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tilelink2: use TLArbiter in HintHandler

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This commit is contained in:
Wesley W. Terpstra 2016-10-07 21:14:03 -07:00
parent 683a2e6785
commit b0e33f4a39
1 changed files with 17 additions and 53 deletions
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70
src/main/scala/uncore/tilelink2/HintHandler.scala
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@ -33,38 +33,20 @@ class TLHintHandler(supportManagers: Boolean = true, supportClients: Boolean = f
val smartClients = edgeIn.client.clients.map(_.supportsHint.max == edgeIn.client.maxTransfer).reduce(_&&_)
val smartManagers = edgeOut.manager.managers.map(_.supportsHint.max == edgeOut.manager.maxTransfer).reduce(_&&_)
if (supportManagers && !smartManagers) {
// State of the Hint bypass
val counter = RegInit(UInt(0, width = log2Up(edgeOut.manager.maxTransfer/edgeOut.manager.beatBytes)))
val hintHoldsD = RegInit(Bool(false))
val outerHoldsD = counter =/= UInt(0)
// Only one of them can hold it
assert (!hintHoldsD || !outerHoldsD)
// Count outer D beats
val beats1 = edgeOut.numBeats1(out.d.bits)
when (out.d.fire()) { counter := Mux(outerHoldsD, counter - UInt(1), beats1) }
// Who wants what?
if (supportManagers && !(passthrough && smartManagers)) {
val address = edgeIn.address(in.a.bits)
val handleA = if (passthrough) !edgeOut.manager.supportsHintFast(address, edgeIn.size(in.a.bits)) else Bool(true)
val hintBitsAtA = handleA && in.a.bits.opcode === TLMessages.Hint
val hintWantsD = in.a.valid && hintBitsAtA
val outerWantsD = out.d.valid
val hint = Wire(out.d)
// Prioritize existing D traffic over HintAck (and finish multibeat xfers)
val hintWinsD = hintHoldsD || (!outerHoldsD && !outerWantsD)
hintHoldsD := hintWantsD && hintWinsD && !in.d.ready
// Hint can only hold D b/c it still wants it from last cycle
assert (!hintHoldsD || hintWantsD)
in.d.valid := Mux(hintWinsD, hintWantsD, outerWantsD)
in.d.bits := Mux(hintWinsD, edgeIn.HintAck(in.a.bits, edgeOut.manager.findIdStartFast(address)), out.d.bits)
out.d.ready := in.d.ready && !hintHoldsD
in.a.ready := Mux(hintBitsAtA, hintWinsD && in.d.ready, out.a.ready)
hint.valid := in.a.valid && hintBitsAtA
out.a.valid := in.a.valid && !hintBitsAtA
out.a.bits := in.a.bits
in.a.ready := Mux(hintBitsAtA, hint.ready, out.a.ready)
hint.bits := edgeIn.HintAck(in.a.bits, edgeOut.manager.findIdStartFast(address))
out.a.bits := in.a.bits
TLArbiter(TLArbiter.lowestIndexFirst)(in.d, (edgeOut.numBeats(out.d.bits), out.d), (UInt(1), hint))
} else {
out.a.valid := in.a.valid
in.a.ready := out.a.ready
@ -75,37 +57,19 @@ class TLHintHandler(supportManagers: Boolean = true, supportClients: Boolean = f
in.d.bits := out.d.bits
}
if (supportClients && !smartClients) {
// State of the Hint bypass
val counter = RegInit(UInt(0, width = log2Up(edgeIn.client.maxTransfer/edgeIn.manager.beatBytes)))
val hintHoldsC = RegInit(Bool(false))
val innerHoldsC = counter =/= UInt(0)
// Only one of them can hold it
assert (!hintHoldsC || !innerHoldsC)
// Count inner C beats
val beats1 = edgeIn.numBeats1(in.c.bits)
when (in.c.fire()) { counter := Mux(innerHoldsC, counter - UInt(1), beats1) }
// Who wants what?
if (supportClients && !(passthrough && smartClients)) {
val handleB = if (passthrough) !edgeIn.client.supportsHint(out.b.bits.source, edgeOut.size(out.b.bits)) else Bool(true)
val hintBitsAtB = handleB && out.b.bits.opcode === TLMessages.Hint
val hintWantsC = out.b.valid && hintBitsAtB
val innerWantsC = in.c.valid
val hint = Wire(in.c)
// Prioritize existing C traffic over HintAck (and finish multibeat xfers)
val hintWinsC = hintHoldsC || (!innerHoldsC && !innerWantsC)
hintHoldsC := hintWantsC && hintWinsC && !out.c.ready
// Hint can only hold C b/c it still wants it from last cycle
assert (!hintHoldsC || hintWantsC)
hint.valid := out.b.valid && hintBitsAtB
in.b.valid := out.b.valid && !hintBitsAtB
out.b.ready := Mux(hintBitsAtB, hint.ready, in.b.ready)
out.c.valid := Mux(hintWinsC, hintWantsC, innerWantsC)
out.c.bits := Mux(hintWinsC, edgeOut.HintAck(out.b.bits), in.c.bits)
in.c.ready := out.c.ready && !hintHoldsC
hint.bits := edgeOut.HintAck(out.b.bits)
in.b.bits := out.b.bits
out.b.ready := Mux(hintBitsAtB, hintWinsC && out.c.ready, in.b.ready)
in.b.valid := out.b.valid && !hintBitsAtB
in.b.bits := out.b.bits
TLArbiter(TLArbiter.lowestIndexFirst)(out.c, (edgeIn.numBeats(in.c.bits), in.c), (UInt(1), hint))
} else if (bce) {
in.b.valid := out.b.valid
out.b.ready := in.b.ready