tlb.cc revision 6757 
1/*
2 * Copyright (c) 2001-2005 The Regents of The University of Michigan
3 * Copyright (c) 2007 MIPS Technologies, Inc.
4 * Copyright (c) 2007-2008 The Florida State University
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met: redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer;
11 * redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution;
14 * neither the name of the copyright holders nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Authors: Nathan Binkert
31 *          Steve Reinhardt
32 *          Jaidev Patwardhan
33 *          Stephen Hines
34 */
35
36#include <string>
37#include <vector>
38
39#include "arch/arm/faults.hh"
40#include "arch/arm/pagetable.hh"
41#include "arch/arm/tlb.hh"
42#include "arch/arm/utility.hh"
43#include "base/inifile.hh"
44#include "base/str.hh"
45#include "base/trace.hh"
46#include "cpu/thread_context.hh"
47#include "mem/page_table.hh"
48#include "params/ArmTLB.hh"
49#include "sim/process.hh"
50
51
52using namespace std;
53using namespace ArmISA;
54
55///////////////////////////////////////////////////////////////////////
56//
57//  ARM TLB
58//
59
60#define MODE2MASK(X)			(1 << (X))
61
62TLB::TLB(const Params *p)
63    : BaseTLB(p), size(p->size), nlu(0)
64{
65    table = new ArmISA::PTE[size];
66    memset(table, 0, sizeof(ArmISA::PTE[size]));
67    smallPages=0;
68}
69
70TLB::~TLB()
71{
72    if (table)
73        delete [] table;
74}
75
76// look up an entry in the TLB
77ArmISA::PTE *
78TLB::lookup(Addr vpn, uint8_t asn) const
79{
80    // assume not found...
81    ArmISA::PTE *retval = NULL;
82    PageTable::const_iterator i = lookupTable.find(vpn);
83    if (i != lookupTable.end()) {
84        while (i->first == vpn) {
85            int index = i->second;
86            ArmISA::PTE *pte = &table[index];
87
88            /* 1KB TLB Lookup code - from ARM ARM Volume III - Rev. 2.50 */
89            Addr Mask = pte->Mask;
90            Addr InvMask = ~Mask;
91            Addr VPN  = pte->VPN;
92            //	    warn("Valid: %d - %d\n",pte->V0,pte->V1);
93            if(((vpn & InvMask) == (VPN & InvMask)) && (pte->G  || (asn == pte->asid)))
94              { // We have a VPN + ASID Match
95                retval = pte;
96                break;
97              }
98            ++i;
99        }
100    }
101
102    DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn,
103            retval ? "hit" : "miss", retval ? retval->PFN1 : 0);
104    return retval;
105}
106
107ArmISA::PTE* TLB::getEntry(unsigned Index) const
108{
109    // Make sure that Index is valid
110    assert(Index<size);
111    return &table[Index];
112}
113
114int TLB::probeEntry(Addr vpn,uint8_t asn) const
115{
116    // assume not found...
117    ArmISA::PTE *retval = NULL;
118    int Ind=-1;
119    PageTable::const_iterator i = lookupTable.find(vpn);
120    if (i != lookupTable.end()) {
121        while (i->first == vpn) {
122            int index = i->second;
123            ArmISA::PTE *pte = &table[index];
124
125            /* 1KB TLB Lookup code - from ARM ARM Volume III - Rev. 2.50 */
126            Addr Mask = pte->Mask;
127            Addr InvMask = ~Mask;
128            Addr VPN  = pte->VPN;
129            if(((vpn & InvMask) == (VPN & InvMask)) && (pte->G  || (asn == pte->asid)))
130              { // We have a VPN + ASID Match
131                retval = pte;
132                Ind = index;
133                break;
134              }
135
136            ++i;
137        }
138    }
139    DPRINTF(Arm,"VPN: %x, asid: %d, Result of TLBP: %d\n",vpn,asn,Ind);
140    return Ind;
141}
142Fault inline
143TLB::checkCacheability(RequestPtr &req)
144{
145  Addr VAddrUncacheable = 0xA0000000;
146  // In ARM, cacheability is controlled by certain bits of the virtual address
147  // or by the TLB entry
148  if((req->getVaddr() & VAddrUncacheable) == VAddrUncacheable) {
149    // mark request as uncacheable
150    req->setFlags(Request::UNCACHEABLE);
151  }
152  return NoFault;
153}
154void TLB::insertAt(ArmISA::PTE &pte, unsigned Index, int _smallPages)
155{
156  smallPages=_smallPages;
157  if(Index > size){
