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/*
* Copyright (c) 2011-2013 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) 2002-2005 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: Ron Dreslinski
* Ali Saidi
* Andreas Hansson
* William Wang
*/
/**
* @file
* Declaration of a non-coherent bus.
*/
#ifndef __MEM_NONCOHERENT_BUS_HH__
#define __MEM_NONCOHERENT_BUS_HH__
#include "mem/bus.hh"
#include "params/NoncoherentBus.hh"
/**
* A non-coherent bus connects a number of non-snooping masters and
* slaves, and routes the request and response packets based on the
* address. The request packets issued by the master connected to a
* non-coherent bus could still snoop in caches attached to a coherent
* bus, as is the case with the I/O bus and memory bus in most system
* configurations. No snoops will, however, reach any master on the
* non-coherent bus itself.
*
* The non-coherent bus can be used as a template for modelling PCI,
* PCIe, and non-coherent AMBA and OCP buses, and is typically used
* for the I/O buses.
*/
class NoncoherentBus : public BaseBus
{
protected:
/**
* Declare the layers of this bus, one vector for requests and one
* for responses.
*/
typedef Layer<SlavePort,MasterPort> ReqLayer;
typedef Layer<MasterPort,SlavePort> RespLayer;
std::vector<ReqLayer*> reqLayers;
std::vector<RespLayer*> respLayers;
/**
* Declaration of the non-coherent bus slave port type, one will
* be instantiated for each of the master ports connecting to the
* bus.
*/
class NoncoherentBusSlavePort : public SlavePort
{
private:
/** A reference to the bus to which this port belongs. */
NoncoherentBus &bus;
public:
NoncoherentBusSlavePort(const std::string &_name,
NoncoherentBus &_bus, PortID _id)
: SlavePort(_name, &_bus, _id), bus(_bus)
{ }
protected:
/**
* When receiving a timing request, pass it to the bus.
*/
virtual bool recvTimingReq(PacketPtr pkt)
{ return bus.recvTimingReq(pkt, id); }
/**
* When receiving an atomic request, pass it to the bus.
*/
virtual Tick recvAtomic(PacketPtr pkt)
{ return bus.recvAtomic(pkt, id); }
/**
* When receiving a functional request, pass it to the bus.
*/
virtual void recvFunctional(PacketPtr pkt)
{ bus.recvFunctional(pkt, id); }
/**
* When receiving a retry, pass it to the bus.
*/
virtual void recvRetry()
{ panic("Bus slave ports always succeed and should never retry.\n"); }
/**
* Return the union of all adress ranges seen by this bus.
*/
virtual AddrRangeList getAddrRanges() const
{ return bus.getAddrRanges(); }
/**
* Get the maximum block size as seen by the bus.
*/
virtual unsigned deviceBlockSize() const
{ return bus.deviceBlockSize(); }
};
/**
* Declaration of the bus master port type, one will be
* instantiated for each of the slave ports connecting to the
* bus.
*/
class NoncoherentBusMasterPort : public MasterPort
{
private:
/** A reference to the bus to which this port belongs. */
NoncoherentBus &bus;
public:
NoncoherentBusMasterPort(const std::string &_name,
NoncoherentBus &_bus, PortID _id)
: MasterPort(_name, &_bus, _id), bus(_bus)
{ }
protected:
/**
* When receiving a timing response, pass it to the bus.
*/
virtual bool recvTimingResp(PacketPtr pkt)
{ return bus.recvTimingResp(pkt, id); }
/** When reciving a range change from the peer port (at id),
pass it to the bus. */
virtual void recvRangeChange()
{ bus.recvRangeChange(id); }
/** When reciving a retry from the peer port (at id),
pass it to the bus. */
virtual void recvRetry()
{ bus.recvRetry(id); }
/**
* Get the maximum block size as seen by the bus.
*/
virtual unsigned deviceBlockSize() const
{ return bus.deviceBlockSize(); }
};
/** Function called by the port when the bus is recieving a Timing
request packet.*/
virtual bool recvTimingReq(PacketPtr pkt, PortID slave_port_id);
/** Function called by the port when the bus is recieving a Timing
response packet.*/
virtual bool recvTimingResp(PacketPtr pkt, PortID master_port_id);
/** Timing function called by port when it is once again able to process
* requests. */
void recvRetry(PortID master_port_id);
/** Function called by the port when the bus is recieving a Atomic
transaction.*/
Tick recvAtomic(PacketPtr pkt, PortID slave_port_id);
/** Function called by the port when the bus is recieving a Functional
transaction.*/
void recvFunctional(PacketPtr pkt, PortID slave_port_id);
public:
NoncoherentBus(const NoncoherentBusParams *p);
virtual ~NoncoherentBus();
unsigned int drain(DrainManager *dm);
/**
* stats
*/
virtual void regStats();
Stats::Scalar dataThroughBus;
};
#endif //__MEM_NONCOHERENT_BUS_HH__
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