drivers/acpi/dispatcher/dswstate.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dswstate - Dispatcher parse tree walk management routines
   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/acparser.h>
  46 #include <acpi/acdispat.h>
  47 #include <acpi/acnamesp.h>
  48
  49 #define _COMPONENT          ACPI_DISPATCHER
  50 ACPI_MODULE_NAME("dswstate")
  51
  52 /* Local prototypes */
  53 #ifdef ACPI_OBSOLETE_FUNCTIONS
  54 acpi_status
  55 acpi_ds_result_insert(void *object,
  56                       u32 index, struct acpi_walk_state *walk_state);
  57
  58 acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state *walk_state);
  59
  60 acpi_status
  61 acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
  62                              struct acpi_walk_state *walk_state);
  63
  64 void *acpi_ds_obj_stack_get_value(u32 index,
  65                                   struct acpi_walk_state *walk_state);
  66 #endif
  67
  68 #ifdef ACPI_FUTURE_USAGE
  69
  70 /*******************************************************************************
  71  *
  72  * FUNCTION:    acpi_ds_result_remove
  73  *
  74  * PARAMETERS:  Object              - Where to return the popped object
  75  *              Index               - Where to extract the object
  76  *              walk_state          - Current Walk state
  77  *
  78  * RETURN:      Status
  79  *
  80  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
  81  *              other words, this is a FIFO.
  82  *
  83  ******************************************************************************/
  84
  85 acpi_status
  86 acpi_ds_result_remove(union acpi_operand_object **object,
  87                       u32 index, struct acpi_walk_state *walk_state)
  88 {
  89         union acpi_generic_state *state;
  90
  91         ACPI_FUNCTION_NAME("ds_result_remove");
  92
  93         state = walk_state->results;
  94         if (!state) {
  95                 ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
  96                             walk_state));
  97                 return (AE_NOT_EXIST);
  98         }
  99
 100         if (index >= ACPI_OBJ_MAX_OPERAND) {
 101                 ACPI_ERROR((AE_INFO,
 102                             "Index out of range: %X State=%p Num=%X",
 103                             index, walk_state, state->results.num_results));
 104         }
 105
 106         /* Check for a valid result object */
 107
 108         if (!state->results.obj_desc[index]) {
 109                 ACPI_ERROR((AE_INFO,
 110                             "Null operand! State=%p #Ops=%X, Index=%X",
 111                             walk_state, state->results.num_results, index));
 112                 return (AE_AML_NO_RETURN_VALUE);
 113         }
 114
 115         /* Remove the object */
 116
 117         state->results.num_results--;
 118
 119         *object = state->results.obj_desc[index];
 120         state->results.obj_desc[index] = NULL;
 121
 122         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 123                           "Obj=%p [%s] Index=%X State=%p Num=%X\n",
 124                           *object,
 125                           (*object) ? acpi_ut_get_object_type_name(*object) :
 126                           "NULL", index, walk_state,
 127                           state->results.num_results));
 128
 129         return (AE_OK);
 130 }
 131
 132 #endif                          /*  ACPI_FUTURE_USAGE  */
 133
 134 /*******************************************************************************
 135  *
 136  * FUNCTION:    acpi_ds_result_pop
 137  *
 138  * PARAMETERS:  Object              - Where to return the popped object
 139  *              walk_state          - Current Walk state
 140  *
 141  * RETURN:      Status
 142  *
 143  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
 144  *              other words, this is a FIFO.
 145  *
 146  ******************************************************************************/
 147
 148 acpi_status
 149 acpi_ds_result_pop(union acpi_operand_object ** object,
 150                    struct acpi_walk_state * walk_state)
 151 {
 152         acpi_native_uint index;
 153         union acpi_generic_state *state;
 154
 155         ACPI_FUNCTION_NAME("ds_result_pop");
 156
 157         state = walk_state->results;
 158         if (!state) {
 159                 return (AE_OK);
 160         }
 161
 162         if (!state->results.num_results) {
 163                 ACPI_ERROR((AE_INFO, "Result stack is empty! State=%p",
 164                             walk_state));
 165                 return (AE_AML_NO_RETURN_VALUE);
 166         }
 167
 168         /* Remove top element */
 169
 170         state->results.num_results--;
 171
 172         for (index = ACPI_OBJ_NUM_OPERANDS; index; index--) {
 173
 174                 /* Check for a valid result object */
 175
 176                 if (state->results.obj_desc[index - 1]) {
 177                         *object = state->results.obj_desc[index - 1];
 178                         state->results.obj_desc[index - 1] = NULL;
 179
 180                         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 181                                           "Obj=%p [%s] Index=%X State=%p Num=%X\n",
 182                                           *object,
 183                                           (*object) ?
