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/*
* Copyright (c) 2014-2015 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Mitch Hayenga
*/
#ifndef __MEM_CACHE_PREFETCH_QUEUED_HH__
#define __MEM_CACHE_PREFETCH_QUEUED_HH__
#include <cstdint>
#include <list>
#include <utility>
#include "base/statistics.hh"
#include "base/types.hh"
#include "mem/cache/prefetch/base.hh"
#include "mem/packet.hh"
struct QueuedPrefetcherParams;
class QueuedPrefetcher : public BasePrefetcher
{
protected:
struct DeferredPacket {
/** Prefetch info corresponding to this packet */
PrefetchInfo pfInfo;
/** Time when this prefetch becomes ready */
Tick tick;
/** The memory packet generated by this prefetch */
PacketPtr pkt;
/** The priority of this prefetch */
int32_t priority;
/**
* Constructor
* @param pfi PrefechInfo object associated to this packet
* @param t Time when this prefetch becomes ready
* @param p PacketPtr with the memory request of the prefetch
* @param prio This prefetch priority
*/
DeferredPacket(PrefetchInfo const &pfi, Tick t, PacketPtr p,
int32_t prio) : pfInfo(pfi), tick(t), pkt(p),
priority(prio) {
}
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
/** Maximum size of the prefetch queue */
const unsigned queueSize;
/** Cycles after generation when a prefetch can first be issued */
const Cycles latency;
/** Squash queued prefetch if demand access observed */
const bool queueSquash;
/** Filter prefetches if already queued */
const bool queueFilter;
/** Snoop the cache before generating prefetch (cheating basically) */
const bool cacheSnoop;
/** Tag prefetch with PC of generating access? */
const bool tagPrefetch;
using const_iterator = std::list<DeferredPacket>::const_iterator;
const_iterator inPrefetch(const PrefetchInfo &pfi) const;
using iterator = std::list<DeferredPacket>::iterator;
iterator inPrefetch(const PrefetchInfo &pfi);
// STATS
Stats::Scalar pfIdentified;
Stats::Scalar pfBufferHit;
Stats::Scalar pfInCache;
Stats::Scalar pfRemovedFull;
Stats::Scalar pfSpanPage;
public:
QueuedPrefetcher(const QueuedPrefetcherParams *p);
virtual ~QueuedPrefetcher();
void notify(const PacketPtr &pkt, const PrefetchInfo &pfi) override;
void insert(const PacketPtr &pkt, PrefetchInfo &new_pfi, int32_t priority);
virtual void calculatePrefetch(const PrefetchInfo &pfi,
std::vector<AddrPriority> &addresses) = 0;
PacketPtr getPacket() override;
Tick nextPrefetchReadyTime() const override
{
return pfq.empty() ? MaxTick : pfq.front().tick;
}
void regStats() override;
};
#endif //__MEM_CACHE_PREFETCH_QUEUED_HH__
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