riscv/rocket-chip
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don't probe the mshr file to inquire about refills

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This commit is contained in:
Andrew Waterman 2013-01-24 17:17:12 -08:00
parent 5b9f938263
commit bb6fbddf1f
1 changed files with 25 additions and 22 deletions
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47
rocket/src/main/scala/nbdcache.scala
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@ -175,7 +175,6 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
val mem_finish = (new FIFOIO) { new GrantAck }
val wb_req = (new FIFOIO) { new WritebackReq }
val probe_writeback = (new FIFOIO) { Bool() }.flip
val probe_refill = (new FIFOIO) { Bool() }.flip
}
val s_invalid :: s_wb_req :: s_wb_resp :: s_meta_clear :: s_refill_req :: s_refill_resp :: s_meta_write_req :: s_meta_write_resp :: s_drain_rpq :: Nil = Enum(9) { UFix() }
@ -185,6 +184,7 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
val line_state = Reg { UFix() }
val refill_count = Reg { UFix(width = log2Up(REFILL_CYCLES)) }
val req = Reg { new MSHRReq() }
val writeback_probed = Reg{Bool()}
val req_cmd = io.req_bits.cmd
val req_idx = req.addr(conf.untagbits-1,conf.offbits)
@ -202,12 +202,13 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
val refill_done = reply && refill_count.andR
val wb_done = reply && (state === s_wb_resp)
val finish_q = (new Queue(2 /* wb + refill */)) { new GrantAck }
finish_q.io.enq.valid := wb_done || refill_done
finish_q.io.enq.bits.master_xact_id := io.mem_rep.bits.master_xact_id
io.wb_req.valid := Bool(false)
when (io.probe_writeback.valid && idx_match && io.probe_writeback.bits) {
writeback_probed := true
}
io.probe_writeback.ready := !idx_match || state != s_wb_req && state != s_wb_resp && state != s_meta_clear
when (state === s_drain_rpq && !rpq.io.deq.valid && !finish_q.io.deq.valid) {
when (state === s_drain_rpq && !rpq.io.deq.valid) {
state := s_invalid
}
when (state === s_meta_write_resp) {
@ -234,24 +235,25 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
}
when (state === s_wb_resp) {
when (reply) { state := s_meta_clear }
when (abort) { state := s_wb_req }
when (abort) { state := Mux(writeback_probed, s_refill_req, s_wb_req) }
}
when (state === s_wb_req) {
io.wb_req.valid := Bool(true)
when (io.probe_writeback.valid && idx_match) {
io.wb_req.valid := Bool(false)
when (io.probe_writeback.bits) { state := s_refill_req }
io.wb_req.valid := true
when (writeback_probed) {
io.wb_req.valid := false
state := s_refill_req
}.elsewhen (io.wb_req.ready) { state := s_wb_resp }
}
when (io.req_sec_val && io.req_sec_rdy) { // s_wb_req, s_wb_resp, s_refill_req
acq_type := conf.co.getAcquireTypeOnSecondaryMiss(req_cmd, conf.co.newStateOnFlush(), io.mem_req.bits)
}
when ((state === s_invalid) && io.req_pri_val) {
when (io.req_pri_val && io.req_pri_rdy) {
line_state := conf.co.newStateOnFlush()
refill_count := UFix(0)
acq_type := conf.co.getAcquireTypeOnPrimaryMiss(req_cmd, conf.co.newStateOnFlush())
req := io.req_bits
writeback_probed := false
state := Mux(conf.co.needsWriteback(io.req_bits.old_meta.state), s_wb_req, s_refill_req)
when (io.req_bits.tag_match) {
@ -264,11 +266,19 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
}
}
val finish_q = (new Queue(2 /* wb + refill */)) { new GrantAck }
finish_q.io.enq.valid := wb_done || refill_done
