tlb.cc revision 5566:3440c9ad49b4
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; 46 47namespace AlphaISA { 48/////////////////////////////////////////////////////////////////////// 49// 50// Alpha TLB 51// 52#ifdef DEBUG 53bool uncacheBit39 = false; 54bool uncacheBit40 = false; 55#endif 56 57#define MODE2MASK(X) (1 << (X)) 58 59TLB::TLB(const Params *p) 60 : BaseTLB(p), size(p->size), nlu(0) 61{ 62 table = new TlbEntry[size]; 63 memset(table, 0, sizeof(TlbEntry[size])); 64 flushCache(); 65} 66 67TLB::~TLB() 68{ 69 if (table) 70 delete [] table; 71} 72 73// look up an entry in the TLB 74TlbEntry * 75TLB::lookup(Addr vpn, uint8_t asn) 76{ 77 // assume not found... 78 TlbEntry *retval = NULL; 79 80 if (EntryCache[0]) { 81 if (vpn == EntryCache[0]->tag && 82 (EntryCache[0]->asma || EntryCache[0]->asn == asn)) 83 retval = EntryCache[0]; 84 else if (EntryCache[1]) { 85 if (vpn == EntryCache[1]->tag && 86 (EntryCache[1]->asma || EntryCache[1]->asn == asn)) 87 retval = EntryCache[1]; 88 else if (EntryCache[2] && vpn == EntryCache[2]->tag && 89 (EntryCache[2]->asma || EntryCache[2]->asn == asn)) 90 retval = EntryCache[2]; 91 } 92 } 93 94 if (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 TlbEntry *entry = &table[index]; 100 assert(entry->valid); 101 if (vpn == entry->tag && (entry->asma || entry->asn == asn)) { 102 retval = updateCache(entry); 103 break; 104 } 105 106 ++i; 107 } 108 } 109 } 110 111 DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn, 112 retval ? "hit" : "miss", retval ? retval->ppn : 0); 113 return retval; 114} 115 116 117Fault 118TLB::checkCacheability(RequestPtr &req, bool itb) 119{ 120// in Alpha, cacheability is controlled by upper-level bits of the 121// physical address 122 123/* 124 * We support having the uncacheable bit in either bit 39 or bit 40. 125 * The Turbolaser platform (and EV5) support having the bit in 39, but 126 * Tsunami (which Linux assumes uses an EV6) generates accesses with 127 * the bit in 40. So we must check for both, but we have debug flags 128 * to catch a weird case where both are used, which shouldn't happen. 129 */ 130 131 132#if ALPHA_TLASER 133 if (req->getPaddr() & PAddrUncachedBit39) 134#else 135 if (req->getPaddr() & PAddrUncachedBit43) 136#endif 137 { 138 // IPR memory space not implemented 139 if (PAddrIprSpace(req->getPaddr())) { 140 return new UnimpFault("IPR memory space not implemented!"); 141 } else { 142 // mark request as uncacheable 143 req->setFlags(req->getFlags() | UNCACHEABLE); 144 145#if !ALPHA_TLASER 146 // Clear bits 42:35 of the physical address (10-2 in Tsunami manual) 147 req->setPaddr(req->getPaddr() & PAddrUncachedMask); 148#endif 149 } 150 // We shouldn't be able to read from an uncachable address in Alpha as 151 // we don't have a ROM and we don't want to try to fetch from a device 152 // register as we destroy any data that is clear-on-read. 153 if (req->isUncacheable() && itb) 154 return new UnimpFault("CPU trying to fetch from uncached I/O"); 155 156 } 157 return NoFault; 158} 159 160 161// insert a new TLB entry 162void 163TLB::insert(Addr addr, TlbEntry &entry) 164{ 165 flushCache(); 166 VAddr vaddr = addr; 167 if (table[nlu].valid) { 168 Addr oldvpn = table[nlu].tag; 169 PageTable::iterator i = lookupTable.find(oldvpn); 170 171 if (i == lookupTable.end()) 172 panic("TLB entry not found in lookupTable"); 173 174 int index; 175 while ((index = i->second) != nlu) { 176 if (table[index].tag != oldvpn) 177 panic("TLB entry not found in lookupTable"); 178 179 ++i; 180 } 181 182 DPRINTF(TLB, "remove @%d: %#x -> %#x\n", nlu, oldvpn, table[nlu].ppn); 183 184 lookupTable.erase(i); 185 } 186 187 DPRINTF(TLB, "insert @%d: %#x -> %#x\n", nlu, vaddr.vpn(), entry.ppn); 188 189 table[nlu] = entry; 190 table[nlu].tag = vaddr.vpn(); 191 table[nlu].valid = true; 192 193 lookupTable.insert(make_pair(vaddr.vpn(), nlu)); 194 nextnlu(); 195} 196 197void 198TLB::flushAll() 199{ 200 DPRINTF(TLB, "flushAll\n"); 201 memset(table, 0, sizeof(TlbEntry[size])); 202 flushCache(); 203 lookupTable.clear(); 204 nlu = 0; 205} 206 207void 208TLB::flushProcesses() 209{ 210 flushCache(); 211 PageTable::iterator i = lookupTable.begin(); 212 PageTable::iterator end = lookupTable.end(); 213 while (i != end) { 214 int index = i->second; 215 TlbEntry *entry = &table[index]; 216 assert(entry->valid); 217 218 // we can't increment i after we erase it, so save a copy and 219 // increment it to get the next entry now 220 PageTable::iterator cur = i; 221 ++i; 222 223 if (!entry->asma) { 224 DPRINTF(TLB, "flush @%d: %#x -> %#x\n", index, entry->tag, entry->ppn); 225 entry->valid = false; 226 lookupTable.erase(cur); 227 } 228 } 229} 230 231void 232TLB::flushAddr(Addr addr, uint8_t asn) 233{ 234 flushCache(); 235 VAddr vaddr = addr; 236 237 PageTable::iterator i = lookupTable.find(vaddr.vpn()); 238 if (i == lookupTable.end()) 239 return; 240 241 while (i != lookupTable.end() && i->first == vaddr.vpn()) { 242 int index = i->second; 243 TlbEntry *entry = &table[index]; 244 assert(entry->valid); 245 246 if (vaddr.vpn() == entry->tag && (entry->asma || entry->asn == asn)) { 247 DPRINTF(TLB, "flushaddr @%d: %#x -> %#x\n", index, vaddr.vpn(), 248 entry->ppn); 249 250 // invalidate this entry 251 entry->valid = false; 252 253 lookupTable.erase(i++); 254 } else { 255 ++i; 256 } 257 } 258} 259 260 261void 262TLB::serialize(ostream &os) 263{ 264 SERIALIZE_SCALAR(size); 265 SERIALIZE_SCALAR(nlu); 266 267 for (int i = 0; i < size; i++) { 268 nameOut(os, csprintf("%s.Entry%d", name(), i)); 269 table[i].serialize(os); 270 } 271} 272 273void 274TLB::unserialize(Checkpoint *cp, const string §ion) 275{ 276 UNSERIALIZE_SCALAR(size); 277 UNSERIALIZE_SCALAR(nlu); 278 279 for (int i = 0; i < size; i++) { 280 table[i].unserialize(cp, csprintf("%s.Entry%d", section, i)); 281 if (table[i].valid) { 282 lookupTable.insert(make_pair(table[i].tag, i)); 283 } 284 } 285} 286 287 288/////////////////////////////////////////////////////////////////////// 289// 290// Alpha ITB 291// 292ITB::ITB(const Params *p) 293 : TLB(p) 294{} 295 296 297void 298ITB::regStats() 299{ 300 hits 301 .name(name() + ".hits") 302 .desc("ITB hits"); 303 misses 304 .name(name() + ".misses") 305 .desc("ITB misses"); 306 acv 307 .name(name() + ".acv") 308 .desc("ITB acv"); 309 accesses 310 .name(name() + ".accesses") 311 .desc("ITB accesses"); 312 313 accesses = hits + misses; 314} 315 316 317Fault 318ITB::translate(RequestPtr &req, ThreadContext *tc) 319{ 320 //If this is a pal pc, then set PHYSICAL 321 if(FULL_SYSTEM && PcPAL(req->getPC())) 322 req->setFlags(req->getFlags() | PHYSICAL); 323 324 if (PcPAL(req->getPC())) { 325 // strip off PAL PC marker (lsb is 1) 326 req->setPaddr((req->getVaddr() & ~3) & PAddrImplMask); 327 hits++; 328 return NoFault; 329 } 330 331 if (req->getFlags() & PHYSICAL) { 332 req->setPaddr(req->getVaddr()); 333 } else { 334 // verify that this is a good virtual address 335 if (!validVirtualAddress(req->getVaddr())) { 336 acv++; 337 return new ItbAcvFault(req->getVaddr()); 338 } 339 340 341 // VA<42:41> == 2, VA<39:13> maps directly to PA<39:13> for EV5 342 // VA<47:41> == 0x7e, VA<40:13> maps directly