From d76b05bde147f3fd76e10a047a24b476b2f882bc Mon Sep 17 00:00:00 2001 From: Andrew Waterman Date: Tue, 13 Mar 2012 02:21:02 -0700 Subject: [PATCH] fix way selection on D$ write upgrades --- rocket/src/main/scala/nbdcache.scala | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/rocket/src/main/scala/nbdcache.scala b/rocket/src/main/scala/nbdcache.scala index 4c9542d5..3e38b505 100644 --- a/rocket/src/main/scala/nbdcache.scala +++ b/rocket/src/main/scala/nbdcache.scala @@ -94,7 +94,7 @@ class LoadDataGen extends Component { class MSHRReq extends Bundle { val tag_miss = Bool() - val old_state = UFix(width = 2) + val old_dirty = Bool() val old_tag = Bits(width = TAG_BITS) val tag = Bits(width = TAG_BITS) @@ -252,7 +252,7 @@ class MSHR(id: Int) extends Component with FourStateCoherence { req := io.req_bits when (io.req_bits.tag_miss) { - state := Mux(needsWriteback(io.req_bits.old_state), s_wb_req, s_refill_req) + state := Mux(io.req_bits.old_dirty, s_wb_req, s_refill_req) } } @@ -774,11 +774,11 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { meta_arb.io.in(2).bits.way_en := ~UFix(0, NWAYS) val early_tag_nack = !meta_arb.io.in(2).ready val cpu_req_tag = Cat(io.cpu.req_ppn, r_cpu_req_idx)(tagmsb,taglsb) - val tag_match_arr = (0 until NWAYS).map( w => isHit(r_cpu_req_cmd, meta.io.resp(w).state) && (meta.io.resp(w).tag === cpu_req_tag)) + val tag_match_arr = (0 until NWAYS).map( w => isValid(meta.io.resp(w).state) && (meta.io.resp(w).tag === cpu_req_tag)) val tag_match = Cat(Bits(0),tag_match_arr:_*).orR - val tag_hit = r_cpu_req_val && tag_match - val tag_miss = r_cpu_req_val && !tag_match val hit_way_oh = Cat(Bits(0),tag_match_arr.reverse:_*)(NWAYS-1, 0) //TODO: use Vec + val tag_hit_arr = (0 until NWAYS).map( w => isHit(r_cpu_req_cmd, meta.io.resp(w).state) && (meta.io.resp(w).tag === cpu_req_tag)) + val tag_hit = Cat(Bits(0),tag_match_arr:_*).orR val meta_resp_way_oh = Mux(meta.io.way_en === ~UFix(0, NWAYS), hit_way_oh, meta.io.way_en) val data_resp_way_oh = Mux(data.io.way_en === ~UFix(0, NWAYS), hit_way_oh, data.io.way_en) val meta_resp_mux = Mux1H(meta_resp_way_oh, meta.io.resp) @@ -809,8 +809,6 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { data_arb.io.in(4).bits.inner_req.offset := io.cpu.req_idx(offsetmsb,ramindexlsb) data_arb.io.in(4).bits.inner_req.idx := io.cpu.req_idx(indexmsb,indexlsb) data_arb.io.in(4).bits.inner_req.rw := Bool(false) - data_arb.io.in(4).bits.inner_req.wmask := UFix(0) // don't care - data_arb.io.in(4).bits.inner_req.data := io.mem.xact_rep.bits.data // don't care data_arb.io.in(4).valid := io.cpu.req_val && req_read data_arb.io.in(4).bits.way_en := ~UFix(0, NWAYS) // intiate load on all ways, mux after tag check val early_load_nack = req_read && !data_arb.io.in(4).ready @@ -831,12 +829,12 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { val drain_store = drain_store_val && data_arb.io.in(2).ready val p_amo = Reg(resetVal = Bool(false)) val p_store_rdy = !(p_store_valid && !drain_store) && !(mshr.io.data_req.valid || r_replay_amo || p_amo) - p_amo := tag_hit && r_req_amo && mshr.io.req.ready && !nack_hit || r_replay_amo - p_store_valid := p_store_valid && !drain_store || (tag_hit && r_req_store && mshr.io.req.ready && !nack_hit) || p_amo + p_amo := r_cpu_req_val && tag_hit && r_req_amo && mshr.io.req.ready && !nack_hit || r_replay_amo + p_store_valid := p_store_valid && !drain_store || (r_cpu_req_val && tag_hit && r_req_store && mshr.io.req.ready && !nack_hit) || p_amo // tag update after a store to an exclusive clean line. val new_hit_state = newStateOnHit(r_cpu_req_cmd, meta_resp_mux.state) - val set_hit_state = tag_hit && meta_resp_mux.state != new_hit_state + val set_hit_state = r_cpu_req_val && tag_hit && meta_resp_mux.state != new_hit_state meta.io.state_req.bits.inner_req.rw := Bool(true) meta.io.state_req.bits.inner_req.idx := Reg(r_cpu_req_idx(indexmsb,indexlsb)) meta.io.state_req.bits.inner_req.data.state := Reg(new_hit_state) @@ -858,8 +856,8 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { // miss handling mshr.io.req.valid := r_cpu_req_val && r_req_readwrite && !nack_hit || flusher.io.mshr_req.valid - mshr.io.req.bits.tag_miss := tag_miss || flusher.io.mshr_req.valid - mshr.io.req.bits.old_state := meta_wb_mux.state + mshr.io.req.bits.tag_miss := !tag_hit || flusher.io.mshr_req.valid + mshr.io.req.bits.old_dirty := needsWriteback(meta_wb_mux.state) && !tag_match // don't wb upgrades mshr.io.req.bits.old_tag := meta_wb_mux.tag mshr.io.req.bits.tag := cpu_req_tag mshr.io.req.bits.idx := r_cpu_req_idx(indexmsb,indexlsb) @@ -867,7 +865,7 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { mshr.io.req.bits.offset := r_cpu_req_idx(offsetmsb,0) mshr.io.req.bits.cmd := r_cpu_req_cmd mshr.io.req.bits.typ := r_cpu_req_type - mshr.io.req.bits.way_oh := replaced_way_oh + mshr.io.req.bits.way_oh := Mux(tag_match, hit_way_oh, replaced_way_oh) mshr.io.req.bits.data := cpu_req_data mshr.io.mem_rep <> io.mem.xact_rep @@ -932,9 +930,9 @@ class HellaCacheUniproc extends HellaCache with FourStateCoherence { io.cpu.req_rdy := flusher.io.req.ready && !(r_cpu_req_val_ && r_req_flush) && !pending_fence io.cpu.resp_nack := r_cpu_req_val_ && !io.cpu.req_kill && nack - io.cpu.resp_val := (tag_hit && !mshr.io.secondary_miss && !nack && r_req_read) || mshr.io.cpu_resp_val + io.cpu.resp_val := (r_cpu_req_val && tag_hit && !mshr.io.secondary_miss && !nack && r_req_read) || mshr.io.cpu_resp_val io.cpu.resp_replay := mshr.io.cpu_resp_val - io.cpu.resp_miss := r_cpu_req_val_ && (!tag_match || mshr.io.secondary_miss) && r_req_read + io.cpu.resp_miss := r_cpu_req_val_ && (!tag_hit || mshr.io.secondary_miss) && r_req_read io.cpu.resp_tag := Mux(mshr.io.cpu_resp_val, mshr.io.cpu_resp_tag, r_cpu_req_tag) io.cpu.resp_type := loadgen.io.typ io.cpu.resp_data := loadgen.io.dout