1/*
2 * Copyright (c) 2001-2005 The Regents of The University of Michigan
3 * Copyright (c) 2007 MIPS Technologies, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Nathan Binkert
30 * Steve Reinhardt
31 * Jaidev Patwardhan
32 */
33
34#include <string>
35#include <vector>
36
37#include "arch/mips/faults.hh"
38#include "arch/mips/pagetable.hh"
39#include "arch/mips/pra_constants.hh"
40#include "arch/mips/tlb.hh"
41#include "arch/mips/utility.hh"
42#include "base/inifile.hh"
43#include "base/str.hh"
44#include "base/trace.hh"
45#include "cpu/thread_context.hh"
46#include "mem/page_table.hh"
47#include "params/MipsTLB.hh"
48#include "sim/process.hh"
49
50using namespace std;
51using namespace MipsISA;
52
53///////////////////////////////////////////////////////////////////////
54//
55// MIPS TLB
56//
57
58static inline mode_type
59getOperatingMode(MiscReg Stat)
60{
61 if ((Stat & 0x10000006) != 0 || (Stat & 0x18) ==0) {
62 return mode_kernel;
63 } else if ((Stat & 0x18) == 0x8) {
64 return mode_supervisor;
65 } else if ((Stat & 0x18) == 0x10) {
66 return mode_user;
67 } else {
68 return mode_number;
69 }
70}
71
72
73TLB::TLB(const Params *p)
74 : BaseTLB(p), size(p->size), nlu(0)
75{
76 table = new PTE[size];
77 memset(table, 0, sizeof(PTE[size]));
78 smallPages = 0;
79}
80
81TLB::~TLB()
82{
83 if (table)
84 delete [] table;
85}
86
87// look up an entry in the TLB
88MipsISA::PTE *
89TLB::lookup(Addr vpn, uint8_t asn) const
90{
91 // assume not found...
92 PTE *retval = NULL;
93 PageTable::const_iterator i = lookupTable.find(vpn);
94 if (i != lookupTable.end()) {
95 while (i->first == vpn) {
96 int index = i->second;
97 PTE *pte = &table[index];
98
99 /* 1KB TLB Lookup code - from MIPS ARM Volume III - Rev. 2.50 */
100 Addr Mask = pte->Mask;
101 Addr InvMask = ~Mask;
102 Addr VPN = pte->VPN;
103 if (((vpn & InvMask) == (VPN & InvMask)) &&
104 (pte->G || (asn == pte->asid))) {
105 // We have a VPN + ASID Match
106 retval = pte;
107 break;
108 }
109 ++i;
110 }
111 }
112
113 DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn,
114 retval ? "hit" : "miss", retval ? retval->PFN1 : 0);
115 return retval;
116}
117
118MipsISA::PTE*
119TLB::getEntry(unsigned Index) const
120{
121 // Make sure that Index is valid
122 assert(Index<size);
123 return &table[Index];
124}
125
126int
127TLB::probeEntry(Addr vpn, uint8_t asn) const
128{
129 // assume not found...
130 PTE *retval = NULL;
131 int Ind = -1;
132 PageTable::const_iterator i = lookupTable.find(vpn);
133 if (i != lookupTable.end()) {
134 while (i->first == vpn) {
135 int index = i->second;
136 PTE *pte = &table[index];
137
138 /* 1KB TLB Lookup code - from MIPS ARM Volume III - Rev. 2.50 */
139 Addr Mask = pte->Mask;
140 Addr InvMask = ~Mask;
141 Addr VPN = pte->VPN;
142 if (((vpn & InvMask) == (VPN & InvMask)) &&
143 (pte->G || (asn == pte->asid))) {
144 // We have a VPN + ASID Match
145 retval = pte;
146 Ind = index;
147 break;
148 }
149 ++i;
150 }
151 }
152 DPRINTF(MipsPRA,"VPN: %x, asid: %d, Result of TLBP: %d\n",vpn,asn,Ind);
153 return Ind;
154}
155
156inline Fault
157TLB::checkCacheability(RequestPtr &req)
158{
159 Addr VAddrUncacheable = 0xA0000000;
160 // In MIPS, cacheability is controlled by certain bits of the virtual
161 // address or by the TLB entry
162 if ((req->getVaddr() & VAddrUncacheable) == VAddrUncacheable) {
163 // mark request as uncacheable
164 req->setFlags(Request::UNCACHEABLE);
165 }
166 return NoFault;
167}
168
169void
