1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
/**
* Copyright (c) 2018 Inria
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Daniel Carvalho
*/
#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
#define __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
#include "mem/cache/base.hh"
#include "mem/cache/blk.hh"
#include "params/BaseReplacementPolicy.hh"
#include "sim/sim_object.hh"
/**
* Replacement candidates as chosen by the indexing policy.
*
* The base functions touch() and reset() must be called by all subclasses
* that override them.
*
* @todo
* Currently the replacement candidates are simply the cache blocks
* derived from the possible placement locations of an address, as
* defined by the getPossibleLocations() from BaseTags. In a future
* patch it should be an inheritable class to allow the replacement
* policies to be used with any table-like structure that needs to
* replace its entries.
*/
typedef std::vector<CacheBlk*> ReplacementCandidates;
/**
* A common base class of cache replacement policy objects.
*/
class BaseReplacementPolicy : public SimObject
{
public:
/**
* Convenience typedef.
*/
typedef BaseReplacementPolicyParams Params;
/**
* Construct and initiliaze this replacement policy.
*/
BaseReplacementPolicy(const Params *p);
/**
* Destructor.
*/
virtual ~BaseReplacementPolicy() {}
/**
* Touch a block to update its replacement data.
* Updates number of references.
*
* This base function must be called by all subclasses that override it.
*
* @param blk Cache block to be touched.
*/
virtual void touch(CacheBlk *blk);
/**
* Reset replacement data for a block. Used when a block is inserted.
* Sets the insertion tick, and update number of references.
*
* This base function must be called by all subclasses that override it.
*
* @param blk Cache block to be reset.
*/
virtual void reset(CacheBlk *blk);
/**
* Find replacement victim among candidates.
*
* @param candidates Replacement candidates, selected by indexing policy.
* @return Cache block to be replaced.
*/
virtual CacheBlk* getVictim(const ReplacementCandidates& candidates) = 0;
};
#endif // __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
|
