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c25ef2d19168392243794946b5f5ecfab10195b8
gem5/src/arch/arm/tlb.cc
Richard Cooper c25ef2d191 arch-arm: Update ARMv8.1-PAN to allow unprivileged instructions. 
Update the ARMv8.1-PAN implementation to allow specified unprivileged
instructions to execute even when the cpsr.pan bit is set. The
specified instructions generate memory requests with the
TLB::ArmFlags::UserMode flags bit set.

See sections D5.4.2 (About PSTATE.PAN) and G5.6.2 (About the PAN bit)
of the Arm Architecture Reference Manual for details.
https://developer.arm.com/documentation/ddi0487/latest/

Change-Id: I9e904e0154de72c2e4cc70cbc49b3c8407a3cb1d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47779
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-07-08 08:48:51 +00:00

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/*
* Copyright (c) 2010-2013, 2016-2021 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.
*
* 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 "arch/arm/tlb.hh"
#include <memory>
#include <string>
#include <vector>
#include "arch/arm/faults.hh"
#include "arch/arm/isa.hh"
#include "arch/arm/pagetable.hh"
#include "arch/arm/reg_abi.hh"
#include "arch/arm/self_debug.hh"
#include "arch/arm/stage2_lookup.hh"
#include "arch/arm/system.hh"
#include "arch/arm/table_walker.hh"
#include "arch/arm/tlbi_op.hh"
#include "arch/arm/utility.hh"
#include "base/compiler.hh"
#include "base/inifile.hh"
#include "base/str.hh"
#include "base/trace.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "debug/Checkpoint.hh"
#include "debug/TLB.hh"
#include "debug/TLBVerbose.hh"
#include "mem/packet_access.hh"
#include "mem/page_table.hh"
#include "mem/request.hh"
#include "params/ArmTLB.hh"
#include "sim/full_system.hh"
#include "sim/process.hh"
#include "sim/pseudo_inst.hh"
namespace gem5
{
using namespace ArmISA;
TLB::TLB(const ArmTLBParams &p)
: BaseTLB(p), table(new TlbEntry[p.size]), size(p.size),
isStage2(p.is_stage2), stage2Req(false), stage2DescReq(false), _attr(0),
directToStage2(false), tableWalker(nullptr), stage2Tlb(nullptr),
test(nullptr), stats(this), rangeMRU(1),
aarch64(false), aarch64EL(EL0), isPriv(false), isSecure(false),
isHyp(false), asid(0), vmid(0), hcr(0), dacr(0),
miscRegValid(false), miscRegContext(0), curTranType(NormalTran)
{
// Cache system-level properties
if (FullSystem) {
ArmSystem *arm_sys = dynamic_cast<ArmSystem *>(p.sys);
assert(arm_sys);
haveLPAE = arm_sys->haveLPAE();
haveVirtualization = arm_sys->haveVirtualization();
haveLargeAsid64 = arm_sys->haveLargeAsid64();
physAddrRange = arm_sys->physAddrRange();
} else {
haveLPAE = false;
haveVirtualization = false;
haveLargeAsid64 = false;
physAddrRange = 48;
}
m5opRange = p.sys->m5opRange();
}
TLB::~TLB()
{
delete[] table;
}
void
TLB::setTableWalker(TableWalker *table_walker)
{
tableWalker = table_walker;
tableWalker->setTlb(this);
}
bool
TLB::translateFunctional(ThreadContext *tc, Addr va, Addr &pa)
{
updateMiscReg(tc);
if (directToStage2) {
assert(stage2Tlb);
return stage2Tlb->translateFunctional(tc, va, pa);
}
TlbEntry *e = lookup(va, asid, vmid, isHyp, isSecure, true, false,
aarch64 ? aarch64EL : EL1, false, BaseMMU::Read);
if (!e)
return false;
pa = e->pAddr(va);
return true;
}
Fault
TLB::finalizePhysical(const RequestPtr &req,
ThreadContext *tc, BaseMMU::Mode mode) const
{
const Addr paddr = req->getPaddr();
if (m5opRange.contains(paddr)) {
uint8_t func;
pseudo_inst::decodeAddrOffset(paddr - m5opRange.start(), func);
req->setLocalAccessor(
[func, mode](ThreadContext *tc, PacketPtr pkt) -> Cycles
{
uint64_t ret;
if (inAArch64(tc))
pseudo_inst::pseudoInst<RegABI64>(tc, func, ret);
else
pseudo_inst::pseudoInst<RegABI32>(tc, func, ret);
if (mode == BaseMMU::Read)
pkt->setLE(ret);
return Cycles(1);
}
);
}
return NoFault;
}
TlbEntry*
TLB::lookup(Addr va, uint16_t asn, vmid_t vmid, bool hyp, bool secure,
bool functional, bool ignore_asn, ExceptionLevel target_el,
bool in_host, BaseMMU::Mode mode)
{
TlbEntry *retval = NULL;
// Maintaining LRU array
int x = 0;
while (retval == NULL && x < size) {
if ((!ignore_asn && table[x].match(va, asn, vmid, hyp, secure, false,
target_el, in_host)) ||
(ignore_asn && table[x].match(va, vmid, hyp, secure, target_el,
in_host))) {
// We only move the hit entry ahead when the position is higher
// than rangeMRU
if (x > rangeMRU && !functional) {
TlbEntry tmp_entry = table[x];
for (int i = x; i > 0; i--)
table[i] = table[i - 1];
table[0] = tmp_entry;
retval = &table[0];
} else {
retval = &table[x];
}
break;
}
++x;
}
DPRINTF(TLBVerbose, "Lookup %#x, asn %#x -> %s vmn 0x%x hyp %d secure %d "
"ppn %#x size: %#x pa: %#x ap:%d ns:%d nstid:%d g:%d asid: %d "
"el: %d\n",
va, asn, retval ? "hit" : "miss", vmid, hyp, secure,
retval ? retval->pfn : 0, retval ? retval->size : 0,
retval ? retval->pAddr(va) : 0, retval ? retval->ap : 0,
retval ? retval->ns : 0, retval ? retval->nstid : 0,
retval ? retval->global : 0, retval ? retval->asid : 0,
retval ? retval->el : 0);
// Updating stats if this was not a functional lookup
if (!functional) {
if (!retval) {
if (mode == BaseMMU::Execute)
stats.instMisses++;
else if (mode == BaseMMU::Write)
stats.writeMisses++;
else
stats.readMisses++;
} else {
if (mode == BaseMMU::Execute)
stats.instHits++;
else if (mode == BaseMMU::Write)
