riscv/rocket-chip
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improve D$ internal interfaces

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This commit is contained in:
Andrew Waterman 2012-03-01 20:20:15 -08:00
parent 28cacd953f
commit 6d03d75835
1 changed files with 47 additions and 67 deletions
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114
rocket/src/main/scala/nbdcache.scala
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@ -94,6 +94,18 @@ class LoadDataGen extends Component {
io.r_dout_subword := extended_subword
}
class MSHRReq extends Bundle {
val ppn = Bits(width = TAG_BITS)
val idx = Bits(width = IDX_BITS)
val way_oh = Bits(width = NWAYS)
val offset = Bits(width = OFFSET_BITS)
val cmd = Bits(width = 4)
val typ = Bits(width = 3)
val tag = Bits(width = DCACHE_TAG_BITS)
val data = Bits(width = CPU_DATA_BITS)
}
class RPQEntry extends Bundle {
val offset = Bits(width = OFFSET_BITS)
val cmd = Bits(width = 4)
@ -157,14 +169,8 @@ class MSHR(id: Int) extends Component with ThreeStateIncoherence {
val req_pri_rdy = Bool(OUTPUT)
val req_sec_val = Bool(INPUT)
val req_sec_rdy = Bool(OUTPUT)
val req_ppn = Bits(TAG_BITS, INPUT)
val req_idx = Bits(IDX_BITS, INPUT)
val req_offset = Bits(OFFSET_BITS, INPUT)
val req_cmd = Bits(4, INPUT)
val req_type = Bits(3, INPUT)
val req_bits = new MSHRReq().asInput
val req_sdq_id = UFix(log2up(NSDQ), INPUT)
val req_tag = Bits(DCACHE_TAG_BITS, INPUT)
val req_way_oh = Bits(NWAYS, INPUT)
val idx_match = Bool(OUTPUT)
val idx = Bits(IDX_BITS, OUTPUT)
@ -185,39 +191,26 @@ class MSHR(id: Int) extends Component with ThreeStateIncoherence {
val idx_ = Reg { Bits() }
val way_oh_ = Reg { Bits() }
val req_load = (io.req_cmd === M_XRD) || (io.req_cmd === M_PFR)
val req_use_rpq = (io.req_cmd != M_PFR) && (io.req_cmd != M_PFW)
val next_state = Mux(io.req_sec_val && io.req_sec_rdy, newStateOnSecondaryMiss(io.req_cmd, state), state)
val req_cmd = io.req_bits.cmd
val req_load = (req_cmd === M_XRD) || (req_cmd === M_PFR)
val req_use_rpq = (req_cmd != M_PFR) && (req_cmd != M_PFW)
val next_state = Mux(io.req_sec_val && io.req_sec_rdy, newStateOnSecondaryMiss(req_cmd, state), state)
val sec_rdy = io.idx_match && !refilled && (needsWriteback(state) || !requested || req_load)
// XXX why doesn't this work?
