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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 "base/fast_alloc.hh"
46 #include "mem/mem_object.hh"
47 #include "mem/packet.hh"
48 #include "mem/port.hh"
49 #include "params/Bridge.hh"
50 #include "sim/eventq.hh"
52 class Bridge : public MemObject
55 /** Declaration of the buses port type, one will be instantiated for each
56 of the interfaces connecting to the bus. */
57 class BridgePort : public Port
59 /** A pointer to the bridge to which this port belongs. */
63 * Pointer to the port on the other side of the bridge
64 * (connected to the other bus).
66 BridgePort *otherPort;
68 /** Minimum delay though this bridge. */
71 /** Min delay to respond to a nack. */
74 /** Pass ranges from one side of the bridge to the other? */
75 std::vector<Range<Addr> > filterRanges;
77 class PacketBuffer : public Packet::SenderState, public FastAlloc {
83 Packet::SenderState *origSenderState;
87 PacketBuffer(PacketPtr _pkt, Tick t, bool nack = false)
88 : ready(t), pkt(_pkt), nackedHere(nack),
89 origSenderState(_pkt->senderState),
90 origSrc(nack ? _pkt->getDest() : _pkt->getSrc() ),
91 expectResponse(_pkt->needsResponse() && !nack)
94 if (!pkt->isResponse() && !nack)
95 pkt->senderState = this;
98 void fixResponse(PacketPtr pkt)
100 assert(pkt->senderState == this);
101 pkt->setDest(origSrc);
102 pkt->senderState = origSenderState;
107 * Outbound packet queue. Packets are held in this queue for a
108 * specified delay to model the processing delay of the
111 std::list<PacketBuffer*> sendQueue;
113 int outstandingResponses;
116 /** If we're waiting for a retry to happen.*/
119 /** Max queue size for outbound packets */
122 /** Max queue size for reserved responses. */
126 * Is this side blocked from accepting outbound packets?
128 bool respQueueFull();
131 void queueForSendTiming(PacketPtr pkt);
133 void finishSend(PacketBuffer *buf);
135 void nackRequest(PacketPtr pkt);
138 * Handle send event, scheduled when the packet at the head of
139 * the outbound queue is ready to transmit (for timing
144 class SendEvent : public Event
149 SendEvent(BridgePort *p) : port(p) {}
150 virtual void process() { port->trySend(); }
151 virtual const char *description() const { 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__