queued.hh

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 * Authors: Mitch Hayenga
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#ifndef __MEM_CACHE_PREFETCH_QUEUED_HH__
#define __MEM_CACHE_PREFETCH_QUEUED_HH__

#include <list>

#include "mem/cache/prefetch/base.hh"
#include "params/QueuedPrefetcher.hh"

class QueuedPrefetcher : public BasePrefetcher
{
  protected:
    struct DeferredPacket {
        Tick tick;
        PacketPtr pkt;
        int32_t priority;
        DeferredPacket(Tick t, PacketPtr p, int32_t pr) : tick(t), pkt(p),
                                                        priority(pr)  {}
        bool operator>(const DeferredPacket& that) const
        {
            return priority > that.priority;
        }
        bool operator<(const DeferredPacket& that) const
        {
            return priority < that.priority;
        }
        bool operator<=(const DeferredPacket& that) const
        {
            return !(*this > that);
        }
    };
    using AddrPriority = std::pair<Addr, int32_t>;

    std::list<DeferredPacket> pfq;

    // PARAMETERS

    const unsigned queueSize;

    const Cycles latency;

    const bool queueSquash;

    const bool queueFilter;

    const bool cacheSnoop;

    const bool tagPrefetch;

    using const_iterator = std::list<DeferredPacket>::const_iterator;
    std::list<DeferredPacket>::const_iterator inPrefetch(Addr address,
            bool is_secure) const;
    using iterator = std::list<DeferredPacket>::iterator;
    std::list<DeferredPacket>::iterator inPrefetch(Addr address,
            bool is_secure);

    // STATS
    Stats::Scalar pfIdentified;
    Stats::Scalar pfBufferHit;
    Stats::Scalar pfInCache;
    Stats::Scalar pfRemovedFull;
    Stats::Scalar pfSpanPage;

  public:
    QueuedPrefetcher(const QueuedPrefetcherParams *p);
    virtual ~QueuedPrefetcher();

    Tick notify(const PacketPtr &pkt);
    PacketPtr insert(AddrPriority& info, bool is_secure);

    // Note: This should really be pure virtual, but doesnt go well with params
    virtual void calculatePrefetch(const PacketPtr &pkt,
                                   std::vector<AddrPriority> &addresses) = 0;
    PacketPtr getPacket();

    Tick nextPrefetchReadyTime() const
    {
        return pfq.empty() ? MaxTick : pfq.front().tick;
    }

    void regStats();
};

#endif //__MEM_CACHE_PREFETCH_QUEUED_HH__