bridge.hh

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/*
 * Copyright (c) 2011-2013 ARM Limited
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 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
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 * modified or unmodified, in source code or in binary form.
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 * Copyright (c) 2006 The Regents of The University of Michigan
 * All rights reserved.
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 * met: redistributions of source code must retain the above copyright
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#ifndef __MEM_BRIDGE_HH__
#define __MEM_BRIDGE_HH__
 
#include <deque>
 
#include "base/types.hh"
#include "mem/port.hh"
#include "params/Bridge.hh"
#include "sim/clocked_object.hh"
 
namespace gem5
{
 
class Bridge : public ClockedObject
{
  protected:
 
    class DeferredPacket
    {
 
      public:
 
        const Tick tick;
        const PacketPtr pkt;
 
        DeferredPacket(PacketPtr _pkt, Tick _tick) : tick(_tick), pkt(_pkt)
        { }
    };
 
    // Forward declaration to allow the response port to have a pointer
    class BridgeRequestPort;
 
    class BridgeResponsePort : public ResponsePort
    {
 
      private:
 
        Bridge& bridge;
 
        BridgeRequestPort& memSidePort;
 
        const Cycles delay;
 
        const AddrRangeList ranges;
 
        std::deque<DeferredPacket> transmitList;
 
        unsigned int outstandingResponses;
 
        bool retryReq;
 
        unsigned int respQueueLimit;
 
        std::unique_ptr<Packet> pendingDelete;
 
        bool respQueueFull() const;
 
        void trySendTiming();
 
        EventFunctionWrapper sendEvent;
 
      public:
 
        BridgeResponsePort(const std::string& _name, Bridge& _bridge,
                        BridgeRequestPort& _memSidePort, Cycles _delay,
                        int _resp_limit, std::vector<AddrRange> _ranges);
 
        void schedTimingResp(PacketPtr pkt, Tick when);
 
        void retryStalledReq();
 
      protected:
 
        bool recvTimingReq(PacketPtr pkt);
 
        void recvRespRetry();
 
        Tick recvAtomic(PacketPtr pkt);
 
        void recvFunctional(PacketPtr pkt);
 
        AddrRangeList getAddrRanges() const;
    };
 
 
    class BridgeRequestPort : public RequestPort
    {
 
      private:
 
        Bridge& bridge;
 
        BridgeResponsePort& cpuSidePort;
 
        const Cycles delay;
 
        std::deque<DeferredPacket> transmitList;
 
        const unsigned int reqQueueLimit;
 
        void trySendTiming();
 
        EventFunctionWrapper sendEvent;
 
      public:
 
        BridgeRequestPort(const std::string& _name, Bridge& _bridge,
                         BridgeResponsePort& _cpuSidePort, Cycles _delay,
                         int _req_limit);
 
        bool reqQueueFull() const;
 
        void schedTimingReq(PacketPtr pkt, Tick when);
 
        bool trySatisfyFunctional(PacketPtr pkt);
 
      protected:
 
        bool recvTimingResp(PacketPtr pkt);
 
        void recvReqRetry();
    };
 
    BridgeResponsePort cpuSidePort;
 
    BridgeRequestPort memSidePort;
 
  public:
 
    Port &getPort(const std::string &if_name,
                  PortID idx=InvalidPortID) override;
 
    void init() override;
 
    typedef BridgeParams Params;
 
    Bridge(const Params &p);
};
 
} // namespace gem5
 
#endif //__MEM_BRIDGE_HH__