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/*
* Copyright (c) 2010, 2012-2019, 2021-2022 Arm Limited
* 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.
*/
#include "arch/arm/table_walker.hh"
#include <cassert>
#include <memory>
#include "arch/arm/faults.hh"
#include "arch/arm/mmu.hh"
#include "arch/arm/pagetable.hh"
#include "arch/arm/system.hh"
#include "arch/arm/tlb.hh"
#include "base/compiler.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "debug/Checkpoint.hh"
#include "debug/Drain.hh"
#include "debug/PageTableWalker.hh"
#include "debug/TLB.hh"
#include "debug/TLBVerbose.hh"
#include "sim/system.hh"
namespace gem5
{
using namespace ArmISA;
TableWalker::TableWalker(const Params &p)
: ClockedObject(p),
requestorId(p.sys->getRequestorId(this)),
port(new Port(*this, requestorId)),
isStage2(p.is_stage2), tlb(NULL),
currState(NULL), pending(false),
numSquashable(p.num_squash_per_cycle),
release(nullptr),
stats(this),
pendingReqs(0),
pendingChangeTick(curTick()),
doL1DescEvent([this]{ doL1DescriptorWrapper(); }, name()),
doL2DescEvent([this]{ doL2DescriptorWrapper(); }, name()),
doL0LongDescEvent([this]{ doL0LongDescriptorWrapper(); }, name()),
doL1LongDescEvent([this]{ doL1LongDescriptorWrapper(); }, name()),
doL2LongDescEvent([this]{ doL2LongDescriptorWrapper(); }, name()),
doL3LongDescEvent([this]{ doL3LongDescriptorWrapper(); }, name()),
LongDescEventByLevel { &doL0LongDescEvent, &doL1LongDescEvent,
&doL2LongDescEvent, &doL3LongDescEvent },
doProcessEvent([this]{ processWalkWrapper(); }, name())
{
sctlr = 0;
// Cache system-level properties
if (FullSystem) {
ArmSystem *arm_sys = dynamic_cast<ArmSystem *>(p.sys);
assert(arm_sys);
_physAddrRange = arm_sys->physAddrRange();
_haveLargeAsid64 = arm_sys->haveLargeAsid64();
} else {
_haveLargeAsid64 = false;
_physAddrRange = 48;
}
}
TableWalker::~TableWalker()
{
;
}
TableWalker::Port &
TableWalker::getTableWalkerPort()
{
return static_cast<Port&>(getPort("port"));
}
Port &
TableWalker::getPort(const std::string &if_name, PortID idx)
{
if (if_name == "port") {
return *port;
}
return ClockedObject::getPort(if_name, idx);
}
void
TableWalker::setMmu(MMU *_mmu)
{
mmu = _mmu;
release = mmu->release();
}
TableWalker::WalkerState::WalkerState() :
tc(nullptr), aarch64(false), el(EL0), physAddrRange(0), req(nullptr),
asid(0), vmid(0), isHyp(false), transState(nullptr),
vaddr(0), vaddr_tainted(0),
sctlr(0), scr(0), cpsr(0), tcr(0),
htcr(0), hcr(0), vtcr(0),
isWrite(false), isFetch(false), isSecure(false),
isUncacheable(false),
secureLookup(false), rwTable(false), userTable(false), xnTable(false),
pxnTable(false), hpd(false), stage2Req(false),
stage2Tran(nullptr), timing(false), functional(false),
mode(BaseMMU::Read), tranType(MMU::NormalTran), l2Desc(l1Desc),
delayed(false), tableWalker(nullptr)
{
}
TableWalker::Port::Port(TableWalker& _walker, RequestorID id)
: QueuedRequestPort(_walker.name() + ".port", reqQueue, snoopRespQueue),
owner{_walker},
reqQueue(_walker, *this),
snoopRespQueue(_walker, *this),
requestorId(id)
{
}
PacketPtr
TableWalker::Port::createPacket(
Addr desc_addr, int size,
uint8_t *data, Request::Flags flags, Tick delay,
Event *event)
{
RequestPtr req = std::make_shared<Request>(
desc_addr, size, flags, requestorId);
req->taskId(context_switch_task_id::DMA);
PacketPtr pkt = new Packet(req, MemCmd::ReadReq);
pkt->dataStatic(data);
auto state = new TableWalkerState;
state->event = event;
state->delay = delay;
pkt->senderState = state;
return pkt;
}
void
TableWalker::Port::sendFunctionalReq(
Addr desc_addr, int size,
uint8_t *data, Request::Flags flags)
{
auto pkt = createPacket(desc_addr, size, data, flags, 0, nullptr);
sendFunctional(pkt);
handleRespPacket(pkt);
}
void
TableWalker::Port::sendAtomicReq(
Addr desc_addr, int size,
uint8_t *data, Request::Flags flags, Tick delay)
{
auto pkt = createPacket(desc_addr, size, data, flags, delay, nullptr);
Tick lat = sendAtomic(pkt);
handleRespPacket(pkt, lat);
}
void
TableWalker::Port::sendTimingReq(
Addr desc_addr, int size,
uint8_t *data, Request::Flags flags, Tick delay,
Event *event)
{
auto pkt = createPacket(desc_addr, size, data, flags, delay, event);
schedTimingReq(pkt, curTick());
}
bool
TableWalker::Port::recvTimingResp(PacketPtr pkt)
{
// We shouldn't ever get a cacheable block in Modified state.
assert(pkt->req->isUncacheable() ||
!(pkt->cacheResponding() && !pkt->hasSharers()));
handleRespPacket(pkt);
return true;
}
void
TableWalker::Port::handleRespPacket(PacketPtr pkt, Tick delay)
{
// Should always see a response with a sender state.
assert(pkt->isResponse());
// Get the DMA sender state.
auto *state = dynamic_cast<TableWalkerState*>(pkt->senderState);
assert(state);
handleResp(state, pkt->getAddr(), pkt->req->getSize(), delay);
delete pkt;
}
void
TableWalker::Port::handleResp(TableWalkerState *state, Addr addr,
Addr size, Tick delay)
{
if (state->event) {
owner.schedule(state->event, curTick() + delay);
}
delete state;
}
void
TableWalker::completeDrain()
{
if (drainState() == DrainState::Draining &&
stateQueues[LookupLevel::L0].empty() &&
stateQueues[LookupLevel::L1].empty() &&
stateQueues[LookupLevel::L2].empty() &&
stateQueues[LookupLevel::L3].empty() &&
pendingQueue.empty()) {
DPRINTF(Drain, "TableWalker done draining, processing drain event\n");
signalDrainDone();
}
}
DrainState
TableWalker::drain()
{
bool state_queues_not_empty = false;
for (int i = 0; i < LookupLevel::Num_ArmLookupLevel; ++i) {
if (!stateQueues[i].empty()) {
state_queues_not_empty = true;
break;
}
}
if (state_queues_not_empty || pendingQueue.size()) {
DPRINTF(Drain, "TableWalker not drained\n");
return DrainState::Draining;
} else {
DPRINTF(Drain, "TableWalker free, no need to drain\n");
return DrainState::Drained;
}
}
void
TableWalker::drainResume()
{
if (params().sys->isTimingMode() && currState) {
delete currState;
currState = NULL;
pendingChange();
}
}
Fault
TableWalker::walk(const RequestPtr &_req, ThreadContext *_tc, uint16_t _asid,
vmid_t _vmid, bool _isHyp, MMU::Mode _mode,
MMU::Translation *_trans, bool _timing, bool _functional,
bool secure, MMU::ArmTranslationType tranType,
bool _stage2Req, const TlbEntry *walk_entry)
{
assert(!(_functional && _timing));
++stats.walks;
WalkerState *savedCurrState = NULL;
if (!currState && !_functional) {
// For atomic mode, a new WalkerState instance should be only created
// once per TLB. For timing mode, a new instance is generated for every
// TLB miss.
DPRINTF(PageTableWalker, "creating new instance of WalkerState\n");
currState = new WalkerState();
currState->tableWalker = this;
} else if (_functional) {
// If we are mixing functional mode with timing (or even
// atomic), we need to to be careful and clean up after
// ourselves to not risk getting into an inconsistent state.
DPRINTF(PageTableWalker,
"creating functional instance of WalkerState\n");
savedCurrState = currState;
currState = new WalkerState();
currState->tableWalker = this;
} else if (_timing) {
// This is a translation that was completed and then faulted again
// because some underlying parameters that affect the translation
// changed out from under us (e.g. asid). It will either be a
// misprediction, in which case nothing will happen or we'll use
// this fault to re-execute the faulting instruction which should clean
// up everything.
if (currState->vaddr_tainted == _req->getVaddr()) {
++stats.squashedBefore;
return std::make_shared<ReExec>();
}
}
pendingChange();
currState->startTime = curTick();
currState->tc = _tc;
// ARM DDI 0487A.f (ARMv8 ARM) pg J8-5672
// aarch32/translation/translation/AArch32.TranslateAddress dictates
// even AArch32 EL0 will use AArch64 translation if EL1 is in AArch64.
