src/mem/physical.hh

   1 /*
   2  * Copyright (c) 2001-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Ron Dreslinski
  29  */
  30
  31 /* @file
  32  */
  33
  34 #ifndef __PHYSICAL_MEMORY_HH__
  35 #define __PHYSICAL_MEMORY_HH__
  36
  37 #include <map>
  38 #include <string>
  39
  40 #include "base/range.hh"
  41 #include "mem/mem_object.hh"
  42 #include "mem/packet.hh"
  43 #include "mem/tport.hh"
  44 #include "params/PhysicalMemory.hh"
  45 #include "sim/eventq.hh"
  46
  47 //
  48 // Functional model for a contiguous block of physical memory. (i.e. RAM)
  49 //
  50 class PhysicalMemory : public MemObject
  51 {
  52   protected:
  53
  54     class MemoryPort : public SimpleTimingPort
  55     {
  56         PhysicalMemory *memory;
  57
  58       public:
  59
  60         MemoryPort(const std::string &_name, PhysicalMemory *_memory);
  61
  62       protected:
  63
  64         virtual Tick recvAtomic(PacketPtr pkt);
  65
  66         virtual void recvFunctional(PacketPtr pkt);
  67
  68         virtual void recvStatusChange(Status status);
  69
  70         virtual void getDeviceAddressRanges(AddrRangeList &resp,
  71                                             bool &snoop);
  72
  73         virtual unsigned deviceBlockSize() const;
  74     };
  75
  76     int numPorts;
  77
  78
  79   private:
  80     // prevent copying of a MainMemory object
  81     PhysicalMemory(const PhysicalMemory &specmem);
  82     const PhysicalMemory &operator=(const PhysicalMemory &specmem);
  83
  84   protected:
  85
  86     class LockedAddr {
  87       public:
  88         // on alpha, minimum LL/SC granularity is 16 bytes, so lower
  89         // bits need to masked off.
  90         static const Addr Addr_Mask = 0xf;
  91
  92         static Addr mask(Addr paddr) { return (paddr & ~Addr_Mask); }
  93
  94         Addr addr;      // locked address
  95         int contextId;     // locking hw context
  96
  97         // check for matching execution context
  98         bool matchesContext(Request *req)
  99         {
 100             return (contextId == req->contextId());
 101         }
 102
 103         LockedAddr(Request *req)
 104             : addr(mask(req->getPaddr())),
 105               contextId(req->contextId())
 106         {
 107         }
 108         // constructor for unserialization use
 109         LockedAddr(Addr _addr, int _cid)
 110             : addr(_addr), contextId(_cid)
 111         {
 112         }
 113     };
 114
 115     std::list<LockedAddr> lockedAddrList;
 116
 117     // helper function for checkLockedAddrs(): we really want to
 118     // inline a quick check for an empty locked addr list (hopefully
 119     // the common case), and do the full list search (if necessary) in
 120     // this out-of-line function
 121     bool checkLockedAddrList(PacketPtr pkt);
 122
 123     // Record the address of a load-locked operation so that we can
 124     // clear the execution context's lock flag if a matching store is
 125     // performed
 126     void trackLoadLocked(PacketPtr pkt);
 127
 128     // Compare a store address with any locked addresses so we can
 129     // clear the lock flag appropriately.  Return value set to 'false'
 130     // if store operation should be suppressed (because it was a
 131     // conditional store and the address was no longer locked by the
 132     // requesting execution context), 'true' otherwise.  Note that
 133     // this method must be called on *all* stores since even
 134     // non-conditional stores must clear any matching lock addresses.
 135     bool writeOK(PacketPtr pkt) {
 136         Request *req = pkt->req;
 137         if (lockedAddrList.empty()) {
 138             // no locked addrs: nothing to check, store_conditional fails
 139             bool isLLSC = pkt->isLLSC();
 140             if (isLLSC) {
 141                 req->setExtraData(0);
 142             }
 143             return !isLLSC; // only do write if not an sc
 144         } else {
 145             // iterate over list...
 146             return checkLockedAddrList(pkt);
 147         }
 148     }
 149
 150     uint8_t *pmemAddr;
 151     int pagePtr;
 152     Tick lat;
 153     Tick lat_var;
 154     std::vector<MemoryPort*> ports;
 155     typedef std::vector<MemoryPort*>::iterator PortIterator;
 156
 157     uint64_t _size;
 158     uint64_t _start;
 159   public:
 160     Addr new_page();
 161     uint64_t size() { return _size; }
 162     uint64_t start() { return _start; }
 163
 164   public:
 165     typedef PhysicalMemoryParams Params;
 166     PhysicalMemory(const Params *p);
 167     virtual ~PhysicalMemory();
 168
 169     const Params *
 170     params() const
 171     {
 172         return dynamic_cast<const Params *>(_params);
 173     }
 174
 175   public:
 176     unsigned deviceBlockSize() const;
 177     void getAddressRanges(AddrRangeList &resp, bool &snoop);
 178     virtual Port *getPort(const std::string &if_name, int idx = -1);
 179     void virtual init();
 180     unsigned int drain(Event *de);
 181
 182   protected:
 183     Tick doAtomicAccess(PacketPtr pkt);
 184     void doFunctionalAccess(PacketPtr pkt);
 185     virtual Tick calculateLatency(PacketPtr pkt);
 186     void recvStatusChange(Port::Status status);
 187
 188   public:
 189     virtual void serialize(std::ostream &os);
 190     virtual void unserialize(Checkpoint *cp, const std::string &section);
 191
 192 };
 193
 194 #endif //__PHYSICAL_MEMORY_HH__