abstract_mem.hh

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/*
 * Copyright (c) 2012 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) 2001-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
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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
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 * 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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 * 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,
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 * Authors: Ron Dreslinski
 *          Andreas Hansson
 */

#ifndef __ABSTRACT_MEMORY_HH__
#define __ABSTRACT_MEMORY_HH__

#include "mem/mem_object.hh"
#include "params/AbstractMemory.hh"
#include "sim/stats.hh"


class System;

class LockedAddr {

  private:

    // on alpha, minimum LL/SC granularity is 16 bytes, so lower
    // bits need to masked off.
    static const Addr Addr_Mask = 0xf;

  public:

    // locked address
    Addr addr;

    // locking hw context
    const ContextID contextId;

    static Addr mask(Addr paddr) { return (paddr & ~Addr_Mask); }

    // check for matching execution context
    bool matchesContext(Request *req) const
    {
        return (contextId == req->contextId());
    }

    LockedAddr(Request *req) : addr(mask(req->getPaddr())),
                               contextId(req->contextId())
    {}

    // constructor for unserialization use
    LockedAddr(Addr _addr, int _cid) : addr(_addr), contextId(_cid)
    {}
};

class AbstractMemory : public MemObject
{
  protected:

    // Address range of this memory
    AddrRange range;

    // Pointer to host memory used to implement this memory
    uint8_t* pmemAddr;

    // Enable specific memories to be reported to the configuration table
    const bool confTableReported;

    // Should the memory appear in the global address map
    const bool inAddrMap;

    // Should KVM map this memory for the guest
    const bool kvmMap;

    std::list<LockedAddr> lockedAddrList;

    // helper function for checkLockedAddrs(): we really want to
    // inline a quick check for an empty locked addr list (hopefully
    // the common case), and do the full list search (if necessary) in
    // this out-of-line function
    bool checkLockedAddrList(PacketPtr pkt);

    // Record the address of a load-locked operation so that we can
    // clear the execution context's lock flag if a matching store is
    // performed
    void trackLoadLocked(PacketPtr pkt);

    // Compare a store address with any locked addresses so we can
    // clear the lock flag appropriately.  Return value set to 'false'
    // if store operation should be suppressed (because it was a
    // conditional store and the address was no longer locked by the
    // requesting execution context), 'true' otherwise.  Note that
    // this method must be called on *all* stores since even
    // non-conditional stores must clear any matching lock addresses.
    bool writeOK(PacketPtr pkt) {
        Request *req = pkt->req;
        if (lockedAddrList.empty()) {
            // no locked addrs: nothing to check, store_conditional fails
            bool isLLSC = pkt->isLLSC();
            if (isLLSC) {
                req->setExtraData(0);
            }
            return !isLLSC; // only do write if not an sc
        } else {
            // iterate over list...
            return checkLockedAddrList(pkt);
        }
    }

    Stats::Vector bytesRead;
    Stats::Vector bytesInstRead;
    Stats::Vector bytesWritten;
    Stats::Vector numReads;
    Stats::Vector numWrites;
    Stats::Vector numOther;
    Stats::Formula bwRead;
    Stats::Formula bwInstRead;
    Stats::Formula bwWrite;
    Stats::Formula bwTotal;

    System *_system;


  private:

    // Prevent copying
    AbstractMemory(const AbstractMemory&);

    // Prevent assignment
    AbstractMemory& operator=(const AbstractMemory&);

  public:

    typedef AbstractMemoryParams Params;

    AbstractMemory(const Params* p);
    virtual ~AbstractMemory() {}

    void init() override;

    bool isNull() const { return params()->null; }

    void setBackingStore(uint8_t* pmem_addr);

    const std::list<LockedAddr>& getLockedAddrList() const
    { return lockedAddrList; }

    void addLockedAddr(LockedAddr addr) { lockedAddrList.push_back(addr); }

    System* system() const { return _system; }

    void system(System *sys) { _system = sys; }

    const Params *
    params() const
    {
        return dynamic_cast<const Params *>(_params);
    }

    AddrRange getAddrRange() const;

    uint64_t size() const { return range.size(); }

    Addr start() const { return range.start(); }

    bool isConfReported() const { return confTableReported; }

    bool isInAddrMap() const { return inAddrMap; }

    bool isKvmMap() const { return kvmMap; }

    void access(PacketPtr pkt);

    void functionalAccess(PacketPtr pkt);

    void regStats() override;

};

#endif //__ABSTRACT_MEMORY_HH__