stats.writeHits++;
else
stats.readHits++;
}
}
return retval;
}
// insert a new TLB entry
void
TLB::insert(Addr addr, TlbEntry &entry)
{
DPRINTF(TLB, "Inserting entry into TLB with pfn:%#x size:%#x vpn: %#x"
" asid:%d vmid:%d N:%d global:%d valid:%d nc:%d xn:%d"
" ap:%#x domain:%#x ns:%d nstid:%d isHyp:%d\n", entry.pfn,
entry.size, entry.vpn, entry.asid, entry.vmid, entry.N,
entry.global, entry.valid, entry.nonCacheable, entry.xn,
entry.ap, static_cast<uint8_t>(entry.domain), entry.ns, entry.nstid,
entry.isHyp);
if (table[size - 1].valid)
DPRINTF(TLB, " - Replacing Valid entry %#x, asn %d vmn %d ppn %#x "
"size: %#x ap:%d ns:%d nstid:%d g:%d isHyp:%d el: %d\n",
table[size-1].vpn << table[size-1].N, table[size-1].asid,
table[size-1].vmid, table[size-1].pfn << table[size-1].N,
table[size-1].size, table[size-1].ap, table[size-1].ns,
table[size-1].nstid, table[size-1].global, table[size-1].isHyp,
table[size-1].el);
//inserting to MRU position and evicting the LRU one
for (int i = size - 1; i > 0; --i)
table[i] = table[i-1];
table[0] = entry;
stats.inserts++;
ppRefills->notify(1);
}
void
TLB::printTlb() const
{
int x = 0;
TlbEntry *te;
DPRINTF(TLB, "Current TLB contents:\n");
while (x < size) {
te = &table[x];
if (te->valid)
DPRINTF(TLB, " * %s\n", te->print());
++x;
}
}
void
TLB::flushAll()
{
DPRINTF(TLB, "Flushing all TLB entries\n");
int x = 0;
TlbEntry *te;
while (x < size) {
te = &table[x];
DPRINTF(TLB, " - %s\n", te->print());
te->valid = false;
stats.flushedEntries++;
++x;
}
stats.flushTlb++;
}
void
TLB::flush(const TLBIALL& tlbi_op)
{
DPRINTF(TLB, "Flushing all TLB entries (%s lookup)\n",
(tlbi_op.secureLookup ? "secure" : "non-secure"));
int x = 0;
TlbEntry *te;
while (x < size) {
te = &table[x];
const bool el_match = te->checkELMatch(
tlbi_op.targetEL, tlbi_op.inHost);
if (te->valid && tlbi_op.secureLookup == !te->nstid &&
(te->vmid == vmid || tlbi_op.el2Enabled) && el_match) {
DPRINTF(TLB, " - %s\n", te->print());
te->valid = false;
stats.flushedEntries++;
}
++x;
}
stats.flushTlb++;
}
void
TLB::flush(const TLBIALLEL &tlbi_op)
{
DPRINTF(TLB, "Flushing all TLB entries (%s lookup)\n",
(tlbi_op.secureLookup ? "secure" : "non-secure"));
int x = 0;
TlbEntry *te;
while (x < size) {
te = &table[x];
const bool el_match = te->checkELMatch(
tlbi_op.targetEL, tlbi_op.inHost);
if (te->valid && tlbi_op.secureLookup == !te->nstid && el_match) {
DPRINTF(TLB, " - %s\n", te->print());
te->valid = false;
stats.flushedEntries++;
}
++x;
}
stats.flushTlb++;
}
void
TLB::flush(const TLBIVMALL &tlbi_op)
{
DPRINTF(TLB, "Flushing all TLB entries (%s lookup)\n",
(tlbi_op.secureLookup ? "secure" : "non-secure"));
int x = 0;
TlbEntry *te;
while (x < size) {
te = &table[x];
const bool el_match = te->checkELMatch(
tlbi_op.targetEL, tlbi_op.inHost);
if (te->valid && tlbi_op.secureLookup == !te->nstid &&
(te->vmid == vmid || !tlbi_op.el2Enabled) && el_match) {
DPRINTF(TLB, " - %s\n", te->print());
te->valid = false;
stats.flushedEntries++;
}
++x;
}
stats.flushTlb++;
}
void
TLB::flush(const TLBIALLN &tlbi_op)
{
bool hyp = tlbi_op.targetEL == EL2;
DPRINTF(TLB, "Flushing all NS TLB entries (%s lookup)\n",
(hyp ? "hyp" : "non-hyp"));
int x = 0;
TlbEntry *te;
while (x < size) {
te = &table[x];
const bool el_match = te->checkELMatch(tlbi_op.targetEL, false);
if (te->valid && te->nstid && te->isHyp == hyp && el_match) {
DPRINTF(TLB, " - %s\n", te->print());
stats.flushedEntries++;
te->valid = false;
}
++x;
}
stats.flushTlb++;
}
void
TLB::flush(const TLBIMVA &tlbi_op)
{
DPRINTF(TLB, "Flushing TLB entries with mva: %#x, asid: %#x "
"(%s lookup)\n", tlbi_op.addr, tlbi_op.asid,
(tlbi_op.secureLookup ? "secure" : "non-secure"));
_flushMva(tlbi_op.addr, tlbi_op.asid, tlbi_op.secureLookup, false,
tlbi_op.targetEL, tlbi_op.inHost);
stats.flushTlbMvaAsid++;
}
void
TLB::flush(const TLBIASID &tlbi_op)
{
DPRINTF(TLB, "Flushing TLB entries with asid: %#x (%s lookup)\n",
tlbi_op.asid, (tlbi_op.secureLookup ? "secure" : "non-secure"));
int x = 0 ;
TlbEntry *te;
while (x < size) {
te = &table[x];
if (te->valid && te->asid == tlbi_op.asid &&
tlbi_op.secureLookup == !te->nstid &&
(te->vmid == vmid || tlbi_op.el2Enabled) &&
te->checkELMatch(tlbi_op.targetEL, tlbi_op.inHost)) {
te->valid = false;
DPRINTF(TLB, " - %s\n", te->print());
stats.flushedEntries++;
}
++x;
}
stats.flushTlbAsid++;
}
void
TLB::flush(const TLBIMVAA &tlbi_op) {
DPRINTF(TLB, "Flushing TLB entries with mva: %#x (%s lookup)\n",
tlbi_op.addr,
(tlbi_op.secureLookup ? "secure" : "non-secure"));
_flushMva(tlbi_op.addr, 0xbeef, tlbi_op.secureLookup, true,
tlbi_op.targetEL, tlbi_op.inHost);
stats.flushTlbMva++;
}
void
TLB::_flushMva(Addr mva, uint64_t asn, bool secure_lookup,
bool ignore_asn, ExceptionLevel target_el, bool in_host)
{
TlbEntry *te;
// D5.7.2: Sign-extend address to 64 bits
mva = sext<56>(mva);
bool hyp = target_el == EL2;
te = lookup(mva, asn, vmid, hyp, secure_lookup, true, ignore_asn,
target_el, in_host, BaseMMU::Read);
while (te != NULL) {
if (secure_lookup == !te->nstid) {
DPRINTF(TLB, " - %s\n", te->print());
te->valid = false;
stats.flushedEntries++;
}
te = lookup(mva, asn, vmid, hyp, secure_lookup, true, ignore_asn,
target_el, in_host, BaseMMU::Read);
}
}
void
TLB::drainResume()
{
// We might have unserialized something or switched CPUs, so make
// sure to re-read the misc regs.
