page_table.cc revision 8601 
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 <fstream>
38#include <map>
39#include <string>
40
41#include "base/bitfield.hh"
42#include "base/intmath.hh"
43#include "base/trace.hh"
44#include "config/the_isa.hh"
45#include "debug/MMU.hh"
46#include "mem/page_table.hh"
47#include "sim/faults.hh"
48#include "sim/sim_object.hh"
49
50using namespace std;
51using namespace TheISA;
52
53PageTable::PageTable(const std::string &__name, uint64_t _pid, Addr _pageSize)
54    : pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
55      pid(_pid), _name(__name)
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
67void
68PageTable::map(Addr vaddr, Addr paddr, int64_t size, bool clobber)
69{
70    // starting address must be page aligned
71    assert(pageOffset(vaddr) == 0);
72
73    DPRINTF(MMU, "Allocating Page: %#x-%#x\n", vaddr, vaddr+ size);
74
75    for (; size > 0; size -= pageSize, vaddr += pageSize, paddr += pageSize) {
76        if (!clobber && (pTable.find(vaddr) != pTable.end())) {
77            // already mapped
78            fatal("PageTable::allocate: address 0x%x already mapped", vaddr);
79        }
80
81        pTable[vaddr] = TheISA::TlbEntry(pid, vaddr, paddr);
82        updateCache(vaddr, pTable[vaddr]);
83    }
84}
85
86void
87PageTable::remap(Addr vaddr, int64_t size, Addr new_vaddr)
88{
89    assert(pageOffset(vaddr) == 0);
90    assert(pageOffset(new_vaddr) == 0);
91
92    DPRINTF(MMU, "moving pages from vaddr %08p to %08p, size = %d\n", vaddr,
93            new_vaddr, size);
94
95    for (; size > 0; size -= pageSize, vaddr += pageSize, new_vaddr += pageSize) {
96        PTableItr iter = pTable.find(vaddr);
97
98        assert(iter != pTable.end());
99
100        pTable[new_vaddr] = pTable[vaddr];
101        pTable.erase(vaddr);
102        pTable[new_vaddr].updateVaddr(new_vaddr);
103        updateCache(new_vaddr, pTable[new_vaddr]);
104    }
105}
106
107void
108PageTable::unmap(Addr vaddr, int64_t size)
109{
110    assert(pageOffset(vaddr) == 0);
111
112    DPRINTF(MMU, "Unmapping page: %#x-%#x\n", vaddr, vaddr+ size);
113
114    for (; size > 0; size -= pageSize, vaddr += pageSize) {
115        PTableItr iter = pTable.find(vaddr);
116
117        assert(iter != pTable.end());
118
119        pTable.erase(vaddr);
120    }
121
122}
123
124bool
125PageTable::isUnmapped(Addr vaddr, int64_t size)
126{
127    // starting address must be page aligned
128    assert(pageOffset(vaddr) == 0);
129
130    for (; size > 0; size -= pageSize, vaddr += pageSize) {
131        if (pTable.find(vaddr) != pTable.end()) {
132            return false;
133        }
134    }
135
136    return true;
137}
138
139bool
140PageTable::lookup(Addr vaddr, TheISA::TlbEntry &entry)
141{
142    Addr page_addr = pageAlign(vaddr);
143
144    if (pTableCache[0].vaddr == page_addr) {
145        entry = pTableCache[0].entry;
146        return true;
147    }
148    if (pTableCache[1].vaddr == page_addr) {
149        entry = pTableCache[1].entry;
150        return true;
151    }
152    if (pTableCache[2].vaddr == page_addr) {
153        entry = pTableCache[2].entry;
154        return true;
155    }
156
157    PTableItr iter = pTable.find(page_addr);
158
159    if (iter == pTable.end()) {
160        return false;
161    }
162
163    updateCache(page_addr, iter->second);
164    entry = iter->second;
165    return true;
166}
167
168bool
169PageTable::translate(Addr vaddr, Addr &paddr)
170{
171    TheISA::TlbEntry entry;
172    if (!lookup(vaddr, entry)) {
173        DPRINTF(MMU, "Couldn't Translate: %#x\n", vaddr);
174        return false;
175    }
176    paddr = pageOffset(vaddr) + entry.pageStart();
177    DPRINTF(MMU, "Translating: %#x->%#x\n", vaddr, paddr);
178    return true;
179}
180
181Fault
182PageTable::translate(RequestPtr req)
183{
184    Addr paddr;
185    assert(pageAlign(req->getVaddr() + req->getSize() - 1)
186           == pageAlign(req->getVaddr()));
187    if (!translate(req->getVaddr(), paddr)) {
188        return Fault(new GenericPageTableFault(req->getVaddr()));
189    }
190    req->setPaddr(paddr);
191    if ((paddr & (pageSize - 1)) + req->getSize() > pageSize) {
192        panic("Request spans page boundaries!\n");
193        return NoFault;
194    }
195    return NoFault;
196}
197
198void
199PageTable::serialize(std::ostream &os)
200{
201    paramOut(os, "ptable.size", pTable.size());
202
203    PTable::size_type count = 0;
204
205    PTableItr iter = pTable.begin();
206    PTableItr end = pTable.end();
207    while (iter != end) {
208        os << "\n[" << csprintf("%s.Entry%d", name(), count) << "]\n";
209
210        paramOut(os, "vaddr", iter->first);
211        iter->second.serialize(os);
212
213        ++iter;
214        ++count;
215    }
216    assert(count == pTable.size());
217}
218
219void
220PageTable::unserialize(Checkpoint *cp, const std::string &section)
221{
222    int i = 0, count;
223    paramIn(cp, section, "ptable.size", count);
224    Addr vaddr;
225    TheISA::TlbEntry *entry;
226
227    pTable.clear();
228
229    while(i < count) {
230        paramIn(cp, csprintf("%s.Entry%d", name(), i), "vaddr", vaddr);
231        entry = new TheISA::TlbEntry();
232        entry->unserialize(cp, csprintf("%s.Entry%d", name(), i));
233        pTable[vaddr] = *entry;
234        ++i;
235    }
236}
237
238