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/*
* Copyright (c) 2013 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.
*/
#include "mem/dramsim3.hh"
#include "base/callback.hh"
#include "base/trace.hh"
#include "debug/DRAMsim3.hh"
#include "debug/Drain.hh"
#include "sim/system.hh"
namespace gem5
{
namespace memory
{
DRAMsim3::DRAMsim3(const Params &p) :
AbstractMemory(p),
port(name() + ".port", *this),
read_cb(std::bind(&DRAMsim3::readComplete,
this, 0, std::placeholders::_1)),
write_cb(std::bind(&DRAMsim3::writeComplete,
this, 0, std::placeholders::_1)),
wrapper(p.configFile, p.filePath, read_cb, write_cb),
retryReq(false), retryResp(false), startTick(0),
nbrOutstandingReads(0), nbrOutstandingWrites(0),
sendResponseEvent([this]{ sendResponse(); }, name()),
tickEvent([this]{ tick(); }, name())
{
DPRINTF(DRAMsim3,
"Instantiated DRAMsim3 with clock %d ns and queue size %d\n",
wrapper.clockPeriod(), wrapper.queueSize());
// Register a callback to compensate for the destructor not
// being called. The callback prints the DRAMsim3 stats.
registerExitCallback([this]() { wrapper.printStats(); });
}
void
DRAMsim3::init()
{
AbstractMemory::init();
if (!port.isConnected()) {
fatal("DRAMsim3 %s is unconnected!\n", name());
} else {
port.sendRangeChange();
}
if (system()->cacheLineSize() != wrapper.burstSize())
fatal("DRAMsim3 burst size %d does not match cache line size %d\n",
wrapper.burstSize(), system()->cacheLineSize());
}
void
DRAMsim3::startup()
{
startTick = curTick();
// kick off the clock ticks
schedule(tickEvent, clockEdge());
}
void
DRAMsim3::resetStats() {
wrapper.resetStats();
}
void
DRAMsim3::sendResponse()
{
assert(!retryResp);
assert(!responseQueue.empty());
DPRINTF(DRAMsim3, "Attempting to send response\n");
bool success = port.sendTimingResp(responseQueue.front());
if (success) {
responseQueue.pop_front();
DPRINTF(DRAMsim3, "Have %d read, %d write, %d responses outstanding\n",
nbrOutstandingReads, nbrOutstandingWrites,
responseQueue.size());
if (!responseQueue.empty() && !sendResponseEvent.scheduled())
schedule(sendResponseEvent, curTick());
if (nbrOutstanding() == 0)
signalDrainDone();
} else {
retryResp = true;
DPRINTF(DRAMsim3, "Waiting for response retry\n");
assert(!sendResponseEvent.scheduled());
}
}
unsigned int
DRAMsim3::nbrOutstanding() const
{
return nbrOutstandingReads + nbrOutstandingWrites + responseQueue.size();
}
void
DRAMsim3::tick()
{
// Only tick when it's timing mode
if (system()->isTimingMode()) {
wrapper.tick();
// is the connected port waiting for a retry, if so check the
// state and send a retry if conditions have changed
if (retryReq && nbrOutstanding() < wrapper.queueSize()) {
retryReq = false;
port.sendRetryReq();
}
}
schedule(tickEvent,
curTick() + wrapper.clockPeriod() * sim_clock::as_int::ns);
}
Tick
DRAMsim3::recvAtomic(PacketPtr pkt)
{
access(pkt);
// 50 ns is just an arbitrary value at this point
return pkt->cacheResponding() ? 0 : 50000;
}
void
DRAMsim3::recvFunctional(PacketPtr pkt)
{
pkt->pushLabel(name());
functionalAccess(pkt);
// potentially update the packets in our response queue as well
for (auto i = responseQueue.begin(); i != responseQueue.end(); ++i)
pkt->trySatisfyFunctional(*i);
pkt->popLabel();
}
bool
DRAMsim3::recvTimingReq(PacketPtr pkt)
{
// if a cache is responding, sink the packet without further action
if (pkt->cacheResponding()) {
pendingDelete.reset(pkt);
return true;
}
// we should not get a new request after committing to retry the
// current one, but unfortunately the CPU violates this rule, so
// simply ignore it for now
if (retryReq)
return false;
// if we cannot accept we need to send a retry once progress can
// be made
bool can_accept = nbrOutstanding() < wrapper.queueSize();
// keep track of the transaction
if (pkt->isRead()) {
if (can_accept) {
outstandingReads[pkt->getAddr()].push(pkt);
// we count a transaction as outstanding until it has left the
// queue in the controller, and the response has been sent
// back, note that this will differ for reads and writes
++nbrOutstandingReads;
}
} else if (pkt->isWrite()) {
if (can_accept) {
