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rocket-chip/src/main/scala/rocket/ScratchpadSlavePort.scala

140 lines
5.5 KiB
Scala

// See LICENSE.SiFive for license details.
package rocket
import Chisel._
import Chisel.ImplicitConversions._
import config._
import coreplex.CacheBlockBytes
import diplomacy._
import tile._
import uncore.constants._
import uncore.tilelink2._
import uncore.util._
import util._
class ScratchpadSlavePort(address: AddressSet)(implicit p: Parameters) extends LazyModule
with HasCoreParameters {
val device = new MemoryDevice
val node = TLManagerNode(Seq(TLManagerPortParameters(
Seq(TLManagerParameters(
address = List(address),
resources = device.reg,
regionType = RegionType.UNCACHED,
executable = true,
supportsArithmetic = if (usingAtomics) TransferSizes(1, coreDataBytes) else TransferSizes.none,
supportsLogical = if (usingAtomics) TransferSizes(1, coreDataBytes) else TransferSizes.none,
supportsPutPartial = TransferSizes(1, coreDataBytes),
supportsPutFull = TransferSizes(1, coreDataBytes),
supportsGet = TransferSizes(1, coreDataBytes),
fifoId = Some(0))), // requests handled in FIFO order
beatBytes = coreDataBytes,
minLatency = 1)))
lazy val module = new LazyModuleImp(this) {
val io = new Bundle {
val tl_in = node.bundleIn
val dmem = new HellaCacheIO
}
val tl_in = io.tl_in(0)
val edge = node.edgesIn(0)
val s_ready :: s_wait :: s_replay :: s_grant :: Nil = Enum(UInt(), 4)
val state = Reg(init = s_ready)
when (io.dmem.resp.valid) { state := s_grant }
when (tl_in.d.fire()) { state := s_ready }
when (io.dmem.s2_nack) { state := s_replay }
when (io.dmem.req.fire()) { state := s_wait }
val acq = Reg(tl_in.a.bits)
when (io.dmem.resp.valid) { acq.data := io.dmem.resp.bits.data }
when (tl_in.a.fire()) { acq := tl_in.a.bits }
val isWrite = acq.opcode === TLMessages.PutFullData || acq.opcode === TLMessages.PutPartialData
val isRead = !edge.hasData(acq)
def formCacheReq(acq: TLBundleA) = {
val req = Wire(new HellaCacheReq)
req.cmd := MuxLookup(acq.opcode, Wire(M_XRD), Array(
TLMessages.PutFullData -> M_XWR,
TLMessages.PutPartialData -> M_XWR,
TLMessages.ArithmeticData -> MuxLookup(acq.param, Wire(M_XRD), Array(
TLAtomics.MIN -> M_XA_MIN,
TLAtomics.MAX -> M_XA_MAX,
TLAtomics.MINU -> M_XA_MINU,
TLAtomics.MAXU -> M_XA_MAXU,
TLAtomics.ADD -> M_XA_ADD)),
TLMessages.LogicalData -> MuxLookup(acq.param, Wire(M_XRD), Array(
TLAtomics.XOR -> M_XA_XOR,
TLAtomics.OR -> M_XA_OR,
TLAtomics.AND -> M_XA_AND,
TLAtomics.SWAP -> M_XA_SWAP)),
TLMessages.Get -> M_XRD))
// treat all loads as full words, so bytes appear in correct lane
req.typ := Mux(isRead, log2Ceil(coreDataBytes), acq.size)
req.addr := Mux(isRead, ~(~acq.address | (coreDataBytes-1)), acq.address)
req.tag := UInt(0)
req
}
val ready = state === s_ready || tl_in.d.fire()
io.dmem.req.valid := (tl_in.a.valid && ready) || state === s_replay
tl_in.a.ready := io.dmem.req.ready && ready
io.dmem.req.bits := formCacheReq(Mux(state === s_replay, acq, tl_in.a.bits))
// the TL data is already in the correct byte lane, but the D$
// expects right-justified store data, so that it can steer the bytes.
io.dmem.s1_data := new LoadGen(acq.size, Bool(false), acq.address(log2Ceil(coreDataBytes)-1,0), acq.data, Bool(false), coreDataBytes).data
io.dmem.s1_kill := false
io.dmem.invalidate_lr := false
// place AMO data in correct word lane
val minAMOBytes = 4
val grantData = Mux(io.dmem.resp.valid, io.dmem.resp.bits.data, acq.data)
val alignedGrantData = Mux(acq.size <= log2Ceil(minAMOBytes), Fill(coreDataBytes/minAMOBytes, grantData(8*minAMOBytes-1, 0)), grantData)
tl_in.d.valid := io.dmem.resp.valid || state === s_grant
tl_in.d.bits := Mux(isWrite,
edge.AccessAck(acq, UInt(0)),
edge.AccessAck(acq, UInt(0), UInt(0)))
tl_in.d.bits.data := alignedGrantData
// Tie off unused channels
tl_in.b.valid := Bool(false)
tl_in.c.ready := Bool(true)
tl_in.e.ready := Bool(true)
}
}
/** Mix-ins for constructing tiles that have optional scratchpads */
trait CanHaveScratchpad extends HasHellaCache with HasICacheFrontend {
val module: CanHaveScratchpadModule
val scratch = tileParams.dcache.flatMap(d => d.scratch.map(s =>
LazyModule(new ScratchpadSlavePort(AddressSet(s, d.dataScratchpadBytes-1)))))
val slaveNode = TLInputNode()
scratch foreach { lm => lm.node := TLFragmenter(p(XLen)/8, p(CacheBlockBytes))(slaveNode) }
def findScratchpadFromICache: Option[AddressSet] = scratch.map { s =>
val finalNode = frontend.node.edgesOut(0).manager.managers.find(_.nodePath.last == s.node)
require (finalNode.isDefined, "Could not find the scratch pad; not reachable via icache?")
require (finalNode.get.address.size == 1, "Scratchpad address space was fragmented!")
finalNode.get.address(0)
}
nDCachePorts += (scratch.isDefined).toInt
}
trait CanHaveScratchpadBundle extends HasHellaCacheBundle with HasICacheFrontendBundle {
val outer: CanHaveScratchpad
val slave = outer.slaveNode.bundleIn
}
trait CanHaveScratchpadModule extends HasHellaCacheModule with HasICacheFrontendModule {
val outer: CanHaveScratchpad
val io: CanHaveScratchpadBundle
outer.scratch.foreach { lm => dcachePorts += lm.module.io.dmem }
}