page_table.cc revision 3347:c182ee45f6b4 
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
50using namespace std;
51using namespace TheISA;
52
53PageTable::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
63PageTable::~PageTable()
64{
65}
66
67Fault
68PageTable::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
94
95void
96PageTable::allocate(Addr vaddr, int64_t size)
97{
98    // starting address must be page aligned
99    assert(pageOffset(vaddr) == 0);
100
101    DPRINTF(MMU, "Allocating Page: %#x-%#x\n", vaddr, vaddr+ size);
102
103    for (; size > 0; size -= pageSize, vaddr += pageSize) {
104        m5::hash_map<Addr,Addr>::iterator iter = pTable.find(vaddr);
105
106        if (iter != pTable.end()) {
107            // already mapped
108            fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
109        }
110
111        pTable[vaddr] = system->new_page();
112        pTableCache[2].paddr = pTableCache[1].paddr;
113        pTableCache[2].vaddr = pTableCache[1].vaddr;
114        pTableCache[1].paddr = pTableCache[0].paddr;
115        pTableCache[1].vaddr = pTableCache[0].vaddr;
116        pTableCache[0].paddr = pTable[vaddr];
117        pTableCache[0].vaddr = vaddr;
118    }
119}
120
121
122
123bool
124PageTable::translate(Addr vaddr, Addr &paddr)
125{
126    Addr page_addr = pageAlign(vaddr);
127    paddr = 0;
128
129    if (pTableCache[0].vaddr == vaddr) {
130        paddr = pTableCache[0].paddr;
131        return true;
132    }
133    if (pTableCache[1].vaddr == vaddr) {
134        paddr = pTableCache[1].paddr;
135        return true;
136    }
137    if (pTableCache[2].vaddr == vaddr) {
138        paddr = pTableCache[2].paddr;
139        return true;
140    }
141
142    m5::hash_map<Addr,Addr>::iterator iter = pTable.find(page_addr);
143
144    if (iter == pTable.end()) {
145        return false;
146    }
147
148    paddr = iter->second + pageOffset(vaddr);
149    return true;
150}
151
152
153Fault
154PageTable::translate(RequestPtr &req)
155{
156    Addr paddr;
157    assert(pageAlign(req->getVaddr() + req->getSize() - 1)
158           == pageAlign(req->getVaddr()));
159    if (!translate(req->getVaddr(), paddr)) {
160        return genPageTableFault(req->getVaddr());
161    }
162    req->setPaddr(paddr);
163    return page_check(req->getPaddr(), req->getSize());
164}
165
166void
167PageTable::serialize(std::ostream &os)
168{
169    paramOut(os, "ptable.size", pTable.size());
170
171    int count = 0;
172
173    m5::hash_map<Addr,Addr>::iterator iter = pTable.begin();
174    m5::hash_map<Addr,Addr>::iterator end = pTable.end();
175    while (iter != end) {
176        paramOut(os, csprintf("ptable.entry%dvaddr", count), iter->first);
177        paramOut(os, csprintf("ptable.entry%dpaddr", count), iter->second);
178
179        ++iter;
180        ++count;
181    }
182    assert(count == pTable.size());
183}
184
185void
186PageTable::unserialize(Checkpoint *cp, const std::string &section)
187{
188    int i = 0, count;
189    paramIn(cp, section, "ptable.size", count);
190    Addr vaddr, paddr;
191
192    pTable.clear();
193
194    while(i < count) {
195        paramIn(cp, section, csprintf("ptable.entry%dvaddr", i), vaddr);
196        paramIn(cp, section, csprintf("ptable.entry%dpaddr", i), paddr);
197        pTable[vaddr] = paddr;
198        ++i;
199   }
200
201}
202
203