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first cut at optimized state transitions

This commit is contained in:
Henry Cook 2015-03-18 17:55:05 -07:00
parent 42aa4aa8ca
commit 1ff184bf62
2 changed files with 94 additions and 94 deletions

View File

@ -174,6 +174,7 @@ abstract trait L2HellaCacheParameters extends CacheParameters with CoherenceAgen
require(amoAluOperandBits <= innerDataBits)
require(rowBits == innerDataBits) // TODO: relax this by improving s_data_* states
val nSecondaryMisses = params(NSecondaryMisses)
val isLastLevelCache = true
}
abstract class L2HellaCacheBundle extends Bundle with L2HellaCacheParameters
@ -594,7 +595,7 @@ class L2VoluntaryReleaseTracker(trackerId: Int, bankId: Int) extends L2XactTrack
class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
val io = new L2XactTrackerIO
val s_idle :: s_meta_read :: s_meta_resp :: s_wb_req :: s_wb_resp :: s_probe :: s_outer_acquire :: s_outer_grant :: s_outer_finish :: s_data_read :: s_data_resp :: s_wait_puts :: s_data_write :: s_inner_grant :: s_meta_write :: s_inner_finish :: Nil = Enum(UInt(), 16)
val s_idle :: s_meta_read :: s_meta_resp :: s_wb_req :: s_wb_resp :: s_inner_probe :: s_outer_acquire :: s_outer_grant :: s_outer_finish :: s_data_read :: s_data_resp :: s_wait_puts :: s_data_write :: s_inner_grant :: s_meta_write :: s_inner_finish :: Nil = Enum(UInt(), 16)
val state = Reg(init=s_idle)
val xact_src = Reg(io.inner.acquire.bits.header.src.clone)
@ -605,15 +606,18 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
val xact_meta = Reg{ new L2Metadata }
val xact_way_en = Reg{ Bits(width = nWays) }
val pending_coh = Reg{ xact_meta.coh.clone }
val pending_puts = Reg(init=Bits(0, width = innerDataBeats))
pending_puts := (pending_puts | addPendingBitWhenHasData(io.inner.acquire))
val present_puts = Reg(init=Bits(0, width = innerDataBeats))
present_puts := (present_puts | addPendingBitWhenHasData(io.inner.acquire))
val is_hit = xact_tag_match && xact_meta.coh.outer.isHit(xact.op_code())
val is_hit = xact_tag_match &&
(xact_meta.coh.outer.isHit(xact.op_code()) ||
(Bool(isLastLevelCache) && // LLC has all the permissions
xact_meta.coh.outer.isValid()))
val do_allocate = xact.allocate()
val needs_writeback = !xact_tag_match && do_allocate &&
(xact_meta.coh.outer.requiresVoluntaryWriteback() ||
xact_meta.coh.inner.requiresProbesOnVoluntaryWriteback())
val needs_more_put_data = !pending_puts.andR
val needs_more_put_data = !present_puts.andR
val release_count = Reg(init = UInt(0, width = log2Up(nCoherentClients+1)))
val pending_probes = Reg(init = Bits(0, width = nCoherentClients))
@ -652,7 +656,10 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
val pending_reads = Reg(init=Bits(0, width = innerDataBeats))
pending_reads := (pending_reads |
addPendingBitWhenWmaskIsNotFull(io.inner.acquire)) &
dropPendingBit(io.data.read)
(dropPendingBit(io.data.read) &
dropPendingBitWhenWmaskIsFull(io.inner.acquire) &
dropPendingBitWhenHasData(io.inner.release) &
dropPendingBitWhenHasData(io.outer.grant))
val curr_read_beat = PriorityEncoder(pending_reads)
val pending_writes = Reg(init=Bits(0, width = innerDataBeats))
@ -683,6 +690,7 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
outgoing = io.ignt(),
dst = io.inner.grant.bits.header.dst),
pending_coh.outer)
val pending_ofin_on_ognt = io.ognt().makeFinish()
val amo_result = xact.data
val amoalu = Module(new AMOALU)
@ -714,11 +722,11 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
