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/*
* Copyright (c) 2008 Princeton University
* Copyright (c) 2016 Georgia Institute of Technology
* 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: Niket Agarwal
* Tushar Krishna
*/
#include "mem/ruby/network/garnet2.0/OutputUnit.hh"
#include "base/stl_helpers.hh"
#include "debug/RubyNetwork.hh"
#include "mem/ruby/network/garnet2.0/Credit.hh"
#include "mem/ruby/network/garnet2.0/Router.hh"
using namespace std;
using m5::stl_helpers::deletePointers;
OutputUnit::OutputUnit(int id, PortDirection direction, Router *router)
: Consumer(router)
{
m_id = id;
m_direction = direction;
m_router = router;
m_num_vcs = m_router->get_num_vcs();
m_vc_per_vnet = m_router->get_vc_per_vnet();
m_out_buffer = new flitBuffer();
for (int i = 0; i < m_num_vcs; i++) {
m_outvc_state.push_back(new OutVcState(i, m_router->get_net_ptr()));
}
}
OutputUnit::~OutputUnit()
{
delete m_out_buffer;
deletePointers(m_outvc_state);
}
void
OutputUnit::decrement_credit(int out_vc)
{
DPRINTF(RubyNetwork, "Router %d OutputUnit %d decrementing credit for "
"outvc %d at time: %lld\n",
m_router->get_id(), m_id, out_vc, m_router->curCycle());
m_outvc_state[out_vc]->decrement_credit();
}
void
OutputUnit::increment_credit(int out_vc)
{
DPRINTF(RubyNetwork, "Router %d OutputUnit %d incrementing credit for "
"outvc %d at time: %lld\n",
m_router->get_id(), m_id, out_vc, m_router->curCycle());
m_outvc_state[out_vc]->increment_credit();
}
// Check if the output VC (i.e., input VC at next router)
// has free credits (i..e, buffer slots).
// This is tracked by OutVcState
bool
OutputUnit::has_credit(int out_vc)
{
assert(m_outvc_state[out_vc]->isInState(ACTIVE_, m_router->curCycle()));
return m_outvc_state[out_vc]->has_credit();
}
// Check if the output port (i.e., input port at next router) has free VCs.
bool
OutputUnit::has_free_vc(int vnet)
{
int vc_base = vnet*m_vc_per_vnet;
for (int vc = vc_base; vc < vc_base + m_vc_per_vnet; vc++) {
if (is_vc_idle(vc, m_router->curCycle()))
return true;
}
return false;
}
// Assign a free output VC to the winner of Switch Allocation
int
OutputUnit::select_free_vc(int vnet)
{
int vc_base = vnet*m_vc_per_vnet;
for (int vc = vc_base; vc < vc_base + m_vc_per_vnet; vc++) {
if (is_vc_idle(vc, m_router->curCycle())) {
m_outvc_state[vc]->setState(ACTIVE_, m_router->curCycle());
return vc;
}
}
return -1;
}
/*
* The wakeup function of the OutputUnit reads the credit signal from the
* downstream router for the output VC (i.e., input VC at downstream router).
* It increments the credit count in the appropriate output VC state.
* If the credit carries is_free_signal as true,
* the output VC is marked IDLE.
*/
void
OutputUnit::wakeup()
{
if (m_credit_link->isReady(m_router->curCycle())) {
Credit *t_credit = (Credit*) m_credit_link->consumeLink();
increment_credit(t_credit->get_vc());
if (t_credit->is_free_signal())
set_vc_state(IDLE_, t_credit->get_vc(), m_router->curCycle());
delete t_credit;
}
}
flitBuffer*
OutputUnit::getOutQueue()
{
return m_out_buffer;
}
void
OutputUnit::set_out_link(NetworkLink *link)
{
m_out_link = link;
}
void
OutputUnit::set_credit_link(CreditLink *credit_link)
{
m_credit_link = credit_link;
}
uint32_t
OutputUnit::functionalWrite(Packet *pkt)
{
return m_out_buffer->functionalWrite(pkt);
}