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  *          Ali Saidi
  31  */
  32
  33 /**
  34  * @file
  35  * Definitions of page table.
  36  */
  37 #include <string>
  38 #include <map>
  39 #include <fstream>
  40
  41 #include "arch/faults.hh"
  42 #include "base/bitfield.hh"
  43 #include "base/intmath.hh"
  44 #include "base/trace.hh"
  45 #include "mem/page_table.hh"
  46 #include "sim/builder.hh"
  47 #include "sim/sim_object.hh"
  48 #include "sim/system.hh"
  49
  50 using namespace std;
  51 using namespace TheISA;
  52
  53 PageTable::PageTable(System *_system, Addr _pageSize)
  54     : pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
  55       system(_system)
  56 {
  57     assert(isPowerOf2(pageSize));
  58     pTableCache[0].vaddr = 0;
  59     pTableCache[1].vaddr = 0;
  60     pTableCache[2].vaddr = 0;
  61 }
  62
  63 PageTable::~PageTable()
  64 {
  65 }
  66
  67 Fault
  68 PageTable::page_check(Addr addr, int64_t size) const
  69 {
  70     if (size < sizeof(uint64_t)) {
  71         if (!isPowerOf2(size)) {
  72             panic("Invalid request size!\n");
  73             return genMachineCheckFault();
  74         }
  75
  76         if ((size - 1) & addr)
  77             return genAlignmentFault();
  78     }
  79     else {
  80         if ((addr & (VMPageSize - 1)) + size > VMPageSize) {
  81             panic("Invalid request size!\n");
  82             return genMachineCheckFault();
  83         }
  84
  85         if ((sizeof(uint64_t) - 1) & addr)
  86             return genAlignmentFault();
  87     }
  88
  89     return NoFault;
  90 }
  91
  92
  93
  94
  95 void
  96 PageTable::allocate(Addr vaddr, int64_t size)
  97 {
  98     // starting address must be page aligned
  99     assert(pageOffset(vaddr) == 0);
 100
 101     DPRINTF(MMU, "Allocating Page: %#x-%#x\n", vaddr, vaddr+ size);
 102
 103     for (; size > 0; size -= pageSize, vaddr += pageSize) {
 104         m5::hash_map<Addr,Addr>::iterator iter = pTable.find(vaddr);
 105
 106         if (iter != pTable.end()) {
 107             // already mapped
 108             fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
 109         }
 110
 111         pTable[vaddr] = system->new_page();
 112         pTableCache[2].paddr = pTableCache[1].paddr;
 113         pTableCache[2].vaddr = pTableCache[1].vaddr;
 114         pTableCache[1].paddr = pTableCache[0].paddr;
 115         pTableCache[1].vaddr = pTableCache[0].vaddr;
 116         pTableCache[0].paddr = pTable[vaddr];
 117         pTableCache[0].vaddr = vaddr;
 118     }
 119 }
 120
 121
 122
 123 bool
 124 PageTable::translate(Addr vaddr, Addr &paddr)
 125 {
 126     Addr page_addr = pageAlign(vaddr);
 127     paddr = 0;
 128
 129     if (pTableCache[0].vaddr == vaddr) {
 130         paddr = pTableCache[0].paddr;
 131         return true;
 132     }
 133     if (pTableCache[1].vaddr == vaddr) {
 134         paddr = pTableCache[1].paddr;
 135         return true;
 136     }
 137     if (pTableCache[2].vaddr == vaddr) {
 138         paddr = pTableCache[2].paddr;
 139         return true;
 140     }
 141
 142     m5::hash_map<Addr,Addr>::iterator iter = pTable.find(page_addr);
 143
 144     if (iter == pTable.end()) {
 145         return false;
 146     }
 147
 148     paddr = iter->second + pageOffset(vaddr);
 149     return true;
 150 }
 151
 152
 153 Fault
 154 PageTable::translate(RequestPtr &req)
 155 {
 156     Addr paddr;
 157     assert(pageAlign(req->getVaddr() + req->getSize() - 1)
 158            == pageAlign(req->getVaddr()));
 159     if (!translate(req->getVaddr(), paddr)) {
 160         return genPageTableFault(req->getVaddr());
 161     }
 162     req->setPaddr(paddr);
 163     return page_check(req->getPaddr(), req->getSize());
 164 }
 165
 166 void
 167 PageTable::serialize(std::ostream &os)
 168 {
 169     paramOut(os, "ptable.size", pTable.size());
 170
 171     int count = 0;
 172
 173     m5::hash_map<Addr,Addr>::iterator iter = pTable.begin();
 174     m5::hash_map<Addr,Addr>::iterator end = pTable.end();
 175     while (iter != end) {
 176         paramOut(os, csprintf("ptable.entry%dvaddr", count), iter->first);
 177         paramOut(os, csprintf("ptable.entry%dpaddr", count), iter->second);
 178
 179         ++iter;
 180         ++count;
 181     }
 182     assert(count == pTable.size());
 183 }
 184
 185 void
 186 PageTable::unserialize(Checkpoint *cp, const std::string &section)
 187 {
 188     int i = 0, count;
 189     paramIn(cp, section, "ptable.size", count);
 190     Addr vaddr, paddr;
 191
 192     pTable.clear();
 193
 194     while(i < count) {
 195         paramIn(cp, section, csprintf("ptable.entry%dvaddr", i), vaddr);
 196         paramIn(cp, section, csprintf("ptable.entry%dpaddr", i), paddr);
 197         pTable[vaddr] = paddr;
 198         ++i;
 199    }
 200
 201 }
 202