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49 * Declaration of the SerialLink Class, modeling Hybrid-Memory-Cube's serial
53 #ifndef __MEM_SERIAL_LINK_HH__
54 #define __MEM_SERIAL_LINK_HH__
58 #include "base/types.hh"
59 #include "mem/port.hh"
60 #include "params/SerialLink.hh"
61 #include "sim/clocked_object.hh"
64 * SerialLink is a simple variation of the Bridge class, with the ability to
65 * account for the latency of packet serialization. We assume that the
66 * serializer component at the transmitter side does not need to receive the
67 * whole packet to start the serialization. But the deserializer waits for the
68 * complete packet to check its integrity first.
70 class SerialLink : public ClockedObject
75 * A deferred packet stores a packet along with its scheduled
86 DeferredPacket(PacketPtr _pkt, Tick _tick) : tick(_tick), pkt(_pkt)
90 // Forward declaration to allow the slave port to have a pointer
91 class SerialLinkMasterPort;
94 * The port on the side that receives requests and sends
95 * responses. The slave port has a set of address ranges that it
96 * is responsible for. The slave port also has a buffer for the
97 * responses not yet sent.
99 class SerialLinkSlavePort : public SlavePort
104 /** The serial_link to which this port belongs. */
105 SerialLink& serial_link;
108 * Master port on the other side of the serial_link.
110 SerialLinkMasterPort& masterPort;
112 /** Minimum request delay though this serial_link. */
115 /** Address ranges to pass through the serial_link */
116 const AddrRangeList ranges;
119 * Response packet queue. Response packets are held in this
120 * queue for a specified delay to model the processing delay
121 * of the serial_link. We use a deque as we need to iterate over
122 * the items for functional accesses.
124 std::deque<DeferredPacket> transmitList;
126 /** Counter to track the outstanding responses. */
127 unsigned int outstandingResponses;
129 /** If we should send a retry when space becomes available. */
132 /** Max queue size for reserved responses. */
133 unsigned int respQueueLimit;
136 * Is this side blocked from accepting new response packets.
138 * @return true if the reserved space has reached the set limit
140 bool respQueueFull() const;
143 * Handle send event, scheduled when the packet at the head of
144 * the response queue is ready to transmit (for timing
147 void trySendTiming();
149 /** Send event for the response queue. */
150 EventFunctionWrapper sendEvent;
155 * Constructor for the SerialLinkSlavePort.
157 * @param _name the port name including the owner
158 * @param _serial_link the structural owner
159 * @param _masterPort the master port on the other side of the
161 * @param _delay the delay in cycles from receiving to sending
162 * @param _resp_limit the size of the response queue
163 * @param _ranges a number of address ranges to forward
165 SerialLinkSlavePort(const std::string& _name, SerialLink&
166 _serial_link, SerialLinkMasterPort& _masterPort,
167 Cycles _delay, int _resp_limit, const
168 std::vector<AddrRange>& _ranges);
171 * Queue a response packet to be sent out later and also schedule
172 * a send if necessary.
174 * @param pkt a response to send out after a delay
175 * @param when tick when response packet should be sent
177 void schedTimingResp(PacketPtr pkt, Tick when);
180 * Retry any stalled request that we have failed to accept at
181 * an earlier point in time. This call will do nothing if no
182 * request is waiting.
184 void retryStalledReq();
188 /** When receiving a timing request from the peer port,
189 pass it to the serial_link. */
190 bool recvTimingReq(PacketPtr pkt);
192 /** When receiving a retry request from the peer port,
193 pass it to the serial_link. */
194 void recvRespRetry();
196 /** When receiving a Atomic requestfrom the peer port,
197 pass it to the serial_link. */
198 Tick recvAtomic(PacketPtr pkt);
200 /** When receiving a Functional request from the peer port,
201 pass it to the serial_link. */
202 void recvFunctional(PacketPtr pkt);
204 /** When receiving a address range request the peer port,
205 pass it to the serial_link. */
206 AddrRangeList getAddrRanges() const;
211 * Port on the side that forwards requests and receives
212 * responses. The master port has a buffer for the requests not
215 class SerialLinkMasterPort : public MasterPort
220 /** The serial_link to which this port belongs. */
221 SerialLink& serial_link;
224 * The slave port on the other side of the serial_link.
226 SerialLinkSlavePort& slavePort;
228 /** Minimum delay though this serial_link. */
232 * Request packet queue. Request packets are held in this
233 * queue for a specified delay to model the processing delay
234 * of the serial_link. We use a deque as we need to iterate over
235 * the items for functional accesses.
237 std::deque<DeferredPacket> transmitList;
239 /** Max queue size for request packets */
240 const unsigned int reqQueueLimit;
243 * Handle send event, scheduled when the packet at the head of
244 * the outbound queue is ready to transmit (for timing
247 void trySendTiming();
249 /** Send event for the request queue. */
250 EventFunctionWrapper sendEvent;
255 * Constructor for the SerialLinkMasterPort.
257 * @param _name the port name including the owner
258 * @param _serial_link the structural owner
259 * @param _slavePort the slave port on the other side of the
261 * @param _delay the delay in cycles from receiving to sending
262 * @param _req_limit the size of the request queue
264 SerialLinkMasterPort(const std::string& _name, SerialLink&
265 _serial_link, SerialLinkSlavePort& _slavePort, Cycles
266 _delay, int _req_limit);
269 * Is this side blocked from accepting new request packets.
271 * @return true if the occupied space has reached the set limit
273 bool reqQueueFull() const;
276 * Queue a request packet to be sent out later and also schedule
277 * a send if necessary.
279 * @param pkt a request to send out after a delay
280 * @param when tick when response packet should be sent
282 void schedTimingReq(PacketPtr pkt, Tick when);
285 * Check a functional request against the packets in our
288 * @param pkt packet to check against
290 * @return true if we find a match
292 bool trySatisfyFunctional(PacketPtr pkt);
296 /** When receiving a timing request from the peer port,
297 pass it to the serial_link. */
298 bool recvTimingResp(PacketPtr pkt);
300 /** When receiving a retry request from the peer port,
301 pass it to the serial_link. */
305 /** Slave port of the serial_link. */
306 SerialLinkSlavePort slavePort;
308 /** Master port of the serial_link. */
309 SerialLinkMasterPort masterPort;
311 /** Number of parallel lanes in this serial link */
314 /** Speed of each link (Gb/s) in this serial link */
319 Port &getPort(const std::string &if_name,
320 PortID idx=InvalidPortID);
324 typedef SerialLinkParams Params;
326 SerialLink(SerialLinkParams *p);
329 #endif //__MEM_SERIAL_LINK_HH__