abstract_mem.hh revision 7733 
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//
50class 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__
195