base_set_assoc.cc revision 12548:285f1792a2da 
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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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
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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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     blks(p->size / p->block_size),
60     dataBlks(new uint8_t[p->size]), // Allocate data storage in one big chunk
61     numSets(p->size / (p->block_size * p->assoc)),
62     sequentialAccess(p->sequential_access),
63     sets(p->size / (p->block_size * p->assoc))
64{
65    // Check parameters
66    if (blkSize < 4 || !isPowerOf2(blkSize)) {
67        fatal("Block size must be at least 4 and a power of 2");
68    }
69    if (!isPowerOf2(numSets)) {
70        fatal("# of sets must be non-zero and a power of 2");
71    }
72    if (assoc <= 0) {
73        fatal("associativity must be greater than zero");
74    }
75
76    setShift = floorLog2(blkSize);
77    setMask = numSets - 1;
78    tagShift = setShift + floorLog2(numSets);
79
80    unsigned blkIndex = 0;       // index into blks array
81    for (unsigned i = 0; i < numSets; ++i) {
82        sets[i].assoc = assoc;
83
84        sets[i].blks.resize(assoc);
85
86        // link in the data blocks
87        for (unsigned j = 0; j < assoc; ++j) {
88            // locate next cache block
89            BlkType *blk = &blks[blkIndex];
90            blk->data = &dataBlks[blkSize*blkIndex];
91            ++blkIndex;
92
93            // invalidate new cache block
94            blk->invalidate();
95
96            //EGH Fix Me : do we need to initialize blk?
97
98            // Setting the tag to j is just to prevent long chains in the hash
99            // table; won't matter because the block is invalid
100            blk->tag = j;
101            blk->whenReady = 0;
102            blk->isTouched = false;
103            sets[i].blks[j]=blk;
104            blk->set = i;
105            blk->way = j;
106        }
107    }
108}
109
110CacheBlk*
111BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
112{
113    Addr tag = extractTag(addr);
114    unsigned set = extractSet(addr);
115    BlkType *blk = sets[set].findBlk(tag, is_secure);
116    return blk;
117}
118
119CacheBlk*
120BaseSetAssoc::findBlockBySetAndWay(int set, int way) const
121{
122    return sets[set].blks[way];
123}
124
125std::string
126BaseSetAssoc::print() const {
127    std::string cache_state;
128    for (unsigned i = 0; i < numSets; ++i) {
129        // link in the data blocks
130        for (unsigned j = 0; j < assoc; ++j) {
131            BlkType *blk = sets[i].blks[j];
132            if (blk->isValid())
133                cache_state += csprintf("\tset: %d block: %d %s\n", i, j,
134                        blk->print());
135        }
136    }
137    if (cache_state.empty())
138        cache_state = "no valid tags\n";
139    return cache_state;
140}
141
142void
143BaseSetAssoc::cleanupRefs()
144{
145    for (unsigned i = 0; i < numSets*assoc; ++i) {
146        if (blks[i].isValid()) {
147            totalRefs += blks[i].refCount;
148            ++sampledRefs;
149        }
150    }
151}
152
153void
154BaseSetAssoc::computeStats()
155{
156    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
157        occupanciesTaskId[i] = 0;
158        for (unsigned j = 0; j < 5; ++j) {
159            ageTaskId[i][j] = 0;
160        }
161    }
162
163    for (unsigned i = 0; i < numSets * assoc; ++i) {
164        if (blks[i].isValid()) {
165            assert(blks[i].task_id < ContextSwitchTaskId::NumTaskId);
166            occupanciesTaskId[blks[i].task_id]++;
167            assert(blks[i].tickInserted <= curTick());
168            Tick age = curTick() - blks[i].tickInserted;
169
170            int age_index;
171            if (age / SimClock::Int::us < 10) { // <10us
172                age_index = 0;
173            } else if (age / SimClock::Int::us < 100) { // <100us
174                age_index = 1;
175            } else if (age / SimClock::Int::ms < 1) { // <1ms
176                age_index = 2;
177            } else if (age / SimClock::Int::ms < 10) { // <10ms
178                age_index = 3;
179            } else
180                age_index = 4; // >10ms
181
182            ageTaskId[blks[i].task_id][age_index]++;
183        }
184    }
185}
186