(xact_src === io.inner.acquire.bits.header.src) &&
xact.conflicts(io.iacq()) &&
Vec(s_meta_read, s_meta_resp, s_wb_req, s_wb_resp,
s_probe, s_outer_acquire, s_outer_grant,
s_inner_probe, s_outer_acquire, s_outer_grant,
s_outer_finish).contains(state) &&
do_allocate &&
ignt_q.io.enq.ready
//TODO: mix Puts and PutBlocks
val can_merge_iacq_put = ((xact.isBuiltInType(Acquire.putType) &&
io.iacq().isBuiltInType(Acquire.putType)) ||
(xact.isBuiltInType(Acquire.putBlockType) &&
@ -727,7 +735,7 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
(xact.client_xact_id === io.iacq().client_xact_id) &&
xact.conflicts(io.iacq()) &&
Vec(s_meta_read, s_meta_resp, s_wb_req, s_wb_resp,
s_probe, s_outer_acquire, s_outer_grant,
s_inner_probe, s_outer_acquire, s_outer_grant,
s_outer_finish, s_data_read,
s_data_resp).contains(state) &&
do_allocate &&
@ -737,7 +745,7 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
io.iacq().addr_block(idxMSB,idxLSB)
io.has_release_match := xact.conflicts(io.irel()) &&
!io.irel().isVoluntary() &&
(state === s_probe)
(state === s_inner_probe)
io.has_acquire_match := can_merge_iacq_put || can_merge_iacq_get
io.has_acquire_conflict := (xact.conflicts(io.iacq()) || in_same_set) &&
(state != s_idle) &&
@ -746,7 +754,7 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
// If we're allocating in this cache, we can use the current metadata
// to make an appropriate custom Acquire, otherwise we copy over the
// built-in Acquire from the inner TL to the outer TL
io.outer.acquire.valid := Bool(false)
io.outer.acquire.valid := state === s_outer_acquire
io.outer.acquire.bits.payload := Mux(do_allocate,
xact_meta.coh.outer.makeAcquire(
client_xact_id = UInt(trackerId),
@ -756,12 +764,11 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
io.outer.acquire.bits.header.src := UInt(bankId)
io.outer.probe.ready := Bool(false)
io.outer.release.valid := Bool(false)
io.outer.grant.ready := Bool(false)
io.outer.finish.valid := Bool(false)
io.outer.grant.ready := state === s_outer_grant
io.outer.finish.valid := state === s_outer_finish
io.outer.finish.bits := pending_ofin
val pending_ofin_on_ognt = io.ognt().makeFinish()
io.inner.probe.valid := Bool(false)
io.inner.probe.valid := state === s_inner_probe && pending_probes.orR
io.inner.probe.bits.header.src := UInt(bankId)
io.inner.probe.bits.header.dst := curr_probe_dst
io.inner.probe.bits.payload := pending_coh.inner.makeProbe(xact)
@ -784,34 +791,34 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
io.inner.acquire.ready := state === s_idle ||
can_merge_iacq_put ||
can_merge_iacq_get
io.inner.release.ready := state === s_probe
io.inner.release.ready := state === s_inner_probe
io.inner.finish.ready := Vec(s_inner_finish, s_meta_write, s_inner_grant,
s_data_write, s_wait_puts, s_data_resp).contains(state)
io.data.read.valid := Bool(false)
io.data.read.valid := state === s_data_read && pending_reads.orR
io.data.read.bits.id := UInt(trackerId)
io.data.read.bits.way_en := xact_way_en
io.data.read.bits.addr_idx := xact.addr_block(idxMSB,idxLSB)
io.data.read.bits.addr_beat := curr_read_beat
io.data.write.valid := Bool(false)
io.data.write.valid := state === s_data_write && pending_writes.orR
io.data.write.bits.id := UInt(trackerId)
io.data.write.bits.way_en := xact_way_en
io.data.write.bits.addr_idx := xact.addr_block(idxMSB,idxLSB)
io.data.write.bits.addr_beat := curr_write_beat
io.data.write.bits.wmask := wmask_buffer(curr_write_beat)
