src/dev/net/etherlink.cc - public/gem5 - Git at Google

 /*
  * 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.
  *
  * 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: Nathan Binkert
  *          Ron Dreslinski
  */

 /* @file
  * Device module for modelling a fixed bandwidth full duplex ethernet link
  */

 #include "dev/net/etherlink.hh"

 #include <cmath>
 #include <deque>
 #include <string>
 #include <vector>

 #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"

 using namespace std;

 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 string &name, Link *tx, Link *rx)
     : EtherInt(name), txlink(tx)
 {
     tx->setTxInt(this);
     rx->setRxInt(this);
 }

 EtherLink::Link::Link(const 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 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 string &base, CheckpointIn &cp)
 {
     bool packet_exists;
     paramIn(cp, base + ".packet_exists", packet_exists);
     if (packet_exists) {
         packet = 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;
     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 = 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");
     }
 }

 EtherLink *
 EtherLinkParams::create()
 {
     return new EtherLink(this);
 }
	/*
	* 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.
	*
	* 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: Nathan Binkert
	* Ron Dreslinski
	*/

	/* @file
	* Device module for modelling a fixed bandwidth full duplex ethernet link
	*/

	#include "dev/net/etherlink.hh"

	#include <cmath>
	#include <deque>
	#include <string>
	#include <vector>

	#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"

	using namespace std;

	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 string &name, Link tx, Link rx)
	: EtherInt(name), txlink(tx)
	{
	tx->setTxInt(this);
	rx->setRxInt(this);
	}

	EtherLink::Link::Link(const 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 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 string &base, CheckpointIn &cp)
	{
	bool packet_exists;
	paramIn(cp, base + ".packet_exists", packet_exists);
	if (packet_exists) {
	packet = 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;
	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 = 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");
	}
	}

	EtherLink *
	EtherLinkParams::create()
	{
	return new EtherLink(this);
	}