arch/alpha/tlb.cc

   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
  29 #include <sstream>
  30 #include <string>
  31 #include <vector>
  32
  33 #include "arch/alpha/tlb.hh"
  34 #include "base/inifile.hh"
  35 #include "base/str.hh"
  36 #include "base/trace.hh"
  37 #include "config/alpha_tlaser.hh"
  38 #include "cpu/exec_context.hh"
  39 #include "sim/builder.hh"
  40
  41 using namespace std;
  42 using namespace EV5;
  43
  44 ///////////////////////////////////////////////////////////////////////
  45 //
  46 //  Alpha TLB
  47 //
  48 #ifdef DEBUG
  49 bool uncacheBit39 = false;
  50 bool uncacheBit40 = false;
  51 #endif
  52
  53 #define MODE2MASK(X)                    (1 << (X))
  54
  55 AlphaTLB::AlphaTLB(const string &name, int s)
  56     : SimObject(name), size(s), nlu(0)
  57 {
  58     table = new AlphaISA::PTE[size];
  59     memset(table, 0, sizeof(AlphaISA::PTE[size]));
  60 }
  61
  62 AlphaTLB::~AlphaTLB()
  63 {
  64     if (table)
  65         delete [] table;
  66 }
  67
  68 // look up an entry in the TLB
  69 AlphaISA::PTE *
  70 AlphaTLB::lookup(Addr vpn, uint8_t asn) const
  71 {
  72     // assume not found...
  73     AlphaISA::PTE *retval = NULL;
  74
  75     PageTable::const_iterator i = lookupTable.find(vpn);
  76     if (i != lookupTable.end()) {
  77         while (i->first == vpn) {
  78             int index = i->second;
  79             AlphaISA::PTE *pte = &table[index];
  80             assert(pte->valid);
  81             if (vpn == pte->tag && (pte->asma || pte->asn == asn)) {
  82                 retval = pte;
  83                 break;
  84             }
  85
  86             ++i;
  87         }
  88     }
  89
  90     DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn,
  91             retval ? "hit" : "miss", retval ? retval->ppn : 0);
  92     return retval;
  93 }
  94
  95
  96 void
  97 AlphaTLB::checkCacheability(MemReqPtr &req)
  98 {
  99     // in Alpha, cacheability is controlled by upper-level bits of the
 100     // physical address
 101
 102     /*
 103      * We support having the uncacheable bit in either bit 39 or bit 40.
 104      * The Turbolaser platform (and EV5) support having the bit in 39, but
 105      * Tsunami (which Linux assumes uses an EV6) generates accesses with
 106      * the bit in 40.  So we must check for both, but we have debug flags
 107      * to catch a weird case where both are used, which shouldn't happen.
 108      */
 109
 110
 111 #if ALPHA_TLASER
 112     if (req->paddr & PAddrUncachedBit39) {
 113 #else
 114     if (req->paddr & PAddrUncachedBit43) {
 115 #endif
 116         // IPR memory space not implemented
 117         if (PAddrIprSpace(req->paddr)) {
 118             if (!req->xc->misspeculating()) {
 119                 switch (req->paddr) {
 120                   case ULL(0xFFFFF00188):
 121                     req->data = 0;
 122                     break;
 123
 124                   default:
 125                     panic("IPR memory space not implemented! PA=%x\n",
 126                           req->paddr);
 127                 }
 128             }
 129         } else {
 130             // mark request as uncacheable
 131             req->flags |= UNCACHEABLE;
 132
 133 #if !ALPHA_TLASER
 134             // Clear bits 42:35 of the physical address (10-2 in Tsunami manual)
 135             req->paddr &= PAddrUncachedMask;
 136 #endif
 137         }
 138     }
 139 }
 140
 141
 142 // insert a new TLB entry
 143 void
 144 AlphaTLB::insert(Addr addr, AlphaISA::PTE &pte)
 145 {
 146     AlphaISA::VAddr vaddr = addr;
 147     if (table[nlu].valid) {
 148         Addr oldvpn = table[nlu].tag;
 149         PageTable::iterator i = lookupTable.find(oldvpn);
 150
 151         if (i == lookupTable.end())
 152             panic("TLB entry not found in lookupTable");
 153
 154         int index;
 155         while ((index = i->second) != nlu) {
 156             if (table[index].tag != oldvpn)
 157                 panic("TLB entry not found in lookupTable");
 158
 159             ++i;
 160         }
 161
 162         DPRINTF(TLB, "remove @%d: %#x -> %#x\n", nlu, oldvpn, table[nlu].ppn);
 163
 164         lookupTable.erase(i);
 165     }
 166
 167     DPRINTF(TLB, "insert @%d: %#x -> %#x\n", nlu, vaddr.vpn(), pte.ppn);
