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/*
* Copyright (c) 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 here under. 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.
*
* 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.
*/
/**
* @file
* Declaration of the Stream generator for issuing memory requests
* with variable/fixed stream and substream IDs.
*/
#ifndef __CPU_TRAFFIC_GEN_STREAM_GEN_HH__
#define __CPU_TRAFFIC_GEN_STREAM_GEN_HH__
#include "params/BaseTrafficGen.hh"
namespace gem5
{
class StreamGen
{
protected:
StreamGen(const BaseTrafficGenParams &p)
: streamIds(p.sids), substreamIds(p.ssids)
{
// A non empty vector of StreamIDs must be provided.
// SubstreamIDs are not mandatory hence having an empty
// vector means that they are not used and no configuration
// error must be thrown
fatal_if(streamIds.empty(),
"Must provide a vector of StreamIDs");
}
public:
virtual ~StreamGen() {};
virtual uint32_t pickStreamID() = 0;
virtual uint32_t pickSubstreamID() = 0;
/**
* Factory method for constructing a Stream generator.
* The Stream generator type is selected by the
* StreamGenType enum parameter.
*
* @params p pointer to BaseTrafficGenParams struct where
* the stream generator type is stored.
* @return a pointer to the newly alocated StremGen
*/
static StreamGen* create(const BaseTrafficGenParams &p);
/**
* Returns true if the substreamID generation is valid
* and hence should be taken into account.
* It is valid if the set of substreamIDs passed as a
* parameter to the TrafficGenerator is a non empty list.
*
* @return true if ssid is valid, false otherwise
*/
bool ssidValid() const { return !substreamIds.empty(); }
protected:
/**
* Store preset Stream and Substream IDs to use for requests
* This is the set of available streamIDs the generator can
* pick. The actual ID being picked for a specific memory
* request is selected by the pickStreamID and pickSubstreamID
* methods.
*/
std::vector<uint32_t> streamIds;
std::vector<uint32_t> substreamIds;
};
class FixedStreamGen : public StreamGen
{
public:
FixedStreamGen(const BaseTrafficGenParams &p)
: StreamGen(p)
{
// For a fixed stream generator only one sid must be provided. The
// ssid can have either 0 (not used) or 1 value.
fatal_if(streamIds.size() != 1 || substreamIds.size() > 1,
"Invalid sids/ssids configuration");
}
uint32_t pickStreamID() override
{ return streamIds[0]; }
uint32_t pickSubstreamID() override
{ return substreamIds[0]; }
};
class RandomStreamGen : public StreamGen
{
public:
RandomStreamGen(const BaseTrafficGenParams &p)
: StreamGen(p)
{}
uint32_t pickStreamID() override
{ return randomPick(streamIds); }
uint32_t pickSubstreamID() override
{ return randomPick(substreamIds); }
protected:
/** Function to pick one of the preset Stream or Substream ID */
uint32_t randomPick(const std::vector<uint32_t> &svec);
};
} // namespace gem5
#endif // __CPU_TRAFFIC_GEN_STREAM_GEN_HH__