miscRegValid = false;
}
void
TLB::takeOverFrom(BaseTLB *_otlb)
{
TLB *otlb = dynamic_cast<TLB*>(_otlb);
/* Make sure we actually have a valid type */
if (otlb) {
_attr = otlb->_attr;
directToStage2 = otlb->directToStage2;
stage2Req = otlb->stage2Req;
stage2DescReq = otlb->stage2DescReq;
/* Sync the stage2 MMU if they exist in both
* the old CPU and the new
*/
if (!isStage2 &&
stage2Tlb && otlb->stage2Tlb) {
stage2Tlb->takeOverFrom(otlb->stage2Tlb);
}
} else {
panic("Incompatible TLB type!");
}
}
TLB::TlbStats::TlbStats(statistics::Group *parent)
: statistics::Group(parent),
ADD_STAT(instHits, statistics::units::Count::get(), "ITB inst hits"),
ADD_STAT(instMisses, statistics::units::Count::get(), "ITB inst misses"),
ADD_STAT(readHits, statistics::units::Count::get(), "DTB read hits"),
ADD_STAT(readMisses, statistics::units::Count::get(), "DTB read misses"),
ADD_STAT(writeHits, statistics::units::Count::get(), "DTB write hits"),
ADD_STAT(writeMisses, statistics::units::Count::get(), "DTB write misses"),
ADD_STAT(inserts, statistics::units::Count::get(),
"Number of times an entry is inserted into the TLB"),
ADD_STAT(flushTlb, statistics::units::Count::get(),
"Number of times complete TLB was flushed"),
ADD_STAT(flushTlbMva, statistics::units::Count::get(),
"Number of times TLB was flushed by MVA"),
ADD_STAT(flushTlbMvaAsid, statistics::units::Count::get(),
"Number of times TLB was flushed by MVA & ASID"),
ADD_STAT(flushTlbAsid, statistics::units::Count::get(),
"Number of times TLB was flushed by ASID"),
ADD_STAT(flushedEntries, statistics::units::Count::get(),
"Number of entries that have been flushed from TLB"),
ADD_STAT(alignFaults, statistics::units::Count::get(),
"Number of TLB faults due to alignment restrictions"),
ADD_STAT(prefetchFaults, statistics::units::Count::get(),
"Number of TLB faults due to prefetch"),
ADD_STAT(domainFaults, statistics::units::Count::get(),
"Number of TLB faults due to domain restrictions"),
ADD_STAT(permsFaults, statistics::units::Count::get(),
"Number of TLB faults due to permissions restrictions"),
ADD_STAT(readAccesses, statistics::units::Count::get(), "DTB read accesses",
readHits + readMisses),
ADD_STAT(writeAccesses, statistics::units::Count::get(), "DTB write accesses",
writeHits + writeMisses),
ADD_STAT(instAccesses, statistics::units::Count::get(), "ITB inst accesses",
instHits + instMisses),
ADD_STAT(hits, statistics::units::Count::get(),
"Total TLB (inst and data) hits",
readHits + writeHits + instHits),
ADD_STAT(misses, statistics::units::Count::get(),
"Total TLB (inst and data) misses",
readMisses + writeMisses + instMisses),
ADD_STAT(accesses, statistics::units::Count::get(),
"Total TLB (inst and data) accesses",
readAccesses + writeAccesses + instAccesses)
{
}
void
TLB::regProbePoints()
{
ppRefills.reset(new probing::PMU(getProbeManager(), "Refills"));
}
Fault
TLB::translateSe(const RequestPtr &req, ThreadContext *tc, BaseMMU::Mode mode,
BaseMMU::Translation *translation, bool &delay, bool timing)
{
updateMiscReg(tc);
Addr vaddr_tainted = req->getVaddr();
Addr vaddr = 0;
if (aarch64)
vaddr = purifyTaggedAddr(vaddr_tainted, tc, aarch64EL, (TCR)ttbcr,
mode==BaseMMU::Execute);
else
vaddr = vaddr_tainted;
Request::Flags flags = req->getFlags();
bool is_fetch = (mode == BaseMMU::Execute);
bool is_write = (mode == BaseMMU::Write);
if (!is_fetch) {
if (sctlr.a || !(flags & AllowUnaligned)) {
if (vaddr & mask(flags & AlignmentMask)) {
// LPAE is always disabled in SE mode
return std::make_shared<DataAbort>(
vaddr_tainted,
TlbEntry::DomainType::NoAccess, is_write,
ArmFault::AlignmentFault, isStage2,
ArmFault::VmsaTran);
}
}
}
Addr paddr;
Process *p = tc->getProcessPtr();
if (!p->pTable->translate(vaddr, paddr))
return std::make_shared<GenericPageTableFault>(vaddr_tainted);
req->setPaddr(paddr);
return finalizePhysical(req, tc, mode);
}
Fault
TLB::checkPermissions(TlbEntry *te, const RequestPtr &req, BaseMMU::Mode mode)
{
// a data cache maintenance instruction that operates by MVA does
// not generate a Data Abort exeception due to a Permission fault
if (req->isCacheMaintenance()) {
return NoFault;
}
Addr vaddr = req->getVaddr(); // 32-bit don't have to purify
Request::Flags flags = req->getFlags();
bool is_fetch = (mode == BaseMMU::Execute);
bool is_write = (mode == BaseMMU::Write);
bool is_priv = isPriv && !(flags & UserMode);
// Get the translation type from the actuall table entry
ArmFault::TranMethod tranMethod = te->longDescFormat ? ArmFault::LpaeTran
: ArmFault::VmsaTran;
// If this is the second stage of translation and the request is for a
// stage 1 page table walk then we need to check the HCR.PTW bit. This
// allows us to generate a fault if the request targets an area marked
// as a device or strongly ordered.
if (isStage2 && req->isPTWalk() && hcr.ptw &&
(te->mtype != TlbEntry::MemoryType::Normal)) {
return std::make_shared<DataAbort>(
vaddr, te->domain, is_write,
ArmFault::PermissionLL + te->lookupLevel,
isStage2, tranMethod);
}
// Generate an alignment fault for unaligned data accesses to device or
// strongly ordered memory
if (!is_fetch) {
if (te->mtype != TlbEntry::MemoryType::Normal) {
if (vaddr & mask(flags & AlignmentMask)) {
stats.alignFaults++;
return std::make_shared<DataAbort>(
vaddr, TlbEntry::DomainType::NoAccess, is_write,
ArmFault::AlignmentFault, isStage2,
tranMethod);
}
}
}
if (te->nonCacheable) {
// Prevent prefetching from I/O devices.
if (req->isPrefetch()) {
// Here we can safely use the fault status for the short
// desc. format in all cases
return std::make_shared<PrefetchAbort>(
vaddr, ArmFault::PrefetchUncacheable,
isStage2, tranMethod);
}
}
if (!te->longDescFormat) {
switch ((dacr >> (static_cast<uint8_t>(te->domain) * 2)) & 0x3) {
case 0:
stats.domainFaults++;
DPRINTF(TLB, "TLB Fault: Data abort on domain. DACR: %#x"
" domain: %#x write:%d\n", dacr,
static_cast<uint8_t>(te->domain), is_write);
if (is_fetch) {
// Use PC value instead of vaddr because vaddr might
// be aligned to cache line and should not be the
// address reported in FAR
return std::make_shared<PrefetchAbort>(
req->getPC(),
ArmFault::DomainLL + te->lookupLevel,
isStage2, tranMethod);
} else
return std::make_shared<DataAbort>(
vaddr, te->domain, is_write,
ArmFault::DomainLL + te->lookupLevel,
isStage2, tranMethod);
case 1:
// Continue with permissions check
break;
case 2:
panic("UNPRED domain\n");
case 3:
return NoFault;
}
}
// The 'ap' variable is AP[2:0] or {AP[2,1],1b'0}, i.e. always three bits
uint8_t ap = te->longDescFormat ? te->ap << 1 : te->ap;
uint8_t hap = te->hap;
if (sctlr.afe == 1 || te->longDescFormat)
ap |= 1;
bool abt;
bool isWritable = true;
// If this is a stage 2 access (eg for reading stage 1 page table entries)
// then don't perform the AP permissions check, we stil do the HAP check
// below.
