tlb.cc revision 5543:3af77710f397
1/* 2 * Copyright (c) 2001-2005 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: Nathan Binkert 29 * Steve Reinhardt 30 * Andrew Schultz 31 */ 32 33#include <string> 34#include <vector> 35 36#include "arch/alpha/pagetable.hh" 37#include "arch/alpha/tlb.hh" 38#include "arch/alpha/faults.hh" 39#include "base/inifile.hh" 40#include "base/str.hh" 41#include "base/trace.hh" 42#include "config/alpha_tlaser.hh" 43#include "cpu/thread_context.hh" 44 45using namespace std; 46using namespace EV5; 47 48namespace AlphaISA { 49/////////////////////////////////////////////////////////////////////// 50// 51// Alpha TLB 52// 53#ifdef DEBUG 54bool uncacheBit39 = false; 55bool uncacheBit40 = false; 56#endif 57 58#define MODE2MASK(X) (1 << (X)) 59 60TLB::TLB(const Params *p) 61 : BaseTLB(p), size(p->size), nlu(0) 62{ 63 table = new TlbEntry[size]; 64 memset(table, 0, sizeof(TlbEntry[size])); 65 flushCache(); 66} 67 68TLB::~TLB() 69{ 70 if (table) 71 delete [] table; 72} 73 74// look up an entry in the TLB 75TlbEntry * 76TLB::lookup(Addr vpn, uint8_t asn) 77{ 78 // assume not found... 79 TlbEntry *retval = NULL; 80 81 if (EntryCache[0]) { 82 if (vpn == EntryCache[0]->tag && 83 (EntryCache[0]->asma || EntryCache[0]->asn == asn)) 84 retval = EntryCache[0]; 85 else if (EntryCache[1]) { 86 if (vpn == EntryCache[1]->tag && 87 (EntryCache[1]->asma || EntryCache[1]->asn == asn)) 88 retval = EntryCache[1]; 89 else if (EntryCache[2] && vpn == EntryCache[2]->tag && 90 (EntryCache[2]->asma || EntryCache[2]->asn == asn)) 91 retval = EntryCache[2]; 92 } 93 } 94 95 if (retval == NULL) { 96 PageTable::const_iterator i = lookupTable.find(vpn); 97 if (i != lookupTable.end()) { 98 while (i->first == vpn) { 99 int index = i->second; 100 TlbEntry *entry = &table[index]; 101 assert(entry->valid); 102 if (vpn == entry->tag && (entry->asma || entry->asn == asn)) { 103 retval = updateCache(entry); 104 break; 105 } 106 107 ++i; 108 } 109 } 110 } 111 112 DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn, 113 retval ? "hit" : "miss", retval ? retval->ppn : 0); 114 return retval; 115} 116 117 118Fault 119TLB::checkCacheability(RequestPtr &req, bool itb) 120{ 121// in Alpha, cacheability is controlled by upper-level bits of the 122// physical address 123 124/* 125 * We support having the uncacheable bit in either bit 39 or bit 40. 126 * The Turbolaser platform (and EV5) support having the bit in 39, but 127 * Tsunami (which Linux assumes uses an EV6) generates accesses with 128 * the bit in 40. So we must check for both, but we have debug flags 129 * to catch a weird case where both are used, which shouldn't happen. 130 */ 131 132 133#if ALPHA_TLASER 134 if (req->getPaddr() & PAddrUncachedBit39) 135#else 136 if (req->getPaddr() & PAddrUncachedBit43) 137#endif 138 { 139 // IPR memory space not implemented 140 if (PAddrIprSpace(req->getPaddr())) { 141 return new UnimpFault("IPR memory space not implemented!"); 142 } else { 143 // mark request as uncacheable 144 req->setFlags(req->getFlags() | UNCACHEABLE); 145 146#if !ALPHA_TLASER 147 // Clear bits 42:35 of the physical address (10-2 in Tsunami manual) 148 req->setPaddr(req->getPaddr() & PAddrUncachedMask); 149#endif 150 } 151 // We shouldn't be able to read from an uncachable address in Alpha as 152 // we don't have a ROM and we don't want to try to fetch from a device 153 // register as we destroy any data that is clear-on-read. 154 if (req->isUncacheable() && itb) 155 return new UnimpFault("CPU trying to fetch from uncached I/O"); 156 157 } 158 return NoFault; 159} 160 161 162// insert a new TLB entry 163void 164TLB::insert(Addr addr, TlbEntry &entry) 165{ 166 flushCache(); 167 VAddr vaddr = addr; 