gem5/src/mem/page_table.hh

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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.
*
* Authors: Steve Reinhardt
*/
/**
* @file
* Declaration of a non-full system Page Table.
*/
#ifndef __PAGE_TABLE__
#define __PAGE_TABLE__
#include <string>
#include "sim/faults.hh"
#include "arch/isa_traits.hh"
#include "base/hashmap.hh"
#include "base/trace.hh"
#include "mem/request.hh"
#include "mem/packet.hh"
#include "sim/sim_object.hh"
class System;
/**
* Page Table Declaration.
*/
class PageTable
{
protected:
m5::hash_map<Addr,Addr> pTable;
struct cacheElement {
Addr paddr;
Addr vaddr;
} ;
struct cacheElement pTableCache[3];
const Addr pageSize;
const Addr offsetMask;
System *system;
public:
PageTable(System *_system, Addr _pageSize = TheISA::VMPageSize);
~PageTable();
Addr pageAlign(Addr a) { return (a & ~offsetMask); }
Addr pageOffset(Addr a) { return (a & offsetMask); }
Fault page_check(Addr addr, int64_t size) const;
void allocate(Addr vaddr, int64_t size);
/**
* Translate function
* @param vaddr The virtual address.
* @return Physical address from translation.
*/
bool translate(Addr vaddr, Addr &paddr);
/**
* Perform a translation on the memory request, fills in paddr
* field of mem_req.
* @param req The memory request.
*/
Fault translate(RequestPtr &req);
/**
* Update the page table cache.
* @param vaddr virtual address (page aligned) to check
* @param paddr physical address (page aligned) to return
*/
inline void updateCache(Addr vaddr, Addr paddr)
{
pTableCache[2].paddr = pTableCache[1].paddr;
pTableCache[2].vaddr = pTableCache[1].vaddr;
pTableCache[1].paddr = pTableCache[0].paddr;
pTableCache[1].vaddr = pTableCache[0].vaddr;
pTableCache[0].paddr = paddr;
pTableCache[0].vaddr = vaddr;
}
void serialize(std::ostream &os);
void unserialize(Checkpoint *cp, const std::string &section);
};
#endif