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rocket-chip/junctions/src/main/scala/memserdes.scala
2015-10-05 20:33:55 -07:00

326 lines
11 KiB
Scala

// See LICENSE for license details.
package junctions
import Chisel._
import scala.math._
case object PAddrBits extends Field[Int]
case object VAddrBits extends Field[Int]
case object PgIdxBits extends Field[Int]
case object PgLevels extends Field[Int]
case object PgLevelBits extends Field[Int]
case object ASIdBits extends Field[Int]
case object PPNBits extends Field[Int]
case object VPNBits extends Field[Int]
case object MIFAddrBits extends Field[Int]
case object MIFDataBits extends Field[Int]
case object MIFTagBits extends Field[Int]
case object MIFDataBeats extends Field[Int]
trait HasMIFParameters {
implicit val p: Parameters
val mifTagBits = p(MIFTagBits)
val mifAddrBits = p(MIFAddrBits)
val mifDataBits = p(MIFDataBits)
val mifDataBeats = p(MIFDataBeats)
}
abstract class MIFModule(implicit val p: Parameters) extends Module with HasMIFParameters
abstract class MIFBundle(implicit val p: Parameters) extends ParameterizedBundle()(p)
with HasMIFParameters
trait HasMemData extends HasMIFParameters {
val data = Bits(width = mifDataBits)
}
trait HasMemAddr extends HasMIFParameters {
val addr = UInt(width = mifAddrBits)
}
trait HasMemTag extends HasMIFParameters {
val tag = UInt(width = mifTagBits)
}
class MemReqCmd(implicit p: Parameters) extends MIFBundle()(p) with HasMemAddr with HasMemTag {
val rw = Bool()
}
class MemTag(implicit p: Parameters) extends MIFBundle()(p) with HasMemTag
class MemData(implicit p: Parameters) extends MIFBundle()(p) with HasMemData
class MemResp(implicit p: Parameters) extends MIFBundle()(p) with HasMemData with HasMemTag
class MemIO(implicit p: Parameters) extends ParameterizedBundle()(p) {
val req_cmd = Decoupled(new MemReqCmd)
val req_data = Decoupled(new MemData)
val resp = Decoupled(new MemResp).flip
}
class MemPipeIO(implicit p: Parameters) extends ParameterizedBundle()(p) {
val req_cmd = Decoupled(new MemReqCmd)
val req_data = Decoupled(new MemData)
val resp = Valid(new MemResp).flip
}
class MemSerializedIO(w: Int)(implicit p: Parameters) extends ParameterizedBundle()(p) {
val req = Decoupled(Bits(width = w))
val resp = Valid(Bits(width = w)).flip
//override def cloneType = new MemSerializedIO(w)(p).asInstanceOf[this.type]
}
class MemSerdes(w: Int)(implicit p: Parameters) extends MIFModule
{
val io = new Bundle {
val wide = new MemIO().flip
val narrow = new MemSerializedIO(w)
}
val abits = io.wide.req_cmd.bits.toBits.getWidth
val dbits = io.wide.req_data.bits.toBits.getWidth
val rbits = io.wide.resp.bits.getWidth
val out_buf = Reg(Bits())
val in_buf = Reg(Bits())
val s_idle :: s_read_addr :: s_write_addr :: s_write_idle :: s_write_data :: Nil = Enum(UInt(), 5)
val state = Reg(init=s_idle)
val send_cnt = Reg(init=UInt(0, log2Up((max(abits, dbits)+w-1)/w)))
val data_send_cnt = Reg(init=UInt(0, log2Up(mifDataBeats)))
val adone = io.narrow.req.ready && send_cnt === UInt((abits-1)/w)
val ddone = io.narrow.req.ready && send_cnt === UInt((dbits-1)/w)
when (io.narrow.req.valid && io.narrow.req.ready) {
send_cnt := send_cnt + UInt(1)
out_buf := out_buf >> UInt(w)
}
when (io.wide.req_cmd.valid && io.wide.req_cmd.ready) {
out_buf := io.wide.req_cmd.bits.toBits
}
when (io.wide.req_data.valid && io.wide.req_data.ready) {
out_buf := io.wide.req_data.bits.toBits
}
io.wide.req_cmd.ready := state === s_idle
io.wide.req_data.ready := state === s_write_idle
io.narrow.req.valid := state === s_read_addr || state === s_write_addr || state === s_write_data
