tlb.hh revision 5877 
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
72    updateVaddr(Addr new_vaddr) {}
73
74    void serialize(std::ostream &os)
75    {
76        SERIALIZE_SCALAR(_pageStart);
77    }
78
79    void unserialize(Checkpoint *cp, const std::string &section)
80    {
81        UNSERIALIZE_SCALAR(_pageStart);
82    }
83
84};
85
86class TLB : public BaseTLB
87{
88  protected:
89    typedef std::multimap<Addr, int> PageTable;
90    PageTable lookupTable;      // Quick lookup into page table
91
92    MipsISA::PTE *table;        // the Page Table
93    int size;                   // TLB Size
94    int nlu;                    // not last used entry (for replacement)
95
96    void nextnlu() { if (++nlu >= size) nlu = 0; }
97    MipsISA::PTE *lookup(Addr vpn, uint8_t asn) const;
98
99    mutable Stats::Scalar<> read_hits;
100    mutable Stats::Scalar<> read_misses;
101    mutable Stats::Scalar<> read_acv;
102    mutable Stats::Scalar<> read_accesses;
103    mutable Stats::Scalar<> write_hits;
104    mutable Stats::Scalar<> write_misses;
105    mutable Stats::Scalar<> write_acv;
106    mutable Stats::Scalar<> write_accesses;
107    Stats::Formula hits;
108    Stats::Formula misses;
109    Stats::Formula invalids;
110    Stats::Formula accesses;
111
112  public:
113    typedef MipsTLBParams Params;
114    TLB(const Params *p);
115
116    int probeEntry(Addr vpn,uint8_t) const;
117    MipsISA::PTE *getEntry(unsigned) const;
118    virtual ~TLB();
119    int smallPages;
120    int getsize() const { return size; }
121
122    MipsISA::PTE &index(bool advance = true);
123    void insert(Addr vaddr, MipsISA::PTE &pte);
124    void insertAt(MipsISA::PTE &pte, unsigned Index, int _smallPages);
125    void flushAll();
126    void demapPage(Addr vaddr, uint64_t asn)
127    {
128        panic("demapPage unimplemented.\n");
129    }
130
131    // static helper functions... really
132    static bool validVirtualAddress(Addr vaddr);
133
134    static Fault checkCacheability(RequestPtr &req);
135
136    // Checkpointing
137    void serialize(std::ostream &os);
138    void unserialize(Checkpoint *cp, const std::string &section);
139
140    void regStats();
141};
142
143class ITB : public TLB {
144  public:
145    typedef MipsTLBParams Params;
146    ITB(const Params *p);
147
148    Fault translate(RequestPtr &req, ThreadContext *tc);
149};
150
151class DTB : public TLB {
152  public:
153    typedef MipsTLBParams Params;
154    DTB(const Params *p);
155
156    Fault translate(RequestPtr &req, ThreadContext *tc, bool write = false);
157};
158
159class UTB : public ITB, public DTB {
160  public:
161    typedef MipsTLBParams Params;
162    UTB(const Params *p);
163
164};
165
166}
167
168
169
170#endif // __MIPS_MEMORY_HH__
171