gem5/arch/alpha/tlb.cc
Kevin Lim bd38b56774 Move TLB faults into the normal fault classes. Now they are executed when the fault is invoked.
--HG--
extra : convert_revision : b5f00fff277e863b3fe43422bc39d0487c482e60
2006-04-22 18:09:08 -04:00

643 lines
17 KiB
C++

/*
* Copyright (c) 2001-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sstream>
#include <string>
#include <vector>
#include "arch/alpha/tlb.hh"
#include "base/inifile.hh"
#include "base/str.hh"
#include "base/trace.hh"
#include "config/alpha_tlaser.hh"
#include "cpu/exec_context.hh"
#include "sim/builder.hh"
using namespace std;
using namespace EV5;
///////////////////////////////////////////////////////////////////////
//
// Alpha TLB
//
#ifdef DEBUG
bool uncacheBit39 = false;
bool uncacheBit40 = false;
#endif
#define MODE2MASK(X) (1 << (X))
AlphaTLB::AlphaTLB(const string &name, int s)
: SimObject(name), size(s), nlu(0)
{
table = new AlphaISA::PTE[size];
memset(table, 0, sizeof(AlphaISA::PTE[size]));
}
AlphaTLB::~AlphaTLB()
{
if (table)
delete [] table;
}
// look up an entry in the TLB
AlphaISA::PTE *
AlphaTLB::lookup(Addr vpn, uint8_t asn) const
{
// assume not found...
AlphaISA::PTE *retval = NULL;
PageTable::const_iterator i = lookupTable.find(vpn);
if (i != lookupTable.end()) {
while (i->first == vpn) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
if (vpn == pte->tag && (pte->asma || pte->asn == asn)) {
retval = pte;
break;
}
++i;
}
}
DPRINTF(TLB, "lookup %#x, asn %#x -> %s ppn %#x\n", vpn, (int)asn,
retval ? "hit" : "miss", retval ? retval->ppn : 0);
return retval;
}
void
AlphaTLB::checkCacheability(MemReqPtr &req)
{
// in Alpha, cacheability is controlled by upper-level bits of the
// physical address
/*
* We support having the uncacheable bit in either bit 39 or bit 40.
* The Turbolaser platform (and EV5) support having the bit in 39, but
* Tsunami (which Linux assumes uses an EV6) generates accesses with
* the bit in 40. So we must check for both, but we have debug flags
* to catch a weird case where both are used, which shouldn't happen.
*/
#if ALPHA_TLASER
if (req->paddr & PAddrUncachedBit39) {
#else
if (req->paddr & PAddrUncachedBit43) {
#endif
// IPR memory space not implemented
if (PAddrIprSpace(req->paddr)) {
if (!req->xc->misspeculating()) {
switch (req->paddr) {
case ULL(0xFFFFF00188):
req->data = 0;
break;
default:
panic("IPR memory space not implemented! PA=%x\n",
req->paddr);
}
}
} else {
// mark request as uncacheable
req->flags |= UNCACHEABLE;
#if !ALPHA_TLASER
// Clear bits 42:35 of the physical address (10-2 in Tsunami manual)
req->paddr &= PAddrUncachedMask;
#endif
}
}
}
// insert a new TLB entry
void
AlphaTLB::insert(Addr addr, AlphaISA::PTE &pte)
{
AlphaISA::VAddr vaddr = addr;
if (table[nlu].valid) {
Addr oldvpn = table[nlu].tag;
PageTable::iterator i = lookupTable.find(oldvpn);
if (i == lookupTable.end())
panic("TLB entry not found in lookupTable");
int index;
while ((index = i->second) != nlu) {
