mshr_queue.cc

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#include "mem/cache/mshr_queue.hh"
 
#include <cassert>
 
#include "debug/MSHR.hh"
#include "mem/cache/mshr.hh"
 
namespace gem5
{
 
MSHRQueue::MSHRQueue(const std::string &_label,
                     int num_entries, int reserve,
                     int demand_reserve, std::string cache_name = "")
    : Queue<MSHR>(_label, num_entries, reserve, cache_name + ".mshr_queue"),
      demandReserve(demand_reserve)
{}
 
MSHR *
MSHRQueue::allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
                    Tick when_ready, Counter order, bool alloc_on_fill)
{
    assert(!freeList.empty());
    MSHR *mshr = freeList.front();
    assert(mshr->getNumTargets() == 0);
    freeList.pop_front();
 
    DPRINTF(MSHR, "Allocating new MSHR. Number in use will be %lu/%lu\n",
            allocatedList.size() + 1, numEntries);
 
    mshr->allocate(blk_addr, blk_size, pkt, when_ready, order, alloc_on_fill);
    mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
    mshr->readyIter = addToReadyList(mshr);
 
    allocated += 1;
    return mshr;
}
 
void
MSHRQueue::deallocate(MSHR* mshr)
{
 
    DPRINTF(MSHR, "Deallocating all targets: %s", mshr->print());
    Queue<MSHR>::deallocate(mshr);
    DPRINTF(MSHR, "MSHR deallocated. Number in use: %lu/%lu\n",
            allocatedList.size(), numEntries);
}
 
 
void
MSHRQueue::moveToFront(MSHR *mshr)
{
    if (!mshr->inService) {
        assert(mshr == *(mshr->readyIter));
        readyList.erase(mshr->readyIter);
        mshr->readyIter = readyList.insert(readyList.begin(), mshr);
    }
}
 
void
MSHRQueue::delay(MSHR *mshr, Tick delay_ticks)
{
    mshr->delay(delay_ticks);
    auto it = std::find_if(mshr->readyIter, readyList.end(),
                            [mshr] (const MSHR* _mshr) {
                                return mshr->readyTime >= _mshr->readyTime;
                            });
    readyList.splice(it, readyList, mshr->readyIter);
}
 
void
MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
{
    mshr->markInService(pending_modified_resp);
    readyList.erase(mshr->readyIter);
    _numInService += 1;
}
 
void
MSHRQueue::markPending(MSHR *mshr)
{
    assert(mshr->inService);
    mshr->inService = false;
    --_numInService;
    mshr->readyIter = addToReadyList(mshr);
}
 
bool
MSHRQueue::forceDeallocateTarget(MSHR *mshr)
{
    bool was_full = isFull();
    assert(mshr->hasTargets());
    // Pop the prefetch off of the target list
    mshr->popTarget();
    // Delete mshr if no remaining targets
    if (!mshr->hasTargets() && !mshr->promoteDeferredTargets()) {
        deallocate(mshr);
    }
 
    // Notify if MSHR queue no longer full
    return was_full && !isFull();
}
 
} // namespace gem5