summaryrefslogtreecommitdiff
path: root/src/arch/x86/pagetable_walker.cc
diff options
context:
space:
mode:
Diffstat (limited to 'src/arch/x86/pagetable_walker.cc')
-rw-r--r--src/arch/x86/pagetable_walker.cc504
1 files changed, 334 insertions, 170 deletions
diff --git a/src/arch/x86/pagetable_walker.cc b/src/arch/x86/pagetable_walker.cc
index cf82727a9..7c386dd02 100644
--- a/src/arch/x86/pagetable_walker.cc
+++ b/src/arch/x86/pagetable_walker.cc
@@ -40,6 +40,7 @@
#include "arch/x86/pagetable.hh"
#include "arch/x86/pagetable_walker.hh"
#include "arch/x86/tlb.hh"
+#include "arch/x86/vtophys.hh"
#include "base/bitfield.hh"
#include "cpu/thread_context.hh"
#include "cpu/base.hh"
@@ -67,12 +68,209 @@ BitUnion64(PageTableEntry)
EndBitUnion(PageTableEntry)
Fault
-Walker::doNext(PacketPtr &write)
+Walker::start(ThreadContext * _tc, BaseTLB::Translation *_translation,
+ RequestPtr _req, BaseTLB::Mode _mode)
+{
+ // TODO: in timing mode, instead of blocking when there are other
+ // outstanding requests, see if this request can be coalesced with
+ // another one (i.e. either coalesce or start walk)
+ WalkerState * newState = new WalkerState(this, _translation, _req);
+ newState->initState(_tc, _mode, sys->getMemoryMode() == Enums::timing);
+ if (currStates.size()) {
+ assert(newState->isTiming());
+ DPRINTF(PageTableWalker, "Walks in progress: %d\n", currStates.size());
+ currStates.push_back(newState);
+ return NoFault;
+ } else {
+ currStates.push_back(newState);
+ Fault fault = newState->startWalk();
+ if (!newState->isTiming()) {
+ currStates.pop_front();
+ delete newState;
+ }
+ return fault;
+ }
+}
+
+Fault
+Walker::startFunctional(ThreadContext * _tc, Addr &addr, Addr &pageSize,
+ BaseTLB::Mode _mode)
+{
+ funcState.initState(_tc, _mode);
+ return funcState.startFunctional(addr, pageSize);
+}
+
+bool
+Walker::WalkerPort::recvTiming(PacketPtr pkt)
+{
+ return walker->recvTiming(pkt);
+}
+
+bool
+Walker::recvTiming(PacketPtr pkt)
+{
+ if (pkt->isResponse() || pkt->wasNacked()) {
+ WalkerSenderState * senderState =
+ dynamic_cast<WalkerSenderState *>(pkt->senderState);
+ pkt->senderState = senderState->saved;
+ WalkerState * senderWalk = senderState->senderWalk;
+ bool walkComplete = senderWalk->recvPacket(pkt);
+ delete senderState;
+ if (walkComplete) {
+ std::list<WalkerState *>::iterator iter;
+ for (iter = currStates.begin(); iter != currStates.end(); iter++) {
+ WalkerState * walkerState = *(iter);
+ if (walkerState == senderWalk) {
+ iter = currStates.erase(iter);
+ break;
+ }
+ }
+ delete senderWalk;
+ // Since we block requests when another is outstanding, we
+ // need to check if there is a waiting request to be serviced
+ if (currStates.size()) {
+ WalkerState * newState = currStates.front();
+ if (!newState->wasStarted())
+ newState->startWalk();
+ }
+ }
+ } else {
+ DPRINTF(PageTableWalker, "Received strange packet\n");
+ }
+ return true;
+}
+
+Tick
+Walker::WalkerPort::recvAtomic(PacketPtr pkt)
+{
+ return 0;
+}
+
+void
+Walker::WalkerPort::recvFunctional(PacketPtr pkt)
+{
+ return;
+}
+
+void
+Walker::WalkerPort::recvStatusChange(Status status)
+{
+ if (status == RangeChange) {
+ if (!snoopRangeSent) {
+ snoopRangeSent = true;
+ sendStatusChange(Port::RangeChange);
+ }
+ return;
+ }
+
+ panic("Unexpected recvStatusChange.\n");
+}
+
+void
+Walker::WalkerPort::recvRetry()
+{
+ walker->recvRetry();
+}
+
+void
+Walker::recvRetry()
+{
+ std::list<WalkerState *>::iterator iter;
+ for (iter = currStates.begin(); iter != currStates.end(); iter++) {
+ WalkerState * walkerState = *(iter);
+ if (walkerState->isRetrying()) {
+ walkerState->retry();
+ }
+ }
+}
+
+bool Walker::sendTiming(WalkerState* sendingState, PacketPtr pkt)
+{
