drivers/acpi/namespace/nsalloc.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsalloc - Namespace allocation and deletion utilities
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2006, R. Byron Moore
   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 <acpi/acnamesp.h>
  46
  47 #define _COMPONENT          ACPI_NAMESPACE
  48 ACPI_MODULE_NAME("nsalloc")
  49
  50 /* Local prototypes */
  51 static void acpi_ns_remove_reference(struct acpi_namespace_node *node);
  52
  53 /*******************************************************************************
  54  *
  55  * FUNCTION:    acpi_ns_create_node
  56  *
  57  * PARAMETERS:  Name            - Name of the new node (4 char ACPI name)
  58  *
  59  * RETURN:      New namespace node (Null on failure)
  60  *
  61  * DESCRIPTION: Create a namespace node
  62  *
  63  ******************************************************************************/
  64
  65 struct acpi_namespace_node *acpi_ns_create_node(u32 name)
  66 {
  67         struct acpi_namespace_node *node;
  68
  69         ACPI_FUNCTION_TRACE("ns_create_node");
  70
  71         node = ACPI_MEM_CALLOCATE(sizeof(struct acpi_namespace_node));
  72         if (!node) {
  73                 return_PTR(NULL);
  74         }
  75
  76         ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_allocated++);
  77
  78         node->name.integer = name;
  79         node->reference_count = 1;
  80         ACPI_SET_DESCRIPTOR_TYPE(node, ACPI_DESC_TYPE_NAMED);
  81
  82         return_PTR(node);
  83 }
  84
  85 /*******************************************************************************
  86  *
  87  * FUNCTION:    acpi_ns_delete_node
  88  *
  89  * PARAMETERS:  Node            - Node to be deleted
  90  *
  91  * RETURN:      None
  92  *
  93  * DESCRIPTION: Delete a namespace node
  94  *
  95  ******************************************************************************/
  96
  97 void acpi_ns_delete_node(struct acpi_namespace_node *node)
  98 {
  99         struct acpi_namespace_node *parent_node;
 100         struct acpi_namespace_node *prev_node;
 101         struct acpi_namespace_node *next_node;
 102
 103         ACPI_FUNCTION_TRACE_PTR("ns_delete_node", node);
 104
 105         parent_node = acpi_ns_get_parent_node(node);
 106
 107         prev_node = NULL;
 108         next_node = parent_node->child;
 109
 110         /* Find the node that is the previous peer in the parent's child list */
 111
 112         while (next_node != node) {
 113                 prev_node = next_node;
 114                 next_node = prev_node->peer;
 115         }
 116
 117         if (prev_node) {
 118                 /* Node is not first child, unlink it */
 119
 120                 prev_node->peer = next_node->peer;
 121                 if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
 122                         prev_node->flags |= ANOBJ_END_OF_PEER_LIST;
 123                 }
 124         } else {
 125                 /* Node is first child (has no previous peer) */
 126
 127                 if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
 128                         /* No peers at all */
 129
 130                         parent_node->child = NULL;
 131                 } else {        /* Link peer list to parent */
 132
 133                         parent_node->child = next_node->peer;
 134                 }
 135         }
 136
 137         ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_freed++);
 138
 139         /*
 140          * Detach an object if there is one then delete the node
 141          */
 142         acpi_ns_detach_object(node);
 143         ACPI_MEM_FREE(node);
 144         return_VOID;
 145 }
 146
 147 /*******************************************************************************
 148  *
 149  * FUNCTION:    acpi_ns_install_node
 150  *
 151  * PARAMETERS:  walk_state      - Current state of the walk
 152  *              parent_node     - The parent of the new Node
 153  *              Node            - The new Node to install
 154  *              Type            - ACPI object type of the new Node
 155  *
 156  * RETURN:      None
 157  *
 158  * DESCRIPTION: Initialize a new namespace node and install it amongst
 159  *              its peers.
 160  *
 161  *              Note: Current namespace lookup is linear search. This appears
 162  *              to be sufficient as namespace searches consume only a small
 163  *              fraction of the execution time of the ACPI subsystem.
