riscv/rocket-chip
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xact init transactors in coherence hub

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This commit is contained in:
Henry Cook 2012-02-26 00:34:40 -08:00
parent bfd0ae125e
commit 2275239f33
1 changed files with 82 additions and 43 deletions
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125
rocket/src/main/scala/coherence.scala
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@ -12,6 +12,12 @@ class HubMemReq extends Bundle {
val is_probe_rep = Bool()
}
class TrackerAllocReq extends Bundle {
val xact_init = new TransactionInit()
val init_tile_id = Bits(width = TILE_ID_BITS)
val data_valid = Bool()
}
class MemData extends Bundle {
val data = Bits(width = MEM_DATA_BITS)
}
@ -154,6 +160,8 @@ trait FourStateCoherence extends CoherencePolicy {
class XactTracker(id: Int) extends Component {
val io = new Bundle {
val mem_req = (new ioDecoupled) { new HubMemReq() }.flip
val alloc_req = (new ioDecoupled) { new TrackerAllocReq() }
val can_alloc = Bool(INPUT)
val xact_finish = Bool(INPUT)
val p_rep_has_data = Bool(INPUT)
val x_init_has_data = Bool(INPUT)
@ -162,22 +170,27 @@ class XactTracker(id: Int) extends Component {
val rep_cnt_dec = Bits(NTILES, INPUT)
val busy = Bool(OUTPUT)
val addr = Bits(PADDR_BITS, OUTPUT)
val tile_id = Bits(TILE_ID_BITS, OUTPUT)
val init_tile_id = Bits(TILE_ID_BITS, OUTPUT)
val tile_xact_id = Bits(TILE_XACT_ID_BITS, OUTPUT)
val sharer_count = Bits(TILE_ID_BITS, OUTPUT)
val t_type = Bits(TTYPE_BITS, OUTPUT)
val pop_p_rep = Bool(OUTPUT)
val pop_p_rep_data = Bool(OUTPUT)
val pop_p_rep = Bits(NTILES, OUTPUT)
val pop_p_rep_data = Bits(NTILES, OUTPUT)
val pop_x_init = Bool(OUTPUT)
val pop_x_init_data = Bool(OUTPUT)
val send_x_rep_ack = Bool(OUTPUT)
}
val valid = Reg(resetVal = Bool(false))
val addr = Reg{ Bits() }
val t_type = Reg{ Bits() }
val tile_id = Reg{ Bits() }
val init_tile_id = Reg{ Bits() }
val tile_xact_id = Reg{ Bits() }
val probe_done = Reg{ Bits() }
//TODO: Decrement the probe count when final data piece is written
// Connent io.mem.ready sig to correct pop* outputs
// P_rep and x_init must be popped on same cycle of receipt
}
abstract class CoherenceHub extends Component
@ -204,23 +217,23 @@ class CoherenceHubNoDir extends CoherenceHub {
}
val trackerList = (0 until NGLOBAL_XACTS).map(new XactTracker(_))
val busy_arr = Vec(NGLOBAL_XACTS){ Wire(){Bool()} }
val addr_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=PADDR_BITS)} }
val tile_id_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_ID_BITS)} }
val tile_xact_id_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_XACT_ID_BITS)} }
val t_type_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=TTYPE_BITS)} }
val sh_count_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_ID_BITS)} }
val send_x_rep_ack_arr = Vec(NGLOBAL_XACTS){ Wire(){Bool()} }
val busy_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bool()} }
val addr_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=PADDR_BITS)} }
val init_tile_id_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_ID_BITS)} }
val tile_xact_id_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_XACT_ID_BITS)} }
val t_type_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=TTYPE_BITS)} }
val sh_count_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=TILE_ID_BITS)} }
