gem5/src/dev/pci/copy_engine.hh

/*
 * Copyright (c) 2012 ARM Limited
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 *
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 * 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) 2008 The Regents of The University of Michigan
 * All rights reserved.
 *
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 * 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
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 * neither the name of the copyright holders nor the names of its
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 * this software without specific prior written permission.
 *
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 */

/* @file
 * Device model for Intel's I/O Acceleration Technology (I/OAT).
 * A DMA asyncronous copy engine
 */

#ifndef __DEV_PCI_COPY_ENGINE_HH__
#define __DEV_PCI_COPY_ENGINE_HH__

#include <vector>

#include "base/statistics.hh"
#include "dev/pci/copy_engine_defs.hh"
#include "dev/pci/device.hh"
#include "params/CopyEngine.hh"
#include "sim/drain.hh"
#include "sim/eventq.hh"

class CopyEngine : public PciDevice
{
    class CopyEngineChannel : public Drainable, public Serializable
    {
      private:
        DmaPort cePort;
        CopyEngine *ce;
        CopyEngineReg::ChanRegs  cr;
        int channelId;
        CopyEngineReg::DmaDesc *curDmaDesc;
        uint8_t *copyBuffer;

        bool busy;
        bool underReset;
        bool refreshNext;
        Addr lastDescriptorAddr;
        Addr fetchAddress;

        Tick latBeforeBegin;
        Tick latAfterCompletion;

        uint64_t completionDataReg;

        enum ChannelState {
            Idle,
            AddressFetch,
            DescriptorFetch,
            DMARead,
            DMAWrite,
            CompletionWrite
        };

        ChannelState nextState;

      public:
        CopyEngineChannel(CopyEngine *_ce, int cid);
        virtual ~CopyEngineChannel();
        Port &getPort();

        std::string name() { assert(ce); return ce->name() + csprintf("-chan%d", channelId); }
        virtual Tick read(PacketPtr pkt)
                        { panic("CopyEngineChannel has no I/O access\n");}
        virtual Tick write(PacketPtr pkt)
                        { panic("CopyEngineChannel has no I/O access\n"); }

        void channelRead(PacketPtr pkt, Addr daddr, int size);
        void channelWrite(PacketPtr pkt, Addr daddr, int size);

        DrainState drain() override;
        void drainResume() override;

        void serialize(CheckpointOut &cp) const override;
        void unserialize(CheckpointIn &cp) override;

      private:
        void fetchDescriptor(Addr address);
        void fetchDescComplete();
        EventFunctionWrapper fetchCompleteEvent;

        void fetchNextAddr(Addr address);
        void fetchAddrComplete();
        EventFunctionWrapper addrCompleteEvent;

        void readCopyBytes();
        void readCopyBytesComplete();
        EventFunctionWrapper readCompleteEvent;

        void writeCopyBytes();
        void writeCopyBytesComplete();
        EventFunctionWrapper writeCompleteEvent;

        void writeCompletionStatus();
        void writeStatusComplete();
        EventFunctionWrapper statusCompleteEvent;


        void continueProcessing();
        void recvCommand();
        bool inDrain();
        void restartStateMachine();
    };

  private:

    Stats::Vector bytesCopied;
    Stats::Vector copiesProcessed;

    // device registers
    CopyEngineReg::Regs regs;

    // Array of channels each one with regs/dma port/etc
    std::vector<CopyEngineChannel*> chan;

  public:
    typedef CopyEngineParams Params;
    const Params &
    params() const
    {
        return dynamic_cast<const Params &>(_params);
    }
    CopyEngine(const Params &params);
    ~CopyEngine();

    void regStats() override;

    Port &getPort(const std::string &if_name,
            PortID idx = InvalidPortID) override;

    Tick read(PacketPtr pkt) override;
    Tick write(PacketPtr pkt) override;

    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;
};

#endif //__DEV_PCI_COPY_ENGINE_HH__