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exresolv.c

/******************************************************************************
 *
 * Module Name: exresolv - AML Interpreter object resolution
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/amlcode.h>
#include <acpi/acdispat.h>
#include <acpi/acinterp.h>
#include <acpi/acnamesp.h>
#include <acpi/acparser.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exresolv")

/* Local prototypes */
static acpi_status
acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
                        struct acpi_walk_state *walk_state);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_to_value
 *
 * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
 *                                    be either an (union acpi_operand_object *)
 *                                    or an acpi_handle.
 *              walk_state          - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert Reference objects to values
 *
 ******************************************************************************/

acpi_status
acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
                   struct acpi_walk_state *walk_state)
{
      acpi_status status;

      ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);

      if (!stack_ptr || !*stack_ptr) {
            ACPI_ERROR((AE_INFO, "Internal - null pointer"));
            return_ACPI_STATUS(AE_AML_NO_OPERAND);
      }

      /*
       * The entity pointed to by the stack_ptr can be either
       * 1) A valid union acpi_operand_object, or
       * 2) A struct acpi_namespace_node (named_obj)
       */
      if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
            status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
            if (ACPI_FAILURE(status)) {
                  return_ACPI_STATUS(status);
            }

            if (!*stack_ptr) {
                  ACPI_ERROR((AE_INFO, "Internal - null pointer"));
                  return_ACPI_STATUS(AE_AML_NO_OPERAND);
            }
      }

      /*
       * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
       * was called (i.e., we can't use an _else_ here.)
       */
      if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
            status =
                acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
                                      (struct acpi_namespace_node,
                                       stack_ptr), walk_state);
            if (ACPI_FAILURE(status)) {
                  return_ACPI_STATUS(status);
            }
      }

      ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p\n", *stack_ptr));
      return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_object_to_value
 *
 * PARAMETERS:  stack_ptr       - Pointer to an internal object
 *              walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Retrieve the value from an internal object. The Reference type
 *              uses the associated AML opcode to determine the value.
 *
 ******************************************************************************/

static acpi_status
acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
                        struct acpi_walk_state *walk_state)
{
      acpi_status status = AE_OK;
      union acpi_operand_object *stack_desc;
      void *temp_node;
      union acpi_operand_object *obj_desc = NULL;
      u16 opcode;

      ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);

      stack_desc = *stack_ptr;

      /* This is an union acpi_operand_object    */

      switch (ACPI_GET_OBJECT_TYPE(stack_desc)) {
      case ACPI_TYPE_LOCAL_REFERENCE:

            opcode = stack_desc->reference.opcode;

            switch (opcode) {
            case AML_NAME_OP:

                  /*
                   * Convert name reference to a namespace node
                   * Then, acpi_ex_resolve_node_to_value can be used to get the value
                   */
                  temp_node = stack_desc->reference.object;

                  /* Delete the Reference Object */

                  acpi_ut_remove_reference(stack_desc);

                  /* Return the namespace node */

                  (*stack_ptr) = temp_node;
                  break;

            case AML_LOCAL_OP:
            case AML_ARG_OP:

                  /*
                   * Get the local from the method's state info
                   * Note: this increments the local's object reference count
                   */
                  status = acpi_ds_method_data_get_value(opcode,
                                                 stack_desc->
                                                 reference.offset,
                                                 walk_state,
                                                 &obj_desc);
                  if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                  }

                  ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                "[Arg/Local %X] ValueObj is %p\n",
                                stack_desc->reference.offset,
                                obj_desc));

                  /*
                   * Now we can delete the original Reference Object and
                   * replace it with the resolved value
                   */
                  acpi_ut_remove_reference(stack_desc);
                  *stack_ptr = obj_desc;
                  break;

            case AML_INDEX_OP:

                  switch (stack_desc->reference.target_type) {
                  case ACPI_TYPE_BUFFER_FIELD:

                        /* Just return - leave the Reference on the stack */
                        break;

                  case ACPI_TYPE_PACKAGE:

                        obj_desc = *stack_desc->reference.where;
                        if (obj_desc) {
                              /*
                               * Valid obj descriptor, copy pointer to return value
                               * (i.e., dereference the package index)
                               * Delete the ref object, increment the returned object
                               */
                              acpi_ut_remove_reference(stack_desc);
                              acpi_ut_add_reference(obj_desc);
                              *stack_ptr = obj_desc;
                        } else {
                              /*
                               * A NULL object descriptor means an unitialized element of
                               * the package, can't dereference it
                               */
                              ACPI_ERROR((AE_INFO,
                                        "Attempt to deref an Index to NULL pkg element Idx=%p",
                                        stack_desc));
                              status = AE_AML_UNINITIALIZED_ELEMENT;
                        }
                        break;

                  default:

                        /* Invalid reference object */

                        ACPI_ERROR((AE_INFO,
                                  "Unknown TargetType %X in Index/Reference obj %p",
                                  stack_desc->reference.target_type,
                                  stack_desc));
                        status = AE_AML_INTERNAL;
                        break;
                  }
                  break;

            case AML_REF_OF_OP:
            case AML_DEBUG_OP:
            case AML_LOAD_OP:

                  /* Just leave the object as-is */

                  break;

            case AML_INT_NAMEPATH_OP:     /* Reference to a named object */

                  /* Dereference the name */

                  if ((stack_desc->reference.node->type ==
                       ACPI_TYPE_DEVICE)
                      || (stack_desc->reference.node->type ==
                        ACPI_TYPE_THERMAL)) {

                        /* These node types do not have 'real' subobjects */

                        *stack_ptr = (void *)stack_desc->reference.node;
                  } else {
                        /* Get the object pointed to by the namespace node */

                        *stack_ptr =
                            (stack_desc->reference.node)->object;
                        acpi_ut_add_reference(*stack_ptr);
                  }

                  acpi_ut_remove_reference(stack_desc);
                  break;

            default:

                  ACPI_ERROR((AE_INFO,
                            "Unknown Reference opcode %X (%s) in %p",
                            opcode, acpi_ps_get_opcode_name(opcode),
                            stack_desc));
                  status = AE_AML_INTERNAL;
                  break;
            }
            break;

      case ACPI_TYPE_BUFFER:

            status = acpi_ds_get_buffer_arguments(stack_desc);
            break;

      case ACPI_TYPE_PACKAGE:

            status = acpi_ds_get_package_arguments(stack_desc);
            break;

      case ACPI_TYPE_BUFFER_FIELD:
      case ACPI_TYPE_LOCAL_REGION_FIELD:
      case ACPI_TYPE_LOCAL_BANK_FIELD:
      case ACPI_TYPE_LOCAL_INDEX_FIELD:

            ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "FieldRead SourceDesc=%p Type=%X\n",
                          stack_desc,
                          ACPI_GET_OBJECT_TYPE(stack_desc)));

            status =
                acpi_ex_read_data_from_field(walk_state, stack_desc,
                                     &obj_desc);

            /* Remove a reference to the original operand, then override */

            acpi_ut_remove_reference(*stack_ptr);
            *stack_ptr = (void *)obj_desc;
            break;

      default:
            break;
      }

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_resolve_multiple
 *
 * PARAMETERS:  walk_state          - Current state (contains AML opcode)
 *              Operand             - Starting point for resolution
 *              return_type         - Where the object type is returned
 *              return_desc         - Where the resolved object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Return the base object and type.  Traverse a reference list if
 *              necessary to get to the base object.
 *
 ******************************************************************************/

acpi_status
acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
                   union acpi_operand_object *operand,
                   acpi_object_type * return_type,
                   union acpi_operand_object **return_desc)
{
      union acpi_operand_object *obj_desc = (void *)operand;
      struct acpi_namespace_node *node;
      acpi_object_type type;
      acpi_status status;

      ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);

      /* Operand can be either a namespace node or an operand descriptor */

      switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
      case ACPI_DESC_TYPE_OPERAND:
            type = obj_desc->common.type;
            break;

      case ACPI_DESC_TYPE_NAMED:
            type = ((struct acpi_namespace_node *)obj_desc)->type;
            obj_desc =
                acpi_ns_get_attached_object((struct acpi_namespace_node *)
                                    obj_desc);

            /* If we had an Alias node, use the attached object for type info */

            if (type == ACPI_TYPE_LOCAL_ALIAS) {
                  type = ((struct acpi_namespace_node *)obj_desc)->type;
                  obj_desc =
                      acpi_ns_get_attached_object((struct
                                           acpi_namespace_node *)
                                          obj_desc);
            }
            break;

      default:
            return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
      }