finish_q.io.enq.bits.master_xact_id := io.mem_rep.bits.master_xact_id
val can_finish = state === s_invalid || state === s_refill_req || state === s_refill_resp
io.mem_finish.valid := finish_q.io.deq.valid && can_finish
finish_q.io.deq.ready := io.mem_finish.ready && can_finish
io.mem_finish.bits := finish_q.io.deq.bits
io.idx_match := (state != s_invalid) && idx_match
io.mem_resp := req
io.mem_resp.addr := Cat(req_idx, refill_count) << conf.ramoffbits
io.tag := req.addr >> conf.untagbits
io.req_pri_rdy := (state === s_invalid)
io.req_pri_rdy := state === s_invalid && !finish_q.io.deq.valid
io.req_sec_rdy := sec_rdy && rpq.io.enq.ready
io.meta_write.valid := state === s_meta_write_req || state === s_meta_clear
@ -282,14 +292,12 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
io.wb_req.bits.way_en := req.way_en
io.wb_req.bits.client_xact_id := Bits(id)
io.probe_writeback.ready := (state != s_wb_resp && state != s_meta_clear && state != s_drain_rpq) || !idx_match
io.probe_refill.ready := (state != s_refill_resp && state != s_drain_rpq) || !idx_match
io.mem_req.valid := state === s_refill_req
io.mem_req.bits.a_type := acq_type
io.mem_req.bits.addr := Cat(io.tag, req_idx).toUFix
io.mem_req.bits.client_xact_id := Bits(id)
io.mem_finish <> finish_q.io.deq
io.mem_req.bits.client_xact_id := Bits(id)
io.meta_read.valid := state === s_drain_rpq
io.meta_read.bits.addr := io.mem_req.bits.addr << conf.offbits
@ -351,7 +359,6 @@ class MSHRFile(implicit conf: DCacheConfig) extends Component {
var fence = Bool(false)
var sec_rdy = Bool(false)
var writeback_probe_rdy = Bool(true)
var refill_probe_rdy = Bool(true)
for (i <- 0 to conf.nmshr-1) {
val mshr = new MSHR(i)
@ -373,7 +380,6 @@ class MSHRFile(implicit conf: DCacheConfig) extends Component {
mshr.io.mem_finish <> mem_finish_arb.io.in(i)
mshr.io.wb_req <> wb_req_arb.io.in(i)
mshr.io.replay <> replay_arb.io.in(i)
mshr.io.probe_refill.valid := io.probe.valid && tag_match
mshr.io.probe_writeback.valid := io.probe.valid
mshr.io.probe_writeback.bits := wb_probe_match
@ -385,7 +391,6 @@ class MSHRFile(implicit conf: DCacheConfig) extends Component {
sec_rdy = sec_rdy || mshr.io.req_sec_rdy
fence = fence || !mshr.io.req_pri_rdy
idx_match = idx_match || mshr.io.idx_match
refill_probe_rdy = refill_probe_rdy && mshr.io.probe_refill.ready
writeback_probe_rdy = writeback_probe_rdy && mshr.io.probe_writeback.ready
}
@ -401,7 +406,7 @@ class MSHRFile(implicit conf: DCacheConfig) extends Component {
io.secondary_miss := idx_match
io.mem_resp := memRespMux(io.mem_rep.bits.client_xact_id)
io.fence_rdy := !fence
io.probe.ready := (refill_probe_rdy || !tag_match) && (writeback_probe_rdy || !wb_probe_match)
io.probe.ready := writeback_probe_rdy || !wb_probe_match
val free_sdq = io.replay.fire() && isWrite(io.replay.bits.cmd)
io.replay.bits.data := sdq(RegEn(replay_arb.io.out.bits.sdq_id, free_sdq))
@ -1018,9 +1023,7 @@ class HellaCache(implicit conf: DCacheConfig, lnconf: LogicalNetworkConfiguratio
val acquire_arb = (new Arbiter(2)) { new Acquire }
acquire_arb.io.in(0) <> wb.io.mem_req
acquire_arb.io.in(1).valid := mshr.io.mem_req.valid && prober.io.req.ready
mshr.io.mem_req.ready := acquire_arb.io.in(1).ready && prober.io.req.ready
acquire_arb.io.in(1).bits := mshr.io.mem_req.bits
acquire_arb.io.in(1) <> mshr.io.mem_req
io.mem.acquire <> FIFOedLogicalNetworkIOWrapper(acquire_arb.io.out)
io.mem.acquire_data <> FIFOedLogicalNetworkIOWrapper(wb.io.mem_req_data)