base_set_assoc.cc revision 11893:3033b3e6a32a 
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
20 * notice, this list of conditions and the following disclaimer;
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26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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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#include "sim/core.hh"
54
55using namespace std;
56
57BaseSetAssoc::BaseSetAssoc(const Params *p)
58    :BaseTags(p), assoc(p->assoc), allocAssoc(p->assoc),
59     numSets(p->size / (p->block_size * p->assoc)),
60     sequentialAccess(p->sequential_access)
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 (numSets <= 0 || !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    /** @todo Make warmup percentage a parameter. */
77    warmupBound = numSets * assoc;
78
79    sets = new SetType[numSets];
80    blks = new BlkType[numSets * assoc];
81    // allocate data storage in one big chunk
82    numBlocks = numSets * assoc;
83    dataBlks = new uint8_t[numBlocks * blkSize];
84
85    unsigned blkIndex = 0;       // index into blks array
86    for (unsigned i = 0; i < numSets; ++i) {
87        sets[i].assoc = assoc;
88
89        sets[i].blks = new BlkType*[assoc];
90
91        // link in the data blocks
92        for (unsigned j = 0; j < assoc; ++j) {
93            // locate next cache block
94            BlkType *blk = &blks[blkIndex];
95            blk->data = &dataBlks[blkSize*blkIndex];
96            ++blkIndex;
97
98            // invalidate new cache block
99            blk->invalidate();
100
101            //EGH Fix Me : do we need to initialize blk?
102
103            // Setting the tag to j is just to prevent long chains in the hash
104            // table; won't matter because the block is invalid
105            blk->tag = j;
106            blk->whenReady = 0;
107            blk->isTouched = false;
108            sets[i].blks[j]=blk;
109            blk->set = i;
110            blk->way = j;
111        }
112    }
113}
114
115BaseSetAssoc::~BaseSetAssoc()
116{
117    delete [] dataBlks;
118    delete [] blks;
119    delete [] sets;
120}
121
122CacheBlk*
123BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
124{
125    Addr tag = extractTag(addr);
126    unsigned set = extractSet(addr);
127    BlkType *blk = sets[set].findBlk(tag, is_secure);
128    return blk;
129}
130
131CacheBlk*
132BaseSetAssoc::findBlockBySetAndWay(int set, int way) const
133{
134    return sets[set].blks[way];
135}
136
137std::string
138BaseSetAssoc::print() const {
139    std::string cache_state;
140    for (unsigned i = 0; i < numSets; ++i) {
141        // link in the data blocks
142        for (unsigned j = 0; j < assoc; ++j) {
143            BlkType *blk = sets[i].blks[j];
144            if (blk->isValid())
145                cache_state += csprintf("\tset: %d block: %d %s\n", i, j,
146                        blk->print());
147        }
148    }
149    if (cache_state.empty())
150        cache_state = "no valid tags\n";
151    return cache_state;
152}
153
154void
155BaseSetAssoc::cleanupRefs()
156{
157    for (unsigned i = 0; i < numSets*assoc; ++i) {
158        if (blks[i].isValid()) {
159            totalRefs += blks[i].refCount;
160            ++sampledRefs;
161        }
162    }
163}
164
165void
166BaseSetAssoc::computeStats()
167{
168    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
169        occupanciesTaskId[i] = 0;
170        for (unsigned j = 0; j < 5; ++j) {
171            ageTaskId[i][j] = 0;
172        }
173    }
174
175    for (unsigned i = 0; i < numSets * assoc; ++i) {
176        if (blks[i].isValid()) {
177            assert(blks[i].task_id < ContextSwitchTaskId::NumTaskId);
178            occupanciesTaskId[blks[i].task_id]++;
179            assert(blks[i].tickInserted <= curTick());
180            Tick age = curTick() - blks[i].tickInserted;
181
182            int age_index;
183            if (age / SimClock::Int::us < 10) { // <10us
184                age_index = 0;
185            } else if (age / SimClock::Int::us < 100) { // <100us
186                age_index = 1;
187            } else if (age / SimClock::Int::ms < 1) { // <1ms
188                age_index = 2;
189            } else if (age / SimClock::Int::ms < 10) { // <10ms
190                age_index = 3;
191            } else
192                age_index = 4; // >10ms
193
194            ageTaskId[blks[i].task_id][age_index]++;
195        }
196    }
197}
198