riscv/rocket-chip
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Merge pull request #955 from freechipsproject/fix-acquire-before-release

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Fix acquire before release
This commit is contained in:
Andrew Waterman 2017-08-13 18:29:58 -07:00 committed by GitHub
commit e945f6e265
1 changed files with 30 additions and 23 deletions
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53
src/main/scala/rocket/DCache.scala
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@ -90,8 +90,14 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
val q_depth = if (rational) (2 min maxUncachedInFlight-1) else 0
val tl_out_a = Wire(tl_out.a)
tl_out.a <> (if (q_depth == 0) tl_out_a else Queue(tl_out_a, q_depth, flow = true))
val tl_out_c = Wire(tl_out.c)
tl_out.c <> (if (cacheParams.acquireBeforeRelease) Queue(tl_out_c, cacheDataBeats, flow = true) else tl_out_c)
val (tl_out_c, release_queue_empty) =
if (cacheParams.acquireBeforeRelease) {
val q = Module(new Queue(tl_out.c.bits, cacheDataBeats, flow = true))
tl_out.c <> q.io.deq
(q.io.enq, q.io.count === 0)
} else {
(tl_out.c, true.B)
}
val s1_valid = Reg(next=io.cpu.req.fire(), init=Bool(false))
val s1_probe = Reg(next=tl_out.b.fire(), init=Bool(false))
@ -116,6 +122,7 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
val s_ready :: s_voluntary_writeback :: s_probe_rep_dirty :: s_probe_rep_clean :: s_probe_retry :: s_probe_rep_miss :: s_voluntary_write_meta :: s_probe_write_meta :: Nil = Enum(UInt(), 8)
val cached_grant_wait = Reg(init=Bool(false))
val release_ack_wait = Reg(init=Bool(false))
val can_acquire_before_release = !release_ack_wait && release_queue_empty
val release_state = Reg(init=s_ready)
val any_pstore_valid = Wire(Bool())
val inWriteback = release_state.isOneOf(s_voluntary_writeback, s_probe_rep_dirty)
@ -238,9 +245,9 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
val s2_data_corrected = (s2_data_decoded.map(_.corrected): Seq[UInt]).asUInt
val s2_data_uncorrected = (s2_data_decoded.map(_.uncorrected): Seq[UInt]).asUInt
val s2_valid_hit_pre_data_ecc = s2_valid_masked && s2_readwrite && !s2_meta_error && s2_hit
val s2_valid_data_error = s2_valid_hit_pre_data_ecc && s2_data_error && !release_ack_wait
val s2_valid_data_error = s2_valid_hit_pre_data_ecc && s2_data_error && can_acquire_before_release
val s2_valid_hit = s2_valid_hit_pre_data_ecc && !s2_data_error && (!s2_waw_hazard || s2_store_merge)
val s2_valid_miss = s2_valid_masked && s2_readwrite && !s2_meta_error && !s2_hit && !release_ack_wait
val s2_valid_miss = s2_valid_masked && s2_readwrite && !s2_meta_error && !s2_hit && can_acquire_before_release
val s2_valid_cached_miss = s2_valid_miss && !s2_uncached && !uncachedInFlight.asUInt.orR
val s2_victimize = Bool(!usingDataScratchpad) && (s2_valid_cached_miss || s2_valid_data_error || s2_flush_valid)
val s2_valid_uncached_pending = s2_valid_miss && s2_uncached && !uncachedInFlight.asUInt.andR
@ -497,8 +504,8 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
metaArb.io.in(6).bits.data := metaArb.io.in(4).bits.data
// release
val (c_first, c_last, releaseDone, c_count) = edge.count(tl_out.c)
val releaseRejected = tl_out.c.valid && !tl_out.c.ready
val (c_first, c_last, releaseDone, c_count) = edge.count(tl_out_c)
val releaseRejected = tl_out_c.valid && !tl_out_c.ready
val s1_release_data_valid = Reg(next = dataArb.io.in(2).fire())
val s2_release_data_valid = Reg(next = s1_release_data_valid && !releaseRejected)
val releaseDataBeat = Cat(UInt(0), c_count) + Mux(releaseRejected, UInt(0), s1_release_data_valid + Cat(UInt(0), s2_release_data_valid))
@ -507,8 +514,8 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
