gem5  v20.1.0.0
dram_rot_gen.cc
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2012-2013, 2016-2017, 2019 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 here under. 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 
39 
40 #include <algorithm>
41 
42 #include "base/random.hh"
43 #include "base/trace.hh"
44 #include "debug/TrafficGen.hh"
45 #include "enums/AddrMap.hh"
46 
49 {
50  // if this is the first of the packets in series to be generated,
51  // start counting again
52  if (countNumSeqPkts == 0) {
54 
55  // choose if we generate a read or a write here
56  if (readPercent == 50) {
57  if ((nextSeqCount % nbrOfBanksUtil) == 0) {
58  // Change type after all banks have been rotated
59  // Otherwise, keep current value
60  isRead = !isRead;
61  }
62  } else {
63  // Set randomly based on percentage
64  isRead = readPercent != 0;
65  }
66 
67  assert((readPercent == 0 && !isRead) ||
68  (readPercent == 100 && isRead) ||
69  readPercent != 100);
70 
71  // Overwrite random bank value
72  // Rotate across banks
73  unsigned int new_bank = nextSeqCount % nbrOfBanksUtil;
74 
75  // Overwrite random rank value
76  // Will rotate to the next rank after rotating through all banks,
77  // for each specified command type.
78 
79  // Use modular function to ensure that calculated rank is within
80  // system limits after state transition
81  unsigned int new_rank = (nextSeqCount / maxSeqCountPerRank) %
82  nbrOfRanks;
83 
84  // Increment nextSeqCount
85  // Roll back to 0 after completing a full rotation across
86  // banks, command type, and ranks
87  nextSeqCount = (nextSeqCount + 1) %
89 
90  DPRINTF(TrafficGen, "DramRotGen::getNextPacket nextSeqCount: %d "
91  "new_rank: %d new_bank: %d\n",
92  nextSeqCount, new_rank, new_bank);
93 
94  // Generate the start address of the command series
95  // routine will update addr variable with bank, rank, and col
96  // bits updated for rotation scheme
97  genStartAddr(new_bank, new_rank);
98 
99  } else {
100  // increment the column by one
101  if (addrMapping == Enums::RoRaBaCoCh ||
102  addrMapping == Enums::RoRaBaChCo)
103  // Simply increment addr by blocksize to
104  // increment the column by one
105  addr += blocksize;
106 
107  else if (addrMapping == Enums::RoCoRaBaCh) {
108  // Explicity increment the column bits
109 
110  unsigned int new_col = ((addr / blocksize /
112  (pageSize / blocksize)) + 1;
114  blockBits + bankBits + rankBits, new_col);
115  }
116  }
117 
118  DPRINTF(TrafficGen, "DramRotGen::getNextPacket: %c to addr %x, "
119  "size %d, countNumSeqPkts: %d, numSeqPkts: %d\n",
121 
122  // create a new request packet
125 
126  // add the amount of data manipulated to the total
128 
129  // subtract the number of packets remained to be generated
130  --countNumSeqPkts;
131 
132  // return the generated packet
133  return pkt;
134 }
DramRotGen::getNextPacket
PacketPtr getNextPacket()
Get the next generated packet.
Definition: dram_rot_gen.cc:48
DramRotGen::nextSeqCount
unsigned int nextSeqCount
Next packet series count used to set rank and bank, and update isRead Incremented at the start of a n...
Definition: dram_rot_gen.hh:123
replaceBits
void replaceBits(T &val, int first, int last, B bit_val)
A convenience function to replace bits first to last of val with bit_val in place.
Definition: bitfield.hh:179
DramGen::nbrOfBanksDRAM
const unsigned int nbrOfBanksDRAM
Number of banks in DRAM.
Definition: dram_gen.hh:133
random.hh
DramGen::numSeqPkts
const unsigned int numSeqPkts
Number of sequential DRAM packets to be generated per cpu request.
Definition: dram_gen.hh:109
MemCmd::ReadReq
@ ReadReq
Definition: packet.hh:82
DramGen::countNumSeqPkts
unsigned int countNumSeqPkts
Track number of sequential packets generated for a request
Definition: dram_gen.hh:112
DramGen::blockBits
const unsigned int blockBits
Number of block bits in DRAM address.
Definition: dram_gen.hh:130
DramGen::rankBits
const unsigned int rankBits
Number of rank bits in DRAM address.
Definition: dram_gen.hh:142
DramGen::bankBits
const unsigned int bankBits
Number of bank bits in DRAM address.
Definition: dram_gen.hh:127
StochasticGen::readPercent
const uint8_t readPercent
Percent of generated transactions that should be reads.
Definition: base_gen.hh:162
MemCmd::WriteReq
@ WriteReq
Definition: packet.hh:85
DramGen::pageBits
const unsigned int pageBits
Number of page bits in DRAM address.
Definition: dram_gen.hh:124
DPRINTF
#define DPRINTF(x,...)
Definition: trace.hh:234
DramGen::genStartAddr
void genStartAddr(unsigned int new_bank, unsigned int new_rank)
Insert bank, rank, and column bits into packed address to create address for 1st command in a series.
Definition: dram_gen.cc:143
DramGen::nbrOfRanks
const unsigned int nbrOfRanks
Number of ranks to be utilized for a given configuration.
Definition: dram_gen.hh:145
DramGen::addr
Addr addr
Address of request.
Definition: dram_gen.hh:115
dram_rot_gen.hh
BaseGen::getPacket
PacketPtr getPacket(Addr addr, unsigned size, const MemCmd &cmd, Request::FlagsType flags=0)
Generate a new request and associated packet.
Definition: base_gen.cc:56
RandomGen::dataManipulated
Addr dataManipulated
Counter to determine the amount of data manipulated.
Definition: random_gen.hh:103
StochasticGen::blocksize
const Addr blocksize
Blocksize and address increment.
Definition: base_gen.hh:150
Packet
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:257
DramRotGen::maxSeqCountPerRank
const unsigned int maxSeqCountPerRank
Number of command series issued before the rank is changed.
Definition: dram_rot_gen.hh:118
trace.hh
DramGen::isRead
bool isRead
Remember type of requests to be generated in series.
Definition: dram_gen.hh:118
DramGen::nbrOfBanksUtil
const unsigned int nbrOfBanksUtil
Number of banks to be utilized for a given configuration.
Definition: dram_gen.hh:136
TrafficGen
The traffic generator is a module that generates stimuli for the memory system, based on a collection...
Definition: traffic_gen.hh:67
DramGen::pageSize
const unsigned int pageSize
Page size of DRAM.
Definition: dram_gen.hh:121
DramGen::addrMapping
Enums::AddrMap addrMapping
Address mapping to be used.
Definition: dram_gen.hh:139

Generated on Wed Sep 30 2020 14:02:09 for gem5 by doxygen 1.8.17