riscv/rocket-chip
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tilelink: Xbar now allows for fanout control

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This commit is contained in:
Wesley W. Terpstra 2017-09-07 15:42:40 -07:00
parent e831acba9c
commit 6879f5bfb1
2 changed files with 41 additions and 8 deletions
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11
src/main/scala/diplomacy/Parameters.scala
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@ -293,3 +293,14 @@ object BufferParams
val flow = BufferParams(1, true, false)
val pipe = BufferParams(1, false, true)
}
case class TriStateValue(value: Boolean, set: Boolean)
{
def update(orig: Boolean) = if (set) value else orig
}
object TriStateValue
{
implicit def apply(value: Boolean): TriStateValue = TriStateValue(value, true)
def unset = TriStateValue(false, false)
}

38
src/main/scala/tilelink/Xbar.scala
View File

@ -3,9 +3,31 @@
package freechips.rocketchip.tilelink
import Chisel._
import freechips.rocketchip.config.Parameters
import freechips.rocketchip.config._
import freechips.rocketchip.diplomacy._
// Trades off slave port proximity against routing resource cost
object ForceFanout
{
def apply[T](
a: TriStateValue = TriStateValue.unset,
b: TriStateValue = TriStateValue.unset,
c: TriStateValue = TriStateValue.unset,
d: TriStateValue = TriStateValue.unset,
e: TriStateValue = TriStateValue.unset)(body: Parameters => T)(implicit p: Parameters) =
{
body(p.alterPartial {
case ForceFanoutKey => p(ForceFanoutKey) match {
case ForceFanoutParams(pa, pb, pc, pd, pe) =>
ForceFanoutParams(a.update(pa), b.update(pb), c.update(pc), d.update(pd), e.update(pe))
}
})
}
}
private case class ForceFanoutParams(a: Boolean, b: Boolean, c: Boolean, d: Boolean, e: Boolean)
private case object ForceFanoutKey extends Field(ForceFanoutParams(false, false, false, false, false))
class TLXbar(policy: TLArbiter.Policy = TLArbiter.roundRobin)(implicit p: Parameters) extends LazyModule
{
val node = TLNexusNode(
@ -157,11 +179,11 @@ class TLXbar(policy: TLArbiter.Policy = TLArbiter.roundRobin)(implicit p: Parame
def filter[T](data: Seq[T], mask: Seq[Boolean]) = (data zip mask).filter(_._2).map(_._1)
// Fanout the input sources to the output sinks
val portsAOI = transpose((in zip requestAIO) map { case (i, r) => TLXbar.fanout(i.a, r) })
val portsBIO = transpose((out zip requestBOI) map { case (o, r) => TLXbar.fanout(o.b, r) })
val portsCOI = transpose((in zip requestCIO) map { case (i, r) => TLXbar.fanout(i.c, r) })
val portsDIO = transpose((out zip requestDOI) map { case (o, r) => TLXbar.fanout(o.d, r) })
val portsEOI = transpose((in zip requestEIO) map { case (i, r) => TLXbar.fanout(i.e, r) })
val portsAOI = transpose((in zip requestAIO) map { case (i, r) => TLXbar.fanout(i.a, r, node.paramsOut.map(_(ForceFanoutKey).a)) })
val portsBIO = transpose((out zip requestBOI) map { case (o, r) => TLXbar.fanout(o.b, r, node.paramsIn .map(_(ForceFanoutKey).b)) })
val portsCOI = transpose((in zip requestCIO) map { case (i, r) => TLXbar.fanout(i.c, r, node.paramsOut.map(_(ForceFanoutKey).c)) })
val portsDIO = transpose((out zip requestDOI) map { case (o, r) => TLXbar.fanout(o.d, r, node.paramsIn .map(_(ForceFanoutKey).d)) })
val portsEOI = transpose((in zip requestEIO) map { case (i, r) => TLXbar.fanout(i.e, r, node.paramsOut.map(_(ForceFanoutKey).e)) })
// Arbitrate amongst the sources
for (o <- 0 until out.size) {
@ -216,10 +238,10 @@ object TLXbar
}
// Replicate an input port to each output port
def fanout[T <: TLChannel](input: DecoupledIO[T], select: Seq[Bool]) = {
def fanout[T <: TLChannel](input: DecoupledIO[T], select: Seq[Bool], force: Seq[Boolean] = Nil) = {
val filtered = Wire(Vec(select.size, input))
for (i <- 0 until select.size) {
filtered(i).bits := IdentityModule(input.bits) // force fanout of wires
filtered(i).bits := (if (force.lift(i).getOrElse(false)) IdentityModule(input.bits) else input.bits)
filtered(i).valid := input.valid && select(i)
}
input.ready := Mux1H(select, filtered.map(_.ready))