gem5/src/arch/x86/tlb.cc
Gabe Black 40b6c9cb2e X86: Move the MSR lookup table out of the TLB and into its own file.
Translating MSR addresses into MSR register indices took a lot of space in the
TLB source and made looking around in that file awkward. This change moves
the lookup into its own file to get it out of the way. It also changes it from
a switch statement to a hash map which should hopefully be a little more
efficient.
2011-09-23 02:42:22 -07:00

450 lines
15 KiB
C++

/*
* Copyright (c) 2007-2008 The Hewlett-Packard Development Company
* All rights reserved.
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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.
*
* Authors: Gabe Black
*/
#include <cstring>
#include "arch/x86/insts/microldstop.hh"
#include "arch/x86/regs/misc.hh"
#include "arch/x86/regs/msr.hh"
#include "arch/x86/faults.hh"
#include "arch/x86/pagetable.hh"
#include "arch/x86/tlb.hh"
#include "arch/x86/x86_traits.hh"
#include "base/bitfield.hh"
#include "base/trace.hh"
#include "config/full_system.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "debug/TLB.hh"
#include "mem/packet_access.hh"
#include "mem/request.hh"
#if FULL_SYSTEM
#include "arch/x86/pagetable_walker.hh"
#else
#include "mem/page_table.hh"
#include "sim/process.hh"
#endif
namespace X86ISA {
TLB::TLB(const Params *p) : BaseTLB(p), configAddress(0), size(p->size)
{
tlb = new TlbEntry[size];
std::memset(tlb, 0, sizeof(TlbEntry) * size);
for (int x = 0; x < size; x++)
freeList.push_back(&tlb[x]);
#if FULL_SYSTEM
walker = p->walker;
walker->setTLB(this);
#endif
}
TlbEntry *
TLB::insert(Addr vpn, TlbEntry &entry)
{
//TODO Deal with conflicting entries
TlbEntry *newEntry = NULL;
if (!freeList.empty()) {
newEntry = freeList.front();
freeList.pop_front();
} else {
newEntry = entryList.back();
entryList.pop_back();
}
*newEntry = entry;
newEntry->vaddr = vpn;
entryList.push_front(newEntry);
return newEntry;
}
TLB::EntryList::iterator
TLB::lookupIt(Addr va, bool update_lru)
{
//TODO make this smarter at some point
EntryList::iterator entry;
for (entry = entryList.begin(); entry != entryList.end(); entry++) {
if ((*entry)->vaddr <= va && (*entry)->vaddr + (*entry)->size > va) {
DPRINTF(TLB, "Matched vaddr %#x to entry starting at %#x "
"with size %#x.\n", va, (*entry)->vaddr, (*entry)->size);
if (update_lru) {
entryList.push_front(*entry);
entryList.erase(entry);
entry = entryList.begin();
}
break;
}
}
return entry;
}
TlbEntry *
TLB::lookup(Addr va, bool update_lru)
{
EntryList::iterator entry = lookupIt(va, update_lru);
if (entry == entryList.end())
return NULL;
else
return *entry;
}
void
TLB::invalidateAll()
{
DPRINTF(TLB, "Invalidating all entries.\n");
while (!entryList.empty()) {
TlbEntry *entry = entryList.front();
entryList.pop_front();
freeList.push_back(entry);
}
}
void
TLB::setConfigAddress(uint32_t addr)
{
configAddress = addr;
}
void
TLB::invalidateNonGlobal()
{
DPRINTF(TLB, "Invalidating all non global entries.\n");
EntryList::iterator entryIt;
for (entryIt = entryList.begin(); entryIt != entryList.end();) {
if (!(*entryIt)->global) {
freeList.push_back(*entryIt);
entryList.erase(entryIt++);
} else {
entryIt++;
}
}
}
void
TLB::demapPage(Addr va, uint64_t asn)
{
EntryList::iterator entry = lookupIt(va, false);
if (entry != entryList.end()) {
freeList.push_back(*entry);
entryList.erase(entry);
}
}
Fault
TLB::translateInt(RequestPtr req, ThreadContext *tc)
{
DPRINTF(TLB, "Addresses references internal memory.\n");
Addr vaddr = req->getVaddr();
Addr prefix = (vaddr >> 3) & IntAddrPrefixMask;
if (prefix == IntAddrPrefixCPUID) {
panic("CPUID memory space not yet implemented!\n");
} else if (prefix == IntAddrPrefixMSR) {
vaddr = (vaddr >> 3) & ~IntAddrPrefixMask;
req->setFlags(Request::MMAPPED_IPR);
MiscRegIndex regNum;
if (!msrAddrToIndex(regNum, vaddr))
return new GeneralProtection(0);
//The index is multiplied by the size of a MiscReg so that
//any memory dependence calculations will not see these as
//overlapping.
req->setPaddr((Addr)regNum * sizeof(MiscReg));
return NoFault;
} else if (prefix == IntAddrPrefixIO) {
// TODO If CPL > IOPL or in virtual mode, check the I/O permission
// bitmap in the TSS.