 184                                           acpi_ut_get_object_type_name(*object)
 185                                           : "NULL", (u32) index - 1, walk_state,
 186                                           state->results.num_results));
 187
 188                         return (AE_OK);
 189                 }
 190         }
 191
 192         ACPI_ERROR((AE_INFO, "No result objects! State=%p", walk_state));
 193         return (AE_AML_NO_RETURN_VALUE);
 194 }
 195
 196 /*******************************************************************************
 197  *
 198  * FUNCTION:    acpi_ds_result_pop_from_bottom
 199  *
 200  * PARAMETERS:  Object              - Where to return the popped object
 201  *              walk_state          - Current Walk state
 202  *
 203  * RETURN:      Status
 204  *
 205  * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
 206  *              other words, this is a FIFO.
 207  *
 208  ******************************************************************************/
 209
 210 acpi_status
 211 acpi_ds_result_pop_from_bottom(union acpi_operand_object ** object,
 212                                struct acpi_walk_state * walk_state)
 213 {
 214         acpi_native_uint index;
 215         union acpi_generic_state *state;
 216
 217         ACPI_FUNCTION_NAME("ds_result_pop_from_bottom");
 218
 219         state = walk_state->results;
 220         if (!state) {
 221                 ACPI_ERROR((AE_INFO,
 222                             "No result object pushed! State=%p", walk_state));
 223                 return (AE_NOT_EXIST);
 224         }
 225
 226         if (!state->results.num_results) {
 227                 ACPI_ERROR((AE_INFO, "No result objects! State=%p",
 228                             walk_state));
 229                 return (AE_AML_NO_RETURN_VALUE);
 230         }
 231
 232         /* Remove Bottom element */
 233
 234         *object = state->results.obj_desc[0];
 235
 236         /* Push entire stack down one element */
 237
 238         for (index = 0; index < state->results.num_results; index++) {
 239                 state->results.obj_desc[index] =
 240                     state->results.obj_desc[index + 1];
 241         }
 242
 243         state->results.num_results--;
 244
 245         /* Check for a valid result object */
 246
 247         if (!*object) {
 248                 ACPI_ERROR((AE_INFO,
 249                             "Null operand! State=%p #Ops=%X Index=%X",
 250                             walk_state, state->results.num_results,
 251                             (u32) index));
 252                 return (AE_AML_NO_RETURN_VALUE);
 253         }
 254
 255         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] Results=%p State=%p\n",
 256                           *object,
 257                           (*object) ? acpi_ut_get_object_type_name(*object) :
 258                           "NULL", state, walk_state));
 259
 260         return (AE_OK);
 261 }
 262
 263 /*******************************************************************************
 264  *
 265  * FUNCTION:    acpi_ds_result_push
 266  *
 267  * PARAMETERS:  Object              - Where to return the popped object
 268  *              walk_state          - Current Walk state
 269  *
 270  * RETURN:      Status
 271  *
 272  * DESCRIPTION: Push an object onto the current result stack
 273  *
 274  ******************************************************************************/
 275
 276 acpi_status
 277 acpi_ds_result_push(union acpi_operand_object * object,
 278                     struct acpi_walk_state * walk_state)
 279 {
 280         union acpi_generic_state *state;
 281
 282         ACPI_FUNCTION_NAME("ds_result_push");
 283
 284         state = walk_state->results;
 285         if (!state) {
 286                 ACPI_ERROR((AE_INFO, "No result stack frame during push"));
 287                 return (AE_AML_INTERNAL);
 288         }
 289
 290         if (state->results.num_results == ACPI_OBJ_NUM_OPERANDS) {
 291                 ACPI_ERROR((AE_INFO,
 292                             "Result stack overflow: Obj=%p State=%p Num=%X",
 293                             object, walk_state, state->results.num_results));
 294                 return (AE_STACK_OVERFLOW);
 295         }
 296
 297         if (!object) {
 298                 ACPI_ERROR((AE_INFO,
 299                             "Null Object! Obj=%p State=%p Num=%X",
 300                             object, walk_state, state->results.num_results));
 301                 return (AE_BAD_PARAMETER);
 302         }
 303
 304         state->results.obj_desc[state->results.num_results] = object;
 305         state->results.num_results++;
 306
 307         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
 308                           object,
 309                           object ?
