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33 * @file Decleration of a simple bus bridge object with no buffering
36 #ifndef __MEM_BRIDGE_HH__
37 #define __MEM_BRIDGE_HH__
44 #include "mem/mem_object.hh"
45 #include "mem/packet.hh"
46 #include "mem/port.hh"
47 #include "sim/eventq.hh"
49 class Bridge : public MemObject
52 /** Decleration of the buses port type, one will be instantiated for each
53 of the interfaces connecting to the bus. */
54 class BridgePort : public Port
56 /** A pointer to the bridge to which this port belongs. */
60 * Pointer to the port on the other side of the bridge
61 * (connected to the other bus).
63 BridgePort *otherPort;
65 /** Minimum delay though this bridge. */
68 class PacketBuffer : public Packet::SenderState {
73 Packet::SenderState *origSenderState;
77 PacketBuffer(Packet *_pkt, Tick t)
78 : ready(t), pkt(_pkt),
79 origSenderState(_pkt->senderState), origSrc(_pkt->getSrc()),
80 expectResponse(_pkt->needsResponse())
82 if (!pkt->isResponse())
83 pkt->senderState = this;
86 void fixResponse(Packet *pkt)
88 assert(pkt->senderState == this);
89 pkt->setDest(origSrc);
90 pkt->senderState = origSenderState;
95 * Outbound packet queue. Packets are held in this queue for a
96 * specified delay to model the processing delay of the
99 std::list<PacketBuffer*> sendQueue;
101 int outstandingResponses;
103 /** Max queue size for outbound packets */
107 * Is this side blocked from accepting outbound packets?
109 bool queueFull() { return (sendQueue.size() == queueLimit); }
111 bool queueForSendTiming(Packet *pkt);
113 void finishSend(PacketBuffer *buf);
116 * Handle send event, scheduled when the packet at the head of
117 * the outbound queue is ready to transmit (for timing
122 class SendEvent : public Event
127 SendEvent(BridgePort *p)
128 : Event(&mainEventQueue), port(p) {}
130 virtual void process() { port->trySend(); }
132 virtual const char *description() { return "bridge send event"; }
139 /** Constructor for the BusPort.*/
140 BridgePort(const std::string &_name,
141 Bridge *_bridge, BridgePort *_otherPort,
142 int _delay, int _queueLimit);
146 /** When receiving a timing request from the peer port,
147 pass it to the bridge. */
148 virtual bool recvTiming(Packet *pkt);
150 /** When receiving a retry request from the peer port,
151 pass it to the bridge. */
152 virtual void recvRetry();
154 /** When receiving a Atomic requestfrom the peer port,
155 pass it to the bridge. */
156 virtual Tick recvAtomic(Packet *pkt);
158 /** When receiving a Functional request from the peer port,
159 pass it to the bridge. */
160 virtual void recvFunctional(Packet *pkt);
162 /** When receiving a status changefrom the peer port,
163 pass it to the bridge. */
164 virtual void recvStatusChange(Status status);
166 /** When receiving a address range request the peer port,
167 pass it to the bridge. */
168 virtual void getDeviceAddressRanges(AddrRangeList &resp,
169 AddrRangeList &snoop);
172 BridgePort portA, portB;
174 /** If this bridge should acknowledge writes. */
179 /** A function used to return the port associated with this bus object. */
180 virtual Port *getPort(const std::string &if_name, int idx = -1);
184 Bridge(const std::string &n, int qsa, int qsb, Tick _delay, int write_ack);
187 #endif //__MEM_BUS_HH__