io.narrow.req.bits := out_buf
when (state === s_idle && io.wide.req_cmd.valid) {
state := Mux(io.wide.req_cmd.bits.rw, s_write_addr, s_read_addr)
}
when (state === s_read_addr && adone) {
state := s_idle
send_cnt := UInt(0)
}
when (state === s_write_addr && adone) {
state := s_write_idle
send_cnt := UInt(0)
}
when (state === s_write_idle && io.wide.req_data.valid) {
state := s_write_data
}
when (state === s_write_data && ddone) {
data_send_cnt := data_send_cnt + UInt(1)
state := Mux(data_send_cnt === UInt(mifDataBeats-1), s_idle, s_write_idle)
send_cnt := UInt(0)
}
val recv_cnt = Reg(init=UInt(0, log2Up((rbits+w-1)/w)))
val data_recv_cnt = Reg(init=UInt(0, log2Up(mifDataBeats)))
val resp_val = Reg(init=Bool(false))
resp_val := Bool(false)
when (io.narrow.resp.valid) {
recv_cnt := recv_cnt + UInt(1)
when (recv_cnt === UInt((rbits-1)/w)) {
recv_cnt := UInt(0)
data_recv_cnt := data_recv_cnt + UInt(1)
resp_val := Bool(true)
}
in_buf := Cat(io.narrow.resp.bits, in_buf((rbits+w-1)/w*w-1,w))
}
io.wide.resp.valid := resp_val
io.wide.resp.bits := io.wide.resp.bits.fromBits(in_buf)
}
class MemDesserIO(w: Int)(implicit p: Parameters) extends ParameterizedBundle()(p) {
val narrow = new MemSerializedIO(w).flip
val wide = new MemIO
}
class MemDesser(w: Int)(implicit p: Parameters) extends Module // test rig side
{
val io = new MemDesserIO(w)
val abits = io.wide.req_cmd.bits.toBits.getWidth
val dbits = io.wide.req_data.bits.toBits.getWidth
val rbits = io.wide.resp.bits.getWidth
val mifDataBeats = p(MIFDataBeats)
require(dbits >= abits && rbits >= dbits)
val recv_cnt = Reg(init=UInt(0, log2Up((rbits+w-1)/w)))
val data_recv_cnt = Reg(init=UInt(0, log2Up(mifDataBeats)))
val adone = io.narrow.req.valid && recv_cnt === UInt((abits-1)/w)
val ddone = io.narrow.req.valid && recv_cnt === UInt((dbits-1)/w)
val rdone = io.narrow.resp.valid && recv_cnt === UInt((rbits-1)/w)
val s_cmd_recv :: s_cmd :: s_data_recv :: s_data :: s_reply :: Nil = Enum(UInt(), 5)
val state = Reg(init=s_cmd_recv)
val in_buf = Reg(Bits())
when (io.narrow.req.valid && io.narrow.req.ready || io.narrow.resp.valid) {
recv_cnt := recv_cnt + UInt(1)
in_buf := Cat(io.narrow.req.bits, in_buf((rbits+w-1)/w*w-1,w))
}
io.narrow.req.ready := state === s_cmd_recv || state === s_data_recv
when (state === s_cmd_recv && adone) {
state := s_cmd
recv_cnt := UInt(0)
}
when (state === s_cmd && io.wide.req_cmd.ready) {
state := Mux(io.wide.req_cmd.bits.rw, s_data_recv, s_reply)
}
when (state === s_data_recv && ddone) {
state := s_data
recv_cnt := UInt(0)
}
when (state === s_data && io.wide.req_data.ready) {
state := s_data_recv
when (data_recv_cnt === UInt(mifDataBeats-1)) {
state := s_cmd_recv
}
data_recv_cnt := data_recv_cnt + UInt(1)
}
when (rdone) { // state === s_reply
when (data_recv_cnt === UInt(mifDataBeats-1)) {
state := s_cmd_recv
}
recv_cnt := UInt(0)
data_recv_cnt := data_recv_cnt + UInt(1)
}
val req_cmd = in_buf >> UInt(((rbits+w-1)/w - (abits+w-1)/w)*w)
io.wide.req_cmd.valid := state === s_cmd
io.wide.req_cmd.bits := io.wide.req_cmd.bits.fromBits(req_cmd)
io.wide.req_data.valid := state === s_data
io.wide.req_data.bits.data := in_buf >> UInt(((rbits+w-1)/w - (dbits+w-1)/w)*w)
val dataq = Module(new Queue(new MemResp, mifDataBeats))
dataq.io.enq <> io.wide.resp
dataq.io.deq.ready := recv_cnt === UInt((rbits-1)/w)
io.narrow.resp.valid := dataq.io.deq.valid
io.narrow.resp.bits := dataq.io.deq.bits.toBits >> (recv_cnt * UInt(w))
}
class MemIOArbiter(val arbN: Int)(implicit p: Parameters) extends MIFModule {
val io = new Bundle {
