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/*
* 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.
*/
#ifndef __MEM_MEM_DELAY_HH__
#define __MEM_MEM_DELAY_HH__
#include "mem/qport.hh"
#include "sim/clocked_object.hh"
namespace gem5
{
struct MemDelayParams;
struct SimpleMemDelayParams;
/**
* This abstract component provides a mechanism to delay
* packets. It can be spliced between arbitrary ports of the memory
* system and delays packets that pass through it.
*
* Specialisations of this abstract class should override at least one
* of delayReq, delayResp, deleySnoopReq, delaySnoopResp. These
* methods receive a PacketPtr as their argument and return a delay in
* Ticks. The base class implements an infinite buffer to hold delayed
* packets until they are ready. The intention is to use this
* component for rapid prototyping of other memory system components
* that introduce a packet processing delays.
*
* NOTE: Packets may be reordered if the delays aren't constant.
*/
class MemDelay : public ClockedObject
{
public:
MemDelay(const MemDelayParams &params);
void init() override;
protected: // Port interface
Port &getPort(const std::string &if_name,
PortID idx=InvalidPortID) override;
class RequestPort : public QueuedRequestPort
{
public:
RequestPort(const std::string &_name, MemDelay &_parent);
protected:
bool recvTimingResp(PacketPtr pkt) override;
void recvFunctionalSnoop(PacketPtr pkt) override;
Tick recvAtomicSnoop(PacketPtr pkt) override;
void recvTimingSnoopReq(PacketPtr pkt) override;
void recvRangeChange() override {
parent.responsePort.sendRangeChange();
}
bool isSnooping() const override {
return parent.responsePort.isSnooping();
}
private:
MemDelay& parent;
};
class ResponsePort : public QueuedResponsePort
{
public:
ResponsePort(const std::string &_name, MemDelay &_parent);
protected:
Tick recvAtomic(PacketPtr pkt) override;
bool recvTimingReq(PacketPtr pkt) override;
void recvFunctional(PacketPtr pkt) override;
bool recvTimingSnoopResp(PacketPtr pkt) override;
AddrRangeList getAddrRanges() const override {
return parent.requestPort.getAddrRanges();
}
bool tryTiming(PacketPtr pkt) override { return true; }
private:
MemDelay& parent;
};
bool trySatisfyFunctional(PacketPtr pkt);
RequestPort requestPort;
ResponsePort responsePort;
ReqPacketQueue reqQueue;
RespPacketQueue respQueue;
SnoopRespPacketQueue snoopRespQueue;
protected:
/**
* Delay a request by some number of ticks.
*
* @return Ticks to delay packet.
*/
virtual Tick delayReq(PacketPtr pkt) { return 0; }
/**
* Delay a response by some number of ticks.
*
* @return Ticks to delay packet.
*/
virtual Tick delayResp(PacketPtr pkt) { return 0; }
/**
* Delay a snoop response by some number of ticks.
*
* @return Ticks to delay packet.
*/
virtual Tick delaySnoopResp(PacketPtr pkt) { return 0; }
};
/**
* Delay packets by a constant time. Delays can be specified
* separately for read requests, read responses, write requests, and
* write responses.
*
* This class does not delay snoops or requests/responses that are
* neither reads or writes.
*/
class SimpleMemDelay : public MemDelay
{
public:
SimpleMemDelay(const SimpleMemDelayParams &params);
protected:
Tick delayReq(PacketPtr pkt) override;
Tick delayResp(PacketPtr pkt) override;
protected: // Params
const Tick readReqDelay;
const Tick readRespDelay;
const Tick writeReqDelay;
const Tick writeRespDelay;
};
} // namespace gem5
#endif //__MEM_MEM_DELAY_HH__