stage2_mmu.cc

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 * Authors: Thomas Grocutt
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#include "arch/arm/stage2_mmu.hh"

#include "arch/arm/faults.hh"
#include "arch/arm/system.hh"
#include "arch/arm/table_walker.hh"
#include "arch/arm/tlb.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"

using namespace ArmISA;

Stage2MMU::Stage2MMU(const Params *p)
    : SimObject(p), _stage1Tlb(p->tlb), _stage2Tlb(p->stage2_tlb),
      port(_stage1Tlb->getTableWalker(), p->sys),
      masterId(p->sys->getMasterId(_stage1Tlb->getTableWalker()->name()))
{
    // we use the stage-one table walker as the parent of the port,
    // and to get our master id, this is done to keep things
    // symmetrical with other ISAs in terms of naming and stats
    stage1Tlb()->setMMU(this, masterId);
    stage2Tlb()->setMMU(this, masterId);
}

Fault
Stage2MMU::readDataUntimed(ThreadContext *tc, Addr oVAddr, Addr descAddr,
    uint8_t *data, int numBytes, Request::Flags flags, bool isFunctional)
{
    Fault fault;

    // translate to physical address using the second stage MMU
    Request req = Request();
    req.setVirt(0, descAddr, numBytes, flags | Request::PT_WALK, masterId, 0);
    if (isFunctional) {
        fault = stage2Tlb()->translateFunctional(&req, tc, BaseTLB::Read);
    } else {
        fault = stage2Tlb()->translateAtomic(&req, tc, BaseTLB::Read);
    }

    // Now do the access.
    if (fault == NoFault && !req.getFlags().isSet(Request::NO_ACCESS)) {
        Packet pkt = Packet(&req, MemCmd::ReadReq);
        pkt.dataStatic(data);
        if (isFunctional) {
            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 *armFault = reinterpret_cast<ArmFault *>(fault.get());
        armFault->annotate(ArmFault::S1PTW, true);
        armFault->annotate(ArmFault::OVA, oVAddr);
    }
    return fault;
}

Fault
Stage2MMU::readDataTimed(ThreadContext *tc, Addr descAddr,
                         Stage2Translation *translation, int numBytes,
                         Request::Flags flags)
{
    Fault fault;
    // translate to physical address using the second stage MMU
    translation->setVirt(descAddr, numBytes, flags | Request::PT_WALK, masterId);
    fault = translation->translateTiming(tc);
    return fault;
}

Stage2MMU::Stage2Translation::Stage2Translation(Stage2MMU &_parent,
        uint8_t *_data, Event *_event, Addr _oVAddr)
    : data(_data), numBytes(0), event(_event), parent(_parent), oVAddr(_oVAddr),
    fault(NoFault)
{
}

void
Stage2MMU::Stage2Translation::finish(const Fault &_fault, RequestPtr req,
                                     ThreadContext *tc, BaseTLB::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 *armFault = reinterpret_cast<ArmFault *>(fault.get());
        armFault->annotate(ArmFault::S1PTW, true);
        armFault->annotate(ArmFault::OVA, oVAddr);
    }

    if (_fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
        parent.getPort().dmaAction(MemCmd::ReadReq, req->getPaddr(), numBytes,
                                   event, data, tc->getCpuPtr()->clockPeriod(),
                                   req->getFlags());
    } else {
        // We can't do the DMA access as there's been a problem, so tell the
        // event we're done
        event->process();
    }
}

ArmISA::Stage2MMU *
ArmStage2MMUParams::create()
{
    return new ArmISA::Stage2MMU(this);
}