// val rpq = (new queue(NRPQ)) { new RPQEntry() }
val rpq_enq_bits = Cat(io.req_offset, io.req_cmd, io.req_type, io.req_sdq_id, io.req_tag)
val rpq = (new queue(NRPQ)) { Bits(width = rpq_enq_bits.getWidth) }
val rpq = (new queue(NRPQ)) { new RPQEntry }
rpq.io.enq.valid := (io.req_pri_val && io.req_pri_rdy || io.req_sec_val && sec_rdy) && req_use_rpq
rpq.io.enq.bits := rpq_enq_bits
rpq.io.enq.bits := io.req_bits
rpq.io.enq.bits.sdq_id := io.req_sdq_id
rpq.io.deq.ready := io.replay.ready && refilled
var rpq_deq_bits = rpq.io.deq.bits
io.replay.bits.tag := rpq_deq_bits
rpq_deq_bits = rpq_deq_bits >> UFix(io.req_tag.width)
io.replay.bits.sdq_id := rpq_deq_bits.toUFix
rpq_deq_bits = rpq_deq_bits >> UFix(io.req_sdq_id.width)
io.replay.bits.typ := rpq_deq_bits
rpq_deq_bits = rpq_deq_bits >> UFix(io.req_type.width)
io.replay.bits.cmd := rpq_deq_bits
rpq_deq_bits = rpq_deq_bits >> UFix(io.req_cmd.width)
io.replay.bits.offset := rpq_deq_bits
rpq_deq_bits = rpq_deq_bits >> UFix(io.req_offset.width)
when (io.req_pri_val && io.req_pri_rdy) {
valid := Bool(true)
state := newStateOnPrimaryMiss(io.req_cmd)
state := newStateOnPrimaryMiss(req_cmd)
requested := Bool(false)
refilled := Bool(false)
ppn := io.req_ppn
idx_ := io.req_idx
way_oh_ := io.req_way_oh
ppn := io.req_bits.ppn
idx_ := io.req_bits.idx
way_oh_ := io.req_bits.way_oh
}
.otherwise {
when (io.mem_req.valid && io.mem_req.ready) {
@ -232,7 +225,7 @@ class MSHR(id: Int) extends Component with ThreeStateIncoherence {
state := next_state
}
io.idx_match := valid && (idx_ === io.req_idx)
io.idx_match := valid && (idx_ === io.req_bits.idx)
io.idx := idx_
io.tag := ppn
io.way_oh := way_oh_
@ -253,22 +246,14 @@ class MSHR(id: Int) extends Component with ThreeStateIncoherence {
io.mem_req.bits.tile_xact_id := Bits(id)
io.replay.valid := rpq.io.deq.valid && refilled
io.replay.bits <> rpq.io.deq.bits
io.replay.bits.idx := idx_
io.replay.bits.way_oh := way_oh_
}
class MSHRFile extends Component {
val io = new Bundle {
val req_val = Bool(INPUT)
val req_rdy = Bool(OUTPUT)
val req_ppn = Bits(TAG_BITS, INPUT)
val req_idx = Bits(IDX_BITS, INPUT)
val req_offset = Bits(OFFSET_BITS, INPUT)
val req_cmd = Bits(4, INPUT)
val req_type = Bits(3, INPUT)
val req_tag = Bits(DCACHE_TAG_BITS, INPUT)
val req_way_oh = Bits(NWAYS, INPUT)
val req_data = Bits(CPU_DATA_BITS, INPUT)
val req = (new ioDecoupled) { new MSHRReq }
val mem_resp_val = Bool(INPUT)
val mem_resp_tag = Bits(MEM_TAG_BITS, INPUT)
@ -288,9 +273,9 @@ class MSHRFile extends Component {
val sdq_val = Reg(resetVal = Bits(0, NSDQ))
val sdq_alloc_id = PriorityEncoder(~sdq_val(NSDQ-1,0))
val sdq_rdy = !sdq_val.andR
val (req_read, req_write) = cpuCmdToRW(io.req_cmd)
val sdq_enq = io.req_val && io.req_rdy && req_write
val sdq = Mem(NSDQ, sdq_enq, sdq_alloc_id, io.req_data)
val (req_read, req_write) = cpuCmdToRW(io.req.bits.cmd)
val sdq_enq = io.req.valid && io.req.ready && req_write
val sdq = Mem(NSDQ, sdq_enq, sdq_alloc_id, io.req.bits.data)
sdq.setReadLatency(1);
sdq.setTarget('inst)
@ -302,7 +287,7 @@ class MSHRFile extends Component {
val replay_arb = (new Arbiter(NMSHR)) { new Replay() }
val alloc_arb = (new Arbiter(NMSHR)) { Bool() }
val tag_match = tag_mux.io.out === io.req_ppn
