206 lines
6.4 KiB
C++
206 lines
6.4 KiB
C++
|
/*
|
||
|
* Copyright (c) 2012 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.
|
||
|
*
|
||
|
* Copyright (c) 2006 The Regents of The University of Michigan
|
||
|
* All rights reserved.
|
||
|
*
|
||
|
* 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: Ali Saidi
|
||
|
* Andreas Hansson
|
||
|
*/
|
||
|
|
||
|
#include "debug/PacketQueue.hh"
|
||
|
#include "mem/packet_queue.hh"
|
||
|
|
||
|
using namespace std;
|
||
|
|
||
|
PacketQueue::PacketQueue(EventManager& _em, Port& _port,
|
||
|
const std::string _label)
|
||
|
: em(_em), label(_label), sendEvent(this), drainEvent(NULL), port(_port),
|
||
|
waitingOnRetry(false)
|
||
|
{
|
||
|
}
|
||
|
|
||
|
PacketQueue::~PacketQueue()
|
||
|
{
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::retry()
|
||
|
{
|
||
|
DPRINTF(PacketQueue, "Queue %s received retry\n", name());
|
||
|
assert(waitingOnRetry);
|
||
|
sendDeferredPacket();
|
||
|
}
|
||
|
|
||
|
bool
|
||
|
PacketQueue::checkFunctional(PacketPtr pkt)
|
||
|
{
|
||
|
pkt->pushLabel(label);
|
||
|
|
||
|
DeferredPacketIterator i = transmitList.begin();
|
||
|
DeferredPacketIterator end = transmitList.end();
|
||
|
bool found = false;
|
||
|
|
||
|
while (!found && i != end) {
|
||
|
// If the buffered packet contains data, and it overlaps the
|
||
|
// current packet, then update data
|
||
|
found = pkt->checkFunctional(i->pkt);
|
||
|
++i;
|
||
|
}
|
||
|
|
||
|
pkt->popLabel();
|
||
|
|
||
|
return found;
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::schedSendEvent(Tick when)
|
||
|
{
|
||
|
// if we are waiting on a retry, do not schedule a send event, and
|
||
|
// instead rely on retry being called
|
||
|
if (waitingOnRetry) {
|
||
|
assert(!sendEvent.scheduled());
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (!sendEvent.scheduled()) {
|
||
|
em.schedule(&sendEvent, when);
|
||
|
} else if (sendEvent.when() > when) {
|
||
|
em.reschedule(&sendEvent, when);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::schedSendTiming(PacketPtr pkt, Tick when)
|
||
|
{
|
||
|
assert(when > curTick());
|
||
|
|
||
|
// nothing on the list, or earlier than current front element,
|
||
|
// schedule an event
|
||
|
if (transmitList.empty() || when < transmitList.front().tick) {
|
||
|
// note that currently we ignore a potentially outstanding retry
|
||
|
// and could in theory put a new packet at the head of the
|
||
|
// transmit list before retrying the existing packet
|
||
|
transmitList.push_front(DeferredPacket(when, pkt));
|
||
|
schedSendEvent(when);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
// list is non-empty and this belongs at the end
|
||
|
if (when >= transmitList.back().tick) {
|
||
|
transmitList.push_back(DeferredPacket(when, pkt));
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
// this belongs in the middle somewhere, insertion sort
|
||
|
DeferredPacketIterator i = transmitList.begin();
|
||
|
++i; // already checked for insertion at front
|
||
|
while (i != transmitList.end() && when >= i->tick)
|
||
|
++i;
|
||
|
transmitList.insert(i, DeferredPacket(when, pkt));
|
||
|
}
|
||
|
|
||
|
void PacketQueue::trySendTiming()
|
||
|
{
|
||
|
assert(deferredPacketReady());
|
||
|
|
||
|
// take the next packet off the list here, as we might return to
|
||
|
// ourselves through the sendTiming call below
|
||
|
DeferredPacket dp = transmitList.front();
|
||
|
transmitList.pop_front();
|
||
|
|
||
|
// attempt to send the packet and remember the outcome
|
||
|
waitingOnRetry = !port.sendTiming(dp.pkt);
|
||
|
|
||
|
if (waitingOnRetry) {
|
||
|
// put the packet back at the front of the list (packet should
|
||
|
// not have changed since it wasn't accepted)
|
||
|
assert(!sendEvent.scheduled());
|
||
|
transmitList.push_front(dp);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::scheduleSend(Tick time)
|
||
|
{
|
||
|
// the next ready time is either determined by the next deferred packet,
|
||
|
// or in the cache through the MSHR ready time
|
||
|
Tick nextReady = std::min(deferredPacketReadyTime(), time);
|
||
|
|
||
|
if (nextReady != MaxTick) {
|
||
|
// if the sendTiming caused someone else to call our
|
||
|
// recvTiming we could already have an event scheduled, check
|
||
|
if (!sendEvent.scheduled())
|
||
|
em.schedule(&sendEvent, std::max(nextReady, curTick() + 1));
|
||
|
} else {
|
||
|
// no more to send, so if we're draining, we may be done
|
||
|
if (drainEvent && !sendEvent.scheduled()) {
|
||
|
drainEvent->process();
|
||
|
drainEvent = NULL;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::sendDeferredPacket()
|
||
|
{
|
||
|
// try to send what is on the list, this will set waitingOnRetry
|
||
|
// accordingly
|
||
|
trySendTiming();
|
||
|
|
||
|
// if we succeeded and are not waiting for a retry, schedule the
|
||
|
// next send
|
||
|
if (!waitingOnRetry) {
|
||
|
scheduleSend();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PacketQueue::processSendEvent()
|
||
|
{
|
||
|
assert(!waitingOnRetry);
|
||
|
sendDeferredPacket();
|
||
|
}
|
||
|
|
||
|
unsigned int
|
||
|
PacketQueue::drain(Event *de)
|
||
|
{
|
||
|
if (transmitList.empty() && !sendEvent.scheduled())
|
||
|
return 0;
|
||
|
drainEvent = de;
|
||
|
return 1;
|
||
|
}
|