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/*
* Copyright (c) 2011-2015 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 crossbar.
*/
#ifndef __MEM_NONCOHERENT_XBAR_HH__
#define __MEM_NONCOHERENT_XBAR_HH__
#include "mem/xbar.hh"
#include "params/NoncoherentXBar.hh"
/**
* A non-coherent crossbar 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 crossbar could still snoop in caches attached to a
* coherent crossbar, 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 crossbar itself.
*
* The non-coherent crossbar can be used as a template for modelling
* PCIe, and non-coherent AMBA and OCP buses, and is typically used
* for the I/O buses.
*/
class NoncoherentXBar : public BaseXBar
{
protected:
/**
* Declare the layers of this crossbar, one vector for requests
* and one for responses.
*/
std::vector<ReqLayer*> reqLayers;
std::vector<RespLayer*> respLayers;
/**
* Declaration of the non-coherent crossbar slave port type, one
* will be instantiated for each of the master ports connecting to
* the crossbar.
*/
class NoncoherentXBarSlavePort : public QueuedSlavePort
{
private:
/** A reference to the crossbar to which this port belongs. */
NoncoherentXBar &xbar;
/** A normal packet queue used to store responses. */
RespPacketQueue queue;
public:
NoncoherentXBarSlavePort(const std::string &_name,
NoncoherentXBar &_xbar, PortID _id)
: QueuedSlavePort(_name, &_xbar, queue, _id), xbar(_xbar),
queue(_xbar, *this)
{ }
protected:
/**
* When receiving a timing request, pass it to the crossbar.
*/
virtual bool recvTimingReq(PacketPtr pkt)
{ return xbar.recvTimingReq(pkt, id); }
/**
* When receiving an atomic request, pass it to the crossbar.
*/
virtual Tick recvAtomic(PacketPtr pkt)
{ return xbar.recvAtomic(pkt, id); }
/**
* When receiving a functional request, pass it to the crossbar.
*/
virtual void recvFunctional(PacketPtr pkt)
{ xbar.recvFunctional(pkt, id); }
/**
* Return the union of all adress ranges seen by this crossbar.
*/
virtual AddrRangeList getAddrRanges() const
{ return xbar.getAddrRanges(); }
};
/**
* Declaration of the crossbar master port type, one will be
* instantiated for each of the slave ports connecting to the
* crossbar.
*/
class NoncoherentXBarMasterPort : public MasterPort
{
private:
/** A reference to the crossbar to which this port belongs. */
NoncoherentXBar &xbar;
public:
NoncoherentXBarMasterPort(const std::string &_name,
NoncoherentXBar &_xbar, PortID _id)
: MasterPort(_name, &_xbar, _id), xbar(_xbar)
{ }
protected:
/**
* When receiving a timing response, pass it to the crossbar.
*/
virtual bool recvTimingResp(PacketPtr pkt)
{ return xbar.recvTimingResp(pkt, id); }
/** When reciving a range change from the peer port (at id),
pass it to the crossbar. */
virtual void recvRangeChange()
{ xbar.recvRangeChange(id); }
/** When reciving a retry from the peer port (at id),
pass it to the crossbar. */
virtual void recvReqRetry()
{ xbar.recvReqRetry(id); }
};
/** Function called by the port when the crossbar is recieving a Timing
request packet.*/
virtual bool recvTimingReq(PacketPtr pkt, PortID slave_port_id);
/** Function called by the port when the crossbar 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 recvReqRetry(PortID master_port_id);
/** Function called by the port when the crossbar is recieving a Atomic
transaction.*/
Tick recvAtomic(PacketPtr pkt, PortID slave_port_id);
/** Function called by the port when the crossbar is recieving a Functional
transaction.*/
void recvFunctional(PacketPtr pkt, PortID slave_port_id);
public:
NoncoherentXBar(const NoncoherentXBarParams *p);
virtual ~NoncoherentXBar();
/**
* stats
*/
virtual void regStats();
Stats::Scalar totPktSize;
};
#endif //__MEM_NONCOHERENT_XBAR_HH__
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