/*
 * Copyright (c) 2012-2014, 2017 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.
 *
 * Authors: Andrew Bardsley
 */

#include "cpu/minor/cpu.hh"

#include "arch/utility.hh"
#include "cpu/minor/dyn_inst.hh"
#include "cpu/minor/fetch1.hh"
#include "cpu/minor/pipeline.hh"
#include "debug/Drain.hh"
#include "debug/MinorCPU.hh"
#include "debug/Quiesce.hh"

MinorCPU::MinorCPU(MinorCPUParams *params) :
    BaseCPU(params),
    pipelineStartupEvent([this]{ wakeupPipeline(); }, name()),
    threadPolicy(params->threadPolicy)
{
    /* This is only written for one thread at the moment */
    Minor::MinorThread *thread;

    for (ThreadID i = 0; i < numThreads; i++) {
        if (FullSystem) {
            thread = new Minor::MinorThread(this, i, params->system,
                    params->itb, params->dtb, params->isa[i]);
            thread->setStatus(ThreadContext::Halted);
        } else {
            thread = new Minor::MinorThread(this, i, params->system,
                    params->workload[i], params->itb, params->dtb,
                    params->isa[i]);
        }

        threads.push_back(thread);
        ThreadContext *tc = thread->getTC();
        threadContexts.push_back(tc);
    }


    if (params->checker) {
        fatal("The Minor model doesn't support checking (yet)\n");
    }

    Minor::MinorDynInst::init();

    pipeline = new Minor::Pipeline(*this, *params);
    activityRecorder = pipeline->getActivityRecorder();
}

MinorCPU::~MinorCPU()
{
    delete pipeline;

    for (ThreadID thread_id = 0; thread_id < threads.size(); thread_id++) {
        delete threads[thread_id];
    }
}

void
MinorCPU::init()
{
    BaseCPU::init();

    if (!params()->switched_out &&
        system->getMemoryMode() != Enums::timing)
    {
        fatal("The Minor CPU requires the memory system to be in "
            "'timing' mode.\n");
    }

    /* Initialise the ThreadContext's memory proxies */
    for (ThreadID thread_id = 0; thread_id < threads.size(); thread_id++) {
        ThreadContext *tc = getContext(thread_id);

        tc->initMemProxies(tc);
    }

    /* Initialise CPUs (== threads in the ISA) */
    if (FullSystem && !params()->switched_out) {
        for (ThreadID thread_id = 0; thread_id < threads.size(); thread_id++)
        {
            ThreadContext *tc = getContext(thread_id);

            /* Initialize CPU, including PC */
            TheISA::initCPU(tc, cpuId());
        }
    }
}

/** Stats interface from SimObject (by way of BaseCPU) */
void
MinorCPU::regStats()
{
    BaseCPU::regStats();
    stats.regStats(name(), *this);
    pipeline->regStats();
}

void
MinorCPU::serializeThread(CheckpointOut &cp, ThreadID thread_id) const
{
    threads[thread_id]->serialize(cp);
}

void
MinorCPU::unserializeThread(CheckpointIn &cp, ThreadID thread_id)
{
    threads[thread_id]->unserialize(cp);
}

void
MinorCPU::serialize(CheckpointOut &cp) const
{
    pipeline->serialize(cp);
    BaseCPU::serialize(cp);
}

void
MinorCPU::unserialize(CheckpointIn &cp)
{
    pipeline->unserialize(cp);
    BaseCPU::unserialize(cp);
}

Addr
MinorCPU::dbg_vtophys(Addr addr)
{
    /* Note that this gives you the translation for thread 0 */
    panic("No implementation for vtophy\n");

    return 0;
}

void
MinorCPU::wakeup(ThreadID tid)
{
    DPRINTF(Drain, "[tid:%d] MinorCPU wakeup\n", tid);
    assert(tid < numThreads);

    if (threads[tid]->status() == ThreadContext::Suspended) {
        threads[tid]->activate();
    }
}

void
MinorCPU::startup()
{
    DPRINTF(MinorCPU, "MinorCPU startup\n");

    BaseCPU::startup();

    for (ThreadID tid = 0; tid < numThreads; tid++) {
        threads[tid]->startup();
        pipeline->wakeupFetch(tid);
    }
}

DrainState
MinorCPU::drain()
{
    // Deschedule any power gating event (if any)
    deschedulePowerGatingEvent();

    if (switchedOut()) {
        DPRINTF(Drain, "Minor CPU switched out, draining not needed.\n");
        return DrainState::Drained;
    }

    DPRINTF(Drain, "MinorCPU drain\n");