+ pkt->senderState = new WalkerSenderState(sendingState, pkt->senderState);
+ return port.sendTiming(pkt);
+}
+
+Port *
+Walker::getPort(const std::string &if_name, int idx)
+{
+ if (if_name == "port")
+ return &port;
+ else
+ panic("No page table walker port named %s!\n", if_name);
+}
+
+void
+Walker::WalkerState::initState(ThreadContext * _tc,
+ BaseTLB::Mode _mode, bool _isTiming)
+{
+ assert(state == Ready);
+ started = false;
+ tc = _tc;
+ mode = _mode;
+ timing = _isTiming;
+}
+
+Fault
+Walker::WalkerState::startWalk()
+{
+ Fault fault = NoFault;
+ assert(started == false);
+ started = true;
+ setupWalk(req->getVaddr());
+ if (timing) {
+ nextState = state;
+ state = Waiting;
+ timingFault = NoFault;
+ sendPackets();
+ } else {
+ do {
+ walker->port.sendAtomic(read);
+ PacketPtr write = NULL;
+ fault = stepWalk(write);
+ assert(fault == NoFault || read == NULL);
+ state = nextState;
+ nextState = Ready;
+ if (write)
+ walker->port.sendAtomic(write);
+ } while(read);
+ state = Ready;
+ nextState = Waiting;
+ }
+ return fault;
+}
+
+Fault
+Walker::WalkerState::startFunctional(Addr &addr, Addr &pageSize)
+{
+ Fault fault = NoFault;
+ assert(started == false);
+ started = true;
+ setupWalk(addr);
+
+ do {
+ walker->port.sendFunctional(read);
+ // On a functional access (page table lookup), writes should
+ // not happen so this pointer is ignored after stepWalk
+ PacketPtr write = NULL;
+ fault = stepWalk(write);
+ assert(fault == NoFault || read == NULL);
+ state = nextState;
+ nextState = Ready;
+ } while(read);
+ pageSize = entry.size;
+ addr = entry.paddr;
+
+ return fault;
+}
+
+Fault
+Walker::WalkerState::stepWalk(PacketPtr &write)
{
assert(state != Ready && state != Waiting);
+ Fault fault = NoFault;
write = NULL;
PageTableEntry pte;
- if (size == 8)
+ if (dataSize == 8)
pte = read->get<uint64_t>();
else
pte = read->get<uint32_t>();
@@ -80,19 +278,22 @@ Walker::doNext(PacketPtr &write)
bool uncacheable = pte.pcd;
Addr nextRead = 0;
bool doWrite = false;
+ bool doTLBInsert = false;
+ bool doEndWalk = false;
bool badNX = pte.nx && mode == BaseTLB::Execute && enableNX;
switch(state) {
case LongPML4:
DPRINTF(PageTableWalker,
"Got long mode PML4 entry %#016x.\n", (uint64_t)pte);
- nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl3 * size;
+ nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl3 * dataSize;
doWrite = !pte.a;
pte.a = 1;
entry.writable = pte.w;
entry.user = pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
entry.noExec = pte.nx;
nextState = LongPDP;
@@ -100,14 +301,15 @@ Walker::doNext(PacketPtr &write)
case LongPDP:
DPRINTF(PageTableWalker,
"Got long mode PDP entry %#016x.\n", (uint64_t)pte);
- nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl2 * size;
+ nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl2 * dataSize;
doWrite = !pte.a;
pte.a = 1;
entry.writable = entry.writable && pte.w;
entry.user = entry.user && pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
nextState = LongPD;
break;
@@ -119,14 +321,15 @@ Walker::doNext(PacketPtr &write)
entry.writable = entry.writable && pte.w;
entry.user = entry.user && pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
if (!pte.ps) {
// 4 KB page
entry.size = 4 * (1 << 10);
nextRead =
- ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl1 * size;
+ ((uint64_t)pte & (mask(40) << 12)) + vaddr.longl1 * dataSize;
nextState = LongPTE;
break;
} else {
@@ -137,9 +340,9 @@ Walker::doNext(PacketPtr &write)
entry.global = pte.g;
entry.patBit = bits(pte, 12);
entry.vaddr = entry.vaddr & ~((2 * (1 << 20)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
}
case LongPTE:
DPRINTF(PageTableWalker,
@@ -149,24 +352,26 @@ Walker::doNext(PacketPtr &write)
entry.writable = entry.writable && pte.w;
