/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup RTEMSTestSuites
 *
 * @brief This source file contains the implementation of CallWithinISR(),
 *   CallWithinISRSubmit(), and CallWithinISRWait().
 */

/*
 * Copyright (C) 2021 embedded brains GmbH (http://www.embedded-brains.de)
 *
 * 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.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "tx-support.h"

#include <rtems/sysinit.h>
#include <rtems/score/chainimpl.h>

#include <bsp.h>

/* Some target architectures need this variable for <tm27.h> */
uint32_t Interrupt_nest;

#define _RTEMS_TMTEST27

#include <tm27.h>

typedef struct {
  Chain_Control pending;
  RTEMS_INTERRUPT_LOCK_MEMBER( lock )
} CallWithinISRContext;

static CallWithinISRContext CallWithinISRInstance = {
#if defined( RTEMS_SMP )
  .lock = RTEMS_INTERRUPT_LOCK_INITIALIZER( "CallWithinISR" ),
#endif
  .pending = CHAIN_INITIALIZER_EMPTY( CallWithinISRInstance.pending )
};

static void CallWithinISRHandler( rtems_vector_number vector )
{
  CallWithinISRContext *ctx;

  (void) vector;
  ctx = &CallWithinISRInstance;

  Clear_tm27_intr();

  while ( true ) {
    rtems_interrupt_lock_context lock_context;
    CallWithinISRRequest        *request;

    rtems_interrupt_lock_acquire( &ctx->lock, &lock_context );
    request = (CallWithinISRRequest *)
      _Chain_Get_unprotected( &ctx->pending );
    rtems_interrupt_lock_release( &ctx->lock, &lock_context );

    if ( request == NULL ) {
      break;
    }

    ( *request->handler )( request->arg );
    _Atomic_Store_uint( &request->done, 1, ATOMIC_ORDER_RELEASE );
  }
}

void CallWithinISR( void ( *handler )( void * ), void *arg )
{
  CallWithinISRRequest request;

  request.handler = handler;
  request.arg = arg;
  CallWithinISRSubmit( &request );
  CallWithinISRWait( &request );
}

void CallWithinISRSubmit( CallWithinISRRequest *request )
{
  CallWithinISRContext        *ctx;
  rtems_interrupt_lock_context lock_context;

  ctx = &CallWithinISRInstance;

  rtems_interrupt_lock_acquire( &ctx->lock, &lock_context );
  _Atomic_Store_uint( &request->done, 0, ATOMIC_ORDER_RELAXED );
  _Chain_Initialize_node( &request->node );
  _Chain_Append_unprotected( &ctx->pending, &request->node );
  rtems_interrupt_lock_release( &ctx->lock, &lock_context );

  Cause_tm27_intr();
}

void CallWithinISRWait( const CallWithinISRRequest *request )
{
  while ( _Atomic_Load_uint( &request->done, ATOMIC_ORDER_ACQUIRE ) == 0 ) {
    /* Wait */
  }
}

static void CallWithinISRInitialize( void )
{
  Install_tm27_vector( CallWithinISRHandler );
}

RTEMS_SYSINIT_ITEM(
  CallWithinISRInitialize,
  RTEMS_SYSINIT_DEVICE_DRIVERS,
  RTEMS_SYSINIT_ORDER_MIDDLE
);