LXR linux/drivers/acpi/executer/exresolv.c

   1
   2/******************************************************************************
   3 *
   4 * Module Name: exresolv - AML Interpreter object resolution
   5 *
   6 *****************************************************************************/
   7
   8/*
   9 * Copyright (C) 2000 - 2007, R. Byron Moore
  10 * All rights reserved.
  11 *
  12 * Redistribution and use in source and binary forms, with or without
  13 * modification, are permitted provided that the following conditions
  14 * are met:
  15 * 1. Redistributions of source code must retain the above copyright
  16 *    notice, this list of conditions, and the following disclaimer,
  17 *    without modification.
  18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19 *    substantially similar to the "NO WARRANTY" disclaimer below
  20 *    ("Disclaimer") and any redistribution must be conditioned upon
  21 *    including a substantially similar Disclaimer requirement for further
  22 *    binary redistribution.
  23 * 3. Neither the names of the above-listed copyright holders nor the names
  24 *    of any contributors may be used to endorse or promote products derived
  25 *    from this software without specific prior written permission.
  26 *
  27 * Alternatively, this software may be distributed under the terms of the
  28 * GNU General Public License ("GPL") version 2 as published by the Free
  29 * Software Foundation.
  30 *
  31 * NO WARRANTY
  32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42 * POSSIBILITY OF SUCH DAMAGES.
  43 */
  44
  45#include <acpi/acpi.h>
  46#include <acpi/amlcode.h>
  47#include <acpi/acdispat.h>
  48#include <acpi/acinterp.h>
  49#include <acpi/acnamesp.h>
  50#include <acpi/acparser.h>
  51
  52#define _COMPONENT          ACPI_EXECUTER
  53ACPI_MODULE_NAME("exresolv")
  54
  55/* Local prototypes */
  56static acpi_status
  57acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
  58                                struct acpi_walk_state *walk_state);
  59
  60/*******************************************************************************
  61 *
  62 * FUNCTION:    acpi_ex_resolve_to_value
  63 *
  64 * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
  65 *                                    be either an (union acpi_operand_object *)
  66 *                                    or an acpi_handle.
  67 *              walk_state          - Current method state
  68 *
  69 * RETURN:      Status
  70 *
  71 * DESCRIPTION: Convert Reference objects to values
  72 *
  73 ******************************************************************************/
  74
  75acpi_status
  76acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
  77                         struct acpi_walk_state *walk_state)
  78{
  79        acpi_status status;
  80
  81        ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
  82
  83        if (!stack_ptr || !*stack_ptr) {
  84                ACPI_ERROR((AE_INFO, "Internal - null pointer"));
  85                return_ACPI_STATUS(AE_AML_NO_OPERAND);
  86        }
  87
  88        /*
  89         * The entity pointed to by the stack_ptr can be either
  90         * 1) A valid union acpi_operand_object, or
  91         * 2) A struct acpi_namespace_node (named_obj)
  92         */
  93        if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
  94                status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
  95                if (ACPI_FAILURE(status)) {
  96                        return_ACPI_STATUS(status);
  97                }
  98
  99                if (!*stack_ptr) {
 100                        ACPI_ERROR((AE_INFO, "Internal - null pointer"));
 101                        return_ACPI_STATUS(AE_AML_NO_OPERAND);
 102                }
 103        }
 104
 105        /*
 106         * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
 107         * was called (i.e., we can't use an _else_ here.)
 108         */
 109        if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
 110                status =
 111                    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
 112                                                  (struct acpi_namespace_node,
 113                                                   stack_ptr), walk_state);
 114                if (ACPI_FAILURE(status)) {
 115                        return_ACPI_STATUS(status);
 116                }
 117        }
 118
 119        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
 120        return_ACPI_STATUS(AE_OK);
 121}
 122
 123/*******************************************************************************
 124 *
 125 * FUNCTION:    acpi_ex_resolve_object_to_value
 126 *
 127 * PARAMETERS:  stack_ptr       - Pointer to an internal object
 128 *              walk_state      - Current method state
 129 *
 130 * RETURN:      Status
 131 *
 132 * DESCRIPTION: Retrieve the value from an internal object. The Reference type
 133 *              uses the associated AML opcode to determine the value.
