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author | Tony Gutierrez <anthony.gutierrez@amd.com> | 2016-01-19 14:28:22 -0500 |
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committer | Tony Gutierrez <anthony.gutierrez@amd.com> | 2016-01-19 14:28:22 -0500 |
commit | 1a7d3f9fcb76a68540dd948f91413533a383bfde (patch) | |
tree | 867510a147cd095f19499d26b7c02d27de4cae9d /src/gpu-compute/schedule_stage.cc | |
parent | 28e353e0403ea379d244a418e8dc8ee0b48187cf (diff) | |
download | gem5-1a7d3f9fcb76a68540dd948f91413533a383bfde.tar.xz |
gpu-compute: AMD's baseline GPU model
Diffstat (limited to 'src/gpu-compute/schedule_stage.cc')
-rw-r--r-- | src/gpu-compute/schedule_stage.cc | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/src/gpu-compute/schedule_stage.cc b/src/gpu-compute/schedule_stage.cc new file mode 100644 index 000000000..068136026 --- /dev/null +++ b/src/gpu-compute/schedule_stage.cc @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2014-2015 Advanced Micro Devices, Inc. + * All rights reserved. + * + * For use for simulation and test purposes only + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. 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. + * + * 3. Neither the name of the copyright holder 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 HOLDER 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. + * + * Author: Sooraj Puthoor + */ + +#include "gpu-compute/schedule_stage.hh" + +#include "gpu-compute/compute_unit.hh" +#include "gpu-compute/gpu_static_inst.hh" +#include "gpu-compute/vector_register_file.hh" +#include "gpu-compute/wavefront.hh" + +ScheduleStage::ScheduleStage(const ComputeUnitParams *p) + : numSIMDs(p->num_SIMDs), + numMemUnits(p->num_global_mem_pipes + p->num_shared_mem_pipes) +{ + for (int j = 0; j < numSIMDs + numMemUnits; ++j) { + Scheduler newScheduler(p); + scheduler.push_back(newScheduler); + } +} + +ScheduleStage::~ScheduleStage() +{ + scheduler.clear(); + waveStatusList.clear(); +} + +void +ScheduleStage::init(ComputeUnit *cu) +{ + computeUnit = cu; + _name = computeUnit->name() + ".ScheduleStage"; + + for (int j = 0; j < numSIMDs + numMemUnits; ++j) { + scheduler[j].bindList(&computeUnit->readyList[j]); + } + + for (int j = 0; j < numSIMDs; ++j) { + waveStatusList.push_back(&computeUnit->waveStatusList[j]); + } + + dispatchList = &computeUnit->dispatchList; +} + +void +ScheduleStage::arbitrate() +{ + // iterate over all Memory pipelines + for (int j = numSIMDs; j < numSIMDs + numMemUnits; ++j) { + if (dispatchList->at(j).first) { + Wavefront *waveToMemPipe = dispatchList->at(j).first; + // iterate over all execution pipelines + for (int i = 0; i < numSIMDs + numMemUnits; ++i) { + if ((i != j) && (dispatchList->at(i).first)) { + Wavefront *waveToExePipe = dispatchList->at(i).first; + // if the two selected wavefronts are mapped to the same + // SIMD unit then they share the VRF + if (waveToMemPipe->simdId == waveToExePipe->simdId) { + int simdId = waveToMemPipe->simdId; + // Read VRF port arbitration: + // If there are read VRF port conflicts between the + // a memory and another instruction we drop the other + // instruction. We don't need to check for write VRF + // port conflicts because the memory instruction either + // does not need to write to the VRF (store) or will + // write to the VRF when the data comes back (load) in + // which case the arbiter of the memory pipes will + // resolve any conflicts + if (computeUnit->vrf[simdId]-> + isReadConflict(waveToMemPipe->wfSlotId, + waveToExePipe->wfSlotId)) { + // FIXME: The "second" member variable is never + // used in the model. I am setting it to READY + // simply to follow the protocol of setting it + // when the WF has an instruction ready to issue + waveStatusList[simdId]->at(waveToExePipe->wfSlotId) + .second = READY; + + dispatchList->at(i).first = nullptr; + dispatchList->at(i).second = EMPTY; + break; + } + } + } + } + } + } +} + +void +ScheduleStage::exec() +{ + for (int j = 0; j < numSIMDs + numMemUnits; ++j) { + uint32_t readyListSize = computeUnit->readyList[j].size(); + + // If no wave is ready to be scheduled on the execution resource + // then skip scheduling for this execution resource + if (!readyListSize) { + continue; + } + + Wavefront *waveToBeDispatched = scheduler[j].chooseWave(); + dispatchList->at(j).first = waveToBeDispatched; + waveToBeDispatched->updateResources(); + dispatchList->at(j).second = FILLED; + + waveStatusList[waveToBeDispatched->simdId]->at( + waveToBeDispatched->wfSlotId).second = BLOCKED; + + assert(computeUnit->readyList[j].size() == readyListSize - 1); + } + // arbitrate over all shared resources among instructions being issued + // simultaneously + arbitrate(); +} + +void +ScheduleStage::regStats() +{ +} |