val inner = Vec(new MemIO, arbN).flip
val outer = new MemIO
}
if(arbN > 1) {
val cmd_arb = Module(new RRArbiter(new MemReqCmd, arbN))
val choice_q = Module(new Queue(cmd_arb.io.chosen, 4))
val (data_cnt, data_done) = Counter(io.outer.req_data.fire(), mifDataBeats)
io.inner.map(_.req_cmd).zipWithIndex.zip(cmd_arb.io.in).map{ case ((req, id), arb) => {
arb.valid := req.valid
arb.bits := req.bits
arb.bits.tag := Cat(req.bits.tag, UInt(id))
req.ready := arb.ready
}}
io.outer.req_cmd.bits := cmd_arb.io.out.bits
io.outer.req_cmd.valid := cmd_arb.io.out.valid && choice_q.io.enq.ready
cmd_arb.io.out.ready := io.outer.req_cmd.ready && choice_q.io.enq.ready
choice_q.io.enq.bits := cmd_arb.io.chosen
choice_q.io.enq.valid := cmd_arb.io.out.fire() && cmd_arb.io.out.bits.rw
io.outer.req_data.bits := io.inner(choice_q.io.deq.bits).req_data.bits
io.outer.req_data.valid := io.inner(choice_q.io.deq.bits).req_data.valid && choice_q.io.deq.valid
io.inner.map(_.req_data.ready).zipWithIndex.foreach {
case(r, i) => r := UInt(i) === choice_q.io.deq.bits && choice_q.io.deq.valid
}
choice_q.io.deq.ready := data_done
io.outer.resp.ready := Bool(false)
for (i <- 0 until arbN) {
io.inner(i).resp.valid := Bool(false)
when(io.outer.resp.bits.tag(log2Up(arbN)-1,0).toUInt === UInt(i)) {
io.inner(i).resp.valid := io.outer.resp.valid
io.outer.resp.ready := io.inner(i).resp.ready
}
io.inner(i).resp.bits := io.outer.resp.bits
io.inner(i).resp.bits.tag := io.outer.resp.bits.tag >> UInt(log2Up(arbN))
}
} else { io.outer <> io.inner.head }
}
object MemIOMemPipeIOConverter {
def apply(in: MemPipeIO)(implicit p: Parameters): MemIO = {
val out = Wire(new MemIO())
in.resp.valid := out.resp.valid
in.resp.bits := out.resp.bits
out.resp.ready := Bool(true)
out.req_cmd.valid := in.req_cmd.valid
out.req_cmd.bits := in.req_cmd.bits
in.req_cmd.ready := out.req_cmd.ready
out.req_data.valid := in.req_data.valid
out.req_data.bits := in.req_data.bits
in.req_data.ready := out.req_data.ready
out
}
}
class MemPipeIOMemIOConverter(numRequests: Int)(implicit p: Parameters) extends MIFModule {
val io = new Bundle {
val cpu = new MemIO().flip
val mem = new MemPipeIO
}
val numEntries = numRequests * mifDataBeats
val size = log2Down(numEntries) + 1
val inc = Wire(Bool())
val dec = Wire(Bool())
val count = Reg(init=UInt(numEntries, size))
val watermark = count >= UInt(mifDataBeats)
when (inc && !dec) {
count := count + UInt(1)
}
when (!inc && dec) {
count := count - UInt(mifDataBeats)
}
when (inc && dec) {
count := count - UInt(mifDataBeats-1)
}
val cmdq_mask = io.cpu.req_cmd.bits.rw || watermark
io.mem.req_cmd.valid := io.cpu.req_cmd.valid && cmdq_mask
io.cpu.req_cmd.ready := io.mem.req_cmd.ready && cmdq_mask
io.mem.req_cmd.bits := io.cpu.req_cmd.bits
io.mem.req_data <> io.cpu.req_data
// Have separate queues to allow for different mem implementations
val resp_data_q = Module((new HellaQueue(numEntries)) { new MemData })
resp_data_q.io.enq.valid := io.mem.resp.valid
resp_data_q.io.enq.bits.data := io.mem.resp.bits.data
val resp_tag_q = Module((new HellaQueue(numEntries)) { new MemTag })
resp_tag_q.io.enq.valid := io.mem.resp.valid
resp_tag_q.io.enq.bits.tag := io.mem.resp.bits.tag
io.cpu.resp.valid := resp_data_q.io.deq.valid && resp_tag_q.io.deq.valid
io.cpu.resp.bits.data := resp_data_q.io.deq.bits.data
io.cpu.resp.bits.tag := resp_tag_q.io.deq.bits.tag
resp_data_q.io.deq.ready := io.cpu.resp.ready
resp_tag_q.io.deq.ready := io.cpu.resp.ready
inc := resp_data_q.io.deq.fire() && resp_tag_q.io.deq.fire()
dec := io.mem.req_cmd.fire() && !io.mem.req_cmd.bits.rw
}