 134 *
 135 ******************************************************************************/
 136
 137static acpi_status
 138acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
 139                                struct acpi_walk_state *walk_state)
 140{
 141        acpi_status status = AE_OK;
 142        union acpi_operand_object *stack_desc;
 143        void *temp_node;
 144        union acpi_operand_object *obj_desc = NULL;
 145        u16 opcode;
 146
 147        ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
 148
 149        stack_desc = *stack_ptr;
 150
 151        /* This is an union acpi_operand_object    */
 152
 153        switch (ACPI_GET_OBJECT_TYPE(stack_desc)) {
 154        case ACPI_TYPE_LOCAL_REFERENCE:
 155
 156                opcode = stack_desc->reference.opcode;
 157
 158                switch (opcode) {
 159                case AML_NAME_OP:
 160
 161                        /*
 162                         * Convert name reference to a namespace node
 163                         * Then, acpi_ex_resolve_node_to_value can be used to get the value
 164                         */
 165                        temp_node = stack_desc->reference.object;
 166
 167                        /* Delete the Reference Object */
 168
 169                        acpi_ut_remove_reference(stack_desc);
 170
 171                        /* Return the namespace node */
 172
 173                        (*stack_ptr) = temp_node;
 174                        break;
 175
 176                case AML_LOCAL_OP:
 177                case AML_ARG_OP:
 178
 179                        /*
 180                         * Get the local from the method's state info
 181                         * Note: this increments the local's object reference count
 182                         */
 183                        status = acpi_ds_method_data_get_value(opcode,
 184                                                               stack_desc->
 185                                                               reference.offset,
 186                                                               walk_state,
 187                                                               &obj_desc);
 188                        if (ACPI_FAILURE(status)) {
 189                                return_ACPI_STATUS(status);
 190                        }
 191
 192                        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 193                                          "[Arg/Local %X] ValueObj is %p\n",
 194                                          stack_desc->reference.offset,
 195                                          obj_desc));
 196
 197                        /*
 198                         * Now we can delete the original Reference Object and
 199                         * replace it with the resolved value
 200                         */
 201                        acpi_ut_remove_reference(stack_desc);
 202                        *stack_ptr = obj_desc;
 203                        break;
 204
 205                case AML_INDEX_OP:
 206
 207                        switch (stack_desc->reference.target_type) {
 208                        case ACPI_TYPE_BUFFER_FIELD:
 209
 210                                /* Just return - leave the Reference on the stack */
 211                                break;
 212
 213                        case ACPI_TYPE_PACKAGE:
 214
 215                                obj_desc = *stack_desc->reference.where;
 216                                if (obj_desc) {
 217                                        /*
 218                                         * Valid obj descriptor, copy pointer to return value
 219                                         * (i.e., dereference the package index)
 220                                         * Delete the ref object, increment the returned object
 221                                         */
 222                                        acpi_ut_remove_reference(stack_desc);
 223                                        acpi_ut_add_reference(obj_desc);
 224                                        *stack_ptr = obj_desc;
 225                                } else {
 226                                        /*
 227                                         * A NULL object descriptor means an unitialized element of
 228                                         * the package, can't dereference it
 229                                         */
 230                                        ACPI_ERROR((AE_INFO,
 231                                                    "Attempt to deref an Index to NULL pkg element Idx=%p",
 232                                                    stack_desc));
 233                                        status = AE_AML_UNINITIALIZED_ELEMENT;
 234                                }
 235                                break;
 236
 237                        default:
 238
 239                                /* Invalid reference object */
 240
 241                                ACPI_ERROR((AE_INFO,
 242                                            "Unknown TargetType %X in Index/Reference obj %p",
 243                                            stack_desc->reference.target_type,
 244                                            stack_desc));
 245                                status = AE_AML_INTERNAL;
 246                                break;
 247                        }
 248                        break;
 249
 250                case AML_REF_OF_OP:
 251                case AML_DEBUG_OP:
 252                case AML_LOAD_OP:
 253
 254                        /* Just leave the object as-is */
 255
 256                        break;
 257
 258                case AML_INT_NAMEPATH_OP:       /* Reference to a named object */