entry.user = entry.user && pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
entry.paddr = (uint64_t)pte & (mask(40) << 12);
entry.uncacheable = uncacheable;
entry.global = pte.g;
entry.patBit = bits(pte, 12);
entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
case PAEPDP:
DPRINTF(PageTableWalker,
"Got legacy mode PAE PDP entry %#08x.\n", (uint32_t)pte);
- nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.pael2 * size;
+ nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.pael2 * dataSize;
if (!pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
nextState = PAEPD;
break;
@@ -178,13 +383,14 @@ Walker::doNext(PacketPtr &write)
entry.writable = pte.w;
entry.user = pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
if (!pte.ps) {
// 4 KB page
entry.size = 4 * (1 << 10);
- nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.pael1 * size;
+ nextRead = ((uint64_t)pte & (mask(40) << 12)) + vaddr.pael1 * dataSize;
nextState = PAEPTE;
break;
} else {
@@ -195,9 +401,9 @@ Walker::doNext(PacketPtr &write)
entry.global = pte.g;
entry.patBit = bits(pte, 12);
entry.vaddr = entry.vaddr & ~((2 * (1 << 20)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
}
case PAEPTE:
DPRINTF(PageTableWalker,
@@ -207,17 +413,18 @@ Walker::doNext(PacketPtr &write)
entry.writable = entry.writable && pte.w;
entry.user = entry.user && pte.u;
if (badNX || !pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
entry.paddr = (uint64_t)pte & (mask(40) << 12);
entry.uncacheable = uncacheable;
entry.global = pte.g;
entry.patBit = bits(pte, 7);
entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
case PSEPD:
DPRINTF(PageTableWalker,
"Got legacy mode PSE PD entry %#08x.\n", (uint32_t)pte);
@@ -226,14 +433,15 @@ Walker::doNext(PacketPtr &write)
entry.writable = pte.w;
entry.user = pte.u;
if (!pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
if (!pte.ps) {
// 4 KB page
entry.size = 4 * (1 << 10);
nextRead =
- ((uint64_t)pte & (mask(20) << 12)) + vaddr.norml2 * size;
+ ((uint64_t)pte & (mask(20) << 12)) + vaddr.norml2 * dataSize;
nextState = PTE;
break;
} else {
@@ -244,9 +452,9 @@ Walker::doNext(PacketPtr &write)
entry.global = pte.g;
entry.patBit = bits(pte, 12);
entry.vaddr = entry.vaddr & ~((4 * (1 << 20)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
}
case PD:
DPRINTF(PageTableWalker,
@@ -256,12 +464,13 @@ Walker::doNext(PacketPtr &write)
entry.writable = pte.w;
entry.user = pte.u;
if (!pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
// 4 KB page
entry.size = 4 * (1 << 10);
- nextRead = ((uint64_t)pte & (mask(20) << 12)) + vaddr.norml2 * size;
+ nextRead = ((uint64_t)pte & (mask(20) << 12)) + vaddr.norml2 * dataSize;
nextState = PTE;
break;
case PTE:
@@ -272,66 +481,73 @@ Walker::doNext(PacketPtr &write)
entry.writable = pte.w;
entry.user = pte.u;
if (!pte.p) {
- stop();
- return pageFault(pte.p);
+ doEndWalk = true;
+ fault = pageFault(pte.p);
+ break;
}
entry.paddr = (uint64_t)pte & (mask(20) << 12);
entry.uncacheable = uncacheable;
entry.global = pte.g;
entry.patBit = bits(pte, 7);
entry.vaddr = entry.vaddr & ~((4 * (1 << 10)) - 1);
- tlb->insert(entry.vaddr, entry);
- stop();
- return NoFault;
+ doTLBInsert = true;
+ doEndWalk = true;
+ break;
default:
panic("Unknown page table walker state %d!\n");
}
- PacketPtr oldRead = read;
- //If we didn't return, we're setting up another read.
- Request::Flags flags = oldRead->req->getFlags();
- flags.set(Request::UNCACHEABLE, uncacheable);
- RequestPtr request =
- new Request(nextRead, oldRead->getSize(), flags);
- read = new Packet(request, MemCmd::ReadExReq, Packet::Broadcast);
- read->allocate();
- //If we need to write, adjust the read packet to write the modified value
- //back to memory.