 164  *
 165  ******************************************************************************/
 166
 167 void acpi_ns_install_node(struct acpi_walk_state *walk_state, struct acpi_namespace_node *parent_node,  /* Parent */
 168                           struct acpi_namespace_node *node,     /* New Child */
 169                           acpi_object_type type)
 170 {
 171         acpi_owner_id owner_id = 0;
 172         struct acpi_namespace_node *child_node;
 173
 174         ACPI_FUNCTION_TRACE("ns_install_node");
 175
 176         /*
 177          * Get the owner ID from the Walk state
 178          * The owner ID is used to track table deletion and
 179          * deletion of objects created by methods
 180          */
 181         if (walk_state) {
 182                 owner_id = walk_state->owner_id;
 183         }
 184
 185         /* Link the new entry into the parent and existing children */
 186
 187         child_node = parent_node->child;
 188         if (!child_node) {
 189                 parent_node->child = node;
 190                 node->flags |= ANOBJ_END_OF_PEER_LIST;
 191                 node->peer = parent_node;
 192         } else {
 193                 while (!(child_node->flags & ANOBJ_END_OF_PEER_LIST)) {
 194                         child_node = child_node->peer;
 195                 }
 196
 197                 child_node->peer = node;
 198
 199                 /* Clear end-of-list flag */
 200
 201                 child_node->flags &= ~ANOBJ_END_OF_PEER_LIST;
 202                 node->flags |= ANOBJ_END_OF_PEER_LIST;
 203                 node->peer = parent_node;
 204         }
 205
 206         /* Init the new entry */
 207
 208         node->owner_id = owner_id;
 209         node->type = (u8) type;
 210
 211         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
 212                           "%4.4s (%s) [Node %p Owner %X] added to %4.4s (%s) [Node %p]\n",
 213                           acpi_ut_get_node_name(node),
 214                           acpi_ut_get_type_name(node->type), node, owner_id,
 215                           acpi_ut_get_node_name(parent_node),
 216                           acpi_ut_get_type_name(parent_node->type),
 217                           parent_node));
 218
 219         /*
 220          * Increment the reference count(s) of all parents up to
 221          * the root!
 222          */
 223         while ((node = acpi_ns_get_parent_node(node)) != NULL) {
 224                 node->reference_count++;
 225         }
 226
 227         return_VOID;
 228 }
 229
 230 /*******************************************************************************
 231  *
 232  * FUNCTION:    acpi_ns_delete_children
 233  *
 234  * PARAMETERS:  parent_node     - Delete this objects children
 235  *
 236  * RETURN:      None.
 237  *
 238  * DESCRIPTION: Delete all children of the parent object. In other words,
 239  *              deletes a "scope".
 240  *
 241  ******************************************************************************/
 242
 243 void acpi_ns_delete_children(struct acpi_namespace_node *parent_node)
 244 {
 245         struct acpi_namespace_node *child_node;
 246         struct acpi_namespace_node *next_node;
 247         struct acpi_namespace_node *node;
 248         u8 flags;
 249
 250         ACPI_FUNCTION_TRACE_PTR("ns_delete_children", parent_node);
 251
 252         if (!parent_node) {
 253                 return_VOID;
 254         }
 255
 256         /* If no children, all done! */
 257
 258         child_node = parent_node->child;
 259         if (!child_node) {
 260                 return_VOID;
 261         }
 262
 263         /*
 264          * Deallocate all children at this level
 265          */
 266         do {
 267                 /* Get the things we need */
 268
 269                 next_node = child_node->peer;
 270                 flags = child_node->flags;
 271
 272                 /* Grandchildren should have all been deleted already */
 273
 274                 if (child_node->child) {
 275                         ACPI_ERROR((AE_INFO, "Found a grandchild! P=%p C=%p",
 276                                     parent_node, child_node));
 277                 }
 278
 279                 /* Now we can free this child object */
 280
 281                 ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_freed++);
 282
 283                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 284                                   "Object %p, Remaining %X\n", child_node,
 285                                   acpi_gbl_current_node_count));
 286
 287                 /*
 288                  * Detach an object if there is one, then free the child node
 289                  */
 290                 acpi_ns_detach_object(child_node);
