1/**
2 * Copyright (c) 2018 Metempsy Technology Consulting
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;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Javier Bueno
29 */
30
31/**
32 * Implementation of the Irregular Stream Buffer prefetcher
33 * Reference:
34 * Jain, A., & Lin, C. (2013, December). Linearizing irregular memory
35 * accesses for improved correlated prefetching. In Proceedings of the
36 * 46th Annual IEEE/ACM International Symposium on Microarchitecture
37 * (pp. 247-259). ACM.
38 */
39
40#ifndef __MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
41#define __MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
42
43#include "base/callback.hh"
| 1/**
2 * Copyright (c) 2018 Metempsy Technology Consulting
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;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Javier Bueno
29 */
30
31/**
32 * Implementation of the Irregular Stream Buffer prefetcher
33 * Reference:
34 * Jain, A., & Lin, C. (2013, December). Linearizing irregular memory
35 * accesses for improved correlated prefetching. In Proceedings of the
36 * 46th Annual IEEE/ACM International Symposium on Microarchitecture
37 * (pp. 247-259). ACM.
38 */
39
40#ifndef __MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
41#define __MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
42
43#include "base/callback.hh"
|
| 44#include "base/sat_counter.hh"
|
44#include "mem/cache/prefetch/associative_set.hh"
45#include "mem/cache/prefetch/queued.hh"
46
47struct IrregularStreamBufferPrefetcherParams;
48
49class IrregularStreamBufferPrefetcher : public QueuedPrefetcher
50{
| 45#include "mem/cache/prefetch/associative_set.hh"
46#include "mem/cache/prefetch/queued.hh"
47
48struct IrregularStreamBufferPrefetcherParams;
49
50class IrregularStreamBufferPrefetcher : public QueuedPrefetcher
51{
|
51 /** Maximum value of the confidence counters */
52 const unsigned maxCounterValue;
| |
53 /** Size in bytes of a temporal stream */
54 const size_t chunkSize;
55 /** Number of prefetch candidates per Physical-to-Structural entry */
56 const unsigned prefetchCandidatesPerEntry;
57 /** Number of maximum prefetches requests created when predicting */
58 const unsigned degree;
59
60 /**
61 * Training Unit Entry datatype, it holds the last accessed address and
62 * its secure flag
63 */
64 struct TrainingUnitEntry : public TaggedEntry {
65 Addr lastAddress;
66 bool lastAddressSecure;
67 };
68 /** Map of PCs to Training unit entries */
69 AssociativeSet<TrainingUnitEntry> trainingUnit;
70
71 /** Address Mapping entry, holds an address and a confidence counter */
72 struct AddressMapping {
73 Addr address;
| 52 /** Size in bytes of a temporal stream */
53 const size_t chunkSize;
54 /** Number of prefetch candidates per Physical-to-Structural entry */
55 const unsigned prefetchCandidatesPerEntry;
56 /** Number of maximum prefetches requests created when predicting */
57 const unsigned degree;
58
59 /**
60 * Training Unit Entry datatype, it holds the last accessed address and
61 * its secure flag
62 */
63 struct TrainingUnitEntry : public TaggedEntry {
64 Addr lastAddress;
65 bool lastAddressSecure;
66 };
67 /** Map of PCs to Training unit entries */
68 AssociativeSet<TrainingUnitEntry> trainingUnit;
69
70 /** Address Mapping entry, holds an address and a confidence counter */
71 struct AddressMapping {
72 Addr address;
|
74 unsigned counter;
75 AddressMapping() : address(0), counter(0)
| 73 SatCounter counter;
74 AddressMapping(unsigned bits) : address(0), counter(bits)
|
76 {}
77 };
78
79 /**
80 * Maps a set of contiguous addresses to another set of (not necessarily
81 * contiguos) addresses, with their corresponding confidence counters
82 */
83 struct AddressMappingEntry : public TaggedEntry {
