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Merge pull request #893 from freechipsproject/width-update

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Width widget enhancements
This commit is contained in:
Wesley W. Terpstra 2017-07-26 12:35:51 -07:00 committed by GitHub
commit f02c921d0f
1 changed files with 98 additions and 71 deletions
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src/main/scala/tilelink/WidthWidget.scala
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@ -26,107 +26,115 @@ class TLWidthWidget(innerBeatBytes: Int)(implicit p: Parameters) extends LazyMod
val inBytes = edgeIn.manager.beatBytes
val outBytes = edgeOut.manager.beatBytes
val ratio = outBytes / inBytes
val keepBits = log2Ceil(outBytes)
val dropBits = log2Ceil(inBytes)
val countBits = log2Ceil(ratio)
val rdata = Reg(UInt(width = (ratio-1)*inBytes*8))
val rmask = Reg(UInt(width = (ratio-1)*inBytes))
val data = Cat(edgeIn.data(in.bits), rdata)
val mask = Cat(edgeIn.mask(in.bits), rmask)
val address = edgeIn.address(in.bits)
val size = edgeIn.size(in.bits)
val hasData = edgeIn.hasData(in.bits)
val limit = UIntToOH1(size, keepBits) >> dropBits
val count = RegInit(UInt(0, width = log2Ceil(ratio)))
val count = RegInit(UInt(0, width = countBits))
val first = count === UInt(0)
val limit = UIntToOH1(size, log2Ceil(outBytes)) >> log2Ceil(inBytes)
val last = count === limit || !hasData
val enable = Seq.tabulate(ratio) { i => !((count ^ UInt(i)) & limit).orR }
when (in.fire()) {
rdata := data >> inBytes*8
rmask := mask >> inBytes
count := count + UInt(1)
when (last) { count := UInt(0) }
}
val cases = Seq.tabulate(log2Ceil(ratio)+1) { i =>
val high = outBytes
val take = (1 << i)*inBytes
(Fill(1 << (log2Ceil(ratio)-i), data(high*8-1, (high-take)*8)),
Fill(1 << (log2Ceil(ratio)-i), mask(high -1, (high-take))))
def helper(idata: UInt): UInt = {
val odata = Seq.fill(ratio) { idata }
val rdata = Reg(Vec(ratio-1, idata))
val pdata = rdata :+ idata
val mdata = (enable zip (odata zip pdata)) map { case (e, (o, p)) => Mux(e, o, p) }
when (in.fire() && !last) {
(rdata zip mdata) foreach { case (r, m) => r := m }
}
val dataMux = Vec.tabulate(log2Ceil(edgeIn.maxTransfer)+1) { lgSize =>
cases(min(max(lgSize - log2Ceil(inBytes), 0), log2Ceil(ratio)))._1
}
val maskMux = Vec.tabulate(log2Ceil(edgeIn.maxTransfer)+1) { lgSize =>
cases(min(max(lgSize - log2Ceil(inBytes), 0), log2Ceil(ratio)))._2
Cat(mdata.reverse)
}
val dataOut = if (edgeIn.staticHasData(in.bits) == Some(false)) UInt(0) else dataMux(size)
lazy val maskFull = edgeOut.mask(address, size)
lazy val maskOut = Mux(hasData, maskMux(size) & maskFull, maskFull)
def reduce(i: Bool): Bool = {
val state = Reg(Bool())
val next = i || (!first && state)
when (in.fire()) { state := next }
next
}
in.ready := out.ready || !last
out.valid := in.valid && last
out.bits := in.bits
edgeOut.data(out.bits) := dataOut
out.bits match {
case a: TLBundleA => a.mask := maskOut
case b: TLBundleB => b.mask := maskOut
case c: TLBundleC => ()
case d: TLBundleD => ()
// addr_lo gets padded with 0s on D channel, the only lossy transform in this core
// this should be safe, because we only care about addr_lo on D to determine which
// piece of data to extract when the D data bus is narrowed. Since we duplicated the
// data to all locations, addr_lo still points at a valid copy.
