pagetable.hh revision 5254:c555f8b07345 
1/*
2 * Copyright (c) 2007 MIPS Technologies, Inc.
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: Jaidev Patwardhan
29 */
30
31#ifndef __ARCH_MIPS_PAGETABLE_H__
32#define __ARCH_MIPS_PAGETABLE_H__
33
34#include "arch/mips/isa_traits.hh"
35#include "arch/mips/utility.hh"
36#include "arch/mips/vtophys.hh"
37#include "config/full_system.hh"
38
39namespace MipsISA {
40
41    struct VAddr
42    {
43        static const int ImplBits = 43;
44        static const Addr ImplMask = (ULL(1) << ImplBits) - 1;
45        static const Addr UnImplMask = ~ImplMask;
46
47        VAddr(Addr a) : addr(a) {}
48        Addr addr;
49        operator Addr() const { return addr; }
50        const VAddr &operator=(Addr a) { addr = a; return *this; }
51
52        Addr vpn() const { return (addr & ImplMask) >> PageShift; }
53        Addr page() const { return addr & Page_Mask; }
54        Addr offset() const { return addr & PageOffset; }
55
56        Addr level3() const
57        { return MipsISA::PteAddr(addr >> PageShift); }
58        Addr level2() const
59        { return MipsISA::PteAddr(addr >> NPtePageShift + PageShift); }
60        Addr level1() const
61        { return MipsISA::PteAddr(addr >> 2 * NPtePageShift + PageShift); }
62    };
63
64    // ITB/DTB page table entry
65    struct PTE
66    {
67      Addr Mask; // What parts of the VAddr (from bits 28..11) should be used in translation (includes Mask and MaskX from PageMask)
68      Addr VPN; // Virtual Page Number (/2) (Includes VPN2 + VPN2X .. bits 31..11 from EntryHi)
69      uint8_t asid; // Address Space ID (8 bits) // Lower 8 bits of EntryHi
70
71      bool G;    // Global Bit - Obtained by an *AND* of EntryLo0 and EntryLo1 G bit
72
73      /* Contents of Entry Lo0 */
74      Addr PFN0; // Physical Frame Number - Even
75      bool D0;   // Even entry Dirty Bit
76      bool V0;   // Even entry Valid Bit
77      uint8_t C0; // Cache Coherency Bits - Even
78
79      /* Contents of Entry Lo1 */
80      Addr PFN1; // Physical Frame Number - Odd
81      bool D1;   // Odd entry Dirty Bit
82      bool V1;   // Odd entry Valid Bit
83      uint8_t C1; // Cache Coherency Bits (3 bits)
84
85      /* The next few variables are put in as optimizations to reduce TLB lookup overheads */
86      /* For a given Mask, what is the address shift amount, and what is the OffsetMask */
87      int AddrShiftAmount;
88      int OffsetMask;
89
90      bool Valid() { return (V0 | V1);};
91        void serialize(std::ostream &os);
92        void unserialize(Checkpoint *cp, const std::string &section);
93    };
94
95};
96#endif // __ARCH_MIPS_PAGETABLE_H__
97
98