1/*
2 * Copyright (c) 2012-2013, 2016-2018 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Thomas Grass
38 * Andreas Hansson
39 * Sascha Bischoff
40 */
41
42#ifndef __CPU_TRAFFIC_GEN_BASE_HH__
43#define __CPU_TRAFFIC_GEN_BASE_HH__
44
45#include <memory>
46#include <tuple>
47
48#include "base/statistics.hh"
49#include "mem/mem_object.hh"
50#include "mem/qport.hh"
51
52class BaseGen;
53class System;
54struct BaseTrafficGenParams;
55
56/**
57 * The traffic generator is a master module that generates stimuli for
58 * the memory system, based on a collection of simple generator
59 * behaviours that are either probabilistic or based on traces. It can
60 * be used stand alone for creating test cases for interconnect and
61 * memory controllers, or function as a black box replacement for
62 * system components that are not yet modelled in detail, e.g. a video
63 * engine or baseband subsystem.
64 */
65class BaseTrafficGen : public MemObject
66{
67 protected: // Params
68 /**
69 * The system used to determine which mode we are currently operating
70 * in.
71 */
72 System *const system;
73
74 /**
75 * Determine whether to add elasticity in the request injection,
76 * thus responding to backpressure by slowing things down.
77 */
78 const bool elasticReq;
79
80 /**
81 * Time to tolerate waiting for retries (not making progress),
82 * until we declare things broken.
83 */
84 const Tick progressCheck;
85
86 private:
87 /**
88 * Receive a retry from the neighbouring port and attempt to
89 * resend the waiting packet.
90 */
91 void recvReqRetry();
92
93 /** Transition to the next generator */
94 void transition();
95
96 /**
97 * Schedule the update event based on nextPacketTick and
98 * nextTransitionTick.
99 */
100 void scheduleUpdate();
101
102 /**
103 * Method to inform the user we have made no progress.
104 */
105 void noProgress();
106
107 /**
108 * Event to keep track of our progress, or lack thereof.
109 */
110 EventFunctionWrapper noProgressEvent;
111
112 /** Time of next transition */
113 Tick nextTransitionTick;
114
115 /** Time of the next packet. */
116 Tick nextPacketTick;
117
118
119 /** Master port specialisation for the traffic generator */
120 class TrafficGenPort : public MasterPort
121 {
122 public:
123
124 TrafficGenPort(const std::string& name, BaseTrafficGen& traffic_gen)
125 : MasterPort(name, &traffic_gen), trafficGen(traffic_gen)
126 { }
127
128 protected:
129
130 void recvReqRetry() { trafficGen.recvReqRetry(); }
131
132 bool recvTimingResp(PacketPtr pkt);
133
134 void recvTimingSnoopReq(PacketPtr pkt) { }
135
136 void recvFunctionalSnoop(PacketPtr pkt) { }
137
138 Tick recvAtomicSnoop(PacketPtr pkt) { return 0; }
139
140 private:
141
142 BaseTrafficGen& trafficGen;
143
144 };
145
146 /**
147 * Schedules event for next update and generates a new packet or
148 * requests a new generatoir depending on the current time.
149 */
150 void update();
151
152 /** The instance of master port used by the traffic generator. */
153 TrafficGenPort port;
154
155 /** Packet waiting to be sent. */
156 PacketPtr retryPkt;
157
158 /** Tick when the stalled packet was meant to be sent. */
159 Tick retryPktTick;
160
161 /** Event for scheduling updates */
162 EventFunctionWrapper updateEvent;
163
164 uint64_t numSuppressed;
165
166 private: // Stats
167 /** Count the number of generated packets. */
168 Stats::Scalar numPackets;
169
170 /** Count the number of retries. */
171 Stats::Scalar numRetries;
172
173 /** Count the time incurred from back-pressure. */
174 Stats::Scalar retryTicks;
175
176 public:
177 BaseTrafficGen(const BaseTrafficGenParams* p);
178
179 ~BaseTrafficGen() {}
180
181 BaseMasterPort& getMasterPort(const std::string &if_name,
182 PortID idx = InvalidPortID) override;
183
184 void init() override;
185
186 DrainState drain() override;
187
188 void serialize(CheckpointOut &cp) const override;
189 void unserialize(CheckpointIn &cp) override;
190
191 /** Register statistics */
192 void regStats() override;
193
194 protected:
195 void start();
196
197 virtual std::shared_ptr<BaseGen> nextGenerator() = 0;
198
199 /**
200 * MasterID used in generated requests.
201 */
202 const MasterID masterID;
203
204 /** Currently active generator */
205 std::shared_ptr<BaseGen> activeGenerator;
206};
207
208#endif //__CPU_TRAFFIC_GEN_BASE_HH__