// Don't put down hardware if we never carry data
edgeOut.data(out.bits) := (if (edgeIn.staticHasData(in.bits) == Some(false)) UInt(0) else helper(edgeIn.data(in.bits)))
(out.bits, in.bits) match {
case (o: TLBundleA, i: TLBundleA) => o.mask := edgeOut.mask(o.address, o.size) & Mux(hasData, helper(i.mask), ~UInt(0, width=outBytes))
case (o: TLBundleB, i: TLBundleB) => o.mask := edgeOut.mask(o.address, o.size) & Mux(hasData, helper(i.mask), ~UInt(0, width=outBytes))
case (o: TLBundleC, i: TLBundleC) => o.error := reduce(i.error)
case (o: TLBundleD, i: TLBundleD) => o.error := reduce(i.error)
case _ => require(false, "Impossible bundle combination in WidthWidget")
}
}
def split[T <: TLDataChannel](edgeIn: TLEdge, in: DecoupledIO[T], edgeOut: TLEdge, out: DecoupledIO[T]) = {
def split[T <: TLDataChannel](edgeIn: TLEdge, in: DecoupledIO[T], edgeOut: TLEdge, out: DecoupledIO[T], sourceMap: UInt => UInt) = {
val inBytes = edgeIn.manager.beatBytes
val outBytes = edgeOut.manager.beatBytes
val ratio = inBytes / outBytes
val keepBits = log2Ceil(inBytes)
val dropBits = log2Ceil(outBytes)
val countBits = log2Ceil(ratio)
val hasData = edgeIn.hasData(in.bits)
val size = edgeIn.size(in.bits)
val data = edgeIn.data(in.bits)
val mask = edgeIn.mask(in.bits)
val hasData = edgeIn.hasData(in.bits)
val limit = UIntToOH1(size, keepBits) >> dropBits
val dataSlices = Vec.tabulate(ratio) { i => data((i+1)*outBytes*8-1, i*outBytes*8) }
val maskSlices = Vec.tabulate(ratio) { i => mask((i+1)*outBytes -1, i*outBytes) }
val filter = Reg(UInt(width = ratio), init = SInt(-1, width = ratio).asUInt)
val maskR = maskSlices.map(_.orR)
val count = RegInit(UInt(0, width = countBits))
val first = count === UInt(0)
val last = count === limit || !hasData
// decoded_size = 1111 (for smallest), 0101, 0001 (for largest)
val sizeOH1 = UIntToOH1(size, log2Ceil(inBytes)) >> log2Ceil(outBytes)
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 (out.fire()) {
filter := new_filter
when (!hasData) { filter := SInt(-1, width = ratio).asUInt }
count := count + UInt(1)
when (last) { count := UInt(0) }
}
val select = Cat(maskR.reverse) & new_filter
val dataOut = if (edgeIn.staticHasData(in.bits) == Some(false)) UInt(0) else Mux1H(select, dataSlices)
val maskOut = Mux1H(select, maskSlices)
// For sub-beat transfer, extract which part matters
val sel = in.bits match {
case a: TLBundleA => a.address(keepBits-1, dropBits)
case b: TLBundleB => b.address(keepBits-1, dropBits)
case c: TLBundleC => c.address(keepBits-1, dropBits)
case d: TLBundleD => {
val sel = sourceMap(d.source)
val hold = Mux(first, sel, RegEnable(sel, first)) // a_first is not for whole xfer
hold & ~limit // if more than one a_first/xfer, the address must be aligned anyway
}
}
val index = sel | count
def helper(idata: UInt, width: Int): UInt = {
val mux = Vec.tabulate(ratio) { i => idata((i+1)*outBytes*width-1, i*outBytes*width) }
mux(index)
}
out <> in
edgeOut.data(out.bits) := dataOut
out.bits match {
case a: TLBundleA => a.mask := maskOut
case b: TLBundleB => b.mask := maskOut
case c: TLBundleC => ()
case d: TLBundleD => () // addr_lo gets truncated automagically