if (isStage2) {
currState->el = EL1;
currState->aarch64 = ELIs64(_tc, EL2);
} else {
currState->el =
MMU::tranTypeEL(_tc->readMiscReg(MISCREG_CPSR), tranType);
currState->aarch64 =
ELIs64(_tc, currState->el == EL0 ? EL1 : currState->el);
}
currState->transState = _trans;
currState->req = _req;
if (walk_entry) {
currState->walkEntry = *walk_entry;
} else {
currState->walkEntry = TlbEntry();
}
currState->fault = NoFault;
currState->asid = _asid;
currState->vmid = _vmid;
currState->isHyp = _isHyp;
currState->timing = _timing;
currState->functional = _functional;
currState->mode = _mode;
currState->tranType = tranType;
currState->isSecure = secure;
currState->physAddrRange = _physAddrRange;
/** @todo These should be cached or grabbed from cached copies in
the TLB, all these miscreg reads are expensive */
currState->vaddr_tainted = currState->req->getVaddr();
if (currState->aarch64)
currState->vaddr = purifyTaggedAddr(currState->vaddr_tainted,
currState->tc, currState->el,
currState->mode==BaseMMU::Execute);
else
currState->vaddr = currState->vaddr_tainted;
if (currState->aarch64) {
currState->hcr = currState->tc->readMiscReg(MISCREG_HCR_EL2);
if (isStage2) {
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL1);
if (currState->secureLookup) {
currState->vtcr =
currState->tc->readMiscReg(MISCREG_VSTCR_EL2);
} else {
currState->vtcr =
currState->tc->readMiscReg(MISCREG_VTCR_EL2);
}
} else switch (currState->el) {
case EL0:
if (HaveExt(currState->tc, ArmExtension::FEAT_VHE) &&
currState->hcr.tge == 1 && currState->hcr.e2h ==1) {
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL2);
currState->tcr = currState->tc->readMiscReg(MISCREG_TCR_EL2);
} else {
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL1);
currState->tcr = currState->tc->readMiscReg(MISCREG_TCR_EL1);
}
break;
case EL1:
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL1);
currState->tcr = currState->tc->readMiscReg(MISCREG_TCR_EL1);
break;
case EL2:
assert(release->has(ArmExtension::VIRTUALIZATION));
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL2);
currState->tcr = currState->tc->readMiscReg(MISCREG_TCR_EL2);
break;
case EL3:
assert(release->has(ArmExtension::SECURITY));
currState->sctlr = currState->tc->readMiscReg(MISCREG_SCTLR_EL3);
currState->tcr = currState->tc->readMiscReg(MISCREG_TCR_EL3);
break;
default:
panic("Invalid exception level");
break;
}
} else {
currState->sctlr = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_SCTLR, currState->tc, !currState->isSecure));
currState->ttbcr = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_TTBCR, currState->tc, !currState->isSecure));
currState->htcr = currState->tc->readMiscReg(MISCREG_HTCR);
currState->hcr = currState->tc->readMiscReg(MISCREG_HCR);
currState->vtcr = currState->tc->readMiscReg(MISCREG_VTCR);
}
sctlr = currState->sctlr;
currState->isFetch = (currState->mode == BaseMMU::Execute);
currState->isWrite = (currState->mode == BaseMMU::Write);
stats.requestOrigin[REQUESTED][currState->isFetch]++;
currState->stage2Req = _stage2Req && !isStage2;
bool long_desc_format = currState->aarch64 || _isHyp || isStage2 ||
longDescFormatInUse(currState->tc);
if (long_desc_format) {
// Helper variables used for hierarchical permissions
currState->secureLookup = currState->isSecure;
currState->rwTable = true;
currState->userTable = true;
currState->xnTable = false;
currState->pxnTable = false;
++stats.walksLongDescriptor;
} else {
++stats.walksShortDescriptor;
}
if (!currState->timing) {
Fault fault = NoFault;
if (currState->aarch64)
fault = processWalkAArch64();
else if (long_desc_format)
fault = processWalkLPAE();
else
fault = processWalk();
// If this was a functional non-timing access restore state to
// how we found it.
if (currState->functional) {
delete currState;
currState = savedCurrState;
}
return fault;
}
if (pending || pendingQueue.size()) {
pendingQueue.push_back(currState);
currState = NULL;
pendingChange();
} else {
pending = true;
pendingChange();
if (currState->aarch64)
return processWalkAArch64();
else if (long_desc_format)
return processWalkLPAE();
else
return processWalk();
}
return NoFault;
}
void
TableWalker::processWalkWrapper()
{
assert(!currState);
assert(pendingQueue.size());
pendingChange();
currState = pendingQueue.front();
// Check if a previous walk filled this request already
// @TODO Should this always be the TLB or should we look in the stage2 TLB?
TlbEntry* te = mmu->lookup(currState->vaddr, currState->asid,
currState->vmid, currState->isHyp, currState->isSecure, true, false,
currState->el, false, isStage2, currState->mode);
// Check if we still need to have a walk for this request. If the requesting
// instruction has been squashed, or a previous walk has filled the TLB with
// a match, we just want to get rid of the walk. The latter could happen
// when there are multiple outstanding misses to a single page and a
// previous request has been successfully translated.
if (!currState->transState->squashed() && (!te || te->partial)) {
// We've got a valid request, lets process it
pending = true;
pendingQueue.pop_front();
// Keep currState in case one of the processWalk... calls NULLs it
if (te && te->partial) {
currState->walkEntry = *te;
}
WalkerState *curr_state_copy = currState;
Fault f;
if (currState->aarch64)
f = processWalkAArch64();
else if (longDescFormatInUse(currState->tc) ||
currState->isHyp || isStage2)
f = processWalkLPAE();
else
f = processWalk();
if (f != NoFault) {
curr_state_copy->transState->finish(f, curr_state_copy->req,
curr_state_copy->tc, curr_state_copy->mode);
delete curr_state_copy;
}
return;
}
// If the instruction that we were translating for has been
// squashed we shouldn't bother.
unsigned num_squashed = 0;
ThreadContext *tc = currState->tc;
while ((num_squashed < numSquashable) && currState &&
(currState->transState->squashed() ||
(te && !te->partial))) {
pendingQueue.pop_front();
num_squashed++;
stats.squashedBefore++;
DPRINTF(TLB, "Squashing table walk for address %#x\n",
currState->vaddr_tainted);
if (currState->transState->squashed()) {
// finish the translation which will delete the translation object
currState->transState->finish(
std::make_shared<UnimpFault>("Squashed Inst"),
currState->req, currState->tc, currState->mode);
} else {
// translate the request now that we know it will work
stats.walkServiceTime.sample(curTick() - currState->startTime);
mmu->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode,
currState->tranType, isStage2);
}
// delete the current request
delete currState;
// peak at the next one
if (pendingQueue.size()) {
currState = pendingQueue.front();
te = mmu->lookup(currState->vaddr, currState->asid,
currState->vmid, currState->isHyp, currState->isSecure, true,
false, currState->el, false, isStage2, currState->mode);
} else {
// Terminate the loop, nothing more to do
currState = NULL;
}
}
pendingChange();
// if we still have pending translations, schedule more work
nextWalk(tc);
currState = NULL;
}
Fault
TableWalker::processWalk()
{
Addr ttbr = 0;
// For short descriptors, translation configs are held in
// TTBR1.
RegVal ttbr1 = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_TTBR1, currState->tc, !currState->isSecure));
const auto irgn0_mask = 0x1;
const auto irgn1_mask = 0x40;
currState->isUncacheable = (ttbr1 & (irgn0_mask | irgn1_mask)) == 0;
// If translation isn't enabled, we shouldn't be here
assert(currState->sctlr.m || isStage2);
const bool is_atomic = currState->req->isAtomic();
const bool have_security = release->has(ArmExtension::SECURITY);
DPRINTF(TLB, "Beginning table walk for address %#x, TTBCR: %#x, bits:%#x\n",
currState->vaddr_tainted, currState->ttbcr, mbits(currState->vaddr, 31,
32 - currState->ttbcr.n));
stats.walkWaitTime.sample(curTick() - currState->startTime);
if (currState->ttbcr.n == 0 || !mbits(currState->vaddr, 31,
32 - currState->ttbcr.n)) {
DPRINTF(TLB, " - Selecting TTBR0\n");
// Check if table walk is allowed when Security Extensions are enabled
if (have_security && currState->ttbcr.pd0) {
if (currState->isFetch)
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::VmsaTran);
else
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1, isStage2,
ArmFault::VmsaTran);
}
ttbr = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_TTBR0, currState->tc, !currState->isSecure));
} else {
DPRINTF(TLB, " - Selecting TTBR1\n");
// Check if table walk is allowed when Security Extensions are enabled
if (have_security && currState->ttbcr.pd1) {
if (currState->isFetch)
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::VmsaTran);
else
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1, isStage2,
ArmFault::VmsaTran);
}
ttbr = ttbr1;
currState->ttbcr.n = 0;
}
Addr l1desc_addr = mbits(ttbr, 31, 14 - currState->ttbcr.n) |
(bits(currState->vaddr, 31 - currState->ttbcr.n, 20) << 2);
DPRINTF(TLB, " - Descriptor at address %#x (%s)\n", l1desc_addr,
currState->isSecure ? "s" : "ns");
// Trickbox address check
Fault f;
f = testWalk(l1desc_addr, sizeof(uint32_t),
TlbEntry::DomainType::NoAccess, LookupLevel::L1, isStage2);
if (f) {
DPRINTF(TLB, "Trickbox check caused fault on %#x\n", currState->vaddr_tainted);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
Request::Flags flag = Request::PT_WALK;
if (currState->sctlr.c == 0 || currState->isUncacheable) {
flag.set(Request::UNCACHEABLE);
}
if (currState->isSecure) {
flag.set(Request::SECURE);
}
bool delayed;
delayed = fetchDescriptor(l1desc_addr, (uint8_t*)&currState->l1Desc.data,
sizeof(uint32_t), flag, LookupLevel::L1,
&doL1DescEvent,
&TableWalker::doL1Descriptor);
if (!delayed) {
f = currState->fault;
}
return f;
}
Fault
TableWalker::processWalkLPAE()
{
Addr ttbr, ttbr0_max, ttbr1_min, desc_addr;
int tsz, n;
LookupLevel start_lookup_level = LookupLevel::L1;
DPRINTF(TLB, "Beginning table walk for address %#x, TTBCR: %#x\n",
currState->vaddr_tainted, currState->ttbcr);
stats.walkWaitTime.sample(curTick() - currState->startTime);
Request::Flags flag = Request::PT_WALK;
if (currState->isSecure)
flag.set(Request::SECURE);
// work out which base address register to use, if in hyp mode we always
// use HTTBR
if (isStage2) {
DPRINTF(TLB, " - Selecting VTTBR (long-desc.)\n");
ttbr = currState->tc->readMiscReg(MISCREG_VTTBR);
tsz = sext<4>(currState->vtcr.t0sz);
start_lookup_level = currState->vtcr.sl0 ?