 168
 169     table[nlu] = pte;
 170     table[nlu].tag = vaddr.vpn();
 171     table[nlu].valid = true;
 172
 173     lookupTable.insert(make_pair(vaddr.vpn(), nlu));
 174     nextnlu();
 175 }
 176
 177 void
 178 AlphaTLB::flushAll()
 179 {
 180     DPRINTF(TLB, "flushAll\n");
 181     memset(table, 0, sizeof(AlphaISA::PTE[size]));
 182     lookupTable.clear();
 183     nlu = 0;
 184 }
 185
 186 void
 187 AlphaTLB::flushProcesses()
 188 {
 189     PageTable::iterator i = lookupTable.begin();
 190     PageTable::iterator end = lookupTable.end();
 191     while (i != end) {
 192         int index = i->second;
 193         AlphaISA::PTE *pte = &table[index];
 194         assert(pte->valid);
 195
 196         // we can't increment i after we erase it, so save a copy and
 197         // increment it to get the next entry now
 198         PageTable::iterator cur = i;
 199         ++i;
 200
 201         if (!pte->asma) {
 202             DPRINTF(TLB, "flush @%d: %#x -> %#x\n", index, pte->tag, pte->ppn);
 203             pte->valid = false;
 204             lookupTable.erase(cur);
 205         }
 206     }
 207 }
 208
 209 void
 210 AlphaTLB::flushAddr(Addr addr, uint8_t asn)
 211 {
 212     AlphaISA::VAddr vaddr = addr;
 213
 214     PageTable::iterator i = lookupTable.find(vaddr.vpn());
 215     if (i == lookupTable.end())
 216         return;
 217
 218     while (i->first == vaddr.vpn()) {
 219         int index = i->second;
 220         AlphaISA::PTE *pte = &table[index];
 221         assert(pte->valid);
 222
 223         if (vaddr.vpn() == pte->tag && (pte->asma || pte->asn == asn)) {
 224             DPRINTF(TLB, "flushaddr @%d: %#x -> %#x\n", index, vaddr.vpn(),
 225                     pte->ppn);
 226
 227             // invalidate this entry
 228             pte->valid = false;
 229
 230             lookupTable.erase(i);
 231         }
 232
 233         ++i;
 234     }
 235 }
 236
 237
 238 void
 239 AlphaTLB::serialize(ostream &os)
 240 {
 241     SERIALIZE_SCALAR(size);
 242     SERIALIZE_SCALAR(nlu);
 243
 244     for (int i = 0; i < size; i++) {
 245         nameOut(os, csprintf("%s.PTE%d", name(), i));
 246         table[i].serialize(os);
 247     }
 248 }
 249
 250 void
 251 AlphaTLB::unserialize(Checkpoint *cp, const string &section)
 252 {
 253     UNSERIALIZE_SCALAR(size);
 254     UNSERIALIZE_SCALAR(nlu);
 255
 256     for (int i = 0; i < size; i++) {
 257         table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
 258         if (table[i].valid) {
 259             lookupTable.insert(make_pair(table[i].tag, i));
 260         }
 261     }
 262 }
 263
 264
 265 ///////////////////////////////////////////////////////////////////////
 266 //
 267 //  Alpha ITB
 268 //
 269 AlphaITB::AlphaITB(const std::string &name, int size)
 270     : AlphaTLB(name, size)
 271 {}
 272
 273
 274 void
 275 AlphaITB::regStats()
 276 {
 277     hits
 278         .name(name() + ".hits")
 279         .desc("ITB hits");
 280     misses
 281         .name(name() + ".misses")
 282         .desc("ITB misses");
 283     acv
 284         .name(name() + ".acv")
 285         .desc("ITB acv");
 286     accesses
 287         .name(name() + ".accesses")
 288         .desc("ITB accesses");
 289
 290     accesses = hits + misses;
 291 }
 292
 293 void
 294 AlphaITB::fault(Addr pc, ExecContext *xc) const
 295 {
 296     if (!xc->misspeculating()) {
 297         xc->setMiscReg(AlphaISA::IPR_ITB_TAG, pc);
 298         xc->setMiscReg(AlphaISA::IPR_IFAULT_VA_FORM,
 299                        xc->readMiscReg(AlphaISA::IPR_IVPTBR) |
 300                        (AlphaISA::VAddr(pc).vpn() << 3));
 301     }
 302 }
 303
 304
 305 Fault
 306 AlphaITB::translate(MemReqPtr &req) const
 307 {
 308     ExecContext *xc = req->xc;
 309
 310     if (AlphaISA::PcPAL(req->vaddr)) {
 311         // strip off PAL PC marker (lsb is 1)
 312         req->paddr = (req->vaddr & ~3) & PAddrImplMask;
 313         hits++;
 314         return NoFault;
 315     }
 316
 317     if (req->flags & PHYSICAL) {
 318         req->paddr = req->vaddr;
 319     } else {
 320         // verify that this is a good virtual address
 321         if (!validVirtualAddress(req->vaddr)) {
 322             fault(req->vaddr, req->xc);
 323             acv++;
 324             return new ItbAcvFault;
