src/mem/page_table.hh

   1 /*
   2  * Copyright (c) 2003 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: Steve Reinhardt
  29  */
  30
  31 /**
  32  * @file
  33  * Declaration of a non-full system Page Table.
  34  */
  35
  36 #ifndef __PAGE_TABLE__
  37 #define __PAGE_TABLE__
  38
  39 #include <string>
  40
  41 #include "arch/isa_traits.hh"
  42 #include "base/hashmap.hh"
  43 #include "base/trace.hh"
  44 #include "mem/request.hh"
  45 #include "mem/packet.hh"
  46 #include "sim/sim_object.hh"
  47
  48 class System;
  49
  50 /**
  51  * Page Table Decleration.
  52  */
  53 class PageTable
  54 {
  55   protected:
  56     m5::hash_map<Addr,Addr> pTable;
  57
  58     struct cacheElement {
  59         Addr paddr;
  60         Addr vaddr;
  61     } ;
  62
  63     struct cacheElement pTableCache[3];
  64
  65     const Addr pageSize;
  66     const Addr offsetMask;
  67
  68     System *system;
  69
  70   public:
  71
  72     PageTable(System *_system, Addr _pageSize = TheISA::VMPageSize);
  73
  74     ~PageTable();
  75
  76     Addr pageAlign(Addr a)  { return (a & ~offsetMask); }
  77     Addr pageOffset(Addr a) { return (a &  offsetMask); }
  78
  79     Fault page_check(Addr addr, int size) const;
  80
  81     void allocate(Addr vaddr, int size);
  82
  83     /**
  84      * Translate function
  85      * @param vaddr The virtual address.
  86      * @return Physical address from translation.
  87      */
  88     bool translate(Addr vaddr, Addr &paddr);
  89
  90     /**
  91      * Perform a translation on the memory request, fills in paddr
  92      * field of mem_req.
  93      * @param req The memory request.
  94      */
  95     Fault translate(RequestPtr &req);
  96
  97 };
  98
  99 #endif