io.data.write.bits.data := data_buffer(curr_write_beat)
io.meta.read.valid := Bool(false)
io.meta.read.valid := state === s_meta_read
io.meta.read.bits.id := UInt(trackerId)
io.meta.read.bits.idx := xact.addr_block(idxMSB,idxLSB)
io.meta.read.bits.tag := xact.addr_block >> UInt(idxBits)
io.meta.write.valid := Bool(false)
io.meta.write.valid := state === s_meta_write
io.meta.write.bits.id := UInt(trackerId)
io.meta.write.bits.idx := xact.addr_block(idxMSB,idxLSB)
io.meta.write.bits.way_en := xact_way_en
io.meta.write.bits.data.tag := xact.addr_block >> UInt(idxBits)
io.meta.write.bits.data.coh := pending_coh
io.wb.req.valid := Bool(false)
io.wb.req.valid := state === s_wb_req
io.wb.req.bits.addr_block := Cat(xact_meta.tag, xact.addr_block(idxMSB,idxLSB))
io.wb.req.bits.coh := xact_meta.coh
io.wb.req.bits.way_en := xact_way_en
@ -824,12 +831,14 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
xact := io.iacq()
xact.data := UInt(0)
wmask_buffer.foreach { w => w := UInt(0) }
pending_puts := Mux(io.iacq().isBuiltInType(Acquire.putBlockType),
present_puts := Mux(io.iacq().isBuiltInType(Acquire.putBlockType),
addPendingBitWhenHasData(io.inner.acquire),
SInt(-1, width = innerDataBeats)).toUInt
pending_reads := Mux(io.iacq().isSubBlockType(),
addPendingBitWhenWmaskIsNotFull(io.inner.acquire),
SInt(-1, width = innerDataBeats)).toUInt
pending_reads := Mux(io.iacq().isBuiltInType(Acquire.putBlockType),
UInt(0),
Mux(io.iacq().isSubBlockType(),
addPendingBitWhenWmaskIsNotFull(io.inner.acquire),
SInt(-1, width = innerDataBeats)).toUInt)
pending_writes := addPendingBitWhenHasData(io.inner.acquire)
pending_resps := UInt(0)
pending_ignt_data := UInt(0)
@ -838,10 +847,7 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
state := s_meta_read
}
}
is(s_meta_read) {
io.meta.read.valid := Bool(true)
when(io.meta.read.ready) { state := s_meta_resp }
}
is(s_meta_read) { when(io.meta.read.ready) { state := s_meta_resp } }
is(s_meta_resp) {
when(io.meta.resp.valid) {
xact_tag_match := io.meta.resp.bits.tag_match
@ -850,31 +856,33 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
pending_coh := io.meta.resp.bits.meta.coh
val _coh = io.meta.resp.bits.meta.coh
val _tag_match = io.meta.resp.bits.tag_match
val _is_hit = _tag_match && _coh.outer.isHit(xact.op_code())
val _is_hit = _tag_match &&
(_coh.outer.isHit(xact.op_code()) ||
(Bool(isLastLevelCache) && // LLC has all the permissions
_coh.outer.isValid()))
val _needs_writeback = !_tag_match && do_allocate &&
(_coh.outer.requiresVoluntaryWriteback() ||
_coh.inner.requiresProbesOnVoluntaryWriteback())
val _needs_probes = _tag_match && _coh.inner.requiresProbes(xact)
val _needs_inner_probes = _tag_match && _coh.inner.requiresProbes(xact)
when(_is_hit) { pending_coh := pending_coh_on_hit }
when(_needs_probes) {
when(_needs_inner_probes) {
pending_probes := mask_incoherent
release_count := PopCount(mask_incoherent)
}
state := Mux(_tag_match,
Mux(_needs_probes, s_probe, Mux(_is_hit, s_data_read, s_outer_acquire)), // Probe, hit or upgrade
Mux(_needs_writeback, s_wb_req, s_outer_acquire)) // Evict ifneedbe
state := Mux(!_tag_match,
Mux(_needs_writeback, s_wb_req, s_outer_acquire),
Mux(_needs_inner_probes, s_inner_probe,
Mux(!is_hit, s_outer_acquire,
Mux(pending_reads.orR, s_data_read,
Mux(!pending_writes.orR, s_inner_grant,
Mux(needs_more_put_data, s_wait_puts, s_data_write))))))
}
}
is(s_wb_req) {
io.wb.req.valid := Bool(true)
when(io.wb.req.ready) { state := s_wb_resp }