 325         }
 326
 327
 328         // VA<42:41> == 2, VA<39:13> maps directly to PA<39:13> for EV5
 329         // VA<47:41> == 0x7e, VA<40:13> maps directly to PA<40:13> for EV6
 330 #if ALPHA_TLASER
 331         if ((MCSR_SP(xc->readMiscReg(AlphaISA::IPR_MCSR)) & 2) &&
 332             VAddrSpaceEV5(req->vaddr) == 2) {
 333 #else
 334         if (VAddrSpaceEV6(req->vaddr) == 0x7e) {
 335 #endif
 336             // only valid in kernel mode
 337             if (ICM_CM(xc->readMiscReg(AlphaISA::IPR_ICM)) !=
 338                 AlphaISA::mode_kernel) {
 339                 fault(req->vaddr, req->xc);
 340                 acv++;
 341                 return new ItbAcvFault;
 342             }
 343
 344             req->paddr = req->vaddr & PAddrImplMask;
 345
 346 #if !ALPHA_TLASER
 347             // sign extend the physical address properly
 348             if (req->paddr & PAddrUncachedBit40)
 349                 req->paddr |= ULL(0xf0000000000);
 350             else
 351                 req->paddr &= ULL(0xffffffffff);
 352 #endif
 353
 354         } else {
 355             // not a physical address: need to look up pte
 356             int asn = DTB_ASN_ASN(xc->readMiscReg(AlphaISA::IPR_DTB_ASN));
 357             AlphaISA::PTE *pte = lookup(AlphaISA::VAddr(req->vaddr).vpn(),
 358                                         asn);
 359
 360             if (!pte) {
 361                 fault(req->vaddr, req->xc);
 362                 misses++;
 363                 return new ItbPageFault;
 364             }
 365
 366             req->paddr = (pte->ppn << AlphaISA::PageShift) +
 367                 (AlphaISA::VAddr(req->vaddr).offset() & ~3);
 368
 369             // check permissions for this access
 370             if (!(pte->xre &
 371                   (1 << ICM_CM(xc->readMiscReg(AlphaISA::IPR_ICM))))) {
 372                 // instruction access fault
 373                 fault(req->vaddr, req->xc);
 374                 acv++;
 375                 return new ItbAcvFault;
 376             }
 377
 378             hits++;
 379         }
 380     }
 381
 382     // check that the physical address is ok (catch bad physical addresses)
 383     if (req->paddr & ~PAddrImplMask)
 384         return genMachineCheckFault();
 385
 386     checkCacheability(req);
 387
 388     return NoFault;
 389 }
 390
 391 ///////////////////////////////////////////////////////////////////////
 392 //
 393 //  Alpha DTB
 394 //
 395 AlphaDTB::AlphaDTB(const std::string &name, int size)
 396     : AlphaTLB(name, size)
 397 {}
 398
 399 void
 400 AlphaDTB::regStats()
 401 {
 402     read_hits
 403         .name(name() + ".read_hits")
 404         .desc("DTB read hits")
 405         ;
 406
 407     read_misses
 408         .name(name() + ".read_misses")
 409         .desc("DTB read misses")
 410         ;
 411
 412     read_acv
 413         .name(name() + ".read_acv")
 414         .desc("DTB read access violations")
 415         ;
 416
 417     read_accesses
 418         .name(name() + ".read_accesses")
 419         .desc("DTB read accesses")
 420         ;
 421
 422     write_hits
 423         .name(name() + ".write_hits")
 424         .desc("DTB write hits")
 425         ;
 426
 427     write_misses
 428         .name(name() + ".write_misses")
 429         .desc("DTB write misses")
 430         ;
 431
 432     write_acv
 433         .name(name() + ".write_acv")
 434         .desc("DTB write access violations")
 435         ;
 436
 437     write_accesses
 438         .name(name() + ".write_accesses")
 439         .desc("DTB write accesses")
 440         ;
 441
 442     hits
 443         .name(name() + ".hits")
 444         .desc("DTB hits")
 445         ;
 446
 447     misses
 448         .name(name() + ".misses")
 449         .desc("DTB misses")
 450         ;
 451
 452     acv
 453         .name(name() + ".acv")
 454         .desc("DTB access violations")
 455         ;
 456
 457     accesses
 458         .name(name() + ".accesses")
 459         .desc("DTB accesses")
 460         ;
 461
 462     hits = read_hits + write_hits;
 463     misses = read_misses + write_misses;
 464     acv = read_acv + write_acv;
 465     accesses = read_accesses + write_accesses;
 466 }
 467
 468 void
 469 AlphaDTB::fault(MemReqPtr &req, uint64_t flags) const