LookupLevel::L1 : LookupLevel::L2;
currState->isUncacheable = currState->vtcr.irgn0 == 0;
} else if (currState->isHyp) {
DPRINTF(TLB, " - Selecting HTTBR (long-desc.)\n");
ttbr = currState->tc->readMiscReg(MISCREG_HTTBR);
tsz = currState->htcr.t0sz;
currState->isUncacheable = currState->htcr.irgn0 == 0;
} else {
assert(longDescFormatInUse(currState->tc));
// Determine boundaries of TTBR0/1 regions
if (currState->ttbcr.t0sz)
ttbr0_max = (1ULL << (32 - currState->ttbcr.t0sz)) - 1;
else if (currState->ttbcr.t1sz)
ttbr0_max = (1ULL << 32) -
(1ULL << (32 - currState->ttbcr.t1sz)) - 1;
else
ttbr0_max = (1ULL << 32) - 1;
if (currState->ttbcr.t1sz)
ttbr1_min = (1ULL << 32) - (1ULL << (32 - currState->ttbcr.t1sz));
else
ttbr1_min = (1ULL << (32 - currState->ttbcr.t0sz));
const bool is_atomic = currState->req->isAtomic();
// The following code snippet selects the appropriate translation table base
// address (TTBR0 or TTBR1) and the appropriate starting lookup level
// depending on the address range supported by the translation table (ARM
// ARM issue C B3.6.4)
if (currState->vaddr <= ttbr0_max) {
DPRINTF(TLB, " - Selecting TTBR0 (long-desc.)\n");
// Check if table walk is allowed
if (currState->ttbcr.epd0) {
if (currState->isFetch)
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::LpaeTran);
else
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::LpaeTran);
}
ttbr = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_TTBR0, currState->tc, !currState->isSecure));
tsz = currState->ttbcr.t0sz;
currState->isUncacheable = currState->ttbcr.irgn0 == 0;
if (ttbr0_max < (1ULL << 30)) // Upper limit < 1 GiB
start_lookup_level = LookupLevel::L2;
} else if (currState->vaddr >= ttbr1_min) {
DPRINTF(TLB, " - Selecting TTBR1 (long-desc.)\n");
// Check if table walk is allowed
if (currState->ttbcr.epd1) {
if (currState->isFetch)
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::LpaeTran);
else
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::LpaeTran);
}
ttbr = currState->tc->readMiscReg(snsBankedIndex(
MISCREG_TTBR1, currState->tc, !currState->isSecure));
tsz = currState->ttbcr.t1sz;
currState->isUncacheable = currState->ttbcr.irgn1 == 0;
// Lower limit >= 3 GiB
if (ttbr1_min >= (1ULL << 31) + (1ULL << 30))
start_lookup_level = LookupLevel::L2;
} else {
// Out of boundaries -> translation fault
if (currState->isFetch)
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::LpaeTran);
else
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2, ArmFault::LpaeTran);
}
}
// Perform lookup (ARM ARM issue C B3.6.6)
if (start_lookup_level == LookupLevel::L1) {
n = 5 - tsz;
desc_addr = mbits(ttbr, 39, n) |
(bits(currState->vaddr, n + 26, 30) << 3);
DPRINTF(TLB, " - Descriptor at address %#x (%s) (long-desc.)\n",
desc_addr, currState->isSecure ? "s" : "ns");
} else {
// Skip first-level lookup
n = (tsz >= 2 ? 14 - tsz : 12);
desc_addr = mbits(ttbr, 39, n) |
(bits(currState->vaddr, n + 17, 21) << 3);
DPRINTF(TLB, " - Descriptor at address %#x (%s) (long-desc.)\n",
desc_addr, currState->isSecure ? "s" : "ns");
}
// Trickbox address check
Fault f = testWalk(desc_addr, sizeof(uint64_t),
TlbEntry::DomainType::NoAccess, start_lookup_level,
isStage2);
if (f) {
DPRINTF(TLB, "Trickbox check caused fault on %#x\n", currState->vaddr_tainted);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
if (currState->sctlr.c == 0 || currState->isUncacheable) {
flag.set(Request::UNCACHEABLE);
}
currState->longDesc.lookupLevel = start_lookup_level;
currState->longDesc.aarch64 = false;
currState->longDesc.grainSize = Grain4KB;
bool delayed = fetchDescriptor(desc_addr, (uint8_t*)&currState->longDesc.data,
sizeof(uint64_t), flag, start_lookup_level,
LongDescEventByLevel[start_lookup_level],
&TableWalker::doLongDescriptor);
if (!delayed) {
f = currState->fault;
}
return f;
}
bool
TableWalker::checkVAddrSizeFaultAArch64(Addr addr, int top_bit,
GrainSize tg, int tsz, bool low_range)
{
// The effective maximum input size is 48 if ARMv8.2-LVA is not
// supported or if the translation granule that is in use is 4KB or
// 16KB in size. When ARMv8.2-LVA is supported, for the 64KB
// translation granule size only, the effective minimum value of
// 52.
const bool have_lva = HaveExt(currState->tc, ArmExtension::FEAT_LVA);
int in_max = (have_lva && tg == Grain64KB) ? 52 : 48;
int in_min = 64 - (tg == Grain64KB ? 47 : 48);
return tsz > in_max || tsz < in_min || (low_range ?
bits(currState->vaddr, top_bit, tsz) != 0x0 :
bits(currState->vaddr, top_bit, tsz) != mask(top_bit - tsz + 1));
}
bool
TableWalker::checkAddrSizeFaultAArch64(Addr addr, int pa_range)
{
return (pa_range != _physAddrRange &&
bits(addr, _physAddrRange - 1, pa_range));
}
Fault
TableWalker::processWalkAArch64()
{
assert(currState->aarch64);
DPRINTF(TLB, "Beginning table walk for address %#llx, TCR: %#llx\n",
currState->vaddr_tainted, currState->tcr);
stats.walkWaitTime.sample(curTick() - currState->startTime);
// Determine TTBR, table size, granule size and phys. address range
Addr ttbr = 0;
int tsz = 0, ps = 0;
GrainSize tg = Grain4KB; // grain size computed from tg* field
bool fault = false;
int top_bit = computeAddrTop(currState->tc,
bits(currState->vaddr, 55),
currState->mode==BaseMMU::Execute,
currState->tcr,
currState->el);
bool vaddr_fault = false;
switch (currState->el) {
case EL0:
{
Addr ttbr0;
Addr ttbr1;
if (HaveExt(currState->tc, ArmExtension::FEAT_VHE) &&
currState->hcr.tge==1 && currState->hcr.e2h == 1) {
// VHE code for EL2&0 regime
ttbr0 = currState->tc->readMiscReg(MISCREG_TTBR0_EL2);
ttbr1 = currState->tc->readMiscReg(MISCREG_TTBR1_EL2);
} else {
ttbr0 = currState->tc->readMiscReg(MISCREG_TTBR0_EL1);
ttbr1 = currState->tc->readMiscReg(MISCREG_TTBR1_EL1);
}
switch (bits(currState->vaddr, 63,48)) {
case 0:
DPRINTF(TLB, " - Selecting TTBR0 (AArch64)\n");
ttbr = ttbr0;
tsz = 64 - currState->tcr.t0sz;
tg = GrainMap_tg0[currState->tcr.tg0];
currState->hpd = currState->tcr.hpd0;
currState->isUncacheable = currState->tcr.irgn0 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, true);
if (vaddr_fault || currState->tcr.epd0)
fault = true;
break;
case 0xffff:
DPRINTF(TLB, " - Selecting TTBR1 (AArch64)\n");
ttbr = ttbr1;
tsz = 64 - currState->tcr.t1sz;
tg = GrainMap_tg1[currState->tcr.tg1];
currState->hpd = currState->tcr.hpd1;
currState->isUncacheable = currState->tcr.irgn1 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, false);
if (vaddr_fault || currState->tcr.epd1)
fault = true;
break;
default:
// top two bytes must be all 0s or all 1s, else invalid addr
fault = true;
}
ps = currState->tcr.ips;
}
break;
case EL1:
if (isStage2) {
if (currState->secureLookup) {
DPRINTF(TLB, " - Selecting VSTTBR_EL2 (AArch64 stage 2)\n");
ttbr = currState->tc->readMiscReg(MISCREG_VSTTBR_EL2);
} else {
DPRINTF(TLB, " - Selecting VTTBR_EL2 (AArch64 stage 2)\n");
ttbr = currState->tc->readMiscReg(MISCREG_VTTBR_EL2);
}
tsz = 64 - currState->vtcr.t0sz64;
tg = GrainMap_tg0[currState->vtcr.tg0];
ps = currState->vtcr.ps;
currState->isUncacheable = currState->vtcr.irgn0 == 0;
} else {
switch (bits(currState->vaddr, top_bit)) {
case 0:
DPRINTF(TLB, " - Selecting TTBR0_EL1 (AArch64)\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR0_EL1);
tsz = 64 - currState->tcr.t0sz;
tg = GrainMap_tg0[currState->tcr.tg0];
currState->hpd = currState->tcr.hpd0;
currState->isUncacheable = currState->tcr.irgn0 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, true);
if (vaddr_fault || currState->tcr.epd0)
fault = true;
break;
case 0x1:
DPRINTF(TLB, " - Selecting TTBR1_EL1 (AArch64)\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR1_EL1);
tsz = 64 - currState->tcr.t1sz;
tg = GrainMap_tg1[currState->tcr.tg1];
currState->hpd = currState->tcr.hpd1;
currState->isUncacheable = currState->tcr.irgn1 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, false);
if (vaddr_fault || currState->tcr.epd1)
fault = true;
break;
default:
// top two bytes must be all 0s or all 1s, else invalid addr
fault = true;
}
ps = currState->tcr.ips;
}
break;
case EL2:
switch(bits(currState->vaddr, top_bit)) {
case 0:
DPRINTF(TLB, " - Selecting TTBR0_EL2 (AArch64)\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR0_EL2);
tsz = 64 - currState->tcr.t0sz;
tg = GrainMap_tg0[currState->tcr.tg0];
currState->hpd = currState->hcr.e2h ?
