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/*
* Copyright (c) 2013 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.
*
* Copyright (c) 2005 The Regents of The University of Michigan
* All rights reserved.
*
* 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: Ron Dreslinski
*/
/**
* @file
* Miss and writeback queue declarations.
*/
#ifndef __MEM_CACHE_PREFETCH_BASE_PREFETCHER_HH__
#define __MEM_CACHE_PREFETCH_BASE_PREFETCHER_HH__
#include <list>
#include "base/statistics.hh"
#include "mem/packet.hh"
#include "params/BaseCache.hh"
#include "sim/clocked_object.hh"
class BaseCache;
class BasePrefetcher : public ClockedObject
{
protected:
/** A deferred packet, buffered to transmit later. */
class DeferredPacket {
public:
Tick tick; ///< The tick when the packet is ready to transmit
PacketPtr pkt; ///< Pointer to the packet to transmit
DeferredPacket(Tick t, PacketPtr p)
: tick(t), pkt(p)
{}
};
/** The Prefetch Queue. */
std::list<DeferredPacket> pf;
// PARAMETERS
/** The number of MSHRs in the Prefetch Queue. */
const unsigned size;
/** Pointr to the parent cache. */
BaseCache* cache;
/** The block size of the parent cache. */
int blkSize;
/** The latency before a prefetch is issued */
const Cycles latency;
/** The number of prefetches to issue */
const unsigned degree;
/** If patterns should be found per context id */
const bool useMasterId;
/** Do we prefetch across page boundaries. */
const bool pageStop;
/** Do we remove prefetches with later times than a new miss.*/
const bool serialSquash;
/** Do we prefetch on only data reads, or on inst reads as well. */
const bool onlyData;
/** Do we trigger/train prefetch on cache misses only, or all accesses. */
const bool onMissOnly;
/** Do we trigger/train prefetch on reads only, or all accesses. */
const bool onReadOnly;
/** Do we tag prefetch's with PC addresses, allowing lower pc-based
prefetchers to prefetch on prefetch requests */
const bool onPrefetch;
/** System we belong to */
System* system;
/** Request id for prefetches */
MasterID masterId;
public:
Stats::Scalar pfIdentified;
Stats::Scalar pfMSHRHit;
Stats::Scalar pfCacheHit;
Stats::Scalar pfBufferHit;
Stats::Scalar pfRemovedFull;
Stats::Scalar pfRemovedMSHR;
Stats::Scalar pfIssued;
Stats::Scalar pfSpanPage;
Stats::Scalar pfSquashed;
void regStats();
public:
typedef BasePrefetcherParams Params;
BasePrefetcher(const Params *p);
virtual ~BasePrefetcher() {}
void setCache(BaseCache *_cache);
/**
* Notify prefetcher of cache access (may be any access or just
* misses, depending on cache parameters.)
* @retval Time of next prefetch availability, or 0 if none.
*/
Tick notify(PacketPtr &pkt, Tick tick);
bool inCache(Addr addr, bool is_secure);
bool inMissQueue(Addr addr, bool is_secure);
PacketPtr getPacket();
bool havePending()
{
return !pf.empty();
}
Tick nextPrefetchReadyTime()
{
return pf.empty() ? MaxTick : pf.front().tick;
}
virtual void calculatePrefetch(PacketPtr &pkt,
std::list<Addr> &addresses,
std::list<Cycles> &delays) = 0;
std::list<DeferredPacket>::iterator inPrefetch(Addr address, bool is_secure);
/**
* Utility function: are addresses a and b on the same VM page?
*/
bool samePage(Addr a, Addr b);
public:
const Params*
params() const
{
return dynamic_cast<const Params *>(_params);
}
};
#endif //__MEM_CACHE_PREFETCH_BASE_PREFETCHER_HH__
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