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/*
* Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
* 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.
*/
/*
* SWallocator_d.cc
*
* Niket Agarwal, Princeton University
*
* */
#include "mem/ruby/network/garnet-fixed-pipeline/SWallocator_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/Router_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/InputUnit_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/OutputUnit_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/GarnetNetwork_d.hh"
SWallocator_d::SWallocator_d(Router_d *router)
{
m_router = router;
m_num_vcs = m_router->get_num_vcs();
m_vc_per_vnet = m_router->get_vc_per_vnet();
m_local_arbiter_activity = 0;
m_global_arbiter_activity = 0;
}
void SWallocator_d::init()
{
m_input_unit = m_router->get_inputUnit_ref();
m_output_unit = m_router->get_outputUnit_ref();
m_num_inports = m_router->get_num_inports();
m_num_outports = m_router->get_num_outports();
m_round_robin_outport.setSize(m_num_outports);
m_round_robin_inport.setSize(m_num_inports);
m_port_req.setSize(m_num_outports);
m_vc_winners.setSize(m_num_outports);
for(int i = 0; i < m_num_inports; i++)
{
m_round_robin_inport[i] = 0;
}
for(int i = 0; i < m_num_outports; i++)
{
m_port_req[i].setSize(m_num_inports);
m_vc_winners[i].setSize(m_num_inports);
m_round_robin_outport[i] = 0;
for(int j = 0; j < m_num_inports; j++)
{
m_port_req[i][j] = false; // [outport][inport]
}
}
}
void SWallocator_d::wakeup()
{
arbitrate_inports(); // First stage of allocation
arbitrate_outports(); // Second stage of allocation
clear_request_vector();
check_for_wakeup();
}
void SWallocator_d::arbitrate_inports()
{
// First I will do round robin arbitration on a set of input vc requests
for(int inport = 0; inport < m_num_inports; inport++)
{
int invc = m_round_robin_inport[inport];
m_round_robin_inport[inport]++;
if(m_round_robin_inport[inport] >= m_num_vcs)
m_round_robin_inport[inport] = 0;
for(int j = 0; j < m_num_vcs; j++)
{
invc++;
if(invc >= m_num_vcs)
invc = 0;
if(m_input_unit[inport]->need_stage(invc, ACTIVE_, SA_) && m_input_unit[inport]->has_credits(invc))
{
if(is_candidate_inport(inport, invc))
{
int outport = m_input_unit[inport]->get_route(invc);
m_local_arbiter_activity++;
m_port_req[outport][inport] = true;
m_vc_winners[outport][inport]= invc;
break; // got one vc winner for this port
}
}
}
}
}
bool SWallocator_d::is_candidate_inport(int inport, int invc)
{
int outport = m_input_unit[inport]->get_route(invc);
int t_enqueue_time = m_input_unit[inport]->get_enqueue_time(invc);
int t_vnet = get_vnet(invc);
int vc_base = t_vnet*m_vc_per_vnet;
if((m_router->get_net_ptr())->isVNetOrdered(t_vnet))
{
for(int vc_offset = 0; vc_offset < m_vc_per_vnet; vc_offset++)
{
int temp_vc = vc_base + vc_offset;
if(m_input_unit[inport]->need_stage(temp_vc, ACTIVE_, SA_) && (m_input_unit[inport]->get_route(temp_vc) == outport) && (m_input_unit[inport]->get_enqueue_time(temp_vc) < t_enqueue_time))
{
return false;
break;
}
}
}
return true;
}
void SWallocator_d::arbitrate_outports()
{
// now I have a set of input vc requests for output vcs. Again do round robin arbitration on these requests
for(int outport = 0; outport < m_num_outports; outport++)
{
int in_port = m_round_robin_outport[outport];
m_round_robin_outport[outport]++;
if(m_round_robin_outport[outport] >= m_num_outports)
m_round_robin_outport[outport] = 0;
for(int inport = 0; inport < m_num_inports; inport++)
{
in_port++;
if(in_port >= m_num_inports)
in_port = 0;
if(m_port_req[outport][in_port]) // This Inport has a request this cycle for this port
{
m_port_req[outport][in_port] = false;
int invc = m_vc_winners[outport][in_port];
int outvc = m_input_unit[in_port]->get_outvc(invc);
flit_d *t_flit = m_input_unit[in_port]->getTopFlit(invc); // removes flit from Input Unit
t_flit->advance_stage(ST_);
t_flit->set_vc(outvc);
t_flit->set_outport(outport);
t_flit->set_time(g_eventQueue_ptr->getTime() + 1);
m_output_unit[outport]->decrement_credit(outvc);
m_router->update_sw_winner(in_port, t_flit);
m_global_arbiter_activity++;
if((t_flit->get_type() == TAIL_) || t_flit->get_type() == HEAD_TAIL_)
{
m_input_unit[in_port]->increment_credit(invc, true); // Send a credit back along with the information that this VC is not idle
assert(m_input_unit[in_port]->isReady(invc) == false); // This Input VC should now be empty
m_input_unit[in_port]->set_vc_state(IDLE_, invc);
m_input_unit[in_port]->set_enqueue_time(invc, INFINITE_);
}
else
{
m_input_unit[in_port]->increment_credit(invc, false); // Send a credit back but do not indicate that the VC is idle
}
break; // got a in request for this outport
}
}
}
}
void SWallocator_d::check_for_wakeup()
{
for(int i = 0; i < m_num_inports; i++)
{
for(int j = 0; j < m_num_vcs; j++)
{
if(m_input_unit[i]->need_stage_nextcycle(j, ACTIVE_, SA_))
{
g_eventQueue_ptr->scheduleEvent(this, 1);
return;
}
}
}
}
int SWallocator_d::get_vnet(int invc)
{
for(int i = 0; i < NUMBER_OF_VIRTUAL_NETWORKS; i++)
{
if(invc >= (i*m_vc_per_vnet) && invc < ((i+1)*m_vc_per_vnet))
{
return i;
}
}
ERROR_MSG("Could not determine vc");
return -1;
}
void SWallocator_d::clear_request_vector()
{
for(int i = 0; i < m_num_outports; i++)
{
for(int j = 0; j < m_num_inports; j++)
{
m_port_req[i][j] = false;
}
}
}
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