to PA<40:13> for EV6 343#if ALPHA_TLASER 344 if ((MCSR_SP(tc->readMiscRegNoEffect(IPR_MCSR)) & 2) && 345 VAddrSpaceEV5(req->getVaddr()) == 2) 346#else 347 if (VAddrSpaceEV6(req->getVaddr()) == 0x7e) 348#endif 349 { 350 // only valid in kernel mode 351 if (ICM_CM(tc->readMiscRegNoEffect(IPR_ICM)) != 352 mode_kernel) { 353 acv++; 354 return new ItbAcvFault(req->getVaddr()); 355 } 356 357 req->setPaddr(req->getVaddr() & PAddrImplMask); 358 359#if !ALPHA_TLASER 360 // sign extend the physical address properly 361 if (req->getPaddr() & PAddrUncachedBit40) 362 req->setPaddr(req->getPaddr() | ULL(0xf0000000000)); 363 else 364 req->setPaddr(req->getPaddr() & ULL(0xffffffffff)); 365#endif 366 367 } else { 368 // not a physical address: need to look up pte 369 int asn = DTB_ASN_ASN(tc->readMiscRegNoEffect(IPR_DTB_ASN)); 370 TlbEntry *entry = lookup(VAddr(req->getVaddr()).vpn(), 371 asn); 372 373 if (!entry) { 374 misses++; 375 return new ItbPageFault(req->getVaddr()); 376 } 377 378 req->setPaddr((entry->ppn << PageShift) + 379 (VAddr(req->getVaddr()).offset() 380 & ~3)); 381 382 // check permissions for this access 383 if (!(entry->xre & 384 (1 << ICM_CM(tc->readMiscRegNoEffect(IPR_ICM))))) { 385 // instruction access fault 386 acv++; 387 return new ItbAcvFault(req->getVaddr()); 388 } 389 390 hits++; 391 } 392 } 393 394 // check that the physical address is ok (catch bad physical addresses) 395 if (req->getPaddr() & ~PAddrImplMask) 396 return genMachineCheckFault(); 397 398 return checkCacheability(req, true); 399 400} 401 402/////////////////////////////////////////////////////////////////////// 403// 404// Alpha DTB 405// 406 DTB::DTB(const Params *p) 407 : TLB(p) 408{} 409 410void 411DTB::regStats() 412{ 413 read_hits 414 .name(name() + ".read_hits") 415 .desc("DTB read hits") 416 ; 417 418 read_misses 419 .name(name() + ".read_misses") 420 .desc("DTB read misses") 421 ; 422 423 read_acv 424 .name(name() + ".read_acv") 425 .desc("DTB read access violations") 426 ; 427 428 read_accesses 429 .name(name() + ".read_accesses") 430 .desc("DTB read accesses") 431 ; 432 433 write_hits 434 .name(name() + ".write_hits") 435 .desc("DTB write hits") 436 ; 437 438 write_misses 439 .name(name() + ".write_misses") 440 .desc("DTB write misses") 441 ; 442 443 write_acv 444 .name(name() + ".write_acv") 445 .desc("DTB write access violations") 446 ; 447 448 write_accesses 449 .name(name() + ".write_accesses") 450 .desc("DTB write accesses") 451 ; 452 453 hits 454 .name(name() + ".hits") 455 .desc("DTB hits") 456 ; 457 458 misses 459 .name(name() + ".misses") 460 .desc("DTB misses") 461 ; 462 463 acv 464 .name(name() + ".acv") 465 .desc("DTB access violations") 466 ; 467 468 accesses 469 .name(name() + ".accesses") 470 .desc("DTB accesses") 471 ; 472 473 hits = read_hits + write_hits; 474 misses = read_misses + write_misses; 475 acv = read_acv + write_acv; 476 accesses = read_accesses + write_accesses; 477} 478 479Fault 480DTB::translate(RequestPtr &req, ThreadContext *tc, bool write) 481{ 482 Addr pc = tc->readPC(); 483 484 mode_type mode = 485 (mode_type)DTB_CM_CM(tc->readMiscRegNoEffect(IPR_DTB_CM)); 486 487 488 /** 489 * Check for alignment faults 490 */ 491 if (req->getVaddr() & (req->getSize() - 1)) { 492 DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->getVaddr(), 493 req->getSize()); 494 uint64_t flags = write ? MM_STAT_WR_MASK : 0; 495 return new DtbAlignmentFault(req->getVaddr(), req->getFlags(), flags); 496 } 497 498 if (PcPAL(pc)) { 499 mode = (req->getFlags() & ALTMODE) ? 