xref: /gem5/src/mem/cache/tags/base.hh

/*
 * Copyright (c) 2003-2005 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.
 *
 * Authors: Erik Hallnor
 *          Ron Dreslinski
 */

/**
 * @file
 * Declaration of a common base class for cache tagstore objects.
 */

#ifndef __BASE_TAGS_HH__
#define __BASE_TAGS_HH__

#include <string>
#include "base/statistics.hh"
#include "base/callback.hh"

class BaseCache;

/**
 * A common base class of Cache tagstore objects.
 */
class BaseTags
{
  protected:
    /** Pointer to the parent cache. */
    BaseCache *cache;

    /** Local copy of the parent cache name. Used for DPRINTF. */
    std::string objName;

    /**
     * The number of tags that need to be touched to meet the warmup
     * percentage.
     */
    int warmupBound;
    /** Marked true when the cache is warmed up. */
    bool warmedUp;

    // Statistics
    /**
     * @addtogroup CacheStatistics
     * @{
     */

    /** Number of replacements of valid blocks per thread. */
    Stats::Vector replacements;
    /** Per cycle average of the number of tags that hold valid data. */
    Stats::Average tagsInUse;

    /** The total number of references to a block before it is replaced. */
    Stats::Scalar totalRefs;

    /**
     * The number of reference counts sampled. This is different from
     * replacements because we sample all the valid blocks when the simulator
     * exits.
     */
    Stats::Scalar sampledRefs;

    /**
     * Average number of references to a block before is was replaced.
     * @todo This should change to an average stat once we have them.
     */
    Stats::Formula avgRefs;

    /** The cycle that the warmup percentage was hit. */
    Stats::Scalar warmupCycle;
    /**
     * @}
     */

  public:

    /**
     * Destructor.
     */
    virtual ~BaseTags() {}

    /**
     * Set the parent cache back pointer. Also copies the cache name to
     * objName.
     * @param _cache Pointer to parent cache.
     */
    void setCache(BaseCache *_cache);

    /**
     * Return the parent cache name.
     * @return the parent cache name.
     */
    const std::string &name() const
    {
        return objName;
    }

    /**
     * Register local statistics.
     * @param name The name to preceed each statistic name.
     */
    void regStats(const std::string &name);

    /**
     * Average in the reference count for valid blocks when the simulation
     * exits.
     */
    virtual void cleanupRefs() {}
};

class BaseTagsCallback : public Callback
{
    BaseTags *tags;
  public:
    BaseTagsCallback(BaseTags *t) : tags(t) {}
    virtual void process() { tags->cleanupRefs(); };
};

#endif //__BASE_TAGS_HH__