q_policy.hh

Go to the documentation of this file.

/*
 * Copyright (c) 2018 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * 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;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * 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.
 *
 * Author: Matteo Andreozzi
 */
 
#ifndef __MEM_QOS_Q_POLICY_HH__
#define __MEM_QOS_Q_POLICY_HH__
 
#include <deque>
#include <unordered_set>
 
#include "mem/packet.hh"
#include "params/QoSMemCtrl.hh"
 
namespace QoS {
 
class MemCtrl;
 
class QueuePolicy
{
  public:
    typedef std::deque<PacketPtr> PacketQueue;
 
    static QueuePolicy* create(const QoSMemCtrlParams* p);
 
    virtual void enqueuePacket(PacketPtr pkt) {};
 
    virtual PacketQueue::iterator selectPacket(PacketQueue* queue) = 0;
 
    void setMemCtrl(MemCtrl* mem) { memCtrl = mem; };
 
    virtual ~QueuePolicy() {};
 
  protected:
    QueuePolicy(const QoSMemCtrlParams* p)
      : memCtrl(nullptr)
    {}
 
    MemCtrl* memCtrl;
};
 
class LifoQueuePolicy : public QueuePolicy
{
  public:
    LifoQueuePolicy(const QoSMemCtrlParams* p)
      : QueuePolicy(p)
    {}
 
    PacketQueue::iterator
    selectPacket(PacketQueue* queue) override
    {
        return queue->end();
    }
};
 
class FifoQueuePolicy : public QueuePolicy
{
  public:
    FifoQueuePolicy(const QoSMemCtrlParams* p)
      : QueuePolicy(p)
    {}
 
    PacketQueue::iterator
    selectPacket(PacketQueue* queue) override
    {
        return queue->begin();
    }
};
 
class LrgQueuePolicy : public QueuePolicy
{
  public:
    LrgQueuePolicy(const QoSMemCtrlParams* p)
      : QueuePolicy(p)
    {}
 
    void enqueuePacket(PacketPtr pkt) override;
 
    PacketQueue::iterator
    selectPacket(PacketQueue* queue) override;
 
  protected:
    std::list<RequestorID> toServe;
};
 
} // namespace QoS
 
#endif /* __MEM_QOS_Q_POLICY_HH__ */