src/mem/cache/prefetch/base.hh

   1 /*
   2  * Copyright (c) 2013-2014 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  * Copyright (c) 2005 The Regents of The University of Michigan
  15  * All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions are
  19  * met: redistributions of source code must retain the above copyright
  20  * notice, this list of conditions and the following disclaimer;
  21  * redistributions in binary form must reproduce the above copyright
  22  * notice, this list of conditions and the following disclaimer in the
  23  * documentation and/or other materials provided with the distribution;
  24  * neither the name of the copyright holders nor the names of its
  25  * contributors may be used to endorse or promote products derived from
  26  * this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  * Authors: Ron Dreslinski
  41  *          Mitch Hayenga
  42  */
  43
  44 /**
  45  * @file
  46  * Miss and writeback queue declarations.
  47  */
  48
  49 #ifndef __MEM_CACHE_PREFETCH_BASE_HH__
  50 #define __MEM_CACHE_PREFETCH_BASE_HH__
  51
  52 #include <cstdint>
  53
  54 #include "base/statistics.hh"
  55 #include "base/types.hh"
  56 #include "mem/packet.hh"
  57 #include "mem/request.hh"
  58 #include "sim/clocked_object.hh"
  59
  60 class BaseCache;
  61 struct BasePrefetcherParams;
  62 class System;
  63
  64 class BasePrefetcher : public ClockedObject
  65 {
  66   protected:
  67
  68     // PARAMETERS
  69
  70     /** Pointr to the parent cache. */
  71     BaseCache* cache;
  72
  73     /** The block size of the parent cache. */
  74     unsigned blkSize;
  75
  76     /** log_2(block size of the parent cache). */
  77     unsigned lBlkSize;
  78
  79     /** System we belong to */
  80     System* system;
  81
  82     /** Only consult prefetcher on cache misses? */
  83     bool onMiss;
  84
  85     /** Consult prefetcher on reads? */
  86     bool onRead;
  87
  88     /** Consult prefetcher on reads? */
  89     bool onWrite;
  90
  91     /** Consult prefetcher on data accesses? */
  92     bool onData;
  93
  94     /** Consult prefetcher on instruction accesses? */
  95     bool onInst;
  96
  97     /** Request id for prefetches */
  98     MasterID masterId;
  99
 100     const Addr pageBytes;
 101
 102     /** Determine if this access should be observed */
 103     bool observeAccess(const PacketPtr &pkt) const;
 104
 105     /** Determine if address is in cache */
 106     bool inCache(Addr addr, bool is_secure) const;
 107
 108     /** Determine if address is in cache miss queue */
 109     bool inMissQueue(Addr addr, bool is_secure) const;
 110
 111     /** Determine if addresses are on the same page */
 112     bool samePage(Addr a, Addr b) const;
 113     /** Determine the address of the block in which a lays */
 114     Addr blockAddress(Addr a) const;
 115     /** Determine the address of a at block granularity */
 116     Addr blockIndex(Addr a) const;
 117     /** Determine the address of the page in which a lays */
 118     Addr pageAddress(Addr a) const;
 119     /** Determine the page-offset of a  */
 120     Addr pageOffset(Addr a) const;
 121     /** Build the address of the i-th block inside the page */
 122     Addr pageIthBlockAddress(Addr page, uint32_t i) const;
 123
 124
 125     Stats::Scalar pfIssued;
 126
 127   public:
 128
 129     BasePrefetcher(const BasePrefetcherParams *p);
 130
 131     virtual ~BasePrefetcher() {}
 132
 133     virtual void setCache(BaseCache *_cache);
 134
 135     /**
 136      * Notify prefetcher of cache access (may be any access or just
 137      * misses, depending on cache parameters.)
 138      * @retval Time of next prefetch availability, or MaxTick if none.
 139      */
 140     virtual Tick notify(const PacketPtr &pkt) = 0;
 141
 142     virtual PacketPtr getPacket() = 0;
 143
 144     virtual Tick nextPrefetchReadyTime() const = 0;
 145
 146     virtual void regStats();
 147 };
 148 #endif //__MEM_CACHE_PREFETCH_BASE_HH__