170TLB::insertAt(PTE &pte, unsigned Index, int _smallPages)
171{
172 smallPages = _smallPages;
173 if (Index > size) {
174 warn("Attempted to write at index (%d) beyond TLB size (%d)",
175 Index, size);
176 } else {
177 // Update TLB
178 DPRINTF(TLB, "TLB[%d]: %x %x %x %x\n",
179 Index, pte.Mask << 11,
180 ((pte.VPN << 11) | pte.asid),
181 ((pte.PFN0 << 6) | (pte.C0 << 3) |
182 (pte.D0 << 2) | (pte.V0 <<1) | pte.G),
183 ((pte.PFN1 <<6) | (pte.C1 << 3) |
184 (pte.D1 << 2) | (pte.V1 <<1) | pte.G));
185 if (table[Index].V0 == true || table[Index].V1 == true) {
186 // Previous entry is valid
187 PageTable::iterator i = lookupTable.find(table[Index].VPN);
188 lookupTable.erase(i);
189 }
190 table[Index]=pte;
191 // Update fast lookup table
192 lookupTable.insert(make_pair(table[Index].VPN, Index));
193 }
194}
195
196// insert a new TLB entry
197void
198TLB::insert(Addr addr, PTE &pte)
199{
200 fatal("TLB Insert not yet implemented\n");
201}
202
203void
204TLB::flushAll()
205{
206 DPRINTF(TLB, "flushAll\n");
207 memset(table, 0, sizeof(PTE[size]));
208 lookupTable.clear();
209 nlu = 0;
210}
211
212void
213TLB::serialize(ostream &os)
214{
215 SERIALIZE_SCALAR(size);
216 SERIALIZE_SCALAR(nlu);
217
218 for (int i = 0; i < size; i++) {
219 nameOut(os, csprintf("%s.PTE%d", name(), i));
220 table[i].serialize(os);
221 }
222}
223
224void
225TLB::unserialize(Checkpoint *cp, const string &section)
226{
227 UNSERIALIZE_SCALAR(size);
228 UNSERIALIZE_SCALAR(nlu);
229
230 for (int i = 0; i < size; i++) {
231 table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
232 if (table[i].V0 || table[i].V1) {
233 lookupTable.insert(make_pair(table[i].VPN, i));
234 }
235 }
236}
237
238void
239TLB::regStats()
240{
241 read_hits
242 .name(name() + ".read_hits")
243 .desc("DTB read hits")
244 ;
245
246 read_misses
247 .name(name() + ".read_misses")
248 .desc("DTB read misses")
249 ;
250
251
252 read_accesses
253 .name(name() + ".read_accesses")
254 .desc("DTB read accesses")
255 ;
256
257 write_hits
258 .name(name() + ".write_hits")
259 .desc("DTB write hits")
260 ;
261
262 write_misses
263 .name(name() + ".write_misses")
264 .desc("DTB write misses")
265 ;
266
267
268 write_accesses
269 .name(name() + ".write_accesses")
270 .desc("DTB write accesses")
271 ;
272
273 hits
274 .name(name() + ".hits")
275 .desc("DTB hits")
276 ;
277
278 misses
279 .name(name() + ".misses")
280 .desc("DTB misses")
281 ;
282
283 accesses
284 .name(name() + ".accesses")
285 .desc("DTB accesses")
286 ;
287
288 hits = read_hits + write_hits;
289 misses = read_misses + write_misses;
290 accesses = read_accesses + write_accesses;
291}
292
293Fault
294TLB::translateInst(RequestPtr req, ThreadContext *tc)
295{
296#if !FULL_SYSTEM
297 Process * p = tc->getProcessPtr();
298
299 Fault fault = p->pTable->translate(req);
300 if (fault != NoFault)
301 return fault;
302
303 return NoFault;
304#else
305 Addr vaddr = req->getVaddr();
306
307 bool misaligned = (req->getSize() - 1) & vaddr;
308
309 if (IsKSeg0(vaddr)) {
310 // Address will not be translated through TLB, set response, and go!
311 req->setPaddr(KSeg02Phys(vaddr));
312 if (getOperatingMode(tc->readMiscReg(MISCREG_STATUS)) != mode_kernel ||
313 misaligned) {
314 AddressErrorFault *Flt = new AddressErrorFault();
315 /* BadVAddr must be set */
316 Flt->badVAddr = vaddr;
317 return Flt;
318 }
319 } else if(IsKSeg1(vaddr)) {
320 // Address will not be translated through TLB, set response, and go!