if (isStage2) {
abt = false;
} else {
switch (ap) {
case 0:
DPRINTF(TLB, "Access permissions 0, checking rs:%#x\n",
(int)sctlr.rs);
if (!sctlr.xp) {
switch ((int)sctlr.rs) {
case 2:
abt = is_write;
break;
case 1:
abt = is_write || !is_priv;
break;
case 0:
case 3:
default:
abt = true;
break;
}
} else {
abt = true;
}
break;
case 1:
abt = !is_priv;
break;
case 2:
abt = !is_priv && is_write;
isWritable = is_priv;
break;
case 3:
abt = false;
break;
case 4:
panic("UNPRED premissions\n");
case 5:
abt = !is_priv || is_write;
isWritable = false;
break;
case 6:
case 7:
abt = is_write;
isWritable = false;
break;
default:
panic("Unknown permissions %#x\n", ap);
}
}
bool hapAbt = is_write ? !(hap & 2) : !(hap & 1);
bool xn = te->xn || (isWritable && sctlr.wxn) ||
(ap == 3 && sctlr.uwxn && is_priv);
if (is_fetch && (abt || xn ||
(te->longDescFormat && te->pxn && is_priv) ||
(isSecure && te->ns && scr.sif))) {
stats.permsFaults++;
DPRINTF(TLB, "TLB Fault: Prefetch abort on permission check. AP:%d "
"priv:%d write:%d ns:%d sif:%d sctlr.afe: %d \n",
ap, is_priv, is_write, te->ns, scr.sif,sctlr.afe);
// Use PC value instead of vaddr because vaddr might be aligned to
// cache line and should not be the address reported in FAR
return std::make_shared<PrefetchAbort>(
req->getPC(),
ArmFault::PermissionLL + te->lookupLevel,
isStage2, tranMethod);
} else if (abt | hapAbt) {
stats.permsFaults++;
DPRINTF(TLB, "TLB Fault: Data abort on permission check. AP:%d priv:%d"
" write:%d\n", ap, is_priv, is_write);
return std::make_shared<DataAbort>(
vaddr, te->domain, is_write,
ArmFault::PermissionLL + te->lookupLevel,
isStage2 | !abt, tranMethod);
}
return NoFault;
}
Fault
TLB::checkPermissions64(TlbEntry *te, const RequestPtr &req,
BaseMMU::Mode mode, ThreadContext *tc)
{
assert(aarch64);
// A data cache maintenance instruction that operates by VA does
// not generate a Permission fault unless:
// * It is a data cache invalidate (dc ivac) which requires write
// permissions to the VA, or
// * It is executed from EL0
if (req->isCacheClean() && aarch64EL != EL0 && !isStage2) {
return NoFault;
}
Addr vaddr_tainted = req->getVaddr();
Addr vaddr = purifyTaggedAddr(vaddr_tainted, tc, aarch64EL, (TCR)ttbcr,
mode==BaseMMU::Execute);
Request::Flags flags = req->getFlags();
bool is_fetch = (mode == BaseMMU::Execute);
// Cache clean operations require read permissions to the specified VA
bool is_write = !req->isCacheClean() && mode == BaseMMU::Write;
bool is_atomic = req->isAtomic();
GEM5_VAR_USED bool is_priv = isPriv && !(flags & UserMode);
updateMiscReg(tc, curTranType);
// If this is the second stage of translation and the request is for a
// stage 1 page table walk then we need to check the HCR.PTW bit. This
// allows us to generate a fault if the request targets an area marked
// as a device or strongly ordered.
if (isStage2 && req->isPTWalk() && hcr.ptw &&
(te->mtype != TlbEntry::MemoryType::Normal)) {
return std::make_shared<DataAbort>(
vaddr_tainted, te->domain, is_write,
ArmFault::PermissionLL + te->lookupLevel,
isStage2, ArmFault::LpaeTran);
}
// Generate an alignment fault for unaligned accesses to device or
// strongly ordered memory
if (!is_fetch) {
if (te->mtype != TlbEntry::MemoryType::Normal) {
if (vaddr & mask(flags & AlignmentMask)) {
stats.alignFaults++;
return std::make_shared<DataAbort>(
vaddr_tainted,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : is_write,
ArmFault::AlignmentFault, isStage2,
ArmFault::LpaeTran);
}
}
}
if (te->nonCacheable) {
// Prevent prefetching from I/O devices.
if (req->isPrefetch()) {
// Here we can safely use the fault status for the short
// desc. format in all cases
return std::make_shared<PrefetchAbort>(
vaddr_tainted,
ArmFault::PrefetchUncacheable,
isStage2, ArmFault::LpaeTran);
}
}
uint8_t ap = 0x3 & (te->ap); // 2-bit access protection field
bool grant = false;
bool wxn = sctlr.wxn;
uint8_t xn = te->xn;
uint8_t pxn = te->pxn;
bool r = (!is_write && !is_fetch);
bool w = is_write;
bool x = is_fetch;
if (ArmSystem::haveEL(tc, EL3) && isSecure && te->ns && scr.sif)
xn = true;
// grant_read is used for faults from an atomic instruction that
// both reads and writes from a memory location. From a ISS point
// of view they count as read if a read to that address would have
// generated the fault; they count as writes otherwise
bool grant_read = true;
DPRINTF(TLBVerbose, "Checking permissions: ap:%d, xn:%d, pxn:%d, r:%d, "
"w:%d, x:%d, is_priv: %d, wxn: %d\n", ap, xn,
pxn, r, w, x, is_priv, wxn);
if (isStage2) {
assert(ArmSystem::haveVirtualization(tc) && aarch64EL != EL2);
// In stage 2 we use the hypervisor access permission bits.