 291
 292                 /*
 293                  * Decrement the reference count(s) of all parents up to
 294                  * the root! (counts were incremented when the node was created)
 295                  */
 296                 node = child_node;
 297                 while ((node = acpi_ns_get_parent_node(node)) != NULL) {
 298                         node->reference_count--;
 299                 }
 300
 301                 /* There should be only one reference remaining on this node */
 302
 303                 if (child_node->reference_count != 1) {
 304                         ACPI_WARNING((AE_INFO,
 305                                       "Existing references (%d) on node being deleted (%p)",
 306                                       child_node->reference_count, child_node));
 307                 }
 308
 309                 /* Now we can delete the node */
 310
 311                 ACPI_MEM_FREE(child_node);
 312
 313                 /* And move on to the next child in the list */
 314
 315                 child_node = next_node;
 316
 317         } while (!(flags & ANOBJ_END_OF_PEER_LIST));
 318
 319         /* Clear the parent's child pointer */
 320
 321         parent_node->child = NULL;
 322
 323         return_VOID;
 324 }
 325
 326 /*******************************************************************************
 327  *
 328  * FUNCTION:    acpi_ns_delete_namespace_subtree
 329  *
 330  * PARAMETERS:  parent_node     - Root of the subtree to be deleted
 331  *
 332  * RETURN:      None.
 333  *
 334  * DESCRIPTION: Delete a subtree of the namespace.  This includes all objects
 335  *              stored within the subtree.
 336  *
 337  ******************************************************************************/
 338
 339 void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
 340 {
 341         struct acpi_namespace_node *child_node = NULL;
 342         u32 level = 1;
 343
 344         ACPI_FUNCTION_TRACE("ns_delete_namespace_subtree");
 345
 346         if (!parent_node) {
 347                 return_VOID;
 348         }
 349
 350         /*
 351          * Traverse the tree of objects until we bubble back up
 352          * to where we started.
 353          */
 354         while (level > 0) {
 355                 /* Get the next node in this scope (NULL if none) */
 356
 357                 child_node = acpi_ns_get_next_node(ACPI_TYPE_ANY, parent_node,
 358                                                    child_node);
 359                 if (child_node) {
 360                         /* Found a child node - detach any attached object */
 361
 362                         acpi_ns_detach_object(child_node);
 363
 364                         /* Check if this node has any children */
 365
 366                         if (acpi_ns_get_next_node
 367                             (ACPI_TYPE_ANY, child_node, NULL)) {
 368                                 /*
 369                                  * There is at least one child of this node,
 370                                  * visit the node
 371                                  */
 372                                 level++;
 373                                 parent_node = child_node;
 374                                 child_node = NULL;
 375                         }
 376                 } else {
 377                         /*
 378                          * No more children of this parent node.
 379                          * Move up to the grandparent.
 380                          */
 381                         level--;
 382
 383                         /*
 384                          * Now delete all of the children of this parent
 385                          * all at the same time.
 386                          */
 387                         acpi_ns_delete_children(parent_node);
 388
 389                         /* New "last child" is this parent node */
 390
 391                         child_node = parent_node;
 392
 393                         /* Move up the tree to the grandparent */
 394
 395                         parent_node = acpi_ns_get_parent_node(parent_node);
 396                 }
 397         }
 398
 399         return_VOID;
 400 }
 401
 402 /*******************************************************************************
 403  *
 404  * FUNCTION:    acpi_ns_remove_reference
 405  *
 406  * PARAMETERS:  Node           - Named node whose reference count is to be
 407  *                               decremented
 408  *
 409  * RETURN:      None.
 410  *
 411  * DESCRIPTION: Remove a Node reference.  Decrements the reference count
 412  *              of all parent Nodes up to the root.  Any node along
 413  *              the way that reaches zero references is freed.
