Files
radiance/src/main/scala/tilelink/Coalescing.scala
2023-05-15 20:42:59 -07:00

2148 lines
76 KiB
Scala

// See LICENSE.SiFive for license details.
package freechips.rocketchip.tilelink
import chisel3._
import chisel3.util._
import org.chipsalliance.cde.config.{Parameters, Field}
import freechips.rocketchip.diplomacy._
// import freechips.rocketchip.devices.tilelink.TLTestRAM
import freechips.rocketchip.util.MultiPortQueue
import freechips.rocketchip.unittest._
// TODO: find better place for these
case class SIMTCoreParams(nLanes: Int = 4)
case class MemtraceCoreParams(tracefilename: String = "undefined", traceHasSource: Boolean = false)
case object SIMTCoreKey extends Field[Option[SIMTCoreParams]](None /*default*/)
case object MemtraceCoreKey extends Field[Option[MemtraceCoreParams]](None /*default*/)
case object CoalescerKey extends Field[Option[CoalescerConfig]](None /*default*/)
trait InFlightTableSizeEnum extends ChiselEnum {
val INVALID: Type
val FOUR: Type
def logSizeToEnum(x: UInt): Type
def enumToLogSize(x: Type): UInt
}
object DefaultInFlightTableSizeEnum extends InFlightTableSizeEnum {
val INVALID = Value(0.U)
val FOUR = Value(1.U)
def logSizeToEnum(x: UInt): Type = {
MuxCase(INVALID, Seq(
(x === 2.U) -> FOUR
))
}
def enumToLogSize(x: Type): UInt = {
MuxCase(0.U, Seq(
(x === FOUR) -> 2.U
))
}
}
// Mapping to reference model param names
// numLanes: Int, <-> config.NUM_LANES
// numPerLaneReqs: Int, <-> config.DEPTH
// sourceWidth: Int, <-> log2ceil(config.NUM_OLD_IDS)
// sizeWidth: Int, <-> config.sizeEnum.width
// coalDataWidth: Int, <-> (1 << config.MAX_SIZE)
// numInflightCoalRequests: Int <-> config.NUM_NEW_IDS
case class CoalescerConfig(
enable: Boolean, // globally enable or disable coalescing
numLanes: Int, // number of lanes (or threads) in a warp
queueDepth: Int, // request window per lane
waitTimeout: Int, // max cycles to wait before forced fifo dequeue, per lane
addressWidth: Int, // assume <= 32
dataBusWidth: Int, // memory-side downstream TileLink data bus size
// this has to be at least larger than word size for
// the coalescer to perform well
// watermark = 2, // minimum buffer occupancy to start coalescing
wordSizeInBytes: Int, // 32-bit system
numOldSrcIds: Int, // num of outstanding requests per lane, from processor
numNewSrcIds: Int, // num of outstanding coalesced requests
respQueueDepth: Int, // depth of the response fifo queues
coalLogSizes: Seq[Int], // list of coalescer sizes to try in the MonoCoalescers
// each size is log(byteSize)
sizeEnum: InFlightTableSizeEnum,
numCoalReqs: Int, // total number of coalesced requests we can generate in one cycle
numArbiterOutputPorts: Int, // total of output ports the arbiter will arbitrate into.
// this has to match downstream cache's configuration
bankStrideInBytes: Int // cache line strides across the different banks
) {
// maximum coalesced size
def maxCoalLogSize: Int = coalLogSizes.max
def wordSizeWidth: Int = {
val w = log2Ceil(wordSizeInBytes)
require(wordSizeInBytes == 1 << w,
s"wordSizeInBytes (${wordSizeInBytes}) is not power of two")
w
}
}
object defaultConfig extends CoalescerConfig(
enable = true,
numLanes = 4,
queueDepth = 1,
waitTimeout = 8,
addressWidth = 24,
dataBusWidth = 4, // 2^3=8 bytes, 64 bit bus
// watermark = 2,
wordSizeInBytes = 4,
// when attaching to SoC, 16 source IDs are not enough due to longer latency
numOldSrcIds = 8,
numNewSrcIds = 8,
respQueueDepth = 4,
coalLogSizes = Seq(4),
sizeEnum = DefaultInFlightTableSizeEnum,
numCoalReqs = 1,
numArbiterOutputPorts = 4,
bankStrideInBytes = 64 // Current L2 is strided by 512 bits
)
class CoalescingUnit(config: CoalescerConfig)(implicit p: Parameters) extends LazyModule {
// Nexus node that captures the incoming TL requests, rewrites coalescable requests,
// and arbitrates between non-coalesced and coalesced requests to a fix number of outputs
// before sending it out to memory. This node is what's visible to upstream and downstream nodes.
// WIP:
// val node = TLNexusNode(
// clientFn = c => c.head,
// managerFn = m => m.head // assuming arbiter generated ids are distinct between edges
// )
// node.in.map(_._2).foreach(edge => require(edge.manager.beatBytes == config.wordSizeInBytes,
// s"input edges into coalescer node does not have beatBytes = ${config.wordSizeInBytes}"))
// node.out.map(_._2).foreach(edge => require(edge.manager.beatBytes == config.maxCoalLogSize,
// s"output edges into coalescer node does not have beatBytes = ${config.maxCoalLogSize}"))
val aggregateNode = TLIdentityNode()
val cpuNode = TLIdentityNode()
// Number of maximum in-flight coalesced requests. The upper bound of this
// value would be the sourceId range of a single lane.
val numInflightCoalRequests = config.numNewSrcIds
// Master node that actually generates coalesced requests.
protected val coalParam = Seq(
TLMasterParameters.v1(
name = "CoalescerNode",
sourceId = IdRange(0, numInflightCoalRequests)
)
)
val coalescerNode = TLClientNode(
Seq(TLMasterPortParameters.v1(coalParam))
)
// merge coalescerNode and cpuNode
aggregateNode :=* coalescerNode
aggregateNode :=* TLWidthWidget(config.wordSizeInBytes) :=* cpuNode
lazy val module = new CoalescingUnitImp(this, config)
}
// Protocol-agnostic bundles that represent a request and a response to the
// coalescer.
class Request(sourceWidth: Int, sizeWidth: Int, addressWidth: Int, dataWidth: Int)
extends Bundle {
require(dataWidth % 8 == 0, s"dataWidth (${dataWidth} bits) is not multiple of 8")
val op = UInt(1.W) // 0=READ 1=WRITE
val address = UInt(addressWidth.W)
val size = UInt(sizeWidth.W)
val source = UInt(sourceWidth.W)
val mask = UInt((dataWidth / 8).W) // write only
val data = UInt(dataWidth.W) // write only
def toTLA(edgeOut: TLEdgeOut): TLBundleA = {
val (plegal, pbits) = edgeOut.Put(
fromSource = this.source,
toAddress = this.address,
lgSize = this.size,
data = this.data
)
val (glegal, gbits) = edgeOut.Get(
fromSource = this.source,
toAddress = this.address,
lgSize = this.size
)
val legal = Mux(this.op.asBool, plegal, glegal)
val bits = Mux(this.op.asBool, pbits, gbits)
// FIXME: this needs to check valid bit as well
// assert(legal, "unhandled illegal TL req gen")
bits
}
}
case class NonCoalescedRequest(config: CoalescerConfig)
extends Request(
sourceWidth = log2Ceil(config.numOldSrcIds),
sizeWidth = config.wordSizeWidth,
addressWidth = config.addressWidth,
dataWidth = config.wordSizeInBytes * 8
)
case class CoalescedRequest(config: CoalescerConfig)
extends Request(
sourceWidth = log2Ceil(config.numNewSrcIds),
sizeWidth = log2Ceil(config.maxCoalLogSize + 1),
addressWidth = config.addressWidth,
dataWidth = (8 * (1 << config.maxCoalLogSize))
)
class Response(sourceWidth: Int, sizeWidth: Int, dataWidth: Int)
extends Bundle {
require(dataWidth % 8 == 0, s"dataWidth (${dataWidth} bits) is not multiple of 8")
val op = UInt(1.W) // 0=READ 1=WRITE
val size = UInt(sizeWidth.W)
val source = UInt(sourceWidth.W)
val data = UInt(dataWidth.W) // read only
val error = Bool()
def toTLD(edgeIn: TLEdgeIn): TLBundleD = {
val apBits = edgeIn.AccessAck(
toSource = this.source,
lgSize = this.size
)
val agBits = edgeIn.AccessAck(
toSource = this.source,
lgSize = this.size,
data = this.data
)
Mux(this.op.asBool, apBits, agBits)
}
def fromTLD(bundle: TLBundleD): Unit = {
this.source := bundle.source
this.op := TLUtils.DOpcodeIsStore(bundle.opcode)
this.size := bundle.size
this.data := bundle.data
this.error := bundle.denied
}
}
case class NonCoalescedResponse(config: CoalescerConfig)
extends Response(
sourceWidth = log2Ceil(config.numOldSrcIds),
sizeWidth = config.wordSizeWidth,
dataWidth = config.wordSizeInBytes * 8
)
case class CoalescedResponse(config: CoalescerConfig)
extends Response(
sourceWidth = log2Ceil(config.numNewSrcIds),
sizeWidth = log2Ceil(config.maxCoalLogSize),
dataWidth = (8 * (1 << config.maxCoalLogSize))
)
// If `ignoreInUse`, just keep giving out new IDs without checking if it is in
// use.