168 if (table[nlu].valid) { 169 Addr oldvpn = table[nlu].tag; 170 PageTable::iterator i = lookupTable.find(oldvpn); 171 172 if (i == lookupTable.end()) 173 panic("TLB entry not found in lookupTable"); 174 175 int index; 176 while ((index = i->second) != nlu) { 177 if (table[index].tag != oldvpn) 178 panic("TLB entry not found in lookupTable"); 179 180 ++i; 181 } 182 183 DPRINTF(TLB, "remove @%d: %#x -> %#x\n", nlu, oldvpn, table[nlu].ppn); 184 185 lookupTable.erase(i); 186 } 187 188 DPRINTF(TLB, "insert @%d: %#x -> %#x\n", nlu, vaddr.vpn(), entry.ppn); 189 190 table[nlu] = entry; 191 table[nlu].tag = vaddr.vpn(); 192 table[nlu].valid = true; 193 194 lookupTable.insert(make_pair(vaddr.vpn(), nlu)); 195 nextnlu(); 196} 197 198void 199TLB::flushAll() 200{ 201 DPRINTF(TLB, "flushAll\n"); 202 memset(table, 0, sizeof(TlbEntry[size])); 203 flushCache(); 204 lookupTable.clear(); 205 nlu = 0; 206} 207 208void 209TLB::flushProcesses() 210{ 211 flushCache(); 212 PageTable::iterator i = lookupTable.begin(); 213 PageTable::iterator end = lookupTable.end(); 214 while (i != end) { 215 int index = i->second; 216 TlbEntry *entry = &table[index]; 217 assert(entry->valid); 218 219 // we can't increment i after we erase it, so save a copy and 220 // increment it to get the next entry now 221 PageTable::iterator cur = i; 222 ++i; 223 224 if (!entry->asma) { 225 DPRINTF(TLB, "flush @%d: %#x -> %#x\n", index, entry->tag, entry->ppn); 226 entry->valid = false; 227 lookupTable.erase(cur); 228 } 229 } 230} 231 232void 233TLB::flushAddr(Addr addr, uint8_t asn) 234{ 235 flushCache(); 236 VAddr vaddr = addr; 237 238 PageTable::iterator i = lookupTable.find(vaddr.vpn()); 239 if (i == lookupTable.end()) 240 return; 241 242 while (i != lookupTable.end() && i->first == vaddr.vpn()) { 243 int index = i->second; 244 TlbEntry *entry = &table[index]; 245 assert(entry->valid); 246 247 if (vaddr.vpn() == entry->tag && (entry->asma || entry->asn == asn)) { 248 DPRINTF(TLB, "flushaddr @%d: %#x -> %#x\n", index, vaddr.vpn(), 249 entry->ppn); 250 251 // invalidate this entry 252 entry->valid = false; 253 254 lookupTable.erase(i++); 255 } else { 256 ++i; 257 } 258 } 259} 260 261 262void 263TLB::serialize(ostream &os) 264{ 265 SERIALIZE_SCALAR(size); 266 SERIALIZE_SCALAR(nlu); 267 268 for (int i = 0; i < size; i++) { 269 nameOut(os, csprintf("%s.Entry%d", name(), i)); 270 table[i].serialize(os); 271 } 272} 273 274void 275TLB::unserialize(Checkpoint *cp, const string §ion) 276{ 277 UNSERIALIZE_SCALAR(size); 278 UNSERIALIZE_SCALAR(nlu); 279 280 for (int i = 0; i < size; i++) { 281 table[i].unserialize(cp, csprintf("%s.Entry%d", section, i)); 282 if (table[i].valid) { 283 lookupTable.insert(make_pair(table[i].tag, i)); 284 } 285 } 286} 287 288 289/////////////////////////////////////////////////////////////////////// 290// 291// Alpha ITB 292// 293ITB::ITB(const Params *p) 294 : TLB(p) 295{} 296 297 298void 299ITB::regStats() 300{ 301 hits 302 .name(name() + ".hits") 303 .desc("ITB hits"); 304 misses 305 .name(name() + ".misses") 306 .desc("ITB misses"); 307 acv 308 .name(name() + ".acv") 309 .desc("ITB acv"); 310 accesses 311 .name(name() + ".accesses") 312 .desc("ITB accesses"); 313 314 accesses = hits + misses; 315} 316 317 318Fault 319ITB::translate(RequestPtr &req, ThreadContext *tc) 320{ 321 //If this is a pal pc, then set PHYSICAL 322 if(FULL_SYSTEM && PcPAL(req->getPC())) 323 req->setFlags(req->getFlags() | PHYSICAL); 324 325 if (PcPAL(req->getPC())) { 326 // strip off PAL PC marker (lsb is 1) 327 req->setPaddr((req->getVaddr() & ~3) & PAddrImplMask); 328 hits++; 329 return NoFault; 330 } 331 332 if (req->getFlags() & PHYSICAL) { 333 req->setPaddr(req->getVaddr()); 334 } else { 