val send_x_rep_ack_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bool()} }
val do_free_arr = Vec(NGLOBAL_XACTS){ Wire(){Bool()} }
val p_rep_has_data_arr = Vec(NGLOBAL_XACTS){ Wire(){Bool()} }
val p_rep_data_idx_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=log2up(NTILES))} }
val rep_cnt_dec_arr = Vec(NGLOBAL_XACTS){ Wire(){Bits(width=NTILES)} }
val do_free_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bool()} }
val p_rep_has_data_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bool()} }
val p_rep_data_idx_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=log2up(NTILES))} }
val rep_cnt_dec_arr = GenArray(NGLOBAL_XACTS){ Wire(){Bits(width=NTILES)} }
for( i <- 0 until NGLOBAL_XACTS) {
busy_arr.write( UFix(i), trackerList(i).io.busy)
addr_arr.write( UFix(i), trackerList(i).io.addr)
tile_id_arr.write( UFix(i), trackerList(i).io.tile_id)
init_tile_id_arr.write( UFix(i), trackerList(i).io.init_tile_id)
tile_xact_id_arr.write( UFix(i), trackerList(i).io.tile_xact_id)
t_type_arr.write( UFix(i), trackerList(i).io.t_type)
sh_count_arr.write( UFix(i), trackerList(i).io.sharer_count)
@ -231,23 +244,6 @@ class CoherenceHubNoDir extends CoherenceHub {
trackerList(i).io.rep_cnt_dec := rep_cnt_dec_arr.read(UFix(i))
}
// Nack conflicting transaction init attempts
val aborting = Wire() { Bits(width = NTILES) }
val initiating = Wire() { Bits(width = NTILES) }
for( j <- 0 until NTILES ) {
val init = io.tiles(j).xact_init
val abort = io.tiles(j).xact_abort
val conflicts = Bits(width = NGLOBAL_XACTS)
for( i <- 0 until NGLOBAL_XACTS) {
val t = trackerList(i).io
conflicts(i) := t.busy(i) && coherenceConflict(t.addr, init.bits.address)
}
aborting(j) := (conflicts.orR || busy_arr.toBits().andR)
abort.valid := init.valid && aborting
abort.bits.tile_xact_id := init.bits.tile_xact_id
init.ready := aborting(j) || initiating(j)
}
// Free finished transactions
for( j <- 0 until NTILES ) {
val finish = io.tiles(j).xact_finish
@ -255,6 +251,7 @@ class CoherenceHubNoDir extends CoherenceHub {
finish.ready := Bool(true)
}
// Reply to initial requestor
// Forward memory responses from mem to tile
val xrep_cnt = Reg(resetVal = UFix(0, log2up(REFILL_CYCLES)))
val xrep_cnt_next = xrep_cnt + UFix(1)
@ -267,11 +264,11 @@ class CoherenceHubNoDir extends CoherenceHub {
io.tiles(j).xact_rep.bits.global_xact_id := idx
io.tiles(j).xact_rep_data.bits.data := io.mem.resp_data
readys := Mux(xrep_cnt === UFix(0), io.tiles(j).xact_rep.ready && io.tiles(j).xact_rep_data.ready, io.tiles(j).xact_rep_data.ready)
io.tiles(j).xact_rep.valid := (UFix(j) === tile_id_arr.read(idx)) && ((io.mem.resp_val && xrep_cnt === UFix(0)) || send_x_rep_ack_arr.read(idx))
io.tiles(j).xact_rep_data.valid := (UFix(j) === tile_id_arr.read(idx))
io.tiles(j).xact_rep.valid := (UFix(j) === init_tile_id_arr.read(idx)) && ((io.mem.resp_val && xrep_cnt === UFix(0)) || send_x_rep_ack_arr.read(idx))
io.tiles(j).xact_rep_data.valid := (UFix(j) === init_tile_id_arr.read(idx))
}
// If there were a ready signal due to e.g. intervening network use:
//io.mem.resp_rdy := readys(tile_id_arr.read(idx)).xact_rep.ready
//io.mem.resp_rdy := readys(init_tile_id_arr.read(idx)).xact_rep.ready
// Create an arbiter for the one memory port
// We have to arbitrate between the different trackers' memory requests
@ -293,28 +290,70 @@ class CoherenceHubNoDir extends CoherenceHub {