84 std::vector<AddressMapping> mappings;
| 75 {}
76 };
77
78 /**
79 * Maps a set of contiguous addresses to another set of (not necessarily
80 * contiguos) addresses, with their corresponding confidence counters
81 */
82 struct AddressMappingEntry : public TaggedEntry {
83 std::vector<AddressMapping> mappings;
|
85 AddressMappingEntry(size_t num_mappings) : mappings(num_mappings)
| 84 AddressMappingEntry(size_t num_mappings, unsigned counter_bits)
85 : mappings(num_mappings, counter_bits)
|
86 {}
87 void reset() override
88 {
89 for (auto &entry : mappings) {
90 entry.address = 0;
| 86 {}
87 void reset() override
88 {
89 for (auto &entry : mappings) {
90 entry.address = 0;
|
91 entry.counter = 0;
| 91 entry.counter.reset();
|
92 }
93 }
94 };
95
96 /** Physical-to-Structured mappings table */
97 AssociativeSet<AddressMappingEntry> psAddressMappingCache;
98 /** Structured-to-Physical mappings table */
99 AssociativeSet<AddressMappingEntry> spAddressMappingCache;
100 /**
101 * Counter of allocated structural addresses, increased by "chunkSize",
102 * each time a new structured address is allocated
103 */
104 uint64_t structuralAddressCounter;
105
106 /**
107 * Add a mapping to the Structured-to-Physica mapping table
108 * @param structuralAddress structural address
109 * @param is_secure whether this page is inside the secure memory area
110 * @param physical_address corresponding physical address
111 */
112 void addStructuralToPhysicalEntry(Addr structuralAddress, bool is_secure,
113 Addr physical_address);
114
115 /**
116 * Obtain the Physical-to-Structured mapping entry of the given physical
117 * address. If the entry does not exist a new one is allocated, replacing
118 * an existing one if needed.
119 * @param paddr physical address
120 * @param is_secure whether this page is inside the secure memory area
121 * @result reference to the entry
122 */
123 AddressMapping& getPSMapping(Addr paddr, bool is_secure);
124 public:
125 IrregularStreamBufferPrefetcher(
126 const IrregularStreamBufferPrefetcherParams *p);
127 ~IrregularStreamBufferPrefetcher() {}
128 void calculatePrefetch(const PrefetchInfo &pfi,
129 std::vector<AddrPriority> &addresses) override;
130};
131#endif//__MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
| 92 }
93 }
94 };
95
96 /** Physical-to-Structured mappings table */
97 AssociativeSet<AddressMappingEntry> psAddressMappingCache;
98 /** Structured-to-Physical mappings table */
99 AssociativeSet<AddressMappingEntry> spAddressMappingCache;
100 /**
101 * Counter of allocated structural addresses, increased by "chunkSize",
102 * each time a new structured address is allocated
103 */
104 uint64_t structuralAddressCounter;
105
106 /**
107 * Add a mapping to the Structured-to-Physica mapping table
108 * @param structuralAddress structural address
109 * @param is_secure whether this page is inside the secure memory area
110 * @param physical_address corresponding physical address
111 */
112 void addStructuralToPhysicalEntry(Addr structuralAddress, bool is_secure,
113 Addr physical_address);
114
115 /**
116 * Obtain the Physical-to-Structured mapping entry of the given physical
117 * address. If the entry does not exist a new one is allocated, replacing
118 * an existing one if needed.
119 * @param paddr physical address
120 * @param is_secure whether this page is inside the secure memory area
121 * @result reference to the entry
122 */
123 AddressMapping& getPSMapping(Addr paddr, bool is_secure);
124 public:
125 IrregularStreamBufferPrefetcher(
126 const IrregularStreamBufferPrefetcherParams *p);
127 ~IrregularStreamBufferPrefetcher() {}
128 void calculatePrefetch(const PrefetchInfo &pfi,
129 std::vector<AddrPriority> &addresses) override;
130};
131#endif//__MEM_CACHE_PREFETCH_IRREGULAR_STREAM_BUFFER_HH__
|