src/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  * Authors: Steve Reinhardt
  29  *          Ron Dreslinski
  30  */
  31
  32 /**
  33  * @file
  34  * Definitions of page table.
  35  */
  36 #include <string>
  37 #include <map>
  38 #include <fstream>
  39
  40 #include "arch/faults.hh"
  41 #include "base/bitfield.hh"
  42 #include "base/intmath.hh"
  43 #include "base/trace.hh"
  44 #include "mem/page_table.hh"
  45 #include "sim/builder.hh"
  46 #include "sim/sim_object.hh"
  47 #include "sim/system.hh"
  48
  49 using namespace std;
  50 using namespace TheISA;
  51
  52 PageTable::PageTable(System *_system, Addr _pageSize)
  53     : pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
  54       system(_system)
  55 {
  56     assert(isPowerOf2(pageSize));
  57 }
  58
  59 PageTable::~PageTable()
  60 {
  61 }
  62
  63 Fault
  64 PageTable::page_check(Addr addr, int size) const
  65 {
  66     if (size < sizeof(uint64_t)) {
  67         if (!isPowerOf2(size)) {
  68             panic("Invalid request size!\n");
  69             return genMachineCheckFault();
  70         }
  71
  72         if ((size - 1) & addr)
  73             return genAlignmentFault();
  74     }
  75     else {
  76         if ((addr & (VMPageSize - 1)) + size > VMPageSize) {
  77             panic("Invalid request size!\n");
  78             return genMachineCheckFault();
  79         }
  80
  81         if ((sizeof(uint64_t) - 1) & addr)
  82             return genAlignmentFault();
  83     }
  84
  85     return NoFault;
  86 }
  87
  88
  89
  90
  91 void
  92 PageTable::allocate(Addr vaddr, int size)
  93 {
  94     // starting address must be page aligned
  95     assert(pageOffset(vaddr) == 0);
  96
  97     for (; size > 0; size -= pageSize, vaddr += pageSize) {
  98         std::map<Addr,Addr>::iterator iter = pTable.find(vaddr);
  99
 100         if (iter != pTable.end()) {
 101             // already mapped
 102             fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
 103         }
 104
 105         pTable[vaddr] = system->new_page();
 106     }
 107 }
 108
 109
 110
 111 bool
 112 PageTable::translate(Addr vaddr, Addr &paddr)
 113 {
 114     Addr page_addr = pageAlign(vaddr);
 115     std::map<Addr,Addr>::iterator iter = pTable.find(page_addr);
 116
 117     if (iter == pTable.end()) {
 118         return false;
 119     }
 120
 121     paddr = iter->second + pageOffset(vaddr);
 122     return true;
 123 }
 124
 125
 126 Fault
 127 PageTable::translate(RequestPtr &req)
 128 {
 129     Addr paddr;
 130     assert(pageAlign(req->getVaddr() + req->getSize() - 1)
 131            == pageAlign(req->getVaddr()));
 132     if (!translate(req->getVaddr(), paddr)) {
 133         return genPageTableFault(req->getVaddr());
 134     }
 135     req->setPaddr(paddr);
 136     return page_check(req->getPaddr(), req->getSize());
 137 }