base_set_assoc.cc revision 11486:f09bb73b3050 
1/*
2 * Copyright (c) 2012-2014 ARM Limited
3 * All rights reserved.
4 *
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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
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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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    blkMask = blkSize - 1;
74    setShift = floorLog2(blkSize);
75    setMask = numSets - 1;
76    tagShift = setShift + floorLog2(numSets);
77    /** @todo Make warmup percentage a parameter. */
78    warmupBound = numSets * assoc;
79
80    sets = new SetType[numSets];
81    blks = new BlkType[numSets * assoc];
82    // allocate data storage in one big chunk
83    numBlocks = numSets * assoc;
84    dataBlks = new uint8_t[numBlocks * blkSize];
85
86    unsigned blkIndex = 0;       // index into blks array
87    for (unsigned i = 0; i < numSets; ++i) {
88        sets[i].assoc = assoc;
89
90        sets[i].blks = new BlkType*[assoc];
91
92        // link in the data blocks
93        for (unsigned j = 0; j < assoc; ++j) {
94            // locate next cache block
95            BlkType *blk = &blks[blkIndex];
96            blk->data = &dataBlks[blkSize*blkIndex];
97            ++blkIndex;
98
99            // invalidate new cache block
100            blk->invalidate();
101
102            //EGH Fix Me : do we need to initialize blk?
103
104            // Setting the tag to j is just to prevent long chains in the hash
105            // table; won't matter because the block is invalid
106            blk->tag = j;
107            blk->whenReady = 0;
108            blk->isTouched = false;
109            blk->size = blkSize;
110            sets[i].blks[j]=blk;
111            blk->set = i;
112            blk->way = j;
113        }
114    }
115}
116
117BaseSetAssoc::~BaseSetAssoc()
118{
119    delete [] dataBlks;
120    delete [] blks;
121    delete [] sets;
122}
123
124CacheBlk*
125BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
126{
127    Addr tag = extractTag(addr);
128    unsigned set = extractSet(addr);
129    BlkType *blk = sets[set].findBlk(tag, is_secure);
130    return blk;
131}
132
133CacheBlk*
134BaseSetAssoc::findBlockBySetAndWay(int set, int way) const
135{
136    return sets[set].blks[way];
137}
138
139std::string
140BaseSetAssoc::print() const {
141    std::string cache_state;
142    for (unsigned i = 0; i < numSets; ++i) {
143        // link in the data blocks
144        for (unsigned j = 0; j < assoc; ++j) {
145            BlkType *blk = sets[i].blks[j];
146            if (blk->isValid())
147                cache_state += csprintf("\tset: %d block: %d %s\n", i, j,
148                        blk->print());
149        }
150    }
151    if (cache_state.empty())
152        cache_state = "no valid tags\n";
153    return cache_state;
154}
155
156void
157BaseSetAssoc::cleanupRefs()
158{
159    for (unsigned i = 0; i < numSets*assoc; ++i) {
160        if (blks[i].isValid()) {
161            totalRefs += blks[i].refCount;
162            ++sampledRefs;
163        }
164    }
165}
166
167void
168BaseSetAssoc::computeStats()
169{
170    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
171        occupanciesTaskId[i] = 0;
172        for (unsigned j = 0; j < 5; ++j) {
173            ageTaskId[i][j] = 0;
174        }
175    }
176
177    for (unsigned i = 0; i < numSets * assoc; ++i) {
178        if (blks[i].isValid()) {
179            assert(blks[i].task_id < ContextSwitchTaskId::NumTaskId);
180            occupanciesTaskId[blks[i].task_id]++;
181            assert(blks[i].tickInserted <= curTick());
182            Tick age = curTick() - blks[i].tickInserted;
183
184            int age_index;
185            if (age / SimClock::Int::us < 10) { // <10us
186                age_index = 0;
187            } else if (age / SimClock::Int::us < 100) { // <100us
188                age_index = 1;
189            } else if (age / SimClock::Int::ms < 1) { // <1ms
190                age_index = 2;
191            } else if (age / SimClock::Int::ms < 10) { // <10ms
192                age_index = 3;
193            } else
194                age_index = 4; // >10ms
195
196            ageTaskId[blks[i].task_id][age_index]++;
197        }
198    }
199}
200