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34 * Declaration of a simple bus bridge object with no buffering
37 #ifndef __MEM_BRIDGE_HH__
38 #define __MEM_BRIDGE_HH__
45 #include "mem/mem_object.hh"
46 #include "mem/packet.hh"
47 #include "mem/port.hh"
48 #include "sim/eventq.hh"
50 class Bridge : public MemObject
53 /** Declaration of the buses port type, one will be instantiated for each
54 of the interfaces connecting to the bus. */
55 class BridgePort : public Port
57 /** A pointer to the bridge to which this port belongs. */
61 * Pointer to the port on the other side of the bridge
62 * (connected to the other bus).
64 BridgePort *otherPort;
66 /** Minimum delay though this bridge. */
71 class PacketBuffer : public Packet::SenderState {
76 Packet::SenderState *origSenderState;
80 bool partialWriteFixed;
84 PacketBuffer(PacketPtr _pkt, Tick t, bool nack = false)
85 : ready(t), pkt(_pkt),
86 origSenderState(_pkt->senderState), origSrc(_pkt->getSrc()),
87 expectResponse(_pkt->needsResponse() && !nack),
88 partialWriteFixed(false), nacked(nack)
91 if (!pkt->isResponse() && !nack)
92 pkt->senderState = this;
95 void fixResponse(PacketPtr pkt)
97 assert(pkt->senderState == this);
98 pkt->setDest(origSrc);
99 pkt->senderState = origSenderState;
100 if (partialWriteFixed)
104 void partialWriteFix(Port *port)
106 assert(!partialWriteFixed);
107 assert(expectResponse);
109 int pbs = port->peerBlockSize();
110 partialWriteFixed = true;
113 data = new uint8_t[pbs];
114 PacketPtr funcPkt = new Packet(pkt->req, MemCmd::ReadReq,
115 Packet::Broadcast, pbs);
117 funcPkt->dataStatic(data);
118 port->sendFunctional(funcPkt);
119 assert(funcPkt->result == Packet::Success);
123 memcpy(data + oldPkt->getOffset(pbs), pkt->getPtr<uint8_t>(),
125 pkt = new Packet(oldPkt->req, MemCmd::WriteInvalidateReq,
126 Packet::Broadcast, pbs);
127 pkt->dataDynamicArray(data);
128 pkt->senderState = oldPkt->senderState;
131 void undoPartialWriteFix()
133 if (!partialWriteFixed)
137 partialWriteFixed = false;
143 * Outbound packet queue. Packets are held in this queue for a
144 * specified delay to model the processing delay of the
147 std::list<PacketBuffer*> sendQueue;
149 int outstandingResponses;
152 /** Max queue size for outbound packets */
156 * Is this side blocked from accepting outbound packets?
160 void queueForSendTiming(PacketPtr pkt);
162 void finishSend(PacketBuffer *buf);
164 void nackRequest(PacketPtr pkt);
167 * Handle send event, scheduled when the packet at the head of
168 * the outbound queue is ready to transmit (for timing
173 class SendEvent : public Event
178 SendEvent(BridgePort *p)
179 : Event(&mainEventQueue), port(p) {}
181 virtual void process() { port->trySend(); }
183 virtual const char *description() { return "bridge send event"; }
190 /** Constructor for the BusPort.*/
191 BridgePort(const std::string &_name,
192 Bridge *_bridge, BridgePort *_otherPort,
193 int _delay, int _queueLimit, bool fix_partial_write);
197 /** When receiving a timing request from the peer port,
198 pass it to the bridge. */
199 virtual bool recvTiming(PacketPtr pkt);
201 /** When receiving a retry request from the peer port,
202 pass it to the bridge. */
203 virtual void recvRetry();
205 /** When receiving a Atomic requestfrom the peer port,
206 pass it to the bridge. */
207 virtual Tick recvAtomic(PacketPtr pkt);
209 /** When receiving a Functional request from the peer port,
210 pass it to the bridge. */
211 virtual void recvFunctional(PacketPtr pkt);
213 /** When receiving a status changefrom the peer port,
214 pass it to the bridge. */
215 virtual void recvStatusChange(Status status);
217 /** When receiving a address range request the peer port,
218 pass it to the bridge. */
219 virtual void getDeviceAddressRanges(AddrRangeList &resp,
220 AddrRangeList &snoop);
223 BridgePort portA, portB;
225 /** If this bridge should acknowledge writes. */
230 /** A function used to return the port associated with this bus object. */
231 virtual Port *getPort(const std::string &if_name, int idx = -1);
235 Bridge(const std::string &n, int qsa, int qsb, Tick _delay, int write_ack,
236 bool fix_partial_write_a, bool fix_partial_write_b);
239 #endif //__MEM_BUS_HH__