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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 "params/Bridge.hh"
49 #include "sim/eventq.hh"
51 class Bridge : public MemObject
54 /** Declaration of the buses port type, one will be instantiated for each
55 of the interfaces connecting to the bus. */
56 class BridgePort : public Port
58 /** A pointer to the bridge to which this port belongs. */
62 * Pointer to the port on the other side of the bridge
63 * (connected to the other bus).
65 BridgePort *otherPort;
67 /** Minimum delay though this bridge. */
70 /** Min delay to respond to a nack. */
73 /** Pass ranges from one side of the bridge to the other? */
74 std::vector<Range<Addr> > filterRanges;
76 class PacketBuffer : public Packet::SenderState {
81 Packet::SenderState *origSenderState;
85 PacketBuffer(PacketPtr _pkt, Tick t, bool nack = false)
86 : ready(t), pkt(_pkt),
87 origSenderState(_pkt->senderState), origSrc(_pkt->getSrc()),
88 expectResponse(_pkt->needsResponse() && !nack)
91 if (!pkt->isResponse() && !nack && !pkt->wasNacked())
92 pkt->senderState = this;
95 void fixResponse(PacketPtr pkt)
97 assert(pkt->senderState == this);
98 pkt->setDest(origSrc);
99 pkt->senderState = origSenderState;
104 * Outbound packet queue. Packets are held in this queue for a
105 * specified delay to model the processing delay of the
108 std::list<PacketBuffer*> sendQueue;
110 int outstandingResponses;
113 /** If we're waiting for a retry to happen.*/
116 /** Max queue size for outbound packets */
119 /** Max queue size for reserved responses. */
123 * Is this side blocked from accepting outbound packets?
125 bool respQueueFull();
128 void queueForSendTiming(PacketPtr pkt);
130 void finishSend(PacketBuffer *buf);
132 void nackRequest(PacketPtr pkt);
135 * Handle send event, scheduled when the packet at the head of
136 * the outbound queue is ready to transmit (for timing
141 class SendEvent : public Event
146 SendEvent(BridgePort *p)
147 : Event(&mainEventQueue), port(p) {}
149 virtual void process() { port->trySend(); }
151 virtual const char *description() { return "bridge send"; }
157 /** Constructor for the BusPort.*/
158 BridgePort(const std::string &_name, Bridge *_bridge,
159 BridgePort *_otherPort, int _delay, int _nack_delay,
160 int _req_limit, int _resp_limit,
161 std::vector<Range<Addr> > filter_ranges);
165 /** When receiving a timing request from the peer port,
166 pass it to the bridge. */
167 virtual bool recvTiming(PacketPtr pkt);
169 /** When receiving a retry request from the peer port,
170 pass it to the bridge. */
171 virtual void recvRetry();
173 /** When receiving a Atomic requestfrom the peer port,
174 pass it to the bridge. */
175 virtual Tick recvAtomic(PacketPtr pkt);
177 /** When receiving a Functional request from the peer port,
178 pass it to the bridge. */
179 virtual void recvFunctional(PacketPtr pkt);
181 /** When receiving a status changefrom the peer port,
182 pass it to the bridge. */
183 virtual void recvStatusChange(Status status);
185 /** When receiving a address range request the peer port,
186 pass it to the bridge. */
187 virtual void getDeviceAddressRanges(AddrRangeList &resp,
191 BridgePort portA, portB;
193 /** If this bridge should acknowledge writes. */
197 typedef BridgeParams Params;
203 const Params *params() const { return _params; }
205 /** A function used to return the port associated with this bus object. */
206 virtual Port *getPort(const std::string &if_name, int idx = -1);
213 #endif //__MEM_BUS_HH__