val cleanReleaseMessage = edge.ProbeAck(b = probe_bits, reportPermissions = s2_report_param)
val dirtyReleaseMessage = edge.ProbeAck(b = probe_bits, reportPermissions = s2_report_param, data = 0.U)
tl_out.c.valid := s2_release_data_valid
tl_out.c.bits := nackResponseMessage
tl_out_c.valid := s2_release_data_valid
tl_out_c.bits := nackResponseMessage
val newCoh = Wire(init = probeNewCoh)
releaseWay := s2_probe_way
@ -524,11 +531,11 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
}.elsewhen (s2_prb_ack_data) {
release_state := s_probe_rep_dirty
}.elsewhen (s2_probe_state.isValid()) {
tl_out.c.valid := true
tl_out.c.bits := cleanReleaseMessage
tl_out_c.valid := true
tl_out_c.bits := cleanReleaseMessage
release_state := Mux(releaseDone, s_probe_write_meta, s_probe_rep_clean)
}.otherwise {
tl_out.c.valid := true
tl_out_c.valid := true
probeNack := !releaseDone
release_state := Mux(releaseDone, s_ready, s_probe_rep_miss)
}
@ -543,21 +550,21 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
}
}
when (release_state === s_probe_rep_miss) {
tl_out.c.valid := true
tl_out_c.valid := true
when (releaseDone) { release_state := s_ready }
}
when (release_state === s_probe_rep_clean) {
tl_out.c.valid := true
tl_out.c.bits := cleanReleaseMessage
tl_out_c.valid := true
tl_out_c.bits := cleanReleaseMessage
when (releaseDone) { release_state := s_probe_write_meta }
}
when (release_state === s_probe_rep_dirty) {
tl_out.c.bits := dirtyReleaseMessage
tl_out_c.bits := dirtyReleaseMessage
when (releaseDone) { release_state := s_probe_write_meta }
}
when (release_state.isOneOf(s_voluntary_writeback, s_voluntary_write_meta)) {
if (edge.manager.anySupportAcquireB)
tl_out.c.bits := edge.Release(fromSource = 0.U,
tl_out_c.bits := edge.Release(fromSource = 0.U,
toAddress = 0.U,
lgSize = lgCacheBlockBytes,
shrinkPermissions = s2_shrink_param,
@ -565,23 +572,23 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
newCoh := voluntaryNewCoh
releaseWay := s2_victim_way
when (releaseDone) { release_state := s_voluntary_write_meta }
when (tl_out.c.fire() && c_first) { release_ack_wait := true }
when (tl_out_c.fire() && c_first) { release_ack_wait := true }
}
tl_out.c.bits.address := probe_bits.address
tl_out.c.bits.data := s2_data_corrected
tl_out_c.bits.address := probe_bits.address
tl_out_c.bits.data := s2_data_corrected
dataArb.io.in(2).valid := inWriteback && releaseDataBeat < refillCycles
dataArb.io.in(2).bits.write := false
dataArb.io.in(2).bits.addr := tl_out.c.bits.address | (releaseDataBeat(log2Up(refillCycles)-1,0) << rowOffBits)
dataArb.io.in(2).bits.addr := tl_out_c.bits.address | (releaseDataBeat(log2Up(refillCycles)-1,0) << rowOffBits)
dataArb.io.in(2).bits.wordMask := ~UInt(0, rowBytes / wordBytes)
dataArb.io.in(2).bits.way_en := ~UInt(0, nWays)
metaArb.io.in(4).valid := release_state.isOneOf(s_voluntary_write_meta, s_probe_write_meta)
metaArb.io.in(4).bits.write := true
metaArb.io.in(4).bits.way_en := releaseWay
metaArb.io.in(4).bits.addr := Cat(io.cpu.req.bits.addr >> untagBits, tl_out.c.bits.address(idxMSB, 0))
metaArb.io.in(4).bits.addr := Cat(io.cpu.req.bits.addr >> untagBits, tl_out_c.bits.address(idxMSB, 0))
metaArb.io.in(4).bits.data.coh := newCoh
metaArb.io.in(4).bits.data.tag := tl_out.c.bits.address >> untagBits
metaArb.io.in(4).bits.data.tag := tl_out_c.bits.address >> untagBits
when (metaArb.io.in(4).fire()) { release_state := s_ready }
// cached response
@ -690,7 +697,7 @@ class DCacheModule(outer: DCache) extends HellaCacheModule(outer) {
// performance events
io.cpu.perf.acquire := edge.done(tl_out_a)
io.cpu.perf.release := edge.done(tl_out.c)
io.cpu.perf.release := edge.done(tl_out_c)
io.cpu.perf.tlbMiss := io.ptw.req.fire()
def encodeData(x: UInt) = x.grouped(eccBits).map(dECC.encode(_)).asUInt