gem5/src/cpu/minor/cpu.cc
Andreas Sandberg ed38e3432c sim: Refactor and simplify the drain API
The drain() call currently passes around a DrainManager pointer, which
is now completely pointless since there is only ever one global
DrainManager in the system. It also contains vestiges from the time
when SimObjects had to keep track of their child objects that needed
draining.

This changeset moves all of the DrainState handling to the Drainable
base class and changes the drain() and drainResume() calls to reflect
this. Particularly, the drain() call has been updated to take no
parameters (the DrainManager argument isn't needed) and return a
DrainState instead of an unsigned integer (there is no point returning
anything other than 0 or 1 any more). Drainable objects should return
either DrainState::Draining (equivalent to returning 1 in the old
system) if they need more time to drain or DrainState::Drained
(equivalent to returning 0 in the old system) if they are already in a
consistent state. Returning DrainState::Running is considered an
error.

Drain done signalling is now done through the signalDrainDone() method
in the Drainable class instead of using the DrainManager directly. The
new call checks if the state of the object is DrainState::Draining
before notifying the drain manager. This means that it is safe to call
signalDrainDone() without first checking if the simulator has
requested draining. The intention here is to reduce the code needed to
implement draining in simple objects.
2015-07-07 09:51:05 +01:00

343 lines
8.6 KiB
C++

/*
* Copyright (c) 2012-2014 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
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* to a hardware implementation of the functionality of the software
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*
* 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;
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* 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
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* 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 "arch/utility.hh"
#include "cpu/minor/cpu.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)
{
/* This is only written for one thread at the moment */
Minor::MinorThread *thread;
if (FullSystem) {
thread = new Minor::MinorThread(this, 0, params->system, params->itb,
params->dtb, params->isa[0]);
} else {
/* thread_id 0 */
thread = new Minor::MinorThread(this, 0, params->system,
params->workload[0], params->itb, params->dtb, params->isa[0]);
}
threads.push_back(thread);
thread->setStatus(ThreadContext::Halted);
ThreadContext *tc = thread->getTC();
if (params->checker) {
fatal("The Minor model doesn't support checking (yet)\n");
}
threadContexts.push_back(tc);
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)
{
if (thread_id != 0)
fatal("Trying to load more than one thread into a MinorCPU\n");
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()
{
DPRINTF(Drain, "MinorCPU wakeup\n");
for (auto i = threads.begin(); i != threads.end(); i ++) {
if ((*i)->status() == ThreadContext::Suspended)
(*i)->activate();
}
DPRINTF(Drain,"Suspended Processor awoke\n");
}
void
MinorCPU::startup()
{
DPRINTF(MinorCPU, "MinorCPU startup\n");
BaseCPU::startup();
for (auto i = threads.begin(); i != threads.end(); i ++)
(*i)->startup();
/* CPU state setup, activate initial context */
activateContext(0);
}
DrainState
MinorCPU::drain()
{
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");
signalDrainDone();
}
void
MinorCPU::drainResume()
{
assert(drainState() == DrainState::Drained);
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");
}
wakeup();
pipeline->drainResume();
}
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);
/* Don't think I need to do anything here */
}
void
MinorCPU::activateContext(ThreadID thread_id)
{
DPRINTF(MinorCPU, "ActivateContext thread: %d", 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();
}
void
MinorCPU::suspendContext(ThreadID thread_id)
{
DPRINTF(MinorCPU, "SuspendContext %d\n", thread_id);
threads[thread_id]->suspend();
}
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()
{
numThreads = 1;
if (!FullSystem && workload.size() != 1)
panic("only one workload allowed");
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;
}