tlb.hh revision 5268 
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 "params/AlphaDTB.hh"
45#include "params/AlphaITB.hh"
46#include "sim/faults.hh"
47#include "sim/sim_object.hh"
48
49class ThreadContext;
50
51namespace AlphaISA
52{
53    class TlbEntry;
54
55    class TLB : public SimObject
56    {
57      protected:
58        typedef std::multimap<Addr, int> PageTable;
59        PageTable lookupTable;  // Quick lookup into page table
60
61        TlbEntry *table;        // the Page Table
62        int size;               // TLB Size
63        int nlu;                // not last used entry (for replacement)
64
65        void nextnlu() { if (++nlu >= size) nlu = 0; }
66        TlbEntry *lookup(Addr vpn, uint8_t asn);
67
68      public:
69        typedef AlphaTLBParams Params;
70        TLB(const Params *p);
71        virtual ~TLB();
72
73        int getsize() const { return size; }
74
75        TlbEntry &index(bool advance = true);
76        void insert(Addr vaddr, TlbEntry &entry);
77
78        void flushAll();
79        void flushProcesses();
80        void flushAddr(Addr addr, uint8_t asn);
81
82        // static helper functions... really EV5 VM traits
83        static bool validVirtualAddress(Addr vaddr) {
84            // unimplemented bits must be all 0 or all 1
85            Addr unimplBits = vaddr & EV5::VAddrUnImplMask;
86            return (unimplBits == 0) || (unimplBits == EV5::VAddrUnImplMask);
87        }
88
89        static Fault checkCacheability(RequestPtr &req);
90
91        // Checkpointing
92        virtual void serialize(std::ostream &os);
93        virtual void unserialize(Checkpoint *cp, const std::string &section);
94
95        // Most recently used page table entries
96        TlbEntry *EntryCache[3];
97        inline void flushCache()
98        {
99            memset(EntryCache, 0, 3 * sizeof(TlbEntry*));
100        }
101
102        inline TlbEntry* updateCache(TlbEntry *entry) {
103            EntryCache[2] = EntryCache[1];
104            EntryCache[1] = EntryCache[0];
105            EntryCache[0] = entry;
106            return entry;
107        }
108    };
109
110    class ITB : public TLB
111    {
112      protected:
113        mutable Stats::Scalar<> hits;
114        mutable Stats::Scalar<> misses;
115        mutable Stats::Scalar<> acv;
116        mutable Stats::Formula accesses;
117
118      public:
119        typedef AlphaITBParams Params;
120        ITB(const Params *p);
121        virtual void regStats();
122
123        Fault translate(RequestPtr &req, ThreadContext *tc);
124    };
125
126    class DTB : public TLB
127    {
128      protected:
129        mutable Stats::Scalar<> read_hits;
130        mutable Stats::Scalar<> read_misses;
131        mutable Stats::Scalar<> read_acv;
132        mutable Stats::Scalar<> read_accesses;
133        mutable Stats::Scalar<> write_hits;
134        mutable Stats::Scalar<> write_misses;
135        mutable Stats::Scalar<> write_acv;
136        mutable Stats::Scalar<> write_accesses;
137        Stats::Formula hits;
138        Stats::Formula misses;
139        Stats::Formula acv;
140        Stats::Formula accesses;
141
142      public:
143        typedef AlphaDTBParams Params;
144        DTB(const Params *p);
145        virtual void regStats();
146
147        Fault translate(RequestPtr &req, ThreadContext *tc, bool write);
148    };
149}
150
151#endif // __ALPHA_MEMORY_HH__
152