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/*
* Copyright (c) 2011-2012,2015,2017 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.
*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* 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.
*/
#ifndef __MEM_GEM5_PROTOCOL_TIMING_HH__
#define __MEM_GEM5_PROTOCOL_TIMING_HH__
#include "mem/packet.hh"
namespace gem5
{
class TimingResponseProtocol;
class TimingRequestProtocol
{
friend class TimingResponseProtocol;
protected:
/**
* Attempt to send a timing request to the peer by calling
* its corresponding receive function. If the send does not
* succeed, as indicated by the return value, then the sender must
* wait for a recvReqRetry at which point it can re-issue a
* sendTimingReq.
*
* @param peer Peer to send packet to.
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool sendReq(TimingResponseProtocol *peer, PacketPtr pkt);
/**
* Check if the peer can handle a timing request.
*
* If the send cannot be handled at the moment, as indicated by
* the return value, then the sender will receive a recvReqRetry
* at which point it can re-issue a sendTimingReq.
*
* @param peer Peer to send packet to.
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool trySend(TimingResponseProtocol *peer, PacketPtr pkt) const;
/**
* Attempt to send a timing snoop response packet to it's peer
* by calling its corresponding receive function. If the send
* does not succeed, as indicated by the return value, then the
* sender must wait for a recvRetrySnoop at which point it can
* re-issue a sendTimingSnoopResp.
*
* @param pkt Packet to send.
*/
bool sendSnoopResp(TimingResponseProtocol *peer, PacketPtr pkt);
/**
* Send a retry to the peer that previously attempted a
* sendTimingResp to this protocol and failed.
*/
void sendRetryResp(TimingResponseProtocol *peer);
/**
* Receive a timing response from the peer.
*/
virtual bool recvTimingResp(PacketPtr pkt) = 0;
/**
* Receive a timing snoop request from the peer.
*/
virtual void recvTimingSnoopReq(PacketPtr pkt) = 0;
/**
* Called by the peer if sendTimingReq was called on this peer (causing
* recvTimingReq to be called on the peer) and was unsuccessful.
*/
virtual void recvReqRetry() = 0;
/**
* Called by the peer if sendTimingSnoopResp was called on this
* protocol (causing recvTimingSnoopResp to be called on the peer)
* and was unsuccessful.
*/
virtual void recvRetrySnoopResp() = 0;
};
class TimingResponseProtocol
{
friend class TimingRequestProtocol;
protected:
/**
* Attempt to send a timing response to the peer by calling
* its corresponding receive function. If the send does not
* succeed, as indicated by the return value, then the sender must
* wait for a recvRespRetry at which point it can re-issue a
* sendTimingResp.
*
* @param peer Peer to send the packet to.
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool sendResp(TimingRequestProtocol *peer, PacketPtr pkt);
/**
* Attempt to send a timing snoop request packet to the peer
* by calling its corresponding receive function. Snoop requests
* always succeed and hence no return value is needed.
*
* @param peer Peer to send the packet to.
* @param pkt Packet to send.
*/
void sendSnoopReq(TimingRequestProtocol *peer, PacketPtr pkt);
/**
* Send a retry to the peer that previously attempted a
* sendTimingReq to this protocol and failed.
*/
void sendRetryReq(TimingRequestProtocol *peer);
/**
* Send a retry to the peer that previously attempted a
* sendTimingSnoopResp to this peer and failed.
*/
void sendRetrySnoopResp(TimingRequestProtocol *peer);
/**
* Receive a timing request from the peer.
*/
virtual bool recvTimingReq(PacketPtr pkt) = 0;
/**
* Availability request from the peer.
*/
virtual bool tryTiming(PacketPtr pkt) = 0;
/**
* Receive a timing snoop response from the peer.
*/
virtual bool recvTimingSnoopResp(PacketPtr pkt) = 0;
/**
* Called by the peer if sendTimingResp was called on this
* protocol (causing recvTimingResp to be called on the peer)
* and was unsuccessful.
*/
virtual void recvRespRetry() = 0;
};
} // namespace gem5
#endif //__MEM_GEM5_PROTOCOL_TIMING_HH__