noncoherent_cache.hh

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/*
 * Copyright (c) 2012-2018 ARM Limited
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 * 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
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 * modified or unmodified, in source code or in binary form.
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 * Copyright (c) 2002-2005 The Regents of The University of Michigan
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 * Authors: Erik Hallnor
 *          Dave Greene
 *          Steve Reinhardt
 *          Ron Dreslinski
 *          Andreas Hansson
 *          Nikos Nikoleris
 */

#ifndef __MEM_CACHE_NONCOHERENT_CACHE_HH__
#define __MEM_CACHE_NONCOHERENT_CACHE_HH__

#include "base/logging.hh"
#include "base/types.hh"
#include "mem/cache/base.hh"
#include "mem/packet.hh"

class CacheBlk;
class MSHR;
struct NoncoherentCacheParams;

class NoncoherentCache : public BaseCache
{
  protected:
    bool access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat,
                PacketList &writebacks) override;

    void handleTimingReqMiss(PacketPtr pkt, CacheBlk *blk,
                             Tick forward_time,
                             Tick request_time) override;

    void recvTimingReq(PacketPtr pkt) override;

    void doWritebacks(PacketList& writebacks,
                      Tick forward_time) override;

    void doWritebacksAtomic(PacketList& writebacks) override;

    void serviceMSHRTargets(MSHR *mshr, const PacketPtr pkt,
                            CacheBlk *blk) override;

    void recvTimingResp(PacketPtr pkt) override;

    void recvTimingSnoopReq(PacketPtr pkt) override {
        panic("Unexpected timing snoop request %s", pkt->print());
    }

    void recvTimingSnoopResp(PacketPtr pkt) override {
        panic("Unexpected timing snoop response %s", pkt->print());
    }

    Cycles handleAtomicReqMiss(PacketPtr pkt, CacheBlk *&blk,
                               PacketList &writebacks) override;

    Tick recvAtomic(PacketPtr pkt) override;

    Tick recvAtomicSnoop(PacketPtr pkt) override {
        panic("Unexpected atomic snoop request %s", pkt->print());
    }

    void functionalAccess(PacketPtr pkt, bool from_cpu_side) override;

    void satisfyRequest(PacketPtr pkt, CacheBlk *blk,
                        bool deferred_response = false,
                        bool pending_downgrade = false) override;

    /*
     * Creates a new packet with the request to be send to the memory
     * below. The noncoherent cache is below the point of coherence
     * and therefore all fills bring in writable, therefore the
     * needs_writeble parameter is ignored.
     */
    PacketPtr createMissPacket(PacketPtr cpu_pkt, CacheBlk *blk,
                               bool needs_writable,
                               bool is_whole_line_write) const override;

    M5_NODISCARD PacketPtr evictBlock(CacheBlk *blk) override;

  public:
    NoncoherentCache(const NoncoherentCacheParams *p);
};

#endif // __MEM_CACHE_NONCOHERENTCACHE_HH__