src/cpu/testers/traffic_gen/linear_gen.cc

   1 /*
   2  * Copyright (c) 2012-2013, 2016-2017 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,
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  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "cpu/testers/traffic_gen/linear_gen.hh"
  39
  40 #include <algorithm>
  41
  42 #include "base/random.hh"
  43 #include "base/trace.hh"
  44 #include "debug/TrafficGen.hh"
  45
  46 void
  47 LinearGen::enter()
  48 {
  49     // reset the address and the data counter
  50     nextAddr = startAddr;
  51     dataManipulated = 0;
  52 }
  53
  54 PacketPtr
  55 LinearGen::getNextPacket()
  56 {
  57     // choose if we generate a read or a write here
  58     bool isRead = readPercent != 0 &&
  59         (readPercent == 100 || random_mt.random(0, 100) < readPercent);
  60
  61     assert((readPercent == 0 && !isRead) || (readPercent == 100 && isRead) ||
  62            readPercent != 100);
  63
  64     DPRINTF(TrafficGen, "LinearGen::getNextPacket: %c to addr %x, size %d\n",
  65             isRead ? 'r' : 'w', nextAddr, blocksize);
  66
  67     // Add the amount of data manipulated to the total
  68     dataManipulated += blocksize;
  69
  70     PacketPtr pkt = getPacket(nextAddr, blocksize,
  71                               isRead ? MemCmd::ReadReq : MemCmd::WriteReq);
  72
  73     // increment the address
  74     nextAddr += blocksize;
  75
  76     // If we have reached the end of the address space, reset the
  77     // address to the start of the range
  78     if (nextAddr > endAddr) {
  79         DPRINTF(TrafficGen, "Wrapping address to the start of "
  80                 "the range\n");
  81         nextAddr = startAddr;
  82     }
  83
  84     return pkt;
  85 }
  86
  87 Tick
  88 LinearGen::nextPacketTick(bool elastic, Tick delay) const
  89 {
  90     // Check to see if we have reached the data limit. If dataLimit is
  91     // zero we do not have a data limit and therefore we will keep
  92     // generating requests for the entire residency in this state.
  93     if (dataLimit && dataManipulated >= dataLimit) {
  94         DPRINTF(TrafficGen, "Data limit for LinearGen reached.\n");
  95         // there are no more requests, therefore return MaxTick
  96         return MaxTick;
  97     } else {
  98         // return the time when the next request should take place
  99         Tick wait = random_mt.random(minPeriod, maxPeriod);
 100
 101         // compensate for the delay experienced to not be elastic, by
 102         // default the value we generate is from the time we are
 103         // asked, so the elasticity happens automatically
 104         if (!elastic) {
 105             if (wait < delay)
 106                 wait = 0;
 107             else
 108                 wait -= delay;
 109         }
 110
 111         return curTick() + wait;
 112     }
 113 }