riscv/rocket-chip
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fix d$ tag raw hazard

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This commit is contained in:
Andrew Waterman 2012-12-07 15:14:20 -08:00
parent e9752f1d72
commit 3f59e439ef
1 changed files with 9 additions and 5 deletions
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14
rocket/src/main/scala/nbdcache.scala
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@ -171,7 +171,7 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
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 :: s_drain_rpq :: Nil = Enum(8) { UFix() }
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() }
val state = Reg(resetVal = s_invalid)
val xacx_type = Reg { UFix() }
@ -203,11 +203,15 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
when (state === s_drain_rpq && !rpq.io.deq.valid && !finish_q.io.deq.valid) {
state := s_invalid
}
when (state === s_meta_write && io.meta_write.ready) {
when (state === s_meta_write_resp) {
// this wait state allows us to catch RAW hazards on the tags via nack_victim
state := s_drain_rpq
}
when (state === s_meta_write_req && io.meta_write.ready) {
state := s_meta_write_resp
}
when (state === s_refill_resp) {
when (refill_done) { state := s_meta_write }
when (refill_done) { state := s_meta_write_req }
when (reply) {
refill_count := refill_count + UFix(1)
line_state := conf.co.newStateOnTransactionReply(io.mem_rep.bits, io.mem_req.bits)
@ -245,7 +249,7 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
state := Mux(conf.co.needsWriteback(io.req_bits.old_meta.state), s_wb_req, s_refill_req)
when (io.req_bits.tag_match) {
when (conf.co.isHit(req_cmd, io.req_bits.old_meta.state)) { // set dirty bit
state := s_meta_write
state := s_meta_write_req
line_state := conf.co.newStateOnHit(req_cmd, io.req_bits.old_meta.state)
}.otherwise { // upgrade permissions
state := s_refill_req
@ -260,7 +264,7 @@ class MSHR(id: Int)(implicit conf: DCacheConfig) extends Component {
io.req_pri_rdy := (state === s_invalid)
io.req_sec_rdy := sec_rdy && rpq.io.enq.ready
io.meta_write.valid := state === s_meta_write || state === s_meta_clear
io.meta_write.valid := state === s_meta_write_req || state === s_meta_clear
io.meta_write.bits.idx := req_idx
io.meta_write.bits.data.state := Mux(state === s_meta_clear, conf.co.newStateOnFlush(), line_state)
io.meta_write.bits.data.tag := io.tag