    /* Need to suspend all threads and wait for Execute to idle.
     * Tell Fetch1 not to fetch */
    if (pipeline->drain()) {
        DPRINTF(Drain, "MinorCPU drained\n");
        return DrainState::Drained;
    } else {
        DPRINTF(Drain, "MinorCPU not finished draining\n");
        return DrainState::Draining;
    }
}

void
MinorCPU::signalDrainDone()
{
    DPRINTF(Drain, "MinorCPU drain done\n");
    Drainable::signalDrainDone();
}

void
MinorCPU::drainResume()
{
    /* When taking over from another cpu make sure lastStopped
     * is reset since it might have not been defined previously
     * and might lead to a stats corruption */
    pipeline->resetLastStopped();

    if (switchedOut()) {
        DPRINTF(Drain, "drainResume while switched out.  Ignoring\n");
        return;
    }

    DPRINTF(Drain, "MinorCPU drainResume\n");

    if (!system->isTimingMode()) {
        fatal("The Minor CPU requires the memory system to be in "
            "'timing' mode.\n");
    }

    for (ThreadID tid = 0; tid < numThreads; tid++){
        wakeup(tid);
    }

    pipeline->drainResume();

    // Reschedule any power gating event (if any)
    schedulePowerGatingEvent();
}

void
MinorCPU::memWriteback()
{
    DPRINTF(Drain, "MinorCPU memWriteback\n");
}

void
MinorCPU::switchOut()
{
    DPRINTF(MinorCPU, "MinorCPU switchOut\n");

    assert(!switchedOut());
    BaseCPU::switchOut();

    /* Check that the CPU is drained? */
    activityRecorder->reset();
}

void
MinorCPU::takeOverFrom(BaseCPU *old_cpu)
{
    DPRINTF(MinorCPU, "MinorCPU takeOverFrom\n");

    BaseCPU::takeOverFrom(old_cpu);
}

void
MinorCPU::activateContext(ThreadID thread_id)
{
    /* Remember to wake up this thread_id by scheduling the
     * pipelineStartup event.
     * We can't wakeupFetch the thread right away because its context may
     * not have been fully initialized. For example, in the case of clone
     * syscall, this activateContext function is called in the middle of
     * the syscall and before the new thread context is initialized.
     * If we start fetching right away, the new thread will fetch from an
     * invalid address (i.e., pc is not initialized yet), which could lead
     * to a page fault. Instead, we remember which threads to wake up and
     * schedule an event to wake all them up after their contexts are
     * fully initialized */
    readyThreads.push_back(thread_id);
    if (!pipelineStartupEvent.scheduled())
        schedule(pipelineStartupEvent, clockEdge(Cycles(0)));
}

void
MinorCPU::wakeupPipeline()
{
    for (auto thread_id : readyThreads) {
        DPRINTF(MinorCPU, "ActivateContext thread: %d\n", thread_id);

        /* Do some cycle accounting.  lastStopped is reset to stop the
         *  wakeup call on the pipeline from adding the quiesce period
         *  to BaseCPU::numCycles */
        stats.quiesceCycles += pipeline->cyclesSinceLastStopped();
        pipeline->resetLastStopped();

        /* Wake up the thread, wakeup the pipeline tick */
        threads[thread_id]->activate();
        wakeupOnEvent(Minor::Pipeline::CPUStageId);

        pipeline->wakeupFetch(thread_id);
        BaseCPU::activateContext(thread_id);
    }

    readyThreads.clear();
}

void
MinorCPU::suspendContext(ThreadID thread_id)
{
    DPRINTF(MinorCPU, "SuspendContext %d\n", thread_id);

    threads[thread_id]->suspend();

    BaseCPU::suspendContext(thread_id);
}

void
MinorCPU::wakeupOnEvent(unsigned int stage_id)
{
    DPRINTF(Quiesce, "Event wakeup from stage %d\n", stage_id);

    /* Mark that some activity has taken place and start the pipeline */
    activityRecorder->activateStage(stage_id);
    pipeline->start();
}

MinorCPU *
MinorCPUParams::create()
{
    return new MinorCPU(this);
}

MasterPort &MinorCPU::getInstPort()
{
    return pipeline->getInstPort();
}

MasterPort &MinorCPU::getDataPort()
{
    return pipeline->getDataPort();
}

Counter
MinorCPU::totalInsts() const
{
    Counter ret = 0;

    for (auto i = threads.begin(); i != threads.end(); i ++)
        ret += (*i)->numInst;

    return ret;
}

Counter
MinorCPU::totalOps() const
{
    Counter ret = 0;

    for (auto i = threads.begin(); i != threads.end(); i ++)
        ret += (*i)->numOp;

    return ret;
}