if (table[index].tag != oldvpn)
panic("TLB entry not found in lookupTable");
++i;
}
DPRINTF(TLB, "remove @%d: %#x -> %#x\n", nlu, oldvpn, table[nlu].ppn);
lookupTable.erase(i);
}
DPRINTF(TLB, "insert @%d: %#x -> %#x\n", nlu, vaddr.vpn(), pte.ppn);
table[nlu] = pte;
table[nlu].tag = vaddr.vpn();
table[nlu].valid = true;
lookupTable.insert(make_pair(vaddr.vpn(), nlu));
nextnlu();
}
void
AlphaTLB::flushAll()
{
DPRINTF(TLB, "flushAll\n");
memset(table, 0, sizeof(AlphaISA::PTE[size]));
lookupTable.clear();
nlu = 0;
}
void
AlphaTLB::flushProcesses()
{
PageTable::iterator i = lookupTable.begin();
PageTable::iterator end = lookupTable.end();
while (i != end) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
// we can't increment i after we erase it, so save a copy and
// increment it to get the next entry now
PageTable::iterator cur = i;
++i;
if (!pte->asma) {
DPRINTF(TLB, "flush @%d: %#x -> %#x\n", index, pte->tag, pte->ppn);
pte->valid = false;
lookupTable.erase(cur);
}
}
}
void
AlphaTLB::flushAddr(Addr addr, uint8_t asn)
{
AlphaISA::VAddr vaddr = addr;
PageTable::iterator i = lookupTable.find(vaddr.vpn());
if (i == lookupTable.end())
return;
while (i->first == vaddr.vpn()) {
int index = i->second;
AlphaISA::PTE *pte = &table[index];
assert(pte->valid);
if (vaddr.vpn() == pte->tag && (pte->asma || pte->asn == asn)) {
DPRINTF(TLB, "flushaddr @%d: %#x -> %#x\n", index, vaddr.vpn(),
pte->ppn);
// invalidate this entry
pte->valid = false;
lookupTable.erase(i);
}
++i;
}
}
void
AlphaTLB::serialize(ostream &os)
{
SERIALIZE_SCALAR(size);
SERIALIZE_SCALAR(nlu);
for (int i = 0; i < size; i++) {
nameOut(os, csprintf("%s.PTE%d", name(), i));
table[i].serialize(os);
}
}
void
AlphaTLB::unserialize(Checkpoint *cp, const string &section)
{
UNSERIALIZE_SCALAR(size);
UNSERIALIZE_SCALAR(nlu);
for (int i = 0; i < size; i++) {
table[i].unserialize(cp, csprintf("%s.PTE%d", section, i));
if (table[i].valid) {
lookupTable.insert(make_pair(table[i].tag, i));
}
}
}
///////////////////////////////////////////////////////////////////////
//
// Alpha ITB
//
AlphaITB::AlphaITB(const std::string &name, int size)
: AlphaTLB(name, size)
{}
void
AlphaITB::regStats()
{
hits
.name(name() + ".hits")
.desc("ITB hits");
misses
.name(name() + ".misses")
.desc("ITB misses");
acv
.name(name() + ".acv")
.desc("ITB acv");
accesses
.name(name() + ".accesses")
.desc("ITB accesses");
accesses = hits + misses;
}
Fault
AlphaITB::translate(MemReqPtr &req) const
{
ExecContext *xc = req->xc;
if (AlphaISA::PcPAL(req->vaddr)) {
// strip off PAL PC marker (lsb is 1)
req->paddr = (req->vaddr & ~3) & PAddrImplMask;
hits++;
return NoFault;
}
if (req->flags & PHYSICAL) {
req->paddr = req->vaddr;
} else {
// verify that this is a good virtual address
if (!validVirtualAddress(req->vaddr)) {
acv++;
return new ItbAcvFault(req->vaddr);
}
// VA<42:41> == 2, VA<39:13> maps directly to PA<39:13> for EV5
// VA<47:41> == 0x7e, VA<40:13> maps directly to PA<40:13> for EV6
