base_set_assoc.cc revision 10263:c00b5ba43967 
1/*
2 * Copyright (c) 2012-2013 ARM Limited
3 * All rights reserved.
4 *
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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.
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18 * modification, are permitted provided that the following conditions are
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26 * this software without specific prior written permission.
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28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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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 <string>
49
50#include "base/intmath.hh"
51#include "mem/cache/tags/base_set_assoc.hh"
52#include "sim/core.hh"
53
54using namespace std;
55
56BaseSetAssoc::BaseSetAssoc(const Params *p)
57    :BaseTags(p), assoc(p->assoc),
58     numSets(p->size / (p->block_size * p->assoc)),
59     sequentialAccess(p->sequential_access)
60{
61    // Check parameters
62    if (blkSize < 4 || !isPowerOf2(blkSize)) {
63        fatal("Block size must be at least 4 and a power of 2");
64    }
65    if (numSets <= 0 || !isPowerOf2(numSets)) {
66        fatal("# of sets must be non-zero and a power of 2");
67    }
68    if (assoc <= 0) {
69        fatal("associativity must be greater than zero");
70    }
71    if (hitLatency <= 0) {
72        fatal("access latency must be greater than zero");
73    }
74
75    blkMask = blkSize - 1;
76    setShift = floorLog2(blkSize);
77    setMask = numSets - 1;
78    tagShift = setShift + floorLog2(numSets);
79    warmedUp = false;
80    /** @todo Make warmup percentage a parameter. */
81    warmupBound = numSets * assoc;
82
83    sets = new SetType[numSets];
84    blks = new BlkType[numSets * assoc];
85    // allocate data storage in one big chunk
86    numBlocks = numSets * assoc;
87    dataBlks = new uint8_t[numBlocks * blkSize];
88
89    unsigned blkIndex = 0;       // index into blks array
90    for (unsigned i = 0; i < numSets; ++i) {
91        sets[i].assoc = assoc;
92
93        sets[i].blks = new BlkType*[assoc];
94
95        // link in the data blocks
96        for (unsigned j = 0; j < assoc; ++j) {
97            // locate next cache block
98            BlkType *blk = &blks[blkIndex];
99            blk->data = &dataBlks[blkSize*blkIndex];
100            ++blkIndex;
101
102            // invalidate new cache block
103            blk->invalidate();
104
105            //EGH Fix Me : do we need to initialize blk?
106
107            // Setting the tag to j is just to prevent long chains in the hash
108            // table; won't matter because the block is invalid
109            blk->tag = j;
110            blk->whenReady = 0;
111            blk->isTouched = false;
112            blk->size = blkSize;
113            sets[i].blks[j]=blk;
114            blk->set = i;
115        }
116    }
117}
118
119BaseSetAssoc::~BaseSetAssoc()
120{
121    delete [] dataBlks;
122    delete [] blks;
123    delete [] sets;
124}
125
126BaseSetAssoc::BlkType*
127BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
128{
129    Addr tag = extractTag(addr);
130    unsigned set = extractSet(addr);
131    BlkType *blk = sets[set].findBlk(tag, is_secure);
132    return blk;
133}
134
135void
136BaseSetAssoc::clearLocks()
137{
138    for (int i = 0; i < numBlocks; i++){
139        blks[i].clearLoadLocks();
140    }
141}
142
143std::string
144BaseSetAssoc::print() const {
145    std::string cache_state;
146    for (unsigned i = 0; i < numSets; ++i) {
147        // link in the data blocks
148        for (unsigned j = 0; j < assoc; ++j) {
149            BlkType *blk = sets[i].blks[j];
150            if (blk->isValid())
151                cache_state += csprintf("\tset: %d block: %d %s\n", i, j,
152                        blk->print());
153        }
154    }
155    if (cache_state.empty())
156        cache_state = "no valid tags\n";
157    return cache_state;
158}
159
160void
161BaseSetAssoc::cleanupRefs()
162{
163    for (unsigned i = 0; i < numSets*assoc; ++i) {
164        if (blks[i].isValid()) {
165            totalRefs += blks[i].refCount;
166            ++sampledRefs;
167        }
168    }
169}
170
171void
172BaseSetAssoc::computeStats()
173{
174    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
175        occupanciesTaskId[i] = 0;
176        for (unsigned j = 0; j < 5; ++j) {
177            ageTaskId[i][j] = 0;
178        }
179    }
180
181    for (unsigned i = 0; i < numSets * assoc; ++i) {
182        if (blks[i].isValid()) {
183            assert(blks[i].task_id < ContextSwitchTaskId::NumTaskId);
184            occupanciesTaskId[blks[i].task_id]++;
185            Tick age = curTick() - blks[i].tickInserted;
186            assert(age >= 0);
187
188            int age_index;
189            if (age / SimClock::Int::us < 10) { // <10us
190                age_index = 0;
191            } else if (age / SimClock::Int::us < 100) { // <100us
192                age_index = 1;
193            } else if (age / SimClock::Int::ms < 1) { // <1ms
194                age_index = 2;
195            } else if (age / SimClock::Int::ms < 10) { // <10ms
196                age_index = 3;
197            } else
198                age_index = 4; // >10ms
199
200            ageTaskId[blks[i].task_id][age_index]++;
201        }
202    }
203}
204