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"
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48#include "mem/page_table.hh"
49#include "params/MipsTLB.hh"
50#include "sim/process.hh"
51
52using namespace std;
53using namespace MipsISA;
54
55///////////////////////////////////////////////////////////////////////
56//
57// MIPS TLB
58//
59
60static inline mode_type
61getOperatingMode(MiscReg Stat)
62{
63 if ((Stat & 0x10000006) != 0 || (Stat & 0x18) ==0) {
64 return mode_kernel;
65 } else if ((Stat & 0x18) == 0x8) {
66 return mode_supervisor;
67 } else if ((Stat & 0x18) == 0x10) {
68 return mode_user;
69 } else {
70 return mode_number;
71 }
72}
73
74
75TLB::TLB(const Params *p)
76 : BaseTLB(p), size(p->size), nlu(0)
77{
78 table = new PTE[size];
79 memset(table, 0, sizeof(PTE[size]));
80 smallPages = 0;
81}
82
83TLB::~TLB()
84{
85 if (table)
86 delete [] table;
87}
88
89// look up an entry in the TLB
90MipsISA::PTE *
91TLB::lookup(Addr vpn, uint8_t asn) const
92{
93 // assume not found...
94 PTE *retval = NULL;
95 PageTable::const_iterator i = lookupTable.find(vpn);
96 if (i != lookupTable.end()) {
97 while (i->first == vpn) {
98 int index = i->second;
99 PTE *pte = &table[index];
100
101 /* 1KB TLB Lookup code - from MIPS ARM Volume III - Rev. 2.50 */
102 Addr Mask = pte->Mask;
103 Addr InvMask = ~Mask;
104 Addr VPN = pte->VPN;
105 if (((vpn & InvMask) == (VPN & InvMask)) &&
106 (pte->G || (asn == pte->asid))) {
107 // We have a VPN + ASID Match
108 retval = pte;
109 break;
110 }
111 ++i;
112 }
113 }
114
115 DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn,
116 retval ? "hit" : "miss", retval ? retval->PFN1 : 0);
117 return retval;
118}
119
120MipsISA::PTE*
121TLB::getEntry(unsigned Index) const
122{
123 // Make sure that Index is valid
124 assert(Index<size);
125 return &table[Index];
126}
127
128int
129TLB::probeEntry(Addr vpn, uint8_t asn) const
130{
131 // assume not found...
132 PTE *retval = NULL;
133 int Ind = -1;
134 PageTable::const_iterator i = lookupTable.find(vpn);
135 if (i != lookupTable.end()) {
136 while (i->first == vpn) {
137 int index = i->second;
138 PTE *pte = &table[index];
139
140 /* 1KB TLB Lookup code - from MIPS ARM Volume III - Rev. 2.50 */
141 Addr Mask = pte->Mask;
142 Addr InvMask = ~Mask;
143 Addr VPN = pte->VPN;
144 if (((vpn & InvMask) == (VPN & InvMask)) &&
145 (pte->G || (asn == pte->asid))) {
146 // We have a VPN + ASID Match
147 retval = pte;
148 Ind = index;
149 break;
150 }
151 ++i;
152 }
153 }
154 DPRINTF(MipsPRA,"VPN: %x, asid: %d, Result of TLBP: %d\n",vpn,asn,Ind);
155 return Ind;
156}
157
158inline Fault
159TLB::checkCacheability(RequestPtr &req)
160{
161 Addr VAddrUncacheable = 0xA0000000;
162 // In MIPS, cacheability is controlled by certain bits of the virtual
163 // address or by the TLB entry
164 if ((req->getVaddr() & VAddrUncacheable) == VAddrUncacheable) {
165 // mark request as uncacheable
166 req->setFlags(Request::UNCACHEABLE);
167 }
168 return NoFault;
169}
170
171void
172TLB::insertAt(PTE &pte, unsigned Index, int _smallPages)
173{
174 smallPages = _smallPages;
175 if (Index > size) {
176 warn("Attempted to write at index (%d) beyond TLB size (%d)",
177 Index, size);
178 } else {
