src/arch/mips/tlb.hh

   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/generic/tlb.hh"
  41 #include "arch/mips/isa_traits.hh"
  42 #include "arch/mips/pagetable.hh"
  43 #include "arch/mips/utility.hh"
  44 #include "arch/mips/vtophys.hh"
  45 #include "base/statistics.hh"
  46 #include "mem/request.hh"
  47 #include "params/MipsTLB.hh"
  48 #include "sim/sim_object.hh"
  49
  50 class ThreadContext;
  51
  52 /* MIPS does not distinguish between a DTLB and an ITLB -> unified TLB
  53    However, to maintain compatibility with other architectures, we'll
  54    simply create an ITLB and DTLB that will point to the real TLB */
  55 namespace MipsISA {
  56
  57 class TLB : public BaseTLB
  58 {
  59   protected:
  60     typedef std::multimap<Addr, int> PageTable;
  61     PageTable lookupTable;      // Quick lookup into page table
  62
  63     MipsISA::PTE *table;        // the Page Table
  64     int size;                   // TLB Size
  65     int nlu;                    // not last used entry (for replacement)
  66
  67     void nextnlu() { if (++nlu >= size) nlu = 0; }
  68     MipsISA::PTE *lookup(Addr vpn, uint8_t asn) const;
  69
  70     mutable Stats::Scalar read_hits;
  71     mutable Stats::Scalar read_misses;
  72     mutable Stats::Scalar read_acv;
  73     mutable Stats::Scalar read_accesses;
  74     mutable Stats::Scalar write_hits;
  75     mutable Stats::Scalar write_misses;
  76     mutable Stats::Scalar write_acv;
  77     mutable Stats::Scalar write_accesses;
  78     Stats::Formula hits;
  79     Stats::Formula misses;
  80     Stats::Formula accesses;
  81
  82   public:
  83     typedef MipsTLBParams Params;
  84     TLB(const Params *p);
  85
  86     int probeEntry(Addr vpn,uint8_t) const;
  87     MipsISA::PTE *getEntry(unsigned) const;
  88     virtual ~TLB();
  89
  90     void takeOverFrom(BaseTLB *otlb) override {}
  91
  92     int smallPages;
  93     int getsize() const { return size; }
  94
  95     MipsISA::PTE &index(bool advance = true);
  96     void insert(Addr vaddr, MipsISA::PTE &pte);
  97     void insertAt(MipsISA::PTE &pte, unsigned Index, int _smallPages);
  98     void flushAll() override;
  99     void demapPage(Addr vaddr, uint64_t asn) override
 100     {
 101         panic("demapPage unimplemented.\n");
 102     }
 103
 104     // static helper functions... really
 105     static bool validVirtualAddress(Addr vaddr);
 106
 107     static Fault checkCacheability(const RequestPtr &req);
 108
 109     // Checkpointing
 110     void serialize(CheckpointOut &cp) const override;
 111     void unserialize(CheckpointIn &cp) override;
 112
 113     void regStats() override;
 114
 115     Fault translateAtomic(
 116             const RequestPtr &req, ThreadContext *tc, Mode mode) override;
 117     void translateTiming(
 118             const RequestPtr &req, ThreadContext *tc,
 119             Translation *translation, Mode mode) override;
 120     Fault finalizePhysical(
 121             const RequestPtr &req,
 122             ThreadContext *tc, Mode mode) const override;
 123
 124   private:
 125     Fault translateInst(const RequestPtr &req, ThreadContext *tc);
 126     Fault translateData(const RequestPtr &req, ThreadContext *tc, bool write);
 127 };
 128
 129 }
 130
 131
 132
 133 #endif // __MIPS_MEMORY_HH__