      /* If type is anything other than a reference, we are done */

      if (type != ACPI_TYPE_LOCAL_REFERENCE) {
            goto exit;
      }

      /*
       * For reference objects created via the ref_of or Index operators,
       * we need to get to the base object (as per the ACPI specification
       * of the object_type and size_of operators). This means traversing
       * the list of possibly many nested references.
       */
      while (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REFERENCE) {
            switch (obj_desc->reference.opcode) {
            case AML_REF_OF_OP:
            case AML_INT_NAMEPATH_OP:

                  /* Dereference the reference pointer */

                  if (obj_desc->reference.opcode == AML_REF_OF_OP) {
                        node = obj_desc->reference.object;
                  } else {    /* AML_INT_NAMEPATH_OP */

                        node = obj_desc->reference.node;
                  }

                  /* All "References" point to a NS node */

                  if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
                      ACPI_DESC_TYPE_NAMED) {
                        ACPI_ERROR((AE_INFO, "Not a NS node %p [%s]",
                                  node,
                                  acpi_ut_get_descriptor_name(node)));
                        return_ACPI_STATUS(AE_AML_INTERNAL);
                  }

                  /* Get the attached object */

                  obj_desc = acpi_ns_get_attached_object(node);
                  if (!obj_desc) {

                        /* No object, use the NS node type */

                        type = acpi_ns_get_type(node);
                        goto exit;
                  }

                  /* Check for circular references */

                  if (obj_desc == operand) {
                        return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
                  }
                  break;

            case AML_INDEX_OP:

                  /* Get the type of this reference (index into another object) */

                  type = obj_desc->reference.target_type;
                  if (type != ACPI_TYPE_PACKAGE) {
                        goto exit;
                  }

                  /*
                   * The main object is a package, we want to get the type
                   * of the individual package element that is referenced by
                   * the index.
                   *
                   * This could of course in turn be another reference object.
                   */
                  obj_desc = *(obj_desc->reference.where);
                  if (!obj_desc) {

                        /* NULL package elements are allowed */

                        type = 0;   /* Uninitialized */
                        goto exit;
                  }
                  break;

            case AML_LOCAL_OP:
            case AML_ARG_OP:

                  if (return_desc) {
                        status =
                            acpi_ds_method_data_get_value(obj_desc->
                                                  reference.
                                                  opcode,
                                                  obj_desc->
                                                  reference.
                                                  offset,
                                                  walk_state,
                                                  &obj_desc);
                        if (ACPI_FAILURE(status)) {
                              return_ACPI_STATUS(status);
                        }
                        acpi_ut_remove_reference(obj_desc);
                  } else {
                        status =
                            acpi_ds_method_data_get_node(obj_desc->
                                                 reference.
                                                 opcode,
                                                 obj_desc->
                                                 reference.
                                                 offset,
                                                 walk_state,
                                                 &node);
                        if (ACPI_FAILURE(status)) {
                              return_ACPI_STATUS(status);
                        }

                        obj_desc = acpi_ns_get_attached_object(node);
                        if (!obj_desc) {
                              type = ACPI_TYPE_ANY;
                              goto exit;
                        }
                  }
                  break;

            case AML_DEBUG_OP:

                  /* The Debug Object is of type "DebugObject" */

                  type = ACPI_TYPE_DEBUG_OBJECT;
                  goto exit;

            default:

                  ACPI_ERROR((AE_INFO,
                            "Unknown Reference subtype %X",
                            obj_desc->reference.opcode));
                  return_ACPI_STATUS(AE_AML_INTERNAL);
            }
      }

      /*
       * Now we are guaranteed to have an object that has not been created
       * via the ref_of or Index operators.
       */
      type = ACPI_GET_OBJECT_TYPE(obj_desc);

      exit:
      /* Convert internal types to external types */

      switch (type) {
      case ACPI_TYPE_LOCAL_REGION_FIELD:
      case ACPI_TYPE_LOCAL_BANK_FIELD:
      case ACPI_TYPE_LOCAL_INDEX_FIELD:

            type = ACPI_TYPE_FIELD_UNIT;
            break;

      case ACPI_TYPE_LOCAL_SCOPE:

            /* Per ACPI Specification, Scope is untyped */

            type = ACPI_TYPE_ANY;
            break;

      default:
            /* No change to Type required */
            break;
      }

      *return_type = type;
      if (return_desc) {
            *return_desc = obj_desc;
      }
      return_ACPI_STATUS(AE_OK);
}

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