class RoundRobinSourceGenerator(sourceWidth: Int, ignoreInUse: Boolean = true)
extends Module {
val io = IO(new Bundle {
val gen = Input(Bool())
val reclaim = Input(Valid(UInt(sourceWidth.W)))
val id = Output(Valid(UInt(sourceWidth.W)))
})
val head = RegInit(UInt(sourceWidth.W), 0.U)
head := Mux(io.gen, head + 1.U, head)
val numSourceId = 1 << sourceWidth
// true: in use, false: available
val occupancyTable = Mem(numSourceId, Valid(UInt(sourceWidth.W)))
when(reset.asBool) {
(0 until numSourceId).foreach { i => occupancyTable(i).valid := false.B }
}
io.id.valid := (if (ignoreInUse) true.B else !occupancyTable(head).valid)
io.id.bits := head
when(io.gen && io.id.valid /* fire */ ) {
occupancyTable(io.id.bits).valid := true.B // mark in use
}
when(io.reclaim.valid) {
occupancyTable(io.reclaim.bits).valid := false.B // mark freed
}
}
class CoalShiftQueue[T <: Data](gen: T, entries: Int, config: CoalescerConfig)
extends Module {
val io = IO(new Bundle {
val queue = new Bundle {
val enq = Vec(config.numLanes, DeqIO(gen.cloneType))
val deq = Vec(config.numLanes, EnqIO(gen.cloneType))
}
val invalidate = Input(Valid(Vec(config.numLanes, UInt(entries.W))))
val coalescable = Input(Vec(config.numLanes, Bool()))
val mask = Output(Vec(config.numLanes, UInt(entries.W)))
val elts = Output(Vec(config.numLanes, Vec(entries, gen)))
})
// val eltPrototype = Wire(Valid(gen))
// eltPrototype.bits := DontCare
// eltPrototype.valid := false.B
val elts = Reg(Vec(config.numLanes, Vec(entries, Valid(gen))))
val writePtr = RegInit(
VecInit(Seq.fill(config.numLanes)(0.asUInt(log2Ceil(entries + 1).W)))
)
val deqDone = RegInit(VecInit(Seq.fill(config.numLanes)(false.B)))
private def resetElts = {
elts.foreach { laneQ =>
laneQ.foreach { entry =>
entry.valid := false.B
entry.bits := DontCare
}
}
}
when(reset.asBool) {
resetElts
}
val controlSignals = Wire(Vec(config.numLanes, new Bundle {
val shift = Bool()
val full = Bool()
val empty = Bool()
}))
// io.coalescable will first turn on for all coalescable chunks, and turn off
// incrementally as time goes on. Therefore, when io.coalescable is all
// turned off, that means we have processed all coalescable chunks at the
// current cycle.
//
// shift hint is when the heads have no more coalescable left this or next cycle
val shiftHint = !(io.coalescable zip io.invalidate.bits.map(_(0)))
.map { case (c, inv) =>
c && !(io.invalidate.valid && inv)
}
.reduce(_ || _)
val syncedEnqValid = io.queue.enq.map(_.valid).reduce(_ || _)
// valid && !fire means we enable enqueueing to a full queue, provided the
// arbiter is taking away all remaining valid queue heads in the next cycle so
// that we make space for the entire next warp.
val syncedDeqValidNextCycle =
io.queue.deq.map(x => x.valid && !x.ready).reduce(_ || _)
for (i <- 0 until config.numLanes) {
val enq = io.queue.enq(i)
val deq = io.queue.deq(i)
val ctrl = controlSignals(i)
ctrl.full := writePtr(i) === entries.U
ctrl.empty := writePtr(i) === 0.U
// shift when no outstanding dequeue, no more coalescable chunks, and not empty
ctrl.shift := !syncedDeqValidNextCycle && shiftHint && !ctrl.empty
// dequeue is valid when:
// head entry is valid, has not been processed by downstream, and is not coalescable
deq.bits := elts.map(_.head.bits)(i)
deq.valid := elts.map(_.head.valid)(i) && !deqDone(i) && !io.coalescable(i)
// can take new entries if not empty, or if full but shifting
enq.ready := (!ctrl.full) || ctrl.shift
when(ctrl.shift) {
// shift, invalidate tail, invalidate coalesced requests
elts(i).zipWithIndex.foreach { case (elt, j) =>
if (j == entries - 1) { // tail
elt.valid := false.B
} else {
elt.bits := elts(i)(j + 1).bits
elt.valid := elts(i)(
j + 1
).valid && !(io.invalidate.valid && io.invalidate.bits(i)(j + 1))
}
}
// reset dequeue mask when new entries are shifted in
deqDone(i) := false.B
// enqueue
when(enq.ready && syncedEnqValid) { // to allow drift, swap for enq.fire
elts(i)(writePtr(i) - 1.U).bits := enq.bits
elts(i)(writePtr(i) - 1.U).valid := enq.valid
}.otherwise {
writePtr(i) := writePtr(i) - 1.U
}
}.otherwise {
// invalidate coalesced requests
when(io.invalidate.valid) {
(elts(i) zip io.invalidate.bits(i).asBools).map { case (elt, inv) =>
elt.valid := elt.valid && !inv
}
}
// enqueue
when(enq.ready && syncedEnqValid) {
elts(i)(writePtr(i)).bits := enq.bits
elts(i)(writePtr(i)).valid := enq.valid
writePtr(i) := writePtr(i) + 1.U
}
deqDone(i) := deqDone(i) || deq.fire
}
}
// When doing spatial-only coalescing, queues should never drift from each
// other, i.e. the queue heads should always contain mem requests from the
// same instruction.
val queueInSync =
controlSignals.map(_ === controlSignals.head).reduce(_ && _) &&
writePtr.map(_ === writePtr.head).reduce(_ && _)
assert(queueInSync, "shift queue lanes are not in sync")
io.mask := elts.map(x => VecInit(x.map(_.valid)).asUInt)
io.elts := elts.map(x => VecInit(x.map(_.bits)))
}
// Software model: coalescer.py
class MonoCoalescer(
config: CoalescerConfig,
coalLogSize: Int,
queueT: CoalShiftQueue[NonCoalescedRequest]
) extends Module {
val io = IO(new Bundle {
val window = Input(queueT.io.cloneType)
val results = Output(new Bundle {
val leaderIdx = Output(UInt(log2Ceil(config.numLanes).W))
val baseAddr = Output(UInt(config.addressWidth.W))
val matchOH = Output(Vec(config.numLanes, UInt(config.queueDepth.W)))
// number of entries matched with this leader lane's head.
// maximum is numLanes * queueDepth
val matchCount =
Output(UInt(log2Ceil(config.numLanes * config.queueDepth + 1).W))
val coverageHits =
Output(UInt((config.maxCoalLogSize - config.wordSizeWidth + 1).W))
val canCoalesce = Output(Vec(config.numLanes, Bool()))
})
})
io := DontCare
// Combinational logic to drive output from window contents.
// The leader lanes only compare their heads against all entries of the
// follower lanes.
val leaders = io.window.elts.map(_.head)
val leadersValid = io.window.mask.map(_.asBools.head)
def printQueueHeads = {
leaders.zipWithIndex.foreach { case (head, i) =>
printf(
s"ReqQueueEntry[${i}].head = v:%d, source:%d, addr:%x\n",
leadersValid(i),
head.source,
head.address
)
}
}
// when (leadersValid.reduce(_ || _)) {
// printQueueHeads
// }
val size = coalLogSize
// NOTE: be careful with Scala integer overflow when addressWidth >= 32
val addrMask = (((1L << config.addressWidth) - 1) - ((1 << size) - 1)).U
def canMatch(req0: Request, req0v: Bool, req1: Request, req1v: Bool): Bool = {
(req0.op === req1.op) &&
(req0v && req1v) &&
((req0.address & this.addrMask) === (req1.address & this.addrMask))
}
// Gives a 2-D table of Bools representing match at every queue entry,
// for each lane (so 3-D in total).
// dimensions: (leader lane, follower lane, follower entry)
val matchTablePerLane = (leaders zip leadersValid).map {
case (leader, leaderValid) =>
(io.window.elts zip io.window.mask).map {
case (followers, followerValids) =>
// compare leader's head against follower's every queue entry
(followers zip followerValids.asBools).map {
case (follower, followerValid) =>
canMatch(follower, followerValid, leader, leaderValid)
// FIXME: disabling halving optimization because it does not give the
// correct per-lane coalescable indication to the shift queue
// // match leader to only followers at lanes >= leader idx
// // this halves the number of comparators
// if (followerIndex < leaderIndex) false.B
// else canMatch(follower, followerValid, leader, leaderValid)
}
}
}
val matchCounts = matchTablePerLane.map(table =>
table
.map(PopCount(_)) // sum up each column
.reduce(_ +& _)
)
val canCoalesce = matchCounts.map(_ > 1.U)
// Elect the leader that has the most match counts.
// TODO: potentially expensive: magnitude comparator
def chooseLeaderArgMax(matchCounts: Seq[UInt]): UInt = {
matchCounts.zipWithIndex
.map { case (c, i) =>
(c, i.U)
}
.reduce[(UInt, UInt)] { case ((c0, i), (c1, j)) =>
(Mux(c0 >= c1, c0, c1), Mux(c0 >= c1, i, j))
}
._2
}
// Elect leader by choosing the smallest-index lane that has a valid
// match, i.e. using priority encoder.
def chooseLeaderPriorityEncoder(matchCounts: Seq[UInt]): UInt = {
PriorityEncoder(matchCounts.map(_ > 1.U))
}
val chosenLeaderIdx = chooseLeaderPriorityEncoder(matchCounts)
val chosenLeader = VecInit(leaders)(chosenLeaderIdx) // mux
// matchTable for the chosen lane, but each column converted to bitflags,
// i.e. Vec[UInt]
val chosenMatches = VecInit(matchTablePerLane.map { table =>
VecInit(table.map(VecInit(_).asUInt))
})(chosenLeaderIdx)
val chosenMatchCount = VecInit(matchCounts)(chosenLeaderIdx)
// coverage calculation
def getOffsetSlice(addr: UInt) = addr(size - 1, config.wordSizeWidth)
// 2-D table flattened to 1-D
val offsets =
io.window.elts.flatMap(_.map(req => getOffsetSlice(req.address)))
val valids = chosenMatches.flatMap(_.asBools)
// indicates for each word in the coalesced chunk whether it is accessed by
// any of the requests in the queue. e.g. if [ 1 1 1 1 ], all of the four
// words in the coalesced data coming back will be accessed by some request
// and we've reached 100% bandwidth utilization.
val hits = Seq.tabulate(1 << (size - config.wordSizeWidth)) { target =>
(offsets zip valids)
.map { case (offset, valid) => valid && (offset === target.U) }
.reduce(_ || _)
}
// debug prints
when(leadersValid.reduce(_ || _)) {
matchCounts.zipWithIndex.foreach { case (count, i) =>
printf(s"lane[${i}] matchCount = %d\n", count);
}
printf("chosenLeader = lane %d\n", chosenLeaderIdx)
printf("chosenLeader matches = [ ")
chosenMatches.foreach { m => printf("%d ", m) }
printf("]\n")
printf("chosenMatchCount = %d\n", chosenMatchCount)
printf("hits = [ ")
hits.foreach { m => printf("%d ", m) }
printf("]\n")
}
io.results.leaderIdx := chosenLeaderIdx
io.results.baseAddr := chosenLeader.address & addrMask
io.results.matchOH := chosenMatches
io.results.matchCount := chosenMatchCount
io.results.coverageHits := PopCount(hits)
io.results.canCoalesce := canCoalesce
}
// Combinational logic that generates a coalesced request given a request
// window, and a selection of possible coalesced sizes. May utilize multiple
// MonoCoalescers and apply size-choosing policy to determine the final
// coalesced request out of all possible combinations.