// The following permissions are described in ARM DDI 0487A.f
// D4-1802
uint8_t hap = 0x3 & te->hap;
grant_read = hap & 0x1;
if (is_fetch) {
// sctlr.wxn overrides the xn bit
grant = !wxn && !xn;
} else if (is_atomic) {
grant = hap;
} else if (is_write) {
grant = hap & 0x2;
} else { // is_read
grant = grant_read;
}
} else {
switch (aarch64EL) {
case EL0:
{
grant_read = ap & 0x1;
uint8_t perm = (ap << 2) | (xn << 1) | pxn;
switch (perm) {
case 0:
case 1:
case 8:
case 9:
grant = x;
break;
case 4:
case 5:
grant = r || w || (x && !wxn);
break;
case 6:
case 7:
grant = r || w;
break;
case 12:
case 13:
grant = r || x;
break;
case 14:
case 15:
grant = r;
break;
default:
grant = false;
}
}
break;
case EL1:
{
if (checkPAN(tc, ap, req, mode, is_priv)) {
grant = false;
grant_read = false;
break;
}
uint8_t perm = (ap << 2) | (xn << 1) | pxn;
switch (perm) {
case 0:
case 2:
grant = r || w || (x && !wxn);
break;
case 1:
case 3:
case 4:
case 5:
case 6:
case 7:
// regions that are writeable at EL0 should not be
// executable at EL1
grant = r || w;
break;
case 8:
case 10:
case 12:
case 14:
grant = r || x;
break;
case 9:
case 11:
case 13:
case 15:
grant = r;
break;
default:
grant = false;
}
}
break;
case EL2:
if (hcr.e2h && checkPAN(tc, ap, req, mode, is_priv)) {
grant = false;
grant_read = false;
break;
}
GEM5_FALLTHROUGH;
case EL3:
{
uint8_t perm = (ap & 0x2) | xn;
switch (perm) {
case 0:
grant = r || w || (x && !wxn);
break;
case 1:
grant = r || w;
break;
case 2:
grant = r || x;
break;
case 3:
grant = r;
break;
default:
grant = false;
}
}
break;
}
}
if (!grant) {
if (is_fetch) {
stats.permsFaults++;
DPRINTF(TLB, "TLB Fault: Prefetch abort on permission check. "
"AP:%d priv:%d write:%d ns:%d sif:%d "
"sctlr.afe: %d\n",
ap, is_priv, is_write, te->ns, scr.sif, sctlr.afe);
// Use PC value instead of vaddr because vaddr might be aligned to
// cache line and should not be the address reported in FAR
return std::make_shared<PrefetchAbort>(
req->getPC(),
ArmFault::PermissionLL + te->lookupLevel,
isStage2, ArmFault::LpaeTran);
} else {
stats.permsFaults++;
DPRINTF(TLB, "TLB Fault: Data abort on permission check. AP:%d "
"priv:%d write:%d\n", ap, is_priv, is_write);
return std::make_shared<DataAbort>(
vaddr_tainted, te->domain,
(is_atomic && !grant_read) ? false : is_write,
ArmFault::PermissionLL + te->lookupLevel,
isStage2, ArmFault::LpaeTran);
}
}
return NoFault;
}
bool
TLB::checkPAN(ThreadContext *tc, uint8_t ap, const RequestPtr &req,
BaseMMU::Mode mode, const bool is_priv)
{
// The PAN bit has no effect on:
// 1) Instruction accesses.
// 2) Data Cache instructions other than DC ZVA
// 3) Address translation instructions, other than ATS1E1RP and
// ATS1E1WP when ARMv8.2-ATS1E1 is implemented. (Unimplemented in
// gem5)
// 4) Instructions to be treated as unprivileged, unless
// HCR_EL2.{E2H, TGE} == {1, 0}
const AA64MMFR1 mmfr1 = tc->readMiscReg(MISCREG_ID_AA64MMFR1_EL1);
if (mmfr1.pan && cpsr.pan && (ap & 0x1) && mode != BaseMMU::Execute) {
if (req->isCacheMaintenance() &&
!(req->getFlags() & Request::CACHE_BLOCK_ZERO)) {
// Cache maintenance other than DC ZVA
return false;
} else if (!is_priv && !(hcr.e2h && !hcr.tge)) {
// Treated as unprivileged unless HCR_EL2.{E2H, TGE} == {1, 0}
return false;
}
return true;
}
return false;
}
Fault
TLB::translateMmuOff(ThreadContext *tc, const RequestPtr &req,
BaseMMU::Mode mode, TLB::ArmTranslationType tranType,
Addr vaddr, bool long_desc_format)
{
bool is_fetch = (mode == BaseMMU::Execute);
bool is_atomic = req->isAtomic();
req->setPaddr(vaddr);
// When the MMU is off the security attribute corresponds to the
// security state of the processor
if (isSecure)
req->setFlags(Request::SECURE);
if (aarch64) {
bool selbit = bits(vaddr, 55);
TCR tcr1 = tc->readMiscReg(MISCREG_TCR_EL1);
int topbit = computeAddrTop(tc, selbit, is_fetch, tcr1, currEL(tc));
int addr_sz = bits(vaddr, topbit, physAddrRange);
if (addr_sz != 0){
Fault f;
if (is_fetch)
f = std::make_shared<PrefetchAbort>(vaddr,
ArmFault::AddressSizeLL, isStage2, ArmFault::LpaeTran);
else
f = std::make_shared<DataAbort>( vaddr,
TlbEntry::DomainType::NoAccess,
is_atomic ? false : mode==BaseMMU::Write,
ArmFault::AddressSizeLL, isStage2, ArmFault::LpaeTran);
return f;
}
}
// @todo: double check this (ARM ARM issue C B3.2.1)
if (long_desc_format || sctlr.tre == 0 || nmrr.ir0 == 0 ||
nmrr.or0 == 0 || prrr.tr0 != 0x2) {
if (!req->isCacheMaintenance()) {
req->setFlags(Request::UNCACHEABLE);
}
req->setFlags(Request::STRICT_ORDER);
}
// Set memory attributes
TlbEntry temp_te;
temp_te.ns = !isSecure;
bool dc = (HaveVirtHostExt(tc)
&& hcr.e2h == 1 && hcr.tge == 1) ? 0: hcr.dc;
bool i_cacheability = sctlr.i && !sctlr.m;
if (isStage2 || !dc || isSecure ||
(isHyp && !(tranType & S1CTran))) {
temp_te.mtype = is_fetch ? TlbEntry::MemoryType::Normal
: TlbEntry::MemoryType::StronglyOrdered;
temp_te.innerAttrs = i_cacheability? 0x2: 0x0;
temp_te.outerAttrs = i_cacheability? 0x2: 0x0;
temp_te.shareable = true;
temp_te.outerShareable = true;
} else {
temp_te.mtype = TlbEntry::MemoryType::Normal;
temp_te.innerAttrs = 0x3;
temp_te.outerAttrs = 0x3;
temp_te.shareable = false;
temp_te.outerShareable = false;
}
temp_te.setAttributes(long_desc_format);
DPRINTF(TLBVerbose, "(No MMU) setting memory attributes: shareable: "
"%d, innerAttrs: %d, outerAttrs: %d, isStage2: %d\n",
temp_te.shareable, temp_te.innerAttrs, temp_te.outerAttrs,
isStage2);
setAttr(temp_te.attributes);
return testTranslation(req, mode, TlbEntry::DomainType::NoAccess);
}
Fault
TLB::translateMmuOn(ThreadContext* tc, const RequestPtr &req,
BaseMMU::Mode mode, BaseMMU::Translation *translation,
bool &delay, bool timing,
bool functional, Addr vaddr,
ArmFault::TranMethod tranMethod)
{
TlbEntry *te = NULL;
bool is_fetch = (mode == BaseMMU::Execute);
TlbEntry mergeTe;
Request::Flags flags = req->getFlags();
Addr vaddr_tainted = req->getVaddr();
Fault fault = getResultTe(&te, req, tc, mode, translation, timing,
functional, &mergeTe);
// only proceed if we have a valid table entry
if ((te == NULL) && (fault == NoFault)) delay = true;
// If we have the table entry transfer some of the attributes to the
// request that triggered the translation
if (te != NULL) {
// Set memory attributes
DPRINTF(TLBVerbose,
"Setting memory attributes: shareable: %d, innerAttrs: %d, "
"outerAttrs: %d, mtype: %d, isStage2: %d\n",
te->shareable, te->innerAttrs, te->outerAttrs,
static_cast<uint8_t>(te->mtype), isStage2);
setAttr(te->attributes);
if (te->nonCacheable && !req->isCacheMaintenance())
req->setFlags(Request::UNCACHEABLE);
// Require requests to be ordered if the request goes to
// strongly ordered or device memory (i.e., anything other
// than normal memory requires strict order).
