CORE/VOSS/src/vos_event.c

/*
 * Copyright (c) 2012-2013 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */

/*============================================================================
  FILE:         vos_event.c

  OVERVIEW:     This source file contains definitions for vOS event APIs
                The five APIs mentioned in this file are used for
                initializing, setting, resetting, destroying an event and
                waiting on an occurance of an event among multiple events.

  DEPENDENCIES:

============================================================================*/

/*============================================================================
  EDIT HISTORY FOR MODULE

============================================================================*/

/*----------------------------------------------------------------------------
 * Include Files
 * -------------------------------------------------------------------------*/
#include "vos_event.h"
#include "vos_trace.h"

/*----------------------------------------------------------------------------
 * Preprocessor Definitions and Constants
 * -------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
 * Type Declarations
 * -------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
 * Global Data Definitions
 * -------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
 * Static Variable Definitions
 * -------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
   Function Definitions and Documentation
 * -------------------------------------------------------------------------*/

/*-------------------------------------------------------------------------

  \brief vos_event_init() - initializes a vOSS event

  The vos_event_init() function initializes the specified event. Upon
  successful initialization, the state of the event becomes initialized
  and not signaled.

  An event must be initialized before it may be used in any other event
  functions.

  Attempting to initialize an already initialized event results in
  a failure.

  \param lock - pointer to the opaque event object to initialize

  \return VOS_STATUS_SUCCESS - event was successfully initialized and
          is ready to be used.

          VOS_STATUS_E_BUSY - The implementation has detected an attempt
          to reinitialize the object referenced by event, a previously
          initialized, but not yet destroyed, event.

          VOS_STATUS_E_FAULT  - event is an invalid pointer.

          VOS_STATUS_E_FAILURE - event could not be created due to
          unknown reasons

       ***VOS_STATUS_E_RESOURCES - System resources (other than memory)
          are unavailable to initilize the event

       ***VOS_STATUS_E_NOMEM - insufficient memory exists to initialize
          the event

  \sa

  ( *** indicates return values do NOT exist yet )
  -------------------------------------------------------------------------*/
VOS_STATUS vos_event_init ( vos_event_t* event )
{

   // Check for null pointer
   if ( NULL == event )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "NULL event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check for 'already initialized' event
   if ( LINUX_EVENT_COOKIE == event->cookie )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "Initialized event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_BUSY;
   }

   // initialize new event
   init_completion(&event->complete);
   event->cookie = LINUX_EVENT_COOKIE;

   return VOS_STATUS_SUCCESS;
}

/*--------------------------------------------------------------------------

  \brief vos_event_set() - sets a vOSS event

  The state of the specified event is set to 'signalled by calling
  \a vos_event_set().

  Any threads waiting on the event as a result of a vos_event_wait() will
  be unblocked and available to be scheduled for execution when the event
  is signaled by a call to \a vos_event_set().

  \param event - the event to set to the signalled state

  \return VOS_STATUS_SUCCESS - the event was successfully signalled.

          VOS_STATUS_E_INVAL - The value specified by event does not refer
          to an initialized event object.

          VOS_STATUS_E_FAULT  - event is an invalid pointer.

          VOS_STATUS_E_FAILURE - event could not be signaled due to
          unknown reasons

  \sa

  -------------------------------------------------------------------------*/

VOS_STATUS vos_event_set ( vos_event_t* event )
{

   // Check for null pointer
   if ( NULL == event )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "NULL event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check if event refers to an initialized object
   if ( LINUX_EVENT_COOKIE != event->cookie )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "Uninitialized event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_INVAL;
   }

   complete(&event->complete);

   return VOS_STATUS_SUCCESS;
}

/*--------------------------------------------------------------------------

  \brief vos_event_reset() - resets a vOSS event - This function isn't required
   for Linux. Therefore, it doesn't do much.

  The state of the specified event is set to 'NOT signalled' by calling
  \a vos_event_reset().  The state of the event remains NOT signalled until an
  explicit call to vos_event_set().

  This function sets the event to a NOT signalled state even if the event was
  signalled multiple times before being signaled.

  \param event - the event to set to the NOT signalled state

  \return VOS_STATUS_SUCCESS - the event state was successfully change to
          NOT signalled.

          VOS_STATUS_E_INVAL - The value specified by event does not refer
          to an initialized event object.