outstandingWrites[pkt->getAddr()].push(pkt);
++nbrOutstandingWrites;
// perform the access for writes
accessAndRespond(pkt);
}
} else {
// keep it simple and just respond if necessary
accessAndRespond(pkt);
return true;
}
if (can_accept) {
// we should never have a situation when we think there is space,
// and there isn't
assert(wrapper.canAccept(pkt->getAddr(), pkt->isWrite()));
DPRINTF(DRAMsim3, "Enqueueing address %lld\n", pkt->getAddr());
// @todo what about the granularity here, implicit assumption that
// a transaction matches the burst size of the memory (which we
// cannot determine without parsing the ini file ourselves)
wrapper.enqueue(pkt->getAddr(), pkt->isWrite());
return true;
} else {
retryReq = true;
return false;
}
}
void
DRAMsim3::recvRespRetry()
{
DPRINTF(DRAMsim3, "Retrying\n");
assert(retryResp);
retryResp = false;
sendResponse();
}
void
DRAMsim3::accessAndRespond(PacketPtr pkt)
{
DPRINTF(DRAMsim3, "Access for address %lld\n", pkt->getAddr());
bool needsResponse = pkt->needsResponse();
// do the actual memory access which also turns the packet into a
// response
access(pkt);
// turn packet around to go back to requestor if response expected
if (needsResponse) {
// access already turned the packet into a response
assert(pkt->isResponse());
// Here we pay for xbar additional delay and to process the payload
// of the packet.
Tick time = curTick() + pkt->headerDelay + pkt->payloadDelay;
// Reset the timings of the packet
pkt->headerDelay = pkt->payloadDelay = 0;
DPRINTF(DRAMsim3, "Queuing response for address %lld\n",
pkt->getAddr());
// queue it to be sent back
responseQueue.push_back(pkt);
// if we are not already waiting for a retry, or are scheduled
// to send a response, schedule an event
if (!retryResp && !sendResponseEvent.scheduled())
schedule(sendResponseEvent, time);
} else {
// queue the packet for deletion
pendingDelete.reset(pkt);
}
}
void DRAMsim3::readComplete(unsigned id, uint64_t addr)
{
DPRINTF(DRAMsim3, "Read to address %lld complete\n", addr);
// get the outstanding reads for the address in question
auto p = outstandingReads.find(addr);
assert(p != outstandingReads.end());
// first in first out, which is not necessarily true, but it is
// the best we can do at this point
PacketPtr pkt = p->second.front();
p->second.pop();
if (p->second.empty())
outstandingReads.erase(p);
// no need to check for drain here as the next call will add a
// response to the response queue straight away
assert(nbrOutstandingReads != 0);
--nbrOutstandingReads;
// perform the actual memory access
accessAndRespond(pkt);
}
void DRAMsim3::writeComplete(unsigned id, uint64_t addr)
{
DPRINTF(DRAMsim3, "Write to address %lld complete\n", addr);
// get the outstanding reads for the address in question
auto p = outstandingWrites.find(addr);
assert(p != outstandingWrites.end());
// we have already responded, and this is only to keep track of
// what is outstanding
p->second.pop();
if (p->second.empty())
outstandingWrites.erase(p);
assert(nbrOutstandingWrites != 0);
--nbrOutstandingWrites;
if (nbrOutstanding() == 0)
signalDrainDone();
}
Port&
DRAMsim3::getPort(const std::string &if_name, PortID idx)
{
if (if_name != "port") {
return ClockedObject::getPort(if_name, idx);
} else {
return port;
}
}
DrainState
DRAMsim3::drain()
{
// check our outstanding reads and writes and if any they need to
// drain
return nbrOutstanding() != 0 ? DrainState::Draining : DrainState::Drained;
}
DRAMsim3::MemoryPort::MemoryPort(const std::string& _name,
DRAMsim3& _memory)
: ResponsePort(_name, &_memory), mem(_memory)
{ }
AddrRangeList
DRAMsim3::MemoryPort::getAddrRanges() const
{
AddrRangeList ranges;
ranges.push_back(mem.getAddrRange());
return ranges;
}
Tick
DRAMsim3::MemoryPort::recvAtomic(PacketPtr pkt)
{
return mem.recvAtomic(pkt);
}
void
DRAMsim3::MemoryPort::recvFunctional(PacketPtr pkt)
{
mem.recvFunctional(pkt);
}
bool
DRAMsim3::MemoryPort::recvTimingReq(PacketPtr pkt)
{
// pass it to the memory controller
return mem.recvTimingReq(pkt);
}
void
DRAMsim3::MemoryPort::recvRespRetry()
{
mem.recvRespRetry();
}
} // namespace memory
} // namespace gem5