queued.hh revision 10623:b9646f4546ad 
1/*
2 * Copyright (c) 2014 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Mitch Hayenga
38 */
39
40#ifndef __MEM_CACHE_PREFETCH_QUEUED_HH__
41#define __MEM_CACHE_PREFETCH_QUEUED_HH__
42
43#include <list>
44
45#include "mem/cache/prefetch/base.hh"
46#include "params/QueuedPrefetcher.hh"
47
48class QueuedPrefetcher : public BasePrefetcher
49{
50  protected:
51    struct DeferredPacket {
52        Tick tick;
53        PacketPtr pkt;
54        DeferredPacket(Tick t, PacketPtr p) : tick(t), pkt(p) {}
55    };
56
57    std::list<DeferredPacket> pfq;
58
59    // PARAMETERS
60
61    /** Maximum size of the prefetch queue */
62    const unsigned queueSize;
63
64    /** Cycles after generation when a prefetch can first be issued */
65    const Cycles latency;
66
67    /** Squash queued prefetch if demand access observed */
68    const bool queueSquash;
69
70    /** Filter prefetches if already queued */
71    const bool queueFilter;
72
73    /** Snoop the cache before generating prefetch (cheating basically) */
74    const bool cacheSnoop;
75
76    /** Tag prefetch with PC of generating access? */
77    const bool tagPrefetch;
78
79    bool inPrefetch(Addr address, bool is_secure) const;
80
81    // STATS
82    Stats::Scalar pfIdentified;
83    Stats::Scalar pfBufferHit;
84    Stats::Scalar pfInCache;
85    Stats::Scalar pfRemovedFull;
86    Stats::Scalar pfSpanPage;
87
88  public:
89    QueuedPrefetcher(const QueuedPrefetcherParams *p);
90    virtual ~QueuedPrefetcher();
91
92    Tick notify(const PacketPtr &pkt);
93
94    // Note: This should really be pure virtual, but doesnt go well with params
95    virtual void calculatePrefetch(const PacketPtr &pkt,
96                                   std::vector<Addr> &addresses) = 0;
97    PacketPtr getPacket();
98
99    Tick nextPrefetchReadyTime() const
100    {
101        return pfq.empty() ? MaxTick : pfq.front().tick;
102    }
103
104    void regStats();
105};
106
107#endif //__MEM_CACHE_PREFETCH_QUEUED_HH__
108
109