val tag_match = tag_mux.io.out === io.req.bits.ppn
var idx_match = Bool(false)
var pri_rdy = Bool(false)
@ -318,15 +303,9 @@ class MSHRFile extends Component {
alloc_arb.io.in(i).valid := mshr.io.req_pri_rdy
mshr.io.req_pri_val := alloc_arb.io.in(i).ready
mshr.io.req_sec_val := io.req_val && sdq_rdy && tag_match
mshr.io.req_ppn := io.req_ppn
mshr.io.req_tag := io.req_tag
mshr.io.req_idx := io.req_idx
mshr.io.req_offset := io.req_offset
mshr.io.req_cmd := io.req_cmd
mshr.io.req_type := io.req_type
mshr.io.req_sec_val := io.req.valid && sdq_rdy && tag_match
mshr.io.req_bits := io.req.bits
mshr.io.req_sdq_id := sdq_alloc_id
mshr.io.req_way_oh := io.req_way_oh
mshr.io.meta_req <> meta_req_arb.io.in(i)
mshr.io.mem_req <> mem_req_arb.io.in(i)
@ -345,12 +324,12 @@ class MSHRFile extends Component {
idx_match = idx_match || mshr.io.idx_match
}
alloc_arb.io.out.ready := io.req_val && sdq_rdy && !idx_match
alloc_arb.io.out.ready := io.req.valid && sdq_rdy && !idx_match
meta_req_arb.io.out <> io.meta_req
mem_req_arb.io.out <> io.mem_req
io.req_rdy := Mux(idx_match, tag_match && sec_rdy, pri_rdy) && sdq_rdy
io.req.ready := Mux(idx_match, tag_match && sec_rdy, pri_rdy) && sdq_rdy
io.mem_resp_idx := mem_resp_idx_mux.io.out
io.mem_resp_way_oh := mem_resp_way_oh_mux.io.out
io.fence_rdy := !fence
@ -828,22 +807,23 @@ class HellaCacheUniproc extends HellaCache with ThreeStateIncoherence {
}
// miss handling
mshr.io.req_val := tag_miss && r_req_readwrite && (!needs_writeback || wb_rdy)
mshr.io.req_ppn := cpu_req_tag
mshr.io.req_idx := r_cpu_req_idx(indexmsb,indexlsb)
mshr.io.req_tag := r_cpu_req_tag
mshr.io.req_offset := r_cpu_req_idx(offsetmsb,0)
mshr.io.req_cmd := r_cpu_req_cmd
mshr.io.req_type := r_cpu_req_type
mshr.io.req_way_oh := replaced_way_oh
mshr.io.req_data := cpu_req_data
mshr.io.req.valid := tag_miss && r_req_readwrite && (!needs_writeback || wb_rdy)
mshr.io.req.bits.ppn := cpu_req_tag
mshr.io.req.bits.idx := r_cpu_req_idx(indexmsb,indexlsb)
mshr.io.req.bits.tag := r_cpu_req_tag
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.data := cpu_req_data
mshr.io.mem_resp_val := refill_val && (~rr_count === UFix(0))
mshr.io.mem_resp_tag := io.mem.xact_rep.bits.tile_xact_id
mshr.io.mem_req <> wb.io.refill_req
mshr.io.meta_req <> meta_arb.io.in(1)
data_arb.io.in(0).bits.inner_req.idx := mshr.io.mem_resp_idx
data_arb.io.in(0).bits.way_en := mshr.io.mem_resp_way_oh
replacer.io.pick_new_way := !io.cpu.req_kill && mshr.io.req_val && mshr.io.req_rdy
replacer.io.pick_new_way := mshr.io.req.valid && mshr.io.req.ready
// replays
val replay = mshr.io.data_req.bits
@ -904,7 +884,7 @@ class HellaCacheUniproc extends HellaCache with ThreeStateIncoherence {
val pending_fence = Reg(resetVal = Bool(false))
pending_fence := (r_cpu_req_val_ && r_req_fence || pending_fence) && !flush_rdy
val nack_hit = p_store_match || replay_val || r_req_write && !p_store_rdy
val nack_miss = needs_writeback && !wb_rdy || !mshr.io.req_rdy
val nack_miss = needs_writeback && !wb_rdy || !mshr.io.req.ready
val nack_flush = !flush_rdy && (r_req_fence || r_req_flush) ||
!flushed && r_req_flush
val nack = early_nack || r_req_readwrite && Mux(tag_match, nack_hit, nack_miss) || nack_flush