Addr IOPort = vaddr & ~IntAddrPrefixMask;
// Make sure the address fits in the expected 16 bit IO address
// space.
assert(!(IOPort & ~0xFFFF));
if (IOPort == 0xCF8 && req->getSize() == 4) {
req->setFlags(Request::MMAPPED_IPR);
req->setPaddr(MISCREG_PCI_CONFIG_ADDRESS * sizeof(MiscReg));
} else if ((IOPort & ~mask(2)) == 0xCFC) {
req->setFlags(Request::UNCACHEABLE);
Addr configAddress =
tc->readMiscRegNoEffect(MISCREG_PCI_CONFIG_ADDRESS);
if (bits(configAddress, 31, 31)) {
req->setPaddr(PhysAddrPrefixPciConfig |
mbits(configAddress, 30, 2) |
(IOPort & mask(2)));
} else {
req->setPaddr(PhysAddrPrefixIO | IOPort);
}
} else {
req->setFlags(Request::UNCACHEABLE);
req->setPaddr(PhysAddrPrefixIO | IOPort);
}
return NoFault;
} else {
panic("Access to unrecognized internal address space %#x.\n",
prefix);
}
}
Fault
TLB::translate(RequestPtr req, ThreadContext *tc, Translation *translation,
Mode mode, bool &delayedResponse, bool timing)
{
uint32_t flags = req->getFlags();
int seg = flags & SegmentFlagMask;
bool storeCheck = flags & (StoreCheck << FlagShift);
delayedResponse = false;
// If this is true, we're dealing with a request to a non-memory address
// space.
if (seg == SEGMENT_REG_MS) {
return translateInt(req, tc);
}
Addr vaddr = req->getVaddr();
DPRINTF(TLB, "Translating vaddr %#x.\n", vaddr);
HandyM5Reg m5Reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
// If protected mode has been enabled...
if (m5Reg.prot) {
DPRINTF(TLB, "In protected mode.\n");
// If we're not in 64-bit mode, do protection/limit checks
if (m5Reg.mode != LongMode) {
DPRINTF(TLB, "Not in long mode. Checking segment protection.\n");
// Check for a NULL segment selector.
if (!(seg == SEGMENT_REG_TSG || seg == SYS_SEGMENT_REG_IDTR ||
seg == SEGMENT_REG_HS || seg == SEGMENT_REG_LS)
&& !tc->readMiscRegNoEffect(MISCREG_SEG_SEL(seg)))
return new GeneralProtection(0);
bool expandDown = false;
SegAttr attr = tc->readMiscRegNoEffect(MISCREG_SEG_ATTR(seg));
if (seg >= SEGMENT_REG_ES && seg <= SEGMENT_REG_HS) {
if (!attr.writable && (mode == Write || storeCheck))
return new GeneralProtection(0);
if (!attr.readable && mode == Read)
return new GeneralProtection(0);
expandDown = attr.expandDown;
}
Addr base = tc->readMiscRegNoEffect(MISCREG_SEG_BASE(seg));
Addr limit = tc->readMiscRegNoEffect(MISCREG_SEG_LIMIT(seg));
// This assumes we're not in 64 bit mode. If we were, the default
// address size is 64 bits, overridable to 32.
int size = 32;
bool sizeOverride = (flags & (AddrSizeFlagBit << FlagShift));
SegAttr csAttr = tc->readMiscRegNoEffect(MISCREG_CS_ATTR);
if ((csAttr.defaultSize && sizeOverride) ||
(!csAttr.defaultSize && !sizeOverride))
size = 16;
Addr offset = bits(vaddr - base, size-1, 0);
Addr endOffset = offset + req->getSize() - 1;
if (expandDown) {
DPRINTF(TLB, "Checking an expand down segment.\n");
warn_once("Expand down segments are untested.\n");
if (offset <= limit || endOffset <= limit)
return new GeneralProtection(0);
} else {
if (offset > limit || endOffset > limit)
return new GeneralProtection(0);
}
}
// If paging is enabled, do the translation.
if (m5Reg.paging) {
DPRINTF(TLB, "Paging enabled.\n");
// The vaddr already has the segment base applied.