 470 {
 471     ExecContext *xc = req->xc;
 472     AlphaISA::VAddr vaddr = req->vaddr;
 473
 474     // Set fault address and flags.  Even though we're modeling an
 475     // EV5, we use the EV6 technique of not latching fault registers
 476     // on VPTE loads (instead of locking the registers until IPR_VA is
 477     // read, like the EV5).  The EV6 approach is cleaner and seems to
 478     // work with EV5 PAL code, but not the other way around.
 479     if (!xc->misspeculating()
 480         && !(req->flags & VPTE) && !(req->flags & NO_FAULT)) {
 481         // set VA register with faulting address
 482         xc->setMiscReg(AlphaISA::IPR_VA, req->vaddr);
 483
 484         // set MM_STAT register flags
 485         xc->setMiscReg(AlphaISA::IPR_MM_STAT,
 486             (((Opcode(xc->getInst()) & 0x3f) << 11)
 487              | ((Ra(xc->getInst()) & 0x1f) << 6)
 488              | (flags & 0x3f)));
 489
 490         // set VA_FORM register with faulting formatted address
 491         xc->setMiscReg(AlphaISA::IPR_VA_FORM,
 492             xc->readMiscReg(AlphaISA::IPR_MVPTBR) | (vaddr.vpn() << 3));
 493     }
 494 }
 495
 496 Fault
 497 AlphaDTB::translate(MemReqPtr &req, bool write) const
 498 {
 499     RegFile *regs = &req->xc->regs;
 500     ExecContext *xc = req->xc;
 501     Addr pc = regs->pc;
 502
 503     AlphaISA::mode_type mode =
 504         (AlphaISA::mode_type)DTB_CM_CM(xc->readMiscReg(AlphaISA::IPR_DTB_CM));
 505
 506
 507     /**
 508      * Check for alignment faults
 509      */
 510     if (req->vaddr & (req->size - 1)) {
 511         fault(req, write ? MM_STAT_WR_MASK : 0);
 512         DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->vaddr,
 513                 req->size);
 514         return genAlignmentFault();
 515     }
 516
 517     if (pc & 0x1) {
 518         mode = (req->flags & ALTMODE) ?
 519             (AlphaISA::mode_type)ALT_MODE_AM(
 520                 xc->readMiscReg(AlphaISA::IPR_ALT_MODE))
 521             : AlphaISA::mode_kernel;
 522     }
 523
 524     if (req->flags & PHYSICAL) {
 525         req->paddr = req->vaddr;
 526     } else {
 527         // verify that this is a good virtual address
 528         if (!validVirtualAddress(req->vaddr)) {
 529             fault(req, (write ? MM_STAT_WR_MASK : 0) |
 530                   MM_STAT_BAD_VA_MASK |
 531                   MM_STAT_ACV_MASK);
 532
 533             if (write) { write_acv++; } else { read_acv++; }
 534             return new DtbPageFault;
 535         }
 536
 537         // Check for "superpage" mapping
 538 #if ALPHA_TLASER
 539         if ((MCSR_SP(xc->readMiscReg(AlphaISA::IPR_MCSR)) & 2) &&
 540             VAddrSpaceEV5(req->vaddr) == 2) {
 541 #else
 542         if (VAddrSpaceEV6(req->vaddr) == 0x7e) {
 543 #endif
 544
 545             // only valid in kernel mode
 546             if (DTB_CM_CM(xc->readMiscReg(AlphaISA::IPR_DTB_CM)) !=
 547                 AlphaISA::mode_kernel) {
 548                 fault(req, ((write ? MM_STAT_WR_MASK : 0) |
 549                             MM_STAT_ACV_MASK));
 550                 if (write) { write_acv++; } else { read_acv++; }
 551                 return new DtbAcvFault;
 552             }
 553
 554             req->paddr = req->vaddr & PAddrImplMask;
 555
 556 #if !ALPHA_TLASER
 557             // sign extend the physical address properly
 558             if (req->paddr & PAddrUncachedBit40)
 559                 req->paddr |= ULL(0xf0000000000);
 560             else
 561                 req->paddr &= ULL(0xffffffffff);
 562 #endif
 563
 564         } else {
 565             if (write)
 566                 write_accesses++;
 567             else
 568                 read_accesses++;
 569
 570             int asn = DTB_ASN_ASN(xc->readMiscReg(AlphaISA::IPR_DTB_ASN));
 571
 572             // not a physical address: need to look up pte
 573             AlphaISA::PTE *pte = lookup(AlphaISA::VAddr(req->vaddr).vpn(),
 574                                         asn);
 575
 576             if (!pte) {
 577                 // page fault
 578                 fault(req, (write ? MM_STAT_WR_MASK : 0) |
 579                       MM_STAT_DTB_MISS_MASK);
 580                 if (write) { write_misses++; } else { read_misses++; }
 581                 return (req->flags & VPTE) ?