- if (doWrite) {
- write = oldRead;
- write->set<uint64_t>(pte);
- write->cmd = MemCmd::WriteReq;
- write->setDest(Packet::Broadcast);
+ if (doEndWalk) {
+ if (doTLBInsert)
+ if (!functional)
+ walker->tlb->insert(entry.vaddr, entry);
+ endWalk();
} else {
- write = NULL;
- delete oldRead->req;
- delete oldRead;
+ PacketPtr oldRead = read;
+ //If we didn't return, we're setting up another read.
+ Request::Flags flags = oldRead->req->getFlags();
+ flags.set(Request::UNCACHEABLE, uncacheable);
+ RequestPtr request =
+ new Request(nextRead, oldRead->getSize(), flags);
+ read = new Packet(request, MemCmd::ReadExReq, Packet::Broadcast);
+ read->allocate();
+ // If we need to write, adjust the read packet to write the modified
+ // value back to memory.
+ if (doWrite) {
+ write = oldRead;
+ write->set<uint64_t>(pte);
+ write->cmd = MemCmd::WriteReq;
+ write->setDest(Packet::Broadcast);
+ } else {
+ write = NULL;
+ delete oldRead->req;
+ delete oldRead;
+ }
}
- return NoFault;
+ return fault;
}
-Fault
-Walker::start(ThreadContext * _tc, BaseTLB::Translation *_translation,
- RequestPtr _req, BaseTLB::Mode _mode)
+void
+Walker::WalkerState::endWalk()
{
- assert(state == Ready);
- tc = _tc;
- req = _req;
- Addr vaddr = req->getVaddr();
- mode = _mode;
- translation = _translation;
+ nextState = Ready;
+ delete read->req;
+ delete read;
+ read = NULL;
+}
+void
+Walker::WalkerState::setupWalk(Addr vaddr)
+{
VAddr addr = vaddr;
-
- //Figure out what we're doing.
CR3 cr3 = tc->readMiscRegNoEffect(MISCREG_CR3);
- Addr top = 0;
// Check if we're in long mode or not
Efer efer = tc->readMiscRegNoEffect(MISCREG_EFER);
- size = 8;
+ dataSize = 8;
+ Addr topAddr;
if (efer.lma) {
// Do long mode.
state = LongPML4;
- top = (cr3.longPdtb << 12) + addr.longl4 * size;
+ topAddr = (cr3.longPdtb << 12) + addr.longl4 * dataSize;
enableNX = efer.nxe;
} else {
// We're in some flavor of legacy mode.
@@ -339,11 +555,11 @@ Walker::start(ThreadContext * _tc, BaseTLB::Translation *_translation,
if (cr4.pae) {
// Do legacy PAE.
state = PAEPDP;
- top = (cr3.paePdtb << 5) + addr.pael3 * size;
+ topAddr = (cr3.paePdtb << 5) + addr.pael3 * dataSize;
enableNX = efer.nxe;
} else {
- size = 4;
- top = (cr3.pdtb << 12) + addr.norml2 * size;
+ dataSize = 4;
+ topAddr = (cr3.pdtb << 12) + addr.norml2 * dataSize;
if (cr4.pse) {
// Do legacy PSE.
state = PSEPD;
@@ -361,44 +577,13 @@ Walker::start(ThreadContext * _tc, BaseTLB::Translation *_translation,
Request::Flags flags = Request::PHYSICAL;
if (cr3.pcd)
flags.set(Request::UNCACHEABLE);
- RequestPtr request = new Request(top, size, flags);
+ RequestPtr request = new Request(topAddr, dataSize, flags);
read = new Packet(request, MemCmd::ReadExReq, Packet::Broadcast);
read->allocate();
- Enums::MemoryMode memMode = sys->getMemoryMode();
- if (memMode == Enums::timing) {
- nextState = state;
- state = Waiting;
- timingFault = NoFault;
- sendPackets();
- } else if (memMode == Enums::atomic) {
- Fault fault;
- do {
- port.sendAtomic(read);
- PacketPtr write = NULL;
- fault = doNext(write);
- assert(fault == NoFault || read == NULL);
- state = nextState;
- nextState = Ready;
- if (write)
- port.sendAtomic(write);
- } while(read);
- state = Ready;
- nextState = Waiting;
- return fault;
- } else {
- panic("Unrecognized memory system mode.\n");
- }
- return NoFault;
-}
-
-bool
-Walker::WalkerPort::recvTiming(PacketPtr pkt)
-{
- return walker->recvTiming(pkt);
}
bool
-Walker::recvTiming(PacketPtr pkt)
+Walker::WalkerState::recvPacket(PacketPtr pkt)
{
if (pkt->isResponse() && !pkt->wasNacked()) {
assert(inflight);
@@ -410,7 +595,7 @@ Walker::recvTiming(PacketPtr pkt)
nextState = Ready;
PacketPtr write = NULL;
read = pkt;
- timingFault = doNext(write);
+ timingFault = stepWalk(write);
state = Waiting;
assert(timingFault == NoFault || read == NULL);
if (write) {
@@ -432,7 +617,7 @@ Walker::recvTiming(PacketPtr pkt)
* well.
