mem/page_table.cc

   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
  29 /**
  30  * @file
  31  * Definitions of page table.
  32  */
  33 #include <string>
  34 #include <map>
  35 #include <fstream>
  36
  37 #include "arch/faults.hh"
  38 #include "base/bitfield.hh"
  39 #include "base/intmath.hh"
  40 #include "base/trace.hh"
  41 #include "mem/page_table.hh"
  42 #include "sim/builder.hh"
  43 #include "sim/sim_object.hh"
  44 #include "sim/system.hh"
  45
  46 using namespace std;
  47 using namespace TheISA;
  48
  49 PageTable::PageTable(System *_system, Addr _pageSize)
  50     : pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
  51       system(_system)
  52 {
  53     assert(isPowerOf2(pageSize));
  54 }
  55
  56 PageTable::~PageTable()
  57 {
  58 }
  59
  60 Fault
  61 PageTable::page_check(Addr addr, int size) const
  62 {
  63     if (size < sizeof(uint64_t)) {
  64         if (!isPowerOf2(size)) {
  65             panic("Invalid request size!\n");
  66             return genMachineCheckFault();
  67         }
  68
  69         if ((size - 1) & addr)
  70             return genAlignmentFault();
  71     }
  72     else {
  73         if ((addr & (VMPageSize - 1)) + size > VMPageSize) {
  74             panic("Invalid request size!\n");
  75             return genMachineCheckFault();
  76         }
  77
  78         if ((sizeof(uint64_t) - 1) & addr)
  79             return genAlignmentFault();
  80     }
  81
  82     return NoFault;
  83 }
  84
  85
  86
  87
  88 void
  89 PageTable::allocate(Addr vaddr, int size)
  90 {
  91     // starting address must be page aligned
  92     assert(pageOffset(vaddr) == 0);
  93
  94     for (; size > 0; size -= pageSize, vaddr += pageSize) {
  95         std::map<Addr,Addr>::iterator iter = pTable.find(vaddr);
  96
  97         if (iter != pTable.end()) {
  98             // already mapped
  99             fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
 100         }
 101
 102         pTable[vaddr] = system->new_page();
 103     }
 104 }
 105
 106
 107
 108 bool
 109 PageTable::translate(Addr vaddr, Addr &paddr)
 110 {
 111     Addr page_addr = pageAlign(vaddr);
 112     std::map<Addr,Addr>::iterator iter = pTable.find(page_addr);
 113
 114     if (iter == pTable.end()) {
 115         return false;
 116     }
 117
 118     paddr = iter->second + pageOffset(vaddr);
 119     return true;
 120 }
 121
 122
 123 Fault
 124 PageTable::translate(RequestPtr &req)
 125 {
 126     Addr paddr;
 127     assert(pageAlign(req->getVaddr() + req->getSize() - 1)
 128            == pageAlign(req->getVaddr()));
 129     if (!translate(req->getVaddr(), paddr)) {
 130         return genMachineCheckFault();
 131     }
 132     req->setPaddr(paddr);
 133     return page_check(req->getPaddr(), req->getSize());
 134 }