//
// Software model: coalescer.py
class MultiCoalescer(
config: CoalescerConfig,
queueT: CoalShiftQueue[NonCoalescedRequest],
coalReqT: Request,
) extends Module {
val invalidateT = Valid(Vec(config.numLanes, UInt(config.queueDepth.W)))
val io = IO(new Bundle {
// coalescing window, connected to the contents of the request queues
val window = Input(queueT.io.cloneType)
// generated coalesced request
val coalReq = DecoupledIO(coalReqT.cloneType)
// invalidate signals going into each request queue's head. Lanes with
// high invalidate bits are what became coalesced into the new request.
val invalidate = Output(invalidateT)
// whether a lane is coalescable. This is used to output non-coalescable
// lanes to the arbiter so they can be flushed to downstream.
val coalescable = Output(Vec(config.numLanes, Bool()))
})
val coalescers = config.coalLogSizes.map(size =>
Module(new MonoCoalescer(config, size, queueT))
)
coalescers.foreach(_.io.window := io.window)
def normalize(valPerSize: Seq[UInt]): Seq[UInt] = {
(valPerSize zip config.coalLogSizes).map { case (hits, size) =>
(hits << (config.maxCoalLogSize - size).U).asUInt
}
}
def argMax(x: Seq[UInt]): UInt = {
x.zipWithIndex.map {
case (a, b) => (a, b.U)
}.reduce[(UInt, UInt)] { case ((a, i), (b, j)) =>
(Mux(a > b, a, b), Mux(a > b, i, j)) // > instead of >= here; want to use largest size
}._2
}
// normalize to maximum coalescing size so that we can do fair comparisons
// between coalescing results of different sizes
val normalizedMatches = normalize(coalescers.map(_.io.results.matchCount))
val normalizedHits = normalize(coalescers.map(_.io.results.coverageHits))
val chosenSizeIdx = Wire(UInt(log2Ceil(config.coalLogSizes.size).W))
val chosenValid = Wire(Bool())
// minimum 25% coverage
val minCoverage =
1.max(1 << ((config.maxCoalLogSize - config.wordSizeWidth) - 2))
// when(normalizedHits.map(_ > minCoverage.U).reduce(_ || _)) {
// chosenSizeIdx := argMax(normalizedHits)
// chosenValid := true.B
// printf("coalescing success by coverage policy\n")
// }.else
when(normalizedMatches.map(_ > 1.U).reduce(_ || _)) {
chosenSizeIdx := argMax(normalizedMatches)
chosenValid := true.B
printf("coalescing success by matches policy\n")
}.otherwise {
chosenSizeIdx := DontCare
chosenValid := false.B
}
def debugPolicyPrint() = {
printf("matchCount[0]=%d\n", coalescers(0).io.results.matchCount)
printf("normalizedMatches[0]=%d\n", normalizedMatches(0))
printf("coverageHits[0]=%d\n", coalescers(0).io.results.coverageHits)
printf("normalizedHits[0]=%d\n", normalizedHits(0))
printf("minCoverage=%d\n", minCoverage.U)
}
// create coalesced request
val chosenBundle = VecInit(coalescers.map(_.io.results))(chosenSizeIdx)
val chosenSize = VecInit(coalescers.map(_.size.U))(chosenSizeIdx)
// flatten requests and matches
val flatReqs = io.window.elts.flatten
val flatMatches = chosenBundle.matchOH.flatMap(_.asBools)
// check for word alignment in addresses
assert(
io.window.elts
.flatMap(_.map(req => req.address(config.wordSizeWidth - 1, 0) === 0.U))
.zip(io.window.mask.flatMap(_.asBools))
.map { case (aligned, valid) => (!valid) || aligned }
.reduce(_ || _),
"one or more addresses used for coalescing is not word-aligned"
)
// note: this is word-level coalescing. if finer granularity is needed, need to modify code
val numWords = (1.U << (chosenSize - config.wordSizeWidth.U)).asUInt
val maxWords = 1 << (config.maxCoalLogSize - config.wordSizeWidth)
val addrMask = Wire(UInt(config.maxCoalLogSize.W))
addrMask := (1.U << chosenSize).asUInt - 1.U
val data = Wire(Vec(maxWords, UInt((config.wordSizeInBytes * 8).W)))
val mask = Wire(Vec(maxWords, UInt(config.wordSizeInBytes.W)))
for (i <- 0 until maxWords) {
val sel = flatReqs.zip(flatMatches).map { case (req, m) =>
// note: ANDing against addrMask is to conform to active byte lanes requirements
// if aligning to LSB suffices, we should add the bitwise AND back
m && ((req.address(
config.maxCoalLogSize - 1,
config.wordSizeWidth
) /* & addrMask*/ ) === i.U)
}
// TODO: SW uses priority encoder, not sure about behavior of MuxCase
data(i) := MuxCase(
DontCare,
flatReqs.zip(sel).map { case (req, s) =>
s -> req.data
}
)
mask(i) := MuxCase(
0.U,
flatReqs.zip(sel).map { case (req, s) =>
s -> req.mask
}
)
}
val coalesceValid = chosenValid
// setting source is deferred, because in order to do proper source ID
// generation we also have to look at the responses coming back, which
// is easier to do at the toplevel.
io.coalReq.bits.source := DontCare
io.coalReq.bits.mask := mask.asUInt
io.coalReq.bits.data := data.asUInt
io.coalReq.bits.size := chosenSize
io.coalReq.bits.address := chosenBundle.baseAddr
io.coalReq.bits.op := io.window.elts(chosenBundle.leaderIdx).head.op
io.coalReq.valid := coalesceValid
io.invalidate.bits := chosenBundle.matchOH
io.invalidate.valid := io.coalReq.fire // invalidate only when fire
io.coalescable := coalescers
.map(_.io.results.canCoalesce.asUInt)
.reduce(_ | _)
.asBools
dontTouch(io.invalidate) // debug
def disable = {
io.coalReq.valid := false.B
io.invalidate.valid := false.B
io.coalescable.foreach { _ := false.B }
}
if (!config.enable) disable
}
class CoalescerSourceGen(
config: CoalescerConfig,
coalReqT: CoalescedRequest,
respT: TLBundleD
) extends Module {
val io = IO(new Bundle {
val inReq = Flipped(Decoupled(coalReqT.cloneType))
val outReq = Decoupled(coalReqT.cloneType)
val inResp = Flipped(Decoupled(respT.cloneType))
})
val sourceGen = Module(
new RoundRobinSourceGenerator(log2Ceil(config.numNewSrcIds), ignoreInUse = false)
)
sourceGen.io.gen := io.inReq.fire // use up a source ID only when request is created
sourceGen.io.reclaim.valid := io.inResp.valid
sourceGen.io.reclaim.bits := io.inResp.bits.source
io.inResp.ready := true.B // should be always ready to reclaim old ID
// TODO: make sourceGen.io.reclaim Decoupled?
io.outReq <> io.inReq
// overwrite bits affected by sourcegen backpressure
io.outReq.valid := io.inReq.valid && sourceGen.io.id.valid
io.outReq.bits.source := sourceGen.io.id.bits
}
class CoalescingUnitImp(outer: CoalescingUnit, config: CoalescerConfig)
extends LazyModuleImp(outer) {
require(
outer.cpuNode.in.length == config.numLanes,
s"number of incoming edges (${outer.cpuNode.in.length}) is not the same as " +
s"config.numLanes (${config.numLanes})"
)
require(
outer.cpuNode.in.head._1.params.sourceBits == log2Ceil(config.numOldSrcIds),
s"TL param sourceBits (${outer.cpuNode.in.head._1.params.sourceBits}) " +
s"mismatch with log2(config.numOldSrcIds) (${log2Ceil(config.numOldSrcIds)})"
)
require(
outer.cpuNode.in.head._1.params.addressBits == config.addressWidth,
s"TL param addressBits (${outer.cpuNode.in.head._1.params.addressBits}) " +
s"mismatch with config.addressWidth (${config.addressWidth})"
)
require(
config.maxCoalLogSize <= config.dataBusWidth,
"multi-beat coalesced reads/writes are currently not supported"
)
val oldSourceWidth = outer.cpuNode.in.head._1.params.sourceBits
val nonCoalReqT = new NonCoalescedRequest(config)
val reqQueues = Module(
new CoalShiftQueue(nonCoalReqT, config.queueDepth, config)
)
val coalReqT = new CoalescedRequest(config)
val coalescer = Module(new MultiCoalescer(config, reqQueues, coalReqT))
coalescer.io.window := reqQueues.io
reqQueues.io.coalescable := coalescer.io.coalescable
reqQueues.io.invalidate := coalescer.io.invalidate
val uncoalescer = Module(new Uncoalescer(config, nonCoalReqT, coalReqT))
// ===========================================================================
// Request flow
// ===========================================================================
//
// Override IdentityNode implementation so that we can instantiate
// queues between input and output edges to buffer requests and responses.
// See IdentityNode definition in `diplomacy/Nodes.scala`.