}
is(s_wb_resp) {
when(io.wb.resp.valid) { state := s_outer_acquire }
}
is(s_probe) {
is(s_wb_req) { when(io.wb.req.ready) { state := s_wb_resp } }
is(s_wb_resp) { when(io.wb.resp.valid) { state := s_outer_acquire } }
is(s_inner_probe) {
// Send probes
io.inner.probe.valid := pending_probes != UInt(0)
when(io.inner.probe.ready) {
pending_probes := pending_probes & ~UIntToOH(curr_probe_dst)
}
@ -892,21 +900,14 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
}
}
when(release_count === UInt(0)) {
state := Mux(is_hit,
Mux(pending_writes.orR,
Mux(needs_more_put_data, s_wait_puts, s_data_write),
s_data_read),
s_outer_acquire)
}
}
is(s_outer_acquire) {
io.outer.acquire.valid := Bool(true)
when(oacq_data_done) {
state := s_outer_grant
state := Mux(!is_hit, s_outer_acquire,
Mux(pending_reads.orR, s_data_read,
Mux(!pending_writes.orR, s_inner_grant,
Mux(needs_more_put_data, s_wait_puts, s_data_write))))
}
}
is(s_outer_acquire) { when(oacq_data_done) { state := s_outer_grant } }
is(s_outer_grant) {
io.outer.grant.ready := Bool(true)
when(io.outer.grant.valid) {
when(io.ognt().hasData()) {
mergeDataOuter(io.ognt().addr_beat, io.ognt().data)
@ -919,51 +920,40 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
pending_ofin.header.src := UInt(bankId)
state := s_outer_finish
}.otherwise {
state := Mux(!do_allocate, s_inner_grant,
Mux(pending_writes.orR,
Mux(needs_more_put_data, s_wait_puts, s_data_write),
s_data_read))
state := Mux(pending_reads.orR, s_data_read,
Mux(!pending_writes.orR, s_inner_grant,
Mux(needs_more_put_data, s_wait_puts, s_data_write)))
}
}
}
}
is(s_outer_finish) {
io.outer.finish.valid := Bool(true)
when(io.outer.finish.ready) {
state := Mux(!do_allocate, s_inner_grant,
Mux(pending_writes.orR,
Mux(needs_more_put_data, s_wait_puts, s_data_write),
s_data_read))
state := Mux(pending_reads.orR, s_data_read,
Mux(!pending_writes.orR, s_inner_grant,
Mux(needs_more_put_data, s_wait_puts, s_data_write)))
}
}
is(s_data_read) {
io.data.read.valid := pending_reads.orR
when(io.data.read.ready) {
when(PopCount(pending_reads) <= UInt(1)) { state := s_data_resp }
}
when(io.data.resp.valid) {
mergeDataInternal(io.data.resp.bits.addr_beat, io.data.resp.bits.data)
}
when(PopCount(pending_reads) === UInt(0)) {
state := Mux(pending_writes.orR,
Mux(needs_more_put_data, s_wait_puts, s_data_write),
s_inner_grant)
when(io.data.read.ready) {
when(PopCount(pending_reads) <= UInt(1)) { state := s_data_resp }
}
}
is(s_data_resp) {
when(io.data.resp.valid) {
mergeDataInternal(io.data.resp.bits.addr_beat, io.data.resp.bits.data)
pending_resps := pending_resps & ~UIntToOH(io.data.resp.bits.addr_beat)
when(PopCount(pending_resps) <= UInt(1)) {
state := Mux(pending_writes.orR,
Mux(needs_more_put_data, s_wait_puts, s_data_write),
s_inner_grant)
}
}
when(PopCount(pending_resps) === UInt(0) ||
(io.data.resp.valid && PopCount(pending_resps) === UInt(1))) {
state := Mux(!pending_writes.orR, s_inner_grant,
Mux(needs_more_put_data, s_wait_puts, s_data_write))
}
}
is(s_wait_puts) { when(!needs_more_put_data) { state := s_data_write } }
is(s_data_write) {
io.data.write.valid := pending_writes.orR
when(io.data.write.ready) {
when(PopCount(pending_writes) <= UInt(1)) { state := s_inner_grant }
}
@ -979,7 +969,6 @@ class L2AcquireTracker(trackerId: Int, bankId: Int) extends L2XactTracker {
}
}
is(s_meta_write) {
io.meta.write.valid := Bool(true)
when(io.meta.write.ready) {
state := Mux(ifin_cnt > UInt(0), s_inner_finish, s_idle)