#if ALPHA_TLASER
if ((MCSR_SP(xc->readMiscReg(AlphaISA::IPR_MCSR)) & 2) &&
VAddrSpaceEV5(req->vaddr) == 2) {
#else
if (VAddrSpaceEV6(req->vaddr) == 0x7e) {
#endif
// only valid in kernel mode
if (ICM_CM(xc->readMiscReg(AlphaISA::IPR_ICM)) !=
AlphaISA::mode_kernel) {
acv++;
return new ItbAcvFault(req->vaddr);
}
req->paddr = req->vaddr & PAddrImplMask;
#if !ALPHA_TLASER
// sign extend the physical address properly
if (req->paddr & PAddrUncachedBit40)
req->paddr |= ULL(0xf0000000000);
else
req->paddr &= ULL(0xffffffffff);
#endif
} else {
// not a physical address: need to look up pte
int asn = DTB_ASN_ASN(xc->readMiscReg(AlphaISA::IPR_DTB_ASN));
AlphaISA::PTE *pte = lookup(AlphaISA::VAddr(req->vaddr).vpn(),
asn);
if (!pte) {
misses++;
return new ItbPageFault(req->vaddr);
}
req->paddr = (pte->ppn << AlphaISA::PageShift) +
(AlphaISA::VAddr(req->vaddr).offset() & ~3);
// check permissions for this access
if (!(pte->xre &
(1 << ICM_CM(xc->readMiscReg(AlphaISA::IPR_ICM))))) {
// instruction access fault
acv++;
return new ItbAcvFault(req->vaddr);
}
hits++;
}
}
// check that the physical address is ok (catch bad physical addresses)
if (req->paddr & ~PAddrImplMask)
return genMachineCheckFault();
checkCacheability(req);
return NoFault;
}
///////////////////////////////////////////////////////////////////////
//
// Alpha DTB
//
AlphaDTB::AlphaDTB(const std::string &name, int size)
: AlphaTLB(name, size)
{}
void
AlphaDTB::regStats()
{
read_hits
.name(name() + ".read_hits")
.desc("DTB read hits")
;
read_misses
.name(name() + ".read_misses")
.desc("DTB read misses")
;
read_acv
.name(name() + ".read_acv")
.desc("DTB read access violations")
;
read_accesses
.name(name() + ".read_accesses")
.desc("DTB read accesses")
;
write_hits
.name(name() + ".write_hits")
.desc("DTB write hits")
;
write_misses
.name(name() + ".write_misses")
.desc("DTB write misses")
;
write_acv
.name(name() + ".write_acv")
.desc("DTB write access violations")
;
write_accesses
.name(name() + ".write_accesses")
.desc("DTB write accesses")
;
hits
.name(name() + ".hits")
.desc("DTB hits")
;
misses
.name(name() + ".misses")
.desc("DTB misses")
;
acv
.name(name() + ".acv")
.desc("DTB access violations")
;
accesses
.name(name() + ".accesses")
.desc("DTB accesses")
;
hits = read_hits + write_hits;
misses = read_misses + write_misses;
acv = read_acv + write_acv;
accesses = read_accesses + write_accesses;
}
Fault
AlphaDTB::translate(MemReqPtr &req, bool write) const
{
ExecContext *xc = req->xc;
Addr pc = xc->readPC();
AlphaISA::mode_type mode =
(AlphaISA::mode_type)DTB_CM_CM(xc->readMiscReg(AlphaISA::IPR_DTB_CM));
/**
* Check for alignment faults
*/
if (req->vaddr & (req->size - 1)) {
DPRINTF(TLB, "Alignment Fault on %#x, size = %d", req->vaddr,
req->size);
uint64_t flags = write ? MM_STAT_WR_MASK : 0;
return new DtbAlignmentFault(req->vaddr, req->flags, flags);
}
if (pc & 0x1) {
mode = (req->flags & ALTMODE) ?