//
(outer.cpuNode.in zip outer.cpuNode.out).zipWithIndex.foreach {
case (((tlIn, _), (tlOut, edgeOut)), lane) =>
// Request queue
val req = Wire(nonCoalReqT)
req.op := TLUtils.AOpcodeIsStore(tlIn.a.bits.opcode)
req.source := tlIn.a.bits.source
req.address := tlIn.a.bits.address
req.data := tlIn.a.bits.data
req.size := tlIn.a.bits.size
// FIXME: req.data is still containing TL-aligned data. This is fine if
// we're simply passing through this data out the other end, but not if
// the outgoing TL edge (tlOut) has different data width from the incoming
// edge (tlIn). Possible TODO to only store the relevant portion of the
// data, at the cost of re-aligning at the outgoing end.
req.mask := tlIn.a.bits.mask
val enq = reqQueues.io.queue.enq(lane)
val deq = reqQueues.io.queue.deq(lane)
enq.valid := tlIn.a.valid
enq.bits := req
// Respect arbiter and uncoalescer backpressure
deq.ready := tlOut.a.ready && uncoalescer.io.coalReq.ready
// Stall upstream core or memtrace driver when shiftqueue is not ready
tlIn.a.ready := enq.ready
tlOut.a.valid := deq.valid
tlOut.a.bits := deq.bits.toTLA(edgeOut)
// debug
// when (tlIn.a.valid) {
// TLPrintf(s"tlIn(${lane}).a",
// tlIn.a.bits.address,
// tlIn.a.bits.size,
// tlIn.a.bits.mask,
// TLUtils.AOpcodeIsStore(tlIn.a.bits.opcode),
// tlIn.a.bits.data,
// 0.U
// )
// }
// when (tlOut.a.valid) {
// TLPrintf(s"tlOut(${lane}).a",
// tlOut.a.bits.address,
// tlOut.a.bits.size,
// tlOut.a.bits.mask,
// TLUtils.AOpcodeIsStore(tlOut.a.bits.opcode),
// tlOut.a.bits.data,
// 0.U
// )
// }
}
val (tlCoal, edgeCoal) = outer.coalescerNode.out.head
// The request coming out of MultiCoalescer still needs to go through source
// ID generation.
// We pull the sourcegen part out of MultiCoalescer to a separate Module to
// reduce IO bloat in the coalescer and top-level clutter.
//
// The overall flow looks like:
// ┌────────────────┐ ┌─────────────────────┐ ┌────────────────────┐
// │ CoalShiftQueue ├─┤ Mono/MultiCoalescer ├─┤ CoalescerSourceGen ├── TileLink req
// └────────────────┘ └─────────────────────┘ └────────────────────┘
// ^
// ┌────────────┐ ┌─────────────┐ │
// │ RespQueues ├─┤ Uncoalescer ├──┴────── TileLink resp
// └────────────┘ └─────────────┘
//
val coalSourceGen = Module(new CoalescerSourceGen(config, coalReqT, tlCoal.d.bits))
coalSourceGen.io.inReq <> coalescer.io.coalReq
coalSourceGen.io.inResp <> tlCoal.d
// This is the final coalesced request.
val coalReq = coalSourceGen.io.outReq
dontTouch(coalReq)
tlCoal.a.valid := coalReq.valid
tlCoal.a.bits := coalReq.bits.toTLA(edgeCoal)
coalescer.io.coalReq.ready := tlCoal.a.ready
tlCoal.b.ready := true.B
tlCoal.c.valid := false.B
// tlCoal.d.ready should be connected to uncoalescer's ready, done below.
tlCoal.e.valid := false.B
require(
tlCoal.params.sourceBits == log2Ceil(config.numNewSrcIds),
s"tlCoal param `sourceBits` (${tlCoal.params.sourceBits}) mismatches coalescer constant"
+ s" (${log2Ceil(config.numNewSrcIds)})"
)
require(
tlCoal.params.dataBits == (1 << config.dataBusWidth) * 8,
s"tlCoal param `dataBits` (${tlCoal.params.dataBits}) mismatches coalescer constant"
+ s" (${(1 << config.dataBusWidth) * 8})"
)
// ===========================================================================
// Response flow
// ===========================================================================
//
// Connect uncoalescer output and noncoalesced response ports to the response
// queues.
// The maximum number of requests from a single lane that can go into a
// coalesced request.
val numPerLaneReqs = config.queueDepth
// FIXME: no need to contain maxCoalLogSize data
val respQueueEntryT = new Response(
oldSourceWidth,
log2Ceil(config.maxCoalLogSize),
(1 << config.maxCoalLogSize) * 8
)
val respQueues = Seq.tabulate(config.numLanes) { _ =>
Module(
new MultiPortQueue(
respQueueEntryT,
// enq_lanes = 1 + M, where 1 is the response for the original per-lane
// requests that didn't get coalesced, and M is the maximum number of
// single-lane requests that can go into a coalesced request.
// (`numPerLaneReqs`).
// TODO: potentially expensive, because this generates more FFs.
// Rather than enqueueing all responses in a single cycle, consider
// enqueueing one by one (at the cost of possibly stalling downstream).
1 + numPerLaneReqs,
// deq_lanes = 1 because we're serializing all responses to 1 port that
// goes back to the core.
1,
// lanes. Has to be at least max(enq_lanes, deq_lanes)
1 + numPerLaneReqs,
// Depth of each lane queue.
// XXX queue depth is set to an arbitrarily high value that doesn't
// make queue block up in the middle of the simulation. Ideally there
// should be a more logical way to set this, or we should handle
// response queue blocking.
config.respQueueDepth
)
)
}
val respQueueNoncoalPort = 0
val respQueueUncoalPortOffset = 1
(outer.cpuNode.in zip outer.cpuNode.out).zipWithIndex.foreach {
case (((tlIn, edgeIn), (tlOut, _)), lane) =>
// Response queue
//
// This queue will serialize non-coalesced responses along with
// coalesced responses and serve them back to the core side.
val respQueue = respQueues(lane)
val resp = Wire(respQueueEntryT)
resp.fromTLD(tlOut.d.bits)
// Queue up responses that didn't get coalesced originally ("noncoalesced" responses).
// Coalesced (but uncoalesced back) responses will also be enqueued into the same queue.
assert(
respQueue.io.enq(respQueueNoncoalPort).ready,
"respQueue: enq port for noncoalesced response is blocked"
)
respQueue.io.enq(respQueueNoncoalPort).valid := tlOut.d.valid
respQueue.io.enq(respQueueNoncoalPort).bits := resp
// TODO: deq.ready should respect upstream ready
respQueue.io.deq(respQueueNoncoalPort).ready := true.B
tlIn.d.valid := respQueue.io.deq(respQueueNoncoalPort).valid
tlIn.d.bits := respQueue.io.deq(respQueueNoncoalPort).bits.toTLD(edgeIn)
// Debug only
val inflightCounter = RegInit(UInt(32.W), 0.U)
when(tlOut.a.valid) {
// don't inc/dec on simultaneous req/resp
when(!tlOut.d.valid) {
inflightCounter := inflightCounter + 1.U
}
}.elsewhen(tlOut.d.valid) {
inflightCounter := inflightCounter - 1.U
}
dontTouch(inflightCounter)
dontTouch(tlIn.a)
dontTouch(tlIn.d)
dontTouch(tlOut.a)
dontTouch(tlOut.d)
}
// Uncoalescer input
//
// connect coalesced request to be recorded in the uncoalescer table
uncoalescer.io.coalReq <> coalReq
uncoalescer.io.invalidate := coalescer.io.invalidate
uncoalescer.io.windowElts := reqQueues.io.elts
// coalesced response to be used to look up the uncoalescer table
uncoalescer.io.coalResp.valid := tlCoal.d.valid
uncoalescer.io.coalResp.bits.fromTLD(tlCoal.d.bits)
// Uncoalescer output
//
// Connect uncoalescer results back into response queue
(respQueues zip uncoalescer.io.respQueueIO).foreach { case (q, uncoalEnqs) =>
require(q.io.enq.length == config.queueDepth + respQueueUncoalPortOffset,
s"wrong number of enq ports for MultiPort response queue")
// slice the ports reserved for uncoalesced response
val qUncoalEnqs = q.io.enq.slice(respQueueUncoalPortOffset, q.io.enq.length)
(qUncoalEnqs zip uncoalEnqs).foreach {
case (enq, uncoalEnq) => {
enq <> uncoalEnq
}
}
}
// uncoalescer backpressure
tlCoal.d.ready := uncoalescer.io.coalResp.ready
// Debug
dontTouch(coalescer.io.coalReq)
val coalRespData = tlCoal.d.bits.data
dontTouch(coalRespData)
dontTouch(tlCoal.a)
dontTouch(tlCoal.d)
}
class Uncoalescer(
config: CoalescerConfig,
nonCoalReqT: NonCoalescedRequest,
coalReqT: CoalescedRequest,
) extends Module {
val inflightTable = Module(new InflightCoalReqTable(config))
val io = IO(new Bundle {
// generated coalesced request, connected to the output of the coalescer.
val coalReq = Flipped(DecoupledIO(coalReqT.cloneType))
// invalidate signal coming out of coalescer.
val invalidate = Input(Valid(Vec(config.numLanes, UInt(config.queueDepth.W))))
// coalescing window, connected to the contents of the request queues.
// Uncoalescer looks at the queue entries that got coalesced into `coalReq`
// in order to record which lanes this coalReq originally came from.
// We only care about window.elts because the coalescer would have made
// sure it only looked at the valid entries.
// TODO: duplicate type construction
val windowElts = Input(Vec(config.numLanes, Vec(config.queueDepth, nonCoalReqT)))
val coalResp = Flipped(Decoupled(new CoalescedResponse(config)))
val respQueueIO = Vec(config.numLanes,
Vec(config.queueDepth, Decoupled(new NonCoalescedResponse(config)))
)
})
// If inflight table is full, we cannot accept new requests to record them.
// This might happen when we sent out many requests and exhausted all source
// IDs, but they haven't come back yet.
io.coalReq.ready := inflightTable.io.enq.ready
// Construct a new entry for the inflight table using generated coalesced request
def generateInflightTableEntry: InflightCoalReqTableEntry = {
val newEntry = Wire(inflightTable.entryT)
newEntry.source := io.coalReq.bits.source
// Do a 2-D copy from every (numLanes * queueDepth) invalidate output of the
// coalescer to every (numLanes * queueDepth) entry in the inflight table.