}
@ -1031,7 +1020,7 @@ class L2WritebackUnitIO extends HierarchicalXactTrackerIO {
class L2WritebackUnit(trackerId: Int, bankId: Int) extends L2XactTracker {
val io = new L2WritebackUnitIO
val s_idle :: s_probe :: s_data_read :: s_data_resp :: s_outer_release :: s_outer_grant :: s_outer_finish :: s_wb_resp :: Nil = Enum(UInt(), 8)
val s_idle :: s_inner_probe :: s_data_read :: s_data_resp :: s_outer_release :: s_outer_grant :: s_outer_finish :: s_wb_resp :: Nil = Enum(UInt(), 8)
val state = Reg(init=s_idle)
val xact_addr_block = Reg(io.wb.req.bits.addr_block.clone)
@ -1057,12 +1046,13 @@ class L2WritebackUnit(trackerId: Int, bankId: Int) extends L2XactTracker {
incoming = io.irel(),
src = io.inner.release.bits.header.src)
val pending_ocoh_on_irel = xact_coh.outer.onHit(M_XWR) // WB is a write
val pending_ofin_on_ognt = io.ognt().makeFinish()
io.has_acquire_conflict := Bool(false)
io.has_acquire_match := Bool(false)
io.has_release_match := !io.irel().isVoluntary() &&
io.irel().conflicts(xact_addr_block) &&
(state === s_probe)
(state === s_inner_probe)
io.outer.acquire.valid := Bool(false)
io.outer.probe.ready := Bool(false)
@ -1076,7 +1066,6 @@ class L2WritebackUnit(trackerId: Int, bankId: Int) extends L2XactTracker {
io.outer.grant.ready := Bool(false) // default
io.outer.finish.valid := Bool(false) // default
io.outer.finish.bits := pending_ofin
val pending_ofin_on_ognt = io.ognt().makeFinish()
io.inner.probe.valid := Bool(false)
io.inner.probe.bits.header.src := UInt(bankId)
@ -1109,15 +1098,15 @@ class L2WritebackUnit(trackerId: Int, bankId: Int) extends L2XactTracker {
xact_way_en := io.wb.req.bits.way_en
xact_id := io.wb.req.bits.id
irel_had_data := Bool(false)
val needs_probes = io.wb.req.bits.coh.inner.requiresProbesOnVoluntaryWriteback()
when(needs_probes) {
val needs_inner_probes = io.wb.req.bits.coh.inner.requiresProbesOnVoluntaryWriteback()
when(needs_inner_probes) {
pending_probes := mask_incoherent
release_count := PopCount(mask_incoherent)
}
state := Mux(needs_probes, s_probe, s_data_read)
state := Mux(needs_inner_probes, s_inner_probe, s_data_read)
}
}
is(s_probe) {
is(s_inner_probe) {
// Send probes
io.inner.probe.valid := pending_probes != UInt(0)
when(io.inner.probe.ready) {

View File

@ -151,12 +151,23 @@ abstract class XactTracker extends CoherenceAgentModule {
}
def addPendingBitWhenHasData[T <: HasTileLinkData with HasTileLinkBeatId](in: DecoupledIO[LogicalNetworkIO[T]]) = {
(Fill(in.bits.payload.tlDataBeats, in.fire() && in.bits.payload.hasData()) &
UIntToOH(in.bits.payload.addr_beat))
Fill(in.bits.payload.tlDataBeats, in.fire() && in.bits.payload.hasData()) &
UIntToOH(in.bits.payload.addr_beat)
}
def dropPendingBitWhenHasData[T <: HasTileLinkData with HasTileLinkBeatId](in: DecoupledIO[LogicalNetworkIO[T]]) = {
~Fill(in.bits.payload.tlDataBeats, in.fire() && in.bits.payload.hasData()) |
~UIntToOH(in.bits.payload.addr_beat)
}
//TODO | with existing wmask_buffer?
def addPendingBitWhenWmaskIsNotFull(in: DecoupledIO[LogicalNetworkIO[Acquire]]) = {
(Fill(in.bits.payload.tlDataBeats, in.fire() && !in.bits.payload.wmask().andR) &
UIntToOH(in.bits.payload.addr_beat))
Fill(in.bits.payload.tlDataBeats, in.fire() && !in.bits.payload.wmask().andR) &
UIntToOH(in.bits.payload.addr_beat)
}
def dropPendingBitWhenWmaskIsFull(in: DecoupledIO[LogicalNetworkIO[Acquire]]) = {
~Fill(in.bits.payload.tlDataBeats, in.fire() && in.bits.payload.wmask().andR) |
~UIntToOH(in.bits.payload.addr_beat)
}
}