base_set_assoc.cc revision 12727:56c23b54bcb1 
1/*
2 * Copyright (c) 2012-2014 ARM Limited
3 * All rights reserved.
4 *
5 * The license below extends only to copyright in the software and shall
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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
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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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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38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 <cassert>
51#include <string>
52
53#include "base/intmath.hh"
54#include "mem/request.hh"
55
56BaseSetAssoc::BaseSetAssoc(const Params *p)
57    :BaseTags(p), assoc(p->assoc), allocAssoc(p->assoc),
58     blks(p->size / p->block_size),
59     numSets(p->size / (p->block_size * p->assoc)),
60     sequentialAccess(p->sequential_access),
61     sets(p->size / (p->block_size * p->assoc)),
62     replacementPolicy(p->replacement_policy)
63{
64    // Check parameters
65    if (blkSize < 4 || !isPowerOf2(blkSize)) {
66        fatal("Block size must be at least 4 and a power of 2");
67    }
68    if (!isPowerOf2(numSets)) {
69        fatal("# of sets must be non-zero and a power of 2");
70    }
71    if (assoc <= 0) {
72        fatal("associativity must be greater than zero");
73    }
74
75    setShift = floorLog2(blkSize);
76    setMask = numSets - 1;
77    tagShift = setShift + floorLog2(numSets);
78
79    unsigned blkIndex = 0;       // index into blks array
80    for (unsigned i = 0; i < numSets; ++i) {
81        sets[i].assoc = assoc;
82
83        sets[i].blks.resize(assoc);
84
85        // link in the data blocks
86        for (unsigned j = 0; j < assoc; ++j) {
87            // Select block within the set to be linked
88            BlkType*& blk = sets[i].blks[j];
89
90            // Locate next cache block
91            blk = &blks[blkIndex];
92
93            // Associate a data chunk to the block
94            blk->data = &dataBlks[blkSize*blkIndex];
95
96            // Associate a replacement data entry to the block
97            blk->replacementData = replacementPolicy->instantiateEntry();
98
99            // Setting the tag to j is just to prevent long chains in the
100            // hash table; won't matter because the block is invalid
101            blk->tag = j;
102
103            // Set its set and way
104            blk->set = i;
105            blk->way = j;
106
107            // Update block index
108            ++blkIndex;
109        }
110    }
111}
112
113void
114BaseSetAssoc::invalidate(CacheBlk *blk)
115{
116    BaseTags::invalidate(blk);
117
118    // Invalidate replacement data
119    replacementPolicy->invalidate(blk->replacementData);
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 (const CacheBlk& blk : blks) {
141        if (blk.isValid())
142            cache_state += csprintf("\tset: %d way: %d %s\n", blk.set,
143                                    blk.way, blk.print());
144    }
145    if (cache_state.empty())
146        cache_state = "no valid tags\n";
147    return cache_state;
148}
149
150void
151BaseSetAssoc::cleanupRefs()
152{
153    for (const CacheBlk& blk : blks) {
154        if (blk.isValid()) {
155            totalRefs += blk.refCount;
156            ++sampledRefs;
157        }
158    }
159}
160
161void
162BaseSetAssoc::computeStats()
163{
164    for (unsigned i = 0; i < ContextSwitchTaskId::NumTaskId; ++i) {
165        occupanciesTaskId[i] = 0;
166        for (unsigned j = 0; j < 5; ++j) {
167            ageTaskId[i][j] = 0;
168        }
169    }
170
171    for (const CacheBlk& blk : blks) {
172        if (blk.isValid()) {
173            assert(blk.task_id < ContextSwitchTaskId::NumTaskId);
174            occupanciesTaskId[blk.task_id]++;
175            assert(blk.tickInserted <= curTick());
176            Tick age = curTick() - blk.tickInserted;
177
178            int age_index;
179            if (age / SimClock::Int::us < 10) { // <10us
180                age_index = 0;
181            } else if (age / SimClock::Int::us < 100) { // <100us
182                age_index = 1;
183            } else if (age / SimClock::Int::ms < 1) { // <1ms
184                age_index = 2;
185            } else if (age / SimClock::Int::ms < 10) { // <10ms
186                age_index = 3;
187            } else
188                age_index = 4; // >10ms
189
190            ageTaskId[blk.task_id][age_index]++;
191        }
192    }
193}
194
195BaseSetAssoc *
196BaseSetAssocParams::create()
197{
198    return new BaseSetAssoc(this);
199}
200