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/*
* Copyright (c) 2015 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) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
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* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
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* 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
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*/
/* @file
* Device module for modelling a fixed bandwidth full duplex ethernet link
*/
#include "dev/net/etherlink.hh"
#include <cassert>
#include <cmath>
#include <deque>
#include <string>
#include <vector>
#include "base/logging.hh"
#include "base/random.hh"
#include "base/trace.hh"
#include "debug/Ethernet.hh"
#include "debug/EthernetData.hh"
#include "dev/net/etherdump.hh"
#include "dev/net/etherint.hh"
#include "dev/net/etherpkt.hh"
#include "params/EtherLink.hh"
#include "sim/core.hh"
#include "sim/serialize.hh"
#include "sim/system.hh"
EtherLink::EtherLink(const Params &p)
: SimObject(p)
{
link[0] = new Link(name() + ".link0", this, 0, p.speed,
p.delay, p.delay_var, p.dump);
link[1] = new Link(name() + ".link1", this, 1, p.speed,
p.delay, p.delay_var, p.dump);
interface[0] = new Interface(name() + ".int0", link[0], link[1]);
interface[1] = new Interface(name() + ".int1", link[1], link[0]);
}
EtherLink::~EtherLink()
{
delete link[0];
delete link[1];
delete interface[0];
delete interface[1];
}
Port &
EtherLink::getPort(const std::string &if_name, PortID idx)
{
if (if_name == "int0")
return *interface[0];
else if (if_name == "int1")
return *interface[1];
return SimObject::getPort(if_name, idx);
}
EtherLink::Interface::Interface(const std::string &name, Link *tx, Link *rx)
: EtherInt(name), txlink(tx)
{
tx->setTxInt(this);
rx->setRxInt(this);
}
EtherLink::Link::Link(const std::string &name, EtherLink *p, int num,
double rate, Tick delay, Tick delay_var, EtherDump *d)
: objName(name), parent(p), number(num), txint(NULL), rxint(NULL),
ticksPerByte(rate), linkDelay(delay), delayVar(delay_var), dump(d),
doneEvent([this]{ txDone(); }, name),
txQueueEvent([this]{ processTxQueue(); }, name)
{ }
void
EtherLink::serialize(CheckpointOut &cp) const
{
link[0]->serialize("link0", cp);
link[1]->serialize("link1", cp);
}
void
EtherLink::unserialize(CheckpointIn &cp)
{
link[0]->unserialize("link0", cp);
link[1]->unserialize("link1", cp);
}
void
EtherLink::Link::txComplete(EthPacketPtr packet)
{
DPRINTF(Ethernet, "packet received: len=%d\n", packet->length);
DDUMP(EthernetData, packet->data, packet->length);
rxint->sendPacket(packet);
}
void
EtherLink::Link::txDone()
{
if (dump)
dump->dump(packet);
if (linkDelay > 0) {
DPRINTF(Ethernet, "packet delayed: delay=%d\n", linkDelay);
txQueue.emplace_back(std::make_pair(curTick() + linkDelay, packet));
if (!txQueueEvent.scheduled())
parent->schedule(txQueueEvent, txQueue.front().first);
} else {
assert(txQueue.empty());
txComplete(packet);
}
packet = 0;
assert(!busy());
txint->sendDone();
}
void
EtherLink::Link::processTxQueue()
{
auto cur(txQueue.front());
txQueue.pop_front();
// Schedule a new event to process the next packet in the queue.
if (!txQueue.empty()) {
auto next(txQueue.front());
assert(next.first > curTick());
parent->schedule(txQueueEvent, next.first);
}
assert(cur.first == curTick());
txComplete(cur.second);
}
bool
EtherLink::Link::transmit(EthPacketPtr pkt)
{
if (busy()) {
DPRINTF(Ethernet, "packet not sent, link busy\n");
return false;
}
DPRINTF(Ethernet, "packet sent: len=%d\n", pkt->length);
DDUMP(EthernetData, pkt->data, pkt->length);
packet = pkt;
Tick delay = (Tick)ceil(((double)pkt->simLength * ticksPerByte) + 1.0);
if (delayVar != 0)
delay += random_mt.random<Tick>(0, delayVar);
DPRINTF(Ethernet, "scheduling packet: delay=%d, (rate=%f)\n",
delay, ticksPerByte);
parent->schedule(doneEvent, curTick() + delay);
return true;
}
void
EtherLink::Link::serialize(const std::string &base, CheckpointOut &cp) const
{
bool packet_exists = packet != nullptr;
paramOut(cp, base + ".packet_exists", packet_exists);
if (packet_exists)
packet->serialize(base + ".packet", cp);
bool event_scheduled = doneEvent.scheduled();
paramOut(cp, base + ".event_scheduled", event_scheduled);
if (event_scheduled) {
Tick event_time = doneEvent.when();
paramOut(cp, base + ".event_time", event_time);
}
const size_t tx_queue_size(txQueue.size());
paramOut(cp, base + ".tx_queue_size", tx_queue_size);
unsigned idx(0);
for (const auto &pe : txQueue) {
paramOut(cp, csprintf("%s.txQueue[%i].tick", base, idx), pe.first);
pe.second->serialize(csprintf("%s.txQueue[%i].packet", base, idx), cp);
++idx;
}
}
void
EtherLink::Link::unserialize(const std::string &base, CheckpointIn &cp)
{
bool packet_exists;
paramIn(cp, base + ".packet_exists", packet_exists);
if (packet_exists) {
packet = std::make_shared<EthPacketData>();
packet->unserialize(base + ".packet", cp);
}
bool event_scheduled;
paramIn(cp, base + ".event_scheduled", event_scheduled);
if (event_scheduled) {
Tick event_time;
paramIn(cp, base + ".event_time", event_time);
parent->schedule(doneEvent, event_time);
}
size_t tx_queue_size = 0;
if (optParamIn(cp, base + ".tx_queue_size", tx_queue_size)) {
for (size_t idx = 0; idx < tx_queue_size; ++idx) {
Tick tick;
EthPacketPtr delayed_packet = std::make_shared<EthPacketData>();
paramIn(cp, csprintf("%s.txQueue[%i].tick", base, idx), tick);
delayed_packet->unserialize(
csprintf("%s.txQueue[%i].packet", base, idx), cp);
fatal_if(!txQueue.empty() && txQueue.back().first > tick,
"Invalid txQueue packet order in EtherLink!\n");
txQueue.emplace_back(std::make_pair(tick, delayed_packet));
}
if (!txQueue.empty())
parent->schedule(txQueueEvent, txQueue.front().first);
} else {
// We can't reliably convert in-flight packets from old
// checkpoints. In fact, gem5 hasn't been able to load these
// packets for at least two years before the format change.
warn("Old-style EtherLink serialization format detected, "
"in-flight packets may have been dropped.\n");
}
}