 582                     (Fault)(new PDtbMissFault) :
 583                     (Fault)(new NDtbMissFault);
 584             }
 585
 586             req->paddr = (pte->ppn << AlphaISA::PageShift) +
 587                 AlphaISA::VAddr(req->vaddr).offset();
 588
 589             if (write) {
 590                 if (!(pte->xwe & MODE2MASK(mode))) {
 591                     // declare the instruction access fault
 592                     fault(req, MM_STAT_WR_MASK |
 593                           MM_STAT_ACV_MASK |
 594                           (pte->fonw ? MM_STAT_FONW_MASK : 0));
 595                     write_acv++;
 596                     return new DtbPageFault;
 597                 }
 598                 if (pte->fonw) {
 599                     fault(req, MM_STAT_WR_MASK |
 600                           MM_STAT_FONW_MASK);
 601                     write_acv++;
 602                     return new DtbPageFault;
 603                 }
 604             } else {
 605                 if (!(pte->xre & MODE2MASK(mode))) {
 606                     fault(req, MM_STAT_ACV_MASK |
 607                           (pte->fonr ? MM_STAT_FONR_MASK : 0));
 608                     read_acv++;
 609                     return new DtbAcvFault;
 610                 }
 611                 if (pte->fonr) {
 612                     fault(req, MM_STAT_FONR_MASK);
 613                     read_acv++;
 614                     return new DtbPageFault;
 615                 }
 616             }
 617         }
 618
 619         if (write)
 620             write_hits++;
 621         else
 622             read_hits++;
 623     }
 624
 625     // check that the physical address is ok (catch bad physical addresses)
 626     if (req->paddr & ~PAddrImplMask)
 627         return genMachineCheckFault();
 628
 629     checkCacheability(req);
 630
 631     return NoFault;
 632 }
 633
 634 AlphaISA::PTE &
 635 AlphaTLB::index(bool advance)
 636 {
 637     AlphaISA::PTE *pte = &table[nlu];
 638
 639     if (advance)
 640         nextnlu();
 641
 642     return *pte;
 643 }
 644
 645 DEFINE_SIM_OBJECT_CLASS_NAME("AlphaTLB", AlphaTLB)
 646
 647 BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
 648
 649     Param<int> size;
 650
 651 END_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
 652
 653 BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaITB)
 654
 655     INIT_PARAM_DFLT(size, "TLB size", 48)
 656
 657 END_INIT_SIM_OBJECT_PARAMS(AlphaITB)
 658
 659
 660 CREATE_SIM_OBJECT(AlphaITB)
 661 {
 662     return new AlphaITB(getInstanceName(), size);
 663 }
 664
 665 REGISTER_SIM_OBJECT("AlphaITB", AlphaITB)
 666
 667 BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
 668
 669     Param<int> size;
 670
 671 END_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
 672
 673 BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
 674
 675     INIT_PARAM_DFLT(size, "TLB size", 64)
 676
 677 END_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
 678
 679
 680 CREATE_SIM_OBJECT(AlphaDTB)
 681 {
 682     return new AlphaDTB(getInstanceName(), size);
 683 }
 684
 685 REGISTER_SIM_OBJECT("AlphaDTB", AlphaDTB)
 686