func (this *Processor) StartPipelineUnits(config *config.Config, recoveryChannel channel.Channel, operationId, address uint32) func() {
// Initialize channels
addressChannel := channel.New(config.InstructionsFetchedPerCycle()) // Branch Predictor -> Fetch
instructionChannel := channel.New(config.InstructionsQueue()) // Fetch -> Decode
operationChannel := channel.New(config.InstructionsDecodedQueue()) // Decode -> Dispatch
executionChannels := map[info.CategoryEnum]channel.Channel{ // Dispatch -> Execute
info.Aritmetic: channel.New(config.AluUnits()),
info.LoadStore: channel.New(config.LoadStoreUnits()),
info.Control: channel.New(config.BranchUnits()),
info.FloatingPoint: channel.New(config.FpuUnits()),
}
commonDataBusChannel := channel.New(channel.INFINITE) // Execute -> Dispatcher (RS & ROB)
closeUnitsHandlers := []func(){}
/////////////////////////////////////////////////////////////////////////////
// Run stage units in parallel //
// - Units are executed as go routines https://blog.golang.org/pipelines) //
/////////////////////////////////////////////////////////////////////////////
// ---------- Fetch ------------ //
fe := fetcher.New(uint32(0), this, config.InstructionsFetchedPerCycle(), config.BranchPredictorType())
fe.Run(addressChannel, instructionChannel)
closeUnitsHandlers = append(closeUnitsHandlers, fe.Close)
// ---------- Decode ------------ //
for index := uint32(0); index < config.DecoderUnits(); index++ {
de := decoder.New(index, this)
de.Run(instructionChannel, operationChannel)
closeUnitsHandlers = append(closeUnitsHandlers, de.Close)
}
// ----- Dispatch / RS / ROB ---- //
di := dispatcher.New(uint32(0), this, operationId, config.TotalRegisters(),
config.ReservationStationEntries(), config.ReorderBufferEntries(), config.InstructionsDispatchedPerCycle(),
config.InstructionsWrittenPerCycle(), config.RegisterAliasTableEntries())
di.Run(operationChannel, executionChannels, commonDataBusChannel, recoveryChannel)
closeUnitsHandlers = append(closeUnitsHandlers, di.Close)
// ------- Execute (Alu) -------- //
for index := uint32(0); index < config.AluUnits(); index++ {
ex := executor.New(index, this, di.Bus(), info.Aritmetic)
ex.Run(executionChannels, commonDataBusChannel)
closeUnitsHandlers = append(closeUnitsHandlers, ex.Close)
}
// ---- Execute (Load Store) ---- //
for index := uint32(0); index < config.LoadStoreUnits(); index++ {
ex := executor.New(index, this, di.Bus(), info.LoadStore)
ex.Run(executionChannels, commonDataBusChannel)
closeUnitsHandlers = append(closeUnitsHandlers, ex.Close)
}
// ------ Execute (Branch) ------ //
for index := uint32(0); index < config.BranchUnits(); index++ {
ex := executor.New(index, this, di.Bus(), info.Control)
ex.Run(executionChannels, commonDataBusChannel)
closeUnitsHandlers = append(closeUnitsHandlers, ex.Close)
}
// ------- Execute (FPU) -------- //
for index := uint32(0); index < config.FpuUnits(); index++ {
ex := executor.New(index, this, di.Bus(), info.FloatingPoint)
ex.Run(executionChannels, commonDataBusChannel)
closeUnitsHandlers = append(closeUnitsHandlers, ex.Close)
}
// Set instruction for fetching to start pipeline
go addressChannel.Add(operation.New(operationId, address))
// Return flush function for all channels
return func() {
// Close units & channels
for _, closeUnitHandler := range closeUnitsHandlers {
closeUnitHandler()
}
// Close channels
addressChannel.Close()
instructionChannel.Close()
operationChannel.Close()
executionChannels[info.Aritmetic].Close()
executionChannels[info.LoadStore].Close()
executionChannels[info.Control].Close()
executionChannels[info.FloatingPoint].Close()
commonDataBusChannel.Close()
}
}
