riscv-bluespec-classic/bs/Bus.bs

92 lines
3.7 KiB
Haskell

package Bus(mkBus) where
import Types
import BusTypes
import TagEngine
import Vector
import Util
import Arbiter
import FIFO
import FIFOF
import SpecialFIFOs
clientRequest :: Arbiter.ArbiterClient_IFC -> Action
clientRequest ifc = ifc.request
busRequestToAddr :: BusRequest -> Addr
busRequestToAddr req = case req of
BusReadRequest (ReadRequest addr _) -> addr
BusWriteRequest (WriteRequest addr _) -> addr
mkBus :: (Addr -> Maybe ServerIdx)
-> Module (Bus inFlightTransactions numClients numServers)
mkBus busMap = do
-- Tag engines for each client to manage transaction tags
tagEngineByClientVec :: Vector numClients (TagEngine inFlightTransactions)
tagEngineByClientVec <- replicateM mkTagEngine
-- Arbitration for clients to send requests to servers
clientArbiter :: Arbiter.Arbiter_IFC numClients
clientArbiter <- mkArbiter False
dummyVar :: Reg(Bool)
dummyVar <- mkReg False
-- Queues to hold requests from clients to servers
requestQueues :: Vector numServers (FIFOF (TaggedBusRequest inFlightTransactions))
requestQueues <- replicateM (mkSizedBypassFIFOF (valueOf inFlightTransactions))
-- Queues to hold responses from servers to clients
responseQueues :: Vector numClients (FIFOF (TaggedBusResponse inFlightTransactions))
responseQueues <- replicateM (mkSizedBypassFIFOF (valueOf inFlightTransactions))
-- Client interface vector
let clients :: Vector numClients (BusClient inFlightTransactions)
clients = genWith $ \clientIdx ->
let
selectedClientRequestQueue :: FIFOF (TaggedBusRequest inFlightTransactions)
selectedClientRequestQueue = (select requestQueues clientIdx)
selectedClientResponseQueue :: FIFOF (TaggedBusResponse inFlightTransactions)
selectedClientResponseQueue = (select responseQueues clientIdx)
selectedTagEngine :: TagEngine inFlightTransactions
selectedTagEngine = (select tagEngineByClientVec clientIdx)
in
interface BusClient
submitRequest :: BusRequest
-> ActionValue (MkTagType inFlightTransactions)
submitRequest busRequest = do
tag <- selectedTagEngine.requestTag
selectedClientRequestQueue.enq (TaggedBusRequest tag busRequest)
return tag
consumeResponse :: ActionValue (TaggedBusResponse inFlightTransactions)
consumeResponse = do
let
busResponse :: (TaggedBusResponse inFlightTransactions)
busResponse = selectedClientResponseQueue.first
selectedClientResponseQueue.deq
return busResponse
-- Server interface vector
let servers :: Vector numServers (BusServer inFlightTransactions numClients)
servers = genWith $ \serverIdx ->
interface BusServer
consumeRequest :: ActionValue (MkTagType inFlightTransactions, BusRequest)
consumeRequest = do
dummyVar := (not dummyVar)
let dummyBusRequest = BusReadRequest (ReadRequest 0 SizeByte)
return (0, dummyBusRequest)
submitResponse :: ( MkClientTagType numClients,
TaggedBusResponse inFlightTransactions
) -> Action
submitResponse (clientTag, taggedBusResponse) = do
dummyVar := (not dummyVar)
return $
interface Bus
clients = clients
servers = servers