 414  *
 415  ******************************************************************************/
 416
 417 static void acpi_ns_remove_reference(struct acpi_namespace_node *node)
 418 {
 419         struct acpi_namespace_node *parent_node;
 420         struct acpi_namespace_node *this_node;
 421
 422         ACPI_FUNCTION_ENTRY();
 423
 424         /*
 425          * Decrement the reference count(s) of this node and all
 426          * nodes up to the root,  Delete anything with zero remaining references.
 427          */
 428         this_node = node;
 429         while (this_node) {
 430                 /* Prepare to move up to parent */
 431
 432                 parent_node = acpi_ns_get_parent_node(this_node);
 433
 434                 /* Decrement the reference count on this node */
 435
 436                 this_node->reference_count--;
 437
 438                 /* Delete the node if no more references */
 439
 440                 if (!this_node->reference_count) {
 441                         /* Delete all children and delete the node */
 442
 443                         acpi_ns_delete_children(this_node);
 444                         acpi_ns_delete_node(this_node);
 445                 }
 446
 447                 this_node = parent_node;
 448         }
 449 }
 450
 451 /*******************************************************************************
 452  *
 453  * FUNCTION:    acpi_ns_delete_namespace_by_owner
 454  *
 455  * PARAMETERS:  owner_id    - All nodes with this owner will be deleted
 456  *
 457  * RETURN:      Status
 458  *
 459  * DESCRIPTION: Delete entries within the namespace that are owned by a
 460  *              specific ID.  Used to delete entire ACPI tables.  All
 461  *              reference counts are updated.
 462  *
 463  ******************************************************************************/
 464
 465 void acpi_ns_delete_namespace_by_owner(acpi_owner_id owner_id)
 466 {
 467         struct acpi_namespace_node *child_node;
 468         struct acpi_namespace_node *deletion_node;
 469         u32 level;
 470         struct acpi_namespace_node *parent_node;
 471
 472         ACPI_FUNCTION_TRACE_U32("ns_delete_namespace_by_owner", owner_id);
 473
 474         if (owner_id == 0) {
 475                 return_VOID;
 476         }
 477
 478         parent_node = acpi_gbl_root_node;
 479         child_node = NULL;
 480         deletion_node = NULL;
 481         level = 1;
 482
 483         /*
 484          * Traverse the tree of nodes until we bubble back up
 485          * to where we started.
 486          */
 487         while (level > 0) {
 488                 /*
 489                  * Get the next child of this parent node. When child_node is NULL,
 490                  * the first child of the parent is returned
 491                  */
 492                 child_node =
 493                     acpi_ns_get_next_node(ACPI_TYPE_ANY, parent_node,
 494                                           child_node);
 495
 496                 if (deletion_node) {
 497                         acpi_ns_remove_reference(deletion_node);
 498                         deletion_node = NULL;
 499                 }
 500
 501                 if (child_node) {
 502                         if (child_node->owner_id == owner_id) {
 503                                 /* Found a matching child node - detach any attached object */
 504
 505                                 acpi_ns_detach_object(child_node);
 506                         }
 507
 508                         /* Check if this node has any children */
 509
 510                         if (acpi_ns_get_next_node
 511                             (ACPI_TYPE_ANY, child_node, NULL)) {
 512                                 /*
 513                                  * There is at least one child of this node,
 514                                  * visit the node
 515                                  */
 516                                 level++;
 517                                 parent_node = child_node;
 518                                 child_node = NULL;
 519                         } else if (child_node->owner_id == owner_id) {
 520                                 deletion_node = child_node;
 521                         }
 522                 } else {
 523                         /*
 524                          * No more children of this parent node.
 525                          * Move up to the grandparent.
 526                          */
 527                         level--;
 528                         if (level != 0) {
 529                                 if (parent_node->owner_id == owner_id) {
 530                                         deletion_node = parent_node;
 531                                 }
 532                         }
 533
 534                         /* New "last child" is this parent node */
 535
 536                         child_node = parent_node;
 537
 538                         /* Move up the tree to the grandparent */
 539
 540                         parent_node = acpi_ns_get_parent_node(parent_node);
 541                 }
 542         }
 543
 544         return_VOID;
 545 }