158    warn("Attempted to write at index (%d) beyond TLB size (%d)",Index,size);
159  } else {
160    // Update TLB
161    DPRINTF(TLB,"TLB[%d]: %x %x %x %x\n",Index,pte.Mask<<11,((pte.VPN << 11) | pte.asid),((pte.PFN0 <<6) | (pte.C0 << 3) | (pte.D0 << 2) | (pte.V0 <<1) | pte.G),
162            ((pte.PFN1 <<6) | (pte.C1 << 3) | (pte.D1 << 2) | (pte.V1 <<1) | pte.G));
163    if(table[Index].V0 == true || table[Index].V1 == true){ // Previous entry is valid
164      PageTable::iterator i = lookupTable.find(table[Index].VPN);
165      lookupTable.erase(i);
166    }
167    table[Index]=pte;
168    // Update fast lookup table
169    lookupTable.insert(make_pair(table[Index].VPN, Index));
170    //    int TestIndex=probeEntry(pte.VPN,pte.asid);
171    //    warn("Inserted at: %d, Found at: %d (%x)\n",Index,TestIndex,pte.Mask);
172  }
173
174}
175
176// insert a new TLB entry
177void
178TLB::insert(Addr addr, ArmISA::PTE &pte)
179{
180  fatal("TLB Insert not yet implemented\n");
181}
182
183void
184TLB::flushAll()
185{
186    DPRINTF(TLB, "flushAll\n");
187    memset(table, 0, sizeof(ArmISA::PTE[size]));
188    lookupTable.clear();
189    nlu = 0;
190}
191
192void
193TLB::serialize(ostream &os)
194{
195    SERIALIZE_SCALAR(size);
196    SERIALIZE_SCALAR(nlu);
197
198    for (int i = 0; i < size; i++) {
199        nameOut(os, csprintf("%s.PTE%d", name(), i));
200        table[i].serialize(os);
201    }
202}
203
204void
205TLB::unserialize(Checkpoint *cp, const string &section)
206{
207    UNSERIALIZE_SCALAR(size);
208    UNSERIALIZE_SCALAR(nlu);
209
210    for (int i = 0; i < size; i++) {
211        table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
212        if (table[i].V0 || table[i].V1) {
213            lookupTable.insert(make_pair(table[i].VPN, i));
214        }
215    }
216}
217
218void
219TLB::regStats()
220{
221    read_hits
222        .name(name() + ".read_hits")
223        .desc("DTB read hits")
224        ;
225
226    read_misses
227        .name(name() + ".read_misses")
228        .desc("DTB read misses")
229        ;
230
231
232    read_accesses
233        .name(name() + ".read_accesses")
234        .desc("DTB read accesses")
235        ;
236
237    write_hits
238        .name(name() + ".write_hits")
239        .desc("DTB write hits")
240        ;
241
242    write_misses
243        .name(name() + ".write_misses")
244        .desc("DTB write misses")
245        ;
246
247
248    write_accesses
249        .name(name() + ".write_accesses")
250        .desc("DTB write accesses")
251        ;
252
253    hits
254        .name(name() + ".hits")
255        .desc("DTB hits")
256        ;
257
258    misses
259        .name(name() + ".misses")
260        .desc("DTB misses")
261        ;
262
263    invalids
264        .name(name() + ".invalids")
265        .desc("DTB access violations")
266        ;
267
268    accesses
269        .name(name() + ".accesses")
270        .desc("DTB accesses")
271        ;
272
273    hits = read_hits + write_hits;
274    misses = read_misses + write_misses;
275    accesses = read_accesses + write_accesses;
276}
277
278Fault
279TLB::translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode)
280{
281#if !FULL_SYSTEM
282    Process * p = tc->getProcessPtr();
283
284    Fault fault = p->pTable->translate(req);
285    if(fault != NoFault)
286        return fault;
287
288    return NoFault;
289#else
290    SCTLR sctlr = tc->readMiscReg(MISCREG_SCTLR);
291    if (!sctlr.m) {
292        req->setPaddr(req->getVaddr());
293        return NoFault;
294    }
295    panic("MMU translation not implemented\n");
296    return NoFault;
297
298
299#endif
300}
301
302void
303TLB::translateTiming(RequestPtr req, ThreadContext *tc,
304        Translation *translation, Mode mode)
305{
306    assert(translation);
307    translation->finish(translateAtomic(req, tc, mode), req, tc, mode);
308}
309
310ArmISA::PTE &
311TLB::index(bool advance)
312{
313    ArmISA::PTE *pte = &table[nlu];
314
315    if (advance)
316        nextnlu();
317
318    return *pte;
319}
320
321ArmISA::TLB *
322ArmTLBParams::create()
323{
324    return new ArmISA::TLB(this);
325}
326