text: /*******************************************************************************
   *
   * Module Name: utxfmutex - external AML mutex access functions
   *
   ******************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2014, Intel Corp.
   * 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.
   */
  
  #define __UTXFMUTEX_C__
  
  #include "acpi.h"
  #include "accommon.h"
  #include "acnamesp.h"
  
  
  #define _COMPONENT          ACPI_UTILITIES
          ACPI_MODULE_NAME    ("utxfmutex")
  
  
  /* Local prototypes */
  
  static ACPI_STATUS
  AcpiUtGetMutexObject (
      ACPI_HANDLE             Handle,
      ACPI_STRING             Pathname,
      ACPI_OPERAND_OBJECT     **RetObj);
  
  
  /*******************************************************************************
   *
   * FUNCTION:    AcpiUtGetMutexObject
   *
   * PARAMETERS:  Handle              - Mutex or prefix handle (optional)
   *              Pathname            - Mutex pathname (optional)
   *              RetObj              - Where the mutex object is returned
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by
   *              Handle:Pathname. Either Handle or Pathname can be NULL, but
   *              not both.
   *
   ******************************************************************************/
  
  static ACPI_STATUS
  AcpiUtGetMutexObject (
      ACPI_HANDLE             Handle,
      ACPI_STRING             Pathname,
      ACPI_OPERAND_OBJECT     **RetObj)
  {
      ACPI_NAMESPACE_NODE     *MutexNode;
      ACPI_OPERAND_OBJECT     *MutexObj;
      ACPI_STATUS             Status;
  
  
      /* Parameter validation */
  
      if (!RetObj || (!Handle && !Pathname))
      {
          return (AE_BAD_PARAMETER);
      }
  
      /* Get a the namespace node for the mutex */
  
      MutexNode = Handle;
      if (Pathname != NULL)
      {
          Status = AcpiGetHandle (Handle, Pathname,
              ACPI_CAST_PTR (ACPI_HANDLE, &MutexNode));
          if (ACPI_FAILURE (Status))
          {
              return (Status);
          }
      }
  
      /* Ensure that we actually have a Mutex object */
  
      if (!MutexNode ||
          (MutexNode->Type != ACPI_TYPE_MUTEX))
      {
          return (AE_TYPE);
      }
  
      /* Get the low-level mutex object */
  
      MutexObj = AcpiNsGetAttachedObject (MutexNode);
      if (!MutexObj)
      {
          return (AE_NULL_OBJECT);
      }
  
      *RetObj = MutexObj;
      return (AE_OK);
  }
  
  
  /*******************************************************************************
   *
   * FUNCTION:    AcpiAcquireMutex
   *
   * PARAMETERS:  Handle              - Mutex or prefix handle (optional)
   *              Pathname            - Mutex pathname (optional)
   *              Timeout             - Max time to wait for the lock (millisec)
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to
   *              AML mutex objects, and allows for transaction locking between
   *              drivers and AML code. The mutex node is pointed to by
   *              Handle:Pathname. Either Handle or Pathname can be NULL, but
   *              not both.
   *
   ******************************************************************************/
  
  ACPI_STATUS
  AcpiAcquireMutex (
      ACPI_HANDLE             Handle,
      ACPI_STRING             Pathname,
      UINT16                  Timeout)
  {
      ACPI_STATUS             Status;
      ACPI_OPERAND_OBJECT     *MutexObj;
  
  
      /* Get the low-level mutex associated with Handle:Pathname */
  
      Status = AcpiUtGetMutexObject (Handle, Pathname, &MutexObj);
      if (ACPI_FAILURE (Status))
      {
          return (Status);
      }
  
      /* Acquire the OS mutex */
  
      Status = AcpiOsAcquireMutex (MutexObj->Mutex.OsMutex, Timeout);
      return (Status);
  }
  
  
  /*******************************************************************************
   *
   * FUNCTION:    AcpiReleaseMutex
   *
   * PARAMETERS:  Handle              - Mutex or prefix handle (optional)
   *              Pathname            - Mutex pathname (optional)
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Release an AML mutex. This is a device driver interface to
   *              AML mutex objects, and allows for transaction locking between
   *              drivers and AML code. The mutex node is pointed to by
   *              Handle:Pathname. Either Handle or Pathname can be NULL, but
   *              not both.
   *
   ******************************************************************************/
  
  ACPI_STATUS
  AcpiReleaseMutex (
      ACPI_HANDLE             Handle,
      ACPI_STRING             Pathname)
  {
      ACPI_STATUS             Status;
      ACPI_OPERAND_OBJECT     *MutexObj;
  
  
      /* Get the low-level mutex associated with Handle:Pathname */
  
      Status = AcpiUtGetMutexObject (Handle, Pathname, &MutexObj);
      if (ACPI_FAILURE (Status))
      {
          return (Status);
      }
  
      /* Release the OS mutex */
  
      AcpiOsReleaseMutex (MutexObj->Mutex.OsMutex);
      return (AE_OK);
  }
  