 310                           acpi_ut_get_object_type_name((union
 311                                                         acpi_operand_object *)
 312                                                        object) : "NULL",
 313                           walk_state, state->results.num_results,
 314                           walk_state->current_result));
 315
 316         return (AE_OK);
 317 }
 318
 319 /*******************************************************************************
 320  *
 321  * FUNCTION:    acpi_ds_result_stack_push
 322  *
 323  * PARAMETERS:  walk_state          - Current Walk state
 324  *
 325  * RETURN:      Status
 326  *
 327  * DESCRIPTION: Push an object onto the walk_state result stack.
 328  *
 329  ******************************************************************************/
 330
 331 acpi_status acpi_ds_result_stack_push(struct acpi_walk_state * walk_state)
 332 {
 333         union acpi_generic_state *state;
 334
 335         ACPI_FUNCTION_NAME("ds_result_stack_push");
 336
 337         state = acpi_ut_create_generic_state();
 338         if (!state) {
 339                 return (AE_NO_MEMORY);
 340         }
 341
 342         state->common.data_type = ACPI_DESC_TYPE_STATE_RESULT;
 343         acpi_ut_push_generic_state(&walk_state->results, state);
 344
 345         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Results=%p State=%p\n",
 346                           state, walk_state));
 347
 348         return (AE_OK);
 349 }
 350
 351 /*******************************************************************************
 352  *
 353  * FUNCTION:    acpi_ds_result_stack_pop
 354  *
 355  * PARAMETERS:  walk_state          - Current Walk state
 356  *
 357  * RETURN:      Status
 358  *
 359  * DESCRIPTION: Pop an object off of the walk_state result stack.
 360  *
 361  ******************************************************************************/
 362
 363 acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state * walk_state)
 364 {
 365         union acpi_generic_state *state;
 366
 367         ACPI_FUNCTION_NAME("ds_result_stack_pop");
 368
 369         /* Check for stack underflow */
 370
 371         if (walk_state->results == NULL) {
 372                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Underflow - State=%p\n",
 373                                   walk_state));
 374                 return (AE_AML_NO_OPERAND);
 375         }
 376
 377         state = acpi_ut_pop_generic_state(&walk_state->results);
 378
 379         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 380                           "Result=%p remaining_results=%X State=%p\n",
 381                           state, state->results.num_results, walk_state));
 382
 383         acpi_ut_delete_generic_state(state);
 384
 385         return (AE_OK);
 386 }
 387
 388 /*******************************************************************************
 389  *
 390  * FUNCTION:    acpi_ds_obj_stack_push
 391  *
 392  * PARAMETERS:  Object              - Object to push
 393  *              walk_state          - Current Walk state
 394  *
 395  * RETURN:      Status
 396  *
 397  * DESCRIPTION: Push an object onto this walk's object/operand stack
 398  *
 399  ******************************************************************************/
 400
 401 acpi_status
 402 acpi_ds_obj_stack_push(void *object, struct acpi_walk_state * walk_state)
 403 {
 404         ACPI_FUNCTION_NAME("ds_obj_stack_push");
 405
 406         /* Check for stack overflow */
 407
 408         if (walk_state->num_operands >= ACPI_OBJ_NUM_OPERANDS) {
 409                 ACPI_ERROR((AE_INFO,
 410                             "Object stack overflow! Obj=%p State=%p #Ops=%X",
 411                             object, walk_state, walk_state->num_operands));
 412                 return (AE_STACK_OVERFLOW);
 413         }
 414
 415         /* Put the object onto the stack */
 416
 417         walk_state->operands[walk_state->num_operands] = object;
 418         walk_state->num_operands++;
 419
 420         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
 421                           object,
 422                           acpi_ut_get_object_type_name((union
 423                                                         acpi_operand_object *)
 424                                                        object), walk_state,
 425                           walk_state->num_operands));
 426
 427         return (AE_OK);
 428 }
 429
 430 /*******************************************************************************
 431  *
 432  * FUNCTION:    acpi_ds_obj_stack_pop
 433  *
 434  * PARAMETERS:  pop_count           - Number of objects/entries to pop
 435  *              walk_state          - Current Walk state
 436  *
 437  * RETURN:      Status
 438  *
 439  * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
 440  *              deleted by this routine.