(newEntry.lanes zip io.invalidate.bits).zipWithIndex
.foreach { case ((laneEntry, laneInv), lane) =>
(laneEntry.reqs zip laneInv.asBools).zipWithIndex
.foreach { case ((reqEntry, inv), i) =>
val req = io.windowElts(lane)(i)
when((io.invalidate.valid && inv)) {
printf(
s"coalescer: reqQueue($lane)($i) got invalidated (source=%d)\n",
req.source
)
}
reqEntry.valid := (io.invalidate.valid && inv)
reqEntry.source := req.source
reqEntry.offset := ((req.address % (1 << config.maxCoalLogSize).U) >> config.wordSizeWidth)
reqEntry.sizeEnum := config.sizeEnum.logSizeToEnum(req.size)
// TODO: load/store op
}
}
assert(
!((io.coalReq.valid === true.B) && (io.coalResp.valid === true.B) &&
(newEntry.source === io.coalResp.bits.source)),
"inflight table: enqueueing and looking up the same srcId at the same cycle is not handled"
)
dontTouch(newEntry)
newEntry
}
inflightTable.io.enq.valid := io.coalReq.valid
inflightTable.io.enq.bits := generateInflightTableEntry
// Look up the table with incoming coalesced responses
inflightTable.io.lookup.ready := io.coalResp.valid
inflightTable.io.lookupSourceId := io.coalResp.bits.source
io.coalResp.ready := true.B // FIXME, see sw model implementation
// Un-coalescing logic
//
def getCoalescedDataChunk(data: UInt, dataWidth: Int, offset: UInt, logSize: UInt): UInt = {
assert(logSize === 2.U, "currently only supporting 4-byte accesses. TODO")
// sizeInBits should be simulation-only construct
val sizeInBits = ((1.U << logSize) << 3.U).asUInt
assert(
(dataWidth > 0).B && (dataWidth.U % sizeInBits === 0.U),
s"coalesced data width ($dataWidth) not evenly divisible by core req size ($sizeInBits)"
)
val numChunks = dataWidth / 32
val chunks = Wire(Vec(numChunks, UInt(32.W)))
val offsets = (0 until numChunks)
(chunks zip offsets).foreach { case (c, o) =>
// FIXME: whether to take the offset from MSB or LSB depends on
// endianness. Right now we're assuming little endian
c := data(32 * (o + 1) - 1, 32 * o)
// If taking from MSB:
// c := (data >> (dataWidth - (o + 1) * 32)) & sizeMask
}
chunks(offset) // MUX
}
// Un-coalesce responses back to individual lanes
// Connect uncoalesced results back into each lane's response queue
val foundRow = inflightTable.io.lookup.bits
(foundRow.lanes zip io.respQueueIO).zipWithIndex.foreach { case ((foundLane, ioEnqs), lane) =>
foundLane.reqs.zipWithIndex.foreach { case (foundReq, depth) =>
val ioEnq = ioEnqs(depth)
// TODO: rather than crashing, deassert tlOut.d.ready to stall downtream
// cache. This should ideally not happen though.
assert(
ioEnq.ready,
s"respQueue: enq port for ${depth}-th uncoalesced response is blocked for lane ${lane}"
)
// TODO: spatial-only coalescing: only looking at 0th srcId entry
ioEnq.valid := false.B
ioEnq.bits := DontCare
// debug
// when (resp.valid) {
// printf(s"${i}-th uncoalesced response came back from lane ${lane}\n")
// }
// dontTouch(q.io.enq(respQueueCoalPortOffset))
when(inflightTable.io.lookup.valid && foundReq.valid) {
ioEnq.valid := foundReq.valid
ioEnq.bits.source := foundReq.source
val logSize = foundRow.sizeEnumT.enumToLogSize(foundReq.sizeEnum)
ioEnq.bits.size := logSize
ioEnq.bits.data :=
getCoalescedDataChunk(
io.coalResp.bits.data,
io.coalResp.bits.data.getWidth,
foundReq.offset,
logSize
)
}
}
}
}
// InflightCoalReqTable is a table structure that records
// for each unanswered coalesced request which lane the request originated
// from, what their original TileLink sourceId were, etc. We use this info to
// split the coalesced response back to individual per-lane responses with the
// right metadata.
class InflightCoalReqTable(config: CoalescerConfig) extends Module {
val offsetBits =
config.maxCoalLogSize - config.wordSizeWidth // assumes word offset
val entryT = new InflightCoalReqTableEntry(
config.numLanes,
config.queueDepth,
log2Ceil(config.numOldSrcIds),
config.maxCoalLogSize,
config.sizeEnum
)
val entries = config.numNewSrcIds
val sourceWidth = log2Ceil(config.numOldSrcIds)
println(s"=========== table sourceWidth: ${sourceWidth}")
println(s"=========== table offsetBits: ${offsetBits}")
println(s"=========== table sizeEnumBits: ${entryT.sizeEnumT.getWidth}")
val io = IO(new Bundle {
val enq = Flipped(Decoupled(entryT))
// TODO: return actual stuff
val lookup = Decoupled(entryT)
// TODO: put this inside decoupledIO
val lookupSourceId = Input(UInt(sourceWidth.W))
})
val table = Mem(
entries,
new Bundle {
val valid = Bool()
val bits = entryT.cloneType
}
)
when(reset.asBool) {
(0 until entries).foreach { i =>
table(i).valid := false.B
table(i).bits.lanes.foreach { l =>
l.reqs.foreach { r =>
r.valid := false.B
r.source := 0.U
r.offset := 0.U
r.sizeEnum := config.sizeEnum.INVALID
}
}
}
}
val full = Wire(Bool())
full := (0 until entries).map(table(_).valid).reduce(_ && _)
dontTouch(full)
// Enqueue logic
io.enq.ready := !full
val enqFire = io.enq.ready && io.enq.valid
when(enqFire) {
// TODO: handle enqueueing and looking up the same entry in the same cycle?
val entryToWrite = table(io.enq.bits.source)
assert(
!entryToWrite.valid,
"tried to enqueue to an already occupied entry"
)
entryToWrite.valid := true.B
entryToWrite.bits := io.enq.bits
}
// Lookup logic
io.lookup.valid := table(io.lookupSourceId).valid
io.lookup.bits := table(io.lookupSourceId).bits
// Dequeue as soon as lookup succeeds
when(io.lookup.fire) {
table(io.lookupSourceId).valid := false.B
}
dontTouch(io.lookup)
}
class InflightCoalReqTableEntry(
val numLanes: Int,
// Maximum number of requests from a single lane that can get coalesced into a single request
val numPerLaneReqs: Int,
val sourceWidth: Int,
val offsetBits: Int,
val sizeEnumT: InFlightTableSizeEnum
) extends Bundle {
class PerCoreReq extends Bundle {
val valid = Bool() // FIXME: delete this
// FIXME: oldId and newId shares the same width
val source = UInt(sourceWidth.W)
val offset = UInt(offsetBits.W)
val sizeEnum = sizeEnumT()
}
class PerLane extends Bundle {
val reqs = Vec(numPerLaneReqs, new PerCoreReq)
}
// sourceId of the coalesced response that just came back. This will be the
// key that queries the table.
val source = UInt(sourceWidth.W)
val lanes = Vec(numLanes, new PerLane)
}
object TLUtils {
def AOpcodeIsStore(opcode: UInt): Bool = {
// 0: PutFullData, 1: PutPartialData, 4: Get
assert(
opcode === TLMessages.PutFullData || opcode === TLMessages.Get,
"unhandled TL A opcode found"
)
Mux(opcode === TLMessages.PutFullData, true.B, false.B)
}
def DOpcodeIsStore(opcode: UInt): Bool = {
assert(
opcode === TLMessages.AccessAck || opcode === TLMessages.AccessAckData,
"unhandled TL D opcode found"
)
Mux(opcode === TLMessages.AccessAck, true.B, false.B)
}
}
// `traceHasSource` is true if the input trace file has an additional source
// ID column. This is useful for using the output trace file genereated by
// MemTraceLogger as the driver.
class MemTraceDriver(
config: CoalescerConfig,
filename: String,
traceHasSource: Boolean = false
)(implicit p: Parameters)
extends LazyModule {
// Create N client nodes together
val laneNodes = Seq.tabulate(config.numLanes) { i =>
val clientParam = Seq(
TLMasterParameters.v1(
name = "MemTraceDriver" + i.toString,
sourceId = IdRange(0, config.numOldSrcIds)
// visibility = Seq(AddressSet(0x0000, 0xffffff))
)
)
TLClientNode(Seq(TLMasterPortParameters.v1(clientParam)))
}
// Combine N outgoing client node into 1 idenity node for diplomatic
// connection.
val node = TLIdentityNode()
laneNodes.foreach { l => node := l }
lazy val module =
new MemTraceDriverImp(this, config, filename, traceHasSource)
}
trait HasTraceLine {
val valid: UInt
val source: UInt
val address: UInt
val is_store: UInt
val size: UInt
val data: UInt
}
// Used for both request and response. Response had address set to 0
// NOTE: these widths have to agree with what's hardcoded in Verilog.
class TraceLine extends Bundle with HasTraceLine {
val valid = Bool()
val source = UInt(32.W)
val address = UInt(64.W) // FIXME: in Verilog this is the same as data width
val is_store = Bool()
val size = UInt(8.W) // this is log2(bytesize) as in TL A bundle
val data = UInt(64.W)
}
class MemTraceDriverImp(
outer: MemTraceDriver,
config: CoalescerConfig,
filename: String,
traceHasSource: Boolean
) extends LazyModuleImp(outer)
with UnitTestModule {
// Current cycle mark to read from trace
val traceReadCycle = RegInit(1.U(64.W))
// A decoupling queue to handle backpressure from downstream. We let the
// downstream take requests from the queue individually for each lane,
// but do synchronized enqueue whenever all lane queue is ready to prevent
// drifts between the lane.
val reqQueues = Seq.fill(config.numLanes)(Module(new Queue(new TraceLine, 2)))
// Are we safe to read the next warp?