*/
bool delayedResponse;
- Fault fault = tlb->translate(req, tc, NULL, mode,
+ Fault fault = walker->tlb->translate(req, tc, NULL, mode,
delayedResponse, true);
assert(!delayedResponse);
// Let the CPU continue.
@@ -441,10 +626,12 @@ Walker::recvTiming(PacketPtr pkt)
// There was a fault during the walk. Let the CPU know.
translation->finish(timingFault, req, tc, mode);
}
+ return true;
}
} else if (pkt->wasNacked()) {
+ DPRINTF(PageTableWalker, "Request was nacked. Entering retry state\n");
pkt->reinitNacked();
- if (!port.sendTiming(pkt)) {
+ if (!walker->sendTiming(this, pkt)) {
inflight--;
retrying = true;
if (pkt->isWrite()) {
@@ -455,50 +642,11 @@ Walker::recvTiming(PacketPtr pkt)
}
}
}
- return true;
-}
-
-Tick
-Walker::WalkerPort::recvAtomic(PacketPtr pkt)
-{
- return 0;
-}
-
-void
-Walker::WalkerPort::recvFunctional(PacketPtr pkt)
-{
- return;
-}
-
-void
-Walker::WalkerPort::recvStatusChange(Status status)
-{
- if (status == RangeChange) {
- if (!snoopRangeSent) {
- snoopRangeSent = true;
- sendStatusChange(Port::RangeChange);
- }
- return;
- }
-
- panic("Unexpected recvStatusChange.\n");
-}
-
-void
-Walker::WalkerPort::recvRetry()
-{
- walker->recvRetry();
+ return false;
}
void
-Walker::recvRetry()
-{
- retrying = false;
- sendPackets();
-}
-
-void
-Walker::sendPackets()
+Walker::WalkerState::sendPackets()
{
//If we're already waiting for the port to become available, just return.
if (retrying)
@@ -509,7 +657,7 @@ Walker::sendPackets()
PacketPtr pkt = read;
read = NULL;
inflight++;
- if (!port.sendTiming(pkt)) {
+ if (!walker->sendTiming(this, pkt)) {
retrying = true;
read = pkt;
inflight--;
@@ -521,7 +669,7 @@ Walker::sendPackets()
PacketPtr write = writes.back();
writes.pop_back();
inflight++;
- if (!port.sendTiming(write)) {
+ if (!walker->sendTiming(this, write)) {
retrying = true;
writes.push_back(write);
inflight--;
@@ -530,17 +678,33 @@ Walker::sendPackets()
}
}
-Port *
-Walker::getPort(const std::string &if_name, int idx)
+bool
+Walker::WalkerState::isRetrying()
{
- if (if_name == "port")
- return &port;
- else
- panic("No page table walker port named %s!\n", if_name);
+ return retrying;
+}
+
+bool
+Walker::WalkerState::isTiming()
+{
+ return timing;
+}
+
+bool
+Walker::WalkerState::wasStarted()
+{
+ return started;
+}
+
+void
+Walker::WalkerState::retry()
+{
+ retrying = false;
+ sendPackets();
}
Fault
-Walker::pageFault(bool present)
+Walker::WalkerState::pageFault(bool present)
{
DPRINTF(PageTableWalker, "Raising page fault.\n");
HandyM5Reg m5reg = tc->readMiscRegNoEffect(MISCREG_M5_REG);
@@ -549,7 +713,7 @@ Walker::pageFault(bool present)
return new PageFault(entry.vaddr, present, mode, m5reg.cpl == 3, false);
}
-}
+/* end namespace X86ISA */ }
X86ISA::Walker *
X86PagetableWalkerParams::create()
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 23:50:24 +0000