io_device.hh

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/*
 * Copyright (c) 2012 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
 * 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.
 *
 * Copyright (c) 2004-2005 The Regents of The University of Michigan
 * All rights reserved.
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#ifndef __DEV_IO_DEVICE_HH__
#define __DEV_IO_DEVICE_HH__

#include "mem/tport.hh"
#include "params/BasicPioDevice.hh"
#include "params/PioDevice.hh"
#include "sim/clocked_object.hh"

class PioDevice;
class System;

template <class Device>
class PioPort : public SimpleTimingPort
{
  protected:
    Device *device;

    Tick
    recvAtomic(PacketPtr pkt) override
    {
        // Technically the packet only reaches us after the header delay,
        // and typically we also need to deserialise any payload.
        Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
        pkt->headerDelay = pkt->payloadDelay = 0;

        const Tick delay =
            pkt->isRead() ? device->read(pkt) : device->write(pkt);
        assert(pkt->isResponse() || pkt->isError());
        return delay + receive_delay;
    }

    AddrRangeList
    getAddrRanges() const override
    {
        return device->getAddrRanges();
    }

  public:
    PioPort(Device *dev) :
        SimpleTimingPort(dev->name() + ".pio", dev), device(dev)
    {}
};

class PioDevice : public ClockedObject
{
  protected:
    System *sys;

    PioPort<PioDevice> pioPort;

    virtual AddrRangeList getAddrRanges() const = 0;

    virtual Tick read(PacketPtr pkt) = 0;

    virtual Tick write(PacketPtr pkt) = 0;

  public:
    typedef PioDeviceParams Params;
    PioDevice(const Params *p);
    virtual ~PioDevice();

    const Params *
    params() const
    {
        return dynamic_cast<const Params *>(_params);
    }

    void init() override;

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

    friend class PioPort<PioDevice>;

};

class BasicPioDevice : public PioDevice
{
  protected:
    Addr pioAddr;

    Addr pioSize;

    Tick pioDelay;

  public:
    typedef BasicPioDeviceParams Params;
    BasicPioDevice(const Params *p, Addr size);

    const Params *
    params() const
    {
        return dynamic_cast<const Params *>(_params);
    }

    AddrRangeList getAddrRanges() const override;
};

#endif // __DEV_IO_DEVICE_HH__