335 // verify that this is a good virtual address 336 if (!validVirtualAddress(req->getVaddr())) { 337 acv++; 338 return new ItbAcvFault(req->getVaddr()); 339 } 340 341 342 // VA<42:41> == 2, VA<39:13> maps directly to PA<39:13> for EV5 343 // VA<47:41> == 0x7e, VA<40:13> maps directly to PA<40:13> for EV6 344#if ALPHA_TLASER 345 if ((MCSR_SP(tc->readMiscRegNoEffect(IPR_MCSR)) & 2) && 346 VAddrSpaceEV5(req->getVaddr()) == 2) 347#else 348 if (VAddrSpaceEV6(req->getVaddr()) == 0x7e) 349#endif 350 { 351 // only valid in kernel mode 352 if (ICM_CM(tc->readMiscRegNoEffect(IPR_ICM)) != 353 mode_kernel) { 354 acv++; 355 return new ItbAcvFault(req->getVaddr()); 356 } 357 358 req->setPaddr(req->getVaddr() & PAddrImplMask); 359 360#if !ALPHA_TLASER 361 // sign extend the physical address properly 362 if (req->getPaddr() & PAddrUncachedBit40) 363 req->setPaddr(req->getPaddr() | ULL(0xf0000000000)); 364 else 365 req->setPaddr(req->getPaddr() & ULL(0xffffffffff)); 366#endif 367 368 } else { 369 // not a physical address: need to look up pte 370 int asn = DTB_ASN_ASN(tc->readMiscRegNoEffect(IPR_DTB_ASN)); 371 TlbEntry *entry = lookup(VAddr(req->getVaddr()).vpn(), 372 asn); 373 374 if (!entry) { 375 misses++; 376 return new ItbPageFault(req->getVaddr()); 377 } 378 379 req->setPaddr((entry->ppn << PageShift) + 380 (VAddr(req->getVaddr()).offset() 381 & ~3)); 382 383 // check permissions for this access 384 if (!(entry->xre & 385 (1 << ICM_CM(tc->readMiscRegNoEffect(IPR_ICM))))) { 386 // instruction access fault 387 acv++; 388 return new ItbAcvFault(req->getVaddr()); 389 } 390 391 hits++; 392 } 393 } 394 395 // check that the physical address is ok (catch bad physical addresses) 396 if (req->getPaddr() & ~PAddrImplMask) 397 return genMachineCheckFault(); 398 399 return checkCacheability(req, true); 400 401} 402 403/////////////////////////////////////////////////////////////////////// 404// 405// Alpha DTB 406// 407 DTB::DTB(const Params *p) 408 : TLB(p) 409{} 410 411void 412DTB::regStats() 413{ 414 read_hits 415 .name(name() + ".read_hits") 416 .desc("DTB read hits") 417 ; 418 419 read_misses 420 .name(name() + ".read_misses") 421 .desc("DTB read misses") 422 ; 423 424 read_acv 425 .name(name() + ".read_acv") 426 .desc("DTB read access violations") 427 ; 428 429 read_accesses 430 .name(name() + ".read_accesses") 431 .desc("DTB read accesses") 432 ; 433 434 write_hits 435 .name(name() + ".write_hits") 436 .desc("DTB write hits") 437 ; 438 439 write_misses 440 .name(name() + ".write_misses") 441 .desc("DTB write misses") 442 ; 443 444 write_acv 445 .name(name() + ".write_acv") 446 .desc("DTB write access violations") 447 ; 448 449 write_accesses 450 .name(name() + ".write_accesses") 451 .desc("DTB write accesses") 452 ; 453 454 hits 455 .name(name() + ".hits") 456 .desc("DTB hits") 457 ; 458 459 misses 460 .name(name() + ".misses") 461 .desc("DTB misses") 462 ; 463 464 acv 465 .name(name() + ".acv") 466 .desc("DTB access violations") 467 ; 468 469 accesses 470 .name(name() + ".accesses") 471 .desc("DTB accesses") 472 ; 473 474 hits = read_hits + write_hits; 475 misses = read_misses + write_misses; 476 acv = read_acv + write_acv; 477 accesses = read_accesses + write_accesses; 478} 479 480Fault 481DTB::translate(RequestPtr &req, ThreadContext *tc, bool write) 482{ 483 Addr pc = tc->readPC(); 484 485 mode_type mode = 486 (mode_type)DTB_CM_CM(tc->readMiscRegNoEffect(IPR_DTB_CM)); 487 488 489 /** 490 * Check for alignment faults 491 */ 492 if (req->getVaddr() & (req->getSize() - 1)) { 493 DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->getVaddr(), 494 req->getSize()); 495 uint64_t flags = write ? MM_STAT_WR_MASK : 0; 496 return new DtbAlignmentFault(req->getVaddr(), req->getFlags(), flags); 497 } 498 499 if (PcPAL(pc)) { 500 mode = (req->getFlags() & ALTMODE) ? 