if (te->mtype != TlbEntry::MemoryType::Normal)
req->setFlags(Request::STRICT_ORDER);
Addr pa = te->pAddr(vaddr);
req->setPaddr(pa);
if (isSecure && !te->ns) {
req->setFlags(Request::SECURE);
}
if (!is_fetch && fault == NoFault &&
(vaddr & mask(flags & AlignmentMask)) &&
(te->mtype != TlbEntry::MemoryType::Normal)) {
// Unaligned accesses to Device memory should always cause an
// abort regardless of sctlr.a
stats.alignFaults++;
bool is_write = (mode == BaseMMU::Write);
return std::make_shared<DataAbort>(
vaddr_tainted,
TlbEntry::DomainType::NoAccess, is_write,
ArmFault::AlignmentFault, isStage2,
tranMethod);
}
// Check for a trickbox generated address fault
if (fault == NoFault)
fault = testTranslation(req, mode, te->domain);
}
if (fault == NoFault) {
// Don't try to finalize a physical address unless the
// translation has completed (i.e., there is a table entry).
return te ? finalizePhysical(req, tc, mode) : NoFault;
} else {
return fault;
}
}
Fault
TLB::translateFs(const RequestPtr &req, ThreadContext *tc, BaseMMU::Mode mode,
BaseMMU::Translation *translation, bool &delay, bool timing,
TLB::ArmTranslationType tranType, bool functional)
{
// No such thing as a functional timing access
assert(!(timing && functional));
updateMiscReg(tc, tranType);
Addr vaddr_tainted = req->getVaddr();
Addr vaddr = 0;
if (aarch64)
vaddr = purifyTaggedAddr(vaddr_tainted, tc, aarch64EL, (TCR)ttbcr,
mode==BaseMMU::Execute);
else
vaddr = vaddr_tainted;
Request::Flags flags = req->getFlags();
bool is_fetch = (mode == BaseMMU::Execute);
bool is_write = (mode == BaseMMU::Write);
bool long_desc_format = aarch64 || longDescFormatInUse(tc);
ArmFault::TranMethod tranMethod = long_desc_format ? ArmFault::LpaeTran
: ArmFault::VmsaTran;
DPRINTF(TLBVerbose,
"CPSR is priv:%d UserMode:%d secure:%d S1S2NsTran:%d\n",
isPriv, flags & UserMode, isSecure, tranType & S1S2NsTran);
DPRINTF(TLB, "translateFs addr %#x, mode %d, st2 %d, scr %#x sctlr %#x "
"flags %#lx tranType 0x%x\n", vaddr_tainted, mode, isStage2,
scr, sctlr, flags, tranType);
if ((req->isInstFetch() && (!sctlr.i)) ||
((!req->isInstFetch()) && (!sctlr.c))){
if (!req->isCacheMaintenance()) {
req->setFlags(Request::UNCACHEABLE);
}
req->setFlags(Request::STRICT_ORDER);
}
if (!is_fetch) {
if (sctlr.a || !(flags & AllowUnaligned)) {
if (vaddr & mask(flags & AlignmentMask)) {
stats.alignFaults++;
return std::make_shared<DataAbort>(
vaddr_tainted,
TlbEntry::DomainType::NoAccess, is_write,
ArmFault::AlignmentFault, isStage2,
tranMethod);
}
}
}
bool vm = hcr.vm;
if (HaveVirtHostExt(tc) && hcr.e2h == 1 && hcr.tge ==1)
vm = 0;
else if (hcr.dc == 1)
vm = 1;
Fault fault = NoFault;
// If guest MMU is off or hcr.vm=0 go straight to stage2
if ((isStage2 && !vm) || (!isStage2 && !sctlr.m)) {
fault = translateMmuOff(tc, req, mode, tranType, vaddr,
long_desc_format);
} else {
DPRINTF(TLBVerbose, "Translating %s=%#x context=%d\n",
isStage2 ? "IPA" : "VA", vaddr_tainted, asid);
// Translation enabled
fault = translateMmuOn(tc, req, mode, translation, delay, timing,
functional, vaddr, tranMethod);
}
// Check for Debug Exceptions
SelfDebug *sd = ArmISA::ISA::getSelfDebug(tc);
if (sd->enabled() && fault == NoFault) {
fault = sd->testDebug(tc, req, mode);
}
return fault;
}
Fault
TLB::translateAtomic(const RequestPtr &req, ThreadContext *tc,
BaseMMU::Mode mode, TLB::ArmTranslationType tranType)
{
updateMiscReg(tc, tranType);
if (directToStage2) {
assert(stage2Tlb);
return stage2Tlb->translateAtomic(req, tc, mode, tranType);
}
bool delay = false;
Fault fault;
if (FullSystem)
fault = translateFs(req, tc, mode, NULL, delay, false, tranType);
else
fault = translateSe(req, tc, mode, NULL, delay, false);
assert(!delay);
return fault;
}
Fault
TLB::translateFunctional(const RequestPtr &req, ThreadContext *tc,
BaseMMU::Mode mode, TLB::ArmTranslationType tranType)
{
updateMiscReg(tc, tranType);
if (directToStage2) {
assert(stage2Tlb);
return stage2Tlb->translateFunctional(req, tc, mode, tranType);
}
bool delay = false;
Fault fault;
if (FullSystem)
fault = translateFs(req, tc, mode, NULL, delay, false, tranType, true);
else
fault = translateSe(req, tc, mode, NULL, delay, false);
assert(!delay);
return fault;
}
void
TLB::translateTiming(const RequestPtr &req, ThreadContext *tc,
BaseMMU::Translation *translation, BaseMMU::Mode mode,
TLB::ArmTranslationType tranType)
{
updateMiscReg(tc, tranType);
if (directToStage2) {
assert(stage2Tlb);
stage2Tlb->translateTiming(req, tc, translation, mode, tranType);
return;
}
assert(translation);
translateComplete(req, tc, translation, mode, tranType, isStage2);
}
Fault
TLB::translateComplete(const RequestPtr &req, ThreadContext *tc,
BaseMMU::Translation *translation, BaseMMU::Mode mode,
TLB::ArmTranslationType tranType, bool callFromS2)
{
bool delay = false;
Fault fault;
if (FullSystem)
fault = translateFs(req, tc, mode, translation, delay, true, tranType);
else
fault = translateSe(req, tc, mode, translation, delay, true);
DPRINTF(TLBVerbose, "Translation returning delay=%d fault=%d\n", delay, fault !=
NoFault);
// If we have a translation, and we're not in the middle of doing a stage
// 2 translation tell the translation that we've either finished or its
// going to take a while. By not doing this when we're in the middle of a
// stage 2 translation we prevent marking the translation as delayed twice,
// one when the translation starts and again when the stage 1 translation
// completes.
