diff options
Diffstat (limited to 'src/mem/bridge.hh')
| -rw-r--r-- | src/mem/bridge.hh | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/src/mem/bridge.hh b/src/mem/bridge.hh new file mode 100644 index 000000000..5f19ded40 --- /dev/null +++ b/src/mem/bridge.hh @@ -0,0 +1,214 @@ +/* + * 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) + : 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__ |