// Don't put down hardware if we never carry data
edgeOut.data(out.bits) := (if (edgeIn.staticHasData(in.bits) == Some(false)) UInt(0) else helper(edgeIn.data(in.bits), 8))
(out.bits, in.bits) match {
case (o: TLBundleA, i: TLBundleA) => o.mask := helper(i.mask, 1)
case (o: TLBundleB, i: TLBundleB) => o.mask := helper(i.mask, 1)
case (o: TLBundleC, i: TLBundleC) => () // error handled by bulk connect
case (o: TLBundleD, i: TLBundleD) => () // error handled by bulk connect
case _ => require(false, "Impossbile bundle combination in WidthWidget")
}
// Repeat the input if we're not last
!last
}
def splice[T <: TLDataChannel](edgeIn: TLEdge, in: DecoupledIO[T], edgeOut: TLEdge, out: DecoupledIO[T]) = {
def splice[T <: TLDataChannel](edgeIn: TLEdge, in: DecoupledIO[T], edgeOut: TLEdge, out: DecoupledIO[T], sourceMap: UInt => UInt) = {
if (edgeIn.manager.beatBytes == edgeOut.manager.beatBytes) {
// nothing to do; pass it through
out <> in
@ -139,7 +147,7 @@ class TLWidthWidget(innerBeatBytes: Int)(implicit p: Parameters) extends LazyMod
edgeIn.data(cated.bits) := Cat(
edgeIn.data(repeated.bits)(edgeIn.manager.beatBytes*8-1, edgeOut.manager.beatBytes*8),
edgeIn.data(in.bits)(edgeOut.manager.beatBytes*8-1, 0))
repeat := split(edgeIn, cated, edgeOut, out)
repeat := split(edgeIn, cated, edgeOut, out, sourceMap)
} else {
// merge input to output
merge(edgeIn, in, edgeOut, out)
@ -147,15 +155,34 @@ class TLWidthWidget(innerBeatBytes: Int)(implicit p: Parameters) extends LazyMod
}
((io.in zip io.out) zip (node.edgesIn zip node.edgesOut)) foreach { case ((in, out), (edgeIn, edgeOut)) =>
splice(edgeIn, in.a, edgeOut, out.a)
splice(edgeOut, out.d, edgeIn, in.d)
// If the master is narrower than the slave, the D channel must be narrowed.
// This is tricky, because the D channel has no address data.
// Thus, you don't know which part of a sub-beat transfer to extract.
// To fix this, we record the relevant address bits for all sources.
// The assumption is that this sort of situation happens only where
// you connect a narrow master to the system bus, so there are few sources.
def sourceMap(source: UInt) = {
require (edgeOut.manager.beatBytes > edgeIn.manager.beatBytes)
val keepBits = log2Ceil(edgeOut.manager.beatBytes)
val dropBits = log2Ceil(edgeIn.manager.beatBytes)
val sources = Reg(Vec(edgeIn.client.endSourceId, UInt(width = keepBits-dropBits)))
val a_sel = in.a.bits.address(keepBits-1, dropBits)
when (in.a.fire()) {
sources(in.a.bits.source) := a_sel
}
val bypass = Bool(edgeIn.manager.minLatency == 0) && in.a.fire() && in.a.bits.source === source
Mux(bypass, a_sel, sources(source))
}
splice(edgeIn, in.a, edgeOut, out.a, sourceMap)
splice(edgeOut, out.d, edgeIn, in.d, sourceMap)
if (edgeOut.manager.anySupportAcquireB && edgeIn.client.anySupportProbe) {
splice(edgeOut, out.b, edgeIn, in.b)
splice(edgeIn, in.c, edgeOut, out.c)
in.e.ready := out.e.ready
out.e.valid := in.e.valid
out.e.bits := in.e.bits
splice(edgeOut, out.b, edgeIn, in.b, sourceMap)
splice(edgeIn, in.c, edgeOut, out.c, sourceMap)
out.e <> in.e
} else {
in.b.valid := Bool(false)
in.c.ready := Bool(true)