1/* 2 * Copyright (c) 2018 Inria 3 * Copyright (c) 2012-2014,2017 ARM Limited 4 * All rights reserved. 5 * 6 * The license below extends only to copyright in the software and shall 7 * not be construed as granting a license to any other intellectual 8 * property including but not limited to intellectual property relating 9 * to a hardware implementation of the functionality of the software 10 * licensed hereunder. You may use the software subject to the license 11 * terms below provided that you ensure that this notice is replicated 12 * unmodified and in its entirety in all distributions of the software, 13 * modified or unmodified, in source code or in binary form. 14 * 15 * Copyright (c) 2003-2005,2014 The Regents of The University of Michigan 16 * All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions are 20 * met: redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer; 22 * redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution; 25 * neither the name of the copyright holders nor the names of its 26 * contributors may be used to endorse or promote products derived from 27 * this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 40 * 41 * Authors: Daniel Carvalho 42 * Erik Hallnor 43 */ 44 45/** 46 * @file 47 * Declaration of a common framework for indexing policies. 48 */ 49 50#ifndef __MEM_CACHE_INDEXING_POLICIES_BASE_HH__ 51#define __MEM_CACHE_INDEXING_POLICIES_BASE_HH__ 52 53#include <vector> 54 55#include "params/BaseIndexingPolicy.hh" 56#include "sim/sim_object.hh" 57 58class ReplaceableEntry; 59 60/** 61 * A common base class for indexing table locations. Classes that inherit 62 * from it determine hash functions that should be applied based on the set 63 * and way. These functions are then applied to re-map the original values. 64 * @sa \ref gem5MemorySystem "gem5 Memory System" 65 */ 66class BaseIndexingPolicy : public SimObject 67{ 68 protected: 69 /** 70 * The associativity. 71 */ 72 const unsigned assoc; 73 74 /** 75 * The number of sets in the cache. 76 */ 77 const uint32_t numSets; 78 79 /** 80 * The amount to shift the address to get the set. 81 */ 82 const int setShift; 83 84 /** 85 * Mask out all bits that aren't part of the set index. 86 */ 87 const unsigned setMask; 88 89 /** 90 * The cache sets. 91 */ 92 std::vector<std::vector<ReplaceableEntry*>> sets; 93 94 /** 95 * The amount to shift the address to get the tag. 96 */ 97 const int tagShift; 98 99 public: 100 /** 101 * Convenience typedef. 102 */ 103 typedef BaseIndexingPolicyParams Params; 104 105 /** 106 * Construct and initialize this policy. 107 */ 108 BaseIndexingPolicy(const Params *p); 109 110 /** 111 * Destructor. 112 */ 113 ~BaseIndexingPolicy() {}; 114 115 /** 116 * Associate a pointer to an entry to its physical counterpart. 117 * 118 * @param entry The entry pointer. 119 * @param index An unique index for the entry. 120 */ 121 void setEntry(ReplaceableEntry* entry, const uint64_t index); 122 123 /** 124 * Get an entry based on its set and way. All entries must have been set 125 * already before calling this function. 126 * 127 * @param set The set of the desired entry. 128 * @param way The way of the desired entry. 129 * @return entry The entry pointer. 130 */ 131 ReplaceableEntry* getEntry(const uint32_t set, const uint32_t way) const; 132 133 /** 134 * Generate the tag from the given address. 135 * 136 * @param addr The address to get the tag from. 137 * @return The tag of the address. 138 */ 139 Addr extractTag(const Addr addr) const; 140 141 /** 142 * Find all possible entries for insertion and replacement of an address. 143 * Should be called immediately before ReplacementPolicy's findVictim() 144 * not to break cache resizing. 145 * 146 * @param addr The addr to a find possible entries for. 147 * @return The possible entries. 148 */ 149 virtual std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr) 150 const = 0; 151 152 /** 153 * Regenerate an entry's address from its tag and assigned indexing bits. 154 * 155 * @param tag The tag bits. 156 * @param entry The entry. 157 * @return the entry's original address. 158 */ 159 virtual Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry) 160 const = 0; 161}; 162 163#endif //__MEM_CACHE_INDEXING_POLICIES_BASE_HH__ 164