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/*
* Copyright (c) 2012-2013, 2015-2016 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.
*/
/**
* @file
* Generic queue entry
*/
#ifndef __MEM_CACHE_QUEUE_ENTRY_HH__
#define __MEM_CACHE_QUEUE_ENTRY_HH__
#include "base/named.hh"
#include "base/types.hh"
#include "mem/packet.hh"
namespace gem5
{
class BaseCache;
/**
* A queue entry base class, to be used by both the MSHRs and
* write-queue entries.
*/
class QueueEntry : public Packet::SenderState, public Named
{
/**
* Consider the Queue a friend to avoid making everything public
*/
template <class Entry>
friend class Queue;
protected:
/** Tick when ready to issue */
Tick readyTime;
/** True if the entry is uncacheable */
bool _isUncacheable;
public:
/**
* A queue entry is holding packets that will be serviced as soon as
* resources are available. Since multiple references to the same
* address can arrive while a packet is not serviced, each packet is
* stored in a target containing its availability, order and other info,
* and the queue entry stores these similar targets in a list.
*/
class Target
{
public:
const Tick recvTime; //!< Time when request was received (for stats)
const Tick readyTime; //!< Time when request is ready to be serviced
const Counter order; //!< Global order (for memory consistency mgmt)
PacketPtr pkt; //!< Pending request packet.
/**
* Default constructor. Assigns the current tick as the arrival time
* of the packet.
*
* @param _pkt The pending request packet.
* @param ready_time The tick at which the packet will be serviceable.
* @param _order Global order.
*/
Target(PacketPtr _pkt, Tick ready_time, Counter _order)
: recvTime(curTick()), readyTime(ready_time), order(_order),
pkt(_pkt)
{}
};
/** True if the entry has been sent downstream. */
bool inService;
/** Order number assigned to disambiguate writes and misses. */
Counter order;
/** Block aligned address. */
Addr blkAddr;
/** Block size of the cache. */
unsigned blkSize;
/** True if the entry targets the secure memory space. */
bool isSecure;
QueueEntry(const std::string &name)
: Named(name),
readyTime(0), _isUncacheable(false),
inService(false), order(0), blkAddr(0), blkSize(0), isSecure(false)
{}
bool isUncacheable() const { return _isUncacheable; }
/**
* Check if entry corresponds to the one being looked for.
*
* @param addr Address to match against.
* @param is_secure Whether the target should be in secure space or not.
* @return True if entry matches given information.
*/
virtual bool matchBlockAddr(const Addr addr, const bool is_secure)
const = 0;
/**
* Check if entry contains a packet that corresponds to the one being
* looked for.
*
* @param pkt The packet to search for.
* @return True if any of its targets' packets matches the given one.
*/
virtual bool matchBlockAddr(const PacketPtr pkt) const = 0;
/**
* Check if given entry's packets conflict with this' entries packets.
*
* @param entry Other entry to compare against.
* @return True if entry matches given information.
*/
virtual bool conflictAddr(const QueueEntry* entry) const = 0;
/**
* Send this queue entry as a downstream packet, with the exact
* behaviour depending on the specific entry type.
*/
virtual bool sendPacket(BaseCache &cache) = 0;
/**
* Returns a pointer to the first target.
*
* @return A pointer to the first target.
*/
virtual Target* getTarget() = 0;
};
} // namespace gem5
#endif // __MEM_CACHE_QUEUE_ENTRY_HH__