base_set_assoc.cc revision 10373:342348537a53 
1/*
2 * Copyright (c) 2012-2013 ARM Limited
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13 *
14 * Copyright (c) 2003-2005,2014 The Regents of The University of Michigan
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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    /** @todo Make warmup percentage a parameter. */
80    warmupBound = numSets * assoc;
81
82    sets = new SetType[numSets];
83    blks = new BlkType[numSets * assoc];
84    // allocate data storage in one big chunk
85    numBlocks = numSets * assoc;
86    dataBlks = new uint8_t[numBlocks * blkSize];
87
88    unsigned blkIndex = 0;       // index into blks array
89    for (unsigned i = 0; i < numSets; ++i) {
90        sets[i].assoc = assoc;
91
92        sets[i].blks = new BlkType*[assoc];
93
94        // link in the data blocks
95        for (unsigned j = 0; j < assoc; ++j) {
96            // locate next cache block
97            BlkType *blk = &blks[blkIndex];
98            blk->data = &dataBlks[blkSize*blkIndex];
99            ++blkIndex;
100
101            // invalidate new cache block
102            blk->invalidate();
103
104            //EGH Fix Me : do we need to initialize blk?
105
106            // Setting the tag to j is just to prevent long chains in the hash
107            // table; won't matter because the block is invalid
108            blk->tag = j;
109            blk->whenReady = 0;
110            blk->isTouched = false;
111            blk->size = blkSize;
112            sets[i].blks[j]=blk;
113            blk->set = i;
114        }
115    }
116}
117
118BaseSetAssoc::~BaseSetAssoc()
119{
120    delete [] dataBlks;
121    delete [] blks;
122    delete [] sets;
123}
124
125BaseSetAssoc::BlkType*
126BaseSetAssoc::findBlock(Addr addr, bool is_secure) const
127{
128    Addr tag = extractTag(addr);
129    unsigned set = extractSet(addr);
130    BlkType *blk = sets[set].findBlk(tag, is_secure);
131    return blk;
132}
133
134void
135BaseSetAssoc::clearLocks()
136{
137    for (int i = 0; i < numBlocks; i++){
138        blks[i].clearLoadLocks();
139    }
140}
141
142std::string
143BaseSetAssoc::print() const {
144    std::string cache_state;
145    for (unsigned i = 0; i < numSets; ++i) {
146        // link in the data blocks
147        for (unsigned j = 0; j < assoc; ++j) {
148            BlkType *blk = sets[i].blks[j];
149            if (blk->isValid())
150                cache_state += csprintf("\tset: %d block: %d %s\n", i, j,
151                        blk->print());
152        }
153    }
154    if (cache_state.empty())
155        cache_state = "no valid tags\n";
156    return cache_state;
157}
158
159void
160BaseSetAssoc::cleanupRefs()
161{
162    for (unsigned i = 0; i < numSets*assoc; ++i) {
163        if (blks[i].isValid()) {
164            totalRefs += blks[i].refCount;
165            ++sampledRefs;
166        }
167    }
168}
169
170void
171BaseSetAssoc::computeStats()
172{
173    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
174        occupanciesTaskId[i] = 0;
175        for (unsigned j = 0; j < 5; ++j) {
176            ageTaskId[i][j] = 0;
177        }
178    }
179
180    for (unsigned i = 0; i < numSets * assoc; ++i) {
181        if (blks[i].isValid()) {
182            assert(blks[i].task_id < ContextSwitchTaskId::NumTaskId);
183            occupanciesTaskId[blks[i].task_id]++;
184            assert(blks[i].tickInserted <= curTick());
185            Tick age = curTick() - blks[i].tickInserted;
186
187            int age_index;
188            if (age / SimClock::Int::us < 10) { // <10us
189                age_index = 0;
190            } else if (age / SimClock::Int::us < 100) { // <100us
191                age_index = 1;
192            } else if (age / SimClock::Int::ms < 1) { // <1ms
193                age_index = 2;
194            } else if (age / SimClock::Int::ms < 10) { // <10ms
195                age_index = 3;
196            } else
197                age_index = 4; // >10ms
198
199            ageTaskId[blks[i].task_id][age_index]++;
200        }
201    }
202}
203