io.tiles(j).probe_rep_data.bits.data,
io.tiles(j).xact_init_data.bits.data)))
// Handle probe replies, which may or may not have data
for( j <- 0 until NTILES ) {
val p_rep = io.tiles(j).probe_rep
val p_rep_data = io.tiles(j).probe_rep_data
val idx = p_rep.bits.global_xact_id
p_rep_has_data_arr.write(idx, p_rep.valid && p_rep.bits.has_data)
p_rep_has_data_arr.write(idx, p_rep.valid && p_rep.bits.has_data && p_rep_data.valid)
p_rep_data_idx_arr.write(idx, UFix(j))
p_rep.ready := foldR(trackerList.map(_.io.pop_p_rep))(_ || _)
p_rep_data.ready := foldR(trackerList.map(_.io.pop_p_rep_data))(_ || _)
p_rep.ready := foldR(trackerList.map(_.io.pop_p_rep(j)))(_ || _)
p_rep_data.ready := foldR(trackerList.map(_.io.pop_p_rep_data(j)))(_ || _)
}
for( i <- 0 until NGLOBAL_XACTS ) {
val flags = Bits(width = NTILES)
for( j <- 0 until NTILES) {
val p_rep = io.tiles(j).probe_rep
flags(j) := p_rep.valid && (p_rep.bits.global_xact_id === UFix(i))
flags(j) := p_rep.valid && !p_rep.bits.has_data && (p_rep.bits.global_xact_id === UFix(i))
}
rep_cnt_dec_arr.write(UFix(i), flags)
}
// Nack conflicting transaction init attempts
val aborting = Wire() { Bits(width = NTILES) }
for( j <- 0 until NTILES ) {
val x_init = io.tiles(j).xact_init
val x_abort = io.tiles(j).xact_abort
val conflicts = Bits(width = NGLOBAL_XACTS)
for( i <- 0 until NGLOBAL_XACTS) {
val t = trackerList(i).io
conflicts(i) := t.busy(i) && coherenceConflict(t.addr, x_init.bits.address) &&
!(x_init.bits.has_data && (UFix(j) === t.init_tile_id))
// Don't abort writebacks stalled on mem.
// TODO: This assumes overlapped writeback init reqs to
// the same addr will never be issued; is this ok?
}
x_abort.bits.tile_xact_id := x_init.bits.tile_xact_id
val want_to_abort = conflicts.orR || busy_arr.flatten().andR
x_abort.valid := want_to_abort && x_init.valid
aborting(j) := want_to_abort && x_abort.ready
}
// Handle transaction initiation requests
// Only one allocation per cycle
// Init requests may or may not have data
val alloc_arb = (new Arbiter(NGLOBAL_XACTS)) { Bool() }
val init_arb = (new Arbiter(NTILES)) { new TrackerAllocReq() }
for( i <- 0 until NGLOBAL_XACTS ) {
alloc_arb.io.in(i).valid := !trackerList(i).io.busy
trackerList(i).io.can_alloc := alloc_arb.io.in(i).ready
trackerList(i).io.alloc_req.bits := init_arb.io.out.bits
trackerList(i).io.alloc_req.valid := init_arb.io.out.valid
}
// Pick a single request of these types to process
//val xact_init_arb = (new Arbiter(NTILES)) { new TransactionInit() }
//val probe_reply_arb = (new Arbiter(NTILES)) { new ProbeReply() }
for( j <- 0 until NTILES ) {
val x_init = io.tiles(j).xact_init
val x_init_data = io.tiles(j).xact_init_data
init_arb.io.in(j).valid := x_init.valid
init_arb.io.in(j).bits.xact_init := x_init.bits
init_arb.io.in(j).bits.init_tile_id := UFix(j)
init_arb.io.in(j).bits.data_valid := x_init_data.valid
x_init.ready := aborting(j) || foldR(trackerList.map(_.io.pop_x_init && init_arb.io.out.bits.init_tile_id === UFix(j)))(_||_)
x_init_data.ready := aborting(j) || foldR(trackerList.map(_.io.pop_x_init_data && init_arb.io.out.bits.init_tile_id === UFix(j)))(_||_)
}
alloc_arb.io.out.ready := init_arb.io.out.valid && !busy_arr.flatten().andR &&
!foldR(trackerList.map(t => t.io.busy && coherenceConflict(t.io.addr, init_arb.io.out.bits.xact_init.address)))(_||_)
}