1/*
2 * Copyright (c) 2018 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 here under.  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: Giacomo Travaglini
38 */
39
40/**
41 * @file
42 * Declaration of the Stream generator for issuing memory requests
43 * with variable/fixed stream and substream IDs.
44 */
45
46#ifndef __CPU_TRAFFIC_GEN_STREAM_GEN_HH__
47#define __CPU_TRAFFIC_GEN_STREAM_GEN_HH__
48
49#include "params/BaseTrafficGen.hh"
50
51class StreamGen
52{
53  protected:
54    StreamGen(const BaseTrafficGenParams *p)
55      : streamIds(p->sids), substreamIds(p->ssids)
56    {
57        // A non empty vector of StreamIDs must be provided.
58        // SubstreamIDs are not mandatory hence having an empty
59        // vector means that they are not used and no configuration
60        // error must be thrown
61        fatal_if(streamIds.empty(),
62            "Must provide a vector of StreamIDs");
63    }
64
65  public:
66    virtual ~StreamGen() {};
67
68    virtual uint32_t pickStreamID() = 0;
69    virtual uint32_t pickSubStreamID() = 0;
70
71    /**
72     * Factory method for constructing a Stream generator.
73     * The Stream generator type is selected by the
74     * StreamGenType enum parameter.
75     *
76     * @params p pointer to BaseTrafficGenParams struct where
77     *           the stream generator type is stored.
78     * @return a pointer to the newly alocated StremGen
79     */
80    static StreamGen* create(const BaseTrafficGenParams *p);
81
82    /**
83     * Returns true if the substreamID generation is valid
84     * and hence should be taken into account.
85     * It is valid if the set of substreamIDs passed as a
86     * parameter to the TrafficGenerator is a non empty list.
87     *
88     * @return true if ssid is valid, false otherwise
89     */
90    bool ssidValid() const { return !substreamIds.empty(); }
91
92  protected:
93    /**
94     * Store preset Stream and Substream IDs to use for requests
95     * This is the set of available streamIDs the generator can
96     * pick. The actual ID being picked for a specific memory
97     * request is selected by the pickStreamID and pickSubStreamID
98     * methods.
99     */
100    std::vector<uint32_t> streamIds;
101    std::vector<uint32_t> substreamIds;
102};
103
104class FixedStreamGen : public StreamGen
105{
106  public:
107    FixedStreamGen(const BaseTrafficGenParams *p)
108      : StreamGen(p)
109    {
110        // For a fixed stream generator only one sid must be provided. The
111        // ssid can have either 0 (not used) or 1 value.
112        fatal_if(streamIds.size() != 1 || substreamIds.size() > 1,
113                 "Invalid sids/ssids configuration");
114    }
115
116    uint32_t pickStreamID() override
117    { return streamIds[0]; }
118
119    uint32_t pickSubStreamID() override
120    { return substreamIds[0]; }
121};
122
123class RandomStreamGen : public StreamGen
124{
125  public:
126    RandomStreamGen(const BaseTrafficGenParams *p)
127      : StreamGen(p)
128    {}
129
130    uint32_t pickStreamID() override
131    { return randomPick(streamIds); }
132
133    uint32_t pickSubStreamID() override
134    { return randomPick(substreamIds); }
135
136  protected:
137    /** Function to pick one of the preset Stream or Substream ID */
138    uint32_t randomPick(const std::vector<uint32_t> &svec);
139};
140
141#endif // __CPU_TRAFFIC_GEN_STREAM_GEN_HH__
142