if (translation && (callFromS2 || !stage2Req || req->hasPaddr() ||
fault != NoFault)) {
if (!delay)
translation->finish(fault, req, tc, mode);
else
translation->markDelayed();
}
return fault;
}
Port *
TLB::getTableWalkerPort()
{
return &tableWalker->getTableWalkerPort();
}
vmid_t
TLB::getVMID(ThreadContext *tc) const
{
AA64MMFR1 mmfr1 = tc->readMiscReg(MISCREG_ID_AA64MMFR1_EL1);
VTCR_t vtcr = tc->readMiscReg(MISCREG_VTCR_EL2);
vmid_t vmid = 0;
switch (mmfr1.vmidbits) {
case 0b0000:
// 8 bits
vmid = bits(tc->readMiscReg(MISCREG_VTTBR_EL2), 55, 48);
break;
case 0b0010:
if (vtcr.vs && ELIs64(tc, EL2)) {
// 16 bits
vmid = bits(tc->readMiscReg(MISCREG_VTTBR_EL2), 63, 48);
} else {
// 8 bits
vmid = bits(tc->readMiscReg(MISCREG_VTTBR_EL2), 55, 48);
}
break;
default:
panic("Reserved ID_AA64MMFR1_EL1.VMIDBits value: %#x",
mmfr1.vmidbits);
}
return vmid;
}
void
TLB::updateMiscReg(ThreadContext *tc, ArmTranslationType tranType)
{
// check if the regs have changed, or the translation mode is different.
// NOTE: the tran type doesn't affect stage 2 TLB's as they only handle
// one type of translation anyway
if (miscRegValid && miscRegContext == tc->contextId() &&
((tranType == curTranType) || isStage2)) {
return;
}
DPRINTF(TLBVerbose, "TLB variables changed!\n");
cpsr = tc->readMiscReg(MISCREG_CPSR);
// Dependencies: SCR/SCR_EL3, CPSR
isSecure = ArmISA::isSecure(tc) &&
!(tranType & HypMode) && !(tranType & S1S2NsTran);
aarch64EL = tranTypeEL(cpsr, tranType);
aarch64 = isStage2 ?
ELIs64(tc, EL2) :
ELIs64(tc, aarch64EL == EL0 ? EL1 : aarch64EL);
hcr = tc->readMiscReg(MISCREG_HCR_EL2);
if (aarch64) { // AArch64
// determine EL we need to translate in
switch (aarch64EL) {
case EL0:
if (HaveVirtHostExt(tc) && hcr.tge == 1 && hcr.e2h == 1) {
// VHE code for EL2&0 regime
sctlr = tc->readMiscReg(MISCREG_SCTLR_EL2);
ttbcr = tc->readMiscReg(MISCREG_TCR_EL2);
uint64_t ttbr_asid = ttbcr.a1 ?
tc->readMiscReg(MISCREG_TTBR1_EL2) :
tc->readMiscReg(MISCREG_TTBR0_EL2);
asid = bits(ttbr_asid,
(haveLargeAsid64 && ttbcr.as) ? 63 : 55, 48);
} else {
sctlr = tc->readMiscReg(MISCREG_SCTLR_EL1);
ttbcr = tc->readMiscReg(MISCREG_TCR_EL1);
uint64_t ttbr_asid = ttbcr.a1 ?
tc->readMiscReg(MISCREG_TTBR1_EL1) :
tc->readMiscReg(MISCREG_TTBR0_EL1);
asid = bits(ttbr_asid,
(haveLargeAsid64 && ttbcr.as) ? 63 : 55, 48);
}
break;
case EL1:
{
sctlr = tc->readMiscReg(MISCREG_SCTLR_EL1);
ttbcr = tc->readMiscReg(MISCREG_TCR_EL1);
uint64_t ttbr_asid = ttbcr.a1 ?
tc->readMiscReg(MISCREG_TTBR1_EL1) :
tc->readMiscReg(MISCREG_TTBR0_EL1);
asid = bits(ttbr_asid,
(haveLargeAsid64 && ttbcr.as) ? 63 : 55, 48);
}
break;
case EL2:
sctlr = tc->readMiscReg(MISCREG_SCTLR_EL2);
ttbcr = tc->readMiscReg(MISCREG_TCR_EL2);
if (hcr.e2h == 1) {
// VHE code for EL2&0 regime
uint64_t ttbr_asid = ttbcr.a1 ?
tc->readMiscReg(MISCREG_TTBR1_EL2) :
tc->readMiscReg(MISCREG_TTBR0_EL2);
asid = bits(ttbr_asid,
(haveLargeAsid64 && ttbcr.as) ? 63 : 55, 48);
} else {
asid = -1;
}
break;
case EL3:
sctlr = tc->readMiscReg(MISCREG_SCTLR_EL3);
ttbcr = tc->readMiscReg(MISCREG_TCR_EL3);
asid = -1;
break;
}
scr = tc->readMiscReg(MISCREG_SCR_EL3);
isPriv = aarch64EL != EL0;
if (haveVirtualization) {
vmid = getVMID(tc);
isHyp = aarch64EL == EL2;
isHyp |= tranType & HypMode;
isHyp &= (tranType & S1S2NsTran) == 0;
isHyp &= (tranType & S1CTran) == 0;
bool vm = hcr.vm;
if (HaveVirtHostExt(tc) && hcr.e2h == 1 && hcr.tge ==1) {
vm = 0;
}
if (hcr.e2h == 1 && (aarch64EL == EL2
|| (hcr.tge ==1 && aarch64EL == EL0))) {
isHyp = true;
directToStage2 = false;
stage2Req = false;
stage2DescReq = false;
} else {
// Work out if we should skip the first stage of translation and go
// directly to stage 2. This value is cached so we don't have to
// compute it for every translation.
bool sec = !isSecure || (isSecure && IsSecureEL2Enabled(tc));
stage2Req = isStage2 ||
(vm && !isHyp && sec &&
!(tranType & S1CTran) && (aarch64EL < EL2) &&
!(tranType & S1E1Tran)); // <--- FIX THIS HACK
stage2DescReq = isStage2 || (vm && !isHyp && sec &&
(aarch64EL < EL2));
directToStage2 = !isStage2 && stage2Req && !sctlr.m;
}
} else {
vmid = 0;
isHyp = false;
directToStage2 = false;
stage2Req = false;
stage2DescReq = false;
}
} else { // AArch32
sctlr = tc->readMiscReg(snsBankedIndex(MISCREG_SCTLR, tc,
!isSecure));
ttbcr = tc->readMiscReg(snsBankedIndex(MISCREG_TTBCR, tc,
!isSecure));
scr = tc->readMiscReg(MISCREG_SCR);
isPriv = cpsr.mode != MODE_USER;
if (longDescFormatInUse(tc)) {
uint64_t ttbr_asid = tc->readMiscReg(
snsBankedIndex(ttbcr.a1 ? MISCREG_TTBR1 :
MISCREG_TTBR0,
tc, !isSecure));
asid = bits(ttbr_asid, 55, 48);
} else { // Short-descriptor translation table format in use
CONTEXTIDR context_id = tc->readMiscReg(snsBankedIndex(
MISCREG_CONTEXTIDR, tc,!isSecure));
asid = context_id.asid;
}
prrr = tc->readMiscReg(snsBankedIndex(MISCREG_PRRR, tc,
!isSecure));
nmrr = tc->readMiscReg(snsBankedIndex(MISCREG_NMRR, tc,
!isSecure));
dacr = tc->readMiscReg(snsBankedIndex(MISCREG_DACR, tc,
!isSecure));
hcr = tc->readMiscReg(MISCREG_HCR);
if (haveVirtualization) {
vmid = bits(tc->readMiscReg(MISCREG_VTTBR), 55, 48);
isHyp = cpsr.mode == MODE_HYP;
isHyp |= tranType & HypMode;
isHyp &= (tranType & S1S2NsTran) == 0;
isHyp &= (tranType & S1CTran) == 0;
if (isHyp) {
sctlr = tc->readMiscReg(MISCREG_HSCTLR);
}
// Work out if we should skip the first stage of translation and go
// directly to stage 2. This value is cached so we don't have to
// compute it for every translation.