currState->tcr.hpd0 : currState->tcr.hpd;
currState->isUncacheable = currState->tcr.irgn0 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, true);
if (vaddr_fault || (currState->hcr.e2h && currState->tcr.epd0))
fault = true;
break;
case 0x1:
DPRINTF(TLB, " - Selecting TTBR1_EL2 (AArch64)\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR1_EL2);
tsz = 64 - currState->tcr.t1sz;
tg = GrainMap_tg1[currState->tcr.tg1];
currState->hpd = currState->tcr.hpd1;
currState->isUncacheable = currState->tcr.irgn1 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, false);
if (vaddr_fault || !currState->hcr.e2h || currState->tcr.epd1)
fault = true;
break;
default:
// invalid addr if top two bytes are not all 0s
fault = true;
}
ps = currState->hcr.e2h ? currState->tcr.ips: currState->tcr.ps;
break;
case EL3:
switch(bits(currState->vaddr, top_bit)) {
case 0:
DPRINTF(TLB, " - Selecting TTBR0_EL3 (AArch64)\n");
ttbr = currState->tc->readMiscReg(MISCREG_TTBR0_EL3);
tsz = 64 - currState->tcr.t0sz;
tg = GrainMap_tg0[currState->tcr.tg0];
currState->hpd = currState->tcr.hpd;
currState->isUncacheable = currState->tcr.irgn0 == 0;
vaddr_fault = checkVAddrSizeFaultAArch64(currState->vaddr,
top_bit, tg, tsz, true);
if (vaddr_fault)
fault = true;
break;
default:
// invalid addr if top two bytes are not all 0s
fault = true;
}
ps = currState->tcr.ps;
break;
}
const bool is_atomic = currState->req->isAtomic();
if (fault) {
Fault f;
if (currState->isFetch)
f = std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L0, isStage2,
ArmFault::LpaeTran);
else
f = std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L0,
isStage2, ArmFault::LpaeTran);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
if (tg == ReservedGrain) {
warn_once("Reserved granule size requested; gem5's IMPLEMENTATION "
"DEFINED behavior takes this to mean 4KB granules\n");
tg = Grain4KB;
}
// Clamp to lower limit
int pa_range = decodePhysAddrRange64(ps);
if (pa_range > _physAddrRange) {
currState->physAddrRange = _physAddrRange;
} else {
currState->physAddrRange = pa_range;
}
auto [table_addr, desc_addr, start_lookup_level] = walkAddresses(
ttbr, tg, tsz, pa_range);
// Determine physical address size and raise an Address Size Fault if
// necessary
if (checkAddrSizeFaultAArch64(table_addr, currState->physAddrRange)) {
DPRINTF(TLB, "Address size fault before any lookup\n");
Fault f;
if (currState->isFetch)
f = std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::AddressSizeLL + start_lookup_level,
isStage2,
ArmFault::LpaeTran);
else
f = std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::AddressSizeLL + start_lookup_level,
isStage2,
ArmFault::LpaeTran);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
// Trickbox address check
Fault f = testWalk(desc_addr, sizeof(uint64_t),
TlbEntry::DomainType::NoAccess, start_lookup_level, isStage2);
if (f) {
DPRINTF(TLB, "Trickbox check caused fault on %#x\n", currState->vaddr_tainted);
if (currState->timing) {
pending = false;
nextWalk(currState->tc);
currState = NULL;
} else {
currState->tc = NULL;
currState->req = NULL;
}
return f;
}
Request::Flags flag = Request::PT_WALK;
if (currState->sctlr.c == 0 || currState->isUncacheable) {
flag.set(Request::UNCACHEABLE);
}
if (currState->isSecure) {
flag.set(Request::SECURE);
}
currState->longDesc.lookupLevel = start_lookup_level;
currState->longDesc.aarch64 = true;
currState->longDesc.grainSize = tg;
currState->longDesc.physAddrRange = _physAddrRange;
if (currState->timing) {
fetchDescriptor(desc_addr, (uint8_t*) &currState->longDesc.data,
sizeof(uint64_t), flag, start_lookup_level,
LongDescEventByLevel[start_lookup_level], NULL);
} else {
fetchDescriptor(desc_addr, (uint8_t*)&currState->longDesc.data,
sizeof(uint64_t), flag, -1, NULL,
&TableWalker::doLongDescriptor);
f = currState->fault;
}
return f;
}
std::tuple<Addr, Addr, TableWalker::LookupLevel>
TableWalker::walkAddresses(Addr ttbr, GrainSize tg, int tsz, int pa_range)
{
const auto* ptops = getPageTableOps(tg);
LookupLevel first_level = LookupLevel::Num_ArmLookupLevel;
Addr table_addr = 0;
Addr desc_addr = 0;
if (currState->walkEntry.valid) {
// WalkCache hit
TlbEntry* entry = &currState->walkEntry;
DPRINTF(PageTableWalker,
"Walk Cache hit: va=%#x, level=%d, table address=%#x\n",
currState->vaddr, entry->lookupLevel, entry->pfn);
currState->xnTable = entry->xn;
currState->pxnTable = entry->pxn;
currState->rwTable = bits(entry->ap, 1);
currState->userTable = bits(entry->ap, 0);
table_addr = entry->pfn;
first_level = (LookupLevel)(entry->lookupLevel + 1);
} else {
// WalkCache miss
first_level = isStage2 ?
ptops->firstS2Level(currState->vtcr.sl0) :
ptops->firstLevel(64 - tsz);
panic_if(first_level == LookupLevel::Num_ArmLookupLevel,
"Table walker couldn't find lookup level\n");
int stride = tg - 3;
int base_addr_lo = 3 + tsz - stride * (3 - first_level) - tg;
if (pa_range == 52) {
int z = (base_addr_lo < 6) ? 6 : base_addr_lo;
table_addr = mbits(ttbr, 47, z);
table_addr |= (bits(ttbr, 5, 2) << 48);
} else {
table_addr = mbits(ttbr, 47, base_addr_lo);
}
}
desc_addr = table_addr + ptops->index(currState->vaddr, first_level, tsz);
return std::make_tuple(table_addr, desc_addr, first_level);
}
void
TableWalker::memAttrs(ThreadContext *tc, TlbEntry &te, SCTLR sctlr,
uint8_t texcb, bool s)
{
// Note: tc and sctlr local variables are hiding tc and sctrl class
// variables
DPRINTF(TLBVerbose, "memAttrs texcb:%d s:%d\n", texcb, s);
te.shareable = false; // default value
te.nonCacheable = false;
te.outerShareable = false;
if (sctlr.tre == 0 || ((sctlr.tre == 1) && (sctlr.m == 0))) {
switch(texcb) {
case 0: // Stongly-ordered
te.nonCacheable = true;
te.mtype = TlbEntry::MemoryType::StronglyOrdered;
te.shareable = true;
te.innerAttrs = 1;
te.outerAttrs = 0;
break;
case 1: // Shareable Device
te.nonCacheable = true;
te.mtype = TlbEntry::MemoryType::Device;
te.shareable = true;
te.innerAttrs = 3;
te.outerAttrs = 0;
break;
case 2: // Outer and Inner Write-Through, no Write-Allocate
te.mtype = TlbEntry::MemoryType::Normal;
te.shareable = s;
te.innerAttrs = 6;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 3: // Outer and Inner Write-Back, no Write-Allocate
te.mtype = TlbEntry::MemoryType::Normal;
te.shareable = s;
te.innerAttrs = 7;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 4: // Outer and Inner Non-cacheable
te.nonCacheable = true;
te.mtype = TlbEntry::MemoryType::Normal;
te.shareable = s;
te.innerAttrs = 0;
te.outerAttrs = bits(texcb, 1, 0);
break;
case 5: // Reserved
panic("Reserved texcb value!\n");
break;
case 6: // Implementation Defined
panic("Implementation-defined texcb value!\n");
break;
case 7: // Outer and Inner Write-Back, Write-Allocate
te.mtype = TlbEntry::MemoryType::Normal;
te.shareable = s;
te.innerAttrs = 5;
te.outerAttrs = 1;
break;
case 8: // Non-shareable Device
te.nonCacheable = true;
te.mtype = TlbEntry::MemoryType::Device;
te.shareable = false;
te.innerAttrs = 3;
te.outerAttrs = 0;
break;
case 9 ... 15: // Reserved
panic("Reserved texcb value!\n");
break;
case 16 ... 31: // Cacheable Memory
te.mtype = TlbEntry::MemoryType::Normal;
te.shareable = s;
if (bits(texcb, 1,0) == 0 || bits(texcb, 3,2) == 0)
te.nonCacheable = true;
te.innerAttrs = bits(texcb, 1, 0);
te.outerAttrs = bits(texcb, 3, 2);
break;
default:
panic("More than 32 states for 5 bits?\n");
}
} else {
assert(tc);
