xbar.hh

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/*
 * Copyright (c) 2011-2015, 2018-2020 ARM Limited
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 *
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 * 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
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 * modified or unmodified, in source code or in binary form.
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 * Copyright (c) 2002-2005 The Regents of The University of Michigan
 * All rights reserved.
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#ifndef __MEM_XBAR_HH__
#define __MEM_XBAR_HH__
 
#include <deque>
#include <unordered_map>
 
#include "base/addr_range_map.hh"
#include "base/types.hh"
#include "mem/qport.hh"
#include "params/BaseXBar.hh"
#include "sim/clocked_object.hh"
#include "sim/stats.hh"
 
namespace gem5
{
 
class BaseXBar : public ClockedObject
{
 
  protected:
 
    template <typename SrcType, typename DstType>
    class Layer : public Drainable, public statistics::Group
    {
 
      public:
 
        Layer(DstType& _port, BaseXBar& _xbar, const std::string& _name);
 
        DrainState drain() override;
 
        const std::string name() const { return _name; }
 
 
        bool tryTiming(SrcType* src_port);
 
        void succeededTiming(Tick busy_time);
 
        void failedTiming(SrcType* src_port, Tick busy_time);
 
        void occupyLayer(Tick until);
 
        void retryWaiting();
 
        void recvRetry();
 
      protected:
 
        virtual void sendRetry(SrcType* retry_port) = 0;
 
      private:
 
        DstType& port;
 
        BaseXBar& xbar;
 
        std::string _name;
 
        enum State { IDLE, BUSY, RETRY };
 
        State state;
 
        std::deque<SrcType*> waitingForLayer;
 
        SrcType* waitingForPeer;
 
        void releaseLayer();
        EventFunctionWrapper releaseEvent;
 
        statistics::Scalar occupancy;
        statistics::Formula utilization;
 
    };
 
    class ReqLayer : public Layer<ResponsePort, RequestPort>
    {
      public:
        ReqLayer(RequestPort& _port, BaseXBar& _xbar,
        const std::string& _name) :
            Layer(_port, _xbar, _name)
        {}
 
      protected:
        void
        sendRetry(ResponsePort* retry_port) override
        {
            retry_port->sendRetryReq();
        }
    };
 
    class RespLayer : public Layer<RequestPort, ResponsePort>
    {
      public:
        RespLayer(ResponsePort& _port, BaseXBar& _xbar,
                  const std::string& _name) :
            Layer(_port, _xbar, _name)
        {}
 
      protected:
        void
        sendRetry(RequestPort* retry_port) override
        {
            retry_port->sendRetryResp();
        }
    };
 
    class SnoopRespLayer : public Layer<ResponsePort, RequestPort>
    {
      public:
        SnoopRespLayer(RequestPort& _port, BaseXBar& _xbar,
                       const std::string& _name) :
            Layer(_port, _xbar, _name)
        {}
 
      protected:
 
        void
        sendRetry(ResponsePort* retry_port) override
        {
            retry_port->sendRetrySnoopResp();
        }
    };
 
    const Cycles frontendLatency;
    const Cycles forwardLatency;
    const Cycles responseLatency;
    const Cycles headerLatency;
    const uint32_t width;
 
    AddrRangeMap<PortID, 3> portMap;
 
    std::unordered_map<RequestPtr, PortID> routeTo;
 
    AddrRangeList xbarRanges;
 
    AddrRange defaultRange;
 
    virtual void recvRangeChange(PortID mem_side_port_id);
 
    PortID findPort(AddrRange addr_range, PacketPtr pkt=nullptr);
 
    PortID
    findPort(PacketPtr pkt)
    {
        return findPort(pkt->getAddrRange(), pkt);
    }
 
    AddrRangeList getAddrRanges() const;
 
    void calcPacketTiming(PacketPtr pkt, Tick header_delay);
 
    std::vector<bool> gotAddrRanges;
    bool gotAllAddrRanges;
 
    std::vector<QueuedResponsePort*> cpuSidePorts;
    std::vector<RequestPort*> memSidePorts;
 
    PortID defaultPortID;
 
    const bool useDefaultRange;
 
    BaseXBar(const BaseXBarParams &p);
 
    statistics::Vector transDist;
    statistics::Vector2d pktCount;
    statistics::Vector2d pktSize;
 
  public:
 
    virtual ~BaseXBar();
 
    Port &getPort(const std::string &if_name,
                  PortID idx=InvalidPortID) override;
 
    void regStats() override;
};
 
} // namespace gem5
 
#endif //__MEM_XBAR_HH__