gem5/mem/page_table.cc

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/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file
* Definitions of page table.
*/
#include <string>
#include <map>
#include <fstream>
#include "arch/faults.hh"
#include "base/bitfield.hh"
#include "base/intmath.hh"
#include "base/trace.hh"
#include "mem/page_table.hh"
#include "sim/builder.hh"
#include "sim/sim_object.hh"
#include "sim/system.hh"
using namespace std;
using namespace TheISA;
PageTable::PageTable(System *_system, Addr _pageSize)
: pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
system(_system)
{
assert(isPowerOf2(pageSize));
}
PageTable::~PageTable()
{
}
Fault
PageTable::page_check(Addr addr, int size) const
{
if (size < sizeof(uint64_t)) {
if (!isPowerOf2(size)) {
panic("Invalid request size!\n");
return genMachineCheckFault();
}
if ((size - 1) & addr)
return genAlignmentFault();
}
else {
if ((addr & (VMPageSize - 1)) + size > VMPageSize) {
panic("Invalid request size!\n");
return genMachineCheckFault();
}
if ((sizeof(uint64_t) - 1) & addr)
return genAlignmentFault();
}
return NoFault;
}
void
PageTable::allocate(Addr vaddr, int size)
{
// starting address must be page aligned
assert(pageOffset(vaddr) == 0);
for (; size > 0; size -= pageSize, vaddr += pageSize) {
std::map<Addr,Addr>::iterator iter = pTable.find(vaddr);
if (iter != pTable.end()) {
// already mapped
fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
}
pTable[vaddr] = system->new_page();
}
}
bool
PageTable::translate(Addr vaddr, Addr &paddr)
{
Addr page_addr = pageAlign(vaddr);
std::map<Addr,Addr>::iterator iter = pTable.find(page_addr);
if (iter == pTable.end()) {
return false;
}
paddr = iter->second + pageOffset(vaddr);
return true;
}
Fault
PageTable::translate(CpuRequestPtr &req)
{
assert(pageAlign(req->vaddr + req->size - 1) == pageAlign(req->vaddr));
if (!translate(req->vaddr, req->paddr)) {
return genMachineCheckFault();
}
return page_check(req->paddr, req->size);
}