173 lines
8.5 KiB
Haskell
173 lines
8.5 KiB
Haskell
package Bus(mkBus, Bus(..)) where
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import Types
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import BusTypes
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import TagEngine
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import Vector
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import Util
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import Arbiter
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import FIFO
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import FIFOF
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import SpecialFIFOs
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import Printf
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clientRequest :: Arbiter.ArbiterClient_IFC -> Action
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clientRequest ifc = ifc.request
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busRequestToAddr :: BusRequest -> Addr
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busRequestToAddr req = case req of
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BusReadRequest (ReadRequest addr _) -> addr
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BusWriteRequest (WriteRequest addr _) -> addr
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dummyRule :: Rules
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dummyRule =
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rules
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"test rule": when True ==> do
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$display "test rule"
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-- we need a way to make serverMap safer...
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mkBus :: (Addr -> Maybe (MkServerIdx numServers))
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-> Module (Bus inFlightTransactions numClients numServers)
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mkBus serverMap = do
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-- Tag engines for each client to manage transaction tags
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tagEngineByClientVec :: Vector numClients (TagEngine inFlightTransactions)
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tagEngineByClientVec <- replicateM mkTagEngine
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-- There are `numClients` clients, each of which needs its own arbiter as
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-- there are up to `numServer` servers that may wish to submit a response
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-- to a given client. Furthermore the rule that routes client requests to
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-- servers makes for another potential requestor as it may determine that
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-- a request is unmappable and instead opt to form and submit a
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-- `BusError UnMapped` response directly to a client response arbiter. Thus
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-- we must arbit between a total of `numServers + 1` requestors.
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responseArbiterByClient :: Vector numClients (Arbiter.Arbiter_IFC (TAdd numServers 1))
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responseArbiterByClient <- replicateM (mkArbiter False)
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-- There are `numServer` servers, each of which needs its own arbiter as
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-- there are up to `numClient` clients that may wish to submit a response
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-- to a given server.
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requestArbiterByServer :: Vector numServers (Arbiter.Arbiter_IFC numClients)
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requestArbiterByServer <- replicateM (mkArbiter False)
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dummyVar :: Reg(Bool)
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dummyVar <- mkReg False
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-- Queues to hold requests from clients
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clientRequestQueues :: Vector numClients (FIFOF (TaggedBusRequest inFlightTransactions))
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clientRequestQueues <- replicateM (mkSizedBypassFIFOF (valueOf inFlightTransactions))
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-- Queues to hold responses to clients
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clientResponseQueues :: Vector numClients (FIFOF (TaggedBusResponse inFlightTransactions))
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clientResponseQueues <- replicateM (mkSizedBypassFIFOF (valueOf inFlightTransactions))
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-- The following two vectors of FIFOs make it easier to push/pull data to/from internal
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-- server methods:
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consumeRequestQueues :: Vector numServers (FIFOF (TaggedBusResponse inFlightTransactions))
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consumeRequestQueues <- replicateM mkBypassFIFOF
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submitResponseQueues :: Vector numServers (FIFOF (TaggedBusResponse inFlightTransactions))
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submitResponseQueues <- replicateM mkBypassFIFOF
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let clientRules :: Vector numClients (Rules)
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clientRules = genWith $ \clientIdx ->
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let
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selectedClientRequestQueue :: FIFOF (TaggedBusRequest inFlightTransactions)
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selectedClientRequestQueue = (select clientRequestQueues clientIdx)
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in
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rules
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(sprintf "client[%d] route request" clientIdx): when True ==> do
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let
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clientRequest :: TaggedBusRequest inFlightTransactions
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clientRequest = selectedClientRequestQueue.first
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targetAddr :: Addr = busRequestToAddr |> clientRequest.busRequest
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targetServerIdx :: (Maybe (MkServerIdx numServers)) = serverMap targetAddr
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case targetServerIdx of
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Just serverIdx -> do
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let
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targetServerArbiter :: Arbiter.Arbiter_IFC numClients
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targetServerArbiter = (select requestArbiterByServer serverIdx)
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arbiterClientSlot :: Arbiter.ArbiterClient_IFC
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arbiterClientSlot = (select targetServerArbiter.clients clientIdx)
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arbiterClientSlot.request
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Nothing -> do
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let
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targetClientResponseArbiter :: Arbiter.Arbiter_IFC (TAdd numServers 1)
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targetClientResponseArbiter = (select responseArbiterByClient clientIdx)
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clientResponseArbiterSlot :: Arbiter.ArbiterClient_IFC
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-- arbiters 0 to n-1 where `n:=numServer` are reserved
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-- for servers to make requests to. Arbiter n is reserved for
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-- when this rule needs to skip making a request to a server
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-- and should instead forward the `BusError UnMapped` response
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-- back to the client. Vector.last selects arbiter `n`
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clientResponseArbiterSlot = Vector.last targetClientResponseArbiter.clients
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let
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responseUnMapped = case clientRequest.busRequest of
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BusReadRequest _ -> BusReadResponse (Left UnMapped)
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BusWriteRequest _ -> BusWriteResponse (Left UnMapped)
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response :: TaggedBusResponse inFlightTransactions
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response = TaggedBusResponse {
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tag = clientRequest.tag;
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busResponse = responseUnMapped
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}
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clientResponseArbiterSlot.request
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(sprintf "client[%d] arbit server response" clientIdx): when True ==> do
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return |> action {}
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addRules |> foldr (<+>) (rules {}) clientRules
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-- Client interface vector
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let clients :: Vector numClients (BusClient inFlightTransactions)
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clients = genWith $ \clientIdx ->
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let
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selectedClientRequestQueue :: FIFOF (TaggedBusRequest inFlightTransactions)
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selectedClientRequestQueue = (select clientRequestQueues clientIdx)
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selectedClientResponseQueue :: FIFOF (TaggedBusResponse inFlightTransactions)
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selectedClientResponseQueue = (select clientResponseQueues clientIdx)
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selectedTagEngine :: TagEngine inFlightTransactions
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selectedTagEngine = (select tagEngineByClientVec clientIdx)
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in
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interface BusClient
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submitRequest :: BusRequest
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-> ActionValue (MkTagType inFlightTransactions)
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submitRequest busRequest = do
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tag <- selectedTagEngine.requestTag
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let taggedReuqest = TaggedBusRequest {tag = tag; busRequest = busRequest}
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selectedClientRequestQueue.enq taggedReuqest
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return tag
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consumeResponse :: ActionValue (TaggedBusResponse inFlightTransactions)
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consumeResponse = do
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let
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busResponse :: (TaggedBusResponse inFlightTransactions)
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busResponse = selectedClientResponseQueue.first
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selectedTagEngine.retireTag busResponse.tag
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selectedClientResponseQueue.deq
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return busResponse
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-- Server interface vector
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let servers :: Vector numServers (BusServer inFlightTransactions numClients)
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servers = genWith $ \serverIdx ->
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interface BusServer
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consumeRequest :: ActionValue (TaggedBusRequest inFlightTransactions)
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consumeRequest = do
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dummyVar := (not dummyVar)
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let dummyBusRequest = BusReadRequest (ReadRequest 0 SizeByte)
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return (TaggedBusRequest {tag = 0; busRequest = dummyBusRequest})
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submitResponse :: ( MkClientTagType numClients,
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TaggedBusResponse inFlightTransactions
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) -> Action
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submitResponse (clientTag, taggedBusResponse) = do
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dummyVar := (not dummyVar)
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return $
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interface Bus
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clients = clients
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servers = servers
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