(AlphaISA::mode_type)ALT_MODE_AM(
xc->readMiscReg(AlphaISA::IPR_ALT_MODE))
: AlphaISA::mode_kernel;
}
if (req->flags & PHYSICAL) {
req->paddr = req->vaddr;
} else {
// verify that this is a good virtual address
if (!validVirtualAddress(req->vaddr)) {
if (write) { write_acv++; } else { read_acv++; }
uint64_t flags = (write ? MM_STAT_WR_MASK : 0) |
MM_STAT_BAD_VA_MASK |
MM_STAT_ACV_MASK;
return new DtbPageFault(req->vaddr, req->flags, flags);
}
// Check for "superpage" mapping
#if ALPHA_TLASER
if ((MCSR_SP(xc->readMiscReg(AlphaISA::IPR_MCSR)) & 2) &&
VAddrSpaceEV5(req->vaddr) == 2) {
#else
if (VAddrSpaceEV6(req->vaddr) == 0x7e) {
#endif
// only valid in kernel mode
if (DTB_CM_CM(xc->readMiscReg(AlphaISA::IPR_DTB_CM)) !=
AlphaISA::mode_kernel) {
if (write) { write_acv++; } else { read_acv++; }
uint64_t flags = ((write ? MM_STAT_WR_MASK : 0) |
MM_STAT_ACV_MASK);
return new DtbAcvFault(req->vaddr, req->flags, flags);
}
req->paddr = req->vaddr & PAddrImplMask;
#if !ALPHA_TLASER
// sign extend the physical address properly
if (req->paddr & PAddrUncachedBit40)
req->paddr |= ULL(0xf0000000000);
else
req->paddr &= ULL(0xffffffffff);
#endif
} else {
if (write)
write_accesses++;
else
read_accesses++;
int asn = DTB_ASN_ASN(xc->readMiscReg(AlphaISA::IPR_DTB_ASN));
// not a physical address: need to look up pte
AlphaISA::PTE *pte = lookup(AlphaISA::VAddr(req->vaddr).vpn(),
asn);
if (!pte) {
// page fault
if (write) { write_misses++; } else { read_misses++; }
uint64_t flags = (write ? MM_STAT_WR_MASK : 0) |
MM_STAT_DTB_MISS_MASK;
return (req->flags & VPTE) ?
(Fault)(new PDtbMissFault(req->vaddr, req->flags,
flags)) :
(Fault)(new NDtbMissFault(req->vaddr, req->flags,
flags));
}
req->paddr = (pte->ppn << AlphaISA::PageShift) +
AlphaISA::VAddr(req->vaddr).offset();
if (write) {
if (!(pte->xwe & MODE2MASK(mode))) {
// declare the instruction access fault
write_acv++;
uint64_t flags = MM_STAT_WR_MASK |
MM_STAT_ACV_MASK |
(pte->fonw ? MM_STAT_FONW_MASK : 0);
return new DtbPageFault(req->vaddr, req->flags, flags);
}
if (pte->fonw) {
write_acv++;
uint64_t flags = MM_STAT_WR_MASK |
MM_STAT_FONW_MASK;
return new DtbPageFault(req->vaddr, req->flags, flags);
}
} else {
if (!(pte->xre & MODE2MASK(mode))) {
read_acv++;
uint64_t flags = MM_STAT_ACV_MASK |
(pte->fonr ? MM_STAT_FONR_MASK : 0);
return new DtbAcvFault(req->vaddr, req->flags, flags);
}
if (pte->fonr) {
read_acv++;
uint64_t flags = MM_STAT_FONR_MASK;
return new DtbPageFault(req->vaddr, req->flags, flags);
}
}
}
if (write)
write_hits++;
else
read_hits++;
}
// check that the physical address is ok (catch bad physical addresses)
if (req->paddr & ~PAddrImplMask)
return genMachineCheckFault();
checkCacheability(req);
return NoFault;
}
AlphaISA::PTE &
AlphaTLB::index(bool advance)
{
AlphaISA::PTE *pte = &table[nlu];
if (advance)
nextnlu();
return *pte;
}
DEFINE_SIM_OBJECT_CLASS_NAME("AlphaTLB", AlphaTLB)
BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
Param<int> size;
END_DECLARE_SIM_OBJECT_PARAMS(AlphaITB)
BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaITB)
INIT_PARAM_DFLT(size, "TLB size", 48)
END_INIT_SIM_OBJECT_PARAMS(AlphaITB)
CREATE_SIM_OBJECT(AlphaITB)
{
return new AlphaITB(getInstanceName(), size);
}
REGISTER_SIM_OBJECT("AlphaITB", AlphaITB)
BEGIN_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
Param<int> size;
END_DECLARE_SIM_OBJECT_PARAMS(AlphaDTB)
BEGIN_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
INIT_PARAM_DFLT(size, "TLB size", 64)
END_INIT_SIM_OBJECT_PARAMS(AlphaDTB)
CREATE_SIM_OBJECT(AlphaDTB)
{
return new AlphaDTB(getInstanceName(), size);
}
REGISTER_SIM_OBJECT("AlphaDTB", AlphaDTB)