321 req->setPaddr(KSeg02Phys(vaddr));
322 } else {
323 /*
324 * This is an optimization - smallPages is updated every time a TLB
325 * operation is performed. That way, we don't need to look at
326 * Config3 _ SP and PageGrain _ ESP every time we do a TLB lookup
327 */
328 Addr VPN;
329 if (smallPages == 1) {
330 VPN = (vaddr >> 11);
331 } else {
332 VPN = ((vaddr >> 11) & 0xFFFFFFFC);
333 }
334 uint8_t Asid = req->getAsid();
335 if (misaligned) {
336 // Unaligned address!
337 AddressErrorFault *Flt = new AddressErrorFault();
338 /* BadVAddr must be set */
339 Flt->badVAddr = vaddr;
340 return Flt;
341 }
342 PTE *pte = lookup(VPN,Asid);
343 if (pte != NULL) {
344 // Ok, found something
345 /* Check for valid bits */
346 int EvenOdd;
347 bool Valid;
348 if ((((vaddr) >> pte->AddrShiftAmount) & 1) == 0) {
349 // Check even bits
350 Valid = pte->V0;
351 EvenOdd = 0;
352 } else {
353 // Check odd bits
354 Valid = pte->V1;
355 EvenOdd = 1;
356 }
357
358 if (Valid == false) {
359 //Invalid entry
360 ItbInvalidFault *Flt = new ItbInvalidFault();
361 /* EntryHi VPN, ASID fields must be set */
362 Flt->entryHiAsid = Asid;
363 Flt->entryHiVPN2 = (VPN >> 2);
364 Flt->entryHiVPN2X = (VPN & 0x3);
365
366 /* BadVAddr must be set */
367 Flt->badVAddr = vaddr;
368
369 /* Context must be set */
370 Flt->contextBadVPN2 = (VPN >> 2);
371 return Flt;
372 } else {
373 // Ok, this is really a match, set paddr
374 Addr PAddr;
375 if (EvenOdd == 0) {
376 PAddr = pte->PFN0;
377 } else {
378 PAddr = pte->PFN1;
379 }
380 PAddr >>= (pte->AddrShiftAmount - 12);
381 PAddr <<= pte->AddrShiftAmount;
382 PAddr |= (vaddr & pte->OffsetMask);
383 req->setPaddr(PAddr);
384 }
385 } else {
386 // Didn't find any match, return a TLB Refill Exception
387 ItbRefillFault *Flt = new ItbRefillFault();
388 /* EntryHi VPN, ASID fields must be set */
389 Flt->entryHiAsid = Asid;
390 Flt->entryHiVPN2 = (VPN >> 2);
391 Flt->entryHiVPN2X = (VPN & 0x3);
392
393 /* BadVAddr must be set */
394 Flt->badVAddr = vaddr;
395
396 /* Context must be set */
397 Flt->contextBadVPN2 = (VPN >> 2);
398 return Flt;
399 }
400 }
401 return checkCacheability(req);
402#endif
403}
404
405Fault
406TLB::translateData(RequestPtr req, ThreadContext *tc, bool write)
407{
408#if !FULL_SYSTEM
409 //@TODO: This should actually use TLB instead of going directly
410 // to the page table in syscall mode.
411 /**
412 * Check for alignment faults
413 */
414 if (req->getVaddr() & (req->getSize() - 1)) {
415 DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->getVaddr(),
416 req->getSize());
417 return new AlignmentFault();
418 }
419
420
421 Process * p = tc->getProcessPtr();
422
423 Fault fault = p->pTable->translate(req);
424 if (fault != NoFault)
425 return fault;
426
427 return NoFault;
428#else
429 Addr vaddr = req->getVaddr();
430
431 bool misaligned = (req->getSize() - 1) & vaddr;
432
433 if (IsKSeg0(vaddr)) {
434 // Address will not be translated through TLB, set response, and go!
435 req->setPaddr(KSeg02Phys(vaddr));
436 if (getOperatingMode(tc->readMiscReg(MISCREG_STATUS)) != mode_kernel ||
437 misaligned) {
438 StoreAddressErrorFault *Flt = new StoreAddressErrorFault();
439 /* BadVAddr must be set */
440 Flt->badVAddr = vaddr;
441
442 return Flt;
443 }
444 } else if(IsKSeg1(vaddr)) {
445 // Address will not be translated through TLB, set response, and go!