          VOS_STATUS_E_FAULT  - event is an invalid pointer.

          VOS_STATUS_E_FAILURE - event could not be signaled due to
          unknown reasons


  \sa

  -------------------------------------------------------------------------*/
VOS_STATUS vos_event_reset ( vos_event_t* event )
{

   // check for null pointer
   if ( NULL == event )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "NULL event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check to make sure it is an 'already initialized' event
   if ( LINUX_EVENT_COOKIE != event->cookie )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "Uninitialized event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_INVAL;
   }

   // (re)initialize event
   INIT_COMPLETION(event->complete);
   return VOS_STATUS_SUCCESS;
}


/*----------------------------------------------------------------------------

  \brief vos_wait_events() - Waits for the first event(s) to be set.

   This API waits for any event in the input array of events to be
   set.  The caller is blocked waiting any event in the array to be
   set or for the timeout to occur.

   If multiple events in the array are set, only one event is identified
   in the return from this call as satisfying the wait condition.  The
   caller is responsible for calling \a vos_wait_events() again to find
   the other events that are set.

  \param events - pointer to an array of events to wait on.

  \param numEvents - Number of events in the events array to wait on.

  \param timeout - Timeout value (in milliseconds).  This function returns
         if this interval elapses, regardless if any of the events have
         been set.  An input value of 0 for this timeout parameter means
         to wait infinitely, meaning a timeout will never occur.

  \param pEventIndex - This is a pointer to the location where the index of
         the event in the event array that satisfied the wait because
         the event was set.

  \return VOS_STATUS_SUCCESS - the wait was satisifed by one of the events
          in the event array being set.  The index into the event arry
          that satisfied the wait can be found at *pEventIndex.

          VOS_STATUS_E_TIMEOUT - the timeout interval elapsed before any of
          the events were set.

          VOS_STATUS_E_INVAL - At least one of the values specified in the
          event array refers to an uninitialized event object.

          VOS_STATUS_E_ABORTED - The event due to which the wait was aborted
          is identified by the index in *pEventIndex.

          VOS_STATUS_E_EMPTY - the events array is empty.  This condition
          is detected by numEvents being 0 on input.

          VOS_STATUS_E_FAULT - event or pEventIndex is an invalid pointer.

          VOS_STATUS_E_FAILURE - default return value if it fails due to
          unknown reasons

  \sa
   --------------------------------------------------------------------------*/
VOS_STATUS vos_wait_events ( vos_event_t* events,
                             v_U8_t numEvents, v_U32_t timeout,
                             v_U8_t *pEventIndex )
{

   return vos_wait_single_event(events,timeout);
}

/*--------------------------------------------------------------------------

  \brief vos_event_destroy() - Destroys a vOSS event - This function doesn't do
   much in Linux. There is no need for the caller to explicitly destroy an event
   after use.

  The os_event_destroy() function shall destroy the event object
  referenced by event.  After a successful return from \a vos_event_destroy()
  the event object becomes, in effect, uninitialized.

  A destroyed event object can be reinitialized using vos_event_init();
  the results of otherwise referencing the object after it has been destroyed
  are undefined.  Calls to vOSS event functions to manipulate the lock such
  as vos_event_set() will fail if the event is destroyed.  Therefore,
  don't use the event after it has been destroyed until it has
  been re-initialized.

  \param event - the event object to be destroyed.

  \return VOS_STATUS_SUCCESS - event was successfully destroyed.

          VOS_STATUS_E_INVAL - The value specified by event is invalid.

          VOS_STATUS_E_FAULT - event is an invalid pointer.

          VOS_STATUS_E_FAILURE - event could not be signaled due to
          unknown reasons

       ***VOS_STATUS_E_BUSY - The implementation has detected an attempt
          to destroy the object referenced by event while it is still being
          referenced (there are threads waiting on this event)
  \sa

   ( *** indicates return values do NOT exist yet )
  -------------------------------------------------------------------------*/

VOS_STATUS vos_event_destroy ( vos_event_t* event )
{
   // check for null pointer
   if ( NULL == event )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "NULL event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check to make sure it is an 'already initialized' event
   if ( LINUX_EVENT_COOKIE != event->cookie )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "Uninitialized event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_INVAL;
   }

   // make sure nobody is waiting on the event
   complete_all(&event->complete);

   // destroy the event
   memset(event, 0, sizeof(vos_event_t));

   return VOS_STATUS_SUCCESS;
}

/*----------------------------------------------------------------------------

  \brief vos_wait_single_event() - Waits for a single event to be set.

