src/mem/cache/mshr_queue.cc

   1 /*
   2  * Copyright (c) 2012-2013, 2015-2016, 2018 ARM Limited
   3  * All rights reserved.
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   5  * The license below extends only to copyright in the software and shall
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   8  * to a hardware implementation of the functionality of the software
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  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Copyright (c) 2003-2005 The Regents of The University of Michigan
  15  * All rights reserved.
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  26  * this software without specific prior written permission.
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  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /** @file
  42  * Definition of MSHRQueue class functions.
  43  */
  44
  45 #include "mem/cache/mshr_queue.hh"
  46
  47 #include <cassert>
  48
  49 #include "mem/cache/mshr.hh"
  50
  51 MSHRQueue::MSHRQueue(const std::string &_label,
  52                      int num_entries, int reserve, int demand_reserve)
  53     : Queue<MSHR>(_label, num_entries, reserve),
  54       demandReserve(demand_reserve)
  55 {}
  56
  57 MSHR *
  58 MSHRQueue::allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
  59                     Tick when_ready, Counter order, bool alloc_on_fill)
  60 {
  61     assert(!freeList.empty());
  62     MSHR *mshr = freeList.front();
  63     assert(mshr->getNumTargets() == 0);
  64     freeList.pop_front();
  65
  66     mshr->allocate(blk_addr, blk_size, pkt, when_ready, order, alloc_on_fill);
  67     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
  68     mshr->readyIter = addToReadyList(mshr);
  69
  70     allocated += 1;
  71     return mshr;
  72 }
  73
  74 void
  75 MSHRQueue::moveToFront(MSHR *mshr)
  76 {
  77     if (!mshr->inService) {
  78         assert(mshr == *(mshr->readyIter));
  79         readyList.erase(mshr->readyIter);
  80         mshr->readyIter = readyList.insert(readyList.begin(), mshr);
  81     }
  82 }
  83
  84 void
  85 MSHRQueue::delay(MSHR *mshr, Tick delay_ticks)
  86 {
  87     mshr->delay(delay_ticks);
  88     auto it = std::find_if(mshr->readyIter, readyList.end(),
  89                             [mshr] (const MSHR* _mshr) {
  90                                 return mshr->readyTime >= _mshr->readyTime;
  91                             });
  92     readyList.splice(it, readyList, mshr->readyIter);
  93 }
  94
  95 void
  96 MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
  97 {
  98     mshr->markInService(pending_modified_resp);
  99     readyList.erase(mshr->readyIter);
 100     _numInService += 1;
 101 }
 102
 103 void
 104 MSHRQueue::markPending(MSHR *mshr)
 105 {
 106     assert(mshr->inService);
 107     mshr->inService = false;
 108     --_numInService;
 109     /**
 110      * @ todo might want to add rerequests to front of pending list for
 111      * performance.
 112      */
 113     mshr->readyIter = addToReadyList(mshr);
 114 }
 115
 116 bool
 117 MSHRQueue::forceDeallocateTarget(MSHR *mshr)
 118 {
 119     bool was_full = isFull();
 120     assert(mshr->hasTargets());
 121     // Pop the prefetch off of the target list
 122     mshr->popTarget();
 123     // Delete mshr if no remaining targets
 124     if (!mshr->hasTargets() && !mshr->promoteDeferredTargets()) {
 125         deallocate(mshr);
 126     }
 127
 128     // Notify if MSHR queue no longer full
 129     return was_full && !isFull();
 130 }