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 "sim/faults.hh"
  42 #include "arch/isa_traits.hh"
  43 #include "base/hashmap.hh"
  44 #include "base/trace.hh"
  45 #include "mem/request.hh"
  46 #include "mem/packet.hh"
  47 #include "sim/sim_object.hh"
  48
  49 class System;
  50
  51 /**
  52  * Page Table Declaration.
  53  */
  54 class PageTable
  55 {
  56   protected:
  57     m5::hash_map<Addr,Addr> pTable;
  58
  59     struct cacheElement {
  60         Addr paddr;
  61         Addr vaddr;
  62     } ;
  63
  64     struct cacheElement pTableCache[3];
  65
  66     const Addr pageSize;
  67     const Addr offsetMask;
  68
  69     System *system;
  70
  71   public:
  72
  73     PageTable(System *_system, Addr _pageSize = TheISA::VMPageSize);
  74
  75     ~PageTable();
  76
  77     Addr pageAlign(Addr a)  { return (a & ~offsetMask); }
  78     Addr pageOffset(Addr a) { return (a &  offsetMask); }
  79
  80     Fault page_check(Addr addr, int64_t size) const;
  81
  82     void allocate(Addr vaddr, int64_t size);
  83
  84     /**
  85      * Translate function
  86      * @param vaddr The virtual address.
  87      * @return Physical address from translation.
  88      */
  89     bool translate(Addr vaddr, Addr &paddr);
  90
  91     /**
  92      * Perform a translation on the memory request, fills in paddr
  93      * field of mem_req.
  94      * @param req The memory request.
  95      */
  96     Fault translate(RequestPtr &req);
  97
  98 };
  99
 100 #endif