riscv/rocket-chip
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Fix IOMSHR state machine bug

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Sending the finish too early causes the CPU response to get dropped.

attn @zhemao
This commit is contained in:
Andrew Waterman 2016-04-26 15:30:24 -07:00
parent 5fd5b58743
commit fe8c91f620
1 changed files with 7 additions and 6 deletions
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13
rocket/src/main/scala/nbdcache.scala
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@ -170,9 +170,15 @@ class IOMSHR(id: Int)(implicit p: Parameters) extends L1HellaCacheModule()(p) {
val grant_word = Reg(UInt(width = wordBits)) val grant_word = Reg(UInt(width = wordBits))
val fq = Module(new FinishQueue(1)) val fq = Module(new FinishQueue(1))
val s_idle :: s_acquire :: s_grant :: s_resp :: s_finish :: Nil = Enum(Bits(), 5)
val state = Reg(init = s_idle)
io.req.ready := (state === s_idle)
fq.io.enq.valid := io.grant.valid && io.grant.bits.requiresAck() fq.io.enq.valid := io.grant.valid && io.grant.bits.requiresAck()
fq.io.enq.bits := io.grant.bits.makeFinish() fq.io.enq.bits := io.grant.bits.makeFinish()
io.finish <> fq.io.deq io.finish.valid := fq.io.deq.valid && (state === s_finish)
io.finish.bits := fq.io.deq.bits
fq.io.deq.ready := io.finish.ready && (state === s_finish)
val storegen = new StoreGen(req.typ, req.addr, req.data, wordBytes) val storegen = new StoreGen(req.typ, req.addr, req.data, wordBytes)
val loadgen = new LoadGen(req.typ, req.addr, grant_word, req_cmd_sc, wordBytes) val loadgen = new LoadGen(req.typ, req.addr, grant_word, req_cmd_sc, wordBytes)
@ -181,11 +187,6 @@ class IOMSHR(id: Int)(implicit p: Parameters) extends L1HellaCacheModule()(p) {
val beat_mask = (storegen.mask << Cat(beat_offset, UInt(0, wordOffBits))) val beat_mask = (storegen.mask << Cat(beat_offset, UInt(0, wordOffBits)))
val beat_data = Fill(beatWords, storegen.data) val beat_data = Fill(beatWords, storegen.data)
val s_idle :: s_acquire :: s_grant :: s_resp :: s_finish :: Nil = Enum(Bits(), 5)
val state = Reg(init = s_idle)
io.req.ready := (state === s_idle)
val addr_block = req.addr(paddrBits - 1, blockOffBits) val addr_block = req.addr(paddrBits - 1, blockOffBits)
val addr_beat = req.addr(blockOffBits - 1, beatOffBits) val addr_beat = req.addr(blockOffBits - 1, beatOffBits)
val addr_byte = req.addr(beatOffBits - 1, 0) val addr_byte = req.addr(beatOffBits - 1, 0)