 441  *
 442  ******************************************************************************/
 443
 444 acpi_status
 445 acpi_ds_obj_stack_pop(u32 pop_count, struct acpi_walk_state * walk_state)
 446 {
 447         u32 i;
 448
 449         ACPI_FUNCTION_NAME("ds_obj_stack_pop");
 450
 451         for (i = 0; i < pop_count; i++) {
 452
 453                 /* Check for stack underflow */
 454
 455                 if (walk_state->num_operands == 0) {
 456                         ACPI_ERROR((AE_INFO,
 457                                     "Object stack underflow! Count=%X State=%p #Ops=%X",
 458                                     pop_count, walk_state,
 459                                     walk_state->num_operands));
 460                         return (AE_STACK_UNDERFLOW);
 461                 }
 462
 463                 /* Just set the stack entry to null */
 464
 465                 walk_state->num_operands--;
 466                 walk_state->operands[walk_state->num_operands] = NULL;
 467         }
 468
 469         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
 470                           pop_count, walk_state, walk_state->num_operands));
 471
 472         return (AE_OK);
 473 }
 474
 475 /*******************************************************************************
 476  *
 477  * FUNCTION:    acpi_ds_obj_stack_pop_and_delete
 478  *
 479  * PARAMETERS:  pop_count           - Number of objects/entries to pop
 480  *              walk_state          - Current Walk state
 481  *
 482  * RETURN:      Status
 483  *
 484  * DESCRIPTION: Pop this walk's object stack and delete each object that is
 485  *              popped off.
 486  *
 487  ******************************************************************************/
 488
 489 acpi_status
 490 acpi_ds_obj_stack_pop_and_delete(u32 pop_count,
 491                                  struct acpi_walk_state * walk_state)
 492 {
 493         u32 i;
 494         union acpi_operand_object *obj_desc;
 495
 496         ACPI_FUNCTION_NAME("ds_obj_stack_pop_and_delete");
 497
 498         for (i = 0; i < pop_count; i++) {
 499
 500                 /* Check for stack underflow */
 501
 502                 if (walk_state->num_operands == 0) {
 503                         ACPI_ERROR((AE_INFO,
 504                                     "Object stack underflow! Count=%X State=%p #Ops=%X",
 505                                     pop_count, walk_state,
 506                                     walk_state->num_operands));
 507                         return (AE_STACK_UNDERFLOW);
 508                 }
 509
 510                 /* Pop the stack and delete an object if present in this stack entry */
 511
 512                 walk_state->num_operands--;
 513                 obj_desc = walk_state->operands[walk_state->num_operands];
 514                 if (obj_desc) {
 515                         acpi_ut_remove_reference(walk_state->
 516                                                  operands[walk_state->
 517                                                           num_operands]);
 518                         walk_state->operands[walk_state->num_operands] = NULL;
 519                 }
 520         }
 521
 522         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
 523                           pop_count, walk_state, walk_state->num_operands));
 524
 525         return (AE_OK);
 526 }
 527
 528 /*******************************************************************************
 529  *
 530  * FUNCTION:    acpi_ds_get_current_walk_state
 531  *
 532  * PARAMETERS:  Thread          - Get current active state for this Thread
 533  *
 534  * RETURN:      Pointer to the current walk state
 535  *
 536  * DESCRIPTION: Get the walk state that is at the head of the list (the "current"
 537  *              walk state.)
 538  *
 539  ******************************************************************************/
 540
 541 struct acpi_walk_state *acpi_ds_get_current_walk_state(struct acpi_thread_state
 542                                                        *thread)
 543 {
 544         ACPI_FUNCTION_NAME("ds_get_current_walk_state");
 545
 546         if (!thread) {
 547                 return (NULL);
 548         }
 549
 550         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Current walk_state %p\n",
 551                           thread->walk_state_list));
 552
 553         return (thread->walk_state_list);
 554 }
 555
 556 /*******************************************************************************
 557  *
 558  * FUNCTION:    acpi_ds_push_walk_state
 559  *
 560  * PARAMETERS:  walk_state      - State to push
 561  *              Thread          - Thread state object
 562  *
 563  * RETURN:      None
 564  *
 565  * DESCRIPTION: Place the Thread state at the head of the state list.