501 (mode_type)ALT_MODE_AM( 502 tc->readMiscRegNoEffect(IPR_ALT_MODE)) 503 : mode_kernel; 504 } 505 506 if (req->getFlags() & PHYSICAL) { 507 req->setPaddr(req->getVaddr()); 508 } else { 509 // verify that this is a good virtual address 510 if (!validVirtualAddress(req->getVaddr())) { 511 if (write) { write_acv++; } else { read_acv++; } 512 uint64_t flags = (write ? MM_STAT_WR_MASK : 0) | 513 MM_STAT_BAD_VA_MASK | 514 MM_STAT_ACV_MASK; 515 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 516 } 517 518 // Check for "superpage" mapping 519#if ALPHA_TLASER 520 if ((MCSR_SP(tc->readMiscRegNoEffect(IPR_MCSR)) & 2) && 521 VAddrSpaceEV5(req->getVaddr()) == 2) 522#else 523 if (VAddrSpaceEV6(req->getVaddr()) == 0x7e) 524#endif 525 { 526 527 // only valid in kernel mode 528 if (DTB_CM_CM(tc->readMiscRegNoEffect(IPR_DTB_CM)) != 529 mode_kernel) { 530 if (write) { write_acv++; } else { read_acv++; } 531 uint64_t flags = ((write ? MM_STAT_WR_MASK : 0) | 532 MM_STAT_ACV_MASK); 533 return new DtbAcvFault(req->getVaddr(), req->getFlags(), flags); 534 } 535 536 req->setPaddr(req->getVaddr() & PAddrImplMask); 537 538#if !ALPHA_TLASER 539 // sign extend the physical address properly 540 if (req->getPaddr() & PAddrUncachedBit40) 541 req->setPaddr(req->getPaddr() | ULL(0xf0000000000)); 542 else 543 req->setPaddr(req->getPaddr() & ULL(0xffffffffff)); 544#endif 545 546 } else { 547 if (write) 548 write_accesses++; 549 else 550 read_accesses++; 551 552 int asn = DTB_ASN_ASN(tc->readMiscRegNoEffect(IPR_DTB_ASN)); 553 554 // not a physical address: need to look up pte 555 TlbEntry *entry = lookup(VAddr(req->getVaddr()).vpn(), asn); 556 557 if (!entry) { 558 // page fault 559 if (write) { write_misses++; } else { read_misses++; } 560 uint64_t flags = (write ? MM_STAT_WR_MASK : 0) | 561 MM_STAT_DTB_MISS_MASK; 562 return (req->getFlags() & VPTE) ? 563 (Fault)(new PDtbMissFault(req->getVaddr(), req->getFlags(), 564 flags)) : 565 (Fault)(new NDtbMissFault(req->getVaddr(), req->getFlags(), 566 flags)); 567 } 568 569 req->setPaddr((entry->ppn << PageShift) + 570 VAddr(req->getVaddr()).offset()); 571 572 if (write) { 573 if (!(entry->xwe & MODE2MASK(mode))) { 574 // declare the instruction access fault 575 write_acv++; 576 uint64_t flags = MM_STAT_WR_MASK | 577 MM_STAT_ACV_MASK | 578 (entry->fonw ? MM_STAT_FONW_MASK : 0); 579 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 580 } 581 if (entry->fonw) { 582 write_acv++; 583 uint64_t flags = MM_STAT_WR_MASK | 584 MM_STAT_FONW_MASK; 585 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 586 } 587 } else { 588 if (!(entry->xre & MODE2MASK(mode))) { 589 read_acv++; 590 uint64_t flags = MM_STAT_ACV_MASK | 591 (entry->fonr ? MM_STAT_FONR_MASK : 0); 592 return new DtbAcvFault(req->getVaddr(), req->getFlags(), flags); 593 } 594 if (entry->fonr) { 595 read_acv++; 596 uint64_t flags = MM_STAT_FONR_MASK; 597 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 598 } 599 } 600 } 601 602 if (write) 603 write_hits++; 604 else 605 read_hits++; 606 } 607 608 // check that the physical address is ok (catch bad physical addresses) 609 if (req->getPaddr() & ~PAddrImplMask) 610 return genMachineCheckFault(); 611 612 return checkCacheability(req); 613} 614 615TlbEntry & 616TLB::index(bool advance) 617{ 618 TlbEntry *entry = &table[nlu]; 619 620 if (advance) 621 nextnlu(); 622 623 return *entry; 624} 625 626/* end namespace AlphaISA */ } 627 628AlphaISA::ITB * 629AlphaITBParams::create() 630{ 631 return new AlphaISA::ITB(this); 632} 633 634AlphaISA::DTB * 635AlphaDTBParams::create() 636{ 637 return new AlphaISA::DTB(this); 638} 639