summaryrefslogtreecommitdiff
path: root/src/mem/cache/noncoherent_cache.hh
blob: 824c7ccc9f18a2421ee75e49784631d1b3f4fa05 (plain)
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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * Copyright (c) 2012-2018 ARM Limited
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Copyright (c) 2002-2005 The Regents of The University of Michigan
 * 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: Erik Hallnor
 *          Dave Greene
 *          Steve Reinhardt
 *          Ron Dreslinski
 *          Andreas Hansson
 *          Nikos Nikoleris
 */

/**
 * @file
 * Specifies a non-coherent cache. The non-coherent cache is expected
 * to be located below the point of coherency. All valid blocks in the
 * non-coherent cache can always be written to without any prior
 * invalidations or snoops.
 */

#ifndef __MEM_CACHE_NONCOHERENT_CACHE_HH__
#define __MEM_CACHE_NONCOHERENT_CACHE_HH__

#include "base/logging.hh"
#include "base/types.hh"
#include "mem/cache/base.hh"
#include "mem/packet.hh"

class CacheBlk;
class MSHR;
struct NoncoherentCacheParams;

/**
 * A non-coherent cache
 */
class NoncoherentCache : public BaseCache
{
  protected:
    bool access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat,
                PacketList &writebacks) override;

    void handleTimingReqMiss(PacketPtr pkt, CacheBlk *blk,
                             Tick forward_time,
                             Tick request_time) override;

    void recvTimingReq(PacketPtr pkt) override;

    void doWritebacks(PacketList& writebacks,
                      Tick forward_time) override;

    void doWritebacksAtomic(PacketList& writebacks) override;

    void serviceMSHRTargets(MSHR *mshr, const PacketPtr pkt,
                            CacheBlk *blk, PacketList& writebacks) override;

    void recvTimingResp(PacketPtr pkt) override;

    void recvTimingSnoopReq(PacketPtr pkt) override {
        panic("Unexpected timing snoop request %s", pkt->print());
    }

    void recvTimingSnoopResp(PacketPtr pkt) override {
        panic("Unexpected timing snoop response %s", pkt->print());
    }

    Cycles handleAtomicReqMiss(PacketPtr pkt, CacheBlk *&blk,
                               PacketList &writebacks) override;

    Tick recvAtomic(PacketPtr pkt) override;

    Tick recvAtomicSnoop(PacketPtr pkt) override {
        panic("Unexpected atomic snoop request %s", pkt->print());
    }

    void functionalAccess(PacketPtr pkt, bool from_cpu_side) override;

    void satisfyRequest(PacketPtr pkt, CacheBlk *blk,
                        bool deferred_response = false,
                        bool pending_downgrade = false) override;

    /*
     * Creates a new packet with the request to be send to the memory
     * below. The noncoherent cache is below the point of coherence
     * and therefore all fills bring in writable, therefore the
     * needs_writeble parameter is ignored.
     */
    PacketPtr createMissPacket(PacketPtr cpu_pkt, CacheBlk *blk,
                               bool needs_writable,
                               bool is_whole_line_write) const override;

    M5_NODISCARD PacketPtr evictBlock(CacheBlk *blk) override;

  public:
    NoncoherentCache(const NoncoherentCacheParams *p);
};

#endif // __MEM_CACHE_NONCOHERENTCACHE_HH__