val reqQueueAllReady = reqQueues.map(_.io.enq.ready).reduce(_ && _)
val sim = Module(new SimMemTrace(filename, config.numLanes, traceHasSource))
sim.io.clock := clock
sim.io.reset := reset.asBool
// 'sim.io.trace_ready.ready' is a ready signal going into the DPI sim,
// indicating this Chisel module is ready to read the next line.
sim.io.trace_read.ready := reqQueueAllReady
sim.io.trace_read.cycle := traceReadCycle
// Read output from Verilog BlackBox
// Split output of SimMemTrace, which is flattened across all lanes,back to each lane's.
val laneReqs = Wire(Vec(config.numLanes, new TraceLine))
val addrW = laneReqs(0).address.getWidth
val sizeW = laneReqs(0).size.getWidth
val dataW = laneReqs(0).data.getWidth
laneReqs.zipWithIndex.foreach { case (req, i) =>
req.valid := sim.io.trace_read.valid(i)
req.source := 0.U // driver trace doesn't contain source id
req.address := sim.io.trace_read.address(addrW * (i + 1) - 1, addrW * i)
req.is_store := sim.io.trace_read.is_store(i)
req.size := sim.io.trace_read.size(sizeW * (i + 1) - 1, sizeW * i)
req.data := sim.io.trace_read.data(dataW * (i + 1) - 1, dataW * i)
}
// Not all fire because trace cycle has to advance even when there is no valid
// line in the trace.
when(reqQueueAllReady) {
traceReadCycle := traceReadCycle + 1.U
}
// Enqueue traces to the request queue
(reqQueues zip laneReqs).foreach { case (reqQ, req) =>
// Synchronized enqueue
reqQ.io.enq.valid := reqQueueAllReady && req.valid
reqQ.io.enq.bits := req // FIXME duplicate valid
}
// Issue here is that Vortex mem range is not within Chipyard Mem range
// In default setting, all mem-req for program data must be within
// 0X80000000 -> 0X90000000
def hashToValidPhyAddr(addr: UInt): UInt = {
Cat(8.U(4.W), addr(27, 0))
}
val sourceGens = Seq.fill(config.numLanes)(Module(
new RoundRobinSourceGenerator(
log2Ceil(config.numOldSrcIds),
ignoreInUse = false
)
))
// Advance source ID for all lanes in synchrony
val syncedSourceGenValid = sourceGens.map(_.io.id.valid).reduce(_ && _)
// Take requests off of the queue and generate TL requests
(outer.laneNodes zip reqQueues).zipWithIndex.foreach { case ((node, reqQ), lane) =>
val (tlOut, edge) = node.out(0)
val req = reqQ.io.deq.bits
// backpressure from downstream propagates into the queue
reqQ.io.deq.ready := tlOut.a.ready && syncedSourceGenValid
// Core only makes accesses of granularity larger than a word, so we want
// the trace driver to act so as well.
// That means if req.size is smaller than word size, we need to pad data
// with zeros to generate a word-size request, and set mask accordingly.
val offsetInWord = req.address % config.wordSizeInBytes.U
val subword = req.size < log2Ceil(config.wordSizeInBytes).U
// `mask` is currently unused
val mask = Wire(UInt(config.wordSizeInBytes.W))
val wordData = Wire(UInt((config.wordSizeInBytes * 8 * 2).W))
val sizeInBytes = Wire(UInt((sizeW + 1).W))
sizeInBytes := (1.U) << req.size
mask := Mux(subword, (~((~0.U(64.W)) << sizeInBytes)) << offsetInWord, ~0.U)
wordData := Mux(subword, req.data << (offsetInWord * 8.U), req.data)
val wordAlignedAddress =
req.address & ~((1 << log2Ceil(config.wordSizeInBytes)) - 1).U(addrW.W)
val wordAlignedSize = Mux(subword, 2.U, req.size)
val sourceGen = sourceGens(lane)
sourceGen.io.gen := tlOut.a.fire
// assert(sourceGen.io.id.valid)
sourceGen.io.reclaim.valid := tlOut.d.valid
sourceGen.io.reclaim.bits := tlOut.d.bits.source
val (plegal, pbits) = edge.Put(
fromSource = sourceGen.io.id.bits,
toAddress = hashToValidPhyAddr(wordAlignedAddress),
lgSize = wordAlignedSize, // trace line already holds log2(size)
// data should be aligned to beatBytes
data =
(wordData << (8.U * (wordAlignedAddress % edge.manager.beatBytes.U))).asUInt
)
val (glegal, gbits) = edge.Get(
fromSource = sourceGen.io.id.bits,
toAddress = hashToValidPhyAddr(wordAlignedAddress),
lgSize = wordAlignedSize
)
val legal = Mux(req.is_store, plegal, glegal)
val bits = Mux(req.is_store, pbits, gbits)
tlOut.a.valid := reqQ.io.deq.valid && syncedSourceGenValid
when(tlOut.a.valid) {
assert(legal, "illegal TL req gen")
}
tlOut.a.bits := bits
tlOut.b.ready := true.B
tlOut.c.valid := false.B
tlOut.d.ready := true.B
tlOut.e.valid := false.B
// debug
dontTouch(reqQ.io.enq)
dontTouch(reqQ.io.deq)
when(tlOut.a.valid) {
TLPrintf(
"MemTraceDriver",
tlOut.a.bits.source,
tlOut.a.bits.address,
tlOut.a.bits.size,
tlOut.a.bits.mask,
req.is_store,
tlOut.a.bits.data,
req.data
)
}
dontTouch(tlOut.a)
dontTouch(tlOut.d)
}
// Give some slack time after trace EOF to the downstream system to make sure
// we receive all (hopefully) outstanding responses back.
val finishCounter = RegInit(200.U(64.W))
when(sim.io.trace_read.finished) {
finishCounter := finishCounter - 1.U
}
io.finished := (finishCounter === 0.U)
when(io.finished) {
assert(
false.B,
"\n\n\nsimulation Successfully finished\n\n\n (this assertion intentional fail upon MemTracer termination)"
)
}
}
class SimMemTrace(filename: String, numLanes: Int, traceHasSource: Boolean)
extends BlackBox(
Map(
"FILENAME" -> filename,
"NUM_LANES" -> numLanes,
"HAS_SOURCE" -> (if (traceHasSource) 1 else 0)
)
)
with HasBlackBoxResource {
val traceLineT = new TraceLine
val addrW = traceLineT.address.getWidth
val sizeW = traceLineT.size.getWidth
val dataW = traceLineT.data.getWidth
val io = IO(new Bundle {
val clock = Input(Clock())
val reset = Input(Bool())
// These names have to match declarations in the Verilog code, eg.
// trace_read_address.
val trace_read =
new Bundle { // can't use HasTraceLine because this doesn't have source
val ready = Input(Bool())
val valid = Output(UInt(numLanes.W))
// Chisel can't interface with Verilog 2D port, so flatten all lanes into
// single wide 1D array.
// TODO: assumes 64-bit address.
val cycle = Input(UInt(64.W))
val address = Output(UInt((addrW * numLanes).W))
val is_store = Output(UInt(numLanes.W))
val size = Output(UInt((sizeW * numLanes).W))
val data = Output(UInt((dataW * numLanes).W))
val finished = Output(Bool())
}
})
addResource("/vsrc/SimMemTrace.v")
addResource("/csrc/SimMemTrace.cc")
addResource("/csrc/SimMemTrace.h")
}
class MemTraceLogger(
numLanes: Int,
// base filename for the generated trace files. full filename will be
// suffixed depending on `reqEnable`/`respEnable`/`loggerName`.
filename: String,
reqEnable: Boolean = true,
respEnable: Boolean = true,
// filename suffix that is unique to this logger module.
// This will be appended to the filename of the generated trace.
loggerName: String = ".logger"
)(implicit
p: Parameters
) extends LazyModule {
val node = TLIdentityNode()
// val beatBytes = 8 // FIXME: hardcoded
// val node = TLManagerNode(Seq.tabulate(numLanes) { _ =>
// TLSlavePortParameters.v1(
// Seq(
// TLSlaveParameters.v1(
// address = List(AddressSet(0x0000, 0xffffff)), // FIXME: hardcoded
// supportsGet = TransferSizes(1, beatBytes),
// supportsPutPartial = TransferSizes(1, beatBytes),
// supportsPutFull = TransferSizes(1, beatBytes)
// )
// ),
// beatBytes = beatBytes
// )
// })
// Copied from freechips.rocketchip.trailingZeros which only supports Scala
// integers
def trailingZeros(x: UInt): UInt = {
Mux(x === 0.U, x.widthOption.get.U, Log2(x & -x))
}
lazy val module = new Impl
class Impl extends LazyModuleImp(this) {
val io = IO(new Bundle {
val numReqs = Output(UInt(64.W))
val numResps = Output(UInt(64.W))
val reqBytes = Output(UInt(64.W))
val respBytes = Output(UInt(64.W))
})
val numReqs = RegInit(0.U(64.W))
val numResps = RegInit(0.U(64.W))
val reqBytes = RegInit(0.U(64.W))
val respBytes = RegInit(0.U(64.W))
io.numReqs := numReqs
io.numResps := numResps
io.reqBytes := reqBytes
io.respBytes := respBytes
val simReq =
if (reqEnable)
Some(Module(new SimMemTraceLogger(false, s"${filename}.${loggerName}.req", numLanes)))
else None
val simResp =
if (respEnable)
Some(Module(new SimMemTraceLogger(true, s"${filename}.${loggerName}.resp", numLanes)))
else None
if (simReq.isDefined) {
simReq.get.io.clock := clock
simReq.get.io.reset := reset.asBool
}
if (simResp.isDefined) {
simResp.get.io.clock := clock
simResp.get.io.reset := reset.asBool
}
val laneReqs = Wire(Vec(numLanes, new TraceLine))
val laneResps = Wire(Vec(numLanes, new TraceLine))
assert(
numLanes == node.in.length,
"`numLanes` does not match the number of TL edges connected to the MemTraceLogger"
)
// snoop on the TileLink edges to log traffic
((node.in zip node.out) zip (laneReqs zip laneResps)).foreach {
case (((tlIn, _), (tlOut, _)), (req, resp)) =>
tlOut.a <> tlIn.a
tlIn.d <> tlOut.d
// requests on TL A channel
//
// Only log trace when fired, e.g. both upstream and downstream is ready
// and transaction happened.
req.valid := tlIn.a.fire
req.size := tlIn.a.bits.size
req.is_store := TLUtils.AOpcodeIsStore(tlIn.a.bits.opcode)
req.source := tlIn.a.bits.source
// TL always carries the exact unaligned address that the client
// originally requested, so no postprocessing required
req.address := tlIn.a.bits.address
when(req.valid) {
TLPrintf(
s"MemTraceLogger (${loggerName}:downstream)",
tlIn.a.bits.source,
tlIn.a.bits.address,
tlIn.a.bits.size,
tlIn.a.bits.mask,
req.is_store,
tlIn.a.bits.data,
req.data
)
}
// TL data
//
// When tlIn.a.bits.size is smaller than the data bus width, need to
// figure out which byte lanes we actually accessed so that
// we can write that to the memory trace.
