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/*
* Copyright (c) 2012 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.
*
* Copyright (c) 2004-2005 The Regents of The University of Michigan
* All rights reserved.
*
* 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.
*
* Authors: Ali Saidi
* Nathan Binkert
*/
#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;
/**
* The PioPort class is a programmed i/o port that all devices that are
* sensitive to an address range use. The port takes all the memory
* access types and roles them into one read() and write() call that the device
* must respond to. The device must also provide getAddrRanges() function
* with which it returns the address ranges it is interested in.
*/
template <class Device>
class PioPort : public SimpleTimingPort
{
protected:
/** The device that this port serves. */
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)
{}
};
/**
* This device is the base class which all devices senstive to an address range
* inherit from. There are three pure virtual functions which all devices must
* implement getAddrRanges(), read(), and write(). The magic do choose which
* mode we are in, etc is handled by the PioPort so the device doesn't have to
* bother.
*/
class PioDevice : public ClockedObject
{
protected:
System *sys;
/** The pioPort that handles the requests for us and provides us requests
* that it sees. */
PioPort<PioDevice> pioPort;
/**
* Every PIO device is obliged to provide an implementation that
* returns the address ranges the device responds to.
*
* @return a list of non-overlapping address ranges
*/
virtual AddrRangeList getAddrRanges() const = 0;
/** Pure virtual function that the device must implement. Called
* when a read command is recieved by the port.
* @param pkt Packet describing this request
* @return number of ticks it took to complete
*/
virtual Tick read(PacketPtr pkt) = 0;
/** Pure virtual function that the device must implement. Called when a
* write command is recieved by the port.
* @param pkt Packet describing this request
* @return number of ticks it took to complete
*/
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:
/** Address that the device listens to. */
Addr pioAddr;
/** Size that the device's address range. */
Addr pioSize;
/** Delay that the device experinces on an access. */
Tick pioDelay;
public:
typedef BasicPioDeviceParams Params;
BasicPioDevice(const Params *p, Addr size);
const Params *
params() const
{
return dynamic_cast<const Params *>(_params);
}
/**
* Determine the address ranges that this device responds to.
*
* @return a list of non-overlapping address ranges
*/
AddrRangeList getAddrRanges() const override;
};
#endif // __DEV_IO_DEVICE_HH__
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