src/arch/x86/pagetable.hh

/*
 * Copyright (c) 2007 The Hewlett-Packard Development Company
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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: Gabe Black
 */

#ifndef __ARCH_X86_PAGETABLE_HH__
#define __ARCH_X86_PAGETABLE_HH__

#include <iostream>
#include <string>

#include "base/bitunion.hh"
#include "base/misc.hh"
#include "base/types.hh"
#include "base/trie.hh"

class Checkpoint;

namespace X86ISA
{
    struct TlbEntry;
}

typedef Trie<Addr, X86ISA::TlbEntry> TlbEntryTrie;

namespace X86ISA
{
    BitUnion64(VAddr)
        Bitfield<20, 12> longl1;
        Bitfield<29, 21> longl2;
        Bitfield<38, 30> longl3;
        Bitfield<47, 39> longl4;

        Bitfield<20, 12> pael1;
        Bitfield<29, 21> pael2;
        Bitfield<31, 30> pael3;

        Bitfield<21, 12> norml1;
        Bitfield<31, 22> norml2;
    EndBitUnion(VAddr)

    struct TlbEntry
    {
        // The base of the physical page.
        Addr paddr;

        // The beginning of the virtual page this entry maps.
        Addr vaddr;
        // The size of the page this represents, in address bits.
        unsigned logBytes;

        // Read permission is always available, assuming it isn't blocked by
        // other mechanisms.
        bool writable;
        // Whether this page is accesible without being in supervisor mode.
        bool user;
        // Whether to use write through or write back. M5 ignores this and
        // lets the caches handle the writeback policy.
        //bool pwt;
        // Whether the page is cacheable or not.
        bool uncacheable;
        // Whether or not to kick this page out on a write to CR3.
        bool global;
        // A bit used to form an index into the PAT table.
        bool patBit;
        // Whether or not memory on this page can be executed.
        bool noExec;
        // A sequence number to keep track of LRU.
        uint64_t lruSeq;

        TlbEntryTrie::Handle trieHandle;

        TlbEntry(Addr asn, Addr _vaddr, Addr _paddr);
        TlbEntry() {}

        void
        updateVaddr(Addr new_vaddr)
        {
            vaddr = new_vaddr;
        }

        Addr pageStart()
        {
            return paddr;
        }

        // Return the page size in bytes
        int size()
        {
            return (1 << logBytes);
        }

        void serialize(std::ostream &os);
        void unserialize(Checkpoint *cp, const std::string &section);
    };
}

#endif