PRRR prrr = tc->readMiscReg(snsBankedIndex(MISCREG_PRRR,
currState->tc, !currState->isSecure));
NMRR nmrr = tc->readMiscReg(snsBankedIndex(MISCREG_NMRR,
currState->tc, !currState->isSecure));
DPRINTF(TLBVerbose, "memAttrs PRRR:%08x NMRR:%08x\n", prrr, nmrr);
uint8_t curr_tr = 0, curr_ir = 0, curr_or = 0;
switch(bits(texcb, 2,0)) {
case 0:
curr_tr = prrr.tr0;
curr_ir = nmrr.ir0;
curr_or = nmrr.or0;
te.outerShareable = (prrr.nos0 == 0);
break;
case 1:
curr_tr = prrr.tr1;
curr_ir = nmrr.ir1;
curr_or = nmrr.or1;
te.outerShareable = (prrr.nos1 == 0);
break;
case 2:
curr_tr = prrr.tr2;
curr_ir = nmrr.ir2;
curr_or = nmrr.or2;
te.outerShareable = (prrr.nos2 == 0);
break;
case 3:
curr_tr = prrr.tr3;
curr_ir = nmrr.ir3;
curr_or = nmrr.or3;
te.outerShareable = (prrr.nos3 == 0);
break;
case 4:
curr_tr = prrr.tr4;
curr_ir = nmrr.ir4;
curr_or = nmrr.or4;
te.outerShareable = (prrr.nos4 == 0);
break;
case 5:
curr_tr = prrr.tr5;
curr_ir = nmrr.ir5;
curr_or = nmrr.or5;
te.outerShareable = (prrr.nos5 == 0);
break;
case 6:
panic("Imp defined type\n");
case 7:
curr_tr = prrr.tr7;
curr_ir = nmrr.ir7;
curr_or = nmrr.or7;
te.outerShareable = (prrr.nos7 == 0);
break;
}
switch(curr_tr) {
case 0:
DPRINTF(TLBVerbose, "StronglyOrdered\n");
te.mtype = TlbEntry::MemoryType::StronglyOrdered;
te.nonCacheable = true;
te.innerAttrs = 1;
te.outerAttrs = 0;
te.shareable = true;
break;
case 1:
DPRINTF(TLBVerbose, "Device ds1:%d ds0:%d s:%d\n",
prrr.ds1, prrr.ds0, s);
te.mtype = TlbEntry::MemoryType::Device;
te.nonCacheable = true;
te.innerAttrs = 3;
te.outerAttrs = 0;
if (prrr.ds1 && s)
te.shareable = true;
if (prrr.ds0 && !s)
te.shareable = true;
break;
case 2:
DPRINTF(TLBVerbose, "Normal ns1:%d ns0:%d s:%d\n",
prrr.ns1, prrr.ns0, s);
te.mtype = TlbEntry::MemoryType::Normal;
if (prrr.ns1 && s)
te.shareable = true;
if (prrr.ns0 && !s)
te.shareable = true;
break;
case 3:
panic("Reserved type");
}
if (te.mtype == TlbEntry::MemoryType::Normal){
switch(curr_ir) {
case 0:
te.nonCacheable = true;
te.innerAttrs = 0;
break;
case 1:
te.innerAttrs = 5;
break;
case 2:
te.innerAttrs = 6;
break;
case 3:
te.innerAttrs = 7;
break;
}
switch(curr_or) {
case 0:
te.nonCacheable = true;
te.outerAttrs = 0;
break;
case 1:
te.outerAttrs = 1;
break;
case 2:
te.outerAttrs = 2;
break;
case 3:
te.outerAttrs = 3;
break;
}
}
}
DPRINTF(TLBVerbose, "memAttrs: shareable: %d, innerAttrs: %d, "
"outerAttrs: %d\n",
te.shareable, te.innerAttrs, te.outerAttrs);
te.setAttributes(false);
}
void
TableWalker::memAttrsLPAE(ThreadContext *tc, TlbEntry &te,
LongDescriptor &l_descriptor)
{
assert(release->has(ArmExtension::LPAE));
uint8_t attr;
uint8_t sh = l_descriptor.sh();
// Different format and source of attributes if this is a stage 2
// translation
if (isStage2) {
attr = l_descriptor.memAttr();
uint8_t attr_3_2 = (attr >> 2) & 0x3;
uint8_t attr_1_0 = attr & 0x3;
DPRINTF(TLBVerbose, "memAttrsLPAE MemAttr:%#x sh:%#x\n", attr, sh);
if (attr_3_2 == 0) {
te.mtype = attr_1_0 == 0 ? TlbEntry::MemoryType::StronglyOrdered
: TlbEntry::MemoryType::Device;
te.outerAttrs = 0;
te.innerAttrs = attr_1_0 == 0 ? 1 : 3;
te.nonCacheable = true;
} else {
te.mtype = TlbEntry::MemoryType::Normal;
te.outerAttrs = attr_3_2 == 1 ? 0 :
attr_3_2 == 2 ? 2 : 1;
te.innerAttrs = attr_1_0 == 1 ? 0 :
attr_1_0 == 2 ? 6 : 5;
te.nonCacheable = (attr_3_2 == 1) || (attr_1_0 == 1);
}
} else {
uint8_t attrIndx = l_descriptor.attrIndx();
// LPAE always uses remapping of memory attributes, irrespective of the
// value of SCTLR.TRE
MiscRegIndex reg = attrIndx & 0x4 ? MISCREG_MAIR1 : MISCREG_MAIR0;
int reg_as_int = snsBankedIndex(reg, currState->tc,
!currState->isSecure);
uint32_t mair = currState->tc->readMiscReg(reg_as_int);
attr = (mair >> (8 * (attrIndx % 4))) & 0xff;
uint8_t attr_7_4 = bits(attr, 7, 4);
uint8_t attr_3_0 = bits(attr, 3, 0);
DPRINTF(TLBVerbose, "memAttrsLPAE AttrIndx:%#x sh:%#x, attr %#x\n", attrIndx, sh, attr);
// Note: the memory subsystem only cares about the 'cacheable' memory
// attribute. The other attributes are only used to fill the PAR register
// accordingly to provide the illusion of full support
te.nonCacheable = false;
switch (attr_7_4) {
case 0x0:
// Strongly-ordered or Device memory
if (attr_3_0 == 0x0)
te.mtype = TlbEntry::MemoryType::StronglyOrdered;
else if (attr_3_0 == 0x4)
te.mtype = TlbEntry::MemoryType::Device;
else
panic("Unpredictable behavior\n");
te.nonCacheable = true;
te.outerAttrs = 0;
break;
case 0x4:
// Normal memory, Outer Non-cacheable
te.mtype = TlbEntry::MemoryType::Normal;
te.outerAttrs = 0;
if (attr_3_0 == 0x4)
// Inner Non-cacheable
te.nonCacheable = true;
else if (attr_3_0 < 0x8)
panic("Unpredictable behavior\n");
break;
case 0x8:
case 0x9:
case 0xa:
case 0xb:
case 0xc:
case 0xd:
case 0xe:
case 0xf:
if (attr_7_4 & 0x4) {
te.outerAttrs = (attr_7_4 & 1) ? 1 : 3;
} else {
te.outerAttrs = 0x2;
}
// Normal memory, Outer Cacheable
te.mtype = TlbEntry::MemoryType::Normal;
if (attr_3_0 != 0x4 && attr_3_0 < 0x8)
panic("Unpredictable behavior\n");
break;
default:
panic("Unpredictable behavior\n");
break;
}
switch (attr_3_0) {
case 0x0:
te.innerAttrs = 0x1;
break;
case 0x4:
te.innerAttrs = attr_7_4 == 0 ? 0x3 : 0;
break;
case 0x8:
case 0x9:
case 0xA:
case 0xB:
te.innerAttrs = 6;
break;
case 0xC:
case 0xD:
case 0xE:
case 0xF:
te.innerAttrs = attr_3_0 & 1 ? 0x5 : 0x7;
break;
default:
panic("Unpredictable behavior\n");
break;
}
}
te.outerShareable = sh == 2;
te.shareable = (sh & 0x2) ? true : false;
te.setAttributes(true);
te.attributes |= (uint64_t) attr << 56;
}
void
TableWalker::memAttrsAArch64(ThreadContext *tc, TlbEntry &te,
LongDescriptor &l_descriptor)
{
uint8_t attr;
uint8_t attr_hi;
uint8_t attr_lo;
uint8_t sh = l_descriptor.sh();
if (isStage2) {
attr = l_descriptor.memAttr();
uint8_t attr_hi = (attr >> 2) & 0x3;
uint8_t attr_lo = attr & 0x3;
DPRINTF(TLBVerbose, "memAttrsAArch64 MemAttr:%#x sh:%#x\n", attr, sh);
if (attr_hi == 0) {
te.mtype = attr_lo == 0 ? TlbEntry::MemoryType::StronglyOrdered
: TlbEntry::MemoryType::Device;
te.outerAttrs = 0;
te.innerAttrs = attr_lo == 0 ? 1 : 3;
te.nonCacheable = true;
} else {
te.mtype = TlbEntry::MemoryType::Normal;
te.outerAttrs = attr_hi == 1 ? 0 :
attr_hi == 2 ? 2 : 1;
te.innerAttrs = attr_lo == 1 ? 0 :
attr_lo == 2 ? 6 : 5;
// Treat write-through memory as uncacheable, this is safe
// but for performance reasons not optimal.
te.nonCacheable = (attr_hi == 1) || (attr_hi == 2) ||
(attr_lo == 1) || (attr_lo == 2);
}
} else {
uint8_t attrIndx = l_descriptor.attrIndx();
DPRINTF(TLBVerbose, "memAttrsAArch64 AttrIndx:%#x sh:%#x\n", attrIndx, sh);
ExceptionLevel regime = s1TranslationRegime(tc, currState->el);
// Select MAIR
uint64_t mair;
switch (regime) {
case EL0:
case EL1:
mair = tc->readMiscReg(MISCREG_MAIR_EL1);
break;
case EL2:
mair = tc->readMiscReg(MISCREG_MAIR_EL2);
break;
case EL3:
mair = tc->readMiscReg(MISCREG_MAIR_EL3);
break;
default:
panic("Invalid exception level");
break;
}
// Select attributes
attr = bits(mair, 8 * attrIndx + 7, 8 * attrIndx);
attr_lo = bits(attr, 3, 0);
attr_hi = bits(attr, 7, 4);
// Memory type
te.mtype = attr_hi == 0 ? TlbEntry::MemoryType::Device : TlbEntry::MemoryType::Normal;
// Cacheability
te.nonCacheable = false;
if (te.mtype == TlbEntry::MemoryType::Device) { // Device memory
te.nonCacheable = true;
}
// Treat write-through memory as uncacheable, this is safe
// but for performance reasons not optimal.
