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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/mem_object.hh"
60 #include "params/SerialLink.hh"
63 * SerialLink is a simple variation of the Bridge class, with the ability to
64 * account for the latency of packet serialization. We assume that the
65 * serializer component at the transmitter side does not need to receive the
66 * whole packet to start the serialization. But the deserializer waits for the
67 * complete packet to check its integrity first.
69 class SerialLink : public MemObject
74 * A deferred packet stores a packet along with its scheduled
85 DeferredPacket(PacketPtr _pkt, Tick _tick) : tick(_tick), pkt(_pkt)
89 // Forward declaration to allow the slave port to have a pointer
90 class SerialLinkMasterPort;
93 * The port on the side that receives requests and sends
94 * responses. The slave port has a set of address ranges that it
95 * is responsible for. The slave port also has a buffer for the
96 * responses not yet sent.
98 class SerialLinkSlavePort : public SlavePort
103 /** The serial_link to which this port belongs. */
104 SerialLink& serial_link;
107 * Master port on the other side of the serial_link.
109 SerialLinkMasterPort& masterPort;
111 /** Minimum request delay though this serial_link. */
114 /** Address ranges to pass through the serial_link */
115 const AddrRangeList ranges;
118 * Response packet queue. Response packets are held in this
119 * queue for a specified delay to model the processing delay
120 * of the serial_link. We use a deque as we need to iterate over
121 * the items for functional accesses.
123 std::deque<DeferredPacket> transmitList;
125 /** Counter to track the outstanding responses. */
126 unsigned int outstandingResponses;
128 /** If we should send a retry when space becomes available. */
131 /** Max queue size for reserved responses. */
132 unsigned int respQueueLimit;
135 * Is this side blocked from accepting new response packets.
137 * @return true if the reserved space has reached the set limit
139 bool respQueueFull() const;
142 * Handle send event, scheduled when the packet at the head of
143 * the response queue is ready to transmit (for timing
146 void trySendTiming();
148 /** Send event for the response queue. */
149 EventFunctionWrapper sendEvent;
154 * Constructor for the SerialLinkSlavePort.
156 * @param _name the port name including the owner
157 * @param _serial_link the structural owner
158 * @param _masterPort the master port on the other side of the
160 * @param _delay the delay in cycles from receiving to sending
161 * @param _resp_limit the size of the response queue
162 * @param _ranges a number of address ranges to forward
164 SerialLinkSlavePort(const std::string& _name, SerialLink&
165 _serial_link, SerialLinkMasterPort& _masterPort,
166 Cycles _delay, int _resp_limit, const
167 std::vector<AddrRange>& _ranges);
170 * Queue a response packet to be sent out later and also schedule
171 * a send if necessary.
173 * @param pkt a response to send out after a delay
174 * @param when tick when response packet should be sent
176 void schedTimingResp(PacketPtr pkt, Tick when);
179 * Retry any stalled request that we have failed to accept at
180 * an earlier point in time. This call will do nothing if no
181 * request is waiting.
183 void retryStalledReq();
187 /** When receiving a timing request from the peer port,
188 pass it to the serial_link. */
189 bool recvTimingReq(PacketPtr pkt);
191 /** When receiving a retry request from the peer port,
192 pass it to the serial_link. */
193 void recvRespRetry();
195 /** When receiving a Atomic requestfrom the peer port,
196 pass it to the serial_link. */
197 Tick recvAtomic(PacketPtr pkt);
199 /** When receiving a Functional request from the peer port,
200 pass it to the serial_link. */
201 void recvFunctional(PacketPtr pkt);
203 /** When receiving a address range request the peer port,
204 pass it to the serial_link. */
205 AddrRangeList getAddrRanges() const;
210 * Port on the side that forwards requests and receives
211 * responses. The master port has a buffer for the requests not
214 class SerialLinkMasterPort : public MasterPort
219 /** The serial_link to which this port belongs. */
220 SerialLink& serial_link;
223 * The slave port on the other side of the serial_link.
225 SerialLinkSlavePort& slavePort;
227 /** Minimum delay though this serial_link. */
231 * Request packet queue. Request packets are held in this
232 * queue for a specified delay to model the processing delay
233 * of the serial_link. We use a deque as we need to iterate over
234 * the items for functional accesses.
236 std::deque<DeferredPacket> transmitList;
238 /** Max queue size for request packets */
239 const unsigned int reqQueueLimit;
242 * Handle send event, scheduled when the packet at the head of
243 * the outbound queue is ready to transmit (for timing
246 void trySendTiming();
248 /** Send event for the request queue. */
249 EventFunctionWrapper sendEvent;
254 * Constructor for the SerialLinkMasterPort.
256 * @param _name the port name including the owner
257 * @param _serial_link the structural owner
258 * @param _slavePort the slave port on the other side of the
260 * @param _delay the delay in cycles from receiving to sending
261 * @param _req_limit the size of the request queue
263 SerialLinkMasterPort(const std::string& _name, SerialLink&
264 _serial_link, SerialLinkSlavePort& _slavePort, Cycles
265 _delay, int _req_limit);
268 * Is this side blocked from accepting new request packets.
270 * @return true if the occupied space has reached the set limit
272 bool reqQueueFull() const;
275 * Queue a request packet to be sent out later and also schedule
276 * a send if necessary.
278 * @param pkt a request to send out after a delay
279 * @param when tick when response packet should be sent
281 void schedTimingReq(PacketPtr pkt, Tick when);
284 * Check a functional request against the packets in our
287 * @param pkt packet to check against
289 * @return true if we find a match
291 bool checkFunctional(PacketPtr pkt);
295 /** When receiving a timing request from the peer port,
296 pass it to the serial_link. */
297 bool recvTimingResp(PacketPtr pkt);
299 /** When receiving a retry request from the peer port,
300 pass it to the serial_link. */
304 /** Slave port of the serial_link. */
305 SerialLinkSlavePort slavePort;
307 /** Master port of the serial_link. */
308 SerialLinkMasterPort masterPort;
310 /** Number of parallel lanes in this serial link */
313 /** Speed of each link (Gb/s) in this serial link */
318 virtual BaseMasterPort& getMasterPort(const std::string& if_name,
319 PortID idx = InvalidPortID);
320 virtual BaseSlavePort& getSlavePort(const std::string& if_name,
321 PortID idx = InvalidPortID);
325 typedef SerialLinkParams Params;
327 SerialLink(SerialLinkParams *p);
330 #endif //__MEM_SERIAL_LINK_HH__