TlbEntry *entry = lookup(vaddr);
if (!entry) {
#if FULL_SYSTEM
Fault fault = walker->start(tc, translation, req, mode);
if (timing || fault != NoFault) {
// This gets ignored in atomic mode.
delayedResponse = true;
return fault;
}
entry = lookup(vaddr);
assert(entry);
#else
DPRINTF(TLB, "Handling a TLB miss for "
"address %#x at pc %#x.\n",
vaddr, tc->instAddr());
Process *p = tc->getProcessPtr();
TlbEntry newEntry;
bool success = p->pTable->lookup(vaddr, newEntry);
if (!success && mode != Execute) {
// Check if we just need to grow the stack.
if (p->fixupStackFault(vaddr)) {
// If we did, lookup the entry for the new page.
success = p->pTable->lookup(vaddr, newEntry);
}
}
if (!success) {
return new PageFault(vaddr, true, mode, true, false);
} else {
Addr alignedVaddr = p->pTable->pageAlign(vaddr);
DPRINTF(TLB, "Mapping %#x to %#x\n", alignedVaddr,
newEntry.pageStart());
entry = insert(alignedVaddr, newEntry);
}
DPRINTF(TLB, "Miss was serviced.\n");
#endif
}
// Do paging protection checks.
bool inUser = (m5Reg.cpl == 3 &&
!(flags & (CPL0FlagBit << FlagShift)));
CR0 cr0 = tc->readMiscRegNoEffect(MISCREG_CR0);
bool badWrite = (!entry->writable && (inUser || cr0.wp));
if ((inUser && !entry->user) || (mode == Write && badWrite)) {
// The page must have been present to get into the TLB in
// the first place. We'll assume the reserved bits are
// fine even though we're not checking them.
return new PageFault(vaddr, true, mode, inUser, false);
}
if (storeCheck && badWrite) {
// This would fault if this were a write, so return a page
// fault that reflects that happening.
return new PageFault(vaddr, true, Write, inUser, false);
}
DPRINTF(TLB, "Entry found with paddr %#x, "
"doing protection checks.\n", entry->paddr);
Addr paddr = entry->paddr | (vaddr & (entry->size-1));
DPRINTF(TLB, "Translated %#x -> %#x.\n", vaddr, paddr);
req->setPaddr(paddr);
if (entry->uncacheable)
req->setFlags(Request::UNCACHEABLE);
} else {
//Use the address which already has segmentation applied.
DPRINTF(TLB, "Paging disabled.\n");
DPRINTF(TLB, "Translated %#x -> %#x.\n", vaddr, vaddr);
req->setPaddr(vaddr);
}
} else {
// Real mode
DPRINTF(TLB, "In real mode.\n");
DPRINTF(TLB, "Translated %#x -> %#x.\n", vaddr, vaddr);
req->setPaddr(vaddr);
}
// Check for an access to the local APIC
#if FULL_SYSTEM
LocalApicBase localApicBase = tc->readMiscRegNoEffect(MISCREG_APIC_BASE);
Addr baseAddr = localApicBase.base * PageBytes;
Addr paddr = req->getPaddr();
if (baseAddr <= paddr && baseAddr + PageBytes > paddr) {
// The Intel developer's manuals say the below restrictions apply,
// but the linux kernel, because of a compiler optimization, breaks
// them.
/*
// Check alignment
if (paddr & ((32/8) - 1))
return new GeneralProtection(0);
// Check access size
if (req->getSize() != (32/8))
return new GeneralProtection(0);
*/
// Force the access to be uncacheable.
req->setFlags(Request::UNCACHEABLE);
req->setPaddr(x86LocalAPICAddress(tc->contextId(), paddr - baseAddr));
}
#endif
return NoFault;
};
Fault
TLB::translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode)
{
bool delayedResponse;
return TLB::translate(req, tc, NULL, mode, delayedResponse, false);
}
void
TLB::translateTiming(RequestPtr req, ThreadContext *tc,
Translation *translation, Mode mode)
{
bool delayedResponse;
assert(translation);
Fault fault =
TLB::translate(req, tc, translation, mode, delayedResponse, true);
if (!delayedResponse)
translation->finish(fault, req, tc, mode);
}
#if FULL_SYSTEM
Tick
TLB::doMmuRegRead(ThreadContext *tc, Packet *pkt)
{
return tc->getCpuPtr()->ticks(1);
}
Tick
TLB::doMmuRegWrite(ThreadContext *tc, Packet *pkt)
{
return tc->getCpuPtr()->ticks(1);
}
Walker *
TLB::getWalker()
{
return walker;
}
#endif
void
TLB::serialize(std::ostream &os)
{
}
void
TLB::unserialize(Checkpoint *cp, const std::string &section)
{
}
} // namespace X86ISA
X86ISA::TLB *
X86TLBParams::create()
{
return new X86ISA::TLB(this);
}