switch (attr_hi) {
case 0x1 ... 0x3: // Normal Memory, Outer Write-through transient
case 0x4: // Normal memory, Outer Non-cacheable
case 0x8 ... 0xb: // Normal Memory, Outer Write-through non-transient
te.nonCacheable = true;
}
switch (attr_lo) {
case 0x1 ... 0x3: // Normal Memory, Inner Write-through transient
case 0x9 ... 0xb: // Normal Memory, Inner Write-through non-transient
warn_if(!attr_hi, "Unpredictable behavior");
[[fallthrough]];
case 0x4: // Device-nGnRE memory or
// Normal memory, Inner Non-cacheable
case 0x8: // Device-nGRE memory or
// Normal memory, Inner Write-through non-transient
te.nonCacheable = true;
}
te.shareable = sh == 2;
te.outerShareable = (sh & 0x2) ? true : false;
// Attributes formatted according to the 64-bit PAR
te.attributes = ((uint64_t) attr << 56) |
(1 << 11) | // LPAE bit
(te.ns << 9) | // NS bit
(sh << 7);
}
}
void
TableWalker::doL1Descriptor()
{
if (currState->fault != NoFault) {
return;
}
currState->l1Desc.data = htog(currState->l1Desc.data,
byteOrder(currState->tc));
DPRINTF(TLB, "L1 descriptor for %#x is %#x\n",
currState->vaddr_tainted, currState->l1Desc.data);
TlbEntry te;
const bool is_atomic = currState->req->isAtomic();
switch (currState->l1Desc.type()) {
case L1Descriptor::Ignore:
case L1Descriptor::Reserved:
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
DPRINTF(TLB, "L1 Descriptor Reserved/Ignore, causing fault\n");
if (currState->isFetch)
currState->fault =
std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L1,
isStage2,
ArmFault::VmsaTran);
else
currState->fault =
std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L1, isStage2,
ArmFault::VmsaTran);
return;
case L1Descriptor::Section:
if (currState->sctlr.afe && bits(currState->l1Desc.ap(), 0) == 0) {
/** @todo: check sctlr.ha (bit[17]) if Hardware Access Flag is
* enabled if set, do l1.Desc.setAp0() instead of generating
* AccessFlag0
*/
currState->fault = std::make_shared<DataAbort>(
currState->vaddr_tainted,
currState->l1Desc.domain(),
is_atomic ? false : currState->isWrite,
ArmFault::AccessFlagLL + LookupLevel::L1,
isStage2,
ArmFault::VmsaTran);
}
if (currState->l1Desc.supersection()) {
panic("Haven't implemented supersections\n");
}
insertTableEntry(currState->l1Desc, false);
return;
case L1Descriptor::PageTable:
{
Addr l2desc_addr;
l2desc_addr = currState->l1Desc.l2Addr() |
(bits(currState->vaddr, 19, 12) << 2);
DPRINTF(TLB, "L1 descriptor points to page table at: %#x (%s)\n",
l2desc_addr, currState->isSecure ? "s" : "ns");
// Trickbox address check
currState->fault = testWalk(l2desc_addr, sizeof(uint32_t),
currState->l1Desc.domain(),
LookupLevel::L2, isStage2);
if (currState->fault) {
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
return;
}
Request::Flags flag = Request::PT_WALK;
if (currState->sctlr.c == 0 || currState->isUncacheable) {
flag.set(Request::UNCACHEABLE);
}
if (currState->isSecure)
flag.set(Request::SECURE);
bool delayed;
delayed = fetchDescriptor(l2desc_addr,
(uint8_t*)&currState->l2Desc.data,
sizeof(uint32_t), flag, -1, &doL2DescEvent,
&TableWalker::doL2Descriptor);
if (delayed) {
currState->delayed = true;
}
return;
}
default:
panic("A new type in a 2 bit field?\n");
}
}
Fault
TableWalker::generateLongDescFault(ArmFault::FaultSource src)
{
if (currState->isFetch) {
return std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
src + currState->longDesc.lookupLevel,
isStage2,
ArmFault::LpaeTran);
} else {
return std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
currState->req->isAtomic() ? false : currState->isWrite,
src + currState->longDesc.lookupLevel,
isStage2,
ArmFault::LpaeTran);
}
}
void
TableWalker::doLongDescriptor()
{
if (currState->fault != NoFault) {
return;
}
currState->longDesc.data = htog(currState->longDesc.data,
byteOrder(currState->tc));
DPRINTF(TLB, "L%d descriptor for %#llx is %#llx (%s)\n",
currState->longDesc.lookupLevel, currState->vaddr_tainted,
currState->longDesc.data,
currState->aarch64 ? "AArch64" : "long-desc.");
if ((currState->longDesc.type() == LongDescriptor::Block) ||
(currState->longDesc.type() == LongDescriptor::Page)) {
DPRINTF(PageTableWalker, "Analyzing L%d descriptor: %#llx, pxn: %d, "
"xn: %d, ap: %d, af: %d, type: %d\n",
currState->longDesc.lookupLevel,
currState->longDesc.data,
currState->longDesc.pxn(),
currState->longDesc.xn(),
currState->longDesc.ap(),
currState->longDesc.af(),
currState->longDesc.type());
} else {
DPRINTF(PageTableWalker, "Analyzing L%d descriptor: %#llx, type: %d\n",
currState->longDesc.lookupLevel,
currState->longDesc.data,
currState->longDesc.type());
}
TlbEntry te;
switch (currState->longDesc.type()) {
case LongDescriptor::Invalid:
DPRINTF(TLB, "L%d descriptor Invalid, causing fault type %d\n",
currState->longDesc.lookupLevel,
ArmFault::TranslationLL + currState->longDesc.lookupLevel);
currState->fault = generateLongDescFault(ArmFault::TranslationLL);
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
return;
case LongDescriptor::Block:
case LongDescriptor::Page:
{
auto fault_source = ArmFault::FaultSourceInvalid;
// Check for address size fault
if (checkAddrSizeFaultAArch64(currState->longDesc.paddr(),
currState->physAddrRange)) {
DPRINTF(TLB, "L%d descriptor causing Address Size Fault\n",
currState->longDesc.lookupLevel);
fault_source = ArmFault::AddressSizeLL;
// Check for access fault
} else if (currState->longDesc.af() == 0) {
DPRINTF(TLB, "L%d descriptor causing Access Fault\n",
currState->longDesc.lookupLevel);
fault_source = ArmFault::AccessFlagLL;
}
if (fault_source != ArmFault::FaultSourceInvalid) {
currState->fault = generateLongDescFault(fault_source);
} else {
insertTableEntry(currState->longDesc, true);
}
}
return;
case LongDescriptor::Table:
{
// Set hierarchical permission flags
currState->secureLookup = currState->secureLookup &&
currState->longDesc.secureTable();
currState->rwTable = currState->rwTable &&
(currState->longDesc.rwTable() || currState->hpd);
currState->userTable = currState->userTable &&
(currState->longDesc.userTable() || currState->hpd);
currState->xnTable = currState->xnTable ||
(currState->longDesc.xnTable() && !currState->hpd);
currState->pxnTable = currState->pxnTable ||
(currState->longDesc.pxnTable() && !currState->hpd);
// Set up next level lookup
Addr next_desc_addr = currState->longDesc.nextDescAddr(
currState->vaddr);
DPRINTF(TLB, "L%d descriptor points to L%d descriptor at: %#x (%s)\n",
currState->longDesc.lookupLevel,
currState->longDesc.lookupLevel + 1,
next_desc_addr,
currState->secureLookup ? "s" : "ns");
// Check for address size fault
if (currState->aarch64 && checkAddrSizeFaultAArch64(
next_desc_addr, currState->physAddrRange)) {
DPRINTF(TLB, "L%d descriptor causing Address Size Fault\n",
currState->longDesc.lookupLevel);
currState->fault = generateLongDescFault(
ArmFault::AddressSizeLL);
return;
}
// Trickbox address check
currState->fault = testWalk(
next_desc_addr, sizeof(uint64_t), TlbEntry::DomainType::Client,
toLookupLevel(currState->longDesc.lookupLevel +1), isStage2);
if (currState->fault) {
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
return;
}
if (mmu->hasWalkCache()) {
insertPartialTableEntry(currState->longDesc);
}
Request::Flags flag = Request::PT_WALK;
if (currState->secureLookup)
flag.set(Request::SECURE);
if (currState->sctlr.c == 0 || currState->isUncacheable) {
flag.set(Request::UNCACHEABLE);
}
LookupLevel L = currState->longDesc.lookupLevel =
(LookupLevel) (currState->longDesc.lookupLevel + 1);
Event *event = NULL;
switch (L) {
case LookupLevel::L1:
assert(currState->aarch64);
case LookupLevel::L2:
case LookupLevel::L3:
event = LongDescEventByLevel[L];
break;
default:
panic("Wrong lookup level in table walk\n");
break;
}
bool delayed;
delayed = fetchDescriptor(next_desc_addr, (uint8_t*)&currState->longDesc.data,
sizeof(uint64_t), flag, -1, event,
&TableWalker::doLongDescriptor);
if (delayed) {
currState->delayed = true;
}
}
return;
default:
panic("A new type in a 2 bit field?\n");
}
}
void
TableWalker::doL2Descriptor()
{
if (currState->fault != NoFault) {
return;
}
currState->l2Desc.data = htog(currState->l2Desc.data,
byteOrder(currState->tc));
DPRINTF(TLB, "L2 descriptor for %#x is %#x\n",
currState->vaddr_tainted, currState->l2Desc.data);
TlbEntry te;
const bool is_atomic = currState->req->isAtomic();
if (currState->l2Desc.invalid()) {
DPRINTF(TLB, "L2 descriptor invalid, causing fault\n");
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
if (currState->isFetch)
currState->fault = std::make_shared<PrefetchAbort>(
currState->vaddr_tainted,
ArmFault::TranslationLL + LookupLevel::L2,
isStage2,
ArmFault::VmsaTran);
else
currState->fault = std::make_shared<DataAbort>(
currState->vaddr_tainted, currState->l1Desc.domain(),
is_atomic ? false : currState->isWrite,
ArmFault::TranslationLL + LookupLevel::L2,
isStage2,
ArmFault::VmsaTran);
return;
}
if (currState->sctlr.afe && bits(currState->l2Desc.ap(), 0) == 0) {
/** @todo: check sctlr.ha (bit[17]) if Hardware Access Flag is enabled
