RubyPrefetcherProxy.cc

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#include "mem/ruby/structures/RubyPrefetcherProxy.hh"
 
#include "debug/HWPrefetch.hh"
#include "mem/ruby/system/RubySystem.hh"
 
namespace gem5
{
 
namespace ruby
{
 
RubyPrefetcherProxy::RubyPrefetcherProxy(AbstractController* _parent,
                          prefetch::Base* _prefetcher,
                          MessageBuffer *_pf_queue)
    :Named(_parent->name()),
    prefetcher(_prefetcher),
    cacheCntrl(_parent),
    pfQueue(_pf_queue),
    pfEvent([this]{ issuePrefetch(); }, name()),
    ppHit(nullptr), ppMiss(nullptr),
    ppFill(nullptr), ppDataUpdate(nullptr)
{
    fatal_if(!cacheCntrl,
            "initializing a RubyPrefetcherProxy without a parent");
    if (prefetcher) {
        fatal_if(!pfQueue,
            "%s initializing a RubyPrefetcherProxy without a prefetch queue",
            name());
        prefetcher->setParentInfo(
            cacheCntrl->params().system,
            cacheCntrl->getProbeManager(),
            RubySystem::getBlockSizeBytes());
    }
}
 
void
RubyPrefetcherProxy::scheduleNextPrefetch()
{
    if (pfEvent.scheduled())
        return;
 
    Tick next_pf_time = std::max(prefetcher->nextPrefetchReadyTime(),
                                 cacheCntrl->clockEdge(Cycles(1)));
    if (next_pf_time != MaxTick) {
        DPRINTF(HWPrefetch, "Next prefetch ready at %d\n", next_pf_time);
        cacheCntrl->schedule(&pfEvent, next_pf_time);
    }
}
 
void
RubyPrefetcherProxy::deschedulePrefetch()
{
    if (pfEvent.scheduled())
        cacheCntrl->deschedule(&pfEvent);
}
 
void
RubyPrefetcherProxy::completePrefetch(Addr addr)
{
    assert(makeLineAddress(addr) == addr);
    assert(issuedPfPkts.count(addr) == 1);
    DPRINTF(HWPrefetch, "Prefetch request for addr %#x completed\n", addr);
    delete issuedPfPkts[addr];
    issuedPfPkts.erase(addr);
}
 
void
RubyPrefetcherProxy::issuePrefetch()
{
    assert(prefetcher);
    assert(pfQueue);
 
    if (pfQueue->areNSlotsAvailable(1, curTick())) {
        PacketPtr pkt = prefetcher->getPacket();
 
        if (pkt) {
            DPRINTF(HWPrefetch, "Next prefetch ready %s\n", pkt->print());
            unsigned blk_size = RubySystem::getBlockSizeBytes();
            Addr line_addr = pkt->getBlockAddr(blk_size);
 
            if (issuedPfPkts.count(line_addr) == 0) {
                DPRINTF(HWPrefetch, "Issued PF request for paddr=%#x, "
                                    "line_addr=%#x, is_write=%d\n",
                                    pkt->getAddr(), line_addr,
                                    pkt->needsWritable());
 
                RubyRequestType req_type = pkt->needsWritable() ?
                                    RubyRequestType_ST : RubyRequestType_LD;
 
                std::shared_ptr<RubyRequest> msg =
                    std::make_shared<RubyRequest>(cacheCntrl->clockEdge(),
                                                  pkt->getAddr(),
                                                  blk_size,
                                                  0, // pc
                                                  req_type,
                                                  RubyAccessMode_Supervisor,
                                                  pkt,
                                                  PrefetchBit_Yes);
 
                // enqueue request into prefetch queue to the cache
                pfQueue->enqueue(msg, cacheCntrl->clockEdge(),
                                    cacheCntrl->cyclesToTicks(Cycles(1)));
 
                // track all pending PF requests
                issuedPfPkts[line_addr] = pkt;
            } else {
                DPRINTF(HWPrefetch, "Aborted PF request for address being "
                                    "prefetched\n");
                delete pkt;
            }
        }
    } else {
        DPRINTF(HWPrefetch, "No prefetch slots are available\n");
    }
 
    scheduleNextPrefetch();
}
 
void
RubyPrefetcherProxy::notifyPfHit(const RequestPtr& req, bool is_read,
                                const DataBlock& data_blk)
{
    assert(ppHit);
    assert(req);
    Packet pkt(req, is_read ? Packet::makeReadCmd(req) :
                              Packet::makeWriteCmd(req));
    // NOTE: for now we only communicate physical address with prefetchers
    pkt.dataStaticConst<uint8_t>(data_blk.getData(getOffset(req->getPaddr()),
                                  pkt.getSize()));
    DPRINTF(HWPrefetch, "notify hit: %s\n", pkt.print());
    ppHit->notify(CacheAccessProbeArg(&pkt, *this));
    scheduleNextPrefetch();
}
 
void
RubyPrefetcherProxy::notifyPfMiss(const RequestPtr& req, bool is_read,
                                 const DataBlock& data_blk)
{
    assert(ppMiss);
    assert(req);
    Packet pkt(req, is_read ? Packet::makeReadCmd(req) :
                              Packet::makeWriteCmd(req));
    // NOTE: for now we only communicate physical address with prefetchers
    pkt.dataStaticConst<uint8_t>(data_blk.getData(getOffset(req->getPaddr()),
                                  pkt.getSize()));
    DPRINTF(HWPrefetch, "notify miss: %s\n", pkt.print());
    ppMiss->notify(CacheAccessProbeArg(&pkt, *this));
    scheduleNextPrefetch();
}
 
void
RubyPrefetcherProxy::notifyPfFill(const RequestPtr& req,
                                 const DataBlock& data_blk,
                                 bool from_pf)
{
    assert(ppFill);
    assert(req);
    Packet pkt(req, Packet::makeReadCmd(req));
    if (from_pf)
        pkt.cmd = Packet::Command::HardPFReq;
    // NOTE: for now we only communicate physical address with prefetchers
    pkt.dataStaticConst<uint8_t>(data_blk.getData(getOffset(req->getPaddr()),
                                  pkt.getSize()));
    DPRINTF(HWPrefetch, "notify fill: %s\n", pkt.print());
    ppFill->notify(CacheAccessProbeArg(&pkt, *this));
    scheduleNextPrefetch();
}
 
void
RubyPrefetcherProxy::notifyPfEvict(Addr blkAddr, bool hwPrefetched,
                                  RequestorID requestorID)
{
    DPRINTF(HWPrefetch, "notify evict: %#x hw_pf=%d\n", blkAddr, hwPrefetched);
    CacheDataUpdateProbeArg data_update(
        blkAddr, false, requestorID, *this);
    data_update.hwPrefetched = hwPrefetched;
    ppDataUpdate->notify(data_update);
    scheduleNextPrefetch();
}
 
void
RubyPrefetcherProxy::regProbePoints()
{
    assert(cacheCntrl);
    ppHit = new ProbePointArg<CacheAccessProbeArg>(
        cacheCntrl->getProbeManager(), "Hit");
    ppMiss = new ProbePointArg<CacheAccessProbeArg>(
        cacheCntrl->getProbeManager(), "Miss");
    ppFill = new ProbePointArg<CacheAccessProbeArg>(
        cacheCntrl->getProbeManager(), "Fill");
    ppDataUpdate =
        new ProbePointArg<CacheDataUpdateProbeArg>(
            cacheCntrl->getProbeManager(), "Data Update");
}
 
} // namespace ruby
} // namespace gem5