xref: /gem5/src/cpu/testers/traffic_gen/linear_gen.hh

/*
 * Copyright (c) 2012-2013, 2017-2018 ARM Limited
 * All rights reserved
 *
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 * 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 here under.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
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 * modified or unmodified, in source code or in binary form.
 *
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 * 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
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 * 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,
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 *
 * Authors: Thomas Grass
 *          Andreas Hansson
 *          Sascha Bischoff
 *          Neha Agarwal
 */

/**
 * @file
 * Declaration of the linear generator that generates sequential
 * requests.
 */

#ifndef __CPU_TRAFFIC_GEN_LINEAR_GEN_HH__
#define __CPU_TRAFFIC_GEN_LINEAR_GEN_HH__

#include "base/bitfield.hh"
#include "base/intmath.hh"
#include "base_gen.hh"
#include "mem/packet.hh"

/**
 * The linear generator generates sequential requests from a
 * start to an end address, with a fixed block size. A
 * fraction of the requests are reads, as determined by the
 * read percent. There is an optional data limit for when to
 * stop generating new requests.
 */
class LinearGen : public StochasticGen
{

  public:

    /**
     * Create a linear address sequence generator. Set
     * min_period == max_period for a fixed inter-transaction
     * time.
     *
     * @param gen Traffic generator owning this sequence generator
     * @param _duration duration of this state before transitioning
     * @param start_addr Start address
     * @param end_addr End address
     * @param _blocksize Size used for transactions injected
     * @param min_period Lower limit of random inter-transaction time
     * @param max_period Upper limit of random inter-transaction time
     * @param read_percent Percent of transactions that are reads
     * @param data_limit Upper limit on how much data to read/write
     */
    LinearGen(BaseTrafficGen &gen, Tick _duration,
              Addr start_addr, Addr end_addr, Addr _blocksize,
              Tick min_period, Tick max_period,
              uint8_t read_percent, Addr data_limit)
        : StochasticGen(gen, _duration, start_addr, end_addr,
                        _blocksize, min_period, max_period, read_percent,
                        data_limit),
          nextAddr(0),
          dataManipulated(0)
    { }

    void enter();

    PacketPtr getNextPacket();

    Tick nextPacketTick(bool elastic, Tick delay) const;

  private:
    /** Address of next request */
    Addr nextAddr;

    /**
     * Counter to determine the amount of data
     * manipulated. Used to determine if we should continue
     * generating requests.
     */
    Addr dataManipulated;
};

#endif