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/*
* Copyright (c) 2006 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.
*/
/**
* @file Decleration of a simple bus bridge object with no buffering
*/
#ifndef __MEM_BRIDGE_HH__
#define __MEM_BRIDGE_HH__
#include <string>
#include <list>
#include <inttypes.h>
#include <queue>
#include "mem/mem_object.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
#include "sim/eventq.hh"
class Bridge : public MemObject
{
public:
enum Side
{
SideA,
SideB
};
protected:
/** Function called by the port when the bus is recieving a Timing
transaction.*/
bool recvTiming(Packet *pkt, Side id);
/** Function called by the port when the bus is recieving a Atomic
transaction.*/
Tick recvAtomic(Packet *pkt, Side id);
/** Function called by the port when the bus is recieving a Functional
transaction.*/
void recvFunctional(Packet *pkt, Side id);
/** Function called by the port when the bus is recieving a status change.*/
void recvStatusChange(Port::Status status, Side id);
/** Process address range request.
* @param resp addresses that we can respond to
* @param snoop addresses that we would like to snoop
* @param id ide of the busport that made the request.
*/
void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, Side id);
/** Event that the SendEvent calls when it fires. This code must reschedule
* the send event as required. */
void timerEvent();
/** Decleration of the buses port type, one will be instantiated for each
of the interfaces connecting to the bus. */
class BridgePort : public Port
{
/** A pointer to the bus to which this port belongs. */
Bridge *bridge;
/** A id to keep track of the intercafe ID this port is connected to. */
Bridge::Side side;
public:
/** Constructor for the BusPort.*/
BridgePort(Bridge *_bridge, Side _side)
: Port(""), bridge(_bridge), side(_side)
{ }
int numQueued() { return outbound.size(); }
protected:
/** Data this is waiting to be transmitted. */
std::list<std::pair<Packet*, Tick> > outbound;
void sendPkt(Packet *pkt);
void sendPkt(std::pair<Packet*, Tick> p);
/** When reciving a timing request from the peer port,
pass it to the bridge. */
virtual bool recvTiming(Packet *pkt)
{ return bridge->recvTiming(pkt, side); }
/** When reciving a retry request from the peer port,
pass it to the bridge. */
virtual Packet* recvRetry();
/** When reciving a Atomic requestfrom the peer port,
pass it to the bridge. */
virtual Tick recvAtomic(Packet *pkt)
{ return bridge->recvAtomic(pkt, side); }
/** When reciving a Functional request from the peer port,
pass it to the bridge. */
virtual void recvFunctional(Packet *pkt)
{ bridge->recvFunctional(pkt, side); }
/** When reciving a status changefrom the peer port,
pass it to the bridge. */
virtual void recvStatusChange(Status status)
{ bridge->recvStatusChange(status, side); }
/** When reciving a address range request the peer port,
pass it to the bridge. */
virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
{ bridge->addressRanges(resp, snoop, side); }
friend class Bridge;
};
class SendEvent : public Event
{
Bridge *bridge;
SendEvent(Bridge *b)
: Event(&mainEventQueue), bridge(b) {}
virtual void process() { bridge->timerEvent(); }
virtual const char *description() { return "bridge delay event"; }
friend class Bridge;
};
SendEvent sendEvent;
/** Sides of the bus bridges. */
BridgePort* sideA;
BridgePort* sideB;
/** inbound queues on both sides. */
std::list<std::pair<Packet*, Tick> > inboundA;
std::list<std::pair<Packet*, Tick> > inboundB;
/** The size of the queue for data coming into side a */
int queueSizeA;
int queueSizeB;
/* if the side is blocked or not. */
bool blockedA;
bool blockedB;
/** Miminum delay though this bridge. */
Tick delay;
/** If this bridge should acknowledge writes. */
bool ackWrites;
public:
/** A function used to return the port associated with this bus object. */
virtual Port *getPort(const std::string &if_name)
{
if (if_name == "side_a") {
if (sideA != NULL)
panic("bridge side a already connected to.");
sideA = new BridgePort(this, SideA);
return sideA;
} else if (if_name == "side_b") {
if (sideB != NULL)
panic("bridge side b already connected to.");
sideB = new BridgePort(this, SideB);
return sideB;
} else
return NULL;
}
virtual void init();
Bridge(const std::string &n, int qsa, int qsb, Tick _delay, int write_ack)
: MemObject(n), sendEvent(this), sideA(NULL), sideB(NULL),
queueSizeA(qsa), queueSizeB(qsb), blockedA(false), blockedB(false),
delay(_delay), ackWrites(write_ack)
{}
/** Check if the port should block/unblock after recieving/sending a packet.
* */
void blockCheck(Side id);
friend class Bridge::SendEvent;
};
#endif //__MEM_BUS_HH__
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