base_set_assoc.cc revision 12684 
1/*
2 * Copyright (c) 2012-2014 ARM Limited
3 * All rights reserved.
4 *
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9 * licensed hereunder.  You may use the software subject to the license
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11 * unmodified and in its entirety in all distributions of the software,
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13 *
14 * Copyright (c) 2003-2005,2014 The Regents of The University of Michigan
15 * All rights reserved.
16 *
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18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
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21 * redistributions in binary form must reproduce the above copyright
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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
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33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Erik Hallnor
41 */
42
43/**
44 * @file
45 * Definitions of a base set associative tag store.
46 */
47
48#include "mem/cache/tags/base_set_assoc.hh"
49
50#include <string>
51
52#include "base/intmath.hh"
53
54BaseSetAssoc::BaseSetAssoc(const Params *p)
55    :BaseTags(p), assoc(p->assoc), allocAssoc(p->assoc),
56     blks(p->size / p->block_size),
57     numSets(p->size / (p->block_size * p->assoc)),
58     sequentialAccess(p->sequential_access),
59     sets(p->size / (p->block_size * p->assoc)),
60     replacementPolicy(p->replacement_policy)
61{
62    // Check parameters
63    if (blkSize < 4 || !isPowerOf2(blkSize)) {
64        fatal("Block size must be at least 4 and a power of 2");
65    }
66    if (!isPowerOf2(numSets)) {
67        fatal("# of sets must be non-zero and a power of 2");
68    }
69    if (assoc <= 0) {
70        fatal("associativity must be greater than zero");
71    }
72
73    setShift = floorLog2(blkSize);
74    setMask = numSets - 1;
75    tagShift = setShift + floorLog2(numSets);
76
77    unsigned blkIndex = 0;       // index into blks array
78    for (unsigned i = 0; i < numSets; ++i) {
79        sets[i].assoc = assoc;
80
81        sets[i].blks.resize(assoc);
82
83        // link in the data blocks
84        for (unsigned j = 0; j < assoc; ++j) {
85            // Select block within the set to be linked
86            BlkType*& blk = sets[i].blks[j];
87
88            // Locate next cache block
89            blk = &blks[blkIndex];
90
91            // Associate a data chunk to the block
92            blk->data = &dataBlks[blkSize*blkIndex];
93
94            // Associate a replacement data entry to the block
95            blk->replacementData = replacementPolicy->instantiateEntry();
96
97            // Setting the tag to j is just to prevent long chains in the
98            // hash table; won't matter because the block is invalid
99            blk->tag = j;
100
101            // Set its set and way
102            blk->set = i;
103            blk->way = j;
104
105            // Update block index
106            ++blkIndex;
107        }
108    }
109}
110
111void
112BaseSetAssoc::invalidate(CacheBlk *blk)
113{
114    BaseTags::invalidate(blk);
115
116    // Invalidate replacement data
117    replacementPolicy->invalidate(blk->replacementData);
118}
119
120CacheBlk*
121BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
122{
123    Addr tag = extractTag(addr);
124    unsigned set = extractSet(addr);
125    BlkType *blk = sets[set].findBlk(tag, is_secure);
126    return blk;
127}
128
129CacheBlk*
130BaseSetAssoc::findBlockBySetAndWay(int set, int way) const
131{
132    return sets[set].blks[way];
133}
134
135std::string
136BaseSetAssoc::print() const {
137    std::string cache_state;
138    for (const CacheBlk& blk : blks) {
139        if (blk.isValid())
140            cache_state += csprintf("\tset: %d way: %d %s\n", blk.set,
141                                    blk.way, blk.print());
142    }
143    if (cache_state.empty())
144        cache_state = "no valid tags\n";
145    return cache_state;
146}
147
148void
149BaseSetAssoc::cleanupRefs()
150{
151    for (const CacheBlk& blk : blks) {
152        if (blk.isValid()) {
153            totalRefs += blk.refCount;
154            ++sampledRefs;
155        }
156    }
157}
158
159void
160BaseSetAssoc::computeStats()
161{
162    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
163        occupanciesTaskId[i] = 0;
164        for (unsigned j = 0; j < 5; ++j) {
165            ageTaskId[i][j] = 0;
166        }
167    }
168
169    for (const CacheBlk& blk : blks) {
170        if (blk.isValid()) {
171            assert(blk.task_id < ContextSwitchTaskId::NumTaskId);
172            occupanciesTaskId[blk.task_id]++;
173            assert(blk.tickInserted <= curTick());
174            Tick age = curTick() - blk.tickInserted;
175
176            int age_index;
177            if (age / SimClock::Int::us < 10) { // <10us
178                age_index = 0;
179            } else if (age / SimClock::Int::us < 100) { // <100us
180                age_index = 1;
181            } else if (age / SimClock::Int::ms < 1) { // <1ms
182                age_index = 2;
183            } else if (age / SimClock::Int::ms < 10) { // <10ms
184                age_index = 3;
185            } else
186                age_index = 4; // >10ms
187
188            ageTaskId[blk.task_id][age_index]++;
189        }
190    }
191}
192
193BaseSetAssoc *
194BaseSetAssocParams::create()
195{
196    return new BaseSetAssoc(this);
197}
198