rtems/score/mrsp.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSScoreMRSP
0007  *
0008  * @brief This header file provides interfaces of the
0009  *   @ref RTEMSScoreMRSP which are used by the implementation and the
0010  *   @ref RTEMSImplApplConfig.
0011  */
0012
0013 /*
0014  * Copyright (C) 2014, 2016 embedded brains GmbH & Co. KG
0015  *
0016  * Redistribution and use in source and binary forms, with or without
0017  * modification, are permitted provided that the following conditions
0018  * are met:
0019  * 1. Redistributions of source code must retain the above copyright
0020  *    notice, this list of conditions and the following disclaimer.
0021  * 2. Redistributions in binary form must reproduce the above copyright
0022  *    notice, this list of conditions and the following disclaimer in the
0023  *    documentation and/or other materials provided with the distribution.
0024  *
0025  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0026  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0027  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0028  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0029  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0030  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0031  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0032  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0033  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0034  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0035  * POSSIBILITY OF SUCH DAMAGE.
0036  */
0037
0038 #ifndef _RTEMS_SCORE_MRSP_H
0039 #define _RTEMS_SCORE_MRSP_H
0040
0041 #include <rtems/score/cpuopts.h>
0042 #include <rtems/score/threadq.h>
0043
0044 #ifdef __cplusplus
0045 extern "C" {
0046 #endif /* __cplusplus */
0047
0048 /**
0049  * @defgroup RTEMSScoreMRSP Multiprocessor Resource Sharing Protocol (MrsP)
0050  *
0051  * @ingroup RTEMSScore
0052  *
0053  * @brief This group contains the implementation to support the Multiprocessor
0054  *   Resource Sharing Protocol (MrsP) .
0055  *
0056  * The Multiprocessor Resource Sharing Protocol (MrsP) is defined in A.  Burns
0057  * and A.J.  Wellings, A Schedulability Compatible Multiprocessor Resource
0058  * Sharing Protocol - MrsP, Proceedings of the 25th Euromicro Conference on
0059  * Real-Time Systems (ECRTS 2013), July 2013.  It is a generalization of the
0060  * Priority Ceiling Protocol to SMP systems.  Each MrsP semaphore uses a
0061  * ceiling priority per scheduler instance.  A task obtaining or owning a MrsP
0062  * semaphore will execute with the ceiling priority for its scheduler instance
0063  * as specified by the MrsP semaphore object.  Tasks waiting to get ownership
0064  * of a MrsP semaphore will not relinquish the processor voluntarily.  In case
0065  * the owner of a MrsP semaphore gets preempted it can ask all tasks waiting
0066  * for this semaphore to help out and temporarily borrow the right to execute
0067  * on one of their assigned processors.
0068  *
0069  * @{
0070  */
0071
0072 #if defined(RTEMS_SMP)
0073
0074 /**
0075  * @brief MrsP control block.
0076  */
0077 typedef struct {
0078   /**
0079    * @brief The thread queue to manage ownership and waiting threads.
0080    */
0081   Thread_queue_Control Wait_queue;
0082
0083   /**
0084    * @brief The ceiling priority used by the owner thread.
0085    */
0086   Priority_Node Ceiling_priority;
0087
0088   /**
0089    * @brief One ceiling priority per scheduler instance.
0090    */
0091   Priority_Control ceiling_priorities[ RTEMS_ZERO_LENGTH_ARRAY ];
0092 } MRSP_Control;
0093
0094 #endif /* RTEMS_SMP */
0095
0096 /** @} */
0097
0098 #ifdef __cplusplus
0099 }
0100 #endif /* __cplusplus */
0101
0102 #endif /* _RTEMS_SCORE_MRSP_H */