bool sec = !isSecure || (isSecure && IsSecureEL2Enabled(tc));
stage2Req = hcr.vm && !isStage2 && !isHyp && sec &&
!(tranType & S1CTran);
stage2DescReq = hcr.vm && !isStage2 && !isHyp && sec;
directToStage2 = stage2Req && !sctlr.m;
} else {
vmid = 0;
stage2Req = false;
isHyp = false;
directToStage2 = false;
stage2DescReq = false;
}
}
miscRegValid = true;
miscRegContext = tc->contextId();
curTranType = tranType;
}
ExceptionLevel
TLB::tranTypeEL(CPSR cpsr, ArmTranslationType type)
{
switch (type) {
case S1E0Tran:
case S12E0Tran:
return EL0;
case S1E1Tran:
case S12E1Tran:
return EL1;
case S1E2Tran:
return EL2;
case S1E3Tran:
return EL3;
case NormalTran:
case S1CTran:
case S1S2NsTran:
case HypMode:
return currEL(cpsr);
default:
panic("Unknown translation mode!\n");
}
}
Fault
TLB::getTE(TlbEntry **te, const RequestPtr &req, ThreadContext *tc,
BaseMMU::Mode mode, BaseMMU::Translation *translation, bool timing,
bool functional, bool is_secure, TLB::ArmTranslationType tranType)
{
// In a 2-stage system, the IPA->PA translation can be started via this
// call so make sure the miscRegs are correct.
if (isStage2) {
updateMiscReg(tc, tranType);
}
Addr vaddr_tainted = req->getVaddr();
Addr vaddr = 0;
ExceptionLevel target_el = aarch64 ? aarch64EL : EL1;
if (aarch64) {
vaddr = purifyTaggedAddr(vaddr_tainted, tc, target_el, (TCR)ttbcr,
mode==BaseMMU::Execute);
} else {
vaddr = vaddr_tainted;
}
*te = lookup(vaddr, asid, vmid, isHyp, is_secure, false, false, target_el,
false, mode);
if (*te == NULL) {
if (req->isPrefetch()) {
// if the request is a prefetch don't attempt to fill the TLB or go
// any further with the memory access (here we can safely use the
// fault status for the short desc. format in all cases)
stats.prefetchFaults++;
return std::make_shared<PrefetchAbort>(
vaddr_tainted, ArmFault::PrefetchTLBMiss, isStage2);
}
// start translation table walk, pass variables rather than
// re-retreaving in table walker for speed
DPRINTF(TLB, "TLB Miss: Starting hardware table walker for %#x(%d:%d)\n",
vaddr_tainted, asid, vmid);
Fault fault;
fault = tableWalker->walk(req, tc, asid, vmid, isHyp, mode,
translation, timing, functional, is_secure,
tranType, stage2DescReq);
// for timing mode, return and wait for table walk,
if (timing || fault != NoFault) {
return fault;
}
*te = lookup(vaddr, asid, vmid, isHyp, is_secure, true, false,
target_el, false, mode);
if (!*te)
printTlb();
assert(*te);
}
return NoFault;
}
Fault
TLB::getResultTe(TlbEntry **te, const RequestPtr &req,
ThreadContext *tc, BaseMMU::Mode mode,
BaseMMU::Translation *translation, bool timing, bool functional,
TlbEntry *mergeTe)
{
Fault fault;
if (isStage2) {
// We are already in the stage 2 TLB. Grab the table entry for stage
// 2 only. We are here because stage 1 translation is disabled.
TlbEntry *s2Te = NULL;
// Get the stage 2 table entry
fault = getTE(&s2Te, req, tc, mode, translation, timing, functional,
isSecure, curTranType);
// Check permissions of stage 2
if ((s2Te != NULL) && (fault == NoFault)) {
if (aarch64)
fault = checkPermissions64(s2Te, req, mode, tc);
else
fault = checkPermissions(s2Te, req, mode);
}
*te = s2Te;
return fault;
}
TlbEntry *s1Te = NULL;
Addr vaddr_tainted = req->getVaddr();
// Get the stage 1 table entry
fault = getTE(&s1Te, req, tc, mode, translation, timing, functional,
isSecure, curTranType);
// only proceed if we have a valid table entry
if ((s1Te != NULL) && (fault == NoFault)) {
// Check stage 1 permissions before checking stage 2
if (aarch64)
fault = checkPermissions64(s1Te, req, mode, tc);
else
fault = checkPermissions(s1Te, req, mode);
if (stage2Req & (fault == NoFault)) {
Stage2LookUp *s2Lookup = new Stage2LookUp(this, stage2Tlb, *s1Te,
req, translation, mode, timing, functional, isSecure,
curTranType);
fault = s2Lookup->getTe(tc, mergeTe);
if (s2Lookup->isComplete()) {
*te = mergeTe;
// We've finished with the lookup so delete it
delete s2Lookup;
} else {
// The lookup hasn't completed, so we can't delete it now. We
// get round this by asking the object to self delete when the
// translation is complete.
s2Lookup->setSelfDelete();
}
} else {
// This case deals with an S1 hit (or bypass), followed by
// an S2 hit-but-perms issue
if (isStage2) {
DPRINTF(TLBVerbose, "s2TLB: reqVa %#x, reqPa %#x, fault %p\n",
vaddr_tainted, req->hasPaddr() ? req->getPaddr() : ~0, fault);
if (fault != NoFault) {
ArmFault *armFault = reinterpret_cast<ArmFault *>(fault.get());
armFault->annotate(ArmFault::S1PTW, false);
armFault->annotate(ArmFault::OVA, vaddr_tainted);
}
}
*te = s1Te;
}
}
return fault;
}
void
TLB::setTestInterface(SimObject *_ti)
{
if (!_ti) {
test = nullptr;
} else {
TlbTestInterface *ti(dynamic_cast<TlbTestInterface *>(_ti));
fatal_if(!ti, "%s is not a valid ARM TLB tester\n", _ti->name());
test = ti;
}
}
Fault
TLB::testTranslation(const RequestPtr &req, BaseMMU::Mode mode,
TlbEntry::DomainType domain)
{
if (!test || !req->hasSize() || req->getSize() == 0 ||
req->isCacheMaintenance()) {
return NoFault;
} else {
return test->translationCheck(req, isPriv, mode, domain);
}
}
Fault
TLB::testWalk(Addr pa, Addr size, Addr va, bool is_secure, BaseMMU::Mode mode,
TlbEntry::DomainType domain, LookupLevel lookup_level)
{
if (!test) {
return NoFault;
} else {
return test->walkCheck(pa, size, va, is_secure, isPriv, mode,
domain, lookup_level);
}
}
} // namespace gem5
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