446 req->setPaddr(KSeg02Phys(vaddr));
447 } else {
448 /*
449 * This is an optimization - smallPages is updated every time a TLB
450 * operation is performed. That way, we don't need to look at
451 * Config3 _ SP and PageGrain _ ESP every time we do a TLB lookup
452 */
453 Addr VPN = (vaddr >> 11) & 0xFFFFFFFC;
454 if (smallPages == 1) {
455 VPN = vaddr >> 11;
456 }
457 uint8_t Asid = req->getAsid();
458 PTE *pte = lookup(VPN, Asid);
459 if (misaligned) {
460 // Unaligned address!
461 StoreAddressErrorFault *Flt = new StoreAddressErrorFault();
462 /* BadVAddr must be set */
463 Flt->badVAddr = vaddr;
464 return Flt;
465 }
466 if (pte != NULL) {
467 // Ok, found something
468 /* Check for valid bits */
469 int EvenOdd;
470 bool Valid;
471 bool Dirty;
472 if ((((vaddr >> pte->AddrShiftAmount) & 1)) == 0) {
473 // Check even bits
474 Valid = pte->V0;
475 Dirty = pte->D0;
476 EvenOdd = 0;
477 } else {
478 // Check odd bits
479 Valid = pte->V1;
480 Dirty = pte->D1;
481 EvenOdd = 1;
482 }
483
484 if (Valid == false) {
485 //Invalid entry
486 DtbInvalidFault *Flt = new DtbInvalidFault();
487 /* EntryHi VPN, ASID fields must be set */
488 Flt->entryHiAsid = Asid;
489 Flt->entryHiVPN2 = (VPN>>2);
490 Flt->entryHiVPN2X = (VPN & 0x3);
491
492 /* BadVAddr must be set */
493 Flt->badVAddr = vaddr;
494
495 /* Context must be set */
496 Flt->contextBadVPN2 = (VPN >> 2);
497
498 return Flt;
499 } else {
500 // Ok, this is really a match, set paddr
501 if (!Dirty) {
502 TLBModifiedFault *Flt = new TLBModifiedFault();
503 /* EntryHi VPN, ASID fields must be set */
504 Flt->entryHiAsid = Asid;
505 Flt->entryHiVPN2 = (VPN >> 2);
506 Flt->entryHiVPN2X = (VPN & 0x3);
507
508 /* BadVAddr must be set */
509 Flt->badVAddr = vaddr;
510
511 /* Context must be set */
512 Flt->contextBadVPN2 = (VPN >> 2);
513 return Flt;
514 }
515 Addr PAddr;
516 if (EvenOdd == 0) {
517 PAddr = pte->PFN0;
518 } else {
519 PAddr = pte->PFN1;
520 }
521 PAddr >>= (pte->AddrShiftAmount - 12);
522 PAddr <<= pte->AddrShiftAmount;
523 PAddr |= (vaddr & pte->OffsetMask);
524 req->setPaddr(PAddr);
525 }
526 } else {
527 // Didn't find any match, return a TLB Refill Exception
528 DtbRefillFault *Flt = new DtbRefillFault();
529 /* EntryHi VPN, ASID fields must be set */
530 Flt->entryHiAsid = Asid;
531 Flt->entryHiVPN2 = (VPN >> 2);
532 Flt->entryHiVPN2X = (VPN & 0x3);
533
534 /* BadVAddr must be set */
535 Flt->badVAddr = vaddr;
536
537 /* Context must be set */
538 Flt->contextBadVPN2 = (VPN >> 2);
539 return Flt;
540 }
541 }
542 return checkCacheability(req);
543#endif
544}
545
546Fault
547TLB::translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode)
548{
549 if (mode == Execute)
550 return translateInst(req, tc);
551 else
552 return translateData(req, tc, mode == Write);
553}
554
555void
556TLB::translateTiming(RequestPtr req, ThreadContext *tc,
557 Translation *translation, Mode mode)
558{
559 assert(translation);
560 translation->finish(translateAtomic(req, tc, mode), req, tc, mode);
561}
562
563
564MipsISA::PTE &
565TLB::index(bool advance)
566{
567 PTE *pte = &table[nlu];
568
569 if (advance)
570 nextnlu();
571
572 return *pte;
573}
574
575MipsISA::TLB *
576MipsTLBParams::create()
577{
578 return new TLB(this);
579}