tlb.hh revision 5014 
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: Nathan Binkert
29 *          Steve Reinhardt
30 */
31
32#ifndef __ALPHA_MEMORY_HH__
33#define __ALPHA_MEMORY_HH__
34
35#include <map>
36
37#include "arch/alpha/ev5.hh"
38#include "arch/alpha/isa_traits.hh"
39#include "arch/alpha/pagetable.hh"
40#include "arch/alpha/utility.hh"
41#include "arch/alpha/vtophys.hh"
42#include "base/statistics.hh"
43#include "mem/request.hh"
44#include "sim/faults.hh"
45#include "sim/sim_object.hh"
46
47class ThreadContext;
48
49namespace AlphaISA
50{
51    class TlbEntry;
52
53    class TLB : public SimObject
54    {
55      protected:
56        typedef std::multimap<Addr, int> PageTable;
57        PageTable lookupTable;  // Quick lookup into page table
58
59        TlbEntry *table;        // the Page Table
60        int size;               // TLB Size
61        int nlu;                // not last used entry (for replacement)
62
63        void nextnlu() { if (++nlu >= size) nlu = 0; }
64        TlbEntry *lookup(Addr vpn, uint8_t asn);
65
66      public:
67        TLB(const std::string &name, int size);
68        virtual ~TLB();
69
70        int getsize() const { return size; }
71
72        TlbEntry &index(bool advance = true);
73        void insert(Addr vaddr, TlbEntry &entry);
74
75        void flushAll();
76        void flushProcesses();
77        void flushAddr(Addr addr, uint8_t asn);
78
79        // static helper functions... really EV5 VM traits
80        static bool validVirtualAddress(Addr vaddr) {
81            // unimplemented bits must be all 0 or all 1
82            Addr unimplBits = vaddr & EV5::VAddrUnImplMask;
83            return (unimplBits == 0) || (unimplBits == EV5::VAddrUnImplMask);
84        }
85
86        static Fault checkCacheability(RequestPtr &req);
87
88        // Checkpointing
89        virtual void serialize(std::ostream &os);
90        virtual void unserialize(Checkpoint *cp, const std::string &section);
91
92        // Most recently used page table entries
93        TlbEntry *EntryCache[3];
94        inline void flushCache()
95        {
96            memset(EntryCache, 0, 3 * sizeof(TlbEntry*));
97        }
98
99        inline TlbEntry* updateCache(TlbEntry *entry) {
100            EntryCache[2] = EntryCache[1];
101            EntryCache[1] = EntryCache[0];
102            EntryCache[0] = entry;
103            return entry;
104        }
105    };
106
107    class ITB : public TLB
108    {
109      protected:
110        mutable Stats::Scalar<> hits;
111        mutable Stats::Scalar<> misses;
112        mutable Stats::Scalar<> acv;
113        mutable Stats::Formula accesses;
114
115      public:
116        ITB(const std::string &name, int size);
117        virtual void regStats();
118
119        Fault translate(RequestPtr &req, ThreadContext *tc);
120    };
121
122    class DTB : public TLB
123    {
124      protected:
125        mutable Stats::Scalar<> read_hits;
126        mutable Stats::Scalar<> read_misses;
127        mutable Stats::Scalar<> read_acv;
128        mutable Stats::Scalar<> read_accesses;
129        mutable Stats::Scalar<> write_hits;
130        mutable Stats::Scalar<> write_misses;
131        mutable Stats::Scalar<> write_acv;
132        mutable Stats::Scalar<> write_accesses;
133        Stats::Formula hits;
134        Stats::Formula misses;
135        Stats::Formula acv;
136        Stats::Formula accesses;
137
138      public:
139        DTB(const std::string &name, int size);
140        virtual void regStats();
141
142        Fault translate(RequestPtr &req, ThreadContext *tc, bool write);
143    };
144}
145
146#endif // __ALPHA_MEMORY_HH__
147