tlb.hh revision 6019 
1/*
2 * Copyright (c) 2001-2005 The Regents of The University of Michigan
3 * Copyright (c) 2007 MIPS Technologies, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Nathan Binkert
30 *          Steve Reinhardt
31 *          Jaidev Patwardhan
32 *          Korey Sewell
33 */
34
35#ifndef __ARCH_MIPS_TLB_HH__
36#define __ARCH_MIPS_TLB_HH__
37
38#include <map>
39
40#include "arch/mips/isa_traits.hh"
41#include "arch/mips/utility.hh"
42#include "arch/mips/vtophys.hh"
43#include "arch/mips/pagetable.hh"
44#include "base/statistics.hh"
45#include "mem/request.hh"
46#include "params/MipsDTB.hh"
47#include "params/MipsITB.hh"
48#include "sim/faults.hh"
49#include "sim/tlb.hh"
50#include "sim/sim_object.hh"
51
52class ThreadContext;
53
54/* MIPS does not distinguish between a DTLB and an ITLB -> unified TLB
55   However, to maintain compatibility with other architectures, we'll
56   simply create an ITLB and DTLB that will point to the real TLB */
57namespace MipsISA {
58
59// WARN: This particular TLB entry is not necessarily conformed to MIPS ISA
60struct TlbEntry
61{
62    Addr _pageStart;
63    TlbEntry() {}
64    TlbEntry(Addr asn, Addr vaddr, Addr paddr) : _pageStart(paddr) {}
65
66    Addr pageStart()
67    {
68        return _pageStart;
69    }
70
71    void serialize(std::ostream &os)
72    {
73        SERIALIZE_SCALAR(_pageStart);
74    }
75
76    void unserialize(Checkpoint *cp, const std::string &section)
77    {
78        UNSERIALIZE_SCALAR(_pageStart);
79    }
80
81};
82
83class TLB : public BaseTLB
84{
85  protected:
86    typedef std::multimap<Addr, int> PageTable;
87    PageTable lookupTable;	// Quick lookup into page table
88
89    MipsISA::PTE *table;	// the Page Table
90    int size;			// TLB Size
91    int nlu;			// not last used entry (for replacement)
92
93    void nextnlu() { if (++nlu >= size) nlu = 0; }
94    MipsISA::PTE *lookup(Addr vpn, uint8_t asn) const;
95
96    mutable Stats::Scalar<> read_hits;
97    mutable Stats::Scalar<> read_misses;
98    mutable Stats::Scalar<> read_acv;
99    mutable Stats::Scalar<> read_accesses;
100    mutable Stats::Scalar<> write_hits;
101    mutable Stats::Scalar<> write_misses;
102    mutable Stats::Scalar<> write_acv;
103    mutable Stats::Scalar<> write_accesses;
104    Stats::Formula hits;
105    Stats::Formula misses;
106    Stats::Formula invalids;
107    Stats::Formula accesses;
108
109  public:
110    typedef MipsTLBParams Params;
111    TLB(const Params *p);
112
113    int probeEntry(Addr vpn,uint8_t) const;
114    MipsISA::PTE *getEntry(unsigned) const;
115    virtual ~TLB();
116    int smallPages;
117    int getsize() const { return size; }
118
119    MipsISA::PTE &index(bool advance = true);
120    void insert(Addr vaddr, MipsISA::PTE &pte);
121    void insertAt(MipsISA::PTE &pte, unsigned Index, int _smallPages);
122    void flushAll();
123    void demapPage(Addr vaddr, uint64_t asn)
124    {
125        panic("demapPage unimplemented.\n");
126    }
127
128    // static helper functions... really
129    static bool validVirtualAddress(Addr vaddr);
130
131    static Fault checkCacheability(RequestPtr &req);
132
133    // Checkpointing
134    void serialize(std::ostream &os);
135    void unserialize(Checkpoint *cp, const std::string &section);
136
137    void regStats();
138};
139
140class ITB : public TLB {
141  public:
142    typedef MipsTLBParams Params;
143    ITB(const Params *p);
144
145    Fault translate(RequestPtr &req, ThreadContext *tc);
146};
147
148class DTB : public TLB {
149  public:
150    typedef MipsTLBParams Params;
151    DTB(const Params *p);
152
153    Fault translate(RequestPtr &req, ThreadContext *tc, bool write = false);
154};
155
156class UTB : public ITB, public DTB {
157  public:
158    typedef MipsTLBParams Params;
159    UTB(const Params *p);
160
161};
162
163}
164
165
166
167#endif // __MIPS_MEMORY_HH__
168