1/*
2 * Copyright (c) 2013-2014, 2017 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andrew Bardsley
38 */
39
40/**
41 * @file
42 *
43 *  The constructed pipeline.  Kept out of MinorCPU to keep the interface
44 *  between the CPU and its grubby implementation details clean.
45 */
46
47#ifndef __CPU_MINOR_PIPELINE_HH__
48#define __CPU_MINOR_PIPELINE_HH__
49
50#include "cpu/minor/activity.hh"
51#include "cpu/minor/cpu.hh"
52#include "cpu/minor/decode.hh"
53#include "cpu/minor/execute.hh"
54#include "cpu/minor/fetch1.hh"
55#include "cpu/minor/fetch2.hh"
56#include "params/MinorCPU.hh"
57#include "sim/ticked_object.hh"
58
59namespace Minor
60{
61
62/**
63 * @namespace Minor
64 *
65 * Minor contains all the definitions within the MinorCPU apart from the CPU
66 * class itself
67 */
68
69/** The constructed pipeline.  Kept out of MinorCPU to keep the interface
70 *  between the CPU and its grubby implementation details clean. */
71class Pipeline : public Ticked
72{
73  protected:
74    MinorCPU &cpu;
75
76    /** Allow cycles to be skipped when the pipeline is idle */
77    bool allow_idling;
78
79    Latch<ForwardLineData> f1ToF2;
80    Latch<BranchData> f2ToF1;
81    Latch<ForwardInstData> f2ToD;
82    Latch<ForwardInstData> dToE;
83    Latch<BranchData> eToF1;
84
85    Execute execute;
86    Decode decode;
87    Fetch2 fetch2;
88    Fetch1 fetch1;
89
90    /** Activity recording for the pipeline.  This is access through the CPU
91     *  by the pipeline stages but belongs to the Pipeline as it is the
92     *  cleanest place to initialise it */
93    MinorActivityRecorder activityRecorder;
94
95  public:
96    /** Enumerated ids of the 'stages' for the activity recorder */
97    enum StageId
98    {
99        /* A stage representing wakeup of the whole processor */
100        CPUStageId = 0,
101        /* Real pipeline stages */
102        Fetch1StageId, Fetch2StageId, DecodeStageId, ExecuteStageId,
103        Num_StageId /* Stage count */
104    };
105
106    /** True after drain is called but draining isn't complete */
107    bool needToSignalDrained;
108
109  public:
110    Pipeline(MinorCPU &cpu_, MinorCPUParams &params);
111
112  public:
113    /** Wake up the Fetch unit.  This is needed on thread activation esp.
114     *  after quiesce wakeup */
115    void wakeupFetch(ThreadID tid);
116
117    /** Try to drain the CPU */
118    bool drain();
119
120    void drainResume();
121
122    /** Test to see if the CPU is drained */
123    bool isDrained();
124
125    /** A custom evaluate allows report in the right place (between
126     *  stages and pipeline advance) */
127    void evaluate() override;
128
129    void minorTrace() const;
130
131    /** Stats registering */
132    void regStats();
133
134    /** Functions below here are BaseCPU operations passed on to pipeline
135     *  stages */
136
137    /** Return the IcachePort belonging to Fetch1 for the CPU */
138    MinorCPU::MinorCPUPort &getInstPort();
139    /** Return the DcachePort belonging to Execute for the CPU */
140    MinorCPU::MinorCPUPort &getDataPort();
141
142    /** To give the activity recorder to the CPU */
143    MinorActivityRecorder *getActivityRecorder() { return &activityRecorder; }
144};
145
146}
147
148#endif /* __CPU_MINOR_PIPELINE_HH__ */
149