 259
 260                        /* Dereference the name */
 261
 262                        if ((stack_desc->reference.node->type ==
 263                             ACPI_TYPE_DEVICE)
 264                            || (stack_desc->reference.node->type ==
 265                                ACPI_TYPE_THERMAL)) {
 266
 267                                /* These node types do not have 'real' subobjects */
 268
 269                                *stack_ptr = (void *)stack_desc->reference.node;
 270                        } else {
 271                                /* Get the object pointed to by the namespace node */
 272
 273                                *stack_ptr =
 274                                    (stack_desc->reference.node)->object;
 275                                acpi_ut_add_reference(*stack_ptr);
 276                        }
 277
 278                        acpi_ut_remove_reference(stack_desc);
 279                        break;
 280
 281                default:
 282
 283                        ACPI_ERROR((AE_INFO,
 284                                    "Unknown Reference opcode %X (%s) in %p",
 285                                    opcode, acpi_ps_get_opcode_name(opcode),
 286                                    stack_desc));
 287                        status = AE_AML_INTERNAL;
 288                        break;
 289                }
 290                break;
 291
 292        case ACPI_TYPE_BUFFER:
 293
 294                status = acpi_ds_get_buffer_arguments(stack_desc);
 295                break;
 296
 297        case ACPI_TYPE_PACKAGE:
 298
 299                status = acpi_ds_get_package_arguments(stack_desc);
 300                break;
 301
 302        case ACPI_TYPE_BUFFER_FIELD:
 303        case ACPI_TYPE_LOCAL_REGION_FIELD:
 304        case ACPI_TYPE_LOCAL_BANK_FIELD:
 305        case ACPI_TYPE_LOCAL_INDEX_FIELD:
 306
 307                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 308                                  "FieldRead SourceDesc=%p Type=%X\n",
 309                                  stack_desc,
 310                                  ACPI_GET_OBJECT_TYPE(stack_desc)));
 311
 312                status =
 313                    acpi_ex_read_data_from_field(walk_state, stack_desc,
 314                                                 &obj_desc);
 315
 316                /* Remove a reference to the original operand, then override */
 317
 318                acpi_ut_remove_reference(*stack_ptr);
 319                *stack_ptr = (void *)obj_desc;
 320                break;
 321
 322        default:
 323                break;
 324        }
 325
 326        return_ACPI_STATUS(status);
 327}
 328
 329/*******************************************************************************
 330 *
 331 * FUNCTION:    acpi_ex_resolve_multiple
 332 *
 333 * PARAMETERS:  walk_state          - Current state (contains AML opcode)
 334 *              Operand             - Starting point for resolution
 335 *              return_type         - Where the object type is returned
 336 *              return_desc         - Where the resolved object is returned
 337 *
 338 * RETURN:      Status
 339 *
 340 * DESCRIPTION: Return the base object and type.  Traverse a reference list if
 341 *              necessary to get to the base object.
 342 *
 343 ******************************************************************************/
 344
 345acpi_status
 346acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
 347                         union acpi_operand_object *operand,
 348                         acpi_object_type * return_type,
 349                         union acpi_operand_object **return_desc)
 350{
 351        union acpi_operand_object *obj_desc = (void *)operand;
 352        struct acpi_namespace_node *node;
 353        acpi_object_type type;
 354        acpi_status status;
 355
 356        ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
 357
 358        /* Operand can be either a namespace node or an operand descriptor */
 359
 360        switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
 361        case ACPI_DESC_TYPE_OPERAND:
 362                type = obj_desc->common.type;
 363                break;
 364
 365        case ACPI_DESC_TYPE_NAMED:
 366                type = ((struct acpi_namespace_node *)obj_desc)->type;
 367                obj_desc =
 368                    acpi_ns_get_attached_object((struct acpi_namespace_node *)
 369                                                obj_desc);
 370
 371                /* If we had an Alias node, use the attached object for type info */
 372
 373                if (type == ACPI_TYPE_LOCAL_ALIAS) {
 374                        type = ((struct acpi_namespace_node *)obj_desc)->type;
 375                        obj_desc =
 376                            acpi_ns_get_attached_object((struct
 377                                                         acpi_namespace_node *)
 378                                                        obj_desc);
 379                }
 380                break;
 381
 382        default:
 383                return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 384        }
 385
 386        /* If type is anything other than a reference, we are done */
 387
 388        if (type != ACPI_TYPE_LOCAL_REFERENCE) {
 389                goto exit;
 390        }
 391
 392        /*
 393         * For reference objects created via the ref_of or Index operators,
 394         * we need to get to the base object (as per the ACPI specification
 395         * of the object_type and size_of operators). This means traversing
 396         * the list of possibly many nested references.
