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tilelink2: first version of Narrower (only supports uncached IO)

This commit is contained in:
Wesley W. Terpstra 2016-09-02 19:30:07 -07:00
parent b004d54d71
commit 5db7ae262b
2 changed files with 119 additions and 0 deletions

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@ -46,6 +46,7 @@ object TLMonitor
assert (is_aligned, "'A' channel PutPartial address not aligned to size") assert (is_aligned, "'A' channel PutPartial address not aligned to size")
assert (bundle.param === UInt(0), "'A' channel PutPartial carries invalid param") assert (bundle.param === UInt(0), "'A' channel PutPartial carries invalid param")
assert ((bundle.mask & ~mask) === UInt(0), "'A' channel PutPartial contains invalid mask") assert ((bundle.mask & ~mask) === UInt(0), "'A' channel PutPartial contains invalid mask")
assert (bundle.mask =/= UInt(0), "'A' channel PutPartial has a zero mask")
} }
when (bundle.opcode === TLMessages.ArithmeticData) { when (bundle.opcode === TLMessages.ArithmeticData) {
@ -111,6 +112,7 @@ object TLMonitor
assert (is_aligned, "'B' channel PutPartial address not aligned to size") assert (is_aligned, "'B' channel PutPartial address not aligned to size")
assert (bundle.param === UInt(0), "'B' channel PutPartial carries invalid param") assert (bundle.param === UInt(0), "'B' channel PutPartial carries invalid param")
assert ((bundle.mask & ~mask) === UInt(0), "'B' channel PutPartial contains invalid mask") assert ((bundle.mask & ~mask) === UInt(0), "'B' channel PutPartial contains invalid mask")
assert (bundle.mask =/= UInt(0), "'B' channel PutPartial has a zero mask")
} }
when (bundle.opcode === TLMessages.ArithmeticData) { when (bundle.opcode === TLMessages.ArithmeticData) {

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@ -0,0 +1,117 @@
// See LICENSE for license details.
package uncore.tilelink2
import Chisel._
// innBeatBytes => the bus width after the adapter
class TLNarrower(innerBeatBytes: Int) extends LazyModule
{
val node = TLAdapterNode(
clientFn = { case Seq(c) => c },
managerFn = { case Seq(m) => m.copy(beatBytes = innerBeatBytes) })
lazy val module = new LazyModuleImp(this) {
val io = new Bundle {
val in = node.bundleIn
val out = node.bundleOut
}
val edge = node.edgesOut(0)
val outerBeatBytes = edge.manager.beatBytes
require (outerBeatBytes < innerBeatBytes)
val ratio = innerBeatBytes / outerBeatBytes
val bce = edge.manager.anySupportAcquire && edge.client.anySupportProbe
def UIntToOH1(x: UInt, width: Int) = (UInt((1 << width) - 1) << x)(width*2-1, width)
def trailingZeros(x: Int) = if (x > 0) Some(log2Ceil(x & -x)) else None
def split(in: HasTLData, fire: Bool): (Bool, UInt, UInt) = {
val dataSlices = Vec.tabulate (ratio) { i => in.data()((i+1)*outerBeatBytes*8-1, i*outerBeatBytes*8) }
val maskSlices = Vec.tabulate (ratio) { i => in.mask()((i+1)*outerBeatBytes -1, i*outerBeatBytes) }
val filter = Reg(UInt(width = ratio), init = SInt(-1, width = ratio).asUInt)
val mask = maskSlices.map(_.orR)
val hasData = in.hasData()
// decoded_size = 1111 (for smallest), 0101, 0001 (for largest)
val sizeOH1 = UIntToOH1(in.size(), log2Ceil(innerBeatBytes)) >> log2Ceil(outerBeatBytes)
val decoded_size = Seq.tabulate(ratio) { i => trailingZeros(i).map(!sizeOH1(_)).getOrElse(Bool(true)) }
val first = filter(ratio-1)
val new_filter = Mux(first, Cat(decoded_size.reverse), filter << 1)
val last = new_filter(ratio-1) || !hasData
when (fire) {
filter := new_filter
when (!hasData) { filter := SInt(-1, width = ratio).asUInt }
}
val select = Cat(mask.reverse) & new_filter
// !!! if never data
(last, Mux1H(select, dataSlices), Mux1H(select, maskSlices))
}
def merge(in: HasTLData, fire: Bool): (Bool, UInt) = {
val count = RegInit(UInt(0, width = log2Ceil(ratio)))
val rdata = Reg(UInt(width = (ratio-1)*outerBeatBytes*8))
val data = rdata << outerBeatBytes*8 | in.data()
val first = count === UInt(0)
val limit = UIntToOH1(in.size(), log2Ceil(innerBeatBytes)) >> log2Ceil(outerBeatBytes)
val last = count === limit || !in.hasData()
val cases = Vec.tabulate (log2Ceil(ratio)+1) { i =>
val pow = 1 << i
Fill(1 << (ratio-i), data((pow+1)*outerBeatBytes*8-1, pow*outerBeatBytes*8))
}
when (fire) {
rdata := data
count := count + UInt(1)
when (last) { count := UInt(0) }
}
// !!! if never data
(last, Mux1H(limit, cases))
}
val in = io.in(0)
val out = io.out(0)
val (alast, adata, amask) = split(in.a.bits, out.a.fire())
in.a.ready := out.a.ready && alast
out.a.valid := in.a.valid
out.a.bits := in.a.bits
out.a.bits.data := adata
out.a.bits.mask := amask
val (dlast, ddata) = merge(out.d.bits, out.d.fire())
out.d.ready := in.d.ready
in.d.valid := out.d.valid && dlast
in.d.bits := out.d.bits
in.d.bits.data := ddata
if (bce) {
require (false)
// C has no wmask !!!
// val (clast, cdata, cmask) = split(in.c.bits, out.c.fire())
// in.c.ready := out.c.ready && clast
// out.c.valid := in.c.valid
// out.c.bits := in.c.bits
// out.c.bits.data := cdata
// out.c.bits.mask := cmask
in.e.ready := out.e.ready
out.e.valid := in.e.valid
out.e.bits := in.e.bits
}
}
}
object TLNarrower
{
// applied to the TL source node; connect (Narrower(x.node, 16) -> y.node)
def apply(x: TLBaseNode, innerBeatBytes: Int)(implicit lazyModule: LazyModule): TLBaseNode = {
val narrower = LazyModule(new TLNarrower(innerBeatBytes))
lazyModule.connect(x -> narrower.node)
narrower.node
}
}