179 // Update TLB
180 DPRINTF(TLB, "TLB[%d]: %x %x %x %x\n",
181 Index, pte.Mask << 11,
182 ((pte.VPN << 11) | pte.asid),
183 ((pte.PFN0 << 6) | (pte.C0 << 3) |
184 (pte.D0 << 2) | (pte.V0 <<1) | pte.G),
185 ((pte.PFN1 <<6) | (pte.C1 << 3) |
186 (pte.D1 << 2) | (pte.V1 <<1) | pte.G));
187 if (table[Index].V0 == true || table[Index].V1 == true) {
188 // Previous entry is valid
189 PageTable::iterator i = lookupTable.find(table[Index].VPN);
190 lookupTable.erase(i);
191 }
192 table[Index]=pte;
193 // Update fast lookup table
194 lookupTable.insert(make_pair(table[Index].VPN, Index));
195 }
196}
197
198// insert a new TLB entry
199void
200TLB::insert(Addr addr, PTE &pte)
201{
202 fatal("TLB Insert not yet implemented\n");
203}
204
205void
206TLB::flushAll()
207{
208 DPRINTF(TLB, "flushAll\n");
209 memset(table, 0, sizeof(PTE[size]));
210 lookupTable.clear();
211 nlu = 0;
212}
213
214void
215TLB::serialize(ostream &os)
216{
217 SERIALIZE_SCALAR(size);
218 SERIALIZE_SCALAR(nlu);
219
220 for (int i = 0; i < size; i++) {
221 nameOut(os, csprintf("%s.PTE%d", name(), i));
222 table[i].serialize(os);
223 }
224}
225
226void
227TLB::unserialize(Checkpoint *cp, const string §ion)
228{
229 UNSERIALIZE_SCALAR(size);
230 UNSERIALIZE_SCALAR(nlu);
231
232 for (int i = 0; i < size; i++) {
233 table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
234 if (table[i].V0 || table[i].V1) {
235 lookupTable.insert(make_pair(table[i].VPN, i));
236 }
237 }
238}
239
240void
241TLB::regStats()
242{
243 read_hits
244 .name(name() + ".read_hits")
245 .desc("DTB read hits")
246 ;
247
248 read_misses
249 .name(name() + ".read_misses")
250 .desc("DTB read misses")
251 ;
252
253
254 read_accesses
255 .name(name() + ".read_accesses")
256 .desc("DTB read accesses")
257 ;
258
259 write_hits
260 .name(name() + ".write_hits")
261 .desc("DTB write hits")
262 ;
263
264 write_misses
265 .name(name() + ".write_misses")
266 .desc("DTB write misses")
267 ;
268
269
270 write_accesses
271 .name(name() + ".write_accesses")
272 .desc("DTB write accesses")
273 ;
274
275 hits
276 .name(name() + ".hits")
277 .desc("DTB hits")
278 ;
279
280 misses
281 .name(name() + ".misses")
282 .desc("DTB misses")
283 ;
284
285 accesses
286 .name(name() + ".accesses")
287 .desc("DTB accesses")
288 ;
289
290 hits = read_hits + write_hits;
291 misses = read_misses + write_misses;
292 accesses = read_accesses + write_accesses;
293}
294
295Fault
296TLB::translateInst(RequestPtr req, ThreadContext *tc)
297{
298#if !FULL_SYSTEM
299 Process * p = tc->getProcessPtr();
300
301 Fault fault = p->pTable->translate(req);
302 if (fault != NoFault)
303 return fault;
304
305 return NoFault;
306#else
307 Addr vaddr = req->getVaddr();
308
309 bool misaligned = (req->getSize() - 1) & vaddr;
310
311 if (IsKSeg0(vaddr)) {
312 // Address will not be translated through TLB, set response, and go!
313 req->setPaddr(KSeg02Phys(vaddr));
314 if (getOperatingMode(tc->readMiscReg(MISCREG_STATUS)) != mode_kernel ||
315 misaligned) {
316 AddressErrorFault *Flt = new AddressErrorFault();
317 /* BadVAddr must be set */
318 Flt->badVAddr = vaddr;
319 return Flt;
320 }
321 } else if(IsKSeg1(vaddr)) {
322 // Address will not be translated through TLB, set response, and go!
