base.hh (12600:e670dd17c8cf) base.hh (12684:44ebd2bc020f)
1/**
2 * Copyright (c) 2018 Inria
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;

--- 17 unchanged lines hidden (view full) ---

26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Daniel Carvalho
29 */
30
31#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
32#define __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
33
1/**
2 * Copyright (c) 2018 Inria
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;

--- 17 unchanged lines hidden (view full) ---

26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Daniel Carvalho
29 */
30
31#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
32#define __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
33
34#include "mem/cache/base.hh"
35#include "mem/cache/blk.hh"
34#include <memory>
35
36#include "params/BaseReplacementPolicy.hh"
37#include "sim/sim_object.hh"
38
39/**
36#include "params/BaseReplacementPolicy.hh"
37#include "sim/sim_object.hh"
38
39/**
40 * The replacement data needed by the replacement policy.
41 * Each replacement policy should have its own replacement data.
42 */
43struct ReplacementData {};
44
45/**
46 * A replaceable entry is used by any table-like structure that needs to
47 * implement replacement functionality. It provides the replacement data
48 * pointer instantiated and needed by the replacement policy used.
49 * @sa Replacement Policies
50 */
51class ReplaceableEntry
52{
53 public:
54 /**
55 * Replacement data associated to this entry.
56 * It is instantiated by the replacement policy.
57 */
58 std::shared_ptr<ReplacementData> replacementData;
59};
60
61/**
40 * Replacement candidates as chosen by the indexing policy.
62 * Replacement candidates as chosen by the indexing policy.
41 *
42 * The base functions touch() and reset() must be called by all subclasses
43 * that override them.
44 *
45 * @todo
46 * Currently the replacement candidates are simply the cache blocks
47 * derived from the possible placement locations of an address, as
48 * defined by the getPossibleLocations() from BaseTags. In a future
49 * patch it should be an inheritable class to allow the replacement
50 * policies to be used with any table-like structure that needs to
51 * replace its entries.
52 */
63 */
53typedef std::vector<CacheBlk*> ReplacementCandidates;
64typedef std::vector<ReplaceableEntry*> ReplacementCandidates;
54
55/**
56 * A common base class of cache replacement policy objects.
57 */
58class BaseReplacementPolicy : public SimObject
59{
60 public:
61 /**
62 * Convenience typedef.
63 */
64 typedef BaseReplacementPolicyParams Params;
65
66 /**
67 * Construct and initiliaze this replacement policy.
68 */
65
66/**
67 * A common base class of cache replacement policy objects.
68 */
69class BaseReplacementPolicy : public SimObject
70{
71 public:
72 /**
73 * Convenience typedef.
74 */
75 typedef BaseReplacementPolicyParams Params;
76
77 /**
78 * Construct and initiliaze this replacement policy.
79 */
69 BaseReplacementPolicy(const Params *p);
80 BaseReplacementPolicy(const Params *p) : SimObject(p) {}
70
71 /**
72 * Destructor.
73 */
74 virtual ~BaseReplacementPolicy() {}
75
76 /**
81
82 /**
83 * Destructor.
84 */
85 virtual ~BaseReplacementPolicy() {}
86
87 /**
77 * Touch a block to update its replacement data.
78 * Updates number of references.
88 * Invalidate replacement data to set it as the next probable victim.
79 *
89 *
80 * This base function must be called by all subclasses that override it.
90 * @param replacement_data Replacement data to be invalidated.
91 */
92 virtual void invalidate(const std::shared_ptr<ReplacementData>&
93 replacement_data) const = 0;
94
95 /**
96 * Update replacement data.
81 *
97 *
82 * @param blk Cache block to be touched.
98 * @param replacement_data Replacement data to be touched.
83 */
99 */
84 virtual void touch(CacheBlk *blk);
100 virtual void touch(const std::shared_ptr<ReplacementData>&
101 replacement_data) const = 0;
85
86 /**
102
103 /**
87 * Reset replacement data for a block. Used when a block is inserted.
88 * Sets the insertion tick, and update number of references.
104 * Reset replacement data. Used when it's holder is inserted/validated.
89 *
105 *
90 * This base function must be called by all subclasses that override it.
91 *
92 * @param blk Cache block to be reset.
106 * @param replacement_data Replacement data to be reset.
93 */
107 */
94 virtual void reset(CacheBlk *blk);
108 virtual void reset(const std::shared_ptr<ReplacementData>&
109 replacement_data) const = 0;
95
96 /**
97 * Find replacement victim among candidates.
98 *
99 * @param candidates Replacement candidates, selected by indexing policy.
110
111 /**
112 * Find replacement victim among candidates.
113 *
114 * @param candidates Replacement candidates, selected by indexing policy.
100 * @return Cache block to be replaced.
115 * @return Replacement entry to be replaced.
101 */
116 */
102 virtual CacheBlk* getVictim(const ReplacementCandidates& candidates) = 0;
117 virtual ReplaceableEntry* getVictim(
118 const ReplacementCandidates& candidates) const = 0;
119
120 /**
121 * Instantiate a replacement data entry.
122 *
123 * @return A shared pointer to the new replacement data.
124 */
125 virtual std::shared_ptr<ReplacementData> instantiateEntry() = 0;
103};
104
105#endif // __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__
126};
127
128#endif // __MEM_CACHE_REPLACEMENT_POLICIES_BASE_HH__