   This API waits for the event to be set.

  \param pEvent - pointer to an event to wait on.

  \param timeout - Timeout value (in milliseconds).  This function returns
         if this interval elapses, regardless if any of the events have
         been set.  An input value of 0 for this timeout parameter means
         to wait infinitely, meaning a timeout will never occur.

  \return VOS_STATUS_SUCCESS - the wait was satisifed by the event being
          set.

          VOS_STATUS_E_TIMEOUT - the timeout interval elapsed before the
          event was set.

          VOS_STATUS_E_INVAL - The value specified by event is invalid.

          VOS_STATUS_E_FAULT - pEvent is an invalid pointer.

  \sa vos_wait_multiple_events()

  --------------------------------------------------------------------------*/
VOS_STATUS vos_wait_single_event ( vos_event_t* event, v_U32_t timeout)
{

   if (in_interrupt())
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "%s cannot be called from interrupt context!!!", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check for null pointer
   if ( NULL == event )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "NULL event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_FAULT;
   }

   // check if cookie is same as that of initialized event
   if ( LINUX_EVENT_COOKIE != event->cookie )
   {
      VOS_TRACE(VOS_MODULE_ID_VOSS, VOS_TRACE_LEVEL_FATAL,
                "Uninitialized event passed into %s", __func__);
      VOS_ASSERT(0);
      return VOS_STATUS_E_INVAL;
   }

   if (timeout)
   {
      long ret;
      ret =
         wait_for_completion_timeout(&event->complete,
                                                   msecs_to_jiffies(timeout));
      if ( 0 >= ret )
      {
        return VOS_STATUS_E_TIMEOUT;
      }
   }
   else
   {
      int ret;
      ret = wait_for_completion_interruptible(&event->complete);
      if ( 0 != ret )
      {
         // negative means interrupted
         return VOS_STATUS_E_TIMEOUT;
      }
   }

   return VOS_STATUS_SUCCESS;
}

/*----------------------------------------------------------------------------

  \brief vos_wait_multiple_events() - Waits for event(s) to be set.
   This is a duplicate of vos_wait_events() function. It ends up calling
   vos_wait_events() with the params passed in.

   This API waits for any event in the input array of events to be
   set.  The caller is blocked waiting any event in the array to be
   set or for the timeout to occur.

   If multiple events in the array are set, only one event is identified
   in the return from this call as satisfying the wait condition.  The
   caller is responsible for calling \a vos_wait_events() again to find
   the other events that are set.

  \param pEventList - pointer to an array of event pointers

  \param numEvents - Number of events

  \param timeout - Timeout value (in milliseconds).  This function returns
         if this interval elapses, regardless if any of the events have
         been set.  An input value of 0 for this timeout parameter means
         to wait infinitely, meaning a timeout will never occur.

  \param pEventIndex - This is a pointer to the location where the index of
         the event in the event array that satisfied the wait because
         the event was set.

  \return VOS_STATUS_SUCCESS - the wait was satisifed by one of the events
          in the event array being set.  The index into the event arry
          that satisfied the wait can be found at *pEventIndex.

          VOS_STATUS_E_TIMEOUT - the timeout interval elapsed before any of
          the events were set.

          VOS_STATUS_E_INVAL - At least one of the values specified in the
          event array refers to an uninitialized event object.  The invalid
          event is identified by the index in *pEventIndex.  Note that only
          the first uninitialized event is detected when this error is
          returned.

          VOS_STATUS_E_EMPTY - the events array is empty.  This condition
          is detected by numEvents being 0 on input.

          VOS_STATUS_E_FAULT - event or pEventIndex is an invalid pointer.

  \sa vos_wait_single_events()

  --------------------------------------------------------------------------*/
VOS_STATUS vos_wait_multiple_events( vos_event_t **events, v_U8_t numEvents,
   v_U32_t timeout, v_U8_t *pEventIndex )
{
   // NO LONGER SUPPORTED
   return VOS_STATUS_E_FAILURE;
}