 566  *
 567  ******************************************************************************/
 568
 569 void
 570 acpi_ds_push_walk_state(struct acpi_walk_state *walk_state,
 571                         struct acpi_thread_state *thread)
 572 {
 573         ACPI_FUNCTION_TRACE("ds_push_walk_state");
 574
 575         walk_state->next = thread->walk_state_list;
 576         thread->walk_state_list = walk_state;
 577
 578         return_VOID;
 579 }
 580
 581 /*******************************************************************************
 582  *
 583  * FUNCTION:    acpi_ds_pop_walk_state
 584  *
 585  * PARAMETERS:  Thread      - Current thread state
 586  *
 587  * RETURN:      A walk_state object popped from the thread's stack
 588  *
 589  * DESCRIPTION: Remove and return the walkstate object that is at the head of
 590  *              the walk stack for the given walk list.  NULL indicates that
 591  *              the list is empty.
 592  *
 593  ******************************************************************************/
 594
 595 struct acpi_walk_state *acpi_ds_pop_walk_state(struct acpi_thread_state *thread)
 596 {
 597         struct acpi_walk_state *walk_state;
 598
 599         ACPI_FUNCTION_TRACE("ds_pop_walk_state");
 600
 601         walk_state = thread->walk_state_list;
 602
 603         if (walk_state) {
 604
 605                 /* Next walk state becomes the current walk state */
 606
 607                 thread->walk_state_list = walk_state->next;
 608
 609                 /*
 610                  * Don't clear the NEXT field, this serves as an indicator
 611                  * that there is a parent WALK STATE
 612                  * Do Not: walk_state->Next = NULL;
 613                  */
 614         }
 615
 616         return_PTR(walk_state);
 617 }
 618
 619 /*******************************************************************************
 620  *
 621  * FUNCTION:    acpi_ds_create_walk_state
 622  *
 623  * PARAMETERS:  owner_id        - ID for object creation
 624  *              Origin          - Starting point for this walk
 625  *              mth_desc        - Method object
 626  *              Thread          - Current thread state
 627  *
 628  * RETURN:      Pointer to the new walk state.
 629  *
 630  * DESCRIPTION: Allocate and initialize a new walk state.  The current walk
 631  *              state is set to this new state.
 632  *
 633  ******************************************************************************/
 634
 635 struct acpi_walk_state *acpi_ds_create_walk_state(acpi_owner_id owner_id,
 636                                                   union acpi_parse_object
 637                                                   *origin,
 638                                                   union acpi_operand_object
 639                                                   *mth_desc,
 640                                                   struct acpi_thread_state
 641                                                   *thread)
 642 {
 643         struct acpi_walk_state *walk_state;
 644         acpi_status status;
 645
 646         ACPI_FUNCTION_TRACE("ds_create_walk_state");
 647
 648         walk_state = ACPI_MEM_CALLOCATE(sizeof(struct acpi_walk_state));
 649         if (!walk_state) {
 650                 return_PTR(NULL);
 651         }
 652
 653         walk_state->data_type = ACPI_DESC_TYPE_WALK;
 654         walk_state->owner_id = owner_id;
 655         walk_state->origin = origin;
 656         walk_state->method_desc = mth_desc;
 657         walk_state->thread = thread;
 658
 659         walk_state->parser_state.start_op = origin;
 660
 661         /* Init the method args/local */
 662
 663 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
 664         acpi_ds_method_data_init(walk_state);
 665 #endif
 666
 667         /* Create an initial result stack entry */
 668
 669         status = acpi_ds_result_stack_push(walk_state);
 670         if (ACPI_FAILURE(status)) {
 671                 ACPI_MEM_FREE(walk_state);
 672                 return_PTR(NULL);
 673         }
 674
 675         /* Put the new state at the head of the walk list */
 676
 677         if (thread) {
 678                 acpi_ds_push_walk_state(walk_state, thread);
 679         }
 680
 681         return_PTR(walk_state);
 682 }
 683
 684 /*******************************************************************************
 685  *
 686  * FUNCTION:    acpi_ds_init_aml_walk
 687  *
 688  * PARAMETERS:  walk_state      - New state to be initialized
 689  *              Op              - Current parse op
 690  *              method_node     - Control method NS node, if any
 691  *              aml_start       - Start of AML
 692  *              aml_length      - Length of AML
 693  *              Info            - Method info block (params, etc.)