 397         */
 398        while (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REFERENCE) {
 399                switch (obj_desc->reference.opcode) {
 400                case AML_REF_OF_OP:
 401                case AML_INT_NAMEPATH_OP:
 402
 403                        /* Dereference the reference pointer */
 404
 405                        if (obj_desc->reference.opcode == AML_REF_OF_OP) {
 406                                node = obj_desc->reference.object;
 407                        } else {        /* AML_INT_NAMEPATH_OP */
 408
 409                                node = obj_desc->reference.node;
 410                        }
 411
 412                        /* All "References" point to a NS node */
 413
 414                        if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
 415                            ACPI_DESC_TYPE_NAMED) {
 416                                ACPI_ERROR((AE_INFO, "Not a NS node %p [%s]",
 417                                            node,
 418                                            acpi_ut_get_descriptor_name(node)));
 419                                return_ACPI_STATUS(AE_AML_INTERNAL);
 420                        }
 421
 422                        /* Get the attached object */
 423
 424                        obj_desc = acpi_ns_get_attached_object(node);
 425                        if (!obj_desc) {
 426
 427                                /* No object, use the NS node type */
 428
 429                                type = acpi_ns_get_type(node);
 430                                goto exit;
 431                        }
 432
 433                        /* Check for circular references */
 434
 435                        if (obj_desc == operand) {
 436                                return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
 437                        }
 438                        break;
 439
 440                case AML_INDEX_OP:
 441
 442                        /* Get the type of this reference (index into another object) */
 443
 444                        type = obj_desc->reference.target_type;
 445                        if (type != ACPI_TYPE_PACKAGE) {
 446                                goto exit;
 447                        }
 448
 449                        /*
 450                         * The main object is a package, we want to get the type
 451                         * of the individual package element that is referenced by
 452                         * the index.
 453                         *
 454                         * This could of course in turn be another reference object.
 455                         */
 456                        obj_desc = *(obj_desc->reference.where);
 457                        if (!obj_desc) {
 458
 459                                /* NULL package elements are allowed */
 460
 461                                type = 0;       /* Uninitialized */
 462                                goto exit;
 463                        }
 464                        break;
 465
 466                case AML_LOCAL_OP:
 467                case AML_ARG_OP:
 468
 469                        if (return_desc) {
 470                                status =
 471                                    acpi_ds_method_data_get_value(obj_desc->
 472                                                                  reference.
 473                                                                  opcode,
 474                                                                  obj_desc->
 475                                                                  reference.
 476                                                                  offset,
 477                                                                  walk_state,
 478                                                                  &obj_desc);
 479                                if (ACPI_FAILURE(status)) {
 480                                        return_ACPI_STATUS(status);
 481                                }
 482                                acpi_ut_remove_reference(obj_desc);
 483                        } else {
 484                                status =
 485                                    acpi_ds_method_data_get_node(obj_desc->
 486                                                                 reference.
 487                                                                 opcode,
 488                                                                 obj_desc->
 489                                                                 reference.
 490                                                                 offset,
 491                                                                 walk_state,
 492                                                                 &node);
 493                                if (ACPI_FAILURE(status)) {
 494                                        return_ACPI_STATUS(status);
 495                                }
 496
 497                                obj_desc = acpi_ns_get_attached_object(node);
 498                                if (!obj_desc) {
 499                                        type = ACPI_TYPE_ANY;
 500                                        goto exit;
 501                                }
 502                        }
 503                        break;
 504
 505                case AML_DEBUG_OP:
 506
 507                        /* The Debug Object is of type "DebugObject" */
 508
 509                        type = ACPI_TYPE_DEBUG_OBJECT;
 510                        goto exit;
 511
 512                default:
 513
 514                        ACPI_ERROR((AE_INFO,
 515                                    "Unknown Reference subtype %X",
 516                                    obj_desc->reference.opcode));
 517                        return_ACPI_STATUS(AE_AML_INTERNAL);
 518                }
 519        }
 520
 521        /*
 522         * Now we are guaranteed to have an object that has not been created
 523         * via the ref_of or Index operators.
 524         */
 525        type = ACPI_GET_OBJECT_TYPE(obj_desc);
 526
 527      exit:
 528        /* Convert internal types to external types */
 529
 530        switch (type) {
 531        case ACPI_TYPE_LOCAL_REGION_FIELD:
 532        case ACPI_TYPE_LOCAL_BANK_FIELD:
 533        case ACPI_TYPE_LOCAL_INDEX_FIELD:
 534
 535                type = ACPI_TYPE_FIELD_UNIT;
 536                break;
 537
 538        case ACPI_TYPE_LOCAL_SCOPE:
 539
 540                /* Per ACPI Specification, Scope is untyped */
 541
 542                type = ACPI_TYPE_ANY;
 543                break;
 544
 545        default:
 546                /* No change to Type required */
 547                break;
 548        }
 549
 550        *return_type = type;
 551        if (return_desc) {
 552                *return_desc = obj_desc;
 553        }
 554        return_ACPI_STATUS(AE_OK);
 555}
 556