// See Section 4.5 Byte Lanes in spec 1.8.1
// This assert only holds true for PutFullData and not PutPartialData,
// where HIGH bits in the mask may not be contiguous.
when(tlIn.a.valid) {
assert(
PopCount(tlIn.a.bits.mask) === (1.U << tlIn.a.bits.size),
"mask HIGH popcount do not match the TL size. " +
"Partial masks are not allowed for PutFull"
)
}
val trailingZerosInMask = trailingZeros(tlIn.a.bits.mask)
val dataW = tlIn.params.dataBits
val mask = ~(~(0.U(dataW.W)) << ((1.U << tlIn.a.bits.size) * 8.U))
req.data := mask & (tlIn.a.bits.data >> (trailingZerosInMask * 8.U))
// when (req.valid) {
// printf("trailingZerosInMask=%d, mask=%x, data=%x\n", trailingZerosInMask, mask, req.data)
// }
// responses on TL D channel
//
// Only log trace when fired, e.g. both upstream and downstream is ready
// and transaction happened.
resp.valid := tlOut.d.fire
resp.size := tlOut.d.bits.size
resp.is_store := TLUtils.DOpcodeIsStore(tlOut.d.bits.opcode)
resp.source := tlOut.d.bits.source
// NOTE: TL D channel doesn't carry address nor mask, so there's no easy
// way to figure out which bytes the master actually use. Since we
// don't care too much about addresses in the trace anyway, just store
// the entire bits.
resp.address := 0.U
resp.data := tlOut.d.bits.data
}
// stats
val numReqsThisCycle =
laneReqs.map { l => Mux(l.valid, 1.U(64.W), 0.U(64.W)) }.reduce {
(v0, v1) => v0 + v1
}
val numRespsThisCycle =
laneResps.map { l => Mux(l.valid, 1.U(64.W), 0.U(64.W)) }.reduce {
(v0, v1) => v0 + v1
}
val reqBytesThisCycle =
laneReqs
.map { l => Mux(l.valid, 1.U(64.W) << l.size, 0.U(64.W)) }
.reduce { (b0, b1) =>
b0 + b1
}
val respBytesThisCycle =
laneResps
.map { l => Mux(l.valid, 1.U(64.W) << l.size, 0.U(64.W)) }
.reduce { (b0, b1) =>
b0 + b1
}
numReqs := numReqs + numReqsThisCycle
numResps := numResps + numRespsThisCycle
reqBytes := reqBytes + reqBytesThisCycle
respBytes := respBytes + respBytesThisCycle
// Flatten per-lane signals to the Verilog blackbox input.
//
// This is a clunky workaround of the fact that Chisel doesn't allow partial
// assignment to a bitfield range of a wide signal.
def flattenTrace(
simIO: Bundle with HasTraceLine,
perLane: Vec[TraceLine]
) = {
// these will get optimized out
val vecValid = Wire(Vec(numLanes, chiselTypeOf(perLane(0).valid)))
val vecSource = Wire(Vec(numLanes, chiselTypeOf(perLane(0).source)))
val vecAddress = Wire(Vec(numLanes, chiselTypeOf(perLane(0).address)))
val vecIsStore = Wire(Vec(numLanes, chiselTypeOf(perLane(0).is_store)))
val vecSize = Wire(Vec(numLanes, chiselTypeOf(perLane(0).size)))
val vecData = Wire(Vec(numLanes, chiselTypeOf(perLane(0).data)))
perLane.zipWithIndex.foreach { case (l, i) =>
vecValid(i) := l.valid
vecSource(i) := l.source
vecAddress(i) := l.address
vecIsStore(i) := l.is_store
vecSize(i) := l.size
vecData(i) := l.data
}
simIO.valid := vecValid.asUInt
simIO.source := vecSource.asUInt
simIO.address := vecAddress.asUInt
simIO.is_store := vecIsStore.asUInt
simIO.size := vecSize.asUInt
simIO.data := vecData.asUInt
}
if (simReq.isDefined) {
flattenTrace(simReq.get.io.trace_log, laneReqs)
assert(
simReq.get.io.trace_log.ready === true.B,
"MemTraceLogger is expected to be always ready"
)
}
if (simResp.isDefined) {
flattenTrace(simResp.get.io.trace_log, laneResps)
assert(
simResp.get.io.trace_log.ready === true.B,
"MemTraceLogger is expected to be always ready"
)
}
}
}
// MemTraceLogger is bidirectional, and `isResponse` is how the DPI module tells
// itself whether it's logging the request stream or the response stream. This
// is necessary because we have to generate slightly different trace format
// depending on this, e.g. response trace will not contain an address column.
class SimMemTraceLogger(isResponse: Boolean, filename: String, numLanes: Int)
extends BlackBox(
Map(
"IS_RESPONSE" -> (if (isResponse) 1 else 0),
"FILENAME" -> filename,
"NUM_LANES" -> numLanes
)
)
with HasBlackBoxResource {
val traceLineT = new TraceLine
val sourceW = traceLineT.source.getWidth
val addrW = traceLineT.address.getWidth
val sizeW = traceLineT.size.getWidth
val dataW = traceLineT.data.getWidth
val io = IO(new Bundle {
val clock = Input(Clock())
val reset = Input(Bool())
val trace_log = new Bundle with HasTraceLine {
val valid = Input(UInt(numLanes.W))
val source = Input(UInt((sourceW * numLanes).W))
// Chisel can't interface with Verilog 2D port, so flatten all lanes into
// single wide 1D array.
// TODO: assumes 64-bit address.
val address = Input(UInt((addrW * numLanes).W))
val is_store = Input(UInt(numLanes.W))
val size = Input(UInt((sizeW * numLanes).W))
val data = Input(UInt((dataW * numLanes).W))
val ready = Output(Bool())
}
})
addResource("/vsrc/SimMemTraceLogger.v")
addResource("/csrc/SimMemTraceLogger.cc")
addResource("/csrc/SimMemTrace.h")
}
class TLPrintf {}
object TLPrintf {
def apply(
printer: String,
source: UInt,
address: UInt,
size: UInt,
mask: UInt,
is_store: Bool,
tlData: UInt,
reqData: UInt
) = {
printf(
s"${printer}: TL source=%d, addr=%x, size=%d, mask=%x, store=%d",
source,
address,
size,
mask,
is_store
)
when(is_store) {
printf(", tlData=%x, reqData=%x", tlData, reqData)
}
printf("\n")
}
}
// Synthesizable unit tests
class DummyDriver(config: CoalescerConfig)(implicit p: Parameters)
extends LazyModule {
val laneNodes = Seq.tabulate(config.numLanes) { i =>
val clientParam = Seq(
TLMasterParameters.v1(
name = "dummy-core-node-" + i.toString,
sourceId = IdRange(0, config.numOldSrcIds)
// visibility = Seq(AddressSet(0x0000, 0xffffff))
)
)
TLClientNode(Seq(TLMasterPortParameters.v1(clientParam)))
}
// Combine N outgoing client node into 1 idenity node for diplomatic
// connection.
val node = TLIdentityNode()
laneNodes.foreach { l => node := l }
lazy val module = new DummyDriverImp(this, config)
}
class DummyDriverImp(outer: DummyDriver, config: CoalescerConfig)
extends LazyModuleImp(outer)
with UnitTestModule {
val sourceIdCounter = RegInit(0.U(log2Ceil(config.numOldSrcIds).W))
sourceIdCounter := sourceIdCounter + 1.U
val finishCounter = RegInit(10000.U(64.W))
finishCounter := finishCounter - 1.U
io.finished := (finishCounter === 0.U)
outer.laneNodes.zipWithIndex.foreach { case (node, lane) =>
assert(node.out.length == 1)
// generate dummy traffic to coalescer to prevent it from being optimized
// out during synthesis
val address = Wire(UInt(config.addressWidth.W))
address := Cat(
(finishCounter + (lane.U % 3.U)),
0.U(config.wordSizeWidth.W)
)
val (tl, edge) = node.out(0)
val (legal, bits) = edge.Put(
fromSource = sourceIdCounter,
toAddress = address,
lgSize = 2.U,
data = finishCounter + (lane.U % 3.U)
)
assert(legal, "illegal TL req gen")
tl.a.valid := true.B
tl.a.bits := bits
tl.b.ready := true.B
tl.c.valid := false.B
tl.d.ready := true.B
tl.e.valid := false.B
}
val dataSum = outer.laneNodes
.map { node =>
val tl = node.out(0)._1
val data = Mux(tl.d.valid, tl.d.bits.data, 0.U)
data
}
.reduce(_ +& _)
// this doesn't make much sense, but it prevents the entire uncoalescer from
// being optimized away
finishCounter := finishCounter + dataSum
}
// A dummy harness around the coalescer for use in VLSI flow.