 694  *              pass_number     - 1, 2, or 3
 695  *
 696  * RETURN:      Status
 697  *
 698  * DESCRIPTION: Initialize a walk state for a pass 1 or 2 parse tree walk
 699  *
 700  ******************************************************************************/
 701
 702 acpi_status
 703 acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state,
 704                       union acpi_parse_object *op,
 705                       struct acpi_namespace_node *method_node,
 706                       u8 * aml_start,
 707                       u32 aml_length,
 708                       struct acpi_parameter_info *info, u8 pass_number)
 709 {
 710         acpi_status status;
 711         struct acpi_parse_state *parser_state = &walk_state->parser_state;
 712         union acpi_parse_object *extra_op;
 713
 714         ACPI_FUNCTION_TRACE("ds_init_aml_walk");
 715
 716         walk_state->parser_state.aml =
 717             walk_state->parser_state.aml_start = aml_start;
 718         walk_state->parser_state.aml_end =
 719             walk_state->parser_state.pkg_end = aml_start + aml_length;
 720
 721         /* The next_op of the next_walk will be the beginning of the method */
 722
 723         walk_state->next_op = NULL;
 724         walk_state->pass_number = pass_number;
 725
 726         if (info) {
 727                 if (info->parameter_type == ACPI_PARAM_GPE) {
 728                         walk_state->gpe_event_info =
 729                             ACPI_CAST_PTR(struct acpi_gpe_event_info,
 730                                           info->parameters);
 731                 } else {
 732                         walk_state->params = info->parameters;
 733                         walk_state->caller_return_desc = &info->return_object;
 734                 }
 735         }
 736
 737         status = acpi_ps_init_scope(&walk_state->parser_state, op);
 738         if (ACPI_FAILURE(status)) {
 739                 return_ACPI_STATUS(status);
 740         }
 741
 742         if (method_node) {
 743                 walk_state->parser_state.start_node = method_node;
 744                 walk_state->walk_type = ACPI_WALK_METHOD;
 745                 walk_state->method_node = method_node;
 746                 walk_state->method_desc =
 747                     acpi_ns_get_attached_object(method_node);
 748
 749                 /* Push start scope on scope stack and make it current  */
 750
 751                 status =
 752                     acpi_ds_scope_stack_push(method_node, ACPI_TYPE_METHOD,
 753                                              walk_state);
 754                 if (ACPI_FAILURE(status)) {
 755                         return_ACPI_STATUS(status);
 756                 }
 757
 758                 /* Init the method arguments */
 759
 760                 status = acpi_ds_method_data_init_args(walk_state->params,
 761                                                        ACPI_METHOD_NUM_ARGS,
 762                                                        walk_state);
 763                 if (ACPI_FAILURE(status)) {
 764                         return_ACPI_STATUS(status);
 765                 }
 766         } else {
 767                 /*
 768                  * Setup the current scope.
 769                  * Find a Named Op that has a namespace node associated with it.
 770                  * search upwards from this Op.  Current scope is the first
 771                  * Op with a namespace node.
