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 void
  94 PageTable::allocate(Addr vaddr, int64_t size)
  95 {
  96     // starting address must be page aligned
  97     assert(pageOffset(vaddr) == 0);
  98
  99     DPRINTF(MMU, "Allocating Page: %#x-%#x\n", vaddr, vaddr+ size);
 100
 101     for (; size > 0; size -= pageSize, vaddr += pageSize) {
 102         m5::hash_map<Addr,Addr>::iterator iter = pTable.find(vaddr);
 103
 104         if (iter != pTable.end()) {
 105             // already mapped
 106             fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
 107         }
 108
 109         pTable[vaddr] = system->new_page();
 110         updateCache(vaddr, pTable[vaddr]);
 111     }
 112 }
 113
 114
 115
 116 bool
 117 PageTable::translate(Addr vaddr, Addr &paddr)
 118 {
 119     Addr page_addr = pageAlign(vaddr);
 120     paddr = 0;
 121
 122     if (pTableCache[0].vaddr == page_addr) {
 123         paddr = pTableCache[0].paddr + pageOffset(vaddr);
 124         return true;
 125     }
 126     if (pTableCache[1].vaddr == page_addr) {
 127         paddr = pTableCache[1].paddr + pageOffset(vaddr);
 128         return true;
 129     }
 130     if (pTableCache[2].vaddr == page_addr) {
 131         paddr = pTableCache[2].paddr + pageOffset(vaddr);
 132         return true;
 133     }
 134
 135     m5::hash_map<Addr,Addr>::iterator iter = pTable.find(page_addr);
 136
 137     if (iter == pTable.end()) {
 138         return false;
 139     }
 140
 141     updateCache(page_addr, iter->second);
 142     paddr = iter->second + pageOffset(vaddr);
 143     return true;
 144 }
 145
 146
 147 Fault
 148 PageTable::translate(RequestPtr &req)
 149 {
 150     Addr paddr;
 151     assert(pageAlign(req->getVaddr() + req->getSize() - 1)
 152            == pageAlign(req->getVaddr()));
 153     if (!translate(req->getVaddr(), paddr)) {
 154         return Fault(new PageTableFault(req->getVaddr()));
 155     }
 156     req->setPaddr(paddr);
 157     return page_check(req->getPaddr(), req->getSize());
 158 }
 159
 160 void
 161 PageTable::serialize(std::ostream &os)
 162 {
 163     paramOut(os, "ptable.size", pTable.size());
 164
 165     int count = 0;
 166
 167     m5::hash_map<Addr,Addr>::iterator iter = pTable.begin();
 168     m5::hash_map<Addr,Addr>::iterator end = pTable.end();
 169     while (iter != end) {
 170         paramOut(os, csprintf("ptable.entry%dvaddr", count), iter->first);
 171         paramOut(os, csprintf("ptable.entry%dpaddr", count), iter->second);
 172
 173         ++iter;
 174         ++count;
 175     }
 176     assert(count == pTable.size());
 177 }
 178
 179 void
 180 PageTable::unserialize(Checkpoint *cp, const std::string &section)
 181 {
 182     int i = 0, count;
 183     paramIn(cp, section, "ptable.size", count);
 184     Addr vaddr, paddr;
 185
 186     pTable.clear();
 187
 188     while(i < count) {
 189         paramIn(cp, section, csprintf("ptable.entry%dvaddr", i), vaddr);
 190         paramIn(cp, section, csprintf("ptable.entry%dpaddr", i), paddr);
 191         pTable[vaddr] = paddr;
 192         ++i;
 193    }
 194
 195 }
 196