// Should not instantiate any memtrace modules.
class DummyCoalescer(implicit p: Parameters) extends LazyModule {
val numLanes = p(SIMTCoreKey).get.nLanes
println(s"============ numLanes: ${numLanes}")
val config = defaultConfig.copy(numLanes = numLanes)
val driver = LazyModule(new DummyDriver(config))
val rams = Seq.fill(config.numLanes + 1)( // +1 for coalesced edge
LazyModule(
// NOTE: beatBytes here sets the data bitwidth of the upstream TileLink
// edges globally, by way of Diplomacy communicating the TL slave
// parameters to the upstream nodes.
new TLRAM(
address = AddressSet(0x0000, 0xffffff),
beatBytes = (1 << config.dataBusWidth)
)
)
)
val coal = LazyModule(new CoalescingUnit(config))
coal.cpuNode :=* driver.node
rams.foreach(_.node := coal.aggregateNode)
lazy val module = new Impl
class Impl extends LazyModuleImp(this) with UnitTestModule {
io.finished := driver.module.io.finished
}
}
class DummyCoalescerTest(timeout: Int = 500000)(implicit p: Parameters)
extends UnitTest(timeout) {
val dut = Module(LazyModule(new DummyCoalescer).module)
dut.io.start := io.start
io.finished := dut.io.finished
}
// tracedriver --> coalescer --> tracelogger --> tlram
class TLRAMCoalescerLogger(filename: String)(implicit p: Parameters)
extends LazyModule {
val numLanes = p(SIMTCoreKey).get.nLanes
val config = defaultConfig.copy(numLanes = numLanes)
val driver = LazyModule(new MemTraceDriver(config, filename))
val coreSideLogger = LazyModule(
new MemTraceLogger(numLanes, filename, loggerName = "coreside")
)
val coal = LazyModule(new CoalescingUnit(config))
val memSideLogger = LazyModule(
new MemTraceLogger(numLanes + 1, filename, loggerName = "memside")
)
val rams = Seq.fill(numLanes + 1)( // +1 for coalesced edge
LazyModule(
// NOTE: beatBytes here sets the data bitwidth of the upstream TileLink
// edges globally, by way of Diplomacy communicating the TL slave
// parameters to the upstream nodes.
new TLRAM(
address = AddressSet(0x0000, 0xffffff),
beatBytes = (1 << config.dataBusWidth)
)
)
)
memSideLogger.node :=* coal.aggregateNode
coal.cpuNode :=* coreSideLogger.node :=* driver.node
rams.foreach { r => r.node := memSideLogger.node }
lazy val module = new Impl
class Impl extends LazyModuleImp(this) with UnitTestModule {
driver.module.io.start := io.start
io.finished := driver.module.io.finished
when(io.finished) {
printf(
"numReqs=%d, numResps=%d, reqBytes=%d, respBytes=%d\n",
coreSideLogger.module.io.numReqs,
coreSideLogger.module.io.numResps,
coreSideLogger.module.io.reqBytes,
coreSideLogger.module.io.respBytes
)
assert(
(coreSideLogger.module.io.numReqs === coreSideLogger.module.io.numResps) &&
(coreSideLogger.module.io.reqBytes === coreSideLogger.module.io.respBytes),
"FAIL: requests and responses traffic to the coalescer do not match"
)
printf("SUCCESS: coalescer response traffic matched requests!\n")
}
}
}
class TLRAMCoalescerLoggerTest(filename: String, timeout: Int = 500000)(implicit
p: Parameters
) extends UnitTest(timeout) {
val dut = Module(LazyModule(new TLRAMCoalescerLogger(filename)).module)
dut.io.start := io.start
io.finished := dut.io.finished
}
// tracedriver --> coalescer --> tlram
class TLRAMCoalescer(implicit p: Parameters) extends LazyModule {
// TODO: use parameters for numLanes
val numLanes = 4
val filename = "vecadd.core1.thread4.trace"
val coal = LazyModule(new CoalescingUnit(defaultConfig))
val driver = LazyModule(new MemTraceDriver(defaultConfig, filename))
val rams = Seq.fill(numLanes + 1)( // +1 for coalesced edge
LazyModule(
// NOTE: beatBytes here sets the data bitwidth of the upstream TileLink
// edges globally, by way of Diplomacy communicating the TL slave
// parameters to the upstream nodes.
new TLRAM(
address = AddressSet(0x0000, 0xffffff),
beatBytes = (1 << defaultConfig.dataBusWidth)
)
)
)
coal.cpuNode :=* driver.node
rams.foreach { r => r.node := coal.aggregateNode }
lazy val module = new Impl
class Impl extends LazyModuleImp(this) with UnitTestModule {
driver.module.io.start := io.start
io.finished := driver.module.io.finished
}
}
class TLRAMCoalescerTest(timeout: Int = 500000)(implicit p: Parameters)
extends UnitTest(timeout) {
val dut = Module(LazyModule(new TLRAMCoalescer).module)
dut.io.start := io.start
io.finished := dut.io.finished
}
////////////
////////////
////////////
//////////// Code for CoalescerXbar
////////////
////////////
// Lazy Module is needed to instantiate outgoing node
class CoalescerXbar(config: CoalescerConfig) (implicit p: Parameters) extends LazyModule {
// Let SIMT's word size be 32, and read/write granularity be 256
// 32 client nodes of edge size 32 for non-coalesced reqs
// And attaching them wigets
val nonCoalNarrowNodes = Seq.tabulate(config.numLanes){i =>
val nonCoalNarrowParam = Seq(
TLMasterParameters.v1(
name = "NonCoalNarrowNode" + i.toString,
sourceId = IdRange(0, config.numOldSrcIds)
)
)
TLClientNode(Seq(TLMasterPortParameters.v1(nonCoalNarrowParam)))
}
val nonCoalWidgets = Seq.tabulate(config.numLanes){ _=>
TLWidthWidget(config.wordSizeInBytes)
}
(nonCoalWidgets zip nonCoalNarrowNodes).foreach{
case(wgt,node)=> wgt := node
}
//Creating a round robin cross tilelink xbar for the un-coalesced
//and connect them to the widgets
val nonCoalXbar = LazyModule(new TLXbar(TLArbiter.roundRobin))
nonCoalWidgets.foreach{nonCoalXbar.node:=_}
// K client nodes of edge size 256 for the coalesced reqs
val coalReqNodes = Seq.tabulate(config.numCoalReqs){ i =>
val coalParam = Seq(
TLMasterParameters.v1(
name = "CoalReqNode" + i.toString,
sourceId = IdRange(0, config.numNewSrcIds)
)
)
TLClientNode(Seq(TLMasterPortParameters.v1(coalParam)))
}
// Create a RR Xbar for the coalesced request
val coalXbar = LazyModule(new TLXbar(TLArbiter.roundRobin))
coalReqNodes.foreach{coalXbar.node:=_}
//Create a Priority XBar between Coalesced and Uncoalesced Request
val outputXbar = LazyModule(new TLXbar(TLArbiter.lowestIndexFirst))
outputXbar.node :=* coalXbar.node
outputXbar.node :=* nonCoalXbar.node
//express output crossbar as an idenity node for simpler downstream connection
val node = TLIdentityNode()
node :=* outputXbar.node
val nonCoalEntryT = new NonCoalescedRequest(config)
val coalEntryT = new CoalescedRequest(config)
val respNonCoalEntryT = new NonCoalescedResponse(config)
val respCoalBundleT = new CoalescedResponse(config)
lazy val module = new CoalescerXbarImpl(
this, config, nonCoalEntryT, coalEntryT, respNonCoalEntryT, respCoalBundleT)
}
class CoalescerXbarImpl(outer: CoalescerXbar,
config: CoalescerConfig,
nonCoalEntryT: Request,
coalEntryT: Request,
respNonCoalEntryT: Response,
respCoalBundleT: CoalescedResponse
) extends LazyModuleImp(outer){
val io = IO(new Bundle {
val nonCoalReqs = Vec(config.numLanes, Flipped(Decoupled(nonCoalEntryT)))
val coalReqs = Vec(config.numCoalReqs, Flipped(Decoupled(coalEntryT)))
val nonCoalResps = Vec(config.numLanes, Decoupled(respNonCoalEntryT))
val coalResp = Decoupled(respCoalBundleT)
}
)
//Create Queues to receive data from upstream
//Stage 1: Create Queue for nonCoalReqs and CoalReqs
val nonCoalReqsQueues = Seq.tabulate(config.numLanes){_=>
Module(new Queue(nonCoalEntryT.cloneType, 1, true, false))
}
val coalReqsQueues = Seq.tabulate(config.numCoalReqs){_=>
Module(new Queue(coalEntryT.cloneType, 1, true, false))
}
//Stage 1a: connect two Queue groups to the input
(io.nonCoalReqs++io.coalReqs zip nonCoalReqsQueues++coalReqsQueues).foreach{
case (req, q) => q.io.enq <> req
}
//Stage 2: connect output of the queue to the respective Node
(nonCoalReqsQueues++coalReqsQueues zip outer.nonCoalNarrowNodes++outer.coalReqNodes).foreach{
case(q, node) =>
val (tlOut, edgeOut) = node.out(0)
q.io.deq.ready := tlOut.a.ready
tlOut.a.valid := q.io.deq.valid
tlOut.a.bits := q.io.deq.bits.toTLA(edgeOut)
}
//The XBar will take care of the rest
//
// Inward data handling
//
// For the uncoalesced data response
(outer.nonCoalNarrowNodes zip io.nonCoalResps).foreach{
case(node,resp) =>
val (tlOut, edgeOut) = node.out(0)
val nonCoalResp = Wire(respNonCoalEntryT)
nonCoalResp.fromTLD(tlOut.d.bits)
tlOut.d.ready := resp.ready
resp.valid := tlOut.d.valid
resp.bits := nonCoalResp
}
//For the coalesced data response
//Have an RR arbiter that holds the response data
val coalRespRRArbiter = Module(new RRArbiter(
outer.node.in(0)._1.d.bits.cloneType,
config.numCoalReqs)
)
outer.coalReqNodes.zipWithIndex.foreach{
case(node, idx) =>
val (tlOut, edgeOut) = node.out(0)
coalRespRRArbiter.io.in(idx) <> tlOut.d
}
//Connect output of arbiter to coalesced reponse output
io.coalResp.valid := coalRespRRArbiter.io.out.valid
coalRespRRArbiter.io.out.ready := io.coalResp.ready
val coalRespBundle = Wire(respCoalBundleT)
coalRespBundle.fromTLD(coalRespRRArbiter.io.out.bits)
io.coalResp.bits := coalRespBundle
}