 772                  */
 773                 extra_op = parser_state->start_op;
 774                 while (extra_op && !extra_op->common.node) {
 775                         extra_op = extra_op->common.parent;
 776                 }
 777
 778                 if (!extra_op) {
 779                         parser_state->start_node = NULL;
 780                 } else {
 781                         parser_state->start_node = extra_op->common.node;
 782                 }
 783
 784                 if (parser_state->start_node) {
 785
 786                         /* Push start scope on scope stack and make it current  */
 787
 788                         status =
 789                             acpi_ds_scope_stack_push(parser_state->start_node,
 790                                                      parser_state->start_node->
 791                                                      type, walk_state);
 792                         if (ACPI_FAILURE(status)) {
 793                                 return_ACPI_STATUS(status);
 794                         }
 795                 }
 796         }
 797
 798         status = acpi_ds_init_callbacks(walk_state, pass_number);
 799         return_ACPI_STATUS(status);
 800 }
 801
 802 /*******************************************************************************
 803  *
 804  * FUNCTION:    acpi_ds_delete_walk_state
 805  *
 806  * PARAMETERS:  walk_state      - State to delete
 807  *
 808  * RETURN:      Status
 809  *
 810  * DESCRIPTION: Delete a walk state including all internal data structures
 811  *
 812  ******************************************************************************/
 813
 814 void acpi_ds_delete_walk_state(struct acpi_walk_state *walk_state)
 815 {
 816         union acpi_generic_state *state;
 817
 818         ACPI_FUNCTION_TRACE_PTR("ds_delete_walk_state", walk_state);
 819
 820         if (!walk_state) {
 821                 return;
 822         }
 823
 824         if (walk_state->data_type != ACPI_DESC_TYPE_WALK) {
 825                 ACPI_ERROR((AE_INFO, "%p is not a valid walk state",
 826                             walk_state));
 827                 return;
 828         }
 829
 830         if (walk_state->parser_state.scope) {
 831                 ACPI_ERROR((AE_INFO, "%p walk still has a scope list",
 832                             walk_state));
 833         }
 834
 835         /* Always must free any linked control states */
 836
 837         while (walk_state->control_state) {
 838                 state = walk_state->control_state;
 839                 walk_state->control_state = state->common.next;
 840
 841                 acpi_ut_delete_generic_state(state);
 842         }
 843
 844         /* Always must free any linked parse states */
 845
 846         while (walk_state->scope_info) {
 847                 state = walk_state->scope_info;
 848                 walk_state->scope_info = state->common.next;
 849
 850                 acpi_ut_delete_generic_state(state);
 851         }
 852
 853         /* Always must free any stacked result states */
 854
 855         while (walk_state->results) {
 856                 state = walk_state->results;
 857                 walk_state->results = state->common.next;
 858
 859                 acpi_ut_delete_generic_state(state);
 860         }
 861
 862         ACPI_MEM_FREE(walk_state);
 863         return_VOID;
 864 }
 865
 866 #ifdef ACPI_OBSOLETE_FUNCTIONS
 867 /*******************************************************************************
 868  *
 869  * FUNCTION:    acpi_ds_result_insert
 870  *
 871  * PARAMETERS:  Object              - Object to push
 872  *              Index               - Where to insert the object
 873  *              walk_state          - Current Walk state
 874  *
 875  * RETURN:      Status
 876  *
 877  * DESCRIPTION: Insert an object onto this walk's result stack
 878  *
 879  ******************************************************************************/
 880
 881 acpi_status
 882 acpi_ds_result_insert(void *object,
 883                       u32 index, struct acpi_walk_state *walk_state)
 884 {
 885         union acpi_generic_state *state;
 886
 887         ACPI_FUNCTION_NAME("ds_result_insert");
 888
 889         state = walk_state->results;
 890         if (!state) {
 891                 ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
 892                             walk_state));
 893                 return (AE_NOT_EXIST);
 894         }
 895
 896         if (index >= ACPI_OBJ_NUM_OPERANDS) {
 897                 ACPI_ERROR((AE_INFO,
 898                             "Index out of range: %X Obj=%p State=%p Num=%X",
 899                             index, object, walk_state,
 900                             state->results.num_results));
 901                 return (AE_BAD_PARAMETER);
 902         }
 903
 904         if (!object) {
 905                 ACPI_ERROR((AE_INFO,
 906                             "Null Object! Index=%X Obj=%p State=%p Num=%X",
 907                             index, object, walk_state,
 908                             state->results.num_results));
 909                 return (AE_BAD_PARAMETER);
 910         }
 911
 912         state->results.obj_desc[index] = object;
 913         state->results.num_results++;
 914
 915         ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 916                           "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
 917                           object,
 918                           object ?