* if set, do l2.Desc.setAp0() instead of generating AccessFlag0
*/
DPRINTF(TLB, "Generating access fault at L2, afe: %d, ap: %d\n",
currState->sctlr.afe, currState->l2Desc.ap());
currState->fault = std::make_shared<DataAbort>(
currState->vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : currState->isWrite,
ArmFault::AccessFlagLL + LookupLevel::L2, isStage2,
ArmFault::VmsaTran);
}
insertTableEntry(currState->l2Desc, false);
}
void
TableWalker::doL1DescriptorWrapper()
{
currState = stateQueues[LookupLevel::L1].front();
currState->delayed = false;
// if there's a stage2 translation object we don't need it any more
if (currState->stage2Tran) {
delete currState->stage2Tran;
currState->stage2Tran = NULL;
}
DPRINTF(PageTableWalker, "L1 Desc object host addr: %p\n",
&currState->l1Desc.data);
DPRINTF(PageTableWalker, "L1 Desc object data: %08x\n",
currState->l1Desc.data);
DPRINTF(PageTableWalker, "calling doL1Descriptor for vaddr:%#x\n",
currState->vaddr_tainted);
doL1Descriptor();
stateQueues[LookupLevel::L1].pop_front();
// Check if fault was generated
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
stats.walksShortTerminatedAtLevel[0]++;
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
}
else if (!currState->delayed) {
// delay is not set so there is no L2 to do
// Don't finish the translation if a stage 2 look up is underway
stats.walkServiceTime.sample(curTick() - currState->startTime);
DPRINTF(PageTableWalker, "calling translateTiming again\n");
mmu->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode,
currState->tranType, isStage2);
stats.walksShortTerminatedAtLevel[0]++;
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
} else {
// need to do L2 descriptor
stateQueues[LookupLevel::L2].push_back(currState);
}
currState = NULL;
}
void
TableWalker::doL2DescriptorWrapper()
{
currState = stateQueues[LookupLevel::L2].front();
assert(currState->delayed);
// if there's a stage2 translation object we don't need it any more
if (currState->stage2Tran) {
delete currState->stage2Tran;
currState->stage2Tran = NULL;
}
DPRINTF(PageTableWalker, "calling doL2Descriptor for vaddr:%#x\n",
currState->vaddr_tainted);
doL2Descriptor();
// Check if fault was generated
if (currState->fault != NoFault) {
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
stats.walksShortTerminatedAtLevel[1]++;
} else {
stats.walkServiceTime.sample(curTick() - currState->startTime);
DPRINTF(PageTableWalker, "calling translateTiming again\n");
mmu->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode,
currState->tranType, isStage2);
stats.walksShortTerminatedAtLevel[1]++;
}
stateQueues[LookupLevel::L2].pop_front();
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
currState = NULL;
}
void
TableWalker::doL0LongDescriptorWrapper()
{
doLongDescriptorWrapper(LookupLevel::L0);
}
void
TableWalker::doL1LongDescriptorWrapper()
{
doLongDescriptorWrapper(LookupLevel::L1);
}
void
TableWalker::doL2LongDescriptorWrapper()
{
doLongDescriptorWrapper(LookupLevel::L2);
}
void
TableWalker::doL3LongDescriptorWrapper()
{
doLongDescriptorWrapper(LookupLevel::L3);
}
void
TableWalker::doLongDescriptorWrapper(LookupLevel curr_lookup_level)
{
currState = stateQueues[curr_lookup_level].front();
assert(curr_lookup_level == currState->longDesc.lookupLevel);
currState->delayed = false;
// if there's a stage2 translation object we don't need it any more
if (currState->stage2Tran) {
delete currState->stage2Tran;
currState->stage2Tran = NULL;
}
DPRINTF(PageTableWalker, "calling doLongDescriptor for vaddr:%#x\n",
currState->vaddr_tainted);
doLongDescriptor();
stateQueues[curr_lookup_level].pop_front();
if (currState->fault != NoFault) {
// A fault was generated
currState->transState->finish(currState->fault, currState->req,
currState->tc, currState->mode);
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
} else if (!currState->delayed) {
// No additional lookups required
DPRINTF(PageTableWalker, "calling translateTiming again\n");
stats.walkServiceTime.sample(curTick() - currState->startTime);
mmu->translateTiming(currState->req, currState->tc,
currState->transState, currState->mode,
currState->tranType, isStage2);
stats.walksLongTerminatedAtLevel[(unsigned) curr_lookup_level]++;
pending = false;
nextWalk(currState->tc);
currState->req = NULL;
currState->tc = NULL;
currState->delayed = false;
delete currState;
} else {
if (curr_lookup_level >= LookupLevel::Num_ArmLookupLevel - 1)
panic("Max. number of lookups already reached in table walk\n");
// Need to perform additional lookups
stateQueues[currState->longDesc.lookupLevel].push_back(currState);
}
currState = NULL;
}
void
TableWalker::nextWalk(ThreadContext *tc)
{
if (pendingQueue.size())
schedule(doProcessEvent, clockEdge(Cycles(1)));
else
completeDrain();
}
bool
TableWalker::fetchDescriptor(Addr descAddr, uint8_t *data, int numBytes,
Request::Flags flags, int queueIndex, Event *event,
void (TableWalker::*doDescriptor)())
{
bool isTiming = currState->timing;
DPRINTF(PageTableWalker,
"Fetching descriptor at address: 0x%x stage2Req: %d\n",
descAddr, currState->stage2Req);
// If this translation has a stage 2 then we know descAddr is an IPA and
// needs to be translated before we can access the page table. Do that
// check here.
if (currState->stage2Req) {
Fault fault;
if (isTiming) {
auto *tran = new
Stage2Walk(*this, data, event, currState->vaddr,
currState->mode, currState->tranType);
currState->stage2Tran = tran;
readDataTimed(currState->tc, descAddr, tran, numBytes, flags);
fault = tran->fault;
} else {
fault = readDataUntimed(currState->tc,
currState->vaddr, descAddr, data, numBytes, flags,
currState->mode,
currState->tranType,
currState->functional);
}
if (fault != NoFault) {
currState->fault = fault;
}
if (isTiming) {
if (queueIndex >= 0) {
DPRINTF(PageTableWalker, "Adding to walker fifo: "
"queue size before adding: %d\n",
stateQueues[queueIndex].size());
stateQueues[queueIndex].push_back(currState);
currState = NULL;
}
} else {
(this->*doDescriptor)();
}
} else {
if (isTiming) {
port->sendTimingReq(descAddr, numBytes, data, flags,
currState->tc->getCpuPtr()->clockPeriod(), event);
if (queueIndex >= 0) {
DPRINTF(PageTableWalker, "Adding to walker fifo: "
"queue size before adding: %d\n",
stateQueues[queueIndex].size());
stateQueues[queueIndex].push_back(currState);
currState = NULL;
}
} else if (!currState->functional) {
port->sendAtomicReq(descAddr, numBytes, data, flags,
currState->tc->getCpuPtr()->clockPeriod());
(this->*doDescriptor)();
} else {
port->sendFunctionalReq(descAddr, numBytes, data, flags);
(this->*doDescriptor)();
}
}
return (isTiming);
}
void
TableWalker::insertPartialTableEntry(LongDescriptor &descriptor)
{
const bool have_security = release->has(ArmExtension::SECURITY);
TlbEntry te;
// Create and fill a new page table entry
te.valid = true;
te.longDescFormat = true;
te.partial = true;
// The entry is global if there is no address space identifier
// to differentiate translation contexts
te.global = !mmu->hasUnprivRegime(
currState->el, currState->hcr.e2h);
te.isHyp = currState->isHyp;
te.asid = currState->asid;
te.vmid = currState->vmid;
te.N = descriptor.offsetBits();
te.vpn = currState->vaddr >> te.N;
te.size = (1ULL << te.N) - 1;
te.pfn = descriptor.nextTableAddr();
te.domain = descriptor.domain();
te.lookupLevel = descriptor.lookupLevel;
te.ns = !descriptor.secure(have_security, currState);
te.nstid = !currState->isSecure;
te.type = TypeTLB::unified;
if (currState->aarch64)
te.el = currState->el;
else
te.el = EL1;
te.xn = currState->xnTable;
te.pxn = currState->pxnTable;
te.ap = (currState->rwTable << 1) | (currState->userTable);
// Debug output
DPRINTF(TLB, descriptor.dbgHeader().c_str());
DPRINTF(TLB, " - N:%d pfn:%#x size:%#x global:%d valid:%d\n",
te.N, te.pfn, te.size, te.global, te.valid);
DPRINTF(TLB, " - vpn:%#x xn:%d pxn:%d ap:%d domain:%d asid:%d "
"vmid:%d hyp:%d nc:%d ns:%d\n", te.vpn, te.xn, te.pxn,
te.ap, static_cast<uint8_t>(te.domain), te.asid, te.vmid, te.isHyp,
te.nonCacheable, te.ns);
DPRINTF(TLB, " - domain from L%d desc:%d data:%#x\n",
descriptor.lookupLevel, static_cast<uint8_t>(descriptor.domain()),
descriptor.getRawData());
// Insert the entry into the TLBs
tlb->multiInsert(te);
}
void
TableWalker::insertTableEntry(DescriptorBase &descriptor, bool long_descriptor)
{
const bool have_security = release->has(ArmExtension::SECURITY);
TlbEntry te;
// Create and fill a new page table entry
te.valid = true;
te.longDescFormat = long_descriptor;
te.isHyp = currState->isHyp;
te.asid = currState->asid;
te.vmid = currState->vmid;
te.N = descriptor.offsetBits();
te.vpn = currState->vaddr >> te.N;
te.size = (1<<te.N) - 1;
te.pfn = descriptor.pfn();
te.domain = descriptor.domain();
te.lookupLevel = descriptor.lookupLevel;
te.ns = !descriptor.secure(have_security, currState);
te.nstid = !currState->isSecure;
te.xn = descriptor.xn();
te.type = currState->mode == BaseMMU::Execute ?
