace); |
| 210 | |
| 211 | |
| 212 | /* Special case for the namespace Root Node */ |
| 213 | |
| 214 | if (StartNode == ACPI_ROOT_OBJECT) |
| 215 | { |
| 216 | StartNode = AcpiGbl_RootNode; |
| 217 | } |
| 218 | |
| 219 | /* Null child means "get first node" */ |
| 220 | |
| 221 | ParentNode = StartNode; |
| 222 | ChildNode = AcpiNsGetNextNode (ParentNode, NULL); |
| 223 | ChildType = ACPI_TYPE_ANY; |
| 224 | Level = 1; |
| 225 | |
| 226 | /* |
| 227 | * Traverse the tree of nodes until we bubble back up to where we |
| 228 | * started. When Level is zero, the loop is done because we have |
| 229 | * bubbled up to (and passed) the original parent handle (StartEntry) |
| 230 | */ |
| 231 | while (Level > 0 && ChildNode) |
| 232 | { |
| 233 | Status = AE_OK; |
| 234 | |
| 235 | /* Found next child, get the type if we are not searching for ANY */ |
| 236 | |
| 237 | if (Type != ACPI_TYPE_ANY) |
| 238 | { |
| 239 | ChildType = ChildNode->Type; |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * Ignore all temporary namespace nodes (created during control |
| 244 | * method execution) unless told otherwise. These temporary nodes |
| 245 | * can cause a race condition because they can be deleted during |
| 246 | * the execution of the user function (if the namespace is |
| 247 | * unlocked before invocation of the user function.) Only the |
| 248 | * debugger namespace dump will examine the temporary nodes. |
| 249 | */ |
| 250 | if ((ChildNode->Flags & ANOBJ_TEMPORARY) && |
| 251 | !(Flags & ACPI_NS_WALK_TEMP_NODES)) |
| 252 | { |
| 253 | Status = AE_CTRL_DEPTH; |
| 254 | } |
| 255 | |
| 256 | /* Type must match requested type */ |
| 257 | |
| 258 | else if (ChildType == Type) |
| 259 | { |
| 260 | /* |
| 261 | * Found a matching node, invoke the user callback function. |
| 262 | * Unlock the namespace if flag is set. |
| 263 | */ |
| 264 | if (Flags & ACPI_NS_WALK_UNLOCK) |
| 265 | { |
| 266 | MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE); |
| 267 | if (ACPI_FAILURE (MutexStatus)) |
| 268 | { |
| 269 | return_ACPI_STATUS (MutexStatus); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | /* |
| 274 | * Invoke the user function, either descending, ascending, |
| 275 | * or both. |
| 276 | */ |
| 277 | if (!NodePreviouslyVisited) |
| 278 | { |
| 279 | if (DescendingCallback) |
| 280 | { |
| 281 | Status = DescendingCallback (ChildNode, Level, |
| 282 | Context, ReturnValue); |
| 283 | } |
| 284 | } |
| 285 | else |
| 286 | { |
| 287 | if (AscendingCallback) |
| 288 | { |
| 289 | Status = AscendingCallback (ChildNode, Level, |
| 290 | Context, ReturnValue); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | if (Flags & ACPI_NS_WALK_UNLOCK) |
| 295 | { |
| 296 | MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE); |
| 297 | if (ACPI_FAILURE (MutexStatus)) |
| 298 | { |
| 299 | return_ACPI_STATUS (MutexStatus); |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | switch (Status) |
| 304 | { |
| 305 | case AE_OK: |
| 306 | case AE_CTRL_DEPTH: |
| 307 | |
| 308 | /* Just keep going */ |
| 309 | break; |
| 310 | |
| 311 | case AE_CTRL_TERMINATE: |
| 312 | |
| 313 | /* Exit now, with OK status */ |
| 314 | |
| 315 | return_ACPI_STATUS (AE_OK); |
| 316 | |
| 317 | default: |
| 318 | |
| 319 | /* All others are valid exceptions */ |
| 320 | |
| 321 | return_ACPI_STATUS (Status); |
| 322 | } |
| 323 | } |
| 324 | |
| 325 | /* |
| 326 | * Depth first search: Attempt to go down another level in the |
| 327 | * namespace if we are allowed to. Don't go any further if we have |
| 328 | * reached the caller specified maximum depth or if the user |
| 329 | * function has specified that the maximum depth has been reached. |
| 330 | */ |
| 331 | if (!NodePreviouslyVisited && |
| 332 | (Level < MaxDepth) && |
| 333 | (Status != AE_CTRL_DEPTH)) |
| 334 | { |
| 335 | if (ChildNode->Child) |
| 336 | { |
| 337 | /* There is at least one child of this node, visit it */ |
| 338 | |
| 339 | Level++; |
| 340 | ParentNode = ChildNode; |
| 341 | ChildNode = AcpiNsGetNextNode (ParentNode, NULL); |
| 342 | continue; |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | /* No more children, re-visit this node */ |
| 347 | |
| 348 | if (!NodePreviouslyVisited) |
| 349 | { |
| 350 | NodePreviouslyVisited = TRUE; |
| 351 | continue; |
| 352 | } |
| 353 | |
| 354 | /* No more children, visit peers */ |
| 355 | |
| 356 | ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode); |
| 357 | if (ChildNode) |
| 358 | { |
| 359 | NodePreviouslyVisited = FALSE; |
| 360 | } |
| 361 | |
| 362 | /* No peers, re-visit parent */ |
| 363 | |
| 364 | else |
| 365 | { |
| 366 | /* |
| 367 | * No more children of this node (AcpiNsGetNextNode failed), go |
| 368 | * back upwards in the namespace tree to the node's parent. |
| 369 | */ |
| 370 | Level--; |
| 371 | ChildNode = ParentNode; |
| 372 | ParentNode = ParentNode->Parent; |
| 373 | |
| 374 | NodePreviouslyVisited = TRUE; |
| 375 | } |
| 376 | } |
| 377 | |
| 378 | /* Complete walk, not terminated by user function */ |
| 379 | |
| 380 | return_ACPI_STATUS (AE_OK); |
| 381 | } |
| 382 | |