src/mem/cache/mshr_queue.cc

   1 /*
   2  * Copyright (c) 2003-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Erik Hallnor
  29  */
  30
  31 /** @file
  32  * Definition of MSHRQueue class functions.
  33  */
  34
  35 #include "mem/cache/mshr_queue.hh"
  36
  37 using namespace std;
  38
  39 MSHRQueue::MSHRQueue(const std::string &_label,
  40                      int num_entries, int reserve, int _index)
  41     : label(_label),
  42       numEntries(num_entries + reserve - 1), numReserve(reserve),
  43       index(_index)
  44 {
  45     allocated = 0;
  46     inServiceEntries = 0;
  47     registers = new MSHR[numEntries];
  48     for (int i = 0; i < numEntries; ++i) {
  49         registers[i].queue = this;
  50         freeList.push_back(&registers[i]);
  51     }
  52 }
  53
  54 MSHRQueue::~MSHRQueue()
  55 {
  56     delete [] registers;
  57 }
  58
  59 MSHR *
  60 MSHRQueue::findMatch(Addr addr) const
  61 {
  62     MSHR::ConstIterator i = allocatedList.begin();
  63     MSHR::ConstIterator end = allocatedList.end();
  64     for (; i != end; ++i) {
  65         MSHR *mshr = *i;
  66         if (mshr->addr == addr) {
  67             return mshr;
  68         }
  69     }
  70     return NULL;
  71 }
  72
  73 bool
  74 MSHRQueue::findMatches(Addr addr, vector<MSHR*>& matches) const
  75 {
  76     // Need an empty vector
  77     assert(matches.empty());
  78     bool retval = false;
  79     MSHR::ConstIterator i = allocatedList.begin();
  80     MSHR::ConstIterator end = allocatedList.end();
  81     for (; i != end; ++i) {
  82         MSHR *mshr = *i;
  83         if (mshr->addr == addr) {
  84             retval = true;
  85             matches.push_back(mshr);
  86         }
  87     }
  88     return retval;
  89 }
  90
  91
  92 bool
  93 MSHRQueue::checkFunctional(PacketPtr pkt, Addr blk_addr)
  94 {
  95     pkt->pushLabel(label);
  96     MSHR::ConstIterator i = allocatedList.begin();
  97     MSHR::ConstIterator end = allocatedList.end();
  98     for (; i != end; ++i) {
  99         MSHR *mshr = *i;
 100         if (mshr->addr == blk_addr && mshr->checkFunctional(pkt)) {
 101             pkt->popLabel();
 102             return true;
 103         }
 104     }
 105     pkt->popLabel();
 106     return false;
 107 }
 108
 109
 110 MSHR *
 111 MSHRQueue::findPending(Addr addr, int size) const
 112 {
 113     MSHR::ConstIterator i = readyList.begin();
 114     MSHR::ConstIterator end = readyList.end();
 115     for (; i != end; ++i) {
 116         MSHR *mshr = *i;
 117         if (mshr->addr < addr) {
 118             if (mshr->addr + mshr->size > addr) {
 119                 return mshr;
 120             }
 121         } else {
 122             if (addr + size > mshr->addr) {
 123                 return mshr;
 124             }
 125         }
 126     }
 127     return NULL;
 128 }
 129
 130
 131 MSHR::Iterator
 132 MSHRQueue::addToReadyList(MSHR *mshr)
 133 {
 134     if (readyList.empty() || readyList.back()->readyTime <= mshr->readyTime) {
 135         return readyList.insert(readyList.end(), mshr);
 136     }
 137
 138     MSHR::Iterator i = readyList.begin();
 139     MSHR::Iterator end = readyList.end();
 140     for (; i != end; ++i) {
 141         if ((*i)->readyTime > mshr->readyTime) {
 142             return readyList.insert(i, mshr);
 143         }
 144     }
 145     assert(false);
 146     return end;  // keep stupid compilers happy
 147 }
 148
 149
 150 MSHR *
 151 MSHRQueue::allocate(Addr addr, int size, PacketPtr &pkt,
 152                     Tick when, Counter order)
 153 {
 154     assert(!freeList.empty());
 155     MSHR *mshr = freeList.front();
 156     assert(mshr->getNumTargets() == 0);
 157     freeList.pop_front();
 158
 159     mshr->allocate(addr, size, pkt, when, order);
 160     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 161     mshr->readyIter = addToReadyList(mshr);
 162
 163     allocated += 1;
 164     return mshr;
 165 }
 166
 167
 168 void
 169 MSHRQueue::deallocate(MSHR *mshr)
 170 {
 171     deallocateOne(mshr);
 172 }
 173
 174 MSHR::Iterator
 175 MSHRQueue::deallocateOne(MSHR *mshr)
 176 {
 177     MSHR::Iterator retval = allocatedList.erase(mshr->allocIter);
 178     freeList.push_front(mshr);
 179     allocated--;
 180     if (mshr->inService) {
 181         inServiceEntries--;
 182     } else {
 183         readyList.erase(mshr->readyIter);
 184     }
 185     mshr->deallocate();
 186     return retval;
 187 }
 188
 189 void
 190 MSHRQueue::moveToFront(MSHR *mshr)
 191 {
 192     if (!mshr->inService) {
 193         assert(mshr == *(mshr->readyIter));
 194         readyList.erase(mshr->readyIter);
 195         mshr->readyIter = readyList.insert(readyList.begin(), mshr);
 196     }
 197 }
 198
 199 void
 200 MSHRQueue::markInService(MSHR *mshr)
 201 {
 202     if (mshr->markInService()) {
 203         deallocate(mshr);
 204     } else {
 205         readyList.erase(mshr->readyIter);
 206         inServiceEntries += 1;
 207     }
 208 }
 209
 210 void
 211 MSHRQueue::markPending(MSHR *mshr)
 212 {
 213     assert(mshr->inService);
 214     mshr->inService = false;
 215     --inServiceEntries;
 216     /**
 217      * @ todo might want to add rerequests to front of pending list for
 218      * performance.
 219      */
 220     mshr->readyIter = addToReadyList(mshr);
 221 }
 222
 223 void
 224 MSHRQueue::squash(int threadNum)
 225 {
 226     MSHR::Iterator i = allocatedList.begin();
 227     MSHR::Iterator end = allocatedList.end();
 228     for (; i != end;) {
 229         MSHR *mshr = *i;
 230         if (mshr->threadNum == threadNum) {
 231             while (mshr->hasTargets()) {
 232                 mshr->popTarget();
 233                 assert(0/*target->req->threadId()*/ == threadNum);
 234             }
 235             assert(!mshr->hasTargets());
 236             assert(mshr->ntargets==0);
 237             if (!mshr->inService) {
 238                 i = deallocateOne(mshr);
 239             } else {
 240                 //mshr->pkt->flags &= ~CACHE_LINE_FILL;
 241                 ++i;
 242             }
 243         } else {
 244             ++i;
 245         }
 246     }
 247 }