323 req->setPaddr(KSeg02Phys(vaddr));
324 } else {
325 /*
326 * This is an optimization - smallPages is updated every time a TLB
327 * operation is performed. That way, we don't need to look at
328 * Config3 _ SP and PageGrain _ ESP every time we do a TLB lookup
329 */
330 Addr VPN;
331 if (smallPages == 1) {
332 VPN = (vaddr >> 11);
333 } else {
334 VPN = ((vaddr >> 11) & 0xFFFFFFFC);
335 }
336 uint8_t Asid = req->getAsid();
337 if (misaligned) {
338 // Unaligned address!
339 AddressErrorFault *Flt = new AddressErrorFault();
340 /* BadVAddr must be set */
341 Flt->badVAddr = vaddr;
342 return Flt;
343 }
344 PTE *pte = lookup(VPN,Asid);
345 if (pte != NULL) {
346 // Ok, found something
347 /* Check for valid bits */
348 int EvenOdd;
349 bool Valid;
350 if ((((vaddr) >> pte->AddrShiftAmount) & 1) == 0) {
351 // Check even bits
352 Valid = pte->V0;
353 EvenOdd = 0;
354 } else {
355 // Check odd bits
356 Valid = pte->V1;
357 EvenOdd = 1;
358 }
359
360 if (Valid == false) {
361 //Invalid entry
362 ItbInvalidFault *Flt = new ItbInvalidFault();
363 /* EntryHi VPN, ASID fields must be set */
364 Flt->entryHiAsid = Asid;
365 Flt->entryHiVPN2 = (VPN >> 2);
366 Flt->entryHiVPN2X = (VPN & 0x3);
367
368 /* BadVAddr must be set */
369 Flt->badVAddr = vaddr;
370
371 /* Context must be set */
372 Flt->contextBadVPN2 = (VPN >> 2);
373 return Flt;
374 } else {
375 // Ok, this is really a match, set paddr
376 Addr PAddr;
377 if (EvenOdd == 0) {
378 PAddr = pte->PFN0;
379 } else {
380 PAddr = pte->PFN1;
381 }
382 PAddr >>= (pte->AddrShiftAmount - 12);
383 PAddr <<= pte->AddrShiftAmount;
384 PAddr |= (vaddr & pte->OffsetMask);
385 req->setPaddr(PAddr);
386 }
387 } else {
388 // Didn't find any match, return a TLB Refill Exception
389 ItbRefillFault *Flt = new ItbRefillFault();
390 /* EntryHi VPN, ASID fields must be set */
391 Flt->entryHiAsid = Asid;
392 Flt->entryHiVPN2 = (VPN >> 2);
393 Flt->entryHiVPN2X = (VPN & 0x3);
394
395 /* BadVAddr must be set */
396 Flt->badVAddr = vaddr;
397
398 /* Context must be set */
399 Flt->contextBadVPN2 = (VPN >> 2);
400 return Flt;
401 }
402 }
403 return checkCacheability(req);
404#endif
405}
406
407Fault
408TLB::translateData(RequestPtr req, ThreadContext *tc, bool write)
409{
410#if !FULL_SYSTEM
411 //@TODO: This should actually use TLB instead of going directly
412 // to the page table in syscall mode.
413 /**
414 * Check for alignment faults
415 */
416 if (req->getVaddr() & (req->getSize() - 1)) {
417 DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->getVaddr(),
418 req->getSize());
419 return new AlignmentFault();
420 }
421
422
423 Process * p = tc->getProcessPtr();
424
425 Fault fault = p->pTable->translate(req);
426 if (fault != NoFault)
427 return fault;
428
429 return NoFault;
430#else
431 Addr vaddr = req->getVaddr();
432
433 bool misaligned = (req->getSize() - 1) & vaddr;
434
435 if (IsKSeg0(vaddr)) {
436 // Address will not be translated through TLB, set response, and go!
437 req->setPaddr(KSeg02Phys(vaddr));
438 if (getOperatingMode(tc->readMiscReg(MISCREG_STATUS)) != mode_kernel ||
439 misaligned) {
440 StoreAddressErrorFault *Flt = new StoreAddressErrorFault();
441 /* BadVAddr must be set */
442 Flt->badVAddr = vaddr;
443
444 return Flt;
445 }
446 } else if(IsKSeg1(vaddr)) {
447 // Address will not be translated through TLB, set response, and go!