500 (mode_type)ALT_MODE_AM( 501 tc->readMiscRegNoEffect(IPR_ALT_MODE)) 502 : mode_kernel; 503 } 504 505 if (req->getFlags() & PHYSICAL) { 506 req->setPaddr(req->getVaddr()); 507 } else { 508 // verify that this is a good virtual address 509 if (!validVirtualAddress(req->getVaddr())) { 510 if (write) { write_acv++; } else { read_acv++; } 511 uint64_t flags = (write ? MM_STAT_WR_MASK : 0) | 512 MM_STAT_BAD_VA_MASK | 513 MM_STAT_ACV_MASK; 514 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 515 } 516 517 // Check for "superpage" mapping 518#if ALPHA_TLASER 519 if ((MCSR_SP(tc->readMiscRegNoEffect(IPR_MCSR)) & 2) && 520 VAddrSpaceEV5(req->getVaddr()) == 2) 521#else 522 if (VAddrSpaceEV6(req->getVaddr()) == 0x7e) 523#endif 524 { 525 526 // only valid in kernel mode 527 if (DTB_CM_CM(tc->readMiscRegNoEffect(IPR_DTB_CM)) != 528 mode_kernel) { 529 if (write) { write_acv++; } else { read_acv++; } 530 uint64_t flags = ((write ? MM_STAT_WR_MASK : 0) | 531 MM_STAT_ACV_MASK); 532 return new DtbAcvFault(req->getVaddr(), req->getFlags(), flags); 533 } 534 535 req->setPaddr(req->getVaddr() & PAddrImplMask); 536 537#if !ALPHA_TLASER 538 // sign extend the physical address properly 539 if (req->getPaddr() & PAddrUncachedBit40) 540 req->setPaddr(req->getPaddr() | ULL(0xf0000000000)); 541 else 542 req->setPaddr(req->getPaddr() & ULL(0xffffffffff)); 543#endif 544 545 } else { 546 if (write) 547 write_accesses++; 548 else 549 read_accesses++; 550 551 int asn = DTB_ASN_ASN(tc->readMiscRegNoEffect(IPR_DTB_ASN)); 552 553 // not a physical address: need to look up pte 554 TlbEntry *entry = lookup(VAddr(req->getVaddr()).vpn(), asn); 555 556 if (!entry) { 557 // page fault 558 if (write) { write_misses++; } else { read_misses++; } 559 uint64_t flags = (write ? MM_STAT_WR_MASK : 0) | 560 MM_STAT_DTB_MISS_MASK; 561 return (req->getFlags() & VPTE) ? 562 (Fault)(new PDtbMissFault(req->getVaddr(), req->getFlags(), 563 flags)) : 564 (Fault)(new NDtbMissFault(req->getVaddr(), req->getFlags(), 565 flags)); 566 } 567 568 req->setPaddr((entry->ppn << PageShift) + 569 VAddr(req->getVaddr()).offset()); 570 571 if (write) { 572 if (!(entry->xwe & MODE2MASK(mode))) { 573 // declare the instruction access fault 574 write_acv++; 575 uint64_t flags = MM_STAT_WR_MASK | 576 MM_STAT_ACV_MASK | 577 (entry->fonw ? MM_STAT_FONW_MASK : 0); 578 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 579 } 580 if (entry->fonw) { 581 write_acv++; 582 uint64_t flags = MM_STAT_WR_MASK | 583 MM_STAT_FONW_MASK; 584 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 585 } 586 } else { 587 if (!(entry->xre & MODE2MASK(mode))) { 588 read_acv++; 589 uint64_t flags = MM_STAT_ACV_MASK | 590 (entry->fonr ? MM_STAT_FONR_MASK : 0); 591 return new DtbAcvFault(req->getVaddr(), req->getFlags(), flags); 592 } 593 if (entry->fonr) { 594 read_acv++; 595 uint64_t flags = MM_STAT_FONR_MASK; 596 return new DtbPageFault(req->getVaddr(), req->getFlags(), flags); 597 } 598 } 599 } 600 601 if (write) 602 write_hits++; 603 else 604 read_hits++; 605 } 606 607 // check that the physical address is ok (catch bad physical addresses) 608 if (req->getPaddr() & ~PAddrImplMask) 609 return genMachineCheckFault(); 610 611 return checkCacheability(req); 612} 613 614TlbEntry & 615TLB::index(bool advance) 616{ 617 TlbEntry *entry = &table[nlu]; 618 619 if (advance) 620 nextnlu(); 621 622 return *entry; 623} 624 625/* end namespace AlphaISA */ } 626 627AlphaISA::ITB * 628AlphaITBParams::create() 629{ 630 return new AlphaISA::ITB(this); 631} 632 633AlphaISA::DTB * 634AlphaDTBParams::create() 635{ 636 return new AlphaISA::DTB(this); 637} 638