 919                           acpi_ut_get_object_type_name((union
 920                                                         acpi_operand_object *)
 921                                                        object) : "NULL",
 922                           walk_state, state->results.num_results,
 923                           walk_state->current_result));
 924
 925         return (AE_OK);
 926 }
 927
 928 /*******************************************************************************
 929  *
 930  * FUNCTION:    acpi_ds_obj_stack_delete_all
 931  *
 932  * PARAMETERS:  walk_state          - Current Walk state
 933  *
 934  * RETURN:      Status
 935  *
 936  * DESCRIPTION: Clear the object stack by deleting all objects that are on it.
 937  *              Should be used with great care, if at all!
 938  *
 939  ******************************************************************************/
 940
 941 acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state * walk_state)
 942 {
 943         u32 i;
 944
 945         ACPI_FUNCTION_TRACE_PTR("ds_obj_stack_delete_all", walk_state);
 946
 947         /* The stack size is configurable, but fixed */
 948
 949         for (i = 0; i < ACPI_OBJ_NUM_OPERANDS; i++) {
 950                 if (walk_state->operands[i]) {
 951                         acpi_ut_remove_reference(walk_state->operands[i]);
 952                         walk_state->operands[i] = NULL;
 953                 }
 954         }
 955
 956         return_ACPI_STATUS(AE_OK);
 957 }
 958
 959 /*******************************************************************************
 960  *
 961  * FUNCTION:    acpi_ds_obj_stack_pop_object
 962  *
 963  * PARAMETERS:  Object              - Where to return the popped object
 964  *              walk_state          - Current Walk state
 965  *
 966  * RETURN:      Status
 967  *
 968  * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
 969  *              deleted by this routine.
 970  *
 971  ******************************************************************************/
 972
 973 acpi_status
 974 acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
 975                              struct acpi_walk_state *walk_state)
 976 {
 977         ACPI_FUNCTION_NAME("ds_obj_stack_pop_object");
 978
 979         /* Check for stack underflow */
 980
 981         if (walk_state->num_operands == 0) {
 982                 ACPI_ERROR((AE_INFO,
 983                             "Missing operand/stack empty! State=%p #Ops=%X",
 984                             walk_state, walk_state->num_operands));
 985                 *object = NULL;
 986                 return (AE_AML_NO_OPERAND);
 987         }
 988
 989         /* Pop the stack */
 990
 991         walk_state->num_operands--;
 992
 993         /* Check for a valid operand */
 994
 995         if (!walk_state->operands[walk_state->num_operands]) {
 996                 ACPI_ERROR((AE_INFO,
 997                             "Null operand! State=%p #Ops=%X",
 998                             walk_state, walk_state->num_operands));
 999                 *object = NULL;
1000                 return (AE_AML_NO_OPERAND);
1001         }
1002
1003         /* Get operand and set stack entry to null */
1004
1005         *object = walk_state->operands[walk_state->num_operands];
1006         walk_state->operands[walk_state->num_operands] = NULL;
1007
1008         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
1009                           *object, acpi_ut_get_object_type_name(*object),
1010                           walk_state, walk_state->num_operands));
1011
1012         return (AE_OK);
1013 }
1014
1015 /*******************************************************************************
1016  *
1017  * FUNCTION:    acpi_ds_obj_stack_get_value
1018  *
1019  * PARAMETERS:  Index               - Stack index whose value is desired.  Based
1020  *                                    on the top of the stack (index=0 == top)
1021  *              walk_state          - Current Walk state
1022  *
1023  * RETURN:      Pointer to the requested operand
1024  *
1025  * DESCRIPTION: Retrieve an object from this walk's operand stack.  Index must
1026  *              be within the range of the current stack pointer.
1027  *
1028  ******************************************************************************/
1029
1030 void *acpi_ds_obj_stack_get_value(u32 index, struct acpi_walk_state *walk_state)
1031 {
1032
1033         ACPI_FUNCTION_TRACE_PTR("ds_obj_stack_get_value", walk_state);
1034
1035         /* Can't do it if the stack is empty */
1036
1037         if (walk_state->num_operands == 0) {
1038                 return_PTR(NULL);
1039         }
1040
1041         /* or if the index is past the top of the stack */
1042
1043         if (index > (walk_state->num_operands - (u32) 1)) {
1044                 return_PTR(NULL);
1045         }
1046
1047         return_PTR(walk_state->
1048                    operands[(acpi_native_uint) (walk_state->num_operands - 1) -
1049                             index]);
1050 }
1051 #endif