448 req->setPaddr(KSeg02Phys(vaddr));
449 } else {
450 /*
451 * This is an optimization - smallPages is updated every time a TLB
452 * operation is performed. That way, we don't need to look at
453 * Config3 _ SP and PageGrain _ ESP every time we do a TLB lookup
454 */
455 Addr VPN = (vaddr >> 11) & 0xFFFFFFFC;
456 if (smallPages == 1) {
457 VPN = vaddr >> 11;
458 }
459 uint8_t Asid = req->getAsid();
460 PTE *pte = lookup(VPN, Asid);
461 if (misaligned) {
462 // Unaligned address!
463 StoreAddressErrorFault *Flt = new StoreAddressErrorFault();
464 /* BadVAddr must be set */
465 Flt->badVAddr = vaddr;
466 return Flt;
467 }
468 if (pte != NULL) {
469 // Ok, found something
470 /* Check for valid bits */
471 int EvenOdd;
472 bool Valid;
473 bool Dirty;
474 if ((((vaddr >> pte->AddrShiftAmount) & 1)) == 0) {
475 // Check even bits
476 Valid = pte->V0;
477 Dirty = pte->D0;
478 EvenOdd = 0;
479 } else {
480 // Check odd bits
481 Valid = pte->V1;
482 Dirty = pte->D1;
483 EvenOdd = 1;
484 }
485
486 if (Valid == false) {
487 //Invalid entry
488 DtbInvalidFault *Flt = new DtbInvalidFault();
489 /* EntryHi VPN, ASID fields must be set */
490 Flt->entryHiAsid = Asid;
491 Flt->entryHiVPN2 = (VPN>>2);
492 Flt->entryHiVPN2X = (VPN & 0x3);
493
494 /* BadVAddr must be set */
495 Flt->badVAddr = vaddr;
496
497 /* Context must be set */
498 Flt->contextBadVPN2 = (VPN >> 2);
499
500 return Flt;
501 } else {
502 // Ok, this is really a match, set paddr
503 if (!Dirty) {
504 TLBModifiedFault *Flt = new TLBModifiedFault();
505 /* EntryHi VPN, ASID fields must be set */
506 Flt->entryHiAsid = Asid;
507 Flt->entryHiVPN2 = (VPN >> 2);
508 Flt->entryHiVPN2X = (VPN & 0x3);
509
510 /* BadVAddr must be set */
511 Flt->badVAddr = vaddr;
512
513 /* Context must be set */
514 Flt->contextBadVPN2 = (VPN >> 2);
515 return Flt;
516 }
517 Addr PAddr;
518 if (EvenOdd == 0) {
519 PAddr = pte->PFN0;
520 } else {
521 PAddr = pte->PFN1;
522 }
523 PAddr >>= (pte->AddrShiftAmount - 12);
524 PAddr <<= pte->AddrShiftAmount;
525 PAddr |= (vaddr & pte->OffsetMask);
526 req->setPaddr(PAddr);
527 }
528 } else {
529 // Didn't find any match, return a TLB Refill Exception
530 DtbRefillFault *Flt = new DtbRefillFault();
531 /* EntryHi VPN, ASID fields must be set */
532 Flt->entryHiAsid = Asid;
533 Flt->entryHiVPN2 = (VPN >> 2);
534 Flt->entryHiVPN2X = (VPN & 0x3);
535
536 /* BadVAddr must be set */
537 Flt->badVAddr = vaddr;
538
539 /* Context must be set */
540 Flt->contextBadVPN2 = (VPN >> 2);
541 return Flt;
542 }
543 }
544 return checkCacheability(req);
545#endif
546}
547
548Fault
549TLB::translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode)
550{
551 if (mode == Execute)
552 return translateInst(req, tc);
553 else
554 return translateData(req, tc, mode == Write);
555}
556
557void
558TLB::translateTiming(RequestPtr req, ThreadContext *tc,
559 Translation *translation, Mode mode)
560{
561 assert(translation);
562 translation->finish(translateAtomic(req, tc, mode), req, tc, mode);
563}
564
565
566MipsISA::PTE &
567TLB::index(bool advance)
568{
569 PTE *pte = &table[nlu];
570
571 if (advance)
572 nextnlu();
573
574 return *pte;
575}
576
577MipsISA::TLB *
578MipsTLBParams::create()
579{
580 return new TLB(this);
581}
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