TypeTLB::instruction : TypeTLB::data;
if (currState->aarch64)
te.el = currState->el;
else
te.el = EL1;
stats.pageSizes[pageSizeNtoStatBin(te.N)]++;
stats.requestOrigin[COMPLETED][currState->isFetch]++;
// ASID has no meaning for stage 2 TLB entries, so mark all stage 2 entries
// as global
te.global = descriptor.global(currState) || isStage2;
if (long_descriptor) {
LongDescriptor l_descriptor =
dynamic_cast<LongDescriptor &>(descriptor);
te.xn |= currState->xnTable;
te.pxn = currState->pxnTable || l_descriptor.pxn();
if (isStage2) {
// this is actually the HAP field, but its stored in the same bit
// possitions as the AP field in a stage 1 translation.
te.hap = l_descriptor.ap();
} else {
te.ap = ((!currState->rwTable || descriptor.ap() >> 1) << 1) |
(currState->userTable && (descriptor.ap() & 0x1));
}
if (currState->aarch64)
memAttrsAArch64(currState->tc, te, l_descriptor);
else
memAttrsLPAE(currState->tc, te, l_descriptor);
} else {
te.ap = descriptor.ap();
memAttrs(currState->tc, te, currState->sctlr, descriptor.texcb(),
descriptor.shareable());
}
// Debug output
DPRINTF(TLB, descriptor.dbgHeader().c_str());
DPRINTF(TLB, " - N:%d pfn:%#x size:%#x global:%d valid:%d\n",
te.N, te.pfn, te.size, te.global, te.valid);
DPRINTF(TLB, " - vpn:%#x xn:%d pxn:%d ap:%d domain:%d asid:%d "
"vmid:%d hyp:%d nc:%d ns:%d\n", te.vpn, te.xn, te.pxn,
te.ap, static_cast<uint8_t>(te.domain), te.asid, te.vmid, te.isHyp,
te.nonCacheable, te.ns);
DPRINTF(TLB, " - domain from L%d desc:%d data:%#x\n",
descriptor.lookupLevel, static_cast<uint8_t>(descriptor.domain()),
descriptor.getRawData());
// Insert the entry into the TLBs
tlb->multiInsert(te);
if (!currState->timing) {
currState->tc = NULL;
currState->req = NULL;
}
}
TableWalker::LookupLevel
TableWalker::toLookupLevel(uint8_t lookup_level_as_int)
{
switch (lookup_level_as_int) {
case LookupLevel::L1:
return LookupLevel::L1;
case LookupLevel::L2:
return LookupLevel::L2;
case LookupLevel::L3:
return LookupLevel::L3;
default:
panic("Invalid lookup level conversion");
}
}
/* this method keeps track of the table walker queue's residency, so
* needs to be called whenever requests start and complete. */
void
TableWalker::pendingChange()
{
unsigned n = pendingQueue.size();
if ((currState != NULL) && (currState != pendingQueue.front())) {
++n;
}
if (n != pendingReqs) {
Tick now = curTick();
stats.pendingWalks.sample(pendingReqs, now - pendingChangeTick);
pendingReqs = n;
pendingChangeTick = now;
}
}
Fault
TableWalker::testWalk(Addr pa, Addr size, TlbEntry::DomainType domain,
LookupLevel lookup_level, bool stage2)
{
return mmu->testWalk(pa, size, currState->vaddr, currState->isSecure,
currState->mode, domain, lookup_level, stage2);
}
uint8_t
TableWalker::pageSizeNtoStatBin(uint8_t N)
{
/* for stats.pageSizes */
switch(N) {
case 12: return 0; // 4K
case 14: return 1; // 16K (using 16K granule in v8-64)
case 16: return 2; // 64K
case 20: return 3; // 1M
case 21: return 4; // 2M-LPAE
case 24: return 5; // 16M
case 25: return 6; // 32M (using 16K granule in v8-64)
case 29: return 7; // 512M (using 64K granule in v8-64)
case 30: return 8; // 1G-LPAE
case 42: return 9; // 1G-LPAE
default:
panic("unknown page size");
return 255;
}
}
Fault
TableWalker::readDataUntimed(ThreadContext *tc, Addr vaddr, Addr desc_addr,
uint8_t *data, int num_bytes, Request::Flags flags, BaseMMU::Mode mode,
MMU::ArmTranslationType tran_type, bool functional)
{
Fault fault;
// translate to physical address using the second stage MMU
auto req = std::make_shared<Request>();
req->setVirt(desc_addr, num_bytes, flags | Request::PT_WALK,
requestorId, 0);
if (functional) {
fault = mmu->translateFunctional(req, tc, BaseMMU::Read,
tran_type, true);
} else {
fault = mmu->translateAtomic(req, tc, BaseMMU::Read,
tran_type, true);
}
// Now do the access.
if (fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
Packet pkt = Packet(req, MemCmd::ReadReq);
pkt.dataStatic(data);
if (functional) {
port->sendFunctional(&pkt);
} else {
port->sendAtomic(&pkt);
}
assert(!pkt.isError());
}
// If there was a fault annotate it with the flag saying the foult occured
// while doing a translation for a stage 1 page table walk.
if (fault != NoFault) {
ArmFault *arm_fault = reinterpret_cast<ArmFault *>(fault.get());
arm_fault->annotate(ArmFault::S1PTW, true);
arm_fault->annotate(ArmFault::OVA, vaddr);
}
return fault;
}
void
TableWalker::readDataTimed(ThreadContext *tc, Addr desc_addr,
Stage2Walk *translation, int num_bytes,
Request::Flags flags)
{
// translate to physical address using the second stage MMU
translation->setVirt(
desc_addr, num_bytes, flags | Request::PT_WALK, requestorId);
translation->translateTiming(tc);
}
TableWalker::Stage2Walk::Stage2Walk(TableWalker &_parent,
uint8_t *_data, Event *_event, Addr vaddr, BaseMMU::Mode _mode,
MMU::ArmTranslationType tran_type)
: data(_data), numBytes(0), event(_event), parent(_parent),
oVAddr(vaddr), mode(_mode), tranType(tran_type), fault(NoFault)
{
req = std::make_shared<Request>();
}
void
TableWalker::Stage2Walk::finish(const Fault &_fault,
const RequestPtr &req,
ThreadContext *tc, BaseMMU::Mode mode)
{
fault = _fault;
// If there was a fault annotate it with the flag saying the foult occured
// while doing a translation for a stage 1 page table walk.
if (fault != NoFault) {
ArmFault *arm_fault = reinterpret_cast<ArmFault *>(fault.get());
arm_fault->annotate(ArmFault::S1PTW, true);
arm_fault->annotate(ArmFault::OVA, oVAddr);
}
if (_fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
parent.getTableWalkerPort().sendTimingReq(
req->getPaddr(), numBytes, data, req->getFlags(),
tc->getCpuPtr()->clockPeriod(), event);
} else {
// We can't do the DMA access as there's been a problem, so tell the
// event we're done
event->process();
}
}
void
TableWalker::Stage2Walk::translateTiming(ThreadContext *tc)
{
parent.mmu->translateTiming(req, tc, this, mode, tranType, true);
}
TableWalker::TableWalkerStats::TableWalkerStats(statistics::Group *parent)
: statistics::Group(parent),
ADD_STAT(walks, statistics::units::Count::get(),
"Table walker walks requested"),
ADD_STAT(walksShortDescriptor, statistics::units::Count::get(),
"Table walker walks initiated with short descriptors"),
ADD_STAT(walksLongDescriptor, statistics::units::Count::get(),
"Table walker walks initiated with long descriptors"),
ADD_STAT(walksShortTerminatedAtLevel, statistics::units::Count::get(),
"Level at which table walker walks with short descriptors "
"terminate"),
ADD_STAT(walksLongTerminatedAtLevel, statistics::units::Count::get(),
"Level at which table walker walks with long descriptors "
"terminate"),
ADD_STAT(squashedBefore, statistics::units::Count::get(),
"Table walks squashed before starting"),
ADD_STAT(squashedAfter, statistics::units::Count::get(),
"Table walks squashed after completion"),
ADD_STAT(walkWaitTime, statistics::units::Tick::get(),
"Table walker wait (enqueue to first request) latency"),
ADD_STAT(walkServiceTime, statistics::units::Tick::get(),
"Table walker service (enqueue to completion) latency"),
ADD_STAT(pendingWalks, statistics::units::Tick::get(),
"Table walker pending requests distribution"),
ADD_STAT(pageSizes, statistics::units::Count::get(),
"Table walker page sizes translated"),
ADD_STAT(requestOrigin, statistics::units::Count::get(),
"Table walker requests started/completed, data/inst")
{
walksShortDescriptor
.flags(statistics::nozero);
walksLongDescriptor
.flags(statistics::nozero);
walksShortTerminatedAtLevel
.init(2)
.flags(statistics::nozero);
walksShortTerminatedAtLevel.subname(0, "Level1");
walksShortTerminatedAtLevel.subname(1, "Level2");
walksLongTerminatedAtLevel
.init(4)
.flags(statistics::nozero);
walksLongTerminatedAtLevel.subname(0, "Level0");
walksLongTerminatedAtLevel.subname(1, "Level1");
walksLongTerminatedAtLevel.subname(2, "Level2");
walksLongTerminatedAtLevel.subname(3, "Level3");
squashedBefore
.flags(statistics::nozero);
squashedAfter
.flags(statistics::nozero);
walkWaitTime
.init(16)
.flags(statistics::pdf | statistics::nozero | statistics::nonan);
walkServiceTime
.init(16)
.flags(statistics::pdf | statistics::nozero | statistics::nonan);
pendingWalks
.init(16)
.flags(statistics::pdf | statistics::dist | statistics::nozero |
statistics::nonan);
pageSizes // see DDI 0487A D4-1661
.init(10)
.flags(statistics::total | statistics::pdf | statistics::dist |
statistics::nozero);
pageSizes.subname(0, "4KiB");
pageSizes.subname(1, "16KiB");
pageSizes.subname(2, "64KiB");
pageSizes.subname(3, "1MiB");
pageSizes.subname(4, "2MiB");
pageSizes.subname(5, "16MiB");
pageSizes.subname(6, "32MiB");
pageSizes.subname(7, "512MiB");
pageSizes.subname(8, "1GiB");
pageSizes.subname(9, "4TiB");
requestOrigin
.init(2,2) // Instruction/Data, requests/completed
.flags(statistics::total);
requestOrigin.subname(0,"Requested");
requestOrigin.subname(1,"Completed");
requestOrigin.ysubname(0,"Data");
requestOrigin.ysubname(1,"Inst");
}
} // namespace gem5